Compressive asphyxia can happen during car repairs and at overcrowded concerts Compressive asphyxia is what occurs when the lungs cannot properly contract and expand to breathe.
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Dr. Pearce agreed that the break was a compressive fracture.
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At 700°C its compressive strength had fallen by about 40%.
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Plus, since the material is slightly compressive, it feels more secure.
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We were applying tourniquets and compressive bandages and treating collapsed lungs.
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They're high-waisted, slightly compressive, pill-resistant, and made from 25 recycled water bottles.
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But, they&aposre not thick enough for squats — and they&aposre not really compressive.
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They're stretchy, never see-through, not too compressive, and the waistband never digs in.
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The shelf's compressive arch, which helps stabilize it, is still a few kilometers inland, he said.
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"This study is able to quantify injury based on rate and magnitude of compressive strain," he added.
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Image via ShutterstockConcrete has high compressive strength, meaning it can hold a lot of weight without getting crushed.
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The smooth, compressive fabric feels great on my skin and it's punctuated by laser-cut holes for breathability.
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The fabric is soft, stretchy, and compressive, and the waistband is nice and wide to hold everything in.
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Girlfriend Collective Compressive High Rise 7/8 Leggings, $68The stretchy, supportive leggings are both comfortable and eco-friendly.
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They're on the thinner side and not ultra-compressive, so I'd look elsewhere if you want thick leggings.
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The tendons are made from bundles of steel wires tightened to produce compressive strength and then encased in concrete.
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The material is flattering, compressive, and stretchy, making them a favorite among eco-conscious shoppers and athleisure-lovers alike.
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What intrigued Dr. Kappelman was what could have caused such a compressive fracture: a fall from a great height.
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Too compressive, to loose and bunchy, or poorly sewn seams that chafe and scratch, the horrors can be endless.
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By soaking glass in a chemical salt bath, the company also introduces compressive stress into the inside of the glass.
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Compressive asphyxia can also occur while co-sleeping, when a parent rolls over onto a smaller child while sharing a bed.
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The cause of death was determined to be compressive asphyxia, Ottawa County Coroner Dr. Dan Cadigan said in a news release.
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The creamy, silky material isn't stuffy and compressive, but it still manages to lengthen the silhouette into a lean, seamless shape.
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That seems like it would make the calcium carbonate more fragile, but it actually creates a compressive force that strengthens the material.
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The Wayne County Medical Examiner's Office listed Laird's manner of death as compressive asphyxia and ruled it a homicide, according to Fox2Detroit.
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When you do that the metal itself is compressed, and it stores up some of that compressive energy, and it can release it later.
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Technology helps financial start-ups gain customers at the expense of traditional banks, which face "fee margin compression because of compressive disruption," he said.
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So, when you go into the microgravity environment and you no longer have any kind of compressive loads on the spine at all, it stretches.
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The barrels in the video above are being squeezed with compressive loads of almost 900,000 pounds — equivalent to the weight of around 60 full-grown elephants.
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Either way, the moondust layers are subjected to temperatures reaching 1,000℃, which melts them into a solid brick structure with a compressive strength comparable to gypsum.
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After 10 days of scanning, the results revealed a series of compressive fractures that were likely caused when one bone jammed into another, a sign of extreme trauma.
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Proponents suggest that for full resolution of the symptoms, these injured nerves and the nerve bundle must be cut away along with the compressive part of the ligament.
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"We differ, though, in suggesting that not all of the fractures in Lucy's skeleton are the same," he said, referring to the subset of compressive fractures they closely studied.
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"There is no science to support the claims that wearing an extremely compressive garment around the waist will instantly strengthen the abdominals and cause specifically abdominal fat loss," Fluger says.
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We found them to be silky, lightweight, and breathable for light exercise and daily wear, but they are definitely not the compressive, thick pair you&aposd want for intense activity.
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Regular concrete can withstand 3,000 to 6,000 pounds of compression pressure per square inch (psi); the concrete used for One World Trade Center has a compressive strength of 12,000 psi.
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The entire bridge is subject only to compressive loads, meaning all of the elements in the bridge get shorter with applied force, according to a statement from Eindhoven University of Technology.
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It's still lightly compressive as a control top, but it doesn't have a tight seam that digs into my waist throughout the day — meaning I actually don't dread putting them on.
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Sporting his signature soul patch and a t-shirt that says "DAD AF," the legendary trance producer DJs his most famous tune into speakers that get destroyed by immense compressive force.
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"This compressive fracture results when the hand hits the ground during a fall, impacting the elements of the shoulder against one another to create a unique signature on the humerus," noted Kappelman.
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A look through surgical journals suggested that the break might be a so-called compressive fracture, in which a force pushes down on a bone, sometimes even driving one bone into another.
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As the drop quickly cools, its outer layer experiences a temperature drop faster than its interior, which results in extreme compressive forces on the outside, but strong tensile (pulling) stresses on the inside.
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Compressive High-Rise Legging, $68, available at Girlfriend CollectiveThe only thing they'll love more than a pair of leggings they can live in is a pair they can feel good about wearing, too.
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But he also observed more compressive fractures, as well as so-called greenstick fractures, in which a bone cracks only on one side, much like what happens when a living tree branch breaks.
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"At present, the most likely hypothesis is also the simplest one: tangential expansion of the cortical layer relative to sublayers generates compressive stress, leading to the mechanical folding of the cortex," the authors note.
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Then he shifted to a form of Cubism, turning objects like Jell-O molds, a telephone and an automobile engine crankshaft into compressive, nearly abstract designs in black, white and velvety shades of gray.
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"The ice shelf loses icebergs like this naturally every few decades, butwe're concerned that this one might extend far enough back that it breaks the"compressive arch" which is holding the ice shelf in place," he said.
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The Ottawa County Coroner&aposs Office say Harley died from "compressive asphyxia," which is what happens when breathing is prevented by external pressure on the body, according to a study from the The American Journal of Forensic Medicine and Pathology.
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Those images were then processed using complex mathematical techniques that allowed the researchers to calculate the compressive stresses inside the drops, which are close to 50 tons per square inch, making the drops as strong as some steels—but only in their heads.
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Find our thoughts below:Mara Leighton, Insider Picks reporter: Ultimate Opaque Control Top Tights, (70 Denier), $38 available at Nordstromand Amazon Compressive, high-waisted clothing somehow always leaves me with a stomach ache, so I treat anything like tights as a necessary evil.
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These are my perfect pair of leggings: They're compressive but not restrictive, jet black and not at all see-through, and they have a waistband that doesn't dig in but doesn't ride down when you're bent like a pretzel during yoga practice.
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Those inner tensile forces are usually what makes glass so fragile, but the compressive forces on the outside counteract what's happening inside, to make it all but impossible for cracks to grow when the head of the glass is hammered, or even shot with a bullet.
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"Not only would this compressive garment make it difficult to breathe normally, but having the torso locked in a position may change how your body moves during exercise, as well as during activities of daily living," says Ashley Fluger, CSCS, PT, an exercise physiologist at the Hospital for Special Surgery.
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In 1994, similar research determined that breaking off the end of a Prince Rupert's Drop results in cracks that travel up the length of the drop towards its head at speeds of over 4,000 miles per hour, releasing all of those compressive stresses at once, and instantly turning the glass object into dust.
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Improvements in two components allow Corning to increase the durability of Gorilla over time: The chemical composition of the glass itself and its deep layer of compressive stress, a sort of armor created in the lab when, after it's put into a molten bath of salt, large ions are stuffed into the glass surface.
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"It feels like this suit represents all the women that have been through a lot mentally, physically with their body to come back and have confidence and to believe in themselves," said Williams, who indicated that the suit's compressive qualities also had a functional role in light of her recurring problems with blood clots, because it facilitated circulation.
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Compressive strength is a key value for design of structures. drum Compressive strength is often measured on a universal testing machine. Measurements of compressive strength are affected by the specific test method and conditions of measurement. Compressive strengths are usually reported in relationship to a specific technical standard.
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The test requirements differ country to country based on the design code. As per Indian codes, compressive strength of concrete is defined as The compressive strength of concrete is given in terms of the characteristic compressive strength of 150 mm size cubes tested after 28 days (fck). In field, compressive strength tests are also conducted at interim duration i.e. after 7 days to verify the anticipated compressive strength expected after 28 days.
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Compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to which withstands loads tending to elongate. In other words, compressive strength resists being pushed together, whereas tensile strength resists tension (being pulled apart). In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently. Some materials fracture at their compressive strength limit; others deform irreversibly, so a given amount of deformation may be considered as the limit for compressive load.
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In long, slender structural elements — such as columns or truss bars — an increase of compressive force F leads to structural failure due to buckling at lower stress than the compressive strength. Compressive stress has stress units (force per unit area), usually with negative values to indicate the compaction. However, in geotechnical engineering, compressive stress is represented with positive values. Compressive stress is defined in the same way as the tensile stress but it has negative values so as to express the compression since dL has the opposite direction.
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In long, slender structural elements — such as columns or truss bars — an increase of compressive force F leads to structural failure due to buckling at lower stress than the compressive strength.
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With both surfaces of the glass already in compression, it takes a certain amount of bending before one of the surfaces can even go into tension. More bending is required to reach the tensile strength. The other surface simply experiences more and more compressive stress. But since the compressive strength is so much larger, no compressive failure is experienced.
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For designers, compressive strength is one of the most important engineering properties of concrete. It is a standard industrial practice that the concrete is classified based on grades. This grade is nothing but the Compressive Strength of the concrete cube or cylinder. Cube or Cylinder samples are usually tested under a compression testing machine to obtain the compressive strength of concrete.
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Usually, compressive stress applied to bars, columns, etc. leads to shortening. Loading a structural element or specimen will increase the compressive stress until it reaches its compressive strength. According to the properties of the material, failure modes are yielding for materials with ductile behavior (most metals, some soils and plastics) or rupturing for brittle behavior (geomaterials, cast iron, glass, etc.).
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Within purely brittle rocks, compressive stress results in fracturing and simple faulting.
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Laser peen induced compressive stresses are also more resistant to heat exposure.
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The negative effects from FOD can be reduced or entirely eliminated by introducing compressive residual stresses in critical fatigue areas into the part during the manufacturing process. These beneficial stresses are induced into the part through cold working the part with peening processes: shot peening, or laser peening. The deeper the compressive residual stress the more significant the fatigue life and damage tolerance improvement. Shot peening typically induces compressive stresses a few thousandths of an inch deep, laser peening typically imparts compressive residual stresses 0.040 to 0.100 inches deep.
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Outstanding compressive strength and high water flow rate characterize this commercial grade drainboard.
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Compressive asphyxia (also called chest compression) is mechanically limiting expansion of the lungs by compressing the torso, hence interfering with breathing. Compressive asphyxia occurs when the chest or abdomen is compressed posteriorly.Jones, Richard. Strangulation . www.forensicmed.co.uk. URL last accessed February 26, 2006.
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The most frequently reported mechanical property of titanium foams is compressive strength. It was generally accepted that the compressive properties of metal foams depended on the properties of the cell wall rather than on pore size. However, more recent research has indicated that smaller pore sizes equate to higher compressive strength. As pore sizes reach nano-dimensions, the relationship is even more clear due to changes in deformation mechanism.
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Hydrostatic compressive stress is used for the determination of the bulk modulus for materials.
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It does not consider the effect of an overload or high stress which may result in a compressive residual stress that may retard crack growth. High stress followed by low stress may have less damage due to the presence of compressive residual stress.
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Plastic deformation from peening induces a residual compressive stress in a peened surface, along with tensile stress in the interior. This stress state resembles the one seen in toughened glass, and is useful for similar reasons. Surface compressive stresses confer resistance to metal fatigue and to some forms of corrosion, since cracks will not grow in a compressive environment. The benefit comes at the expense of higher tensile stresses deeper in the part.
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Concrete is strong in compression but weak in tension. When tensile loads are applied, concrete undergoes fracture easily. The reason behind this phenomenon can be explained as follows. The aggregates in concrete are capable of taking compressive stresses so that concrete withstands compressive loading.
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With rapid advances in optical fabrication, digital processing power, and computational models for human perception, a new generation of display technology is emerging: compressive light field displays. These architectures explore the co-design of optical elements and compressive computation while taking particular characteristics of the human visual system into account. Compressive display designs include dual and multilayer devices that are driven by algorithms such as computed tomography and Non-negative matrix factorization and non-negative tensor factorization.
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Excessive temperatures cause a drop in the Compressive strength due to the "crossover" effect. Higher temperatures would reduce the cycle time and therefore improve the economy of the manufacturing process, however, the compressive strength obtained would also be lower. Therefore, it is a trade- off between cost saving benefits and the loss in compressive strength. Depending on the type of project and economic considerations, either the cycle time is designed to suit the concrete mix or vice versa.
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In lean concretes (with a high water-cement ratio) the crushing strength of the aggregates is not so significant. The internal forces in common shapes of structure, such as arches, vaults, columns and walls are predominantly compressive forces, with floors and pavements subjected to tensile forces. Compressive strength is widely used for specification requirement and quality control of concrete. Engineers know their target tensile (flexural) requirements and will express these in terms of compressive strength. Wired.
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This aligns the molecular structure of the fiber in a better configuration for tensile and compressive strength.
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Fault gouge is seen as the salmon-colored rock in the center of the picture above the backpack. from Tavan Har, the Gobi, Mongolia. Gouge-filled faults can be weak planes in rock masses. If compressive stresses are enough these can cause compressive yielding or eventually rock fracture.
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The complementarity of wavelets and noiselets means that noiselets can be used in compressed sensing to reconstruct a signal (such as an image) which has a compact representation in wavelets.E. Candes and J. Romberg, Sparsity and incoherence in compressive sampling, 23 (2007), pp. 969–985. . MRI data can be acquired in noiselet domain, and, subsequently, images can be reconstructed from undersampled data using compressive-sensing reconstruction.K. Pawar, G. Egan, and Z. Zhang, Multichannel Compressive Sensing MRI Using Noiselet Encoding, 05 (2015), .
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Exfoliation joints have modified the near-surface portions of massive granitic rocks in Yosemite National Park, helping create the many spectacular domes, including Half Dome shown here. Large compressive tectonic stresses parallel to the land (or a free) surface can create tensile mode fractures in rock, where the direction of fracture propagation is parallel to the greatest principle compressive stress and the direction of fracture opening is perpendicular to the free surface. This type of fracturing has been observed in the laboratory since at least 1900 (in both uniaxial and biaxial unconfined compressive loading; see Gramberg, 1989). Tensile cracks can form in a compressive stress field due to the influence of pervasive microcracks in the rock lattice and extension of so-called wing cracks from near the tips of preferentially oriented microcracks, which then curve and align with the direction of the principle compressive stress.
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Whereas the plastic resins are strong in compressive loading and relatively weak in tensile strength, the glass fibers are very strong in tension but tend not to resist compression. By combining the two materials, GRP becomes a material that resists both compressive and tensile forces well.Erhard, Gunter. Designing with Plastics. Trans.
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Making little perturbations with the tip of a hair, one can see whether shock waves are compressive or undercompressive.
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Physical concepts such as compressive and tensile force also become visible, particularly in combination with other forms or materials.
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In very ductile materials like Man-Ten steel compressive loading does contribute to the crack growth according to \gamma = 0.22.
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It was observed in experimental study that with partial replacement of 2% CF with cement, the compressive strength is increased.
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The processes of thermal and chemical toughening can increase the tensile strength of glass. Glass has a compressive strength of .
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Conventional spectral imaging techniques typically scan adjacent zones of the underlying spectral scene and then merge the results to construct a spectral data cube. In contrast, compressive spectral imaging (CSI), which naturally embodies the principles of compressed sensing (CS), involves the acquisition of the spatial-spectral information in 2-dimensional sets of multiplexed projections. The remarkable advantage of compressive spectral imaging is that the entire data cube is sensed with just a few measurements and in some cases with as little as a single FPA snapshot such that the entire data set can be obtained during a single detector integration period. In general, compressive spectral imaging systems exploit different optical phenomena such as spatial, spectral, or spatial-spectral coding and dispersion, to acquire the compressive measurements.
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Rule based DFM analysis for forging. Forging is the controlled deformation of metal into a specific shape by compressive forces. The forging process goes back to 8000 B.C. and evolved from the manual art of simple blacksmithing. Then as now, a series of compressive hammer blows performs the shaping or forging of the part.
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This causes the initial crack to enlarge quickly (propagate) as the surrounding material is overwhelmed by the stress concentration, leading to fracture. A material having compressive residual stress helps to prevent brittle fracture because the initial crack is formed under compressive (negative tensile) stress. To cause brittle fracture by crack propagation of the initial crack, the external tensile stress must overcome the compressive residual stress before the crack tips experience sufficient tensile stress to propagate. The manufacture of some swords utilises a gradient in martensite formation to produce particularly hard edges (notably the katana).
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Interference fits are commonly used with fasteners to induce compressive stress around holes to improve the fatigue life of a joint.
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This mineral is hard, and provides compressive strength. Thus, the collagen and mineral together are a composite material with excellent tensile and compressive strength, which can bend under a strain and recover its shape without damage. This is called elastic deformation. Forces that exceed the capacity of bone to behave elastically may cause failure, typically bone fractures.
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These contractions can apply or resist compressive forces to the overall structure. A balance of synchronized, compressive and resistive forces along the three lines of action, enable the muscle to move in diverse and complex ways. Contraction of helical fibers causes elongation and shortening of the hydrostat. Unilateral contraction of these muscles can cause a bending movement.
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At the end of the Cretaceous, the tectonic regime changed to a compressive phase, due to the movement of the Caribbean Plate.
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Worrisome sign and symptoms include voice hoarseness, rapid increase in size, compressive symptoms (such as dyspnoea or dysphagia) and appearance of lymphadenopathy.
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Though generally section modulus is calculated for the extreme tensile or compressive fibres in a bending beam, often compression is the most critical case due to onset of flexural torsional (F/T) buckling. Generally (except for brittle materials like concrete) tensile extreme fibres have a higher allowable stress or capacity than compressive fibres. In the case of T-sections if there are tensile fibres at the bottom of the T they may still be more critical than the compressive fibres at the top due to a generally much larger distance from the neutral axis so despite having a higher allowable stress the elastic section modulus is also lower. In this case F/T buckling must still be assessed as the beam length and restraints may result in reduced compressive member bending allowable stress or capacity.
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Establishing a small preload as a part of the test method eliminates those compressive forces on specimens and improves the repeatability of results.
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Notable extensions are Orthogonal Matching Pursuit (OMP), Stagewise OMP (StOMP), compressive sampling matching pursuit (CoSaMP), Generalized OMP (gOMP), and Multipath Matching Pursuit (MMP).
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Eur Spine J, 1999. 8(3): p. 244-8.Pinto, D.S., et al., Aggressive Vertebral Body Hemangioma Causing Compressive Myelopathy - Two Case Reports.
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However, as more layers are added, the increasing subsurface compressive stress "bleeds" back through the melted surface layer to produce the desired surface compressive stress. Depending on material properties and the desired compressive stresses, generally about 18 spots/mm2 to 70 spots/mm2 or greater spot densities are applied, about 100 times the spot densities of the high pulse energy process. The effects of the higher spot densities on processing times are compensated for in part by the higher pulse frequency, 60 Hz, of the low energy lasers. Newer generations of these laser systems are projected to operate at higher frequencies.
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The shockwave generated coldwork (plastic strain) in the workpiece material creates compressive and tensile residual stresses to maintain an equilibrium state of the material. These residual stresses are compressive at the workpiece surface and gradually fade into low tensile stresses below and surrounding the laser peened area. The cold work also work hardens the surface layer. The compressive residual stresses, and to a lesser extent, the cold work, from laser peening have been shown to prevent and mitigate high cycle fatigue (HCF), low cycle fatigue (LCF), stress corrosion cracking, fretting fatigue and to some degree, wear and corrosion pitting.
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The flange region (sheet metal in the die shoulder area) experiences a radial drawing stress and a tangential compressive stress due to the material retention property. These compressive stresses (hoop stresses) result in flange wrinkles (wrinkles of the first order). Wrinkles can be prevented by using a blank holder, the function of which is to facilitate controlled material flow into the die radius.
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"Traumatic asphyxia" or "crush asphyxia" usually refers to compressive asphyxia resulting from being crushed or pinned under a large weight or force. An example of traumatic asphyxia includes cases where an individual has been using a car-jack to repair a car from below, and is crushed under the weight of the vehicle. Pythons, anacondas, and other constrictor snakes kill through compressive asphyxia.
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One of the more tried and tested is: "The more compressive load exerted on the gasket, the longer it will last". There are several ways to measure a gasket material's ability to withstand compressive loading. The "hot compression test" is probably the most accepted of these tests. Most manufacturers of gasket materials will provide or publish the results of these tests.
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The formation of the Haungling dome is still unknown. There are three evolutionary models established including those driven by both compressive and extensional forces.
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Solid stress is heterogeneous in tumors with tensile stresses distributed more at the periphery of the tumor, and compressive stresses more at the tumor core.
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Ghost imaging has also been proposed for X-ray FEL applications. Classical ghost imaging with compressive sensing has also been demonstrated with ultra-relativistic electrons.
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Since a tectonic graben is typically characterized by tensional features, the common interpretation meets basic difficulties with the structurally dominant compressive style that was observed.
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The container compression test measures the compressive strength of packages such as boxes, drums, and cans. It usually provides a plot of deformation vs compressive force. It is commonly used to evaluate shipping containers made of corrugated fiberboard as well as wooden boxes and crates. Industrial and consumer packages other than boxes can also be subjected to compression testing: drum, pail, bottle, tub etc.
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Tumours and other compressive lesions could often present with visual impairment and/or visual field defects. Careful clinical assessment could aid in accurate diagnosis of the cause of the visual field defect and loss of vision. Compressive lesions of the visual pathway, especially lesions affecting optic nerve require a multi-disciplinary approach involving neurosurgeon, physician as well as the ophthalmologist. Treatment is given according to the cause.
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Concrete and ceramics typically have much higher compressive strengths than tensile strengths. Composite materials, such as glass fiber epoxy matrix composite, tend to have higher tensile strengths than compressive strengths. Metals are difficult to test to failure in tension vs compression. In compression metals fail from buckling/crumbling/45deg shear which is much different (though higher stresses) than tension which fails from defects or necking down.
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Increases in fatigue life and strength are proportionally related to the depth of the compressive residual stresses imparted. Shot peening imparts compressive residual stresses approximately 0.005 inches (0.1 mm) deep, while laser peening can go 0.040 to 0.100 inches (1 to 2.5 mm) deep, or deeper. # Deep cryogenic treatment. The use of Deep Cryogenic treatment has been shown to increase resistance to fatigue failure.
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For it to be considered safety glass, the surface compressive stress should exceed . As a result of the increased surface stress, if the glass is ever broken it only breaks into small circular pieces as opposed to sharp jagged shards. This characteristic makes tempered glass safe for high-pressure and explosion proof applications. It is this compressive surface stress that gives the tempered glass increased strength.
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The cracking caused by ASR can have several negative impacts on concrete, including: # Expansion: The swelling nature of ASR gel increases the chance of expansion in concrete elements. # Compressive strength: The effect of ASR on compressive strength can be minor for low expansion levels, to relatively higher degrees at larger expansion. (Swamy R.N. 1986) points out that the compressive strength is not very accurate parameter to study the severity of ASR; however, the test is done because of its simplicity. # Tensile strength / Flexural capacity: Researches show that ASR cracking can significantly reduce the tensile strength of concrete; therefore reducing the flexural capacity of beams.
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The criteria are extended to three-dimensional problems where the maximum stress criteria are used for transverse normal stress component. The failure modes included in Hashin’s criteria are as follows. # Tensile fibre failure for σ11 ≥ 0 # Compressive fibre failure for σ11 < 0 # Tensile matrix failure for σ22 + σ33 > 0 # Compressive matrix failure for σ22 + σ33 < 0 # Interlaminar tensile failure for σ33 > 0 # Interlaminar compression failure for σ33 < 0 where, σij denote the stress components and the tensile and compressive allowable strengths for lamina are denoted by subscripts T and C, respectively. XT, YT, ZT denotes the allowable tensile strengths in three respective material directions.
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Cement and water are not required. The concrete doesn't have to be cured, instead it is simply heated to above the melting point of sulfur, 140 °C, and after cooling it reaches high strength immediately. The best mixture for tensile and compressive strength is 65% JSC-1 lunar regolith simulant and 35% sulfur, with an average compressive strength of 33.8 MPa and tensile strength of 3.7 MPa. Addition of 2% metal fiber increase the compressive strength to 43.0 MPaPRODUCTION OF LUNAR CONCRETE USING MOLTEN SULFUR Final Research Report for JoVe NASA Grant NAG8 - 278 by Dr. Husam A. Omar Addition of silica also increases the strength of the concrete.
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In the case of Monte Burney, these magmas then underwent some fractionation during ascent, as it was retarded by the tectonic regimen, which is somewhat compressive.
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Also, stylolites are indicators of compressive stress in tectonic studies, and development of transverse stylolites contributes to crustal shortening parallel to the direction of their column.
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Scarps of this type are considered by Strom and others to be compressive thrust faults resulting from overall shortening of the mercurian crust early in its history.
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Journal of Glaciology and Geocryology, 20(1998)2, pp. 167–171 [in Chinese]. # Li, Zhijun & Riska, K. 1998. Uniaxial Compressive Strength of Fine Grain Ethanol Model Ice.
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It enhances glycosaminoglycan modification and product secretion. Aggrecan plays an important role in mediating chondrocyte-chondrocyte and chondrocyte-matrix interactions through its ability to bind hyaluronan. Aggrecan provides intervertebral disc and cartilage with the ability to resist compressive loads. The localized high concentrations of aggrecan provide the osmotic properties necessary for normal tissue function with the GAGs producing the swelling pressure that counters compressive loads on the tissue.
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While more tensile cold working increases the tensile yield strength, the local initial compressive yield strength after tensile cold working is actually reduced. The greater the tensile cold working, the lower the compressive yield strength. The Bauschinger effect is normally associated with conditions where the yield strength of a metal decreases when the direction of strain is changed. It is a general phenomenon found in most polycrystalline metals.
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If the condensation rate of vapor is much faster than the escaping speed of vapor out of concrete due to sufficiently high heating rate or adequately dense pore structure, a large pore pressure can cause spalling. At the same time, thermal expansion on the surface will generate a perpendicular compressive stress opposing the tensile stress within the concrete. Spalling occurs when the compressive stress exceeds the tensile stress.
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Temperatures elevated above degrade the mechanical properties of concrete, including compressive strength, fracture strength, tensile strength, and elastic modulus, with respect to deleterious effect on its structural changes.
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Idealisation of arching action forces in laterally restrained slab Arching or compressive membrane action (CMA) in reinforced concrete slabs occurs as a result of the great difference between the tensile and compressive strength of concrete. Cracking of the concrete causes a migration of the neutral axis which is accompanied by in-plane expansion of the slab at its boundaries. If this natural tendency to expand is restrained, the development of arching action enhances the strength of the slab. The term arching action is normally used to describe the arching phenomenon in one-way spanning slabs and compressive membrane action is normally used to describe the arching phenomenon in two-way spanning slabs.
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Pervious concrete has a common strength of though strengths up to can be reached. There is no standardized test for compressive strength."Specification for Pervious Concrete." ACI 522.1-08.
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The shorter wavelength decreases the absorption of beam energy while traveling through water to the target. Due to access constraints, no opaque overlay is applied to the target surface. This factor, combined with the small spot size, requires many shots to achieve a significant surface compressive stress and depths of 1 mm. The first layers applied produce a tensile surface stress due to surface melting, although a compressive stress is developed below the melt layer.
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Sharma et al. utilized acicular spacers and achieved porosities up to 60% where pores were undistorted. In samples employing fine particles, porosities up to 70% were achievable before noting distortion in the pores. However, the bimodal pore distribution observed in coarse-spacer samples showed to be beneficial in terms of mechanical properties in that higher compressive strengths were observed, beyond those that might exist due to the inverse relationship of porosity and compressive strength alone.
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For example, there are compressively strained bonds directly next to an edge dislocation and tensilely strained bonds beyond the end of an edge dislocation. These form compressive strain fields and tensile strain fields, respectively. Strain fields are analogous to electric fields in certain ways. Specifically, the strain fields of dislocations obey similar laws of attraction and repulsion; in order to reduce overall strain, compressive strains are attracted to tensile strains, and vice versa.
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Bend dominated structures are usually such as tetrakaidecahedron structure have higher n values that result in non-linear density-to-stiffness ratio, since loading on these crystals are shear rather than tensile as in their stretch-dominated counterpart. However, these structures can also be highly compressive. For instance, 3-D simple cubic bulk graphene aerogels created using layer-by-layer lithography showed lightweight, highly conductive and supercompressible (up to 90% compressive strain) properties.
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The hip joint is unique in that it experiences combined mechanical loads. An axial load along the shaft of the femur results in compressive stress. Bending load at the neck of the femur causes tensile stress along the upper part of the neck and compressive stress along the lower part of the neck. While osteoarthritis and osteoporosis are associated with bone fracture as we age, these diseases are not the cause of the fracture alone.
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There is also a relationship between the magnetic flux and compression in which when the compressive stress increases, the magnetic flux changes less drastically. Terfenol-D is mostly used for its magnetostrictive properties, in which it changes shape when exposed to magnetic fields in a process called magnetization. Magnetic heat treatment is shown to improve the magnetostrictive properties of Terfenol-D at low compressive stress for certain ratios of Tb and Dy.
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The original concept envisioned by Tsiolkovsky was a compression structure. Building a compression structure from the ground up proved an unrealistic task as there was no material in existence with enough compressive strength to support its own weight under such conditions. Other ideas use very tall compressive towers to reduce the demands on launch vehicles. The vehicle is "elevated" up the tower, which may extend above the atmosphere and is launched from the top.
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Compressive stresses are produced by offset and converging slip-strike motions between the Calaveras Fault and the Clayton-Marsh Creek- Greenville Fault which manifest in the Mount Diablo Thrust Fault.
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Marine Environmental Science, 17(1998)4, pp. 42–47 [in Chinese]. # Li, Zhijun & Riska, K. 1998. Experimental Study on the Uniaxial Compressive Strength Characteristics of Fine Grain Ethanol Model Ice.
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Whether in commercial or civil engineering applications, this drainboard has proven superior long term performance in regards to water flow rate, compressive strength, and chemical and environmental stress crack resistance.
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In soil mechanics, compressive stresses and pressures are considered to be positive and tensile stresses are considered to be negative, which is different from the solid mechanics sign convention for stress.
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Heavy-duty drainboard, ideally suited for applications in underground areas such as foundation walls, lagging or caisson walls, and retaining walls where high compressive strength and water flow rates are required.
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Compressed sensing typically starts with taking a weighted linear combination of samples also called compressive measurements in a basis different from the basis in which the signal is known to be sparse. The results found by Emmanuel Candès, Justin Romberg, Terence Tao and David Donoho, showed that the number of these compressive measurements can be small and still contain nearly all the useful information. Therefore, the task of converting the image back into the intended domain involves solving an underdetermined matrix equation since the number of compressive measurements taken is smaller than the number of pixels in the full image. However, adding the constraint that the initial signal is sparse enables one to solve this underdetermined system of linear equations.
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The second unusual property of the drops, namely the strength of the heads, is a direct consequence of large compressive residual stresses—up to —that exist in the vicinity of the head's outer surface. This stress distribution is measured by using glass's natural property of stress-induced birefringence and by employing techniques of 3D photoelasticity. The high fracture toughness due to residual compressive stresses makes Prince Rupert's drops one of the earliest examples of toughened glass.
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The test was pioneered by L Carlson and AW Skempton in 1948. There has been some dispute over its accuracy since then. Carlson and Skempton believed that it provided a higher value than that indicated by unconfined compressive tests and in fact agreed better with the values expected in geotechnical theory. However 1973 research claimed that the test actually provided an under-estimate of shear strength compared to compressive tests where a good quality of sample is obtainable.
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Baraniuk has been active in the development of digital signal processing, image processing, and machine learning systems, with numerous contributions to the theory of wavelets and compressive sensing. His work with Kevin Kelly on the Rice "single-pixel camera" applied the ideas of compressive sensing to design a novel imaging system that was selected by MIT Technology Review as a TR10 Top 10 Emerging Technology in 2007.TR10: Digital Imaging, Reimagined, Technology Review, 2007.Photography, The Economist, 2006.
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Low plasticity burnishing (LPB) is a method of metal improvement that provides deep, stable surface compressive residual stresses with little cold work for improved damage tolerance and metal fatigue life extension. Improved fretting fatigue and stress corrosion performance has been documented, even at elevated temperatures where the compression from other metal improvement processes relax. The resulting deep layer of compressive residual stress has also been shown to improve high cycle fatigue (HCF) and low cycle fatigue (LCF) performance.
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The Great Mosque of Djenné, Mali, is built in adobe. The struts projecting from the wall serve as decoration, as well as supports for scaffolding during maintenance. Adobe walls are load bearing, i.e. they carry their own weight into the foundation rather than by another structure, hence the adobe must have sufficient compressive strength. In the United States, most building codes call for a minimum compressive strength of 300 lbf/in2 (2.07 newton/mm2) for the adobe block.
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Voroninski's PhD thesis kicked off the study of phase retrieval in the applied mathematics community, by providing the PhaseLift algorithm along with the first mathematical recovery guarantees for phase retrieval. His research has also led to solutions to open problems in computer vision, quantum operator theory, optimization and the theory of deep learning and compressive sensing. More recently, Voroninski's research connected the fields of deep learning and inverse problems, resolving the sample complexity bottleneck for compressive phase retrieval.
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Peening a surface spreads it plastically, causing changes in the mechanical properties of the surface. Its main application is to avoid the propagation of microcracks from a surface. Such cracks do not propagate in a material that is under compressive stress; shot peening can create such stress on the surface. Shot peening is often called for in aircraft repairs to relieve tensile stresses built up in the grinding process and replace them with beneficial compressive stresses.
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In regard to skeletal muscle denervation there are two distinct diagnoses: entrapment and compressive neuropathies or non-entrapment neuropathies. Entrapment and compressive neuropathy syndromes occur due to compression and/or constriction on a specific location for a segment of a single nerve or multiple nerve sites. This entrapment or compression can be diagnosed based on multiple factors including physical examination, electrodiagnostic test and clinical history. Following denervation, muscular atrophy and degeneration occurs within affected skeletal muscle tissue.
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The Resal effect is a structural engineering term which refers to the way the compressive force acting on a flange of a tapered beam reduces the effective shear force acting on the beam.
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This low energy process achieves compressive residual stress magnitudes and depths equivalent to the high energy process with nominal depths of . However, the smaller spot size will not permit depths deeper than this.
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Local mechanical deformations occur in the form of a treatment track. The weld toe is deformed plastically. The induced compressive residual stress prevents the track cracking and the crack propagation on the surface.
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Deaths from human crushes and stampedes are found to be caused primarily by compressive asphyxiation; trampling is a lesser killer.Fruin, John. The Causes and Prevention of Crowd Disasters . www.crowddynamics.com. Retrieved November 22, 2010.
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Those loads then cause the composite panel to deform, usually bending inwards between bulkheads as most loads are compressive and directed inwards. Stress in the structure is calculated from the loads and bending.
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The results of the testing confirm that the degree of alteration or kaolinization, and associated changes in mineralogy of the granite, is directly related to reduction in uniaxial compressive strength and dry density.
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Volcanism resumed as evidenced by the Late Cretaceous Tutu Formation, consisting of volcaniclastic turbidites, basalt, and andesite. A diabase dike swarm followed and then compressive folding attributed to the Caribbean Plate colliding with the Bahama Platform. The Late Eocene saw the intrusion of Narrows pluton and Virgin Gorda batholith, associated with the Greater Antilles arc magmatism, and more compressive folding associated with the spreading of the Cayman Trough. This spreading is also tied to sinistral strike-slip faulting at 39 Ma.
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The Skagit River bridge had last been inspected for cracks in August and November 2012 with only minor work needed. Besides fracturing, some bridges with critical non- redundant parts can also suddenly fail from buckling of compressive members (the opposite of cracking of tensile members). In through-truss bridges the critical compressive parts are the top-chord beams running horizontally along the top of the bridge, parallel to the roadway edges. They carry most of the weight of the bridge and traffic.
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A systematic review shows GIC has higher retention rates than resin composite in follow up periods of up to 5 years. Unfortunately, reviews for Class II restorations in permanent teeth with glass ionomer cement are scarce with high bias or short study periods. However, a study [2003] of the compressive strength and the fluoride release was done on 15 commercial fluoride- releasing restorative materials. A negative linear correlation was found between the compressive strength and fluoride release (r2=0.7741), i.e.
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The most widely used and studied foams are glass microspheres (in epoxy or polymers), and cenospheres or ceramics (in aluminium). One can change the volume fraction of microballoons or use microballoons of different effective density, the latter depending on the average ratio between the inner and outer radii of the microballoons. The compressive properties of syntactic foams, in most cases, strongly depend on the properties of microballoons. In general, the compressive strength of the material is proportional to its density.
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The mortar must have greater vapor permeability and softer compressive strength than the original mortar. The mortar should also not be stronger (in compressive strength) than the masonry units because it will not have give. Rather than the mortar relieving the stress, the masonry units will, which will cause further damage to the masonry unit, such as cracking or spalling. This is when the face or outer section of a masonry unit breaks away from the rest of the unit.
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High-strength concrete has a compressive strength greater than 40 MPa (5800 psi). In the UK, BS EN 206-1BS EN 206-1 defines High strength concrete as concrete with a compressive strength class higher than C50/60. High-strength concrete is made by lowering the water-cement (W/C) ratio to 0.35 or lower. Often silica fume is added to prevent the formation of free calcium hydroxide crystals in the cement matrix, which might reduce the strength at the cement- aggregate bond.
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This implies that for small compressive forces, the only equilibrium state is given by \theta = 0, while if the force exceeds the value k_\theta/L there is suddenly another mode of deformation possible.
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Therapy usually consists of prednisolone, nonetheless some cases may require surgery. Tamoxifen has been proposed as part of a treatment plan. Treatment is directed to surgical relief of compressive symptoms. Tamoxifen may also be beneficial.
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" The Journal of Hand Surgery 4, no. 1 (January 1979): 48-51. .Hartz, C R, R L Linscheid, R R Gramse, and J R Daube. "The pronator teres syndrome: compressive neuropathy of the median nerve.
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The high compressive strength of 34 GPa, predicted for ideal crystals, is never obtained in the real bulk material due to the formation and movement of dislocations. However, it has been reached in Ni nanoparticles.
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Crushing strengths and fire resistance tests carried out on Sydney sandstone showed that the compressive strength was 2.57 tons per square inch, or 39.9 megapascals (MPa). The crushing strength for ashlar masonry and lintels averaged 4,600 pounds per square inch (31.7 MPa). Recent tests have recorded compressive strengths of up to 70 MPa. In fire resistance tests, designed to assess the resistance to collapse of a building in a fire, the sandstone came through better than some of the very hard stones, especially the granites.
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Fractures formed in this way are sometimes called axial cleavage, longitudinal splitting, or extensional fractures, and are commonly observed in the laboratory during uniaxial compression tests. High horizontal or surface-parallel compressive stress can result from regional tectonic or topographic stresses, or by erosion or excavation of overburden. With consideration of the field evidence and observations of occurrence, fracture mode, and secondary forms, high surface- parallel compressive stresses and extensional fracturing (axial cleavage) seems to be the most plausible theory explaining the formation of exfoliation joints.
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By varying the laser power density, pulse duration, and number of successive shots on an area, a range of surface compressive stress magnitudes and depths can be achieved. The magnitude of surface stresses are comparable to shot peening, but the depths are much greater, ranging up to 5 mm when using multiple shots on a spot. Generally spot densities of about 10 spots/cm2 to 40 spots/cm2 are applied. The compressive stress depth achieved with the most common processing parameters ranges from deep.
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The deeper the well, the more overburden pressure, which means the greater the annular compressive stress conditions. On the rocks lying at depths of 3–5 km the compressive stresses may reach up-to 75–125 MPa. In the near-well zone, as a result of concentration these stresses increase and sometimes become equal to double 150–250 MPa. If the tectonic stresses is several times higher than stresses from the weight of rocks, the stresses in the near-well zone may be even greater.
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Compressed sensing (also known as compressive sensing, compressive sampling, or sparse sampling) is a signal processing technique for efficiently acquiring and reconstructing a signal, by finding solutions to underdetermined linear systems. This is based on the principle that, through optimization, the sparsity of a signal can be exploited to recover it from far fewer samples than required by the Nyquist–Shannon sampling theorem. There are two conditions under which recovery is possible.CS: Compressed Genotyping, DNA Sudoku – Harnessing high throughput sequencing for multiplexed specimen analysis.
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Depending on the part geometry, part material, shot material, shot quality, shot intensity, and shot coverage, shot peening can increase fatigue life up to 1000%. Plastic deformation induces a residual compressive stress in a peened surface, along with tensile stress in the interior. Surface compressive stresses confer resistance to metal fatigue and to some forms of stress corrosion. The tensile stresses deep in the part are not as problematic as tensile stresses on the surface because cracks are less likely to start in the interior.
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The defining feature of these models is that tensile failure is predicted at low stresses. On the other hand, as the stress state becomes increasingly compressive, failure and yield requires higher and higher values of stress.
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Wood Sci. Technol. 24(4), 345–354. the comparison of the mechanical properties of cement-aggregate mixesHong, Z. and Lee, A.W.C. (1986) Compressive strength of cylindrical samples as an indicator of wood- cement compatibility. For. Prod.
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With the types of wood that are used for molded wood, the compressive strength is between 50 and 62 N/cm². It guarantees long-lasting furniture that endures even frequent use as in schools, for instance.
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Due to the forces acting on the cylinder, the piston rod is the most stressed component and has to be designed to withstand high amounts of bending, tensile and compressive forces. Depending on how long the piston rod is, stresses can be calculated differently. If the rods length is less than 10 times the diameter, then it may be treated as a rigid body which has compressive or tensile forces acting on it. In which case the relationship is: : F = A \sigma Where: :F is the compressive or tensile force :A is the cross-sectional area of the piston rod :\sigma is the stress However, if the length of the rod exceeds the 10 times the value of the diameter, then the rod needs to be treated as a column and buckling needs to be calculated as well.
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Mosby, 2003. describe several compressive etiologies, which are important to understand if they are to be successfully managed. The usual suspects are pituitary adenomas, craniopharyngiomas, and meningiomas. Pituitary tumors are the most common cause of chiasmal syndromes.
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A concrete (or asphalt) drain body is required to encase the channel to give the channel compressive strength and rigidity to ensure the drain will be able to withstand the traffic load it was designed to handle.
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Some of the property ranges of the composites are density (400–1500 kg/m³), compressive strength (1–26 MPa) and flexural strength (0.5–4.0 MPa).Karade SR. 2003. An Investigation of Cork Cement Composites. PhD Thesis. BCUC.
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Shear stress is proportional to the speed inside the vessel as well as the pressure drop between two fixed points on the vessel wall. The precise mechanism of vessel remodelling is believed to be high stress on the inner wall of the vessel which can induce growth, which heads toward uniform compressive and tensile stress on both sides of the vessel wall. Generally, it has been found that circumferential residual stress is compressive and tensile, indicating that inner layers of the endothelial tube grow more than outer layers.Chuong, C.J. and Fung, Y.C. (1986).
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Compressive forces built up along the entire length of the broad continental shelf. The Sierran Arc, also called the Cordilleran Mesozoic magmatic arc, started to form from heat and pressure generated from the subduction. Compressive forces caused thrust faults to develop and granitic blobs of magma called plutons to rise in the Death Valley region and beyond, most notably creating the Sierra Nevada Batholith to the west. Thrust faulting was so severe that the continental shelf was shortened and some parts of older formations were moved on top of younger rock units.
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Prestressing concrete is a technique that greatly increases the load-bearing strength of concrete beams. The reinforcing steel in the bottom part of the beam, which will be subjected to tensile forces when in service, is placed in tension before the concrete is poured around it. Once the concrete has hardened, the tension on the reinforcing steel is released, placing a built-in compressive force on the concrete. When loads are applied, the reinforcing steel takes on more stress and the compressive force in the concrete is reduced, but does not become a tensile force.
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Despite the extensive volcanism that gives Io its distinctive appearance, nearly all its mountains are tectonic structures, and are not produced by volcanoes. Instead, most Ionian mountains form as the result of compressive stresses on the base of the lithosphere, which uplift and often tilt chunks of Io's crust through thrust faulting. The compressive stresses leading to mountain formation are the result of subsidence from the continuous burial of volcanic materials. The global distribution of mountains appears to be opposite that of volcanic structures; mountains dominate areas with fewer volcanoes and vice versa.
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15 (2006) S29-S38) Standard lithography patterning techniques can be used to selectively deposit strain-inducing capping layers, to deposit a compressive film over only the PMOS, for example. Capping layers are key to the Dual Stress Liner (DSL) approach reported by IBM-AMD. In the DSL process, standard patterning and lithography techniques are used to selectively deposit a tensile silicon nitride film over the NMOS and a compressive silicon nitride film over the PMOS. A second prominent approach involves the use of a silicon- rich solid solution, especially silicon-germanium, to modulate channel strain.
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Unicirc can also be used in males when the foreskin is tight or adherent to the glans (phimosis), after a dorsal slit (similar to that performed in newborns). Frenulectomies can be performed under topical anesthetic immediately prior to Unicirc circumcision. An international group of researchers estimated that compressive instruments (like Unicirc and Gomco) could displace up to 85% of surgical circumcisions. A meta-analysis of randomized controlled trials suggested that compressive instruments were associated with less blood loss, more rapid healing, and less pain compared to other techniques.
