Your hair can either be high porosity (easily absorbs moisture) or low porosity (doesn't easily absorb moisture).
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With the right amount of porosity, the same vortex appeared.
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Well, its porosity could be at the root of the problem.
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She noted that the porosity value of the rocks was surprisingly high.
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In simple terms, porosity translates to how easily your hair absorbs moisture.
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Core samples would have quickly revealed the dubious porosity of the rock.
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"When your parched hair gets softer, you have more porosity," he explains.
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So, how do you know whether your hair has high or low porosity?
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Knowing your hair porosity helps you determine what ingredients and products are best.
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If your strands fall somewhere in the middle, you can consider your porosity normal.
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Its porosity has been altered and it is no more able to hold water.
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Typically, hair with high porosity is prone to damage, breakage, and gaps, Bailey explains.
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Jekyll And Mr. Hyde Hair Is MesmerizingDoes The Porosity Of Your Hair Really Matter?
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But even if you've skipped all those treatments, your daily routine could effect your porosity.
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Then you're dealing with cuticles that are tightly sealed, leaving you with low porosity curls.
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If so, that's a sign that your cuticles are lifted, which means your porosity is high.
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"Hair porosity" is a term I've heard thrown around on the internet more and more recently.
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Low-porosity hair, on the other hand, has a tendency to be on the stubborn side.
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Bailey says that those with low-porosity hair should make sure to use products with low protein.
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For those with high-porosity hair, both experts stress the importance of incorporating a deep-conditioning treatment.
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Redway and Bailey both note that your porosity can change depending on how you treat your tresses.
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If you frequently heat style or color your hair, you can safely assume that your porosity is high.
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It's perfect for my low porosity hair because it's not as thick and heavy as most hair oils.
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And if it takes longer than a couple of minutes to sink, you most likely have medium porosity.
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If it takes a long time for your hair to get wet (or dry), your porosity is probably low.
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That porosity, they found, made the soil more amenable to bioremediation, a process in which bacteria consume environmental pollutants.
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"This pushes us to get a better understanding of what low-porosity rocks might behave like on Mars," she said.
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The scientists built a computer model of these meteors entering the atmosphere, allowing that porosity to change as they traveled.
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That's when all the little micro differences — the mineral content, porosity, grittiness, organic matter — start to make a macro difference.
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Depending on porosity or depending in how sometimes the hair could be dried, your hair could contract to a 4A.
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Understanding your hair's porosity, or how well your hair absorbs and retains moisture, is the first step towards proper deep conditioning.
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The uppermost zone of high porosity has not been completed at this time based on initial results from the two lower zones.
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Ion-exchange resins are high-porosity forms of polystyrene tweaked with extra chemical groups that let them capture molecules of different sorts.
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The inside of the shell is basically a silicon sponge, and its porosity means it can accommodate swelling when the battery is charging.
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"We think … the geometry of our model, the porosity, is more efficient at generating digital revenue than any other model we know about."
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When it comes to natural hair, knowing your specific porosity is important because, simply put, it will help you better understand your hair.
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Proctor & Gamble Principal Scientist Rolanda Wilkerson, PhD, says that before you plaster on pounds of product, you should get familiar with your hair's porosity.
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Parts of the surface, like the rocky region where Rosetta's lander Philae wound up, are more dense, with a porosity lower than 50 percent.
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"There's much more porosity in the art world now between the market, the collector base, galleries and the nonprofit world of museums," Mr. Shiner said.
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What you may not know is that understanding your hair's porosity just may be the secret to softer, shinier, more voluminous, and all around healthier strands.
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Redway adds that natural treatments like apple-cider vinegar and Aztec Secret's Indian Healing Clay Mask are great for low-porosity types to help restore balance.
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"Increased porosity has direct bearing on the strength of the material, but we have yet to measure the strength of the space-formed material," said Radlinska.
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Like one of the era's famed nightclubs or music venues, there was a compelling air of exclusivity at its core, but it had some porosity to it.
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"When you factor in how you take care of your hair, two women with similar curl patterns could fall differently on a hair-porosity scale," says Redway.
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The pore structure and porosity of the material are clearly quite crucial to the performance of the separator in a battery in addition to the separator material [5].
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High-density soil sampling, carried out every few years to track properties such as mineral content and porosity, can predict the fertility of different parts of a field.
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Genel said on Monday it had found that fracture porosity within the Shiranish - one of the three principal producing units at Taq Taq - was lower than estimated in 2011.
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Aura uses a layering technique, first adding a filler to even out porosity, add back missing warm tones (gold and orange, in my case), and help seal the cuticle.
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For most ladies and gents, porosity is genetic, but elements like environmental stresses, hard water, heat-styling, and chemical treatments can also affect where on the scale your strands lie.
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"Coke also provides carbon as a reductant, acts as structural support to hold the ore burden, and provides porosity for rising hot gas and sinking molten iron," the CGEP report says.
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Click here to uncover your hair's porosity level first — there's a simple "float test" that makes it easy — then keep clicking for tricks to make your mask day that much better.
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ADNOC said it was exploring and appraising deposits in tight reservoirs, a term that refers to gas found in rocks of low permeability and porosity that typically need fracking to recover.
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He also said the company could attract foreign investors to develop the Achimov formation in Yamal, one of the most challenging projects in Siberia because of its low permeability and porosity.
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Obviously, this doesn't mean anyone should go around detonating landmines as the desire strikes them, but the researchers suggest using less toxic explosions to increase the porosity of soils contaminated by TNT.
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The middle zone of high porosity, which is approximately 20 feet structurally higher than the lower zone and the producing interval in the Strittmatter #1 well, was completed and swab tested after stimulation.
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"Reduction in reserve estimates for Taq Taq is a consequence of a reassessment of the gross rock volume above the oil water contact and fracture porosity in the undrained cretaceous Shiranish reservoir," Genel said.
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It took me three months to decide that I'm a 3B curl type with high-porosity strands (time I wish I could get back) and another three months to master a silk press (time well spent).
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The head of the Paris region, Valerie Pecresse, told Le Journal du Dimanche that LR could blow up if Wauquiez is elected leader, warning against his possible "porosity" to the far-right National Front's (FN) ideas.
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"That includes the risk not only of, say, wholesale diversion of a shipping container full of weapons, but also the porosity of security forces over a period of time," said ARES intelligence specialist N.R. Jenzen-Jones.
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The team reckons it should be able to tweak the properties, by using different metallic and bridging molecules, to create new kinds of highly compressible materials that also provide other useful properties—such as porosity or chemical functionality.
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These colors are more or less opaque, but an illusion of transparency results from the visual porosity and interpenetration of the areas of pattern with the blocks of color behind them, rather than any actual translucency (of glazes, e.g.).
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Wilson then coats them, rather unorthodoxly, with an arsenal of naturally toxic chemicals — lithium, barium and silicon carbide — that slowly eat away at the special kind of terracotta clay she employs; and bits of paper embedded in the material burn during the firing process, creating her work's signature porosity.
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"It is a huge blind spot within the community of chemists of how to determine what it is that we're looking for when you're dealing with different kinds of porosity in the hair, different kinds of the hair shaft, and how moisturizing and hydration penetrates for our textures," she says.
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This illustrates the known relationship between porosity and Young's modulus wherein Young's modulus decreases linearly with increasing porosity. Achievable porosity through the space- holder method is directly related to the type and amount of space-holder utilized (up to a threshold maximum achievable porosity level).
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The curly girl method also requires one to know one's hair porosity. There are low, medium and high hair porosity. Low hair porosity is when the hair cuticles are tightly shut. Low porosity hair has difficulty obtaining moisture but once moisture is absorbed it will remain moisturized.
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These hairdos require very little daily upkeep and help strands stay moisturized. Hair Porosity Natural hair can have low, high, or medium porosity. Low porosity hair cuticles are very tightly closed and don't absorb water or product easily. High porosity hair cuticles are very open and absorb water and product easily.
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The dolomitization that took place in the region has increased the porosity primarily in the more deeply buried lagoonal back reef facies. The pre-existing porosity has also been preserved well due to the dolomitization. Porosity in the region is dominated by vuggy, moldic, intercrystalline, as well as fracture types of porosity. Generally, the mean porosity of the Leduc Formation is 5.2%, with the permeability of the rocks in the region being an even spread.
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Roughness indicates varying degree of porosity of the paper. Porosity is a direct indication of paper to accept ink or water.
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Porosity is the ratio of pore volume to its total volume. Porosity is controlled by: rock type, pore distribution, cementation, diagenetic history and composition. Porosity is not controlled by grain size, as the volume of between-grain space is related only to the method of grain packing. Rocks normally decrease in porosity with age and depth of burial.
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In cases where porosity still remains present after the degassing process, porosity sealing can be accomplished through a process called metal impregnating.
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Porosity is inherent to most manufacturing processes. Porosity is only considered a defect if it is interconnected and creates a leak path can affect the part's structural integrity and performance. Vacuum impregnation seals porosity and leak paths for the following reasons.
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Only by crushing the rock can the core analysis yield the total porosity seen by the logs. The traditional Petroleum Engineering and core analysis definition of effective porosity is the sum of the interconnected pore space—that is, excluding isolated pores. Therefore in practice, for the vast majority of sedimentary rocks, this definition of effective porosity equates to total porosity.
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This calculates to a porosity between 0.43 and 0.36. Typical bulk density of clay soil is between 1.1 and 1.3 g/cm3. This calculates to a porosity between 0.58 and 0.51. This seems counterintuitive because clay soils are termed heavy, implying lower porosity.
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This calculates to a porosity between 0.43 and 0.36. Typical bulk density of clay soil is between 1.1 and 1.3 g/cm3. This calculates to a porosity between 0.58 and 0.51. This seems counterintuitive because clay soils are termed heavy, implying lower porosity.
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Inner porosity (or micro-porosity) has been shown to reduce stiffness; thus, reduce the risk of stress-shielding effects, while also offering improved osseointegration.
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Casting porosity is a consequence of one or more of the following: gasification of contaminants at molten-metal temperatures; shrinkage that takes place as molten metal solidifies; and unexpected or uncontrolled changes in temperature or humidity. While porosity is inherent in die casting manufacturing, its presence may lead to component failure where pressure integrity is a critical characteristic. Porosity may take on several forms from interconnected micro-porosity, folds, and inclusions to macro porosity visible on the part surface. The end result of porosity is the creation of a leak path through the walls of a casting that prevents the part from holding pressure.
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The ratio of holes to solid that the wind "sees". Aerodynamic porosity is less than visual porosity, by an amount that depends on the constriction of holes.
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Porosity sealing is done through the process of vacuum impregnation. Vacuum impregnation is a preferred OEM process that seals porosity and leak paths in metal castings, sintered metal parts and electrical castings that form during the casting or molding process. Vacuum impregnation stops casting porosity (a phenomenon that occurs in the die-cast manufacturing process and allows manufacturers to use parts that would otherwise be scrapped.) Porosity occurs naturally and is found in most materials. In metal castings, porosity is typically considered any void found in the casting.
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Casting porosity can be caused by gas formation or solidification while the metal is being moved from a liquid state to a solid state. This porosity can range in size, from sub- micron to voids greater than 10 mm, depending on the casting. Casting defects caused by porosity can affect the part’s structural integrity, creating a failure point. Porosity can also prevent the part from being pressure tight.
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This characteristic allows a neutron porosity log to be used with other porosity logs (such as a density log) to detect gas zones and identify gas-liquid contacts.
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It is noted that the porosity can reduce the strength of the bone, but also reduce its weight. The porosity and the manner that porosity is structured affect the strength of material. Thus, the micro structure of trabecular bone is typically oriented and grain of porosity is aligned in a direction at which mechanical stiffness and strength are greatest. Because of the microstructual directionality, the mechanical properties of trabecular bone is highly an-isotropic.
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It was also found that a silicon wafer with medium to low porosity displayed more stability. Hence, the porosity of porous silicon is varied depending on its potential application areas.
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These low thermal conductivities were achieved through the generation of an alternating high-porosity, low-porosity microstructure or the synthesis of a low-conductivity precursor composition with rare-earth dopants.
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The value for specific yield is less than the value for porosity because some water will remain in the medium even after drainage due to intermolecular forces. Often the porosity or effective porosity is used as an upper bound to the specific yield. Typically Sy is orders of magnitude larger than Ss.
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The deposits are primarily trench-wedge turbidites (Spinelli et al., 2007). There are indications of an increase in the retention of porosity within the rock. Typically porosity reduces with increasing depth.
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Porosity, even after consolidation, can limit the applications of spray formed material, for example rotating gas turbine components must have zero porosity because of the detrimental effect on high-cycle fatigue (HCF).
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Geodynamics of the Lithosphere (2nd edn.), K. Stüwe (2007), New York: Springer] Empirical studies show that the porosity of rocks decreases exponentially with depth. In general we can describe this with the relationship: where \phi is the porosity of the rock at depth z, \phi_0 is the porosity at the surface and c is a rock specific compaction constant.
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Hydrogen gas porosity is an aluminium casting defect in the form of a porosity or void in an aluminium casting caused by a high level of hydrogen gas (H2) dissolved in the aluminium at liquid phase. The solubility of hydrogen in solid aluminium is much smaller than in liquid aluminium. As the aluminium freezes, some of the hydrogen comes out of solution and forms bubbles, creating porosity in the solid aluminium. Aluminium foundries want to produce high-quality aluminum castings with minimum porosity.
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Consequently, when a gas-filled formation is logged, which has a lower number of hydrogen atoms than a water-filled formation of the same porosity, the porosity estimate will be lower than the true porosity. The density tool, on the other hand, measures the total number of formation electrons. Like the neutron tool, water-filled formations are used in its calibration process. Under these conditions, a lower number of electrons is equivalent to a lower formation density, or a higher formation porosity.
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Therefore, logging a gas-filled formation, results in a porosity estimate that is higher than the true porosity. Overlaying the neutron and density curves in a gas-bearing zone results in the classic crossover separation.
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This improves machinability by making it more efficient, eliminating tool chatter, and improving the machined finish. Powder metal porosity absorbs oils, fluids, deburring fluids, pre-plating cleaners, and acids. If the porosity is not sealed, fluids may bleed out and negatively affect the finish. Sealing the porosity before secondary finishes will eliminate any failure mode that could develop from bleed out of pretreatments.
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A porous medium is most often characterised by its porosity. Other properties of the medium (e.g. permeability, tensile strength, electrical conductivity, tortuosity) can sometimes be derived from the respective properties of its constituents (solid matrix and fluid) and the media porosity and pores structure, but such a derivation is usually complex. Even the concept of porosity is only straightforward for a poroelastic medium.
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Soil porosity is complex. Traditional models regard porosity as continuous. This fails to account for anomalous features and produces only approximate results. Furthermore, it cannot help model the influence of environmental factors which affect pore geometry.
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Soil porosity is complex. Traditional models regard porosity as continuous. This fails to account for anomalous features and produces only approximate results. Furthermore it cannot help model the influence of environmental factors which affect pore geometry.
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Nuclear logs include density logs and neutron logs, as well as gamma ray logs which are used for correlation. The basic principle behind the use of nuclear technology is that a neutron source placed near the formation whose porosity is being measured will result in neutrons being scattered by the hydrogen atoms, largely those present in the formation fluid. Since there is little difference in the neutrons scattered by hydrocarbons or water, the porosity measured gives a figure close to the true physical porosity whereas the figure obtained from electrical resistivity measurements is that due to the conductive formation fluid. The difference between neutron porosity and electrical porosity measurements therefore indicates the presence of hydrocarbons in the formation fluid.
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The process is called liquid polymer infiltration (LPI), or polymer infiltration and pyrolysis (PIP). Here also a porosity of about 15% is common due to the shrinking of the polymer. The porosity is reduced after every cycle.
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This effect was suggested to be exacerbated by centrifugal effects from the billet rotation. As sprayed the billet porosity is typically 1–2% with a region of higher porosity in the splat-quenched region adjacent to the substrate. The very top of the billet often shows increased porosity because the top is rapidly chilled by the atomising gas which continues to chill the billet for 10–60 seconds after spraying. There has also been little progress in understanding and quantifying the underlying physics that controls as-sprayed porosity.
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Porosity is defined as the fraction of void within the pSi layer and can be determined easily by weight measurement. During formation of porous silicon layer through anodization, the porosity of a wafer can be increased through increasing current density, decreasing HF concentration and thicker silicon layer. The porosity of porous silicon may range from 4% for macroporous layers to 95% for mesoporous layers. A study by Canham in 1995 found that "a 1 µm thick layer of high porosity silicon completely dissolved within a day of in- vitro exposure to a simulated body fluid".
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Gas porosity is the formation of bubbles within the casting after it has cooled. This occurs because most liquid materials can hold a large amount of dissolved gas, but the solid form of the same material cannot, so the gas forms bubbles within the material as it cools. Gas porosity may present itself on the surface of the casting as porosity or the pore may be trapped inside the metal, which reduces strength in that vicinity. Nitrogen, oxygen and hydrogen are the most encountered gases in cases of gas porosity.
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A popular method of obtaining a formation porosity estimate is based on the simultaneous use of neutron and density logs. Under normal logging conditions, the porosity estimates obtained from these tools agree, when plotted on an appropriate lithology and fluid scale. However, in the case of a reservoir where there is gas instead of water or oil in the pore space, the two porosity logs separate, to form what is referred to as gas crossover. Under these conditions, the true formation porosity lies between the measured neutron and density values.
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There are many ways to test porosity in a substance or part, such as industrial CT scanning. The term porosity is used in multiple fields including pharmaceutics, ceramics, metallurgy, materials, manufacturing, hydrology, earth sciences, soil mechanics and engineering.
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A high porosity will lead to air bubbles (known as voids) in the rods, which decrease the quality of the welding. The highest quality of plastic welding rods are therefore those with zero porosity, which are called voidless.
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The heterogeneous character makes it difficult to summarize the general mechanical properties for trabecular bone. High porosity makes trabecular bone compliant and large variations in architecture leads to high heterogeneity. The modulus and strength vary inversely with porosity and highly depend on the porosity structure. Additionally, the effects of aging and small cracks of trabecular bones on their mechanical properties will be analyzed more in final drafts.
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Well sorted rocks are generally porous, while poorly sorted rocks have low porosity.
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In surface layer of the ingots torsions or subcrustal porosity were not detected.
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Vitreous bodies have open porosity, and may be either opaque or translucent. In this context, "zero porosity" may be defined as less than 1% water absorption. However, various standard procedures define the conditions of water absorption.Whitewares: Production, Testing and Quality Control.
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For example, clay minerals tend to fill up pore space and thereby reducing porosity.
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Geological heterogeneity is the spatial distribution of porosity and permeability in a reservoir rock.
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In the field of formation evaluation, porosity is one of the key measurements to quantify oil and gas reserves. Neutron porosity measurement employs a neutron source to measure the hydrogen index in a reservoir, which is directly related to porosity. The Hydrogen Index (HI) of a material is defined as the ratio of the concentration of hydrogen atoms per cm3 in the material, to that of pure water at 75 °F. As hydrogen atoms are present in both water and oil- filled reservoirs, measurement of the amount allows estimation of the amount of liquid-filled porosity.
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The significance of the porosity is that it gives the idea of water storage capacity of the aquifer. Qualitatively, porosity less than 5% is considered to be small, between 5 and 20% as medium and the percentage exceeding 20% is considered as large.
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The initial porosity of a sediment depends on its lithology. Mudstones start with porosities of >60%, sandstones typically ~40% and carbonates sometimes as high as 70%. Results from hydrocarbon exploration wells show clear porosity reduction trends with depth.Sclater, J.G. & Christie, P.A.F. 1980.
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Because of their high porosity, CI chondrites have only a density of 2.2 g/cm3.
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The porosity left by the sublimation of solvent crystals is typically between 2–200 μm.
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If we humidity dried core samples, (some of) the electrochemically bound CBW would be retained, but none of the capillary-bound microporous water (notwithstanding comments in ). Therefore, although the figure infers that a humidity-dried core could produce an effective porosity similar to a log analysis effective porosity, the effective porosity from the core will usually be higher (see “Examples” section)—notwithstanding comments in . Traditionally, true CBW has been directly measured neither on cores nor by logs, although NMR measurement holds promise. At a given height above the free-water level, the capillary water becomes “irreducible”. This capillary water forms the irreducible water saturation (“Swi”) with respect to effective porosity (notwithstanding the inclusion of microporous water as Vsh during the log analysis) whereas for total porosity, the CBW and capillary water combined form the “Swi”.
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Upper Cambrian Cooper Ridge Dolomite, Upper Cambrian Rose Run Sandstone, and Lower Ordovician Beekmantown Dolomite compose the lowest reservoir units. The secondary vuggy porosity of the two dolomitic units are a result of extensive leaching during subaerial exposure of stromatolites. The intercrystalline porosity with in the dolomite units is attributed to hydrothermal dissolution. Within the Sun Rose sandstone unit, the primary porosity is attributed to the oversized pores and the occurrence of enlarged intergranular pores.
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The available space for air and moisture in wood depends on the density and porosity of wood. Porosity is the volume fraction of void space in a solid. The porosity is reported to be 1.2 to 4.6% of dry volume of wood cell wall (Siau, 1984). On the other hand, permeability is a measure of the ease with which fluids are transported through a porous solid under the influence of some driving forces, e.g.
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The electron beam directed vapor deposition (EB-DVD) process used to apply the TBC to turbine airfoils produces a columnar microstructure with several levels of porosity. The porosity between the columns is critical to providing strain tolerance (via a very low in-plane modulus), as it would otherwise spall on thermal cycling due to thermal expansion mismatch with the superalloy substrate. The porosity within the columns reduces the thermal conductivity of the coating.
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They differ in their porosity, specific gravity, optical properties, presence of animal components, and surface chemistries.
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Measurement of the porosity of an activated carbon by the adsorption of saturated carbon tetrachloride vapour.
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This porosity type is common with hair that has suffered little to no damage (either from heat styling tools or from chemicals) and thus it is the preferred porosity level. Medium porosity hair is when the hair cuticles are loose, allowing moisture to be easily absorbed and retained. High porosity is when there are gaps in the hair cuticles which allows the hair to easily absorb the moisture but also easily lose the moisture just as easily as it was absorbed. These gaps are caused by long term damage to the hair from things like over-manipulation, heat damage and chemical damage from hair dyes and relaxers.
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If the proportionality between pore throat radii and porosity exists then a proportionality between porosity and hydraulic conductivity may exist. However, as grain size or sorting decreases the proportionality between pore throat radii and porosity begins to fail and therefore so does the proportionality between porosity and hydraulic conductivity. For example: clays typically have very low hydraulic conductivity (due to their small pore throat radii) but also have very high porosities (due to the structured nature of clay minerals), which means clays can hold a large volume of water per volume of bulk material, but they do not release water rapidly and therefore have low hydraulic conductivity.
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The increased rate is a result of the greater surface area associated with porosity. Porosity produces rougher absorber surfaces. Use of particulate precursors allows for printing on a large variety of substrates with materials utilization of 90% or more. Little research and development supported this technique.
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Parts created through the additive manufacturing process are susceptible to the same porosity that plagues those created through more traditional methods. The porosity is inherent to the properties of the material and technology. The two primary materials that vacuum impregnation seals are plastic and sintered metal.
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Die castings and permanent mold castings commonly contain internal porosity. This porosity is generally localized to the deepest cross-sections of the part and does not extend to the outer skin. However, if the part is also machined, the internal porosity will be exposed and the part will leak if pressurized. Machined die castings that need to hold fluids (intake manifolds, coolant connectors, transmission cases, pump housings and fluid power components) are routinely sealed for life using acrylic resins.
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Effects of sorting on alluvial porosity. Black represents solids, blue represents pore space. Well sorted (grains of approximately all one size) materials have higher porosity than similarly sized poorly sorted materials (where smaller particles fill the gaps between larger particles). The graphic illustrates how some smaller grains can effectively fill the pores (where all water flow takes place), drastically reducing porosity and hydraulic conductivity, while only being a small fraction of the total volume of the material.
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So the same rock may have different porosity in different locations due to the local water saturation.
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This geological stores and groundwater flows taking advantage of permeability, porosity and cracking the rock that hosts.
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In most cases, the higher porosity at the billet base and top are scalped and recycled. Ultrasonic inspection is sometimes used to determine the depth of the chill zone regions to prevent unnecessary wastage. Depending on the alloy system and the final application, the remaining bulk material is usually processed to close porosity and subjected to a range of thermo- mechanical treatments. Spray formed materials are rarely used in the as- sprayed condition and are often treated by HIPing to remove porosity.
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Critical Moment of the Halibut Field, AustraliaThe reservoir rocks in this field are primarily sandstones from the Latrobe Group. The secondary porosity accounts for the majority of the porosity, and therefore its ability to contain hydrocarbons. The reason for this is due to the high amount of dolomite cement which filled up the pores, and then was dissolved by the hydrocarbons migrating into the pores. The porosity of the sandstones are 20-25%, and the permeability is 5000-7000 md.
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Rock salt has an effective porosity of nearly 50% on the surface, while the effective porosity decreases to less than 10% at a depth of 10 m. When the burial depth reaches about 45 m, the pore spaces are completely filled. After rock salt losses its porosity, it becomes almost incompressible and keeps a constant density of 2.2 g/cm3 as the depth continue to increase. When rock salt reaches a depth of 6–8 km, other rocks are metamorphosed into greenschist.
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VARTM can produce parts with less porosity than regular transfer molding with a proportional increase in casting strength.
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For tables of common porosity values for earth materials, see the "further reading" section in the Hydrogeology article.
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If a rock unit of low porosity is highly fractured, it can also make a good aquifer (via fissure flow), provided the rock has a hydraulic conductivity sufficient to facilitate movement of water. Porosity is important, but, alone, it does not determine a rock's ability to act as an aquifer. Areas of the Deccan Traps (a basaltic lava) in west central India are good examples of rock formations with high porosity but low permeability, which makes them poor aquifers. Similarly, the micro-porous (Upper Cretaceous) Chalk Group of south east England, although having a reasonably high porosity, has a low grain-to-grain permeability, with its good water-yielding characteristics mostly due to micro-fracturing and fissuring.
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Porosity can be used to decrease the modulus of a polymer as seen in polymer foams, and as seen in bone, a change in porosity and therefore density can also be used to create a mechanical gradient along its cross-section.Sherwood, J.K.; Griffith, L.G.; Brown, S. U.S. Patent No. 6454811, 2002.
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By burrowing, the earthworm improves soil porosity, creating channels that enhance the processes of aeration and drainage.Bill Mollison, Permaculture: A Designer's Manual, Tagari Press, (December 1, 1988), 576 pages, . Increases in porosity enhance infiltration and thus reduce adverse effects of surface runoff. Other important soil organisms include nematodes, mycorrhiza and bacteria.
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The presence of fine particulate impurities in a soil can decrease its permeability by progressive clogging of its porosity.
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Due to porosity problems in ferritic steels and limited benefits, however, it is not a popular shielding gas additive.
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"Clay layers" are dry clay (Vcl) which also form part of the grain volume. If a core sample is dried in a normal dry oven (non-humidified atmosphere) the clay layers and quartz together form the grain volume, with all other components constituting core analysis “total porosity” (notwithstanding comments in ). This core total porosity will generally be equivalent to the total porosity derived from the density log when representative values for matrix and fluid density are used. The clay layers contain groups (often termed “structural water”).
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A dramatic example of a core effective porosity vs log effective porosity discrepancy comes from some Greensand reservoirs in Western Australia. Greensands are green because of iron-bearing glauconite which is usually recognized as illite/mica or mixed layer illite-smectite clay by x-ray diffraction. The glauconite per se will incorporate electrochemically bound water (CBW) because of the clay types. More importantly for the consideration of effective porosity, though, glauconite grains (part of the Vsh) have intra- particular microporous pore space which retains capillary-bound water.
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Technically, ceramics are composed of raw materials such as powders and natural or synthetic chemical additives, favoring either compaction (hot, cold or isostatic), setting (hydraulic or chemical), or accelerating sintering processes. According to the formulation and shaping process used, bioceramics can vary in density and porosity as cements, ceramic depositions, or ceramic composites. Porosity is often desired in bioceramics including bioglasses. Towards improving the performance of transplanted porous bioceramics, numerous processsing techniques are available for the control of porosity, pore size distribution and pore alignment.
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Log interpreters often find it difficult to accurately estimate the true formation porosity from these two curves. Neutron and density logging tools have different responses to the presence of gas in the formation because of differences in the physics of the measurements. A neutron tool response is sensitive mainly to the number of hydrogen atoms in the formation. During the calibration process, water-filled formations are used to develop porosity algorithms, and under these conditions, a lower number of hydrogen atoms is equivalent to a lower porosity.
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Heavy apparently refers to a gravitational moisture content effect in combination with terminology that harkens back to the relative force required to pull a tillage implement through the clayey soil at field moisture content as compared to sand. Porosity of subsurface soil is lower than in surface soil due to compaction by gravity. Porosity of 0.20 is considered normal for unsorted gravel size material at depths below the biomantle. Porosity in finer material below the aggregating influence of pedogenesis can be expected to approximate this value.
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Heavy apparently refers to a gravitational moisture content effect in combination with terminology that harkens back to the relative force required to pull a tillage implement through the clayey soil at field moisture content as compared to sand. Porosity of subsurface soil is lower than in surface soil due to compaction by gravity. Porosity of 0.20 is considered normal for unsorted gravel size material at depths below the biomantle. Porosity in finer material below the aggregating influence of pedogenesis can be expected to approximate this value.
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The dolomite is concentrated to sub-vertical fault zones associated with the Proterozoic basement. However, the dominant porosity throughout the Black River and Trenton Limestone in the Mansfield Natural Gas Field is controlled by the fractures. Porosity values in the dolomitized Black River and Trenton reservoirs range from 5 to 16 percent.
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Hydrogen porosity can be reduced by reducing the amount of hydrogen in the liquid aluminium alloy, by degassing or sparging. (Sometimes a small hydrogen concentration is intentionally maintained; some very fine hydrogen porosity can be preferable to internal voids caused by shrinkage.) Directional solidification can drive impurities to one end of the casting.
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Consolidated rocks (e.g., sandstone, shale, granite or limestone) potentially have more complex "dual" porosities, as compared with alluvial sediment. This can be split into connected and unconnected porosity. Connected porosity is more easily measured through the volume of gas or liquid that can flow into the rock, whereas fluids cannot access unconnected pores.
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After the shakeout of the casting it is inspected for defects. The most common defects are misruns and cold shuts. These defects can be caused by cold dies, low metal temperature, dirty metal, lack of venting, or too much lubricant. Other possible defects are gas porosity, shrinkage porosity, hot tears, and flow marks.
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Porosity formation, known as Kirkendall porosity, in these nickel- aluminum superalloys have been observed when diffusion bonding has been used.Karunaratne, M.S.A, P. Carter, and R.C. Reed. "On the diffusion of aluminium and titanium in the Ni-rich Ni–Al–Ti system between 900 and 1200°C." Acta Materialia 49.5 (2001): 861-875.
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However, there is an anomalous preservation of porosity at depth at drill site 1173. This has been attributed to post- depositional opal cementation that is preserving the porosity (Spinelli et al., 2007). The detrital clays, primarily smectite, display variation over time and location in the Nankai Trough as well as the Shikoku basin.
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However the porosity is relatively low at 1.4 percent. The analog for this is the Utica Shale reservoirs in Quebec.
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Highly fractured rocks can make good aquifers or hydrocarbon reservoirs, since they may possess both significant permeability and fracture porosity.
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Porosity logs measure the fraction or percentage of pore volume in a volume of rock. Most porosity logs use either acoustic or nuclear technology. Acoustic logs measure characteristics of sound waves propagated through the well-bore environment. Nuclear logs utilize nuclear reactions that take place in the downhole logging instrument or in the formation.
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Porosity can be proportional to hydraulic conductivity; for two similar sandy aquifers, the one with a higher porosity will typically have a higher hydraulic conductivity (more open area for the flow of water), but there are many complications to this relationship. The principal complication is that there is not a direct proportionality between porosity and hydraulic conductivity but rather an inferred proportionality. There is a clear proportionality between pore throat radii and hydraulic conductivity. Also, there tends to be a proportionality between pore throat radii and pore volume.
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Arc blow can also cause porosity in the weld, as can joint contamination, high welding speed, and a long welding arc, especially when low-hydrogen electrodes are used. Porosity, often not visible without the use of advanced nondestructive testing methods, is a serious concern because it can potentially weaken the weld. Porosity is caused when the gaseous shield did not sufficiently shield the molten weld metal while the bead is laid or while it is cooling. What happens is that the weld bead is overexposed to and absorbs; nitrogen, oxygen, and hydrogen from the atmosphere.
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The coating, being very thin, does not alter the look or feel of solid objects, or the vapor porosity of fabrics.
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Such method gives nanofoams with an organized structure and allows to control the surface area and porosity of the fabricated material.
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This causes porosity to remain on grain boundaries rather than becoming trapped inside grains, allowing them to be eliminated later in the sintering process. This greatly improves the material's optical transparency, because porosity causes light scattering. Porosities as low as one part per million were reported. The resulting grain size was in the range 10–50 μm.
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Often both the solid matrix and the pore network (also known as the pore space) are continuous, so as to form two interpenetrating continua such as in a sponge. However, there is also a concept of closed porosity and effective porosity, i.e. the pore space accessible to flow. Many natural substances such as rocks and soil (e.g.
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Volume fractions can be converted to mass fractions if the density of each phase is known. Image analysis can measure porosity, pore-size distribution and volume fractions of secondary phases by ASTM E1245. Porosity measurements do not require etching. Multi-phase microstructures do not require etching if the contrast between phases is adequate, as is usually the case.
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Due to wind erosion and porosity, portions of the rock fragments are broken off while paintings are visible on the remaining ruins.
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Without regular cleaning, historic buildings made of limestone, because of their high porosity, will continue to decay as a result of biological colonization.
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Hyperion is redder than Phoebe and closely matches the color of the dark material on Iapetus. Hyperion has a porosity of about 0.46.
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Porosity may also lead to out-gassing during the painting process, leaching of plating acids and tool chatter in machining pressed metal components.
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Lower porosity, while decreases the speed of filtration, increases the quality of filtered air. This parameter is measured in pores per linear inch.
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Highly porous ACC was also found to be stable in ambient conditions for up to 3 weeks with most of its porosity retained.
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Porous silicon studies conducted in 1995 showed that the behavior of porous silicon can be altered in between "bio-inert", "bioactive" and "resorbable" by varying the porosity of the silicon sample. The in-vitro study used simulated body fluid containing ion concentration similar to the human blood and tested the activities of porous silicon sample when exposed to the fluids for prolonged period of time. It was found that high porosity mesoporous layers were completely removed by the simulated body fluids within a day. In contrast, low to medium porosity microporous layers displayed more stable configurations and induced hydroxyapatite growth.
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A soil with good soil structure typically has a mix of micro-, meso-, and macropores. Therefore, with more aggregation, you would expect to have a higher total porosity compared to a poorly aggregated soil (Nimmo, 2004Nimmo, J.R., 2004, Porosity and Pore Size Distribution, in Hillel, D., ed. Encyclopedia of Soils in the Environment: London, Elsevier, v. 3, p. 295-303.).
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Although, sintering does not deplete the compact part of porosity. In general, powder metal parts contain five to twenty-five percent porosity after sintering. To allow efficient stacking of product in the furnace during sintering and prevent parts sticking together, many manufacturers separate ware using ceramic powder separator sheets. These sheets are available in various materials such as alumina, zirconia, and magnesia.
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Jha et al. achieved 65-80% porosity through the use of NaCl as a space-holder and a cold compaction process at various pressures with two-stage sintering. In this case, NaCl was removed through dissolution after the second stage of sintering. Resulting Young's moduli (8–15 GPa) were considerably lower than the Young's modulus of 29 GPa achieved for 50% porosity foams.
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Sliced Porosity Block - CapitaLand Raffles City Chengdu is a building complex built in Chengdu, China designed by Steven Holl Architects. It was built from 2008 to 2012. It celebrated its topping out in October 2011 at 123 meters. Sliced Porosity Block consists of 5 mixed-use towers with offices, apartments, retail and a hotel, which surround a large public plaza.
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A fluid will penetrate through the pores in the casting and eventually soak through, like a sponge. This is because at porosity percentages above the 'pore percolation threshold', pores link up into continuous channels. The pore percolation threshold depends on the characteristics of the material, but it is normally very roughly around 20%. A 60% dense component has 40% porosity.
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Schematic representation of a two-stage coalescing filter set. Coalescing filters aren’t actually filters, rather they operate more as a consolidation element. The idea behind these devices is that the compressed air is forced through gaps or porosity within an otherwise solid element. These gaps and/or porosity are microscopic and small enough that water vapor wets to the internal surfaces.
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Reservoir quality parameters almost always include porosity and permeability, but may include measures of clay content, cementation factors, and other factors that affect the storage and deliverability of fluids contained in the pores of those rocks. Geostatistical techniques are most often used to populate the cells with porosity and permeability values that are appropriate for the rock type of each cell.
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The Wasatch Formation is a tight gas reservoir rock in the Greater Natural Buttes Field in the Uinta Basin of Utah and Colorado. The formation is characterized by porosity ranging from 6 to 20 % and permeability of up to 1 mD. Based on 409 samples from the Wasatch Formation, average porosity is 8.75 percent and average permeability is 0.095 mD.
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Stylolite development can be improved with porosity, as it localizes stress on grains, increasing the stress there. Therefore, it is suggested that bedding-parallel stylolites form in areas of high porosity,Merino, E., Ortoleva, P., and Strickholm, P., 1983. Generation of evenly-spaced pressure-solution seams during (late) diagenesis: a kinetic theory. Contributions to Mineralogy and Petrology, 82: 360-370.
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Contrary to popular belief, light soils do not weigh less than heavy soils on an air dry basis nor do they have more porosity.
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Other techniques, such as sol–gel process chemistry, are also used. CMCs obtained with this process usually have a high porosity of about 20%.
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The residual porosity is about 10 to 15% which is high; the production rate is low; the capital investment, production and processing costs are high.
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As sediment transport and deposition continues, new sediments are deposited atop previously deposited beds, burying them. Burial continues and the weight of overlying sediments causes an increase in temperature and pressure. This increase in temperature and pressure causes loose grained sediments become tightly packed, reducing porosity, essentially squeezing water out of the sediment. Porosity is further reduced by the precipitation of minerals into the remaining pore spaces.
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Hydrothermal solutions, meteoric groundwater, porosity, permeability, solubility, and time are all influential factors. After deposition, sediments are compacted as they are buried beneath successive layers of sediment and cemented by minerals that precipitate from solution. Grains of sediment, rock fragments and fossils can be replaced by other minerals during diagenesis. Porosity usually decreases during diagenesis, except in rare cases such as dissolution of minerals and dolomitization.
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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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Another commonly employed space-holder for titanium foams is urea, which yilded porosities from 20 to 75%. Wen et al. produced foams exhibiting a bimodal pore distribution with porosities ranging from 55 to 75%, Young's moduli between 3–6.4 GPa, and a plateau stress of 10–35 MPa. An inverse relationship between plateau stress and porosity was observed with increased porosity resulting in decreased plateau stress.
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Gas porosity can sometimes be difficult to distinguish from micro shrinkage because microshrinkage cavities can contain gases as well. In general, microporosities will form if the casting is not properly risered or if a material with a wide solidification range is cast. If neither of these are the case then most likely the porosity is due to gas formation. Blowhole defect in a cast iron part.
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In die casting the most common defects are misruns and cold shuts. These defects can be caused by cold dies, low metal temperature, dirty metal, lack of venting, or too much lubricant. Other possible defects are gas porosity, shrinkage porosity, hot tears, and flow marks. Flow marks are marks left on the surface of the casting due to poor gating, sharp corners, or excessive lubricant.
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Tight oil shale formations are heterogeneous and vary widely over relatively short distances. Tight oil reservoirs subjected to fracking can be divided into four different groups. Type I has little matrix porosity and permeability – leading to fractures dominating both storage capacity and fluid flow pathways. Type II has low matrix porosity and permeability, but here the matrix provides storage capacity while fractures provide fluid-flow paths.
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The Strange–Rahman–Smith equation is used in the cryoporometry method of measuring porosity. NMR cryoporometry is a recent technique for measuring total porosity and pore size distributions. NMRC is based on two equations: the Gibbs–Thomson equation, which maps the melting point depression to pore size, and the Strange–Rahman–Smith equation, which maps the melted signal amplitude at a particular temperature to pore volume.
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A currently exciting application for NMR Cryoporometry is the measurement of porosity and pore-size distributions, in the study of carbon, charcoal and biochar. Biochar is regarded as an important soil enhancer (used since pre-history), and offers great possibilities for carbon dioxide removal from the biosphere. Materials studied by NMR cryoporometry include: Possible future application include measuring porosity and pore-size distributions in porous medical implants.
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The upper limit (wet end) of LLWR is determined not only at water content at field capacity (FC), but also the capability of providing adequate aeration for plant roots (usually taken as a minimum air filled porosity of 10%). The upper limit is then defined as: min q {air filled porosity = 0.1, FC}. Rather than air-filled porosity at 10%, LaoSheng Wu from UC Riverside proposed moisture content where Oxygen gas diffusion rate ODR value of 0.2 micro-g/cm2/min as criteria for satisfactory aeration status. The lower limit (dry end) is not only limited to permanent wilting point (PWP) but also the ability of root penetration.
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The neutron porosity log works by bombarding a formation with high energy epithermal neutrons that lose energy through elastic scattering to near thermal levels before being absorbed by the nuclei of the formation atoms. Depending on the particular type of neutron logging tool, either the gamma ray of capture, scattered thermal neutrons or scattered, higher energy epithermal neutrons are detected.Schlumberger Oilfield Glossary The neutron porosity log is predominantly sensitive to the quantity of hydrogen atoms in a particular formation, which generally corresponds to rock porosity. Boron is known to cause anomalously low neutron tool count rates due to it having a high capture cross section for thermal neutron absorption.
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5 µm thin nanocellulose film at 23 °C and 0% RH. In a related study, a more than 700-fold decrease in oxygen permeability of a polylactide (PLA) film when a nanocellulose layer was added to the PLA surface was reported. The influence of nanocellulose film density and porosity on film oxygen permeability has been explored. Some authors have reported significant porosity in nanocellulose films, which seems to be in contradiction with high oxygen barrier properties, whereas Aulin et al. measured a nanocellulose film density close to density of crystalline cellulose (cellulose Iß crystal structure, 1.63 g/cm3) indicating a very dense film with a porosity close to zero.
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Retrieved on 31 July 2016. The high porosity and surface area of silica aerogels allow them to be used in a variety of environmental filtration applications.
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Plating operations submerge the parts in acid solutions. The residual acid can seep into the porosity, which causes corrosion. Sealing the components before plating eliminates corrosion.
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It has a porosity ranging from 16% to 30% and a permeability of 360 millidarcies. The shallow section contains silty, bioturbated sands with poor reservoir quality.
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This includes racemization rate variation among species and organs, and is affected by the depth of decomposition, porosity, and catalytic effects of local metals and minerals.
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The results imply that the degree of grain boundary cracking, and hence intergranular fracture, is largely determined by boundary porosity, or the amount of atomic misfit.
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Due to the random structure and high porosity of an Xbloc breakwater, an artificial reef habitat is created for various species of marine fauna and flora.
