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"attenuation" Definitions
  1. the action of making something weaker or less effective

1000 Sentences With "attenuation"

How to use attenuation in a sentence? Find typical usage patterns (collocations)/phrases/context for "attenuation" and check conjugation/comparative form for "attenuation". Mastering all the usages of "attenuation" from sentence examples published by news publications.

Attenuation is non-trivial at anything beyond, say, a few dozen meters.
They even have independent local power supplies for truly phobic level of interference attenuation.
Two years after completing growth-attenuation therapy, his height has stabilized around 43 inches.
Their walls should be stuffed with sound-attenuation material and topped off with acoustic sealant.
But as greater height in girls became increasingly acceptable, even desirable, growth attenuation fell into disfavor.
Her veins throbbed with the attenuation of pleasure, and she struggled to focus on soft weak reality.
The flaws and limits inherent in overexposure are boredom and attenuation of message — not weakening of power.
The system uses a mathematical model to "see" people in the room based on signal strength and attenuation.
Four settings dictate how open the headphone is, with the most closed option providing the most bass and external noise attenuation.
I say attenuation rather than isolation, because honestly, even the closed-back cans leak sound in and out quite a lot.
" Pidot noted that the report supported "monitored natural attenuation"—seeing if pollution dissipates on its own—and giving companies "technical impracticability waivers.
But because growth-attenuation therapy for very young children is so new and unstudied, its prolonged effects on their bodies remain unknown.
Kappy had never administered growth-attenuation therapy, but he was an author of a paper justifying and laying out guidelines for its practice.
Before undergoing growth-attenuation therapy, Nykkole was given both a hysterectomy and a bilateral mastectomy at the University of Minnesota Masonic Children's Hospital.
Beyerdynamic touts 18dB of ambient noise attenuation just by virtue of the design, which has been inspired by the company's work on pilot headsets.
The system, created by researchers at UC Santa Barbara, uses a single Wi-Fi router outside of the room to measure attenuation and signal drops.
Karrie Shogren, co-director of the Kansas University Center on Developmental Disabilities, believes that growth-attenuation therapy is too often administered without consulting developmental specialists.
" There are obstacles with both approaches, including issues with "signal scattering, attenuation, and signal-to-noise ratio typically seen with state of the art noninvasive neural interfaces.
For the treatment they called "growth-attenuation therapy" to be most effective — resulting in a shorter and lighter child — a careful monitoring of calories was also required.
Allowing precocious puberty, which happens to be common in children with disabilities, to proceed without intervention is like letting a kind of natural growth attenuation take place.
Damage to any of these systems will cause an attenuation in your hearing ability, but there is a wide range of severity based on the degree of injury.
And that if you de-sentimentalize your view of government, you will come to a conclusion that there is more to fear than an attenuation of majority rule.
Conversely, parents who back growth attenuation tend to believe that maximizing pleasurable experiences and minimizing unpleasant ones is the best way to serve a child with extreme disabilities.
The crisp attenuation of the melodic elements undercuts the atmospheric qualities, repeatedly jolting Carti awake while achieving a cognitive dissonance that renders the album both addictive and inscrutable.
That attenuation preceded Trump and Macron, and it has causes that go beyond any two leaders, including fundamental changes in the demographic makeup of both sides of the Atlantic.
The broader trends may have something to do with longer-term Republican ascendance and the attenuation of traditional white working-class allegiance to the Democratic Party, or they may not.
Often textural attenuation thins out musical force, as the bleepy loop on "Clownin" fizzles into mist and the piano on "Twitter Fingers" spirals around at a tempo shy of moderate.
Kittay says that she hopes new parents considering growth-attenuation therapy will not rush into an intractable decision while still coming to terms with a child's diagnosis of intellectual and developmental disability.
Although the intermittent percussion effects crunch nicely, Jewel foregrounds the highest and most linear synthesizers above all, which convincingly recalls rain while also pointing the album's textural palette toward thin, bleepy attenuation.
In part this was because of genetics and his various health problems, but it was also partly a result of his having been through a controversial medical intervention known as growth-attenuation therapy.
Sandy Walker was a member of the Seattle Growth Attenuation and Ethics Working Group, a panel of concerned parents, medical experts, scholars and bioethicists who developed ethical and policy guidelines for health professionals.
To get the best attenuation of external noise and the purest sound, you'll want to use the Comply stuff, but I've been favoring the basic silicone tips because they're quicker and easier to use.
The Studio 3s have a ton of passive noise attenuation, which is to say that even when wearing them on your head without any tech being active, they do a good job muffling external sounds.
"However, the limited bandwidth of a microphone, strong attenuation of aerial acoustic signals, as well as various interferences in the audible band, poses significant challenges in using acoustic signals for indoor localization," the paper explains.
The trunks, branches and above-ground roots growing from the stems of mangrove trees dissipate wave energy and reduce coastal erosion, functioning as a natural braking mechanism on the water - a phenomenon known as "wave attenuation".
The withering of local community, together with the attenuation of the civic ethic, doomed America's once-vibrant republican tradition to a long period of retreat, though it has recently begun showing signs of a possible resurgence.
"A small 2013 study done in trained male sprinters concluded that, 'combining creatine and sodium bicarbonate increased peak and mean power and had the greatest attenuation of decline in relative peak power over six repeat sprints,'" Preiato says.
I find the 535s strike the perfect balance between the deep penetration and extreme noise attenuation of something like the Etymotics (which, by the way, require lubrication before insertion) and the practicality of a more regular pair of earbuds.
A good night's sleep is now a perk for million-dollar apartments, according to the Washington Post, which reported on a luxury condominium building in Denver whose units will include air filtration, lighting, and sound attenuation that's dedicated to sleep.
It features attenuation areas, five feet below ground level, which allow water to drain away, perforated brick facades to deal with heat and humidity and shaded paths and verandahs which allows the use of air-conditioning to be limited to classrooms.
"The attenuation of Clinton's strength in the upper Midwest was so dramatic and evident immediately, because those rural counties come in first in many instances, and they complete first, which for our model is the most important thing," he says.
But while we worried about the liberal vision, our own ideological side was adapting to the family's attenuation in darker ways — speaking not to singletons or single mothers, but to powerful post-familial anxieties among the middle-aged and old.
But in 2019, perhaps surprisingly given the general attenuation of benefits like vacations and pensions to the American worker, more employees at the country's largest and most prominent companies are finding that their companies' health care plans include fertility coverage.
But Hamilton also foresaw its attenuation under the influence of a commercial order, and if he did not wholeheartedly welcome this development, he still considered it both necessary and inevitable, if America was to become the commercial and military empire he envisioned.
That may upset your fellow gym-goers, but you can mute their complaints thanks to the active noise-canceling DSP and full-duplex echo attenuation built into the Backbeats, while 13mm neodymium speakers and a lossless Bluetooth codec fill your ears with sonic perfection.
Because of the basic physics of the closed-back design, you also get better bass response — with Clark claiming the C Flows can reach down into the single digits of Hz (the lower limit of human hearing is 20Hz) — and better attenuation of outside noise.
In other words, a story about the internet is also a story about the attenuation of non-online forms of community, about fatherlessness and family breakdown, about the travails of the "some college" demographic, about the social crisis of coal country and the Rust Belt.
In Meijer's sharp, haunting stories, most of that violence is perpetrated by men — a note she sounds without attenuation, in a way that will undoubtedly call forth protests of "Not all…" in some readers and approving nods of "Right, right, the patriarchy is a horror show" in others.
It's a philosophical failure, the result of a long-term attenuation in the idea of an Atlantic community — the West — united not only by a shared history or common enemies, but also by a unifying set of ethical and political ideals, and the sense that those ideals entwine our destinies.
The mass attenuation coefficient is equal to the molar attenuation coefficient divided by the molar mass.
In chemistry, mass attenuation coefficients are often used for a chemical species dissolved in a solution. In that case, the mass attenuation coefficient is defined by the same equation, except that the "density" is the density of only that one chemical species, and the "attenuation" is the attenuation due to only that one chemical species. The actual attenuation coefficient is computed by :\mu = (\mu/\rho)_1 \rho_1 + (\mu/\rho)_2 \rho_2 + \ldots, where each term in the sum is the mass attenuation coefficient and density of a different component of the solution (the solvent must also be included). This is a convenient concept because the mass attenuation coefficient of a species is approximately independent of its concentration (as long as certain assumptions are fulfilled).
Frequency-dependent attenuation of electromagnetic radiation in standard atmosphere. In many cases, attenuation is an exponential function of the path length through the medium. In chemical spectroscopy, this is known as the Beer–Lambert law. In engineering, attenuation is usually measured in units of decibels per unit length of medium (dB/cm, dB/km, etc.) and is represented by the attenuation coefficient of the medium in question.
In optical fibers, attenuation is the rate at which the signal light decreases in intensity. For this reason, glass fiber (which has a low attenuation) is used for long-distance fiber optic cables; plastic fiber has a higher attenuation and, hence, shorter range. There also exist optical attenuators that decrease the signal in a fiber optic cable intentionally. Attenuation of light is also important in physical oceanography.
This mechanism allows for synchronization of transcription and translation, a key element in attenuation. A similar attenuation mechanism regulates the synthesis of histidine, phenylalanine and threonine.
Mechanism of transcriptional attenuation of the trp operon. Attenuation is a second mechanism of negative feedback in the trp operon. The repression system targets the intracellular trp concentration whereas the attenuation responds to the concentration of charged tRNAtrp. Thus, the trpR repressor decreases gene expression by altering the initiation of transcription, while attenuation does so by altering the process of transcription that's already in progress. While the TrpR repressor decreases transcription by a factor of 70, attenuation can further decrease it by a factor of 10, thus allowing accumulated repression of about 700-fold.
Attenuation: In addition to geometric spreading, absorption and scattering of energy during propagation results in the loss of energy. The attenuation length is the distance at which intensity drops to 1/e(37%) to initial intensity. Environmental factors such as fog, rain and turbulence disturb signal transmission and decreases attenuation length.
They also noted a temporary augmentation of the excitatory response occurring after the attenuation. As a control they tested for attenuation when voltage-sensitive channels were activated by a hyperpolarization current. They concluded that attenuation is not caused by hyperpolarization but by an opening of synaptic receptor channels causing conductance variations.
This is an active area of research and a range of approaches have been developed. One method uses a Dixon MRI sequence, and segments the resultant image into fat and water, with pre-set attenuation factors. Disadvantages of this method include a lack of bone attenuation, and loss of the true continuous range of attenuation factors. Comparisons with PET-CT attenuation maps for oncology purposes however have shown that this is a usable technique.
Attenuation decreases the intensity of electromagnetic radiation due to absorption or scattering of photons. Attenuation does not include the decrease in intensity due to inverse-square law geometric spreading. Therefore, calculation of the total change in intensity involves both the inverse-square law and an estimation of attenuation over the path. The primary causes of attenuation in matter are the photoelectric effect, compton scattering, and, for photon energies of above 1.022 MeV, pair production.
The mass attenuation coefficient, or mass narrow beam attenuation coefficient of the volume of a material characterizes how easily it can be penetrated by a beam of light, sound, particles, or other energy or matter. In addition to visible light, mass attenuation coefficients can be defined for other electromagnetic radiation (such as X-rays), sound, or any other beam that can be attenuated. The SI unit of mass attenuation coefficient is the square metre per kilogram (). Other common units include cm2/g (the most common unit for X-ray mass attenuation coefficients) and mL⋅g−1⋅cm−1 (sometimes used in solution chemistry).
The forearc mantle extends from where the subducting slab meets the cold nose of the mantle wedge, this occurs at depths from 10–40 km. Low seismic attenuation, and high seismic velocities characterize this region. There is a boundary between this low attenuation region and a high attenuation region on the forearc side of the arc volcanoes. To image the mantle wedge region below volcanic arcs P-wave, S-wave and seismic attenuation images should be used in coordination.
Soft tissue and bone have different attenuation coefficients to X-rays. A single X-ray beam passing through the body will be attenuated by both soft tissue and bone, and it is not possible to determine, from a single beam, how much attenuation was attributable to the bone. However, the attenuation coefficients vary with the energy of the X-rays, and, crucially, the ratio of the attenuation coefficients also varies. DXA uses two energies of X-ray.
Regression dilution was first mentioned, under the name attenuation, by Spearman (1904). Those seeking a readable mathematical treatment might like to start with Frost and Thompson (2000), or see correction for attenuation.
The Bragg curve shows the attenuation effect in free air.
In this way, the probe provides a uniform 10× attenuation from DC (with the attenuation provided by the resistors) to very high AC frequencies (with the attenuation provided by the capacitors). In the past, the bypass capacitor in the probe head was adjustable (to achieve this 10× attenuation). More modern probe designs use a laser-trimmed thick-film electronic circuit in the head that combines the 9 megohm resistor with a fixed-value bypass capacitor; they then place a small adjustable capacitor in parallel with the oscilloscope's input capacitance. Either way, the probe must be adjusted so that it provides uniform attenuation at all frequencies.
Attenuation theory is a model of selective attention proposed by Anne Treisman, and can be seen as a revision of Donald Broadbent's filter model. Treisman proposed attenuation theory as a means to explain how unattended stimuli sometimes came to be processed in a more rigorous manner than what Broadbent's filter model could account for. As a result, attenuation theory added layers of sophistication to Broadbent's original idea of how selective attention might operate: claiming that instead of a filter which barred unattended inputs from ever entering awareness, it was a process of attenuation. Thus, the attenuation of unattended stimuli would make it difficult, but not impossible to extract meaningful content from irrelevant inputs, so long as stimuli still possessed sufficient "strength" after attenuation to make it through a hierarchical analysis process.
Attenuation is a regulatory feature found throughout Archaea and Bacteria causing premature termination of transcription.Merino E, Yanofsky C (2005). "Transcription attenuation: a highly conserved regulatory strategy used by bacteria." Trends Genet 21:260–4.
Frequency response of an example bandpass filter. The frequencies between a stopband and a passband define the transition band. A stopband is a band of frequencies, between specified limits, through which a circuit, such as a filter or telephone circuit, does not allow signals to pass, or the attenuation is above the required stopband attenuation level. Depending on application, the required attenuation within the stopband may typically be a value between 20 and 120 dB higher than the nominal passband attenuation, which often is 0 dB.
Averaging and converting the attenuation values into logarithms are possible only if the attenuation does not vary over time. Thus, for relatively small variances, the difference is small but for large variances, the difference is significant.
It can be converted into fluid compressibility. Attenuation is a measure of viscous properties. It can be converted into viscous longitudinal modulus. In the case of a Newtonian liquid, attenuation yields information on the volume viscosity.
The coefficients mn can be adjusted by the designer to set the frequency of one of the two poles of attenuation, ω∞, in each stopband. The second pole of attenuation is dependent and cannot be set separately.
Other measures may use a different factor than e, such as the decadic attenuation coefficient below. The broad-beam attenuation coefficient counts forward-scattered radiation as transmitted rather than attenuated, and is more applicable to radiation shielding.
A similar attenuation mechanism regulates the synthesis of histidine, phenylalanine and threonine.
In CT imaging, attenuation describes the density or darkness of the image.
In reflection seismology, the anelastic attenuation factor, often expressed as seismic quality factor or Q (which is inversely proportional to attenuation factor), quantifies the effects of anelastic attenuation on the seismic wavelet caused by fluid movement and grain boundary friction. As a seismic wave propagates through a medium, the elastic energy associated with the wave is gradually absorbed by the medium, eventually ending up as heat energy. This is known as absorption (or anelastic attenuation) and will eventually cause the total disappearance of the seismic wave.Toksoz, W.M., & Johnston, D.H. 1981.
The variation of the signal is determined by the prediction model according to the atmospheric changes, topographic profile and free space. These variations are described with the help of statistical estimates which have deviations that contribute to the total attenuation of the signal. The statistical estimates or attenuation variables of this prediction model are: I) Situation variability (Ys); II) Time variability (Yt); II) Location variability (YL). The reference attenuation (W) is determined as a function of the distance, attenuation variables and an urban factor for an area or point-to-point.
Moreover, mutational analysis destabilizing or disrupting the base-pairing of the antiterminator hairpin results in increased termination of several folds; consistent with the attenuation model, this mutation fails to relieve attenuation even with starved Trp. In contrast, complementary oligonucleotides targeting strand 1 increases the operon expression by promoting the antiterminator formation. Furthermore, in histidine operon, compensatory mutation shows that the pairing ability of strands 2–3 matters more than their primary sequence in inhibiting attenuation. In attenuation, where the translating ribosome is stalled determines whether the termination hairpin will be formed.
The degree of attenuation can change in relation to the content of the underlying message; with larger amounts of attenuation taking place for incoherent messages that possess little benefit to the person hearing them. Incoherent messages receive the greatest amounts of attenuation because any interference they might exhibit upon the attended message would be more detrimental than that of comprehensible, or complimentary information. The level of attenuation can have a profound impact on whether an input will be perceived or not, and can dynamically vary depending upon attentional demands.
Light attenuation by ZBLAN and silica fibers Attenuation in fiber optics, also known as transmission loss, is the reduction in intensity of the light beam (or signal) with respect to distance traveled through a transmission medium. Attenuation coefficients in fiber optics usually use units of dB/km through the medium due to the very high quality of transparency of modern optical transmission media. The medium is usually a fiber of silica glass that confines the incident light beam to the inside. Attenuation is an important factor limiting the transmission of a signal across large distances.
One way to detect fiber tapping is by noting increased attenuation added at the point of tapping. Some systems can detect sudden attenuation on a fiber link and will automatically raise an alarm. There are, however, tappers which allow tapping without significant added attenuation. In either case there should be a change of scattering pattern in that point in line which, potentially, can be detectable.
The typical effects of some of these on filter frequency response are shown in figure 11. Bridging across a single resonator (figure 11b) can produce a pole of attenuation in the high stopband. Bridging across two resonators (figure 11c) can produce a pole of attenuation in both the high and the low stopband. Using multiple bridges (figure 11d) will result in multiple poles of attenuation.
In physics, attenuation or, in some contexts, extinction is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates. Hearing protectors help reduce acoustic flux from flowing into the ears. This phenomenon is called acoustic attenuation and is measured in decibels (dBs).
Long copper wires suffer from attenuation at high frequencies. The fact that OFDM can cope with this frequency selective attenuation and with narrow-band interference are the main reasons it is frequently used in applications such as ADSL modems.
STC is used to avoid saturation of the receiver from close in ground clutter by adjusting the attenuation of the receiver as a function of distance. More attenuation is applied to returns close in and is reduced as the range increases.
Mathematical Q models provide a model of the earth's response to seismic waves. In reflection seismology, the anelastic attenuation factor, often expressed as seismic quality factor or Q, which is inversely proportional to attenuation factor, quantifies the effects of anelastic attenuation on the seismic wavelet caused by fluid movement and grain boundary friction. When a plane wave propagates through a homogeneous viscoelastic medium, the effects of amplitude attenuation and velocity dispersion may be combined conveniently into the single dimensionless parameter, Q. As a seismic wave propagates through a medium, the elastic energy associated with the wave is gradually absorbed by the medium, eventually ending up as heat energy. This is known as absorption (or anelastic attenuation) and will eventually cause the total disappearance of the seismic wave.
It is possible to extrapolate the cumulative attenuation distribution at a given location by using the CCIR interpolation formula:CCIR [1990] Report 564-4 "Propagation data and prediction methods required for earth-space telecommunication systems" : Ap = A001 0.12 p−(0.546 − 0.0043 log10 p). where Ap is the attenuation in dB exceeded for a p percentage of the time and A001 is the attenuation exceeded for 0.01% of the time.
However, the Bacteroid-trp RNA motif likely operates via the same mechanism of attenuation.
Tomographic studies of the underlying crust indicate a pattern of seismic attenuation beneath Tipas.
Stokes' law (sound attenuation) provides relationship among attenuation, dynamic viscosity and volume viscosity of the Newtonian fluid. This type of rheometer works at much higher frequencies than others. It is suitable for studying effects with much shorter relaxation times than any other rheometer.
These tests for checking attenuation values summarize the real- world attenuation in a personal attenuation rating (PAR). The PAR is unique to the HPD tested and the individual wearing the protection. When obtaining a PAR, it is recommended to test both ears individually as there may be asymmetry between ears. This asymmetry can be caused by anatomical differences between ears or improper fit of the HPD and could lead to a unilateral threshold shift.
Complex values of permittivity and permeability typically correspond to attenuation in a medium. Most of the work in metamaterials is focused on the real parts of these parameters, which relate to wave propagation rather than attenuation. The loss (imaginary) components are small in comparison to the real parts and are often neglected in such cases. However, the loss terms (ε2 and µ2) can also be engineered to create high attenuation and correspondingly large absorption.
PET-MRI systems don't offer a direct way to obtain attenuation maps, unlike stand-alone PET or PET-CT systems. Stand alone PET systems' attenuation correction (AC) is based on a transmission scan (mu - map) acquired using a 68Ge (Germanium-68) rotating rod source, which directly measures photon attenuation at 511 keV. PET-CT systems use a low-dose CT scan for AC. Since X-rays have a range of energies lower than 511 keV, AC values are closely approximated from Hounsfield units. There is no correlation between MR image intensity and electron intensity, therefore conversion of MR images into an attenuation map is difficult.
Levy, pp. 529 Like the Chebyshev filter, the Achieser-Zolotarev filter has equal ripple attenuation in the passband. The essential difference is that the first peak in attenuation of the Achieser-Zolotarev filter is greater than the design preset ripple for the other peaks.Cameron et al.
Q in cm−1) is variously called opacity, absorption coefficient, and attenuation coefficient. In nuclear physics, area cross-sections (e.g. σ in barns or units of 10−24 cm2), density mean free path (e.g. τ in grams/cm2), and its reciprocal the mass attenuation coefficient (e.g.
Seismically, the high bottom simulating reflectors are considered indicative of gas hydrates (Colwell et al., 2004). Methane-rich horizons have been identified as areas of higher attenuation of sonic frequencies (10 to 20 kHz) and only slight attenuation of seismic frequencies (30 to 110 Hz) (Matsushima, 2006).
The hold control is often set to ensure the gate does not close during short pauses between words or sentences in a speech signal. The range control is used to set the amount of attenuation to be applied to the signal when the gate is closed. Often there will be complete attenuation, that is no signal will pass when the gate is closed. In some circumstances, complete attenuation is not desired and the range can be changed.
Various mathematical forms such as Gamma function, lognormal or exponential forms are usually used to model the DSD. Mie or Rayleigh scattering theory with point matching or t-matrix approach is used to calculate the scattering cross section, and specific rain attenuation. Since rain is a non-homogeneous process in both time and space, specific attenuation varies with location, time and rain type. Total rain attenuation is also dependent upon the spatial structure of rain field.
In contrast-enhanced CT, small GISTs are seen as smooth, sharply defined intramural masses with homogeneous attenuation.
In many of the above methods, MRI artifacts (e.g. from physiological motion) can affect attenuation correction accuracy.
The tube output is then adjusted for overall size. The output is also typically modulated for each rotation in response to changes in attenuation over patient length. Some systems adjust output during each rotation, which is known as rotational modulation, based on measured attenuation in the previous rotation.
The optical depth equals the absorbance times ln(10). The term absorption refers to the physical process of absorbing light, while absorbance does not always measure absorption: it measures attenuation (of transmitted radiant power). Attenuation can be caused by absorption, but also reflection, scattering, and other physical processes.
Attenuation, the opposite of amplification, is necessary when voltages to be digitized are beyond the ADC range. This form of signal conditioning decreases the input signal amplitude so that the conditioned signal is within ADC range. Attenuation is typically necessary when measuring voltages that are more than 10 V.
Should all of these physical characteristics be identical between messages, then attenuation can not effectively take place at an early level based on these properties. Instead, attenuation will occur during the identification of words and meaning, and this is where the capacity to handle information can be scarce.
Often, this is achieved at the expense of pass-band or stop-band ripple. The bandwidth of the filter is simply the difference between the upper and lower cutoff frequencies. The shape factor is the ratio of bandwidths measured using two different attenuation values to determine the cutoff frequency, e.g., a shape factor of 2:1 at 30/3 dB means the bandwidth measured between frequencies at 30 dB attenuation is twice that measured between frequencies at 3 dB attenuation.
Once the custom mold is made, it will need to be inspected by the Audiologist for proper fit on the patient. Hearing protection should also be verified using real-ear methods to ensure proper attenuation. Real-ear attentuation at threshold (REAT) measurements test how tones of varying frequency are attenuated with and without the custom mold in place. Testing for low-frequency attenuation can help to verify the earmold fit while testing high-frequency attenuation can verify the properties of the filter used.
Because of this variability, there could be deviations (δ) more or less significant to the attenuation of the transmitted signal. The received signal (W) is obtained signal level attenuated in free space (W0) attenuated by the sum of the attenuation formed by random variables. If transmitter and receiver are at known points, the location variable has a value of zero. The reference attenuation defined as a function of distance also features 3 ranges for prediction: I) line-of-sight; II) diffraction; III) scatter.
A first finishing layer is then applied on top of the substrate panels and when dried, produces a first layer of sound attenuation. A second finishing layer may also be added to create a second system of sound attenuation. If the second density if less than or equal to that of the first layer, the sound attenuation of the second layer would be greater than the first and vice versa. This allows for the flexibility of changing the acoustic properties of the space.
ITU-R P.525 is the International Telecommunications Union radiocommunications standard for the calculation of free-space attenuation.
For instance, the NRR is determined by the mean attenuation minus two standard deviations. Thus, it translates to a 98% statistic. That is, at least 98 percent of users should be able to achieve that level of attenuation. The SNR and HML are a mean minus one standard deviation statistic.
Attenuation is an important consideration in the modern world of wireless telecommunication. Attenuation limits the range of radio signals and is affected by the materials a signal must travel through (e.g., air, wood, concrete, rain). See the article on path loss for more information on signal loss in wireless communication.
A closely related concept is molar absorptivity. They are quantitatively related by :(mass attenuation coefficient) × (molar mass) = (molar absorptivity).
Other applications include helpful algorithms in seismic data regularization, prediction error filters, and noise attenuation in geophysical digital systems.
Since then commonly used commercial/ research terahertz imaging systems have used pulsed lasers to generate terahertz images. The image can be developed based on either the attenuation or phase delay of the transmitted terahertz pulse. Since the beam is scattered more at the edges and also different materials have different absorption coefficients, the images based on attenuation indicates edges and different materials inside of an objects. This approach is similar to X-ray transmission imaging, where images are developed based on attenuation of the transmitted beam.
The Figure provided in provided an estimation of the attenuation that the ultrasound would suffer as it propagated through air. The figures from this graph correspond to completely linear propagation, and the exact effect of the nonlinear demodulation phenomena on the attenuation of the ultrasonic carrier waves in air was not considered. There is an interesting dependence on humidity. Nevertheless, a 50 kHz wave can be seen to suffer an attenuation level in the order of 1 dB per meter at one atmosphere of pressure.
Monitored Natural Attenuation is in situ bioremediation that occurs with little to no human intervention. This process relies on the natural microbial populations sustained within the contaminated sites to over time reduce the contaminants to a desired level. During monitored natural attenuation the site is monitored in order to track the progress of the bioremediation. Monitored natural attenuation is used in sites where the source of contamination is no longer present, often after other more active types of in situ bioremediation have been conducted.
Copper is more reliable than radio links. Signal attenuation with copper wires and cables can be resolved with signal amplifiers.
Bianca Albanese et al. Energy Attenuation Performance of Impact Protection Worn by Motorcyclists in Real-World Crashes. Traffic Inj Prev.
In some applications, such as in the design of graphic equalizers or CD players, the filters are designed according to a set of objective criteria such as pass band, pass band attenuation, stop band, and stop band attenuation, where the pass bands are the frequency ranges for which audio is attenuated less than a specified maximum, and the stop bands are the frequency ranges for which the audio must be attenuated by a specified minimum. In more complex cases, an audio filter can provide a feedback loop, which introduces resonance (ringing) alongside attenuation. Audio filters can also be designed to provide gain (boost) as well as attenuation. In other applications, such as with synthesizers or sound effects, the aesthetic of the filter must be evaluated subjectively.
33–37 Both these methods have significant errors due to laser extinction, signal attenuation, and secondary emissionC. T. Brown, V. G. McDonell, and D. G. Talley, (2002). Accounting for Laser Extinction, Signal Attenuation, and Secondary Emission while Performing Optical Patternation in a Single Plane, Proceedings of ILASS Americas ’00, Madison, Wisconsin, pp. 195-199.
Signal attenuation could be measured as well, as the coupling with the additional surface mass will reduce the wave energy. In the case of mass-sensing, as the change in the signal will always be due to an increase in mass from a reference signal of zero additional mass, signal attenuation can be effectively used.
In this case SvO_2 \, ≈ 60% (venous oxygen saturation). Then oxyhemoglobin and deoxyhemoglobin will have similar contributions to the total absorption (black) and the effective attenuation (magenta) coefficient spectra, as shown in Figure 6 (b). Figure 7: : Effective penetration depth in breast tissue (StO2 ≈ 70%). Effective attenuation coefficient: λmin = 730 nm; NIR window = (626 - 1316) nm.
Most oscilloscopes provide for probe attenuation factors, displaying the effective sensitivity at the probe tip. Historically, some auto-sensing circuitry used indicator lamps behind translucent windows in the panel to illuminate different parts of the sensitivity scale. To do so, the probe connectors (modified BNCs) had an extra contact to define the probe's attenuation. (A certain value of resistor, connected to ground, "encodes" the attenuation.) Because probes wear out, and because the auto-sensing circuitry is not compatible between different oscilloscope makes, auto-sensing probe scaling is not foolproof.
In brewing, attenuation refers to the conversion of sugars into alcohol and carbon dioxide by the fermentation process; the greater the attenuation, the more sugar has been converted into alcohol. A more attenuated beer is drier and more alcoholic than a less attenuated beer made from the same wort. Attenuation can be quantified by comparing the specific gravity — the density of a solution, relative to pure water — of the extract before and after fermentation, quantities termed the original and final gravities. Specific gravity can be measured by buoyancy, with a hydrometer.
53 Because fermentation produces ethanol, which has a lower density than water (gravity of 0.787 at °C ), the apparent attenuation overestimates the actual percentage of sugars consumed. Brewers generally refer to this apparent attenuation when using the word without qualification, although the measurement of real attenuation — the actual percentage of sugar consumed by the yeast — is an important indicator of yeast health and for producing certain styles of beer. A beer which does not attenuate to the expected level in fermentation will have more residual sugar and thus be sweeter and heavier- bodied.
Attenuation distortion is the distortion of an analog signal that occurs during transmission when the transmission medium does not have a flat frequency response across the bandwidth of the medium or the frequency spectrum of the signal.Rowe, Standord H. II, Network Technology & Service Integration (5th Edition), 2002, Prentice-Hall, Inc., 2002 Attenuation distortion occurs when some frequencies are attenuated more than other frequencies. When an analog signal of constant amplitude across its frequency spectrum suffers attenuation distortion, some frequencies of the received signal arrive being greater in amplitude (louder), relative to other frequencies.
To overcome the effects of attenuation distortion, communications circuits have special equalization equipment attached at the ends of the circuit or in between, designed to attenuate the signal evenly across the frequency spectrum, or to allow the signal to be received at equal amplitude for all frequencies. Attenuation distortion can still occur in a properly equipped circuit if this equalization filter is not properly maintained or adjusted. In DSL circuits, echoes due to impedance mismatch often cause attenuation distortion so severe that some frequencies must be automatically mapped out and not used.
Attenuation in fiber optics, also known as transmission loss, is the reduction in intensity of the light beam (or signal) with respect to distance travelled through a transmission medium. Attenuation coefficients in fiber optics usually use units of dB/km through the medium due to the relatively high quality of transparency of modern optical transmission media. The medium is typically a fiber of silica glass that confines the incident light beam to the inside. Attenuation is an important factor limiting the transmission of a digital signal across large distances.
Y. B. Kudriashov. Radiation Biophysics. . Page xxi. Tarkhanov found a marked attenuation of excitability and a total suppression of acidic reflexes.