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Crustal thickening that led to mountain building was caused by a combination of compressive forces and conductive heating initiated by subduction, which led to deformation. The Sevier River area of central Utah is the namesake of this event.
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A reinforced concrete column is a structural member designed to carry compressive loads, composed of concrete with an embedded steel frame to provide reinforcement. For design purposes, the columns are separated into two categories: short columns and slender columns.
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As many pre-Portland mix buildings are still standing and have original mortar, the arguments for greater compressive strength and ease of use may be more a result of current practice and a lack of understanding of older techniques.
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Flexural vibrations cause alternating tensile and compressive strains to build up on opposite sides of the neutral axis leading to a thermal imbalance. Irreversible heat flow which is driven by the temperature gradient causes vibrational energy to be dissipated.
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Compression testing of a concrete cylinder Same cylinder after failure Engineers usually specify the required compressive strength of concrete, which is normally given as the 28-day compressive strength in megapascals (MPa) or pounds per square inch (psi). Twenty eight days is a long wait to determine if desired strengths are going to be obtained, so three-day and seven-day strengths can be useful to predict the ultimate 28-day compressive strength of the concrete. A 25% strength gain between 7 and 28 days is often observed with 100% OPC (ordinary Portland cement) mixtures, and between 25% and 40% strength gain can be realized with the inclusion of pozzolans such as flyash, and supplementary cementitious materials (SCMs) such as slag cement. Strength gain depends on the type of mixture, its constituents, the use of standard curing, proper testing by certified technicians, and care of cylinders in transport.
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The area is currently in a compressive stress regime with the maximum horizontal stress orientated northwest-southeast. This results from a combination of the continuing collision between the Indian and Eurasian Plates and the subduction of the Philippine Sea Plate.
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The compressive technique reached an upper limit with a rod. For longer measures, a tensive measure such as a string or rope was used. This reached an upper limit with sagging of the string. Next was a surveyor's telescope (visual).
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It has more facile viscous flow behavior and a lower tendency to crystallize upon being pulled into fibers. 13-93 bioactive glass powder could be dispersed into a binder to create ink for robocasting or direct ink 3D printing technique. The mechanical properties of the resulting porous scaffolds have been studied in various works of literature. The printed 13-93 bioactive glass scaffold in the study by Liu et al. was dried in ambient air, fired to 600 °C under the O2 atmosphere to remove the processing additives, and sintered in air for 1 hour at 700 °C. In the pristine sample, the flexural strength (11 ± 3 MPa) and flexural modulus (13 ± 2 MPa) are comparable to the minimum value of those of trabecular bones while the compressive strength (86 ± 9 MPa) and compressive modulus (13 ± 2 GPa) are close to the cortical bone values. However, the fracture toughness of the as-fabricated scaffold was 0.48 ± 0.04 MPa·m1/2, indicating that it is more brittle than human cortical bone whose fracture toughness is 2-12 MPa·m1/2. After immersing the sample in a simulated body fluid (SBF) or subcutaneous implantation in the dorsum of rats, the compressive strength and compressive modulus decrease sharply during the initial two weeks but more gradually after two weeks.
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This gives the concrete using this type of cement a three-day compressive strength equal to the seven-day compressive strength of types I and II. Its seven-day compressive strength is almost equal to 28-day compressive strengths of types I and II. The only downside is that the six- month strength of type III is the same or slightly less than that of types I and II. Therefore, the long-term strength is sacrificed. It is usually used for precast concrete manufacture, where high one-day strength allows fast turnover of molds. It may also be used in emergency construction and repairs, and construction of machine bases and gate installations. Type IV Portland cement is generally known for its low heat of hydration. Its typical compound composition is: 28% (C3S), 49% (C2S), 4% (C3A), 12% (C4AF), 1.8% MgO, 1.9% (SO3), 0.9% ignition loss, and 0.8% free CaO. The percentages of (C2S) and (C4AF) are relatively high and (C3S) and (C3A) are relatively low. A limitation on this type is that the maximum percentage of (C3A) is seven, and the maximum percentage of (C3S) is thirty-five. This causes the heat given off by the hydration reaction to develop at a slower rate.
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Forking refers to an aqueduct which has become split into multiple, separate channels as a result of incomplete fusion of the median fissure. These channels may connect back together to form a single aqueduct again, or they may abruptly stop and form a dead-end. Both of these deformations disrupt the laminar flow of CSF through the ventricular system, causing the force by the aqueduct on its surroundings to be lower than the compressive force being applied to the aqueduct. This greater compressive force could effectively stop the flow of CSF if the aqueduct closes due to the force.
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While osteoarthritis is a degenerative joint disease that may cause gross cartilage loss and morphological damage to other joint tissues, more subtle biochemical changes occur in the earliest stages of osteoarthritis progression. The water content of healthy cartilage is finely balanced by compressive force driving water out and hydrostatic and osmotic pressure drawing water in. Collagen fibres exert the compressive force, whereas the Gibbs–Donnan effect and cartilage proteoglycans create osmotic pressure which tends to draw water in. However, during onset of osteoarthritis, the collagen matrix becomes more disorganized and there is a decrease in proteoglycan content within cartilage.
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In certain cases, the plane stress model can be used in the analysis of gently curved surfaces. For example, consider a thin-walled cylinder subjected to an axial compressive load uniformly distributed along its rim, and filled with a pressurized fluid. The internal pressure will generate a reactive hoop stress on the wall, a normal tensile stress directed perpendicular to the cylinder axis and tangential to its surface. The cylinder can be conceptually unrolled and analyzed as a flat thin rectangular plate subjected to tensile load in one direction and compressive load in another other direction, both parallel to the plate.
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Some petrophysicists use acoustic and density measurements of rocks to compute their mechanical properties and strength. They measure the compressional (P) wave velocity of sound through the rock and the shear (S) wave velocity and use these with the density of the rock to compute the rocks' compressive strength, which is the compressive stress that causes a rock to fail, and the rocks' flexibility, which is the relationship between stress and deformation for a rock. Converted-wave analysis is also used to determine subsurface lithology and porosity. These measurements are useful to design programs to drill wells that produce oil and gas.
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Additionally, from scanning electron microscopy, it was found that the variation in trabecular architecture with different anatomic sites lead to different modulus. To understand structure-anisotropy and material property relations, one must correlate the measured mechanical properties of anisotropic trabecular specimens with the stereologic descriptions of their architecture. The compressive strength of trabecular bone is also very important because it is believed that the inside failure of trabecular bone arise from compressive stress. On the stress-strain curves for both trabecular bone and cortical bone with different apparent density, there are three stage in stress-strain curve.
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13-93 porous glass scaffolds were synthesized using a polyurethane foam replication method in the report by Fu et al. The stress-strain relationship was examined in obtained from the compressive test using eight samples with 85 ± 2% porosity. The resultant curve demonstrated a progressive breaking down of the scaffold structure and the average compressive strength of 11 ± 1 MPa, which was in the range of human trabecular bone and higher than competitive bioactive materials for bone repairing such as hydroxyapatite scaffolds with the same extent of pores and polymer-ceramic composites prepared by the thermally induced phase separation (TIPS) method.
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The compressive sampling project is fundamental research into signal processing in collabrotation with Delft University of Technology. In the context of radio astronomy capture, analysis and processing of signals is extremely compute intensive on enormous datasets. The goal is to do sampling and compression simultaneously and use machine learning to detect what to keep and what to throw away, preferably as close to the data collectors as possible. This project's goal is to develop compressive sampling algorithms to use in capturing the signal and to calibrate the patterns to keep, in an ever- increasing number of pattern clusters.
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Two intersecting beams integral to parking garage slab that will contain both reinforcing steel and the wiring, junction boxes and other electrical components necessary to install the overhead lighting for the garage level beneath it. A beam bends under bending moment, resulting in a small curvature. At the outer face (tensile face) of the curvature the concrete experiences tensile stress, while at the inner face (compressive face) it experiences compressive stress. A singly reinforced beam is one in which the concrete element is only reinforced near the tensile face and the reinforcement, called tension steel, is designed to resist the tension.
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A doubly reinforced beam is one in which besides the tensile reinforcement the concrete element is also reinforced near the compressive face to help the concrete resist compression. The latter reinforcement is called compression steel. When the compression zone of a concrete is inadequate to resist the compressive moment (positive moment), extra reinforcement has to be provided if the architect limits the dimensions of the section. An under-reinforced beam is one in which the tension capacity of the tensile reinforcement is smaller than the combined compression capacity of the concrete and the compression steel (under-reinforced at tensile face).
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The addition of dysprosium made it easier to induce magnetostrictive responses by making the alloy require a lower level of magnetic fields. When the ratio of Tb and Dy is increased, the resulting alloy's magnetostrictive properties will operate at temperatures as low as −200 °C, and when decreased, it may operate at a maximum of 200 °C. The composition of Terfenol-D allows it to have a large magnetostriction and magnetic flux when a magnetic field is applied to it. This case exists for a large range of compressive stresses, with a trend of decreasing magnetostriction as the compressive stress increases.
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By convention, filled symbols are used to plot data from stations where the P-wave first motion recorded was up (a compressive wave), hollow symbols for down (a tensional wave), with dots for stations with arrivals too weak to get a sense of motion. If there are sufficient observations, one may draw two well-constrained orthogonal great circles that divide the compressive from the tensional observations and these are the nodal planes. Observations from stations with no clear first motion normally lie close to these planes. By convention the compressional quadrants are colour- filled and the tensional left white.
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Among these treatments, induction hardening is one of the most widely employed to improve component durability. It determines in the work-piece a tough core with tensile residual stresses and a hard surface layer with compressive stress, which have proved to be very effective in extending the component fatigue life and wear resistance. Induction surface hardened low alloyed medium carbon steels are widely used for critical automotive and machine applications which require high wear resistance. Wear resistance behavior of induction hardened parts depends on hardening depth and the magnitude and distribution of residual compressive stress in the surface layer.
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Thorough mixing is essential to produce uniform, high-quality concrete. has shown that the mixing of cement and water into a paste before combining these materials with aggregates can increase the compressive strength of the resulting concrete.Premixed cement paste . Concreteinternational.com (1 November 1989).
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Thastyron has a compressive strength of 56 pound-force per square inch (psi) and a tensile strength of 43 psi. Rastra has a low toxicity level. Rastra is highly frost, fungus, and mildew-resistant. The sound insulation is greater than 50 decibel(dB).
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Geodynamic model of Io. Violent volcanic activities cause rapid resurfacing on Io. Newly formed surfaces keep pushing the older layer inwards. As the older layer is squeezed to a smaller sphere, horizontal compressive force cause shortening (horizontal contraction) at the older layer.
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The state also has a good potential for wind generated electricity, and is one of the leading states in generating wind power.Kasisomayajula, S.R., 2013. Compressive study on importance of wind power in India. American Journal of Engineering Research, 2(03), pp.27-35.
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DeVore has been active in the development of many areas of applied mathematics such as numerical analysis of partial differential equations, machine learning algorithms, approximation of functions, wavelet transforms, and statistics. He has also made significant contributions to the theory of compressive sensing.
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The first one is sparsity, which requires the signal to be sparse in some domain. The second one is incoherence, which is applied through the isometric property, which is sufficient for sparse signals.M. Davenport, "The Fundamentals of Compressive Sensing", SigView, April 12, 2013.
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One hypothesis is a transition from a primarily shield volcano structure to a primarily corona structure due to continued lithosphere thinning and lack of resurfacing flows. Another hypothesis is Irnini Mons was originally a corona which was uplifted due to compressive forces.
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Growth can also cause compressive vascular problems like central retinal vein occlusion. Lastly, growth also causes the tumor to exceed its blood supply. In these cases, necrotic areas form inside the tumor. Necrosis can (in turn) cause intraocular and rarely orbital inflammation.
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Some manufacturers create the brick by baking it for over a week. It has an average compressive strength of approximately 23,000 PSI. The ASTM specification C-279 creates specifications for acid brick properties. Acid brick is not resistant against hydrofluoric acid or strong alkali.
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The Santa Cruz Mountains are largely the result of compressive uplift caused by a leftward bend of the San Andreas Fault. The Salinian Block basement rocks are overlain by Miocene rock strata of the Lompico Sandstone, the Vaqueros Sandstone and the Santa Margarita Formation.
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26 The curved ribs, extending from the same point on the wall, are spaced equidistant from each other, forming conoid shapes. The resulting conoids, however, require great compressive forces to keep shape. Spandrels usually provide pressure along the upper edge of the conoids.Trowles (2008); p.
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Under extreme compressive stresses and pressure, marine sedimentary rocks were uplifted, during a series of mountain building periods called "orogenies" over the span of 250 million years and ending with the Appalachian or Alleghanian orogeny occurring over 325 million to 260 million years ago.
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1-5 in Price, N.J., McClay, K.R. (Eds.), Thrust and Nappe Tectonics. Geological Society, Special Publications vol. 9, London, 528 p. Other mechanisms, such as push from behind, action of tangential compressive forces, and shortening of the basement, are essentially variations of the previous mechanisms.
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The westward component of the North American Plate's motion results in some compressive force along the San Andreas and its associated faults such as the Calaveras Fault, thus helping lift the Coast Ranges. The Calaveras Fault shares the same relative motions of the San Andreas.
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Traumatic asphyxia occurs when a powerful compressive force is applied to the thoracic cavity. This is most often seen in motor vehicle accidents, as well as industrial and farming accidents. However, it can be present anytime a significant pressure is applied to the thorax.
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The mechanical strength of bioconcrete is about 25% weaker than normal concrete, making its compressive strength significantly lower. There are also some organisms such as Pesudomonas aeruginosa that are effective in creating biocement but are unsafe to be near humans so these must be avoided.
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Caldie is a chromium-molybdenum-vanadium alloyed tool steel manufactured by Uddeholms AB. It is intended for cold work processes, such as blanking and piercing, applied to difficult materials such as advanced high strength steel, where compressive strength and chipping and cracking resistance are important.
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Conventionally the term Concrete refers only to concrete that is reinforced with iron or steel. However, other materials are often used to reinforce concrete e.g. organic and inorganic fibres, composites in different forms. While compared to its compressive strength, concrete is weak in tension.
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Dave Weagle also developed the Split Pivot suspension and Delta System which are both used in cycling. Weagle's design currently holds multiple patents, including US7128329, which is the world's first and remains to be the only published account on the method of mathematically and geometrically characterizing linkage chain/ belt-driven, and shaft-driven motorcycle and bicycle suspensions. The 7128329 introduced several new concepts and measurements to the suspension world, specifically the concept of characterizing anti-squat as a curve or area when graphed as a function of anti-squat versus compressive travel. The portfolio also proposed the same basic measurement for braking squat versus compressive travel distance.
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The decrease in the mechanical properties was attributed to the partial conversion of the glass filaments in the scaffolds into a layer mainly composed of a porous hydroxyapatite-like material. Another work by Kolan and co-workers used selective laser sintering instead of conventional heat treatment. After the optimization of the laser power, scan speed, and heating rate, the compressive strength of the sintered scaffolds varied from 41 MPa for a scaffold with ~50% porosity to 157 MPa for dense scaffolds. The in vitro study using SBF resulted in a decrease in the compressive strength but the final value was similar to that of human trabecular bone.
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The field of compressive sensing is related to several topics in signal processing and computational mathematics, such as underdetermined linear-systems, group testing, heavy hitters, sparse coding, multiplexing, sparse sampling, and finite rate of innovation. Its broad scope and generality has enabled several innovative CS-enhanced approaches in signal processing and compression, solution of inverse problems, design of radiating systems, radar and through-the-wall imaging, and antenna characterization. Imaging techniques having a strong affinity with compressive sensing include coded aperture and computational photography. Conventional CS reconstruction uses sparse signals (usually sampled at a rate less than the Nyquist sampling rate) for reconstruction through constrained l_{1} minimization.
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Brazilian orthopedist Sydney Haje developed a non-surgical protocol for treating pectus carinatum as well as pectus excavatum. The method involves wearing a compressive orthosis and adhering to an exercise protocol. Mild cases have also reportedly been treated with corset-like orthopedic support vests and exercise.
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After surgery, the hand is wrapped in a light compressive bandage for one week. People start bending and extending their fingers as soon as the anesthesia has resolved. It is often common to experience tingling within the first week of surgery. Hand therapy is often recommended.
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Graphene has been investigated for tissue engineering. It has been used as a reinforcing agent to improve the mechanical properties of biodegradable polymeric nanocomposites for engineering bone tissue applications. Dispersion of low weight % of graphene (≈0.02 wt.%) increased in compressive and flexural mechanical properties of polymeric nanocomposites.
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She also has eight heeling tanks that can be used to free the icebreaker from compressive pack ice. Like the steam-powered icebreakers built before the war, she was also fitted with deck gun mounts.J/m Voiman pitkä talvi 1965-1966. Suomen Merimies-Unioni SMU ry.
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Once documented the benign nature of the nodule, the selection criteria for treatment with the laser concern injuries sufficiently massive to create cosmetic damages or local compressive symptoms and those patients who have contraindications at surgery or anesthesia or will not, for aesthetic reasons, to undergo surgery.
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Shear zones accommodate compressive stress by movement on foliation planes. Shearing at ductile conditions may occur by fracturing of minerals and growth of sub-grain boundaries, as well as by lattice glide. This occurs particularly on platy minerals, especially micas. Mylonites are essentially ductile shear zones.
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Complex jury struts on a Fleet Canuck A lift strut can be so long and thin that it bends too easily. Jury struts are small subsidiary struts used to stiffen it.Crane 1997, Page 294. Problems which jury struts prevent include resonant vibration and buckling under compressive loads.
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When a house is purpose-built with a bunker, the normal location is a reinforced below-ground bathroom with large cabinets. One common design approach uses fibre-reinforced plastic shells. Compressive protection may be provided by inexpensive earth arching. The overburden is designed to shield from radiation.
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Unlike cylinders, jiggers always provided a tension pull, rather than a compressive push. The first jiggers pre-dated the development of flexible steel wire rope and so they used wrought iron chain, rather than the natural fibre rope otherwise available. Later machines did switch to wire rope.
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Tension band fixation is the most common form of internal fixation used for non-comminuted olecranon fractures. It is typically reserved for noncomminuted fractures that are proximal to the coronoid. This procedure is performed using Kirschner wire (K-wires) which converts tensile forces into compressive force.
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The TFCC is important in load transmission across the ulnar aspect of the wrist. The TFC transmits and absorbs compressive forces. The ulnar variance influences the amount of load that is transmitted through the distal ulna. The load transmission is directly proportional to this ulnar variance.
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Visual field defects may be one of the first signs of non-functional pituitary tumor. These are much less frequent than functional adenomas. Systemic hormonal aberrations such as Cushing’s syndrome, galactorrhea and acromegaly usually predate the compressive signs. Pituitary tumors often encroach upon the middle chiasm from below.
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The bodies of the dead were taken to the Moscow morgues for autopsy and identification. Later the bodies were returned to the victims' relatives for burial. A total of 66 people died in this stampede. According to the post-mortem examinations, all of them died of compressive asphyxia.
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Freeze-casting solidification set-up. Compressive strength of freeze-cast titanium materials created via freeze-casting. Freeze-casting is a directional solidification technique that is utilized to fabricate materials exhibiting anisotropic, elongated pore structures. Pore morphology is defined, in large part, by the morphology of the solidified fluid.
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These inner and outer edges of the beam or rod are known as the 'extreme fibers'. Most materials generally fail under tensile stress before they fail under compressive stress, so the maximum tensile stress value that can be sustained before the beam or rod fails is its flexural strength.
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They found that the concrete carried compressive forces, while steel bars carried the tension forces. This made concrete a better material for structures. Joseph Monier, from France, is credited with being the first to understand the principles of reinforced concrete. He embedded an iron-wire mesh into concrete.
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The characteristic physical finding is tenderness over the proximal median nerve, which is aggravated by resisted pronation of the forearm.Hartz, C R, R L Linscheid, R R Gramse, and J R Daube. "The pronator teres syndrome: compressive neuropathy of the median nerve." The Journal of Bone and Joint Surgery.
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The mechanical properties of articular cartilage in load-bearing joints such as the knee and hip have been studied extensively at macro, micro, and nano-scales. These mechanical properties include the response of cartilage in frictional, compressive, shear and tensile loading. Cartilage is resilient and displays viscoelastic properties.
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Much of the problem was ignorance by steamboat operators. In those early days, the physics and mechanics of boiler explosions were not well understood.Brockman, Exploding Steamboats Designers did not know the tensile, compressive, or shear strengths of metals. Engineers did not know the effects of scaling, mud, etc.
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Fig. 2: Critical stress vs slenderness ratio for steel, for E = 200GPa, yield strength = 240MPa. The following assumptions are made while deriving Euler's formula: # The material of the column is homogeneous and isotropic. # The compressive load on the column is axial only. # The column is free from initial stress.
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Aphrodite Terra is named after the goddess of love, the Greek equivalent of the Roman goddess Venus. It is about the same size as Africa, and much rougher than Ishtar Terra. The surface appears buckled and fractured which suggests large compressive forces. There are also numerous extensive lava flows.
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Upon irradiation with UV-light, the solution polymerizes and creates cross- linked network, which is non-covalently attached to the TiNSs. This creates a composite that resists orthogonally applied compressive forces, but easily deforms due to shear forces.RIKEN. "A repulsive material: New hydrogel dominated by electrostatic repulsion." ScienceDaily.
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Indriids such as the sifakas use their toothcombs to gouge bark or dead wood (bark-prising), which is done before scent-marking with the gland on their chest. The more robust structure of their toothcomb is thought to help it withstand the compressive forces experienced during regular bark-prising.
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Fuller saw ephemeralization as an inevitable trend in human development. The progression was from "compression" to "tension" to "visual" to "abstract electrical" (i.e., nonsensorial radiation, such as radio waves, x rays, etc.). Length measurement technologies in human development, for example, started with a compressive measure, such as a ruler.
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Among the receptors described, Marasco identified that there were receptors relatively unresponsive to compressive stimuli but were acutely responsive to any kind of stimulus that brushed or slid across the surface of the nose (Stimuli applied with large displacements and high velocity). In contrast, there were other receptors that responded robustly to small magnitude compression of any kind but were not responsive to sweeping stimuli. The receptors that were sensitive to sweeping were maximally activated across a broad range of frequencies from 5–150 Hz at large displacements ranging from 85–485 μm. Conversely, the receptors that respond to compressive stimuli showed a narrow peak of maximal activity at 250–300 Hz with displacements from 10–28 μm.
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Autofrettage is a metal cold forming technique in which a pressure vessel is subjected to enormous pressure, causing internal portions of the part to yield plastically, resulting in internal compressive residual stresses once the pressure is released. The goal of autofrettage is to increase the durability of the final product. Inducing residual compressive stresses into materials can also increase their resistance to stress corrosion cracking; that is, non- mechanically-assisted cracking that occurs when a material is placed in a corrosive environment in the presence of tensile stress. The technique is commonly used in manufacture of high-pressure pump cylinders, warship and tank gun barrels, and fuel injection systems for diesel engines.
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The US is rapidly expanding its use of relatively rigid, prestressed concrete railroad ties as a precursor to the development of high-speed rail systems. Imaging a concrete beam before and after application of a compressive pre-load confirms that the use of a StereoDIC system is an effective and accurate non-contact approach for measuring small surface strain fields. StereoDIC measurements provide essential data to reliably estimate the transfer length and confirm that the entire concrete portion of the beam has the required compressive stress to maintain compression throughout service life. The adhesion of uncured, unidirectional composite tows that are adhered to a similar composite tow using automated fiber placement (AFP) processing can be tested using StereoDIC.
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So the "over-reinforced concrete" beam fails by crushing of the compressive-zone concrete and before the tension zone steel yields, which does not provide any warning before failure as the failure is instantaneous. A balanced-reinforced beam is one in which both the compressive and tensile zones reach yielding at the same imposed load on the beam, and the concrete will crush and the tensile steel will yield at the same time. This design criterion is however as risky as over-reinforced concrete, because failure is sudden as the concrete crushes at the same time of the tensile steel yields, which gives a very little warning of distress in tension failure.Nilson, Darwin, Dolan.
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A gamma value \gamma < 1 is sometimes called an encoding gamma, and the process of encoding with this compressive power-law nonlinearity is called gamma compression; conversely a gamma value \gamma > 1 is called a decoding gamma, and the application of the expansive power-law nonlinearity is called gamma expansion.
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A new display technology called "compressive light field" is being developed. These prototype displays use layered LCD panels and compression algorithms at the time of display. Designs include dual and multilayer devices that are driven by algorithms such as computed tomography and Non-negative matrix factorization and non-negative tensor factorization.
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Anodes are subject to a variety of mechanical stresses during creation, transportation and use. Anodes must be resistant to compressive force, resistant to elastic stress,Sadler, B.A. and B.J. Welch. Anode Consumption Mechanisms- A Practical Review of the Theory & Anode Property Considerations. in Seventh Australasian Aluminium Smelting Technology Conference & Workshops. 2001.
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For example, in a real experiment setup it is impossible to reproduce any theoretical boundary condition perfectly. Additionally, the results of compressive tests can be very sensitive to imperfections and the actual boundary conditions. Therefore, the measured critical load during the experiment can be very different from what is predicted.
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This is mainly due to the mismatch of thermal expansion coefficients between TaC and SiBCN ceramic matrix. Since TaC has a larger coefficient of thermal expansion than that of SiBCN matrix, TaC particles endures tensile stress while the matrix endures tensile stress in radial direction and compressive stress in tangential direction.
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This simple idea involved corrugating the flue pipes inside the boiler, improving both their heat transfer capability and compressive strength, enabling smaller boilers working at higher pressures to be used with improved safety. "Fox Corrugated" was adopted as standard by the Admiralty and major steamship lines and was widely patented.
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Laurell 1992, p. 77. Sampo was equipped for escort icebreaker duties with a towing winch, a cable and a stern notch. In difficult ice conditions the ship being assisted was taken into tow, and in extremely difficult compressive ice it was pulled to the icebreaker's stern notch.Laurell 1992, p. 198-200.
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Differentiation of chondroblasts is favored in an environment with high compressive force and low partial oxygen pressure which combine to inhibit protein 3, a protein which inhibits cartilage differentiation. These preferences are important since mature cartilage tissue is avascular and thus would be ill-suited to a high oxygen environment.
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After concrete solidifies, tendons apply compressive stress to concrete 5\. Prestressed beam without load 6\. Prestressed beam with load Prestressed concrete is a form of concrete used in construction. It is substantially "prestressed" (compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service.
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Halit et al. showed that steam curing improved the 1 day compressive strength values of high volume fly ash concrete mixtures (40%, 50% and 60% fly ash by replacement) from 10MPa to about 20MPa which is sufficient to enable the removal of formwork and greatly aids the precast concrete industry.
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This reduced the number of steps to climb. The deck was to carry the entire weight of the bridge span, as a tension load. The canopy was to carry the structure's main compressive loads. The diagonal struts would carry either compression or tension forces, depending on their angle and position.
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Ice blast is not abrasive. It does not remove strongly adherent tough coatings like abrasive media would. However, ice blast can remove coatings with weakened adhesion resulting from coating defects or corrosion. As an ice particle impacts on a coating, it causes a compressive stress on the coating and target system.
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An irregular bone is one that does not have an easily classified shape and defies description. These bones tend to have more complex shapes, like the vertebrae that support the spinal cord and protect it from compressive forces. Many facial bones, particularly the ones containing sinuses, are classified as irregular bones.
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A vertebra can also be described in terms of the shape of the ends of the centrum. Centra with flat ends are acoelous, like those in mammals. These flat ends of the centra are especially good at supporting and distributing compressive forces. Amphicoelous vertebra have centra with both ends concave.
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Biomineralization, biologically-controlled mineralization, occurs when crystal morphology, growth, composition, and location is completely controlled by the cellular processes of a specific organism. Examples include the shells of invertebrates, such as molluscs and brachiopods. Additionally, mineralization of collagen provides the crucial compressive strength for the bones, cartilage, and teeth of vertebrates.
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When a compressive force is applied in the knee joint, a tensile force is transmitted to the menisci. The femur attempts to spread the menisci anteroposteriorly in extension and mediolaterally in flexion. Shrive et al. further studied the effects of a radial cut in the peripheral rim of the menisci during loading.
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The northwest-striking wrinkle ridge set is thought to have originated from a global compressive event, as similar ridges are observed in Antoniadi crater (in Syrtis Major Planum to the east) and in Schiaparelli crater (in Terra Sabaea to the south). None of the three wrinkle ridge sets dominate any of the other.
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Foam rubber is a type of open-cell foam. Closed-cell foams do not have interconnected pores. The closed-cell foams normally have higher compressive strength due to their structures. However, closed-cell foams are also, in general more dense, require more material, and as a consequence are more expensive to produce.
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In North America, a more pragmatic approach has been adopted and research into compressive membrane action has primarily stemmed from the work of Hewitt and BatchelorHewitt , B.E. and Batchelor, B. de V., 'Punching shear strength of restrained slabs', J. Struct. Div., Proc. ASCE, Vol. 101, No. ST9, September 1975, pp 1837–1853.
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Another example occurs during semiconductor fabrication and microsystem fabrication when thin film materials with different thermal and crystalline properties are deposited sequentially under different process conditions. The stress variation through a stack of thin film materials can be very complex and can vary between compressive and tensile stresses from layer to layer.
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As a load-bearing wall, the compressive strength of wood and mortar allows for roofing to be tied directly into the wall. Different mortar mixtures and insulation fill material both affect the wall's overall R value, or resistance to heat flow; and conversely, to its inherent thermal mass, or heat/cool storage capacity.
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Diamond has compressive yield strength of 130–140GPa. This exceptionally high value, along with the hardness and transparency of diamond, are the reasons that diamond anvil cells are the main tool for high pressure experiments. These anvils have reached pressures of .Improved diamond anvil cell allows higher pressures Physics World November 2012.
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Neither is superior for this application, and the technique should be selected based on individual project needs. Costs vary depending on project needs. Shotcrete swimming pools are typically more durable and longer lasting than poured concrete. Poured concrete can have a compressive strength of 2,500-3,000 psi, whereas shotcrete exceeds 4,000 psi.
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Compressive stress results in deformation which shortens the object but also expands it outwards. In engineering, deformation refers to the change in size or shape of an object. Displacements are the absolute change in position of a point on the object. Deflection is the relative change in external displacements on an object.
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The shotcrete mix is a 4,000 psi (28 MPa) compressive strength design. In some cases, pattern or spot rock bolts are also installed. Where wider and taller halls are used, modeling is employed to assist with the liner design. Interior finishing of the caves is an integral part of the construction process.
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In the case of uniaxial stress or simple tension, \sigma_1 eq 0, \sigma_3 = \sigma_2=0, the von Mises criterion simply reduces to :\sigma_1 = \sigma_y\,\\!, which means the material starts to yield when \sigma_1 reaches the yield strength of the material \sigma_y, in agreement with the definition of tensile (or compressive) yield strength.
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E. Hockett and N.A. Lindsay, Journal of Physics E: Scientific Instruments 4 (1971), 520-522. The machine is patented under the name of "United States Patent 4109516".Cam plastometer (freepatentsonline.com) In the machine, deformation compressive forces are applied to a specimen by two flat, opposing platens which impact a flat, rectangular specimen.
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High-energy ions can be used to bombard these ceramic thermal barrier coatings and change the tensile stress into compressive stress. Ion bombardment also increases the density of the film, changes the grain size and modifies amorphous films to polycrystalline films. Low-energy ions are used for the surfaces of semiconductor films.
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Euler's critical load is the compressive load (unit: Newton, it is a force) at which a slender column will suddenly bend or buckle. It is given by the formula: : Fig. 1: Column effective length factors for Euler's critical load. In practical design, it is recommended to increase the factors as shown above.
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Compressed sensing combined with a moving aperture has been used to increase the acquisition rate of images in a transmission electron microscope. In scanning mode, compressive sensing combined with random scanning of the electron beam has enabled both faster acquisition and less electron dose, which allows for imaging of electron beam sensitive materials.
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In difficult ice conditions the ship being assisted was taken into tow, and in extremely difficult compressive ice it was pulled to the icebreaker's stern notch.Laurell 1992, p. 198-200. For salvage operations Voima had a powerful centrifugal pump capable of pumping 1,000 tons of water per hour.Laurell 1992, p. 58-59.
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There are two types of fitting that may be used. Crimped or compressive. Crimped connectors are less expensive but require a specialised crimping tool. Compression fittings are tightened with normal spanners and are designed to allow sections of the system to be easily disassembled, they are also popular for small works, esp.
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Application of Results from the Research Project 'A Ship in Compressive Ice' to Ship Operability. The 13th International Conference on Port and Ocean Engineering under Arctic Conditions (POAC), 15–18 August 1995, Murmansk, Russia. # Lensu, M. & Heale, S. & Riska, K. & Kujala, P. 1996. Ice Environment and Ship Hull Loading along the NSR.
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Chandrasekar explaining the physics of Prince Rupert's drops In 1994, Srinivasan Chandrasekar, an engineering professor at Purdue University, and Munawar Chaudhri, head of the materials group at the University of Cambridge, used high-speed framing photography to observe the drop-shattering process and concluded that while the surface of the drops experiences highly compressive stresses, the inside experiences high tension forces, creating a state of unequal equilibrium which can easily be disturbed by breaking the tail. However, this left the question of how the stresses are distributed throughout a Prince Rupert's drop. In a further study published in 2017, the team collaborated with Hillar Aben, a professor at Tallinn University of Technology in Estonia using a transmission polariscope to measure the optical retardation of light from a red LED as it travelled through the glass drop, and used the data to construct the stress distribution throughout the drop. This showed that the heads of the drops have a much higher surface compressive stress than previously thought at up to , but that this surface compressive layer is also thin, only about 10% of the diameter of the head of a drop.
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The mechanical strength is also rarely studied in Heusler compounds. One study has shown that, in off-stoichiometric Ni2MnIn, the material reaches a peak strength of 475 MPa at 773 K, which drastically reduces to below 200 MPa at 973 K. In another study, a polycrystalline Heusler alloy composed of the Ni-Mn-Sn ternary composition space was found to possess a peak compressive strength of about 2000 MPa with plastic deformation up to 5%. However, the addition of Indium to the Ni-Mn-Sn ternary alloy not only increases the porosity of the samples, but it also reduces the compressive strength to 500 MPa. It is unclear from the study what percentage of the porosity increase from the Indium addition reduces the strength.
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The compressive forces applied to the foot are distributed along five rays, three medial (side of big toe) and two lateral (side of little toe). The lateral rays stretch over the cuboid bone to the heel bone and the medial rays over the three cuneiform bones and the navicular bone to the ankle bone. Because the ankle bone is placed over the heel bone, these rays are adjacent near the toes but overriding near the heel, and together they form the arches of the foot that are optimized to distributed compressive forces across an uneven terrain. In this context the heel thus forms the posterior point of support that together with the balls of the large and little toes bear the brunt of the loads.
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Baraniuk has received numerous awards, including a NATO postdoctoral fellowship from NSERC in 1992, the National Young Investigator award from the National Science Foundation in 1994,NSF Awards Help Nurture Creativity in Research, Rice News, 1995. a Young Investigator Award from the Office of Naval Research in 1995, the Rosenbaum Fellowship from the Isaac Newton Institute of Cambridge University in 1998,Professors Receive Sloan, Rosenbaum Fellowships, Rice News, 1998. the University of Illinois at Urbana–Champaign ECE Young Alumni Achievement Award in 2000, and the Wavelet Pioneer Award from SPIE in 2008. He also received the 2012 Compressive Sampling Pioneer award from SPIE for his work on compressive sensing and the 2014 Technical Achievement Award from IEEE Signal Processing Society.
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The resulting stress distribution from the bending of the graphene walls is isotropic and can contribute to the high yield stress observed. The density of the aerogel also can affect the properties observed significantly. The normalized Young’s modulus is shown computationally to follow a power law distribution governed by the following equation: where E is the Young's modulus, Similarly, the compressive strength that describes the yield stress before plastic deformation under compression in graphene aerogels follows a power law distribution. where σy is the compressive strength, ρ is the density of the graphene aerogel, Es is the modulus of graphene, ρs is the density of graphene, and n is the power law scaling factor that describes the system different from the exponent observed in the modulus.
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The compressive strength and hardness of diamond and various other materials, such as boron nitride,Blank, V.; Popov, M.; Pivovarov, G.; Lvova, N. et al. (1998). "Ultrahard and superhard phases of fullerite C60: comparison with diamond on hardness and wear". Diamond and Related Materials 7 (2–5): 427. is attributed to the diamond cubic structure.
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For instance, pure diamond is an electrical insulator, but diamond with boron added is an electrical conductor (and, in some cases, a superconductor), allowing it to be used in electronic applications. Nitrogen impurities hinder movement of lattice dislocations (defects within the crystal structure) and put the lattice under compressive stress, thereby increasing hardness and toughness.
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This is thought to indicate that compressive stress from the longitudinal stressing in combination with heat from the sun caused the problem. The bridge was then reinforced, first temporarily using outside pre-stressing bars, and then permanently using carbon fibre laminates in sections with minor fissures, and tie struts in the worst affected sections.
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Alternative fuels in cement manufacture – CEMBUREAU brochure, 1997 A team at the University of Edinburgh has developed the 'DUPE' process based on the microbial activity of Sporosarcina pasteurii, a bacterium precipitating calcium carbonate, which, when mixed with sand and urine, can produce mortar blocks with a compressive strength 70% of that of conventional construction materials.
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Compressive protection may be provided by inexpensive earth arching. The overburden is designed to shield from radiation. To prevent the shelter from floating to the surface in high groundwater, some designs have a skirt held-down with the overburden. A properly designed, properly installed home shelter does not become a sinkhole in the lawn.
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The following stresses are induced in the shafts. # Shear stresses due to the transmission of torque (due to torsional load). # Bending stresses (tensile or compressive) due to the forces acting upon the machine elements like gears and pulleys as well as the self weight of the shaft. # Stresses due to combined torsional and bending loads.
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Compomers have poorer mechanical properties than dental composites, with a lower compressive, flexural and tensile strength. Therefore, compomers are not an ideal material for load bearing restorations. In terms of wear resistance, compomers wear less quickly than glass ionomer and resin modified glass ionomer cements, but do not perform as well as dental composites.
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Pipes and pressure vessels subject to external overpressure, caused for example by steam cooling within the pipe and condensing into water with subsequent massive pressure drop, risk buckling due to compressive hoop stresses. Design rules for calculation of the required wall thickness or reinforcement rings are given in various piping and pressure vessel codes.
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A cisternal tumor extends outside the auditory canal. A compressive tumor infringes upon the cerebellum or brainstem. Very large tumors may obstruct cerebrospinal fluid drainage. The tumor may develop within the auditory canal, where the vestibulocochlear nerve which supplies the inner ear penetrates the skull (intracanalicular neuroma) or outside the canal (extra-canalicular neuroma).
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In the higher order differencing schemes, as the name suggests, the convective transport equation is discretized with higher order or blended differencing schemes. Such methods include the Compressive Interface Capturing Scheme for Arbitrary Meshes (CICSAM) and High Resolution Interface Capturing (HRIC) scheme, which are both based on the Normalized Variable Diagram (NVD) by Leonard.
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On impact, the ice particle melts. The coating and target system under compressive stress will react in the opposite direction, producing a tensile stress. When the tensile stress exceeds the coating adhesion force, coating lifting takes place. The lifted coating is in the force of chips and would be carried by the residual water.
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Millook Haven, North Cornwall, UK Chevron folds are a structural feature characterized by repeated well behaved folded beds with straight limbs and sharp hinges. Well developed, these folds develop repeated set of v-shaped beds. They develop in response to regional or local compressive stress. Inter- limb angles are generally 60 degrees or less.
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Masonry has high compressive strength under vertical loads but has a low tensile strength (against twisting or stretching) unless reinforced. The tensile strength of masonry walls can be increased by thickening the wall, or by building masonry piers (vertical columns or ribs) at intervals. Where practical, steel reinforcements such as windposts can be added.
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Immediately after screeding, the concrete is compacted to improve the bond and smooth the surface. Excessive compaction of pervious concrete results in higher compressive strength, but lower porosity (and thus lower permeability). Jointing varies little from other concrete slabs. Joints are tooled with a rolling jointing tool prior to curing or saw cut after curing.
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Also high concentrated calcium chloride (CaCl2, 70% more) is well known as accelerator of Portland cement. So high concentrated -over 70%- Calcium Chloride solution sets MTA within 12 minutes. Or Pozzolanic reaction is also faster set chemical reaction of calcium silicate hydrate. But pozzolanic reacted cement has lower compressive strength at 15 MPa maximum.
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By contrast, a semi-monocoque is a hybrid combining a tensile stressed skin and a compressive structure made up of longerons and ribs or frames. Other semi-monocoques, not to be confused with true monocoques, include vehicle unibodies, which tend to be composites, and inflatable shells or balloon tanks, both of which are pressure stabilised.
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Erythema nodosum is self- limiting and usually resolves itself within 3–6 weeks. A recurring form does exist, and in children, it is attributed to repeated infections with streptococcus. Treatment should focus on the underlying cause. Symptoms can be treated with bed rest, leg elevation, compressive bandages, wet dressings, and nonsteroidal anti-inflammatory agents (NSAIDs).
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The Bauschinger effect. The Bauschinger effect refers to a property of materials where the material's stress/strain characteristics change as a result of the microscopic stress distribution of the material. For example, an increase in tensile yield strength occurs at the expense of compressive yield strength. The effect is named after German engineer Johann Bauschinger.
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Their compressive strength was designed to reach 30 MPa. However, the lowest values measured in two inspections were only 21.9 MPa and 25.5 MPa, respectively. Guangzhou Metro and Beijing Chang Cheng Bilfinger Berger Construction Engineering Co., Ltd. (BCBB), contractor of the Jiahewanggang–Longgui section, commissioned two inspection companies to perform a total of three inspections.
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Their treatment involves the resection of the optic nerve. The supposed artifactual nature of Wilbrand's knee has implications for the degree of resection that can be obtained, namely by cutting the optic nerve immediately at the junction with the chiasm without fear of potentially resulting visual field deficits. The vast majority of chiasmal syndromes are compressive. Ruben et al.
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Like a person in a bed, an oven needs a mattress underneath, as well as a blanket over top, but where a person may weigh a couple of hundred pounds, an oven may weigh thousands. Nature offers few materials that combine compressive strength, insulative properties, and imperviousness to high temperatures, but recent technology has greatly expanded the options.
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49, No. 2, Feb 1983, p 182-187. The product, sold under the name Cerestore, raised some concerns among dentists for its wear on opposing teeth and its accuracy of fit.G.K. Philip & C.E. Brukl, “Compressive strengths of conventional, twin foil, and all-ceramic crowns,” J. Prosthetic Dentistry, Vol. 50, No. 8, Aug 1984, p 215-220.
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Ceramic armor is armor used by armored vehicles and in personal armor to resist projectile penetration through high hardness and compressive strength. Ceramics are often used where light weight is important, as they weigh less than metal alloys for a given degree of resistance. The most common materials are alumina, boron carbide, silicon carbide, and titanium diboride.
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It also has the benefit of the glass ionomer component releasing fluoride and has superior adhesive properties. RMGICs are now recommended over traditional GICs for basing cavities. There is a great difference between the early and new hybrid composites. Initially, resin-based composite restorations in dentistry were very prone to leakage and breakage due to weak compressive strength.
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Superplasticizers are concrete admixtures designed to increase the concrete fluidity and workability of concrete or to decrease its water-to-cement (w/c) ratio. By reducing the water content in concrete, it decreases its porosity, improving so the mechanical properties (compressive and tensile strength) and the durability of concrete (lower water, gas and solutes transport properties).
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A poorly designed bridge may break as soon as the player begins to test it, unable to support its own weight. While testing the bridge, the stress on each section can be seen, representing both tensile stress and compressive stress. If the stress becomes too great, that section breaks and disintegrates, possibly jeopardizing the entire structure.
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In addition, she has large ballast tanks and high-capacity pumps that can be used for rapid heeling and trimming to release the icebreaker if she is immobilized by compressive pack ice. Like her sister ship Otso, Kontio has also been retrofitted with a bow thruster to assist manoeuvering.Häkkinen, P. Muistiinpanot JM Otson vierailusta. Teknillinen Korkeakoulu, 2009.
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Thin layers of ironstone and marcasite, as well as concentrations of marcasite, occur throughout the shale. The Chagrin Shale is classified as a weak to medium-strong rock, with a compressive strength anywhere from to . The strength of the rock is much lower near soil/rock interface (where there is stress relief), and if there is weathering.
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Similarly, XC, YC, ZC denotes the allowable compressive strengths in three respective material directions. Further, S12, S13 and S23 denote allowable shear strengths in the respective principal material directions. Endeavors have been made to incorporate MMF with multiple progressive damage models and fatigue models for strength and life prediction of composite structures subjected to static or dynamic loadings.
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Artificial grafts maintain comparable compressive strength, but occasionally lack similarity to human bone in response to lateral or frictional forces. In particular, the topography of artificial bone is inaccurate compared to its natural counterpart. In Grant et al., artificial bone grafts produced by fused deposition had on average a 20% lower coefficient of friction compared to real bone.
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Clay bricks expand as they absorb heat and moisture. This places compression stress on the bricks and mortar, encouraging bulging or flaking. A joint replacing mortar with elastomeric sealant will absorb the compressive forces without damage. Concrete decking (most typically in sidewalks) can suffer similar horizontal issues, which is usually relieved by adding a wooden spacer between the slabs.
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Deformed arch at the Gozo Aqueduct, Malta An arch is a pure compression form. It can span a large area by resolving forces into compressive stresses, and thereby eliminating tensile stresses. This is sometimes denominated "arch action". As the forces in the arch are transferred to its base, the arch pushes outward at its base, denominated "thrust".