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In fact, the morphology of the crystals, their size, their porosity and their specific surface after crystallization determine the powder's filterability, flowability, dispersability and dissolvability properties.
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Lockport Dolomite is the primary reservoir rock for the Mansfield Natural Gas Field. The Lockport Dolomite is a microcrystalline dolomite that varies in thickness from 5 to 40 feet, and is linked to bioherm buildups. Porosity in the Lockport Dolomite is highly influenced on the vuggy and molic nature of the dolomite itself. The porosity vaules range from 3.4 percent in the microcrystalline dolomite to 9.6 percent in the vuggy dolomite.
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Greensands may cause varying degrees of difficulty for porosity log analysis. radicals affect neutron logs; the iron component is troublesome, and varying clay hydration needs to be considered for density log interpretation. The iron component affects the NMR logs and clay affects the sonic log. Therefore it is essential to have a core - or at least a good understanding of the geology - before invoking total vs effective porosity relationships.
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The commonly used enthalpy-porosity model in commercial CFD codes assumes, a linear enthalpy-temperature relationship and ignores hysteresis.[8] The alternate is to use enthalpy-porosity method. When used to simulate PCM sails and a PCM plate-fin unit it produce reasonable temperature prediction in global space temperature terms. However there are inaccuracies in transient simulations where time dependent PCM and local wall and air temperatures are of interest.
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In saturated groundwater aquifers, all available pore spaces are filled with water (volumetric water content = porosity). Above a capillary fringe, pore spaces have air in them too. Most soils have a water content less than porosity, which is the definition of unsaturated conditions, and they make up the subject of vadose zone hydrogeology. The capillary fringe of the water table is the dividing line between saturated and unsaturated conditions.
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Mason Gully has an unusually high porosity and different mineralogy when compared to other H5 chondrites. Its porosity comes from intergranular void spaces rather than microscopic cracks, which is likely due to the low shock the rock has experienced. Whilst lithophile elemental abundances are consistent with other H chondrites, the uranium and titanium abundances are noticeably lower. Conversely, heavy refractory elements are enriched relative to the H chondrite group.
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52, p. 473 (1973) The additive served to control grain growth during densification, so that porosity remained on grain boundaries and not trapped inside grains where it would be quite difficult to eliminate during the initial stages of sintering. Typically, as polycrystalline ceramics densify during heat treatment, grains grow in size while the remaining porosity decreases both in volume fraction and in size. Optically transparent ceramics must be virtually pore-free.
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When no porosity is allowed in a cast part then the pore-free casting process is used. It is identical to the standard process except oxygen is injected into the die before each shot to purge any air from the mould cavity. This causes small dispersed oxides to form when the molten metal fills the die, which virtually eliminates gas porosity. An added advantage to this is greater strength.
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Drying of hydrogels under controlled circumstances may yield xerogels and aerogels. A xerogel is a solid that retains significant porosity (15-50%) with a very small pore size (1–10 nm). In an aerogel, the porosity is somewhat higher and the pores are more than an order of magnitude larger, resulting in an ultra-low-density material with a low thermal conductivity and an almost translucent, smoke-like appearance.
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If concrete pores are completely and permanently saturated (for instance in submerged structures) CO2 diffusion is prevented. On the other hand, for completely dry concrete, the chemical reaction of carbonation cannot occur. Another influencing factor for CO2 diffusion rate is concrete porosity. Concrete obtained with higher w/c ratio or obtained with an incorrect curing process presents higher porosity at hardened state, and is therefore subjected to a higher carbonation rate.
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Factors such as temperature, fluid type, pressure, pore type, porosity, saturation and others are interrelated in such a way that when one element changes others change as well.
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Putting the radioactive charge in the wireline string Locked case for radioactive source for logging job Nuclear tools measure formation properties through the interaction of reservoir molecules with radiation emitted from the logging tool. The two most common properties measured by nuclear tools are formation porosity and rock density: Formation porosity is determined by installing a radiation source capable of emitting fast neutrons into the downhole environment. Any pore spaces in the rock are filled with fluid containing hydrogen atoms, which slow the neutrons down to an epithermal or thermal state. This atomic interaction creates gamma rays which are then measured in the tool through dedicated detectors, and interpreted through a calibration to a porosity.
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Pottery Science: Materials, Process And Products. Allen Dinsdale. Ellis Horwood. 1986. Due to its porosity, earthenware, with a water absorption of 5-8%, must be glazed to be watertight.
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Despite these disadvantages, spray forming remains an economic process for the production of difficult to manufacture, niche alloys. Large-scale porosity is more difficult to heal effectively and must be minimised by careful process control. In some cases, porosity is controlled by alloy additions which react with dissolved and entrapped gas to form a solid phase e.g. titanium added to copper billets to form titanium nitride with dissolved and entrapped nitrogen gas.
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Below the water table, where in general all pore spaces are saturated with water, is the phreatic zone. Substrate with low porosity that permits limited transmission of groundwater is known as an aquitard. An aquiclude is a substrate with porosity that is so low it is virtually impermeable to groundwater. A confined aquifer is an aquifer that is overlain by a relatively impermeable layer of rock or substrate such as an aquiclude or aquitard.
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Gassmann fluid substitution requires that the porosity remain constant. The assumption being that, all other things being equal, different saturating fluids should not affect the porosity of the rock. This does not take into account diagenetic processes, such as cementation or dissolution, that vary with changing geochemical conditions in the pores. For example, quartz cement is more likely to precipitate in water-filled pores than it is in hydrocarbon-filled ones (Worden and Morad, 2000).
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The vacuum impregnation process seals internal leak paths to make it leak free and suitable for use. In the course of sealing castings against porosity, the parts would be processed through the following four stations: #Impregnation Chamber: The operator would seal the chamber and draw a vacuum. This would remove air in the porosity and leak path in the casting wall. Parts would then be covered with sealant, and positive pressure applied.
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ScanIP can be used to create computational models suitable for detailed visualisation, analysis and export for simulation in CAE solvers. Scanned image data can be easily processed to identify regions of interest, measure defects, quantify statistics such as porosity, and generate CAD and CAE models. Example applications include research into characterising composites,Alghamdi, A., Khan, A., Mummery, P., Sheikh, M., 2013. The characterisation and modelling of manufacturing porosity of a 2-D carbon/carbon composite.
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Because most of the above techniques are limited when it comes to the control of porosity and pore size, computer assisted design and manufacturing techniques have been introduced to tissue engineering. First, a three-dimensional structure is designed using CAD software. The porosity can be tailored using algorithms within the software. The scaffold is then realized by using ink-jet printing of polymer powders or through Fused Deposition Modeling of a polymer melt.
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Fu, L., Milliken, K.L., and Sharp, J.M. Jr., 1994. Porosity and permeability variations in fractured and Liesegang-banded Breathitt sandstones (Middle Pennsylvanian), eastern Kentucky: diagenetic controls and implications for modeling dual-porosity systems. Journal of Hydrology, 154: 351-381. Liesegang rings are referred to as examples of geochemical self-organization, meaning that their distribution in the rock does not seem to be directly related to features that were established prior to Liesegang ring formation.
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Stroke 2016.Liebeskind DS, Agbayani E, Woolf GW, et al. Imaging of clot porosity prior to endovascular thrombectomy. Cerebral Large Artery Disease Posters, poster presentation at International Stroke Conference 2017.
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In most materials the sintered grain size is proportion to the inverse square root of the fractional porosity, implying that pores are the most effective retardant for grain growth during sintering.
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Mercerised pulp is a bleached pulp that is treated with hot diluted alkali to get extra high bulk and high porosity. The pulp feels and looks similar to a cotton ball.
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Charcoal's porosity brings better retention of organic matter, of water and of dissolved nutrients, Cited in . as well as of pollutants such as pesticides and aromatic poly-cyclic hydrocarbons. Cited in .
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In this equation, D is the diffusion coefficient for the lithium ion. It has a value of in the electrolyte. The value for ε, the porosity of the electrolyte, is 0.724.
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There are a number of problems that can be encountered during the casting process. The main types are: gas porosity, shrinkage defects, mold material defects, pouring metal defects, and metallurgical defects.
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Hierarchic porosity can be achieved by using polymer-derived ceramics with or without utilizing a templating method. Templating yields an ordered array of mesopores in addition to the disordered network of micropores. It has been shown that the initial crystal structure of the carbide is the primary factor affecting the CDC porosity, especially for low- temperature chlorine treatment. In general, a larger spacing between carbon atoms in the lattice correlates with an increase in the average pore diameter.
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Tombecka has an determined mass of kilograms and a high (metallic) density of 7.50 g/cm3 with no porosity at all. The results correspond to an overall mean-diameter of 35.18 kilometers.
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In other metals, chills may be used to promote directional solidification of the casting. In controlling the way a casting freezes, it is possible to prevent internal voids or porosity inside castings.
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AIChE J., 5: 270-271 In practice, the constrictivity together with the porosity and tortuosity are often used in models as purely empirical parameters to establish the effective diffusivities in porous media.
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Where the sedimentary rocks are sandstones with high porosity, and the structure and stratigraphy allow hydrocarbons to be trapped on their upward migration, oilfields are found.Keller, Margaret. Ventura Basin Province. 1988, Dept.
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4, Article 7. Smaller seeds have increased heat transfer, which leads to lower drying time. Seeds with lower amounts of porosity also have lower tendencies to lose water during the process of drying.
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Her doctoral thesis was supervised by Isidro López-Aparicio (es), and was called La mediación cultural: Mecanismos de porosidad para construir cultura contemporánea sostenible (Cultural mediation: Porosity mechanisms to build contemporary sustainable culture).
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The plant dies back to the roots each winter. The stem has a chambered pith. Leaves: The leaves are alternate with coarse texture with moderate porosity. Leaves can reach sixteen inches in length.
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These included combo type logs where resistivity logs and porosity logs were recorded in one pass in the borehole. The two types of porosity logs (acoustic logs and nuclear logs) date originally from the 1940s. Sonic logs grew out of technology developed during World War II. Nuclear logging has supplemented acoustic logging, but acoustic or sonic logs are still run on some combination logging tools. Nuclear logging was initially developed to measure the natural gamma radiation emitted by underground formations.
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SiC–SiC composites have a relatively high thermal conductivity and can operate at very high temperatures due to their inherently high creep and oxidation resistance. Residual porosity and stoichiometry of the material can vary its thermal conductivity, with increasing porosity leading to lower thermal conductivity and presence of Si–O–C phase also leading to lower thermal conductivity. In general, a typical well processed SiC–SiC composite can achieve a thermal conductivity of around 30 W/m-K at 1000 Celsius.
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The upper layers consist of vesiculara and amygdaloidal zeolitic basalt while the bottom layer consists of massive basalt. The lava flows are individually different in their ability to receive as well as hold water in storage and to transmit it. The difference in the productivity of groundwater in various flows arises as a result of their inherent physical properties such as porosity and permeability. The groundwater occurs under water table conditions and is mainly controlled by the extent of its secondary porosity i.e.
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Air permeability is expressed in terms of the Gurley value, the time required for a specified amount of air to pass through a specified area of the separator under a specified pressure. The Gurley value reflects the tortuosity of the pores, when the porosity and thickness of the separator is fixed. A separator with uniform porosity is vital to battery life cycle. Deviations from uniform permeability produce uneven current density distribution, which causes the formation of crystals on the anode.
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In southern Florida, the composition of strata was anhydrite, with interbred dolomite and fossiliferous chalky limestone. One of the major differences in the strata samples from each location was the difference in the porousness of each layer. It was observed that there were minor signs of poorly developed porosity in the Florida sample, while the sample collected in Andros No. 1 showed large, thick areas of well-developed porosity. This information allowed geologists to conclude that at approximately 14,500 ft.
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All require good dimensional stability, no curling or cockling, good surface strength and surface smoothness. For ink-jet paper it is also important with sufficient and uniform porosity to counteract spreading of the ink.
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The Sliced Porosity Block is heated and cooled with 468 geothermal wells and the large ponds in the plaza harvest recycled rainwater, while the natural grasses and lily pads create a natural cooling effect.
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Such proximity produces a kind of porosity that allows the Sparrows to monitor the Crows––thus, facilitating their subversion of the existing social hierarchy.Wang, Yiman. (2008). Crows and Sparrows: Allegory on a Historical Threshold.
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The Ancha Formation is a thin (less than saturated thickness) but locally important aquifer for domestic wells south of Santa Fe. Its porosity is much greater than the underlying beds of the Tesuque Formation.
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Brewery's spent grains could be recycled through their incorporation in a traditional ceramic paste used in the manufacture of common bricks. This incorporation affects the mechanical strength, porosity, and thermal conductivity of the ceramic material.
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It can identify various mineral and organic additives. The structure and porosity of the ceramic material can be precisely measured. The original firing temperature can be determined. The origin of the clay can be identified.
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The matrix potential can vary considerably among soils. In the case that water drains into less-moist soil zones of similar porosity, the matrix potential is generally in the range of −10 to −30 kPa.
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Ice in the Martian Regolith in Mars, H.H. Kieffer et al., Eds.; University of Arizona Press: Tucson, AZ, pp. 523–554. The high porosity and permeability of the megaregolith permitted the deep infiltration of groundwater.
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Grain size, porosity and second-phase content have all been correlated with ceramic properties such as mechanical strength σ by the Hall–Petch equation. Hardness, toughness, dielectric constant and many other properties are microstructure-dependent.
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When the petrophysical rock model is complete, a statistical database is created to describe the rock types and their known properties such as porosity and permeability. Lithotypes are described, along with their distinct elastic properties.
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Finally, and crucially, their porosity means that they can be infiltrated by materials with useful properties, or processed with other materials in. For example, the component could be dipped in molten copper, such that the copper is drawn up by capillary action into the porosity, increasing the conductivity of the component vastly. Alternatively, copper powder could be used as a filler powder in place of some alumina to the same end. Freeze-cast components, in their basic form, are ideal for use as heat-resisting objects.
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Gas porosity is the fraction of a rock or sediment filled with a gas. Determining the true porosity of a gas filled formation has always been a problem in the oil industry. While natural gas is a hydrocarbon, similar to oil, the physical properties of the fluids are very different, making it very hard to correctly quantify the total amount of gas in a formation. Well logging interpretation of the amount of hydrocarbon in the pore space of a formation, relies on the fluid being oil.
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Subject to various assumptions and corrections, values of apparent porosity can be derived from any neutron log. One can not underestimate the slow down of neutrons by other elements even if they are less effective. Certain effects, such as lithology, clay content, and amount and type of hydrocarbons, can be recognized and corrected for only if additional porosity information is available, for example from sonic and/or density log. Any interpretation of a neutron log alone should be undertaken with a realization of the uncertainties involved.
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The discovery of its satellite enabled the first accurate measure of Euphrosyne's mass in 2020, at , and thus a density of . The low density suggests that Euphrosyne is half water ice if internal porosity is 20%.
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Some progress has been made in ophiolites from Oman. But the major problem is that these artificial processes require sufficient porosity-permeability so that the fluids can flow but this is hardly the case in peridotites.
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Some heads with this casting number would fail (but not all of them) as GM had different suppliers for the same head. The failure was due to undetected porosity around the oil drains in the head.
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Such geosynthetic aggregates replace conventional gravel while simultaneously increasing porosity, increasing hydraulic conductivity and eliminating the fine dust "fines" inherent to gravel aggregates which otherwise serve to clog and disrupt the operation of many drainage applications.
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Values for attributes such as porosity, permeability and water saturation are associated with each cell. The value of each attribute is implicitly deemed to apply uniformly throughout the volume of the reservoir represented by the cell.
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The Keg River Formation is composed of dark dolomite with intercrystalline or vuggy porosity and wackestone limestone. The Rainbow Member and upper Keg River Member are reef formations deposited in the Rainbow, Zama and Bitscho sub-basins.
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Oxford University PressDOI.org They often precede large faults. They develop in porous rocks, such as sandstone. Material in a deformation band has a much smaller grain size, poorer sorting, and a lower porosity than the original sandstone.
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Amalthea's density implies that the moon is composed of water ice with a porosity of 10–15%, and Adrastea may be similar. No surface details of Adrastea are known, due to the low resolution of available images.
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Some developments using feed-back control have proved successful in improving the variations in billet diameter and improving yield in specific systems but these have yet to find widespread implementation. Porosity resulting from gas entrapment and solidification shrinkage is a significant problem in spray formed materials. A typical spray formed billet will contain 1-2% porosity with a pore size dependent on alloy freezing range and various process parameters. Hot isostatic pressing (HIPing) or thermo-mechanical processing can heal these pores if they are small (less than 30 μm).
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Glauconite can constitute a large percentage of the reservoir rock, and therefore the associated intra-particular pore space can be significant. Log effective porosities calculated at 25% in some Greensand reservoirs have yielded core analysis effective porosities of 35% at equivalent depths. The difference is the glauconitic microporosity which contains water at reservoir conditions and is included as part of the Vsh (non-effective porosity) by log analysis. However, glauconitic microporosity is measured as part of the effective porosity in core plugs, even if they are humidity dried.
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To achieve the bulk value, porosity could play an important role. If the mineral grain density is chosen to be 3100 kg m−3, 10% to 23% porosity could give a 200 kg m−3 drop in the bulk density. If the pore spaces are filled with water or ice, bulk density decrease is also expected. A further drop in bulk density could be explained by increasing density with depth, with the surface layer more porous than the deeper Mars, and the increase of density with depth also has geographical variation.
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Liquid-state sintering is required for making cemented carbide and tungsten carbide. Sintered bronze in particular is frequently used as a material for bearings, since its porosity allows lubricants to flow through it or remain captured within it. Sintered copper may be used as a wicking structure in certain types of heat pipe construction, where the porosity allows a liquid agent to move through the porous material via capillary action. For materials that have high melting points such as molybdenum, tungsten, rhenium, tantalum, osmium and carbon, sintering is one of the few viable manufacturing processes.
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In aluminium castings, hydrogen is the only gas that dissolves in significant quantity, which can result in hydrogen gas porosity.Gas Porosity in Aluminum Casting, Compiled AFS Literature, March 2002 For casting that are a few kilograms in weight the pores are usually in size. In larger casting, they can be up to a millimetre (0.040 in) in diameter. To prevent gas porosity the material may be melted in a vacuum, in an environment of low-solubility gases, such as argon or carbon dioxide, or under a flux that prevents contact with the air.
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Schematic diagram of the back-stripping technique relating to equation (). The loaded column relates to equation (), and the unloaded column to equations () and () As a result of their porosity, sedimentary strata are compacted by overlaying sedimentary layers after deposition. Consequently, the thickness of each layer in a sedimentary sequence was larger at the time of its deposition than it is when measured in the field. In order to consider the influence of sediment compaction on the thickness and density of the stratigraphic column, the porosity must be known.
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Using well-studied plants is important because there has already been substantial bodies of work to test them in various conditions, so responses can be verified with certainty. Such plants are also valuable because they are genetically identical as crops as opposed to natural variants of the same species. Typically urban soil has had the topsoil stripped away and has led to soil with low aeration, porosity, and drainage. Typical measures of soil health are microbial biomass and activity, enzymes, soil organic matter (SOM), total nitrogen, available nutrients, porosity, aggregate stability, and compaction.
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When the part is withdrawn from the resin bath, it is drained and/or cleaned and then cured. Curing can consist of polymerizing the internal resin or evaporating the solvent, which leaves an insulating dielectric material between different voltage components. Porosity sealing (Resin Impregnation) fills all interior spaces, and may or may not leave a thin coating on the surface, depending on the wash/rinse performance. The main application of vacuum impregnation porosity sealing is in boosting the dielectric strength of transformers, solenoids, lamination stacks or coils, and some high voltage components.
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This early attempt to exploit the Bakken Formation using horizontal drilling failed because the wells were placed in the shale members of the Bakken. Findley found that the dolomitic middle Bakken member in Montana had oil shows and porosity in sample cuttings, as well as porosity on well logs. Also, the porous middle Bakken member could be mapped over a large area in Montana, which Findley called a "Sleeping Giant". The Bakken formation had long been known to produce small amounts of oil throughout much of the deeper Williston Basin.
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Type III are microporous reservoirs with high matrix porosity but low matrix permeability, thus giving induced fractures dominance in fluid-flow paths. Type IV is macroporous reservoirs with high matric porosity and permeability, thus the matrix provides both storage capacity and flow paths while fractures only enhance permeability. Even in a single horizontal drill hole, the amount recovered may vary, as may recovery within a field or even between adjacent wells. This makes evaluation of plays and decisions regarding the profitability of wells on a particular lease difficult.
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Pre-treatment of the slurries before filtration is required if the solid suspension has settled down. Coagulation as pre-treatment can improve the performance of filter press because it increases the porosity of the filter cake leading to faster filtration. Varying the temperature, concentration and pH can control the size of the flocs. Moreover, if the filter cake is impermeable and difficult for the flow of filtrate, filter aid chemical can be added to the pre-treatment process to increase the porosity of the cake, reduce the cake resistance and obtain thicker cake.
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These rows are generally turned to improve porosity and oxygen content, mix in or remove moisture, and redistribute cooler and hotter portions of the pile. Windrow composting is a commonly used farm scale composting method. Composting process control parameters include the initial ratios of carbon and nitrogen rich materials, the amount of bulking agent added to assure air porosity, the pile size, moisture content, and turning frequency. The temperature of the windrows must be measured and logged constantly to determine the optimum time to turn them for quicker compost production.
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All rocks have a certain degree of porosity, with some rock types having a much higher porosity than others. This means that between the individual grains of the rock, there are small pores which can be filled with a gas (usually air) or a fluid. The commonest pore fluid is water, and the presence of water can vary the friction on a fault to a large degree. As water accumulates in the pore space of a body of rock around a fault, the pressure inside the pores builds.
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The next step is to use information from appraisal wells to estimate the porosity of the rock. The porosity, or the percentage of the total volume that contains fluids rather than solid rock, is 20–35% or less. It can give information on the actual capacity. Laboratory testing can determine the characteristics of the reservoir fluids, particularly the expansion factor of the oil, or how much the oil expands when brought from the high pressure and high temperature of the reservoir to a "stock tank" at the surface.
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The key concept is while low porosity, brittle rocks may have very little natural storage or flow capability, the rock is subjected to stresses that generate fractures, and these fractures can actually store a very large volume of hydrocarbons, capable of being recovered at very high rates. One of the most famous examples of a prolific naturally fractured reservoir was the Austin Chalk formation in South Texas. The chalk had very little porosity, and even less permeability. However, tectonic stresses over time created one of the most extensive fractured reservoirs in the world.
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Vitrified tile is made by hydraulic pressing a mixture of clay, quartz, feldspar and silica, which make vitreous surface. Thus creating a single mass making them hard with low porosity. Different clay bodies reach vitrification at different temperatures.
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Shells from pecans, almonds, Brazil nuts, acorns, and most other nuts are useful in composting."Composting Nut shells.", GardenWeb, accessed November 07, 2010. Their high porosity makes them also ideal in the production of activated carbon by pyrolysis.
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The process of manufacturing yarn is complex, and each step in this process can change the porosity, thinness, and flexibility of the final fabric[2]. The steps of yarn-making are carding, combing, drawing out, twisting, and spinning.
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Based upon radar data, the near surface solid density of Vibilia is 2.4. The density had been calibrated against that of 433 Eros; the uncalibrated figure is 3.2 g/cm3. Carry gives a density of with a low porosity.
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Soil compaction is also impacts infiltration capacity. Compaction of soils results in decreased porosity within the soils, which decreases infiltration capacity. Hydrophobic soils can develop after wildfires have happened, which can greatly diminish or completely prevent infiltration from occurring.
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In a cave system, the epiphreatic zone or floodwater zone is the zone between the vadose zone above and phreatic zone below. It is regularly flooded and has a significant porosity. It has a great potential for cave formation.
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Macrophytes are absent, consequently porosity is very low. Exclusion of species is due either to high temperature (travertine), high pH/ionic strength (tufa) or absence of light (speleothems). Pedley (1990)Pedley, H.M. 1990. Classification and environmental models of cool freshwater tufas.
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Sulfur hexafluoride can be added to shield gas for aluminium welding to bind hydrogen in the weld area to reduce weld porosity.Method of welding material with reduced porosity – Patent Application 20070045238. Freepatentsonline.com (2005-08-29). Retrieved on 2010-02-08.
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The drying process could take several days, depending on the humidity, the size, wall-thickness, and porosity of the vessel. Even when drying was complete, vessels remained between 3-5% saturated with water, which was only expelled during the firing process.
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Media Art Net - Bunting, Heath: Biography Mediakunstnetz.de. (2010) His work often explores the porosity of borders, both in physical space and online.BorderXing Guide Irational.org. (2001). In 1997, his online work Visitors Guide to London Interview with Heath Bunting Nettime. (1998).
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He put forward a theory that porosity in shales was an index of pressure metamorphism liable to indicate the presence of oil, years before the approach was documented in the literature. He was awarded a Ph.D. from Stanford University in 1937.
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Additionally, peak absorption wavelength underwent a red-shift as a larger amount of reducing agent (HAuCl4) was added and porosity of the particles increased. For semiconductor nanoparticles, the maximum optical absorption is often in the near-infrared and mid-infrared region.
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Patient age, sex, race, and other factors affect bone thickness and porosity, making some examinations more difficult or even impossible. Most can still be performed to obtain acceptable responses, sometimes requiring using alternative sites from which to view the vessels.
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Results showed that the grain sizes were identical when the samples were sintered to the same density, proving that grain size is a function of specimen density rather than CRH temperature mode. In rate- controlled sintering (RCS), the densification rate in the open-porosity phase is lower than in the CRH method. By definition, the relative density, ρrel, in the open-porosity phase is lower than 90%. Although this should prevent separation of pores from grain boundaries, it has been proven statistically that RCS did not produce smaller grain sizes than CRH for alumina, zirconia, and ceria samples.
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Gibson & Ashby micromechanical models for porous materials provide mathematical equations for the prediction of mechanical parameters based on experimentally determined geometric constants. The constants of proportionality are determined by fitting experimental data to various mathematical models for structures consisting of cubes and solid struts and are dependent upon cell geometry. A limitation of the Gibson & Ashby model is that it is most accurate for foams exhibiting porosities higher than 70%, although experimental comparisons for lower porosity foams have shown agreement with this model. Ye & Dunand found reasonable agreement to the Gibson & Ashby model for titanium foams exhibiting 42% porosity.
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Biomedical implants should have low density for patient comfort and high porosity and surface area to facilitate vascularization and the ingrowth of new bone. Ideally, the implant will allow sufficiently easy fluid flow for cell nutrition and osteoblast multiplication as well as migration for cellular colonization of the implant to become uniform. The pores contained within the foam's cellular matrix mimic the extracellular matrix of bone, allowing the body to fixate with the implant. The porosity of the implant also promotes apposition and facilitates vascularization−as cells are able to attach, reproduce and form basic functions.
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Vacuum desiccator bell jar with 316 stainless steel sample tree, dishes with flowers of sulfur and saturated potassium nitrate solution in the bottom. Flowers of sulfur (FOS) testing was developed to determine the porosity of metallic coatings susceptible to sulfur induced corrosion [see below ASTM B809-95(2018)]. Applicable substrates are silver, copper, copper alloys and any other metal or metal alloy with which sulfur will react. For porosity testing, coatings can be single or multiple layers of any metal that is not corroded and sealed by a self-limiting reaction in the reducing sulfur environment of the FOS test.
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The inclusion of iron and chromium rich regions probably originate from a molten nozzle that did not have enough time to be distributed through the melt. The bulk density of the samples varied between 7.45 and 9.4 g/cm3 (the densities of UO2 and ZrO2 are 10.4 and 5.6 g/cm3). The porosity of samples varied between 5.7% and 32%, averaging at 18±11%. Striated interconnected porosity was found in some samples, suggesting the corium was liquid for a sufficient time for formation of bubbles of steam or vaporized structural materials and their transport through the melt.
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Thus it can be said that porosity is the sum of specific yield and specific retention. Specific yield of soils differ from each other in the sense that some soil types have strong molecular attraction with the water held in their pores while others have less. It is found experimentally that cohesionless soils have high specific yield than cohesive soils because the former has significantly less molecular attraction then the latter. Coarse-grained soils or rocks such as coarse sandstone can have specific yields that are closer to their actual porosity in the range 20 to 35%.
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The carbon particles used in the GDL can be larger than those employed in the catalyst because surface area is not the most important variable in this layer. GDL should be around 15–35 µm thick to balance needed porosity with mechanical strength. Often, an intermediate porous layer is added between the GDL and catalyst layer to ease the transitions between the large pores in the GDL and small porosity in the catalyst layer. Since a primary function of the GDL is to help remove water, a product, flooding can occur when water effectively blocks the GDL.
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Mathematically, overburden pressure can be derived as: : S = ρb× D×g where :g = acceleration due to gravity : S = overburden pressure : ρb = average formation bulk density : D = vertical thickness of the overlying sediments The bulk density of the sediment is a function of rock matrix density, porosity within the confines of the pore spaces, and porefluid density. This can be expressed as : ρb = φρf \+ (1 – φ)ρm where : φ = rock porosity : ρf = formation fluid density : ρm = rock matrix densityJerome Jacob Schubert, 1995, pp. 1-3, 4.Rehm, Bill; Schubert, Jerome; Haghshenas, Arash; Paknejad, Amir Saman; Hughes, Jim (2008).
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After this first slice is generated, the powder bed moves downwards, and a new batch of metal powder is rolled over the top of the slice. The second layer is then sintered with the laser, and the process is repeated until all the slices in the CAD file have been processed. Due to the nature of many additive manufacturing processes, porosity can be present in products made by selective laser melting. Many products will often undergo a heat treatment or hot isostatic pressing procedure to densify the product and reduce porosity which can result in cracking.
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In sedimentology, compaction is the process by which a sediment progressively loses its porosity due to the effects of pressure from loading. This forms part of the process of lithification. When a layer of sediment is originally deposited, it contains an open framework of particles with the pore space being usually filled with water. As more sediment is deposited above the layer, the effect of the increased loading is to increase the particle-to- particle stresses resulting in porosity reduction primarily through a more efficient packing of the particles and to a lesser extent through elastic compression and pressure solution.
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He argues, "Security seeks to close a city down. Porosity seeks to open it up. Somewhere between the two a solution must be found within our capitalist system. If we can't find the balance, they'll close the cities and cities will die".
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Dry soil can allow rapid infiltration by capillary action; this force diminishes as the soil becomes wet. Compaction reduces the porosity and the pore sizes. Surface cover increases capacity by retarding runoff, reducing compaction and other processes. Higher temperatures reduce viscosity, increasing infiltration.
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Indiana University Math. Journal, 39 (3):877-936, 1990. It can be approximated by the implicit surface : \cos(x) + \cos(y) + \cos(z) = 0 \ . The P surface has been considered for prototyping tissue scaffolds with a high surface-to-volume ratio and porosity.
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The surface may not heat up significantly, allowing the coating of flammable substances. Coating quality is usually assessed by measuring its porosity, oxide content, macro and micro-hardness, bond strength and surface roughness. Generally, the coating quality increases with increasing particle velocities.
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The density log measures the bulk density of a formation by bombarding it with a radioactive source and measuring the resulting gamma ray count after the effects of Compton Scattering and Photoelectric absorption. This bulk density can then be used to determine porosity.
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Another approach, proposed by Rousselier, is based on continuum damage mechanics (CDM) and thermodynamics. Both models form a modification of the von Mises yield potential by introducing a scalar damage quantity, which represents the void volume fraction of cavities, the porosity f.
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Immiscible CO2 helps to saturate oil, resulting in swelling and reduction of viscosity of the liquid phase and consequently improving mobilization by extra driving pressure. Concomitantly, other gases and solvents may dissolve carbonate rock, leading to an increase in rock permeability and porosity.
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Medium porosity is more balance and absorbs water, product, and moisture easily. In order to best treat naturally curly hair, celebrity hairstylist Andre Walker created a hair typing system. This categorizes hair into four categories based on how tight curls are coiled.
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Chloride inclusions (MgCl2, NaCl, CaCl2, …) are a special type of inclusion as they are liquid in liquid metal. When aluminium solidifies, they form spherical voids similar to hydrogen gas porosity but the void contains a chloride crystal formed when aluminium became colder.
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The structures have a very high surface to volume ratios and porosity. This material is multifunctional owing to its unique structure. The void can be used to encapsulate various multifunctional nanomaterial or even as a nanoreactor. Their shells can also be functionalized.
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Dichlorodifluoromethane with argon can be used for protective atmosphere for melting of aluminium-lithium alloys.Blanketing atmosphere for molten aluminum-lithium or pure lithium – Patent EP0268841. Freepatentsonline.com. Retrieved on 2010-02-08. It reduces the content of hydrogen in the aluminium weld, preventing the associated porosity.
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This structural water is never part of the pore volume. However, since neutron logs sense H (hydrogen) and all hydrogen so-sensed is allocated as pore space, then neutron logs will overestimate porosity in argillaceous rocks by sensing as part of the pore space.
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Metals are mixed to achieve a desired goal or need. As an example, a base metal for jewellery needs to be castable, polishable, have good flow characteristics, have the ability to cast fine detail without an excessive amount of porosity and cast at between .
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The largest advantage in fabricating titanium foams is that the mechanical and functional properties can be adjusted through manufacturing manipulations that vary porosity and cell morphology. The high appeal of titanium foams is directly correlated to a multi-industry demand for advancement in this technology.
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For both compaction methods, the resulting pore morphology is dependent upon the morphology of the metallic powder, making it difficult to control the size, shape, and distribution of the pores. Another disadvantage includes the relatively high probability of pore collapse and limited achievable porosity levels.
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The samples are then oven dried and weighed. Bulk density = (mass of oven dry soil)/volume The bulk density of soil is inversely related to the porosity of the same soil. The more pore space in a soil the lower the value for bulk density.
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Category:Petroleum production A Flow Zone Unit is a term used by a Reservoir Engineer and is used in modelling the conditions in an oil reservoir. Flow units are defined with aim of better understanding reservoir unit flow behaviour and relation between porosity and permeability.
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The absorbent kraft paper is a normal kraft paper with controlled absorbency, which means a high degree of porosity. It is made of clean low kappa hardwood kraft with good uniformity. The grammage is 80 - 120 g/m2 and normally 2-4 plies are used.
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The Ozona formation is part of the larger, unconventional Canyon sandstone system, a tight gas play within the Val Verde basin. Tight reservoirs such as this are characterized by low permeability and low porosity, however the basin is still gas saturated and currently producing today.
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The porosity of the copper ingots and the natural brittleness of tin suggest that both metal ingots were easy to break. As Bass et al. proposes, a metalsmith could simply break off a piece of the ingot whenever he liked for a new casting.
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Ellipsometric porosimetry measures the change of the optical properties and thickness of the materials during adsorption and desorption of a volatile species at atmospheric pressure or under reduced pressure depending on the application. The EP technique is unique in its ability to measure porosity of very thin films down to 10 nm, its reproducibility and speed of measurement. Compared to traditional porosimeters, Ellipsometer porosimeters are well suited to very thin film pore size and pore size distribution measurement. Film porosity is a key factor in silicon based technology using low-κ materials, organic industry (encapsulated organic light-emitting diodes) as well as in the coating industry using sol gel techniques.
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Semi-solid metal (SSM) casting is a modified die casting process that reduces or eliminates the residual porosity present in most die castings. Rather than using liquid metal as the feed material, SSM casting uses a higher viscosity feed material that is partially solid and partially liquid. A modified die casting machine is used to inject the semi-solid slurry into reusable hardened steel dies. The high viscosity of the semi-solid metal, along with the use of controlled die filling conditions, ensures that the semi-solid metal fills the die in a non- turbulent manner so that harmful porosity can be essentially eliminated.
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All commercially available electrodes contain deoxidizing metals such as silicon, manganese, titanium and aluminum in small percentages to help prevent oxygen porosity. Some contain denitriding metals such as titanium and zirconium to avoid nitrogen porosity. Depending on the process variation and base material being welded the diameters of the electrodes used in GMAW typically range from 0.7 to 2.4 mm (0.028 – 0.095 in) but can be as large as 4 mm (0.16 in). The smallest electrodes, generally up to 1.14 mm (0.045 in) are associated with the short-circuiting metal transfer process, while the most common spray-transfer process mode electrodes are usually at least 0.9 mm (0.035 in).
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Movement of gases is by diffusion from high concentrations to lower, the diffusion coefficient decreasing with soil compaction. Oxygen from above atmosphere diffuses in the soil where it is consumed and levels of carbon dioxide in excess of above atmosphere diffuse out with other gases (including greenhouse gases) as well as water. Soil texture and structure strongly affect soil porosity and gas diffusion. It is the total pore space (porosity) of soil, not the pore size, and the degree of pore interconnection (or conversely pore sealing), together with water content, air turbulence and temperature, that determine the rate of diffusion of gases into and out of soil.
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This unit is generally thinner than the lower sedimentary unit. It consists of mainly sands and gravels from the Pleistocene. This unit along with the lower sedimentary unit have high porosity and high permeability, resulting in high water yields. Agriculture typically uses these units for irrigation.
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Surface area and porosity of filter packing materials influence treatment performance.Dahab, M.F. 1982 Effect of media design on the performance of fixed-bed anaerobic filters. Water Science & Technology, 15, 369–383. Thus materials with low granulometry and large surface area may improve the performance of the vermifilter.
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A hydrocarbon reservoir is an underground reservoir that keeps hydrocarbons trapped inside. Reservoir rocks have high porosity and permeability while the surrounding rocks that act as barriers have low permeability. Therefore, hydrocarbons that exist as liquid and/or gas can only stay in the reservoir rocks.
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Some inkjet papers are made from high quality deinked pulp or chemical pulps. Quality inkjet paper requires good dimensional stability, no curling or cockling, and good surface strength. For most purposes surface smoothness is required. Sufficient and even porosity is required to counteract spreading of the ink.
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Retrieved 28 Nov 2017. and elements other than copper can be used in alloys to reduce tarnishing, as well as casting porosity and firescale. Such elements include germanium, zinc, platinum, silicon, and boron. Recent examples of alloys using these metals include argentium, sterlium, sterilite and silvadium.
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Elephant ivory is solid dentin. The structure of the dentinal tubules contributes to both its porosity and its elasticity. Elephant tusks are formed with a thin cap of enamel, which soon wears away, leaving the dentin exposed. Exposed dentin in humans causes the symptom of sensitive teeth.
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In the electrophoretic process, electrically charged particles dispersed in a special liquid are transported through an electric field into the preform, which has the opposite electrical charge polarity. This process is under development, and is not yet used industrially. Some remaining porosity must be expected here, too.
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The important parameters in determining a good site for carbon storage are: rock porosity, rock permeability, absence of faults, and geometry of rock layers. The medium in which the CO2 is to be stored ideally has a high porosity and permeability, such as sandstone or limestone. Sandstone can have a permeability ranging from 1 to 10−5 Darcy, and can have a porosity as high as ≈30%. The porous rock must be capped by a layer of low permeability which acts as a seal, or caprock, for the CO2. Shale is an example of a very good caprock, with a permeability of 10−5 to 10−9 Darcy. Once injected, the CO2 plume will rise via buoyant forces, since it is less dense than its surroundings. Once it encounters a caprock, it will spread laterally until it encounters a gap. If there are fault planes near the injection zone, there is a possibility the CO2 could migrate along the fault to the surface, leaking into the atmosphere, which would be potentially dangerous to life in the surrounding area.
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Therefore, they have to be drained. However, in contrast to Gleysols, drainage with channels or pipes is in many cases insufficient. It is necessary to have a higher porosity in the subsoil in order to improve the hydraulic conductivity. This may be achieved by deep loosening or deep ploughing.
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He is well known in the field of mesoporous carbon nitride and was the first one to introduce porosity in carbon nitride materials which find applications in different areas of research including catalysis, energy storage and conversion and carbon dioxide capture, and photocatalytic water splitting for hydrogen generation.
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Jeong, 132 Due to the low firing temperatures often used in producing onggi, they are rarely found archaeologically since the sherds return to the clay state or are used as grog. Features of Onggi include its Breathability, Stability, Suitability for Fermentation, Economical Price, Porosity and Diversity of use.
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Tapioca starch can be burnt off easily through the sintering process and is insoluble in titanium. Titanium foams consisting of a bimodal pore distribution (macropores ranging from 100 to 300 μm) and 64–79% porosity, exhibited yield strengths of 23–41 MPa and Young's moduli of 1.6–3.7 GPa.
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A casting defect is an undesired irregularity in a metal casting process. Some defects can be tolerated while others can be repaired, otherwise they must be eliminated. They are broken down into five main categories: gas porosity, shrinkage defects, mould material defects, pouring metal defects, and metallurgical defects.
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The aquifer properties of the aquifer essentially depend upon the composition of the aquifer. The most important properties of the aquifer are porosity and specific yield which in turn give its capacity to release the water in the pores and its ability to transmit the flow with ease.
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Named for two men; Green and Ampt. The Green- AmptWater Resources Engineering, 2005 Edition, John Wiley & Sons, Inc. method of infiltration estimation accounts for many variables that other methods, such as Darcy's law, do not. It is a function of the soil suction head, porosity, hydraulic conductivity and time.
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A powder mixture of metal and normal glass can be plasma-sprayed in vacuum, with a suitable composition resulting in a TBC comparable to YSZ. Additionally, metal-glass composites have superior bond- coat adherence, higher thermal expansion coefficients, and no open porosity, which prevents oxidation of the bond-coat.
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The GDL electrically connects the catalyst and current collector. It must be porous, electrically conductive, and thin. The reactants must be able to reach the catalyst, but conductivity and porosity can act as opposing forces. Optimally, the GDL should be composed of about one third Nafion or 15% PTFE.
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Fire flooding works best when the oil saturation and porosity are high. Combustion generates the heat within the reservoir itself. Continuous injection of air or other gas mixture with high oxygen content will maintain the flame front. As the fire burns, it moves through the reservoir toward production wells.
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Continuoolithus had a remarkably high porosity and therefore a high rate of gas exchange, which is associated with incubation of eggs in covered nests. Continuoolithus canadensis eggshell was thick. Other specimens differ in shell thickness: some fragments referred to C. sp. have a slightly thinner shell, C. cf.
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IEEE transactions on instrumentation and measurement. 02/2019;68(2):586-594. doi: 10.1109/TIM.2018.2847780 The main purpose of NDE is to detect defects in the weld and the joint fit-up. Examples include joint mismatch, cracks, porosity, voids, inclusions, lack of penetration and lack of fusion (cold joints).
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As roots and rhizomes grow they are thought to disturb and loosen the medium, increasing its porosity, which may allow more effective fluid movement in the rhizosphere. When roots decay they leave behind ports and channels known as macropores which are effective in channeling water through the soil.
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Porosity Storage Reservoirs are man-made water storage reservoirs located in shallow alluvial (sand and gravel) deposits. The porosity, or void space, refers to the open spaces between the sand and gravel, and it is in this area that the water is stored. By separating and isolating a portion of an alluvial deposits through the use of walls made of natural materials, large reservoirs of water (up to a 100,000 acre feet) can be built up to 150 feet below ground. Securely storing water underground in this way protects the water from evaporative loss, unwanted contamination and is seen as low impact to the environment, compared to traditional dams and above ground water reservoirs.