However, in the third week, parenchymal volume loss commonly appears as a hypoattenuation (decreased attenuation) with a negative mass effect (shrinkage).
In a study on middle cerebral artery occlusion (MCAO) rats, those treated with MNET experienced a significant attenuation of neurological damage.
The carbonyl group attenuation at about 6 micrometres can be detected quite easily, and degree of oxidation of the polymer calculated.
In telecommunications, a cutback technique is a destructive technique for determining certain optical fiber transmission characteristics, such as attenuation and bandwidth.
The attenuation constant for a particular propagation mode in an optical fiber is the real part of the axial propagation constant.
In eccentric contractions, elastic tendons have the ability to operate as power attenuation. Tendons exhibit power attenuation that allows the muscle-tendon systems to absorb energy. This rate exceeds the muscle's maximum capacity for energy. In comparison, power amplification of tendons allow for greater output of power that can exceed the capacity of their respective muscle.
A PAR can be reported as C-weighted values, A-weighted values, or attenuation values for specific frequencies. The PAR can then be used to determine if the HPD is providing adequate attenuation so that an individual's noise exposure does not exceed the recommended limits set forth by regulatory agencies such as the Occupational Safety and Health Administration (OSHA).
This same phenomenon is seen as one of the limiting factors in the transparency of infrared missile domes. Further attenuation is caused by light absorbed by residual materials, such as metals or water ions, within the fiber core and inner cladding. Light leakage due to bending, splices, connectors, or other outside forces are other factors resulting in attenuation.
After the initial phase of attenuation, information is then passed on to a hierarchy of analyzers that perform higher level processes to extract more meaningful content (see "Hierarchical analyzers" section below). The crucial aspect of attenuation theory is that attended inputs will always undergo full processing, whereas irrelevant stimuli often lack a sufficiently low threshold to be fully analyzed, resulting in only physical qualities being remembered rather than semantics. Additionally, attenuation and then subsequent stimuli processing is dictated by the current demands on the processing system. It is often the case that not enough resources are present to thoroughly process unattended inputs.
In genetics, attenuation is a proposed mechanism of control in some bacterial operons which results in premature termination of transcription and is based on the fact that, in bacteria, transcription and translation proceed simultaneously. Attenuation involves a provisional stop signal (attenuator), located in the DNA segment that corresponds to the leader sequence of mRNA. During attenuation, the ribosome becomes stalled (delayed) in the attenuator region in the mRNA leader. Depending on the metabolic conditions, the attenuator either stops transcription at that point or allows read-through to the structural gene part of the mRNA and synthesis of the appropriate protein.
Toksoz, W.M., & Johnston, D.H. 1981. Seismic Wave Attenuation. SEG. The frequency-dependent attenuation of seismic waves leads to decreased resolution of seismic images with depth. Transmission losses may also occur due to friction or fluid movement, and for a given physical mechanism, they can be conveniently described with an empirical formulation where elastic moduli and propagation velocity are complex functions of frequency.
Both scattering and attenuation are heavily influenced by the amount of organic matter dissolved in the water. Another problem with water is that light attenuation is a function of the wavelength. This means that different color get attenuated faster than others, leading to color degradation. Red and orange light is the first to get attenuated, followed by yellows and greens.
Danish military radio relay node Because of the high frequencies used, a line-of-sight path between the stations is required. Additionally, in order to avoid attenuation of the beam, an area around the beam called the first Fresnel zone must be free from obstacles. Obstacles in the signal field cause unwanted attenuation. High mountain peak or ridge positions are often ideal.
Higher power can overcome the loss to rain fade. Measurements of rain attenuation in Indonesia have been done for satellite communication links in Padang, Cibinong, Surabaya and Bandung. The DAH Model for rain attenuation prediction is valid for Indonesia, as is the ITU model. The DAH model has become an ITU recommendation since 2001 (Recommendation No. ITU-R P.618-7).
Alternatively, a stopband corner frequency may be specified as a point where a transition band and a stopband meet: a frequency for which the attenuation is larger than the required stopband attenuation, which for example may be 30 dB or 100 dB. In the case of a waveguide or an antenna, the cutoff frequencies correspond to the lower and upper cutoff wavelengths.
In May 2008 ended the gravel mining and began the partial attenuation of the lakes. Now, some Maasplassen are equipped for recreation or nature.
Television pictures propagated via F2 tend to suffer from characteristic ghosting and smearing. Picture degradation and signal strength attenuation increases with each subsequent F2 hop.
Acoustic attenuation in a lossy medium plays an important role in many scientific researches and engineering fields, such as medical ultrasonography, vibration and noise reduction.
For lossy media, more intricate models need to be applied in order to take into account frequency-dependent attenuation and phase speed. Such models include acoustic wave equations that incorporate fractional derivative terms, see also the acoustic attenuation article or the survey paper.S. P. Näsholm and S. Holm, "On a Fractional Zener Elastic Wave Equation," Fract. Calc. Appl. Anal. Vol. 16, No 1 (2013), pp.
Using a WE/SS 8P8C crimp die set on a Tyco/AMP 8P8C plug crushes the top of the connector and damages the crimp die set, and vice versa. Both types of 8P8C plugs are available in shielded and unshielded varieties for different attenuation tolerances as needed. Shielded plugs are more expensive and require shielded cable, but have a lower attenuation, and may reduce signal noise.
Attenuation-to-Crosstalk ratio (ACR) is the difference between the signal attenuation produced NEXT and is measured in decibels (dB). The ACR indicates how much stronger the attenuated signal is than the crosstalk at the destination (receiving) end of a communications circuit. The ACR figure must be at least several decibels for proper performance. If the ACR is not large enough, errors will be frequent.
On the other hand, acoustic wave equations based on fractional derivative viscoelastic models are applied to describe the power law frequency dependent acoustic attenuation. Chen and Holm proposed the positive fractional derivative modified Szabo's wave equation and the fractional Laplacian wave equation. See Holm S., Näsholm, S. P., "Comparison of Fractional Wave Equations for Power Law Attenuation in Ultrasound and Elastography," Ultrasound Med. Biol., 40(4), pp.
Transmission scans directly measure attenuation values at 511keV. Attenuation occurs when photons emitted by the radiotracer inside the body are absorbed by intervening tissue between the detector and the emission of the photon. As different LORs must traverse different thicknesses of tissue, the photons are attenuated differentially. The result is that structures deep in the body are reconstructed as having falsely low tracer uptake.
Lord Rayleigh, The theory of sound, 2ndedition, Dover, New York (2), Sec.322, (1945). This shows that he related thermoacoustics to the interplay of density variations and heat injection. The formal theoretical study of thermoacoustics started by Kramers in 1949 when he generalized the Kirchhoff theory of the attenuation of sound waves at constant temperature to the case of attenuation in the presence of a temperature gradient.
In a wireless network with link adaptation, and without co-channel interference from nearby wireless networks, the bit rate depends heavily on the carrier to noise ratio (CNR), which depends on the attenuation on the link between the transmitter and receiver, i.e. the path loss. For maximum throughput scheduling, links that are affected by low attenuation should be considered as inexpensive, and should be given scheduling priority.
This new NRR should be subtracted from the individuals time weighted average (TWA) noise exposure. It must then be determined if the attenuation is appropriate for the level of noise the individual is exposed to. There are several fit testing devices on the market that will measure the attenuation an individual receives when wearing their HPD. These systems typically use one of two methods to verify fit.
Although kinetic imaging has been used only with X-rays thus far, in theory, the kinetic method can be applied to any imaging technique that uses penetrating radiation, such as X-ray radiography or transmission electron microscopy. These imaging techniques are similar in that they involve reconstruction of the 2-D projectional image ("shadow image") of the studied 3-D object obtained by calculating the attenuation of the penetrating radiation along every projectional axis. The detectors measure an attenuation- related parameter specific to the type of radiation (usually transmitted photon number). Traditionally, these parameters are binned into a single image from which the attenuation values can be calculated.
Research has shown that Bayesian methods that involve a Poisson likelihood function and an appropriate prior probability (e.g., a smoothing prior leading to total variation regularization or a Laplacian distribution leading to \ell_1-based regularization in a wavelet or other domain), such as via Ulf Grenander's Sieve estimator or via Bayes penalty methods or via I.J. Good's roughness method may yield superior performance to expectation-maximization- based methods which involve a Poisson likelihood function but do not involve such a prior. Attenuation correction: Quantitative PET Imaging requires attenuation correction. In these systems attenuation correction is based on a transmission scan using 68Ge rotating rod source.
These findings based on feature integration theory and the attenuation model contradicted those of Broadbent's model because Broadbent stated that people could not make meaningful connections.
The anelastic attenuation factor (or Q) is a seismic attribute that can be determined from seismic reflection data for both reservoir characterisation and advanced seismic processing.
In a cascaded topology, the propagation constant, attenuation constant and phase constant of individual sections may be simply added to find the total propagation constant etc.
Some of the acoustic energy travelled round trip distances of over . The sound signals provided one of the early measurements of underwater sound attenuation at low frequencies.
The second law of thermodynamics ensures a higher attenuation of shear wave reflected energy, this tends to impede the utilization of shear wave information for smaller earthquakes.
Harding's Pits are managed by local volunteers under a management firm, which has successfully fought off the Borough Council's attempts to turn them into an attenuation drain.
The ITU Single Vegetative Obstruction Model is a Radio propagation model that quantitatively approximates the attenuation due to the vegetation in the middle of a telecommunication link.
In biochemistry, the molar attenuation coefficient of a protein at depends almost exclusively on the number of aromatic residues, particularly tryptophan, and can be predicted from the sequence of amino acids. Similarly, the extinction coefficient of nucleic acids at 260 nm can be predicted given the nucleotide sequence. If the molar attenuation coefficient is known, it can be used to determine the concentration of a protein in solution.
Dissipative silencers attenuate sound by transferring sound energy to heat. Dissipative silencers are used when broadband attenuation with low pressure drop is desired. In typical ductwork, high frequencies propagate down the duct as a beam, and minimally interact with the outer, lined edges. Sound attenuators with baffles that break the line of sight or elbow attenuators with a bend provide better high frequency attenuation than conventional lined ductwork.
Some probe designs have additional pins surrounding the BNC or use a more complex connector than a BNC. These extra connections allow the probe to inform the oscilloscope of its attenuation factor (10×, 100×, other). The oscilloscope can then adjust its user displays to automatically take into account the attenuation and other factors caused by the probe. These extra pins can also be used to supply power to active probes.
Amplitude Versus Offset (AVO) is a technique used in seismic inversion to forecast the existence of reservoirs and the rock types surrounding it. Literature reviews and studies incorporate the analysis of AVO and seismic inversion in oil exploration and rock physics studies. Seismic waves projected into oil reservoirs undergoing steam injection give data that show the existence of high values of wave attenuation. This attenuation is usually based on velocity dispersion.
Improved spectral decomposition techniques have shown the frequency dependent parameters more clearly. Saturated rocks, for example, have seismic low frequency effects concerning hydrocarbon-saturated rocks. Furthermore, hydrocarbon-saturated zones have extremely high values of attenuation from the direct quality factor (Q) measurements. Systemic variations of frequencies with offset, where the standard amplitude against the offset is the AVO, disregards attenuation resulting in the use of the purely reflective model.
The noise in the model captures external interference and/or electronic noise in the receiver. If the attenuation term is complex it also describes the relative time a signal takes to get through the channel. The statistics of the random attenuation are decided by previous measurements or physical simulations. Channel models may be continuous channel models in that there is no limit to how precisely their values may be defined.
Example of strong attenuation when a line of thunderstorms moves over (from left to right images) a 5 cm wavelength weather radar (red arrow). Source: Environment Canada Microwaves used in weather radars can be absorbed by rain, depending on the wavelength used. For 10 cm radars, this attenuation is negligible. That is the reason why countries with high water content storms are using 10 cm wavelength, for example the US NEXRAD.
Under certain conditions the Beer–Lambert law fails to maintain a linear relationship between attenuation and concentration of analyte.Mehta A.Limitations and Deviations of Beer–Lambert Law These deviations are classified into three categories: # Real—fundamental deviations due to the limitations of the law itself. # Chemical—deviations observed due to specific chemical species of the sample which is being analyzed. # Instrument—deviations which occur due to how the attenuation measurements are made.
The molar attenuation coefficient is also known as the molar extinction coefficient and molar absorptivity, but the use of these alternative terms has been discouraged by the IUPAC.
This facilitates a rough computation of the attenuation of the plane wave by the knife-edge of height h at a location (x, z) beyond the knife edge.
1), as long as the assumption that all directions are represented in the capillaries (ie there is no net coherent flow in any direction) is satisfied. Fig. 1. It is responsible for a signal attenuation in diffusion MRI, which depends on the velocity of the flowing blood and the vascular architecture. Similarly to molecular diffusion, the effect of pseudodiffusion on the signal attenuation depends on the b value. However, the rate of signal attenuation resulting from pseudodiffusion is typically an order of magnitude greater than molecular diffusion in tissues, so its relative contribution to the diffusion-weighted MRI signal becomes significant only at very low b values, allowing diffusion and perfusion effects to be separated.
A standard linear solid Q model (SLS) for attenuation and dispersion is one of many mathematical Q models that gives a definition of how the earth responds to seismic waves. When a plane wave propagates through a homogeneous viscoelastic medium, the effects of amplitude attenuation and velocity dispersion may be combined conveniently into a single dimensionless parameter, Q, the medium-quality factor. Transmission losses may occur due to friction or fluid movement, and whatever the physical mechanism, they can be conveniently described with an empirical formulation where elastic moduli and propagation velocity are complex functions of frequency. Ursin and ToverudUrsin B. and Toverud T. 2002 Comparison of seismic dispersion and attenuation models.
In turn, structural differences in the pant-hoot are observed based upon habitat differentiation within populations. Pant-hoot calls are used as a form of long-distance communication between members of chimp parties, therefore, sound attenuation is an important consideration in the production of these calls. Individuals living in forest ecosystems must modify the structure of their pant-hoot to reduce the effects of degradation and attenuation on the transmission of their call due to the high number trees obstructing the pathway of the travelling sound. These obstructions increase the possibility of refraction and scattering of the sound waves, therefore increasing the rate of attenuation and decreasing the effectiveness of the calls.
A logarithmic resistor ladder is an electronic circuit composed of a series of resistors and switches, designed to create an attenuation from an input to an output signal, where the logarithm of the attenuation ratio is proportional to a digital code word that represents the state of the switches. The logarithmic behavior of the circuit is its main differentiator in comparison with digital- to-analog converters in general, and traditional R-2R Ladder networks specifically. Logarithmic attenuation is desired in situations where a large dynamic range needs to be handled. The circuit described in this article is applied in audio devices, since human perception of sound level is properly expressed on a logarithmic scale.
Bianca Albanese et al. Energy Attenuation Performance of Impact Protection Worn by Motorcyclists in Real- World Crashes. Traffic Inj Prev. 2017 May 29;18(sup1):S116-S121. doi: 0.1080/15389588.2017.1311014.
Her innovative method uses a model that sharpens the peaks of the measured attenuation histograms of the images to minimize noise while preventing too much smoothing of the data.
In the case of acoustic rheometers, the raw data are converted into extensional viscosity or volume viscosity. Instruments that employ ultrasound attenuation spectroscopy are referred to as Acoustic spectrometers.
Other methods for estimating ventricular volume exist, but the Massardo method is sufficiently accurate and simple to perform, avoiding the need for blood samples, attenuation corrections or decay corrections.
National Acoustic LaboratoriesThe HEARing CRC The review results (which include attenuation measures and user ratings of comfort, fit and sound quality) are available at What Plug?.What Plug? A more expensive option is the custom molded musician's earplug, which is custom-made for the individual listener. These earplugs are typically made out of silicone or vinyl materials and come with a vent and a variety of filters that can change the amount of attenuation provided.
The most common application for this phenomenon is microwave rain radar, but rain scatter propagation can be a nuisance causing unwanted signals to intermittently propagate where they are not anticipated or desired. Similar reflections may also occur from insects though at lower altitudes and shorter range. Rain also causes attenuation of point-to-point and satellite microwave links. Attenuation values up to 30 dB have been observed on 30 GHz during heavy tropical rain.
The devices may be attached to the bird being tracked by a harness, or to the band on the bird's leg. The weights of geolocators range from 0.3g upwards, with a battery life of 6 months to 5 years. The main accuracy limitation of light level geolocation is due to the uncertainty in the amount of attenuation of the ambient light level at any particular time. Light attenuation can have many causes e.g.
A set of many such projections under different angles organized in 2D is called sinogram (see Fig. 3). In X-ray CT, the line integral represents the total attenuation of the beam of x-rays as it travels in a straight line through the object. As mentioned above, the resulting image is a 2D (or 3D) model of the attenuation coefficient. That is, we wish to find the image \mu(x,y).
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. Path loss is a major component in the analysis and design of the link budget of a telecommunication system. This term is commonly used in wireless communications and signal propagation. Path loss may be due to many effects, such as free-space loss, refraction, diffraction, reflection, aperture-medium coupling loss, and absorption.
This is much larger than the attenuation length for gamma rays. Radiopure copper for nEXO has been completed. It is planned for installation in the SNOLAB "Cryopit". Video available at .
The real part of the propagation constant is the attenuation constant and is denoted by Greek lowercase letter α (alpha). It causes signal amplitude to decrease along a transmission line.
Either type is capable of good harmonic rejection if a small additional loss is acceptable. The low-pass π has exceptional harmonic attenuation at any setting, including the lowest-loss.
In this way, the attenuation of the stopbands can be deepened over a broad frequency range.Taylor & Huang, p.361. Figure 11. Schematic bridging arrangements and their effect on frequency response.
Zhuo M and Gebhart GF (2002). Facilitation and attenuation of a visceral nociceptive reflex from the rostroventral medulla in the rat. Gastroenterology 122, 1007-1019.Zhuo M and Gebhart GF (2002).
The high level of attenuation (or data signal loss) from access BPL power cables had two critical effects: It limited bandwidth, and it attracted opposition from groups within the radio community.
Research conducted on microRNA processing showed an evidence of attenuation process in Eukaryotes. After co-transcriptional endonucleolitical cleavage by Drosha 5'->3' exonuclease XRN2 may terminate further transcription by torpedo mechanism.
In this case SaO_2 \, ≈ 98% (arterial oxygen saturation). Then oxyhemoglobin will be dominant in the total absorption (black) and the effective attenuation (magenta) coefficient spectra, as shown in Figure 6 (a).
The phenomenon that one part of the detector cannot differentiate between different tissues is called the "Partial Volume Effect". That means that a big amount of cartilage and a thin layer of compact bone can cause the same attenuation in a voxel as hyperdense cartilage alone. Water has an attenuation of 0 Hounsfield units (HU), while air is −1,000 HU, cancellous bone is typically +400 HU, and cranial bone can reach 2,000 HU or more (os temporale) and can cause artifacts. The attenuation of metallic implants depends on the atomic number of the element used: Titanium usually has an amount of +1000 HU, iron steel can completely extinguish the X-ray and is, therefore, responsible for well-known line-artifacts in computed tomograms.
Preclinical SPECT is a quantitative imaging modality. The uptake of SPECT tracers in organs (regions) of interest can be calculated from reconstructed images. The small size of laboratory animals diminishes the photon’s attenuation in the body of the animal (compared to one in human-sized objects). Nevertheless, depending on the energy of γ-photons and the size of the animal that is used for imaging, correction for photon attenuation and scattering might be required to provide good quantification accuracy.
In a single channel communication system the deamplification and loss present on them can be simplistically taken as attenuation by a percentage g, then amplifiers restore the signal power level to the same value at transmission setup by operating at a gain of 1/ (1-g). E.g. if we experience 6dB attenuation in transmission, i.e. 75% loss, then we have to amplify the signal by a factor of 4x to restore the signal to the transmitter levels.
Trp operon genes are arranged in the same order in E. coli and Bacillus subtilis. Regulation of trp operons in both organisms depends on the amount of trp present in the cell. However, the primary regulation of tryptophan biosynthesis in B. subtilis is via attenuation, rather than repression, of transcription. In B. subtilis, tryptophan binds to the eleven-subunit tryptophan-activated RNA-binding attenuation protein (TRAP), which activates TRAP's ability to bind to the trp leader RNA.
Higher power may result in melting or cracking. Absorptive filter attenuation values are usually valid for the visible spectrum (500–800 nm) and are not valid outside of that spectral region. Some filters can be ordered and calibrated for near-infrared wavelengths, up to the long wavelength absorption edge of the substrate (around 2.2 μm for glasses). Typically, one can expect about 5-10% variation of the attenuation across a ND filter, unless specified otherwise to the manufacturer.
The docking and undocking mechanism are observed to be affected not only by the ligand, but also with other factors like Mg salt. Like any other riboswitch, the two most common types of gene regulation mediated by preQ1 riboswitch are through transcription attenuation or inhibition of translation initiation. Ligand binding to the transcriptional riboswitch in bacterial causes modification in the structure of riboswitch unit, which leads to hindrance in the activity of RNA polymerase causing attenuation of transcription.
Attenuation was first observed by Charles Yanofsky in the trp operon of E. coli.C. Yanofsky, "Attenuation in the control of expression of bacterial operons", Nature 289:751 (1981) The first observation was linked to two separate scientific facts. Mutations which knocked out the trp R (repressor) gene still showed some regulation of the trp operon (these mutants were not fully induced/repressed by tryptophan). The total range of trp operon regulation is about 700 X (on/off).
Semantically, the transition probability is the probability that the symbol o is received given that i was transmitted over the channel. Statistical and physical modelling can be combined. For example, in wireless communications the channel is often modelled by a random attenuation (known as fading) of the transmitted signal, followed by additive noise. The attenuation term is a simplification of the underlying physical processes and captures the change in signal power over the course of the transmission.
Figure 1: Interaural attenuation with air conduction. Figure 2: Interaural attenuation with bone conduction When sound is applied to one ear the contralateral cochlea can also be stimulated to varying degrees, via vibrations through the bone of the skull. When the stimuli presented to the test ear stimulates the cochlea of the non-test ear, this is known as cross hearing. Whenever it is suspected that cross hearing has occurred it is best to use masking.
However, it demonstrates the other benefits of being smooth, adjustable bandwidth. Like the , this window naturally offers a "flat top" to control the amplitude attenuation of a time-series (on which we don't have a control with Gaussian window). In essence, it offers a good (controllable) compromise, in terms of spectral leakage, frequency resolution and amplitude attenuation, between the Gaussian window and the rectangular window. See also for a study on time-frequency representation of this window (or function).
UMTRA Site (Colorado, US) from 1957 (above) until 2008 (below), in which biostimulation tasks were carried out. Aside from bioreduction, biosorption, bioaccumulation and biomineralization, which are bacterial strategies for natural attenuation of radioactive contamination, there are also human methods that increase the efficiency or speed of microbial processes. This accelerated natural attenuation involves an intervention in the contaminated area to improve conversion rates of radioactive waste, which tend to be slow. There are two variants: biostimulation and bioaugmentation.
The United States Environmental Protection Agency (EPA) requires that all hearing protection devices be labeled with their associated noise reduction rating (NRR). The NRR provides the estimated attenuation of the hearing protection device. The NRR obtained in the lab is often higher than the attenuation provided in the field. To determine the amount of noise reduction afforded by a hearing protection device for the A weighted scale, OSHA recommends that 7 dB be subtracted from the NRR.
Bone conduction hearing device bypassing the middle ear may be a more appropriate treatment for these patients. Good transmission of sound in the bone, with reduced attenuation and distortion may be possible.
During the construction of the Avon Ring Road extensions in the 1990s, an attenuation reservoir was constructed in the Siston Common area to minimise flooding effects from surface run-off during rainstorms.
During his life, Fitch founded or was associated at a high level with several companies, including John Fitch & Co., Inc., Advanced Power Systems International, Race Safety, Inc., Impact Attenuation, Inc., Impact Dynamics, LLC.
The PAC method is related to nuclear magnetic resonance and the Mössbauer effect, but shows no signal attenuation at very high temperatures. Today only the time-differential perturbed angular correlation (TDPAC) is used.
The attenuation (drawing) speed is important in the nozzle design. Although slowing this speed down can make coarser fiber, it is uneconomic to run at speeds for which the nozzles were not designed.
Several earplugs on the market claim to be for musicians, but are not in fact by definition a musician's earplug. By having a thin acoustical bypass channel, they allow for a slightly better frequency response and lower attenuation than simple earplugs, but far from the level of fidelity that membrane-based earplugs provide. These types of earplugs do not provide the flat attenuation that is characteristic of a musician's plug, but may still be useful for some, due to their lower price points.
Mucoid impaction of the upper and lower airways is a common finding. Plugs are hypodense but appear on CT with high attenuation (over 70 Hounsfield units) in up to 20% of patients. Where present it is a strong diagnostic factor of ABPA and distinguishes symptoms from other causes of bronchiectasis. CT scans may more rarely reveal mosaic-appearance attenuation, centrilobular lung nodules, tree-in-bud opacities and pleuropulmonary fibrosis (a finding consistent with CPA, a disease with ABPA as a known precursor).
Graphic equalizers used for tone control provide independent elevation or attenuation of individual bands of frequencies. Wide frequency range graphic equalizers of high resolution can provide elevation or attenuation in 1/3 octave bands spanning from approximately 30 Hz to 18 kHz. Parametric equalizers can control not only the amount of boost and cut but also the specific frequency at which the boost and cut takes place and the range of frequencies (bandwidth) affected. Elaborate circuits may also use amplifiers.
Because there were so many different sources of infrasound, methods of detecting were of interest for the military and civilians. Long distance propagation of infrasound is allowed by ground reflection and molecular attenuation. The ground acts as a reflecting service for incoming energy and molecular attenuation is zero at infrasonic frequencies. The infrasonic sensing array contained a minimum variance distortion-less response beam former to enhance the detection and estimation performance of the acoustic system by improving the signal to noise ratio.
The second is to find the canonical (minimal) forms of these functions and the relationships (transforms) between different forms representing the same transfer function. Finally, it is not, in general, possible to find an exact finite-element solution to an ideal transfer function - such as zero attenuation at all frequencies below a given cutoff frequency and infinite attenuation above. The third task is therefore to find approximation techniques for achieving the desired responses. Initially, the work revolved around one-port impedances.
Lee, pages 252–254 It is possible to completely eliminate errors in the detector and meter if a precision variable attenuator is used in the test setup. In this technique a minimum is first found and the attenuator adjusted so that the meter is indicating precisely some convenient mark. A maximum is then found and the attenuation increased until the meter is indicating the same mark. The amount the attenuation had to be increased is the VSWR of the standing wave.
In some situations the insulation is in reference to noise mitigation. In these circumstances a large air space improves the noise insulation quality or sound transmission class. Asymmetric double glazing, using different thicknesses of glass rather than the conventional symmetrical systems (equal glass thicknesses used for both lights) will improve the acoustic attenuation properties of the IGU. If standard air spaces are used, sulfur hexafluoride can be used to replace or augment an inert gas and improve acoustical attenuation performance.
Acoustic balance and control was another early objective of dropped ceilings.Suspended Ceiling Construction, retrieved January 15, 2014 A noisy room can overstimulate occupants, while a too quiet interior may seem dull and uninviting. The acoustic performance of suspended ceilings has improved dramatically over the years, with enhanced sound absorption and attenuation. This is sometimes achieved by adding insulation known as Sound Attenuation Batts (SABs), more commonly referred to as "sound batts", above the panels to help deaden sounds and keep adjacent rooms quieter.
The Beer–Lambert law can be applied to the analysis of a mixture by spectrophotometry, without the need for extensive pre-processing of the sample. An example is the determination of bilirubin in blood plasma samples. The spectrum of pure bilirubin is known, so the molar attenuation coefficient ε is known. Measurements of decadic attenuation coefficient μ10 are made at one wavelength λ that is nearly unique for bilirubin and at a second wavelength in order to correct for possible interferences.
The individual wears their HPD and a microphone is placed inside the ear canal and another microphone is placed outside of the ear. A sound is played and the difference between the microphones is the attenuation for that individual, known as the personal attenuation rating (PAR). In the second method, a series of sounds are played for the individual, and the lowest level that they can detect the sound is recorded. The individual then wears the HPD and the same sounds are played.
Bandform diagram showing frequency response of a general image filter. The ωc are the critical frequencies (the frequency where cut-off begins) and the ω∞ are the poles of attenuation in the stop bands.
For each of these ranges, there are attenuation coefficients defined according to link geometry. These variables also consider the topography that is defined as terrain irregularity parameter ∆h(d) for a reference distance (D0).
Modern premium components make it easy to produce amplifiers that are essentially flat over the audio band, with less than 3 dB attenuation at 6 Hz and 70 kHz, well outside the audible range.
Bjørn Ursin and Tommy Toverud Ursin B. and Toverud T. 2002 Comparison of seismic dispersion and attenuation models. Studia Geophysica et Geodaetica 46, 293–320. published an article where they compared different Q models.
The sum of the scattering, photoelectric, and pair-production cross-sections (in barns) is charted as the "atomic attenuation coefficient" (narrow-beam), in barns.Nondestructive Testing Handbook Volume 4 Radiographic Testing, ASNT, 2002, chapter 22.
Microbending causes light attenuation induced by deformation of the fiber while macrobending causes the leakage of light through the fiber cladding and this is more likely to happen where the fiber is excessively bent.
It has also been established that sexual desire and frequency of sex decreased as the length of marriage increased. Further investigation has revealed that this attenuation occurs within the first 2 years of marriage.
In electrical engineering and telecommunications, attenuation affects the propagation of waves and signals in electrical circuits, in optical fibers, and in air. Electrical attenuators and optical attenuators are commonly manufactured components in this field.
1 (‑10X) attenuation factor; this helps to isolate the capacitive load presented by the probe cable from the signal being measured. Some probes have a switch allowing the operator to bypass the resistor when appropriate.
A method for establishing attenuation coefficients with which actual HU values can be derived from CBCT HU values was published in 2010 and further research is currently under way to perfect this method in vivo.
The decibel is useful for representing large ratios and for simplifying representation of multiplied effects such as attenuation from multiple sources along a signal chain. Its application in systems with additive effects is less intuitive.
Katz J. Clinical Handbook of Audiology. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2002. A reduction or loss of energy occurs with cross hearing, which is referred to as interaural attenuation (IA) or transcranial transmission loss.
Essentials of Ultrasound Physics, James A. Zagzebski, Mosby Inc., 1996. Attenuation also occurs in earthquakes; when the seismic waves move farther away from the hypocenter, they grow smaller as they are attenuated by the ground.
The molar attenuation coefficient is a measurement of how strongly a chemical species attenuates light at a given wavelength. It is an intrinsic property of the species. The SI unit of molar attenuation coefficient is the square metre per mole (), but in practice, quantities are usually expressed in terms of M−1⋅cm−1 or L⋅mol−1⋅cm−1 (the latter two units are both equal to ). In older literature, the cm2/mol is sometimes used; 1 M−1⋅cm−1 equals 1000 cm2/mol.
Fluorescent proteins have been developed for fluorescence microscopy imaging and are unique in that they can be genetically encoded and therefore do not need to be delivered into the body. Using photoacoustic microscopy, fluorescent proteins can be visualized at depths beyond the limit of typical microscopy methods. Frequency-dependent acoustic attenuation in tissue and dampening of higher frequencies limits the bandwidth of light propagation through deeper regions in tissue. Fluorescent proteins act as light source at the target region, bypassing the limitation of optical attenuation.
Imperfections in the glass create mirrors that reflect the light back along the fiber. Impedance discontinuities cause attenuation, attenuation distortion, standing waves, ringing and other effects because a portion of a transmitted signal will be reflected back to the transmitting device rather than continuing to the receiver, much like an echo. This effect is compounded if multiple discontinuities cause additional portions of the remaining signal to be reflected back to the transmitter. This is a fundamental problem with the daisy chain method of connecting electronic components.