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However, in more difficult ice conditions each ramming would move the ship forwards only . In snow-covered ice and drift ice Murtaja could not operate efficiently due to her inefficient hull form. Sometimes the crew had to rely on hacking and sawing the ice or even explosives to release the ship from compressive ice fields.Laurell 1992, pp. 44–46.
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Grinding concrete exposes aggregate stones. Aggregate is the component of a composite material that resists compressive stress and provides bulk to the composite material. For efficient filling, aggregate should be much smaller than the finished item, but have a wide variety of sizes. For example, the particles of stone used to make concrete typically include both sand and gravel.
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Panic and a stampede ensued as fans tried to escape. Gates were locked and the stadium's compromised design left a bottleneck, with fewer exits than originally planned. Ghana Institute of Architects called the stadium a "death trap." After the hour-long ordeal, it was found that 116 deaths resulted from compressive asphyxia and 10 fans died from trauma.
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Ultra-high- performance concrete is a new type of concrete that is being developed by agencies concerned with infrastructure protection. UHPC is characterized by being a steel fibre-reinforced cement composite material with compressive strengths in excess of 150 MPa, up to and possibly exceeding 250 MPa."Ultra High Performance Fibre-Reinforced Concretes." Association Francaise de Genie Civil, 2002.
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One prominent approach involves the use of a strain-inducing capping layer. CVD silicon nitride is a common choice for a strained capping layer, in that the magnitude and type of strain (e.g. tensile vs compressive) may be adjusted by modulating the deposition conditions, especially temperature.Martyniuk, M, Antoszewski, J. Musca, C.A., Dell, J.M., Faraone, L. Smart Mater. Struct.
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Consider as a simple example a rigid beam of length L, hinged in one end and free in the other, and having an angular spring attached to the hinged end. The beam is loaded in the free end by a force F acting in the compressive axial direction of the beam, see the figure to the right.
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By orienting the folding side of the chain upward his ram chain acted as a self-supporting telescoping beam with negligible sag. Used in this manner the need for a separate guide was eliminated. An early conception of chain used as a telescoping column instead a horizontal rammer was by Eldridge E. Long, who was awarded a US patent for his “Lifting Jack” in 1933, which he believed was “particularly adapted for use upon automobiles”. It used a double chain configuration, each chain linking solid bearing blocks that were stacked to resist compressive loads. In 1951, Yaichi Hayakawa was awarded a US patent for his “Interlocking Chain Stanchion” which eliminated bearing blocks by integrating the compressive path of force into the interlocking links of two roller-like chains.
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There are several means of achieving compaction of a material. Some are more appropriate for soil compaction than others, while some techniques are only suitable for particular soils or soils in particular conditions. Some are more suited to compaction of non-soil materials such as asphalt. Generally, those that can apply significant amounts of shear as well as compressive stress, are most effective.
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Due to a concentration gradient of the ions, mass transport must take place. As the larger cation diffuses from the molten salt into the surface, it replaces the smaller ion from the modifier. The larger ion squeezing into surface introduces compressive stress in the glass's surface. A common example is treatment of sodium oxide modified silicate glass in molten potassium chloride.
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In the 19th century, Potsdam Sandstone was highly regarded as a building material. There was extensive quarrying for Potsdam Sandstone in the Potsdam area, beginning in 1809.The Potsdam Red Sandstone quarries, Scientific American, January 7, 1893, page 8-10. Properties of the rock that give it value as a building material include high compressive strength, attractive reddish coloring, and resistance to weathering.
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Hodgkin's usually present in 40-50's with nodular sclerosing type (7), and non-Hodgkin's in all age groups. Can also be primary mediastinal B-cell lymphoma with exceptionally good prognosis. Common symptoms include fever, weight loss, night sweats, and compressive symptoms such as pain, dyspnea, wheezing, Superior vena cava syndrome, pleural effusions (10,11). Diagnosis usually by CT showing lobulated mass.
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Fine grained sediments and carbonate rocks formed from 1675 to 1590. Then this was folded in the Isan Orogeny 1620 to 1520 Mya, overlapping with sedimentation. At 1620 Mya the compressive force was north-south, but this changed to east-west at 1520 Mya The Kalkadoon Botholith and Ewn intruded the central Kalkadoon-Ewen Province between 180 and 1850 Mya.
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The Christensen failure criterion is a material failure theory for isotropic materials that attempts to span the range from ductile to brittle materials. It has a two-property form calibrated by the uniaxial tensile and compressive strengths T \left (\sigma_T\right ) and C \left (\sigma_C\right ). The theory was developed by R. M. Christensen and first published in 1997.Christensen, R.M. (1997).
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A thick external cell wall influences the direction of growth by impeding expansion towards the outside of the cell and instead promote expansion parallel to the epidermis layer.. Data suggest that waviness of pavement cells may be initiated by compressive mechanical stresses in a feedback loop that solidifies and augments cell shapes resulting in local reinforcement of the cell wall .
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Hydraulic force increase A hydraulic press is a machine press using a hydraulic cylinder to generate a compressive force. It uses the hydraulic equivalent of a mechanical lever, and was also known as a Bramah press after the inventor, Joseph Bramah, of England.Parker, Dana T. Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II, p. 87, Cypress, CA, 2013. .
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One theory states that the calving rate is primarily a function of the ratio of tensile stress to vertical compressive stress, i.e., the calving rate is a function of the ratio of the largest to smallest principle stress. Another theory, based on preliminary research, shows that the calving rate increases as a power of the spreading rate near the calving front.
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Laid > in the shape of arches, vaults and domes, it quickly hardened into a rigid > mass, free from many of the internal thrusts and strains that troubled the > builders of similar structures in stone or brick.D.S. Robertson (1969). > Greek and Roman Architecture, Cambridge, p. 233 Modern tests show that opus caementicium had as much compressive strength as modern Portland-cement concrete (ca. ).
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Concrete has relatively high compressive strength, but much lower tensile strength. Therefore, it is usually reinforced with materials that are strong in tension (often steel). The elasticity of concrete is relatively constant at low stress levels but starts decreasing at higher stress levels as matrix cracking develops. Concrete has a very low coefficient of thermal expansion and shrinks as it matures.
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Mechanical methods to relieve undesirable surface tensile stresses and replace them with beneficial compressive residual stresses include shot peening and laser peening. Each works the surface of the material with a media: shot peening typically uses a metal or glass material; laser peening uses high intensity beams of light to induce a shock wave that propagates deep into the material.
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Diagram of Geologic Tension In geology, the term "tension" refers to a stress which stretches rocks in two opposite directions. The rocks become longer in a lateral direction and thinner in a vertical direction. One important result of tensile stress is jointing in rocks. However, tensile stress is rare because most subsurface stress is compressive, due to the weight of the overburden.
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Courtney, T. H.. Mechanical Behavior of Materials. Waveland Press (2005) , 392-396 Other defects, such as voids, occur in the semi-crystalline polymer under tensile stress and can drive the formation of the neck. The voids can be observed via small angle x-ray scattering. Unlike crazes these voids do not transfer stresses.. Notably, cavitation is not observed under compressive stress or shearing.
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In the design and installation of CWR, a figure known as the "rail neutral temperature" (RNT) is calculated. The tensile and compressive longitudinal forces on the CWR are added. The RNT is the notional temperature when the total equals zero.Pyrgidis C. Railway Transportation Systems: Design, Construction and Operation CRC Press, 2016 A similar figure is the "stress free temperature" (SFT).
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The No. 4 engine has fatigue failure of its No. 1 propellor blade. According to lab results, the blade had previously been bent which resulted "in the disruption of the compressive stresses in the shot peened area of the propeller blade" being the probable cause because the unbalanced loads on the engine mounts resulted in the separation of the entire engine.
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The degree of reduction in thickness under compressive forces or pressure is known as compressibility of the paper. It influences the ability of paper to change its surface contour and conform to make contact with the printing plate or blanket during print production. Not to be confused with Compression Strength, a mechanical property of all materials, with units of pressure.
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Additions of small amount (0.5 weight %) of nanoreinforcement (carbon nanotubes or nanoclay) in the polymer matrix of composites, fiber sizing or interlaminar layers can improve fatigue resistance, shear or compressive strength, and fracture toughness of the composites by 30% to 80%. Research has also shown that incorporating small amounts of carbon nanotubes (CNT) can increase the lifetime up to 1500%.
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It is often discussed specifically in application of braid groups, which notably are infinite (and the group elements can take variable quantities of space to represent). The computed shared secret is an element of the group, so in practice this scheme must be accompanied with a sufficiently secure compressive hash function to normalize the group element to a usable bitstring.
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Mountains on Io (generally, structures rising above the surrounding plains) have a variety of morphologies. Plateaus are most common. These structures resemble large, flat- topped mesas with rugged surfaces. Other mountains appear to be tilted crustal blocks, with a shallow slope from the formerly flat surface and a steep slope consisting of formerly sub-surface materials uplifted by compressive stresses.
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SPIE, 7334-17, (2009) a multiaperture spectral filter approach,S. A. Mathews, "Design and fabrication of a low-cost, multispectral imaging system," Applied Optics 47: F71-F76 (2008). a compressive-sensing–based approach using a coded aperture,A. Wagadarikar, R. John, R. Willett, and D. Brady, "Single disperser design for coded aperture snapshot spectral imaging," Applied Optics 47: B44-B51 (2008).
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The set cement has low compressive strength and cannot withstand or support condensation of a restoration. It is thus good practice to place a stronger separate lining material (e.g. glass ionomer or resin- modified glass ionomer) over CaOH before packing the final restorative material. CaOH cement is not adhesive to tooth tissues and thus does not provide a coronal seal.
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Water freezing in the wall is another cause of spalling. In restoration work of pre-20th century structures, there should be a high ratio of lime and aggregate to Portland. This reduces the compressive strength of the mortar but allows the wall system to function better. The lime mortar acts as a wick that helps to pull water from the brick.
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The modernized process typically uses a controlled atmosphere in a temperature- controlled furnace. Mechanical aids such as a hydraulic press or torque plates (bolted clamps) are also typically used to apply compressive force on the billet during lamination. These provide for the implementation of lower temperature solid-state diffusion between the interleaved layers, thus allowing the inclusion of non-traditional materials.
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1 bottom). The difference, called the drying creep or Pickett effect (or stress-induced shrinkage), represents a hygro- mechanical coupling between strain and pore humidity changes. Drying shrinkage at high humidities (Fig. 1 top and middle) is caused mainly by compressive stresses in the solid microstructure which balance the increase in capillary tension and surface tension on the pore walls.
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The northeast-oriented Giudicárie line off-sets the (east-west) Periadriatic Seam by 100 kilometers. The fault zone contains older (Tertiary) mylonites, showing it was a ductile shearzone in that period. These mylonites have been overprinted by brittle thrusting still active today. The northwest dipping fault plane serves as a dextral transform fault as well as a compressive thrust fault.
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Ultrasonic impact treatment (UIT) is a metallurgical processing technique, similar to work hardening, in which ultrasonic energy is applied to a metal object. This technique is part of the High Frequency Mechanical Impact (HFMI) processes. Other acronyms are also equivalent: Ultrasonic Needle Peening (UNP), Ultrasonic Peening (UP). Ultrasonic impact treatment can result in controlled residual compressive stress, grain refinement and grain size reduction.
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Carrot Stix partnered with CEC International, a technology company, to bring back this brand into the market. It is managed by a Fortune 500 international company for supply chain. Through nano silica technology, Nano size microspheres of silica are produced. Added to the special resin, this microspheres of silica improves compressive strength making the blank even more durable without adding weight.
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This dynamic is called resting pressure and is considered safe and comfortable for long-term treatment. Conversely, the stability of the bandage creates a very high resistance to stretch when pressure is applied through internal muscle contraction and joint movement. This force is called working pressure. Long stretch compression bandages have long stretch properties, meaning their high compressive power can be easily adjusted.
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The coded aperture snapshot spectral imager (CASSI) was the first spectral imager designed to take advantage of compressive sensing theory. CASSI employs binary coded apertures that create a transmission pattern at each column, such that these patterns are orthogonal with respect to all other columns. The spatial-spectral projection at the detector array is modulated by the binary mask in such a way that each wavelength of the data cube is affected by a shifted modulation code. More recent CSI systems include the CASSI using colored coded apertures (C-CASSI) instead of the black and white masks; a compact version of the colored CASSI, called snapshot colored compressive spectral imager (SCCSI), and a variation of the latter that uses a black-and-white coded aperture in the convolutional plane, known as the spatial–spectral encoded hyperspectral imager (SSCSI).
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Similarly when crossing into a sudden ground depression, the inertia of the wheel slows the rate at which it descends. If the wheel inertia is large enough, the wheel may be temporarily separated from the road surface before it has descended back into contact with the road surface. This unsprung weight is cushioned from uneven road surfaces only by the compressive resilience of the tire (and wire wheels if fitted), which aids the wheel in remaining in contact with the road surface when the wheel inertia prevents close-following of the ground surface. However, the compressive resilience of the tire results in rolling resistance which requires additional kinetic energy to overcome, and the rolling resistance is expended in the tire as heat due to the flexing of the rubber and steel bands in the sidewalls of the tires.
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In uniaxial compression, the forces are directed along one direction only, so that they act towards decreasing the object's length along that direction. The compressive forces may also be applied in multiple directions; for example inwards along the edges of a plate or all over the side surface of a cylinder, so as to reduce its area (biaxial compression), or inwards over the entire surface of a body, so as to reduce its volume. Technically, a material is under a state of compression, at some specific point and along a specific direction x, if the normal component of the stress vector across a surface with normal direction x is directed opposite to x. If the stress vector itself is opposite to x, the material is said to be under normal compression or pure compressive stress along x.
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F. Yang, S. Wang, and C. Deng, "Compressive sensing of image reconstruction using multi-wavelet transform", IEEE 2010 The current smallest upper bounds for any large rectangular matrices are for those of Gaussian matrices.B. Bah and J. Tanner "Improved Bounds on Restricted Isometry Constants for Gaussian Matrices" Web forms to evaluate bounds for the Gaussian ensemble are available at the Edinburgh Compressed Sensing RIC page.
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Not until the Late Jurassic to Early Cretaceous did Huangling massif uplift. This period is critical for the tectonic development of Huangling massif since the dome-shaped structure was formed. The dome-shaped structure indicated a compressional environment. The dome has a steeper west flank and a gentle east flank, indicating the compressive stress exerted to the west and to the east were different.
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In addition, she had six centrifugal pumps for moving 100 tons of water in five minutes between the fore and aft peak tanks to adjust her trim and release the icebreaker from compressive ice. For escort operations she had a towing winch and a stern notch that was considerably larger than in the older icebreakers. Her single piece cast iron rudder weighed 9 tons.
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Higher baking temperatures increase the mechanical properties and thermal conductivity, and decrease the air and CO2 reactivity.W. K. Fischer, et al., "Baking parameters and the resulting anode quality," in TMS Annual Meeting, Denver, CO, USA, 1993, pp. 683–689 The specific electrical resistance of the coke-type anodes is higher than that of the graphitized ones, but they have higher compressive strength and lower porosity.
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Range of motion exercises are required to prevent stiffness in addition to potentially long term loss of range of motion of the affected digit.Digital edema-control techniques will reduce the time taken to regain range of motion. Examples of such techniques include massage and compressive wraps. An increased amount of swelling during the rehabilitation period is indicative of an undiagnosed fracture or an overly aggressive rehabilitation programme.
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It tenses the skin of the palm on the ulnar side during a grip action, and deepens the hollow of the palm. The palmaris brevis may protect the ulnar nerve and ulnar artery from compressive forces during repetitive grasping actions. The muscle has a fatigue resistant fiber type profile, which supports the idea of a protective function to the ulnar neurovasculature during repetitive intermittent grasping tasks.
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Non-precision gear couplings use backlash to allow for slight angular misalignment. However, backlash is undesirable in precision positioning applications such as machine tool tables. It can be minimized by tighter design features such as ball screws instead of leadscrews, and by using preloaded bearings. A preloaded bearing uses a spring or other compressive force to maintain bearing surfaces in contact despite reversal of direction.
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The atomic bonds are longer due to the smaller radius of the solute atom. Similarly, if a larger atom is added to the lattice a compressive stress field is created. The atomic bonds are shorter due to the larger radius of the solute atom. The stress fields created by adding solute atoms form the basis of the material strengthening process that occurs in alloys.
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Eventually, a dental company named Ormco started developing lingual brackets in conjunction with Dr. Kurz. After working on several prototypes of brackets initially, the company also faced same problems: Irritation caused to the tongue and high bracket failure rate. Then, an inclined plane was added to the lingual brackets and the company saw lower failure rates. This plane allowed the shearing forces to convert into compressive forces.
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The optic tract syndrome is characterized by a contralateral, incongruous homonymous hemianopia, contralateral relative afferent pupillary defect (RAPD), and optic atrophy due to retrograde axonal degeneration. Causes of optic tract lesions are also classified into intrinsic and extrinsic forms. Intrinsic lesions include demyelinating diseases and infarction. Such lesions produce optic tract syndrome type II. Extrinsic or compressive lesions are caused by pituitary craniopharyngioma, tumours of optic thalamus.
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The management of true cauda equina syndrome frequently involves surgical decompression. When cauda equina syndrome is caused by a herniated disk early surgical decompression is recommended. Cauda equina syndrome of sudden onset is regarded as a medical/surgical emergency. Surgical decompression by means of laminectomy or other approaches may be undertaken within 6, 24 or 48 hours of symptoms developing if a compressive lesion, e.g.
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The surface wants to expand creating a compressive stress. The radius of curvature R is measured as the change of the gap of a capacitor by \Delta d. Figure 2b shows the two electrodes of the capacitor formed by the sample and a capacitor electrode c. The capacitor electrode is surrounded by a guard electrode in order to minimize the effects of stray capacitances.
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CNTs are not nearly as strong under compression. Because of their hollow structure and high aspect ratio, they tend to undergo buckling when placed under compressive, torsional, or bending stress. On the other hand, there was evidence that in the radial direction they are rather soft. The first transmission electron microscope observation of radial elasticity suggested that even van der Waals forces can deform two adjacent nanotubes.
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There is a theorem (see Courant and Friedrichs) that states that a non-constant state of flow adjacent to a constant value is always a simple wave. All expansion fans including Prandtl–Meyer expansion fan are simple waves. Compressive waves until shock wave forms are also simple waves. Weak shocks (including sound waves) are also simple waves up to second- order approximation in the shock strength.
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Magnesium can be removed either thermally or by reactive measures through the dissolution in acid. Esen & Bor found a critical content of magnesium as a space holder to be 55-60%, above which compacts shrink excessively during sintering. Foams ranging in porosity from 45 to 70% with a bimodal pore distribution and compressive strength of 15 MPa (for 70% porosity) were demonstrated. Kim et al.
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Titanium foams exhibiting dendritic and lamellar pore structures have been produced, through the use of non-aqueous and aqueous processing respectively. These materials exhibit anisotropic mechanical properties as a result of their anisotropic pore structures. Compressive strength for loads applied parallel to the wall direction of titanium foams are found to be, on average, 2.5 times greater than for those applied perpendicular to the wall direction.
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Therefore, compressive stress in the direction perpendicular to the half plane promotes positive climb, while tensile stress promotes negative climb. This is one main difference between slip and climb, since slip is caused by only shear stress. One additional difference between dislocation slip and climb is the temperature dependence. Climb occurs much more rapidly at high temperatures than low temperatures due to an increase in vacancy motion.
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Deep rolling is a method of cold work deformation and burnishing of internal combustion engine crankshaft journal fillets to increase durability and design safety factors. Compressive residual stresses can be measured below the surface of a deep-rolled fillet. Other types of fillets on shafts or tubes can also benefit from this method. Cast iron crankshafts will experience the most improvement potentially doubling their fatigue life.
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Papillary adenocarcinoma is a histological form of lung cancer that is diagnosed when the malignant cells of the tumor form complex papillary structures and exhibit compressive, destructive growth that replaces the normal lung tissue.Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (Eds.): World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Lung, Pleura, Thymus and Heart. IARC Press: Lyon, France 2004.
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Hence the intermediate processes that occur to the material under uniaxial compression before the incidence of plastic deformation make the compressive test fraught with difficulties. A material generally deforms elastically under the influence of small forces; the material returns quickly to its original shape when the deforming force is removed. This phenomenon is called elastic deformation. This behavior in materials is described by Hooke's Law.
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Burnishing is normally undesirable in mechanical components for a variety of reasons, sometimes simply because its effects are unpredictable. Even light burnishing will significantly alter the surface finish of a part. Initially the finish will be smoother, but with repetitive sliding action, grooves will develop on the surface along the sliding direction. The plastic deformation associated with burnishing will harden the surface and generate compressive residual stresses.
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It is also used in testing a specimen, for a process where the crosshead moves to load the specimen to a specified value before a test starts. Data is not captured during the preload segment. When tensile specimens are initially placed into testing grips, they can be subjected to small compressive forces. These forces can cause specimens to bend imperceptibly, causing inaccurate and inconsistent results.
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While the compressive properties of plastic lumber are equal or greater than those of wood, the modulus of elasticity is very low. Moreover, plastic lumber is subject to far more creep than wood. Use in load-bearing structures requires different considerations from wood. Plastic lumber can present issues with fire containment: it performed worse than a variety of wood and composite materials in a test.
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Temperature and pressure can affect how the tubing and the packer behave as this could cause changes in the packer and tubing expansion rates. If the packer allows free motion then the tubing can elongate or shorten. If not the tensile and compressive forces can develop within.Dorohov M., Kostryba I, Biletskyi V. Experimental research on the sealing ability of borehole packers // Eastern-European Journal of Enterprise Technologies.
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The same is done to be forewarned of an event of failure and take necessary precautions. The characteristic strength is defined as the strength of the concrete below which not more than 5% of the test results are expected to fall. For design purposes, this compressive strength value is restricted by dividing with a factor of safety, whose value depends on the design philosophy used.
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This material can serve to provide additional stability in the event of high winds if the crib is very tall. Advantages of crib construction include its simplicity and strength. Logs need only be cut and notched for stability, then lain crosswise until a certain height is reached. As each layer of wood is only used as a compressive layer, the wood need not be strong.
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Scanning electron microscopy image of bone mineral Bone mineral (also called inorganic bone phase, bone salt, or bone apatite) is the inorganic component of bone tissue. It gives bones their compressive strength. Bone mineral is formed from carbonated hydroxyapatite with lower crystallinity. Bone mineral is formed from globular and plate structures distributed among the collagen fibrils of bone and forming yet a larger structure.
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The Woodlark Plate is a small tectonic plate located in the eastern half of the island of New Guinea. It subducts beneath the Caroline plate along its northern border while the Maoke Plate converges on the west, the Australian plate converges on the south, and on the east an undefined compressive zone which may be a transform fault marking the boundary with the adjoining Solomon Sea Plate.
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But actual bioceramic aggregates are composed of pure medical graded calcium silicate based material. 4\. Calcium aluminate bioceramic material - (alumina cement in minerals, calcium aluminate cements in bioceramics) Alumina is an initial fast setting element and high compressive strength. It has been used as dental products as luting agent. Calcium aluminate cement (bioceramic) has been developed for dental products and root-end filling material.
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Compressive myelopathy at the C6-C7 level due to disc protrussion Spinal cord compression develops when the spinal cord is compressed by bone fragments from a vertebral fracture, a tumor, abscess, ruptured intervertebral disc or other lesion. It is regarded as a medical emergency independent of its cause, and requires swift diagnosis and treatment to prevent long-term disability due to irreversible spinal cord injury.
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In: Geological Society, London, Special Publications; 2007; v. 271; p. 63-68 (abstract)Venice, an online exhibit produced in ARTH 470z at the University of Mary Washington : Istrian stone Limestone is a biogenetic stone composed of calcium carbonate from the tests and shells of marine creatures laid down over eons. Istrian stone approaches the compressive strength and density of marble, which is metamorphosed limestone.
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The wood is used to make cricket bats. S. alba wood has a low density and a lower transverse compressive strength. This allows the wood to bend, which is why it can be used to make baskets. Willow bark contains indole-3-butyric acid, which is a plant hormone stimulating root growth; willow trimmings are sometimes used to clone rootstock in place of commercially synthesized root stimulator.
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These structures resemble large, flat-topped mesas with rugged surfaces. Other mountains appear to be tilted crustal blocks, with a shallow slope from the formerly flat surface and a steep slope consisting of formerly sub-surface materials uplifted by compressive stresses. Both types of mountains often have steep scarps along one or more margins. Only a handful of mountains on Io appear to have a volcanic origin.
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A spring type accumulator is similar in operation to the gas-charged accumulator above, except that a heavy spring (or springs) is used to provide the compressive force. According to Hooke's law the magnitude of the force exerted by a spring is linearly proportional to its change of length. Therefore, as the spring compresses, the force it exerts on the fluid is increased linearly.
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Channels cross this terrain and some have an interesting bow shape to them. Aphrodite Terra also has mountain ranges but they are only about half the size of the mountains on Ishtar. Aphrodite Terra has two main regions: Ovda Regio in the west and Thetis Regio in the east. Ovda Regio has ridges running in two directions, suggesting that the compressive forces are acting in several directions.
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Intensity is a key parameter of the shot peening process. After some development of the process, an analog was needed to measure the effects of shot peening. John Almen noticed that shot peening made the side of the sheet metal that was exposed begin to bend and stretch. He created the Almen strip to measure the compressive stresses in the strip created by the shot peening operation.
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Usually the pipe goes through a Rotary table - machinery that makes the pipe rotate. After the slips is placed around the drill pipe, it is lowered so that the teeth on the inside grip the pipe and the slips are pulled down. The wedges then holds the drill pipe by the compressive force. After work is completed, the drill string is raised, thereby unlocking the gripping action.
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One manufacturing method involves epitaxial growth of silicon on top of a relaxed silicon-germanium underlayer. Tensile strain is induced in the silicon as the lattice of the silicon layer is stretched to mimic the larger lattice constant of the underlying silicon-germanium. Conversely, compressive strain could be induced by using a solid solution with a smaller lattice constant, such as silicon-carbon. See, e.g.
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Elastic instability of a rigid beam supported by an angular spring. Elastic instability is a form of instability occurring in elastic systems, such as buckling of beams and plates subject to large compressive loads. There are a lot of ways to study this kind of instability. One of them is to use the method of incremental deformations based on superposing a small perturbation on an equilibrium solution.
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Recently the Canning Dam has been subjected to considerable cracking of the upper parts of the dam and upper gallery. Investigations have shown that cracking was due to strong AAR (alkali aggregate reactivity) in the concrete. AAR results in swelling of the concrete, which may cause secondary compressive stresses, localised map cracks, and, ultimately structural cracks. In addition, the concrete tensile strength and elasticity significantly decreases.
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The difference in residual stress between the harder cutting edge and the softer back of the sword gives such swords their characteristic curve.Prince Rupert's Drops In toughened glass, compressive stresses are induced on the surface of the glass, balanced by tensile stresses in the body of the glass. Due to the residual compressive stress on the surface, toughened glass is more resistant to cracks, but shatter into small shards when the outer surface is broken. A demonstration of the effect is shown by Prince Rupert's Drop, a material-science novelty in which a molten glass globule is quenched in water: Because the outer surface cools and solidifies first, when the volume cools and solidifies, it "wants" to take up a smaller volume than the outer "skin" has already defined; this puts much of the volume in tension, pulling the "skin" in, putting the "skin" in compression.
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From the analysis by Akhmeteli and Gavrilin: The total force on a hemi-spherical shell of radius R by an external pressure P is \pi R^2 P. Since the force on each hemisphere has to balance along the equator the compressive stress will be, assuming h< :\sigma = \pi R^2 P / 2 \pi R h = R P / 2 h where h is the shell thickness. Neutral buoyancy occurs when the shell has the same mass as the displaced air, which occurs when h/R = \rho_a/(3 \rho_s), where \rho_a is the air density and \rho_s is the shell density, assumed to be homogeneous. Combining with the stress equation gives :\sigma = (3/2)(\rho_s/\rho_a)P. For aluminum and terrestrial conditions Akhmeteli and Gavrilin estimate the stress as 3.2\cdot 10^8 Pa, of the same order of magnitude as the compressive strength of aluminum alloys.
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With documented expertise in statistics and optimization tools, Giannakis' research team contributed innovative solutions to challenging science and engineering problems by capitalizing on the data deluge, while jointly leveraging physics-guided and data-driven models. Their key novelties have markedly advanced machine learning with data collected at distributed agents, and offered learning models that account for nonlinear data dependencies, structures, dynamics, and outliers. They were the first to develop consensus-based distributed (gossip) schemes for classification, sparse regression, and clustering using the alternating direction method of multipliers (ADMM); and pioneered a solver based on judiciously designed cluster-heads to speed up decentralized optimization. Sparsity and low rank were the data structures they exploited early on to develop online estimators of sparse signals; to cope with perturbed compressive sampling using sparse total least-squares, and also insightfully link compressive sensing with robust statistics, simply because data outliers are sparse.
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Mohr–Coulomb theory is a mathematical model (see yield surface) describing the response of brittle materials such as concrete, or rubble piles, to shear stress as well as normal stress. Most of the classical engineering materials somehow follow this rule in at least a portion of their shear failure envelope. Generally the theory applies to materials for which the compressive strength far exceeds the tensile strength.Juvinal, Robert C. & Marshek, Kurt .
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Strengthening of materials is useful in many applications. A primary application of strengthened materials is for construction. In order to have stronger buildings and bridges, one must have a strong frame that can support high tensile or compressive load and resist plastic deformation. The steel frame used to make the building should be as strong as possible so that it does not bend under the entire weight of the building.
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A bow's central mount for other components such as the limbs, sights, stabilizers and quivers is called the riser. Risers are designed to be as rigid as possible. The central riser of a compound bow is usually made of aluminum, magnesium alloy, or carbon fiber and many are made of 7075 aluminum alloy. Limbs are made of fiberglass-based composite materials and are capable of taking high tensile and compressive forces.
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This mandrel forces the material outward and compresses the material against the back side of the tapered rollers. This compressive loading fuses the circumferential fissures and sets the initial internal diameter and OD values. The formed tube is then cooled and can be cold worked to refine the diameters and to achieve the desired yield strengths. Mannesmann mills can produce tubes as large as 300 mm (12 in) in diameter.
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Thus, a tight QL may be another hidden cause of low back pain (Janda 1987). When the hip adductors are tight or hypertonic, their antagonist (gluteus medius) may experience reciprocal inhibition. The gluteus medius will become weak and inhibited. This in turn may cause hypertonicity of ipsilateral QL. Chronic hypertonicity of QL tends to cause low back pain due to its ability to create compressive stress on lumbar segment.
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Macor has a density of 2.52 g/cm3, a Young's modulus of 66.9 GPa at 25 °C, a specific stiffness of 26.55 m2s−2, a Poisson’s Ratio of 0.29 and a thermal conductivity of 1.46 W/(m·K). It has a low-temperature (25 to 300 °C) thermal expansion of 9.3 K−1. Its compressive strength is 50 lb/in2 (~350 MPa). Nominal engineering properties are comparable to borosilicate glass.
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Cervical vertebra with intervertebral disc Intervertebral discs consist of an outer fibrous ring, the anulus fibrosus disci intervertebralis, which surrounds an inner gel-like center, the nucleus pulposus. The anulus fibrosus consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen. Type I is concentrated toward the edge of the ring, where it provides greater strength. The stiff laminae can withstand compressive forces.
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The average density of granite is between , its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6·1019 Pa·s. The melting temperature of dry granite at ambient pressure is ; it is strongly reduced in the presence of water, down to 650 °C at a few kBar pressure. Granite has poor primary permeability overall, but strong secondary permeability through cracks and fractures if they are present.
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Most SRJs are designed with an offset housing, allowing for higher compressive loads in a smaller space. Alternatively, the joint can be assembled backwards for higher tensile load capability but less range of motion. An alternative to the SRJ is the universal joint, which consists of two revolute joints. By using spherical rolling joints instead of universal, designers can reduce the number of joints to achieve the same result.
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When solute and solvent atoms differ in size, local stress fields are created that can attract or repel dislocations in their vicinity. This is known as the size effect. By relieving tensile or compressive strain in the lattice, the solute size mismatch can put the dislocation in a lower energy state. In substitutional solid solutions, these stress fields are spherically symmetric, meaning they have no shear stress component.
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Landslide Slope stabilization is the use of geofoam in order to reduce the mass and gravitational force in an area that may be subject to failure, such as a landslide. Geofoam is up to 50 times lighter than other traditional fills with similar compressive strengths. This allows geofoam to maximize the available right-of-way on an embankment. Geofoam's light weight and ease of installation reduces construction time and labor costs.
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In a one-dimensional relaxation test, the material is subjected to a sudden strain that is kept constant over the duration of the test, and the stress is measured over time. The initial stress is due to the elastic response of the material. Then, the stress relaxes over time due to the viscous effects in the material. Typically, either a tensile, compressive, bulk compression, or shear strain is applied.
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Concrete strength values are usually specified as the lower-bound compressive strength of either a cylindrical or cubic specimen as determined by standard test procedures. The strengths of concrete is dictated by its function. Very low-strength— or less—concrete may be used when the concrete must be lightweight. Lightweight concrete is often achieved by adding air, foams, or lightweight aggregates, with the side effect that the strength is reduced.
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The socket wall reflects the responsiveness to the external forces. Osteoblasts and newly formed osteoid line the areas of tension, whereas lines of compression are lined by osteoclasts. The forces also influence the number, density, and alignment of trabeculae inside the bone. The bony trabeculae are aligned in the path of tensile and compressive stresses to provide maximum resistance to occlusal forces with a minimum of bone substance.
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However, the strain to rupture remains roughly the same at around 1. The effect of temperature on rock plasticity has been explored by several teams of researchers.Griggs, Turner, Heard (1960) It is observed that the peak stress decreases with temperature. Extension tests (with confining pressure greater than the compressive stress) show that the intermediate principal stress as well as the strain rate has an effect on the strength.
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ET. An hour before the start of the concert, "thousands were tightly packed around the entrance doors", and by 7:20 p.m. ET the crowd consisted of 8,000 people. Some members of the crowd rushed the gates on the plaza level on the west side of the Coliseum, crushing those at the front. The incident resulted in the death of 11 individuals by compressive asphyxia and injuries to 23.
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Aerial View of Marine Parade (photo taken from roof of Edgewater Towers showing buildings under construction). 1968. Sol Sapir Architect and developer Nathan Beller. Constructed with high-compressive bricks without columns.The Weekly Review, 12 April 2014, Shaping Melbourne, N.Clerehan. Plans for an earlier 12 storey development of 35 flats at 13, The Esplanade by Roy Grounds, Frederick Romberg and Robin Boyd Architects with developer A. V. Jennings Construction CompanyThe Age.
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Railway steel contracts at low temperatures and expands at high temperatures.Bibel G. Train Wreck: The Forensics of Rail Disasters JHU Press, 2012 In extreme cold, a length of CWR suffers tensile stress. This stress can cause railway steel to fracture.Brockbank W. The Effects of Cold on Iron and Steel The Railway Times vol 23 p76 11 March 1871 In extreme heat, a length of CWR suffers compressive stress.
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Some of the earliest examples of concrete slabs were built by Roman engineers. Because concrete is quite strong in resisting compressive loads, but has relatively poor tensile or torsional strength, these early structures consisted of arches, vaults and domes. The most notable concrete structure from this period is the Pantheon in Rome. To mould this structure, temporary scaffolding and formwork or falsework was built in the future shape of the structure.
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A column under a centric axial load exhibiting the characteristic deformation of buckling. When subjected to compressive forces it is possible for structural elements to deform significantly due to the destabilising effect of that load. The effect can be initiated or exacerbated by possible inaccuracies in manufacture or construction. The Euler buckling formula defines the axial compression force which will cause a strut (or column) to fail in buckling.
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It has proven very popular as a root-end filling material and has shown generally high success rates. MTA produces a high pH environment, which is bactericidal, and may stimulate osteoblasts to produce bone to fill in any defects caused by infection. Modified versions of zinc oxide eugenol cement (ZOE) cement, such as IRM or Super EBA, have high compressive strength, high tensile strength, neutral pH, and low solubility.
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Therefore, a delay period is allowed to elapse before the commencement of the curing process to allow the concrete to gain a certain minimum tensile strength. The setting time of the concrete is an important criterion to determine the delay period. Generally, the delay period is equal to the initial setting time which has been found to give satisfactory results. Lesser delay periods result in compressive strength losses.
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The bridge was a post-tensioned concrete structure. Concrete structures are generally ten times heavier than equivalent steel designs. The bridge was made using a new formulation for concrete intended to stay cleaner than standard concrete formulations. In the main bridge span, the concrete floor deck, roof, and diagonal struts each contained post-tensioning cables whose compressive effect on the concrete could be adjusted after the concrete was cured.
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For example, Touri et al. developed a method to incorporate carbon nanotubes (CNTs) into the structure without interfering with the material's bioactive properties. CNTs were chosen because of their large aspect ratio and high strength. By synthesizing Bioglass 45S5 on a CNT scaffold, the researchers were able to create a composite that more than doubled the compressive strength and the elastic modulus when compared to the pure glass.
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Solemya elarraichensis is endemic to the volcanic area in the Gulf of Cadiz, off the coast of Spain. The whole area is under compressive deformation and mud volcanism and the processes associated with the escape of hydrocarbon-rich fluids sustain a broad diversity of chemosynthetic organisms. The area includes over forty mud volcanoes, a type of cold seep, at depths between , and active methane seepage occurs in several places.
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Reinforcing concrete with steel improves strength and durability. On its own, concrete has good compressive strength, but lacks tension and shear strength and can be subject to cracking when bearing loads for long periods of time. Steel offers high tension and shear strength to make up for what concrete lacks. Steel behaves similarly to concrete in changing environments, which means it will shrink and expand with concrete, helping avoid cracking.
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Elastic modulus is simply defined as the ratio of stress to strain within the proportional limit. Physically, it represents the stiffness of a material within the elastic range when tensile or compressive load are applied. It is clinically important because it indicates the selected biomaterial has similar deformable properties with the material it is going to replace. These force-bearing materials require high elastic modulus with low deflection.
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All patients indicated satisfaction with the bone product. In another study, which examined replicate goat femurs, hydroxyapatite nanocrystals were produced and mixed on- site before loading a 3D printer. The study noted a slight decrease in compressive strength of the femurs, which could be attributed to imperfect printing and an increased ratio of cancellous bone. In general, 3D printing techniques produce implants with few adverse effects in patients.
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Masonry is commonly used for walls and buildings. Brick and concrete block are the most common types of masonry in use in industrialized nations and may be either load-bearing or non load bearing. Concrete blocks, especially those with hollow cores, offer various possibilities in masonry construction. They generally provide great compressive strength and are best suited to structures with light transverse loading when the cores remain unfilled.
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Compression becomes clinically significant only if it causes appreciable hemodynamic changes in venous flow or venous pressure, or if it leads to acute or chronic DVT. In addition to compression, the vein develops intraluminal fibrous spurs from the effects of the chronic pulsatile compressive force from the artery. The narrowed turbulent channel predisposes the patient to thrombosis. The compromised blood flow often causes collateral blood vessels to form.
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Hydro-slotting perforation technology is the process of opening the productive formation through the casing and cement sheath to produce the oil or gas product flow (intensification, stimulation). The process has been used for industrial drilling since 1980, and involves the use of an underground hydraulic slotting engine (tool, equipment). The technology helps to minimize compressive stress following drilling in the well-bore zone (which reduces the permeability in the zone).
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This first approach increases the friction locking the bar into place, while the second makes use of the high compressive strength of concrete. Common rebar is made of unfinished tempered steel, making it susceptible to rusting. Normally the concrete cover is able to provide a pH value higher than 12 avoiding the corrosion reaction. Too little concrete cover can compromise this guard through carbonation from the surface, and salt penetration.
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The concrete is in the shape of an arch and carries compressive load internal to the beam. The steel strands act as a tie for the arch and carry the tensile load internal to the beam. The FRP shell carries the shear and bending moment internal to the beam. This means that the beam acts structurally in a hybrid nature, somewhere between a tied-arch and a beam.
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Hydraulic lime sets by reaction with water called hydration. When a stronger lime mortar is required, such as for external or structural purposes, a pozzolan can be added, which improves its compressive strength and helps to protect it from weathering damage. Pozzolans include powdered brick, heat treated clay, silica fume, fly ash, and volcanic materials. The chemical set imparted ranges from very weak to almost as strong as Portland cement.
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With historic structures, this may be a controversial strategy as it could have a detrimental effect to the historic fabric. The presence of Portland allows for a more stable mortar. The stability and predictability make the mixed mortar more user friendly, particularly in applications where entire wall sections are being laid. Contractors and designers may prefer mixes that contain Portland due to the increased compressive strength over a straight lime mortar.
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The concrete then cracks either under excess loading, or due to internal effects such as early thermal shrinkage while it cures. Ultimate failure leading to collapse can be caused by crushing the concrete, which occurs when compressive stresses exceed its strength, by yielding or failure of the rebar when bending or shear stresses exceed the strength of the reinforcement, or by bond failure between the concrete and the rebar.
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A diagram showing the diffusion of atoms and vacancies under Nabarro–Herring Creep. Nabarro–Herring (NH) creep is a form of diffusion creep, while dislocation glide creep does not involve atomic diffusion. Nabarro–Herring creep dominates at high temperatures and low stresses. As shown in the figure on the right, the lateral sides of the crystal are subjected to tensile stress and the horizontal sides to compressive stress.
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The cam plastometer is a physical testing machine. It measures the resistance of non-brittle materials to compressive deformation at constant true-strain rates. In this way, it can be compared a bit to the Gleeble(R). In the early days, the machine operates at relatively low strain rates, but over time it has been enhanced and currently it can operate over a wide range of strain ratesJ.
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These pressures resulted in a bridge noted as innovative for precision and accuracy of construction and quality control. This was the first use of structural alloy steel in a major building construction, through use of cast chromium steel components. The completed bridge also relied on significant—and unknown—amounts of wrought iron. Eads argued that the great compressive strength of steel was ideal for use in the upright arch design.
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When the compressive force is removed the spring returns to its original state. The minimal number of static equilibria of homogeneous, convex bodies (when resting under gravity on a horizontal surface) is of special interest. In the planar case, the minimal number is 4, while in three dimensions one can build an object with just one stable and one unstable balance point. Such an object is called a gömböc.
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Autogenous or autogenic mills are so-called due to the self-grinding of the ore: a rotating drum throws larger rocks of ore in a cascading motion which causes impact breakage of larger rocks and compressive grinding of finer particles. It is similar in operation to a SAG mill as described below but does not use steel balls in the mill. Also known as ROM or "Run Of Mine" grinding.
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Ultrasonic impact treatment (UIT) uses ultrasound to enhance the mechanical and physical properties of metals. It is a metallurgical processing technique in which ultrasonic energy is applied to a metal object. Ultrasonic treatment can result in controlled residual compressive stress, grain refinement and grain size reduction. Low and high cycle fatigue are enhanced and have been documented to provide increases up to ten times greater than non-UIT specimens.
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One of the early designers of reinforced concrete, Robert Maillart, employed reinforced concrete in a number of arched bridges. His first bridge was simple, using a large volume of concrete. He then realized that much of the concrete was very cracked, and could not be a part of the structure under compressive loads, yet the structure clearly worked. His later designs simply removed the cracked areas, leaving slender, beautiful concrete arches.
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With elevated temperature, concrete will lose its hydration product because of water evaporation. Therefore its resistance of moisture flow of concrete decreases and the number of unhydrated cement grains grows with the loss of chemically bonded water, resulting in lower compressive strength.. Also, the decomposition of calcium hydroxide in concrete forms lime and water. When temperature decreases, lime will reacts with water and expands to cause a reduction of strength.
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The Laramide orogeny produced intermontane structural basins and adjacent mountain blocks by means of deformation. This style of deformation is typical of continental plates adjacent to convergent margins of long duration that have not sustained continent/continent collisions. This tectonic setting produces a pattern of compressive uplifts and basins, with most of the deformation confined to block edges. Twelve kilometers of structural relief between basins and adjacent uplifts is not uncommon.
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In the case of beams and slabs, the effectiveness of FRP strengthening depends on the performance of the resin chosen for bonding. This is particularly an issue for shear strengthening using side bonding or U-wraps. Columns are typically wrapped with FRP around their perimeter, as with closed or complete wrapping. This not only results in higher shear resistance, but more crucial for column design, it results in increased compressive strength under axial loading.
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In the past decade, reverse engineering of materials found in nature such as bone matter has gained funding in academia. The structure of bone matter is optimized for its purpose of bearing a large amount of compressive stress per unit weight. The goal is to replace crude steel with bio-material for structural design. Over the past decade the Finite element method (FEM) has also entered the Biomedical sector highlighting further engineering aspects of Biomechanics.
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Bigger Faster Stronger, March/April 2008, pp. 36–38. Squatting below parallel qualifies a squat as deep while squatting above it qualifies as shallow. Some authorities caution against deep squats; though the forces on the ACL and PCL decrease at high flexion, compressive forces on the menisci and articular cartilages in the knee peak at these same high angles.Clarkson, HM, and Gilewich, GB (1999) Musculoskeletal Assessment: Joint Range of Motion And Manual Muscle Strength.
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Hip abduction is performed primarily by the hip abductors (gluteus medius and minimus). When the gluteus medius/minimus are weak or inhibited, the TFL (tensor fasciae latae) or QL will compensate by becoming the prime mover. The most impaired movement pattern of hip abduction is when the QL initiates the movement, which results in hip hiking during swing phase of gait. Hip hiking places excessive side-bending compressive stresses on the lumbar segments.