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In practice, petrologic models employ advanced forms of the polybaric concept for greater physical plausibility. Such models incorporate interconnected porosity to facilitate buoyant flow of liquids from lherzolitic or harzburgitic assemblages, such as replacive dunite formation in migration channels. The porosity has to consist of at least two or a continuum of size scales to account for U-series disequilibria and major/trace element chemistry of abyssal peridotites. The realization that polybaric near-fractional melting may be the dominant form of basalt petrogenesis was a consequence of difficulties with a simpler paradigm involving only a chemically distinct primary melt, in equilibrium with residual mantle minerals, undergoing fractionation (and transportation) to yield basaltic and Mid-Ocean Ridge Basalt (MORB) lava.
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The most common method for producing porous carbide- derived carbons involves high-temperature etching with halogens, most commonly chlorine gas. The following generic equation describes the reaction of a metal carbide with chlorine gas (M: Si, Ti, V; similar equations can be written for other CDC precursors): :MC (solid) + 2 Cl2 (gas) → MCl4(gas) + C (solid) Halogen treatment at temperatures between 200 and 1000 °C has been shown to yield mostly disordered porous carbons with a porosity between 50 and ~80 vol% depending on the precursor. Temperatures above 1000 °C result in predominantly graphitic carbon and an observed shrinkage of the material due to graphitization. Different bulk porosity of CDCs derived from different carbide precursors.
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Charcoal burns at temperatures exceeding . By comparison the melting point of iron is approximately . Due to its porosity, it is sensitive to the flow of air and the heat generated can be moderated by controlling the air flow to the fire. For this reason charcoal is still widely used by blacksmiths.
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The factors that go into determining race track condition include the surface conditions, type of surface, and track configuration. The surface conditions are influenced by the type of surface factoring in soil type, and if the track is dirt, turf, artificial surface; plus surface density, porosity, compaction and moisture content.
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The field lies in of water at total depth of . The reservoir is nearly and has an average pay thickness of with an average porosity of 33% and permeability of 5–10 Darcies. The reservoir consists of sandstones of Heimdal formation of Paleocene age, Lista formation and has high viscosity.
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The Debolt Formation is commonly subdivided into a lower and upper unit. Lower Debolt rocks are bioclastic limestones deposited on a stable carbonate ramp. These lower Debolt rocks are rarely dolomitized and therefore have little porosity or commercial use. Upper Debolt sedimentation is characterized by a number of shallowing upwards facies.
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These scaffolds possess macro-, micro-, and nano-structured pores, and the porosity can be tailored for specific applications. These 3D all-carbon scaffolds/architectures may be used for the fabrication of the next generation of energy storage, supercapacitors, field emission transistors, high-performance catalysis, photovoltaics, and biomedical devices, implants, and sensors.
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J Non-Cryst Solids 2010;356:517-24. However, the influence of the composition on the properties and compatibility of bioactive and biodegradable glasses is not fully understood. The scaffolds fabricated by melt quench technique have much less porosity which causes healing and defects in tissue integration during in-vivo testing.
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This is the main reason why vacuum impregnation is used on any material-die cast, powder metal, plastic, wire harnesses. Vacuum impregnation prevents fluids or gases from leaking by sealing the porosity and leak paths. If the leak paths are not sealed, then fluids or gases may leak from the part.
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Porosity of surface soil typically decreases as particle size increases. This is due to soil aggregate formation in finer textured surface soils when subject to soil biological processes. Aggregation involves particulate adhesion and higher resistance to compaction. Typical bulk density of sandy soil is between 1.5 and 1.7 g/cm3.
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334px The process of infiltration can continue only if there is room available for additional water at the soil surface. The available volume for additional water in the soil depends on the porosity of the soilHogan, C. Michael (2010). "Abiotic factor" in Encyclopedia of Earth. eds Emily Monosson and C. Cleveland.
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This limits the reactants ability to access the catalyst and significantly decreases performance. Teflon can be coated onto the GDL to limit the possibility of flooding. Several microscopic variables are analyzed in the GDLS such as: porosity, tortuosity and permeability. These variables have incidence over the behavior of the fuel cells.
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Shorter processing times are preferred to restrict the concentration of nitrogen in the case, as nitrogen addition is more difficult to control than carbon. An excess of nitrogen in the work piece can cause high levels of retained austenite and porosity, which are undesirable in producing a part of high hardness.
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Science Direct. Web.Janssen, M.M.P.. "Diffusion in the nickel-rich part of the Ni−Al system at 1000° to 1300°C; Ni3Al layer growth, diffusion coefficients, and interface concentrations." Metallurgical Transactions 4.6 (1973): 1623-1633.Springer Link. Web. It is important then to use Darken’s findings to predict this porosity formation.
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Most of the oil and gas migrates long distances up to the Northern Shelf from the Midland Basin. This most likely allows the oil in the San Andres to be more mature that the rest of the Upper Permian. The trap is stratigraphic with an up-dip porosity pinch out.
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The components of the gross rock (bulk) volume as a strip. The individual components are not to scale. For example, porosity and pore volume are over-emphasised for illustrative purposes. Adapted from Eslinger and PevearEslinger, E. and Pevear, D. "Clay Minerals for Petroleum Geologists and Engineers", SEPM Short Course No. 22, 1988.
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Water Resources Management, 21(2), 427–467. For instance in radar data (ground penetrating radar), which is able to penetrate the ground deep into meters, may show some diffuse reflection for ‘rough’ surface relative to the wavelength used. The change in lithology may suggest soft rock and unconsolidated sediments, where porosity is high.
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However, instead of a bone fragment-end reconnecting to bone, the fragment-end connects to an implant surface. In a study on fibroblastic interactions with high-porosity Ti6Al4V alloy, the metal foam was supportive of cell attachment and proliferation, migration through the porous network, and proved capable of sustaining a large cell population.
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"Porosity", Schlumberger Oilfield Glossary. Retrieved 12 October 2018. This is typically calculated using data from an instrument that measures the reaction of the rock to bombardment by neutrons or by gamma rays but can also be derived from sonic and NMR logging. Water saturation: The fraction of the pore space occupied by water.
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Unconfined aquifers have storativities (typically then called specific yield) greater than 0.01 (1% of bulk volume); they release water from storage by the mechanism of actually draining the pores of the aquifer, releasing relatively large amounts of water (up to the drainable porosity of the aquifer material, or the minimum volumetric water content).
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Porosity Sealing or Resin Impregnation is similar to potting, but doesn't use a shell or a mold. Parts are submerged in a polymerizable monomer or solvent- based low viscosity plastic solution. The pressure above the fluid is lowered to a full vacuum. After the vacuum is released, the fluid flows into the part.
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Hence, plotting the logarithm of the measured in-situ electrical conductivity against the logarithm of the measured in-situ porosity (Pickett plot), according to Archie's law a straight-line relationship is expected with slope equal to the cementation exponent m and intercept equal to the logarithm of the in-situ brine conductivity.
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Alginate may be used in a hydrogel consisting of microparticles or bulk gels combined with nerve growth factor in bioengineering research to stimulate brain tissue for possible regeneration. In research on bone reconstruction, alginate composites have favorable properties encouraging regeneration, such as improved porosity, cell proliferation, and mechanical strength, among other factors.
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Foreland basins are considered to be hypothermal basins (cooler than normal), with low geothermal gradient and heat flow. Heat flow values average between 1 and 2 HFU (40–90 mWm−2 (Allen & Allen 2005). Rapid subsidence may be responsible for these low values. Over time sedimentary layers become buried and lose porosity.
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Instead, its composition shows similarities to that of Mars' surface.Citron, R. I.; Genda, H.; & Ida, S. (2015), "Formation of Phobos and Deimos via a giant impact", Icarus, 252, p. 334-338, doi:10.1016/j.icarus.2015.02.011 Phobos's density is too low to be solid rock, and it is known to have significant porosity.
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Casting is a solidification process, which means the solidification phenomenon controls most of the properties of the casting. Moreover, most of the casting defects occur during solidification, such as gas porosity and solidification shrinkage. Solidification occurs in two steps: nucleation and crystal growth. In the nucleation stage solid particles form within the liquid.
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Nuclear magnetic resonance (NMR) in porous materials covers the application of using NMR as a tool to study the structure of porous media and various processes occurring in them. This technique allows the determination of characteristics such as the porosity and pore size distribution, the permeability, the water saturation, the wettability, etc.
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Both HEPA and ULPA filter media have similar designs. The filter media is like an enormous web of randomly arranged fibres. When air passes through this dense web, the solid particles get attached to the fibres and thus eliminated from the air. Porosity is one of the key consideration of these fibres.
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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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Brown has suggested that large low- density bodies must be composed almost entirely of water ice, since he presumed that bodies of this size would necessarily be solid. However, this leaves unexplained why TNOs both larger than 1000 km and smaller than 400 km, and indeed comets, are composed of a substantial fraction of rock, leaving only this size range to be primarily icy. Experiments with water ice at the relevant pressures and temperatures suggest that substantial porosity could remain in this size range, and it is possible that adding rock to the mix would further increase resistance to collapsing into a solid body. Bodies with internal porosity remaining from their formation could be at best only partially differentiated, in their deep interiors.
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A top view and side view sketch of the motion of an Annular Fluidized Beds The annular fluidized bed is a new type of fluidized bed that has a specific type of motion where it moves in radial. There is relatively little axial mixing of gases and there is radial motion. The axial flow profile of the annular fluidized bed can be determined by pressure drops along the plant height, which can be divided into three major parts: the annulus, the bottom and the top part of the mixing chamber. Based on the height of the bed, while the annulus has a porosity close to the solids minimal fluidization porosity, each region of bed is characterized by different pressure gradients.
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The freeze-thaw cycles tend to push plants out of the soil. In addition, the high porosity of the soil makes a fellfield a difficult place for plants to grow. Fellfields often have typical patterns of rocks: lines of rocks that have been pushed out of the soil, and slid into a low region.
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Two-dimensional stretching created sheets with greater strength, porosity, and air flow, opening up possibilities for many new applications. By 1971, Gore was experimenting with laminates, combining the stretched membrane with supporting materials for added strength. Based on this work, the company developed a waterproof laminate called expanded polytetrafluoroethylene (ePTFE), now trademarked as Gore-Tex.
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Cultivation, earthworms, frost action and rodents mix the soil and decreases the size of the peds. This structure allows for good porosity and easy movement of air and water. This combination of ease in tillage, good moisture and air handling capabilities, and good structure for planting and germination, are definitive of the phrase good tilth.
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When stormwater is passed through a filter media, solids and other pollutants are removed. Most media remove solids by mechanical processes. The gradation of the media, irregularity of shape, porosity, and surface roughness characteristics all influence solids removal. Many other pollutants such as nutrients and metals can be removed through chemical and/or biological processes.
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It is not the pore fluid that dominates the electrical conductivity; it is the grain wetting fluid that dominates the electrical conductivity. Sedimentary rock will typically possess the thin layer of water required for current flow. This means ERH can effectively be used for treatment of sedimentary bedrock, which typically has significant primary porosity.
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Among the significant factors, is whether porosity was desirable or not. Thus, in modern water jugs like zirs and gullas, the water seeps through the walls, so that the contents can be cooled through evaporation.Janine D. Bourriau, Paul T. Nicholson, Pamela J. Rose: "Pottery." Paul T. Nicholson, Ian Shaw (ed.): Ancient Egyptian Materials and Technology.
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The paper is microcrepped to give porosity and elasticity. Microcrepping is done by drying with loose draws allowing it to shrink. This is causing the paper to elongate 4% in machine direction and 10% in cross direction before busting. Machine direction elongation can be further improved by pressing between very elastic cylinders causing more microcrepping.
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The process of grinding requires an abrasive component with material properties harder than the workpiece. Most common grinders employ a rotating surface being brought in contact with a work surface. The wheel component of grinder itself is generally composed of abrasive grains held together by a bond structure which contain some amount of porosity.
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The alignment and fusion assembly of adipose-derived stem cells on mechanically patterned matrices. Biomaterials 33(29):6943. Several other design criteria considered in muscle tissue engineering include the scaffold porosity, stiffness, biocompatibility, and degradation timeline. Substrate stiffness should ideally be in the myogenic range, which has been shown to be 10-15 kPa.
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The primary functions of polyacrylamide soil conditioners are to increase soil tilth, aeration, and porosity and reduce compaction, dustiness and water run-off. Secondary functions are to increase plant vigor, color, appearance, rooting depth and emergence of seeds while decreasing water requirements, diseases, erosion and maintenance expenses. FC 2712 is used for this purpose.
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Osteoporotic bone is largely decreased in strength and increased in porosity due to the loss in calcium. Because the formation of PTH regulates the calcium level in the blood, it can affect all areas of the body. The overactivity of a parathyroid gland is known as hyperparathyroidism. It is unknown what directly causes hyperparathyroidism.
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Biochar is a porous charcoal that has been designed to produce high surface area per unit volume and small amounts of residual resins. Biochar serves as a catalyst that enhances plant uptake of nutrients and water. Its surface area and porosity enable it to adsorb or retain nutrients and water and provide a microorganism habitat.
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A sonic log provides a formation interval transit time, which typically a function of lithology and rock texture but particularly porosity. The logging tool consists of a piezoelectric transmitter and receiver and the time taken to for the sound wave to travel the fixed distance between the two is recorded as an interval transit time.
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The porosity may absorb oils, fluids, deburring fluids, pre-plating cleaners, and acids. If not sealed, then any gases or fluids may affect the finish by outgassing or bleeding out. Sealing the leak paths before secondary finishes will eliminate any failure mode that could develop from outgassing, chemical compatibility, or bleed out of pretreatments.
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The Formation is composed of crystalline and dolomitized limestone (Cooking Lake Formation) in off-reef areas, bituminous shale and argillaceous limestone, detrital limestone (reef fallout), stromatoporoid calcarenite (Duvernay Formation), gray shale, argillaceous limestone, argillaceous dolomite, crystalline dolomite (Ireton Formation). In reef build-ups, it consists of massive limestone and dolomite with porosity (Leduc Formation).
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Some applications of PVDF are pressure sensors, hydrophones, and shock wave sensors. Due to their flexibility, piezoelectric composites have been proposed as energy harvesters and nanogenerators. In 2018, it was reported by Zhu et al. that a piezoelectric response of about 17 pC/N could be obtained from PDMS/PZT nanocomposite at 60% porosity.
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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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In addition, the porosity allows for more flexibility and a lighter skeleton that is easier to support. One other consideration may be that diets today have much lower amounts of calcium than the diets of other primates or the tetrapedal ancestors to humans which may lead to higher likelihood to show signs of osteoporosis.
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The anode can be particularly problematic, as the oxidation of the hydrogen produces steam, which further dilutes the fuel stream as it travels along the length of the cell. This polarization can be mitigated by reducing the reactant utilization fraction or increasing the electrode porosity, but these approaches each have significant design trade-offs.
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Scanning electron micrograph of dentin that was kept moist after rinsing off the etchant. The abundant intertubular porosity serves as a pathway for the penetration of the dentin adhesive. T, Dentinal tubule. (From Sturdevant Art and Science of Operative Dentistry, 7th edition, p157) One of the important factors in determining the dentinal bonding is collagen.
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Slag inclusions, undercut, and cracks are usually unacceptable. Some porosity, cracks, and slag inclusions are visible and may not need further inspection to require their removal. Small defects such as these can be verified by Liquid Penetrant Testing (Dye check). Slag inclusions and cracks just below the surface can be discovered by Magnetic Particle Inspection.
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Eco-Cement sets and hardens by sequestering CO2 from the atmosphere and is recyclable. The rate of absorption of CO2 varies with the degree of porosity and the amount of MgO. Carbonation occurs quickly at first and more slowly towards completion. A typical Eco-Cement concrete block would be expected to fully carbonate within a year.
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A hydraulic press is used to place the rough slug under tremendous pressure. This removes any possible porosity, and also pushes the alloy grains together tighter than can be achieved by simple casting alone. The end result is a much stronger material. Aftermarket performance pistons made from the most common 4032 and 2618 alloys are typically forged.
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This refers to the process whereby one mineral is dissolved and a new mineral fills the space via precipitation. Replacement can be partial or complete. Complete replacement destroys the identity of the original minerals or rock fragments giving a biased view of the original mineralogy of the rock. Porosity can also be affected by this process.
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Chlorine dioxide pouches placed inside fruit-packing boxes kill pathogens but don’t damage fruit. Some packets are made of materials with known porosity to allow vapors from the pouch to escape. These pouches, also called sachets, can be placed in other packages to help control the atmosphere. Uses include: volatile corrosion inhibitors, desiccants, oxygen scavengers, etc.
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The uppermost unit is the Willamette silt unit. This unit is composed of fine grained silts. The silt unit covers the lowland, but in some areas it has been washed away by erosion. The high porosity of this unit makes it suitable for storing water, but the low permeability makes it difficult to extract large quantities.
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Queenston Shale is composed of shale with minor amounts of siltstone and sandstones throughout the reservoir unit. The upper portion of the unit is composed of a sandstone that is classified as a fine-grained quartz arenite. The porosity values of this unit are 3 to 4 percent. There is little to no diageneses in this unit.
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Angrites are a rare group of achondrites consisting mostly of the mineral augite with some olivine, anorthite and troilite. The group is named for the Angra dos Reis meteorite. Angrites are basaltic rocks, often having porosity, with vesicle diameters of up to . They are the oldest igneous rocks, with crystallization ages of around 4.55 billion years.
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The densities range from less than 0.4 to 2.6 g/cm3. The least dense objects are thought to be largely composed of ice and have significant porosity. The densest objects are likely composed of rock with a thin crust of ice. There is a trend of low densities for small objects and high densities for the largest objects.
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Ingrain, Inc. operated digital rock physics laboratories in Houston, Brazil, Colombia, and Abu Dhabi with imaging technology that allowed it to compute the physical properties and fluid flow characteristics of rocks from petroleum reservoirs, including porosity, absolute and relative permeability, electrical resistivity and conductivity, and elasticity. Financial backers included Energy Ventures, a venture capital firm specializing in upstream technology.
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Product also suffers from poor creep performance due to the small grain sizes and there can be cavitation porosity in some alloys. Surface texture is generally good however. With dedicated tooling, dies and machines are costly. The main advantage of the process is that it can be used to produce large complex components in one operation.
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Fused filament fabrication (FFF) has been used to create microstructures with a three- dimensional internal geometry. Sacrificial structures or additional support materials are not needed. Structure using polylactic acid (PLA) can have fully controllable porosity in the range 20%–60%. Such scaffolds could serve as biomedical templates for cell culturing, or biodegradable implants for tissue engineering.
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The caveats are several. Cretaceous rocks, deposited near their provenance areas, tend to be petrologically immature, and secondary porosity in them may be hard to predict. Buried source rocks beneath the deepest depocenters may be overmature. Some traps may be breached by Neogene faults: one offshore well encountered oil staining, suggesting oil passed through these Cenozoic rocks and escaped.
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Much of the soils around the Andes are derived from volcanic material. In this soils weathering has produced water-retentive allophane that can allow the vegetation to withstand drought. These soils develop chiefly from volcanic ash and wind-redeposited ash deposits that can reach several meters in height. These kind of soils have high porosity and low bulk density.
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Special panels carrying shimmering mobile reflective disks are scattered across this mesh. The porosity of these materials enables Deya to appear different in form depending on how it is lit. The Deya will house the residents' community and recreational facilities, including a swimming pool, gymnasium, spas, running track, sporting facilities, virtual golf, cinema, meeting spaces and function facilities.
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Operator skill is a major factor as improper electrode manipulation or machine setup can cause porosity. A drawing of FCAW at the weld point Another type of FCAW uses a shielding gas that must be supplied by an external source. This is known informally as "dual shield" welding. This type of FCAW was developed primarily for welding structural steels.
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From the early 1980s Honda had begun equipping newer models with cast wheels called ComCast stating "...that technology has solved the casting porosity problem and that cast wheels are now used on Hondas for styling and marketing reasons". ComCast wheels were a combination of pressed-together cast aluminium hub and spokes with a hollow extruded aluminium rim.
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High Resolution Sequence Stratigraphy: Innovations and Applications. Geology Society Special Publication 104. 51–64 Parasequence boundaries may be distinguished by differences in physical and chemical properties across the surface such as; formation water salinity, hydrocarbon properties, porosity, compressional velocities and mineralogy. Parasequence boundaries may not form a barrier to hydrocarbon accumulation but may inhibit vertical reservoir communication.
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The simplest recommended technique is to identify any porosity of the coating as revealed by the presence of surface spots. These surface spots form where the environmental sulfur has penetrated and reacted with the base metal, producing a metal sulfide. Chalcocite, copper (I) sulfide is dark-grey to black. Silver (I) sulfide is also grey-black.
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Physical properties of rye affect attributes of the final food product such as seed size and surface area, and porosity. The surface area of the seed directly correlates to the drying and heat transfer time.Jouki, Mohammad; Emam-Djomeh, Zahra; and Khazaei, Naimeh (2012) "Physical Properties of Whole Rye Seed (Secale cereal)," International Journal of Food Engineering: Vol. 8: Iss.
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Sizing is added to paper to create a resistance to water as well as to fill in the gaps between the fibers. Porosity is a measure of how the paper responds to a liquid. There are several popular stamp collecting terms. On- paper refers to any stamp that is still adhering to another piece of paper.
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In metallurgy, gas flushing removes dissolved gases from the molten metal prior to the material being processed. For example, before casting aluminium alloys, argon bubbles are injected into liquid aluminium using a rotary degasser. The argon bubbles rise to the surface, bringing with them some of the dissolved hydrogen. The degassing step reduces the occurrence of hydrogen gas porosity.
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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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The paper is microcrepped to give porosity and elasticity. Microcrepping is done by drying with loose draws allowing it to shrink. This causes the paper to elongate 4% in the machine direction and 10% in the cross direction without breaking. Machine direction elongation can be further improved by pressing between very elastic cylinders causing more microcrepping.
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The solution to this problem is to seal the internal voids prior to plating. As explained above, the porosity is saturated with monomer and is then rinsed completely clear of the surface. The resin cures to a durable polymer. Thus, the exposed surface metal is free to be plated while the interior spaces are sealed dry.
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Charcoal "osek", formed from the smouldering embers of branches from the Ite or Itet tree (peanut butter cassia, scientifically known as Senna didymobotrya), is used as a milk preservative. Women use the embers to coat the inside of the cleaned gourd. The charcoal has various effects. It lines the inside of the gourd, reducing its porosity rendering it airtight.
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Smooth chondrite interplanetary dust particle. Cosmic dust is made of dust grains and aggregates into dust particles. These particles are irregularly shaped, with porosity ranging from fluffy to compact. The composition, size, and other properties depend on where the dust is found, and conversely, a compositional analysis of a dust particle can reveal much about the dust particle's origin.
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The Rosetta flyby demonstrated that the mass of Lutetia is (1.700 ± 0.017) kg, smaller than the pre-flyby estimate of 2.57 kg. It has one of the highest densities seen in asteroids at 3.4 ± 0.3 g/cm3. Taking into account possible porosity of 10–15%, the bulk density of Lutetia exceeds that of a typical stony meteorite.
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The second of these was developed by Lea and Nurse.Lea F M, Nurse R W, J.Soc.Chem.Ind., 58, p 227 (1939) The bed is 25 mm in diameter and 10 mm thick. The desired porosity (which may vary in the range 0.4 to 0.6) is obtained by using a calculated weight of sample, pressed to precisely these dimensions.
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In commercial reticulated foam, up to 98% of the faces are removed. The dodecahedron is sometimes given as the basic unit for these foams, but the most representative shape is a polyhedron with 13 faces. Cell size and cell size distribution are critical parameters for most applications. Porosity is typically 95%, but can be as high as 98%.
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This problem is minimized by including vents along the parting lines, however, even in a highly refined process there will still be some porosity in the center of the casting.Degarmo, p. 330-331. Most die casters perform other secondary operations to produce features not readily castable, such as tapping a hole, polishing, plating, buffing, or painting.
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It is used in pyrotechnic special effects such as the generation of black smoke and simulated explosions. It is used to create artificial pores in the manufacture of high-porosity grinding wheels. In the past, naphthalene was administered orally to kill parasitic worms in livestock. Naphthalene and its alkyl homologs are the major constituents of creosote.
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Vitrification is the progressive partial fusion of a clay, or of a body, as a result of a firing process. As vitrification proceeds, the proportion of glassy bond increases and the apparent porosity of the fired product becomes progressively lower.'Role Of Accessory Minerals On The Vitrification Of Whiteware Compositions.' N.M.Ghoneim; E.H.Sallam; D.M. Ebrahim. Ceram.Int. 16. No.1. 1990.
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Since the metal-imidazole-metal angle is similar to the 145° Si-O-Si angle in zeolites, ZIFs have zeolite-like topologies. As of 2010, 105 ZIF topologies have been reported in the literature. Due to their robust porosity, resistance to thermal changes, and chemical stability, ZIF’s are being investigated for applications such as carbon capture.
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Heavy oil production is a developing technology for extracting heavy oil in industrial quantities. Estimated reserves of heavy oil are over 6 trillion barrels, three times that of conventional oil and gas. Factors that affect the difficulty of putting reserves into production include permeability, porosity, depth and pressure. The density and viscosity of the oil is the determining factor.
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Application pressure impacts the overall weld penetration and joint quality. Pressure is manually applied either through the weld rod directly or to the speed tip nozzle. Welding technique and joint design both influence the amount of pressure that is translated to the weld. Inadequate pressure can result in weld interface porosity, poor wettability, and lack of fusion defects.
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Porosity of topsoil is a measure of the pore space in soil which typically decreases as grain size increases. This is due to soil aggregate formation in finer textured surface soils when subject to soil biological processes. Aggregation involves particulate adhesion and higher resistance to compaction. Typical bulk density of sandy soil is between 1.5 and 1.7 g/cm3.
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Solid water ice would have a dielectric of 3.0–3.2. Basalt rock which is widespread on Mars would yield 8. So using a ternary diagram from a paper by Ali Bramson et al., the researchers decided the ice-rich layer was a mixture composed of 50–80% water ice, 0–30% rocky content, and 15–50% porosity.
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2003, 32, pp 276-288. COFs are another class of porous polymeric materials, consisting of porous, crystalline, covalent bonds that usually have rigid structures, exceptional thermal stabilities (to temperatures up to 600 °C), are stable in water and low densities. They exhibit permanent porosity with specific surface areas surpassing those of well-known zeolites and porous silicates.
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Although water-insoluble, the porous body of earthenware allows water to penetrate. A glaze can be applied that will protect the vessel from water. Due to its porosity, earthenware is susceptible to moisture and creates problems including cracks, breaks and mold growth. Porcelain and stoneware is fired at the highest temperatures between 1200–1400 °C or 2192–2552 °F.
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Opposite of frost is heat and humidity. When the humidity is high molds can begin to form on ceramic, particularly ones in which there is no glaze. Spores of molds are found throughout the atmosphere and will attached to any organic residues nearby, such as ceramics. Earthenware ceramics are frequently affected due to their porosity and lack of glaze.
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Sintered metal fiber structures and products display high porosity properties, while remaining structurally strong and durable. This benefits the function and structure of specific applications like filtration or electrodes. Coated metallic filaments helps to minimize tarnishing. When suitable adhesives and films are used, they are not affected by salt water, chlorinated water in swimming pools or climatic conditions.
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PCL can be combined with other materials such as gelatin, collagen, chitosan, and calcium phosphate to improve the differentiation and proliferation capacity (2, 17). PLLA is another popular synthetic polymer. PLLA is well known for its superior mechanical properties, biodegradability and biocompatibility. It shows efficient cell migration ability due to its high spatial interconnectivity, high porosity and controlled alignment.
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In gas tungsten arc welding (GTAW), inert gases are used to shield the tungsten from contamination. It also shields the fluid metal (created from the arc) from the reactive gases in air which can cause porosity in the solidified weld puddle. Inert gases are also used in gas metal arc welding (GMAW) for welding non- ferrous metals.Davis, J.R., ed.
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At ambient pressure, the mercury does not invade the interparticle spaces or the pores of the sample. At increasing pressure, the mercury invades smaller and smaller pores, with the relationship between pore diameter and pressure being known. A continuous trace of pressure versus volume can then be generated, which allows for a complete characterization of the sample's porosity.
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A weighting system is used within the algorithm, making the process more objective. From the posterior PDF, realizations are generated using a Markov chain Monte Carlo algorithm. These realizations are statistically fair and produce models of high detail, accuracy and realism. Rock properties like porosity can be cosimulated from the elastic properties determined by the geostatistical inversion.
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The use of SLS refers to the process as applied to a variety of materials such as plastics, glass, and ceramics, as well as metals. What sets SLM apart from other 3D printing process is the ability to fully melt the powder, rather than heating it up to a specific point where the powder grains can fuse together, allowing the porosity of the material to be controlled. On the other hand, SLM can go one step further than SLS, by using the laser to fully melt the metal, meaning the powder is not being fused together but actually liquified long enough to melt the powder grains into a homogeneous part. Therefore, SLM can produce stronger parts because of reduced porosity and greater control over crystal structure, which helps prevent part failure.
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Sandstones may vary in permeability from less than one to over 50,000 millidarcys (md). Permeabilities are more commonly in the range of tens to hundreds of millidarcies. A rock with 25% porosity and a permeability of 1 md will not yield a significant flow of water. Such “tight” rocks are usually artificially stimulated (fractured or acidized) to create permeability and yield a flow.
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Chemically speaking, increases in temperature can also cause chemical reaction rates to increase. This increases the solubility of most common minerals (aside from evaporites). Furthermore, beds thin and porosity decreases allowing cementation to occur by the precipitation of silica or carbonate cements into remaining pore space. In this process minerals crystallize from watery solutions that percolate through the pores between grain of sediment.
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They are specified for a defined temperature range and over the full voltage range for a defined lifetime. They can differ enormously depending on the combination of electrode porosity, pore size and electrolyte. Generally a lower current load increases capacitor life and increases the number of cycles. This can be achieved either by a lower voltage range or slower charging and discharging.
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A basic quality measurement system generally includes basis weight and moisture profile measurements and in addition average basis weight of the paper web and moisture control related to these variables. Caliper is also one of the basic measurements. Other commonly used continuous measurements include: ash content, color, brightness, smoothness and gloss, coat weight, formation], porosity, fiber orientation, and surface properties (topography).
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Calcareous sinter is a freshwater calcium carbonate deposit, also known as calc-sinter. Deposits are characterised by low porosity and well-developed lamination. Calcareous sinter should not be confused with siliceous sinter, which the term sinter more frequently refers to. It has been suggested that the term "sinter" should be restricted to siliceous spring deposits and be dropped for calcareous deposits entirely.
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The seismoelectrical method (which is different from the electroseismic physical principle) is based on the generation of electromagnetic fields in soils and rocks by seismic waves. This technique is still under development and in the future it may have applications like detecting and characterizing fluids in the underground by their electrical properties, among others, usually related to fluids (porosity, transmissivity, physical properties).
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Supports are used to give mechanical stability to catalyst nanoparticles or powders. Supports immobilize the particle reducing its mobility and favouring the chemical stabilization: they can be considered as solid capping agents. Supports also allow the nanoparticles to be easily recycled. One of the most promising supports is graphene for its porosity, electronic properties, thermal stability and active surface area.
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Isostatically pressed nickel alloys Hot isostatic pressing (HIP) is a manufacturing process, used to reduce the porosity of metals and increase the density of many ceramic materials. This improves the material's mechanical properties and workability. The HIP process subjects a component to both elevated temperature and isostatic gas pressure in a high pressure containment vessel. The pressurizing gas most widely used is argon.
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Physical properties of elements and compounds that provide conclusive evidence of chemical composition include odor, color, volume, density (mass per unit volume), melting point, boiling point, heat capacity, physical form and shape at room temperature (solid, liquid or gas; cubic, trigonal crystals, etc.), hardness, porosity, index of refraction and many others. This section discusses some physical properties of materials in the solid state.
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Disadvantages of this process include reduced pore connectivity, limited achievable porosity, and a complicated experimental set-up. However, a unique aspect of the HIP process with respect to titanium (and other polymorphic materials) is that transformation superplasticity can be enhanced through the HIP process by way of thermal cycling, or by cycling around the alpha/beta allotropic temperature boundaries of the metal.
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Adler, 93. In order to make their pottery watertight, Bunzlauer potters applied a coating of liquid clay, or slip. When fired, the slip glaze varied from a chocolate to dark brown. Since the fabric of Bunzlauer ware retains some porosity, the pottery conveniently has been suited for cooking over an open fire or for baking in an oven, as well as for storage.
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The Heterogeneous Catalysis Department, led by Ferdi Schüth, is concentrated on the synthesis and characterization of inorganic materials with an application focus in heterogeneous catalysis. Especially important are high surface area materials with controlled porosity and nanostructured catalysts. Reactions studied include model reactions, such as carbon monoxide oxidation, and energy relevant conversions, i.e. methane activation, biomass conversion, ammonia decomposition and catalyzed hydrogen storage.
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Pulsed-laser welding has advantages over continuous wave (CW) laser welding. Some of these advantages are lower porosity and less spatter. Pulsed-laser welding also has some disadvantages such as causing hot cracking in aluminum alloys. Thermal analysis of the pulsed-laser welding process can assist in prediction of welding parameters such as depth of fusion, cooling rates, and residual stresses.
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CI chondrites contain between 17 and 22 weight % water. Their high porosity (of up to 30%) seems to be correlated to that fact. The water is not occurring freely, but is rather tied up in water-bearing silicates. Strong aqueous alteration at rather low temperatures (at 50 to 150 °C)Zolensky, M. E. & Thomas, K. L. (1995). GCA, 59, p. 4707–4712.
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Thin film composites membranes typically suffer from compaction effects under pressure. As the water pressure increases, the polymers are slightly reorganized into a tighter fitting structure that results in a lower porosity, ultimately limiting the efficiency of the system designed to use them. In general, the higher the pressure, the greater the compaction. Surface fouling: Colloidal particulates, bacteria infestation (biofouling).
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There has been recent development in utilizing FOS testing for porosity of conformal coatings.Hindin, Barry and Jose Fernandez, (2019). Testing of Conformal Coatings Using the Flowers-of- Sulfur Test, www.researchgate.net/publication/242097164 Nominally 1 square centimeter silver coupon cleaned per ASTM B810-01a (Reapproved 2017) Cleaning Method I The material under test is suspended inside a container over a source of powdered sulfur.
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A sharper snap implied hard paper because the hardness is a characteristic of the amount or kind of sizing used when making the paper. Porous paper is used to describe paper as absorbent, usually in contrast to less absorbent paper used in the stamps of the same country. Porosity is a characteristic of paper. Wood fibers are hydrophilic or water loving.
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The amount of radiolytic H2 production in seafloor sediments is dependent on the quantities of radioactive isotopes present, sediment porosity, and grain size. These criteria indicate that certain sediment types, such as abyssal clays and siliceous oozes, may have higher radiolytic H2 production relative to other seafloor strata. Also, radiolytic H2 production has been measured in seawater intrusions into subseafloor basement basalts.
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Olivine and pyroxene were detected on Ida by Galileo. The mineral content appears to be homogeneous throughout its extent. Galileo found minimal variations on the surface, and the asteroid's spin indicates a consistent density. Assuming that its composition is similar to OC meteorites, which range in density from 3.48 to 3.64 g/cm3, Ida would have a porosity of 11–42%.
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More energy would be required to penetrate the porosity with sealant than to evacuate the air. The operator would then release the pressure and drain the chamber. #Excess Sealant Recovery: The operator would remove excess sealant through gravity, rotation or centrifugal force. #Wash/Rinse Station: The operator would wash residual sealant from the part's internal passages, taps, pockets and features.
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In this case, the Buchan field is fairly fractured due to its location on an old fault line. Therefore, there are numerous fissures in the reservoir which increase its porosity and permeability. Three other major problems of the field’s geology would have to be overcome during the drilling stage (Hill 1979). Initially there were problems with the geophysical data of the field.
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Metallic parts produced by casting are comparatively inexpensive, but are often subject to metallurgical flaws like porosity and microstructural defects. Friction stir processing can be used to introduce a wrought microstructure into a cast component and eliminate many of the defects. By vigorously stirring a cast metal part to homogenize it and reduce the grain size, the ductility and strength are increased.
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Phase Change Material (PCMs) are also used in molten-salt energy storage, while research on obtaining shape-stabilized PCMs using high porosity matrices is ongoing. Several parabolic trough power plants in SpainParabolic Trough Thermal Energy Storage Technology Parabolic Trough Solar Power Network. 4 April 2007. Accessed December 2007 and solar power tower developer SolarReserve use this thermal energy storage concept.
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Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure the "accessible void", the total amount of void space accessible from the surface (cf. closed-cell foam).
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These techniques include all the approaches that have been successfully employed for the preparation of non-woven meshes of different polymers. In particular, non- woven polyglycolide structures have been tested for tissue engineering applications: such fibrous structures have been found useful to grow different types of cells. The principal drawbacks are related to the difficulties in obtaining high porosity and regular pore size.
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The hydrogen present in the flame or atmosphere at high temperature reacts with the oxide, yielding metallic copper and water vapour, steam. The steam bubbles exert high pressure in the metal structure, leading to cracks and joint porosity. Oxygen- free copper is not sensitive to this effect, however the most readily available grades, e.g. electrolytic copper or high-conductivity copper, are.
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Even though COFs are usually harder to characterize in terms of their properties than MOFs because COFs have no single crystal structure, COFs can be characterized by some following methods. Powder X-ray diffraction (PXRD) is used to determine structure. Morphology is understood by Scanning electron microscopy (SEM). Finally, porosity, in some meaning surface area, is measured by N2 isotherm.
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Porous minerals is a subcategory of mineral makeup ingredients where the porosity of the mineral particles enables extraordinary absorption capacity compared to non-porous mineral materials. This feature improves sebum control, long-lasting mattifying effect or gives a matte texture when used in makeup. Porous minerals can also act as carriers, absorbing a wide range of substances into its porous network.
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TBC and associated layers. Cooling air is often flowed through the metal substrate to enhance cooling.An effective TBC needs to meet certain requirements to perform well in aggressive thermo-mechanical environments. To deal with thermal expansion stresses during heating and cooling, adequate porosity is needed, as well as appropriate matching of thermal expansion coefficients with the metal surface that the TBC is coating.
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This is due to mathematical assumptions that have to be made such as all grains being spherical. The spherical shape affects the interpretation of the size since the diameter is different for spherical and non-spherical grains. The packing of the grains within the bed is also dependent on the shape of the grains. This then affects the porosity and hydraulic flow.
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"It's like banging on the side of a sieve to make the flour go through," Head said. "Regolith is jostled into holes rather than sitting on the surface, which makes Ina look a lot younger." Porosity could also skew crater counts. Laboratory experiments using a high-speed projectile cannon have shown that impacts into porous targets make much smaller craters.
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In higher concentrations (up to 25% hydrogen), it may be used for welding conductive materials such as copper. However, it should not be used on steel, aluminum or magnesium because it can cause porosity and hydrogen embrittlement. Shielding gas mixtures of three or more gases are also available. Mixtures of argon, carbon dioxide and oxygen are marketed for welding steels.
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211-213 The structure was discovered using seismic reflection data in the 1960s, although the initial interpretations were distorted due to zones of high gas saturation in the overlying Cenozoic rocks causing low seismic velocities. However, the high porosity of the reservoir rock does cause an increase in seismic amplitude which can be used with an isopach map to determine net pay.
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To create the cake layer, the particle size has to be as large as practically possible. Larger particle size increases the porosity of the cake layer and allows feed liquid to pass through. Particle shape is equally important, because it determines the surface area per unit mass. As it decreases, less surface area is available to bind moisture, providing a drier cake.
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Non-frost-susceptible soils may be too dense to promote water flow (low hydraulic conductivity) or too open in porosity to promote capillary flow. Examples include dense clays with a small pore size and therefore a low hydraulic conductivity and clean sands and gravels, which contain small amounts of fine particles and whose pore sizes are too open to promote capillary flow.
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This is a consequence of porosity in the amorphous LPI, and residual silicon in the LSI-matrix. ;Silicon carbide fibers Silicon carbide fibers are produced via pyrolysis of organic polymers, and therefore their corrosion properties are similar to those of the silicon carbide found in LPI-matrices. These fibers are thus more sensitive to bases and oxidizing media than pure silicon carbide.
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Soil porosity consists of the void part of the soil volume and is occupied by gases or water. Soil consistency is the ability of soil materials to stick together. Soil temperature and colour are self-defining. Resistivity refers to the resistance to conduction of electric currents and affects the rate of corrosion of metal and concrete structures which are buried in soil.
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Kim K, Kim P, Lee J, Kim S, Park S. Non-destructive identification of weld-boundary and porosity formation during laser transmission welding by using optical coherence tomography. IEEE access. 2018;6:76768-76775. doi: 10.1109/ACCESS.2018.2882527Carrigan TD, Forrest BE, Andem HN, Gui K, Johnson L. Nondestructive testing of nonmetallic pipelines using microwave reflectometry on an in-line inspection robot.
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When the formation contains hydrocarbon, or contains very low porosity, its resistivity will be high. High resistivity values may indicate a hydrocarbon bearing formation. Usually while drilling, drilling fluids invade the formation, changes in the resistivity are measured by the tool in the invaded zone. For this reason, several resistivity tools with different investigation lengths are used to measure the formation resistivity.
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Continental stretching: an explanation of the post-mid-Cretaceous subsidence of the Central North Sea Basin. Journal of Geophysical Research, 85, 3711–3739. In sediments compacted under self-weight, especially in sedimentary basins, the porosity profiles often show an exponential decrease, called Athy's law as first shown by Athy in 1930. A mathematical analytical solution was obtained by Fowler and YangA.
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This porosity is what gives the catalyst the high surface area essential for reduction of NOx. However, the pores are easily plugged by fine particulates, ammonium sulfate, ammonium bisulfate (ABS), and silicon compounds. Many of these contaminants can be removed while the unit is on line by ultrasonic horns or soot blowers. The unit can also be cleaned during a turnaround or by raising the exhaust temperature.
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Some types of filter are fitted with a carbon core to act as a deodorizing adsorbent.FAQ from British Berkefeld on New Millennium Concepts They may also be impregnated with silver to inhibit bacterial growth. Some types, depending on their grade of porosity, also remove certain microscopic fungi and particulate matter. The filters without silver impregnation are sterilized by autoclaving or by steam sterilizer after a thorough cleaning.
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This increases the porosity of the cake and reduces resistance of the cake during filtration. In a rotary filter, the filter aid may be applied as a precoat; subsequently, thin slices of this layer are sliced off with the cake. The use of filter aids is usually limited to cases where the cake is discarded or where the precipitate can be chemically separated from the filter.
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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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Using quantitative electron microscopy for process mineralogy applications. JOM - Journal of the Minerals, Metals and Materials Society, 52, 4, 24-25. QEMSCAN data includes bulk mineralogy and calculated chemical assays. By mapping the sample surface, textural properties and contextual information such as particle and mineral grain size and shape, mineral associations, mineral liberation, elemental deportment, porosity, and matrix density can be calculated, visualized, and reported numerically.
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Sintering in practice is the control of both densification and grain growth. Densification is the act of reducing porosity in a sample, thereby making it more dense. Grain growth is the process of grain boundary motion and Ostwald ripening to increase the average grain size. Many properties (mechanical strength, electrical breakdown strength, etc.) benefit from both a high relative density and a small grain size.