The wavelength of SHF waves creates strong reflections from metal objects the size of automobiles, aircraft, and ships, and other vehicles. This and the narrow beamwidths possible with high gain antennas and the low atmospheric attenuation as compared with higher frequencies make SHF the main frequencies used in radar. Attenuation and scattering by moisture in the atmosphere increase with frequency, limiting the use of high SHF frequencies for long range applications. Small amounts of microwave energy are randomly scattered by water vapor molecules in the troposphere.
The inner sections of the filter are most commonly chosen to be constant k since these produce the greatest stopband attenuation. However, one or two m-type sections might also be included to improve the rate of fall from pass to stopband. A low value of m is chosen for m-types used for this purpose. The lower the value of m, the faster the transition, while at the same time, the stopband attenuation becomes less, increasing the need to use extra k-type sections as well.
In the most recent measurement of the significant impact of secondary electrons on resolution, it was found that 93 eV photoelectrons (from a gold underlayer) had a 1/e attenuation length of 28 nm in resist. The electron number attenuation was measured from the fraction of electrons captured in an electrical current from the resist. This indicates 37% of the released electrons still migrate beyond 28 nm from the exposure release point. More details on secondary electrons in EUV photoresist exposure are provided below.
At frequencies in the "windows" between these absorption peaks, millimeter waves have much less atmospheric attenuation and greater range, so many applications use these frequencies. Millimeter wavelengths are the same order of size as raindrops, so precipitation causes additional attenuation due to scattering (rain fade) as well as absorption. The high free space loss and atmospheric absorption limits useful propagation to a few kilometers. Thus, they are useful for densely packed communications networks such as personal area networks that improve spectrum utilization through frequency reuse.
3 dB attenuation is also where power is half its maximum. This same half-power gain convention is also used in spectral width, and more generally for the extent of functions as full width at half maximum (FWHM). In electronic filter design, a filter specification may require that within the filter passband, the gain is nominally 0 dB with a small variation, for example within the ±1 dB interval. In the stopband(s), the required attenuation in decibels is above a certain level, for example >100 dB.
Therefore, the method is most sensitive to abrupt changes in the decrement of the refractive index. This leads to stronger contrast outlining the surfaces and structural boundaries of the sample (edge enhancement) compared with a conventional radiogram. PBI can be used to enhance the contrast of an absorption image, in this case the phase information in the image plane is lost but contributes to the image intensity (edge enhancement of attenuation image). However it is also possible to separate the phase and the attenuation contrast, i.e.
Her research has evaluated the attenuation of source zone and groundwater plume as a result of the Bemidji oil spill. After the rupture of a high-pressure oil pipe in 1979, the United States Geological Survey established a crude oil research site in an effort to understand the natural attenuation of hydrocarbons. A combination of fermentation and methanogenesis is the main Natural Source Zone Depletion process (NSZD). NSZDs describe the change in composition of oil or fuel that occurs naturally due to volatilisation, biodegradation or dissolution.
Image produced by the Oak Ridge National Laboratory's neutron radiography facility . Neutron imaging is the process of making an image with neutrons. The resulting image is based on the neutron attenuation properties of the imaged object. The resulting images have much in common with industrial X-ray images, but since the image is based on neutron attenuating properties instead of X-ray attenuation properties, some things easily visible with neutron imaging may be very challenging or impossible to see with X-ray imaging techniques (and vice versa).
Rhodamine 6B. The beam radiant power becomes weaker as it passes through solution The Beer–Lambert law, also known as Beer's law, the Lambert–Beer law, or the Beer–Lambert–Bouguer law relates the attenuation of light to the properties of the material through which the light is travelling. The law is commonly applied to chemical analysis measurements and used in understanding attenuation in physical optics, for photons, neutrons, or rarefied gases. In mathematical physics, this law arises as a solution of the BGK equation.
Dust particles, as well as water droplets, cause attenuation of the RF energy, resulting in a loss of effective range. In both cases, a lower pulse repetition frequency makes the radar less susceptible to atmospheric conditions.
A spectrophotometer built with a high quality double monochromator can produce light of sufficient purity and intensity that the instrument can measure a narrow band of optical attenuation of about one million fold (6 AU, Absorbance Units).
In comparison with conventional screening methods like mammography, USCT systems offer potentially an increased specificity for breast cancer detection, as multiple breast cancer characteristic properties are imaged at the same time: speed-of-sound, attenuation and morphology.
Periodic short-interval diffuse discharges are a type of EEG abnormality with periodicity less than 4.0 seconds. They can consist of sharp waves or spikes, spike and wave, polyspikes or triphasics with background attenuation in between transients.
The Vienna II-Au is a FET condenser microphone made by ADK Microphones. It includes a switchable low frequency cut-off (1st order, -3dB @ 100 Hz or 160 Hz) and a switchable attenuation pad (-8dB or -16dB).
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.
The Poisson model of a cellular network proves to be more tractable than a hexagonal model. Meanwhile, this observation could be argued by the fact that a detailed and precise derivation for the channel attenuation probability distribution function between a random node and a reference base-station for a hexagonal model was explicitly derived in; and this result could be used to tractably derive the outage probability. In the presence of sufficiently strong and independent log-normal shadow fading (or shadowing) and a singular power-law attenuation function, it was observed by simulationT. X. Brown.
Other photons are transmitted unaffected and, if the radiation is in the visible region (400–700 nm), the transmitted light appears as the complementary color (here red). By recording the attenuation of light for various wavelengths, an absorption spectrum can be obtained. In physics, absorption of electromagnetic radiation is how matter (typically electrons bound in atoms) takes up a photon's energy — and so transforms electromagnetic energy into internal energy of the absorber (for example, thermal energy). A notable effect (attenuation) is to gradually reduce the intensity of light waves as they propagate through a medium.
The attenuation constant \alpha/2 is also identical to the (negative) real part of the propagation constant, which may also be referred to as \alpha using a notation inconsistent with the above use. When referencing a source one must always be careful to note whether a number such as \alpha or \delta refers to the decay of the field itself, or of the intensity (power) associated with that field. It can also be ambiguous as to whether a positive number describes attenuation (reduction of the field) or gain; this is usually obvious from the context.
Compared to lower bands, radio waves in this band have high atmospheric attenuation: they are absorbed by the gases in the atmosphere. Therefore, they have a short range and can only be used for terrestrial communication over about a kilometer. Absorption increases with frequency until at the top end of the band the waves are attenuated to zero within a few meters. Absorption by humidity in the atmosphere is significant except in desert environments, and attenuation by rain (rain fade) is a serious problem even over short distances.
In 1997 Bekins joined the staff at the United States Geological Survey, where she combines field research with computer models to understand the geology of North America. In 1998 Bekins was appointed to the National Research Council Intrinsic Remediation committee, with whom she wrote the book Natural Attenuation for Groundwater Remediation. She studies the attenuation of petroleum hydrocarbons and the effects of fluids on boundary faults. To investigate these, Bekins served as the onboard scientist for several Ocean Drilling Program vessels, including trips to Lesser Antilles, the Peru margin and the Mariana Convergent margin.
The attenuator sequence has its codons translated into a leader peptide, but is not part of the trp operon gene sequence. The attenuator allows more time for the attenuator sequence domains to form loop structures, but does not produce a protein that is used in later tryptophan synthesis. Attenuation is a second mechanism of negative feedback in the trp operon. While the TrpR repressor decreases transcription by a factor of 70, attenuation can further decrease it by a factor of 10, thus allowing accumulated repression of about 700-fold.
If several known chemicals are dissolved in a single solution, the concentrations of each can be calculated using a light absorption analysis. First, the mass attenuation coefficients of each individual solute or solvent, ideally across a broad spectrum of wavelengths, must be measured or looked up. Second, the attenuation coefficient of the actual solution must be measured. Finally, using the formula :\mu = (\mu/\rho)_1 \rho_1 + (\mu/\rho)_2 \rho_2 + \ldots, the spectrum can be fitted using ρ1, ρ2, … as adjustable parameters, since μ and each are functions of wavelength.
Contemporary scanners can estimate attenuation using integrated x-ray CT equipment, in place of earlier equipment that offered a crude form of CT using a gamma ray (positron emitting) source and the PET detectors. While attenuation-corrected images are generally more faithful representations, the correction process is itself susceptible to significant artifacts. As a result, both corrected and uncorrected images are always reconstructed and read together. 2D/3D reconstruction: Early PET scanners had only a single ring of detectors, hence the acquisition of data and subsequent reconstruction was restricted to a single transverse plane.
Just as the acoustic energy was transmitted through the air as pressure differentials (or deformations), the acoustic energy travels through the material which makes up the wall in the same manner. Deformation causes mechanical losses via conversion of part of the sound energy into heat, resulting in acoustic attenuation, mostly due to the wall's viscosity. Similar attenuation mechanisms apply for the air and any other medium through which sound travels. The fraction of sound absorbed is governed by the acoustic impedances of both media and is a function of frequency and the incident angle.
Listening to music in a mood-incongruent state, such as someone sad listening to happy music, allows for possible mood attenuation through distraction, and enforces positive thoughts for the individual such as feelings of happiness, encouragement, a sense of hope, a change in perception, etc. In mood attenuation through distraction people are allowed time to “cool off” and let their heightened mood dwindle. Enforcing feelings of positivity can allow for the participant to model his or her actions and behaviors towards ones that are congruent with the type of music that is being used.
The ionizing capability of X-rays can be utilized in cancer treatment to kill malignant cells using radiation therapy. It is also used for material characterization using X-ray spectroscopy. Attenuation length of X-rays in water showing the oxygen absorption edge at 540 eV, the energy−3 dependence of photoabsorption, as well as a leveling off at higher photon energies due to Compton scattering. The attenuation length is about four orders of magnitude longer for hard X-rays (right half) compared to soft X-rays (left half).
In a wireless communication system, the link margin (LKM), measured in dB, is the difference between the minimum expected power received at the receiver's end, and the receiver's sensitivity (i.e., the received power at which the receiver will stop working). A 15 dB link margin means that the system could tolerate an additional 15 dB of attenuation between the transmitter and the receiver, and it would still just barely work. It is typical to design a system with at least a few dB of link margin, to allow for attenuation that is not modeled elsewhere.
New in situ oxidation technologies have become popular for remediation of a wide range of soil and groundwater contaminants. Remediation by chemical oxidation involves the injection of strong oxidants such as hydrogen peroxide, ozone gas, potassium permanganate or persulfates. Oxygen gas or ambient air can also be injected to promote growth of aerobic bacteria which accelerate natural attenuation of organic contaminants. One disadvantage of this approach is the possibility of decreasing anaerobic contaminant destruction natural attenuation where existing conditions enhance anaerobic bacteria which normally live in the soil prefer a reducing environment.
Ultrasound attenuation spectroscopy is a method for characterizing properties of fluids and dispersed particles. It is also known as acoustic spectroscopy There is an international standard for this method.ISO 20998-1:2006 "Measurement and characterization of particles by acoustic methods"Dukhin, A.S. and Goetz, P.J. "Ultrasound for characterizing colloids", Elsevier, 2002 Measurement of attenuation coefficient versus ultrasound frequency yields raw data for further calculation of various system properties. Such raw data are often used in the calculation of the particle size distribution in heterogeneous systems such as emulsions and colloids.
Despite the use of common cores, such loading coils do not comprise transformers, as they do not provide coupling to other circuits. Loading coils inserted periodically in series with a pair of wires reduce the attenuation at the higher voice frequencies up to the cutoff frequency of the low-pass filter formed by the inductance of the coils (plus the distributed inductance of the wires) and the distributed capacitance between the wires. Above the cutoff frequency, attenuation increases rapidly. The shorter the distance between the coils, the higher the cut-off frequency.
The columella is straight, with an anterior oblique attenuation. The siphonal canal is wide and hardly differentiated.Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 pp.
Using PhysX, the engine uses many features such as destructible environments, and cloth and water simulations, and particles that can be fully affected by environmental factors. The audio in the engine features 3D sound positioning, spatialisation and attenuation.
Chapter 1. Chapter 2. Without attenuation, the impervious cover in a typical urban area limits groundwater percolation and causes five times the amount of runoff generated by a typical woodland of the same size.U.S. Environmental Protection Agency (EPA).
Mass extinction coefficient is an old term for this quantity. The mass attenuation coefficient can be thought of as a variant of absorption cross section where the effective area is defined per unit mass instead of per particle.
Some cellular repeater systems can also include an omnidirectional antenna for rebroadcasting the signal indoors. Depending on attenuation from obstacles, the advantage of using an omnidirectional antenna is that the signal will be equally distributed in all directions.
The T-section will be matched internally with `ZiTm`. This has the additional incidental advantage of producing two poles of attenuation in the stopband at different frequencies. This is a consequence of m and mm' necessarily being different values.
Sarcandra glabra is an herb native to Southeast Asia. It is also known as herba sarcandrae or glabrous sarcandra herb. Aromatic oils may be extracted from the leaves. This extract may reduce immunologic attenuation due to stress, in mice.
For these end stopbands, there is only one pole of attenuation in each, as would be expected from the reduced number of resonators. These forms are the maximum allowable complexity while maintaining invariance of bandform and one image impedance.
Seismic inverse Q filtering is a data processing technology for enhancing the resolution of reflection seismology images. Q is the anelastic attenuation factor or the seismic quality factor, a measure of the energy loss as the seismic wave moves.
From 1946 through 1948 Bourdeau was involved in experiments measuring the attenuation of the X-band as it passed through the rocket exhaust and the measurement of the electrical field surrounding the midsection of the V-2 during flight .
The angstrom exponent of the attenuation for these materials is 1. If aromatic components are present, they will contribute increased absorption at shorter wavelengths. The aethalometer data will increase at shorter wavelengths, and the apparent angstrom exponent will increase.
The abstract states: 'Analysis of galaxies with overlapping images offers a direct way to probe the distribution of dust extinction and its effects on the background light.' This catalogue was also used in a study of ultraviolet attenuation laws.
The best coaxial cable impedances in high-power, high-voltage, and low-attenuation applications were experimentally determined at Bell Laboratories in 1929 to be 30, 60, and 77 Ω, respectively. For a coaxial cable with air dielectric and a shield of a given inner diameter, the attenuation is minimized by choosing the diameter of the inner conductor to give a characteristic impedance of 76.7 Ω. When more common dielectrics are considered, the best-loss impedance drops down to a value between 52–64 Ω. Maximum power handling is achieved at 30 Ω. The approximate impedance required to match a centre-fed dipole antenna in free space (i.e., a dipole without ground reflections) is 73 Ω, so 75 Ω coax was commonly used for connecting shortwave antennas to receivers. These typically involve such low levels of RF power that power-handling and high-voltage breakdown characteristics are unimportant when compared to attenuation.
Attenuation diagram, day and night Ionospheric absorption (or ISAB) is the scientific name for absorption occurring as a result of the interaction between various types of electromagnetic waves and the free electrons in the ionosphere, which can interfere with radio transmissions.
Bucladesine (50-100nM/mouse) showed significant attenuation in the morphine withdrawal syndrome in the wild-type mice. In addition, its high dose (200nM/mouse) combination with H-89, as a protein kinase inhibitor, had additive attenuating effect on withdrawal syndromes.
The benefit of the beamline HOM load configuration, however, is a greater absorptive bandwidth and HOM attenuation as compared to antenna coupling. This benefit can be the difference between a stable vs. an unstable particle beam for high current accelerators.
These lower levels seem to be linked to the rescue of stress-induced attenuation of CA1 long-term potentiation.H. Tamano et al. 2013. Preventative effect of theanine intake on stress-induced imparirments of hippocampal long-term potentiation and recognition memory.
Small earthquakes from the basin are barely recorded on land because of high mantle attenuation. Most of the earthquakes, as well as volcanic activities locate at the east boundary of Lau Basin, along the Tonga Ridge which is very volcanically active.
16, No 1 (2013), pp. 26-50, DOI: 10.2478/s13540-013-- 0003-1 Link to e-print For frequency band-limited waves, Ref.S. P. Näsholm: "Model-based discrete relaxation process representation of band-limited power- law attenuation." J. Acoust. Soc.
Am. Vol. 133, Issue 3, pp. 1742-1750 (2013) DOI: 10.1121/1.4789001 Link to e-print describes a model-based method to attain causal power-law attenuation using a set of discrete relaxation mechanisms within the Nachman et al. framework.
Plasmid RNAIII is a non-coding RNA found in bacterial plasmids including pIP501. RNAIII acts by transcriptional attenuation of the essential repR-mRNA. RNAIII is composed of four stem-loops with loops L3 and L4 that interact with the RNA target.
Attenuators are 5'-cis acting regulatory regions which fold into one of two alternative RNA structures which determine the success of transcription.Naville M, Gautheret, D (2009). "Transcription attenuation in bacteria: theme and variations". Briefings in Functional Genomics 9 (2):178-189.
In optical fibers the main attenuation source is scattering from molecular level irregularities (Rayleigh scattering)I. P. Kaminow, T. Li (2002), Optical fiber telecommunications IV, Vol.1, p. 223 due to structural disorder and compositional fluctuations of the glass structure.
When stacked, the smaller SRRs (high-frequency) in the range face the radar source first (like a stack of donuts that get progressively larger as one moves away from the radar source) stacks of three have been shown to be effective in providing wide-band attenuation. SRR technology acts very much in the same way that antireflective coatings operate at optical wavelengths. SRR technology provides the most effective radar attenuation of any technologies known previously and is one step closer to reaching complete invisibility (total stealth, "cloaking"). Work is also progressing in visual wavelengths, as well as infrared wavelengths (LIDAR-absorbing materials).
529 The region of high attenuation of the Achieser-Zolotarev filter can be made to occur below the guide cutoff frequency, in which case the response is indistinguishable from a low-pass response because the low-frequency attenuation is masked by the guide cutoff effect. As with the Chebychev filter, the designer of an Achieser-Zolotarev filter can exchange increased steepness of the transition band for more passband ripple.Levy pp. 528–530 The advantage of the Zolotarev response is that it results in a filter with a better impedance match to the connecting waveguides compared to the Chebyshev filter or image-parameter filters.
The "static" image is similar to the conventional radiographic image in most cases; however, there could be a significant difference if the studied object is moving. In this case, the "static" image is less affected by the motion noise than the ordinary calculated radiographic image. The reason is that the E(D) values are calculated by averaging the series of attenuation values computed from the corresponding series of photon numbers (from the underexposed images) and converted into a logarithm. On the other hand, the attenuation values of common radiographs are calculated from a single summed up photon number converted into a logarithm.
This method can only measure the bone mineral content of limbs. If the isotope source is changed to X-ray source, that is, single energy X-ray absorptiometer (SXA), the principle and determination method is the same as SPA, but the radiation source is different. Bone density The basic principle of single-photon bone mineral density measuring instrument is to calculate the attenuation degree of single-energy gamma photon beam through bone tissue. The more attenuation degree is, the more absorbed by bone minerals, the more bone mineral content and the higher bone mineral density are.
They are normally used to detect alpha and beta particles, and can enable discrimination between them by providing a pulse output proportional to the energy deposited in the chamber by each particle. They have a high efficiency for beta, but lower for alpha. The efficiency reduction for alpha is due to the attenuation effect of the entry window, though distance from the surface being checked also has a significant effect, and ideally a source of alpha radiation should be less than 10mm from the detector due to attenuation in air. These chambers operate at very slight positive pressure above ambient atmospheric pressure.
When we know the energy dissipation (attenuation), we can calculate the time shift due to dispersion because there is a relation between attenuation and the dispersion in a seismic media. Dispersion equations are obtained from the application of an integral transform in the frequency domain that are of the Kramers-Krönig type. This effect is described in the article ‘Dispersive body waves’ by Futterman (1962).Futterman (1962) ‘Dispersive body waves’. Journal of Geophysical Research 67. p.5279-91 For a better understanding of dispersion waves in seismic medias I would recommend the book 'Seismic inverse Q-filtering' by Yanghua Wang (2008).
Treisman's attenuation model of selective attention retains both the idea of an early selection process, as well as the mechanism by which physical cues are used as the primary point of discrimination. However, unlike Broadbent's model, the filter now attenuates unattended information instead of filtering it out completely. Treisman further elaborated upon this model by introducing the concept of a threshold to explain how some words came to be heard in the unattended channel with greater frequency than others. Every word was believed to contain its own threshold that dictated the likelihood that it would be perceived after attenuation.
This study first theorized and proposed to use glass fibres to implement optical communication, the ideas (especially structural features and materials) described are largely the basis of today's optical fibre communications. In 1965, Page 2 Kao with Hockham concluded that the fundamental limitation for glass light attenuation is below 20 dB/km (decibels per kilometer, is a measure of the attenuation of a signal over a distance), which is a key threshold value for optical communications. However, at the time of this determination, optical fibres commonly exhibited light loss as high as 1,000 dB/km and even more.
On 19 November 1996 Bayern-Chemie completed the latest in a series of tests designed to assess the attenuation of signals by the boron rich exhaust plume of the TDR, a concern highlighted by opponents of this form of ramjet propulsion. Tests were conducted with signals transmitted through the plume at various angles. The initial results suggested that the attenuation was much less than expected.. The Eurofighter and Gripen, with two-way datalinks, allow the launch platform to provide updates on targets or re-targeting when the missile is in flight. The datalink is capable of transmitting information such as kinematic status.
This headset had an active attenuation bandwidth of approximately 50–500 Hz, with a maximum attenuation of approximately 20 dB. 1986 – Dick Rutan and Jeana Yeager used prototype headsets built by Bose in their around-the-world flight.Special Lay- Language Paper for the 75th Anniversary Meeting of the Acoustical Society of America, May 2004 Escape the Noise: Bose Learning Centre 1992 - The Japanese market Nissan Bluebird became the first car in the world to be sold with an ANC system installed. Its effect was limited and it was to be another twenty years before such technology reached wider adoption in automobiles.
It has been used to measure and monitor the progression of chemical reactions, such as the setting and hardening of concrete from cement paste to solid. Acoustic spectrometry has also been used to measure the volume fraction of colloids in a dispersion medium, as well as for the investigation of physical properties of colloidal dispersions, such as aggregation and particle size distribution. Typically, these experiments are carried out with sinusoidal excitation signals and the experimental observation of signal attenuation. From a comparison of theoretical attenuation to experimental observation, the particle size distribution and aggregation phenomena are inferred.
Ultrasound transmission tomography (UTT) is a form of tomography involving ultrasound. Like X-ray tomography, the attenuation of the ultrasound as it passes through the object can be measured, but since the speed of sound is so much lower than the speed of light, the delay as it passes through the object can also be measured, allowing estimation of both the attenuation coefficient and the index of refraction. Traditional ultrasound imaging primarily detects boundaries between different media. Also unlike X-rays, the paths through the object are not necessarily straight lines, as they are deflected at each boundary.
Similar to a noise reduction rating (NRR) required on hearing protection devices in the United States, a personal attenuation rating (PAR) is obtained from an attenuation measurement at one or more than one frequency. However, the PAR is regarded as more accurate than the NRR because it is calculated per individual and per hearing protection device, while NRR is a generalized estimate of potential sound reduction based on the protection provided to a small population of people. It gives the evaluator an estimate of the total noise exposure an individual is receiving when wearing hearing protection.
The A. lagunensis blooms cause a substantial increase in light attenuation, which in turn contributes to marine biodiversity loss, particularly phytoplankton communities and benthic invertebrates. A. lagunensis thrives in low-light conditions, where it can maintain high growth rates at 150 umol photons m−2 s−1, thus an increase in light attenuation causes a positive feedback which further perpetuates blooms. Aureoumbra lagunensis nutrient uptake is unlike other common microalgae. It uptakes inorganic nitrogen in the form of ammonium (NH4+) and nitrite (NO2−) and organic nitrogen in the form of urea, but does not utilize nitrate (NO3−).
Brown tides caused by A. lagunensis lead to substantial light attenuation, a loss in intensity of light travelling to the bottom of water. In the Texas Brown tide, the increase in light attenuation caused a decrease in seagrass beds which was abundant prior to the brown tide. This contributed to a loss in biomass in terms of primary producers and in turn the diversity of benthic invertebrates in Laguna Madre. The benthic phototrophs compete with A. lagunensis for nutrients, especially those regenerated in sediments, an important source of recycled nutrient in shallow lagoons that host these blooms.
The majority of splenosis implants are found after splenic injury by trauma or after splenectomy. Splenic fragments can become implanted anywhere in the abdominal cavity. With imaging splenosis appears as dense well circumscribed lesion with attenuation and enhancement patterns similar to splenic parenchyma.
The imaging depth of photoacoustic microscopy is mainly limited by the ultrasonic attenuation. The spatial (i.e. axial and lateral) resolutions depend on the ultrasonic transducer used. An ultrasonic transducer with high central frequency and broader bandwidth are chosen to obtain high axial resolution.
Its mechanism remains unknown, but it is tempting to speculate a regulatory involvement of the NusA protein, which expression has been shown to lower the operon expression, and which is already involved in the attenuation of the Trp, His and S10 operons.
CobraNet is an alternative to analog audio, which suffers from signal degradation over long cable runs due to electromagnetic interference, high-frequency attenuation, and voltage drop. Additionally, the use of digital multiplexing allows audio to be transmitted using less cabling than analog audio.
Francis Deck. December 22, 2005. GK Backline 600 Review Some bass players decry the attenuation of midrange frequencies, holding that the midrange area centered on 500 Hz will make the bass instrumental line stand out more satisfyingly in the mix.Ernie Ball. Forums.
More recently, muons have been used to image magma chambers to predict volcanic eruptions. Nagamine et al. continue active research into the prediction of volcanic eruptions through cosmic ray attenuation radiography. Minato used cosmic ray counts to radiograph a large temple gate.
Reactive silencers are very common in muffler design of automobiles and trucks. Attenuation is primarily achieved through sound reflection, area change, and tuned chambers. The design of reactive silencers from scratch is mathematically intensive, so manufacturers often have a number of prefabricated designs.
This is called core-shell model. The smaller the nanoparticle becomes, the larger the volume fraction of this amorphous portion becomes. In PAC measurements, this is shown by the decrease of the crystalline frequency component in a reduction of the amplitude (attenuation).
The scientific study of the genetics of MVEV has been facilitated by the construction and manipulation of an infectious cDNA clone of the virus. Mutations in the envelope gene have been linked to the attenuation of disease in mouse models of infection.
Intensity VI was felt in San Diego, while El Centro was marked as I–IV (Not Felt–Light). This was likely due to a difference in local geological features, and the attenuation factor along the path to each area, sometimes called "earthquake shadows".
A Fiber Optics Communication Lab is established in the department, provides education on fiber optics communication, analog and digital link, attenuation: banding, and impurities. Other labs include Printed Circuit Board Lab and Electrical Machine Lab. The department contributes to IEEE by doing research.
Unlike active crossovers which include a built-in amplifier, passive crossovers have an inherent attenuation within the passband, typically leading to a reduction in damping factor before the voice coil Elliott Sound Products. Rod Elliott, 2004. Active Vs. Passive Crossovers. Retrieved on June 16, 2009.
Khan, H., et al. (2011). Antinociceptive activity of aerial parts of Polygonatum verticillatum: Attenuation of both peripheral and central pain mediators. Phytotherapy Research 25(7) 1024-30. An herbal remedy called rhizoma polygonati is a mix of Polygonatum species used in traditional Chinese medicine.
Operation is similar to that of a klystron, except that coupled-cavity TWTs are designed with attenuation between the slow-wave structure instead of a drift tube. The slow- wave structure gives the TWT its wide bandwidth. A free electron laser allows higher frequencies.
Instead, the 2B1Q - encoding used by the baud rate #Vs# at a constant transmission rate #VUE# in half and allows the signal to a lower frequency band to relocate. This in turn has a positive effect on the attenuation of the signal and its range.
Unlike conventional internally- lined ductwork, which is only effective at attenuating mid- and high-frequency noise, sound attenuators can achieve broader band attenuation in relatively short lengths. Certain types of sound attenuators are essentially a Helmholtz resonator used as a passive noise-control device.
SAR is capable of high-resolution remote sensing, independent of flight altitude, and independent of weather, as SAR can select frequencies to avoid weather- caused signal attenuation. SAR has day and night imaging capability as illumination is provided by the SAR.Tomographic SAR. Gianfranco Fornaro.
Knowing their limitations and using them with the local NEXRAD can supplement the data available to a meteorologist. Due to the spread of dual-polarization radar systems, robust and efficient approaches for the compensation of rain attenuation are currently implemented by operational weather services.
Very few boys have ever been treated for excessive tallness in North America, but this also has been done more often in Europe.More recently, growth attenuation treatment has been in the news as part of the controversial Ashley Treatment administered to a developmentally disabled girl.
A pseudosubarachnoid hemorrhage is an apparent increased attenuation on CT scans within the basal cisterns that mimics a true subarachnoid hemorrhage. This occurs in cases of severe cerebral edema, such as by cerebral hypoxia. It may also occur due to intrathecally administered contrast material, leakage of high-dose intravenous contrast material into the subarachnoid spaces, or in patients with cerebral venous sinus thrombosis, severe meningitis, leptomeningeal carcinomatosis, intracranial hypotension, cerebellar infarctions, or bilateral subdural hematomas. In a true subarachnoid hemorrhage, there is higher attenuation of the basal cisterns, and blood that has leaked from a vessel or formed a hematoma is more highly attenuated due to the absorption of plasma.
The attenuation of the window adds to the attenuation of air, so the window should have a density as low as 1.5 to 2.0 mg/cm2 to give an acceptable level of detection efficiency. The article on stopping power explains in more detail the ranges for particles types of various energies. The counting efficiency of photon radiation (gamma and X-rays above 25 keV) depends on the efficiency of radiation interaction in the tube wall, which increases with the atomic number of the wall material. Chromium iron is a commonly used material, which gives an efficiency of about 1% over a wide range of energies.
Futterman (1962) p.5280 :K(iw) =k(w)+ i a(w) \quad (1.3) Here a(w) is taken positive to assure that energy is lost from the wave to the medium. Now when K(w) are separated into a real part for attenuation and an imaginary part for dispersion, we can introduce the Kramer-Krönig relation by a Hilbert transform H of the attenuation a(w): :K(iw) = H(a(w))+ i a(w) \quad (1.4) For our calculations to be valid we must make two assumptions: (a) the absorption coefficient a(w) is strictly linear in the frequency, over the range of measurement. We can call it bw.
Telecommunication and broadcast networks can be affected by volcanic ash in the following ways: attenuation and reduction of signal strength; damage to equipment; and overloading of network through user demand. Signal attenuation due to volcanic ash is not well documented; however, there have been reports of disrupted communications following the 1969 Surtsey eruption and 1991 Mount Pinatubo eruption. Research by the New Zealand-based Auckland Engineering Lifelines Group determined theoretically that impacts on telecommunications signals from ash would be limited to low frequency services such as satellite communication. Signal interference may also be caused by lightning, as this is frequently generated within volcanic eruption plumes.
In the example diagram, the resistors placed in series with the capacitors, R1, are made equal to the unwanted stray resistance present in the inductors. This ensures that the attenuation at high frequency is the same as the attenuation at low frequency and brings the filter back to a flat response. The purpose of the shunt resistors, R2, is to bring the image impedance of the filter back to the original design R0. The resulting filter is the equivalent of a box attenuator formed from the R1's and R2's connected in cascade with an ideal lattice filter as shown in the diagram.
The pollutant species black carbon appears gray or black due to the absorption of electromagnetic energy by partially mobile electrons in the graphitic microstructure of the black carbon particles. This absorption is purely ‘resistive’ and displays no resonant bands: consequently, the material appears gray rather than colored. The attenuation of light transmitted through a deposit of these particles increases linearly with the frequency of the electromagnetic radiation, i.e. inversely with respect to wavelength. Aethalometer measurements of optical attenuation on a filter deposit will increase at shorter wavelengths as λ(-α) where the parameter α (the Angstrom exponent) has the value α = 1 for ‘gray’ or ‘black’ materials.