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It appears that when the Straight Creek Fault became stuck the north–south compressive force that it had accommodated by strike-slip motion was transferred to the crust of the Puget Lowland, which subsequently folded and faulted, and the various blocks jammed over one another. Other scarps associated with the Seattle fault have been identified by LIDAR-based mapping;. trenching has generally shown the faulting to be more complex than was first realized., p.1389.
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The two layers of the cuticle have different properties. The outer layer is where most of the thickening, biomineralization and sclerotisation takes place, and its material tends to be strong under compressive stresses, though weaker under tension. When a rigid region fails under stress, it does so by cracking. The inner layer is not as highly sclerotised, and is correspondingly softer but tougher; it resists tensile stresses but is liable to failure under compression.
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It is outstanding at mitigating foreign object damage in turbine blades. The plastic strain introduced by laser peening is much lower than that introduced by other impact peening technologies. As a result, the residual plastic strain has much greater thermal stability than the more heavily cold worked microstructures. This enables the laser peened compressive stresses to be retained at higher operating temperatures during long exposures than is the case for the other technologies.
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The response of these surface atoms would be to attempt to reduce their interatomic distance in order to increase surrounding charge density. Therefore, surface atoms would create a positive surface stress (tensile). In the other words, if the surface charge density is the same as in the bulk, surface stress would be zero. Surface stress, which created by redistribution of electron density around surface atoms, can be both positive (tensile) or negative (compressive).
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Stylized cacti decorate a sound/retaining wall in Scottsdale, Arizona Prestressed concrete is a form of reinforced concrete that builds in compressive stresses during construction to oppose tensile stresses experienced in use. This can greatly reduce the weight of beams or slabs, by better distributing the stresses in the structure to make optimal use of the reinforcement. For example, a horizontal beam tends to sag. Prestressed reinforcement along the bottom of the beam counteracts this.
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When an object formed of a single material, like a wooden beam or a steel rod, is bent (Fig. 1), it experiences a range of stresses across its depth (Fig. 2). At the edge of the object on the inside of the bend (concave face) the stress will be at its maximum compressive stress value. At the outside of the bend (convex face) the stress will be at its maximum tensile value.
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In a composite steel deck, the dissimilar materials in question are steel and concrete. A composite steel deck combines the tensile strength of steel with the compressive strength of concrete to improve design efficiency and reduce the material necessary to cover a given area. Additionally, composite steel decks supported by composite steel joists can span greater distances between supporting elements and have reduced live load deflection in comparison to previous construction methods.
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The American design code that guides design engineers in using CMU as a structural system is the Masonry Standards Joint Committee's Building Code Requirements & Specification for Masonry Structures (TMS 402/ACI 530/ASCE 5). The compressive strength of concrete masonry units and masonry walls varies from approximately to based on the type of concrete used to manufacture the unit, stacking orientation, the type of mortar used to build the wall, and other factors.
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The piezoelectric effect is the generation of electric charge when certain materials are under stress. In the case of piezo switches, the force could be compressive pressure that causes the (typically disc-shaped) piezo element to bend very slightly like a drumhead. Thus piezo switches produce a single, brief "on" pulse. This pulse can vary with the amount of pressure which is applied, since higher pressures generate higher voltages which take longer to dissipate.
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The Andean orogeny, active since the Cretaceous, has formed several volcanic arcs to the west of the Cesar- Ranchería Basin Sediments from the Late Permian to Triassic periods are absent in the Cesar-Ranchería Basin, but evidenced in the surrounding orogens. Intense magmatism and metamorphism affected the Sierra Nevada de Santa Marta and the Central Ranges of the Colombian Andes. The compressive phase is associated with the Hercynian orogeny, leading to the formation of Pangea.
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The Al2O3 content of alkali aluminosilicate glasses is typically 10-25% and the alkali content over 10%. The high alkali content prepares the glass for ion exchange with bigger alkali ions in order to improve the surface compressive strength. Due to this particular feature, this glass type is especially suitable for the use in touch displays, solar cells cover glass and laminated safety glass. High transformation temperatures and outstanding mechanical properties, e.g.
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Prestressed concrete is a method for overcoming the concrete's natural weakness in tension. It can be used to produce beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. Prestressing tendons (generally of high tensile steel cable or rods) are used to provide a clamping load which produces a compressive stress that offsets the tensile stress that the concrete compression member would otherwise experience due to a bending load.
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Only the aftermost three of her seven cargo hatches are exposed. Compressive buckling of the port gunwale between the fifth and the sixth hatch and the depression of bottom hull plating nearby suggests that the vessel initially buried its bow in the bottom at a steep angle, then bent "up" and to port amidships as it settled until the after portion came to rest on the bottom, supported by its steel after deckhouse.
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While CT scans and subsequent bone models are highly indicative of real bone for internal composition, the final product relies on the resolution of the printer. In cases where printer defects occur, the most likely issue is a decrease in compressive strength due to unintentional voids. After implantation, decreased cellular proliferation and differentiation is evident as patients increase with age. This prolongs the integration of grafts and hinders the formation of bone tissue.
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Arabian plate boundaries with the Eurasian, African and Indian plates The quake reportedly occurred within the subducting Arabian Plate below the overriding Eurasian Plate. The Strait of Hormuz separates two forms of plate collision. To the northwest, continental crust portions of the Arabian and Eurasian Plates are colliding, resulting in compressive faulting. To the southeast, dense oceanic crust of the Arabian Plate is subducting underneath the Eurasian Plate at the Makran Trench.
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In most head trauma cases, CT scans are the standard diagnostic method; however it is not ideal for imaging small lesions, so MRI is used to identify Kernohan's notch. It is important to distinguish Kernohan's notch from direct brain stem injuries. Case studies have shown that in patients with chronic subdural hematoma, a compressive deformity of the crus cerebri without an abnormal MRI signal may predict a better recovery in patients with Kernohan's notch.
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The result is a candidate for "the most durable building material in human history". In contrast, modern concrete exposed to saltwater deteriorates within decades. Crystal structure of tobermorite: elementary unit cell Compressive strengths for modern Portland cements are typically at the level and have improved almost ten-fold since 1860. There are no comparable mechanical data for ancient mortars, although some information about tensile strength may be inferred from the cracking of Roman concrete domes.
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Solid nitrogen has several properties relevant to its formation of rocks in the outer Solar System. Even at the low temperatures of solid nitrogen it is fairly volatile and can sublime to form an atmosphere, or condense back into nitrogen frost. At 58 K the ultimate compressive strength is 0.24 MPa. Strength increases as temperature lowers becoming 0.54 MPa at 40.6 K. Elastic modulus varies from 161 to 225 MPa over the same range.
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The collagen, mostly collagen type II, constrains the proteoglycans. The ECM responds to tensile and compressive forces that are experienced by the cartilage. Cartilage growth thus refers to the matrix deposition, but can also refer to both the growth and remodeling of the extracellular matrix. Due to the great stress on the patellofemoral joint during resisted knee extension, the articular cartilage of the patella is among the thickest in the human body.
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The rolled steel "profile" or cross section of steel columns takes the shape of the letter "". The two wide flanges of a column are thicker and wider than the flanges on a beam, to better withstand compressive stress in the structure. Square and round tubular sections of steel can also be used, often filled with concrete. Steel beams are connected to the columns with bolts and threaded fasteners, and historically connected by rivets.
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For example, the defect is nucleated at positions experiencing high tensile stress in armchair-type CNTs, and at positions experiencing high compressive stress in zigag-type CNTs. Applied stresses can overcome the energy barrier needed to move 5-7 defect pairs. Another way of understanding this is that when strained, a CNT releases strain by forming these defects spontaneously. For example, in (5,5) tubes, a critical tensile strain of ~5% results in defect generation.
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The Bollman truss suspends the deck from a network of tension members, while the top chord resists compressive forces. The system is therefore referred to as a suspension truss. Bollman published a booklet describing the Harpers Ferry bridge and the system in general as a “suspension and trussed bridge” which is accurate as the design lacks an active lower chord required of a strict truss bridge. Later descriptions used "suspension truss" for the design.
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Most cast irons have a chemical composition of 2.5–4.0% carbon, 1–3% silicon, and the remainder iron. Grey cast iron has less tensile strength and shock resistance than steel, but its compressive strength is comparable to low- and medium-carbon steel. These mechanical properties are controlled by the size and shape of the graphite flakes present in the microstructure and can be characterised according to the guidelines given by the ASTM.
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This subsidence of older crust may imply enormous horizontal compressive stress. This stress is related to resurfacing rate (v), Io's radius (R), subsidence distance (ΔR) and Yong's modulus. The subsidence- generated horizontal stress is equal to E/(1-V)× ΔR/R. This stress is more than enough to cause faulting on Io. # Thermal stress: thermal stress is another possible stress source on Io, as increasing temperature in Io's crust can cause expansion of the crust.
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Comparison of Tresca criterion to Von Mises criterion If the stress exceeds a critical value, as was mentioned above, the material will undergo plastic, or irreversible, deformation. This critical stress can be tensile or compressive. The Tresca and the von Mises criteria are commonly used to determine whether a material has yielded. However, these criteria have proved inadequate for a large range of materials and several other yield criteria are also in widespread use.
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The risk for lumbar disc disease is increased in overweight individuals due to the increased compressive force on the nucleus pulposus. Severe spinal cord compression is considered a surgical emergency and requires decompression to preserve motor and sensory function. Cauda equina syndrome refers to severe compression of the cauda equina and presents initially with pain followed by motor and sensory. Bladder incontinence is seen in later stages of the cauda equina syndrome.
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Fairbairn realised that the hoop stress was twice the longitudinal stress, an important factor in the assembly of boiler shells from rolled sheets joined by riveting. Later work was applied to bridge building, and the invention of the box girder. In the Chepstow Railway Bridge, the cast iron pillars are strengthened by external bands of wrought iron. The vertical, longitudinal force is a compressive force, which cast iron is well able to resist.
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E is Young's modulus, α is thermal expansion coefficient, To is temperature original, and Tf is the final temperature. σ=Εα(Tf-To)=ΕαΔT When Tf is greater than To, the constraints exert a compressive force on the material. The opposite happens while cooling; when Tf is less than To, the stress will be tensile. A welding example involves heating and cooling of metal which is a combination of thermal expansion, contraction, and temperature gradients.
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Up to a certain height, a tower can be made with the supporting structure with parallel sides. However, above a certain height, the compressive load of the material is exceeded and the tower will fail. This can be avoided if the tower's support structure tapers up the building. A second limit is that of buckling—the structure requires sufficient stiffness to avoid breaking under the loads it faces, especially those due to winds.
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Compression test on a universal testing machine Compression of solids has many implications in materials science, physics and structural engineering, for compression yields noticeable amounts of stress and tension. By inducing compression, mechanical properties such as compressive strength or modulus of elasticity, can be measured. Compression machines range from very small table top systems to ones with over 53 MN capacity. Gases are often stored and shipped in highly compressed form, to save space.
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Designing a strong curved jib required Fairbairn's advanced theoretical understanding of the mechanics of a box girder. The tension forces were carried by the outer, convex surface of the girder which was made of back plates being chain-riveted together. The inner surface carried a compressive load. To avoid plate crumpling, it was made as a cellular structure: an inner plate and webs formed three rectangular cells, effectively box girders in their own right.
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Crazes generally propagate perpendicular to the applied tension. Crazing occurs mostly in amorphous, brittle polymers like polystyrene (PS), acrylic (PMMA), and polycarbonate; it is typified by a whitening of the crazed region. The white colour is caused by light-scattering from the crazes. The production of crazing is a reversible process, after applied compressive stress or elevated temperature (higher than glass transformation temperature), it may disappear and the materials will return to optically homogeneous state.
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T slots allow bars to be joined with special connectors. Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed through a die of the desired cross-section. The two main advantages of this process over other manufacturing processes are its ability to create very complex cross-sections, and to work materials that are brittle, because the material only encounters compressive and shear stresses.
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These relations are similar to those associated with highly degraded, ancient basins on Mars (Chicarro and others, 1983). The smooth plains material displays numerous ridges that generally resemble lunar mare ridges and also are considered to be of tectonic origin. The mercurian ridges are probably related to minor compressive stresses that postdate smooth plains emplacement. Numerous lineaments are associated with basin rim material, but most of these lineaments are probably related to ejecta deposition.
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Plagiosuchus has very small teeth and a large area for muscle attachment behind the skull, suggesting that it could suction feed by rapidly opening its mouth. Unlike semiaquatic temnospondyls, terrestrial temnospondyls have skulls that are adapted for biting land-living prey. The sutures between the bones of the skull in the dissorophoid Phonerpeton are able to withstand a high degree of compression. Compressive forces would have been experienced when biting down on prey.
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The Solidification/Stabilization method utilizes chemically reactive formulations that form stable solids that are non-hazardous or less-hazardous than the original materials. Solidification refers to the physical changes in the contaminated material when a certain binding agent is added. These changes include an increase in compressive strength, a decrease in permeability, and condensing of hazardous materials. Stabilization refers to the chemical changes between the stabilizing agent (binding agent) and the hazardous constituent.
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The Municipality does not lie along any known fault zones/lines. As to its bedrock foundations, old sediments and pyroclastics which are more stable than poorly consolidated sediments (e.g. limestone, shale or alluvial deposits) in terms of compressive strength/load bearing capacity comprise roughly 67.50% of the total municipal land area. The remaining 32.50% is composed of metamorphosed rocks, volcanic and highly crystallized rocks which are situated in areas of highest relief.
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The ECM of joint cartilage comprises many classes of macromolecules; collagen (type I, II, VI, X collagen fibrils) and proteoglycans. The ratio and the proportion of collagen play an important role in the tensile and compressive strength, as well as the elasticity of the tissue. The content of collagen in cartilage is different between joints and soft tissue structures. For example, cartilage in the knee has a different structure to the ankle.
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A marathon runner wearing running sleeves in Taipei, 2016. Sleeves made from Spandex or Lycra are used by long-distance runners and other endurance athletes. The compressive effect prevents swelling of the arm muscles and the build-up of lactic acid; they also provide insulation in cold weather and solar ultraviolet protection. During 2010 FIFA World Cup, arm warmers featuring the participating national teams became a phenomenon in the host country South Africa and abroad.
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Radial neuropathy is not necessarily permanent. The majority of radial neuropathies due to an acute compressive event (Saturday night palsy) do recover without intervention. If the injury is demyelinating (meaning only the myelin sheath surrounding the nerve is damaged), then full recovery typically occurs within 2–4 weeks. If the injury is axonal (meaning the underlying nerve fiber itself is damaged) then full recovery may take months or years, or may never occur.
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Buckling occurs when compressive loads are applied to the material and instead of cracking the material bows. This is undesirable because most tools that are designed to be straight will be inadequate if curved. If the buckling continues, it will create tension on the outer side of the bend and compression on the inner side, potentially fracturing the material. In engineering there are multiple types of failure based upon the application of the material.
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The alveolar bone is the bone of the jaw which forms the alveolus around teeth. Like any other bone in the human body, alveolar bone is modified throughout life. Osteoblasts create bone and osteoclasts destroy it, especially if force is placed on a tooth. As is the case when movement of teeth is attempted through orthodontics, an area of bone under compressive force from a tooth moving toward it has a high osteoclast level, resulting in bone resorption.
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However, as of 2017 JSC Mars-1A is no longer available. After milling to reduce its particle size, JSC Mars-1A can geopolymerize in alkaline solutions forming a solid material. Tests show that the maximum compressive and flexural strength of the 'martian' geopolymer is comparable to that of common clay bricks. JSC-1A) and Martian (JSC MARS-1A) dust simulants produced at the University of BirminghamAlexiadis, Alberini, Meyer; Geopolymers from lunar and Martian soil simulants, Adv.
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The pinnacle had two purposes: # Ornamental – adding to the loftiness and verticity of the structure. They sometimes ended with statues, such as in Milan Cathedral. # Structural – the pinnacles were very heavy and often rectified with lead, in order to enable the flying buttresses to contain the stress of the structure vaults and roof. This was done by adding compressive stress (a result of the pinnacle weight) to the thrust vector and thus shifting it downwards rather than sideways.
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The following six parameters are used to classify a rock mass using the RMR system #Uniaxial compressive strength of rock material #Rock quality designation (RQD) #Spacing of discontinuities #Condition of discontinuities. #Groundwater conditions #Orientation of discontinuities Each of the six parameters is assigned a value corresponding to the characteristics of the rock. These values are derived from field surveys and laboratory tests. The sum of the six parameters is the "RMR value", which lies between 0 and 100.
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Animation of a pulsejet engine Pulsejet engines are characterized by simplicity, low cost of construction, and high noise levels. While the thrust-to-weight ratio is excellent, thrust specific fuel consumption is very poor. The pulsejet uses the Lenoir cycle, which, lacking an external compressive driver such as the Otto cycle's piston, or the Brayton cycle's compression turbine, drives compression with acoustic resonance in a tube. This limits the maximum pre-combustion pressure ratio, to around 1.2 to 1.
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The basalt at Spier's has many distinctive holes or bubbles, known as vesicles. These formed when gases such as steam and carbon dioxide escaped as the compressive pressure got less in the molten rock as the lava reached the surface. The largest numbers of bubbles occur when the hardened skin of the lava surface prevented the bubbles from rising to the surface and bursting. Olivine crystal faces are visible, a mineral rich in silica, iron and magnesium.
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Decorative plate made of Nano concrete with High-Energy Mixing (HEM) Nanoconcrete (also spelled "nano concrete"' or "nano-concrete") is a class of materials that contains Portland cement particles that are no greater than 100 μm and particles of silica no greater than 500 μm, which fill voids that would otherwise occur in normal concrete, thereby substantially increasing the material's strength. It is widely used in foot and highway bridges where high flexural and compressive strength are indicated.
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For musculoskeletal rehabilitation, aquatic therapy is typically used to treat acute injuries as well as subjective pain of chronic conditions, such as arthritis. Water immersion has compressive effects and reflexively regulates blood vessel tone. Muscle blood flow increases by about 225% during immersion, as increased cardiac output is distributed to skin and muscle tissue. Flotation is able to counteract the effects of gravitational force on joints, creating a low impact environment for joints to perform within.
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It has considerable compressive or crushing strength, but is somewhat deficient in shearing strength, and distinctly weak in tensile or pulling strength. Steel, on the other hand, is easily procurable in simple forms such as long bars, and is extremely strong. But it is difficult and expensive to work up into customized forms. Concrete had been avoided for making beams, slabs and thin walls because its lack of tensile strength doomed it to fail in such circumstances.
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These cover only a very small portion of the surface area. Friction and wear originate at these points, and thus understanding their behavior becomes important when studying materials in contact. When the surfaces are subjected to a compressive load, the asperities deform through elastic and plastic modes, increasing the contact area between the two surfaces until the contact area is sufficient to support the load. The relationship between frictional interactions and asperity geometry is complex and poorly understood.
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Another challenging element was the shamal which often creates sandstorms. Over of concrete, weighing more than were used to construct the concrete and steel foundation, which features 192 piles; each pile is 1.5 metre in diameter by 43 m in length, buried more than deep. The foundation was designed to support the total building weight of approximately . This weight was then divided by the compressive strength of concrete of which is 30 MPa which yielded a 450 sq.
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Blunt force trauma is seen as the most common form of trauma. It results in abrasions, bone fractures, lacerations, or contusions. An example of this type of trauma is falling from a high elevation. Sharp force trauma is “a narrowly focused, dynamic, slow-loaded, compressive force with a sharp object that produces damage to hard tissue in the form of an incision.” This can involve a variety of weapons or tools, like knives, that have beveled edge.
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When a person steps on a blast mine and activates it, the mine's main charge detonates, creating a blast shock wave consisting of hot gases travelling at extremely high velocity. The shock wave sends a huge compressive force upwards, ejecting the mine casing and any soil covering the mine along with it. When the blast wave hits the surface, it quickly transfers the force into the subject's footwear and foot. This results in a massive compression force being applied.
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At high partial pressure in the adsorption/desorption the Kelvin equation gives the pore size distribution of the sample. In mercury porosimetry, the mercury is forced into the aerogel porous system to determine the pores' size, but this method is highly inefficient since the solid frame of aerogel will collapse from the high compressive force. The scattering method involves the angle-dependent deflection of radiation within the aerogel sample. The sample can be solid particles or pores.
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The Shillong Plateau is a plateau in eastern Meghalaya state, northeastern India. The plateau's southern, northern and western ridges form the Garo, Khasi and Jaintia Hills respectively. The plateau shows numerous fracture lineaments in satellite images and has been subjected to extensive and compressive forces in the N-S and E-W direction respectively. Several deep earthquakes point to tectonic activity in the mantle, such as from the 1897 Assam earthquake along the blind Oldham Fault.
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Because of this, when wetted, gel-type biopolymers form hydrogels which have decreased tensile strength but significantly higher compressive strength compared to the original soil. Protein-based biopolymers, though less common, have been used as an alternative to polysaccharides for projects requiring greater water resistance. Biopolymers may increasingly replace synthetic polymers for soil stabilization projects. They are more environmentally friendly than many other chemical soil additives, and can achieve the same amount of strengthening at much lower concentrations.
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The structure of polyacrylamide (PAM), a common synthetic polymer flocculating agent used to increase aggregate sizes in clay-rich soils. Soil characteristics that have been altered by addition of polymers include compressive strength, volume stability, hydraulic durability, and conductivity. Polymers can help prevent soil erosion and increase infiltration of water by strengthening soil aggregates and supporting soil structure. The properties of the soil itself are a dominant control on the ability of polymers to interact with it.
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In modern practice, a slightly oversized die is pushed slowly through the barrel by a hydraulically driven ram. The amount of initial underbore and oversize of the die are calculated to strain the material around the bore past its elastic limit into plastic deformation. A residual compressive stress remains on the barrel's inner surface, even after final honing and rifling. The technique has been applied to the expansion of tubular components down hole in oil and gas wells.
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Nitro-powered plane being wiped down after a flight LiPo battery Most planes need a powerplant to drive them, the exception being gliders. The most popular types for radio-controlled aircraft are internal combustion engines, electric motors, jet engines, and rocket engines. Three types of internal combustion engines are available being small 2 and 4 stroke engines. Glowplug engines use methanol and oil as fuel, compressive ignition ('diesel') burn paraffin with ether as an ignition agent.
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As thousands of spectators were leaving the ground by stairway 13, it appears that someone may have fallen, causing a massive chain- reaction pile-up of people. The loss included many children, five of them schoolmates from the town of Markinch in Fife. The youngest child to die was Nigel Patrick Pickup of Liverpool, age 9. Most of the deaths were caused by compressive asphyxia, with bodies being stacked up to six feet deep in the area.
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The failure or fracture of a product or component as a result of a single event is known as mechanical overload. It is a common failure mode.The terms are used in forensic engineering and structural engineering when analysing product failure. Failure may occur because either the product is weaker than expected owing to a stress concentration, or the applied load is greater than expected and exceeds the normal tensile strength, shear strength or compressive strength of the product.
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Strength of materials is defined as the maximum stress that can be endured before fracture occurs. Strength of biomaterials (bioceramics) is an important mechanical property because they are brittle. In brittle materials like bioceramics, cracks easily propagate when the material is subject to tensile loading, unlike compressive loading. A number of methods are available for determining the tensile strength of materials, such as the bending flexural test, the biaxial flexural strength test and the weibull approach.
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The stage to the Fennian orogeny was set by a collision between Keitele and Karelia about 1920–1910 million years ago which resulted in a reorganization of the local plate tectonics. As concequence the Bergslagen microcontinents collided with the Keitele–Karelia collage starting the Fennian orogeny. The until then linear Fennian orogen was "buckled" from 1870 million years ago onwards due to an orthogonal change in tectonic compressive stress. This resulted in various oroclines around the Gulf of Bothnia.
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Are US crashworthiness standards dooming passenger rail? National Association of Railroad Passengers, 2013 Federal requirements for buff strength were set in 1999 at for all passenger-carrying units, unless reduced by waivers or special order. The Federal Static and Strength Regulation (49 Code of Federal Regulations § 238.203) requires that a passenger rail car be able to support a longitudinal static compressive load of without permanent deformation. There are other strength requirements associated with end- structure design.
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In graphene aerogels, the π-π interaction can greatly enhance stiffness due to the highly curved and folded regions of graphene as observed through transmission electron microscopy images. The mechanical properties of graphene aerogel has been shown to depend on the microstructure and thus varies across studies. The role that microstructure plays in the mechanical properties depends on several factors. Computational simulations on graphene aerogels show graphene walls bend when a tensile or compressive stress is applied.
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They are interpreted to be the surface expression of thrust faults that formed due to compression along the volcano's flanks. Flank terraces are also common on Olympus Mons and the other Tharsis shield volcanoes. The source of the compressive stresses is still debated. The flank terraces may be due to compressional failure of the volcano, flexing of the underlying lithosphere due to the volcano's massive weight, cycles of magma chamber inflation and deflation, or shallow gravitational slumping.
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Many geosynthetic aggregates are also made from recycled materials. Being polymer based, recyclable plastics can be reused in the production of these new age aggregates. For example, Ring Industrial Group's EZflow product lines are produced with geosynthetic aggregate pieces that are more than 99.9% recycled polystyrene. This polystyrene, that would have otherwise been destined for a landfill, is instead gathered, melted, mixed, reformulated and expanded to create low density aggregates that maintain high strength properties while under compressive loads.
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A sesamoid bone is a small, round bone that, as the name suggests, is shaped like a sesame seed. These bones form in tendons (the sheaths of tissue that connect bones to muscles) where a great deal of pressure is generated in a joint. The sesamoid bones protect tendons by helping them overcome compressive forces. Sesamoid bones vary in number and placement from person to person but are typically found in tendons associated with the feet, hands, and knees.
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Low-temperature solid oxide fuel cells (LT-SOFCs), operating lower than 650 °C, are of great interest for future research because the high operating temperature is currently what restricts the development and deployment of SOFCs. A low-temperature SOFC is more reliable due to smaller thermal mismatch and easier sealing. Additionally, a lower temperature requires less insulation and therefore has a lower cost. Cost is further lowered due to wider material choices for interconnects and compressive nonglass/ceramic seals.
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A child sliding down a slide at constant speed would be in mechanical equilibrium, but not in static equilibrium (in the reference frame of the earth or slide). Another example of mechanical equilibrium is a person pressing a spring to a defined point. He or she can push it to an arbitrary point and hold it there, at which point the compressive load and the spring reaction are equal. In this state the system is in mechanical equilibrium.
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While Vaygach is slightly smaller than the Arktika-class nuclear icebreakers, with an overall length of nearly and beam of she is still among the largest polar icebreakers ever built. At the maximum draught of , Vaygach has a displacement of 21,000 tons. However, she can also operate at a reduced draught of only . Vaygach has a traditional icebreaker hull with highly raked stem and sloping sides to reduce the ice loads in compressive ice fields and improve maneuverability.
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The parts are then oil quenched, and the resulting part has a harder case than possibly achieved for carburization, and the addition of the carbonitrided layer increases the residual compressive stresses in the case such that the contact fatigue resistance and strength gradient are both increased. Studies are showing that carbonitriding improves corrosion resistance.Yazıcı, A., Zeybek, M.S., Güler, H., Koç, M., Pekitkan, F. G., 2017 Effect of Carbonitriding on Corrosion Resistance of Steel 30MnB5 in Two Acidic Environments.
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It is characterized by resistance to water and moisture. The ratio of lime in the mixture can be modified in order to completely eliminate water-related erosion. Experiments on capillary water absorption have shown that increased amounts of lime in the mixture results in an increase in quantity and in reduced width of capillary canals, proving the material’s erosion resistance. Compressive and shear strength and modules of elasticity and rigidity present advantages in terms of earthquake resistance.
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Spalling Examining the structure before working will also help establish the strength and permeability of the original mortar in order to match the new. It helps to establish what the original components of the old mortar are in order to find the best match. It is essential that the mortar used for repointing have similar performance characteristics to the original mortar used in a building. Such performance characteristics include permeability, compressive strength, and coefficient of thermal expansion.
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Armaignac claimed that his method produced a perfectly round pupil in one sitting. Other physicians, such as Victor Morax, did not tattoo the cornea, but changed its appearance using other methods. Morax split the corneal tissue into two vertical layers, introducing the coloring substance under the pedicle flap and placing a compressive dressing over the eye. Various methods have been introduced throughout history, collectively evolving into several mainstream methods that have proven to be the most effective to date.
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Micro-reinforced ultra-high-performance concrete is the next generation of UHPC. In addition to high compressive strength, durability and abrasion resistance of UHPC, micro-reinforced UHPC is characterized by extreme ductility, energy absorption and resistance to chemicals, water and temperature. Press release from Ducon GMBH, Mörfelden-Walldorf, Germany The continuous, multi-layered, three dimensional micro-steel mesh exceeds UHPC in durability, ductility and strength. The performance of the discontinuous and scattered fibers in UHPC is relatively unpredictable.
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Columns at the Airavatesvara Temple, India Compression members are structural elements that are pushed together or carry a load, more technically they are subjected only to axial compressive forces. That is, the loads are applied on the longitudinal axis through the centroid of the member cross section, and the load over the cross sectional area gives the stress on the compressed member. In buildings, posts and columns are almost always compression members as are the top chord of trusses.
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In the United States acetabular labrum tears usually occur in the anterior or anterior-superior area, possibly due to a sudden change from labrum to acetabular cartilage. The most common labrum tears in Japan are in the posterior region, likely due to the customary practice of sitting on the floor. Posterior labrum tears in the Western world usually occur when a force drives the femoral head posteriorly which transfers shear and compressive forces to the posterior labrum.
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The TFC is an articular discus that lies on the pole of the distal ulna. It has a triangular shape and a biconcave body; the periphery is thicker than its center. The central portion of the TFC is thin and consists of chondroid fibrocartilage; this type of tissue is often seen in structures that can bear compressive loads. This central area is often so thin that it is translucent and in some cases it is even absent.
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In a natural environment, this occurs when rapid sediment compaction, thermal fluid expansion, or fluid injection causes the pore fluid pressure, σp, to exceed the pressure of the least principal normal stress, σn. When this occurs, a tensile fracture opens perpendicular to the plane of least stress.[4] Tensile fracturing may also be induced by applied compressive loads, σn, along an axis such as in a Brazilian disk test. This applied compression force results in longitudinal splitting.
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The reason of asymmetric folding will be discussed in the later part. Besides, a large number of recumbent folds trending N-S can be found on Zigui Basin and Dangyang Basin, they extrude to the west and to the east respectively. During Late Jurassic to Early Cretaceous, there was a compressive environment causing the uplift of Huangling massif and folding in Huangling Complex. The exhumation of Huangling massif and formation of recumbent folds plus vertical crustal shortening occurred at the same time.
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This is one reason why ductile host materials, rather than brittle, are needed. To form a close-fitting thread that will not be loose afterwards, roll-forming requires a lobed tool rather than a constant diameter cylindrical tool. This is particularly the case when the tool and the fastener are the same, such as for a screw. A lobed or polygonal form allows residual compressive stresses from the forming parts of the thread to be relieved in the undercut clearance between the lobes.
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Richie Duncan of Kodama Zomes, based in southern Oregon has invented a structural system based on a hanging zome geometry, suspended from an overhead anchor point. Constructed of metal compressive elements and webbing tensile elements, the structures are able to be assembled and disassembled. This suspended zome system has been used in furniture, performing arts, and treehouse applications. Yann Lipnick of Zomadic Concepts in France has an extensive study of, and multiple project construction of zomes in many different materials.
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Each ring consists of nine segments that had an average 28 day cylinder compressive strength of 70 MPa and can resist at least 127 years as a service life against subsea conditions. Only 0.3% of produced segments were found to be deficient due to existence of cracks width more than 0.2 mm. On the other hand, twin tunnels (each has approximately 950 m length) were completed in 445 calendar days with a cross section of each by classical mining method.
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By modelling of dislocations and their stress fields as either a positive (compressive field) or negative (tensile field) charges we can understand how dislocations interact with each other in the lattice. If two like fields come in contact with one another they will be repelled by one another. On the other hand, if two opposing charges come into contact with one another they will be attracted to one another. These two interactions will both strengthen the material in different ways.
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The crowd in the Leppings Lane Stand overspilled onto the pitch, where the many injured and traumatised fans who had climbed to safety congregated. Football players from both teams were ushered to their respective dressing rooms, and told that there would be a 30-minute postponement. Those still trapped in the pens were packed so tightly that many victims died of compressive asphyxia while standing. Meanwhile, on the pitch, police, stewards and members of the St John Ambulance service were overwhelmed.
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Kadamba yields a pulp of satisfactory brightness and performance as a hand sheet. The wood can be easily impregnated with synthetic resins to increase its density and compressive strength. The wood has a density of 290–560 kg/cu m at 15% moisture content, a fine to medium texture; straight grain; low luster and has no characteristic odor or taste. It is easy to work, with hand and machine tools, cuts cleanly, gives a very good surface and is easy to nail.
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Execution is achieved by first crossing the ankles, grasping the heel of one foot and pulling that foot into the opposite knee, this creates the signature “4” shape for which the figure- four gets its name. As a secondary effect, it creates a significant amount of pressure against the ribs of the practitioner's opponent, hindering normal breathing and perpetuating swift fatigue. If executed with enough force, the resulting trauma to the ribcage can be substantial, in some cases even causing compressive asphyxia.
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Coverage effect of surface stress without surface reconstruction usually result a compressive stress (assuming clean surface as reference or zero stress). Induced surface stress of number of different coverages on Ni(100) and Pt(111) surface is shown in figure 4. In all cases, it shows an initially linear increase of the induced stress with coverage, followed by an increase larger than linear at higher coverages. The non-linear increase is first thought to be due to the repulsive interaction between adsorbates.
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The Kuqa Basin is bounded by the Tarim Basin to the south and the Tian Shan orogenic belt to the north. The Kuqa depression was probably part of the north Tarim continental margin at the Paleozoic time. Under compressive tectonic loading and gravitational loading, the Kuqa depression became an intra-continental foreland basin. The cross-section of the basin is asymmetric and its depositional center lies close to the Tian Shan orogenic belt, the sediment thickness thins towards the Tarim craton.
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The annealing process took much longer than it did for plate glass, often lasting three to five days. This left the glass very strong, with a compressive strength about 40 percent greater than marble. If the product was to be affixed to another surface (such as the exterior of a building), one side of the slab was grooved before the glass hardened. The exposed side(s) of the material was flame polished, which left the product highly reflective and brilliant.
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However, nerve conduction studies are helpful in confirming the diagnosis, quantifying the severity, and ruling out involvement of other nerves (suggesting a mononeuritis multiplex or polyneuropathy). A scan is not usually necessary, but may be helpful if a tumour or other local compressive lesion is suspected. Nerve injury, as a mononeuropathy, may cause similar symptoms to compression neuropathy. This may occasionally cause diagnostic confusion, particularly if the patient does not remember the injury and there are no obvious physical signs to suggest it.
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Sutured wound on the teats of a cow Bite wounds from other animals (and rarely humans) are a common occurrence. Wounds from objects that the animal may step on or run into are also common. Usually these wounds are simple lacerations that can be easily cleaned and sutured, sometimes using a local anesthetic. Bite wounds, however, involve compressive and tensile forces in addition to shearing forces, and can cause separation of the skin from the underlying tissue and avulsion of underlying muscles.
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During the 1920s concrete gained popularity as a material for bridge construction since it was cheaper than stone yet similar in its compressive strength. Designers of the new Anoka–Champlin Bridge used an arch form and encased steel to compensate for concrete's low tensile strength. Since it did not require painting, as steel did, the bridge was considered relatively low maintenance. Construction workers built the Anoka–Champlin Bridge's concrete arches using falsework—scaffolds and wooden forms used to pour concrete.
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The gap was formed by the development of three major structural features: the Pine Mountain Thrust Sheet, the Middlesboro Syncline, and the Rocky Face Fault. Lateral compressive forces of sedimentary rocks from deep layers of the Earth's crust pushing upward 320 to 200 million years ago created the thrust sheet. Resistance on the fault from the opposing Cumberland Mountain to Pine Mountain caused the U-shaped structure of the Middlesboro Syncline. The once flat-lying sedimentary rocks were deformed roughly 40 degrees northwest.
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The AFZ has gone through periods of inactivity and reactivation since its inception in the Cretaceous. The fault series was formed through a complex series of tectonic regimes dating back to the Early Jurassic, when the Andean back-arc basin separated from the Pacific Ocean. Intra-arc ductile deformation occurred in the Late Jurassic, creating north-striking mylonitic shear zones. A belt formed through a compressive regime in the early Cretaceous, followed by a compression of the Andean basement in the mid-Cretaceous.
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The strength of polymer chains can be enhanced by cross-linking, which increases the interactions between chains through bonding with another reactant. The high mechanical strength of soil/polymer mixtures after cross- linking can make many polymers more suited for soil stabilization projects. Curing time after polymer addition can also affect the strength of the polymer-soil structures formed. After seven days of curing, the liquid polymer SS299 resulted in soil with two times the compressive strength of untreated soil.
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The compressive strength of the concrete for both the reaction wall and the strong floor is 350 kg/cm2 During experiments, full-scale and large-scale constructions are mounted onto the strong floor. Hydraulic actuators then exert forces on the test objects, making it possible to see the resistance of various structures and performances of seismic isolators and energy dissipaters. The experimental data has helped proved that seismic theories can be applied, and are a reference to earthquake resistant building designs.
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He has been a PI or a Co-PI on more than $28 Million of funded research from the NSF, DOD, SRC, and the industry. Massoud has published more than 300 papers in leading peer-reviewed journals and conference publications. Hit research include machine learning, autonomous vehicles, healthcare systems, smart cities, intelligent transportation systems, and smart and embedded systems. Massoud's research group at Rice University [7][8][9] was responsible for developing the world’s first realization of compressive sensing systems for signals.
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Boudinaged quartz vein (with strain fringe) showing sinistral shear sense, Starlight Pit, Fortnum Gold Mine, Western Australia In geology, shear is the response of a rock to deformation usually by compressive stress and forms particular textures. Shear can be homogeneous or non-homogeneous, and may be pure shear or simple shear. Study of geological shear is related to the study of structural geology, rock microstructure or rock texture and fault mechanics. The process of shearing occurs within brittle, brittle-ductile, and ductile rocks.
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There are over 60 variants of Bloom filters, many surveys of the field, and a continuing churn of applications (see e.g., Luo, et al ). Some of the variants differ sufficiently from the original proposal to be breaches from or forks of the original data structure and its philosophy. A treatment which unifies Bloom filters with other work on random projections, compressive sensing, and locality sensitive hashing remains to be done (though see Dasgupta, et al for one attempt inspired by neuroscience).
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Dr. Jordaan is a Fellow of the Royal Society of Canada. He was awarded the Horst Leipholz Medal in 1999 for his contributions to mechanics for his work on compressive ice failure, the P.L. Pratley Award in 2001 and the Casimir Gzowski Award in 2018, all from the Canadian Society for Civil Engineering. The ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering held a special symposium in honour of Dr. Jordaan for his contributions to ice engineering.
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Hearst Mining building (stone, left) with expansion (shot peened aluminum alloy, right). Peening is the process of working a metal's surface to improve its material properties, usually by mechanical means, such as hammer blows, by blasting with shot (shot peening) or blasts of light beams with laser peening. Peening is normally a cold work process, with laser peening being a notable exception. It tends to expand the surface of the cold metal, thereby inducing compressive stresses or relieving tensile stresses already present.
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The ball is loaded at a normal state to the surface of a component with a hydraulic cylinder that is in the body of the tool. LPB can be performed in conjunction with chip forming machining operations in the same CNC machining tool. The ball rolls across the surface of a component in a pattern defined in the CNC code, as in any machining operation. The tool path and normal pressure applied are designed to create a distribution of compressive residual stress.
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Since then, most aircraft structures have been specified in alloys of this type. The first aircraft designed in 7075-T6 was the Navy’s P2V patrol bomber. A higher-strength alloy in the same series, 7178-T6 (78,000-psi yield strength), was developed in 1951; it has not generally displaced 7075-T6, which has superior fracture toughness. Alloy 7178-T6 is used primarily in structural members where performance is critical under compressive loading. Alloy 7079-T6 was introduced in the United States in 1954.
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There are three structural zones in articular cartilage including a superficial tangential zone, a middle transitional zone and a deep zone. In the tangential zone, collagen fibers are aligned parallel to the surface and become gradually randomly aligned while moving into the deep zone. Collagen fibers in the superficial zone are aligned parallel to the surface in order to restrict shear stresses. Similarly, collagen fibers are aligned perpendicular to the surface in the deep zone in order to restrict compressive forces.
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Among common computational imaging techniques are lensless imaging, computational speckle imaging,Katz et al., "Non-invasive single-shot imaging through scattering layers and around corners via speckle correlations", Nature Photonics 8, 784–790 (2014) ptychography and Fourier ptychography. Computational imaging technique often draws on compressive sensing or phase retrieval techniques, where the angular spectrum of the object is being reconstructed. Other techniques are related to the field of computational imaging, such as digital holography, computer vision and inverse problems such as tomography.
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During its manufacture, the glass is toughened by ion exchange. The material is immersed in a molten alkaline potassium salt at a temperature of approximately , wherein smaller sodium ions in the glass are replaced by larger potassium ions from the salt bath. The larger ions occupy more volume and thereby create a surface layer of high residual compressive stress, giving the glass surface increased strength, ability to contain flaws, and overall crack-resistance,. making it resistant to damage from everyday use.
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The builders can make an adobe chimney by stacking simple adobe bricks in a similar fashion as the surrounding walls. In 1927, the Uniform Building Code (UBC) was adopted in the United States. Local ordinances, referencing the UBC added requirements to building with adobe. These included: restriction of building height of adobe structures to 1-story, requirements for adobe mix (compressive and shear strength) and new requirements which stated that every building shall be designed to withstand seismic activity, specifically lateral forces.
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To improve the fatigue strength, a radius is often rolled at the ends of each main and crankpin bearing. The radius itself reduces the stress in these critical areas, but since the radius in most cases is rolled, this also leaves some compressive residual stress in the surface, which prevents cracks from forming. Microfinishing is a grinding process to produce a smooth finish on the surface of a metallic object, which is also used to prevent cracks developing from fatigue stress.
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This helps in early detection of the symptoms in patients with Guillain–Barré syndrome. It is also used in the diagnosis of diabetic thoraco abdominal neuropathy. The second technique involves stimulating the intercostal nerves to study the somatosensory evoked potentials, for localizing the non compressive spinal cord lesions. Pradhan was successful in elucidating the mechanisms of neurophysiological F‑response generation in healthy and diseased bodies and discovered a phenomenon, F-response multiplicity, a symptom of the lower motor neuron disorder.
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For actuator applications, maximum rotation of magnetic moments leads to the highest possible magnetostriction output. This can be achieved by processing techniques such as stress annealing and field annealing. However, mechanical pre-stresses can also be applied to thin sheets to induce alignment perpendicular to actuation as long as the stress is below the buckling limit. For example, it has been demonstrated that applied compressive pre-stress of up to ~50 MPa can result in an increase of magnetostriction by ~90%.
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The largest cytoskeletal structure of the three types of polymers is the microtubules with a diameter of 25 nm. Unlike actin filaments, microtubules are stiff, hollow structures that radiate outwards from the microtubule organizing center (MTOC). Composed of tubulin proteins, microtubules are dynamic structures that allows them to shrink or grow with the addition or removal of tubulin proteins. In terms of cell mechanics, microtubules’ main purpose is to resist compressive cellular forces and act as a transportation system for motor proteins.
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Hempcrete has been used in France since the early 1990s to construct non-weight bearing insulating infill walls, as hempcrete does not have the requisite strength for constructing foundation and is instead supported by the frame. Hempcrete was also used to renovate old buildings made of stone or lime. France continues to be an avid user of hempcrete, and it grows in popularity there annually. The typical compressive strength is around 1 MPa, around 5% that of residential grade concrete.
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The interior and lower line or curve of an arch is known as the intrados. Old arches sometimes need reinforcement due to decay of the keystones, forming what is known as bald arch. In reinforced concrete construction, the principle of the arch is used so as to benefit from the concrete's strength in resisting compressive stress. Where any other form of stress is raised, such as tensile or torsional stress, it has to be resisted by carefully placed reinforcement rods or fibres.
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For FRP-reinforced concrete, aesthetics and possibly water-tightness will be the limiting criteria for crack width control. FRP rods also have relatively lower compressive strengths than steel rebar, and accordingly require different design approaches for reinforced concrete columns. One drawback to the use of FRP reinforcement is their limited fire resistance. Where fire safety is a consideration, structures employing FRP have to maintain their strength and the anchoring of the forces at temperatures to be expected in the event of fire.
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One of the advantages about using mycelium based composites is that properties can be altered depending on fabrication process and the use of different fungus. Properties depend on type of fungus used and where they are grown. Additionally, fungi has an ability to degrade the cellulose component of the plant to make composites in a preferable manner. Some important mechanical properties such as compressive strength, morphology, tensile strength, hydrophobicity, and flexural strength can be modified as well for different use of the composite.
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"Whatever Floats Your Boat, Clemson Student Chapter of the American Society of Civil Engineers" . ces.clemson.edu Microballoons give syntactic foam its light weight, low thermal conductivity, and a resistance to compressive stress that far exceeds that of other foams.Common Microballoons have a density of 0.15 to 0.20 g/cm3, with an isostatic crush strength of 300 to 500 psi. Denser, high strength forms offer 0.38 g/cm3 with 5500 psi strength, and 0.6 g/cm3 (still offering considerable flotation) with 18,000 psi crush pressure.
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A modern universal testing machine Test fixture for three point flex test A universal testing machine (UTM), also known as a universal tester, materials testing machine or materials test frame, is used to test the tensile strength and compressive strength of materials. An earlier name for a tensile testing machine is a tensometer. The "universal" part of the name reflects that it can perform many standard tensile and compression tests on materials, components, and structures (in other words, that it is versatile).