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Pınargözü Cave is located within a karst region of the western Taurus Mountains, which encompasses nearly . The karst in that region is Triassic period limestone. Because of limestone's extreme porosity, it is highly susceptible to erosion; karst areas typically have large numbers of caves and chambers, and the Pınargözü Cave is no exception. Estimates for the number of caves in the area vary widely.
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Titanium foams are characterized structurally by their pore topology (relative percentage of open vs. closed pores), porosity (the multiplicative inverse of relative density), pore size and shape, and anisotropy. Microstructures are most often examined by optical microscopy, scanning electron microscopy and X-ray tomography. Categorizing titanium foams in terms of pore structure (as either open- or close-celled) is the most basic form of differentiation.
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A wide range of methods can be used to create these gradients including gradients in reinforcing fillers, cross-link density or porosity to name a few. 3D printing has been used to combine several of these methods in one manufacturing technique.Dizon, J. R. C.; Espera, A. H.; Chen, Q.; Advincula, R. C., Mechanical characterization of 3D-printed polymers. Additive Manufacturing 2018, 20, 44-67.
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Nuclear graphite for the UK Magnox reactors was manufactured from petroleum coke mixed with coal-based binder pitch heated and extruded into billets, and then baked at 1,000 °C for several days. To reduce porosity and increase density, the billets were impregnated with coal tar at high temperature and pressure before a final bake at 2,800 °C. Individual billets were then machined into the final required shapes.
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To consider the applications of freeze-casting, we should consider the properties of the freeze-cast component. First, and critically, it is not fully dense. It contains only about 60–70% solid matter, the remainder being air in the form of porosity. This is turn leads to an interesting property of freeze-castings – they are often porous, not merely at the surface, but throughout their thickness.
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Histamine also causes blood vessels to become porous, allowing the tissue to become edematous because proteins from the bloodstream leak into the extravascular space, which increases its osmolar load and draws water into the area. Increased porosity of blood vessels also facilitates the entry of inflammatory cells like leukocytes into the wound site from the bloodstream.Dealey C. (1999). The care of wounds: A guide for nurses.
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Characteristics of puffcorn, notably diameter, porosity, and homogenous structure, are appearance attributes that aid in the perception of quality of the extruded product. The appearance of these products are enhanced as extrusion feed rate is increased, while increases in extrusion temperature and feed moisture content diminish it. Colour changes during extrusion occur due to product expansion, the decomposition of ingredient pigments, or chemical reactions.
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The underlying physics of this process can be described by polymeric creep. The pneumatic and adhesive effect are strongly correlated with the size of the pores within memory foam. Smaller pores leads to higher internal surface area and reduced air flow, increasing adhesion and the pneumatic effect respectively. Thus, by changing the cell structure and porosity of the memory foam, the properties can be controlled.
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Miller also works in biomedical engineering, creating three-dimensional scaffolds through the control of proteins and peptides. She explores the relationship between mesoscopic structure, material properties and cell response. She has studied how proteins self-assemble, including what causes them to unfold and form fibril structures. The morphology (roughness, porosity) and mechanical properties (such as Young's modulus and viscosity) can be controlled through self-assembly.
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With these methods, chemical reactivity, melt viscosity, and wetting between the two components should be considered carefully. Some issues with infiltrating melted Si is that the free Si can lower the composite's resistance to oxidation and creep. However, this technique usually yields lower residual porosity (~5%) compared to the other two techniques due to higher densification rates.Hillig, W. B. (1988), Melt Infiltration Approach to Ceramic Matrix Composites.
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Research on artificial bone materials has revealed that bioactive and resorbable silicate glasses (bioglass), glass-ceramics, and calcium phosphates exhibit mechanical properties that similar to human bone. Similar mechanical property does not assure biocompatibility. The body's biological response to those materials depends on many parameters including chemical composition, topography, porosity, and grain size. If the material is metal, there is a risk of corrosion and infection.
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3, p.9 Because of higher-than-expected temperatures at this depth and location, instead of the expected , drilling deeper was deemed unfeasible. The unexpected decrease in density, the greater porosity, and the unexpectedly high temperatures, caused the rock to behave somewhat like a plastic, making drilling nearly impossible. Kola Superdeep Borehole, Murmansk, Russia (Atlas Obscura, accessed 14 August 2020) Drilling was terminated in 1992.
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Those processes rely in the principle that an increase in temperature will induce the reduction or annihilation of pores.Kasperovich, G.; Hausmann, J., Improvement of fatigue resistance and ductility of TiAl6V4 processed by selective laser melting. Journal of Materials Processing Technology 2015, 220, 202-214. Hot isostatic pressing (HIP) is a manufacturing process, used to reduce the porosity of metals and increase the density of many ceramic materials.
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Solvent casting and particulate leaching (SCPL) allows for the preparation of structures with regular porosity, but with limited thickness. First, the polymer is dissolved into a suitable organic solvent (e.g. polylactic acid could be dissolved into dichloromethane), then the solution is cast into a mold filled with porogen particles. Such porogen can be an inorganic salt like sodium chloride, crystals of saccharose, gelatin spheres or paraffin spheres.
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The most common reasons for terracotta to fail are: poor manufacturing, improper installation, weathering, freeze/thaw cycling, and salt formation from atmospheric pollution. The porosity of terracotta greatly impacts its performance. The ability or inability for water and pollutants to enter into the material is directly correlated to its structural capacity. Terracotta is very strong in compression but weak in tension and shear strength.
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PDF file available on CD from www.consrv.ca.gov. pp. 290, 532 When grouped with the underlying Sespe Formation, because of its high porosity and the presence of an impermeable cap in the overlying Rincon Formation, it is the second-most important producing horizon in Southern California.Keller, Margaret. Ventura Basin Province, U.S. Geological Survey Digital Data Series DDS-30, Release 2, one CD-ROM, 19 p.
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Hydraulic residence time (HRT) is an important factor in the transport of environmental toxins or other chemicals through groundwater. The amount of time that a pollutant spends traveling through a delineated subsurface space is related to the saturation and the hydraulic conductivity of the soil or rock. Porosity is another significant contributing factor to the mobility of water through the ground (e.g. toward the water table).
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The two-barrel engine was unchanged. For 1963, the four- barrel was bumped to 11.0:1 compression and an even at 5000 rpm and at 3200 rpm, a respectable /liter. The great expense of the aluminum engine led to its cancellation after the 1963 model year. The engine had an abnormally high scrap ratio due to hidden block-casting porosity problems, which caused serious oil leaks.
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Nature, Volume 87 edited by Sir Norman Lockyer With Henri Sainte-Claire Deville, he worked on determining vapor densities at high temperatures and conducted studies on the porosity of metals at high temperatures. Also with Deville, he helped advance the concept of "chemical dissociation". In addition, he performed significant studies of lithium salts, and with Paul Hautefeuille, he conducted research on the solubility of gases in metals.
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Trumao is the name of a soil of the Andosol order found in southern and central Chile. Trumaos are formed from young volcanic ash, by volcanic ash redeposited by aeolian processes or by volcanic ash mobilized as alluvium. Trumaos are characterized by containing the following minerals: allophane, imogolite plus a series of paracrystalline and non-crystalline clays. These soils have high porosity and low bulk density.
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Porcelain tiles can be vitrified to reduce their porosity and increase their strength. Vitrified porcelain tiles are created by combining clay with other elements such as quartz, silica or feldspar under incredibly high temperatures. The vitrification process creates porcelain tiles that contain a glass substrate. The glass substrate gives the tiles a sleek appearance, provides added strength and makes the tiles water and scratch-resistant.
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This risk is avoided through the use of firecracker welding. As the electrode position is also constant relative to the weld, the risk of porosity is also reduced, to the level of a skilled welder. The process is also suitable for use in areas with limited access. Once started it continues automatically, without needing enough space for a skilled welder with sight of the weld.
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The porosity of soils is critical in determine the infiltration capacity. Soils that have smaller pore sizes, such as clay, have lower infiltration capacity and slower infiltration rates than soils that have large pore size, such as sands. One exception to this rule is when clay is present in dry conditions. In this case, the soil can develop large cracks which leads to higher infiltration capacity.
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The finest of turquoise reaches a maximum Mohs hardness of just under 6, or slightly more than window glass. Characteristically a cryptocrystalline mineral, turquoise almost never forms single crystals, and all of its properties are highly variable. X-ray diffraction testing shows its crystal system to be triclinic. With lower hardness comes lower specific gravity (2.60–2.90) and greater porosity; these properties are dependent on grain size.
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A plastic welding rod, also known as a thermoplastic welding rod, is a rod with circular or triangular cross-section used to bind two pieces of plastic together. They are available in a wide range of colors to match the base material's color. Spooled plastic welding rod is known as "spline". An important aspect of plastic welding rod design and manufacture is the porosity of the material.
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Visual inspection, just like the name implies, is a visual investigation of the weldment. The inspector is typically looking for visual indications such as discolorations, weld defects, discontinuities, porosity, notches, scratches, etc. Typically visual inspection is broken down into different categories or groups for the qualifying inspection criteria. These groupings may vary among standards and each group has a certain level of imperfections that they consider acceptable.
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X-ray testing of plastics is similar to that of metal weldments, but uses much lower radiation intensity due to the plastics having a lower density than metals. The x-ray testing is used to find imperfections that are below the surface. These imperfections include porosity, solid inclusions, voids, crazes, etc. The x-ray transmits radiation through the tested object onto a film or camera.
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In the electronic industry, the fabrics are used primarily for insulation and seals, because of its low porosity. Ceramic fabric's industrial uses include furnace linings, furnace zone dividers, door seals, tube seals, gaskets, and expansion joints. In addition to being an effective thermal insulator, these fabrics do not shrink or elongate with high temperature changes, making them useful for industrial uses that involve high temperatures.
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Cherts are subject to problems when used as concrete aggregates. Deeply weathered chert develops surface pop-outs when used in concrete that undergoes freezing and thawing because of the high porosity of weathered chert. The other concern is that certain cherts undergo an alkali-silica reaction with high-alkali cements. This reaction leads to cracking and expansion of concrete and ultimately to failure of the material.
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In 2011 Cowie joined the University of Bergen as a Professor of Geodynamics. Here she is co-leader of the Statoil-Norwegian Multi-Rift Project. Cowie has intensively investigated geological faults. She has studied the way that faults propagate, the variations in space and time due to the interactions of faults, the rates at which they slip and how damage zones develop in high porosity sandstones.
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For artificial cultivation, container culture is a must, and the growing medium must be naturally acidic. Additionally, all other soil additives must be devoid of any calcium that could buffer the pH to above 5. High quality peat moss or pine duff work well, and pH neutral perlite can be added to improve porosity. Due to the risk of calcium bicarbonate, tap water is unsuitable.
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The dry process involves extruding, annealing and stretching steps. The final porosity depends on the morphology of the precursor film and the specifics of each step. The extruding step is generally carried out at a temperature higher than the melting point of the polymer resin. This is because the resins are melted to shape them into a uniaxially-oriented tubular film, called a precursor film.
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Let's say it's the modern chain mail. Power Metal fiber filters can reach very high porosity, at very low pore sizes, which makes them suitable for HEPA and ULPA filtration. These filters are used in, amongst others, nuclear power plants as a safety measure to prevent eventual release of radio- active steam. Marine Metal fiber filters are used for the purification of marine fuel and lube oil.
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Collagen fibers in a cross-sectional area of dense connective tissue. Due to their high porosity and large surface area-to-volume ratio, nanofibers are widely used to construct scaffolds for biological applications. Major examples of natural polymers used in scaffold production are collagen, cellulose, silk fibroin, keratin, gelatin and polysaccharides such as chitosan and alginate. Collagen is a natural extracellular component of many connective tissues.
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Riesenstein is composed of Neogene Miocene (from to ) quartzite. In contrast to quartzites produced by metamorphism, the Tertiary sedimentary quartzites were the product of intense weathering of local Triassic Buntsandstein sandstones in a tropical climate. This entailed bleaching of sandstone and silicification by movement of silica-saturated groundwater through the strata. Consequently, the rock is practically made completely of quartz, with very little porosity.
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The Presta was designed as an intermediate glider, to fit in the company's line between the Apco Allegra and the Bagheera, with higher performance than the Allegra. The sail is made from 46gr/m2 "Zero Porosity" ripstop nylon. The design uses an Active Double Valve System to allow closed cells to be easily inflated on launch. The four models are each named for their relative size.
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Surface magnetic resonance (or magnetic resonance sounding) is based on the principle of Nuclear magnetic resonance (NMR) and measurements can be used to indirectly estimate the water content of saturated and unsaturated zones in the earth's subsurface.Anatoly Legtchenko(2013)Magnetic Resonance Imaging for Groundwater wiley, New york city SNMR is used to estimate aquifer properties, including quantity of water contained in the aquifer, Porosity, and Hydraulic conductivity.
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In the processing of glass-ceramics, molten glass is cooled down gradually before reheating and annealing. In this heat treatment the glass partly crystallizes. In many cases, so-called 'nucleation agents' are added in order to regulate and control the crystallization process. Because there is usually no pressing and sintering, glass-ceramics do not contain the volume fraction of porosity typically present in sintered ceramics.
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Both are affected by climate and the type of organisms present. Soils with humus can vary in nitrogen content but typically have 3 to 6 percent nitrogen. Raw organic matter, as a reserve of nitrogen and phosphorus, is a vital component affecting soil fertility. Humus also absorbs water, and expands and shrinks between dry and wet states to a higher extent than clay, increasing soil porosity.
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Geosteering only practically became possible with the advent of deep reading 2 MHz resistivity LWD tools from the major LWD vendors (BakerHughes Reservoir Navigation Tool, SperrySun and Schlumberger) and other tools in the early 1990s, and the forward modeling software from a number of vendors capable of predicting resistivity tool responses for different relative angles and formation resistivities. Prior to this, Gamma ray gave some bed information, but was rarely used to dynamically adjust the well path in relation to the best oil saturation and porosity. The advent of nuclear tools for porosity and azimuthally sensitive gamma and resistivity tools, improved the ability to infer whether the wellbore should be steered up or down. The development of the Troll Oilfield by Norsk Hydro (Later Statoil and Equinor) would not have been possible without the ability to precisely geosteer within a 4-meter thick horizon to avoid gas above and water below.
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This is a very important mechanism in biology where fluids inside a blood vessel need to be regulated and controlled. Permeation can occur through most materials including metals, ceramics and polymers. However, the permeability of metals is much lower than that of ceramics and polymers due to their crystal structure and porosity. Permeation is something that must be considered carefully in many polymer applications, due to their high permeability.
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The Cairn Formation was originally deposited as limestones and mudstones in intertidal to subtidal reef environments, and was extensively dolomitized during later diagenesis. It now consists primarily of buff to dark grey, very fine to medium grained crystalline dolomite with good intercrystalline, biomoldic and vuggy porosity. Most of it is classified as floatstone, with stromatoporoids and other fossils supported in a dolomite matrix.Bloy, G.R., Leggett, S.R. and Hunter, I.G. 1989.
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The second major disadvantage is one of process control. As it is essentially a free-forming process with many interdependent variables, it has proved difficult to predict the shape, porosity or deposition rate for a given alloy. Much of the control is based on operator experience and empirical relationships. It is partly the process complexity and lack of robust process control that has prevented the widespread commercialisation of this process.
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On the other hand, telogenesis can also change framework grains to clays, thus reducing porosity. These changes are dependent on the specific conditions that the rock is exposed as well as the composition of the rock and pore waters. Specific pore waters, can cause the further precipitation of carbonate or silica cements. This process can also encourage the process of oxidation on a variety of iron bearing minerals.
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It has been demonstrated that the tortuosity increases when the porosity decreases. Usually subjective estimation is used. However, several ways to adapt methods estimating tortuosity in 2-D have also been tried. The methods include arc-chord ratio, arc-chord ratio divided by number of inflection points and integral of square of curvature, divided by length of the curve (curvature is estimated assuming that small segments of curve are planar).
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The volume of water escaping from within and beneath the forearc results in some of Earth's most dynamic and complex interactions between aqueous fluids and rocks. Most of this water is trapped in pores and fractures in the upper lithosphere and sediments of the subducting plate. The average forearc is underrun by a solid volume of oceanic sediment that is thick. This sediment enters the trench with 50–60% porosity.
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In higher concentrations (up to 25% hydrogen), it may be used for welding conductive materials such as copper. However, it should not be used on steel, aluminum or magnesium because it can cause porosity and hydrogen embrittlement; its application is usually limited only to some stainless steels. Nitric oxide addition serves to reduce production of ozone. It can also stabilize the arc when welding aluminium and high-alloyed stainless steel.
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This group has been subjected to much research due to its hydrocarbon implications. This has allowed researchers to reconstruct paleoshorelines, and paleoflow directions. Multiple transgressions and regressions are recorded in the rocks from the upper Paleocene to the Eocene. Throughout the area, the surrounding sandstones display a high amount of dolomite cement present, which drastically decreases porosity (it can make up to 30% of the total rock volume).
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Thus it is possible to increase the signal by using stronger seismic sources.Dean T, Dupuis C, Herrmann R, Valuri J (2012) A brute-strength approach to improving the quality of Seismoelectric data. SEG Las Vegas annual meeting, SEG technical program expanded abstracts, pp 1–6. The electrokinetic effect is produced by several kinds of contrasts between layers like porosity contrasts, potential contrasts, viscosity contrasts and saturation in fluids contrasts among others.
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Limnodrilus hoffmeisteri is conveyor-belt feeder that ingests particles in deep sediments and egests them on the sediment surface in the form of pseudofeces. The activities of this worm can alter sediment stratification, increase the water content and porosity of sediment, change the distribution of sediment particle size, alter the oxygen and nutrient dynamics in the sediment and across the sediment-water interface, and influence the process of sediment resuspension.
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A further complication can arise in that humidity drying of cores may sometimes leave water of condensation in clay-free micropores. Log derivation of effective porosity includes CBW as part of the volume of shale (Vsh). Vsh is greater than the volume of Vcl not only because it incorporates CBW, but also because Vsh includes clay size (and silt-size) quartz (and other mineral) grains, not just pure clay.
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Surface nuclear magnetic resonance (SNMR), also known as magnetic resonance Sounding (MRS), is a geophysical technique specially designed for hydrogeology. It is based on the principle of nuclear magnetic resonance (NMR) and measurements can be used to indirectly estimate the water content of saturated and unsaturated zones in the earth's subsurface. SNMR is used to estimate aquifer properties, including the quantity of water contained in the aquifer, porosity, and hydraulic conductivity.
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Polyaniline nanofibers have been shown to be incredibly successful as chemical sensors, as they perform better than conventional polyaniline films in numerous tests.Virji, S.; Huang, J.; Kaner, R.B.; Weiller, B.H.; Nano Lett., 2004, 4 (3), 491–496() This performance difference has been attributed to their high surface area, porosity, and small diameters which enhance diffusion of materials through the nanofibers. Polyaniline nanofiber sensors function through a change in resistance.
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Experimental investigation of solvent injection into heavy oil layered reservoirs using micromodel, E. Hadi, 2009. 106\. Experimental and modeling investigation of Asphaltene precipitation during CO2 injection in an Iranian crude oil sample, A. Alizadeh, 2009. 107\. Experimental investigation of the effect of gas recycling on the Asphaltene precipitation in an Iranian oil reservoir, H. Nakhli, 2009. 108\. Investigation of re-infiltration phenomena in a dual porosity model, R. Askarinezhad, 2009. 109\.
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Silica membranes are mesoporous and can be made with high uniformity (the same structure throughout the membrane). The high porosity of these membranes gives them very high permeabilities. Synthesized membranes have smooth surfaces and can be modified on the surface to drastically improve selectivity. Functionalizing silica membrane surfaces with amine containing molecules (on the surface silanol groups) allows the membranes to separate CO2 from flue gas streams more effectively.
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Onggi, which are made by a specialized group of workmen called onggijang (), has been influenced by the characteristics and climate of the regions where it has been made. Therefore, there are shapes and sizes of onggi and ways of manufacturing it that vary from region to region.Jeong, 138 Nevertheless, all onggi types share some properties. These are biodegradability, porosity, and its proof against rot as well as firmness or "vertebration".
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One important consideration deriving from Kirkendall's work is the presence of pores formed during diffusion. These voids act as sinks for vacancies, and when enough accumulate they can become substantial and expand in an attempt to restore equilibrium. Porosity occurs due to the difference in diffusion rate of the two species. Pores in metals have ramifications for mechanical, thermal, and electrical properties, and thus control over their formation is often desired.
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Gipson’s early research was focused on shale deposits—with specific interest in clay mineralogy and its relationship to shale porosity and burial depths, as well as the development of improved methods for studying clay mineralogy. He was the first to identify large-scale faceted peaks in the equatorial region of Mars from images returned by the Mariner 9. His later research was focused mostly on collaborations studying potential petroleum reservoirs.
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Detonation spraying produces coatings of very high chemical bond strength and hardness. Coatings are of low porosity, oxygen content and have a low to medium surface roughness. This is achieved due to the extremely high temperatures and velocities produced by the detonation gun during surface coating application. These properties make detonation spraying the standard of comparison for all other thermal spray coatings (wire arc, plasma, flame, HVAF, HVOF, Warm, Cold).
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Organoapatites may assist in-bone in-growth at the implant interface. The foams were manufactured using a modified HIP process, which exploits the allotropic nature of titanium to create higher porosity foams. Previous in vitro experimentation with the organoapatite-titanium foam held promising results including the possibility that ingrown tissue within these coated pores will improve the lifetime use of the foam through reduction of stress- shielding effects.
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Applying MPTO to Mechanically loaded components with a high number of different material densities, the optimization results show graded and sometimes anisotropic porosity distributions which are very similar to natural bone structures. This allows the macro- and microstructure of a mechanical component in one step. This method uses the Rapid Prototyping techniques, 3D printing and selective laser sintering to produce very stiff, light weight components with graded porosities calculated by MPTO.
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Mathia, E. J., Bowen, L., Thomas, K. M., & Aplin, A. C. (2016). Evolution of porosity and pore types in organic-rich, calcareous, Lower Toarcian Posidonia Shale. Marine and Petroleum Geology, 75, 117–139. On the other hand, Black shale formation in the Toarcian of NW Germany is associated with a major turnover in phytoplankton assemblages interpreted as the response to lowered salinities in surface waters of the epicontinental sea.
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Prevention is of prior importance at an early developmental age as the defective tooth is more likely to have caries and post-eruptive breakdown due to its increased porosity. Appropriate dietary advice and toothpaste with a fluoride level of at least 1,000 ppm F should be recommended. For treating spontaneous hypersensitivity professional applications of fluoride varnish (e.g. Duraphat 22,600ppm F) or 0.4% stannous fluoride gel may be helpful.
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The porosity and makeup of most stone does, however, leave it prone to certain types of damage if unsealed. Staining is the most common form of damage. It is the result of oils or other liquids penetrating deeply into the capillary channels and depositing material that is effectively impossible to remove without destroying the stone. Salt Attack occurs when salts dissolved in water are carried into the stone.
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The Rubiales Oil Field is an oil field located in the Llanos Basin, Meta Department, Colombia. It was discovered in 1981 and was first developed, operated and owned by Pacific Rubiales Energy. The field produces heavy oil (11.3-14.5° API) from the C7 unit of the Carbonera Formation.ANH, 2006, p.7 The porosity of the reservoir formation is between 28 and 33% and the permeability ranges from 3 to 5 Darcies.
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Open shrinkage defects are open to the atmosphere, therefore as the shrinkage cavity forms, air compensates. There are two types of open air defects: pipes and caved surfaces. Pipes form at the surface of the casting and burrow into the casting, while caved surfaces are shallow cavities that form across the surface of the casting. Closed shrinkage defects, also known as shrinkage porosity, are defects that form within the casting.
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Textured Soy Protein is a soy flour product often used in plant based meat which has been shown to support the growth of bovine cells by the Levenberg Group at the Israel Institute of Technology. It’s spongy texture enables efficient cell seeding and its porosity encourages oxygen transfer. Additionally, it degrades during cell differentiation into compounds that are beneficial to certain cells. Mycellium are the roots of mushrooms.
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Fragments are still termed allochems if they have undergone chemical transformations – for example if an aragonite shell were to dissolve and be later replaced by calcite, the replacement would still be deemed an allochem.Scholle, P. A., and D. S. Ulmer-Scholle (2003) A Color Guide to the Petrography of Carbonate Rocks: Grains, textures, porosity, diagenesis. American Association of Petroleum Geologists Memoir no. 77. Tulsa, Oklahoma, American Association of Petroleum Geologists.
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As noted before, mudrocks make up fifty percent of the Earth's sedimentary geological record. They are widespread on Earth, and important for various industries. Metamorphosed shale can hold emerald and gold, and mudrocks can host ore metals such as lead and zinc. Mudrocks are important in the preservation of petroleum and natural gas, due to their low porosity, and are commonly used by engineers to inhibit harmful fluid leakage from landfills.
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Kapuni's gas is CO2-rich, containing approximately 40-45 mol% CO2. This has facilitated significant diagenesis and the development of secondary porosity, especially in the K3E reservoir, one of the field's main producing reservoirs. Beginning approximately 5 Ma, thermal maturation of source rocks expelled CO2, which dissolved into groundwater. The acidic groundwater migrated updip towards the crest of the Kapuni anticline, dissolving feldspar and carbonates along its route.
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All these factors affect the porosity and permeability of sandy aquifers. Sandy deposits formed in shallow marine environments and in windblown sand dune environments have moderate to high permeability while sandy deposits formed in river environments have low to moderate permeability. Rainfall and snowmelt enter the groundwater where the aquifer is near the surface. Groundwater flow directions can be determined from potentiometric surface maps of water levels in wells and springs.
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Applying stains can be very easy or very difficult depending on the type of substrate, type of stain, and the ambient conditions. Fresh, "green" lumber accepts stain poorly, while aged wood absorbs stains relatively well. Porosity of wood can vary greatly, even within the same piece of wood. End grain and bias-cut grain are far more absorbent, thus will accept more pigment and will darken considerably in those areas.
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Hydrogen forms whenever molten aluminium comes into contact with water vapor, and easily dissolves into the melt. The gas tends to come out of the solution and forms bubbles when the melt solidifies. The detrimental effects arising from the presence of an excess of dissolved hydrogen in aluminium are numerous. Hydrogen causes porosity in aluminum products leading to many casting defects, reduced mechanical properties like fatigue and lower corrosion resistance.
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The advantage of using nanocellulose instead of wood-based pulp fibers is that the nanofibrils can reinforce the thin cells in the starch foam. Moreover, it is possible to prepare pure nanocellulose aerogels applying various freeze-drying and super critical drying techniques. Aerogels and foams can be used as porous templates. Tough ultra-high porosity foams prepared from cellulose I nanofibril suspensions were studied by Sehaqui et al.
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Mixture theory is used to model multiphase systems using the principles of continuum mechanics generalised to several interpenetrable continua. The basic assumption is that, at any instant of time, all phases are present at every material point, and momentum and mass balance equations are postulated. Like other models, mixture theory requires constitutive relations to close the system of equations. Krzysztof Wilmanski extended the model by introducing a balance equation of porosity.
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The process was described in 1975 by Lewis A. E. and A. J. Rothman. In the LLNL RISE process a part of the oil shale deposit (roughly 20% of the total deposit) is removed by the conventional mining technique. The remaining deposit is then broken up with explosives to increase porosity of the deposit. As a result, a large underground retort chamber by square and high is created.
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Soil organisms decompose organic compounds, including manure, plant residues, and pesticides, preventing them from entering water and becoming pollutants. They sequester nitrogen and other nutrients that might otherwise enter groundwater, and they fix nitrogen from the atmosphere, making it available to plants. Many organisms enhance soil aggregation and porosity, thus increasing infiltration and reducing surface runoff. Soil organisms prey on crop pests and are food for above-ground animals.
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Because the porosity of the surface soil results in virtually zero runoff, lenses are easily polluted by fecal waste, burials, and chemical spills. Corruption of a lens can take years to "flush out" and reform, depending on the ratio of recharge to losses. A few natural depressions on the atoll rim capture the abundant rainfall to form areas of freshwater wetlands.D. R. Stoddart (1971): "Land vegetation of Diego Garcia".
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Suspended solids (or SS), is the mass of dry solids retained by a filter of a given porosity related to the volume of the water sample. This includes particles 10 μm and greater. Colloids are particles of a size between 1 nm (0.001 µm) and 1 µm depending on the method of quantification. Because of Brownian motion and electrostatic forces balancing the gravity, they are not likely to settle naturally.
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Polyacrylamide gels are composed of a stacking gel and separating gel. Stacking gels have a higher porosity relative to the separating gel, and allow for proteins to migrate in a concentrated area. Additionally, stacking gels usually have a pH of 6.8, since the neutral glycine molecules allow for faster protein mobility. Separating gels have a pH of 8.8, where the anionic glycine slows down the mobility of proteins.
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Separating gels allow for the separation of proteins and have a relatively lower porosity. Here, the proteins are separated based on size (in SDS-PAGE) and size/ charge (Native PAGE). Chemical buffer stabilizes the pH value to the desired value within the gel itself and in the electrophoresis buffer. The choice of buffer also affects the electrophoretic mobility of the buffer counterions and thereby the resolution of the gel.
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Graphene aerogels are synthetic materials that exhibit high porosity and low density. Typical synthesis of graphene aerogels involve reducing a precursor graphene oxide solution to form graphene hydrogel. The solvent can be subsequently removed from the pores by freeze-drying and replacing with air. The resulting structure consists of a network of covalently bonded graphene sheets surrounding large pockets of air resulting in densities on orders of 3 mg cm−3.
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Since pore permeability is relative to the wavelength and frequency, most rocks meet the assumption. However, for seismic waves, only unconsolidated sands satisfy this assumption, because of their high permeability and porosity. On the other hand, for the high frequencies such as logging and laboratory frequencies, most rocks can meet this assumption. As a result, the velocities calculated using Gassmann's equation are lower than those measured using logging or laboratory frequencies.
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There are different methods to form these such as through crushing or grinding of the biocement. The permeability of biocement is also higher compared to normal cement. This is due to the higher porosity of biocement and this can leader to larger crack propagation when exposed to strong enough forces. The fact that biocement is now roughly 20% composed of a self healing agent also decreases its mechanical strength.
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It also has less tendency to crack and shrink. Some Cast Earth walls do soak up water, however, depending upon the porosity of the earthen materials used. For example, decomposed granite tends to be prone to absorption if the eaves of the roof is inadequate or it is exposed to water for a prolonged time, i.e. days. Limestone materials however, tend to repel water once the walls are completely dried/cured.
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During the porous head debacle, GM faced bankruptcy – therefore dealers failed to recall affected models. Due in part, to the engine's immense prominence and demand, many businesses now specialize in the repair of porous GM C20XE/LET heads – by either sleeving the affected gallery or by injecting a polymer based substance into the porous region. Reportedly, a small number of total GM C20XE cylinder heads ever exhibited significant symptoms of porosity.
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CMs, like other C-chondrites, are subjected to a serious observation bias. C-chondrites are friable, due to both macro-scale porosity and micro-scale matrices of phyllosilicates, with many chondrules also having layers such as phyllosilicates. The meteorites have been described as "tuff" (compacted volcanic ash). As one example, the Tagish Lake meteorite provided ~10 kg of samples, from a meteor estimated to be 60-90 tons before entry.
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Modern developments relate to seismology, continuum mechanics, discontinuum mechanics, and transport phenomena. In the petroleum engineering industry, geomechanics is used to predict important parameters, such as in-situ rock stress, modulus of elasticity, leak-off coefficient and Poisson's ratio. Reservoir parameters that include: formation porosity, permeability and bottom hole pressure can be derived from geomechanical evaluation. The geotechnical engineers relies on various techniques to obtain reliable data for geomechanical models.
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Fibrous ceramic filters are made from several different types of ceramic fibers that are mixed together to form a porous medium. This medium can be formed into almost any shape and can be customized to suit various applications. The porosity can be controlled in order to produce high flow, lower efficiency or high efficiency lower volume filtration. Fibrous filters have an advantage over wall flow design of producing lower back pressure.
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With the porosity properties of silty sandstone, and the ability of clay-rich soil to absorb tremendous amounts of water, it is not surprising that Spanish Fork canyon has experienced several landslide events throughout its geologic history. The thistle slide has reactivated several times since its main activity in 1983, and will continue to do so until the ideal landslide conditions created by the local weather patterns change.
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It was established that Nintoku Seamount's sedimentary cap consists of sandstone and siltstone containing well-rounded to subrounded basalt blocks, volcanic ash, fossil fragments of mollusks, benthic foraminifers, bryozoans, and coralline red algae. These observations indicate a shallow-water, high-rate depositional setting. Little variation was found in the density, grain size, or porosity of the volcanic rock, and it was stable in composition, except for the volcanic- sedimentary cover.
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Two of the most prevalent quality problems in GMAW are dross and porosity. If not controlled, they can lead to weaker, less ductile welds. Dross is an especially common problem in aluminium GMAW welds, normally coming from particles of aluminium oxide or aluminum nitride present in the electrode or base materials. Electrodes and workpieces must be brushed with a wire brush or chemically treated to remove oxides on the surface.
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Parameters such as jet stream movement and polymer concentration have to be controlled to produce nanofibers with uniform diameters and morphologies. The electrospinning technique transforms many types of polymers into nanofibers. An electrospun nanofiber network resembles the extracellular matrix (ECM) well. This resemblance is a major advantage of electrospinning because it opens up the possibility of mimicking the ECM with regards to fiber diameters, high porosity, and mechanical properties.
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Gelation is influenced by temperature, polymer concentration, and solvent properties. Temperature regulates the structure of the fiber network: low gelation temperature results in formation of nanoscale fiber networks while high gelation temperature leads to the formation of a platelet-like structure. Polymer concentration affects fiber properties: an increase in polymer concentration decreases porosity and increases mechanical properties such as tensile strength. Solvent properties influence morphology of the scaffolds.
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Image analysis can measure the shape factors of individual grains by ASTM E1382. Second-phase content and porosity are measured the same way in a microstructure, such as ASTM E562. Procedure E562 is a point-fraction method based on the stereological principle of point fraction = volume fraction, i.e., Pp = Vv. Second-phase content in ceramics, such as carbide whiskers in an oxide matrix, is usually expressed as a mass fraction.
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Continuoolithus nests would have been incubated under vegetation and sediment, unlike nests of Troodon and oviraptorids, which were incubated by brooding adults. Adaptations in the eggshell, such as high porosity and prominent ornamentation, would have helped the embryo breathe while buried. One fossil egg contains a tiny embryonic skeleton at an exceptionally young stage of development (perhaps eight to ten days old) showing the earliest stages of bone development.
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Gas inclusions is a wide variety of defects that includes porosity, blow holes, and pipes (or wormholes). The underlying cause for gas inclusions is the entrapment of gas within the solidified weld. Gas formation can be from any of the following causes- high sulphur content in the workpiece or electrode, excessive moisture from the electrode or workpiece, too short of an arc, or wrong welding current or polarity..
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A condition assessment of the monument was conducted by McKay Lodge Conservation Laboratory. They found several condition issues some originating from the poor quality of the original cast and others due to climate. The condition problems included casting porosity, patches and plugs, chill cracks, weaknesses in armature, and a general need for cleaning. In 2013 the Restore Kosciuszko Monument Project successfully raised funds to fully restore the monument.
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KOLOS are randomly placed on rubble mound breakwaters in two layers. Like most of the concrete armour units, the hydraulic stability of KOLOS is dictated by its self weight and interlocking with surrounding units. KOLOS is found to have almost the same level of porosity as Dolos with a layer coefficient of 1. The random placement of the units facilitates increased rate of placement and less dependence on complex placement techniques.
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Refueling involved rotating the core to the channel containing the element requiring replacement and pushing in a new element. The used element would be pushed out into the center and fall to the base of the reactor to be collected. At full power the reactor used up 1 to 6 fuel elements per day depending on enrichment and porosity of the fuel element. It produced 3MW of thermal energy.
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When the depositing particles attract each other, they will deposit and aggregate at the same time. This situation will result in a porous layer made of particle aggregates at the surface, and is referred to as ripening. The porosity of this layer will depend whether the particle aggregation process is fast or slow. Slow aggregation will lead to a more compact layer, while fast aggregation to a more porous one.
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The Prima was designed as a beginner glider for use in flight training of students for both gliding and paramotor flying. The glider is made from Gelvenor 42 g/m2 "Zero Porosity" ripstop nylon. The design has progressed through four generations of models, the Prima, Prima 2, 3 and 4, each improving on the last. The Prima 4 incorporates leading edge battens and an improved landing flare capability.
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Cigarette paper has been specially engineered by creating bands of different porosity to create "fire-safe" cigarettes. These cigarettes have a reduced idle burning speed which allows them to self-extinguish. This fire-safe paper is manufactured by mechanically altering the setting of the paper slurry. New York was the first U.S. state to mandate that all cigarettes manufactured or sold within the state comply with a fire-safe standard.
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Symbol used to represent in situ permeability tests in geotechnical drawings Permeability in fluid mechanics and the Earth sciences (commonly symbolized as k) is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it. The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness.
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Unconsolidated alluvial deposits up to 15 meters thick overly many areas of basement rock in Sierra Leone. Along the coast is the Bullom Group, a belt of unconsolidated sands and gravels 10 to 20 meters thick, overlying sands and clays 30 to 80 meters thick. The formation is a moderately productive aquifer. The Saionya Scarp and Rokel River Group form a consolidated, near-surface weathered regolith aquifer in metasedimentary rocks, with low intergranular porosity.
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Dissolution of framework silicate grains and previously formed carbonate cement may occur during deep burial. Conditions that encourage this are essentially opposite of those required for cementation. Rock fragments and silicate minerals of low stability, such as plagioclase feldspar, pyroxenes, and amphiboles, may dissolve as a result of increasing burial temperatures and the presence of organic acids in pore waters. The dissolution of frame work grains and cements increases porosity particularly in sandstones.
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Observation of the satellite's orbit has made possible an accurate determination of Hermione's mass. For the best-fit "snowman" model, the density is found to be 1.8 ± 0.2 g/cm³, giving a porosity on the order of 20%, and possibly indicating that the main components are fractured solid bodies, rather than the asteroid being a rubble pile. Occultations by Hermione have been successfully observed three times so far, the last time in February 2004.
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The Slochteren reservoir rock in Groningen is an eolian sandstone from the Rotliegend (lower Permian). This reservoir has excellent porosity and permeability characteristics and supplies the vast majority of the Dutch natural gas reserves. The lateral equivalent of this reservoir comes at surface near the German town of Bad Bentheim. The latest Permian deposits in the area of northwestern Europe was characterised by the laying down of thick successions of rocksalt and anhydrite.
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Energy efficiency is related to the nature of anode materials, as well as the porosity of baked anodes. Around 10% of cell power is consumed to overcome the electrical resistance of prebaked anode (50–60 μΩm). Carbon is consumed more than theoretical value due to a low current efficiency and non-electrolytic consumption. Inhomogeneous anode quality due to the variation in raw materials and production parameters also affects its performance and the cell stability.
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Generally, above basement unit is the Columbia River basalt unit, consisting of flood-basalt lavas. In this unit, water is stored in the region between two lava flows, where weather has created porosity in the rock unit. Because of this, water is able to flow horizontally through the unit, but generally has very low vertical permeability. Above the Columbia River Basalt is the lower sedimentary unit, which also sometimes directly overlays the basement unit.
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Muga silkworms on a som tree Muga silk is the product of the silkworm Antheraea assamensis endemic to Assam. The larvae of these moths feed on som (Machilus bombycina) and sualu (Litsaea polyantha) leaves. The silk produced is known for its glossy, fine texture and durability. It was previously reported that muga silk cannot be dyed or bleached due to "low porosity", but this is incorrect; muga takes dye like any other silk.
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Hydrocarbons throughout the delta and in the Delta Field are produced from the Agbada Formation, mainly in the form of sandstone and unconsolidated sands. Thicker sand reservoirs represent stacked channels and point bars, distributary channels, and coastal barrier bars are important reservoir types in the delta. The paralic sandstones have porosity values of 40% and 2 darcys permeability.Edwards, J.D., and Santogrossi, P.A., 1990, Summary and conclusions, in, Edwards, J.D., and Santogrossi, P.A., eds.
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Various methods may be employed to create voids or pores in a silicon dioxide dielectric. Voids can have a relative dielectric constant of nearly 1, thus the dielectric constant of the porous material may be reduced by increasing the porosity of the film. Relative dielectric constants lower than 2.0 have been reported. Integration difficulties related to porous silicon dioxide implementation include low mechanical strength and difficult integration with etch and polish processes.
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The extrudate is cut to the desired length by blades at the output of the extruder, which rotate about the die openings at a specific speed. The product is then cooled and dried, becoming rigid while maintaining porosity. Cooking takes place within the extruder, where the product produces its own friction and heat due to the pressure generated (10–20 bar). The process can induce both protein denaturation and starch gelatinization under some conditions.
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That analysis gave Arco the confidence to push Vorwata as a viable drilling target to expedite certification of gas reserves. Vorwata No. 1 was drilled in late 1996, Brown's porosity prediction was exactly correct, and the well tested at in January 1997. Subsequent appraisal confirmed that Vorwata was a significant gas accumulation. The Wiriagar Deep/Vorwata complex, together with satellite gas accumulations, has now been named Tangguh by the Republic of Indonesia.
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Clinton sandstone, Medina sandstone, and Tuscarora Sandstone reservoirs are compositionally mature quartz arenites, sublithicarenites, and subarkoses sandstones that are very fine to fine grained. The cement composition ranges from silica rich to calcite rich. Total thickness of the reservoir unit ranges from 100 to 700 feet over the entire basin. Porosity within this unit ranges from 3 to 15 percent, which is due to the varying degrees of diagenesis of feldspars and the silica cement.
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This can result in the precipitation of a certain chemical species producing colouring and staining of the rock, or the formation of concretions. Concretions are roughly concentric bodies with a different composition from the host rock. Their formation can be the result of localized precipitation due to small differences in composition or porosity of the host rock, such as around fossils, inside burrows or around plant roots.For concretions, see Collinson et al.
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Butt welds are welds where two pieces of metal to be joined are in the same plane.Henderson, 50 These types of welds require only some kind of preparation and are used with thin sheet metals that can be welded with a single pass.Funk Common issues that can weaken a butt weld are the entrapment of slag, excessive porosity, or cracking. For strong welds, the goal is to use the least amount of welding material possible.
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Therefore, conventional gardening concepts can not be applied for vertical gardening. In the words of Solano, "making a vertical garden is not just putting plants on a wall." Ignacio Solano's patent corrects and perfects the concept of vertical garden designed by French landscape architect Patrick Blanc. The result is a hydroponic system, in which is used a phytogenerant material, the texture, porosity and absorptive capacity of which are suitable to perform the function of substrate.
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Plastic materials are formed by sintering for applications that require materials of specific porosity. Sintered plastic porous components are used in filtration and to control fluid and gas flows. Sintered plastics are used in applications requiring caustic fluid separation processes such as the nibs in whiteboard markers, inhaler filters, and vents for caps and liners on packaging materials. Sintered ultra high molecular weight polyethylene materials are used as ski and snowboard base materials.