But the Italian strain is to a considerable extent modified by the Dürer heritage. This Dürer influence is manifest in a tendency to overcrowding in composition, in a degree of attenuation in the proportions of, and a poverty of contour in, the nude figure, and also in a leaning to the selection of Gothic forms for draperies. These peculiarities are even noticeable in Cornelius's principal work of the "Last Judgment", in the Ludwigskirche in Munich. The attenuation and want of flexibility of contour in the nude are perhaps most conspicuous in his frescoes of classical subjects in the Glyptothek, especially in that representing the contention for the body of Patroclus.
After being recorded the information from the modulated waves can be extracted and used to create an image of the object in a second step. Unlike X-ray or other physical properties which provide typically only one information, ultrasound provides multiple information of the object for imaging: the attenuation the wave's sound pressure experiences indicate on the object's attenuation coefficient, the time-of-flight of the wave gives speed of sound information, and the scattered wave indicates on the echogenicity of the object (e.g. refraction index, surface morphology, etc.). Unlike conventional ultrasound sonography, which uses phased array technology for beamforming, most USCT systems utilize unfocused spherical waves for imaging.
The SI unit of attenuation coefficient is the reciprocal metre (m−1). Extinction coefficient is an old term for this quantity but is still used in meteorology and climatology. Most commonly, the quantity measures the value of downward e-folding distance of the original intensity as the energy of the intensity passes through a unit (e.g. one meter) thickness of material, so that an attenuation coefficient of 1 m−1 means that after passing through 1 metre, the radiation will be reduced by a factor of e, and for material with a coefficient of 2 m−1, it will be reduced twice by e, or e2.
Significant attenuation (isolation) is needed to prevent the transmitter's output from overloading the receiver's input, so such duplexers employ multi-pole filters. Duplexers are commonly made for use on the 30-50 MHz ("low band"), 136-174 MHz ("high band"), 380-520 MHz ("UHF"), plus the 790–862 MHz ("800"), 896-960 MHz ("900") and 1215-1300 MHz ("1200") bands. There are two predominant types of duplexer in use - "notch duplexers", which exhibit sharp notches at the "unwanted" frequencies and only pass through a narrow band of wanted frequencies and "bandpass duplexers", which have wide- pass frequency ranges and high out-of-band attenuation.
SNR/HML are tested with an experienced subject-fit protocol. NRR (SF) is tested with a naive subject-fit protocol. According to Murphy, et al. (2004), these three protocols will yield different amounts of attenuation with the NRR being the greatest and NRR (SF) being the least.
The Pier 5 uplands opened in June 2017. Pier 5 contains a marina which opened in May 2016. After reports of rough water conditions, a new wave-attenuation system was installed at the site and completed in May 2019. The marina also has a floating dock.
As of 2012 there has only been one small-scale study comparing CROS systems. One study of the BAHA system showed a benefit depending on the patient's transcranial attenuation. Another study showed that sound localisation was not improved, but the effect of the head shadow was reduced.
The amount of contrast that seeps into a thrombus can be quantified by the density difference of thrombi between non- contrast computed tomography (NCCT) and CT angiography (CTA) images. Two measures for thrombus perviousness have been introduced: (1) the void fraction and (2) thrombus attenuation increase (TAI).
These muscle tendon unit structures appear well designed to aid in the ground-reaction transmission of forces that is essential for locomotion. In addition, the pads of the distal paw appear to allow load attenuation, by enhancing shock absorption during the paw's contact with the ground.
Although there is some attenuation into the uplands, the presence of dense settlement in relatively minor valleys such as the Nahr al Amarna as well as on the upland plains to the west, provides a counterweight to the better known spreads of settlement along the Euphrates.
An actual wide-band L pad used to match 50 ohms to 75 ohms. An L pad is a network composed of two impedances that typically resemble the letter capital "L" when drawn on a schematic. It is commonly used for attenuation and for impedance matching.
The operation of the recognition threshold is simple: for every possible input, an individual has a certain threshold or "amount of activation required" in order to perceive it. The lower this threshold, the more easily and likely an input is to be perceived, even after undergoing attenuation.
In physics, the meter water equivalent (often m.w.e. or mwe) is a standard measure of cosmic ray attenuation in underground laboratories. A laboratory at a depth of 1000 m.w.e is shielded from cosmic rays equivalently to a lab below the surface of a body of water.
65 (.72 corrected for attenuation). Mean level of g thus increases with perceived job prestige. It has also been found that the dispersion of general intelligence scores is smaller in more prestigious occupations than in lower level occupations, suggesting that higher level occupations have minimum g requirements.
It is still not entirely understood how this neuroprotective action comes about. It has however been hypothesized, that the attenuation of overactive glutamate overflow and reduction of oxidative stress might be the reason for it.Hurtado-Alvarado, G., Domínguez-Salazar, E., Velázquez-Moctezuma, J., & Gómez-González, B. (2016).
Thus tissue oxygen saturation can be defined as StO_2 \, = 0.2 x SaO_2 \, \+ 0.8 x SvO_2 \, ≈ 70%. The total absorption (black) and the effective attenuation (magenta) coefficient spectra for breast tissue is shown in Figure 6 (c). In addition, the effective penetration depth is plotted in Figure 7.
This result is collected for the geometric transformations of the sound source. The transformation is controlled by both delay and attenuation. As for the second pass, the sound objects will be generated to final sound track after being created, modulated and summed. Related detailed work can be found.
The larvae feed on Metrosideros species. The larva makes a rough case of frass with a loose lip. The case is somewhat flattened, pouch shaped, with a short obtuse curved attenuation posteriorly, the middle is widened and the whole case is of a dull dark brownish and fuscous color.
By the late 1980s, several studies also tested optical properties of biological tissues at different wavelengths to produce spectra.B. C. Wilson, W. P. Jeeves, and D. M. Lowe, “In vivo and post mortem measurements of the attenuation spectra of light in mammalian tissues,” Photochem. Photobiol., vol. 42, pp.
The "kinetic" image is derived from the distribution width (e.g., variance or standard deviation) of attenuation at the pixel level. This image has a new type of contrast based on motion: static components do not appear while moving objects appear brighter if they fluctuate more or move faster.
Individuals with pes cavus display characteristic reduced load-attenuation features, and other structures proximal to the foot may compensate with increased load transfer (i.e., excessive loading to the knees, hips, lumbo-pelvic joints or lumbar vertebrae). Foot disorders are common in captive elephants. However, the cause is poorly understood.
When viewing space from Earth, the attenuation, interstellar dust, and stars in the plane of the Milky Way (the galactic plane) obstruct the view of around 20% of the extragalactic sky at visible wavelengths. As a result, optical galaxy catalogues are usually incomplete close to the galactic plane.
Attenuation of the virus by engineering a deletion of Met-51 of the matrix protein ablates virtually all infection of normal tissues, while replication in tumour cells is unaffected. Recent research has shown that this virus has the potential to cure brain tumours, thanks to its oncolytic properties.
An attenuated vaccine is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable (or "live"). Attenuation takes an infectious agent and alters it so that it becomes harmless or less virulent. These vaccines contrast to those produced by "killing" the virus (inactivated vaccine).
Since the fireball can expand to hundreds of kilometers at high altitude, this means that a typical attenuation of 1 dB per kilometer through a fireball at mid to high-altitudes which expands to 10 km will completely attenuate the signal, making tracking objects on the far side impossible.
The amount reaching the Earth's surface (as insolation) is further reduced by atmospheric attenuation, which varies. At any given moment, the amount of solar radiation received at a location on the Earth's surface depends on the state of the atmosphere, the location's latitude, and the time of day.
Beta gauge particulate samplers have an appearance that is similar to a reel to reel tape recorder. Air is pulled through a filter tape to accumulate a sample, the mass of the tape before and after sampling is determined by advancing the tape spot into the beta attenuation cell.
Permeability can influence Stoneley wave propagation in three ways. Stoneley waves can be partly reflected at sharp impedance contrasts such as fractures, lithology, or borehole diameter changes. Moreover, as formation permeability increases, Stoneley wave velocity decreases, thereby inducing dispersion. The third effect is the attenuation of Stoneley waves.
Also referred to as F-MIRE (field microphone in real ear). This method measures attenuation by placing a small microphone inside the ear canal while hearing protection is worn. Sound pressure levels (SPL) are measured inside and outside of the ear simultaneously and used to calculate a PAR.
Seismic inverse Q-filtering employs a wave propagation reversal procedure that compensates for energy absorption and corrects wavelet distortion due to velocity dispersion.Wang 2008, From Preface. By compensating for amplitude attenuation with a model of the visco- elastic attenuation model type, seismic data can provide true relative- amplitude information for amplitude inversion and subsequent reservoir characterization. By correcting the phase distortion due to velocity dispersion, seismic data with enhanced vertical resolution can yield correct timings for lithological identification.Wang 2008, From the back cover However, Wang's outline of the subject is excellent and to follow his path, inverse Q filtering can be introduced based on the 1-D one-way propagation wave equation.
Beams may encounter losses as they travel through materials which will cause attenuation of the beam intensity. A property common to non-diffracting (or propagation-invariant) beams, such as the Airy beam and Bessel beam, is the ability to control the longitudinal intensity envelope of the beam without significantly altering the other characteristics of the beam. This can be used to create Airy beams which grow in intensity at they travel and can be used to counteract losses, therefore maintaining a beam of constant intensity as it propagates. In temporal domain, an analogous modified dispersion-free attenuation-compensating Airy-based ("rocket") pulse was previously proposed and demonstrated in, designed to compensate media losses as it propagates through dispersive media.
These differences are most likely attributed to incorrect insertion or poor earplug fit. Because the actual amount of attenuation is typically less than the labeled NRR, the U.S. Department of Labor/OSHA suggest "derating" or reducing the NRR when using it to evaluate total noise exposure when wearing the HPD. OSHA's training manual has uses a 7 dBA correction factor: NRR- 7dBA= estimated noise exposure in the late 1990s the US National Institute for Occupational Health and Safety (NIOSH) recommended a different derating scheme for HPDs but now encourages the hearing protection fit- testing. Hearing protection fit-testing has been developed in order to determine the actual attenuation of the device as it is worn for an individual.
In atlas methods a standard MR image, with associated CT attenuation data, can be warped to fit the actual patient anatomy. Disadvantages of this method include difficulty with unusual anatomy, a need for a suitable library of images, and the need to account for MR coil attenuation. Synthetic, or Substitute CT (sCT) methods to generate CT like data from MRI are also of interest for radiotherapy planning, and have been primarily investigated for sites in the head. While some of these use an atlas technique, many take a voxel approach where actual voxel intensities (contrast data) are used in combination with machine learning (trained on MR/CT data) to assign electron density values.
It covers a total area of 225 km². Radiometric dating has yielded ages of 1.7 ± 0.4 to 0.431 ± 0.012 million years ago. Together with Cerro el Condor and Peinado it forms the Culampaja line, a line of volcanoes that reaches Cerro Blanco. Strong seismic attenuation is observed beneath Sierra Nevada.
ITU-T G.694.2, "WDM applications: CWDM wavelength grid" ITU-T website Many CWDM wavelengths below 1470 nm are considered unusable on older G.652 specification fibers, due to the increased attenuation in the 1270–1470 nm bands. Newer fibers which conform to the G.652.C and G.652.
ICF walls have much lower rates of acoustic transmission. Standard thickness ICF walls have shown sound transmission coefficients (STC) between 46 and 72 compared to 36 for standard fiberglass insulation and drywall. The level of sound attenuation achieved is a function of wall thickness, mass, component materials and air tightness.
A fiber optic filter is a component with two or more ports that provides wavelength sensitive loss, isolation and/or return loss. Fiber optic filters are in-line, wavelength selective, components that allow a specific range of wavelengths to pass through (or reflect) with low attenuation for classification of filter types.
The technique of serial passage has been around since the 1800s. In particular, Louis Pasteur’s work with the rabies vaccine in the late 1800s exemplifies this method. Pasteur created several vaccines over the course of his lifetime. His work prior to rabies involved virus attenuation, but not through serial passage.
Errors-in-variables models (or "measurement error models") extend the traditional linear regression model to allow the predictor variables X to be observed with error. This error causes standard estimators of β to become biased. Generally, the form of bias is an attenuation, meaning that the effects are biased toward zero.
As such, seismic interferometry is commonly used to estimate ground roll to aid in its removal. Seismic interferometry simplifies estimates of shear wave velocity and attenuation in a standing building. Seismic interferometry has been applied to image the seismic scattering Chaput et al., 2012 and velocity structure Brenguier et al.
Atmospheric attenuation in dB/km as a function of frequency over the EHF band. Peaks in absorption at specific frequencies are a problem, due to atmosphere constituents such as water vapour (H2O) and molecular oxygen (O2). The vertical scale is exponential. Millimeter waves propagate solely by line-of- sight paths.
The antenna design resembles a modified Yagi-Uda antenna. It consists of a W-shaped dipole and a reflector. As with the Moxon antenna, the design omits the directors found in a Yagi-Uda. Its antenna gain is between 5dBi and 6dBi, the forward/reverse attenuation is up to 20dB.
Mechanism of transcriptional attenuation of the trp operon. An example is the trp gene in bacteria. When there is a high level of tryptophan in the region, it is inefficient for the bacterium to synthesize more. When the RNA polymerase binds and transcribes the trp gene, the ribosome will start translating.
FIGURE 5. Selected images form CT performed using a Cholangiocarcinoma specific protocol. 5a is a portal venous phase image demonstrating a single low attenuation mass which does not appear to enhance. 5b is a 15 minute delayed image which demonstrates delayed enhancement of the liver mass (arrow) characteristic of Cholangiocarcinoma.
274 Selection of optimum PWM carrier frequency for AC drives involves balancing noise, heat, motor insulation stress, common-mode voltage-induced motor bearing current damage, smooth motor operation, and other factors. Further harmonics attenuation can be obtained by using an LCR low-pass sine wave filter or dV/dt filter.
Stroynowski received a PhD from Stanford University in 1979 in the field of Genetics under the supervision of Joshua Lederberg. She became an American citizen in 1982. At Stanford, working with Charles Yanofsky, she discovered the attenuation system regulating bacterial amino acid synthesis pathways.Iwona Stroynowski, Magda van Cleemput, and Charles Yanofsky.
A 6 dB increase in PSRR roughly equates to an increase in attenuation by a factor of 2. Most LDOs have relatively high PSRR at lower frequencies (10 Hz – 1 kHz). However, a Performance LDO is distinguished in having high PSRR over a broad frequency spectrum (10 Hz – 5 MHz).
Koutavas et al. (2006) used δ18O of G. ruber foraminifera to study the El Niño–Southern Oscillation (ENSO) and it's variability through the mid-Holocene.Koutavas A, Demenocal PB, Olive GC, Lynch-Stieglitz J. 2006. Mid-Holocene El Ni˜ no- Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments.
The testing involves running the batteries on the natural attenuation rate curve, which measures the rate of decay over time on a curve. Early reports have indicated that customer testing indicated good consistency with little decay, which is very promising given the market potential for the products in several major Chinese provinces.
Pickups are usually designed to feed a high input impedance, typically a megohm or more, and a low-impedance load increases attenuation of higher frequencies. Typical maximum frequency of a single-coil pickup is arount 5 kHz, with the highest note on a typical guitar fretboard having a fundamental frequency of 1.17 kHz.
This event took Greek seismologists by surprise as it came from a previously unknown fault, originating in an area that was for a long time considered of a particularly low seismicity. The highest recorded peak ground acceleration was 0.3g, at 15 km from the epicentre, with attenuation predicting 0.6g acceleration at the centre.
Damping is caused by the resistance in the circuit. It determines whether or not the circuit will resonate naturally (that is, without a driving source). Circuits that will resonate in this way are described as underdamped and those that will not are overdamped. Damping attenuation (symbol ) is measured in nepers per second.
It is clear that electric field strength is inversely proportional to the distance between the transmitter and the receiver. However, this relation is impractical for calculating the field strength produced by terrestrial transmitters, where reflections and attenuation caused by objects around the transmitter or receiver may affect the electrical field strength considerably.
Any given point within the subject is crossed from many directions by many different beams at different times. Information regarding attenuation of these beams is collated and subjected to computation to generate two dimensional images in three planes (axial, coronal, and sagittal) which can be further processed to produce a three dimensional image.
The standard linear solid model is developed from the stress-strain relation. Using a linear combination of springs and dashpots to represent elastic and viscous components, Ursin and Toverud used one relaxation time.Ursin B. and Toverud T. 2002 Comparison of seismic dispersion and attenuation models. Studia Geophysica et Geodaetica 46, 293–320.
Inductive sensors evaluate the attenuation of a high-frequency electro- magnetic field which has been generated by eddy currents in the work piece. The application of single-coil design types allows side or height correction. Multiple-coil sensors allow correction in two coordinate directions and, moreover, influence on the weld torch orientation.
The species is named for the curious resemblance of the larva to a young larva of one of the Sphingidae, the protruding tubercle above the head having exactly the appearance of an anal horn, while the attenuation of the body posteriorly represents the form of a Sphingid larva in the reverse position.
Depth-resolving THz imaging with tomosynthesis. Optics Express, 17(12), 9558. doi: 10.1364/oe.17.009558 This technique also has an advantage over terahertz CT. Terahertz CT is significantly affected by reflection and refraction, especially for wide and flat plate samples, which has a large incidence angle at the edge and severe signal attenuation.
The mean free path turns out to be minimal (5–10 Å) in the energy range of low-energy electrons (20–200 eV). This effective attenuation means that only a few atomic layers are sampled by the electron beam and as a consequence the contribution of deeper atoms to the diffraction progressively decreases.
The attenuation of light of all frequencies and wavelengths is due to the combined mechanisms of absorption and scattering. Transparency can provide almost perfect camouflage for animals able to achieve it. This is easier in dimly-lit or turbid seawater than in good illumination. Many marine animals such as jellyfish are highly transparent.
The Hazel Brook rises in nearby Cribbs Causeway and its flow into the River Trym is controlled by an attenuation reservoir at Catbrain, which reduces the silt flowing into the system from the many shopping malls in the area. Measurements of pollution by the city council show the water to be relatively clean.
Since the wavelengths of hard X-rays are similar to the size of atoms, they are also useful for determining crystal structures by X-ray crystallography. By contrast, soft X-rays are easily absorbed in air; the attenuation length of 600 eV (~2 nm) X-rays in water is less than 1 micrometer.
In 1933, Marcel Minnaert published a solution for the acoustic resonance frequency of a single bubble in water, the so-called Minnaert resonance. The Minnaert resonance or Minnaert frequency is the acoustic resonance frequency of a single bubble in an infinite domain of water (neglecting the effects of surface tension and viscous attenuation).
On high resolution CT air trapping has a typical imaging appearance, although often evaluation with both maximum inhalation and exhalation, or inspiratory and expiratory views, are needed for a more specific diagnosis. One of its typical imaging patterns is mosaic attenuation. In the classic presentation, the lung will appear normal at inspiration, but on exhalation, the diseased portions of the lung which have lost connective tissue recoil will remain lucent while the healthy portions of the lung will become more dense due to atelectasis. This helps distinguish it from mosaic attenuation due to patchy fibrosis, as occurs with nonspecific interstitial pneumonia, and in early usual interstitial pneumonitis (the hallmark imaging diagnosis of interstitial lung disease) in which there is no change with inspiration and expiration.
If an object that changes a LOS link to NLOS is not a good conductor but an intermediate material, it absorbs some of the RF power incident upon it. However, if it has finite thickness the absorption is also finite and the resulting attenuation of the radio waves may be tolerable and an NLOS link may be set up using radio waves that actually pass through the material. As an example, wireless local area networks (WLANs) often use finite absorption NLOS links to communicate between a WLAN access point and WLAN client(s) in the typical office environment. The radio frequencies used, typically a few gigahertz (GHz) normally passes through a few thin office walls and partitions with tolerable attenuation.
One of the performance issues addressed by the waffle-iron filter is that in many waveguide filters the attenuation is dependent on the transmission modes of the incident signal and some filters can be quite bad at suppressing spurious modes which may be contained in this signal. For instance, with the corrugated waveguide filter, on which the waffle-iron filter is based, attenuation of TEn0 modes in the stopband is strongly dependent on the mode number. This is not the case with the waffle-iron filter which attenuates all TEn0 modes nearly equally up to a certain frequency. The limit is the frequency at which the distance between the metal teeth is greater than half the free-space wavelength of the signal.
The Standard Reference Method or SRM"Beer 10-A Spectrophotometric Color Method", ASBC Methods of Analysis is one of several systems modern brewers use to specify beer color. Determination of the SRM value involves measuring the attenuation of light of a particular wavelength (430 nm) in passing through 1 cm of the beer, expressing the attenuation as an absorption and scaling the absorption by a constant (12.7 for SRM; 25 for EBC). The SRM (or EBC) number represents a single point in the absorption spectrum of beer. As such it cannot convey full color information which would require 81 points, but it does remarkably well in this regard (it conveys 92% of spectral information) even when fruit beers are considered.
The folding is modulated by a sensing mechanism producing either a Rho-independent terminator, resulting in interrupted transcription and a non-functional RNA product; or an anti-terminator structure, resulting in a functional RNA transcript. There are now many equivalent examples where the translation, not transcription, is terminated by sequestering the Shine-Dalgarno sequence (ribosomal binding site) in a hairpin-loop structure. While not meeting the previous definition of (transcriptional) attenuation, these are now considered to be variants of the same phenomena and are included in this article. Attenuation is an ancient regulatory system, prevalent in many bacterial species providing fast and sensitive regulation of gene operons and is commonly used to repress genes in the presence of their own product (or a downstream metabolite).
While these protection strategies do slightly reduce the exposure, they provide almost no protection from externally penetrating gamma radiation, which is the cause of acute radiation syndrome and can be extremely lethal in high dosages. Naturally, shielding the entire body from high-energy gamma radiation is optimal, but the required mass to provide adequate attenuation makes functional movement nearly impossible. Recent scientific studies have shown the feasibility of partial body shielding as a viable protection strategy against externally penetrating gamma radiation. The concept is based in providing sufficient attenuation to only the most radio-sensitive organs and tissues in efforts to defer the onset of acute radiation syndrome, the most immediate threat to humans from high doses of gamma radiation.
Its observation by CoRoT provided an extremely high quality ligthcurve. Global parameters could then be improved and new ephemeris for the orbital motion as well as for another long term variation were derived. This long period variation seems to originate from a periodic light attenuation by circumstellar dust. The light curve of HD 174884.
Anne Treisman, a graduate student of Broadbent's, was not fully convinced by the notion of a filter performing decisions as to what stimuli gain conscious awareness. She proposed an alternative mechanism, attenuation theory. This theory supports an early-selection filter. However, in this case, the filter also attenuates stimuli presented to the unattended channel.
In time-domain measurements, short light pulses of the order of hundreds of picoseconds are delivered to the breast and its optical properties are retrieved from the features of the re-emitted pulses, which have undergone delay, broadening and attenuation. Time-correlated single photon counting is fundamental to cope with the low-level output signal.
Thurston (1994), p. 428 In 1956 Mason and H. E. Bömmel found experimental evidence for electron-phonon coupling in pure samples of lead and tin. The work was relevant to measurement of parameters in BCS theory of superconductivity. In 1964 Mason and T. B. Bateman measured attenuation and velocity changes in doped germanium and silicon.
Researchers at the University of St. Andrews have further utilised Airy beams to make a large field of view (FOV) while maintaining high axial contrast in a light-sheet microscope. This technique has been adapted to use multi-photon excitation and attenuation-compensated Airy beams to achieve imaging at greater depths within biological specimens.
Second sound is a wave in which the densities of the superfluid and normal components oscillate out of phase with each other. Much of our knowledge about the turbulence in superfluids comes from the measurement of the attenuation of second sound, which gives a measure of the density of vortex lines in the superfluid.
Attenuation of Cf-mediated defence responses at elevated temperatures correlates with a decrease in elicitor-binding sites. MPMI 15: 1040–9. on cultivated tomato (Cooke 1883), although it is originally from South and Central America. The causal fungus of tomato leaf mold may also be referred to as Cladosporium fulvum (Cooke 1883), a former name.
APOE−/− knockout mice show marked attenuation of cerebral malaria and increased survival, as well as decreased sequestration of parasites and T cells within the brain, likely due to protection of the blood-brain barrier. Human studies have shown that the APOE2 polymorphism correlates with earlier infection, and APOE3/4 polymorphisms increase likelihood of severe malaria.
Iwona Teresa Stroynowski née Fleszar (born 1950) is a Polish-born American immunologist who is Professor in the Department of Immunology and Microbiology at University of Texas Southwestern Medical Center in Dallas, TX. She discovered the process of gene expression control called attenuation early in her career, the first example of a riboswitch mechanism.
This behavior is a UV-induced positive gravitaxis. This gravitaxis and negative phototaxis induced by light coming from the water surface form a ratio-metric depth-gauge. Such a depth gauge is based on the different attenuation of light across the different wavelengths in water. In clear water blue light (470 nm) penetrates the deepest.
Low attenuation Signals transmitted on optical fiber attenuate much less than through other media like metal cables or wireless media.M. Vidmar, “Optical-fiber communications: Components and systems”, Informacije MIDEM, vol. 31., no. 4., 2001 By using optical fiber, the radio signals can gap larger transmission distances, reducing the need of additional repeaters or amplifiers.
Internal scattering can result in as much as 10 dB of attenuation. Meanwhile, the pyramid shapes are cut at angles that maximize the number of bounces a wave makes within the structure. With each bounce, the wave loses energy to the foam material and thus exits with lower signal strength.E Knott, J Shaeffer, M Tulley, Radar Cross Section.
Measurements of the radio background and ice attenuation length were reported. The first ARA station was installed in the season (Antarctic summer season; winter in northern hemisphere) 2011–2012; stations 2 and 3 were installed in the season 2012–2013 and stations 4 and 5 in season 2017–2018. The ARA array had five stations as of 2018.
In teleceptive active sensing, geometric spread cost is doubled, because signal is emitted and returned. As a result, fraction of energy returned decreases as the fourth power of the distance between organism and target. Directionality also plays a role in energy expenditure in producing signals. Increase in directionality and narrow range result in longer attenuation length.
Am. Ind. Hyg. Assoc. J., 51:326-330 (1990). This attenuation is due to the ability of water, methane, and other compounds with high ionization energies to absorb the photons emitted by the UV lamp without leading to the production of an ion current. This reduces the number of energetic photons available to ionize target analytes.
Picture degradation and signal-strength attenuation increases with each subsequent Sporadic E hop. Sporadic E usually affects the lower VHF band I (TV channels 2 – 6) and band II (88 – 108 MHz FM broadcast band). The typical expected distances are about . However, under exceptional circumstances, a highly ionized Es cloud can propagate band I VHF signals down to approximately .
Frequency-selective time-varying fading causes a cloudy pattern to appear on a spectrogram. Time is shown on the horizontal axis, frequency on the vertical axis and signal strength as grey-scale intensity. In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency.
However, at lower energy levels this attenuation can become too great, so air gaps are left in the collar to allow low energy radiation to have a greater effect. In practice, compensation filter design is an empirical compromise to produce an acceptably uniform response, and a number of different materials and geometries are used to obtain the required correction.
CT scan can show the full extent of the polyp, which may not be fully appreciated with physical examination alone. Imaging is also required for planning surgical treatment. On a CT scan, a nasal polyp generally has an attenuation of 10–18 Hounsfield units, which is similar to that of mucus. Nasal polyps may have calcification.
There have been some models that theorize the pathway of selective auditory attention, notably the early selection model, late selection model, and attenuation model. Selective hearing is not a physiological disorder but rather it is the capability of humans to block out sounds and noise. It is the notion of ignoring certain things in the surrounding environment.
Having a full bladder for the transabdominal portion of the exam is helpful because sound travels through fluid with less attenuation to better visualize the uterus and ovaries which lies posteriorly to the bladder. The procedure is by definition invasive when performed transvaginally. Scans are performed by health care professionals called sonographers, or gynecologists trained in ultrasound.
Although repetition priming is most often associated with neural attenuation for repeated presentation of stimuli, increases in neural responses have also been measured in a number of experimental contexts. For example, when performing mathematical calculations, when repeated stimuli are degraded, in studies involving a backward masking paradigm and when stimuli have no pre-existing associations or meaning.
The highest attenuation of homœopathy and the most potent rises above matter into mind. This discovery leads to more light. From it may be learned that either human faith or the divine Mind is the healer and that there is no efficacy in a drug.Eddy, Science and Health, "Science, Theology, Medicine" , pp. 152–153; Schoepflin 2003, p. 113ff.
Idle time typically comprises greater than 80% of the daily cycle; during this time, microbial attenuation processes are likely to be significant. Most removal occurs where water is in contact with the biofilm. The processes that occur in the biofilm have not been identified. When the standing water layer reaches the level of the outlet tube, the flow stops.
There are many different algorithms that can be implemented to achieve a given coupling between ports including less efficient "images" for attenuation or power splitting. WSS based on MEMSMarom, D. M. et al. (2002) "Wavelength-selective 1×4 switch for 128 WDM channels at 50 GHz spacing," in Proc. Optical Fiber Communications), Anaheim, CA, Postdeadline Paper FB7, pp.
The attenuation values of ND filters are specified logarithmically. A ND 3 filter transmits 10−3 of the incident beam power. Placing the largest attenuator last before the CCD sensor will result in the best rejection of ghost images due to multiple reflections. Reflective filters are made with a thin metallic coating and hence operate over a larger bandwidth.
An ND 3 metallic filter will be good over 200–2000 nm. The attenuation will rapidly increase outside this spectral region because of absorption in the glass substrate. These filters reflect rather than absorb the incident power, and hence can handle higher input average powers. However, they are less well suited to the high peak powers of pulsed lasers.
Acoustic attenuation is a measure of the energy loss of sound propagation in media. Most media have viscosity, and are therefore not ideal media. When sound propagates in such media, there is always thermal consumption of energy caused by viscosity. For inhomogeneous media, besides media viscosity, acoustic scattering is another main reason for removal of acoustic energy.
Seismic interferometry applications are currently limited by a number of factors. Real world media and noise represent limitations for current theoretical development. For example, for interferometry to work noise sources must be uncorrelated and completely surround the region of interest. In addition, attenuation and geometrical spreading are largely neglected and need to be incorporated into more robust models.
Some of methods are based on light scattering. Others apply ultrasound, such as ultrasound attenuation spectroscopy for testing concentrated nano-dispersions and microemulsions. There is also a group of traditional techniques for characterizing surface charge or zeta potential of nano-particles in solutions. This information is required for proper system stabilization, preventing its aggregation or flocculation.
Forest blocks adjacent to major cities and towns are under development as urban parks, acting as urban "lung" spaces.The vegetation in urban open spaces act as a sink for carbon dioxide. They reduce pollution and produce oxygen. They allow rain water percolation and ground water recharge in addition to facilitating storm water drainage and flood attenuation.
Germanium-doped core fibers can be radiation hard even at high concentrations of germanium. Such fibers reach saturation, anneal well at higher temperatures and are also responsive to photo-bleaching. In case of phosphorus-doped core fibers, attenuation increases linearly with increasing phosphorus content and these fibers do not reach saturation. Recovery is very difficult even at higher temperatures.
Not everyone is a good candidate for TRT. Factors associated with suitability for TRT and predisposing for favorable outcome are: lower loudness of tinnitus, higher pitch of tinnitus, shorter duration of tinnitus since onset, recognition of tinnitus attenuation by sound generator, lower hearing thresholds (i.e. better hearing), high Tinnitus Handicap Inventory (THI) score, and positive attitude toward therapy.
In this case it must have the same audio power level as the source of the unwanted sound. Alternatively, the transducer emitting the cancellation signal may be located at the location where sound attenuation is wanted (e.g. the user's ear). This requires a much lower power level for cancellation but is effective only for a single user.
Qara Iskander () ruled the Kara Koyunlu or Black Sheep Turcoman tribe from 1420 to 1436. His struggles with the Timurid ruler Shah Rukh show that he was a brave leader, but he was not able to continue developing what he inherited from his father Qara Yusuf and his reign saw the decline and attenuation of the Kara Koyunlu.