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While bulk synthesis of such nanoparticles as carbon nanotubes is currently too expensive for widespread use, some less extreme nanostructured materials can be synthesized by traditional methods, including electrospinning and spray pyrolysis. One important aggregate made by spray pyrolysis is glass microspheres. Often called microballoons, they consist of a hollow shell several tens of nanometers thick and approximately one micrometer in diameter. Casting them in a polymer matrix yields syntactic foam, with extremely high compressive strength for its low density.
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Ericson's Test“Median Nerve Entrapments,” Ericson WB, Singh V, in “Peripheral Nerve Entrapments: Clinical Diagnosis and Management,” Trescot AM, Editor. Springer, April 2016, p369-382“Management of Compressive Neuropathies of the Upper Extremity,” Kalliainen LK, Ericson WB, in “Grabb and Smith’s Plastic Surgery, 8th Edition”, Chung K et al editors, Lippincott Williams & Wilkins, 2018. Chapter 70. is a clinical maneuver for assessing the strength of the FDP and FPL muscles in anterior interosseous nerve syndrome, and other proximal entrapments of the median nerve.
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Concrete is a mixture of cement and aggregate, giving a robust, strong material that is very widely used. Plywood is used widely in construction Composite sandwich structure panel used for testing at NASA Concrete is the most common artificial composite material of all and typically consists of loose stones (aggregate) held with a matrix of cement. Concrete is an inexpensive material, and will not compress or shatter even under quite a large compressive force. However, concrete cannot survive tensile loading (i.e.
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Topology is relevant to physics in areas such as condensed matter physics, quantum field theory and physical cosmology. The topological dependence of mechanical properties in solids is of interest in disciplines of mechanical engineering and materials science. Electrical and mechanical properties depend on the arrangement and network structures of molecules and elementary units in materials. The compressive strength of crumpled topologies is studied in attempts to understand the high strength to weight of such structures that are mostly empty space.
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Wrapping around sections (such as bridge or building columns) can also enhance the ductility of the section, greatly increasing the resistance to collapse under earthquake loading. Such 'seismic retrofit' is the major application in earthquake-prone areas, since it is much more economic than alternative methods. If a column is circular (or nearly so) an increase in axial capacity is also achieved by wrapping. In this application, the confinement of the CFRP wrap enhances the compressive strength of the concrete.
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Michel Soto Chalhoub is a civil engineer who pioneered modern practice in shock, vibration, and seismic design using energy dissipating devices [ref]. He developed his methodologies while at the University of California, Berkeley, where he earned his Ph.D. in dynamics and seismic design.University of California, Berkeley. "Theoretical and Experimental Studies of Earthquake Isolation and Fluid Containers - Berkeley Press 1987", Berkeley Press 1987, CA.14th World Conference on Earthquake Engineering."Compressive and Bending Behavior of Fiber-Reinforced Elastomeric Bearings - Beijing, China, 2008".
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This unit has a complex history of deposition; it was reworked in place and probably includes brecciated plutonic rocks and possibly ancient volcanic flows. Deposition of the intercrater plains material was waning as the next oldest basins (Dostoevskij, Tolstoj) were formed. Partly overlapping their formation was the deposition of the intermediate plains material, probably emplaced partly as distal basin ejecta and partly as volcanic flows. Regional deformation of these plains units by compressive tectonics, forming scarps, was contemporaneous with their deposition.
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This is critical because maximum stresses are typically at the surface of the material. Mitigation of these lower surface stresses can be accomplished by a multi-stage post process with varied shot diameters and other surface treatments that remove the low residual stress layer. The compressive residual stress in a metal alloy is produced by the transfer of kinetic energy (K.E.) from a moving mass (shot particle or ball peen) into the surface of a material with the capacity to plastically deform.
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The ultimate strength of concrete is influenced by the water-cementitious ratio (w/cm), the design constituents, and the mixing, placement and curing methods employed. All things being equal, concrete with a lower water-cement (cementitious) ratio makes a stronger concrete than that with a higher ratio. The total quantity of cementitious materials (portland cement, slag cement, pozzolans) can affect strength, water demand, shrinkage, abrasion resistance and density. All concrete will crack independent of whether or not it has sufficient compressive strength.
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Concrete has relatively high compressive strength, but significantly lower tensile strength. As a result, without compensating, concrete would almost always fail from tensile stresses (Stress (mechanics)#Mohr's circle) even when loaded in compression. The practical implication of this is that concrete elements subjected to tensile stresses must be reinforced with materials that are strong in tension (often steel). The elasticity of concrete is relatively constant at low stress levels but starts decreasing at higher stress levels as matrix cracking develops.
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But the main advantage is the speed of response, there are few other effects able to control such large amounts of mechanical or hydraulic power so rapidly. Unfortunately, the increase in apparent viscosity experienced by most Electrorheological fluids used in shear or flow modes is relatively limited. The ER fluid changes from a Newtonian liquid to a partially crystalline "semi-hard slush". However, an almost complete liquid to solid phase change can be obtained when the electrorheological fluid additionally experiences compressive stress.
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For instance, core materials have limited compressive strength at elevated temperatures; even a small over-pressure can collapse the coreThis can be foam or honeycomb, generally, both of which are weakened by exposure to curing temperatures. and ruin the workload. In a poorly designed autoclave, oscillation of the pressure can result in chattering of the inlet and outlet valves. One means of preventing this is utilizing large valves for filling and dumping and small valves for trimming at and near the setpoint.
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At this time, the sediments were marine or showed the influence of the sea, as shown in the deposits of the Higuerueles and Villar del Arzobispo Formations in the Galve Sub-basin. Finally, during the Early Cretaceous and Oligocene–Miocene there were compressive phases with tectonic inversion and formation of continental basins.Sánchez Hernández & Benton, 2014, p.582 Camarillas Formation, in beds of similar age to the La Maca outcrop in the Galve area where the remains of an iguanodontid dinosaur have been found.
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These potassium ions are larger than the sodium ions and therefore wedge into the gaps left by the smaller sodium ions when they migrate to the potassium nitrate solution. This replacement of ions causes the surface of the glass to be in a state of compression and the core in compensating tension. The surface compression of chemically strengthened glass may reach up to 690 MPa. The strengthening mechanism depends on the fact that the compressive strength of glass is significantly higher than its tensile strength.
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Each wedge-shaped voussoir turns aside the thrust of the mass above, transferring it from stone to stone to the springer's bottom face ("impost"), which is horizontal and passes the thrust on to the supports. Voussoir arches distribute weight efficiently, and take maximum advantage of the compressive strength of stone, as in an arch bridge. The outer boundary of a voussoir is referred to as an extrados. In Visigothic and Moorish architectural traditions, the voussoirs are often in alternating colours, usually red and white.
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In the Early Mesozoic, as the South China Craton subducted beneath the North China Craton, the accumulation of continental material facilitates orogenic belt forming at the collision area. Examples include the Qinling-Tongbai-Dabie belt, Longmenshan thrust belt and Indochina belt. The Xuefengshan-Jiuling belt lying in the middle of the South China Craton also formed due to the compressive force. Huangling massif was quite stable because its location in the middle of South China Craton was shielded from the uplift orogenic events at the rim.
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This meant that the Thin Man bomb design that the laboratory had developed would not work properly. The Laboratory turned to an alternative, albeit more technically difficult, design, an implosion-type nuclear weapon. In September 1943, mathematician John von Neumann had proposed a design in which a fissile core would be surrounded by two different high explosives that produced shock waves of different speeds. Alternating the faster- and slower-burning explosives in a carefully calculated configuration would produce a compressive wave upon their simultaneous detonation.
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The intervertebral disc functions to separate the vertebrae from each other and provides the surface for the shock-absorbing gel of the nucleus pulposus. The nucleus pulposus of the disc functions to distribute hydraulic pressure in all directions within each intervertebral disc under compressive loads. The nucleus pulposus consists of large vacuolated notochord cells, small chondrocyte-like cells, collagen fibrils, and aggrecan, a proteoglycan that aggregates by binding to hyaluronan. Attached to each aggrecan molecule are glycosaminoglycan (GAG) chains of chondroitin sulfate and keratan sulfate.
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They shelter a large ovoid cavity that represents "a passage, a marker, and an aperture that reframes the site". The void represents the absence of the slain officer, and is shaped like an oblong stone from a memorial cairn which had been constructed at trailside by Collier's friends from MITOC. The design was carefully evaluated by John Ochsendorf and his students using computer simulation to study its resistance to a major earthquake. Compressive forces on each block were calculated to be in the range of .
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The plate can withstand compressive loads from the metatarsal head because of the orientation of the fibers in its fibrocartilage. The skeleton of the foot rests on a multi- layered ligamentous system of beams and trusses that responds to weight- bearing on irregular surfaces. A transverse system at the MTP joints is formed by the plantar plates and the deep transverse metatarsal ligament. The strong, longitudinal fibres of the deep plantar fascia are inserted along this transverse system to form a strong longitudinal system.
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In addition, because the tendon is a multi-stranded structure made up of many partially independent fibrils and fascicles, it does not behave as a single rod, and this property also contributes to its flexibility. The proteoglycan components of tendons also are important to the mechanical properties. While the collagen fibrils allow tendons to resist tensile stress, the proteoglycans allow them to resist compressive stress. These molecules are very hydrophilic, meaning that they can absorb a large amount of water and therefore have a high swelling ratio.
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An issue with the T-beam compared to the I-beam is the lack of the bottom flange. In addition, this makes the beam not as versatile because of the weaker side not having the flange making it have less tensile strength. Concrete beams are often poured integrally with the slab, forming a much stronger –shaped beam. These beams are very efficient because the slab portion carries the compressive loads and the reinforcing bars placed at the bottom of the stem carry the tension.
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Tuffeau has a very low density compared with many other rocks, being half as dense as granite, comparable in density with ebony, and only about 10 to 20% heavier than water. It has porosity of up to 50%, whereas that of granite is only about 1%. The compressive strength of the stone is a factor of 10 to 20 times less than that of granite. When mixed with local sand and flinty clays from later eras, tuffeau is said to create the best vineyards soils.
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Vasography was first described by Belfield in 1913, where a vasotomy was initially done and the vas deferens was subsequently intubated. After almost 40 years of being overlooked, Boreau revived the procedure in the 1950s. Then, vasography was somewhat overused for various fertility disorders and other diseases such as tuberculosis, prostate cancer, hemospermia, and compressive fibrolipomatosis, without considering the possible risks and complications from the procedure. Today, vasography is used to determine the location of obstruction in azoospermic patients who have demonstrated spermatogenesis by testis biopsy.
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The Statnamic load test is a type of test for assessing the load-carrying capacity of deep foundations which is faster and less expensive than the static load test. The Statnamic test was conceived in 1985, with the first prototype tests carried out in 1988 through collaboration between Berminghammer Foundation Equipment of Canada and TNO Building Research of the Netherlands (Middendorp et al., 1992 & Middendorp, 2000). Guidance on rapid load pile testing can be found in: Methods for Axial Compressive Force Pulse (Rapid) Testing of Deep Foundations.
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Residual stress in a roll-formed hollow structural section causes it to gape when cut with a band-saw. Residual stresses are stresses that remain in a solid material after the original cause of the stresses has been removed. Residual stress may be desirable or undesirable. For example, laser peening imparts deep beneficial compressive residual stresses into metal components such as turbine engine fan blades, and it is used in toughened glass to allow for large, thin, crack- and scratch-resistant glass displays on smartphones.
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On 1 December 1955, Voima was transferred back to the Finnish Maritime Administration.Uusi Suomi, 11 February 1954. s. 10. Voima breaking ice shortly after delivery Although the commissioning of the new icebreaker did not go as planned, Voima still brought a long-awaited relief to the Finnish winter navigation. During the extremely difficult winter of 1956, she broke all previous records by escorting or otherwise assisting 616 icebound ships, among them the steam-powered icebreakers Sampo and Tarmo that had been immobilized by compressive pack ice.
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Typical seismogram. The compressive P-waves (following the red lines) – essentially sound passing through rock – are the fastest seismic waves, and arrive first, typically in about 10 seconds for an earthquake around 50 km away. The sideways-shaking S-waves (following the green lines) arrive some seconds later, traveling a little over half the speed of the P-waves; the delay is a direct indication of the distance to the quake. S-waves may take an hour to reach a point 1000 km away.
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In order to obtain a suitable reactivity, the obtained fragments are ground to reach the same fineness as Portland cement. The main components of blast furnace slag are CaO (30-50%), SiO2 (28-38%), Al2O3 (8-24%), and MgO (1-18%). In general increasing the CaO content of the slag results in raised slag basicity and an increase in compressive strength. The MgO and Al2O3 content show the same trend up to respectively 10-12% and 14%, beyond which no further improvement can be obtained.
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Compressive forces detached sedimentary units across western Utah and Nevada from their Precambrian basement rocks and pushed them eastward. The weight of the resulting high mountain range that formed to the west, lowered much of Utah and allowed the sea to invade. This grew into a vast sea that periodically divided North America in the Cretaceous called the Western Interior Seaway. Non-marine sediments of the approximately 100- to 94-million-year-old Dakota Sandstone were deposited on the shore of this seaway early in the Cretaceous.
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Elsewhere these formations have a combined thickness of over 9,000 feet (2,740 m). The Flagstaff is a white-colored, fossil rich layer that is composed of limestone, tufa and conglomerate that erodes into ledges and slopes. Compressive forces caused by the Laramide orogeny were followed by some minor stretching as a new equilibrium was established. This created weaknesses in the crust that allowed magma to intrude toward the surface to create composite volcanos west of the area some 25 to 20 million years ago.
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Fuller's geometric explorations provided an experiential basis for designing and refining a philosophical language. His overarching concern was the co-occurring relationship between tensile and compressive tendencies within an eternally regenerative Universe. "Universe" is a proper name he defined in terms of "partially overlapping scenarios" while avoiding any static picture or model of same. His Universe was "non-simultaneously conceptual": > Because of the fundamental nonsimultaneity of universal structuring, a > single, simultaneous, static model of Universe is inherently both > nonexistent and conceptually impossible as well as unnecessary.
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Cast iron is not a good structural material for handling tension or bending moments because of its brittleness and relatively low tensile strength compared to steel and wrought iron. Cast iron has good compressive strength and was successfully used for structural components that were largely in compression in well designed bridges and buildings. In a few instances bridges and buildings built with cast iron failed when misused. Cast iron was used as early as the 9th century in pagoda construction in Tang Dynasty China.
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19, 2009, Article acknowledges traffic engineer John J. Fruin and G. Keith Still of Crowd Dynamics Ltd. In a crowd crush, people are subjected to compressive forces by being pushed from all sides (or against a barrier such as a wall) with nowhere to move into. In a progressive crowd collapse one person falls, creating a space in the crowd into which others fall, creating an even larger hole. Those who have fallen are squashed by the weight of many people on top of them (vertical stacking).
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At heightened temperatures, the hydration process moves more rapidly and the formation of the Calcium Silicate Hydrate crystals is more rapid. The formation of the gel and colloid is more rapid and the rate of diffusion of the gel is also higher. However, the reaction being more rapid leaves lesser time for the hydration products to arrange suitably, hence the later age strength or the final compressive strength attained is lower in comparison to normally cured concrete. This has been termed as the crossover effect.
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These abutments can be made from a variety of materials, such as titanium, surgical stainless steel and gold. The adjacent images show how a ceramic abutment can enhance a ceramic crown by giving it a more lifelike appearance. Ceramic abutments have to be used with care, however, since their compressive strength is nowhere near that of titanium, gold or other noble metals. Most clinicians feel more comfortable using a metal prosthetic abutment in the posterior molar areas, due to the increased masticatory forces present in these areas.
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The universal expansion joint can absorb not only axial movements but angular and lateral movements as well. It consists of two metal bellows with an intermediate pipe and connectors on both sides. As a special form of the axial expansion joint, the universal expansion joint has only a limited pressure resistance for stability reasons and, moreover, loads the adjacent pipe supports with the axial compressive force resulting from the internal pressure. It is usually used to compensate large axial and lateral movements at low pressure.
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Magnesium wrought alloy proof stress is typically 160-240 MPa, tensile strength is 180-440 MPa and elongation is 7-40%. The most common wrought alloys are: : AZ31 : AZ61 : AZ80 : Elektron 675 : ZK60 : M1A : HK31 : HM21 : ZE41 : ZC71 ZM21 AM40 AM50 AM60 K1A M1 ZK10 ZK20 ZK30 ZK40 Wrought magnesium alloys have a special feature. Their compressive proof strength is smaller than tensile proof strength. After forming, wrought magnesium alloys have a stringy texture in the deformation direction, which increases the tensile proof strength.
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The rift system may have been the result of extensional forces behind the continental collision of the Grenville Orogeny to the east which in part overlaps the timing of the rift development. Later compressive forces from the Grenville Orogeny likely played a major role in the rift's failure and closure. Had the rifting process continued, the eventual result would have been sundering of the North American craton and creation of a sea. The Midcontinent Rift appears to have progressed almost to the point where the ocean intruded.
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Flat arch construction grew in popularity with the increasing number of buildings using steel and iron structural members in their design. New building code requirements for fireproofing aided in the use and proliferation of structural clay tile in skyscrapers and other large buildings. After 1910, manufactures began to test and develop stronger and more complex structural clay tile systems that worked better in compression. Greater compressive strength, found largely in the invention of the end pressure arch, allowed the material to be used in longer floor spans.
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It is essential that each structural component be designed and tested to withstand both the tensile and compressive loads that the member will be subjected to over its lifespan. Expanded polystyrene cores are now in precast concrete panels for structural use, making them lighter and serving as thermal insulation. Multi-storey car parks are commonly constructed using precast concrete. The constructions involve putting together precast parking parts which are multi-storey structural wall panels, interior and exterior columns, structural floors, girders, wall panels, stairs, and slabs.
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As the elastic modulus of material increases fracture resistance decreases. It is desirable that the biomaterial elastic modulus is similar to bone. This is because if it is more than bone elastic modulus then load is born by material only; while the load is bear by bone only if it is less than bone material. The Elastic modulus of a material is generally calculated by bending test because deflection can be easily measured in this case as compared to very small elongation in compressive or tensile load.
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The disc cutters create compressive stress fractures in the rock, causing it to chip away from the tunnel face. The excavated rock (muck) is transferred through openings in the cutter head to a belt conveyor, where it runs through the machine to a system of conveyors or muck cars for removal from the tunnel. Open-type TBMs have no shield, leaving the area behind the cutter head open for rock support. To advance, the machine uses a gripper system that pushes against the tunnel walls.
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The diagnosis of toxic or nutritional optic neuropathy is usually established by a detailed medical history and careful eye examination. If the medical history clearly points to a cause, neuroimaging to rule out a compressive or infiltrative lesion is optional. However, if the medical history is atypical or does not clearly point to a cause, neuroimaging is required to rule out other causes and confirm the diagnosis. In most cases of suspected toxic or nutritional optic neuropathy that require neuroimaging, an MRI scan is obtained.
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As with natural bone, the primary issue with bone scaffolds is brittle failure. They typically follow linear elastic behavior, and under compressive forces experiences a plateau and recovery reminiscent of cellular solids as well as trabecular bone. The elastic modulus of natural bone ranges from 10 to 20 GPa; it requires a high stiffness to withstand constant mechanical load. Bone scaffolds must therefore be as stiff as natural bone, or the scaffold will fail through crack nucleation and propagation before the host tissue can regenerate.
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He developed this in several ways, from the close-packing of spheres and the number of compressive or tensile members required to stabilize an object in space. One confirming result was that the strongest possible homogeneous truss is cyclically tetrahedral.Edmondson, Amy, "A Fuller Explanation", Birkhauser, Boston, 1987, p19 tetrahedra, p110 octet truss He had become a guru of the design, architecture, and 'alternative' communities, such as Drop City, the community of experimental artists to whom he awarded the 1966 "Dymaxion Award" for "poetically economic" domed living structures.
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In the figure it can be seen that the compressive loading (indicated by the arrow) has caused deformation in the cylinder so that the original shape (dashed lines) has changed (deformed) into one with bulging sides. The sides bulge because the material, although strong enough to not crack or otherwise fail, is not strong enough to support the load without change. As a result, the material is forced out laterally. Internal forces (in this case at right angles to the deformation) resist the applied load.
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The power law dependence observed agrees with trends between density and modulus and compressive strength observed in experimental studies on graphene aerogels. The macroscopic geometric structure of the aerogel has been shown both computationally and experimentally to affect mechanical properties observed. 3D printed periodic hexagonal graphene aerogel structures exhibited an order of magnitude larger modulus compared to bulk graphene aerogels of the same density when is applied along the vertical axis. The dependence of stiffness on structure is commonly observed in other cellular structures.
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Creep also explains one of several contributions to densification during metal powder sintering by hot pressing. A main aspect of densification is the shape change of the powder particles. Since this change involves permanent deformation of crystalline solids, it can be considered a plastic deformation process and thus sintering can be described as a high temperature creep process. The applied compressive stress during pressing accelerates void shrinkage rates and allows a relation between the steady-state creep power law and densification rate of the material.
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An arch extending from the top of the centrum is called a neural arch, while the haemal arch or chevron is found underneath the centrum in the caudal vertebrae of fish. The centrum of a fish is usually concave at each end (amphicoelous), which limits the motion of the fish. In contrast, the centrum of a mammal is flat at each end (acoelous), a shape that can support and distribute compressive forces. The vertebrae of lobe-finned fishes consist of three discrete bony elements.
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Electroless nickel plating also can produce coatings that are free of built-in mechanical stress, or even have compressive stress. A disadvantage is the higher cost of the chemicals, which are consumed in proportion to the mass of nickel deposited; whereas in electroplating the nickel ions are replenished by the metallic nickel anode. Automatic mechanisms may be needed to replenish those reagents during plating. The specific characteristics vary depending on the type of EN plating and nickel alloy used, which are chosen to suit the application.
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240px The pubic symphysis is a nonsynovial amphiarthrodial joint. The width of the pubic symphysis at the front is 3–5 mm greater than its width at the back. This joint is connected by fibrocartilage and may contain a fluid-filled cavity; the center is avascular, possibly due to the nature of the compressive forces passing through this joint, which may lead to harmful vascular disease. The ends of both pubic bones are covered by a thin layer of hyaline cartilage attached to the fibrocartilage.
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She used an Instron Tensile Testing machine to assess the weight, compressive strength and tensile strength of the fabrics used. As a result of her findings, a number of balloons were ruled unfit for use. Vadala also used the Instron to test laminated light weight materials to see if they were suitable for use in aircraft. Her publications include Failure mechanisms for advanced composite sandwich construction in hostile environments (1979) and Triaxially Woven Fabrics of Kevlar, Dacron Polyester and Hybrids of Kevlar and Dacron Polyester (1980).
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Construction of the boiler is unusual, as the steel tube plates are merely held in place by friction and the tubes are only lightly expanded into them with a tapered drift. Around the outside of the boiler shell are three heat-shrunk steel rings, the compressive stress of which retains the tubeplate. For additional strength, the boiler shell is further wrapped in a helical layer of piano wire. As the boiler is fired by a flat liquid-fuel burner, no enclosed firebox is required.
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Microbial induced calcium carbonate precipitation has been proposed as an alternative cementation technique to improve the properties of potentially liquefiable sand. The increase in shear strength, confined compressive strength, stiffness and liquefaction resistance was reported due to calcium carbonate precipitation resulting from microbial activity. The increase of soil strength from MICP is a result of the bonding of the grains and the increased density of the soil. Research has shown a linear relationship between the amount of carbonate precipitation and the increase in strength and porosity.
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Gas discharge provided through this process initiates the polymerization of a group of monomers. Finally, pressure-induced polymerization applies pressure or compressive forces to solutions of monomers in order to create units which undergo polymerization and produce polymers. Another method tested in a study to produce sodium polyacrylate as an alternative to current methods began with Butyl acrylate-acrylic acid copolymer and poly (butyl acrylate). They were synthesized via suspension polymerization by using butyl acrylate as the main monomer and acrylic acid as a secondary monomer.
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This led to significant changes in properties that are dominantly influenced by the matrix in CFRPs such as compressive, interlaminar shear, and impact properties. The epoxy matrix used for engine fan blades is designed to be impervious against jet fuel, lubrication, and rain water, and external paint on the composites parts is applied to minimize damage from ultraviolet light. The carbon fibers can cause galvanic corrosion when CRP parts are attached to aluminum. Carbon Fiber Reinforced Plastics are very hard to machine, and causes significant tool wear.
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At 28 days, the compressive strength was 4,180 psi / 28.8 MPa (N/mm²). The 56-day strength exceeded the requirements for 4,500 psi (31.1 MPa) concrete, even taking into account the safety margin as recommended by the American Concrete Institute.ACI 318 "Building Code Requirements for Structural Concrete and Commentary" The concrete made in this way was workable and sufficiently strong, exceeding the 75% standard of pozzolanic activity at both 7 days and 28 days. The surface smoothness of pozzolans in the concrete was also increased.
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The articulation between the second metacarpal and the capitate is considered uniquely specialized in hominids. On the second metacarpal, the facet for the capitate is directed proximally, almost perpendicular to the facet for the third metacarpal, while the corresponding facet on the capitate is oriented distally. This is to receive compressive forces generated by the pad-to-pad opposition between the thumb and the index finger. In contrast, in apes, including fossil apes such as Dryopithecus and Proconsul, these facets are oriented in a sagittal plane.
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Silver whiskers growing out of surface-mount resistors Metal whiskering is a phenomenon which occurs in electrical devices when metals form long whisker- like projections over time. Tin whiskers were noticed and documented in the vacuum tube era of electronics early in the 20th century in equipment that used pure, or almost pure, tin solder in their production. It was noticed that small metal hairs or tendrils grew between metal solder pads causing short circuits. Metal whiskers form in the presence of compressive stress.
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The most effective drugs belong to the neuroleptic variety such as monoamine-depleting drugs and dopamine receptor-blocking drugs. Of the monoamine-depleting drugs, tetrabenazine is most powerful against tics and results in fewest side effects. A non-neuroleptic drug found to be safe and effective in treating tics is topiramate. Botulinum toxin injection in affected muscles can successfully treat tics; involuntary movements and vocalizations can be reduced, as well as life-threatening tics that have the potential of causing compressive myelopathy or radiculopathy.
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A Tubing spider is a tool used primarily in the oil industry for gripping the drill string while assembling or reassembling parts of the string. The spider is normally operated hydraulically from a remote location. The spider consists of multiple gripper tools, sometimes constructed as wedge-shaped arms (Slips (oil drilling)) that holds the string by the downward force of the pipe. Teeth on the inside of the slips grip the pipe, and the resulting compressive force inward on the drill pipe holds the pipe securely.
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Because of the way that bone is formed, bone has a high compressive strength of about , poor tensile strength of 104–121 MPa, and a very low shear stress strength (51.6 MPa). This means that bone resists pushing (compressional) stress well, resist pulling (tensional) stress less well, but only poorly resists shear stress (such as due to torsional loads). While bone is essentially brittle, bone does have a significant degree of elasticity, contributed chiefly by collagen. Mechanically, bones also have a special role in hearing.
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On 3 May 2018, the Autostrade company had announced a call for tenders for a structural upgrade of the viaduct to the value of €20,159,000, with a deadline of 11 June 2018. The work on the reinforcement of the stays on pillars 9 and 10 would have needed to be finished within five years. Workers were installing new heavy concrete Jersey barriers on the Ponte Morandi before it collapsed, reducing the already low compressive pre-stress on the concrete of the stays and increasing the loads.
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Even a one- inch (25 mm) deviation from cross-sectional roundness results in over 30 percent decrease of hydrostatic load.US Naval Academy Minor deviations are resisted by the stiffener rings, and the total pressure force of several million longitudinally-oriented tons must be distributed evenly over the hull by using a hull with a circular cross section. This design is the most resistant to compressive stress and without it no material could resist water pressure at submarine depths. A submarine hull requires expensive transversal construction, with stiffener rings located more frequently than the longitudinals.
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The downward compressive force from the mast is partially carried by the crossmember and partially by a stainless steel compression post and tensioned tie rod assembly called a "dolphin striker". The H16 may be equipped with two trapeze wires either side to allow both the helm and crew to trapeze. "Cat seats" can be fitted to allow disabled sailors to sail the H16. The rudder assembly consists of a rudder on each hull fitted to a Hobie-patented automatically releasing stock comprising a casting, a cam, and a spring-loaded plunger.
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The sole is a sensory organ by which we can perceive the ground while standing and walking. The subcutaneous tissue in the sole has adapted to deal with the high local compressive forces on the heel and the ball (between the toes and the arch) by developing a system of "pressure chambers." Each chamber is composed of internal fibrofatty tissue covered by external collagen connective tissue. The septa (internal walls) of these chambers are permeated by numerous blood vessels, making the sole one of the most vascularized, or blood-enriched, regions in the human body.
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Fiber-reinforced composites (FRCs) consist of a matrix of one material containing parallel embedded fibers. There are two variants of fiber-reinforced composites, one with stiff fibers and a ductile matrix and one with ductile fibers and a stiff matrix. The former variant is exemplified by fiberglass which contains very strong but delicate glass fibers embedded in a softer plastic matrix resilient to fracture. The latter variant is found in almost all buildings as reinforced concrete with ductile, high tensile-strength steel rods embedded in brittle, high compressive-strength concrete.
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To add extra strength to the foundation, the existing soils are compacted further, Soil Improvements such as stone columns are installed, or the unsatisfactory soils are removed and a new fill soil is brought in, graded, and compacted to meet requirements. The second layer is the asphalt paving. This pavement differs from typical highway and road pavement as the loads are generally more stationary as well as much smaller in magnitude. This type of pavement contains Hydraulically Bound Materials (HBM), an ingredient used to provide higher compressive strength to the asphalt.
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For this strengthening mechanism, solute atoms of one element are added to another, resulting in either substitutional or interstitial point defects in the crystal (see Figure 1). The solute atoms cause lattice distortions that impede dislocation motion, increasing the yield stress of the material. Solute atoms have stress fields around them which can interact with those of dislocations. The presence of solute atoms impart compressive or tensile stresses to the lattice, depending on solute size, which interfere with nearby dislocations, causing the solute atoms to act as potential barriers.
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Her midship fuel stores could hold 450 tons of coal, which was fed to the fireboxes at a rate of 3–4 tons per hour by six stokers and was enough for roughly one week of sailing in ice. Like the other Finnish state-owned icebreakers, Tarmo was equipped for escort icebreaker duties with a towing winch, a cable and a stern notch. In difficult ice conditions the ship being assisted was taken into tow, and in extremely difficult compressive ice it was pulled to the icebreaker's stern notch.Laurell 1992, p. 198-200.
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Critical resolved shear stress (CRSS) is the component of shear stress, resolved in the direction of slip, necessary to initiate slip in a grain. Resolved shear stress (RSS) is the shear component of an applied tensile or compressive stress resolved along a slip plane that is other than perpendicular or parallel to the stress axis. The RSS is related to the applied stress by a geometrical factor, m, typically the Schmid factor:Schmid E., Boas W., Plasticity of Crystals with Special Reference to Metals, F.A. Hughes & Co. Ltd., 1935.
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In the western Mediterranean, the relative motions of the Eurasian and African plates produce a combination of lateral and compressive forces, concentrated in a zone known as the Azores–Gibraltar Fault Zone. Along its northeast margin, the African Plate is bounded by the Red Sea Rift where the Arabian Plate is moving away from the African Plate. The New England hotspot in the Atlantic Ocean has probably created a short line of mid- to late-Tertiary age seamounts on the African Plate but appears to be currently inactive.
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Atomic bonds farther and farther away from the dislocation centre are less and less stretched which is why the stress field dissipates as the distance from the dislocation centre increases. Each dislocation within the material has a stress field associated with it. The creation of these stress fields is a result of the material trying to dissipate mechanical energy that is being exerted on the material. By convention, these dislocations are labelled as either positive or negative depending on whether the stress field of the dislocation is mostly compressive or tensile.
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Blending of pozzolans with Portland cement is of limited interference in the conventional production process and offers the opportunity to convert waste (for example, fly ash) into durable construction materials. A reduction of 40 percent of Portland cement in the concrete mix is usually feasible when replaced with a combination of pozzolanic materials. Pozzolans can be used to control setting, increase durability, reduce cost and reduce pollution without significantly reducing the final compressive strength or other performance characteristics. The properties of hardened blended cements are strongly related to the development of the binder microstructure, i.e.
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Frost damage of early-age concrete is particularly harmful for the concrete mechanical resistance because the ice volume expansion causes micro-cracks in the concrete structures, and as a consequence it lowers the compressive strength of concrete. Therefore, when concreting at cold temperature cannot be avoided, it is essential to have a minimum curing time at a temperature sufficiently above the freezing point of the concrete pore water, so that the early strength of concrete is high enough to resist the inner tensile stress caused by water freezing.
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Further, the bridge is a significant technical accomplishment in the management of compressive and tension forces in metal truss members. Its design and innovative solution to the pressures of compression and tension is of historical significance in demonstrating the development of engineering and truss bridge technology. Completed in 1870, it replaces an earlier bridge that was opened in 1856 and destroyed in 1867. The present bridge is a metal truss bridge and is currently the fourth oldest existing Australian metal trusses, following Hawthorn (1861), Gundagai Road Bridge (1867) and Redesdale (1868).
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In general, because the ratio of the typical tie rod's length to its cross section is usually very large, it would buckle under the action of compressive forces. The working strength of a tie rod is the product of the allowable working stress and the rod's minimum cross-sectional area. If threads are cut into a cylindrical rod, that minimum area occurs at the root of the thread. Often rods are upset (made thicker at the ends) so that the tie rod does not become weaker when threads are cut into it.
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The critical diagnosis of this neoplasm is often difficult because of its similarity with other primary or secondary papillary lesions of the pineal region, including parenchymal pineal tumors, papillary ependymoma, papillary meningioma, choroid plexus papilloma, and metastatic papillary carcinoma. Papillary tumors characteristically show a discrete, compressive border with adjacent pineal gland and brain parenchyma. The nuclei tend to be regular, round-to-oval and contain stippled chromatin. The cytoplasmic and often nuclear expression of S100 protein is present in nearly all tumor cells, and vimentin typically stains tumor cell cytoplasm adjacent to vessel walls.
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36, Issue 17, 2014, pp. 1938–1948. 137\. Ahmadi Y. & Kharrat R., A Compositional Reservoir Simulation and Experimental Investigation of Asphaltene Onset Pressure, Journal of Petroleum Science and Technology, Vol. 32, Issue 18 (2014) pp. 2253–2262. 138\. Zarghertalebi M, Barati N, Kharrat R., Influences of Hydrophilic and Hydrophobic silica nanoparticles on anionic surfactant properties: Interfacial and adsorption behaviors, Journal of Petroleum Science and Engineering, Vol 119 (2014) 36-43. 139\. Farrokhrouz M., Reza Asef R., Kharrat R., Empirical estimation of uniaxal compressive strength of shale formations, GEOPHYSICS, Volume 79, Issue 4, July 2014. 140\.
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Laser peening (LP), or laser shock peening (LSP), is a surface engineering process used to impart beneficial residual stresses in materials. The deep, high magnitude compressive residual stresses induced by laser peening increase the resistance of materials to surface-related failures, such as fatigue, fretting fatigue and stress corrosion cracking. Laser shock peening can also be used to strengthen thin sections, harden surfaces, shape or straighten parts (known as laser peen forming), break up hard materials, compact powdered metals and for other applications where high pressure, short duration shock waves offer desirable processing results.
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The deep compressive stresses are due to the shock wave peak pressure being maintained above the HEL to greater depths than for other peening technologies. There may be instances where it is cost effective not to apply the opaque overlay and laser peen the bare surface of the work piece directly. When laser peening a bare, metallic surface a thin, micrometer-range, layer of surface material is vaporized. The rapid rise in temperature causes surface melting to a depth dependent on pulse energy and duration, and target melting point.
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By selectively laser shocking areas on the surface of metal sheets or plates, or smaller items such as airfoils, the associated compressive residual stresses cause the material to flex in a controllable manner. In this way a particular shape can be imparted to a component, or a distorted component might be brought back into the desired shape. Thus, this process is capable of bringing manufactured parts back into design tolerance limits and form shaping thin section parts. Another variation is to use the shock wave for spallation testing of materials.
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This county is an agglomeration of several distinct geologic terranes, as is most of the greater San Francisco Bay Area, which is one of the most geologically complex regions in the world. The great local mountain Mount Diablo has been formed and continues to be elevated by compressive forces resulting from the action of plate tectonics and at its upper reaches presents ancient seabed rocks scraped from distant oceanic sedimentation locations and accumulated and lifted by these great forces. Younger deposits at middle altitudes include pillow lavas, the product of undersea volcanic eruptions.
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While uncontrolled residual stresses are undesirable, some designs rely on them. In particular, brittle materials can be toughened by including compressive residual stress, as in the case for toughened glass and pre-stressed concrete. The predominant mechanism for failure in brittle materials is brittle fracture, which begins with initial crack formation. When an external tensile stress is applied to the material, the crack tips concentrate stress, increasing the local tensile stresses experienced at the crack tips to a greater extent than the average stress on the bulk material.
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The tower's trapezoid aperture is made up of structural steel and reinforced concrete. A large number of forces, such as wind loads, the people in the building and heavy equipment housed in the building, act on the SWFC's structure. These compressive and bending forces are carried down to the ground by the diagonal- braced frame (with added outrigger trusses). The design employs an effective use of material, because it decreases the thickness of the outer core shear walls and the weight of the structural steel in the perimeter walls.
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Several aspects of bamboo are extremely valuable to both cyclists and bicycle manufacturers: high strength-to-weight ratio, vibration control, and sustainable growth. Because of bamboo's tendency to grow straight, it does not exhibit "knots" and "turns" in its wood, unlike other types of wood. As a result, bamboo has a higher specific tensile strength than steel, as well as a higher specific compressive strength than concrete. This tendency also allows for excellent vibration control, which, in turn, provides for a smoother ride and increased stability on rough terrain.
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In addition, the majority of the weathering in the boulders occurs at the exposed top surfaces, not on the bottoms; thus, the stresses would not be balanced. Furthermore, if slow weathering created the stresses, then there would be ringing rock boulder fields in deserts throughout the world, a condition which does not occur. An important point made in the experiment is the observation that the rock slices expanded when the stress was released. This distinction requires that the rock was under extreme compressive stress, not tension as the slow weathering theory implies.
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The building's design is centered around durability, ecology, and sustainability. The building is said to draw upon the physiology of the tardigrade, a creature known for its durability, for its structural strength. In addition, the walls are angled inward at 4 degrees to "create a compressive structure with a low center of gravity further aiding in resistance to lateral turnover forces produced by strong earthquakes." A variety of both standard and non-standard building materials were used including: Concrete, insulating concrete forms, hardwall (a type of gypsum plaster)dictionary.
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The benefits of burnishing often include combatting fatigue failure, preventing corrosion and stress corrosion, texturing surfaces to eliminate visual defects, closing porosity, creating surface compressive residual stress. There are several forms of burnishing processes, the most common are roller burnishing and ball burnishing (a subset of which is also referred to as ballizing). In both cases, a burnishing tool runs against the workpiece and plastically deforms its surface. In some instances of the latter case (and always in ballizing), it rubs, in the former it generally rotates and rolls.
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This northward movement gave rise to compressive forces between northern Greenland and the Arctic Archipelago, setting the stage for the Eurekan orogeny. Seafloor spreading reached the northern Labrador Sea 60–40 million years ago and Greenland moved simultaneously past Ellesmere Island along the Nares Strait. Approximately of Paleocene separation occurred between Greenland and Baffin Island, producing oceanic crust within Baffin Bay. With the commencement of active seafloor spreading in the Norwegian Sea during the Early Eocene, the direction of seafloor spreading changed in both the Labrador Sea and Baffin Bay.
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Panic and a stampede ensued as fans tried to escape. After the hour-long ordeal, it was found that 117 deaths resulted from compressive asphyxia and 10 fans died from trauma. In January 2020 the team was banned from the Baba Yara stadium temporarily, after violent reactions by their supporters, which led to one of their fans being hit by a rubber bullet that was fired by the police. The fans were seen in various footages, throwing projectiles onto the pitch, because they were displeased with a decision the referee made.
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Faulting is pervasive in the Kapuni Group and predominantly consists of southwest-northeast right- lateral and northwest-southeast left-lateral strike-slip faults. These faults were formed under transpressional and compressional stress regimes during the Late Eocene to Late Miocene and are indicative of an east-west direction of maximum compressive stress. In the northern portion of the Kapuni Anticline, these two dominant fault trends become nearly orthogonal to one another. This is a result of fault block rotation that produced necessary extension along the anticline's younger units during fold growth.
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The interosseous membrane divides the forearm into anterior and posterior compartments, serves as a site of attachment for muscles of the forearm, and transfers loads placed on the forearm. The interosseous membrane is designed to shift compressive loads (as in doing a hand-stand) from the distal radius to the proximal ulna. The fibers within the interosseous membrane are oriented obliquely so that when force is applied the fibers are drawn taut, shifting more of the load to the ulna. This reduces the wear and tear of placing the whole load on a single joint.
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Soil cement is a construction material, a mix of pulverized natural soil with small amount of portland cement and water, usually processed in a tumble, compacted to high density. Hard, semi-rigid durable material is formed by hydration of the cement particles. Soil cement is frequently used as a construction material for pipe bedding, slope protection, and road construction as a subbase layer reinforcing and protecting the subgrade. It has good compressive and shear strength, but is brittle and has low tensile strength, so it is prone to forming cracks.
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Low shear strength has been the primary reason for limited range of applications. In the absence of external pressure the maximum shear strength is about 100 kPa. If the fluid is compressed in the magnetic field direction and the compressive stress is 2 MPa, the shear strength is raised to 1100 kPa."Mechanical properties of magnetorheological fluids under squeeze- shear mode" by Wang, Hong-yun; Zheng, Hui-qiang; Li, Yong-xian; Lu, Shuang If the standard magnetic particles are replaced with elongated magnetic particles, the shear strength is also improved.
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The result is internal (compressive) stress that can appear to add to the hardness measured for a sample of DLC. Hardness is often measured by nanoindentation methods in which a finely pointed stylus of natural diamond is forced into the surface of a specimen. If the sample is so thin that there is only a single layer of nodules, then the stylus may enter the DLC layer between the hard cobblestones and push them apart without sensing the hardness of the sp3 bonded volumes. Measurements would be low.
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Connecting rod and piston from a car engine A connecting rod, also called a con rod, is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft. The connecting rod is required to transmit the compressive and tensile forces from the piston, and rotate at both ends. The predecessor to the connecting rod is a mechanic linkage used by water mills to convert rotating motion of the water wheel into reciprocating motion.
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Generalized geologic map of the Yosemite area. (Based on a USGS image) The exposed geology of the Yosemite area includes primarily granitic rocks with some older metamorphic rock. The first rocks were laid down in Precambrian times, when the area around Yosemite National Park was on the edge of a very young North American continent. The sediment that formed the area first settled in the waters of a shallow sea, and compressive forces from a subduction zone in the mid-Paleozoic fused the seabed rocks and sediments, appending them to the continent.
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In Cryo Electron Tomography, where the limited number of projections are acquired due to the hardware limitations and to avoid the biological specimen damage, it can be used along with compressive sensing techniques or regularization functions (e.g. Huber function) to improve the reconstruction for better interpretation. Here is an example that illustrates the benefits of iterative image reconstruction for cardiac MRI.I Uyanik, P Lindner, D Shah, N Tsekos I Pavlidis (2013) Applying a Level Set Method for Resolving Physiologic Motions in Free-Breathing and Non-gated Cardiac MRI.
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The remodeling of bone in response to loading is achieved via mechanotransduction, a process through which forces or other mechanical signals are converted to biochemical signals in cellular signaling. Mechanotransduction leading to bone remodeling involves the steps of mechanocoupling, biochemical coupling, signal transmission, and cell response. The specific effects on bone structure depend on the duration, magnitude and rate of loading, and it has been found that only cyclic loading can induce bone formation. When loaded, fluid flows away from areas of high compressive loading in the bone matrix.
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He was a gardener, not a licensed engineer, and sold his patents to contractors who built the first generation of reinforced concrete bridges in Europe. He also perfected the technique of pre-stressing concrete, which leaves permanent compressive stresses in concrete arches. By the early twentieth century, reinforced concrete became an acceptable substitute in construction for all previous structural materials, such as stone, wood, and steel. People such as Monier had developed useful techniques for design and construction, but no one had created new forms that showed the full aesthetic nature of reinforced concrete.
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Compression of the median nerve in the region of the elbow or proximal part of the forearm can cause pain and/or numbness in the distribution of the distal median nerve, and weakness of the muscles innervated by the anterior interosseous nerve: the flexor pollicis longus ("FPL"), the flexor digitorum profundus of the index finger ("FDP IF"), and the pronator quadratus ("PQ").Hartz, C R, R L Linscheid, R R Gramse, and J R Daube. "The pronator teres syndrome: compressive neuropathy of the median nerve." The Journal of Bone and Joint Surgery.
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This is sometimes a result of the sizes of the atoms in the alloy, because larger atoms exert a compressive force on neighboring atoms, and smaller atoms exert a tensile force on their neighbors, helping the alloy resist deformation. Sometimes alloys may exhibit marked differences in behavior even when small amounts of one element are present. For example, impurities in semiconducting ferromagnetic alloys lead to different properties, as first predicted by White, Hogan, Suhl, Tian Abrie and Nakamura. Some alloys are made by melting and mixing two or more metals.