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In the early stages, this transformation of sediment into sedimentary rock (lithification) is accompanied simply by a reduction in porosity, while its component mineralogy remains unaltered. As the rock is carried deeper by further deposition above, its organic content is transformed into kerogens and bitumens. The process of diagenesis excludes surface alteration (weathering) and metamorphism. There is no sharp boundary between diagenesis and metamorphism, but the latter occurs at higher temperatures and pressures.
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The climate is a mild tropical climate with abundant rainfall, especially in the northern parts and areas of higher elevation. The terrain is characterized by gentle slopes with no defined waterways. Although rainfall is occasionally very heavy (one storm in 2003 brought 36 inches (90 cm) of rain in 24 hours), flooding is rare due to the slope and porosity of the volcanic rock. The vegetation ranges from rainforest to desert shrub and coastal strand.
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Once pore waters have permeated the surface and return to the surface, aragonite, brucite, and calcite chimneys are formed as calcium carbonates precipitate out of solution. Younger chimneys are primarily brucite and aragonite, being white and flaky in appearance. As vents mature, porosity decreases as precipitates clog fluid pathways. Mineral compositions change with aragonite succeeded by calcite and brucite being removed through dissolution, and the chimneys darken to a grey or brown color.
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Taking this approach speeds the process and improves accuracy. Individual PDFs are merged using bayesian inference techniques, resulting in a posterior PDF conditioned to the whole data set. The algorithm determines the weighting of each data source, eliminating potential bias. The posterior PDF is then input to a Markov chain Monte Carlo algorithm to generate realistic models of impedance and lithofacies, which are then used to co-simulate rock properties such as porosity.
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It should not be autoclaved as that can cause cracking, warping, or splitting. Wood has grain that will rise if not properly finished, dramatically changing the texture. The porosity of wood and inability to be safely sterilized renders it inappropriate as a material for initial piercings or unhealed stretches. Some types of wood are strongly discouraged for piercing jewelry as they can cause allergic reactions or otherwise be irritating for the skin.
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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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In this case, a temperature below the melting point of NaCl was used; titanium is less creep resistant than NiTi, which allows for densification at lower temperatures. The resulting foams achieved porosity of 50–67% with minimal observable microporosity. Anisotropic pore shape in some areas alluded to NaCl's deformation during HIP, which is desirable for some applications. Additionally, an observed, rough inner surface of the pores holds advantages for biomedical implant applications.
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The lower thermal conductivity of titanium may also be appreciated in rocket construction. The specific strength, overall energy absorbing capability and high melting point all reinforce titanium's superiority to aluminum in aerospace and military applications. When used for aerospace applications, levels of porosity close to 90% are desired. Titanium foams are capable of retaining their high tensile strength at temperatures up to 400 °C; a limit imposed by the metal's low resistance to oxidation.
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Titanium foams are lightweight, stiff, and possess the capability to resist blast. Furthermore, the use of titanium-based foams exhibiting homogenous porosity distribution would significantly decrease the risks associated with strain localization. The high strength-to-weight ratio of titanium foams offers an opportunity to provide increased bending and shearing stiffness as well as energy absorption capabilities during periods of bending. Titanium foams may be utilized in environments with elevated temperatures (up to 400 °C).
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Peptide scaffolds formed from LEGO peptides has been used extensively for 3D cell culturing as they closely resemble the porosity and the structure of extra- cellular matrices. These scaffolds have also been used in cell proliferation and differentiation into desired cell types. Experimentations with rat neurons demonstrated LEGO peptides’ usefulness in cell culturing. Rat neurons that were attached to the peptides projected functional axons that followed the contour as set out by the peptide scaffolds.
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Sitting 500 ft in the air, 'Deya' (which means cloud in Bengali) connects the two towers that make up Atmosphere. Deya houses club facilities for the residents of Atmosphere. Initially conceived as a cloud changing in porosity and form, Deya is not a physical extension of the tower as such, since the majority of the spaces within are open air. The skin is composed of expanded mesh panels wrapped around structural ribs.
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Standard procedure calls for equilibrating the test chamber at temperature and relative humidity before inserting the test specimens. Porosity results are determined by the distribution, number and sizes of dark spots on the materials under test. Again, the dark spots are due to reaction of the moist sulfur vapors with the underlying silver or copper material. One may choose to include silver or both silver and copper reference coupons into the humid sulfur test.
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When muscle is cultivated in vivo, this issue is circumvented as the ECM delivers nutrients into the muscle through blood vessels. As such, many emerging scaffolds are aiming to replicate such networks. Similarly, scaffolds must simulate many of the other characteristics of the ECM, most notably porosity, crystallinity, degradation, biocompatibility and functionality. Few materials which emulate all these characteristics have been identified leading to the possibility of blending different materials with complementary properties.
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In 2007, Podorov et al. proposed an exact analytical solution of CDXI problem for particular cases. In 2016 using the coherent diffraction imaging (CXDI) beamline at ESRF (Grenoble, France), the researchers quantified the porosity of large faceted nanocrystalline layers at the origin of photoluminescence emission band in the infrared. It has been shown that phonons can be confined in sub-micron structures, which could help enhance the output of photonic and photovoltaic (PV) applications.
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The sintering response of the investigated powder was studied by careful microstructural observations using scanning electron microscopy and optical microscopy both in reflection and transmission. The key to this method is to keep porosity intergranular during pre-sintering, so that it can be removed subsequently by HIP treatment. It was found that agglomerates of closely packed particles are helpful to reach that purpose, since they densify fully and leave only intergranular porosity.Mouzon, J., et al.
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They noted a juxtacortical lesion 25 by 18 cm wide made of bone that resembled woven fibers. Although woven bone forms in accessory dental bone, in other locations, it is a sign of injury or illness. The woven bone's "undulating fibrous bundles" were observed oriented in the direction of the m. brachialis. The lesion's fusion and lack of porosity at its near and far ends indicate the periostitis was inactive or healed.
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Radiographic testing utilizes short wavelength electromagnetic radiation. The wavelength is so small that it can penetrate the CFRP while light cannot. X-ray testing can detect voids, porosity, inclusions, trans-laminar cracks, resin-to-fiber ratio, non-uniform fiber distribution and fiber orientation, such as fiber folds, wrinkles or weld lines. A flaw of X-ray testing is if the defect is perpendicular to the x-ray beam, the defect will not be detected.
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Historical floor at the Jagdmagazin, Jagdschloss Grunewald, Germany In Germany, clinker bricks (German: Klinkerziegel) are named according to the German Institute for Standardization's DIN 105. They differ between full clinker (KMz) with a density of and high hole clinker (KHLz) with a density of . Because of their low porosity, clinker bricks are inferior thermal insulators, compared to normal bricks. Canal clinkers are named according to the German Institute for Standardization’s DIN 4051.
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Magnesium alloys, especially precipitation hardened alloys, are used in casting. Sand, permanent mold and die casting methods are used, but plaster-of-Paris casting has not yet been perfected. Sand casting in green-sand molds requires a special technique, because the magnesium reacts with moisture in the sand, forming magnesium oxide and liberating hydrogen. The oxide forms blackened areas called burns on the surface of the casting, and the liberated hydrogen may cause porosity.
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The chemically resistant sediments comprising the Big Clifty, and similar siliciclastics, act as a caprock over the dissolving carbonates. The presence of the Big Clifty is one of several contributory factors that create favorable conditions for the formation, and subsequent preservation, of connected cavernous porosity in the Mammoth-Flint Ridge cave system. The Big Clifty Sandstone also appears as sandstone knobs throughout south-central Kentucky, including the Pilot Rock on the border of Todd County.
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Cement, lime or bitumen stabilization can allow clay soil to withstand flooding or allow sands to be used in traditional bags with a non-structural plaster skin. Because earthbag walls are usually thick a large amount of stabilizer is needed. Thermal insulating properties are important for climates that experience temperature extremes. The thermal insulating value of a material is directly related to both the porosity of the material and the thickness of the wall.
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Carbon nanotubes are among the numerous candidates for tissue engineering scaffolds since they are biocompatible, resistant to biodegradation and can be functionalized with biomolecules. However, the possibility of toxicity with non-biodegradable nano-materials is not fully understood. To achieve the goal of tissue reconstruction, scaffolds must meet some specific requirements. High porosity and adequate pore size are necessary to facilitate cell seeding and diffusion throughout the whole structure of both cells and nutrients.
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In basalt petrogenesis polybaric melting implies that liquids are incrementally separated from residues across a range of pressures and subsequently mix and move through the mantle without equilibrating with surrounding mantle minerals. This model was developed to better approximate basalt petrogenesis in modeling and experiments. It usually involves polybaric near-fractional melting (e.g., constant intergranular porosity in the rock during melting and/or reactive porous flow in melt extraction) along an adiabatic path.
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Methanides are a subset of carbides distinguished by their tendency to decompose in water producing methane. Three examples are aluminium carbide , magnesium carbide and beryllium carbide . Transition metal carbides are not saline carbides but their reaction with water is very slow and is usually neglected. For example, depending on surface porosity, 5–30 atomic layers of titanium carbide are hydrolyzed, forming methane within 5 minutes at ambient conditions, following by saturation of the reaction.
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The development of spongiosa bone is slightly higher that of Acheloma (a terrestrial amphibian), but is much less extensive than aquatic amphibians such as Rhinesuchus and Trimerorhachis. Seymouria's vertebrae are more robust in shape compared to Discosauriscus, and have a low amount of cartilage despite a high amount of porosity. Seymouria are inferred to have undergone metamorphosis very early in life, likely due to environmental stresses from fluctuating wet and dry seasons.
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In materials science, the espresso crema effect is an analogue model for superficial material alteration. Alteration processes such as weathering can influence the physical character and chemical composition of matter near the surface, without affecting the bulk medium beneath. Increases in porosity can increase light refraction, diffuse reflection and scattering, resulting in a brightening of the material's surface. Besides the physical changes, chemical differences compared to the bulk medium may be involved.
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107-119 Such models are so far simplistic and they were developed based on: (A) Fundamental conservation laws, cellular growth, retention kinetics of biomass, and biomass in oil and aqueous phases. The main aim was to predict porosity retention as a function of distance and time. (B) Filtration model to express bacterial transport as a function of pore size; and relate permeability with the rate of microbial penetration by applying Darcy's law.
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This second generation RVD has improved depth resolution in the analysis of seismic data. This allows for correlation with conventional geological studies.Rex International Holding 2015 Operational Plan, 9 February 2015 In 2016 the company announced that it had developed its third version of the technology. The company claims this version can both detect rock porosity and permeability suitable for containing oil as well as identify liquid content, distinguishing between oil and liquid hydrocarbons.
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Scaffolds act as three-dimensional artificial templates in which the tissue targeted for reconstruction is cultured to grow onto. The high porosity of hydrogels allows for the diffusion of cells during migration, as well as the transfer of nutrients and waste products away from cellular membranes. Scaffolds are subject to harsh processing conditions during tissue culturing. These include mechanical stimulation to promote cellular growth, a process which places stress on the scaffold structure.
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Traditionally, the properties of rocks and minerals beneath the earth's surface were defined through seismic exploration and seismology from earthquakes. Travel time, variations in phase and amplitude of seismic waves produced during seismic exploration show rock and fluid properties at the subsurface level. Previously, exploration seismology explored seismic data only for rock formations that could hold hydrocarbons. However, due technological advances, seismic data became useful to determine pore fluids, saturation, porosity and lithology.
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The C-S-H is strongly hydrophilic, and has a colloidal microstructure disordered from a few nanometers up. The paste has a porosity of about 0.4 to 0.55 and an enormous internal surface area, roughly 500 m2/cm3. Its main component is the tri-calcium silicate hydrate gel (3 CaO · 2 SiO3 · 3 H20, in short C3-S2-H3). The gel forms particles of colloidal dimensions, weakly bound by van der Waals forces.
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Another class of high performance polymer frameworks with regular porosity and high surface area is based on triazine materials which can be achieved by dynamic trimerization reaction of simple, cheap, and abundant aromatic nitriles in ionothermal conditions (molten zinc chloride at high temperature (400 °C)). CTF-1 is a good example of this chemistry.Kuhn, P.; Antonietti, M.; Thomas, A.; Porous, Covalent Triazine-Based Frameworks Prepared by Ionothermal Synthesis. Angew. Chem. Int. Ed. 2008.
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Waismann introduced the concept of open texture, or porosity to describe the universal possibility of vagueness in empirical statements. It is based on the Wittgenstein, Philosophical Investigations, particularly Section 80. According to the philosopher, even after measures have been taken to ensure that a statement is precise, there remains an inexhaustible source of vagueness due to an indefinite number of possibilities. Waismann's notion of vagueness is slightly different from his concept of open texture.
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Sphaerium nucleus was described by Studer 1820, who placed it in the genus Cyclas. It was later thought to be a subspecies of Sphaerium corneum. Subsequently it was raised to a full species again as Sphaerium nucleus (Studer, 1820) due to its having a different form of kidney, and the shell having a broad hinge plate, dense porosity and more tumid shells with broad umbones. Unlike S. corneum it has a preference for temporary habitats.
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Caries disease process results in structural changes to the dental hard tissue. The diffusion of ions out of the tooth, known as the demineralisation process, will result in loss of mineral content. The resulting region will be filled mainly by bacteria and water. This region will have greater porosity than the surrounding tissue, which results in a distinct change in the optical properties of the affected dental tissue, providing evidence of caries-induced change.
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Some caries excavation methods lead to leaving caries-affected dentin behind to serve as the bonding substrate, mostly in indirect pulp capping. It is reported that the immediate bond strengths to caries-affected dentin are 20-50% lower than to sound dentin, and even lower with caries-infected dentin. How does caries progression correlates with this? First, it reduces mineral content, increases porosity and changes the dentinal collagen structure and its distribution too.
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However, when thawed they can sometimes turn slightly mushy, so they are best frozen after steaming or frying. Due to their natural porosity, morels may contain trace amounts of soil which cannot be easily washed out. Any visible soil should be removed with a brush, after cutting the body in half lengthwise, if needed. Mushroom hunters sometimes recommend soaking morels in a bowl of salt water briefly prior to cooking, although many chefs would disagree.
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The San Andres Formation of Slaughter Field is a restricted platform carbonate play consisting of flat-lying, bioturbated wackestones and packstones of the San Andres Formation and produces from nearly 5000 feet depth. This is the younger, shallower section of the lower San Andres. The reservoir rock has an average porosity of approximately 11% and a uniform permeability of 0.2 to 30 mD. The source rock is organic-rich calcareous shale and shaley limestone.
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The Simba was designed as a competition glider for the Serial Class and the Open Class, replacing the Apco Bagheera in that role. The Simba is made from 46gr/m2 "Zero Porosity" ripstop nylon. The Simba was produced in regular and competition models, with competition version differing only in the type of line used. The competition model employs unsheathed Aramid lines of identical lengths and layout to the sheathed lines of the regular model.
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Evaporites such as Anhydrites are also more present in the Leduc Formation, however they are also present in the Swan Hills Formation. The Swan Hills formation also holds some differences to the Leduc Formation. The porosity types in both formations differ, and the types of fossilized biota also differ. Vuggy, moldic, intercrystalline, and fracture porosities are present in the Leduc Formation whereas the primary porosities in the Swan Hills Formation are interparticle and interfossil.
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Shale beds that are deposited during the rift-drift stage have high porosity and low permeability. This encloses much fluid which under pressure causing the whole shale bed to turn into a viscous, low density, high mobility layer. The over-pressured shale layers trigger and initiate the growth faults in the same way as the evaporite layers does. Earthquakes arise and result from the release of the force along the growth fault plane.
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The process temperature is above , that is above the melting point of silicon, and the process conditions are controlled such that the carbon fibers of the C/C-preform almost completely retain their mechanical properties. This process is called liquid silicon infiltration (LSI). Sometimes, and because of its starting point with C/C, the material is abbreviated as C/C-SiC. The material produced in this process has a very low porosity of about 3%.
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In-process inspections can show problems with the weld such as discoloration, indicating thermal degradation, bubbles, scratches, and weld bead problems. Visual inspection of the completed weld can detect joint fit-up and tool problems such as mismatch, angular misalignment, notches, and insufficient weld size as well as surface breaking weld defects like porosity, cracks, and excessive flash. As with most NDE techniques, technical training, experience, and skill is important for a successful inspection.
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This is a stratigraphic representation of the seismic data using the seismic interpretation to define the layers. The stratigraphic grid model is then mapped to the corner point grid by adjusting the zones. Using the porosity and permeability models and a saturation height function, initial saturation models are built. If volumetric calculations identify problems in the model, changes are made in the petrophysical model without causing the model to stray from the original input data.
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C. Fowler and X. S. Yang, Fast and slow compaction in sedimentary basins, SIAM Journal of Applied Mathematics, 59, 365-385 (1998.) to show the theoretical basis for Athy's law. This process can be easily observed in experiments and used as a good approximation to many real data.D. B. Bahr, E. W. Hutton, J. P. Syvitski, L. F. Pratson, Exponential approximations to compacted sediment porosity profiles, Computers & Geosciences, 27, 691-700 (2001).
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The results of this process causes the silica particles to group together to combine into spherical nanostructured particles. By grouping these silica nanoparticles into a nanostructured particle, a certain percentage of porosity develops within the nanostructure related to the amount of TMCS concentration. Increasing the amount of TMCS concentration reduces the specific surface area of the silica nanostructured particles. The exhibited hydrophobicity is a result of the chemical reaction occurring between the silica particles and the TMCS.
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The Willamette Lowland basin-fill aquifer is composed of many geologic units that are broadly separated into six hydrogeological categories. These categories are listed from lowest to highest. The lowest unit is the basement confining unit, composed of tertiary marine sedimentary rocks and Eocene volcanic rocks near the Oregon Coast Range, and volcanic and volcaniclastic rocks near the Cascade Range. This unit has low permeability and low porosity, but still can provide water at a low rate.
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Foundations of a good well log data quality are data consistency, tool calibration, tool reliability, and wireline service company performance. In collecting right and good quality data, proper and valid calibrations and verifications of all the equipment, consistent complementary readings checks (e. g. density and neutron logs or porosity logs) and repeatability of recorded logs are all essential. Basic steps in log quality control are:Hoover, R. (2006): QA/QC and Geophysical Projects, Highway Geophysics-NDE Conference, www.umr.
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Black River and Trenton Limestones are composed of carbonate mudstone, wackestones, and fossiliferous limestones. This unit is the result of a reef complex, which has a high porosity. The major gas and oil reservoir in the Black River and Trenton Limestones are located in northern Ohio and the Southern Tier of New York. This is composed of a medium to coarse grained dolomite, that is highly altered due to the ascending fluids altering the limestone to dolomite.
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The field was discovered in 1967, and has been producing oil and gas since 1970.Malek,R; Mehin,K, 1998 Oil and Gas Resources of Victoria Department of Natural Resources and Environment 1998 Petroleum Development The water depth is 73 m, and there are 14 producing wells. The oil water contact is located at approximately 2399 m depth. The porosity is 22%, and the permeability is 5000-7000 millidarcy. The oil gravity is 43.3, and is paraffinic.
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Geologically, this area is part of a structural downwarp that occurred during the late Pliocene. Rocks within the region are all sedimentary and mostly marine. Oil accumulations, of which there are many in the Ventura province, mainly occur in anticlinal settings modified by faulting; stratigraphy is also influential in creating traps for hydrocarbons. Where the sedimentary rocks are sandstones with high porosity, and the structure and stratigraphy allow hydrocarbons to be trapped on their upward migration, oilfields are found.
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The difference in water vapor uptake between the sorption and desorption isotherms is called the hysteresis. The shape and location of the isotherm hysteresis can elucidate information about the sorption mechanism and sample porosity. Although an isotherm experiment is the most common use of a DVS instrument, humidity (or other vapor) ramping experiments can be performed to investigate vapor-induced phase changes. These changes include: glassy to rubbery transitions, amorphous to crystalline conversions, and sample deliquescence.
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Mobius Sea by Goodwin (1986) Goodwin is the director of Richard Goodwin Pty Ltd, a Sydney- based practice that has evolved from performance art to sculpture, installations, parasitic architecture and freeway infrastructure. Goodwin's artwork is held in major collections including the Art Gallery of NSW, Sydney and regional galleries across Australia.Richard Goodwin Pty Ltd \- He regularly consults on major infrastructure projects such as bridges and freeway walls. Goodwin's core agenda is creating what he calls "porosity".
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In practicing this agenda, he tests the functional and aesthetic boundaries of public space through both art and architecture. He has opened up new dimensions in the planning of urban spaces and the way architecture interacts with its physical and cultural context. In 1996, Goodwin established the Porosity Studio at COFA . The studio enquires into the way patterns of inhabiting and moving through the cities weaves a level of political richness into the fabric of architecture.
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Since 2004 the studios have been supported by a number of cooperations such as the British Council. They have been run as intensive workshops internationally in cities such as Glasgow, Cardiff, Milan, Beijing and Rotterdam. The Australian Research Council (ARC)'s prestigious Discovery Grant was awarded to Goodwin in 2002. The research project argued for 'Porosity' as a way of describing an urban experience which turns the building inside out and de-emphasises the obsession with facades.
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The earliest ceramics made by humans were pottery objects (i.e. pots or vessels) or figurines made from clay, either by itself or mixed with other materials like silica, hardened and sintered in fire. Later ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, amorphous ceramic coatings on top of the crystalline ceramic substrates. Ceramics now include domestic, industrial and building products, as well as a wide range of ceramic art.
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Water content (θ) is also a directly measurable property; it is the fraction of the total rock which is filled with liquid water. This is also a fraction between 0 and 1, but it must also be less than or equal to the total porosity. The water content is very important in vadose zone hydrology, where the hydraulic conductivity is a strongly nonlinear function of water content; this complicates the solution of the unsaturated groundwater flow equation.
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The model generated is of higher quality, and does not suffer from tuning and interference caused by the wavelet. CSSI transforms seismic data to a pseudo-acoustic impedance log at every trace. Acoustic impedance is used to produce more accurate and detailed structural and stratigraphic interpretations than can be obtained from seismic (or seismic attribute) interpretation. In many geological environments acoustic impedance has a strong relationship to petrophysical properties such as porosity, lithology, and fluid saturation.
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The extraction of metals in the Cober valley was carried out for centuries with silver and lead being mined at Wheal Pool (also known as Castle Wary mine) in 1780. In the mid-19th century tin-waste (leavings) from mines on Porkellis Moor was reducing the porosity of the bar. From Trenear to the Loe tinners, were able to work-up (i.e. extract) the waste, as recorded in October 1880, following heavy rain the week before.
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Recently discovered petroleum-bearing formations off the coast of northeastern Brazil hold coquina reservoirs of oil. The coquinas are generally heterogeneous in their porosity and permeability, but like other lacustrine carbonates, they are uncommonly reservoirs. Corbett et al. (2015) in their discussion of the reservoirs say the finding of the Badejo Field (Campos Basin) in 1975 was the first hydrocarbon discovery in the coquinas of the Lagoa Feia, followed by that of the Pampo and Linguado Fields in 1978.
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The pore space of soil contains the liquid and gas phases of soil, i.e., everything but the solid phase that contains mainly minerals of varying sizes as well as organic compounds. In order to understand porosity better a series of equations have been used to express the quantitative interactions between the three phases of soil. Macropores or fractures play a major role in infiltration rates in many soils as well as preferential flow patterns, hydraulic conductivity and evapotranspiration.
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On most Gram-stained preparations, Gram-negative organisms appear red or pink due to their counterstain. Due to the presence of higher lipid content, after alcohol- treatment, the porosity of the cell wall increases, hence the CVI complex (crystal violet – iodine) can pass through. Thus, the primary stain is not retained. In addition, in contrast to most Gram-positive bacteria, Gram- negative bacteria have only a few layers of peptidoglycan and a secondary cell membrane made primarily of lipopolysaccharide.
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DNA testing can confirm the diagnosis, however, it cannot exclude it because not all mutations causing OI are known and/or tested for. OI type II is often diagnosed by ultrasound during pregnancy, where already multiple fractures and other characteristic features may be present. Relative to control, OI cortical bone shows increased porosity, canal diameter, and connectivity in micro-computed tomography. Severe types of OI can usually be detected before birth by using an in-vitro genetic testing technique.
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Resistivity logging measures the subsurface electrical resistivity, which is the ability to impede the flow of electric current. This helps to differentiate between formations filled with salty waters (good conductors of electricity) and those filled with hydrocarbons (poor conductors of electricity). Resistivity and porosity measurements are used to calculate water saturation. Resistivity is expressed in ohms or ohms/meter, and is frequently charted on a logarithm scale versus depth because of the large range of resistivity.
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Foamed aluminium Regular foamed aluminium A metal foam is a cellular structure consisting of a solid metal (frequently aluminium) with gas-filled pores comprising a large portion of the volume. The pores can be sealed (closed-cell foam) or interconnected (open-cell foam). The defining characteristic of metal foams is a high porosity: typically only 5–25% of the volume is the base metal. The strength of the material is due to the square-cube law.
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The amount of oil that is recoverable is determined by a number of factors, including the permeability of the rock, the strength of natural drives (the associated gas present, pressure from adjacent water or gravity), porosity of the reservoir rock, i.e. the rock storage capacity, and the viscosity of the oil. When the reservoir rocks are "tight", as in shale, oil generally cannot flow through, but when they are permeable, as in sandstone, oil flows freely.
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In addition, sol-gel bioglasses have much higher porosity, which leads to a greater surface area and degree of integration in the body. Newer methods include flame and microwave synthesis of Bioglass, which has been gaining attention in recent years. Flame synthesis works by baking the powders directly in a flame reactor. Microwave synthesis is a rapid and low-cost powder synthesis method in which precursors are dissolved in water, transferred to an ultrasonic bath, and irradiated.
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Other authors have written curly hair care guides which focus on specific hair types. Curly Like Me: How to Grow Your Hair Healthy, Long, and Strong by Teri LaFlesh provides natural hair care tips especially for tight curls. Better than Good Hair: The Curly Girl Guide to Healthy, Gorgeous Natural Hair by Nikki Walton focuses on Afro-textured hair. Writers at the Naturally Curly website provide hair care advice based on curl pattern, porosity, and other factors.
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Like its source rocks, Kapuni's reservoir layers are located in the Eocene Mangahewa Formation and were deposited as part of a general transgressive sequence. The reservoirs are predominantly sandstones, shales, and coals deposited in shore, fluvial, and estuarine environments. Kapuni's reservoirs are located below a depth of 3000 m. They range in average thickness from 20 m to 130 m, average natural- gas fraction from 0.06 to 0.95, and average porosity from 12.2% to 16.8% by volume.
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Intervals of coarser clasts experienced net dissolution, while finer-grained intervals experienced precipitation of authigenic clays, carbonates, and quartz. Precipitation of quartz and carbonate cements began approximately 4 Ma at temperatures exceeding 100 °C. The carbon isotope signature of carbonate cements in the K3E reservoir suggests an intraformational origin. As a result of diagenesis, the K3E reservoir contains areas exhibiting significant secondary porosity and enhanced reservoir quality along with tight, cemented regions of poor reservoir quality.
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In the 1980s started the commercialization of air-laid paper, which gave better bulk, porosity, strength, softness, and water absorption properties compared with normal tissue paper. Also in the 1980s started the use of superabsorbents in diapers and reduced the need for fluff pulp and is now down to 15 grams or even less. The demand of the pulp in diapers has gone from being the absorbent of liquid to giving the products dry and wet strength.
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Numerical modeling is also used to design the power delivery system (PDS), the power requirements from the utility and the project capital requirements. Electrical heating increases the temperature of the soil and groundwater by conducting current through the resistive connate water that fills the porosity of the soil. The increase in temperature raises the vapor pressure of volatile and semi-volatile contaminants, increasing their ability to volatilize and be recovered through conventional techniques such as soil vapor extraction.
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He also produced paintings for the Indianapolis Art Museum during that period. In 1976 he turned exclusively to theory and experimental projects. He designed a light pavilion in the Sliced Porosity Block, Chengdu, China with Steven Holl, and buildings in Havana, Cuba.Domus Magazine March 2013 In 1988, Woods co-founded the Research Institute for Experimental Architecture, a nonprofit institution devoted to the advancement of experimental architectural thought and practice while promoting the concept and perception of architecture itself.
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The pressure and heat applied in calendering depend on the type of the finish required. The purposes of calendering are to upgrade the fabric hand and to impart a smooth, silky touch to the fabric, to compress the fabric and reduce its thickness, to improve the opacity of the fabric, to reduce the air permeability of the fabric by changing its porosity, to impart different degree of luster of the fabric, and to reduce the yarn slippage.
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Because the cathode does not change properties during discharge, terminal voltage is quite stable until the cell approaches exhaustion. Power capacity is a function of several variables: cathode area, air availability, porosity, and the catalytic value of the cathode surface. Oxygen entry into the cell must be balanced against electrolyte water loss; cathode membranes are coated with (hydrophobic) Teflon material to limit water loss. Low humidity increases water loss; if enough water is lost the cell fails.
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The Hebron field is separated into three distinct fault blocks: The Hebron Fault Block, The West Ben Nevis Fault Block and the Ben Nevis Fault Block. Reservoir reside in each of these due to the deposition of the Egret Source Rock in the middle Kimmeridgian. The Hebron Fault block, also called "pool one", contains the majority of the producible hydrocarbons for the field in the Ben Nevis Sandstone formation. It contains heavy oil but has good porosity and permeability.
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Several astronomers have considered Ixion to be a possible dwarf planet under the expectation that it is large enough to have assumed a round shape under hydrostatic equilibrium, although studies in 2019 suggest that objects around the size of Ixion may retain significant internal porosity and thus represent a transitional zone between small Solar System bodies and dwarf planets. Ixion is currently not known to have a natural satellite; thus its mass and density remain unknown.
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Several theories have been posited to explain the formation of binary- asteroid systems. Many systems have significant macro-porosity (a "rubble- pile" interior). The satellites orbiting large main-belt asteroids such as 22 Kalliope, 45 Eugenia or 87 Sylvia may have formed by disruption of a parent body after impact or fission after an oblique impact. Trans-Neptunian binaries may have formed during the formation of the Solar System by mutual capture or three-body interaction.
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Optimal extraction is possible only if the initial glass composition and thermal treatment are chosen such that combine structures form, and not droplet structures. The texture is influenced by the composition of the initial glass, which directs size and type of decomposition areas. In the context of porous glasses, "texture" implies properties like specific pore volume, specific surface, pore size, and porosity. The emerging areas of decomposition depend on time and temperature of the thermal treatment.
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The frozen emulsion is subsequently freeze-dried to remove the dispersed water and the solvent, thus leaving a solidified, porous polymeric structure. While emulsification and freeze-drying allow for a faster preparation when compared to SCPL (since it does not require a time-consuming leaching step), it still requires the use of solvents. Moreover, pore size is relatively small and porosity is often irregular. Freeze-drying by itself is also a commonly employed technique for the fabrication of scaffolds.
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The movement of fluid through a porous medium such as paper is governed by permeability (earth sciences), geometry and evaporation effects. Collectively these factors results in evaporation limited capillary penetration that can be tuned by controlling porosity and device geometry. Paper is a porous medium in which fluid is transported primarily by wicking and evaporation. The capillary flow during wetting can be approximated by Washburn's equation, which is derived from Jurin's Law and the Hagen–Poiseuille equation.
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Agarose is sometimes used instead of agar to measure microorganism motility and mobility. Motile species will be able to migrate, albeit slowly, throughout the porous gel and infiltration rates can then be visualized. The gel's porosity is directly related to the concentration of agar or agarose in the medium, so different concentration gels may be used to assess a cell's swimming, swarming, gliding and twitching motility. Under-agarose cell migration assay may be used to measure chemotaxis and chemokinesis.
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Pigments support a structure of fine porosity and form a light scattering surface. The surface charge of the pigment plays an important role in dispersion consistency. The surface charge of calcium carbonate is negative and not dependent on pH, however it can decompose under acidic conditions. Kaolin has negatively charged faces while the charge of its laterals depend on pH, being positive in acidic conditions and negative in basic conditions with an isoelectric point at 7.5.
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Centrifugation can also be used to accelerate the process of phase separation. Removal of the remaining liquid (solvent) phase requires a drying process, which is typically accompanied by a significant amount of shrinkage and densification. The rate at which the solvent can be removed is ultimately determined by the distribution of porosity in the gel. The ultimate microstructure of the final component will clearly be strongly influenced by changes imposed upon the structural template during this phase of processing.
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It would therefore appear desirable to process a material in such a way that it is physically uniform with regard to the distribution of components and porosity, rather than using particle size distributions which will maximize the green density. The containment of a uniformly dispersed assembly of strongly interacting particles in suspension requires total control over particle- particle interactions. Monodisperse colloids provide this potential.Allman III, R. M. in Microstructural Control Through Colloidal Consolidation, Aksay, I. A., Adv. Ceram.
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To make polyoxymethylene homopolymer, anhydrous formaldehyde must be generated. The principal method is by reaction of the aqueous formaldehyde with an alcohol to create a hemiformal, dehydration of the hemiformal/water mixture (either by extraction or vacuum distillation) and release of the formaldehyde by heating the hemiformal. The formaldehyde is then polymerized by anionic catalysis, and the resulting polymer stabilized by reaction with acetic anhydride. Due to the manufacturing process, large-diameter cross-sections may have pronounced centerline porosity.
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Gupta has studied aluminum, magnesium, iron and invar matrix syntactic foams. His work produced the development of a magnesium-alloy matrix syntactic foam that has density of 0.9 g/cc and can float on water. Gupta and his team were the first to create this lightweight metal matrix composite with no porosity in the matrix, which received media attention. At this density level, metal matrix composites can compete against polymer matrix composites but also provide higher temperature withstanding capabilities.
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PEA microbeads intended for drug delivery can be made through water/oil/water double emulsion methods. By blending PEA with Poly-ε-caprolactone, beads can be given membrane porosity. Microbeads were placed into a variety of solutions including a synthetic stomach acid, pancreatin, Hank's buffer, and newborn calf serum. The degradation of the microcapsules and therefore the release of the drug was the greatest in newborn calf serum, followed by pancreatin, then synthetic stomach acid, and lastly Hank's buffer.
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Within the field of fuel cell research, MOFs are being studied as potential electrolyte materials and electrode catalysts that could someday replace traditional polymer membranes and Pt catalysts, respectively. As electrolyte materials, the inclusion of MOFs seems at first counter-intuitive. Fuel cell membranes generally have low porosity to prevent fuel crossover and loss of voltage between the anode and cathode. Additionally, membranes tend to have low crystallinity because the transport of ions is more favorable in disordered materials.
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An early turquoise mine in Madan, Khorasan Province, Iran Turquoise is treated to enhance both its colour and durability (increased hardness and decreased porosity). As is so often the case with any precious stones, full disclosure about treatment is frequently not given. Gemologists can detect these treatments using a variety of testing methods, some of which are destructive, such as the use of a heated probe applied to an inconspicuous spot, which will reveal oil, wax or plastic treatment.
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The Waterbird was revolutionary in its canopy design, its unique tow yoke harness arrangement, its construction, and the use of zero porosity fabrics which allowed it to be used over water safely. The majority of commercial parasail operators then moved to the 16-gore canopy arrangement. In 1976 Gaskin founded his company, Waterbird Parakites, which is still in operation today, producing commercial and recreational 16-gore parasails. In April 2013, the first ASTM parasail weather standard was approved.
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Photograph of YPM 1647, a specimen of A. arcuatus Old restoration A. arcuatus has paramedian scutes that are much wider than they are long, even in comparison to other species of Aetosaurus. There is very little pitting on the surface of the scutes, although the porosity of the sandstone that makes up the casts has been mistaken for pitting. The tail narrows significantly past the base. The carapace is "waisted", meaning that it narrows in front of the pelvis.
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This water, accessible to vegetation, has a volume equal to the porosity of the soil (n) multiplied by its saturation (s) and the depth of the plant's roots (Z_{r}). The differential equation ds(t)/dt describes how the soil saturation changes over time. The terms on the right hand side describe the rates of rainfall (R), interception (I), runoff (Q), evapotranspiration (E), and leakage (L). These are typically given in millimeters per day (mm/d).
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It is generally uncertain what type of dinosaurs laid faveoloolithid eggs, though they are conjectured to have been laid by sauropods.Tanaka, K., Zelenitsky, D. K., & Therrien, F. (2015) "Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs." PLoS ONE, 10(11), e0142829. Unlike most dinosaur eggs, where the shell membrane and the calcareous eggshell form sequentially, in dictyoolithids and faveoloolithids (including Hemifaveoloolithus) the membrane and shell would develop simultaneously, comparable to eggs of modern tuataras.
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It was certified as a purely DHV Class 1 glider, from which it takes its name. The four model sizes produced are each named for their relative size. The design is made from high- tenacity, low-porosity material of 49 g/m2 and incorporates diagonal tapes instead of the more commonly used whole diagonal ribs. The tapes form triangles, in conjunction with reinforcement tapes on the bottom surface of the glider wing and prevent airfoil deformation.
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Cranial bones can also be useful for detecting evidence of physiological perturbations. The reconstructed frontal, parietal, and occipital bone fragments of Anzick-1 were analyzed for these indicators of health; however, the crania showed no evidence of cribra orbitalia or porotic hyperostosis, conditions that can indicate diseases. Porotic hyperostosis is characterized by porous lesions on the parietal, occipital, and sometimes frontal bones. Cribra orbitalia is another pathological skeletal lesion that manifests as porosity on the orbital roof.
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The Fiesta was designed as a beginner glider, plus a tandem version for flight training, the Fiesta 42 Bi, indicting "bi-place" or two seater. The sail is made from 46gr/m2 "Zero Porosity" ripstop nylon. The design progressed through two generations of models, the Fiesta and Fiesta II. The two-place models in the line are named for their rough wing area in square metres, while the solo ones are named for their relative size.
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Another example is the deposition of silicon carbide, which is usually conducted from a mixture of hydrogen and methyl- trichlorosilane (MTS, ; it is also common in silicone production). Under defined condition this gas mixture deposits fine and crystalline silicon carbide on the hot surface within the preform. This CVI procedure leaves a body with a porosity of about 10–15%, as access of reactants to the interior of the preform is increasingly blocked by deposition on the exterior.
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Enlargement of a proper weld cross section At this point in the manufacturing process the parts have been cut, shaped and ready for welding. Although each step in the process is important, good welds are of particular significance because they hold the pieces together and prevent leaks when done correctly. The weld must be 1/4 inch wide and have deep penetration into the metal. A proper weld is continuous, convex in shape and exhibits no porosity.
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A consolidated ridge is one whose base has undergone complete freezing. The term consolidated layer is used to designate freezing up of the rubble just below the water line. The existence of a consolidated layer depends on air temperature — in this layer, the water between individual blocks is frozen, with a resulting reduction in porosity and an increase in mechanical strength. A keel's depth of an ice ridge is much higher than its sail's height - typically about four times.
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Pro.R.K.Dhir and Prof.B.Bhattacharjee Dr. Bhattacharjee has been pursuing research in the realms of concrete technology, construction materials and building sciences. His contributions in the area of micro-structural characterisation of cement based materials through implementation of Mercury Intrusion Porosimetry (MIP) and Back Scattered Electron Microscopy (BSE) have been of particular prominence. His findings on the porosity and pore size distribution of concrete and its relation to in situ strength continue to remain very well acclaimed amongst the scientific community.
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South of the Save River, unconsolidated sediments are an important source of groundwater, overlying the Mozambique Basin. A 30 kilometer wide belt of dune sands occupies the southern coast of the country, atop Cretaceous and Paleogene rocks and form a moderately productive unconfined aquifer. Thick alluvium in the Limpopo River and Incomati River valleys forms a major aquifer in high porosity sands north of Maputo. Marine and continental sandstones dominate deeper Cretaceous- Paleogene sedimentary aquifers and some also contain layers of limestone.
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In the process of burial, it is possible that siliciclastic deposits may subsequently be uplifted as a result of a mountain building event or erosion. When uplift occurs, it exposes buried deposits to a radically new environment. Because the process brings material to or closer to the surface, sediments that undergo uplift are subjected to lower temperatures and pressures as well as slightly acidic rain water. Under these conditions, framework grains and cement are again subjected to dissolution and in turn increasing porosity.
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1,197,956, "Sound Absorbing Materials for Walls and Ceilings," issued September 12, 1916, p.2, lines 26-30 Designed with a graded porosity to increase their range of absorption, the stone-like finish of Akoustolith tiles consisted of a mix of coarser aggregate to facilitate the absorption of low pitches. Similarly, the bedding face consisted of a mix of finer aggregate to absorb higher pitches. Eventually, different grades of the material were sold; these varied in size and sound-absorption coefficients.
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340 °C), the average molecular weight of the product is so low that no liquid product phase occurs under reaction conditions. The catalyst particles moving around in the reactor are small (particle diameter 100 µm) and carbon deposition on the catalyst does not disturb reactor operation. Thus a low catalyst porosity with small pore diameters as obtained from fused magnetite (plus promoters) after reduction with hydrogen is appropriate. For maximising the overall gasoline yield, C3 and C4 alkenes have been oligomerized at Sasol.
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Because mesocrystals are made up of nanoparticles, the properties of the nanoparticles themselves are, in some cases, passed to the whole mesocrystal structure. This allows for the practical application of mesocrystals because they are "potentially more stable analogues of nanoparticulate materials." High porosity is generally a quality of mesocrystals, this is the property shared with mesoporous materials. Closed, internal pores are good for thermal and dielectric insulation and the open pores then aid in absorption and could be utilized for medical delivery.
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It is noted that the running of constant DC is usually implemented to ensure steady tip-concentration of HF resulting in a more homogeneous porosity layer although pulsed current is more appropriate for the formation of thick silicon wafers bigger than 50 µm.Halimaoui A. 1997, "Porous silicon formation by anodization", in Properties of Porous Silicon. Canham, L. T., Institution of Engineering and Technology, London, pp. 12–22. It was noted by Halimaoui that hydrogen evolution occurs during the formation of porous silicon.
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An example of this phenomenon is pumice, which, when in its unfractured state, can make a poor aquifer. Porosity does not directly affect the distribution of hydraulic head in an aquifer, but it has a very strong effect on the migration of dissolved contaminants, since it affects groundwater flow velocities through an inversely proportional relationship. Darcy's law is commonly applied to study the movement of water, or other fluids through porous media, and constitutes the basis for many hydrogeological analyses.
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The pore elimination occurs faster for a trial with many pores of uniform size and higher porosity where the boundary diffusion distance is smaller. For the latter portions of the process, boundary and lattice diffusion from the boundary become important. Control of temperature is very important to the sintering process, since grain-boundary diffusion and volume diffusion rely heavily upon temperature, the size and distribution of particles of the material, the materials composition, and often the sintering environment to be controlled.
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Writing in Architecture Week (August 4, 2004), Hauer explains that "Continuity and potential infinity have been at the very center of my sculpture from early on." Hauer made an extensive study of biomorphic form, especially what he calls "saddle surfaces," which combine convex and concave curvature and thus allow for smooth self-combination, sometimes in multiple dimensions. Another inspiration is the sculpture of Henry Moore, with its fluid curves and porosity. Hauer's enthusiasm caught the imagination of his colleague at Yale, Norman Carlberg.
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Mechanisms of chemical change, such as the uptake of F− or CO3− may cause recrystallization where hydroxyapatite is dissolved and re-precipitated allowing for the incorporation or substitution of exogenous material. # Once an individual has been interred, microbial attack, the most common mechanism of bone deterioration, occurs rapidly. During this phase, most bone collagen is lost and porosity is increased. The dissolution of the mineral phase caused by low pH permits access to the collagen by extracellular microbial enzymes thus microbial attack.