Acoustic rheometers employ a piezo-electric crystal that can easily launch a successive wave of extensions and contractions into the fluid. This non-contact method applies an oscillating extensional stress. Acoustic rheometers measure the sound speed and attenuation of ultrasound for a set of frequencies in the megahertz range. Sound speed is a measure of system elasticity.
In 1904, Charles Spearman was responsible for figuring out how to correct a correlation coefficient for attenuation due to measurement error and how to obtain the index of reliability needed in making the correction.Traub, R. (1997). Classical Test Theory in Historical Perspective. Educational Measurement: Issues and Practice 16 (4), 8–14. doi:doi:10.1111/j.1745-3992.1997.tb00603.
Contrast agents are commonly used to improve the visibility of blood vessels and the gastrointestinal tract. Several types of contrast agent are in use in medical imaging and they can roughly be classified based on the imaging modalities where they are used. Most common contrast agents work based on X-ray attenuation and magnetic resonance signal enhancement.
Wideband material refers to material that can convey Microwave signals (light/sound) over a variety of wavelengths. These materials possess exemplary attenuation and dielectric constants, and are excellent dielectrics for semiconductor gates. Examples of such material include gallium nitride (GaN) and silicon carbide (SiC). SiC has been used extensively in the creation of lasers for several years.
On chest x-ray, there will be abnormal tissue density or an isolated cystic shadow over the cardiophrenic angle. On transthoracic echocardiogram, there is lack of flow on the affected area on colour Doppler. On cardiac CT scan, there is non-enhancing, homogenous attenuation of the affected area. Cardiac CT is good for precise localisation of percardial anatomy.
During activities such as overhand baseball pitching, this ligament is subjected to extreme tension, which places the overhand-throwing athlete at risk for injury. Acute or chronic disruption and/or attenuation of the ulnar collateral ligament often result in medial elbow pain, valgus instability, neurologic deficiency, and impaired throwing performance. There are both non-surgical and surgical treatment options.
The longer wavelengths have the advantage of diffracting more, and so line of sight is not as necessary to obtain a good signal. Because the frequencies that cell phones use are too high to reflect off the ionosphere as shortwave radio waves do, cell phone waves cannot travel via the ionosphere. (See Diffraction and Attenuation for more details).
X-rays are attenuated based on a material's density. Denser materials will stop more X-rays. With neutrons, a material's likelihood of attenuation of neutrons is not related to its density. Some light materials such as boron will absorb neutrons while hydrogen will generally scatter neutrons, and many commonly used metals allow most neutrons to pass through them.
Traditional remediation approaches consist of soil excavation and disposal to landfill and groundwater "pump and treat". In-situ technologies include but are not limited to: solidification and stabilization, soil vapor extraction, permeable reactive barriers, monitored natural attenuation, bioremediation-phytoremediation, chemical oxidation, steam-enhanced extraction and in situ thermal desorption and have been used extensively in the USA.
The thyroid gland has a very high iodine concentration, resulting in high CT attenuation (80–100 Hounsfield Units). The presence of thyroiditis can be suggested by a diffusely enlarged and hypo-attenuating (around 45 Hounsfield Units) thyroid gland. This is probably due to follicular cell destruction and reduced thyroid iodine concentration. Marked homogenous enhancement is typically expected.
This may be done with a gate with its ducking function engaged or by a dedicated ducker. A typical application is to achieve an impression similar to the "pumping" effect. The difference between ducking and side-chain pumping is that in ducking the attenuation is by a specific range while side-chain compression creates variable attenuation.Hodgson, Jay (2010).
She graduated from the Bronx High School of Science in New York and received her B.A. at Barnard College in 1954, her M.S. at Columbia University in 1957, and her Ph.D. at Columbia University in 1960. where her advisor was Richard Garwin. Her PhD looked into measuring the attenuation of a magnetic field by Type-I superconducting films.
Air filled structures (especially bronchi) are enhanced. MinIP is mainly used to diagnose lung diseases with computed tomography scans where the attenuation values are reduced (for example traction bronchectasis and emphysema). Another application is for assessing the bile tree and pancreatic duct which compared to the surrounding tissue is hypoattenuating (especially after intravenous contrast media administration).
Bridging wires are rods that couple together resonators that are not adjacent. They can be used to produce poles of attenuation in the stopband. This has the benefit of increasing the stopband rejection. When the pole is placed near the passband edge, it also has the benefit of increasing roll-off and narrowing the transition band.
To be rated, hearing protection is tested under ANSI S3.19-1974 to provide a range of attenuation values at each frequency that can then be used to calculate a Noise Reduction Rating (NRR). Under this standard a panel of ten subjects are tested three times each in a laboratory to determine the attenuation over a range of 9 frequencies. In the European Union, hearing protectors are required to be tested according to the International Organization for Standardization (ISO) acoustical testing standard, ISO 4869 Part 1 and the Single Number Rating (SNR) or High/Middle/Low (HML) ratings are calculated according to ISO 4869 Part 2. In Brazil, hearing protectors are tested according to the American National Standards Institute ANSI S12.6-1997 and are rated using the Noise Reduction Rating Subject Fit NRR(SF).
An optical isolator is a two-port passive component that allows light (in a given wavelength range) to pass through with low attenuation in one direction, while isolating (providing a high attenuation for) light propagating in the reverse direction. Isolators are used as both integral and in-line components in laser diode modules and optical amplifiers, and to reduce noise caused by multi-path reflection in high-bitrate and analog transmission systems. An optical circulator operates in a similar way to an optical isolator, except that the reverse propagating lightwave is directed to a third port for output, instead of being lost. An optical circulator can be used for bidirectional transmission, as a type of branching component that distributes (and isolates) optical power among fibers, based on the direction of the lightwave propagation.
Although the exact mechanism of T box leader is still unclear and currently being studied, it has recently been recognized as a member of an expanding group of RNAs that are phylogenetically conserved across many gram-positive bacteria. They are structurally complex and able to directly sense physiological signals which results in the control of downstream gene expression. This controlling of gene expression is accomplished by transcriptional attenuation—a general transcriptional regulation strategy that senses when an alteration in the rate of transcription is necessary and initiating alteration at a particular site (sometimes preceding one or more genes of an operon). The operons that encode aminoacyl-tRNA synthetases, regulated by tRNA-mediated transcriptional attenuation, contain a leader region that specifies a transcript segment that can fold and eventually form a complex set of structures.
At these high frequencies, the short wavelengths give the radiation a very directional quality, similar to visible light. Many molecules possess rotational and vibrational states excited by very specific wavelengths in this band, thus the atmospheric gases such as oxygen, water vapor, carbon dioxide and nitrogen can absorb, and be excited causing variable beam attenuation effects dependent on meteorological and atmospheric conditions.
In particular, the transfer function of the similar sample, which is half thinner, could be interpreted as the square root (i.e. half-iteration) of the transfer function of the initial sample. Similar example is suggested for a nonlinear optical fiber. ;Nonlinear acoustics: It may make sense to characterize the nonlinearities in the attenuation of shock waves in a homogeneous tube.
Pathfinder airbag on Mars ILC designs and manufactures inflatable structures for use in earth orbit, lunar, and planetary exploration. Inflatable structures have been used on a number of space missions for a variety of applications including specialized flexible containment covers (Hubble Space Telescope), impact attenuation airbag systems, and inflatable aerodynamic decelerators.NASA, Atmospheric Entry Decelerator Technologies . Retrieved on 2011-02-11.
He has authored or co-authored more than 200 technical reports, more than 70 refereed journal papers and 7 books.Sicking, Dean L., "Curriculum Vitae: Dean L. Sicking, Ph.D., P.E.", University of Alabama at Birmingham. Accessed May 8, 2016. Additionally, Sicking has developed functional performance standards for a number of different impact attenuation systems, including developing nationally accepted performance standards for roadside safety features.
These widely distributed sequences are responsible for triggering the end of transcription upon normal completion of gene or operon transcription, mediating early termination of transcripts as a means of regulation such as that observed in transcriptional attenuation, and to ensure the termination of runaway transcriptional complexes that manage to escape earlier terminators by chance, which prevents unnecessary energy expenditure for the cell.
A multiburst signal is an electronic waveform used to test analog transmission, recording, and display systems. The test pattern consists of several short periods of specific frequencies. The contrast of each may be measured by inspection and recorded, giving a plot of attenuation vs. frequency. The NTSC3.58 multiburst pattern consists of 500 kHz, 1 MHz, 2 MHz, 3 MHz, and 3.58 MHz blocks.
Alternatively, a signal may be intentionally oversampled without an intermediate frequency to reduce the requirements on the anti-alias filter. For example, CD audio typically extends up to 20 kHz, but is sampled with a 22.05 kHz Nyquist rate. By oversampling by 2.05 kHz, both aliasing and attenuation of higher audio frequencies can be prevented even with less than ideal filters.
The electrical conductivity of the ground, the transmitted center frequency, and the radiated power all may limit the effective depth range of GPR investigation. Increases in electrical conductivity attenuate the introduced electromagnetic wave, and thus the penetration depth decreases. Because of frequency-dependent attenuation mechanisms, higher frequencies do not penetrate as far as lower frequencies. However, higher frequencies may provide improved resolution.
In addition, signal amplitude is increased across the microstrip transmission lines by suspending them above the ground plane at a predetermined distance. In other words, they are not in contact with a solid substrate. Dielectric signal loss is reduced significantly, reducing signal attenuation. This system was designed to boost the performance of the Monolithic microwave integrated circuit (MMIC), among other benefits.
Waveguide filter designs sometimes use the Achieser-Zolotarev response as low-pass filters. It is used in this role because it provides a better impedance match than the more common Chebyshev filter. The higher attenuation at the very lowest frequencies is acceptable in waveguide filters because in this medium there is always a guide cutoff frequency below which waves cannot propagate anyway.Levy p.
Interference on telephone lines is even more disruptive than it is on telegraph lines. Telephone companies converted to balanced circuits, which had the incidental benefit of reducing attenuation, hence increasing range. As electrical power distribution became more commonplace, this measure proved inadequate. Two wires, strung on either side of cross bars on utility poles, shared the route with electrical power lines.
A loaded twisted pair has intentionally added inductance and was formerly common practice on telecommunication lines. The added inductors are known as load coils and reduce attenuation for voiceband frequencies but increase it on higher frequencies. Load coils reduce distortion in voiceband on very long lines. In this context a line without load coils is referred to as an unloaded line.
These tomographic images show a low velocity, high attenuation region above the subducting slab. The slowest velocities in these volcanic arc regions are Vp= 7.4 km·s−1 and Vs= 4 km·s−1. Mantle wedge regions that do not have associated arc volcanism do not show such low velocities. This can be attributed to the melt production in the mantle wedge.
66, Jan 1978, pp.174–204 When windowing is implemented, some signal attenuation occurs and there is a broadening of the main pulse, so both signal-to-noise ratio and range resolution are impaired by the process. Preferably, the transmitted and received pulses should be modified in equal measure, but when this is impractical, windowing in the compression filter alone is still beneficial.
The reflections increase in size from nearest to farthest of the IDT to account for losses due to preceding reflectors and wave attenuation. Data is encoded using Pulse Position Modulation (PPM). The crystal is logically divided into groups, such that each group typically has a length equal to the inverse of the bandwidth. Each group is divided into slots of equal width.
Paul G. Richards (born March 1943) is an English-born, American seismologist who has made fundamental contributions to the theory of seismic wave link propagation and in methods to understand how the recorded shapes of seismic waves are affected by processes of diffraction, attenuation and scattering. He is the Mellon Professor of the Natural Sciences at Lamont-Doherty Earth Observatory of Columbia University.
Therefore, when Akt is activated, PTEN is further repressed in a positive feedback loop. The pathway is also controlled by protein phosphatase 2A (PP2A), which dephosphorylates Akt at Thr308 and phosphatase PHLPP dephosphorylates Akt at Ser473. Another protein important in Akt attenuation is Carboxy Terminal Modulator Protein (CTMP). CTMP binds to the regulatory domain of Akt, blocking its phosphorylation and activation.
It is regulated by feedback inhibition in the form of transcriptional attenuation. That is, transcription is reduced in the presence of the pathway's end-products, the branched-chain amino acids. The ilvBNC operon encodes the ilvBN (ALS I) pair and a ketol-acid reductoisomerase (ilvC). It is similarly regulated, but is specific to isoleucine and leucine; valine does not affect it directly.
The SRMP produces a marked attenuation (reduction) in the perennial flooding of the Agno River affecting at least 16 Pangasinan and Tarlac towns. It is complemented by the 3-phase, PhP9.7 billion Agno Flood Control Project managed by DPWH. Phase I is completed; Phase II is in progress; and Phase III will begin in 2004 and be completed in 2009.
TLTs generally contain a fixed or preset local oscillator (LO) and a preset gain, though the LO and gain may be adjustable in some models. Most models have a negative gain (i.e., signal attenuation), with -15 dB being the most common value. Test loop translators can cover one or more of the satellite communication bands S, C, X, Ku, DBS, and Ka.
The number of teeth, their size, and the gap between them are all design parameters that can be used to control the design of the filter. As an example, a filter with a 3:1 stopband might have five teeth across the width of the waveguide. The number of rows of teeth down the length of the waveguide primarily affects the stopband attenuation.
The more rows of teeth, the better the attenuation, each row being equivalent to a lumped element circuit filter section. A filter with ten rows of teeth has a theoretical stopband rejection of around and one with seven rows around .Matthaei et al., pp.392, 938 The earliest waffle-iron filters were designed with the image parameter method of filter design.
The outer conductor is usually sheathed in a protective PVC outer jacket (A). All these have a common axis. The dimension and material of the conductors and insulation determine the cable's characteristic impedance and attenuation at various frequencies. In loudspeaker design, coaxial speakers are a loudspeaker system in which the individual driver units radiate sound from the same point or axis.
This is advantageous because it allows a communication system to possess both low dispersion and low attenuation. However, when used in wavelength division multiplexing systems, dispersion-shifted fibers can suffer from four-wave mixing which causes intermodulation of the independent signals. As a result, nonzero dispersion shifted fiber is often used. Dispersion-shifted fiber is specified in ITU-T G.653.
Transmissometers are referred to as telephotometers, transmittance meters, or hazemeters. The term transmissometer is also used by oceanographers and limnologists to refer to a device for measuring the optical properties of natural water. In this context, a transmissometer measures the transmittance or attenuation of incident radiation from a light source with a select wavelength, often 660 nm, through a defined cell volume.
Data suggests that proximal apical and basal dendrites are more compressed but offer a wider local range of activity than distal apical dendrites. In CA3 neurons the inputs are stratified and run in bands parallel to the cell body layer. Dendritic attenuation of synaptic current is described by an exponential relationship. The closer to the body the dendrite, the higher the EPSP amplitude.
The crystal's stability and its high Q factor allow crystal filters to have precise center frequencies and steep band-pass characteristics. Typical crystal filter attenuation in the band-pass is approximately 2-3dB. Crystal filters are commonly used in communication devices such as radio receivers. A crystal filter is very often found in the intermediate frequency (IF) stages of high-quality radio receivers.
Studies supporting the representational theory of unilateral neglect show that right hemisphere lesion patients with left unilateral neglect failed to respond to their left contralateral nostril on olfactory double simultaneous stimulation in spite of adequate olfactory sensitivity. This demonstrated that the occurrence of unilateral neglect is not a function of sensory attenuation, in fact, olfactory sensitivity did not correlate with number of extinctions.
The GABAA receptor inverse agonist reduced GABA transmission, and the result was attenuation of the impact of context in eliciting the renewal effect. This research suggests that GABAergic mechanisms (mechanisms pertaining to neurons that produce GABA as their output) mediate ABA renewal and spontaneous recovery in appetitive conditioning. As such, spontaneous recovery and renewal are believed to share a common psychological mechanism.
The cable capacitance of 90 pF in parallel with the scope input of 20 pF (total capacitance 110 pF) and 1 megohm also gives a time constant of 110 microseconds. In practice, there will be an adjustment so the operator can precisely match the low frequency time constant (called compensating the probe). Matching the time constants makes the attenuation independent of frequency.
Due to the electrical and magnetic interaction, the angular momentum of the intermediate state I_i experiences a torque about its axis of symmetry. Quantum-mechanically, this means that the interaction leads to transitions between the M states. The second \gamma- quantum (\gamma_2) is then sent from the intermediate level. This population change is the reason for the attenuation of the correlation.
Illustration of regression dilution (or attenuation bias) by a range of regression estimates in errors-in-variables models. Two regression lines (red) bound the range of linear regression possibilities. The shallow slope is obtained when the independent variable (or predictor) is on the abscissa (x-axis). The steeper slope is obtained when the independent variable is on the ordinate (y-axis).
The threonine operon leader is an RNA element. Threonine is one of at least 6 amino acid operons are known to be regulated by attenuation. In each a leader sequence of 150–200 bp is found upstream of the first gene in the operon. This leader sequence can assume two different secondary structures known as the terminator and the anti-terminator structure.
Distamycin inhibits the transcription and increases the activity of the topoisomerase II. Derivates from distamycin are used as alkylating antineoplastic agents to combat tumours. Derivates with fluorophores are used as fluorescent tags for double-stranded DNA. The compound is hygroscopic, and sensible to light, freeze and hydrolysis. Its molar attenuation coefficient is 37,000 M−1 cm−1 at a wavelength of 303 nm.
Humor is also a known mood- repair strategy. Humor is able to bring about a sense of attenuation and allow for individuals to engage in pleasurable activities. Engaging in activities that can evoke a humorous response can often lead individuals to laughter. Laughter is able to increase serotonin levels which are known to bring about a greater level of contentment.
Several studies have shown that bone density may be measured by QCT using CT images that were ordered for other purposes. Using pre-existing images, including CT colonography exams,Pickhardt et al., "Simultaneous screening for osteoporosis at CT colonography: Bone mineral density assessment using MDCT attenuation techniques compared with the DXA reference standard," Journal of Bone and Mineral Research, vol. 26, no.
However, since MRI appearance is practically pathognomonic, biopsy is rarely needed for verification. On ultrasound, cavernous haemangiomas in liver appeared as homogenous, hyperechoic lesions with posterior acoustic enhancement. On CT or MRI scans, it shows peripheral globular/nodular enhancement in the arterial phase, with portions of attenuation of enhancing areas. In the portal venous phase, it shows progressive centripetal enhancement.
Sempere's outdoor sculpture of metal rods at the Juan March Foundation in Madrid inspired two Spanish physicists to develop a new method for cancelling noise. Discussing the mechanics of sound attenuation over beers, they realized that the sculpture might reveal an optimum arrangement of materials that dampens noise not by absorbing it, but by interfering with the transmission of sound waves.
The findings on chest imaging in DIPNECH patients are bilateral and diffuse. The most frequent findings on a computed tomography (CT) of the chest are multiple primary nodules and/or masses, on a background of mosaic attenuation and airway wall thickening. The nodules have an indolent pattern of growth and are found throughout the lungs. The nodules are typically rounded and well-defined.
For instance, the sample may absorb energy from the beam, resulting in an attenuation of the output that is detectable by the transducer. Two conventional multipass cells are called the White cell and Herriott cell. The presently popular and commercially used multipass cell also known and the Circular Multipass Cell are widely used in Trace gas sensing, Environmental and Industrial processes.
There are many different types of HPDs available for use, including earmuffs, earplugs, electronic hearing protection devices, and semi- insert devices. One can measure the personal attenuation rating through a hearing protection fit-testing system. Earmuff style hearing protection devices are designed to fit over the outer ear, or pinna. Earmuff HPDs typically consist of two ear cups and a head band.
Naturally occurring within the soil are microbial populations that utilize hydrocarbons as a source of energy and Carbon. Upwards to twenty percent of microbial soil populations have the ability to metabolize hydrocarbons. These populations can through either accelerated or natural monitored attenuation be utilized to neutralize within the soil hydrocarbon pollutants. The metabolic mode of hydrocarbon remediation is primarily aerobic.
Quote- "The Ducrete/DUAGG replaces the conventional aggregate in concrete producing concrete with a density of 5.6 to 6.4 g/cm3 (compared to 2.3 g/cm3 for conventional concrete). This shielding material has the unique feature of having both high Z and low Z elements in a single matrix. Consequently, it is very effective for the attenuation of gamma and neutron radiation ..."M.
Beamed energy coupled with a vehicle scooping hydrogen from the interstellar medium is another variant. A laser array in the solar system beams to a collector on a vehicle which uses something like a linear accelerator to produce thrust. This solves the fusion reactor problem for the ramjet. There are limitations because of the attenuation of beamed energy with distance.
Since the attenuation is defined as proportional to the logarithm of the ratio between P(x) and P(y), where P is the power at point x and y respectively. Using the cutback technique, the power transmitted through a fiber of known length is measured and compared with the same measurement for the same fiber cut to a length of 2m approximately.
In telecommunication, the term shadow loss has the following meanings: # The attenuation caused to a radio signal by obstructions in the propagation path. # In a reflector antenna, the relative reduction in the effective aperture of the antenna caused by the masking effect of other antenna parts, such as a feed horn or a secondary reflector, which parts obstruct the radiation path.
Hydroxyl ion absorption is the absorption in optical fibers of electromagnetic waves, including the near-infrared, due to the presence of trapped hydroxyl ions remaining from water as a contaminant. The hydroxyl (OH−) ion, can penetrate glass during or after product fabrication, resulting in significant attenuation of discrete optical wavelengths, e.g., centred at 1.383 μm, used for communications via optical fibres.
An American Airlines MD-82 similar to the one involved Seat chart for American Airlines Flight 1420 created by the NTSB, revealing the location of passengers and lack of injury, severity of injuries, and deaths The aircraft involved in the incident was a McDonnell Douglas MD-82 (registration '), a derivative of the McDonnell Douglas DC-9 and part of the McDonnell Douglas MD-80 series of aircraft. It was delivered new to American Airlines in 1983, and had been operated continuously by the airline since, accumulating a total of 49,136 flight hours. The aircraft was powered by Pratt & Whitney JT8D-217C turbofan jet engines. The aircraft was equipped with X-band weather radar, which is susceptible to attenuation during heavy precipitation, and did not have an attenuation alert to warn the flight crew of system impairment during heavy rainfall.
Solar irradiance spectrum above atmosphere and at surface In some fields, such as solar energy and photovoltaics, air mass is indicated by the acronym AM; additionally, the value of the air mass is often given by appending its value to AM, so that AM1 indicates an air mass of 1, AM2 indicates an air mass of 2, and so on. The region above Earth's atmosphere, where there is no atmospheric attenuation of solar radiation, is considered to have "air mass zero" (AM0). Atmospheric attenuation of solar radiation is not the same for all wavelengths; consequently, passage through the atmosphere not only reduces intensity but also alters the spectral irradiance. Photovoltaic modules are commonly rated using spectral irradiance for an air mass of 1.5 (AM1.5); tables of these standard spectra are given in ASTM G 173-03.
100BASE- LFX is a non-standard term to refer to Fast Ethernet transmission. It is very similar to 100BASE-FX but achieves longer distances up to 4-5 km over a pair of multi-mode fibers through the use of Fabry–Pérot laser transmitter running on 1310 nm wavelength. The signal attenuation per km at 1300 nm is about half the loss of 850nm.
As the wavefront of the ground wave travels along the Earth's surface it is attenuated. The degree of attenuation is dependent upon a variety of factors. Frequency of the radio signal is one of the major determining factor as losses rise with increasing frequency. As a result, it makes this form of propagation impracticable above the bottom end of the HF portion of the spectrum (3 MHz).
The type of antenna and its polarization has a major effect on ground wave propagation. Vertical polarization is subject to considerably less attenuation than horizontally polarized signals. In some cases the difference can amount to several tens of decibels. It is for this reason that medium wave broadcast stations use vertical antennas, even if they have to be made physically short by adding inductive loading.
The plots shown of image impedance and attenuation are the plots of a low-pass prototype filter section. The prototype has a cut-off frequency of ωc=1 rad/s and a nominal impedance R0=1Ω. This is produced by a filter half-section where L=1 henry and C=1 farad. This prototype can be impedance scaled and frequency scaled to the desired values.
An AVO anomaly is most commonly expressed as increasing (rising) AVO in a sedimentary section, often where the hydrocarbon reservoir is "softer" (lower acoustic impedance) than the surrounding shales. Typically amplitude decreases (falls) with offset due to geometrical spreading, attenuation and other factors. An AVO anomaly can also include examples where amplitude with offset falls at a lower rate than the surrounding reflective events.
While in the breathalyzer room the officer asks the defendant the questions on his alcohol influence report. The defendant's responses are incriminating. Under this scenario because the initial stop was unconstitutional all evidence that resulted from the stop would be subject to suppression. Therefore, the exclusionary rule exceptions, attenuation, independent source and inevitable discovery, do not come into play, and derivative evidence would be fully admissible.
Likewise, manually setting the probe attenuation is prone to user error. Setting the probe scaling incorrectly is a common error, and throws the reading off by a factor of 10. Special high voltage probes form compensated attenuators with the oscilloscope input. These have a large probe body, and some require partly filling a canister surrounding the series resistor with volatile liquid fluorocarbon to displace air.
In that sense, it includes the termination of transport by saltation or true bedload transport. Settling is the falling of suspended particles through the liquid, whereas sedimentation is the termination of the settling process. In estuarine environments, settling can be influenced by the presence or absence of vegetation. Trees such as mangroves are crucial to the attenuation of waves or currents, promoting the settlement of suspended particles.
MEMS based WSS typically produce good extinction ratios, but poor open loop performance for setting a given attenuation level. The main limitations of the technology arise from the channelization that the mirrors naturally enforce. During manufacturing, the channels must be carefully aligned with the mirrors, complicating the manufacturing process. Post- manufacturing alignment adjustments have been mainly limited to adjusting the gas pressure within the hermetic enclosure.
Charles Yanofsky (born April 17, 1925 - March 16, 2018) was an American geneticist on the faculty of Stanford University who contributed to the establishment of the one gene-one enzyme hypothesis and discovered attenuation, a riboswitch mechanism in which messenger RNA changes shape in response to a small molecule and thus alters its binding ability for the regulatory region of a gene or operon.
Absorption spectrum (attenuation coefficient vs. wavelength) of liquid water (red) atmospheric water vapor (green) and ice (blue line) between 667 nm and 200 μm. The plot for vapor is a transformation of data Synthetic spectrum for gas mixture "Pure H2O" (296K, 1 atm) retrieved from Hitran on the Web Information System. Asymmetric top molecules have at most one or more 2-fold rotation axes.
Attenuation is proportional to frequency, so ground waves are the main mode of propagation at lower frequencies, in the MF, LF and VLF bands. Ground waves are used by radio broadcasting stations in the MF and LF bands, and for time signals and radio navigation systems. At even lower frequencies, in the VLF to ELF bands, an Earth-ionosphere waveguide mechanism allows even longer range transmission.
To measure TAI, the mean attenuation (density, in Hounsfield Units) of a clot is measured on NCCT (ρthrombusNCCT) and subtracted from the thrombus density measured on CTA (ρthrombusCTA). CTA thrombus density increases after administration of the high-density contrast fluid used in CTA: Δthrombus = ρthrombusCTA – ρthrombusNCCT A manual (volume of interest [ROI]-based) and semi-automated (full thrombus segmentation) method have been described to measure thrombus density.
In 2021, society is deeply engaged in a virtual Internet, which has a degenerative effect referred to as "nerve attenuation syndrome," or NAS. Another major issue is the takeover of society by large corporations, many of which are based in east Asia. In Japan, the Yakuza organized crime family acts as corporate enforcement. Their brutal tactics make the transmission of data to be a dangerous business.
BVS is often used for the determination of attenuation coefficients, dynamic moduli, and especially damping ratios. BVS was developed primarily to overcome shortcomings in the functional ranges of other viscoelastic characterization techniques. For example, resonant ultrasound spectroscopy (RUS), another popular technique for studying viscoelastic solids, experiences difficulty in determining a material's parameters below its resonant frequency. Furthermore, BVS is less sensitive to sample preparation than RUS.
Contrast enhanced MRI of the conus medullaris and cauda equina of patient with VHL depicts a hemangioblastoma of the conus with extension into the nerve roots. The primary diagnosis is made with a computed tomography scan (CT scan). On a scan, hemangioblastoma shows as a well-defined, low attenuation region in the posterior fossa with an enhancing nodule on the wall. Sometimes multiple lesions are present.
Earth's Gravity according to PREM. Green curves show hypothetical Earths with density constant (dashed) and decreasing linearly from center to surface (stippled). The Preliminary reference Earth model (PREM) is a one-dimensional model representing the average Earth properties as a function of planetary radius. It includes a table of Earth properties, including elastic properties, attenuation, density, pressure, and gravity, as a function of planetary radius.
Attenuation is made possible by the fact that in prokaryotes (which have no nucleus), the ribosomes begin translating the mRNA while RNA polymerase is still transcribing the DNA sequence. This allows the process of translation to affect transcription of the operon directly. At the beginning of the transcribed genes of the trp operon is a sequence of at least 130 nucleotides termed the leader transcript (trpL; ).
The Equal-Level Far-End Crosstalk (ELFEXT) test measures Far-End Crosstalk (FEXT). FEXT is very similar to NEXT, but happens at the receiver side of the connection. Due to attenuation on the line, the signal causing the crosstalk diminishes as it gets further away from the transmitter. Because of this, FEXT is usually less detrimental to a signal than NEXT, but still important nonetheless.
Later, some manufacturers of LAN equipment, such as Datapoint for ARCNET, adopted RG-62 as their coaxial cable standard. The cable has the lowest capacitance per unit-length when compared to other coaxial cables of similar size. All of the components of a coaxial system should have the same impedance to avoid internal reflections at connections between components (see Impedance matching). Such reflections may cause signal attenuation.
The above filter realised as a ladder low-pass filter. Component values are given in terms of L and C, the component values of a constant k half-section. The same filter minimised by combining components in series or parallel where appropriate. Another reason for using m-types in the body of the filter is to place an additional pole of attenuation in the stopband.
Reproduction for Japanese mantis shrimp occurs between mature inter molt pairs. Female Japanese mantis shrimp achieve reproductive maturity by late spring to early summer lasting until fall while males have year round reproductive maturity. There are several behavioral components in its courtship. One mating behavior that it demonstrates is attenuation between male and female where they face each other and mutually stroke antennas for several seconds.
GBP2 expression have a strong correlation with T cell metagene which seems an association with the infiltration of T cell in the breast cancer. However, a recent study showed that GBP2 can regulate dynamin-related protein 1 (Drp1) to block the translocation of Drp1 to the mitochondria which lead to an attenuation of the Drp1 dependent mitochondrial fission and also an invasion of breast cancer cells.
257-279, March 2005. There are several ways of employing such communication but the most common is by using hydrophones. Underwater communication is difficult due to factors such as multi-path propagation, time variations of the channel, small available bandwidth and strong signal attenuation, especially over long ranges. Compared to terrestrial communication, underwater communication has low data rates because it uses acoustic waves instead of electromagnetic waves.
A common theme throughout Zobel's work is the issue of impedance matching. The obvious approach to filter design is to design directly for the attenuation characteristics desired. With modern computing power, a brute force approach is possible and easy, simply incrementally adjusting each component while recalculating in an iterative process until the desired response is achieved. However, Zobel developed a more indirect line of attack.
Initially Kao worked in the team of Antoni E. Karbowiak (Toni Karbowiak), who was working under Alec Reeves to study optical waveguides for communications. Kao's task was to investigate fibre attenuation, for which he collected samples from different fibre manufacturers and also investigated the properties of bulk glasses carefully. Kao's study primarily convinced himself that the impurities in material caused the high light losses of those fibres.
Acousto-electric effect is a nonlinear phenomenon of generation of electric current in a piezo-electric semiconductor by a propagating acoustic wave. The generated electric current is proportional to the intensity of the acoustic wave and to the value of its electron-induced attenuation. The effect was theoretically predicted in 1953 by Parmenter. Its first experimental observation was reported in 1957 by Weinreich and White.