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The articular cartilage extracellular matrix (ECM) has a highly specialized architecture that is zonally organized: the superficial zone consists mostly of collagen II fibers aligned parallel to the articular surface to resist shear forces, whereas the deep zone consists of the same fibers aligned perpendicularly to the bone interface to absorb compressive loads. The biochemical breakdown of the articular cartilage results in osteoarthritis – the most common type of joint disease. Osteoarthritis affects over 30 million individuals in the United States alone, and is the leading cause of chronic disability amongst the elderly.
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LiH is a diamagnetic and an ionic conductor with a conductivity gradually increasing from at 443 °C to 0.18 Ω−1cm−1 at 754 °C; there is no discontinuity in this increase through the melting point. The dielectric constant of LiH decreases from 13.0 (static, low frequencies) to 3.6 (visible-light frequencies). LiH is a soft material with a Mohs hardness of 3.5. Its compressive creep (per 100 hours) rapidly increases from < 1% at 350 °C to > 100% at 475 °C, meaning that LiH can't provide mechanical support when heated.
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At the end of his collecting time in Colorado, in September 1871, he heard tell of a strange petrified forest and rock formation at Florissant and went there on horseback to investigate. Realizing the scientific importance of the site, he collected 25 lbs. of compressive shale fossil rocks containing insects and leaves and sent these via Edwards to Samuel Hubbard Scudder, a Harvard University paleontologist, whose publications and lectures after analyzing the fossils alerted the rest of the scientific community to this important site, now the Florissant Fossil Beds National Monument.
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The development of the vascular network is self-organized at each point in the tissue due to the balance between compressive forces of tissue expansion and circumferential stretch of the vessel walls. Over time, this means that migrating lines become straight rather than curving; this is akin to imagining two moving boundaries pushing on each other. Straight vessels are usually parallel to isopressure lines because the boundaries have acted to equilibriate pressure gradients. In addition, vessel direction tends to follow the direction of the normal to the steepest stress gradient.
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Finishing treatments are defined as processes that negate surface finishes imparted by traditional and non-traditional processes or improve the surface integrity. For example, compressive residual stress can be enhanced via peening or roller burnishing or the recast layer left by EDMing can be removed via chemical milling.. Finishing treatments can affect the workpiece surface in a wide variety of manners. Some clean and/or remove defects, such as scratches, pores, burrs, flash, or blemishes. Other processes improve or modify the surface appearance by improving smoothness, texture, or color.
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In some cases, when performing certain routines, smothering is combined with simultaneous compressive asphyxia. One example is overlay, in which an adult accidentally rolls over onto an infant during co- sleeping, an accident that often goes unnoticed and is mistakenly thought to be sudden infant death syndrome. Other accidents involving a similar mechanism are cave-ins or when an individual is buried in sand or grain. In homicidal cases, the term burking is often ascribed to a killing method that involves simultaneous smothering and compression of the torso.
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In cases where people have stacked up on each other forming a human pile, estimations have been made of around 380 kg (838 lbs) of compressive weight in the lowest layer. "Positional" or "restraint" asphyxia is when a person is restrained and left alone prone, such as in a police vehicle, and is unable to reposition himself or herself in order to breathe. The death can be in the vehicle, or following loss of consciousness to be followed by death while in a coma, having presented with anoxic brain damage.
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The final compressive strength of sandcrete can be as high as 4.6 N/mm2, which is much less than concrete's 40 N/mm2. Sandcrete is unsuitable for load-bearing columns, and is mainly used for walls, or for foundations if no suitable alternative is available. As material for walls, its strength is less than that of fired clay bricks, but sandcrete is considerably cheaper. Sandcrete is the main building material for walls of single-storey buildings (such as houses and schools) in countries such as Ghana and Nigeria.
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Since ancient times, when there were the first coal mines, it was observed, that increasing the depth of the development the coal tunnel, under the action of overburden pressure, surrounding rocks become harder and little-permeable. To solve this problem they developed a cavern of a certain form in the rock. More modern mining geo- mechanics explain the reason for the occurrence of this effect in relation to drilling wells. During any drilling process in the well there is formed the annular compressive stress conditions around the wellbore zone.
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Layer-by-layer (LbL) assembly when nanometer scale layers of nanoparticulates and a polymers are added one by one. LbL composites display performance parameters 10-1000 times better that the traditional nanocomposites made by extrusion or batch-mixing. Nanoparticles such as graphene, carbon nanotubes, molybdenum disulfide and tungsten disulfide are being used as reinforcing agents to fabricate mechanically strong biodegradable polymeric nanocomposites for bone tissue engineering applications. The addition of these nanoparticles in the polymer matrix at low concentrations (~0.2 weight %) cause significant improvements in the compressive and flexural mechanical properties of polymeric nanocomposites.
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The circumference of the tire can be modeled as a series of very small spring elements whose spring constants vary according to manufacturing conditions. These spring elements are compressed as they enter the road contact area, and recover as they exit the footprint. Variation in the spring constants in both radial and lateral directions cause variations in the compressive and restorative forces as the tire rotates. Given a perfect tire, running on a perfectly smooth roadway, the force exerted between the car and the tire will be constant.
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Deepsea Challenger was secretly built in Australia, in partnership with the National Geographic Society and with support from Rolex, in the Deepsea Challenge program. The construction of the submersible was headed by Australian engineer Ron Allum. Many of the submersible developer team members hail from Sydney's cave-diving fraternity including Allum himself with many years' cave-diving experience. Working in a small engineering workshop in Leichhardt, Sydney, Allum created new materials including a specialized structural syntactic foam called Isofloat, capable of withstanding the huge compressive forces at the depth.
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Victoria Hall Disaster Memorial in Mowbray Park With the compressive asphyxia of 183 children between 3 and 14 years old, the disaster is the worst of its kind in British history. Queen Victoria sent a message of condolence to the grieving families and contributed to the disaster fund. Donations sent from all over Britain totalled £5,000 and were used for the children's funerals and a memorial in Mowbray Park. The memorial, of a grieving mother holding a dead child, was later moved to Bishopwearmouth Cemetery where it gradually fell into disrepair and was vandalised.
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Körting double-acting gas engine Some early gas engines, such as Lenoir's original engines, from around 1860, were double-acting and followed steam engines in their design. Internal combustion engines soon switched to single-acting cylinders. This was for two reasons: as for the high-speed steam engine, the high force on each piston and its connecting rod was so great that it placed large demands upon the bearings. A single-acting piston, where the direction of the forces was consistently compressive along the connecting rod, allowed for tighter bearing clearances.
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Steel dams use relatively thin steel plates in contact with the water body, with a framework of steel behind them transmitting the load to the ground. The plates are slanted upwards in the direction of water flow, so that the weight of the water puts compressive forces on the girders holding the plates up. This transmits force to the ground without the bending moment that a vertical wall of plates would engender. It was believed at the time that these dams could be constructed faster and more cheaply than masonry dams.
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This allows the customer to specify what the concrete has to be able to withstand in terms of ground conditions, exposure, and strength, and allows the concrete manufacturer to design a mix that meets that requirement using the materials locally available to a batching plant. This is verified by laboratory testing, such as performing cube tests to verify compressive strength and supplemented by field testing, such as slump tests done on site to verify plasticity of the mix. The performance of a concrete mix can be altered by use of admixtures.
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Often, retrograde metamorphism will not form a foliation because the unroofing of a metamorphic belt is not accompanied by significant compressive stress. Thermal metamorphism in the aureole of a granite is also unlikely to result in the growth of mica in a foliation, although the growth of new minerals may overprint existing foliation(s). Alignment of tabular minerals in metamorphic rocks, igneous rocks and intrusive rocks may form a foliation. Typical examples of metamorphic rocks include porphyroblastic schists where large, oblate minerals form an alignment either due to growth or rotation in the groundmass.
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The dam's light weight and prefabricated components must have made assembly easy relative to the laborious job of quarrying and setting stone. Steel dams use relatively thin steel plates in contact with the water surface, with a framework of steel behind them transmitting the load to the ground. The plates are slanted upwards in the direction of water flow, so that the weight of the water puts compressive forces on the girders holding the plates up. This transmits force to the ground without the bending moment that a vertical wall of plates would engender.
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One of the characteristics of a brittle failure is that the two broken parts can be reassembled to produce the same shape as the original component as there will not be a neck formation like in the case of ductile materials. A typical stress–strain curve for a brittle material will be linear. For some materials, such as concrete, tensile strength is negligible compared to the compressive strength and it is assumed zero for many engineering applications. Glass fibers have a tensile strength stronger than steel, but bulk glass usually does not.
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Concrete is a mixture of coarse (stone or brick chips) and fine (generally sand or crushed stone) aggregates with a paste of binder material (usually Portland cement) and water. When cement is mixed with a small amount of water, it hydrates to form microscopic opaque crystal lattices encapsulating and locking the aggregate into a rigid structure. The aggregates used for making concrete should be free from harmful substances like organic impurities, silt, clay, lignite etc. Typical concrete mixes have high resistance to compressive stresses (about ); however, any appreciable tension (e.g.
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Biotensegrity, a term coined by Dr. Stephen Levin, is the application of tensegrity principles to biological structures. Biological structures such as muscles, bones, fascia, ligaments and tendons, or rigid and elastic cell membranes, are made strong by the unison of tensioned and compressed parts. The musculoskeletal system maintains tension in a continuous network of muscles and connective tissues, while the bones provide discontinuous compressive support. Even the human spine, which seems at first glance like a stack of vertebrae resting on each other, is actually a tensegrity structure.
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The glass frit bonding, starting with alignment of the wafers, is a thermo-compressive process that takes place in the bonding chamber at specific pressure. Under bonding pressure wafers are heated up to the process temperature around 430 °C for a few minutes. On the one hand a short bonding time causes the glass frit to spread insufficiently, on the other hand a longer bonding time causes the glass frit to be overflown subsequently leaving voids. The alignment has to be very precise and stable to prevent shifting.
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The other chamber contains an inert gas (typically nitrogen), usually under pressure, that provides the compressive force on the hydraulic fluid. Inert gas is used because oxygen and oil can form an explosive mixture when combined under high pressure. As the volume of the compressed gas changes, the pressure of the gas (and the pressure on the fluid) changes inversely. For low pressure water system use the water usually fills a rubber bladder within the tank (pictured), preventing contact with the tank which would otherwise need to be corrosion resistant.
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Compressed fiber gasket Gaskets are normally made from a flat material, a sheet such as paper, rubber, silicone, metal, cork, felt, neoprene, nitrile rubber, fiberglass, polytetrafluoroethylene (otherwise known as PTFE or Teflon) or a plastic polymer (such as polychlorotrifluoroethylene). One of the more desirable properties of an effective gasket in industrial applications for compressed fiber gasket material is the ability to withstand high compressive loads. Most industrial gasket applications involve bolts exerting compression well into the 14 MPa (2000 psi) range or higher. Generally speaking, there are several truisms that allow for better gasket performance.
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Annular Seal (RTJ Seal) is a high integrity, high temperature, high pressure seal for applications in the oil industry, oilfield drilling, pressure vessel connections, pipes, valves and more. The movement of the ring packing (RTJ) can be described as an irregular flow in the groove of the deformed sealing flange due to the axial compressive load. Colored seal (RTJ seal) has a small load area, which leads to a large surface pressure between the sealing surface and the groove, the maintenance properties are poor and not suitable for reuse.
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During the constrained HPT process, the material experiences shear deformation between a fixed and a rotating anvil, without losing its original dimensions. High pressure torsion (HPT) can be traced back to the experiments that won Percy Bridgman the 1946 Nobel Prize in Physics, though its use in metal processing is considerably more recent. In this method, a disk of the material to be strained is placed between 2 anvils. A large compressive stress (typically several gigapascals) is applied, while one anvil is rotated to create a torsion force.
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In asymmetric rolling (ASR), a rolling mill is modified such that one roll has a higher velocity than the other. This is typically done with either independent speed control or by using rolls of different size. This creates a region in which the frictional forces on the top and bottom of the sheet being rolled are opposite, creating shear stresses throughout the material in addition to the normal compressive stress from rolling. Unlike other SPD processes, ASR does not maintain the same net shape, but the effect on the microstructure of the material is similar.
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In a solid, the amount of compression generally depends on the direction x, and the material may be under compression along some directions but under traction along others. If the stress vector is purely compressive and has the same magnitude for all directions, the material is said to be under isotropic or hydrostatic compression at that point. This is the only type of static compression that liquids and gases can bear. In a mechanical longitudinal wave, or compression wave, the medium is displaced in the wave's direction, resulting in areas of compression and rarefaction.
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Because of the distribution of mass throughout a person's body, the magnitude of the reaction force varies between a person's feet and head. At any horizontal cross-section of a person's body (as with any column), the size of the compressive force being resisted by the tissues below the cross-section is equal to the weight of the portion of the body above the cross-section. In the pose adopted in the accompanying illustration, the shoulders carry the weight of the outstretched arms and are subject to a considerable torque.
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The sleeve is used to evenly distribute the compressive forces of the flare nut to the flared end of the tube. Materials commonly used to fabricate JIC fittings include forged carbon steel, forged stainless steel, forged brass, machined brass, Monel and nickel-copper alloys. JIC fittings are commonly used in the Fluid Power industry in a diagnostic and test-point setting. A three-way JIC coupling provides a port inline of circuit by which a user can connect a measurement or diagnostic device to take pressure readings and perform circuit and system diagnostics.
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A similar argument has been made for replacement of metal fuselages, wings and tails of aircraft. # Induce residual stresses Peening a surface can reduce such tensile stresses and create compressive residual stress, which prevents crack initiation. Forms of peening include: shot peening, using high-speed projectiles, high-frequency impact treatment (also called high-frequency mechanical impact) using a mechanical hammer, and laser peening which uses high-energy laser pulses. Low plasticity burnishing can also be used to induce compresses stress in fillets and cold work mandrels can be used for holes.
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In fact, high Portland cement content mixtures can actually crack more readily due to increased hydration rate. As concrete transforms from its plastic state, hydrating to a solid, the material undergoes shrinkage. Plastic shrinkage cracks can occur soon after placement but if the evaporation rate is high they often can actually occur during finishing operations, for example in hot weather or a breezy day. In very high-strength concrete mixtures (greater than 70 MPa) the crushing strength of the aggregate can be a limiting factor to the ultimate compressive strength.
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Structural design, concrete material design and properties are often specified in accordance with national/regional design codes such as American Concrete Institute. Compressive strength tests are conducted by certified technicians using an instrumented, hydraulic ram which has been annually calibrated with instruments traceable to the Cement and Concrete Reference Laboratory (CCRL) of the National Institute of Standards and Technology (NIST) in the U.S., or regional equivalents internationally. Standardized form factors are 6" by 12" or 4" by 8" cylindrical samples, with some laboratories opting to utilize cubic samples. These samples are compressed to failure.
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Prestressing tendons (generally of high tensile steel cable or rods) are used to provide a clamping load which produces a compressive stress that offsets the tensile stress that the concrete compression member would, otherwise, experience due to a bending load. To prevent catastrophic collapse in response earth shaking (in the interest of life safety), a traditional reinforced concrete frame should have ductile joints. Depending upon the methods used and the imposed seismic forces, such buildings may be immediately usable, require extensive repair, or may have to be demolished.
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Lymphocytic meningitis is also characterized by possibly co-occurring with EM rash, facial palsy, or partial vision obstruction and having much lower percentage of polymorphonuclear leukocytes in CSF. Lyme radiculopathy affecting the limbs is often misdiagnosed as a radiculopathy caused by nerve root compression, such as sciatica. Although most cases of radiculopathy are compressive and resolve with conservative treatment (e.g., rest) within 4–6 weeks, guidelines for managing radiculopathy recommend first evaluating risks of other possible causes that, although less frequent, require immediate diagnosis and treatment, including infections such as Lyme and shingles.
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They were the first self- anchored suspension bridges built in the United States. The design’s solid plate deck-stiffening girder provided compressive support while lowering visual barriers between Pittsburgh and the historically distinct North side (formerly Allegheny City), annexed in 1907 in a contentious fight. The American Bridge Company, the builder and steel supplier for these three bridges, was headquartered nearby, as was the Foundation Company which had the pier/abutment masonry contract. Local election campaigns during the period highlighted the intent to use local suppliers and labor.
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Compared to stone, these materials are compressive, making them fairly shatterproof. These were then hafted onto a shaft to be used as javelins. It is possible that Aurignacian craftsmen further hafted bone barbs onto the spearheads, but firm evidence of such technology is recorded earliest 23,500 years ago, and does not become more common until the Mesolithic. Aurignacian craftsmen produced lozenge-shaped (diamond-like) spearheads. By 30,000 years ago, spearheads were manufactured with a more rounded-off base, and by 28,000 years ago spindle-shaped heads were introduced.
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The Midhurst White brick suffered from excessive weathering especially in coastal areas, and as a result houses built with them needed to be rendered. The bricks did, however, have a much greater compressive strength than ordinary "red" bricks and could bear heavy loads without fracture. In 2012, the Midhurst Conservation Area draft plan described the bricks as "not attractive", preferring traditional red bricks. The bricks were used in the light wells of Battersea Power Station, and at Broadcasting House and the headquarters of the Royal Institute of British Architects.
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The use of various strain engineering techniques has been reported by many prominent microprocessor manufacturers, including AMD, IBM, and Intel, primarily with regards to sub-130 nm technologies. One key consideration in using strain engineering in CMOS technologies is that PMOS and NMOS respond differently to different types of strain. Specifically, PMOS performance is best served by applying compressive strain to the channel, whereas NMOS receives benefit from tensile strain. Many approaches to strain engineering induce strain locally, allowing both n-channel and p-channel strain to be modulated independently.
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Replication studies have shown that the time required for their production varies greatly, depending on the rock type. It can take one minute to create a 12 mm deep cupule on weathered sandstone, but 45,000 and 60,000 hammer-stone strokes on unweathered quartzite. The resistance of a rock to kinetic impact is determined by its hardness, toughness and strength. Hardness, in this context, is a complex articulation of several factors, essentially a measure of how resistant rock is to various kinds of permanent shape change when a compressive force is applied to it.
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Calcaneal fractures are often attributed to shearing stress adjoined with compressive forces combined with a rotary direction (Soeur, 1975). These forces are typically linked to injuries in which an individual falls from a height, involvement in an automobile accident, or muscular stress where the resulting forces can lead to the trauma of fracture. Overlooked aspects of what can lead to a calcaneal fracture are the roles of osteoporosis and diabetes. Unfortunately, the prevention of falls and automobile accidents is limited and applies to unique circumstances that should be avoided.
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Previously in 2009, the designer also evaluated one of the two connecting passages as safe upon demand of BCBB with the standard for its compressive strength at the lowest permissible value of 25 MPa. In the wake of widespread media coverage, the Construction Commission of Guangzhou launched an investigation into the incident. The commission invited an independent expert group to inspect the connecting passages. The expert group reaffirmed that despite their quality was indeed below the design standard, the passages were safe for operation and needed not be strengthened or rebuilt.
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Portland Cement Bags Another commonly used treatment is cement-based solidification and stabilization. Cement is used because it can treat a range of hazardous wastes by improving physical characteristics and decreasing the toxicity and transmission of contaminants. The cement produced is categorized into 5 different divisions, depending on its strength and components. This process of converting sludge into cement might include the addition of pH adjustment agents, phosphates, or sulfur reagents to reduce the settling or curing time, increase the compressive strength, or reduce the leach ability of contaminants.
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In cases of co-sleeping ("overlay"), the weight of an adult or large child may compress an infant's chest, preventing proper expansion of the chest. Risk factors include large or obese adults, parental fatigue or impairment (sedation by drugs or alcohol) of the co-sleeping adult and a small shared sleeping space (for example, both adult and infant sharing a couch). In fatal crowd disasters, compressive asphyxia from being crushed against the crowd causes the large part of the deaths, rather than blunt trauma from trampling. This is what occurred at the Ibrox disaster in 1971, where 66 Rangers fans died; the 1979 The Who concert disaster where 11 died; the Luzhniki disaster in 1982, when 66 FC Spartak Moscow fans died; and at the Hillsborough disaster in 1989, 96 Liverpool fans were crushed to death in an overcrowded terrace, 95 of the 96 victims died from compressive asphyxia, with 93 dying directly from it and 2 others dying from related complications. In confined spaces, people push and lean against each other; evidence from bent steel railings in several fatal crowd accidents have shown horizontal forces over 4500 N (equivalent to a weight of approximately 450 kg, or 1014 lbs).
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Composites of MAX phases, an emerging class of ternary carbides or nitrides with aluminium or titanium alloys have been studied since 2006 as high-value materials exhibiting favourable properties of ceramics in terms of hardness and compressive strength alongside ductility and fracture toughness typically associated with metals. Such cermet materials, including aluminium-MAX phase composites, have potential applications in automotive and aerospace applications. Some types of cermets are also being considered for use as spacecraft shielding as they resist the high velocity impacts of micrometeoroids and orbital debris much more effectively than more traditional spacecraft materials such as aluminum and other metals.
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The design of glass-fiber-reinforced concrete panels uses a knowledge of its basic properties under tensile, compressive, bending and shear forces, coupled with estimates of behavior under secondary loading effects such as creep, thermal response and moisture movement. There are a number of differences between structural metal and fiber-reinforced composites. For example, metals in general exhibit yielding and plastic deformation, whereas most fiber-reinforced composites are elastic in their tensile stress-strain characteristics. However, the dissimilar nature of these materials provides mechanisms for high-energy absorption on a microscopic scale comparable to the yielding process.
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Often, a hole is drilled through the bead to allow easier fitting. It uses the natural tensile or compressive strength of the metal the ring is made of, usually surgical stainless steel, niobium, or titanium, to hold the bead tightly in place. The bead or ball itself may additionally be made from coloured glass, acrylic or ceramic, or a gemstone. This is a popular piece of body jewelry because it conveniently allows the wearer to remove the ring by simply removing the captive bead, the bead is held firmly in place so that it will not easily fall out.
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The precise tensile strength of bulk diamond is unknown;however, compressive strength up to 60 GPa has been observed, and it could be as high as 90–100 GPa in the form of nanometer-sized wires or needles (~100-300 nanometers in diameter),with a corresponding local maximum tensile elastic strain in excess of 9%. The anisotropy of diamond hardness is carefully considered during diamond cutting. Diamond has a high refractive index (2.417) and moderate dispersion (0.044) properties that give cut diamonds their brilliance. Scientists classify diamonds into four main types according to the nature of crystallographic defects present.
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458x458px A T-beam (or tee beam), used in construction, is a load-bearing structure of reinforced concrete, wood or metal, with a -shaped cross section. The top of the -shaped cross section serves as a flange or compression member in resisting compressive stresses. The web (vertical section) of the beam below the compression flange serves to resist shear stress and to provide greater separation for the coupled forces of bending. The T-beam has a big disadvantage compared to an I-beam (with shape) because it has no bottom flange with which to deal with tensile forces.
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A metal tube is filled with a liquid, preferably water and placed between lower and upper die sections of stamping dies. 2\. The ends of the liquid-filled tube are sealed to confine the liquid within the tube at approximately atmospheric pressure. 3\. The liquid-filled sealed tube is stamped in a conventional die to form the tube into a desired configuration, such as a box-shaped structural member. The compressive forces produced as the die closes to form stamped tube also compress the liquid within the interior of the sealed tube as it changes shape.
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Conspicuous materials include fly ash, a by-product of coal-fired power plants; ground granulated blast furnace slag, a byproduct of steelmaking; and silica fume, a byproduct of industrial electric arc furnaces. Structures employing Portland cement concrete usually include steel reinforcement because this type of concrete can be formulated with high compressive strength, but always has lower tensile strength. Therefore, it is usually reinforced with materials that are strong in tension, typically steel rebar. Other materials can also be used as a concrete binder, the most prevalent alternative is asphalt, which is used as the binder in asphalt concrete.
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The Kammanassie Mountain is one of the prominent east-west trending ranges composing the southern branch of the Cape Fold Belt. It was formed as a result of north-south oriented compressive stress during the Cape Orogeny 123-200 million years ago. The Kammanassie mountain range comprises almost exclusively the resistant quartz arenites of the Table Mountain Group, overlain on the lower slopes by the shale of the Bokkeveld group. Soils generally form a thin (<1 m) veneer of silty sands/sandy silts as a result of the steepslopes of the Kammanassie Mountain and predominantly quartzitic rocks.
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The 20mm/yr dextral (right lateral) strike slip Sagaing Fault detaches the Burma microplate from the Sunda plate. The arc-parallel fault spans over 1400 km in a north-south direction, remarkably linear for the central 700 km (at 17°N to 23°N latitude) and forms a slight arc shape swinging N10°E and N170°E direction at the north and south ends of the fault respectively. Northward, the Sagaing fault terminates at the Jade Mine belt (~ 24.5°N) and splays into a 200 km width compressive horsetail structure. Southward, it is connected to the active Andaman spreading rift.
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The Pacific Plate is a major section of the Earth's crust, gradually expanding by the eruption of magma along the East Pacific Rise to the southeast. It is also being subducted far to the northwest into the Aleutian Trench under the North American Plate well north of San Francisco. In California, the plate borders the North American Plate along a transform boundary, the San Andreas Fault. The westward component of the North American Plate's motion and the irregularity of the San Andreas Fault results in some compressive force along the San Andreas and its associated faults, thus helping lift the Coast Ranges.
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Unexpected erosion of hard, sound, unweathered granite in the unlined spillway discharge channel was caused by rock failure under high in-situ compressive stress. This type of erosion due to high in-situ stress has not been reported elsewhere in the world. Remedial works involved building a training wall to separate the original single spillway into a service spillway and a secondary (emergency) spillway. A concrete slab, anchored to the underlying rock was constructed in the floor of the main scour channel to provide some additional protection on those rare occasions when the secondary spillway will discharge water over this area.
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Thermal conductivity is a common property targeted for maximization by creating thermal composites. In this case, the basic idea is to increase thermal conductivity by adding a highly conducting solid (such as the copper mesh) into the relatively low-conducting PCM, thus increasing overall or bulk (thermal) conductivity. If the PCM is required to flow, the solid must be porous, such as a mesh. Solid composites such as fiberglass or kevlar prepreg for the aerospace industry usually refer to a fiber (the kevlar or the glass) and a matrix (the glue, which solidifies to hold fibers and provide compressive strength).
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Bones are made of cells called osteoclasts and osteoblasts. Two different kinds of bone resorption are possible: direct resorption, which starts from the lining cells of the alveolar bone, and indirect or retrograde resorption, which takes place when the periodontal ligament has been subjected to an excessive amount and duration of compressive stress.Robling, Alexander G., Alesha B Castillo, and Charles H. Turner, "Biochemical and Molecular Regulation of Bone Remodeling", Annual Review of Biochemical Engineering, (April 3, 2006) pp 1–12 Another important factor associated with tooth movement is bone deposition. Bone deposition occurs in the distracted periodontal ligament.
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Power brakes are a system of hydraulics used to slow down or stop most motor vehicles. It uses a combination of mechanical components to multiply the force applied to the brake pedal by the driver into enough force to actuate the brakes and stop a vehicle that can weigh several tons. The brake pedal is connected to the vacuum booster which is the first step of the force multiplication. The booster passes the force to the master cylinder, which applies a compressive force to a liquid (hydraulic or brake fluid) and forces it through the brake lines to the brake calipers.
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In sliding friction, increased compressive stress is proportionally equal to a rise in potential energy and temperature within the contact zone. The reasons for accumulation of energy during sliding can be a reduction of energy loss away from the contact zone, due to a small surface area on the surface boundary thus low heat conductivity. Another reason is the energy that is continuously forced into the metals, which is a product of acceleration and pressure. In cooperation, these mechanisms allow a constant accumulation of energy causing increased energy density and temperature in the contact zone during sliding.
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During a Watsu session, the recipient's heart and respiration rates decrease, depth of respiration increases, muscle tone decreases, and recipients report a deep state of relaxation. Robert Scaer suggested that deep relaxation of Watsu balances the autonomic nervous system (ANS), decreasing sympathetic response and increasing parasympathetic response, with far-reaching benefits. Compressive forces of hydrostatic pressure combine with deep relaxation to enhance functioning of the lymphatic system and reduce swelling in cases of edema. For orthopedic impairments, combined effects of relaxation, warm water, and gentle movement decreases muscle spasm, provides pain relief, improves soft tissue mobility, and increases range of motion.
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In 2018, Christian Klimczak (University of Georgia), Corbin L. Kling, and Paul K. Byrne (North Carolina State University) reported a comparative assessment of eight different regions on Mars thought to have been formed through the activity of large and extensive thrust faults, comparing them to terrestrial thrust belts and certain compressive features observed on Mercury. The Phlegra Montes was among the tectonically-controlled systems examined by the researchers, who identified nine major thrust faults bounding the region. They also submitted an abstract to attend the European Planetary Science Congress in Berlin to discuss their recent work.
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A spar is a pole of wood, metal or lightweight materials such as carbon fibre used in the rigging of a sailing vessel to carry or support its sail. These include yards, booms, and masts, which serve both to deploy sail and resist compressive and bending forces, as well as the bowsprit and spinnaker pole. In larger vessels during the age of sail, spare spars could be roped together to provide a temporary surface known as a "spar deck". These served as jury- rigged repairs for permanent decks, or as an additional platform under which to shelter goods or crew.
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With the obsolescence of very large guns following World War II, metallurgical advances encouraged use of monoblock (one-piece) construction for postwar guns of medium caliber. In a procedure called autofrettage, a bored monoblock tube is filled with hydraulic fluid at pressures higher than the finished gun will experience during firing. Upon release of hydraulic pressure, the internal diameter of the monoblock tube will have been increased by approximately 6%. The outer portion of the finished monoblock rebounds to approximately its original diameter and exerts compressive forces on the inner portion similar to the separate cylinders of a built-up gun.
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Anatolian Plate The Anatolian Plate or the Turkish Plate is a continental tectonic plate comprising most of the Anatolia (Asia Minor) peninsula (and the country of Turkey). To the east, the East Anatolian Fault, a left lateral transform fault, forms a boundary with the Arabian Plate. To the south and southwest is a convergent boundary with the African Plate. This convergence manifests in compressive features within the oceanic crust beneath the Mediterranean as well as within the continental crust of Anatolia itself, and also by what are generally considered to be subduction zones along the Hellenic and Cyprus arcs.
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Numerous studies have shown decreases in both compressive and tensile strength as well as elastic modulus of concrete at around a dosage of around 1019 neutrons per square centimeter. These trends were also shown to exist in reinforced concrete, a composite of both concrete and steel. The knowledge gained from current analyses of materials in fission reactors in regards to the effects of temperature, irradiation dosage, materials compositions, and surface treatments will be helpful in the design of future fission reactors as well as the development of fusion reactors. Solids subject to radiation are constantly being bombarded with high energy particles.
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Structural lumber may also be produced from recycled plastic and new plastic stock. Its introduction has been strongly opposed by the forestry industry."Recycling and Deregulation: Opportunities for Market Development" Resource Recycling, September 1996 Blending fiberglass in plastic lumber enhances its strength, durability, and fire resistance."ASTM D6108 – 09 Standard Test Method for Compressive Properties of Plastic Lumber and Shapes" ASTM Committee D20.20 on Plastic Lumber Plastic fiberglass structural lumber can have a "class 1 flame spread rating of 25 or less, when tested in accordance with ASTM standard E 84," which means it burns more slowly than almost all treated wood lumber.
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The top shell consists of a 3K plain weave carbon prepreg laminate (1 layer per side) sandwiching a lightweight 3/8 ” nomex honeycomb core. The chassis and bottom shell, have been joined together as one structural component. These have also been constructed of the same 3K plain weave prepreg carbon fiber over both 3/” aluminum honeycomb (with core- bonding sheet adhesive) and 1/” nomex core, depending on the structural requirements of the region in question. Chassis ‘hard-points’ were reinforced with solid Kevlar 285 layups 3/8” thick to resist the out-of-plane compressive stresses resulting from tensioned bolts.
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Expansion joints are required in large ducted air systems to allow fixed pieces of piping to be largely free of stress as thermal expansion occurs. Bends in elbows also can accommodate this. Expansion joints also isolate pieces of equipment such as fans from the rigid ductwork thereby reducing vibration to the ductwork as well as allowing the fan to “grow” as it comes up to the operating air system temperature without putting stress on the fan or the fixed portions of ductwork. An expansion joint is designed to allow deflection in the axial (compressive), lateral (shear), or angular (bending) deflections.
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Taymyr has a traditional icebreaker hull with highly raked stem and sloping sides to reduce the ice loads in compressive ice fields and improve maneuverability. The special cold-resistant steel used in the hull was delivered by the Soviet Union. Although designed for a crew of slightly over 100, the large superstructure of Taymyr contains accommodation and facilities for 138 personnel. In addition to messes and other social premises, there is a large auditorium that doubles as a recreational room and a winter garden that can be used to provide fresh vegetables for the crew during the polar night.
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The Earth's gravity gradient is dominated by the component due to Earth's near-spherical shape, which results in a vertical tensile gravity gradient of 3,080 E (an elevation increase of 1 m gives a decrease of gravity of about 0.3 mGal), and horizontal compressive gravity gradients of one half that, or 1,540 E. Earth's rotation perturbs this in a direction-dependent manner by about 5 E. Gravity gradient anomalies in mountainous areas can be as large as several hundred eotvos. The eotvos unit is named for the physicist Loránd Eötvös, who made pioneering studies of the gradient of the Earth's gravitational field.
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The use of steel for structural purposes was initially slow. The Bessemer process in 1855 made steel production more efficient, and cheap steels, which had high tensile and compressive strengths plus good ductility were available from about 1870, but wrought and cast iron continued to satisfy most of the demand for iron-based building products, due mainly to problems of producing steel from alkaline ores. These problems, caused principally by the presence of phosphorus, were solved by Sidney Gilchrist Thomas in 1879. It was not until 1880 that an era of construction based on reliable mild steel began.
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Structural testing is the evaluation of an object (which might be an assembly of objects) to ascertain its characteristics of physical strength. Testing includes evaluating compressive strength, shear strength, tensile strength, all of which may be conducted to failure or to some satisfactory margin of safety. Evaluations may also be indirect, using techniques such as x-ray ultrasound, and ground-penetrating radar, among others, to assess the quality of the object. Structural engineers conduct structural testing to evaluate material suitability for a particular application and to evaluate the capacity of existing structures to withstand foreseeable loads.
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In British and European (except former Soviet Union countries) practice, locomotives usually have buffers at each end to absorb compressive loads ("buffets"Oxford English Dictionary: Buff 1). The tensional load of drawing the train (draft force) is carried by the coupling system. Together these control slack between the locomotive and train, absorb minor impacts and provide a bearing point for pushing movements. In Canadian and American practice, all of the forces between the locomotive and cars are handled through the coupler – particularly the Janney coupler, long standard on American railroad rolling stock – and its associated draft gear, which allows some limited slack movement.
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Similarly, in the case of lumbosacral radiculopathy, a straight leg raise maneuver or a femoral nerve stretch test may demonstrate radiculopathic symptoms down the leg. Deep tendon reflexes (also known as a Stretch reflex) may be diminished or absent in areas innervated by a particular nerve root. Although most cases of radiculopathy are compressive and resolve with conservative treatment within 4-6 weeks, guidelines for managing radiculopathy recommend first excluding possible causes that, although rare, require immediate attention, among them the following. Cauda equina syndrome should be investigated in case of saddle anesthesia, loss of bladder or bowel control, or leg weakness.
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Blind thrust faults generally exist near tectonic plate margins, in the broad disturbance zone. They form when a section of the Earth's crust is under high compressive stresses, due to plate margin collision, or the general geometry of how the plates are sliding past each other. Diagram of blind-thrust faulting As shown in the diagram, a weak plate under compression generally forms thrusting sheets, or overlapping sliding sections. This can form a hill and valley landform, with the hills being the strong sections, and the valleys being the highly disturbed thrust faulted and folded sections.
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Nanotechnology may be used as part of tissue engineering to help reproduce or repair or reshape damaged tissue using suitable nanomaterial-based scaffolds and growth factors. Tissue engineering if successful may replace conventional treatments like organ transplants or artificial implants. Nanoparticles such as graphene, carbon nanotubes, molybdenum disulfide and tungsten disulfide are being used as reinforcing agents to fabricate mechanically strong biodegradable polymeric nanocomposites for bone tissue engineering applications. The addition of these nanoparticles in the polymer matrix at low concentrations (~0.2 weight %) leads to significant improvements in the compressive and flexural mechanical properties of polymeric nanocomposites.
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The tectonic regime in this part of the world is extremely complex and involves a number of minor as well as major plates. The Solomon Sea Plate is an oceanic crustal plate remnant which is disappearing into two subduction zones, one to its north, the other on its southwest margin. Its southeast margin runs along the Woodlark Rise, an undefined compressive zone which may be a transform fault marking the boundary with the adjoining Woodlark Plate. The northern subduction zone is located where the Solomon Plate is diving below the South Bismarck Plate to the northwest and the Pacific Plate to the northeast.
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The numbers stand for the minimum compressive strength at 28 days in newtons per square millimeter (N/mm2). For example, the NHL 3.5 strength ranges from 3.5 N/mm2 (510 psi) to 10 N/mm2 (1,450 psi)."The Use og Lime-based Mortars in New Build" These are similar to the old classification of feebly hydraulic, moderately hydraulic and eminently hydraulic, and although different, some people continue to refer to them interchangeably. The terminology for hydraulic lime mortars was improved by the skilled French civil engineer Louis Vicat in the 1830s from the older system of water limes and feebly, moderately and eminently.
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Hiroko and her husband Eugene Pijanowski brought the craft of mokume gane back to the United States and began teaching it to their students, at this point the artform re-emerged in the public eye. Today, jewelry, flatware, hollowware, spinning tops and other artistic objects are made using this material. Modern processes are highly controlled and include a compressive force on the billet. This has allowed the technique to include many nontraditional components such as titanium, platinum, iron, bronze, brass, nickel silver, and various colors of karat gold including yellow, white, sage, and rose hues as well as sterling silver.
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The Beardmore orogeny was a mountain building event in the Neoproterozoic affecting what is now Antarctica. The event is preserved in the Trans- Antarctic Mountains, potentially in the Shackleton Range and by argillite- greywacke series in the Horlick Mountains, Queen Maud Land and the Thiel Mountains. Upright folds, asymmetric overturned or recumbent isoclinal folds first identified by Elliott in 1975 was interpreted in 1992 by Edmund Stump as indicative of compressive and convergent tectonic activity. The orogeny is expressed as an unconformity in the Transantarctic Mountains, between folded Late Proterozoic strata and overlying Early or Middle Cambrian sediments.
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The structural elements can be classified as one- dimensional (ropes, struts, beams, arches), two-dimensional (membranes, plates, slab, shells, vaults), or three-dimensional (solid masses). The latter was the main option available to early structures such as Chichen Itza. A one- dimensional element has one dimension much larger than the other two, so the other dimensions can be neglected in calculations; however, the ratio of the smaller dimensions and the composition can determine the flexural and compressive stiffness of the element. Two-dimensional elements with a thin third dimension have little of either but can resist biaxial traction.
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The two nodal planes intersect at the N (neutral)-axis. The P and T axes are also often plotted; with the N axis these three directions respectively match the directions of the maximum, minimum and intermediate principal compressive stresses associated with the earthquake. The P-axis is plotted in the centre of the white segment, the T-axis in the centre of the colour-filled segment. USGS focal mechanism for the 2004 Indian Ocean earthquake The fault plane responsible for the earthquake will be parallel to one of the nodal planes, the other being called the auxiliary plane.
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Nanoparticles such as graphene, carbon nanotubes, molybdenum disulfide and tungsten disulfide are being used as reinforcing agents to fabricate mechanically strong biodegradable polymeric nanocomposites for bone tissue engineering applications. The addition of these nanoparticles in the polymer matrix at low concentrations (~0.2 weight %) leads to significant improvements in the compressive and flexural mechanical properties of polymeric nanocomposites. Potentially, these nanocomposites may be used to create novel, mechanically strong, light weight composite bone implants. The results suggest that mechanical reinforcement is dependent on the nanostructure morphology, defects, dispersion of nanomaterials in the polymer matrix, and the cross- linking density of the polymer.
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Uniaxial compression In mechanics, compression is the application of balanced inward ("pushing") forces to different points on a material or structure, that is, forces with no net sum or torque directed so as to reduce its size in one or more directions.Ferdinand Pierre Beer, Elwood Russell Johnston, John T. DeWolf (1992), "Mechanics of Materials". (Book) McGraw-Hill Professional, It is contrasted with tension or traction, the application of balanced outward ("pulling") forces; and with shearing forces, directed so as to displace layers of the material parallel to each other. The compressive strength of materials and structures is an important engineering consideration.
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HSS is often filled with concrete to improve fire rating, as well as robustness. When this is done, the product is referred to as a Lally column after its inventor John Lally of Waltham, Massachusetts. (The pronunciation is often corrupted to lolly column.) For example, barriers around parking areas (bollards) made of HSS are often filled, to at least bumper height, with concrete. This is an inexpensive (when replacement costs are factored in) way of adding compressive strength to the bollard, which can help prevent unsightly local denting, though it does not generally significantly increase the overall structural properties of the bollard.
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Example of the retrieval of an unknown signal (gray line) from few measurements (black dots) using the knowledge that the signal is sparse in the Hermite polynomials basis (purple dots show the retrieved coefficients). Compressed sensing takes advantage of the redundancy in many interesting signals—they are not pure noise. In particular, many signals are sparse, that is, they contain many coefficients close to or equal to zero, when represented in some domain.Candès, E.J., & Wakin, M.B., An Introduction To Compressive Sampling, IEEE Signal Processing Magazine, V.21, March 2008 This is the same insight used in many forms of lossy compression.
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Outram had built it of stone and, due to its low height, it had needed to be constructed in four short spans. The narrow openings had impeded the unprecedented overflow and Outram replaced it with a single span cast iron structure, similar to the Holmes Aqueduct on the Derby Canal. Outram's Stakes aqueduct at Stalybridge Outram set out to overcome the problems with the Holmes Aqueduct by making the walls thicker where they joined the baseplates which were also thicker. However a major stress was the compressive force along the top of the wall plates where they bow outwards or inwards.
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When the tool, made up of the ultrasonic transducer, pins and other components, comes into contact with the work piece it acoustically couples with the work piece, creating harmonic resonance. This harmonic resonance is performed at a carefully calibrated frequency, to which metals respond very favorably, resulting in compressive residual stress, stress relief and grain structure improvements. Depending on the desired effects of treatment a combination of different frequencies and displacement amplitude is applied. Depending on the tool and the Original Equipment Manufacturer, these frequencies range between 15 and 55 kHz, with the displacement amplitude of the resonant body of between .
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This hexagonal phase is often referred to as a (28×5) structure, distorted and rotated by about 0.81° relative to the [011] crystal direction. Molecular dynamics simulations indicate that this rotation occurs to partly relieve a compressive strain developed in the formation of this hexagonal reconstruction, which is nevertheless favored thermodynamically over the unreconstructed structure. However, this rotation disappears in a phase transition at approximately T = 970 K, above which an un-rotated hexagonal structure is observed. A second phase transition is observed at T = 1170 K, in which an order-disorder transition occurs as entropic effects dominate at high temperature.
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Concrete tests can measure the "plastic" (unhydrated) properties of concrete prior to, and during placement. As these properties affect the hardened compressive strength and durability of concrete (resistance to freeze-thaw), the properties of workability (slump/flow), temperature, density and age are monitored to ensure the production and placement of 'quality' concrete. Depending on project location, tests are performed per ASTM International, European Committee for Standardization or Canadian Standards Association. As measurement of quality must represent the potential of concrete material delivered and placed, it is imperative that concrete technicians performing concrete tests are certified to do so according to these standards.
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Overall, there is enough concrete in the dam to pave a two-lane highway from San Francisco to New York. Concrete cores were removed from the dam for testing in 1995; they showed that "Hoover Dam's concrete has continued to slowly gain strength" and the dam is composed of a "durable concrete having a compressive strength exceeding the range typically found in normal mass concrete". Hoover Dam concrete is not subject to alkali–silica reaction (ASR), as the Hoover Dam builders happened to use nonreactive aggregate, unlike that at downstream Parker Dam, where ASR has caused measurable deterioration.
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Mount Dorothy Reservoir was completed in 1961 to meet the increasing need for water in the western suburbs of Sydney, particularly at Wentworthville and Westmead. Mount Dorothy Reservoir (WS 73) is one of only two reservoirs using prestressed concrete technology to be built by the Metropolitan Water Sewerage & Drainage Board, although a number of similar reservoirs have been taken over by the Board. It was the first in the board's area to employ the technology. The reservoir was also wrapped in a stressed steel wire providing compressive and tensile strength to the walls of the reservoir.
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This is because annealed glass, which has almost no internal stress, usually forms microscopic surface cracks, and in the absence of surface compression, any applied tension to the glass causes tension at the surface, which can drive crack propagation. Once a crack starts propagating, tension is further concentrated at the tip of the crack, causing it to propagate at the speed of sound in the material. Consequently, annealed glass is fragile and breaks into irregular and sharp pieces. On the other hand, the compressive stresses on a tempered glass contain the flaw and prevent its propagation or expansion.
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Operation of a dodge type jaw crusher Dodge type jaw crusher A jaw crusher uses compressive force for breaking of particle. This mechanical pressure is achieved by the two jaws of the crusher of which one is fixed while the other reciprocates. A jaw or toggle crusher consists of a set of vertical jaws, one jaw is kept stationary and is called a fixed jaw while the other jaw called a swing jaw, moves back and forth relative to it, by a cam or pitman mechanism, acting like a class II lever or a nutcracker. The volume or cavity between the two jaws is called the crushing chamber.