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Lalwani et al. have reported a novel radical initiated thermal crosslinking method to fabricated macroscopic, free- standing, porous, all-carbon scaffolds using single- and multi-walled carbon nanotubes as building blocks. These scaffolds possess macro-, micro-, and nano- structured pores and the porosity can be tailored for specific applications. These 3D all-carbon scaffolds/architectures may be used for the fabrication of the next generation of energy storage, supercapacitors, field emission transistors, high-performance catalysis, photovoltaics, and biomedical devices and implants.
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The defining preservation process is that which preserves organic film plus phyllosilicate. For this preservation to occur, the organisms must be protected from decay. There are a few ways that this can happen; for instance they can be chemically protected within the sediment by phyllosilicates or biopolymers, which inhibit the action of decay related enzymes. Alternatively the sediment could be "sealed" soon after the organisms were buried within it, with a reduction in porosity preventing oxygen from reaching the organic material.
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A coal in Alabama and a coal in Colorado may have radically different Langmuir parameters, despite otherwise similar coal properties. As production occurs from a coal reservoir, the changes in pressure are believed to cause changes in the porosity and permeability of the coal. This is commonly known as matrix shrinkage/swelling. As the gas is desorbed, the pressure exerted by the gas inside the pores decreases, causing them to shrink in size and restricting gas flow through the coal.
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For titanium foams consisting of partially sintered powders, the minimum solid area consists of the neck area between powders through the cross-section of cell walls between macropores. The mathematical relationships in MSA models are relatively consistent with the Gibson & Ashby model. However, the MSA models are designed to predict mechanical property parameters over a broader range of porosity levels. Like the Gibson & Ashby models, MSA models were derived assuming idealized (defect-free) structures containing uniform pore shapes, size and distribution.
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Percolation trenches are often used to treat runoff from impervious surfaces, such as sidewalks and parking lots, on sites where there is limited space available for managing stormwater. They are effective at treating stormwater only if the soil has sufficient porosity. To function properly, a trench must be designed with a pretreatment structure such as a grass channel or swale, in order to capture sediment and avoid clogging the trench.Atlanta Regional Commission. Atlanta, GA. “Georgia Stormwater Manual: Volume 2.” Section 3.2.
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Authigenic clays tend to reduce the porosity of sediments, thus reducing permeability. In metamorphic petrology an authigenic mineral is one formed in situ during metamorphism, again by precipitation from fluids or recrystallization. For any mineral to be precipitated, the water must be oversaturated with respect to that mineral. For calcite, this means that the area of deposition must be above the carbonate compensation depth, or that the pore waters are sufficiently saturated due to dissolution of other grains that precipitation can begin.
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Carbon aerogels are composed of particles with sizes in the nanometer range, covalently bonded together. They have very high porosity (over 50%, with pore diameter under 100 nm) and surface areas ranging between 400 and 1,000 m2/g. They are often manufactured as composite paper: non-woven paper made of carbon fibers, impregnated with resorcinol–formaldehyde aerogel, and pyrolyzed. Depending on the density, carbon aerogels may be electrically conductive, making composite aerogel paper useful for electrodes in capacitors or deionization electrodes.
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Sandy soils will involve mainly capillary binding, and will therefore release most of the water at higher potentials, while clayey soils, with adhesive and osmotic binding, will release water at lower (more negative) potentials. At any given potential, peaty soils will usually display much higher moisture contents than clayey soils, which would be expected to hold more water than sandy soils. The water holding capacity of any soil is due to the porosity and the nature of the bonding in the soil.
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A paleoburrow is an underground shelter (tunnel, burrow, lair, etc.) excavated by extinct paleo-vertebrate megafauna (i.e., giant mammals, such as ground sloths) that lived in the prehistoric era.II Congresso sobre Planejamento e Gestão das Zonas Costeiras dos Países de Expressão Portuguesa UFRGS - agosto/2015ANAIS do 31º Congresso Brasileiro de Espeleologia Cavernas.org - agosto/2015 A crotovina is a paleoburrow filled with sediments (sands, clays, etc.) that have been deposited over the centuries through rainfall and accumulated due to the porosity of the terrain.
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Cass Materials in Perth, Australia is using a dietary fibre called Nata de Coco (derived from coconuts) to create nanocellulose sponges for their BNC scaffold. Nata de Coco is biocompatible, has a high porosity, facilitates cell adhesion and is biodegradable. Immersion Jet Spinning is a method of creating scaffolds by spinning polymers into fibres initially developed by the Parker Group at Harvard University. iRJS platform uses centrifugal force to extrude a polymer solution through an opening in a rotating reservoir.
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Flammario has an estimated mass of with a theoretical bulk density of (marked as unrealistically high by the author of the publication) due to its low macroporosity, i.e. the lack of voids within the body. Small Solar System bodies may have 20% of more porosity (which decreases with the size of the body due to self-gravity). The carbonaceous outer-belt asteroids typically show a higher macroporosity than the basaltic, stony asteroids from the inner regions of the asteroid belt.
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The physical and chemical properties of biochars as determined by feedstocks and technologies are crucial for the application of biochars in the industry and environment. Different characterization data are employed to biochars and determine their performances in a specific use. For example, the guidelines published by the International Biochar Initiative provide standardized methods in evaluating the product quality of biochar for soil application. The properties of biochar can be characterized in several respects, including the proximate and elemental composition, pH value, porosity etc.
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These conventional investigation methods need to be supplemented with dye traces, measurement of spring discharges, and analysis of water chemistry. U.S. Geological Survey dye tracing has determined that conventional groundwater models that assume a uniform distribution of porosity are not applicable for karst aquifers. Linear alignment of surface features such as straight stream segments and sinkholes develop along fracture traces. Locating a well in a fracture trace or intersection of fracture traces increases the likelihood to encounter good water production.
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More importantly the transition zone from normal pressure to this overpressure happens over some extremely thin Lower Cretaceous layers, which in parts are only 30 m thick. These initial findings suggested that this would be a marginal field which would be difficult to extract from. This data also suggested that extraction would be limited due to a low porosity and permeability. However, as with all fields, as more was investigated from production data, new facts about the geology were revealed.
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A second hole was most likely also on the missing half of the loaf. The bread had no pronounced crust and it was baked from a very finely ground and sifted wheat flour. A microscopic examination of the surface showed that the dough contained only remarkable small traces of wear fine millstones. The dough itself was kneaded thoroughly and showed only very small porosity, suggesting that neither a wild yeast fermentation nor a sourdough were used to leaven the bread loaf.
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They require a dry, clean surface during application to gain adhesion. Topical sealers may alter the coefficient of friction which can make substrates slick when wet – a condition that can be remedied by adding anti-skid materials. Life span is generally 1-5 years, although high-end epoxy/urethane systems can last significantly longer. Penetrating Sealers: Penetrating sealers can be applied to dry or damp surfaces and should be properly matched with substrate porosity in order to effectively penetrate the surface and react.
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There are three most common types of sealing. First, long immersion in boiling-hot (96–100°C/205-212°F) deionized water or steam is the simplest sealing process, although it is not completely effective and reduces abrasion resistance by 20%. The oxide is converted into its hydrated form and the resulting swelling reduces the porosity of the surface. Second, mid- temperature sealing process which works at 160-180°F (60-80°C) in solutions containing organic additives and metal salts.
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It is obtained by dividing the fouling rate by the foulant concentration. The fouling rate constant (m/s) can be obtained by dividing the normalized fouling rate by the mass density of the process fluid (kg/m3). Deposit thickness (μm) and porosity (%) are also often used for description of fouling amount. The relative reduction of diameter of piping or increase of the surface roughness can be of particular interest when the impact of fouling on pressure drop is of interest.
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Gas is light compared to oil causing density logging (gamma ray emitting sensors) based measurements to produce anomalous signals. Similarly, measurements that rely on detecting hydrogen (neutron emitting sensors) can miss detecting or correctly interpreting the presence of gas because of the lower hydrogen concentration in gas, compared to oil. By properly combining the two erroneous answers from density and neutron logging, it is possible to arrive at a more accurate porosity than would be possible by interpreting each of the measurements separately.
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The horizontal motion of sea ice is quite difficult to model because ice is a non-Newtonian fluid. Sea ice will deform primarily at fracture points which in turn will form at the points of greatest stress and lowest strength, or where the ratio between the two is a maximum. Ice thickness, salinity and porosity will all affect the strength of the ice. The motion of the ice is driven primarily by ocean currents, though to a lesser extent by wind.
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The quantitative response of neutron tool to gas or light hydrocarbon depends primarily on hydrogen index and "excavation effect". The hydrogen index can be estimated from the composition and density of the hydrocarbons Given a fixed volume, gas has considerably lower hydrogen concentration. When pore spaces in the rock are excavated and replaced with gas, the formation has smaller neutron-slowing characteristic, hence the terms "Excavation Effect". If this effect is ignored, a neutron log will show a low porosity value.
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The heavy rare-earth elements are hosted in yttrofluorite which is soluble in dilute sulfuric acid, making heap leach extraction feasible. The natural porosity and permeability of the rhyolite provide the micro-conduits that allow the acid to penetrate to the interior of the large crush size (one inch, or 2.5 cm) for the heap leach. The even grade of heavy rare-earth mineralization throughout the deposit leads to a consistent, unchanging quality of raw material for the heap leach.
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Additive manufacturing is a popular upcoming form of industry which allows for complex geometries and unique performance characteristics for AM parts. The main issue with mechanical properties of AM parts is the introduction of microstructural heterogeneities within layers of deposited material. These defects, including porosity and unique interfaces, result in anisotropy of the mechanical response of the workpiece, which is undesirable. To combat this anisotropic mechanical response, a Bouligand- inspired tool path is used to deposit the material in a twisted Bouligand structure.
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As a gel, an agar or agarose medium is porous and therefore can be used to measure microorganism motility and mobility. The gel's porosity is directly related to the concentration of agarose in the medium, so various levels of effective viscosity (from the cell's "point of view") can be selected, depending on the experimental objectives. A common identification assay involves culturing a sample of the organism deep within a block of nutrient agar. Cells will attempt to grow within the gel structure.
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Compaction by vibrocompression vacuum process uses elastomeric molds in which a crushed stone/resin mix is cast on a moving belt. The mixture of approximately 93% stone aggregates and 7% polyester resin by weight (66% quartz and 34% resin by volume) is heated and compressed under vacuum in a large press. The vibration helps compact the mixture and results in an isotropic slab with virtually no porosity. Engineered stone is then processed in basically the same manner as its natural counterpart.
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These cases show that flowers of sulfur was one of the earliest fungicides and insecticides used agriculturally. More recent sources also show that flowers of sulfur acts a fungicide, insecticide, and fumigant, as well as an agent in the treatment of numerous skin diseases. Flowers of Sulfur (FoS) Tests have also been used to test porosity of metallic finishes over silver, copper, and copper alloy substrates. The original FoS test method was standardized by ASTM through ASTM-B809 which was established in 1990.
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The metallographic analysis method has been optimized for over the years on a wide variety of alloys. The measurement principle is the following: A predetermined quantity of liquid aluminum is filtered under controlled conditions using a very fine porosity filter. Inclusions in the melt are concentrated at the filter surface by a factor of about 10,000. The filter, along with the residual metal, is then cut, mounted and polished before being analyzed under an optical microscope by a trained PoDFA metallographer.
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For digital imaging, the lack of contrast may be partially addressed after the radiographic images are taken, using digital imaging software. Radiography can detect porosity, voids and possibly differences in fiber density or orientation in the composite matrix due to the welding process. Lack of fusion may not be visible by RT unless it is perpendicular to the direction of the source of radiation. Computed Tomography (CT), a subset of radiographic testing, is proving useful for the inspection of thermoplastic composite welds.
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Both elements can have toxic effects on soil, plants and hence for humans or animals as consumer. Another opportunity to increase soil fertility besides from using mineral fertilizer is liming. Through liming the pH level and base saturation should be raised to a level more suitable for microorganisms and especially earth worms in the topsoil. Through an increased activity of soil fauna a loosening of the soil and following a higher porosity and improved water and air permeability should be reached.
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Used commercially mainly for aluminium and magnesium alloys, SSM castings can be heat treated to the T4, T5 or T6 tempers. The combination of heat treatment, fast cooling rates (from using uncoated steel dies) and minimal porosity provides excellent combinations of strength and ductility. Other advantages of SSM casting include the ability to produce complex shaped parts net shape, pressure tightness, tight dimensional tolerances and the ability to cast thin walls.10th International Conference Semi-Solid Processing of Alloys and Composites, Eds.
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In a 1992 paper "The Deep Hot Biosphere" in the Proceedings of the National Academy of Sciences,. Gold first suggested that microbial life is widespread in the porosity of the crust of the Earth, down to depths of several kilometers, where rising temperatures finally set a limit. The subsurface life obtains its energy not from photosynthesis but from chemical sources in fluids migrating upwards through the crust. The mass of the deep biosphere may be comparable to that of the surface biosphere.
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In ultra-high vacuum systems, some very odd leakage paths and outgassing sources must be considered. The water absorption of aluminium and palladium becomes an unacceptable source of outgassing, and even the absorptivity of hard metals such as stainless steel or titanium must be considered. Some oils and greases will boil off in extreme vacuums. The porosity of the metallic vacuum chamber walls may have to be considered, and the grain direction of the metallic flanges should be parallel to the flange face.
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Formerly, the Rhine was flowing into the Rhone, until the barrier constituted by the Kaiserstuhl disappeared. Thanks to their porosity, these weak rocks house Europe's largest water table. The estimated water quantity amounts to 300 billions cubic metres (of which 50 billions only in Alsace).Les bords du Rhin, Découverte nature, Éditions Ouest-France Numerous sand and gravel pits can be encountered in the Ried, thus making Alsace one of the most productive regions in France, in terms of building materials.
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Soil moisture is a general term describing the amount of water present in the vadose zone, or unsaturated portion of soil below ground. Since plants depend on this water to carry out critical biological processes, soil moisture is integral to the study of ecohydrology. Soil moisture is generally described as water content, \theta, or saturation, S. These terms are related by porosity, n, through the equation \theta = nS. The changes in soil moisture over time are known as soil moisture dynamics.
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A gram of activated carbon can have a surface area in excess of , with being readily achievable. Carbon aerogels, while more expensive, have even higher surface areas, and are used in special applications. Under an electron microscope, the high surface-area structures of activated carbon are revealed. Individual particles are intensely convoluted and display various kinds of porosity; there may be many areas where flat surfaces of graphite-like material run parallel to each other, separated by only a few nanometers or so.
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Another way of inhibiting dendrite growth that Archer investigated is the incorporation of a porous nanostructured membrane, which prevents the formation of subsurface structures in the lithium electrode. The key nanoscale organic hybrid materials (NOHMs) were formed by grafting polyethylene oxide onto silica, subsequently cross-linked with polypropylene oxide to create strong, porous membranes. The intermediate porosity allows liquid electrolytes to flow but prevents dendrites from passing through. The incorporation of such membranes does not not require significant changes in battery design.
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Examples of synthetic polymers include poly(lactic acid) (PLA), polycaprolactone (PCL), polyurethane (PU), poly(lactic-co-glycolic acid) (PLGA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and poly(ethylene-co- vinylacetate) (PEVA). Polymer chains are connected via covalent bonds. The diameters of nanofibers depend on the type of polymer used and the method of production. All polymer nanofibers are unique for their large surface area-to- volume ratio, high porosity, appreciable mechanical strength, and flexibility in functionalization compared to their microfiber counterparts.
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Taking into account their generally inferior quality compared to forged wheels, the main advantage of cast wheels is the relatively low cost of production. And although cast wheels are more affordable than forged wheels, cast wheels are heavier than forged wheels for a given required load. Manufacturing defects found in cast wheels include cavities or porosity and a different metallurgical microstructure, entailing larger grain size. Cast wheels will tend to fracture upon overbearing high-speed impact, whereas forged wheels will tend to bend.
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NMR logging exploits the large magnetic moment of hydrogen, which is abundant in rocks in the form of water. The NMR signal amplitude is proportional to the quantity of hydrogen nuclei present in a formation and can be calibrated to give a value for porosity that is free from lithology effects. Uniquely, a petrophysicist can also analyse the rate of decay of the NMR signal amplitude to obtain information on the permeability of the formation - a crucial quantity in hydrocarbon exploration.
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Many species have long roots that may reach or more into the soil, which can aid slope stabilization, erosion control, and soil porosity for precipitation absorption. Also, their roots can reach moisture more deeply than other grasses and annual plants during seasonal or climatic droughts. The plants provide habitat and food for insects (including Lepidoptera), birds, small animals and larger herbivores, and support beneficial soil mycorrhiza. The leaves supply material, such as for basket weaving, for indigenous peoples and contemporary artists.
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The Leduc Formation consists of fossil reefs that are highly porous, which makes them excellent reservoirs for oil and gas. They were deposited as limestone and mudstone in shallow water reef environments. Stromatoporoids were the primary reef-building organisms, and rock-types range from skeletal mudstones and floatstones to finer grained muddy packstones and wackestones. Many, but not all, of the reefs were later subjected to dolomitization during diagenesis, which increased their porosity, and they now consist of dolomite rather than limestone.
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Ali Sharif, Tight gas resources in Western Australia, Western Australia Department of Mines and Petroleum, Sept. 2007. Although shales have low permeability and low effective porosity, shale gas is usually considered separate from tight gas, which is contained most commonly in sandstone, but sometimes in limestone. Tight gas is considered an unconventional source of natural gas. Rock with permeabilities as little as one nanodarcy, reservoir stimulation may be economically productive with optimized spacing and completion of staged fractures to maximize yield concerning cost.
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In its type locality, the Collón Curá Formation is characterized by homogeneous greyish- yellow well-consolidated massive vitrocrystalline tuffs without visible sedimentary structures, but with calcareous concretions. The tuffaceous sediments contain pieces of white pumice with a vesicular character up to in size. The volcanic crystals in the tuff comprise andesine, hornblende and hypersthene in an argillaceous matrix. The concretions in the formation can reach up to in size and result from secondary diagenesis replacing the primary porosity of the sediments.
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At extreme levels CO2 is toxic. This suggests a possible negative feedback control of soil CO2 concentration through its inhibitory effects on root and microbial respiration (also called 'soil respiration'). In addition, the soil voids are saturated with water vapour, at least until the point of maximal hygroscopicity, beyond which a vapour-pressure deficit occurs in the soil pore space. Adequate porosity is necessary, not just to allow the penetration of water, but also to allow gases to diffuse in and out.
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In the next step of seismic to simulation, seismic inversion techniques combine well and seismic data to produce multiple equally plausible 3D models of the elastic properties of the reservoir. Seismic data is transformed to elastic property log(s) at every trace. Deterministic inversion techniques are used to provide a good overall view of the porosity over the field, and serve as a quality control check. To obtain greater detail needed for complex geology, additional stochastic inversion is then employed.
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Gore-Tex membrane under an electron microscope In 1969, Gore was researching a process for stretching extruded PTFE into pipe thread tape when he discovered that the polymer could be "expanded" into a porous form of PTFE, characterized by extremely high strength and porosity. He and others had attempted to stretch rods of PTFE by about 10%. His discovery of the right conditions for stretching PTFE was a happy accident, born partly of frustration. Instead of slowly stretching the heated material, he applied a sudden, accelerating yank.
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Quaternary alluvial aquifers and the 20 to 40 meter unconsolidated sands of the Kalahari Group, in western and northeastern Zambia are recharged by rainwater, although the Kalahari Group has some issues with brackish water. Several units of the Katanga Supergroup form consolidated, fracture flow aquifers in the Roan dolomite, Kundelungu limestone, Roan quartzites and Muva Supergroup. Brackish water is held in the unconfined, high porosity Karoo Group sandstones. By contrast, Karoo basalts, interbedded with sandstones and recharged through fractures tend to yield high quality water.
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Manwë has significant and irregular photometric variability, demonstrating that its components are not tidally locked. The surfaces of Manwë and Thorondor appear to be very red. The composition of Manwë is unknown but likely to be mostly ice, because the nominal density (with large uncertainty) is less than that of water. At least one other Kuiper belt object, , has been found with a density of less than 1 g/cm3, which implies an object made mostly of ice with a low rock fraction and high porosity.
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Chart showing seal, source, reservoir, and critical moment of the Mansfield Natural Gas Field. The Utica Shale is a thinly laminated black shale that is high in organic content, and is the primary source rock in the Mansfield Natural Gas Field. The Utica shale is a relatively thin unit ranging from 50 to 90 feet in thickness and when acting as a reservoir it is self-sourced and highly fractured. Due to the presence of the fractures, it then induces porosity in the unit.
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Illustration of seasonal fluctuations in the water table. Specific storage (Ss) and its depth- integrated equivalent, storativity (S=Ssb), are indirect aquifer properties (they cannot be measured directly); they indicate the amount of groundwater released from storage due to a unit depressurization of a confined aquifer. They are fractions between 0 and 1. Specific yield (Sy) is also a ratio between 0 and 1 (Sy ≤ porosity) and indicates the amount of water released due to drainage from lowering the water table in an unconfined aquifer.
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In these cases, very low porosity is desirable and can often be achieved. Sintered metal powder is used to make frangible shotgun shells called breaching rounds, as used by military and SWAT teams to quickly force entry into a locked room. These shotgun shells are designed to destroy door deadbolts, locks and hinges without risking lives by ricocheting or by flying on at lethal speed through the door. They work by destroying the object they hit and then dispersing into a relatively harmless powder.
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At high temperatures, the rate of collagen loss will be accelerated and extreme pH can cause collagen swelling and accelerated hydrolysis. Due to the increase in porosity of bones through collagen loss, the bone becomes susceptible to hydrolytic infiltration where the hydroxyapatite, with its affinity for amino acids, permits charged species of endogenous and exogenous origin to take up residence. # The hydrolytic activity plays a key role in the mineral phase transformations that exposes the collagen to accelerated chemical- and bio- degradation. Chemical changes affect crystallinity.
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Biochar is charcoal produced at relatively low temperatures from a biomass of wood and leafy plant materials in an environment with very low or no oxygen. Amending soil with biochar has been observed to increase the activity of arbuscular mycorrhizal fungi. Tests of high porosity materials such as zeolite, activated carbon and charcoal show that microbial growth substantially improves with charcoal. It may be that small pieces of charcoal migrate within the soil, providing a habitat for bacteria that decompose the biomass in the surface ground cover.
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Compared to porcelain, onggi has a microporous structure and has been found to assist in the fermentation in food processing such as the preparation of gochujang (fermented chili pepper, bean and rice paste), doenjang (fermented bean paste), kimchi (fermented seasoned vegetables), and soy sauce. Onggi with proper porosity and permeability needs to be used in order to produce an optimally ripened quality in fermented foodstuff. Fine-tuned onggi containers are, in fact, suitable for many different kinds of fermented products.Changwon Jeonmun Daehak, 7, 39-64.
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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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Seismic data may be inspected and interpreted on its own without inversion, but this does not provide the most detailed view of the subsurface and can be misleading under certain conditions. Because of its efficiency and quality, most oil and gas companies now use seismic inversion to increase the resolution and reliability of the data and to improve estimation of rock properties including porosity and net pay.Pendrel, J., "Seismic Inversion—A Critical Tool in Reservoir Characterization", Scandinavian Oil-Gas Magazine, No. 5/6, 2006, pp. 19–22 .
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Titanium undergoes allotropic transformation from its α-phase (hexagonal close-packed (hcp) structure at temperatures less than 882.5 °C) to its β-phase (body centered cubic, bcc) structure at temperatures above 882.3 °C). Alpha-phase titanium products typically exhibit medium to high strength with excellent creep strength, whereas beta-phase titanium products typically exhibit very high strength and low ductility. Foams created under thermal cycling conditions have been shown to exhibit increased porosity due to the density difference between allotropic phases. Davis et al.
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These characteristics mean impactors tend to compress the surface, rather than excavating it, and most material that is blown off the surface never returns. The latest analyses of data obtained by Cassini during its flybys of Hyperion in 2005 and 2006 show that about 40 percent of it is empty space. It was suggested in July 2007 that this porosity allows craters to remain nearly unchanged over the eons. The new analyses also confirmed that Hyperion is composed mostly of water ice with very little rock.
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Geochemical evidence suggests these rocks provided most of the basin's oil, and a major pulse of oil generation and migration was in the Cenozoic. The overlying Upper Jurassic-Upper Cretaceous clastic succession, ~ thick, has negligible source potential but contains high-quality reservoirs with largely secondary porosity of ~15% or more. Above, mostly offshore, lie Cenozoic mudstone, sandstone and volcanic deposits, up to ~ thick in some fault-bounded depocenters. The Cenozoic deposits have gas-prone Type III and II kerogen, with up to 2.5% TOC locally.
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Most of the fossilized environments are open sea and marine settings, with abundance of shells and coral fragments. The relation between the sea environments and the less present terrestrial match with the paleogeography of the Lower Toarcian of Europe, where a main sea covered most part of the modern countries, with emerged lands such as the Amoricanian Massif or the Bohemian Massif.Mathia, E. J., Bowen, L., Thomas, K. M., & Aplin, A. C. (2016). Evolution of porosity and pore types in organic-rich, calcareous, Lower Toarcian Posidonia Shale.
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Teeth affected with MIH are at an increased risk of acquiring dental caries. This is because the properties of the enamel are altered by increased porosity and decreased hardness. Essentially, the balance between mineralisation and demineralisation shifts to favour demineralisation of enamel, giving the tooth less resilience in structure, thereby making it vulnerable to caries. The poor structural properties of the enamel in teeth with MIH also increase the likelihood of cavitation of any lesions, thereby causing the lesion to progress at a faster rate.
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Low heat input, caused by low welding current or high welding speed, can limit penetration and cause the weld bead to lift away from the surface being welded. If there is too much heat input, however, the weld bead grows in width while the likelihood of excessive penetration and spatter increases. Additionally, if the welding torch is too far from the workpiece the shielding gas becomes ineffective, causing porosity within the weld. This results in a weld with pinholes, which is weaker than a typical weld.
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Diamond grit in suspension might start at 9 micrometres and finish at one micrometre. Generally, polishing with diamond suspension gives finer results than using silicon carbide papers (SiC papers), especially with revealing porosity, which silicon carbide paper sometimes "smear" over. After grinding the specimen, polishing is performed. Typically, a specimen is polished with a slurry of alumina, silica, or diamond on a napless cloth to produce a scratch-free mirror finish, free from smear, drag, or pull-outs and with minimal deformation remaining from the preparation process.
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Although cover crops can perform multiple functions in an agroecosystem simultaneously, they are often grown for the sole purpose of preventing soil erosion. Soil erosion is a process that can irreparably reduce the productive capacity of an agroecosystem. Dense cover crop stands physically slow down the velocity of rainfall before it contacts the soil surface, preventing soil splashing and erosive surface runoff. Additionally, vast cover crop root networks help anchor the soil in place and increase soil porosity, creating suitable habitat networks for soil macrofauna.
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Petrophysics (from the Greek πέτρα, petra, "rock" and φύσις, physis, "nature") is the study of physical and chemical rock properties and their interactions with fluids. A major application of petrophysics is in studying reservoirs for the hydrocarbon industry. Petrophysicists are employed to help reservoir engineers and geoscientists understand the rock properties of the reservoir, particularly how pores in the subsurface are interconnected, controlling the accumulation and migration of hydrocarbons. Some of the key properties studied in petrophysics are lithology, porosity, water saturation, permeability and density.
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Joseph LeConte, a professor of chemistry and geology at South Carolina University, wrote a pamphlet for the Nitre Bureau on the process for the manufacture of saltpeter in 1862. Nitre beds were constructed of a clay floor, well rammed, that was impervious to water, but with a drain to remove the fluids. Then black earth was added to a raised bed over this floor, made of dark manure. Twigs, leaves and other elements were added to create air passages and porosity through the dirt.
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If the hydrogen concentration in the melt is too high, the resulting casting will be porous; the hydrogen will exit the molten solution, leaving minuscule air pockets, as the metal cools and solidifies. Porosity often seriously deteriorates the mechanical properties of the metal. An efficient way of removing hydrogen from the melt is to bubble a dry, insoluble gas through the melt by purging or agitation. When the bubbles go up in the melt, they catch the dissolved hydrogen and bring it to the surface.
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Modern forging uses machine driven impact hammers or presses which deform the work-piece by controlled pressure. The forging process is superior to casting in that the parts formed have denser microstructures, more defined grain patterns, and less porosity, making such parts much stronger than a casting. All metals and alloys are forge-able, but each will have a forge-ability rating from high to low or poor. The factors involved are the material's composition, crystal structure and mechanical properties all considered within a temperature range.
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In 1974, it win a bid for Federal Oil Shale Lease C-a in the Rio Blanco County. In 1977, the company started preparations to demonstrate its modified in-situ extraction process. The demonstration program included construction of two in-situ retorts using company-developed techniques for rubbling and ignition of the oil shale deposit, and operation the process through surface drill holes. The mining and blasting (3 simultaneous, underground, nuclear explosions ) used in this process created a bed with close to 40% porosity.
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Chalcogen heterocycles capped with MIDA boronates Hydrogen-bonded organic frameworks (HOFs) are porous organic materials that are connected by non-covalent interactions such as hydrogen bonds and π-π interactions. However, due to the relatively weak strength of hydrogen bonds, HOFs rarely exhibit permanent porosity upon removal of solvent molecules. Nonetheless, the weak interactions in HOFs allow the formation of single crystals, which are more amenable to crystallographic studies compared to COFs. Second, HOFs can be easily regenerated through dissolution and recrystallization due to their weak interactions.
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The relatively high estimated density (in stark contrast to many similarly sized TNOs) increases the chance that the object has no internal porosity and has collapsed into hydrostatic equilibrium (a requirement of being certified as a Dwarf Planet), but confirmation of this hypothesis requires observations to refine the size and light curve details, preferably with determination of the orbit of any satellite that may exist. In visible light, this object is neutral or slightly red in color and has a flat, featureless reflectance spectrum.
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In contrast, the foam formed by soap bubbles is composed solely of intact (fully enclosed) bubbles. In a reticulated foam only the lineal boundaries where the bubbles meet (Plateau borders) remain. Foam before reticulation (left), after reticulation (right) The solid component of a reticulated foam may be an organic polymer like polyurethane, a ceramic or a metal. These materials are used in a wide range of applications where the high porosity and large surface area are needed, including filters, catalyst supports, fuel tank inserts, and loudspeaker covers.
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Rubber separators are stable in battery acid and provide valuable electrochemical advantages that other materials cannot. An effective separator must possess a number of mechanical properties; such as permeability, porosity, pore size distribution, specific surface area, mechanical design and strength, electrical resistance, ionic conductivity, and chemical compatibility with the electrolyte. In service, the separator must have good resistance to acid and oxidation. The area of the separator must be a little larger than the area of the plates to prevent material shorting between the plates.
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Vertical stress of a soil Soil resistance is a major aspect in the design and calculation of an earthing system/grounding installation. Its resistance depends on the efficiency of the removal of unwanted currents to zero potential (ground). The resistance of a geological material depends on several components: the presence of metal ores, the temperature of the geological layer, the presence of archeological or structural features, the presence of dissolved salts, and contaminants, porosity and permeability. There are several basic methods for measuring soil resistance.
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Output and sales for the assembly-line cars were down after 1970 largely due to reduced engine compression ratios and a change from gross to net horsepower ratings. In later years, air quality regulations further limited the power in part due to the addition of catalytic converters and single exhaust pipes. However, Stage 2 parts were available over the Buick parts counter although the Stage 2 heads were discontinued after about 75 sets were produced. The discontinuation was due to porosity problems with castings.
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Yields are usually greater than 85% because there is no riser and any metal in the pouring tube just falls back into the ladle for reuse.. The vast majority of LPPM casting are from aluminum and magnesium, but some are copper alloys. Advantages include very little turbulence when filling the mold because of the constant pressure, which minimizes gas porosity and dross formation. Mechanical properties are about 5% better than gravity permanent mold castings. The disadvantage is that cycles times are longer than gravity permanent mold castings.
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Coking is the heating of coal in the absence of oxygen to a temperature above 600 °C, to drive off the volatile components of the raw coal, leaving a hard, strong, porous material of high carbon content, called coke. Coke consists almost entirely of hydrocarbons. The porosity gives it a high surface area, which makes it burn faster (as does a sheet of paper versus a wooden log). When a kilogram of coke is burned it releases more heat than a kilogram of the original coal.
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Due to the high porosity and low density, graphene aerogel has been explored as a potential replacement in flight balloons. The large degree of recoverable compressibility and overall stiffness of the structure has been utilized in studies in graphene sponges capable of both holding 1000x its weight in liquid while recovering all of the absorbed liquid without structural damage to the sponge due to the elasticity of the graphene structure. This has environmental implications potentially contributing to off shore oil cleanup.Chen, Bo, et al. (2015).
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Ripstop nylon is the primary material used in hot air balloons Ripstop nylon is a light-weight nylon fabric with interwoven ripstop reinforcement threads in a crosshatch pattern. The material comes in many different colors, sizes, and thicknesses. It is woven with coarse, strong warp and filling yarns at intervals so that tears will not spread. Ripstop nylon may be waterproof, water resistant, fire resistant, or have zero porosity (will not allow air or water through), and comes in light, medium and heavy weights.
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The melting point of the nickel-phosphorus alloy deposited by the EN process is significanly lower than that of pure nickel (1445 °C), and decreases as the phosphorus content increases, down to 890 °C at about 14% P. The magnetic properties of the coatings decrease with increasing phosphorus contents. Coatings with more than 11.2% P are non-magnetic. Solderability of low-phosphorus coatings is good, but decreases with increasing P contents. Porosity decreases as the phosphorus contents increases, while hardness, wear resistance, and resistance to corrosion increase.
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At a subduction zone, where one plate is diving under another, a thick wedge of sediment tends to form. At first the sediment has 50 to 60 percent porosity; as it is compressed, fluids are expelled to form cold seeps or gas hydrates. Abyssal plains are the region between continental margins and mid-ocean ridges, usually at depths below 4 kilometers. The ocean surface is very poor in nutrients such as nitrate, phosphate and iron, limiting the growth of phytoplankton; this results in low sedimentation rates.
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25143 Itokawa (provisional designation ) is a sub-kilometer near-Earth object of the Apollo group and a potentially hazardous asteroid. It was discovered by the LINEAR program in 1998 and later named after Japanese rocket engineer Hideo Itokawa. The peanut-shaped S-type asteroid has a rotation period of 12.1 hours and measures approximately in diameter. Due to its low density and high porosity, Itokawa is considered to be a rubble pile, consisting of numerous boulders of different sizes rather than of a single solid body.
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His work encompasses a vast breadth of geoscience, administrative, and management areas, including seismic interpretation, seismic data processing, geophysical research, well-logging, computing coordination, emergency preparedness, government relations, and chief scientist. His research work at while at EPR included pioneering work on in well-logging formation/velocity/porosity relationships and in the 3D seismic exploration method. After retirement from Exxon, he joined GeoQuest in 1981; and, in 1983, he was named president of GeoQuest International. In 1986, he resigned his position as president of GeoQuest's Services Division.
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The dimensionality and topology of the 2D COFs result from both the shape of the monomers and the relative and dimensional orientations of their reactive groups. These materials contain desirable properties in fields of materials chemistry including thermal stability, tunable porosity, high specific surface area, and the low density of organic material. By careful selection of organic building units, long range π-orbital overlap parallel to the stacking direction of certain organic frameworks can be achieved. 2D polymerization under thermodynamic control (top) versus kinetic control (bottom).
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Polymers of intrinsic microporosity (PIMs) are a unique class of microporous material developed by research efforts led by Neil McKeown, Peter Budd, et al. PIMs contain a continuous network of interconnected intermolecular voids less than 2 nm in width. Classified as a porous organic polymer, PIMs generate porosity from their rigid and contorted macromolecular chains that do not efficiently pack in the solid state. PIMs are composed of a fused ring sequences interrupted by Spiro-centers or other sites of contortion along the backbone.
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Some discussion has taken place regarding the cause of the flexibility. At one time it was ascribed to the presence of thin scales of mica which were believed to permit a certain amount of motion between adjacent grains of quartz. More probably, however, it is due to the porous character of the rock together with the interlocking junctions between the sand grains. The porosity allows interstitial movement, while the hinge- like joints by which the particles are connected hold them together in spite of the displacement.
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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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A 90% decrease in porosity has also been observed in MICP treated soil. Light microscopic imaging suggested that the mechanical strength enhancement of cemented sandy material is caused mostly due to point- to-point contacts of calcium carbonate crystals and adjacent sand grains. One- dimensional column experiments allowed the monitoring of treatment progration by the means of change in pore fluid chemistry. Triaxial compression tests on untreated and bio-cemented Ottawa sand have shown an increase in shear strength by a factor of 1.8.
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The settled solids are anaerobically digested, reducing the volume of solids. The liquid component flows through the dividing wall into the second chamber, where further settlement takes place. The excess liquid, now in a relatively clear condition, then drains from the outlet into the septic drain field, also referred to as a leach field, drain field or seepage field, depending upon locality. A percolation test is required prior to installation to ensure the porosity of the soil is adequate to serve as a drain field.
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MARMOT is a finite element-based phase field code for modeling irradiation-induced microstructure evolution. MARMOT predicts the effect of radiation damage on microstructure evolution, including void nucleation and growth, bubble growth, grain boundary migration, and gas diffusion and segregation. The phase field equations can be coupled with heat conduction and solid mechanics from ELK to consider the effect of temperature and stress gradients on the evolution. In addition, MARMOT calculates the effect of the microstructure evolution on various bulk material properties, including thermal conductivity and porosity.
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A petroleum reservoir or oil and gas reservoir is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. Petroleum reservoirs are broadly classified as conventional and unconventional reservoirs. In conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability, while in unconventional reservoirs, the rocks have high porosity and low permeability, which keeps the hydrocarbons trapped in place, therefore not requiring a cap rock. Reservoirs are found using hydrocarbon exploration methods.
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Any oxygen in contact with the weld pool, whether from the atmosphere or the shielding gas, causes dross as well. As a result, sufficient flow of inert shielding gases is necessary, and welding in moving air should be avoided. In GMAW the primary cause of porosity is gas entrapment in the weld pool, which occurs when the metal solidifies before the gas escapes. The gas can come from impurities in the shielding gas or on the workpiece, as well as from an excessively long or violent arc.
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Subsequent sublimation of the ice within the SSZ yields a green ceramic preform with porosity in a nearly exact replica of these ice crystals. The microstructure of a freeze-cast within the SSZ is defined by its wavelength (λ) which is the average thickness of a single ceramic wall plus its adjacent macropore. Several publications have reported the effects of solidification kinetics on the microstructures of freeze-cast materials. It has been shown that λ follows an empirical power-law relationship with solidification velocity (υ) (Eq.
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Grain size can be measured by the line-fraction or area-fraction methods of ASTM E112. In the line-fraction methods, a statistical grain size is calculated from the number of grains or grain boundaries intersecting a line of known length or circle of known circumference. In the area-fraction method, the grain size is calculated from the number of grains inside a known area. In each case, the measurement is affected by secondary phases, porosity, preferred orientation, exponential distribution of sizes, and non-equiaxed grains.
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Vitrification is not the only way to stabilize the waste into a form that will not react or degrade for extended periods. Immobilization via direct incorporation into a phosphate based crystalline ceramic host is also used. The diverse chemistry of phosphate ceramics under various conditions demonstrate a versatile material that can withstand chemical, thermal and radioactive degradation over time. The properties of phosphates, particularly ceramic phosphates, of stability over a wide pH range, low porosity and minimization of secondary waste introduces possibilities for new waste immobilization techniques.
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The production of CMC material with high crack resistance requires a step to weaken this bond between the fibers and matrix. This is achieved by depositing a thin layer of pyrolytic carbon or boron nitride on the fibers, which weakens the bond at the fiber/matrix interface, leading to the fiber pull-out at crack surfaces, as shown in the SEM picture at the top of this article. In oxide-CMCs, the high porosity of the matrix is sufficient to establish a weak bond.
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The principles of sintering-based methods are simple ("sinter" has roots in the English "cinder"). The firing is done at a temperature below the melting point of the ceramic. Once a roughly-held-together object called a "green body" is made, it is baked in a kiln, where atomic and molecular diffusion processes give rise to significant changes in the primary microstructural features. This includes the gradual elimination of porosity, which is typically accompanied by a net shrinkage and overall densification of the component.
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These changes are thought to be due to the accumulation of glucosepane in tissue. It is proposed that this is due to a change in the fibril density caused by age-related differences in water retention. Computational studies using all-atom simulations revealed that glucosepane results in less tightly held helical structure in the collagen molecule and increase porosity to water. This was confirmed with water content measurement that showed higher content in Achilles and anterior tibias tendon tissue from older individuals compared to young people.
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The paper for holding the tobacco blend may vary in porosity to allow ventilation of the burning ember or contain materials that control the burning rate of the cigarette and stability of the produced ash. The papers used in tipping the cigarette (forming the mouthpiece) and surrounding the filter stabilize the mouthpiece from saliva and moderate the burning of the cigarette, as well as the delivery of smoke with the presence of one or two rows of small laser- drilled air holes. www.jti.com. Retrieved November 2, 2006.
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Three dimensional computer model of a fracture and fault network (DFN/DFFN), showing the different geological sets in colours, generated by the DMX Protocol using a combination of probabilistic and deterministic procedures Since the mid-1980s, 2D and 3D computer modeling of fault and fracture networks has become common practice in Earth Sciences. Dershowitz, S., Wallmann, P.C., and Doe, T.W. (1992); Discrete feature dual porosity analysis of fractured rock masses: Applications to fractured reservoirs and hazardous waste. In: J.R. Tillerson & W.R. Wawersik (eds. Rock Mechanics.
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Sizing is used during paper manufacture to reduce the paper's tendency when dry to absorb liquid, with the goal of allowing inks and paints to remain on the surface of the paper and to dry there, rather than be absorbed into the paper. This provides a more consistent, economical, and precise printing, painting, and writing surface. This is achieved by curbing the paper fibers' tendency to absorb liquids by capillary action. In addition, sizing affects abrasiveness, creasibility, finish, printability, smoothness, and surface bond strength and decreases surface porosity and fuzzing.
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A basic quality measurement system generally includes basis weight and moisture profile measurements and in addition average basis weight of the paper web and moisture control related to these variables. Caliper is also one of the basic measurements. Other commonly used continuous measurements include: ash content, color, brightness, smoothness and gloss, coat weight, formation, porosity, fiber orientation, and surface properties (topography). QCS is used in paper machines, board machines, tissue machines, pulp drying machines, and other plastic or metal film processes In modern systems QCS applications can be embedded to distributed control systems.
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TEM analysis showed that TaC helps dissolution of carbonitride phase and converts to TaC-binder phase. The resulting is a formation of “black-core-white rim” structure with decreasing grain size in the region of 3-5 wt% TaC addition and increasing transverse rupture strength (TRS). 0-3 wt% TaC region showed a decrease in the TRS because the TaC addition decreases the wettability between binder and carbonitride phase and creates pores. Further addition of TaC beyond 5 wt% also decreases TRS because TaC agglomerates during sintering and porosity again forms.