When T1-weighted imaging is contrast-enhanced through the addition of gadolinium, the open ring enhancement can be viewed as a white ring around the lesion. A more specific MRI, Fluid attenuation inversion recovery (FLAIR) MRI show the signal intensity of the brain. Subjects with tumefactive multiple sclerosis may see a reduction of diffusion of the white matter in the affected area of the brain.
Specific mitigation strategies and recommendations have been presented by the Marine Mammal Commission (2007). They offer multiple ways to alleviate noise pollution in the ocean. Some strategies include removing the source of noise, employing sound attenuation devices, limiting the use of the sound source and monitoring operational requirements. They recommend improving research programs, creating consistent regulation standards that are better enforced and improving mitigation strategies.
Internal sound attenuation material my further reduce noise levels. Frequency sensitivity underwater also differs significantly to that in air, with a consistently higher threshold of hearing underwater, but also significantly skewed. An underwater noise weighting scale is available to assess noise hazard according to frequency sensitivity for wet conduction. Hearing loss in divers is a known problem and has many factors, one of which is noise exposure.
This structure forms when the cell has an excess of leucine and ribosome movement over the leader transcript is not impeded. When there is a deficiency of the charged leucyl tRNA the ribosome translating the leader peptide stalls and the antiterminator structure can form. This allows RNA polymerase to transcribe the operon. At least 6 amino acid operons are known to be regulated by attenuation.
Pliocene volcanic chain Cristi (2.5±1.3 mya), Lemp (2.8±0.3 mya) and Rodrigo (adakites 4.4 mya) north and Puntiagudo south is largely buried beneath the massif. Tomographic analysis of the area has indicated the presence of a large high-attenuation zone in the crust beneath Tres Cruces and the neighbouring Ojos del Salado volcano, which may indicate ongoing or incipient melting of the underlying crust.
The Histidine operon leader is an RNA element found in the bacterial histidine operon. At least 6 amino acid operons are known to be regulated by attenuation. In each a leader sequence of 150–200 bp is found upstream of the first gene in the operon. This leader sequence can assume two different secondary structures known as the terminator and the anti-terminator structure.
BLOXR is a healthcare technology company based in Salt Lake City, Utah. BLOXR specializes in designing products that protect medical professionals from radiation exposure without the use of lead or other toxic heavy metals. The company was founded by CEO Ashok C Khandkar. In 2012, BLOXR created a line of products that incorporates XPF technology for medical, dental, and veterinary professionals for radiation attenuation purposes.
Because laboratories at the same depth (in meters) can have greatly varied levels of cosmic ray penetration, the m.w.e. provides a convenient and consistent way of comparing cosmic ray levels in different underground locations. Cosmic ray attenuation is dependent on the density of the material of the overburden, so the m.w.e. is defined as the product of depth and density (also known as an interaction depth).
PPE for hearing protection consists of earplugs and earmuffs. Workers who are regularly exposed to noise levels above the NIOSH recommendation should be furnished hearing protection by the employers, as they are a low-cost intervention. A personal attenuation rating can be objectively measured through a hearing protection fit-testing system. The effectiveness of hearing protection varies with the training offered on their use.
The emerging technology of magnetic resonance (MR) offers a more direct measurement. Most ash gauges employ gamma attenuation principles. Coal analyzers were first introduced in the early 1980s with the US and Australia leading the way. The demand for coal analyzers has been highest in the US, due to the need to control sulfur as mandated by the Clean Air Act Amendments of 1977.
The backscattering method is also employed in fiber optics applications to detect optical faults. Light propagating through a fiber optic cable gradually attenuates due to Rayleigh scattering. Faults are thus detected by monitoring the variation of part of the Rayleigh backscattered light. Since the backscattered light attenuates exponentially as it travels along the optical fiber cable, the attenuation characteristic is represented in a logarithmic scale graph.
Hematopoietic stem cells (HSCs) regenerate the blood system throughout life and maintain homeostasis . DNA strand breaks accumulate in long term HSCs during aging. This accumulation is associated with a broad attenuation of DNA repair and response pathways that depends on HSC quiescence. DNA ligase 4 (Lig4) has a highly specific role in the repair of double-strand breaks by non-homologous end joining (NHEJ).
The type locality is the Auckland Islands, and the species authority is Montagne 1842. It is found around South America from Argentina, Chile and Peru, and around Australia and New Zealand including Macquarie Island.Contreras-Porcia, L., Callejas, S., Thomas, D., Sordet, C., Pohnert, G., Contreras, A., Lafuente, A., Flores-Molina, M.R. & Correa, J.A.. (2012). Seaweeds early development: detrimental effects of desiccation and attenuation by algal extracts.
Here a simple ordering is implied. The attenuation and amplification of variety were major themes in Stafford Beer's work in management (the profession of control, as he called it). The number of staff needed to answer telephones, control crowds or tend to patients are clear examples. The application of natural and analogue signals to variety analysis require an estimate of Ashby's "powers of discrimination" (see above quote).
Rowland, 237-239 The style of the Sultanganj figure is comparable to slightly earlier stone Buddha figures from Sarnath in "the smoothly rounded attenuation of body and limbs" and the very thin, clinging body garment, indicated in the lightest of ways. The figure has "a feeling of animation imparted by the unbalanced stance and the movement suggested by the sweeping silhouette of the enveloping robe".
The high level of attenuation within the infrasonic bandwidth (below 10 Hz) of the seismic field observed in natural oil-saturated porous media during the last years (explained by mesoscopic homogeneous models) is the main responsible of the passive seismic wave field shifting within a low frequency range. Pressure differences between regions with different fluid/solid properties induce frequency-dependency of the attenuation (Qp and Qs reservoir factors) and velocity dispersion (Vp, Vs) of the low frequency wave field. Infrasonic passive seismic spectroscopy quantifies the absorption and the wave field dispersion within the low frequency bandwidth giving the most predominant areas linked with possible oil-saturated and porous media. The low frequency seismic field is not usually reachable by the active seismic surveys being either the explosive waves mainly in the high frequency and the vibroseis currently built not to reach such a low frequencies.
A high-pass filter (HPF) is an electronic filter that passes signals with a frequency higher than a certain cutoff frequency and attenuates signals with frequencies lower than the cutoff frequency. The amount of attenuation for each frequency depends on the filter design. A high-pass filter is usually modeled as a linear time-invariant system. It is sometimes called a low-cut filter or bass-cut filter.
Since higher frequency of echolocation call attenuates with distance faster than low frequency, this species uses low frequency calls with high intensity, which last longer and thus are suitable for prey detection with long-range in open areas.Lawrence, B. D. and Simmons, J. A. (1982). Measurements of atmospheric attenuation at ultrasonic frequencies and the significance for echolocation by bats. Journal of the Acoustical Society of America, 71: 585-590.
How well the variables are measured affects the correlation of X and Y. The correction for attenuation tells one what the estimated correlation is expected to be if one could measure X′ and Y′ with perfect reliability. Thus if X and Y are taken to be imperfect measurements of underlying variables X' and Y' with independent errors, then r_{x'y'} estimates the true correlation between X' and Y'.
Stainless steel tubs resist hard water, and preserve heat to dry dishes more quickly. They also come at a premium price. Dishwashers can be bought for as expensive as $1,500+, but countertop dishwashers are also available for under $300. Older models used baked enamel tubs, while some used a vinyl coating bonded to a steel tub, which provided protection of the tub from acidic foods and provided some sound attenuation.
This compound elicits nociception in a mouse model through TRPA1 activation. PF-4840154 is used as a reference agonist of the TRPA1 channel for in-vitro high-throughput screening purposes, and is superior to allyl isothiocyanate for this use. The TRPA1 channel is considered an attractive pain target based on the fact that TRPA1 knockout mice showed near complete attenuation of pain behaviors in some pre-clinical development models.
Since most of these LRL devices are powered by low voltage, low current AA, AAA or 9v cells, the resultant power available for emissions is quite minuscule at best, and the return signal would suffer even greater attenuation. Examples exist of LRL devices having no internal power source at all, and these are advertised as being self-powered or powered by ambient static electricity; these are indistinguishable from dowsing rods.
Propagation path attenuation may be below free-space loss. Some of the lesser inversion types related to warm ground and cooler air moisture content occur regularly at certain times of the year and time of day. A typical example could be the late summer, early morning tropospheric enhancements that bring in signals from distances up to few hundred kilometers for a couple of hours, until undone by the Sun's warming effect.
Examples are shown in Figure 2. For poorly studied regions in developing countries, the uncertainty of the estimated intensities can be substantial, as shown by the different curves, because attenuation is poorly known. Another factor that can lead to variations of observed intensity of shaking is the condition of the soil beneath a particular structure. The waves are amplified in unconsolidated soils compared to hard rock (Figure 3).
The scintillator must be shielded from all ambient light so that external photons do not swamp the ionization events caused by incident radiation. To achieve this a thin opaque foil, such as aluminized mylar, is often used, though it must have a low enough mass to minimize undue attenuation of the incident radiation being measured. The article on the photomultiplier tube carries a detailed description of the tube's operation.
OHL is preventable, but currently the interventions to prevent it involve many components. Stricter legislation might reduce noise levels in the workplace. Hearing protection devices, such as earmuffs and earplugs can reduce noise exposure to safe levels, but, instructions are needed on how to put plugs into the ears correctly to achieve potential attenuation. Giving workers information on their noise exposure levels by itself was not shown to decrease noise.
Skylight glazing and automobile windshields typically use laminated glass. In geographical areas requiring hurricane-resistant construction, laminated glass is often used in exterior storefronts, curtain walls and windows. Laminated glass is also used to increase the sound insulation rating of a window, where it significantly improves sound attenuation compared to monolithic glass panes of the same thickness. For this purpose a special "acoustic PVB" compound is used for the interlayer.
It was shown that immunization with vaccinia virus with deleted SPI-2 and 1 and coexpressing IFNγ leads to strong attenuation but without decreasing host immune response. Host reaction was comparable to that on MVA virus (modified virus Ankara) which serves as a smallpox vaccine nowadays. The Copenhagen strain of vaccinia virus only has a truncated version of this protein. Vaccinia virus encodes two more serpin - SPI-1 and SPI-3.
If this is the case, and if other active hydrate formations share this characteristic, more methane may be released (and influence climate change) than was anticipated prior to the study, according to researchers.Trehu, Anne M.; and Flueh, Ernst R. "Estimating the Thickness of the Free Gas Zone beneath Hydrate Ridge, Oregon Continental Margin, from Seismic Velocities and Attenuation." Journal of Geophysical Research: Solid Earth. 106.B2 (2001): 2035-045. Web.
Therefore, the sensitivity of MSOT depends on the contrast agent used, its distribution and accumulation in the target tissue, and its resistance to photobleaching by the illuminating light. Sensitivity also depends on the ultrasound detector employed, the amount of light energy applied, the voxel size and spectral unmixing method. As imaging depth increases, light and ultrasound attenuation together reduce the optoacoustic signal and therefore the overall detection sensitivity.
The technology uses laser in the same way computed tomography uses X-Rays, these beams travel through tissue and suffer attenuation. A laser detector measures the intensity drop and the data is collected as the laser detector moves across the breast creating a tomography image. CTLM images show hemoglobin distribution in a tissue and can detect areas of Angiogenesis surrounding malignant tumors, that stimulate this angiogenesis to obtain nutrients for growth.
This was first fired several metres above the water, then lowered and fired in successive steps until reaching a considerable depth. Firing from underwater posed no problems, and there was substantial noise attenuation. To lower the cost of the rocket, he intended it to be built of inexpensive materials, specifically 8 mm steel sheeting. The rocket would be built at a sea-side shipbuilder and towed to sea for launch.
OpenAL (Open Audio Library) is a cross-platform audio application programming interface (API). It is designed for efficient rendering of multichannel three- dimensional positional audio. Its API style and conventions deliberately resemble those of OpenGL. OpenAL is an environmental 3D audio library, which can add realism to a game by simulating attenuation (degradation of sound over distance), the Doppler effect (change in frequency as a result of motion), and material densities.
Time gain compensation (TGC) is a setting applied in diagnostic ultrasound imaging to account for tissue attenuation. By increasing the received signal intensity with depth, the artifacts in the uniformity of a B-mode image intensity are reduced. This means that a TGC module will increase the amount of gain given to an input signal, as its sampling time increases monotonically. This counteracts the excessive sound-dampening properties of human tissue.
One disadvantage of the m-type section was that at frequencies past the pole of attenuation, the response of the filter started to increase again, reaching a peak somewhere in the stop-band and then falling again.Ghosh, Smarajit, Network Theory: Analysis and Synthesis, Prentice Hall of India, pp. 564–569. Zobel overcame this problem by designing hybrid filters using a mixture of constant k and m-type sections.
Zobel, O J, Electrical Network and Method of Transmitting Electric Currents, , filed 9 Aug 1922, issued 19 Oct 1926. Perhaps one of Zobel's most fascinating inventions is the lattice filter section. This section is both constant resistance and flat response zero attenuation across the band, yet it is constructed out of inductors and capacitors. The only signal parameter it modifies is the phase of the signal at different frequencies.
In ducks, BMPs are not expressed at all. These results indicate that in avian lineages, the disruption of BMP signaling in interdigital tissue caused webbed feet to arise. The magnitude of attenuation in this pathway is correlated with the amount of interdigital tissue preserved. Other genetic changes implicated in webbed feet development in avians include reduction of TGFβ-induced chondrogenesis and reduction of msx-1 and msx-2 gene expression.
With the growing recognition of the utility of CT imaging in using guidance strategies to match treatment volume position and treatment field placement, several systems have been designed that place an actual conventional 2-D CT machine in the treatment room alongside the treatment linear accelerator. The advantage is that the conventional CT provides accurate measure of tissue attenuation, which is important for dose calculation (e.g. CT on rails).
All the doses were obtained by attenuation, but later ones were progressively more virulent. The Pasteur- Roux vaccine attenuated the harvested virus samples by allowing them to dry for five to ten days. Similar nerve tissue-derived vaccines are still used in some countries, and while they are much cheaper than modern cell culture vaccines, they are not as effective. Neural tissue vaccines also carry a certain risk of neurological complications.
Polonium-based sources of alpha particles were produced in the former Soviet Union. Such sources were applied for measuring the thickness of industrial coatings via attenuation of alpha radiation.Bagnall, p. 225 Because of intense alpha radiation, a one-gram sample of 210Po will spontaneously heat up to above generating about 140 watts of power. Therefore, 210Po is used as an atomic heat source to power radioisotope thermoelectric generators via thermoelectric materials.
The combination concept of ATES and enhanced natural attenuation (ATES-ENA) can possibly be used in the Netherlands and China, especially in urbanized areas. These areas in both countries are confronted with organic groundwater contaminations. Currently, the combination concept may be better applicable for the Netherlands with more mature technology and application of ATES. And the overlapping between ATES and groundwater contamination also promotes the need of this combined technology.
Lateral scattering by the air along the light beam is quantified as an attenuation coefficient. Any departure from the clear air extinction coefficient (e.g. in fog) is measured and is inversely proportional to the visibility (the greater the loss, the lower is the visibility). These devices are found in automatic weather stations for general visibility, along airport runways for runway visual range, or along roads for visual conditions.
Mid-infrared lasers are important tools for spectroscopic sensing applications. Many molecules such as those in pollution and greenhouse gases have strong rotational and vibrational resonances in the mid-infrared region of the spectrum. For most sensing applications, the laser wavelength must also be within one of the atmospheric window to avoid signal attenuation. An important requirement for this type of application is that single-mode emission is obtained.
Together, this causes vascular remodeling and narrowing of the pulmonary arteries. These changes result in increased vascular resistance and PAH. Due to the potential anti-proliferative and anti-fibrotic activity of terguride, this potential medicine could offer the hope of achieving reversal of pulmonary artery vascular remodeling and attenuation of disease progression. In May 2008, terguride was granted orphan drug status for the treatment of pulmonary arterial hypertension.
The N100 depends upon unpredictability of stimulus: it is weaker when stimuli are repetitive, and stronger when they are random. When subjects are allowed to control stimuli, using a switch, the N100 may decrease. This effect has been linked to intelligence, as the N100 attenuation for self-controlled stimuli occurs the most strongly (i.e., the N100 shrinks the most) in individuals who are also evaluated as having high intelligence.
Optical fiber is the most common type of channel for optical communications. The transmitters in optical fiber links are generally light-emitting diodes (LEDs) or laser diodes. Infrared light, rather than visible light is used more commonly, because optical fibers transmit infrared wavelengths with less attenuation and dispersion. The signal encoding is typically simple intensity modulation, although historically optical phase and frequency modulation have been demonstrated in the lab.
This is to combat attenuation that can render the signal indistinguishable from the noise.ATIS Telecom Glossary 2000 , ATIS Committee T1A1 Performance and Signal Processing (approved by the American National Standards Institute), 28 February 2001. Another advantage of digital systems over analog is that their output is easier to store in memory, i.e. two voltage states (high and low) are easier to store than a continuous range of states.
However, some early implementations used heavier coaxial cables and some recent implementations (especially high-speed ones) use optical fibers.Stallings, pp. 514–16. When optic fibers are used, the distinction must be made between multimode fibers and single-mode fibers. Multimode fibers can be thought of as thicker optical fibers that are cheaper to manufacture devices for, but that suffers from less usable bandwidth and worse attenuation—implying poorer long-distance performance.
In particle physics the concept of the mean free path is not commonly used, being replaced by the similar concept of attenuation length. In particular, for high-energy photons, which mostly interact by electron–positron pair production, the radiation length is used much like the mean free path in radiography. Independent-particle models in nuclear physics require the undisturbed orbiting of nucleons within the nucleus before they interact with other nucleons.
The flexibility of the canal system has a significant effect on low-frequency signal attenuation. The flexibility of the sensing element placed in the canal system may add to the sensitivity of the Canal Artificial Line (CALL) system. Experimental data proves that this factor creates a significant jump in the sensitivity of the system. Geometric improvements in the canal system and optimizing the sensing equipment for better results.
Example of airborne and structure-borne transmission of sound, where Lp is sound pressure level, A is attenuation, P is acoustical pressure, S is the area of the wall [m²], and τ is the transmission coefficient Acoustic transmission is the transmission of sounds through and between materials, including air, wall, and musical instruments. The degree to which sound is transferred between two materials depends on how well their acoustical impedances match.
Q-switching is achieved by putting some type of variable attenuator inside the laser's optical resonator. When the attenuator is functioning, light which leaves the gain medium does not return, and lasing cannot begin. This attenuation inside the cavity corresponds to a decrease in the Q factor or quality factor of the optical resonator. A high Q factor corresponds to low resonator losses per roundtrip, and vice versa.
Longwave is used for broadcasting only within ITU Region 1. The long-wave broadcasters are located in western, northern, central, and southeastern Europe, the former Soviet Union, Mongolia, Algeria, and Morocco. Typically, a larger geographic area can be covered by a long-wave broadcast transmitter compared to a medium-wave one. This is because ground-wave propagation suffers less attenuation due to limited ground conductivity at lower frequencies.
Engaging in emotional activities contrary to the emotions the participant is currently experiencing, like helping others or experiencing pleasure things, may also increase the speed of attenuation by diverting the focus of their mood towards other things.Thayer, R. E., Newman, J., & McClain, T. M. (1994). Self- regulation of mood: Strategies for changing a bad mood, raising energy, and reducing tension. Journal of Personality and Social Psychology, 67(5), 910–25.
The most common findings on HRCT are diffuse hyperdense ground- glass attenuation and subpleural linear calcifications, often most predominant in the inferior and posterior portions of the lungs. Additionally, the medial aspects of the lungs appear to be more heavily involved than the lateral aspects. Ground-glass opacities, probably due to small calculi in the air space, are the most common finding in children and in patients with early- stage PAM.
In addition, travelling overland posed more difficulty than traversing water due to the lack of motion attenuation generated by wave drag. Considerable skill on the part of the pilot was typically required to counter the effects of phenomena such as cross winds and ground slopes.Paine and Syms 2012, pp. 93-94. In 1961, the SR.N1 was outfitted with a flexible skirt which greatly improved the effective depth of the air cushion.
Another multiphysics research topic recently explored by his group is acoustic-electroelastic structure interaction for wireless power transfer using ultrasound waves. Erturk and collaborators have lately been conducting research at the intersection of metamaterials and smart structures. Recently they developed the first Gradient-Index Phononic Crystal Lens-based piezoelectric energy harvester. Low-frequency broadband vibration attenuation via locally-resonant finite elastic metamaterials is another research area explored by Erturk and collaborators.
Ultrasound when applied in specific configurations can produce short bursts of light in an exotic phenomenon known as sonoluminescence. This phenomenon is being investigated partly because of the possibility of bubble fusion (a nuclear fusion reaction hypothesized to occur during sonoluminescence). Ultrasound is used when characterizing particulates through the technique of ultrasound attenuation spectroscopy or by observing electroacoustic phenomena or by transcranial pulsed ultrasound. Audio can be propagated by modulated ultrasound.
The stream has provided power for watermills and battery mills in the past and some mill buildings still survive. Wildlife is supported by nature reserves through which the Siston Brook runs. Flooding has caused problems in the past, but modern measures to alleviate this include an attenuation reservoir and proposals to reinstate historic weirs and sluices. The name Siston is believed to derive from Anglo-Saxon, meaning Sige's Farmstead.
Distribution networks are usually made of a variety of conductor types, and terminating into loads of different impedances, which also vary over time. Such infrastructure results in a communication channel which has a time dependent amplitude and phase response that varies with frequency. Interference and impulsive noise produced by motors, switching power supplies and halogen lamps reduces the reliability of communication signals. Due to line attenuation, the noise is location dependent.
His later work on surface excitations and on optical amplification, attenuation and detection has also proved to be important. Loudon worked at the University of Essex as Professor, Chairman and Dean. He has also worked at British Telecom, Royal Radar Establishment, Bell Telephone Laboratories and Radio Corporation of America, and he has been a consultant to these organisations over several years, contributing to both applied and fundamental research.
To widen the bandwidth multiple stubs may be used, and the structure then takes on the form of a stub filter. The design proceeds as if it were a filter except that a different parameter is optimised. In a frequency filter typically the parameter optimised is stopband rejection, passband attenuation, steepness of transition, or some compromise between these. In a matching network the parameter optimised is the impedance match.
Various forms of ultrasonic inspection are used for plastic welds. Plastics have higher attenuation and a lower sound velocity compared to metals which can make these techniques more challenging. In 2010, a joint European project, TestPEP, was started to develop and validate ultrasonic NDE techniques on plastic welded pipe. The use of plastic pipe is limited in safety critical applications due to the lack of accepted NDE techniques and acceptance criteria.
The depth is, roughly, where radiation is degraded down to 1% of its surface strength. Accordingly, its thickness depends on the extent of light attenuation in the water column. As incoming light at the surface can vary widely, this says little about the net growth of phytoplankton. Typical euphotic depths vary from only a few centimetres in highly turbid eutrophic lakes, to around 200 meters in the open ocean.
Likewise with CATV, although many broadcast TV installations and CATV headends use 300 Ω folded dipole antennas to receive off-the-air signals, 75 Ω coax makes a convenient 4:1 balun transformer for these as well as possessing low attenuation. The arithmetic mean between 30 Ω and 77 Ω is 53.5 Ω; the geometric mean is 48 Ω. The selection of 50 Ω as a compromise between power- handling capability and attenuation is in general cited as the reason for the number. 50 Ω also works out tolerably well because it corresponds approximately to the feedpoint impedance of a half-wave dipole, mounted approximately a half-wave above "normal" ground (ideally 73 Ω, but reduced for low-hanging horizontal wires). RG-62 is a 93 Ω coaxial cable originally used in mainframe computer networks in the 1970s and early 1980s (it was the cable used to connect IBM 3270 terminals to IBM 3274/3174 terminal cluster controllers).
The Fresnel reflection of a beam from a glass plate is different for the s- and p-polarizations (s is parallel to the surface of the glass, and p is perpendicular to s) and changes as a function of angle of incidence – keep this in mind if you expect that the two polarizations have different beam profiles. To prevent distortion of the beam profile, the glass should be of optical quality — surface flatness of λ/10 (λ=633 nm) and scratch-dig of 40-20 or better. A half-wave plate followed by a polarizing beam splitter form a variable attenuator and this combination is often used in optical systems. The variable attenuator made in this fashion is not recommended for attenuation for beam profiling applications because: (1) the beam profile in the two orthogonal polarizations may be different, (2) the polarization beam cube may have a low optical damage threshold value, and (3) the beam can be distorded in cube polarizers at very high attenuation.
Optical fiber Optical fiber can be used as a medium for telecommunication and computer networking because it is flexible and can be bundled into cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. This allows long distances to be spanned with few repeaters. In 1966 Charles K. Kao and George Hockham proposed optical fibers at STC Laboratories (STL) at Harlow, England, when they showed that the losses of 1000 dB/km in existing glass (compared to 5-10 dB/km in coaxial cable) was due to contaminants, which could potentially be removed. Optical fiber was successfully developed in 1970 by Corning Glass Works, with attenuation low enough for communication purposes (about 20dB/km), and at the same time GaAs (Gallium arsenide) semiconductor lasers were developed that were compact and therefore suitable for transmitting light through fiber optic cables for long distances.
Endemic stability is a state where animals are affected at a low levels or not as susceptible to the disease, and this may be encouraged in endemic areas. Vaccination is available and should be performed in breeds that are susceptible to infection. Live attenuated vaccine are being used in many countries like India, Iran, Turkey etc. Which is a basically a Lymphocyte infected with Theileria annulata schizont stage and passaged for attenuation.
Both modern computing power and the practice of directly implementing filter transfer functions in the digital domain have largely rendered this practice obsolete. A different prototype is required for each order of filter in each class. For those classes in which there is attenuation ripple, a different prototype is required for each value of ripple. The same prototype may be used to produce filters which have a different bandform from the prototype.
Due to their high attenuation of light, the effective range of plastic optical cables is limited to . They can temporarily fail or be permanently damaged if tightly bent. Although less commonly available and more expensive than plastic optical fiber (POF) cables, glass or silica optical fibers have lower losses and can extend the range of the TOSLINK system. Optical cables are not susceptible to electrical problems such as ground loops and RF interference.
Oftentimes, modified amateur radio transceivers are used, violating the restrictions for the Freenet service. With the maximum permitted ERP of 500 mW, a range of 1 km can be assumed. Due to the lower frequencies in the VHF band, signal attenuation from objects, such as houses and trees, is not as high as in the UHF band used by SRD and PMR446 radios. Originally, the Freenet frequencies were allocated until the end of 2005.
ASTM International has issued what it calls the “ASTM Standard Specification for Impact Attenuation of Surface Systems Under and Around Playground Equipment”, which is known by its numerical designation, F1292.F1292 This standard accounts for both the deceleration of the head during impact and the length of time the head takes to stop moving. The test simulates the impact of a child’s head hitting the surface from various heights of the playground equipment.
Typically a signal at 3.0 MHz will suffer an attenuation that may be in the region of 20 to 60 dB more than one at 0.5 MHz dependent upon a variety of factors in the signal path including the distance. In view of this it can be seen why even high power HF radio broadcast stations may only be audible for a few miles from the transmitting site via the ground wave.
Surface run- off in the upper catchment of the Hazel Brook, especially from the large retail centre at Cribbs Causeway, sends a good deal of silt into the system, slowing the flow and creating a risk of flooding downstream in the Trym. This problem has now been partially alleviated by the construction of the Catbrain attenuation reservoir near Cribbs Causeway. Measurements of pollution by the city council show the water to be relatively clean.
These were achieved at the cost of an increase in filter circuit complexity.Darlington, p.5 A more systematic method of producing image filters was introduced by Hendrik Bode (1930), and further developed by several other investigators including Piloty (1937–1939) and Wilhelm Cauer (1934–1937). Rather than enumerate the behaviour (transfer function, attenuation function, delay function and so on) of a specific circuit, instead a requirement for the image impedance itself was developed.
Leaves of Acer stewarti are simple in structure, with perfectly actinodromus vein structure and are generally oval in shape. The leaves are five-lobed with the basal two lobes as deeply incised as the teeth on the upper lobes. The leaves have five primary veins and are over long by wide in overall dimensions. A. stewarti has large teeth with a distinct attenuation similar to the extinct A. washingtonense and the modern species A. spicatum.
The sampled sound engine piggybacked on the video circuit. As the raster scan returned from the right side of the screen to the left, one byte of data was placed into a PWM generator instead of the screen. This provided 8-bit sampled monaural sound sampled at the 22.25 kHz horizontal blanking rate. General purpose 6522 outputs could mute the sampled sound, or set its volume to one of 8 levels of attenuation.
Properly designed wind screens produce negligible treble attenuation. In common with other classes of dynamic microphone, ribbon microphones don't require phantom power; in fact, this voltage can damage some older ribbon microphones. Some new modern ribbon microphone designs incorporate a preamplifier and, therefore, do require phantom power, and circuits of modern passive ribbon microphones, i.e., those without the aforementioned preamplifier, are specifically designed to resist damage to the ribbon and transformer by phantom power.
Audio is transmitted in digital form, and provides reduced susceptibility to electromagnetic interference, crosstalk, coloration, and attenuation owing to cable impedance. Use of Ethernet by CobraNet offers many high availability features such as Spanning Tree Protocol, link aggregation, and network management. For critical applications, CobraNet devices can be wired with redundant connections to the network. In this configuration, if one CobraNet device, cable, or Ethernet switch fails, the other takes over almost immediately.
In 1984, Ford Motor Company incorporated a new design as a feature on the Lincoln Continental Mark VII. In 1986, Toyota Soarer introduced the first electronically controlled (TEMS), a semi-active full air suspension (spring constant, variable attenuation force). Dunlop Systems Coventry UK were also pioneers of Electronically Controlled Air Suspension (ECAS) for off-road vehicles - the term ECAS was successfully trade marked. The system was first fitted to the 93MY Land Rover Range Rover.
The explanation of blue color by Rayleigh in 1871 is a famous example of applying dimensional analysis to solving problems in physics; (see top figure). Scattering and absorption are major causes of the attenuation of sunlight radiation by the atmosphere. Scattering varies as a function of the ratio of particle diameters (of particulates in the atmosphere) to the wavelength of the incident radiation. When this ratio is less than about one-tenth, Rayleigh scattering occurs.
Unlike acoustic radiation forces on incompressible particles, net forces can be generated in the absence of attenuation or reflection of the sound wave. Bubbles with resonance frequency above the acoustic driving frequency travel up the pressure gradient, while those with a lower resonance frequency travel down the pressure gradient. In acoustic standing waves, small bubbles accumulate at pressure antinodes, whereas large bubble accumulate at pressure nodes.Leighton, T.G., Walton, A.J. and Pickworth, M.J.W., 1990.
In 1992, Hughes Research Laboratory conducted a research project to study electromagnetic wave propagation in unmagnetized plasma. A series of high voltage spark gaps were used to generate UV radiation, which creates plasma via photoionization in a waveguide. Plasma filled missile radomes were tested in an anechoic chamber for attenuation of reflection. At about the same time, R. J. Vidmar studied the use of atmospheric pressure plasma as electromagnetic reflectors and absorbers.
These confine the radio waves by total internal reflection from the step in refractive index due to the change in dielectric constant at the material surface. p. 2-3, 10 At millimeter wave frequencies and above, metal is not a good conductor, so metal waveguides can have increasing attenuation. At these wavelengths dielectric waveguides can have lower losses than metal waveguides. Optical fiber is a form of dielectric waveguide used at optical wavelengths.
Both the tap and its unterminated branch cause unwanted signal reflections, also called echoes. Digital subscriber lines (DSL) can be affected by a bridged tap, depending on where the tap is bridged. DSL signals reflect from the discontinuities, sending the signal back through the cable pair, much like a tennis ball against a brick wall. The echoed signal is now out of phase and mixed with the original, creating, among other impairments, attenuation distortion.
A couple of other challenges the group faced was reprogramming the system because photon source attenuation was high and performing system analyses to identify losses and errors in system components. With these corrections, the scientists were capable of implementing a coin flipping protocol by introducing a small honest abort probability, the probability that two honest participants cannot obtain a coin flip at the end of the protocol, but at a short communication distance.