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Prior to the Eocene Epoch (55.8 ±0.2 to 33.9 ±0.1 Ma) the convergence rate of the Farallon and North American Plates was fast and the angle of subduction was shallow. During the Eocene the Farallon Plate subduction-associated compressive forces of the Laramide orogeny ended, plate interactions changed from orthogonal compression to oblique strike-slip, and volcanism in the Basin and Range Province flared up. It is suggested that this plate continued to be underthrust until about 19 Ma, at which time it was completely consumed and volcanic activity ceased, in part. Olivine basalt from the oceanic ridge erupted around 17 Ma and extension began.
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Squats can be used for some rehabilitative activities because they hone stability without excessive compression on the tibiofemoral joint and anterior cruciate ligament. Deeper squats are associated with higher compressive loads on patellofemoral joint and it is possible that people who suffer from pain in this joint cannot squat at increased depths. For some knee rehabilitation activities, patients might feel more comfortable with knee flexion between 0 and 50 degrees because it places less force compared to deeper depths. Another study shows that decline squats at angles higher than 16 degrees may not be beneficial for the knee and fails to decrease calf tension.
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Made of six to twelve sails covered in reed matting or cloth material, these windmills were used to grind corn and draw up water, and were used in the gristmilling and sugarcane industries. Horizontal-axle windmills were later used extensively in Northwestern Europe to grind flour beginning in the 1180s, and many Dutch windmills still exist. High altitude wind power is the focus of over 30 companies worldwide using tethered technology rather than ground-hugging compressive-towers. Oil is being saved by using wind for powering cargo ships by use of the mechanical energy converted from the wind's kinetic energy using very large kites.SkySails. SkySails.
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Biorock samples range in compressive strength from 3720 to 5350 lbf/in² (26 to 37MPa) - for comparison, the concrete typically used in sidewalks has a strength of about 3500 lbf/in² (24 MPa). Main components of biorock include magnesium hydroxide and calcium carbonate. This composition is chiefly the result of the ionic composition of seawater. One kilowatt hour of electricity accretes about 0.4 to 1.5 kg (0.9 to 3.3 lb) of biorock, depending on parameters such as depth, electric current, salinity and water temperature. no. 243 In one study, Porites development was compared between colonies with and without an electric field for 6 months.
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Vesta is the second largest body in the asteroid belt after Ceres. This image from the Hubble Space Telescope shows that it is not perfectly spherical. The mass of a planet has consequences for its structure by having a large mass, especially while it is in the hand of process of formation. A body which is more than about one ten-thousandth of the mass of the Earth can overcome its compressive strength and achieve hydrostatic equilibrium: it will be roughly spherical, and since 2006 has been classified as a dwarf planet if it orbits around the Sun (that is, if it is not the satellite of another planet).
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Sagittal section through the foot From above To distribute the compressive forces exerted on the heel during gait, and especially the stance phase when the heel contacts the ground, the sole of the foot is covered by a layer of subcutaneous connective tissue up to 2 cm thick (under the heel). This tissue has a system of pressure chambers that both acts as a shock absorber and stabilises the sole. Each of these chambers contains fibrofatty tissue covered by a layer of tough connective tissue made of collagen fibers. These septa ("walls") are firmly attached both to the plantar aponeurosis above and the sole's skin below.
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A photon bubble is a type of radiation-driven instability that can occur in the magnetized, radiation-supported gas surrounding neutron stars, black hole accretion disks or at the edge of ultra-compact HII regions around young, massive stars. The instability occurs as follows. A compressive magnetohydrodynamical wave propagating at right angles to the direction of propagation of the radiation creates variations in the density of the gas. More radiation is able to pass through the low density regions than through the high density regions, and the imbalance in radiation pressure acts to drive gas out of the low density regions, along the magnetic field lines.
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A sandwich panel is a composite of three or more materials bonded together to form a structural panel. It takes advantage of the shear strength of a low density core material and the high compressive and tensile strengths of the GFRC facing to obtain high strength-to-weight ratios. Public Library Lope de Vega in Tres Cantos, Madrid The theory of sandwich panels and functions of the individual components may be described by making an analogy to an I-beam. The core in a sandwich panel is comparable to the web of an I-beam, which supports the flanges and allows them to act as a unit.
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This process is grain- size sensitive and occurs at low strain rates or very high temperatures, and is accommodated by migration of lattice defects from areas of low to those of high compressive stress. The main mechanisms of diffusive mass transfer are Nabarro-Herring creep, Coble creep, and pressure solution. Nabarro–herring creep, or volume diffusion, acts at high homologous temperatures and is grain size dependent with the strain-rate inversely proportional to the square of the grain size (creep rate decreases as the grain size increases). During Nabarro-Herring creep, the diffusion of vacancies occurs through the crystal lattice [microtectonics], which causes grains to elongate along the stress axis.
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Downstream to the southwest of the valley system lies the Cerberus Palus plain. The outflow channel's route during its formation likely followed a pre-existing southwest- trending pathway, as it is bounded to the south by a wrinkle ridge associated with compressive stresses emanating from the Elysium volcanic province. It emanates from its source at Cerberus Fossae in two channels that converge approximately 25 km southwest of the fissure; after a further 80 km, the valley becomes distributary, with some of its offshoots breaching the south- bounding wrinkle ridge. Geomorphic evidence of valley-affiliated deposits disappears at its southwestern end under recent lava flows.
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Ordinary shock waves are compressive, that is, they fulfill the Lax conditions: the characteristic speed (in air, the speed of sound) behind the shock is greater than that of the shock itself, which is greater than the characteristic speed in front of the shock. The characteristic speed is the speed of small, travelling perturbations. These conditions seem to be necessary for a shock wave to remain and not decay. If the peak of a wave moves faster than at its base, then the wave front becomes self-sharpening and eventually becomes a nearly discontinuous shock, a sharp wave front which remains so when it travels.
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The beginning of fan vaulting dates to the 14th century when Romanesque and Norman buildings were adapted by inserting a “shell form” into the existing structure.Salter 2011, p. 70. This “shell form” differed from earlier versions of Gothic vaulting primarily in its structural character. Whereas earlier Gothic vaulting directed load paths to its ribs, fan vaulting distributed loads across the curved vaulting. For the conoid to function properly, it had to be supported on all sides; as “walls that support it vertically, the tas-de-charge supports its bottom, and the central spandrel panel provides the necessary compressive load along its upper edge.”Leedy 1980, p. 22.
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RMGIC, also known as hybrid cements, was developed with the purpose of eliminating weaknesses of the traditional glass-ionomer (GI) to enhance its existing properties. The addition of polymerisable resins (hydrophilic methacrylate monomers) results in higher compressive and tensile strength, as well as lower solubility, all of which are ideal properties of a dental luting agent. The setting reaction takes place with the relatively quick polymerisation of resins and gradual acid-base reaction of GI. At the early stage of setting reaction, RMGIC has a certain degree of solubility at the margins. Therefore, it is important to keep the margin dry for around 10 minutes to minimise loss of marginal cement.
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In May 2008 Putzmeister pumped concrete with more than 21 MPA ultimate compressive strength of gravel to surpass the 600 meters weight of the effective area of each column from the foundation to the next fourth level, and the rest was by metal columns jacketed or covered with concrete to a then world record delivery height of , the 156th floor. Three tower cranes were used during construction of the uppermost levels, each capable of lifting a 25-tonne load. The remaining structure above was constructed of lighter steel. In 2003, 33 test holes were drilled to study the strength of the bedrock underlying the structure.
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In the Earth's crust, anisotropy may be caused by preferentially aligned joints or microcracks, by layered bedding in sedimentary formations, or by highly foliated metamorphic rocks. Crustal anisotropy resulting from aligned cracks can be used to determine the state of stress in the crust, since in many cases, cracks are preferentially aligned with their flat faces oriented in the direction of minimum compressive stress. In active tectonic areas, such as near faults and volcanoes, anisotropy can be used to look for changes in preferred orientation of cracks that may indicate a rotation of the stress field. Both seismic P-waves and S-waves may exhibit anisotropy.
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6,542 meter high Nevado Sajama is one of several volcanoes along Cordillera Occidental The Andes of Bolivia began to rise about 200 million years ago (mya) during the Jurassic. The western margin of what is now South America had been the place of several other orogenies before the Andes rose. It has been hypothesized that the central Andes gained its great height 26 to 14 mya as result of a compressive failure of the lithosphere beneath Bolivia and neighboring areas.Geology of the Altiplano, Oregon State University The great heights of the Altiplano, Codillera Occidental and Cordillera Oriental are isostatically compensated by an up to 70 km deep crust.
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Concrete containing GGBS cement has a higher ultimate strength than concrete made with Portland cement. It has a higher proportion of the strength-enhancing calcium silicate hydrates (CSH) than concrete made with Portland cement only, and a reduced content of free lime, which does not contribute to concrete strength. Concrete made with GGBS continues to gain strength over time, and has been shown to double its 28-day strength over periods of 10 to 12 years. The optimum dosage of Ground granulated blast-furnace slag (GGBS) for replacement in concrete was reported to be 20-30% by mass to provide higher compressive strength compared to the concrete made with only cement.
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The Lake Manly lake system as it might have looked during its last maximum extent 22,000 years ago (USGS image) In the early-to-mid- Mesozoic the western edge of the North American continent was pushed against the oceanic plate under the Pacific Ocean, creating a subduction zone. A subduction zone is a type of contact between different crustal plates where heavier crust slides below lighter crust. Erupting volcanoes and uplifting mountains were created as a result, and the coastline was pushed to the west. The Sierran Arc started to form to the northwest from heat and pressure generated from subduction, and compressive forces caused thrust faults to develop.
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The challenge was to come up with new experimental techniques, specimens, and devices to test soft solids under extreme multidimensional crash loads, to simulate a typical collision event. He developed a trapezoid-shaped specimen to deduce the local stress-strain relation for metal foams to be incorporated into finite element analysis (FEA) codes. For the constitutive equation and crash failure surfaces, he developed a butterfly-shaped specimen, and modified the Arcan apparatus, deriving equations for determining shear and compressive or tensile stresses in the test section of the specimen. Due to the difficulty of handling the butterfly-shaped specimen, he developed a Universal Biaxial Testing Device with an altered specimen geometry.
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Cellebrite was established in Israel in 1999 by Avi Yablonka, Yaron Baratz, and Yuval Aflalo. Cellebrite's first manufactured hardware and software offered a compressive phone-to-phone data transfer devices and offered contact synchronization and content transfer tools for mobile phones, intended for use by wireless carrier sales and support staff in retail stores. Initially, Cellebrite's commercial products were used as a tool for migration from IS-95 (CDMA) enabled mobile phones to the GSM standard. Later, Cellebrite Wireless Carriers & Retailers' Universal Memory Exchanger (UME) gained additional data extraction and transfer capabilities, as well as additional mobile phone diagnostics, backup, and application management and delivery.
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Micronized purified flavonoid fraction (generic name diosmiplex, commercial name Vasculera) is a 2nd generation diosmin classified as a medical food by the FDA in the United States for the potential treatment of chronic venous insufficiency. Diosmiplex is the only phlebotonic, , sold as a medical food product purported for the management of chronic venous insufficiency. Diosmiplex is recommended by the American Working Group in Chronic Venous Disease as a medical therapy, alone or combined with compressive therapy, for chronic venous disease symptoms and venous ulcers, having "beneficial outcomes without serious adverse events", concurring with the previous guidance of the International European Society for Vascular Surgery.
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Circular storage structures such as silos and tanks can use prestressing forces to directly resist the outward pressures generated by stored liquids or bulk-solids. Horizontally curved tendons are installed within the concrete wall to form a series of hoops, spaced vertically up the structure. When tensioned, these tendons exert both axial (compressive) and radial (inward) forces onto the structure, which can directly oppose the subsequent storage loadings. If the magnitude of the prestress is designed to always exceed the tensile stresses produced by the loadings, a permanent residual compression will exist in the wall concrete, assisting in maintaining a watertight crack-free structure.
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Chain of transmission of stress forces in a granular media In the study of the physics of granular materials, a force chain consists of a set of particles within a compressed granular material that are held together and jammed into place by a network of mutual compressive forces. Between these chains are regions of low stress whose grains are shielded for the effects of the grains above by vaulting and arching. A set of interconnected force chains is known as a force network. Force networks are an emergent phenomenon that are created by the complex interaction of the individual grains of material and the patterns of pressure applied within the material.
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In the case of the more common compound dome, the pendentives are part of the surface of a larger sphere below that of the dome itself and form a circular base for either the dome or a drum section. The fields of engineering and architecture have lacked common language for domes, with engineering focused on structural behavior and architecture focused on form and symbolism. Additionally, new materials and structural systems in the 20th century have allowed for large dome-shaped structures that deviate from the traditional compressive structural behavior of masonry domes and popular usage of the term has expanded to mean "almost any long-span roofing system".
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A masonry dome produces thrusts downward and outward. They are thought of in terms of two kinds of forces at right angles from one another: meridional forces (like the meridians, or lines of longitude, on a globe) are compressive only, and increase towards the base, while hoop forces (like the lines of latitude on a globe) are in compression at the top and tension at the base, with the transition in a hemispherical dome occurring at an angle of 51.8 degrees from the top. The thrusts generated by a dome are directly proportional to the weight of its materials. Grounded hemispherical domes generate significant horizontal thrusts at their haunches.
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The branched structure of the oculomotor nerve means that damage sustained at different points along its pathway, or damage caused in different ways (compression versus loss of blood supply vs neuropathy, for example), will result in different muscle groups or, indeed, different individual muscles being affected, thus producing different presentation patterns. Compressive oculomotor nerve damage could result in compression of the parasympathetic fibers before any disruption of the motor fibers occurs, since the parasympathetic fibers run on the outside of the nerve. Therefore, one could have mydriasis (a "blown" pupil) as a result of parasympathetic fiber compression before lid ptosis and the "down and out" position are seen.
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In 2008, Houssam Toutanji, of the University of Alabama in Huntsville, and Richard Grugel, of the Marshall Space Flight Center, used a lunar soil simulant to determine whether lunarcrete could be made without water, using sulfur (obtainable from lunar dust) as the binding agent. The process to create this sulfur concrete required heating the sulfur to 130-140 °C. After exposure to 50 cycles of temperature changes, from -27 °C to room temperature, the simulant lunarcrete was found to be capable of withstanding compressive pressures of 17MPa, which Toutanji and Grugel believed could be raised to 20MPa if the material were reinforced with silica (also obtainable from lunar dust).
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Other compressive spinal causes include lumbar spinal stenosis, a condition in which the spinal canal, the space the spinal cord runs through, narrows and compresses the spinal cord, cauda equina, or sciatic nerve roots. This narrowing can be caused by bone spurs, spondylolisthesis, inflammation, or a herniated disc, which decreases available space for the spinal cord, thus pinching and irritating nerves from the spinal cord that become the sciatic nerve. This is the most frequent cause after age 50. Sciatic pain due to spinal stenosis is most commonly brought on by standing, walking, or sitting for extended periods of time, and reduces when bending forward.
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A 500 mm lens A 150–500mm telephoto zoom lens An example of the telephoto's compressive effect. The focal length is 200mm, from the traffic sign it is 320 meters to the ship. In contrast to a telephoto lens, for any given focal length a simple lens of non- telephoto design is constructed from one lens (which can, to minimize aberrations, consist of several elements to form an achromatic lens). To focus on an object at infinity, the distance from this single lens to focal plane of the camera (where the sensor or film is respectively) has to be adjusted to this focal length.
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Wires were steel. Unlike the compressive wave, however, the torsional waves are considerably more resistant to problems caused by mechanical imperfections, so much so that the wires could be wound into a loose coil and pinned to a board. Due to their ability to be coiled, the wire-based systems could be built as "long" as needed, and tended to hold considerably more data per unit; 1k units were typical on a board only 1 foot square. Of course this also meant that the time needed to find a particular bit was somewhat longer as it traveled through the wire, and access times on the order of 500 microseconds were typical.
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The locomotive body is a welded monocoque design, constructed of steel plates and profiled members, which has a compressive strength of and a tensile strength of . The Class 21E has a single cab and a gangway along the centre of the locomotive. It is equipped with a wireless data transmission system which can send the locomotive operation status, fault data and energy consumption data via GSM and Wi-Fi to a trackside station for analysis. It is also equipped with an axle temperature alarm device, fire alarm system, closed-circuit television (CCTV) system, wheel flange lubricating device and, as personnel safety measure, high voltage protective interlocking devices.
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The underside of the labrum is continuous with the acetabular articular cartilage so any compressive forces that affect the labrum may also cause articular cartilage damage, particularly at the junction between the two, the chondrolabral junction. The labrum may be damaged or torn as part of an underlying process, such as FAI or dysplasia (shallow hip socket), or may be injured directly by a traumatic event. Depending on the type of tear, the labrum may be either trimmed (debrided) or repaired. Removing or debriding the labrum is becoming less popular as the latest research shows that results are more predictable in the long term if the labrum can be repaired.
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With the variation of the lath thickness and use of coarse straw and manure, the clay coat of plaster was thick in comparison to later lime-only and gypsum plasters. In Economy Village, the lime top coats are thin veneers often an eighth inch or less attesting to the scarcity of limestone supplies there. Clay plasters with their lack of tensile and compressive strength fell out of favor as industrial mining and technology advances in kiln production led to the exclusive use of lime and then gypsum in plaster applications. However, clay plasters still exist after hundreds of years clinging to split lath on rusty square nails.
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Traditionally, they were called coolants as they were used to prevent frictional heat build up which could damage the workpiece (such as ruining the temper of a blade). Some research suggests that the heat transport property of a lubricant is less important when dealing with metals as the metal will quickly conduct heat from the work surface. More important are their effects upon lessening tensile stresses while increasing some compressive stresses and reducing "thermal and mechanical stresses during chip formation".Grinding Stresses, Grinding Wheel Institute, 1964 Various shapes are also used as heads on rotary tools used in precision work, such as scale modelling.
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On December 3, 1979, 11 teenagers and young adults were killed by compressive asphyxia and 26 other people were injured in a rush for seating at the opening of a sold-out rock concert by the English rock band The Who. On that evening, there were a total of 18,348 ticketed fans attending, which included 14,770 in general admission seats. The concert was using festival seating, where seats are available on a first-come, first-served basis. When the waiting fans outside the Coliseum heard the band performing a late sound check, they thought that the concert was beginning and tried to rush into the still-closed doors.
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Germanium doping of up to 20% in the P-channel MOSFET source and drain causes uniaxial compressive strain in the channel, increasing hole mobility. Carbon doping as low as 0.25% in the N-channel MOSFET source and drain causes uniaxial tensile strain in the channel, increasing electron mobility. Covering the NMOS transistor with a highly stressed silicon nitride layer is another way to create uniaxial tensile strain. As opposed to wafer-level methods of inducing strain on the channel layer prior to MOSFET fabrication, the aforementioned methods use strain induced during the MOSFET fabrication itself to alter the carrier mobility in the transistor channel.
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Sodium polyacrylate is a commonly used electronegative polyelectrolyte which could be used to construct self-healing hydrogels and super-absorbents. Novel chitosan/sodium polyacrylate polyelectrolyte complex hydrogels (CPG) have been fabricated successfully in a study by cross-linking chitosan and sodium polyacrylate with epichlorohydrin (ECH) through the inhibiting protonation effect of chitosan in an alkali/urea aqueous solution. The CPG had a high swelling ratio because of sodium polyacrylate and acted differently in various pH solutions, physiological solutions, and salt solutions with different concentrations. As a result, CPG had smart responsive properties to different situations and exhibited high compressive strength, good biocompatibility and in-vitro biodegradability.
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As the Finnpusku system is designed to operate independently in the severe ice conditions of the Bothnian Sea, special attention has been paid to the hull form. The spoon-shaped bow has a low stem angle to reduce icebreaking resistance and the sides of the barge are flared to prevent the combination from becoming immobilized by ice ridges and compressive ice fields. When the pusher is coupled to the barge, the deep stern notch forms a streamlined aftship with seakeeping characteristics similar to those of conventional ships. When coupled, the power for the ramps, pumps, floodlights and other equipment on board the barge is taken from the pusher.
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A sub-surface compressive residual stress profile is measured using techniques such as x-ray diffraction and hardness profile testings. The X-axis is depth in mm or inches and the Y-axis is residual stress in ksi or MPa. The maximum residual stress profile can be affected by the factors of shot peening, including: part geometry, part material, shot material, shot quality, shot intensity, and shot coverage. For example, shot peening a hardened steel part with a process and then using the same process for another unhardened part could result in overpeening; causing a sharp decrease in surface residual stresses, but not affecting sub-surface stresses.
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Hearst Mining building clad in stone on the left, with extension on the right covered in shot peened aluminum alloy Shot peening is a cold working process used to produce a compressive residual stress layer and modify the mechanical properties of metals and composites. It entails striking a surface with shot (round metallic, glass, or ceramic particles) with force sufficient to create plastic deformation."Shot Peening," Tool and Manufacturing Engineers Handbook (TMEH), Volume 3, Society of Manufacturing Engineers, 1985 In machining, shot peening is used to strengthen and relieve stress in components like steel automobile crankshafts and connecting rods. In architecture it provides a muted finish to metal.
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The locomotive body is a welded monocoque design, constructed of steel plates and profiled members which has a compressive strength of and a tensile strength of . The Class 20E is equipped with a wireless data transmission system which can send the locomotive operation status, fault data and energy consumption data via GSM and Wi-Fi to a trackside station for analysis. It is also equipped with an axle temperature alarm device, fire alarm system, closed-circuit television (CCTV) system, wheel flange lubricating device and, as personnel safety measure, high voltage protective interlocking devices. The AC traction motors are powered through insulated-gate bipolar transistor (IGBT) control.
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The Gairloch Bridge is an example of the earliest use of concrete, where it was restricted to applications requiring only compressive strength such as piers and abutments. The introduction to Queensland of reinforced concrete a few years after the bridge was built broadened the applications of concrete to include components requiring tensile strength. The place is important in demonstrating the principal characteristics of a particular class of cultural places. The Gairloch Bridge is important in demonstrating the principal characteristics of submersible bridges: it is a low level bridge, crossing only the main channel of the river, and is designed to present the least possible obstruction to flood waters and debris.
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In the oil and gas industry, a drill bit is a tool designed to produce a generally cylindrical hole (wellbore) in the earth’s crust by the rotary drilling method for the discovery and extraction of hydrocarbons such as crude oil and natural gas. This type of tool is alternately referred to as a rock bit, or simply a bit. The hole diameter produced by drill bits is quite small, from about to , compared to the depth of the hole, which can range from to more than . Subsurface formations are broken apart mechanically by cutting elements of the bit by scraping, grinding or localized compressive fracturing.
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On 11 October 2010, news broke that the concrete structures of two connecting passages in the north extension of Line 3 between Jiahewanggang and Longgui had substandard compressive strength. The quality of the two connecting passages was found to be questionable as early as August 2009. But it not was brought to light until a technician who worked for a company that inspected their quality posted scanned copies of the original inspection reports in his blog in August 2010, and the media picked up the story in October 2010. The connecting passages were intended as connections between two metro tunnels for the maintenance crew and emergency escape corridors for passengers.
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Articular cartilage, most notably that which is found in the knee joint, is generally characterized by very low friction, high wear resistance, and poor regenerative qualities. It is responsible for much of the compressive resistance and load bearing qualities of the knee joint and, without it, walking is painful to impossible. Osteoarthritis is a common condition of cartilage failure that can lead to limited range of motion, bone damage and invariably, pain. Due to a combination of acute stress and chronic fatigue, osteoarthritis directly manifests itself in a wearing away of the articular surface and, in extreme cases, bone can be exposed in the joint.
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Surgical approaches have also been used successfully in TOS. Microsurgery can be used approaching the area from above the collar bone (supraclavicular) followed by neurolysis of the brachial plexus, removal of the scalene muscle (scalenectomy), and the release of the underlying (subclavicular) blood vessels. This approach avoids the use of resection, and has been found to be an effective treatment. In cases where the first rib (or a fibrous band extending from the first rib) is compressing a vein, artery, or the nerve bundle, part of the first rib and any compressive fibrous tissue, can be removed in a first rib resection and thoracic outlet decompression surgical procedure; scalene muscles may also need to be removed (scalenectomy).
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In 2011, with Ifat levy, Stephanie Lazzaro and Robb Rutledge, he published the first demonstration that activity patterns in the human medial prefrontal cortex, measured in the absence of choice behavior, could be used to predict later choices by the same individuals in the Journal of Neuroscience.Levy, I., Lazzaro, S., Rutledge, R.B., & Glimcher, P.W. (2011). Choice from non-choice: Predicting consumer preferences from blood oxygenation level-dependent signals obtained during passive viewing. Journal of Neuroscience, 31(1): 118-125 In 2013, with Kenway Louie and Mel Win Khaw, he demonstrated that efficient compressive encoding of subjective value by neurons in the brains of monkeys predicts novel anomalies in choice behavior which they subsequently observed in both monkeys and humans.
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Pages 22–24 extensive model testing at Wärtsilä's new ice model test basin showed that the ice resistance could be reduced by replacing the bow propellers with a "clean" hull and adopting an air bubbling system to lubricate the hull. The patented Wärtsilä Air Bubbling System (WABS) onboard Otso consists of three compressors with a combined output of 1,900kW that pump air through 46 nozzles located below the waterline on both sides of the vessel. At low speeds, the system can also be used for manoeuvering. In addition, she has large ballast tanks and high-capacity pumps that can be used for rapid heeling and trimming to release the icebreaker if she is immobilized by compressive pack ice.
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The stiff-arm fend is particularly effective because its force is applied down the length of a straight arm, directly into the shoulder. This puts the arm bones exclusively under compressive axial stress, the stress to which bone is strongest, and ensures that minimal torque is applied to the shoulder joint. As such, the force that can be applied by a stiff-arm fend can easily repel or topple an oncoming defender. The same techniques are practised by some schools of martial artists when striking or punching; by ensuring that the direction of the force is directly down a locked, straight arm, martial artists can punch through bricks and tiles without damaging their arms.
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To form an ionic bond, either a valence or bonding electron separates from one atom and becomes attached to another atom to form oppositely charged ions. The bonding in the static position is when the ions occupy an equilibrium position where the resulting force between them is zero. When the ions are exerted in tension force, the inter-ionic spacing increases creating an electrostatic attractive force, while a repulsing force under compressive force between the atomic nuclei is dominant. Covalent bonding takes place when one of the constituent atoms loses one or more electrons, with the other atom gaining the electrons, resulting in an electron cloud that is shared by the molecule as a whole.
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The mechanical properties of the tendon are dependent on the collagen fiber diameter and orientation. The collagen fibrils are parallel to each other and closely packed, but show a wave-like appearance due to planar undulations, or crimps, on a scale of several micrometers. In tendons, the collagen fibres have some flexibility due to the absence of hydroxyproline and proline residues at specific locations in the amino acid sequence, which allows the formation of other conformations such as bends or internal loops in the triple helix and results in the development of crimps. The crimps in the collagen fibrils allow the tendons to have some flexibility as well as a low compressive stiffness.
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In prehistoric times, particularly the Miocene epoch, portions of the landforms now in the area (then marshy and grassy savanna) were populated by a wide range of now extinct mammals, known in modern times by the fossil remains excavated in the southern part of the county. In the northern part of the county, significant coal and sand deposits were formed in even earlier geologic eras. Other areas of the county have ridges exposing ancient but intact (not fossilized) seashells, embedded in sandstone layers alternating with limestone. Layers of volcanic ash ejected from geologically recent but now extinct volcanoes, compacted and now tilted by compressive forces, may be seen at the site of some road excavations.
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Ionic crystals are made up of quite different ions, such as Na+ and Cl− in common salt, for example, while covalent crystals such as diamond are made up of atoms that share electrons in a covalent bond. In either case, attractive and repulsive forces resist moving an atom/ion or a set of them from their equilibrium positions, thus giving solids their rigidity against compressive, tensile, and shear stresses. The nature and strength of these forces is important for the scientific understanding of solids since they determine the way the solid responds to these stresses (elastic constants), the velocity of sound waves in it, its infra-red absorption, and many other properties.
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Several compositional ratios or so-called hydraulic indices have been used to correlate slag composition with hydraulic activity; the latter being mostly expressed as the binder compressive strength. The glass content of slags suitable for blending with Portland cement typically varies between 90-100% and depends on the cooling method and the temperature at which cooling is initiated. The glass structure of the quenched glass largely depends on the proportions of network- forming elements such as Si and Al over network-modifiers such as Ca, Mg and to a lesser extent Al. Increased amounts of network-modifiers lead to higher degrees of network depolymerization and reactivity. Common crystalline constituents of blast-furnace slags are merwinite and melilite.
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Finally, the elasticity of the barrel can be tested by applying internal pressure once more, but this time care is taken to ensure that the inner layers are not stretched beyond their new elastic limit. The end result is an inner surface of the gun barrel with a residual compressive stress able to counterbalance the tensile stress that would be induced when the gun is discharged. In addition the material has a higher tensile strength as a result of the heat treatment process.Brassey's Battlefield Weapons Systems & Technology Volume II, Guns, Mortars & Rockets by J W Ryan Royal Military College of Science, Shrivenham, UK. In early practice of autofrettage of a gun barrel, the barrel was pressurized hydraulically.
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Photo of the fold looking south from the Strike Valley Overlook (USGS) The Laramide orogeny compacted the region from about 70 million to 50 million years ago and in the process created the Rocky Mountains. Many monoclines (a type of gentle upward fold in rock strata) were also formed by the deep compressive forces of the Laramide. One of those monoclines, called the Waterpocket Fold, is the major geographic feature of the park. The 100 mile (160 km) long fold has a north-south alignment with a steeply east-dipping side. The rock layers on the west side of the Waterpocket Fold have been lifted more than 7,000 feet (2,100 m) higher than the layers on the east.
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Inopinaves is a clade of neoavian birds recovered in a compressive genomic systematic study using nearly 200 species in 2015, that contains the clades Opisthocomiformes (Hoatzin) and Telluraves (core landbirds); the study shows that the Hoatzin diverged from other birds 64 million years ago.Prum, R.O. et al. (2015) A comprehensive phylogeny of birds (Aves) using targeted next- generation DNA sequencing. Nature. doi:10.1038/nature15697 Previous studies have placed the Hoatzin in different parts of the bird family tree; however, despite its unusual and primitive morphology, genetic studies have shown the hoatzin is not as primitive or as ancient as once thought, and that it could be a very derived bird that reverted to or retains some plesiomorphic traits.
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A conventional bicycle wheel consists of a thin rim kept under high compressive stress by the (roughly normal) inward pull of a large number of spokes. It can be considered as a loaded column that has been bent into a circle. If spoke tension is increased beyond a safe level or if part of the rim is subject to a certain lateral force, the wheel spontaneously fails into a characteristic saddle shape (sometimes called a "taco" or a "pringle") like a three-dimensional Euler column. If this is a purely elastic deformation the rim will resume its proper plane shape if spoke tension is reduced or a lateral force from the opposite direction is applied.
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The debris deposit is the accumulated mass of the avalanched snow once it has come to rest in the runout zone. For the image at left, many small avalanches form in this avalanche path every year, but most of these avalanches do not run the full vertical or horizontal length of the path. The frequency with which avalanches form in a given area is known as the return period. The start zone of an avalanche must be steep enough to allow snow to accelerate once set in motion, additionally convex slopes are less stable than concave slopes, because of the disparity between the tensile strength of snow layers and their compressive strength.
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Whereas a first order upwind scheme smears the interface, a downwind scheme of the same order will cause a false distribution problem which will cause erratic behavior in case of the flow is not oriented along a grid line. As these lower-order schemes are inaccurate, and higher-order schemes are unstable and induce oscillations, it has been necessary to develop schemes which keep the free-surface sharp while also producing monotonic profiles for C. Over the years, a multitude of different methods for treating the advection have been developed. In the original VOF-article by Hirt, a donor-acceptor scheme was employed. This scheme formed a basis for the compressive differencing schemes.
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Pratt trusses were introduced to Australia from the United States in 1892 with the construction of the light- rail Yass Tramway. Thereafter they became the standard for Main Line railways for spans over . While previous forms of truss had lent themselves to construction from timber, with stocky timber sections with good compressive and buckling resistance forming the diagonal members, the Pratt Truss reversed the direction of load in the diagonal members, enabling light rods or flat bars to be used in tension, making steel trusses highly efficient. The New South Wales Railways continued to employ the use of steel Pratt trusses for major bridge crossings until the advent of reinforced and prestressed concrete in the 1970s.
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In quantum theory, the word adiabatic can mean something perhaps near isentropic, or perhaps near quasi- static, but the usage of the word is very different between the two disciplines. On the one hand, in quantum theory, if a perturbative element of compressive work is done almost infinitely slowly (that is to say quasi- statically), it is said to have been done adiabatically. The idea is that the shapes of the eigenfunctions change slowly and continuously, so that no quantum jump is triggered, and the change is virtually reversible. While the occupation numbers are unchanged, nevertheless there is change in the energy levels of one-to-one corresponding, pre- and post-compression, eigenstates.
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The process of the protective coating formation, called revitalization, is based on physical-chemical interaction between surfaces of the parts on the spots of virtual contact covered with revitalizant in a boundary or mixed lubrication mode. As a result a gradient cermet coating is formed, containing positive compressive stresses all over its depth and concentration of carbon, increasing at the surface (up to the formation of diamond-like structures). Distinctive feature of the process is a hardening of the coating with its simultaneous growthDzhus R. N. System-physic approach to the explanation of anti-wear friction with the use of revitalizants / /Public Information and Computer Technology: Collection of scientific papers. 23rd Publication – Kharkiv: National Aerospace University "Kharkiv Aviation Institute".
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The geological map of Portugal at the scale of 1:500,000 shows the contact between the Schist-Greywacke Complex of the "Beiras Group" and the Variscan Granitic Complex of the North of Portugal. The "Beiras Group" is formed by a dense series of thin lentils of marine origin, of clay and sandstones, that later suffered low grade regional metamorphism (facies of the green schist) during the initial compressive phases of the Variscan orogeny. The Panasqueira mines are located in the area of the Schist-Greywacke Complex of the Beiras Group, in Central Iberian Zone (ZCI). It is a region where metamorphism sedimentary formations predominates, but where there is also a large number of acidic and basic eruptive manifestations.
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Strom and others argued that the ridges were formed by compressive stress generated by subsidence of the floor, and the fractures by subsequent uplift of the center of the basin to produce crustal lengthening and the observed fracture pattern. The origin of the material itself is doubtful. It may consist of sheets of volcanic material emplaced shortly after the basin was formed or it may be material formed by the Caloris event either as melt or as the upper part of a plug of plastic material that rose in the crater floor as part of the impact process. Whatever the origin of this material, it seems clear that it covers the original floor of the excavated crater.
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As such, devices such as a Starling Resistor are often used to predict fluid flow under these conditions. Fluid is forced through an elastically deforming tube which passes through a region of high external pressure causing a flattening of the tube depending on the relative pressures of the inside and outside of the tube. In the absence of any flow (puD pd), an increase in pe generates a compressive stress in the tube wall causing it to buckle from a circular to an elliptic cross-section (except, of course, near its ends, where it is attached to the rigid tubes). Buckling to a shape with more than two lobes may arise in short, tethered, or inhomogeneous tubes.
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Glasgow Tower, Scotland's tallest tower, and the IMAX Cinema at the Glasgow Science Centre From the 1980s there was a backlash against the statism and compressive nature of modernist architecture. Instead there was a move towards a form of post-modernism that looked to a clash of styles with a renewed emphasis on visual aesthetics that invoked classicism. There was also a combination of the private and the public. This movement against modernism also included renewed influence by the Scots baronial and Mackintosh-inspired designs; these can be seen respectively in the Scandic Crown Hotel (1988–89) in the Old Town in Edinburgh and the National Library Causewayside Building (1985–87, extended 1993–94).
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Although the construction of such a massive habitable statite would be a gigantic undertaking, and the required material science behind it is early stage, there are other engineering feats and required materials proposed in other Dyson sphere variants. In theory, if enough satellites were created and deployed around their star, they would compose a non-rigid version of the Dyson shell mentioned below. Such a shell would not suffer from the drawbacks of massive compressive pressure, nor are the mass requirements of such a shell as high as the rigid form. Such a shell would, however, have the same optical and thermal properties as the rigid form, and would be detected by searchers in a similar fashion (see below).
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Dental compomers are another type of white filling material although their use is not as widespread. Compomers were formed by modifying dental composites with poly-acid in an effort to combine the desirable properties of dental composites, namely their good aesthetics, and glass ionomer cements, namely their ability to release fluoride over a long time. Whilst this combination of good aesthetics and fluoride release may seem to give compomers a selective advantage, their poor mechanical properties (detailed below) limits their use. Compomers have a lower wear resistance and a lower compressive, flexural and tensile strength than dental composites, although their wear resistance is greater than resin-modified and conventional glass ionomer cements.
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Deperdussin Monocoque, with wooden shell construction Monocoque (), also called structural skin, is a structural system in which loads are supported by an object's external skin, similar to an egg shell. The word monocoque is a French term for "single shell" or (of boats) "single hull".Merriam-Webster Dictionary, 2011 First used for boats, a true monocoque carries both tensile and compressive forces within the skin and can be recognised by the absence of a load-carrying internal frame. Few metal aircraft can strictly be regarded as pure monocoques, as they use a metal shell or sheeting reinforced with frames riveted to the skin, but most wooden aircraft are described as monocoques, even though they also incorporate frames.
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Different from "true" arches, "false" or corbelled arches are built of horizontally laid stones or bricks, not of wedge-shaped voussoirs converging towards, and being held together by a central keystone. Unlike "true" arches, not all of the structure's tensile stresses caused by the weight of the superstructure are transformed into compressive stresses. Corbel arches and vaults require significantly thickened walls and an abutment of other stone or fill to counteract the effects of gravity, which otherwise would tend to collapse each side of the archway inwards. Some arches use a stepped style, keeping the block faces rectangular, while other form or select them to give the arch smooth edges, usually with a pointed shape.
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The rings associated with the four ancient basins are the oldest structures within the mapped area and have to some degree controlled the structural trends of subsequent tectonism. Several of the lobate ridges described by Strom follow arcuate patterns along rings of the Barma-Vincente Basin; Hero Rupes is an example. These lobate ridges appear to be of compressive tectonic origin and, although global in distribution, may be deflected locally by the presence of preexisting, basin-related structure. Additional effects of these ancient basin rings may be seen where the rim of Dostoevskij intersects the Barma-Vincente rings (for example, the horst at –40°, 174°); parts of the Dostoevskij rim appear to have been structurally accented by this intersection.
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Prior to the Eocene Epoch (55.8 ±0.2 to 33.9 ±0.1 Ma) the convergence rate of the Farallon and North American Plates was fast, the angle of subduction was shallow, and the slab width was huge. During the Eocene the Farallon Plate subduction-associated compressive forces of the Laramide, Sevier and Nevada orogenies ended, plate interactions changed from orthogonal compression to oblique strike-slip, and volcanism in the Basin and Range Province flared up (Mid-Tertiary ignimbrite flare-up). It is suggested that this plate continued to be underthrust until about 19 Ma, at which time it was completely consumed and volcanic activity ceased, in part. Olivine basalt from the oceanic ridge erupted around 17 Ma and extension began.
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In geology, the slab gap hypothesis is one of the explanations put forward to explain several instances of crustal extension that occur inland near former subduction zones. Standard plate tectonic theory holds that once a trench is closed by an overriding plate reaching a rift/spreading center, the plate that has just been fully consumed continues to descend beneath the overriding plate for some time, transmitting compressive pressures to the overriding plate above as well as occasional volcanism. Meanwhile, the descending plate leaves behind it a "window" of inactivity. In this view, there is no mantle upwelling, so once the crustal rift is overridden, the only residual effects are from the remnant descending plate slab.
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Under compressive stress, the ceramic static bearing has a low risk of failure, but a SiC shaft sleeve does not have this situation and must, therefore, have a large wall thickness and/or be specially designed. In large pumps with shafts in diameter, the risk of failure is higher due to the changing requirements on the pump performance – for example, load changes during operation. The introduction of SiC/SiC as a shaft sleeve material has proven to be very successful. Test rig experiments showed an almost triple specific load capability of the bearing system with a shaft sleeve made of SiC/SiC, sintered SiC as static bearing, and water at as lubricant.
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A piggyback basin (also piggy-back, thrust-sheet-top, detached, or satellite basin) is a minor sedimentary basin developed on top of a moving thrust sheet as part of a foreland basin system. Piggyback basins form in the wedge-top depositional zone of a foreland basin system as new thrusts in the foreland cut up through the existing footwall containing the eroded wedge-top basins in the old thrust sheet. The basin is separated from the foredeep by an anticline or syndepositional growth structures. The piggyback basin is named after its tendency to be carried passively toward the hinterland with the old thrust sheet in response to the compressive forces of the new thrust sheet.
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These may be supplied with concrete mixed on site, or may be provided with 'ready-mixed' concrete made at permanent mixing sites. Portland cement is also used in mortars (with sand and water only), for plasters and screeds, and in grouts (cement/water mixes squeezed into gaps to consolidate foundations, road-beds, etc.). When water is mixed with Portland cement, the product sets in a few hours, and hardens over a period of weeks. These processes can vary widely, depending upon the mix used and the conditions of curing of the product, but a typical concrete sets in about 6 hours and develops a compressive strength of 8 MPa in 24 hours.
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Design of the fs23 was started in 1953 and took thirteen years, including a hiatus while the fs24 Phönix was developed. The goal of the fs23 designers was a lightweight high-performance glider to meet the proposed 13m mini-standard class for competition gliders. To achieve this goal the students at Akaflieg Stuttgart thoroughly tested fibreglass re-inforced composites, as well as birch ply and balsa/fibreglass sandwiches, for E- and G-modulus, compressive and torsional strength as well as bonding and rivetting methods. Once the testing was complete the aircraft could be designed to ensure adequate strength with light weight, (1/3 to 2/3 the weight of typical gliders of the time), and good aerodynamic qualities, the result being the fs23 Hidalgo.
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The flanks of the east-west trending Uinta Mountains contain a sequence of Paleozoic and Mesozoic strata ranging from the Cambrian Lodore Formation to the Cretaceous Mancos Shale, all of which have been tilted during the uplift of the mountain range. The uplift of the range dates to the Laramide orogeny, about 70 to 50 million years ago, when compressive forces produced high-angle reverse faults on both north and south sides of the present mountain range. The east-west orientation of the Uintas is anomalous compared to most of the ranges of the Rocky Mountains; it may relate to changing stress patterns and rotation of the Colorado Plateau.Hamilton, W.B., 1981, Plate-tectonic mechanism of Laramide deformation, in Boyd, D.W., and Lillegraven, J.A., eds.
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The main mechanism of detonation propagation is of a powerful pressure wave that compresses the unburnt gas ahead of the wave to a temperature above the autoignition temperature. In technical terms, the reaction zone (chemical combustion) is a self-driven shock wave where the reaction zone and the shock are coincident, and the chemical reaction is initiated by the compressive heating caused by the shock wave. The process is similar to ignition in a Diesel engine, but much more sudden and violent. Under certain conditions, mainly in terms of geometrical conditions (such as partial confinement and many obstacles in the flame path that cause turbulent flame eddy currents), a subsonic flame may accelerate to supersonic speed, transitioning from deflagration to detonation.
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The lattice structure transitioned from FCC to BCC as Al content increased and with Al content in the range of 12.5 to 19.3 at%, the γ′ phase formed and strengthened the alloy at both room and elevated temperatures. With Al content at 19.3 at%, a lamellar eutectic structure formed composed of γ′ and B2 phases. Due to high γ′ phase fraction of 70 vol%, the alloy had a compressive yield strength of 925 MPa and fracture strain of 29% at room temperature and high yield strength at high temperatures as well with values of 789, 546, and 129 MPa at the temperatures of 973, 1123, and 1273K. In general, refractory high-entropy alloys have exceptional strength at elevated temperatures but are brittle at room temperature.
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Prince Rupert's drops have remained a scientific curiosity for nearly 400 years due to two unusual mechanical properties: when the tail is snipped, the drop disintegrates explosively into powder, whereas the bulbous head can withstand compressive forces of up to . The explosive disintegration arises due to multiple crack bifurcation events when the tail is cut – a single crack is accelerated in the tensile residual stress field in the center of the tail and bifurcates after it reaches a critical velocity of . Given these high speeds, the disintegration process due to crack bifurcation can only be inferred by looking into the tail and employing high speed imaging techniques. This is perhaps why this curious property of the drops remained unexplained for centuries.
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Mortar beds were used underneath almost every tile or stone installation until the late 1950s when a chemical engineer, Henry M. Rothberg, invented the technology which introduced latex to sand/cement mortar mixes, and created a new industry based on thin bed adhesive installations by founding Laticrete International, Inc. Mortars used in this technique typically have a compressive strength ranging from at least 400 psi (2.8 MPa) to 1600 psi (11 MPa), when tested using ANSI testing procedures. However, with advancements in technology and materials, the potential strengths of the thick bed mortar system have increased. Quality controlled manufacturing processes create thick bed mortar mixes which combine carefully graded, high quality aggregates (sand) in a precise ratio with portland cement.
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Most of the tunnel passes through the Upper Hythe C and D layers and the Lower Hythe A layer, which are described as "Weak, locally very weak to moderately strong, slightly clayey fine-to-medium sandstone with occasional thin beds of clayey/silty fine sand" and typically has Uniaxial Compressive Strength (UCS) values of 2–5 MPa. The rock is heavily fractured and has mean fracture centres varying from . The southern end of the tunnel however passes through the "less competent" Upper Hythe A and B layers which are described as "medium-dense thinly bedded and thinly laminated, clean-to-silty and clayey fine and medium sand with subordinate weak-to-strong sandstone, cherty sandstone and chert". Most of the tunnel is above the predicted water table.