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Coal plies and particles have different relative densities, determined by vitrinite content, rank, ash value/mineral content and porosity. Coal is usually washed by passing it over a bath of liquid of known density. This removes high-ash value particle and increases the saleability of the coal as well as its energy content per unit volume. Thus, coals must be subjected to a float-sink test in the laboratory, which will determine the optimum particle size for washing, the density of the wash liquid required to remove the maximum ash value with the minimum work.
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Interfacial cross-linking is derived from interfacial polycondensation, and was developed to avoid the use of toxic diamines, for pharmaceutical or cosmetic applications. In this method, the small bifunctional monomer containing active hydrogen atoms is replaced by a biosourced polymer, like a protein. When the reaction is performed at the interface of an emulsion, the acid chloride reacts with the various functional groups of the protein, leading to the formation of a membrane. The method is very versatile, and the properties of the microcapsules (size, porosity, degradability, mechanical resistance) can be customized.
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The earth preferentially attenuates higher frequencies, resulting in the loss of signal resolution as the seismic wave propagates. Quantitative seismic attribute analysis of amplitude versus offset effects is complicated by anelastic attenuation because it is superimposed upon the AVO effects.Dasgupta, R., & Clark, R.A. (1998) Estimation of Q from surface seismic reflection data. Geophysics 63, 2120-2128 The rate of anelastic attenuation itself also contains additional information about the lithology and reservoir conditions such as porosity, saturation and pore pressure so it can be used as a useful reservoir characterization tool.
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Phosphate coatings are often used to provide corrosion resistance—however, phosphate coatings alone do not provide this because the coating is porous, so oil or another sealer are used to achieve corrosion resistance. Zinc and manganese coatings are used to help break in components subject to wear and help prevent galling. Most phosphate coatings serve as a surface preparation for further coating and/or painting, a function they perform effectively, with excellent adhesion and electric isolation. The porosity allows the additional materials to seep into the phosphate coating after drying and become mechanically interlocked.
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The fines are then blended with alloy additions; cold compacted into a green compact at up to 415 MPa then vacuum sintered at 1260 °C to produce a 99.5% dense component. Hot isostatic pressing (HIP) can further increase the density of these parts and produce components more economically than cast or wrought parts, but the porosity present in the material degrades fatigue and fracture properties. The BE approach has been used to produce valves for the Toyota Altezza, golf club heads and softball bats.F.H. Froes Developments in Titanium P/M.
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Sheets of greaseproof paper Greaseproof paper is paper that is impermeable to oil or grease and is normally used in cooking or food packaging. Normally greaseproof paper is produced by refining the paper stock and thus create a sheet with very low porosity. This sheet is passed between hard pressure rollers (supercalendered) to further increase the density, creating a paper called glassine. The glassine is treated with starches, alginates or carboxymethyl cellulose (CMC) in a size press to fill pores or treat the paper chemically to make it fat repellent.
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Douglas, J. G., 1976, Gippsland Basin; in Douglas, J. G., Abele, C., Benedek, S. Dettmann, M. E., Kenley, P. R., and Lawrence, C. R., Chapter 7, Mesozoic; in Douglas, J. G., and Ferguson, J. A., eds., Geology of Victoria, Geological Society of Australia Special Publication No. 5, p.158-176. The coals and shales of this group are the main source rock in this field, and throughout the basin. Sandstone from this group makes up the reservoir rocks, and exhibits a porosity of 20-25%, and a permeability of 5000-7000 millidarcies.
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The term "gel" in this instance refers to the matrix used to contain, then separate the target molecules. In most cases, the gel is a crosslinked polymer whose composition and porosity are chosen based on the specific weight and composition of the target to be analyzed. When separating proteins or small nucleic acids (DNA, RNA, or oligonucleotides) the gel is usually composed of different concentrations of acrylamide and a cross- linker, producing different sized mesh networks of polyacrylamide. When separating larger nucleic acids (greater than a few hundred bases), the preferred matrix is purified agarose.
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Kern Front Oil Field Structure Map The Kern Front Field contains two major producing units, the Etchegoin Formation and the Chanac, both sedimentary, but unconformably overlain. The Etchegoin is a Pliocene marine sand, and the Chanac is a Pliocene non-marine sand. Each is interbedded with silts and clays, and the sands have a high porosity, ranging from 25-33 percent, making them singularly suitable as petroleum reservoirs. Overlying the Etchegoin and Chanac formations is the Pleistocene Kern River Formation, which is highly productive in the adjacent Kern River Oil Field.
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The Nova Argon introduced in 2000 was DHV certified with unsheathed Kevlar lines, which greatly reduced drag in flight. The introduction of the Nova Carbon in 2001 resulted in delays filling customer orders as demand exceeded the ability of the fabric manufacturer to provide the cloth for construction. In 2002 The Carbon wing developed porosity in the field after delivery to customers, resulting in parachute-like descents. The fault lay with a batch of fabric which the fabric manufacturer had sub-contracted to a new factory and which had produced a sub-standard product.
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"The bricks that built the Black Country", Black Country Bugle, 12 May 2014 accessed 30 June 2016 This type of brick was used for foundations and was extensively used for bridges and tunnels in canal construction, and later, for railways. Its lack of porosity makes it suitable for capping brick walls, and its hard-wearing properties makes it ideal for steps and pathways. It is also used as a general facing brick for decorative reasons. Staffordshire Blue bricks have traditionally been "Class A" with a water absorption of less than 4.5%.
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Air permeability is a measure of the ability of air to pass through a fabric. Air permeability is defined as "the volume of air in cubic centimetres (cm3) which is passed through in one second through 100cm2 of the fabric at a pressure difference of 10 cm head of water", also known as the Gurley unit. Factors that affect air permeability include porosity, fabric thickness and construction, yarn density, twist, and crimp, layering, and moisture within the fabric. The concept of air permeability is important for the design of active wear and insect netting.
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At the same time, convective flow and finite strength of the mantle lead to long- wavelength planetary-scale free-air gravity anomalies over the entire planet. Variation in crustal thickness, magmatic and volcanic activities, impact- induced Moho-uplift, seasonal variation of polar ice caps, atmospheric mass variation and variation of porosity of the crust could also correlate to the lateral variations. Over the years models consisting of an increasing but limited number of spherical harmonics have been produced. Maps produced have included free-air gravity anomaly, Bouguer gravity anomaly, and crustal thickness.
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Metis has an irregular shape and measures 60 × 40 × 34 km across, which makes it the second smallest of the four inner satellites of Jupiter. Therefore, a very rough estimate of its surface area could be placed between 5,800 and 11,600 square kilometers (approx. 8,700). The bulk composition and mass of Metis are not known, but assuming that its mean density is like that of Amalthea (~0.86 g/cm3), its mass can be estimated as ~3.6×1016 kg. This density would imply that it is composed of water ice with a porosity of 10–15%.
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Shielding gas became a subject receiving much attention, as scientists attempted to protect welds from the effects of oxygen and nitrogen in the atmosphere. Porosity and brittleness were the primary problems, and the solutions that developed included the use of hydrogen, argon, and helium as welding atmospheres. During the following decade, further advances allowed for the welding of reactive metals like aluminum and magnesium. This in conjunction with developments in automatic welding, alternating current, and fluxes fed a major expansion of arc welding during the 1930s and then during World War II.Lincoln Electric, p.
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Mass movements that occur during sintering consist of the reduction of total porosity by repacking, followed by material transport due to evaporation and condensation from diffusion. In the final stages, metal atoms move along crystal boundaries to the walls of internal pores, redistributing mass from the internal bulk of the object and smoothing pore walls. Surface tension is the driving force for this movement. A special form of sintering (which is still considered part of powder metallurgy) is liquid-state sintering in which at least one but not all elements are in a liquid state.
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This process begins by roasting concentrates that are mixed with coal and briquetted in two stages. The briquettes are then heated in an autogenous coker at and then charged into the retort. There are three reasons to briquette the calcine: to ensure free downward movement of the charge; to permit heat transfer across a practical size cross-section; to allow adequate porosity for the passage of reduced zinc vapour to the top of the retort. The reduced zinc vapour that is collected at the top of the retort is then condensed to a liquid.
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Biochar is capable of decreasing soil acidity and if soaked in nutrient rich liquid can slowly release nutrients and provide habitat for microbes in soil due to its high porosity surface area. The goal is an economically viable process that could be included in modern agriculture. Average poor tropical soils are easily enrichable to terra preta nova by the addition of charcoal and condensed smoke. Terra preta may be an important avenue of future carbon sequestration while reversing the current worldwide decline in soil fertility and associated desertification.
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Species that feed on decaying plant material open drainage and aeration channels in the soil by removing roots. Fecal material of soil mesofauna remains in channels which can be broken down by smaller animals. Soil mesofauna do not have the ability to reshape the soil and, therefore, are forced to use the existing pore space in soil, cavities, or channels for locomotion. Soil Macrofauna, earthworms, termites, ants and some insect larvae, can make the pore spaces and hence can change the soil porosity, one aspect of soil morphology.
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The space-holder technique is the most commonly employed method for producing titanium foams. The space-holder technique allows for the fabrication of higher porosity foams (35–80% ) than other techniques, while also giving the engineer more control over pore fraction, shape and connectivity. Mechanical properties can be adjusted through the size, shape and quantity of space-holders employed. The space-holder technique was first demonstrated by Zhao and Sun for the fabrication of aluminum foams in a powder metallurgical method, which consisted of the incorporation of NaCl as a space-holder.
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The degree of homogeneity in pore distribution of the final product is primarily dependent on the adequacy of mixing of the precursor. The difference in particle size between the titanium powders and the spacers directly impacts the ability to adequately mix the preform. The greater the size difference, the more difficult it is to control this process. Nonhomogeneous mixing resulting from the use of spacers considerably larger than the titanium particles employed and has shown adverse effects in the stability of the precursor after removal of spacer and in the distribution of porosity.
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Potential structural applications for titanium foams include their general incorporation into light-weight structures and as components for mechanical energy absorption. The most important considerations for the use of titanium foams in structural applications includes their porosity, specific strength, ductility in compression and cost. Because of low manufacturing costs, most metal foams marketed for structural applications are of a close- celled aluminum variety. In comparison, titanium foam manufacturing incurs a higher cost, but this cost is defensible in space applications where the material offers an otherwise incomparable reduction in overall weight.
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Natural bone exhibits the ability to adjust local fiber away from the low-stress regions toward high stress regions through the distribution of porosity, thus maximizing overall comfort. Using finite element analysis, researchers examined the effect of filling pores with bone on mechanical properties. They concluded that bone ingrowth significantly improved the mechanical properties, evidenced by decreased localized plasticity and stress concentrations. In effect, the titanium foam in the study allowed the bone to exhibit its natural ability to adjust local fiber away from the low-stress regions toward high stress regions.
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Soil composition by Volume and Mass, by phase: air, water, void (pores filled with water or air), soil, and total. Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, crops, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ratio, which can range from 0 (completely dry) to the value of the materials' porosity at saturation. It can be given on a volumetric or mass (gravimetric) basis.
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Selective laser melting is very useful as a full-time materials and process engineer. Requests such as requiring a quick turnaround in manufacturing material or having specific applications that need complex geometries are common issues that occur in industry. Having SLM would really improve the process of not only getting parts created and sold, but making sure the properties align with whatever is needed out in the field. Current challenges that occur with SLM are having a limit in processable materials, having undeveloped process settings and metallurgical defects such as cracking and porosity.
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Normally, the mixtures are made with primarily helium (often about 75% or higher) and a balance of argon. These mixtures increase the speed and quality of the AC welding of aluminum, and also make it easier to strike an arc. Another shielding gas mixture, argon-hydrogen, is used in the mechanized welding of light gauge stainless steel, but because hydrogen can cause porosity, its uses are limited. Similarly, nitrogen can sometimes be added to argon to help stabilize the austenite in austenitic stainless steels and increase penetration when welding copper.
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Although the wells indicate a potentially productive source rock, they also indicate that many of the target reservoirs are composed of volcaniclastic rocks with low porosity due to secondary mineralisation and are thus unlikely to store hydrocarbons in large quantities. This is not an anomalous view based solely on published data from one well, but based on information from multiple sources. Volcaniclastic-rich deposits are probably present in many parts of the basin, which is to be expected, given the major volcanic sediment source that lay to the west at the time of sedimentary deposition.
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Vacuum pressure casting (VPC), properly referred to as vacuum assist direct pour, uses gas pressure and a vacuum to improve the quality of the casting and minimize porosity. Typically VPC machines consist of an upper and a lower chamber—the upper chamber, or melting chamber, housing the crucible, and the lower casting chamber housing the investment mould. Both chambers are connected via a small hole containing a stopper. A vacuum is pulled in the lower chamber, while pressure is applied in the upper, and then the stopper is removed.
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There are several ways to determine the porosity of aerogel: the three main methods are gas adsorption, mercury porosimetry, and scattering method. In gas adsorption, nitrogen at its boiling point is adsorbed into the aerogel sample. The gas being adsorbed is dependent on the size of the pores within the sample and on the partial pressure of the gas relative to its saturation pressure. The volume of the gas adsorbed is measured by using the Brunauer, Emmit and Teller formula (BET), which gives the specific surface area of the sample.
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Lastly, a chemical response allows for a severe inflammatory reaction during attempted tissue-mesh integration, including fibroblastic cell proliferation. Ultimately, the goal for surgical mesh creation is to formulate one that has a minimal in vivo reaction to maximize comfort for the patient, avoid infection, and ensure clean integration into the body for tissue repair. A number of factors play into mesh biocompatibility. Mesh porosity is the ratio of pore to total area, and plays a role in the development of either bacterial infection or smooth tissue regeneration depending on pore size.
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The Non-limiting water range (NLWR) represents the range of water content in the soil where limitations to plant growth (such as water potential, air- filled porosity, or soil strength) are minimal. John Letey (1985) from UC Riverside introduced the NLWR concept in an attempt to integrate several physical properties associated with plant or root growth to refine the concept of available water capacity. Alvaro Pires da Silva, Bev Kay. and Ed Perfect (University of Guelph, Ontario) (1994) refined the concept and termed it least limiting water range (LLWR).
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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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Mudrocks, especially black shale, are the source and containers of precious petroleum sources throughout the world. Since mudrocks and organic material require quiet water conditions for deposition, mudrocks are the most likely resource for petroleum. Mudrocks have low porosity, they are impermeable, and often, if the mudrock is not black shale, it remains useful as a seal to petroleum and natural gas reservoirs. In the case of petroleum found in a reservoir, the rock surrounding the petroleum is not the source rock, whereas black shale is a source rock.
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Most petrophysicists are employed (SS) to compute what are commonly called conventional (or reservoir) petrophysical properties. These are: Lithology: A description of the rock's physical characteristics, such as grain size, composition and texture. By studying the lithology of local geological outcrops and core samples, geoscientists can use a combination of log measurements, such as natural gamma, neutron, density and resistivity, to determine the lithology down the well. Porosity: \phi (Anti=tattilization)The percentage of a given volume of rock that is pore space and can therefore contain fluids.
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The diffraction pattern is recorded in the far field using electron imaging plates to a resolution of 0.0025 1/Å. Using a typical HIO reconstruction method an image is produced with Å resolution in which the DWCNT chirality (lattice structure) can be directly observed. Zuo found that it is possible to start with non- random phases based on a low resolution image from a TEM to improve the final image quality. LEFT Volume representation of a particle formed by a collection of octahedral Si nanoparticles, RIGHT The central slice showing the high degree of porosity.
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In the fabrication of solid oxide fuel cells EPD techniques are widely employed for the fabrication of porous ZrO2 anodes from powder precursors onto conductive substrates. EPD processed have a number of advantages which have made such methods widely used"Electrodeposition of nanostructured coatings and their characterization – a review" Sci. Technol. Adv. Mater. 9 (2008) 043001 (free download) #The process applies coatings which generally have a very uniform coating thickness without porosity. #Complex fabricated objects can easily be coated, both inside cavities as well as on the outside surfaces.
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Porous asphalt is produced and placed using the same methods as conventional asphalt concrete; it differs in that fine (small) aggregates are omitted from the asphalt mixture. The remaining large, single-sized aggregate particles leave open voids that give the material its porosity and permeability. To ensure pavement strength, fiber may be added to the mix or a polymer-modified asphalt binder may be used. Generally, porous asphalt pavements are designed with a subsurface reservoir that holds water that passes through the pavement, allowing it to evaporate and/or percolate slowly into the surround soils.
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One improvement over the standard design of ceramic vacuum filter is to use serialized pore size distributions of non-fibrous porous ceramic filters. The porosity of this type of ceramic can be varied from 20% to 60% by volume, which allows a low- pressure drop of liquid and gas flow. Custom sizes from 1 mm diameter/0.5 mm bore of porous ceramic filters are available for a range of designs. A non- fibrous porous ceramic filter is more resistant in alkaline and acidic conditions compared to fibrous ceramic filters.
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Additional applications of SiC/SiC CMCs include combustion and turbine section components of aero-propulsion and land-based gas turbine engines, thermal protection systems, thruster nozzles, reusable rocket nozzles, and turbopump components for space vehicles. With the development and implementation of future SiC/SiC CMCs, the SiC fiber creep and rupture properties must be examined. Defects such as grain size, impurities, porosity, and surface toughness all contribute to SiC fiber creep and rupture. Due to relatively low toughness, low damage tolerance, and large variability in mechanical properties, CMCs have been limited to less critical components.
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It would therefore appear desirable to process a material in such a way that it is physically uniform with regard to the distribution of components and porosity, rather than using particle size distributions which will maximize the green density. The containment of a uniformly dispersed assembly of strongly interacting particles in suspension requires total control over particle-particle interactions. A number of dispersants such as ammonium citrate (aqueous) and imidazoline or oleyl alcohol (nonaqueous) are promising solutions as possible additives for enhanced dispersion and deagglomeration. Monodisperse nanoparticles and colloids provide this potential.
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The use of solid freeform fabrication in design of composite scaffolds When designing implanted biomaterials, key criteria are biocompatibility, osteoconductivity, high porosity and biomechanics compatibility. Artificial bone was initially made of materials like metals and solid ceramics, which are strong enough to sustain the loading in bone. However, the rigidity of those materials created an enormous burden on patients and was not consistent with the criteria for implanting biomaterials. Artificial bones made of metal and ceramic tend to do poorly in terms of biocompatibility since it is difficult to blend into bone tissues.
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The hills consist of Precambrian igneous and metamorphic rock, the oldest of which are about 670 million years old. The rocks are characterised by low porosity and high secondary permeability via fissures. Malvern water is rainwater and snow meltwater that percolates through fissures created by the pressures of tectonic movements about 300 million years ago when advancing sedimentary layers of Silurian shale and limestone were pushed into and under older Precambrian rock. When the fissures are saturated, a water table forms and the water emerges as springs around the fault lines between the strata.
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The cementation exponent models how much the pore network increases the resistivity, as the rock itself is assumed to be non-conductive. If the pore network were to be modelled as a set of parallel capillary tubes, a cross-section area average of the rock's resistivity would yield porosity dependence equivalent to a cementation exponent of 1. However, the tortuosity of the rock increases this to a higher number than 1. This relates the cementation exponent to the permeability of the rock, increasing permeability decreases the cementation exponent.
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The sandstone retains its porosity, is hardened by the strength of its grain structure and thus its abrasion resistance is increased. Schwarzes Loch ("Black Hole") The area of Mühlsteinbrüche has as additional geological feature: its pronounced columnar sandstone. Its best known rock formation is the Große und Kleine Orgel ("Great and Little Organ"), whose appearance is easily confused with that of columnar basalt. The columns, which are completely atypical for sandstone, have a diameter of up to 15 centimetres and are bundled vertically on a solid, non- columnar sandstone block.
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The most common quality problems associated with SMAW include weld spatter, porosity, poor fusion, shallow penetration, and cracking. Weld spatter, while not affecting the integrity of the weld, damages its appearance and increases cleaning costs. Secondary finishing services are often required due to the aesthetic appearance caused by the occurrence of molten splatter. It can be caused by excessively high current, a long arc, or arc blow, a condition associated with direct current characterized by the electric arc being deflected away from the weld pool by magnetic forces.
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The Bungle Bungle Range, lying fully within the park, has elevations as high as above sea level. It is famous for the sandstone domes, unusual and visually striking with their striping in alternating orange and grey bands. The banding of the domes is due to differences in clay content and porosity of the sandstone layers: the orange bands consist of oxidised iron compounds in layers that dry out too quickly for cyanobacteria to multiply; the grey bands are composed of cyanobacteria growing on the surface of layers of sandstone where moisture accumulates.
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The Vaqueros Formation is a sedimentary geologic unit primarily of Upper Oligocene and Lower Miocene age, which is widespread on the California coast and coastal ranges in approximately the southern half of the state. It is predominantly a medium-grained sandstone unit, deposited in a shallow marine environment. Because of its high porosity and nearness to petroleum source rocks, in many places it is an oil-bearing unit, wherever it has been configured into structural or stratigraphic traps by folding and faulting. Being resistant to erosion, it forms dramatic outcrops in the coastal mountains.
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Current observations are consistent with Phobos being a rubble pile. In addition, images obtained by the Viking probes in the 1970s clearly showed a natural object, not an artificial one. Nevertheless, mapping by the Mars Express probe and subsequent volume calculations do suggest the presence of voids and indicate that it is not a solid chunk of rock but a porous body.Clark, Stuart; "Cheap Flights to Phobos" in New Scientist magazine, 30 January 2010 The porosity of Phobos was calculated to be 30% ± 5%, or a quarter to a third being empty.
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Modern glass bricks were preceded by Falconnier Hollow Glass Bricks in the late nineteenth century. Falconnier Bricks were blown glass bricks available in multiple colors and were formed in molds while the glass was molten. An early 20th century summary of glass brick use: The Falconnier bricks could be used for walls or roofs and were joined together with wire and cement. The suggested use for Falconnier glass bricks was in greenhouse construction due to the non- conductivity of the glass for temperature control and lack of porosity of glass for moisture control.
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The methods include: Visual Inspection (VT) is typically the first option for any attempt at NDT, being the least expensive, as it requires the least specialized training and usually few if any special tools. Defects on the surfaces of thermoplastic composite welds can be detected visually if they are of sufficient size. Weld defects such as misalignment, porosity, lack of fusion and degradation of the matrix and/or fibers may be visually apparent. Subsurface defects may not be visible, unless the composite matrix was nearly transparent and the embedded fibers did not obscure them.
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A high-performance software for the simulation of casting processes provides opportunities for an interactive or automated evaluation of results (here, for example, of mold filling and solidification, porosity and flow characteristics). Picture: Componenta B.V., The Netherlands) Casting process simulation uses numerical methods to calculate cast component quality considering mold filling, solidification and cooling, and provides a quantitative prediction of casting mechanical properties, thermal stresses and distortion. Simulation accurately describes a cast component's quality up-front before production starts. The casting rigging can be designed with respect to the required component properties.
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Dye penetrant inspection (DP), also called liquid penetrate inspection (LPI) or penetrant testing (PT), is a widely applied and low-cost inspection method used to check surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). The penetrant may be applied to all non-ferrous materials and ferrous materials, although for ferrous components magnetic- particle inspection is often used instead for its subsurface detection capability. LPI is used to detect casting, forging and welding surface defects such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks on in-service components.
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Therefore RANKL can more readily bind to RANK and cause the increased osteoclastogenesis and bone resorption seen in osteoporosis. Decreased estrogen is a common cause of osteoporosis that can be seen in other conditions such as ovariectomy, ovarian failure, anorexia, and hyperprolactinaemia. Osteoblastic synthesis of bone does not increase to compensate for the accelerated bone resorption as the lower estrogen levels result in increased rates of osteoblast apoptosis. The higher rate of bone resorption compared to bone formation leads to the increased porosity and low bone mineral density of individuals with osteoporosis.
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CMPs have been investigated for several applications since their discovery. Surface areas in CMPs can exceed 1000 m2/g in many cases, although related porous aromatic frameworks, which lack extended conjugation, can have much higher surface areas of more than 5500 m2/g. The porosity of these materials has led to their evaluation as sorbents. Recent work has focused on their potential in terms of catalysis, for example in the form of 'metal-organic CMPs', and also for light harvesting, and supercapacitors taking advantage of their highly conjugated nature.
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Claude Ledoux is a Belgian composer, born in 1960. Claude Ledoux, photograph by Nao Momitani For many years now, the composer has explored the idea of "musical crossing borders" as he attempts to reflect our fragmented world in his musical processes. As a result, his works has been marked by interactions between contemporary sounds and popular musics, non-European idioms and technology. His recent works, accordingly, demonstrate this interest in the "cultural porosity" in which emotion arises from geographical and historical encounters, linking spirituality to the most sensual aspects of our material existence.
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Also included is a small catalog of unsaturated soil hydraulic properties, as well as pedotransfer functions based on neural networks. Both HYDRUS models also consider various provisions for simulating non-equilibrium flow and transport. The flow equation for the latter purpose can consider dual-porosity-type flow with a fraction of the water content being mobile, and a fraction immobile. The transport equations additionally were modified to allow consideration of kinetic attachment/detachment processes of solutes to the solid phase, and hence of solutes having a finite size.
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Use a high quality mature compost to avoid nutrient and oxygen competition with plants. In a container garden, as in bedding mixes, compost may be a beneficial ingredient in potting media, used up to 30 percent of the total mix, depending on salinity and maturity. It is considered a partial substitute for peat moss, but generally lacks the porosity and water-holding capacity of peat so must be used in limited percentages. The nutrient content of compost can also reduce the need for supplemental chemical fertilizers, although this has to be determined in each situation.
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As these shadows receive no insolation, most of the heat they receive is scattered and emitted radiation from the surrounding topography. Usually, horizontal heat conduction from adjacent warmer areas can be neglected due to the high porosity and therefore low thermal conductivity of the uppermost layers of airless bodies. Consequently, the temperatures of these permanent shadows can be modeled using ray casting or ray tracing algorithms coupled with 1D vertical heat conduction models. In some cases, such as bowl-shaped craters, it is possible to obtain an expression for the equilibrium temperature of these shadows.
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Schematic of the Sumatra Trench and the associated island arcs and back- arc regions Ocean crust forms at mid-ocean ridges and is removed by subduction. The top half kilometer or so is a series of basaltic flows, and only this layer has enough porosity and permeability to allow fluid flow. Less suitable for life are the layers of sheeted dikes and gabbros underneath. Mid- ocean ridges are a hot, rapidly changing environment with a steep vertical temperature gradient, so life can only exist in the top few meters.
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AutoCAST is a software program for casting methods design, simulation and optimization developed by Indian Institute of Technology Bombay. It uses geometric reasoning for automating the design of casting methods elements – cores, mold cavity layout, feeders, feed aids and gating channels. Fast and intelligent simulation technology is employed to visualize mold filling and casting solidification in near-real time. Foundry engineers can quickly import a 3D model of cast part, create methods elements, simulate the casting, predict internal defects (like shrinkage porosity and sand inclusion), and modify the methods design to improve quality and yield.
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The anode material typically consists of a porous (3-6 μm, 45-70% material porosity) Ni based alloy. Ni is alloyed with either Chromium or Aluminum in the 2-10% range. These alloying elements allow for formation of LiCrO2/LiAlO2 at the grain boundaries, which increases the materials' creep resistance and prevents sintering of the anode at the high operating temperatures of the fuel cell. Recent research has looked at using nano Ni and other Ni alloys to increase the performance and decrease the operating temperature of the fuel cell.
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By varying the degree of cross-linking, the fractionation properties of the gel can be altered. These highly specialized gel filtration and chromatographic media are composed of macroscopic beads synthetically derived from the polysaccharide dextran. The organic chains are cross-linked to give a three-dimensional network having functional ionic groups attached by ether linkages to glucose units of the polysaccharide chains. Available forms include anion and cation exchangers, as well as gel filtration resins, with varying degrees of porosity; bead sizes fall in discrete ranges between 20 and 300 µm.
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Rosalind Franklin worked on porosity of coal during World War II. Victor Goldschmidt lectured on rare elements in coal ash during World War II. Marcello Pirani was scientific consultant during 1941—1947, concerned with carbonaceous materials resistant to high temperatures. The family of John G. Bennett have a web site that contains information about him and BCURA Peter H. Given, Head of Organic Chemistry, went on to Pennsylvania State University, achieving distinction in U.S. BCURA activities were subject of a review published in Nature Volume 153 Number 3873 p 104 (22 January 1944).
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Because of Ina's extreme porosity, the researchers say, its craters are much smaller than they would normally be, and many craters might not be visible at all. That could drastically alter the age estimate derived from crater counts. The researchers estimate that the porous surface would reduce by a factor of three the size of craters on Ina's mounds. In other words, an impactor that would make a 100-foot-diameter crater in lunar basalt bedrock would make a crater of a little over 30 feet in a foam deposit.
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The fort is located in the Chiltern Hills at an altitude of over . The porosity of the ground in the area severely limited the availability of surface water, essential for livestock, and therefore precluded year-round settlement adjacent to most of the upland pastures. However, there are two aquifer-fed water sources: Holy (or Holly) and Bury Ponds. The constancy of this supply, over many hundreds of years, is cited as being crucial to the decision as to where to site the hill fort and for the early establishment of the isolated community at Cholesbury.
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Multiple theories explaining the origin of this lake have been formulated. One version is that it is the remnants of a post-glacial lake, which has undergone drastic changes in size over the years and the other theory is that it is of fluvial origin from an old flood spill channel or ox- bows of the Jhelum River. The dendritic drainage pattern of the catchment signifies that its rock strata have low levels of porosity. Lithologically, a variety of rock types have been discerned namely, igneous, metamorphic and sedimentary.
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As the carbon dioxide content increases over 20%, spray transfer GMAW becomes increasingly problematic, especially with smaller electrode diameters. Argon is also commonly mixed with other gases, oxygen, helium, hydrogen and nitrogen. The addition of up to 5% oxygen (like the higher concentrations of carbon dioxide mentioned above) can be helpful in welding stainless steel, however, in most applications carbon dioxide is preferred. Increased oxygen makes the shielding gas oxidize the electrode, which can lead to porosity in the deposit if the electrode does not contain sufficient deoxidizers.
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Carbon dioxide can be separated from air or flue gas with absorption, adsorption, membrane gas separation, or gas hydrates technologies. Absorption, or carbon scrubbing, with amines is the dominant capture technology. Carbon dioxide adsorbs to a MOF (Metal–organic framework) through physisorption or chemisorption based on the porosity and selectivity of the MOF leaving behind a Greenhouse gas poor gas stream that is more environmentally friendly. The carbon dioxide is then stripped off the MOF using temperature swing adsorption (TSA) or pressure swing adsorption (PSA) so the MOF can be reused.
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Three common quantitative analyses of microstructures are grain size, second-phase content and porosity. Microstructures are measured by the principles of stereology, in which three- dimensional objects are evaluated in 2-D by projections or cross-sections. Microstructures exhibiting heterogeneous grain sizes, with certain grains growing very large, occur in diverse ceramic systems and this phenomenon is known as abnormal grain growth or AGG. The occurrence of AGG has consequences, positive or negative, on mechanical and chemical properties of ceramics and its identification is often the goal of ceramographic analysis.
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At such burial depths, the density of rock salt is slightly decreased as a result of thermal expansion. However, unlike rock salt, as the burial depth increases, shale and most other sedimentary rocks decrease in porosity and increase in density progressively. In the first 1000 m of burial depth, rock salt has a higher density compared with other rocks such as shale. When the buried material reaches a critical depth of 1.2-1.3 km, the density of rock salt and other rocks are roughly the same, where neutral buoyancy is reached.
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Journal of Nanoparticle Research, 15(6), 1676. doi: 10.1007/s11051-013-1676-4 as vesicles for the delivery of genetic information. . These methods typically rely on functionalization of the surface or manipulation of porosity of a nanocarrier in order to optimize the loading and delivery of genetic information. DNA nanostructures have been shown to be a highly programmable modality in terms of delivery of small interfering RNA (siRNA), exploring the optimal design parameters necessary for plant cell internalizationZhang, H., Demirer, G., Ye, T., Goh, N., Aditham, A., Cunningham, F., Fan, C., & Landry, M. (2019).
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Dip coating of inorganic sols (or so-called sol-gel synthesis) is a way of creating thin inorganic or polymeric coatings. In sol-gel synthesis the speed of deposition is an important parameter that affects, for example, layer thickness, density and porosity. The sol-gel technique is a deposition method that is widely used in material science to create protective coatings, optical coatings, ceramic coatings and similar surfaces. This technique starts with the hydrolysis of a liquid precursor (sol), which undergoes poly-condensation to gradually obtain a gel.
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Due to complex geometry, it may be necessary to cut the sheets to place them more easily in the lower mould. Then, while the upper mould cavity is closing, the material is pushed throughout the mould until closed. Pressure is maintained, together with elevated temperature, to allow the curing of the resin and low porosity. This stage has a heavy influence on the mechanical performances of the final product, as the viscous flow into the mold cavity tends to orient the fibers along the direction of the flow.
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Barron was the first to discover that nanoparticle derived ceramics could be designed to have intra-granular porosity, meaning that the pores are within the crystal grain rather than between the crystal grains as normally observed. This had implications in composites and in membranes and separation processes. Through his research, Barron developed a process that forms hollow spheres of ceramic with exceptional crush strength. Barron rationalized that if hollow ceramic spheres could be made on a large scale they could replace dense ceramics being used in oil extraction and minimize waste.
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Bakken oil: tight, sweet, low porosity, low permeability (difficult to extract);State of North Dakota Bakken Formation Reserve Estimates. Adapted from CSUR "Understanding Tight Oil" The Bakken shale oil and gas boom underway since 2009, driven by hydraulic fracturing technologies, has contributed to record growth, high employment rates and increase in population, in the province of Saskatchewan. Hydraulic fracturing has benefited small towns like Kindersley which saw its population increase to over 5,000 with the boom. Kindersley sells its treated municipal wastewater to oilfield service companies to use in hydraulic fracturing.
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One should in principle be able to achieve the ultimate in homogeneity of distribution and thereby optimize composite performance. This can also have other ramifications, such as allowing more useful composite performance to be achieved in a body having porosity, which might be desired for other factors, such as limiting thermal conductivity. There are also some opportunities to utilize melt processing for fabrication of ceramic, particulate, whisker and short-fibre, and continuous-fibre composites. Clearly, both particulate and whisker composites are conceivable by solid-state precipitation after solidification of the melt.
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This statistical approach creates multiple, equi-probable models consistent with the seismic, wells, and geology. Geostatistical inversion simultaneously inverts for impedance and discrete properties types, and other petrophysical properties such as porosity can then be jointly cosimulated. The output volumes are at a sample rate consistent with the reservoir model because making synthetics of finely sampled models is the same as from well logs. Inversion properties are consistent with well log properties because the histograms used to generate the output rock properties from the inversion are based on well log values for those rock properties.
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Motealleh M., Kharrat R., Hashemi A. N, An Experimental Investigation of Water-Alternating-CO2 Coreflooding in a Carbonate Oil Reservoir in Different Initial Core Conditions, Journal of Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Volume: 35, Issue: 13 (2013) pages 1187 - 1196\. 107\. Bina O., Kharrat R., Shadizadeh S.R., The Proper Simulation of Free Fall Gravity Drainage in the Commercial Simulator Environment, Journal of: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Volume: 35, Issue: 12, (2013) pages 1161 – 1173\. 108\. Saidian M., Ghazanfari M.H.N Massihi M., Kharrat R., Monitoring the Role of Fracture Geometrical Characteristics on Fingering Initiation/Development during Heavy Oil Miscible Displacements in Fractured Porous Media, Journal of Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Volume: 35, Issue: 12, (2013), pages 1129 - 1139\. 109\. Kharrat R., Intelligent Prediction of Porosity and Permeability from Well Logs for One of the Iranian Fractured Carbonate Reservoirs Journal of Petroleum Science and Technology, Volume: 29, Issue: 20, (2013), pages 2095 - 2112\. 110\. Zargaria H., Poordada S., Kharrat R., Porosity and Permeability Prediction Based on Computational Intelligences as Artificial Neural Networks (ANNs) and Adaptive Neuro-Fuzzy Inference Systems (ANFIS) in Southern Carbonate Reservoir of Iran Journal of Petroleum Science and Technology, Volume: 31, Issue: 10, (2013) pages 1066 - 1077\. 111\.
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Range of geological processes at different temperature recorded by monazite, zircon and apatite in U-Pb datingSince the diffusion of reactants between the dissolving phase and the precipitating phase is slow, the fluid is essential for providing easy transport for the reactants. Yet as the reaction proceeds, the dissolving phase and the fluid are separated by the solid precipitating phase, blocking the transport of reactants. Therefore, there must be some interconnected porosity in the precipitating phase, which allows the fluid to infiltrate and fuel the reaction front. Most other geochronometers usually have a much lower closure temperature.
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The HGS model is a three-dimensional control-volume finite element simulator which is designed to simulate the entire terrestrial portion of the hydrologic cycle. It uses a globally implicit approach to simultaneously solve the 2D diffusive-wave equation and the 3D form of Richards’ equation. HGS also dynamically integrates key components of the hydrologic cycle such as evaporation from bare soil and water bodies, vegetation-dependent transpiration with root uptake, snowmelt and soil freeze/thaw. Features such as macro pores, fractures, and tile drains can either be incorporated discretely or using a dual-porosity, dual permeability formulation.
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Herodotus, The Histories, 7.170.1, "and made this their dwelling place, accordingly changing from Cretans to Messapians of Iapygia" To this day, in the Grecìa Salentina, a group of towns not far from Lecce, the griko language is still spoken. In terms of industry, the "Lecce stone"—a particular kind of limestoneInvestigation on porosity change of Lecce stone—is one of the city's main exports, because it is very soft and workable, thus suitable for sculptures. Lecce is also an important agricultural centre, chiefly for its olive oil and wine production, as well as an industrial centre specializing in ceramic production.
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In flight, it breaks a small twig from a tree and presses it into the saliva, angling the twig downwards so that the central part of the nest is the lowest. It continues adding globs of saliva and twigs until it has made a crescent-shaped cup. Cup-shaped nest insulation has been found to be related to nest mass, nest wall thickness, nest depth, nest weave density/porosity, surface area, height above ground and elevation above sea level. More recently, nest insulation has been found to be related to the mass of the incubating parent.
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Turgot and Lavoisier created the Régie des Poudres et Salpêtres a few years before the French Revolution. Niter-beds were prepared by mixing manure with either mortar or wood ashes, common earth and organic materials such as straw to give porosity to a compost pile typically high, wide, and long. The heap was usually under a cover from the rain, kept moist with urine, turned often to accelerate the decomposition, then finally leached with water after approximately one year, to remove the soluble calcium nitrate which was then converted to potassium nitrate by filtering through potash.
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Gore-Tex Medical Devices Sample Kit, Science History Institute Some of the company's earliest successful products, based on work with laminates, were burn bandages developed for the Park-Davis company, microfiltration products for Millipore Corporation, and a membrane for blood oxygenation for Baxter International. Creating Gore-Tex tubes for use as vascular grafts was another area of rapid development. Gore-Tex is particularly useful internally in medical applications because it is nearly inert inside the body. In addition, the porosity of Gore-Tex permits the body's own tissue to grow through the material, integrating grafted material into the circulation system.
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381-382 Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production.Ben E. Law and Charles W. Spencer, 1993, "Gas in tight reservoirs-an emerging major source of energy," in David G. Howell (ed.), The Future of Energy Gasses, US Geological Survey, Professional Paper 1570, p.233-252. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses.
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338x338px The origin of Mars' moons, Phobos and Deimos (pictured right), is unknown and remains controversial. One theory is that the moons are captured asteroids. However, the moons' near circular orbits and low inclination relative to the Martian equator are not in agreement with the capture hypothesis. The detection of minerals on Phobos similar to those in the Martian lithosphere, and the unusually low density and high porosity of Phobos, such that the moon would not be expected to remain aggregate if dynamically captured, suggest that the moons could have formed via accretion in Martian orbit, similar to how Earth's Moon formed.
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The physics of dunking is driven by the porosity of the biscuit and the surface tension of the beverage. A biscuit is porous and, when dunked, capillary action draws the liquid into the interstices between the crumbs. Dunking is first reported with ancient Romans softening their hard unleavened wafers (Latin: bis coctum – "twice baked") in wine. Modern day dunking has its roots in naval history when, in the 16th century, biscuits known as "hard tack" were on board Royal Navy ships, which were so hard that the British sailors would dunk them in beer in order to soften them up.
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Overall interval in which pay volumes occur is the gross pay; smaller portions of the reservoir that meet further criteria for pay (such as permeability and hydrocarbon saturation) are net pay. Net pay is determined through placing cut offs on properties like permeability, porosity, water saturation or volume of shale. Care needs to be taken to cut out the part of the gross rock volume that has the ability to allow fluids to flow and actually stores hydrocarbons. In other cases when determining "Net Reservoir" the remaining rock is that rock that can still store flow hydrocarbons but is not necessary containing hydrocarbons.
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Since the asteroid is likely to be a rubble pile, accounting for a possible porosity of 20–40% leads to the material density of 4.2–5.8 g/cm3, which means that Kalliope is probably made of a mixture of metal with silicates. Spectroscopic studies have shown, however, evidence of hydrated minerals and silicates, which indicate rather a stony surface composition. Kalliope also has a low radar albedo, which is inconsistent with a purely metallic surface. Lightcurve analysis indicates that Kalliope's pole most likely points towards ecliptic coordinates (β, λ) = (−23°, 20°) with a 10° uncertainty, which gives Kalliope an axial tilt of 103°.
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For this reason, the color will survive repeated washing, typically 4–5 shampoos or a few weeks, before undergoing significant fading or washing out entirely. Semi-permanents may still contain the suspected carcinogen p-phenylenediamine (PPD) or other related colorants. The U.S. Environmental Protection Agency reported that in rats and mice chronically exposed to PPD in their diet, the PPT appears to simply depress body weight of the animals, with no other clinical signs of toxicity observed in several studies.p-Phenylenediamine, U.S. Environmental Protection Agency The final color of each strand of hair will depend on its original color and porosity.
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The bulk density of soil depends greatly on the mineral make up of soil and the degree of compaction. The density of quartz is around 2.65 g/cm³ but the (dry) bulk density of a mineral soil is normally about half that density, between 1.0 and 1.6 g/cm³. In contrast, soils rich in soil organic carbon and some friable clays tend to have lower bulk densities (<1.0 g/cm³) due to a combination of the low-density of the organic materials themselves and increased porosity. For instance, peat soils have bulk densities from 0.02 g/cm³ to 0.98 g/cm³.
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Grundy et al. propose that dark, low-density TNOs in the size range of approximately are transitional between smaller, porous (and thus low-density) bodies and larger, denser, brighter and geologically differentiated planetary bodies (such as dwarf planets). Bodies in this size range should have begun to collapse the interstitial spaces left over from their formation, but not fully, leaving some residual porosity. Many TNOs in the size range of about have oddly low densities, in the range of about , that are substantially less than dwarf planets such as Pluto, Eris and Ceres, which have densities closer to 2.
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Meerschaum became a premium substitute for the clay pipes of the day and remains prized to this day, although since the mid-1800s briar pipes have become the most common pipes for smoking. The use of briar wood, beginning in the early 1820s, greatly reduced demand for clay pipes and, to a lesser degree, meerschaum pipes. The qualities of meerschaum were combined with those of briar pipes by lining briar pipes with meerschaum bowls. Some smokers believe that meerschaum-lined briar pipes give the porosity and sweet-smoking qualities of meerschaum along with the heat-absorbing qualities and durability of briar.