Attached to the muzzle of the weapon is the Blast Attenuation Device (BAD), used to reduce the blast effects on the mortar crew. To increase cooling efficiency, the breech end is finned; though first-hand accounts attest that the level of cooling is negligible. The cannon also has a crew-removable breech plug and firing pin. High explosive rounds fired by the M252 weigh and can have an effective kill radius of .
20-21Aitken, Hugh (2014) Syntony and Spark: The origins of radio, p. 195-218 These antennas functioned as quarter-wave monopole antennas. The length of the antenna determined the wavelength of the waves produced and thus their frequency. Longer, lower frequency waves have less attenuation with distance. As Marconi tried longer antennas, which radiated lower frequency waves, probably in the MF band around 2 MHz, he found that he could transmit further.
Insertion loss, also referred to as attenuation, refers to the loss of signal strength at the far end of a line compared to the signal that was introduced into the line. This loss is due to the electrical resistance of the copper cable, the loss of energy through the cable insulation, and impedance mismatches introduced at the connectors. Insertion loss is usually expressed in decibels dB. Insertion loss increases with distance and frequency.
In this model the attenuation of a neural response is hypothesised to be due to an overall reduction in the amplitude of a neuron's firing. Whether this reduction occurs across all neurons that responded to the initial stimulus or just the critical subset of those that initially responded maximally, is still unclear. However, evidence does suggest that a mechanism like this reduces redundant neural firing and enhances efficiencies in processing in the early visual cortex.
Loaded lines are lines designed with deliberately increased inductance. This is done by adding iron or some other magnetic metal to the cable or adding coils. The purpose is to ensure that the line meets the Heaviside condition, which eliminates distortion caused by frequency-dependent attenuation and dispersion, and ensures that \scriptstyle Z_0 is constant and resistive. The secondary constants are here related to the primary constants by;Connor, pp. 19–21.
Baryte is used inter alia in sound attenuation, radiation protection and the deep mining industry. Fluorspar or fluorite is used in the metal industry as a plasticiser (e.g. in welding electrodes) in the glass and ceramics industry and in the chemical industry for the production of hydrofluoric acid. The pit, which is operated by the firm of Sachtleben Bergbau is the last active mine of the many that were once worked in the Black Forest.
These intense rain areas, for example, supercells, often have a horizontal length of no more than a few kilometers: putting the ground stations at a sufficient distance the possibility of rain fade in the downlink signal will be reduced. The configuration works when the attenuation is not great at the two stations simultaneously. This is usually a valid assumption. Site diversity systems have been known to minimize disruption of service by major satellite carriers.
The flicker of fluorescent lamps, even with magnetic ballasts, is so rapid that it is unlikely to present a hazard to individuals with epilepsy. Early studies suspected a relationship between the flickering of fluorescent lamps with magnetic ballasts and repetitive movement in autistic children. However, these studies had interpretive problems and have not been replicated. LED lamps generally do not benefit from flicker attenuation through phosphor persistence, the notable exception being white LEDs.
When space constraints do not allow for a straight attenuator, an elbow or transitional attenuator can be used. Duct silencers are prominently featured in systems where fiberglass internal duct liner is prohibited. While fiberglass's contribution to air quality is insignificant, many higher education projects have adopted a limit on internal fiberglass liner. In these situations, the project acoustician must rely on duct silencers as the primary means of fan noise and duct-borne noise attenuation.
Each of these insults attenuates DDAH activity in vitro and in vivo. The attenuation of DDAH allows ADMA to accumulate, and to block NO synthesis. The adverse effect of these stimuli can be reversed in vitro by antioxidants, which preserve the activity of DDAH. The sensitivity of DDAH to oxidative stress is conferred by a critical sulfhydryl in the active site of the enzyme that is required for the metabolism of ADMA.
AT&T; fought a legal battle with Pupin over his claim. Pupin was first to patent but Campbell had already conducted practical demonstrations before Pupin had even filed his patent (December 1899),Pupin, M.I., Art of Reducing Attenuation of Electrical Waves and Apparatus Therefore, US patent 0 652 230, filed 14 December 1899, issued 19 June 1900. Campbell's delay in filing being due to the slow internal machinations of AT&T.;Brittain, p.
A high-pass filter (HPF) is an electronic filter that passes signals with a frequency higher than a certain cutoff frequency and attenuates signals with frequencies lower than the cutoff frequency. The amount of attenuation for each frequency depends on the filter design. A high-pass filter is usually modeled as a linear time-invariant system. It is sometimes called a low-cut filter or bass-cut filter in the context of audio engineering.
Von Voorhis and Hillyard (1977) used an EEG to observe event-related potentials (ERPs) of visual stimuli. Participants were asked to attend to, or disregard specific stimuli presented. Results demonstrated that when attending to visual stimuli, the amount of voltage fluctuation was greater at occipital sites for attended stimuli when compared to unattended stimuli. Voltage modulations were observed after 100ms of stimuli onset, consistent with what would be predicted by attenuation of irrelevant inputs.
To compensate for the loss of useful signal in traditional noise attenuation approaches because of incorrect parameter selection or inadequacy of denoising assumptions, a weighting operator can be applied on the initially denoised section for the retrieval of useful signal from the initial noise section. The new denoising process is referred to as the local orthogonalization of signal and noise . It has a wide range of applications in many signals processing and seismic exploration fields.
When (p)ppGpp is absent, pathogenicity is compromised for reasons that vary with the organism studied. Deleting relA and spoT genes, but not relA alone, gave a (p)ppGpp0 state that resulted in strong attenuation in mice and noninvasiveness in vitro. Vaccine tests reveal that 30 days after single immunization with the (p)ppGpp0 strain, mice were protected from challenge with wild-type Salmonella at a dose 106-fold above the established LD50.
Low frequency (LF) is the ITU designation for radio frequencies (RF) in the range of 30–300 kHz. Since its wavelengths range from 10–1 km, respectively, it is also known as the kilometre band or kilometre wave. LF radio waves exhibit low signal attenuation, making them suitable for long-distance communications. In Europe and areas of Northern Africa and Asia, part of the LF spectrum is used for AM broadcasting as the "longwave" band.
Attenuation constants, in fields such as optical fiber communication and radio propagation path loss, are often expressed as a fraction or ratio to distance of transmission. dB/m represents decibel per meter, dB/mi represents decibel per mile, for example. These quantities are to be manipulated obeying the rules of dimensional analysis, e.g., a 100-meter run with a 3.5 dB/km fiber yields a loss of 0.35 dB = 3.5 dB/km × 0.1 km.
Most commonly, quantities called "dynamic range" or "signal-to-noise" (of the camera) would be specified in 20 log dB, but in related contexts (e.g. attenuation, gain, intensifier SNR, or rejection ratio) the term should be interpreted cautiously, as confusion of the two units can result in very large misunderstandings of the value. Photographers typically use an alternative base-2 log unit, the stop, to describe light intensity ratios or dynamic range.
Absorption spectrum (attenuation coefficient vs. wavelength) of liquid water (red), atmospheric water vapor (green) and ice (blue line) between 667 nm and 200 μm. The plot for vapor is a transformation of data Synthetic spectrum for gas mixture Pure H2O (296K, 1 atm) retrieved from Hitran on the Web Information System. Liquid water absorption spectrum across a wide wavelength range The absorption of electromagnetic radiation by water depends on the state of the water.
The amount of protection from noise can vary based on the physical fit of the device. Hearing protection devices with accurate placement (an airtight seal) and/or accurate insertion (deep into the ear canal) will provide the most attenuation of noise. There are many challenges to achieving the needed protection from the device, from barriers to adequate use, to issues related to comfort, convenience, lack of training, to beliefs and attitudes towards its use.
Studies show seismic wave reflection between an elastic overburden and an equivalent medium have coefficients of reflection that vary with frequency. This variation, depends on the behavior of AVO at the interface. The calculation of synthetic seismographs for the ideal model is carried out using the reflectivity technique for those materials whose velocities and attenuations are frequency dependent. This is usually used since the effects of velocity and attenuation variations are detectable on stacked data.
The molar attenuation coefficient at the absorption peak of YOYO-1 is nearly 105 cm−1M−1, among the high values of typical organic dyes. The fluorescence quantum yield of YOYO-1 in water is very small (<0.1%) and thus nonfluorescent. Upon binding to DNA, its quantum yield enhances >1000 fold and reaches up to 50%, among the brightest fluorescent organic dyes. Under light excitation, photoblinking and photobleaching are observed for YOYO-1 in DNA.
By convention, with the independent variable on the x-axis, the shallower slope is obtained. Green reference lines are averages within arbitrary bins along each axis. Note that the steeper green and red regression estimates are more consistent with smaller errors in the y-axis variable. Regression dilution, also known as regression attenuation, is the biasing of the regression slope towards zero (the underestimation of its absolute value), caused by errors in the independent variable.
Attenuation is made possible by the fact that in prokaryotes (which have no nucleus), the ribosomes begin translating the mRNA while RNA polymerase is still transcribing the DNA sequence. This allows the process of translation to directly affect transcription of the operon. At the beginning of the transcribed genes of the trp operon is a sequence of 140 nucleotides termed the leader transcript (trpL). This transcript includes four short sequences designated 1-4.
Therefore, in order to obtain reasonable amplitude, the amplitude spectrum of the computed filter has to be clipped at some maximum gain to prevent undue amplitude at later times. On basis of this concept Wang proposed a stabilized inverse Q filtering approach that was able to compensate simultaneously for both attenuation and dispersion.”Wang 2008 p.66 The unclipped version of Wang’s solution is presented in the wikipedia article seismic inverse Q filtering.
Seismic tomography is similar to medical x-ray computed tomography (CT scan) in that a computer processes receiver data to produce a 3D image, although CT scans use attenuation instead of traveltime difference. Seismic tomography has to deal with the analysis of curved ray paths which are reflected and refracted within the earth and potential uncertainty in the location of the earthquake hypocenter. CT scans use linear x-rays and a known source.
Schematic of an X-ray image intensifier The overall function of an image intensifier is to convert incident x-ray photons to light photons of sufficient intensity to provide a viewable image. This occurs in several stages. The first is conversion of X-ray photons to light photons by the input phosphor. Sodium activated Cesium Iodide is typically used due to its high conversion efficiency thanks to high atomic number and mass attenuation coefficient.
The closer the wind farm, the stronger the return, and the combined signal from many towers is stronger. In some conditions, the radar can even see toward and away velocities that generate false positives for the tornado vortex signature algorithm on weather radar; such an event occurred in 2009 in Dodge City, Kansas. As with other structures that stand in the beam, attenuation of radar returns from beyond windmills may also lead to underestimation.
The cost of a larger antenna, klystron and other related equipment is offset by this benefit. For a 5 cm radar, absorption becomes important in heavy rain and this attenuation leads to underestimation of echoes in and beyond a strong thunderstorm. Canada and other northern countries use this less costly kind of radar as the precipitation in such areas is usually less intense. However, users must consider this characteristic when interpreting data.
Most internet service providers in France now offer digital television (IPTV) packages through triple-play set-top box. However, some subscribers have too much attenuation distortion on their lines to benefit from the service, and France does not yet have 100% DSL coverage. French cable providers Noos SA and UPC France SA and Numericable merged to become the largest cable operator in France. They provide cable television (using multiple brands) through their set top boxes.
One characteristic of ultrasound previously discussed is that of attenuation of an ultrasound signal partly due to the conversion of mechanical wave energy to thermal energy. Researchers and doctors have made medical applications to harness this heat conversion and use it in successful medical procedures. Ultrasound energy is a form of therapy being studied as an anticancer treatment. Intensified ultrasound energy can be directed at cancer cells to heat them and kill them.
Music is often used for two different reasons in mood repair strategies. The first is to allow the listener to identify themselves with the current music and to allow for some ventilation or mood attenuation. The other is a form of mood-repair strategy which allows the listener to take action to achieve their desired mood. These two approaches are considered the mood-congruent listening approach and the mood-incongruent listening approach, respectively.
Surgical treatment is best, when it can be performed. Pressure within the portal vein is measured as the shunt is closed, and it must be kept below 20 cm H2O or else portal hypertension will ensue. Methods of shunt attenuation should aim to slowly occlude the vessel over several weeks to months in order to avoid complications associated with portal hypertension. These methods include ameroid ring constrictors, cellophane banding, intravascular or percutaneous silicone hydraulic occluders.
SynGAP1 is a complex protein with several functions that may be regulated temporally via complex isoforms. A well-documented function of SynGAP1 involves NMDA receptor-mediated synaptic plasticity and membrane insertion of AMPA receptors through the suppression of upstream signaling pathways. However, SynGAP1 has also been shown to function cooperatively with Unc51.1 in axon formation. One way SynGAP1 affects these processes is through the MAP kinase signaling pathway by attenuation of Ras signalling.
This attenuation, known as atmospheric extinction, is described quantitatively by the Beer–Lambert law. "Air mass" normally indicates relative air mass, the ratio of absolute air masses (as defined above) at oblique incidence relative to that at zenith. So, by definition, the relative air mass at the zenith is 1. Air mass increases as the angle between the source and the zenith increases, reaching a value of approximately 38 at the horizon.
Angiomyolipoma seen as a hyperechoic mass in the upper pole of an adult kidney on renal ultrasonography. Renal ultrasonography of a person with tuberous sclerosis and multiple angiomyolipomas in the kidney: Measurement of kidney length on the US image is illustrated by ‘+’ and a dashed line. CT scan of a renal angiomyolipoma. It involves the renal cortex, and has an attenuation of less than 20 HU on the Hounsfield scale, which are typical characteristics.
Digital audio provides several advantages over traditional analog audio distribution. Audio transmitted over analog cables can be adversely affected by signal degradation due to electromagnetic interference, high-frequency attenuation, and voltage drop over long cable runs. Thanks to digital multiplexing, the cabling requirements for digital audio distribution are almost always reduced when compared to analog audio. Dante also provides specific advantages over first-generation audio over Ethernet technologies, such as CobraNet and EtherSound.
A phase 2b study of statin patients was presented at the 2014 American College of Cardiology. Monthly or bimonthly injections resulted in significantly reduced LDL-C at week 12. The Phase 3 SPIRE trials were dose-finding studies and found bococizumab to significantly reduce LDL cholesterol levels, but was commonly associated with anti-drug antibodies. The development of anti-drug antibodies with bococizumab led to an attenuation in LDL lowering at 52 weeks.
Lentic systems gain most of their energy from photosynthesis performed by aquatic plants and algae. This autochthonous process involves the combination of carbon dioxide, water, and solar energy to produce carbohydrates and dissolved oxygen. Within a lake or pond, the potential rate of photosynthesis generally decreases with depth due to light attenuation. Photosynthesis, however, is often low at the top few millimeters of the surface, likely due to inhibition by ultraviolet light.
Schematic illustration of minimal intensity projection. In scientific visualization, minimum intensity projection (MinIP) is a method for visualization of structures with low intensity in a specific volume. A two- dimensional image of a selected volume (for example all images that make up a 10 mm slab) is generated where each pixel is represented by displaying the lowest attenuation value in each voxel. Example of a coronal MPR (slice thickness 10 mm) with minimal intensity projection.
In practice, the orthogonal polarizations may not be associated with degenerate modes. OS1 and OS2 are standard single- mode optical fiber used with wavelengths 1310 nm and 1550 nm (size 9/125 µm) with a maximum attenuation of 1 dB/km (OS1) and 0.4 dB/km (OS2). OS1 is defined in ISO/IEC 11801,ISO/IEC 11801:2002, Information technology -- Generic cabling for customer premises. and OS2 is defined in ISO/IEC 24702.
The cutoff effect is an artifact of using lumped inductors. With loading methods using continuous distributed inductance there is no cutoff. Without loading coils, the line response is dominated by the resistance and capacitance of the line with the attenuation gently increasing with frequency. With loading coils of exactly the right inductance, neither capacitance nor inductance dominate: the response is flat, waveforms are undistorted and the characteristic impedance is resistive up to the cutoff frequency.
Pyramidal RAM attenuates signal by two effects: scattering and absorption. Scattering can occur both coherently, when reflected waves are in-phase but directed away from the receiver, or incoherently where waves are picked up by the receiver but are out of phase and thus have lower signal strength. This incoherent scattering also occurs within the foam structure, with the suspended carbon particles promoting destructive interference. Internal scattering can result in as much as 10 dB of attenuation.
Hints of emerging evolutionary resistance in a rebounding population of an afflicted frog species were reported from ecological study of an epizootically endangered stream-breeding frog Mixophyes fleayi reported from subtropical Australia. Rebound of frog species in Panama after decline are not associated with pathogen attenuation, but rather a host factor - whether an evolved genetic resistance to the fungus infection, or an otherwise acquired trait (such as a hypothetically protective microbial colonization) is yet to be identified.
In Denmark, Hansen et al. studied 92,164 AMI patients. Mortality rates were higher on weekends within seven days of admission in 1997-99 (absolute difference ranging from 0.8 to 1.1%), with weekend-weekday hazard-ratios of 1.13 (95% CI 1.03-1.23) at day 2 and 1.10 (95% CI 1.01-1.18) at day 7. But there were no significant differences in 2000-09 and suggesting an attenuation of the initial 'weekend-effect', perhaps relating to more equitable care.
Indicating a long 14 year production run. The main differences between the non-storage, non-digital analog 2200 series are as follows: the 2200 series is mostly 2 channel, with 2245, 2246, 2247, and 2252 being the 4 channel exceptions (the two extra channels having only two vertical attenuation values). The 2335 and 2336 are 2 channel, ruggedized versions mostly made for the military. The 2400 series are 4 channel, 2 of the channels having full attenuators.
In practice, there is an adjustment so the operator can precisely match the low frequency time constant (called compensating the probe). Matching the time constants makes the attenuation independent of frequency. At low frequencies (where the resistance of R is much less than the reactance of C), the circuit looks like a resistive divider; at high frequencies (resistance much greater than reactance), the circuit looks like a capacitive divider. The result is a frequency compensated probe for modest frequencies.
Neutral density (ND) filters have a constant attenuation across the range of visible wavelengths, and are used to reduce the intensity of light by reflecting or absorbing a portion of it. They are specified by the optical density (OD) of the filter, which is the negative of the common logarithm of the transmission coefficient. They are useful for making photographic exposures longer. A practical example is making a waterfall look blurry when it is photographed in bright light.
The same devices could be used to create new types of optical amplifiers to compensate for signal attenuation along transmission lines. A more elaborate application of optical transistors is the development of an optical digital computer in which components process photons rather than electrons. Further, optical transistors that operate using single photons could form an integral part of quantum information processing where they can be used to selectively address individual units of quantum information, known as qubits.
Pi pads, O pads and split O pads The unbalanced pi pad can be converted to a balanced O pad by putting one half of Rz in each side of a balanced line. The simple four element O pad attenuates the differential mode signal but does little to attenuate any common mode signal. To insure attenuation of the common mode signal also, a split O pad can be created by splitting and grounding Rx and Ry.
Correction for attenuation is a statistical procedure developed by Charles Spearman in 1904 that is used to "rid a correlation coefficient from the weakening effect of measurement error" (Jensen, 1998), a phenomenon known as regression dilution. In measurement and statistics, the correction is also called disattenuation. The correction assures that the correlation across data units (for example, people) between two sets of variables is estimated in a manner that accounts for error contained within the measurement of those variables.
Oxygenated and Deoxygenated Hemoglobin fNIRS is based on the absorption of near infrared light by hemoglobin. The light moves, or propagates, through the head and lends information about blood volume, flow and oxygenation. This technique is safe, non-invasive, and can be used with other imaging modalities. To specify, fNIRS is a non-invasive imaging method involving the quantification of chromophore concentration resolved from the measurement of near infrared (NIR) light attenuation or temporal or phasic changes.
On fine jazz guitars, the parallel wiring produces significantly cleaner sound, as the lowered source impedance drives capacitive cable with lower high frequency attenuation. A side-by-side humbucking pickup senses a wider section of each string than a single-coil pickup.Tillman, Donald (2002). By picking up a larger portion of the vibrating string, more lower harmonics are present in the signal produced by the pickup in relation to high harmonics, resulting in a "fatter" tone.
Various types of cyanobacteria inhabit Lake Chillisquaque. The specific genera that inhabit the lake vary at different times of the year and also at different depths within the lake. Due to the presence of light attenuation in the lake, light plays a role in determining which species of cyanobacteria inhabit it. In September 2009, the most common type of microbe on the surface of Lake Chillisquaque was Oscillatoria, which made up approximately 75 percent of the total.
It may be involved in breast cancer, and its protein signaling is, it is presumed, a molecular switch that governs adipogenesis. Gain-of-function of Wnt10b in mouse hearts has shown to improve cardiac tissue repair after myocardial injury, by promoting coronary vessel formation and attenuating pathological fibrosis.Paik DT, Rai M, Ryzhov S, Sanders LN, Aisagbonhi O, Funke MJ, Feoktistov I, Hatzopoulos AK. Wnt10b gain-of-function improves cardiac repair by arteriole formation and attenuation of fibrosis. Circ Res.
Mitochondrial transcription termination factor 1, also known as MTERF1, is a protein which in humans is encoded by the MTERF gene. This gene encodes a mitochondrial transcription termination factor. This protein participates in attenuating transcription from the mitochondrial genome; this attenuation allows higher levels of expression of 16S ribosomal RNA relative to the tRNA gene downstream. The product of this gene has three leucine zipper motifs bracketed by two basic domains that are all required for DNA binding.
This freshwater microalgal species is globally distributed. It usually occurs in small, acidic lakes with high concentrations of dissolved organic carbon, which result in sharp gradients of light intensity due to rapid attenuation of light with depth. During the last decades, G. semen has spread in northern Europe to many non-humic lakes with higher pH. There is evidence that brownification of lakes in these areas, decreasing pH and higher water temperature initiated the spreading of this species.
Deep-focus earthquakes give rise to minimal surface waves. Their focal depth causes the earthquakes to be less likely to produce seismic wave motion with energy concentrated at the surface. The path of deep-focus earthquake seismic waves from focus to recording station goes through the heterogeneous upper mantle and highly variable crust only once. Therefore, the body waves undergo less attenuation and reverberation than seismic waves from shallow earthquakes, resulting in sharp body wave peaks.
A large damping capacity is desirable for materials used in structures where unwanted vibrations are induced during operation such as machine tool bases or crankshafts. Materials like brass and steel have small damping capacities allowing vibration energy to be transmitted through them without attenuation. An example of a material with a large damping capacity is gray cast iron. An understanding of this effect can be gained from observation of a stress-strain diagram with exaggerated features.
The optical pulse is attenuated as it propagates along the fiber. For a single mode fiber operating at 1550 nm, a typical attenuation is 0.2 dB/km. Since the light must make a double pass along each section of fiber, this means each 1 km causes a total loss of 0.4 dB. The maximum range of the system occurs when the amplitude of the reflected pulse becomes so low it is impossible to obtain a clear signal from it.
These two radars, both operating in the C-band, are less susceptible to attenuation in precipitation and have overall greater ranges for doppler products. Throughout the rest of the 90s and into 2000, development of the first SMART-R, SR-1, began. During development, a fire in the garage housing SR-1 broke out, destroying the truck and several components. Much of the radar survived, however, and the project continued with the completion of SR-1 in late 2001.
Ultrasound attenuation is frequency-dependent: higher frequencies are attenuated faster with increasing depth. Selecting ultrasound detectors that are most sensitive at the appropriate frequency can improve sensitivity at the target imaging depth, but at the cost of spatial resolution. Earlier calculations predicted that MSOT should be able to detect concentrations of organic fluorochromes as low as 5 nM.R.A. Kruger, W.L. Kiser, D.R. Reinecke, G.A. Kruger, K.D. Miller, "Thermoacoustic molecular imaging of small animals", Molecular imaging 2 (2003) 113-123.
These calculations did not properly account for frequency-dependent attenuation of ultrasound in tissue or for the requirements of spectral unmixing.D. Razansky, J. Baeten, V. Ntziachristos, "Sensitivity of molecular target detection by multispectral optoacoustic tomography (MSOT)", Med. Phys. 36 (2009) 939-945. Experimental results suggest an in vivo detection sensitivity of 0.1-1 μM for organic dyes with a minimum detectable optical absorption coefficient of 0.1–1 cm−1, such as indocyanine green and Alexa fluochromes.
An optical link is a telecommunications link that consists of a single end-to- end optical circuit. A cable of optical fibers, possibly concatenated into a dark fiber link, is the simplest form of an optical link. Other forms of optical link can include single-"colour" links over a wavelength division multiplex infrastructure, and/or links that use optical amplifiers to compensate for attenuation over long distances. Other forms of optical links include free-space optical telecommunication links.
Currently, at the Institute for Quantum Computing there are efforts to produce a pair of entangled photons and transmit one of the photons to some other part of the world by reflecting it off a satellite. The main issue now is the decoherence the photon experiences whilst interacting with particles in the atmosphere. Similarly, some attempts have been made to use optical fibres, although the attenuation of the signal has kept this from becoming a reality.
The single listener model in OpenAL is tailored to a single human user and is not fit for artificial intelligence or robotic simulations or multiple human participants as in collaborative musical performances. In these cases a multiple listener model is required. OpenAL also fails to take into account sound propagation delays (the speed of sound is used for the Doppler effect only). The distance to a sound source only translates into an amplitude effect (attenuation) and not a delay.
The changes in synaptic connections and strength are results from LTP and LTD and are strongly regulated by the release of brain-derived neurotrophic factor (BDNF), an activity-dependent synapse-development protein. In addition to BDNF, Nogo-66 receptors, and more specifically NgR1, are also involved in the development and regulation of neuronal structure. Damage to this receptor leads to pointless LTP and attenuation of LTD. Both situations imply that NgR1 is a regulator of synaptic plasticity.
Oxytrex is an investigational drug currently in clinical trials. It combines the well known opioid agonist oxycodone in the treatment of pain with an ultra-low dose of naltrexone, an opioid antagonist. Naltrexone can have markedly different pharmacokinetics at ultra-low doses which may include, the attenuation of a pre-established opioid tolerance, the prevention of tolerance from the oxycodone in the formulation, and the possible amplification of oxycodone. It is being developed by Pain Therapeutics, Inc. opioids.
The Stratospheric Aerosol and Gas Experiment (SAGE) is a series of remote sensing satellite instruments used to study the chemical composition of earth's atmosphere. Specifically, SAGE has been used to study the Earth's ozone layer and aerosols at the troposphere through the stratosphere. The SAGE instruments use solar occultation measurement technique to determine chemical concentrations in the atmosphere. Solar occultation measurement technique measures sunlight through the atmosphere and ratios that measurement with a sunlight measurement without atmospheric attenuation.
Infrared (IR) spectroscopy by ATR is applicable to the same chemical or biological systems as the transmission method. One advantage of ATR-IR over transmission-IR is the limited path length into the sample. This avoids the problem of strong attenuation of the IR signal in highly absorbing media such as aqueous solutions. For ultraviolet or visible light (UV/Vis) the evanescent light path is sufficiently short such that interaction with the sample is decreased with wavelength.
3D-chiral materials can exhibit optical activity, which manifests itself as circular birefringence, causing polarization rotation for linearly polarized waves, and circular dichroism, causing different attenuation of left- and right-handed circularly polarized waves. The former can be exploited to realize polarization rotators, while the latter can be used to realize circular polarizers. Optical activity is weak in natural chiral materials, but it can be enhanced by orders of magnitude in an artificial chiral materials, i.e., chiral metamaterials.
While optical activity is normally observed for transmitted light, polarization rotation and different attenuation of left- handed and right-handed circularly polarized waves can also occur for light reflected by chiral substances. These phenomena of specular circular birefringence and specular circular dichroism are jointly known as specular optical activity. Specular optical activity is weak in natural materials. Extrinsic 3d chirality associated with oblique illumination of metasurfaces lacking two-fold rotational symmetry leads to large specular optical activity.
Eileen Barker asserts that the controversy surrounding certain new religious movements can turn violent in a deviancy amplification spiral.Barker, Eileen, Introducing New Religious Movements , Retrieved 22 November 2006. In his autobiography, Lincoln Steffens details how news reporting can be used to create the impression of a crime wave where there is none, in the chapter "I Make a Crime Wave". Button and TunleyButton, Mark and Tunley, Martin (2015) Explaining Fraud Deviancy Attenuation in the United Kingdom.
In combination with the radar located at WCPO's transmission tower site, both radars were named "Ultimate Doppler Radar", though the transmitter dome was eventually put out of service. The new radar operates at a height of with its base above sea level. Attenuation at the site leaves a radius around the radar blank. In July 2007, WCPO launched a radar system with satellite imagery to allow fine street-level detail of weather events to specific locations.
Elastic mechanisms in animals are very important in the movement of vertebrate animals. The muscles that control vertebrate locomotion are affiliated with tissues that are springy, such as tendons, which lie within the muscles and connective tissue. A spring can be a mechanism for different actions involved in hopping, running, walking, and serve in other diverse functions such as metabolic energy conservation, attenuation of muscle power production, and amplification of muscle power production.Roberts, Thomas J., and Emanuel Azizi.
Median and posterior tibial SEPs are used in a variety of clinical settings. They can detect, localize and quantify focal interruptions along the somatosensory pathways, which may be due to any number of focal neurological problems, including trauma, compression, multiple sclerosis, tumor or other focal lesions. SEPs are also sensitive to cortical attenuation due to diffuse central nervous system (CNS) disorders. This is seen in a variety of neurodegenerative disorders and metabolic problems such as vitamin B12 deficiency.
As opposite to air, water attenuates light exponentially. This results in hazy images with very low contrast. The main reasons for light attenuation are light absorption (where energy is removed from the light) and light scattering, by which the direction of light is changed. Light scattering can further be divided into forward scattering, which results in an increased blurriness and backward scattering that limits the contrast and is responsible for the characteristic veil of underwater images.
In a fMRI study that examined if meaning was implicitly extracted from unattended words, or if the extraction of meaning could be avoided by simultaneously presenting distracting stimuli; it was found that when competing stimuli create sufficient attentional demand, no brain activity was observed in response to the unattended words, even when directly fixated upon. These results are in keeping with what would be predicted by an attenuation style of selection and run contrary to classical late selection theory.
The reception or transmission of radio waves, a form of electromagnetic radiation, to or from an antenna within a Faraday cage is heavily attenuated or blocked by the cage; however, a Faraday cage has varied attenuation depending on wave form, frequency, or distance from receiver/transmitter, and receiver/transmitter power. Near-field, high- powered frequency transmissions like HF RFID are more likely to penetrate. Solid cages generally attenuate fields over a broader range of frequencies than mesh cages.
The above coordinate transformation can be left as-is in the transformed wave equations, or can be combined with the material description (e.g. the permittivity and permeability in Maxwell's equations) to form a UPML description. The coefficient σ/ω depends upon frequency--this is so the attenuation rate is proportional to k/ω, which is independent of frequency in a homogeneous material (not including material dispersion, e.g. for vacuum) because of the dispersion relation between ω and k.
It has also been used to prove that backpropagating action potentials invade dendritic spines without voltage attenuation, establishing a sound basis for future work on Long-term potentiation. Its use here was that it provided a way to accurately measure the voltage in the tiny dendritic spines with an accuracy unattainable with standard two-photon microscopy. Meanwhile, SHG can efficiently convert near-infrared light to visible light to enable imaging- guided photodynamic therapy, overcoming the penetration depth limitations.
In a later addition to this existing theory of selective attention, Anne Treisman developed the attenuation model. In this model, information, when processed through a filter mechanism, is not completely blocked out as Broadbent might suggest. Instead, the information is weakened (attenuated), allowing it to pass through all stages of processing at an unconscious level. Treisman also suggested a threshold mechanism whereby some words, on the basis of semantic importance, may grab one's attention from the unattended stream.
Under resting conditions, vagal tone prevails and variations in heart period are largely dependent on vagal modulation. The vagal and sympathetic activity constantly interact. Because the sinus node is rich in acetylcholinesterase, the effect of any vagal impulse is brief because the acetylcholine is rapidly hydrolyzed. Parasympathetic influences exceed sympathetic effects probably through two independent mechanisms: a cholinergically induced reduction of norepinephrine released in response to sympathetic activity, and a cholinergic attenuation of the response to an adrenergic stimulus.