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The uplift of the Serranía del Perijá made the Cesar-Ranchería Basin an intermontane basin A second phase of compressive margin has been noted in the Cesar-Ranchería Basin by the strong differences between the sedimentary thicknesses of the Paleocene formations. During this stage in the basin development, the Cesar-Ranchería Basin was connected to the Middle Magdalena Valley to the west. The Paleocene Lisama Formation has a reduced thickness in the northern part of the Middle Magdalena Valley due to erosion, while the Paleocene section in the Cesar-Ranchería Basin is very thick. This has been explained by the tilt of the Sierra Nevada de Santa Marta and the formation of several thick-skinned thrust faults in the basin.
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The Phlegra Montes are a system of eroded Hesperian–Noachian-aged massifs and knobby terrain in the mid-latitudes of the northern lowlands of Mars, extending northwards from the Elysium Rise towards Vastitas Borealis for nearly . The mountain ranges separate the large plains provinces of Utopia Planitia (west) and Amazonis Planitia (east), and were named in the 1970s after a classical albedo feature. The massif terrains are flanked by numerous parallel wrinkle ridges known as the Phlegra Dorsa. The mountain ranges were first mapped against imagery taken during NASA's Viking program in the 1970s, and the area is thought to have been uplifted due to regional-scale compressive stresses caused by the contemporary formations of the Elysium and Tharsis volcanic provinces.
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The block moves in a northwest direction while the rest of the North American Plate is moving in a southwest direction. In far northern California, this produces a zone of convergence which has resulted in the compressive uplift of the Coast Ranges. At its core, the SNGV block consists primarily of the Sierra Nevada batholith which has been tilted westward like a large trapdoor with its "hinge" lying deep beneath the sediments which fill California's Central Valley. This tilt is attributed to the buoyancy of the eastern part of the block due to the greater subterranean heat associated with the tectonics of the adjacent Great Basin, compounded by the weight of sediments accumulating over the western portion of the block.
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Zimmerli first published a report in 1940. John Almen did more research, and during World War 2 introduced it to the aircraft industry.. By 1950, peening became an accepted process and was being included in engineering literature. In the same year, peen forming was invented to form the wing skin of the Super Constellation aircraft. In the early 1970s peening experienced a major innovation when researchers such as Allan Clauer at Battelle labs in Columbus, Ohio applied high intensity laser beams onto metal components to achieve deep compressive residual stresses, which they patented as Laser Shock Peening, and became known as laser peening in the late 1990s, when it was first applied to gas fired turbine engine fan blades for the U.S. Air Force.
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The tectonic setting of western North America changed drastically as the Farallon Plate under the Pacific Ocean to the west was shallowly subducted below North American Plate. Called the Laramide orogeny, the compressive forces generated from this collision erased the Cretaceous Seaway, fused the Sierran Arc to the rest of North America and created the Rocky Mountains. This mountain-building event started in the Mesozoic 80 million years ago and lasted well into the first half of the Cenozoic era 30 million years ago.Smith, Windows into the Earth (2000), page 101 Teton fault block Some 60 million years ago, these forces uplifted the low-lying coastal plain in the Teton region and created the north-south-trending thrust faults of the nearby Wyoming Overthrust Belt.
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In this typical context, external forces and reactions to those forces are considered to act only at the nodes and result in forces in the members that are either tensile or compressive. For straight members, moments (torques) are explicitly excluded because, and only because, all the joints in a truss are treated as revolutes, as is necessary for the links to be two-force members. A planar truss is one where all members and nodes lie within a two-dimensional plane, while a space truss has members and nodes that extend into three dimensions. The top beams in a truss are called top chords and are typically in compression, the bottom beams are called bottom chords, and are typically in tension.
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Low W/C ratios and the use of silica fume make concrete mixes significantly less workable, which is particularly likely to be a problem in high-strength concrete applications where dense rebar cages are likely to be used. To compensate for the reduced workability, superplasticizers are commonly added to high-strength mixtures. Aggregate must be selected carefully for high-strength mixes, as weaker aggregates may not be strong enough to resist the loads imposed on the concrete and cause failure to start in the aggregate rather than in the matrix or at a void, as normally occurs in regular concrete. In some applications of high-strength concrete the design criterion is the elastic modulus rather than the ultimate compressive strength.
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These factors include scratch or abrasion resistance (Rosiwal scale), toughness, strength, ductility, indentation hardness (measured by the Brinell scale and expressed in BHN, or measured by the Vickers test and expressed in kg/mm²) and brittleness factor.Iyengar, KT, Raviraj, S 2001. Analytical study of fracture in concrete beams using blunt crack model. Journal of Engineering Mechanics 127: 828–834. Abrasion hardness, indentation hardness and brittleness factor (ratio of the uniaxial compressive strength and the uniaxial tensile strength) combine to determine the “composite hardness index” θ, which governs the production coefficient ρ: ρ = V θ² The approximate cupule volume V is determined by: V = π × d × (R² + r² + R × r) ⁄ 3 in which r = mean radius at rim and d = cupule depth.
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The simulation was run at grain sizes of nm and at room temperature. It was found that in the grain size of range 3.1 nm to 40 nm, inverse Hall-Petch relationship was observed. This is because when the grain size decreases at nm scale, there is an increase in the density of grain boundary junctions which serves as a source of crack growth or weak bonding. However, it was also observed that at grain size below 3.1nm, a pseudo Hall-Petch relationship was observed, which results an increase in strength. This is due to a decrease in stress concentration of grain boundary junctions and also due to the stress distribution of 5-7 defects along the grain boundary where the compressive and tensile stress are produced by the pentagon and heptagon rings, etc.
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The major difference between the plantar plates of the MTP and IP joints is that they blend with the transverse metatarsal ligament in the MTP joints (not present in the toes). The MTP joint of the first toe differs from those of the other toes in that other muscles act on the joint, and in the presence of two sesamoid bones. The plantar plate is firm but flexible fibrocartilage with a composition similar to that found in the menisci of the knee (composed roughly of 75% type-I collagen), and can thus withstand compressive loads and act as a supportive articular surface. Most of its fibers are oriented longitudinally, in the same direction as the plantar fascia, and the plate can thus sustain substantial tensile loads in this direction.
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Compressive deformation during the Penokean orogeny reactivated the GLTZ, which followed deposition of the Marquette Range Supergroup sediments and resulted in a north-side up motion along steep brittle-ductile faults in the eastern, low-grade portion of the Marquette Trough In the western portion of the Marquette syncline, a second episode of GLTZ reactivation took place during the uplift of the post-Huronian 2,400- to 2,100-million-year-old granitic Southern Complex. The Northern and Southern complexes of the Upper Peninsula are highly migmatized and intensely foliated, with the intensity of foliation increasing toward margins. The western part of the Southern Complex shows intricate phases of folding and foliation. These Late Archean rocks form a roughly north–south belt lying south of Marquette extending to the Michigan-Wisconsin border.
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The stern notch of the SA-15 class ships, such as the Kandalaksha, allows safe assistance from icebreakers in particularly difficult ice conditions. The hull form of the SA-15 class ships, a result of intensive model tests in both open water and model ice, is very different from that of conventional merchant vessels, being more akin to polar icebreakers than traditional cargo ships. The bow design puts equal emphasis on both icebreaking and seakeeping characteristics, meaning that in addition to good icebreaking and manoeuvring capabilities in various ice conditions the vessel must be able to operate in open water without bottom slamming or shipping of green water occurring in rough seas. The sides are flared to prevent the ship from stopping or being damaged when operating in compressive ice fields.
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The SA-15 class freighters are designed to break level ice up to one metre () in thickness with a snow layer of in continuous motion without icebreaker assistance and operate in all prevailing ice conditions encountered in the arctic regions such as ridges and compressive ice. Designed for year-round operation in the North Sea Route, the freighters were intended to operate unescorted during the summer navigation period and, if necessary, with assistance from Arktika-class icebreakers in the more severe ice conditions during winter. The ships are equipped with a stern notch, similar to the towing notches found in icebreakers, to allow safe pushing assistance from an icebreaker. The ships were the first freighters in ten years to be built to the highest Soviet ice class notation available for merchant ships, ULA.
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Medical Society of Gage's skull, tamping iron, and post-accident history. Harlow saw Gage's survival as demonstrating "the wonderful resources of the system in enduring the shock and in overcoming the effects of so frightful a lesion, and as a beautiful display of the recuperative powers of nature", and listed what he saw as the circumstances favoring it: For Harlow's description of the pre-accident Gage, see § Background, above. Despite its very large diameter and mass (compared to a weapon-fired projectile) the tamping iron's relatively low velocity drastically reduced the energy available to compressive and concussive "shock waves". Harlow continued: Barker writes that "[Head injuries] from falls, horse kicks, and gunfire, were well known in preCivil War America [and] every contemporary course of lectures on surgery described the diagnosis and treatment" of such injuries.
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During the early 1940s Axis engineers developed a sonic cannon that could cause fatal vibrations in its target body. A methane gas combustion chamber leading to two parabolic dishes pulse-detonated at roughly 44 Hz. This sound, magnified by the dish reflectors, caused vertigo and nausea at by vibrating the middle ear bones and shaking the cochlear fluid within the inner ear. At distances of , the sound waves could act on organ tissues and fluids by repeatedly compressing and releasing compressive resistant organs such as the kidneys, spleen, and liver. (It had little detectable effect on malleable organs such as the heart, stomach and intestines.) Lung tissue was affected at only the closest ranges as atmospheric air is highly compressible and only the blood rich alveoli resist compression.
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Tempered glass, which is used for the side windows of most vehicles, is manufactured with an extremely high surface compressive stress and high internal tensile stress, giving it strength and durability, but also leading it to abruptly shatter into thousands of tiny pieces when it breaks. When thrown with moderate speed at a side-window, a sharp shard of the exceptionally hard aluminium oxide ceramic used in spark plugs focuses the impact energy into a small enough area without blunting to initiate cracking, releasing the internal energy and shattering the glass.National Geographic demonstration video However, ninja rocks are ineffective if the shards are insufficiently sharp, thrown with too little energy, or thrown against windshields, as these are made of a laminated type of safety glass, and therefore do not shatter.
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Matching the elastic modulus makes it possible to limit movement and delamination at the biointerface between implant and tissue as well as avoiding stress concentration that can lead to mechanical failure. Other important properties are the tensile and compressive strengths which quantify the maximum stresses a material can withstand before breaking and may be used to set stress limits that a device may be subject to within or external to the body. Depending on the application, it may be desirable for a biomaterial to have high strength so that it is resistant to failure when subjected to a load, however in other applications it may be beneficial for the material to be low strength. There is a careful balance between strength and stiffness that determines how robust to failure the biomaterial device is.
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It begins with lying with the back on the floor, typically with the arms across the chest or hands behind the head and the knees bent in an attempt to reduce stress on the back muscles and spine, and then elevating both the upper and lower vertebrae from the floor until everything superior to the buttocks is not touching the ground. Some argue that situps can be dangerous due to high compressive lumbar load and may be replaced with the crunch in exercise programs. Strength exercises such as sit-ups and push-ups do not cause the spot reduction of fat. Gaining a "six pack" requires both abdominal muscle hypertrophy training and fat loss over the abdomen—which can only be done by losing fat from the body as a whole.
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Sufficient internal pressure, caused by the body's gravitation, will turn a body plastic, and sufficient plasticity will allow high elevations to sink and hollows to fill in, a process known as gravitational relaxation. Bodies smaller than a few kilometers are dominated by non-gravitational forces and tend to have an irregular shape and may be rubble piles. Larger objects, where gravitation is significant but not dominant, are "potato" shaped; the more massive the body is, the higher its internal pressure, the more solid it is and the more rounded its shape, until the pressure is sufficient to overcome its internal compressive strength and it achieves hydrostatic equilibrium. At this point a body is as round as it is possible to be, given its rotation and tidal effects, and is an ellipsoid in shape.
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The acceleration, or rate of change in piston velocity, is the limiting factor. The piston acceleration is directly proportional to the magnitude of the G-forces experienced by the piston- connecting rod assembly. As long as the G-forces acting on the piston- connecting rod assembly multiplied by their own mass is less than the compressive and tensile strengths of the materials they are constructed from and as long as it does not exceed the bearing load limits, the engine can safely rev without succumbing to physical or structural failure. Redlines vary anywhere from a few hundred revolutions per minute (rpm) (in very large engines such as those in trains and generators) to more than 10,000 rpm (in smaller, usually high-performance engines such as motorcycles, some sports cars, and pistonless rotary engines).
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In 1995, Michael J. Pruis and Kenneth L. Tanaka of the United States Geological Survey published an abstract for the 26th Lunar and Planetary Science Conference, identifying tectonic features in the Martian northern plains that were inconsistent with a plate tectonics- based model introduced in 1994 by Norman J. Sleep of Stanford University. The orientation of the Phlegra Montes was reported as consistent with Sleep's model, assuming that they were superposed by transform faults. However, Tanaka and Pruis did not identify any transform offset in this region. Due to the parallel nature of the Phlegra Dorsa ridges to the massifs, and the presence of perpendicular graben (extensional stresses), there is a strong implication of a localized east-west compressive stress in contradiction to the predictions made by Sleep's model.
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Conversely, if the probing stylus enters a film thick enough to have several layers of nodules so it cannot be spread laterally, or if it enters on top of a cobblestone in a single layer, then it will measure not only the real hardness of the diamond bonding, but an apparent hardness even greater because the internal compressive stress in those nodules would provide further resistance to penetration of the material by the stylus. Nanoindentation measurements have reported hardness as great as 50% more than values for natural crystalline diamond. Since the stylus is blunted in such cases or even broken, actual numbers for hardness that exceed that of natural diamond are meaningless. They only show that the hard parts of an optimal ta-C material will break natural diamond rather than the inverse.
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As part of Operation St. Elias, Jack Souther studied the stratigraphy, structure and evolution of the Wrangell lavas of southwest Yukon in the mid 1970s. He was surprised by the difference in volcanic style between the Wrangell lavas where an enormous volume of andesite lava had issued without any apparent breaks and was accompanied by profound tectonic uplift and compressive folding, in contrast to the episodic eruption of alkaline basalt and highly fractionated silicic peralkaline rocks at Edziza. The differences in eruptive style and chemistry of the Wrangell lavas led Souther to speculate they were related to a calc-alkaline volcanic arc that formed along a converging plate boundary. In 1977, a book published under the title Volcanic Regimes in Canada included a chapter on Cordilleran tectonics by Jack Souther.
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Improvements in HCF, corrosion fatigue and SCC are documented, with fatigue strength enhancement attributed to improved finish, the development of a compressive surface layer, and the increased yield strength of the cold worked surface. LPB was developed and patented by Lambda Technologies in Cincinnati, Ohio in 1996. Since then, LPB has been developed to produce compression in a wide array of materials to mitigate surface damage, including fretting, corrosion pitting, stress corrosion cracking (SCC), and foreign object damage (FOD), and is being employed to aid in daily MRO operations. To this day, LPB is the only metal improvement method applied under continuous closed-loop process control and has been successfully applied to turbine engines, piston engines, propellers, aging aircraft structures, landing gear, nuclear waste material containers, biomedical implants, armaments, fitness equipment and welded joints.
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Within the portion of North American crust overlying the Gorda slab, motion on faults is reverse, and in April 1992, a M = 7.1 earthquake ruptured the southern portion of the Cascadia subduction zone. Similar to the general seismicity patterns in the region, the majority of the aftershocks for this event had vertical strike- slip motions and were located within the Gorda plate, or on the MTF at depths between 23–35 km. None of the aftershocks were consistent with northeast underthrusting of the Gorda plate beneath North America, as was the case in the main event. This set of earthquake geometries implies a stress field characterized by N-NW, horizontal principal compressive stress; this is consistent with the orientation of compression in the GDZ northwest of the MTJ.
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The Cedar Hills landslide was not as severe as the Thistle slide because the slope of the hill was not as steep, resulting in a lower normal stress. Also, shale tends to have a higher compressive strength than sandstone, so the overburden did not have as great an influence on the shale. Luckily for the residents of Cedar Hills, the slide has stopped for now, and hopefully will continue to be stagnant, though the geologic evidence shows that this is not likely. Precautions were taken after the 2005 slide to reduce the stress on the hillside, including the construction of a retaining wall to reduce the effects of the vertical stress (sigma 1), and gravel drains to help remove water from the hillside to help rocks maintain cohesive strength.
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As of 2016 the pathophysiology is poorly understood; while inflammation appears to play a role, the relationships among changes to the structure of tissue, the function of tendons, and pain are not understood and there are several competing models, none of which had been fully validated or falsified. Molecular mechanisms involved in inflammation includes release of inflammatory cytokines like IL-1β which reduces the expression of type I collagen mRNA in human tenocytes and causes extracellular matrix degradation in tendon. There are multifactorial theories that could include: tensile overload, tenocyte related collagen synthesis disruption, load-induced ischemia, neural sprouting, thermal damage, and adaptive compressive responses. The intratendinous sliding motion of fascicles and shear force at interfaces of fascicles could be an important mechanical factor for the development of tendinopathy and predispose tendons to rupture.
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Unlike lintels, which are subject to bending stress, jack arches are composed of individual masonry elements cut or formed into a wedge shape that efficiently uses the compressive strength of the masonry in the same manner as a regular arch. Like regular arches, jack arches require a mass of masonry to either side to absorb the considerable lateral thrust created by the jack arch. Jack arches have the advantage of being constructed from relatively small pieces of material that can be handled by individuals, as opposed to lintels which must necessarily be monolithic and which must be oversized unless reinforced by other means. In small-scale brick masonry projects, jack arches are typically sawn from an appropriately sized fired- clay lintel, giving a more precise and consistent joint width than field-sawn shapes.
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Self-leveling concrete being applied to a kitchen floor Self-leveling concrete is polymer-modified cement that has high flow characteristics and, in contrast to traditional concrete, does not require the addition of excessive amounts of water for placement. Self-leveling concrete is typically used to create a flat and smooth surface with a compressive strength similar to or higher than that of traditional concrete prior to installing interior floor coverings. Self- leveling concrete has increased in popularity as the degree of flatness and smoothness required for floor covering products has increased, with vinyl goods becoming thinner and floor tiles becoming larger, for example. Self- consolidating (or self-compacting) concrete (SCC) is a separate type of highly mobile (fluid) concrete formulation, which is based on superplasticizers, and is therefore also somewhat self-leveling.
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In other desirable woods such as Osage orange and mulberry the sapwood is almost useless and is normally removed entirely. Longbows, because of their narrow limbs and rounded cross-section (which does not spread out stress within the wood as evenly as a flatbow’s rectangular cross section), need to be less powerful, longer or of more elastic wood than an equivalent flatbow. In Europe the last approach was used, with yew being the wood of choice, because of its high compressive strength, light weight, and elasticity. Yew is the best widespread European timber that will make good self longbows, (other woods such as Elm can make longbows but require heat treating of the belly and a wider belly/narrower back, while still falling into the definition of a longbow) and has been the main wood used in European bows since Neolithic times.
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In March 2019, Carolyn Taylor, a Bendigo based physiotherapist claims the activewear company's leggings infringe her patent that was filed in 2010 and licensed to manufacturers. Mr Clarkson said Lorna Jane had been designing and manufacturing compressive and supportive Activewear since 1989 when Ms Clarkson started hand-making leotards and short tights for herself and for clients in her aerobics classes. "Compression and support tights have been part of our business for the last 30 years, over 20 years before this patent was lodged," Mr Clarkson said. In January 2020, these proceedings were dismissed by order of the Federal Court, with the consent of both parties. The Applicants’ claim against Lorna Jane for patent infringement (which Lorna Jane has always denied) has been dismissed. Lorna Jane's cross-claim that the Applicants’ patent is invalid has also been dismissed.
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Jaguar C-Type frame In a (tubular) spaceframe chassis, the suspension, engine, and body panels are attached to a three-dimensional skeletal frame of tubes, and the body panels have little or no structural function. To maximize rigidity and minimize weight, the design makes maximum use of triangles, and all the forces in each strut are either tensile or compressive, never bending, so they can be kept as thin as possible. The first true spaceframe chassis were produced in the 1930s by Buckminster Fuller and William Bushnell Stout (the Dymaxion and the Stout Scarab) who understood the theory of the true spaceframe from either architecture or aircraft design. The 1951 Jaguar C-Type racing sports car that won the Le Mans 24 hours twice, had a lightweight, multi-tubular, triangulated frame, over which an aerodynamic aluminum body was crafted.
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Subsequently, the first patent on laser shock peening was granted to Phillip Mallozzi and Barry Fairand in 1974.Mallozzi, P. J. and Fairand, B. P. "Altering Material Properties", , 26 November 1974 Research into the effects and possible applications of laser peening continued throughout the 1970s and early 1980s by Allan Clauer, Barry Fairand and coworkers, supported by funding from the National Science Foundation3, NASA, Army Research Office, U. S. Air Force, and internally by Battelle. This research explored the in-material effects in more depth and demonstrated the creation of deep compressive stresses and the accompanying increase in fatigue and fretting fatigue life achieved by laser peening.Clauer, A. H.; Holbrook, J. H. and Fairand, B. P. "Effects of Laser Induced Shock Waves on Metals", in Shock Waves and High- Strain-Rate Phenomena in Metals, M. A. Meyers and L. E. Murr, Eds.
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When the test fixture has thousands of test probes, the sum of the individual probe forces can reach hundreds of pounds. Such force is sufficient to deform the DUT (a printed circuit board, for example) to the point where the attached inflexible electronic component packages (such as Ball Grid Arrays) may fracture, or their solder joints may fail. Strain gage testing can reveal areas on the DUT where these net forces are excessive when the DUT is clamped into the test fixture, thus showing where supports must be added to the opposite side of the test fixture to counteract the test probe forces. Where a support counteracts the test probe forces, the test probe force is converted from a deformative force distorting the DUT to a compressive force, squeezing the DUT circuit board without deforming its generally planar shape.
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The westward component of the North American Plate's motion results in some compressive force along the San Andreas and its associated faults, thus helping lift the Pacific Coast Ranges and other parallel inland ranges to the west of the Central Valley, in this region most notably the Diablo Range. The Hayward Fault shares the same relative motions of the San Andreas. As with portions of other faults, a large extent of the Hayward Fault trace is formed from a narrow complex zone of deformation which can span hundreds of feet in width. The transform boundary defined by the San Andreas Fault is not perfectly straight, and the stresses between the Pacific and North American Plates are diffused over a wide region of the West, extending as far as the eastern side of the Sierra Nevada Mountains.
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In principle, the multi-anvil press is similar in design to a machine press except that it uses force magnification to amplify pressure by reducing the area over which force is applied: :P=F/A This is analogous to the mechanical advantage utilized by a lever, except the force is applied linearly, instead of angularly. For example, a typical multi-anvil could apply 9,806,650 N(equivalent to a load of 1000 t) onto a 10 mm octahedral assembly, which has a surface area of 346.41 mm2, to produce a pressure of 28.31 GPa inside the sample, while the pressure in the hydraulic ram is a mere 0.3 GPa. Therefore, using smaller assemblies can increase the pressure in the sample. The load that can be applied is limited by the compressive yield strength of the tungsten carbide cubes, especially for heated experiments.
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Craig Edward DeForest (born August 13, 1968) is an American solar physicist and the Vice-Chair of the American Astronomical Society's Solar Physics Division. He leads the heliophysics research group at the Boulder, Colorado offices of the Southwest Research Institute and holds an adjunct faculty position at the University of Colorado, Boulder. His wide-ranging contributions to the field of experimental astrophysics of the Sun include: early work on the MSSTA, a sounding rocket that prototyped modern normal- incidence EUV optics such as are used on the Solar Dynamics Observatory; his discovery of sound waves in the solar corona in 1998; Observation of Quasi- Periodic Compressive Waves in Solar Polar Plumes, Astrophys. J. 501, 217 standardization of computer vision techniques that are used to measure and track magnetic fields on the solar surface;Solar Magnetic Tracking.
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Australopithecines, in general, seem to have had a high incidence rate of vertebral pathologies, possibly because their vertebrae were better adapted to withstand suspension loads in climbing than compressive loads while walking upright. Lucy presents marked thoracic kyphosis (hunchback) and was diagnosed with Scheuermann's disease, probably caused by overstraining her back, which can lead to a hunched posture in modern humans due to irregular curving of the spine. Because her condition presented quite similarly to that seen in modern human patients, this would indicate a basically human range of locomotor function in walking for A. afarensis. The original straining may have occurred while climbing or swinging in the trees, though, even if correct, this does not indicate that her species was maladapted for arboreal behaviour, much like how humans are not maladapted for bipedal posture despite developing arthritis.
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Tensile and compressive stresses increase proportionally with bending moment, but are also dependent on the second moment of area of the cross- section of a beam (that is, the shape of the cross-section, such as a circle, square or I-beam being common structural shapes). Failure in bending will occur when the bending moment is sufficient to induce tensile stresses greater than the yield stress of the material throughout the entire cross-section. In structural analysis, this bending failure is called a plastic hinge, since the full load carrying ability of the structural element is not reached until the full cross-section is past the yield stress. It is possible that failure of a structural element in shear may occur before failure in bending, however the mechanics of failure in shear and in bending are different.
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In 2012, Caleb M. Brown and Anthony P. Russell suggested that the stiffened tails were probably not used as defence against flank-butting, but may have enabled the animals to take a tripodal stance during intra-specific combat, with the tail as support. Brown and Russell found that the tail could thereby help in resisting compressive, tensile, and torsional loading when the animal delivered or received blows with the dome. A 2013 study by Joseph E. Peterson and colleagues identified lesions in skulls of Stegoceras and other pachycephalosaurs, which were interpreted as infections caused by trauma. Lesions were found on 22% of sampled pachycephalosaur skulls (a frequency consistent across genera), but were absent from flat-headed specimens (which have been interpreted as juveniles or females), which is consistent with use in intra-specific combat (for territory or mates).
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There may also be a number of different critical cases that require consideration, such as there being different values for orthogonal and principal axes and in the case of unequal angle sections in the principal axes there is a section modulus for each corner. For a conservative (safe) design, civil structural engineers are often concerned with the combination of the highest load (tensile or compressive) and lowest elastic section modulus for a given section station along a beam, although if the loading is well understood one can take advantage of different section modulus for tension and compression to get more out of the design. For aeronautical and space applications where designs must be much less conservative for weight saving, structural testing is often required to ensure safety as reliance on structural analysis alone is more difficult (and expensive) to justify.
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By constructing the schottky contact, the electrons will pass to the counter electrode from the surface of the tip when the counter electrode is in contact with the regions of the negative potential, whereas no current will be generated when it is in contact with the regions of the positive potential, in the case of n-type semiconductive nanostructure (p-type semiconductive structure will exhibit the reversed phenomenon since the hole is mobile in this case). The formation of the schottky contact also contributes to the generation of direct current output signal consequently. For the second case, a model with a vertically grown nanowire stacked between the ohmic contact at its bottom and the schottky contact at its top is considered. When the force is applied toward the tip of the nanowire, the uniaxial compressive is generated in the nanowire.
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The adenoma may be the prime causative factor behind the headache or may serve to exacerbate a headache caused by other factors. Amongst the types of headaches experienced are both chronic and episodic migraine, and more uncommonly various unilateral headaches; primary stabbing headache, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) \- another type of stabbing headache characterized by short stabs of pain -, cluster headache, and hemicrania continua (HS). Compressive symptoms of pituitary adenomas (visual field deficits, decreased visual acuity, headaches) are more commonly seen with macroadenomas (which are greater than 10 mm in diameter) than with microadenomas (which are less than 10 mm in diameter). Non-secreting adenomas can go undetected for an extended time because no obvious abnormalities are seen; the gradual reduction in normal activities due to decreased production of hormones is rather less evident.
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As the faces slide in opposite directions, tension is created at the tip, and a mode I fracture is created in the direction of the σh-max, which is the direction of maximum principal stress. Shear-failure criteria is an expression that attempts to describe the stress at which a shear rupture creates a crack and separation. This criterion is based largely off of the work of Charles Coulomb, who suggested that as long as all stresses are compressive, as is the case in shear fracture, the shear stress is related to the normal stress by: σs= C+μ(σn-σf), where C is the cohesion of the rock, or the shear stress necessary to cause failure given the normal stress across that plane equals 0. μ is the coefficient of internal friction, which serves as a constant of proportionality within geology.
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In rail welding, the weld charge can weigh up to . The hardened sand mould is heavy and bulky, must be securely clamped in a very specific position and then subjected to intense heat for several minutes before firing the charge. When rail is welded into long strings, the longitudinal expansion and contraction of steel must be taken into account. British practice sometimes uses a sliding joint of some sort at the end of long runs of continuously welded rail, to allow some movement, although by using a heavy concrete sleeper and an extra amount of ballast at the sleeper ends, the track, which will be prestressed according to the ambient temperature at the time of its installation, will develop compressive stress in hot ambient temperature, or tensile stress in cold ambient temperature, its strong attachment to the heavy sleepers preventing buckling or other deformation.
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Porcelain materials can be strengthened by soaking fired material in molten salt to allow exchange of sodium and potassium ions on the surface as this successfully create compressive stresses on the outer layer, by controlling cooling after firing, and by the use of pure alumina inserts, a core of alumina or alumina powder, as they act as crack stoppers and are highly compatible to porcelain. Tooth colored dental composite materials are either used as direct filling or as construction material of an indirect inlay. It is usually cured by light. Nano-ceramic particles embedded in a resin matrix, are less brittle and therefore less likely to crack, or chip, than all-ceramic indirect fillings; they absorb the shock of chewing more like natural teeth, and more like resin or gold fillings, than do ceramic fillings; and at the same time more resistant to wear than all-resin indirect fillings.
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Pont du Gard, France, a Roman era aqueduct circa 19 BC. Structural engineering dates back to 2700 B.C.E. when the step pyramid for Pharaoh Djoser was built by Imhotep, the first engineer in history known by name. Pyramids were the most common major structures built by ancient civilizations because the structural form of a pyramid is inherently stable and can be almost infinitely scaled (as opposed to most other structural forms, which cannot be linearly increased in size in proportion to increased loads). The structural stability of the pyramid, whilst primarily gained from its shape, relies also on the strength of the stone from which it is constructed, and its ability to support the weight of the stone above it.CV The limestone blocks were often taken from a quarry near the building site and have a compressive strength from 30 to 250 MPa (MPa = Pa × 106).
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The prohibitive cost and effort of replacing these materials in kind led to the choice of a cast-stone with fiberglass support that mimics the buff brick in both color and finish. Through the use of a cast material, Page & Turnbull was able to create a fiberglass mold to be used for casting each arch as a unit that could then be inserted into sections where original fabric had been lost. The addition of fiberglass as a support material—that allows for both flexibility and compressive strength—was seen as an added benefit in meeting concerns over the building's continued seismic safety. Creating visual continuity between the new and the old was critical in this instance due to the significance of the long stretch of the nave; here an obvious alteration in material or color would detract from the pattern of springing arches that continues through the length of the structure.
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The relationship between acceleration and velocity vectors in an orbiting spacecraft US astronaut Marsha Ivins demonstrates the effect of weightlessness on long hair during STS-98 Long periods of weightlessness occur on spacecraft outside a planet's atmosphere, provided no propulsion is applied and the vehicle is not rotating. Weightlessness does not occur when a spacecraft is firing its engines or when re-entering the atmosphere, even if the resultant acceleration is constant. The thrust provided by the engines acts at the surface of the rocket nozzle rather than acting uniformly on the spacecraft, and is transmitted through the structure of the spacecraft via compressive and tensile forces to the objects or people inside. Weightlessness in an orbiting spacecraft is physically identical to free-fall, with the difference that gravitational acceleration causes a net change in the direction, rather than the magnitude, of the spacecraft's velocity.
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Examples of epsilon photography include focal stack photography, High dynamic range (HDR) photography, lucky imaging, multi-image panorama stitching and confocal stereo. The common thread for all the aforementioned imaging techniques is that multiple images are captured in order to produce a composite image of higher quality, such as richer color information, wider-field of view, more accurate depth map, less noise/blur and greater resolution. Since Epsilon photography at times may require the capture of hundreds of images, recently an alternative called Compressive Epsilon Photography was proposed where one captures only a select few images instead and generates the rest of the images of the stack by making use of prior information about the scene or relationship among the images in the stack. The reconstructed stack of images can be used as before for novel photography applications such as light field recovery, depth estimation, refocusing and synthetic aperture photography.
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One unusual feature of these layered sedimentary rocks is that they have been tilted to the south-east at a very steep angle and therefore are seen edge-on in the outcrops on the foreshore and is formally known as the Strathmore Syncline. When these layers are followed south- eastwards for several kilometres, the degree of tilting towards the SE is seen to decrease until the layers are near horizontal and then steepen again as they begin to tilt towards the NW, thus defining a broad U-shaped fold in the rock strata known as a syncline. The tilting of the strata took place when two regions of the Earth's lithosphere (the relatively rigid outer layer of the planet which includes the Crust and uppermost Mantle) were subjected to strong compressive forces over a long period. This took place between about 500 and 400 million years ago when two plates were in collision, bringing together the ancient continents of Avalonia and Laurentia.
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However, Latham stated neither body showed signs of compressive neck injuries, knife wounds, drugging or poisoning, and that both girls had most likely died of asphyxiation. In a direct reference to Huntley's claims both girls' deaths had been accidental, Latham stated that "only one person knows what happened" after the friends entered his home. However, he further stressed the cause of death was undoubtedly murder, adding: "Ten-year-old girls don't just drop dead." In reference to Carr's attempts to pervert the course of justice, Latham stated that "as surely as night follows day" the two had conspired to concoct a false alibi to divert suspicion from Huntley, although he warned the jury Carr could only be convicted of assisting an offender if they believed she had known Huntley had murdered the girls, adding her actual motive for providing lies to police with reference to the charge of perverting the course of justice was irrelevant.
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Where a tubular girder is used as a bridge span (i.e. loaded in the centre rather than at one end, like a crane) the compressive force is in the top web of the girder and so the cells are placed at the top. Dynamic forces (moving loads, wind) may also require both faces to be cellular. (The preserved Britannia Bridge section shows that both top and bottom flanges were of cellular construction, but (according to Fairbairn) the cellular construction of the bottom flange was adopted, not because of the nature of the forces it had to withstand, but because of their magnitude and the consequent "practical difficulties which would have been encountered, had it been attempted to achieve the requisite sectional area in a solid mass") In some ways this isn't a "cellular girder" as such (compared to a spaceframe or geodesic construction) as the cells don't share loads from the entire girder, but merely act to stiffen one plate in isolation.
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Boron was used at many locations in this dry system; it has a high cross- section for the absorption of slow neutrons, which fission U and Pu, but a low cross-section for the absorption of fast neutrons, which fission U. Because of this characteristic, B deposited onto the surface of the secondary stage would prevent predetonation of the spark plug by stray neutrons from the primary without interfering with the subsequent fissioning of the U of the fusion tamper wrapping the secondary. Boron also played a role in increasing the compressive plasma pressure around the secondary by blocking the sputtering effect, leading to higher thermonuclear efficiency. Because the structural foam holding the secondary in place within the casing was doped with B, the secondary was compressed more highly, at a cost of some radiated neutrons. An example of the usefulness of B can be seen by the fact that the fizzled Castle Koon MORGENSTERN device didn't use it in its design.
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The implosion system was quite lightweight at , because it eliminated the aluminium pusher shell around the tamper and used the more compact ring lenses, a design feature shared with the Mark 5, 12, 13 and 18 designs. The explosive material of the inner charges in the MK 7 was changed to the more powerful Cyclotol 75/25, instead of the Composition B used in most stockpiled bombs at that time, as Cyclotol 75/25 was denser than Composition B and thus could generate the same amount of explosive force in a smaller volume (it provided 13 percent more compressive energy than Comp B). The composite uranium-plutonium COBRA core was levitated in a type-D pit. COBRA was Los Alamos' most recent product of design work on the "new principles" of the hollow core. A copper pit liner encased within the weapon-grade plutonium inner capsule prevented DT gas diffusion in plutonium, a technique first tested in Greenhouse Item.
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Green sand is made up of basic sand (shell sand), bentonite or another binder, pitch powder or coal dust, and uninvited dust. Green sand properties cannot be standardized for all foundries and castings as such, yet place to place and job to job the specifications can be set to maintain minimal amount of rejection. A basic set of parameters to test are: # Fineness number (grain size/AFS Number) of the base sand # Moisture content in the mixture (ranges from 2-7% depending on the casting method) # Permeability (ability of compacted mould to pass air through it) # Total clay content (dust content) # Active clay content (presence of active bentonite/clay which can readily bond) # Compressive strength # Hardness ('B' or 'C' Scale) For parameters 1, 2, 4 and 5 standard bulk material sampling methods can be applicable or sampling can be done with help of sand muller, sand sampler and sand splitter to do it in a standardized manner.
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Internally, beams subjected to loads that do not induce torsion or axial loading experience compressive, tensile and shear stresses as a result of the loads applied to them. Typically, under gravity loads, the original length of the beam is slightly reduced to enclose a smaller radius arc at the top of the beam, resulting in compression, while the same original beam length at the bottom of the beam is slightly stretched to enclose a larger radius arc, and so is under tension. Modes of deformation where the top face of the beam is in compression, as under a vertical load, are known as sagging modes and where the top is in tension, for example over a support, is known as hogging. The same original length of the middle of the beam, generally halfway between the top and bottom, is the same as the radial arc of bending, and so it is under neither compression nor tension, and defines the neutral axis (dotted line in the beam figure).
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In a triaxial shear test, stress is applied to a sample of the material being tested in a way which results in stresses along one axis being different from the stresses in perpendicular directions. This is typically achieved by placing the sample between two parallel platens which apply stress in one (usually vertical) direction, and applying fluid pressure to the specimen to apply stress in the perpendicular directions. (Testing apparatus which allows application of different levels of stress in each of three orthogonal directions are discussed below, under "True Triaxial test".) The application of different compressive stresses in the test apparatus causes shear stress to develop in the sample; the loads can be increased and deflections monitored until failure of the sample. During the test, the surrounding fluid is pressurized, and the stress on the platens is increased until the material in the cylinder fails and forms sliding regions within itself, known as shear bands.
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Either way, the functionality and morphology of the arms in the Dmanisi hominins appears to have been more similar to the arms of earlier Homo or australopithecines than to modern humans.'''''' Overall, the spine in the Dmanisi hominins appears to have been more similar to the spines of modern humans and early H. erectus than to the spines of australopithecines. The fossil vertebrae recovered at Dmanisi show lumbar lordosis, the orientation of the facet joints suggests that the range of spinal flexion in the Dmanisi hominins was comparable to modern humans and the relatively large cross-sectional areas of the vertebrae indicates resistance to increased compressive loads, suggesting that the hominins were capable of running and long-range walking. Because fossils of the lower leg, from the femur down to the metatarsals, have been found, it is possible to reconstruct the orientation and positioning of the feet of the Dmanisi hominins relative to their walking direction.
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Shortly before he began working on the development of the diamond anvil cell, Weir worked in the Leather Section at the National Bureau of Standards, where he developed a piston/cylinder device for high pressure experiments on leather and similar materials. He then used this device for unfunded discretionary work on the compressibility of (and phase transitions in) many other materials. Ultimately, this discretionary work brought him into contact with Alvin Van Valkenburg (a mineralogist by training), who was also pursuing high-pressure research at the National Bureau of Standards, along with Ellis Lippincott from the University of Maryland, College Park and Elmer Bunting from the National Bureau of Standards. After a failed experiment that involved compressing a sample with a diamond piston inserted into a cylindrical hole bored into a 7.5 carat diamond crystal, Weir proposed an opposed anvil device that would take advantage of the high compressive strength of diamond (as opposed to its less impressive tensile strength) to perform infrared absorption measurements at high pressure.
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Geological structure of Reelfoot Rift The faults responsible for the NMSZ are embedded in a subsurface geological feature known as the Reelfoot Rift that formed during the breakup of the supercontinent Rodinia in the Neoproterozoic era (about 750 million years ago). The resulting rift system failed to split the continent, but has remained as an aulacogen (a scar or zone of weakness) deep underground, and its ancient faults appear to have made the Earth's crust in the New Madrid area mechanically weaker than much of the rest of North America. This relative weakness is important, because it would allow the relatively small east-west compressive forces associated with the continuing continental drift of the North American plate to reactivate old faults around New Madrid, making the area unusually prone to earthquakes in spite of it being far from the nearest tectonic plate boundary. Since other ancient rifts are known to occur in North America, but not all are associated with modern earthquakes, other processes could be at work to locally increase mechanical stress on the New Madrid faults.
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The technical requirements were outlined in a tender specification published by the Finnish Transport Agency on 11 February 2013. According to the specification, the new icebreaker would have to be at least equivalent to the most powerful Finnish icebreakers in service at the time — the 16.2-megawatt quad-screw Urho-class icebreakers — in terms of icebreaking capability. Optimized for escort icebreaker operations in the northern Baltic Sea, the vessel would have to be powerful enough to operate without becoming immobilized in all prevailing ice conditions, including compressive pressure ridge fields, and maintain an average escort speed of through the winter. The bollard pull and propulsion power would have to be sufficient to allow continuous operation in level ice with a thickness of and snow cover as well as make the vessel capable of opening a channel through uniform ice field at a speed of . The specification also called for excellent maneuverability, demonstrated by the ability to turn 180 degrees in 3 minutes within two ship's lengths in the aforementioned ice conditions.
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Moreover in a study published in the journal of Cleaner Production authors preformed a model where they proved that improved the compressive strength of the concrete while reducing emissions as a result, in so allowing for a cement loading reduction while at the same time having a "4.6% reduction in the carbon footprint" Another proposed method of capturing emissions is to absorb CO2 in the curing process, by the use of an admixture (a dicalcium silicate y phase) as the concrete cures. The use of coal ash or another suitable substitute, could theoretically have CO2 emissions below 0 kg/m3, compared to portland cement concrete at 400 kg/m3. The most effective method of production of this concrete would use the exhaust gas of a power plant, where an isolated chamber could control temperature and humidity. In August 2019, reduced CO2 cement was announced which "reduces the overall carbon footprint in precast concrete by 70%.". The base of these cement being primarily of wollastonite (CaSiO3) and rankinite (3CaO·2SiO2) in contrast to traditional portland cement alite (3CaO·SiO2) belite (2 CaO · SiO2).
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Concrete is, after all, a macro-material strongly influenced by its nano-properties and understanding it at this new level is yielding new avenues for improvement of strength, durability and monitoring as outlined in the following paragraphs Silica (SiO2) is present in conventional concrete as part of the normal mix. However, one of the advancements made by the study of concrete at the nanoscale is that particle packing in concrete can be improved by using nano- silica which leads to a densifying of the micro and nanostructure resulting in improved mechanical properties. Nano-silica addition to cement based materials can also control the degradation of the fundamental C-S-H (calcium- silicatehydrate) reaction of concrete caused by calcium leaching in water as well as block water penetration and therefore lead to improvements in durability. Related to improved particle packing, high energy milling of ordinary Portland cement (OPC) clinker and standard sand, produces a greater particle size diminution with respect to conventional OPC and, as a result, the compressive strength of the refined material is also 3 to 6 times higher (at different ages).
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In metal alloys with substitutional solute elements, such as aluminum-magnesium alloys, dynamic strain aging leads to negative strain rate sensitivity which causes instability in plastic flow.Aboulfadi, H., Deges, J., Choi, P., Raabe, D. (2015) "Dynamic strain aging studied at the atomic scale," Acta Materialia 86:34-42 The diffusion of solute elements around a dislocation can be modeled based on the energy required to move a solute atom across the slip plane of the dislocation.Curtin, W.A., Olmsted, D.L., Hector Jr., L.G. (2006) "A predictive mechanism for dynamic strain ageing in aluminium-magnesium alloys," Nature Materials 5:875-880 An edge dislocation produces a stress field which is compressive above the slip plane and tensile below.Cai, W., Nix, W.D. (2016) "Imperfections in Crystalline Solids," Cambridge University Press, In Al-Mg alloys, the Mg atom is larger than an Al atom and has lower energy on the tension side of the dislocation slip plane; therefore, Mg atoms in the vicinity of an edge dislocation are driven to diffuse across the slip plane (see figure).
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It has been proposed that a biosphere could be contained between two concentric spheres, placed on the interior of a rotating sphere (in which case, the force of artificial "gravity" is perpendicular to the axis of rotation, causing all matter placed on the interior of the sphere to pool around the equator, effectively rendering the sphere a Niven ring for purposes of habitation, but still fully effective as a radiant-energy collector) or placed on the outside of the sphere where it would be held in place by the star's gravity. In such cases, some form of illumination would have to be devised, or the sphere made at least partly transparent, because the star's light would otherwise be completely hidden. If assuming a radius of 1 AU, then the compressive strength of the material forming the sphere would have to be immense to prevent implosion due to the star's gravity. Any arbitrarily selected point on the surface of the sphere can be viewed as being under the pressure of the base of a dome 1 AU in height under the Sun's gravity at that distance.
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Since the carrier ring used in constant seating stress gaskets take this deflection into account when creating the carrier ring for a given flange size, pressure class, and material, the carrier ring profile can be adjusted to enable the gasket seating stress to be radially uniform across the entire sealing area. Further, because the sealing elements are fully confined by the flange faces in opposing channels on the carrier ring, any in-service compressive forces acting on the gasket are transmitted through the carrier ring and avoid any further compression of the sealing elements, thus maintaining a 'constant' gasket seating stress while in-service. Thus, the gasket is immune to common gasket failure modes that include creep relaxation, high system vibration, or system thermal cycles. The fundamental concept underlying the improved sealability for constant seating stress gaskets are that (i) if the flange sealing surfaces are capable of attaining a seal, (ii) the sealing elements are compatible with the process fluid and application, and (iii) the sufficient gasket seating stress is achieved on installation necessary to affect a seal, then the possibility of the gasket leaking in- service is greatly reduced or eliminated altogether.
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