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Increased oxygen makes the shielding gas oxidize the electrode, which can lead to porosity in the deposit if the electrode does not contain sufficient deoxidizers. Excessive oxygen, especially when used in application for which it is not prescribed, can lead to brittleness in the heat affected zone. Argon-oxygen blends with 1–2% oxygen are used for austenitic stainless steel where argon-CO2 can not be used due to required low content of carbon in the weld; the weld has a tough oxide coating and may require cleaning. Hydrogen is used for welding of nickel and some stainless steels, especially thicker pieces.
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Similar to OIP, HCIIP is calculated using measures of the total reservoirs volume correcting for the non reservoir rock, the porosity and the water saturation in this pore space. Lastly the volume at reservoir conditions (high pressures and temperatures) is converted to the associated volume at surface conditions.HCIIP Calculation and Formula on the Petroleum Geology Forums Oil in place must not be confused with oil reserves, that are the technically and economically recoverable portion of oil volume in the reservoir. Current recovery factors for oil fields around the world typically range between 10 and 60 percent; some are over 80 percent.
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The attenuation of these gamma rays gives an accurate measure of formation density; this has been a standard oilfield tool since 1965. Another source is americium berylium (Am- Be) neutron source used in evaluation of the porosity of the formation, and this has been used since 1950. In a drilling context, these sources are used by trained personnel, and radiation exposure of those personnel is monitored. Usage is covered by licenses from International Atomic Energy Agency (IAEA) guidelines, SU or European Union protocols, and the Environment Agency in the UK. Licenses are required for access, transport, and use of radioactive sources.
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A scaffold or matrix serves as a temporary supporting structure (extracellular matrix), the initial architecture, on which the cells can grow three-dimensionally into the desired tissue. A scaffold must provide the environment needed for cellular growth and differentiation; it must provide the strength to withstand mechanical stress and guide their growth. Moreover, scaffolds should be biodegradable and degrade at the same rate as the tissue regenerates to be optimally replaced by the host tissue. There are numerous scaffolds to choose from and when choosing a scaffold biocompatibiltiy, porosity and stability should also be held into account.
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Victoria University of Wellington: School of Architecture. The texture, porosity and depth of the substrate, those that in a natural ecosystem are edaphic factors, have been tested to the point of finding fitogenerate materials with perfect levels of absorption and humidity for the development of more than forty living families of plants represented by around 120 species. Moreover, the substrate used in the system developed by Ignacio Solano provides the ecosystem with the necessary resistance to serve as a high-durability biotope. Environmental factors such as light, temperature and humidity are controlled by automated systems in interior vertical ecosystems.
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Copper nanoparticles display unique characteristics including catalytic and antifungal/antibacterial activities that are not observed in commercial copper. First of all, copper nanoparticles demonstrate a very strong catalytic activity, a property that can be attributed to their large catalytic surface area. With the small size and great porosity, the nanoparticles are able to achieve a higher reaction yield and a shorter reaction time when utilized as reagents in organic and organometallic synthesis. In fact, copper nanoparticles that are used in a condensation reaction of iodobenzene attained about 88% conversion to biphenyl, while the commercial copper exhibited only a conversion of 43%.
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Cross-section of a hillslope depicting the vadose zone, capillary fringe, water table, and saturated zone The phreatic zone, or zone of saturation, is the part of an aquifer, below the water table, in which relatively all pores and fractures are saturated with water. Above the water table is the vadose zone. The phreatic zone size, color, and depth may fluctuate with changes of season, and during wet and dry periods. Depending on the characteristics of soil particles, their packing and porosity, the boundary of a saturated zone can be stable or instable, exhibiting fingering patterns known as Saffman–Taylor instability.
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None of this geologic structure is visible on the ground surface since the Central Valley is wide and flat, but enough wells had been drilled in the general vicinity to give early prospectors the idea that a petroleum reservoir might be nearby. Underneath several hundred feet of Holocene-age alluvium, deposited by thousands of years of runoff from the mountains that ring the Central Valley, is the Pleistocene Tulare Formation, which forms an impermeable cap to the underlying San Joaquin Clay, the principal gas-bearing unit. This unit varies in thickness from 2,200 to , and has an average porosity of 28%.
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Several brands of rolling papers Rolling papers are small sheets, rolls, or leaves of paper which are sold for rolling cigarettes either by hand or with a rolling machine. When rolling a cigarette, one fills the rolling paper with tobacco, cannabis, cloves, damiana, hash or other herbs. The paper for holding the tobacco blend may vary in porosity to allow ventilation of the burning ember or contain materials that control the burning rate of the cigarette and stability of the produced ash. Civil War re-enactors often use cigarette rolling papers to make combustible cartridges for cap & ball rifles and revolvers.
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35(8): p. 644–651. In order to assess the potential impact of diagenesis on archaeological or fossil bones, many factors need to be assessed, beginning with elemental and mineralogical composition of bone and enveloping soil, as well as the local burial environment (geology, climatology, groundwater). The composite nature of bone, comprising one-third organic (mainly protein collagen) and two thirds mineral (calcium phosphate mostly in the form of hydroxyapatite) renders its diagenesis more complex. Alteration occurs at all scales from molecular loss and substitution, through crystallite reorganization, porosity and microstructural changes, and in many cases, to disintegration of the complete unit.
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Other asteroids, possibly including Itokawa, have been found to be contact binaries, two major bodies touching, with or without rubble filling the boundary. Large interior voids are possible because of the very low gravity of most asteroids. Despite a fine regolith on the outside (at least to the resolution that has been seen with spacecraft), the asteroid's gravity is so weak that friction between fragments dominates and prevents small pieces from falling inwards and filling up the voids. All the largest asteroids (1 Ceres, 2 Pallas, 4 Vesta, 10 Hygiea, 704 Interamnia) are solid objects without any macroscopic internal porosity.
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Often a feasibility study using the wells logs will indicate whether separation of the desired lithotype can be achieved with P-impedance alone or whether S-impedance is also required. This will dictate whether a pre- or post-stack inversion is needed. Simultaneous Inversion (SI) is a pre-stack method that uses multiple offset or angle seismic sub-stacks and their associated wavelets as input; it generates P-impedance, S-impedance and density as outputs (although the density output resolution is rarely as high as the impedances). This helps improve discrimination between lithology, porosity and fluid effects.
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Comet C/2014 Q2 (Lovejoy) surrounded by glowing carbon vapor Of the other discovered allotropes, carbon nanofoam is a ferromagnetic allotrope discovered in 1997. It consists of a low-density cluster-assembly of carbon atoms strung together in a loose three-dimensional web, in which the atoms are bonded trigonally in six- and seven-membered rings. It is among the lightest known solids, with a density of about 2 kg/m. Similarly, glassy carbon contains a high proportion of closed porosity, but contrary to normal graphite, the graphitic layers are not stacked like pages in a book, but have a more random arrangement.
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The resulting foams consisted of 32-36% porosity with more complete densification than they observed when producing NiTi foams using a sodium fluoride (NaF) space-holder. However, processing parameters resulted in molten NaCl and a metal/salt blend in the cavities of the foam. Certain risks are associated with using a molten space-holder including reaction with the metal, dissolving of the space-holder in the metal and prevention of densification through the creation of a thin layer of liquid between the metal and particles. Near complete densification was achieved when NaCl was used as a permanent space-holder in pure titanium foam.
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Natural stone tiles can be stained by spilled liquids; they must be sealed and periodically resealed with a sealant in contrast to ceramic tiles which only need their grout lines sealed. However, because of the complex, nonrepeating patterns in natural stone, small amounts of dirt on many natural stone floor tiles do not show. The tendency of floor tiles to stain depends not only on a sealant being applied, and periodically reapplied, but also on their porosity or how porous the stone is. Slate is an example of a less porous stone while limestone is an example of a more porous stone.
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Design problems resulted in too much water in the helium system, leading to corrosion. The designers had intended for the water injectors to maintain pressure in the bearings about equal to the gas pressure in the system. In practice, the gas pressure varied more than expected, allowing excessive water to escape into the circulator. The capacity of the gas cleaning system did not account for the excess water from the bearings, and assumed that high-temperature reactions in the graphite reactor core would reduce the impact of residual water in the helium, based on the porosity of typical core graphite.
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In order to minimize porosity the metal may be gravity cast or the molding cavity may be pressurized. Another system slowly rocks the casting dies as the molding cavity fills to "shake" the air bubbles out.. The metal cores can be made from a number of low melting point alloys, with the most common being a mixture of 58% bismuth and 42% tin, which is used for molding nylon 66. One of the main reasons it is used is because it expands as it cools which packs the mold well. Other alloys include tin-lead-silver alloys and tin-lead-antimony alloys.
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For GTAW of carbon and stainless steels, the selection of a filler material is important to prevent excessive porosity. Oxides on the filler material and workpieces must be removed before welding to prevent contamination, and immediately prior to welding, alcohol or acetone should be used to clean the surface. Preheating is generally not necessary for mild steels less than one inch thick, but low alloy steels may require preheating to slow the cooling process and prevent the formation of martensite in the heat-affected zone. Tool steels should also be preheated to prevent cracking in the heat-affected zone.
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Simulant of the surface of Ryugu produced by the University of Tokyo Observations from Hayabusa 2 showed that the surface of Ryugu is very young and has an age of 8.9 ± 2.5 Million years based on the data collected from the artificial crater that was created with an explosive by Hayabusa 2. The surface of Ryugu is porous and contains no or very little dust. The measurements with the radiometer on board of MASCOT, which is called MARA, showed a low thermal conductivity of the boulders. This was an in situ measurement of the high porosity of the boulder material.
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She studied the porosity of coal using helium to determine its density. Through this, she discovered the relationship between the fine constrictions in the pores of coals and the permeability of the porous space. By concluding that substances were expelled in order of molecular size as temperature increased, she helped classify coals and accurately predict their performance for fuel purposes and for production of wartime devices such as gas masks. This work was the basis of her Ph.D. thesis The physical chemistry of solid organic colloids with special reference to coal for which the University of Cambridge awarded her a Ph.D. in 1945.
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This dredge field is the largest in the state, both in terms of volume of material dredged, and amount of gold recovered (5.14 million ounces, estimated). The dredgers also created over 200 ponds, which are fed by a network of underground rivers, which in turn were formed due to the porosity of the ground. The water in these ponds is usually clear blue, the impurities having been filtered by the gravel. The Debris Commission also built both the Englebright Dam to the east and the Daguerre Point Dam west of the goldfields to trap debris caused by hydraulic mining.
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The slag created by the flux is also easy to remove. The main advantages of this process is that in a closed shop environment, it generally produces welds of better and more consistent mechanical properties, with fewer weld defects than either the SMAW or GMAW processes. In practice it also allows a higher production rate, since the operator does not need to stop periodically to fetch a new electrode, as is the case in SMAW. However, like GMAW, it cannot be used in a windy environment as the loss of the shielding gas from air flow will produce porosity in the weld.
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Small amounts of calcined gypsum are added to earth to create strong structures directly from cast earth, an alternative to adobe (which loses its strength when wet). The conditions of dehydration can be changed to adjust the porosity of the hemihydrate, resulting in the so-called α- and β-hemihydrates (which are more or less chemically identical). On heating to , the nearly water-free form, called γ-anhydrite (CaSO4·nH2O where n = 0 to 0.05) is produced. γ-Anhydrite reacts slowly with water to return to the dihydrate state, a property exploited in some commercial desiccants.
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Formation testing is so far the only tool that can directly measure a rock formation's permeability down a well. In case of its absence, which is common in most cases, an estimate for permeability can be derived from empirical relationships with other measurements such as porosity, NMR and sonic logging. Thickness of rock with enough permeability to deliver fluids to a well bore. This property is often called “Net reservoir rock.” In the oil and gas industry, another quantity “Net Pay” is computed which is the thickness of rock that can deliver hydrocarbons to the well bore at a profitable rate.
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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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M-type asteroids are the third most common asteroid type. There are also M-types whose composition is uncertain. For example, 22 Kalliope has an accurately known density that is far too low for a solid metallic object or even a metal rubble pile: a rubble pile of iron-nickel metal would need about 70% porosity which is inconsistent with packing considerations. 22 Kalliope and 21 Lutetia have features in their spectra which appear to indicate the presence of hydration minerals and silicates, anomalously low radar albedos inconsistent with a metallic surface, as well as characteristics more in common with C-type asteroids.
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Thus a reduction of the original particle size well below the wavelength of visible light (~ 0.5 μm or 500 nm) eliminates much of the light scattering, resulting in a translucent or even transparent material. Furthermore, results indicate that microscopic pores in sintered ceramic nanomaterials, mainly trapped at the junctions of microcrystalline grains, cause light to scatter and prevented true transparency. It has been observed that the total volume fraction of these nanoscale pores (both intergranular and intragranular porosity) must be less than 1% for high-quality optical transmission, i.e. the density has to be 99.99% of the theoretical crystalline density.
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Curious and inspired by the Copernican cosmology and hardly understood new ideas of vast, endless, empty space where light would propagate, bodies of matter could move about unhindered, and sound cannot be detected, von Guericke set about replicating this nothing phenomenon on Earth. Von Guericke first started investigating the concept of a vacuum through the use of fire pumps by pumping water out of wooden barrels. However, he soon realised that the porosity of wood was allowing unwanted water, filled with dissolved air, to enter. The pressure fluctuations experienced inside the barrel were allowing this encapsulated air to escape: spoiling the vacuum inside.
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Melamine also enters the fabrication of melamine poly-sulfonate used as superplasticizer for making high-resistance concrete. Sulfonated melamine formaldehyde (SMF) is a polymer used as cement admixture to reduce the water content in concrete while increasing the fluidity and the workability of the mix during its handling and pouring. It results in concrete with a lower porosity and a higher mechanical strength, exhibiting an improved resistance to aggressive environments and a longer lifetime. The use of melamine as fertilizer for crops had been envisioned during the 1950s and 1960s because of its high nitrogen content (2/3).
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The primary reservoirs in the Middle Magdalena Basin are fluvial sandstones and conglomerates from the Churro and Chuspas Groups, which have 20 to 25% porosity and 0.5 to 1 D permeability. The main source of hydrocarbons is the La Luna limestone, with a Total Organic Carbon (TOC) content of 3 to 4% and Type II marine kerogen, sealed by overlying Eocene shales. There are three types of traps that house hydrocarbons in the Middle Magdalena Basin. The two structural traps are large anticlines in the center of the basin and smaller anticlines along the western margin.
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Problems with noise or dust contamination of the environments do not occur. Particulate materials are a promising heat storage and heat transfer media for high temperature applications such as industrial processes, conventional power plants or Concentrating Solar Power (CSP). The flow behavior of the bulk material not only influences the design of the heat exchanger, but also affects the thermal behavior, since the contact time at the walls strongly depends on particle flowability. Occurrence of attrition leads to a deteriorated flow pattern, because the mean grain size and bulk porosity decrease as grain size distribution widens.
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SiC/SiC composites are mainly processed through three different methods. However, these processing methods are often subjected to variations in order to create the desired structure or property: # Chemical Vapor Infiltration (CVI) – The CVI method uses a gas phase SiC precursor to first grow SiC whiskers or nanowires in a preform, using conventional techniques developed with CVD. Following the growth of the fibers, the gas is again infiltrated into the preform to densify and create the matrix phase. Generally, the densification rate is slow during CVI, thus this process creates relatively high residual porosity (10–15%).
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A suitable detector, positioned at a certain distance from the source, can measure either epithermal neutron population, thermal neutron population, or the gamma rays emitted after the absorption. Mechanics of elastic collisions predict that the maximum energy transfer occurs during collisions of two particles of equal mass. Therefore, a hydrogen atom (H) will cause a neutron to slow down the most, as they are of roughly equal mass. As hydrogen is fundamentally associated to the amount of water and/or oil present in the pore space, measurement of neutron population within the investigated volume is directly linked to porosity.
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A triple phase boundary (TPB) is a geometrical class of phase boundary and the location of contact between three different phases. A simple example of a TPB is a coastline where land, air and sea meet to create an energetic location driven by solar, wind and wave energy capable of supporting a high level of biodiversity. This concept is particularly important in the description of electrodes in fuel cells and batteries. For example for fuel cells, the three phases are an ion conductor (electrolyte), an electron conductor, and a virtual "porosity" phase for transporting gaseous or liquid fuel molecules.
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The quality of printed structures depends on the various factors include powder properties such as particle size and shape, density, roughness, and porosity. Furthermore, the particle distribution and their thermal properties affect a lot on the flowability of the powder. Commercially-available materials used in SLS come in powder form and include, but are not limited to, polymers such as polyamides (PA), polystyrenes (PS), thermoplastic elastomers (TPE), and polyaryletherketones (PAEK). Polyamides are the most commonly used SLS materials due to their ideal sintering behavior as a semi-crystalline thermoplastic, resulting in parts with desirable mechanical properties.
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Tree uprooting causes considerable soil displacement by producing mounds, mixing the soil, or inverting vertical sections of soil. Burrowing animals, such as earth worms and small mammals form passageways for air and water transport which changes the soil properties, such as the vertical particle-size distribution, soil porosity, and nutrient content. Invertebrates that burrow and consume plant detritus help produce an organic- rich topsoil known as the soil biomantle, and thus contribute to the formation of soil horizons. Small mammals such as pocket gophers also play an important role in the production of soil, possibly with an equal magnitude to abiotic processes.
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As more wave energy enters the chamber, it combines with and reinforces the standing wave, increasing its intensity. Since the resonance chamber is an enclosed space that has an opening where the sound wave enters and exits after bouncing off of the internal walls producing resonance, commonly acoustic resonance as in many musical instruments (see Sound board (music)), the material of the chamber, particularly that of the actual internal walls, its shape and the position of the opening, as well as the finish (porosity) of the internal walls are contributing factors for the final resulting sound produced.
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Traps for conventional hydrocarbon accumulations are mostly stratigraphic for carbonate rock reservoirs and both structural and stratigraphic in clastic-rock reservoirs. Stratigraphic traps in carbonate rocks result from a combination of facies and depositional topography, erosion, updip pinchout of facies, and diagenetically controlled enhanced- permeability and porosity zones. A good example of a carbonate stratigraphic trap is the pinnacle reef traps of the Chappel Limestone, where local porous grainstone and packstone are restricted to isolated buildups or reef clusters on the eroded Ellenburger Group. Chappel pinnacle reefs are draped and sealed by the overlying Barnett Shale.
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A high density is required, so residual porosity must be minimised in the final part. A matrix using a titanium alloy is extremely expensive to manufacture but the metal is favoured for its lightness, strength and resistance to corrosion, which is a constant problem. The backing plate can be made from steel, but, as its main function is to improve the stability and stiffness of the assemblage, aluminium is more weight-efficient in light AFVs only to be protected against light anti-tank weapons. A deformable composite backing plate can combine the function of a metal backing plate and an elastic layer.
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A pervious concrete street Pervious concrete (also called porous concrete, permeable concrete, no fines concrete and porous pavement) is a special type of concrete with a high porosity used for concrete flatwork applications that allows water from precipitation and other sources to pass directly through, thereby reducing the runoff from a site and allowing groundwater recharge. Pervious concrete is made using large aggregates with little to no fine aggregates. The concrete paste then coats the aggregates and allows water to pass through the concrete slab. Pervious concrete is traditionally used in parking areas, areas with light traffic, residential streets, pedestrian walkways, and greenhouses.
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The ingestion of the paint by the women, brought about while licking the brushes, resulted in a condition called radium jaw (radium necrosis), a painful swelling and porosity of the upper and lower jaws that ultimately led to many of their deaths. This led to litigation against U.S. Radium by the so-called Radium Girls, starting with former dial painter Marguerite Carlough in 1925. The case was eventually settled in 1926 and several more suits were brought against the company in 1927 by Grace Fryer and Katherine Schaub. The company did not stop the hand painting of dials until 1947.
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A composite bearing is used to maintain separation and control friction between two moving parts. The distinguishing characteristic of a composite bearing is that the bearing is made from a combination of materials such as a resin reinforced with fibre and this may also include friction reducing lubricants and ingredients. A composite bearing is not simply a PTFE bearing in a carrier of another material, this is a PTFE bearing in a carrier. The plain composite bearing can be lighter than a rolling element bearing but this is not always a feature as some composites are extremely dense which results in lower porosity.
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Further studies will be done to incorporate all the findings and establish future planning. The operator Lundin gave a total gross resource estimate in the range of 12 to 46 million barrels of oil equivalentsLundin Petroleum: Oil Discovery in the Rolvsnes Prospect, offshore Norway, retrieved 28 January 2016. With the use of Rex International Holding’s proprietary Rex Virtual Drilling technology, the Company identified the key risks associated with the Rolvsnes well to be the irregular porosity and permeability distributions in the unconventional weathered and fractured basement reservoir. This was also the first time that RVD was applied in this kind of rocks.
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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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Sonic tools, such as the Baker Hughes XMAC-F1, consist of multiple piezoelectric transducers and receivers mounted on the tool body at fixed distances. The transmitters generate a pattern of sound waves at varying operating frequencies into the down hole formation. The signal path leaves the transmitter, passes through the mud column, travels along the borehole wall and is collected at multiple receivers spaced out along the tool body. The time it takes for the sound wave to travel through the rock is dependent on a number of properties of the existing rock, including formation porosity, lithology, permeability and rock strength.
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Bakken Core samples Although often neglected, core samples always degrade to some degree in the process of cutting the core, handling it, and studying it. Non- destructive techniques are increasingly common, e.g., the use of MRI scanning to characterize grains, pore fluids, pore spaces (porosity) and their interactions (constituting part of permeability) but such expensive subtlety is likely wasted on a core that has been shaken on an unsprung lorry for 300 km of dirt road. What happens to cores between the retrieval equipment and the final laboratory (or archive) is an often neglected part of record keeping and core management.
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The intersection between pore density and size determines the degree or magnitude of the flow rate through the media. This idea can be illustrated by a comparison of the ways water moves through clay versus gravel. The retention time through a specified vertical distance in clay will be longer than through the same distance in gravel, even though they are both characterized as high porosity materials. This is because the pore sizes are much larger in gravel media than in clay, and so there is less hydrostatic tension working against the subsurface pressure gradient and gravity.
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Some fiamme are formed from flattened hot, relatively low viscosity, high porosity fragments of volcanic glass or pumice. But this is not the only way they can form: they can also form when pumice lapilli are altered to clay and compact during diagenesis; and fiamme are also widely reported in viscous lavas (andesites to rhyolites) where they form by shear-induced autobrecciation of pumiceous or obsidian zones, followed by shear and annealing of the fragments. Fiamme can also result from patchy alteration and recrystalisation of volcanic rocks, or by patchy revesiculation of welded tuff matrix (especially in rheomorphic peralkaline tuffs).
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Then it starts necking and finally fractures. The appearance of necking in ductile materials is associated with geometrical instability in the system. Due to the natural inhomogeneity of the material, it is common to find some regions with small inclusions or porosity within it or surface, where strain will concentrate, leading to a locally smaller area than other regions. For strain less than the ultimate tensile strain, the increase of work-hardening rate in this region will be greater than the area reduction rate, thereby make this region harder to be further deform than others, so that the instability will be removed, i.e.
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In the laboratory Soil bulk density, pore-size distribution, water permeability and the relative apparent gas diffusion coefficient give a good overview of the permeability of soils to air and water and therefore on the degree of compaction. Since the coarse pores are most important for water infiltration, gas exchange and transport, focusing on them when measuring the porosity and the diffusion coefficient is recommended.Frey, B.; Kremer, J.; Rüdt, A.; Sciacca, S.; Matthies, D. and Lüscher, P. (2009). Compaction of forest soils with heavy logging machinery affects soil bacterial community structure, European Journal of Soil Biology 45: 312 - 320.
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Tilt filling, also known as tilt casting, is an uncommon filling technique where the crucible is attached to the gating system and both are slowly rotated so that the metal enters the mold cavity with little turbulence. The goal is to reduce porosity and inclusions by limiting turbulence. For most uses tilt filling is not feasible because the following inherent problem: if the system is rotated slow enough to not induce turbulence, the front of the metal stream begins to solidify, which results in mis-runs. If the system is rotated faster it induces turbulence, which defeats the purpose.
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Porosity gives a measure of the water storage capability of soil but not all the water present in the soil pores is available for extraction by pumping for the use of humans or draining by gravity. The pores in the soil hold back sufficient quantity of water on account of forces like surface tension and molecular attraction. Hence the actual amount of water that can be extracted from the unit volume of aquifer by pumping or under the action of gravity is called as specific yield. The fraction of water held back in the aquifer is known as specific retention.
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In the processing of fine ceramics, the irregular particle sizes and shapes in a typical powder often lead to non-uniform packing morphologies that result in packing density variations in the powder compact. Uncontrolled flocculation of powders due to attractive van der Waals forces can also give rise to microstructural heterogeneities.Onoda, G. Y. and Hench, L. L., Ceramic Processing Before Firing (Wiley & Sons, New York, 1979). Differential stresses that develop as a result of non-uniform drying shrinkage are directly related to the rate at which the solvent can be removed, and thus highly dependent upon the distribution of porosity.
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NMR Cryoporometry (NMRC) is a recent technique for measuring total porosity and pore size distributions. It makes use of the Gibbs-Thomson effect : small crystals of a liquid in the pores melt at a lower temperature than the bulk liquid : The melting point depression is inversely proportional to the pore size. The technique is closely related to that of the use of gas adsorption to measure pore sizes (Kelvin equation). Both techniques are particular cases of the Gibbs Equations (Josiah Willard Gibbs): the Kelvin Equation is the constant temperature case, and the Gibbs-Thomson Equation is the constant pressure case.
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A typical symptom of a porous head is usually a 'mayonnaise'-like substance forming somewhere inside the cooling system (usually, this can be found residing on the coolant reservoir cap). However, depending on the degree of porosity, symptoms of a porous head have a tendency to vary. Many C20XE operators have described the symptom as a curry-like residue or in more severe cases, a thick brown sludge which may overcome the entire cooling system. In such instances, engine oil will readily react with the sulfur in rubber components, hence quickly degrading coolant pipes and hoses to the point of failure.
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The rocks are characterised by low porosity and high secondary permeability via fissures. Malvern water is rainwater and snow meltwater that percolates through fissures created by the pressures of tectonic movements about 300 million years ago when advancing sedimentary layers of Silurian shale and limestone were pushed into and under older Precambrian rock. When the fissures are saturated, a water table forms and the water emerges as springs around the fault lines between the strata. Depending on rainfall, the flow can vary from as little as 36 litres (8 gallons) per minute to over 350 litres (77 gallons) per minute.
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The Bentley Field, located on the UK continental shelf in block 9/3b in 110 m of water, contains approximately in-place of heavy (10 to 12 oAPI) viscous (1500 cP) crude. The field is four-way dip closed at uppermost Palaeocene, lowermost Eocene, Dornoch sandstone level, and covers an area of about 16 km by 5 km at a depth of around 1.1 km TVDss. The reservoir is high porosity (33%), net to gross pay (90%) and with ultra-high apparent horizontal permeabilities approaching 50 Darcies based on flow-test measurements, but consistent with unconsolidated sand.
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Moreover, the size of the grain boundaries scales directly with particle size. Thus a reduction of the original particle size well below the wavelength of visible light (about 1/15 of the light wavelength or roughly 600/15 = 40 nanometers) eliminates much of light scattering, resulting in a translucent or even transparent material. Computer modeling of light transmission through translucent ceramic alumina has shown that microscopic pores trapped near grain boundaries act as primary scattering centers. The volume fraction of porosity had to be reduced below 1% for high-quality optical transmission (99.99 percent of theoretical density).
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There was a large amount of variation in the density, structure, porosity, and grain size of the recovered volcanic rock, varying widely with depth. The bulk of the volcanic rock is basalt of aphyric to olivine-phyric lava, and tholeiitic or alkalic in composition. The basaltic lavas from Koko Seamount resemble those drilled during Leg 55, at Suiko Seamount. Studies suggested that the magnetic arrangement of the rock, used to determine its latitude at formation (magnets align to the North pole; also, the drift and position of the Hawaii hotspot at various times is important to hotspot studies), were relatively stable.
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The brightness of varies by less than over hours and days, suggesting that it either has a very long rotation period, an approximately spheroidal shape, or a rotation axis pointing towards Earth. Brown estimated, prior to the discovery of its satellite, that was very likely to be a dwarf planet, due to its large size. However, Grundy et al. calculate that bodies such as , less than about 1000 km in diameter, with albedos less than ≈0.2 and densities of ≈1.2 g/cm3 or less, may retain a degree of porosity in their physical structure, having never collapsed into fully solid bodies.
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With the exception of some thin sandy units in the inner Moray Firth, this sequence has neither source potential nor reservoir capacity and is not generally considered a drilling target. Its thickness and homogeneity does make it a common target for carrying out directional drilling manoeuvers. In the Shearwater and Eastern Trough Area Project areas (around 56°30' N 02°30'E, UKCS quadrants 22,23,29 and 30), the Chalk Group can be significantly overpressured. Further south in UKCS quadrant 30 and Norwegian quadrants 1 and 2, this overpressure helps preserve porosity and enables the Chalk to be an effective reservoir.
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The electrode is a metallic alloy wire, called a MIG wire, whose selection, alloy and size, is based primarily on the composition of the metal being welded, the process variation being used, joint design, and the material surface conditions. Electrode selection greatly influences the mechanical properties of the weld and is a key factor of weld quality. In general the finished weld metal should have mechanical properties similar to those of the base material with no defects such as discontinuities, entrained contaminants or porosity within the weld. To achieve these goals a wide variety of electrodes exist.
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Generally, the amount of gas entrapped is directly related to the cooling rate of the weld pool. Because of its higher thermal conductivity, aluminum welds are especially susceptible to greater cooling rates and thus additional porosity. To reduce it, the workpiece and electrode should be clean, the welding speed diminished and the current set high enough to provide sufficient heat input and stable metal transfer but low enough that the arc remains steady. Preheating can also help reduce the cooling rate in some cases by reducing the temperature gradient between the weld area and the base metal.
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An understanding of the intensity of past storms has large implications for our understanding of how storm intensity might change with climate change occurring today. During the Cretaceous, CO2 levels were much higher and the global temperature was much higher. With an understanding of how storm intensity changed throughout this time period towards today, we can begin to understand how it will change with our changing climate. Tempestite deposits are also highly sought after petroleum reservoirs, as they are large laterally continuous sheet like deposits that have the potential to hold high volumes of petroleum with good permeability and porosity.
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Additionally, copper and chemotherapies have been used to keep the tree or plant from killing itself via wilting . Oak wilt infects and kills all oak species but affects the two main groups, red and white oaks, differently. Mostly, red oak group trees die faster from oak wilt disease than white oak group trees, and red oak group trees spread oak wilt two ways - underground and overland - where white oak group trees spread oak wilt one way only, underground. Oaks in North and Central America are sorted into two groups based mostly upon the porosity and corresponding leaf shape.
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While akadama is more costly than alternative soil components, it is prized by many growers for its ability to retain water and nutrients while still providing porosity and free drainage. For all of its qualities, many bonsai growers consider the cost of akadama prohibitive or unnecessary. Still other growers claim that when subjected to cold and wet climates, the granules progressively break down into smaller particles which inhibit drainage, an unwanted characteristic of bonsai soil. This problem can be avoided either by incorporating sand or grit in the soil mix, or by using the deeper-mined, harder grades.
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Most of the oil in the Cymric field is in a sandstone formation known as the Tulare, which is divided into three units: the Tulare I, II, and Amnicola. All are of Pleistocene age. The Tulare formation was created mainly in a braided stream and fan delta depositional environment, while the depositional characteristics of the Amnicola suggest a lacustrine (lake) environment, as well as braided stream. These kinds of rocks have high porosity (around 35%) but low permeability, allowing considerable oil to accumulate in the formation, while a combination of structural and stratigraphic traps keep the oil from migrating further upward.
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This results in a high efficiency of neutron use (neutron economy), and a higher breeding ratio, especially with small reactors. One weakness of the two-fluid design is the necessity of periodically replacing the core-blanket barrier due to fast neutron damage. ORNL chose graphite for its barrier material because of its low neutron absorption, compatibility with the molten salts, high temperature resistance, and sufficient strength and integrity to separate the fuel and blanket salts. The effect of neutron radiation on graphite is to slowly shrink and then swell it, causing an increase in porosity and a deterioration in physical properties.
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Given sufficient time, an undifferentiated soil will evolve a soil profile which consists of two or more layers, referred to as soil horizons. These differ in one or more properties such as in their texture, structure, density, porosity, consistency, temperature, color, and reactivity. The horizons differ greatly in thickness and generally lack sharp boundaries; their development is dependent on the type of parent material, the processes that modify those parent materials, and the soil-forming factors that influence those processes. The biological influences on soil properties are strongest near the surface, while the geochemical influences on soil properties increase with depth.
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Where these aggregates can be identified, a soil can be said to be developed, and can be described further in terms of color, porosity, consistency, reaction (acidity), etc. Water is a critical agent in soil development due to its involvement in the dissolution, precipitation, erosion, transport, and deposition of the materials of which a soil is composed. The mixture of water and dissolved or suspended materials that occupy the soil pore space is called the soil solution. Since soil water is never pure water, but contains hundreds of dissolved organic and mineral substances, it may be more accurately called the soil solution.
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While the mechanical behavior of ceramics is often dominated by flaws, i.e. porosity, instead of grain size, grain-size strengthening is also observed in high-density ceramic specimens . Additionally, nanocrystalline ceramics have been shown to sinter more rapidly than bulk ceramics, leading to higher densities and improved mechanical properties, although extended exposure to the high pressures and elevated temperatures required to sinter the part to full density can result in coarsening of the nanostructure. The large volume fraction of grain boundaries associated with nanocrystalline materials causes interesting behavior in ceramic systems, such as superplasticity in otherwise brittle ceramics.
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Inventory Map of sampling points- The sampling was performed on the first two layers (0 – 20 cm and 20 – 40 cm) because, at this level, takes place the most important ions exchange. They were made at eight points around of Fetzara Lake or a total of 16 samples. The soil samples were dried to fresh air ground and sieved to 2 mm to obtain the fine particles that will be used for all chemical and physicochemical analysis. The soil analysis carried out concerning the density, porosity, carbon and organic matter, pH, electrical conductivity and soluble salts.
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The largest issue in integrating AM techniques into medical device manufacturing is biocompatibility. These issues arise from the stability of 3D printed polymers in the body and the difficulty of sterilizing regions between printed layers. In addition to the use of primary cleaners and solvents to remove surface impurities, which are commonly isopropyl alcohol, peroxides, and bleach, secondary solvents must be use in succession to remove the cleaning chemicals applied before them, a problem that increases with the porosity of the material used. Common compatibility AM materials include nylon and tissue material from the host patient.
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Shielding gas became a subject receiving much attention as scientists attempted to protect welds from the effects of oxygen and nitrogen in the atmosphere. Porosity and brittleness were the primary problems and the solutions that developed included the use of hydrogen, argon, and helium as welding atmospheres. During the following decade, further advances allowed for the welding of reactive metals such as aluminum and magnesium. This, in conjunction with developments in automatic welding, alternating current, and fluxes fed a major expansion of arc welding during the 1930s and then during World War II. During the middle of the century, many new welding methods were invented.
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All of the Spraberry Trend oil fields produce from a single enormous sedimentary unit known as the Spraberry Sand, which consists of complexly mixed fine sandstone and calcareous or silicate mudstone and siltstone, deposited in a deep water environment distinguished by channel systems and their associated submarine fans, all of Permian age. The sands are interbedded with shales, and typically pinch-out updip. Oil accumulated in stratigraphic traps as it migrated upward from source rocks until encountering impermeable barriers, either in the internal shaly members or the overlying impermeable formation. Unlike many of the oil-bearing rocks of West Texas, however, the very low porosity and permeability hamper economic oil recovery.
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Primer is a paint product that allows finishing paint to adhere much better than if it were used alone. It is designed to adhere to surfaces and to form a binding layer that is better prepared to receive the paint. Compared to paint, a primer is not intended to be used as the outermost durable finish and can instead be engineered to have improved filling and binding properties with the material underneath. Sometimes this is achieved by chemistry, as in the case of aluminium primer, but more often this is achieved through controlling the primer's physical properties such as its porosity, tackiness, and hygroscopy.
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Quaternary Eolianite outcrop at Aikerness on the Mainland The presence of bitumens throughout Orkney show that hydrocarbons have at least locally been produced and migrated. The permanent lake laminites from the flagstone sequences are moderate to good source rocks and are currently marginally mature at the surface as a result of burial after the Devonian.Hydrocarbon Potential Orkney Devonian, Hall, Adrian and Brown, John, "Orkney Landscapes" (online) (Edinburgh, Scotland) September 2005, Last update 10-Nov-2008 Two large exhumed oil accumulations have been described from Orkney, the Yesnaby and Houton Head reservoir systems. At Yesnaby bitumens occur throughout the presumed trap in the aeolian Yesnaby Sandstone with good porosity and permeability.
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Vorwata had a potential technical problem: At Jurassic level, it was several thousand feet deeper than the Wiriagar anticline, and generally accepted wisdom was that porosity would be low and reservoir quality poor. John Duncan became exploration VP of Arco Indonesia in 1992, and in addition to managing the Indonesian exploration program was also a technical expert on burial history analysis. Recognizing that there might be a more optimistic scenario for Vorwata Jurassic reservoir quality, Duncan consulted with Alton Brown of Arco's geoscience technology group in Plano. Brown analyzed burial history, facies controls and diagenesis, and concluded that conventional wisdom was wrong and reservoir quality would be fine.
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Hydraulic retention time and hydraulic loading rate both affect treatment and effluent quality. Hydraulic retention time is the actual time the wastewater is in contact with the filter media and is related to the depth of the vermifilter (which may increase over time due to the accumulation of earthworm vermicastings), reactor volume and type of material used (porosity). The hydraulic retention time determines wastewater inflow rate (hydraulic loading as influent volume per hour). In principle, provided the environment is aerobic, the longer the wastewater remains inside the filter, the greater the BOD5 and COD removal efficiency will be, but at the expense of hydraulic loading.
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The outcome of the research opened up an entire new chapter in the way the fabric of the city is viewed by civic authorities. The ARC awarded Richard Goodwin again in 2009 with a Linkage Grant to develop the research further through sensors and gaming engine technologies in collaboration with Russell Lowe and the Emergency Information Coordination Unit (EICU) run under the NSW Department of Lands. Goodwin is the author of Porosity: the Architecture of Invagination and has published many articles on issues of public space, \- \- and chapters in collected works. \- \- Moreover, a number of articles \- \- and books have been published on his work.
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The phrase "X-ray welding" also has an older, unrelated usage in quality control. In this context, an X-ray welder is a tradesman who consistently welds at such a high proficiency that he rarely introduces defects into the weld pool, and is able to recognize and correct defects in the weld pool, during the welding process. It is assumed (or trusted) by the Quality Control Department of a fabrication or manufacturing shop that the welding work performed by an X-ray welder would pass an X-ray inspection. For example, defects like porosity, concavities, cracks, cold laps, slag and tungsten inclusions, lack of fusion & penetration, etc.
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Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. When conditions are right for dissolution, the removal of calcite can dramatically increase the porosity and permeability of the rock, and if it continues for a long period of time may result in the formation of caves. On a landscape scale, continued dissolution of calcium carbonate-rich rocks can lead to the expansion and eventual collapse of cave systems, resulting in various forms of karst topography.
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In some places, certain high-porosity sandstones within the Sespe unit have been deformed into anticlinal structures, and contain considerable amounts of petroleum and has produced of oil in Ventura County, California. For example, both the South Mountain and West Montalvo Oil Fields have producing horizons within the Sespe, and as such the unit is of economic importance. Within Southern California, the combined Sespe-Vaqueros coarse-grained clastic rocks form the second-most important petroleum-bearing unit, second only to the Pliocene-age Pico and Repetto Formations, which are usually much nearer the surface. The overlying Rincon Formation, a shale deposited in a deep-sea environment, serves as an impermeable cap.
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Characteristic of this rock unit is that it is full of oil – almost 50% of the unit is saturated, and the unit has high porosity, in the 45% to 70% range – but very little of the oil has been recoverable from the unit (only three to four percent so far). According to Chevron's estimate, there are approximately of oil in place in the Lost Hills Field, only five percent of which has been extracted. The oil in place is about twenty times greater than the California Department of Oil and Gas reserves estimate (), which is volume that can be economically produced.Pasqual R. Perri, et al.
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According to Mary Keller, "The book is a lesbian exploration of permeability, porosity, identity within contemporary Judaism". She writes that the name of the novel intentionally refers to the famous play and film "The Dybbuk" by S. Ansky, in order to appropriate the Jewish tradition which in itself rejects the lesbian identity and the novel's core concept of a dybbuk, to harness its transgressive nature, for "the promise of transformation" desired by contemporary feminist writers. Howard Schwartz emphasizes the transformative nature of this choice as well, noting that in the contemporary version, as exemplified by Galford, the dybbuk emerges as a sympathetic character, unlike the original tale.
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An illustration of the different components of the Elementary Osmotic Pump. The Elementary Osmotic Pump (EOP) was developed by ALZA in 1974, and was the first practical example of an osmotic pump based drug release system for oral use. It was introduced to the market in the early 1980s in Osmosin (indomethacin) and Acutrim (phenylpropanolamine), but unexpectedly severe issues with GI irritation and cases of GI perforation led to the withdrawal of Osmosin. Merck & Co. later developed the Controlled-Porosity Osmotic Pump (CPOP) with the intention of addressing some of the issues that led to Osmosin's withdrawal via a new approach to the final stage of the release mechanism.
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The cut surfaces of the foam have a slightly porous mat finish as the cutting process passes through a large number of bubbles, leaving what is called an open cell surface finish, but the bulk of the foam remains closed cell. The open cell finish is the most stretchy and the least tear resistant. It is relatively form fitting and comfortable on the skin, but the porosity encourages bacterial growth if not well washed after use, and the foam surface does not slide freely against skin. The cut surfaces are usually bonded to a nylon knit fabric, which provides much greater tear resistance, at the expense of some loss of flexibility.
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The ECM is the 3-dimensional mesh of glycoproteins, collagen and enzymes responsible for transmitting mechanical and biochemical cues to the cell. Scaffolds need to simulate the characteristics of the ECM. Porosity. Pores are minute openings on the surface of the scaffold. They can be created in order on the surface of the biomaterial in order to release pre-existing cellular components that could interfere with tissue development. They also help diffuse gas and nutrients to the innermost layers of adherent cells which prevents developing a “necrotic centre” (created when cells which are not in direct contact with the culture medium have died due to a lack of nutrients). Vascularization.
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The BMD is corrected for porosity of the bone, estimated by a texture analysis performed on the cortical part of the bone. Like other technologies for estimating the bone mineral density, the outputs are an areal BMD value, a T-score and a Z-score for assessing osteoporosis and the risk of bone fracture. Digital X-ray radiogrammetry is primarily used in combination with digital mammography for osteoporosis screening, where same mammography machine that is used to acquire breast X-ray images is also used to acquire a hand image for BMD measurement. Due to high precision, DXR is also used for monitoring change in bone mineral density over time.
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