Active cables are copper cables for data transmission that use an electronic circuit to boost the performance of the cable. Without an electronic circuit a cable is considered a 'passive' cable. Passive cables are liable to degrade the data they carry, due to "channel impairments" including attenuation, crosstalk and group velocity distortion. In active cables, a circuit using one or several integrated circuits is embedded in the cable to compensate for some or all of these impairments.
Early analog synthesizers used technology from electronic analog computers and laboratory test equipment. They were generally "modular" synthesizers, consisting of a number of independent electronic modules connected by patch cables into a patchbay that resembled the jackfields used by 1940s-era telephone operators. Synthesizer modules in early analog synthesizers included voltage-controlled oscillators (VCOs), voltage-controlled filters (VCFs), and voltage-controlled amplifiers (VCAs). The control voltage varied frequency in VCOs and VCFs, and attenuation (gain) in VCAs.
Because of their long wavelength, radio waves in this frequency range can diffract over obstacles like mountain ranges and travel beyond the horizon, following the contour of the Earth. This mode of propagation, called ground wave, is the main mode in the longwave band. The attenuation of signal strength with distance by absorption in the ground is lower than at higher frequencies, and falls with frequency. Low frequency ground waves can be received up to from the transmitting antenna.
In 1964, Treisman proposed her Attenuation Theory, which modified Broadbent's Filter model by stating that unattended information is attenuated rather than completely filtered out. Treisman used a dichotic listening task during which participants heard multiple languages and different voices (male vs. female). She showed that a difference between two equally known languages allowed no more efficient selection than a difference in subject matter between two messages in the same language. Unknown foreign languages, however, produced less interference.
The Big Bog lies at , very close to the trade wind inversion layer, leading to persistent transport of moisture rich air by the northeast trade winds up the steep mountain slopes. These trade winds condense to form clouds and precipitation. Its moniker as the cloudiest place in the Hawaiian Islands is verified by the fact that its average solar radiation and potential evapotranspiration are the lowest amongst recorded locations, and relative humidity and cloud attenuation are the highest.
This leaves increasing L which is the usual solution adopted. The required increase in L is achieved by loading the cable with a metal with high magnetic permeability. It is also possible to load a cable of conventional construction by adding discrete loading coils at regular intervals. This is not identical to a distributed loading, the difference being that with loading coils there is distortionless transmission up to a definite cut-off frequency beyond which the attenuation increases rapidly.
FePt Coercivity Due to their superparamagnetism and controllable shape, size, and surface, iron-platinum nanoparticles have great potential for advancing medicine in many fields, including imagining, pathogen detection, and targeted cancer therapy. The NPs can be conjugated with antibodies for tissue-specific delivery, providing a systematic way to customize for either technology. FePt NPs are compatible for CT scans because of their strong ability to absorb x-rays.Page for X-Ray Mass Attenuation Coefficients for Pt. .
Since plants require a nearly continuous supply of water, but most regions receive sporadic rainfall, the water-holding capacity of soils is vital for plant survival. Soils can effectively remove impurities, kill disease agents, and degrade contaminants, this latter property being called natural attenuation. Typically, soils maintain a net absorption of oxygen and methane and undergo a net release of carbon dioxide and nitrous oxide. Soils offer plants physical support, air, water, temperature moderation, nutrients, and protection from toxins.
Fountain Creek Watershed Drainage, Flood Control, and Greenway District was created on April 30, 2009, under Senate Bill 09-141. Overseen by nine board members, the "District's primary goals are to create healthy and safe waterways and establish greater recreation and appreciation opportunities, all through regional collaboration." Its projects include wetland restoration, sediment removal, water quality improvements, flood attenuation, erosion management and aquatic and wildlife habitat management. An additional trail is to be added at Clear Spring Ranch.
Close up of an aethalometer control panel Work in the 1970s at Tihomir Novakov's lab at the Lawrence Berkeley National Laboratory established the quantitative relationship between the optical attenuation of a deposit of particles on a fibrous filter, and the carbon content of that deposit. Improvements in optical and electronic technology permitted the measurement of very small increases in attenuation, such as would occur during the passage of typical ambient air through a filter on a 5- or 10-minute timebase. The development of personal computers and analog-digital interfaces permitted the real-time calculation of data, and mathematical conversion of the signals to a concentration of black carbon expressed in units of nanograms or micrograms of Black Carbon per cubic meter of air. The first-ever Aethalometer was developed at the Lawrence Berkeley National Laboratory by Anthony D. A. Hansen (who would later found Magee Scientific), Hal Rosen and Tihomir Novakov, and was utilised in an EPA visibility study at Houston in September 1980, with the first real-time data chart of black carbon concentrations in ambient air published in 1981.
The ocean data products that can be derived from the measurements are mainly the chlorophyll concentration, the optical diffuse attenuation coefficients, the concentration of dissolved organic material or yellow substance, and the concentration of suspended particles in the near-surface zone of the sea. In operational oceanography, satellite derived data products are used in conjunction with numerical models and in situ measurements to provide forecasting and now casting of the ocean state. Such information is of genuine interest for many categories of users.
The name hybrid comes from these special mixed-winding transformers. An effective hybrid would have high trans-hybrid loss, which means that relatively little of the incoming audio would appear on the outgoing port. Too much leakage can cause echoes when there is a delay in the transmission path, as there is with satellite, mobile phone, and VoIP links. This is a result of a talker's voice traversing to the far-end hybrid and returning to his own receiver with insufficient attenuation.
An abscess and a THAD (white arrow) on a contrast CT in native, arterial, portal and delayed phase. (Creative Commons Attribution License) Transient hepatic attenuation differences (THAD) are areas of enhancement during the arterial phase of contrast CT of the liver. THAD is thought to be a physiological phenomenon resulting from regional variation in the blood supply by the portal vein and/or the hepatic artery. THAD may in some cases be associated with liver tumors such as a hepatocellular carcinoma.
1000BASE-ZX is a non-standard but multi-vendor term to refer to Gigabit Ethernet transmission using 1,550 nm wavelength to achieve distances of at least over single-mode fiber. Some vendors specify distances up to over single-mode fiber, sometimes called 1000BASE-EZX. Ranges beyond 80 km are highly dependent upon the path loss of the fiber in use, specifically the attenuation figure in dB per km, the number and quality of connectors/patch panels and splices located between transceivers.
100BASE-ZX is a non-standard but multi- vendor term to refer to Fast Ethernet transmission using 1,550 nm wavelength to achieve distances of at least 70km over single-mode fiber. Some vendors specify distances up to 160km over single-mode fiber, sometimes called 100BASE-EZX. Ranges beyond 80 km are highly dependent upon the path loss of the fiber in use, specifically the attenuation figure in dB per km, the number and quality of connectors/patch panels and splices located between transceivers.
Ships making use of the MF marine bands often use inverted L antennas as these are able to radiate a significant proportion of the signal that is vertically polarized. At distances that are typically towards the edge of the ground wave coverage area, some sky-wave signal may also be present, especially at night when the D layer attenuation is reduced. This may serve to reinforce or cancel the overall signal resulting in figures that will differ from those that may be expected.
The latter approach has induced permanent infertility when injected into laboratory mice. However, there is some attenuation of efficacy when it is actually transmitted virally. In addition to rabbits and mice, this approach has been explored for other animals. Researchers have attempted to replicate similar results when targeting the red fox (Vulpes vulpes) in Australia using such vectors as Salmonella typhimurium, vaccinia, and canine herpesvirus, but no reduction in fertility has been achieved thus far for a variety of reasons.
For example, if some mechanism allows the full transmission of the leading part of a pulse while strongly attenuating the pulse maximum and everything behind (distortion), the pulse maximum is effectively shifted forward in time, while the information on the pulse does not come faster than c without this effect. However, group velocity can exceed c in some parts of a Gaussian beam in vacuum (without attenuation). The diffraction causes the peak of the pulse to propagate faster, while overall power does not.
Transmission. In this mode, either attenuation or phase shift of the X-ray beam by the sample can be measured. Absorption contrast can be used to map the sample’s density. Particular elemental constituents can be located using measurements on each side of an absorption edge to give an element-specific difference image with moderate sensitivity. Phase-contrast imaging can be sensitive to internal structure even when absorption is low and can be enhanced by tuning the X-ray energy. Diffraction.
This preparation received the name of its two discoverers (Bacillum Calmette-Guérin, or BCG, for short). Attenuation was achieved by cultivating them in a bile-containing substrate, based on idea given by a Norwegian researcher, Kristian Feyer Andvord (1855–1934). From 1908 to 1921, Guérin and Calmette strived to produce less and less virulent strains of the bacillus, by transferring them to successive cultures. Finally, in 1921, they used BCG to successfully vaccine newborn infants in the Charité in Paris.
Another adaptive use of fluorescence is to generate orange and red light from the ambient blue light of the photic zone to aid vision. Red light can only be seen across short distances due to attenuation of red light wavelengths by water. Many fish species that fluoresce are small, group- living, or benthic/aphotic, and have conspicuous patterning. This patterning is caused by fluorescent tissue and is visible to other members of the species, however the patterning is invisible at other visual spectra.
Red dust from the storm reached New Zealand on the morning of 25 September 2009, behind a weather front that brought cold temperatures to the North Island. It was observed by satellite, atmospheric monitoring equipment (a beta attenuation monitor) at Auckland International Airport and by dust settling on the ground. Dust settled across Auckland as well as in the Northland, Waikato, Bay of Plenty and Taranaki districts of the North Island and it also reached the South Island's West Coast.
Darlington considers the topology of coupled tuned circuits to involve a separate approximation technique to the insertion-loss method, but also producing nominally flat passbands and high attenuation stopbands. The most common topology for these is shunt anti- resonators coupled by series capacitors, less commonly, by inductors, or in the case of a two-section filter, by mutual inductance. These are most useful where the design requirement is not too stringent, that is, moderate bandwidth, roll-off and passband ripple.
A land treatment unit (LTU) is a location in which land is treated, usually through bioremediation processes, to reduce the toxicity of the soil. LTUs are becoming more common as more sites requiring clean-up are identified. Land treatment units are areas where hazardous waste is applied or incorporated into the soil surface. Land treatment units are typically units consisting of natural soils where natural biological and chemical degradation and attenuation processes immobilize, transform, or degrade hazardous constituents over time.
In statistics, errors-in-variables models or measurement error models are regression models that account for measurement errors in the independent variables. In contrast, standard regression models assume that those regressors have been measured exactly, or observed without error; as such, those models account only for errors in the dependent variables, or responses. Illustration of regression dilution (or attenuation bias) by a range of regression estimates in errors-in-variables models. Two regression lines (red) bound the range of linear regression possibilities.
Time Domain (TD) system introduces a short NIR pulse with a pulse length usually in the order of picoseconds—around 70 ps. Through time-of- flight measurements, photon path-length may be directly observed by dividing resolved time by the speed of light. Information about hemodynamic changes can be found in the attenuation, decay, and time profile of the back-scattered signal. For this photon-counting technology is introduced, which counts 1 photon for every 100 pulses to maintain linearity.
Diffuse correlation spectroscopy (DCS) systems use localized gradients in light attenuation to determine absolute ratios of oxy-Hb and deoxy-Hb. Using a spatial measurement, DCS systems do not require knowledge of photon path- length to make this calculation, however measured concentrations of oxy-Hb and deoxy-Hb are relative to the unknown coefficient of scattering in the media. This technique is most commonly used in cerebral oxymetry systems that report a Tissue Oxygenation Index (TOI) or Tissue Saturation Index (TSI).
The presence of reflectors in the environment surrounding a transmitter and receiver create multiple paths that a transmitted signal can traverse. As a result, the receiver sees the superposition of multiple copies of the transmitted signal, each traversing a different path. Each signal copy will experience differences in attenuation, delay and phase shift while travelling from the source to the receiver. This can result in either constructive or destructive interference, amplifying or attenuating the signal power seen at the receiver.
Humans may jam echolocating animals deliberately or accidentally. Recent efforts have been made to develop acoustic jamming deterrents to exclude bats from buildings or bridges, or to keep bats away from wind turbines where large numbers of mortalities occur. These deterrents have been shown to reduce bat activity over a small area. However, scaling up acoustic deterrents to large volumes for applications such as keeping bats away from wind turbines is difficult because of the high atmospheric attenuation of ultrasound.
In 1933 he and Sally P. Mead began analysis of waveguide propagation discovered analytically by their colleague George C. Southworth. Their analysis uncovered the transverse modes. Schelkunoff appears to have been the first to notice the important practical consequences of the fact that attenuation in the TE01 mode decays inversely with the 3/2 power of the frequency. In 1935 he and his colleagues reported that coaxial cable, then new, could transmit television pictures or up to 200 telephone conversations.
TRPA1 knockout mice showed near complete attenuation of nocifensive behaviors to formalin, tear-gas and other reactive chemicals . TRPA1 antagonists are effective in blocking pain behaviors induced by inflammation (complete Freund's adjuvant and formalin). Although it is not firmly confirmed whether noxious cold sensation is mediated by TRPA1 in vivo, several recent studies clearly demonstrated cold activation of TRPA1 channels in vitro. In the heat-sensitive loreal pit organs of many snakes TRPA1 is responsible for the detection of infrared radiation.
Strong ground motions damage buildings, sometimes bringing about collapse. Shaking of the ground decreases with distance from the release of energy, the hypocenter, or, more accurately expressed, from the entire area of rupture. To calculate the intensity of shaking at a given settlement, the computer looks up the attenuation (decrease in amplitude) for seismic waves that travel the distance to the settlement in question. Such calculations are similar to those made to assess the seismic hazard, part of the field of engineering seismology.
In Earth's atmosphere, the dominant scattering efficiency of blue light is compared to red or green light. Scattering and absorption are major causes of the attenuation of sunlight radiation by the atmosphere. During broad daylight, the sky is blue due to Rayleigh scattering, while around sunrise or sunset, and especially during twilight, absorption of irradiation by ozone helps maintain blue color in the evening sky. At sunrise or sunset, tangentially incident solar rays illuminate clouds with orange to red hues.
Indium Phosphide (InP) is used to produce efficient lasers, sensitive photodetectors and modulators in the wavelength window typically used for telecommunications, i.e., 1550 nm wavelengths, as it is a direct bandgap III-V compound semiconductor material. The wavelength between about 1510 nm and 1600 nm has the lowest attenuation available on optical fibre (about 0.26 dB/km). InP is a commonly used material for the generation of laser signals and the detection and conversion of those signals back to electronic form.
The payload consisted of two sets of proportional counters, each with ~0.084 m2 effective area. The counters were sensitive with more than 10% efficiency to X-ray photons in the ~2–20 keV range. The lower energy limit was determined by the attenuation of the beryllium windows of the counter plus a thin thermal shroud that was needed to maintain temperature stability of the spacecraft. The upper energy limit was determined by the transmission properties of the counter filling gas.
The length of the shell attains 13.8 mm, its diameter 5.1 mm. It's close in appearance to Eucithara fusiformis (Reeve, 1846) from which the slight fusiform shell may be distinguished by the sharper angulation of the whorls, a more attenuation of the body whorl, a finer liration on the straight columella and the slightly longer spire. The slight sinus towards the lower part of the incrassate outer lip is comparatively conspicuous. It is white with red dots between the whorls.
An optical communications repeater is used in a fiber-optic communications system to regenerate an optical signal. Such repeaters are used to extend the reach of optical communications links by overcoming loss due to attenuation of the optical fibre. Some repeaters also correct for distortion of the optical signal by converting it to an electrical signal, processing that electrical signal and then retransmitting an optical signal. Such repeaters are known as optical-electrical-optical (OEO) due to the conversion of the signal.
X-ray generators produce X-rays by applying a high voltage between the cathode and the anode of an X-ray tube and in heating the tube filament to start the electron emission. The electrons are then accelerated in the resulting electric potential and collide with the anode, which is usually made of Tungsten. The X-ray that are emitted by this generator are directed towards the object to control. They cross it and are absorbed according to the object material's attenuation coefficient.
High- specification acoustic foams, developed by loudspeaker manufacturers such as PMC, with similar characteristics to longhaired wool, provide repeatable results for consistent production. The density of the polymer, the diameter of the pores and the sculptured profiling are all specified to provide the correct absorption for each speaker model. Quantity and position of the foam is critical to engineer a low-pass acoustic filter that provides adequate attenuation of the upper bass frequencies, whilst allowing an unimpeded path for the low bass frequencies.
In order for the transcribing polymerase to concomitantly capture the alternative structure, the time scale of the structural modulation must be comparable to that of the transcription. To ensure that the ribosome binds and begins translation of the leader transcript immediately following its synthesis, a pause site exists in the trpL sequence. Upon reaching this site, RNA polymerase pauses transcription and apparently waits for translation to begin. This mechanism allows for synchronization of transcription and translation, a key element in attenuation.
Unfavourable atmospheric conditions remained in place throughout most of the day, but an attenuation of wind shear allowed some maintenance of the storm's convection. MFR issued a final bulletin on Francisco on 7 February following the disappearance of most of the storm's convection. However, the system's wind circulation remained well-defined as the remnants curved west. Over the following week, Francisco's remnants continued west to west- northwest, and dry air was initially forecast to prevent any deep convection from reemerging.
Penstocks are incorporated into the surface water management systems (drainage) of many landfill sites. Attenuation lagoons are constructed in order to store storm water, limiting the discharge from the site to pre-development rate (green field rate). Penstocks are installed at the outfall from the lagoon so that in the rare event that the surface water becomes contaminated the penstock may be closed. This will have the effect of isolating the site from the watercourse, preventing contamination of the environment.
Crime, Law and Social Change, 63: 49-64 have also presented a theory that offers the opposite to deviancy amplification, which they call deviancy attenuation. In this they argue using the case of fraud that there are some large problems, which those in positions of power are able to attenuate through not accurately measuring it, leading to statistics which under-estimate the problem, leading to less resources dedicated to it, re- enforcing the belief of those in power it is not a problem.
This slow attenuation over distance allows far-field transmissions to communicate effectively over a long range. The properties that make long range communication possible are a disadvantage for short range communication systems. The NFMI system uses a short range (less than 2 meters). The standard modulation schemes used in typical RF communications (amplitude modulation, phase modulation, and frequency modulation) can be used in near-field magnetic induction system NFMI systems are designed to contain transmission energy within the localized magnetic field.
It also was the first radio receiver in the world. Ground-based and mobile detectors calculate the direction and severity of lightning from the current location using radio direction-finding techniques along with an analysis of the characteristic frequencies emitted by lightning. Ground-based systems use triangulation from multiple locations to determine distance, while mobile systems estimate distance using signal frequency and attenuation. Space-based detectors on satellites can be used to locate lightning range, bearing and intensity by direct observation.
A lattice filter with compensation for the resistance of its inductors and its equivalent circuit With ideal components there is no need to use resistors in the design of lattice filters. However, practical considerations of properties of real components leads to resistors being incorporated. Sections designed to equalise low audio frequencies will have larger inductors with a high number of turns. This results in significant resistance being in the inductive branches of the filter, which in turn causes attenuation at low frequencies.
The Mantra yoga is stated by the Yogatattva as a discipline of auditory recitation of mantras but stated to be an inferior form of yoga. It is the practice of mantra recitation or intonations of the sounds of alphabet, for 12 years. This gradually brings knowledge and special powers of inner attenuation, asserts the text. This mantra-based method of yoga, asserts Yogatattva, is suited for those with dull wit and incapable of practicing the other three types of yoga.
However, a small deletion of the receptor binding region causes attenuation of toxin B activity. The translocation region contains a hydrophobic stalk-like structure, which may help residues 958–1130 in forming membrane spanning pores. The receptor binding region that includes the C-terminal repetitive region (CRR) increases the TcdB membrane interaction but does not participate in pore formation. In addition, cysteine protease and translocation regions both have complex structures that play an important functional role in translocation and receptor binding.
National Science Foundation. Power attenuation by the use of the tendons can allow the muscle-tendon system the ability to absorb energy at a rate beyond the muscles maximum capacity to absorb energy. Power amplification mechanisms are able to work because the spring and muscles contain different intrinsic limits of power. Muscles in a skeletal system can be limited in their maximum power production. Power amplification by the use of the tendons allows the muscle to produce power beyond the muscle’s capacity.
A 3.73 rear axle uses carbon fiber plates in its limited slip differential or an optional Torsen differential. The quad exhaust system is made up of two standard Mustang GT outlets and two side pipes that exit on either side of the rear crossover. The side pipes send the exhaust through a set of metal "attenuation" discs to create an extra growling exhaust sound. The discs are removable and include a spacer plate sized to match aftermarket exhaust dump valves.
They are not reflected by the ionosphere nor do they travel along the Earth as ground waves as lower frequency radio waves do. At typical power densities they are blocked by building walls and suffer significant attenuation passing through foliage. Absorption by atmospheric gases is a significant factor throughout the band and increases with frequency. However, it is maximum at a few specific absorption lines, mainly those of oxygen at 60 GHz and water vapor at 24 GHz and 184 GHz.
In the fall of 1970, the company announced that researchers Robert D. Maurer, Donald Keck, Peter C. Schultz, and Frank Zimar had demonstrated an optical fiber with a low optical attenuation of 17 dB per kilometer by doping silica glass with titanium. A few years later they produced a fiber with only 4 dB/km, using germanium oxide as the core dopant. Such low attenuations made fiber optics practical for telecommunications and networking. Corning became the world's leading manufacturer of optical fiber.
The Deutsch & Deutsch model was later revised by Norman in 1968, who added that the strength of an input was also an important factor for its selection. A criticism of both the original Deutsch & Deutsch model, as well as the revised Deutsch–Norman selection model is that all stimuli, including those deemed irrelevant, are processed fully. When contrast against Treisman's attenuation model, the late selection approach appears wasteful with its thorough processing of all information before selection of admittance into working memory.
He showed also that the scale centres are ossified, formed from irregular crystals, which he illustrated in some detail. In their micro-CT scans, Scherz et al. found that the scales of G. megalepis and other species have the same degree of x-ray attenuation as bone, and concluded that this suggested the presence of osteoderm as well. They noted that, like in Schmidt's illustrations, a zone toward the tip of the scales lacks ossifications as visible in micro-CT scans.
This conclusion opened the intense race to find low-loss materials and suitable fibres for reaching such criteria. Kao, together with his new team (members including T. W. Davies, M. W. Jones, and C. R. Wright), pursued this goal by testing various materials. They precisely measured the attenuation of light with different wavelengths in glasses and other materials. During this period, Kao pointed out that the high purity of fused silica (SiO2) made it an ideal candidate for optical communication.
The atmospheric attenuation of microwaves in dry air with a precipitable water vapor level of 0.001 mm. The downward spikes in the graph corresponds to frequencies at which microwaves are absorbed more strongly, such as by oxygen molecules. Microwave transmission is the transmission of information by microwave radio waves. Although an experimental microwave telecommunication link across the English Channel was demonstrated in 1931, the development of radar in World War II provided the technology for practical exploitation of microwave communication.
The additional wire pair usage and growing bandwidth increases the need to keep NEXT in check. ;Far-end crosstalk (FEXT): FEXT measures the interference between two pairs of a cable measured at the far end of the cable with respect to the interfering transmitter. ;Equal level far end crosstalk (ELFEXT): ELFEXT measures the FEXT with attenuation compensation. ; (AXT): AXT is interference caused by other cables routed close to the cable of interest as opposed to signals contained in the same cable.
According to Mitschke, "The advantage of using a logarithmic measure is that in a transmission chain, there are many elements concatenated, and each has its own gain or attenuation. To obtain the total, addition of decibel values is much more convenient than multiplication of the individual factors." However, for the same reason that humans excel at additive operation over multiplication, decibels are awkward in inherently additive operations:R. J. Peters, Acoustics and Noise Control, Routledge, 12 November 2013, 400 pages, p.
At the receiver side, the demodulator typically performs: # Bandpass filtering. # Automatic gain control, AGC (to compensate for attenuation, for example fading). # Frequency shifting of the RF signal to the equivalent baseband I and Q signals, or to an intermediate frequency (IF) signal, by multiplying the RF signal with a local oscillator sine wave and cosine wave frequency (see the superheterodyne receiver principle). # Sampling and analog-to-digital conversion (ADC) (sometimes before or instead of the above point, for example by means of undersampling).
The transducer is typically separated from the test object by a couplant (such as oil) or by water, as in immersion testing. However, when ultrasonic testing is conducted with an Electromagnetic Acoustic Transducer (EMAT) the use of couplant is not required. There are two methods of receiving the ultrasound waveform: reflection and attenuation. In reflection (or pulse-echo) mode, the transducer performs both the sending and the receiving of the pulsed waves as the "sound" is reflected back to the device.
To uncage molecules, a photolysis system is required to cleave the covalent bond. An example system can consist of a light source (generally a laser or a lamp), a controller for the amount of light that enters, a guide for the light, and a delivery system. Often, the design function in such a way that a medium is met between the diffusing light that may cause additional, unwanted photolysis and light attenuation; both being significant problems with a photolysis system.
Rebreather and reclaim systems are significantly quieter, as there is no bubble noise most of the time. The type of headgear affects noise sensitivity and noise hazard depending on whether transmission is wet or dry. Human hearing underwater is less sensitive with wet ears than in air, and a neoprene hood provides substantial attenuation. When wearing a helmet sensitivity is similar to in surface air, as hearing sensitivity is not significantly affected by the breathing gas or chamber atmosphere composition or pressure.
Stabilized inverse Q filtering is a data processing technology for enhancing the resolution of reflection seismology images where the stability of the method used is considered. Q is the anelastic attenuation factor or the seismic quality factor, a measure of the energy loss as the seismic wave moves. To obtain a solution when we make computations with a seismic model we always have to consider the problem of instability and try to obtain a stabilized solution for seismic inverse Q filtering.
Successful emulation of radiosity required a theoretical understanding and graphic application of patch view factors, path tracing and global illumination algorithms. Texture maps were usually produced with image editing software, such as Adobe Photoshop. The advantage of this method is decreased rendering time and easily modifiable overall lighting strategies. Another common approach similar to false radiosity is the manual placement of standard omni-type lights with limited attenuation in places in the 3D scene where the artist would expect radiosity reflections to occur.
Neglecting losses, the gain demonstrates a linear dependence on the number of devices (stages). Unlike the multiplicative nature of a cascade of conventional amplifiers, the DA demonstrates an additive quality. It is this synergistic property of the DA architecture that makes it possible for it to provide gain at frequencies beyond that of the unity-gain frequency of the individual stages. In practice, the number of stages is limited by the diminishing input signal resulting from attenuation on the input line.
This means that a network designed by Bartlett's theorem, while having exactly the filter response predicted, also adds a constant attenuation in addition to the filter response. In impedance matching networks, a usual design criteria is to maximise power transfer. The output response is "the same shape" relative to the voltage of the theoretical ideal generator driving the input. It is not the same relative to the actual input voltage which is delivered by the theoretical ideal generator via its load impedance.
The NIR window can be computed based on the absorption coefficient spectrum or the effective attenuation coefficient spectrum. A possible criterion for selecting the NIR window is given by the FWHM of the inverse of these spectra as shown in Figure 7. In addition to the total concentration of hemoglobin, the oxygen saturation will define the concentration of oxy and deoxyhemoglobin in tissue and so the total absorption spectrum. Depending on the type of tissue, we can consider different situations.
In astronomy, air mass or airmass is the "amount of air that one is looking through" (Green 1992) when seeing a star or other celestial source from below Earth's atmosphere. It is formulated as the integral of air density along the light ray. As it penetrates the atmosphere, light is attenuated by scattering and absorption; the thicker atmosphere through which it passes, the greater the attenuation. Consequently, celestial bodies when nearer the horizon appear less bright than when nearer the zenith.
Schwarzschild's equation has been expressed in different forms and symbols by different authors. The quantity nσλ is known as the absorption coefficient (βa), a measure of attenuation with units of cm−1. The absorption coefficient is fundamentally the product of a quantity of absorbers per unit volume (formally cm−3) times an efficiency of absorption (area/absorber, formally cm2). Several sources replace nσλ with kλr, where kλ is the absorption coefficient per unit density and r is the density of the gas.
X-ray radiography procedures involves the diagnosis of cancer cells through the process of image acquisition. These techniques rely on the absorption of x-rays on the exposed tissue in order to improve image quality. In certain radiological procedures such as Radiofrequency therapy, a contrast agent is injected into the targeted cancer tissue and result in increased x-ray attenuation. Radiofrequency therapy treatment involves the destruction of tumor cancer tissue cells through the differential heating of cancer tissue by radio-frequency diathermy.
The equipment or other mechanical components are necessarily linked to surrounding objects (the supporting joint - with the support; the unsupporting joint - the pipe duct or cable), thus presenting the opportunity for unwanted transmission of vibrations. Using a suitably designed vibration- isolator (absorber), vibration isolation of the supporting joint is realized. The accompanying illustration shows the attenuation of vibration levels, as measured before installation of the functioning gear on a vibration isolator as well as after installation, for a wide range of frequencies.
The reason is that the attenuation coefficient also depends on concentration and density, even in the absence of any interactions. These changes are, however, usually negligible except for high concentrations and large oscillator strength. For high concentrations and/or oscillator strengths, it is the integrated absorbance which is linearly depending on concentration, at least as long as there are no local field effects. If there are local field effects, they can be approximately taken into account by applying the Lorentz-Lorenz relation.
Ancillary Terrestrial Component (ATC) is a U.S. Federal Communications Commission-approvedAncillary Terrestrial Component (ATC) technique for using a "terrestrial" network of cell-phone towers to supplement a Mobile Satellite Service (MSS) provided by orbiting communications satellites. Satellite communications can be degraded by various factors, including attenuation in urban areas due to buildings etc. ATC allows the operators to reuse the same satellite spectrum in a terrestrial network to increase coverage and performance for their customers in highly shadowed regions e.g. within houses.
Congress did not grant the Court jurisdiction to hear writs of error from the circuit courts in criminal cases until 1889, for capital crimes, and 1891, for other "infamous" crimes. The Judicial Code of 1911 abolished the circuit courts, transferred the trial of crimes to the district courts, and extended the Court's appellate jurisdiction to all crimes.Brent D. Stratton, Criminal Law: The Attenuation Exception to the Exclusionary Rule: A Study in Attenuated Principle and Dissipated Logic, 75 139, 139 n.1 (1984).
Due to the attenuation of soft X-rays by the residual atmosphere at balloon altitudes these early experiments were restricted to energies above ~20 keV. Observations down to lower energies were begun with a series of high altitude sounding rocket experiments; by this stage Steve Holt had already joined the program. A 1972 rocket-borne observation of Cas A, the youngest supernova remnant in our galaxy, yielded the first detection of an X-ray spectral line, iron K-line emission at ~7 keV.
Thermobarometric data also indicate a magma origin depth of . Beneath Tuzgle, a high seismic attenuation plume rises from an earthquake cluster at depth up to the volcano and is probably linked to asthenospheric upwelling. In the ground beneath Tuzgle, seismic tomography has found a thick layer of low velocity, probably linked to a lower density of the rock, at a depth of . Magnetotelluric analysis has found several deep () conductive layers and one shallow one, possibly formed by the aquifers in the area.
This results in nearly constant attenuation with frequency over two successive repeater sections, and eliminates the need for large slope equalization and adjustments. Singing and crosstalk are minimized because the high-level output of a repeater is at a different frequency than the low-level input to other repeaters. It also diminishes group delay distortion. A repeater that receives on the high band from both direction and sends on the low band is called Hi-Lo; the other kind Lo-Hi.
Initially participant equipment and the CityLink switches were mainly located on the 48th floor of the Sky Tower. This deck is air-conditioned and enclosed with low-attenuation glass, allowing point-to-point radio shots back to base without needing weatherproofing and resource consent for external antennas. CityLink have also extended APE's L2 LAN outside of the Sky Tower so it is possible to connect to APE at a number of locations in the Auckland CBD without having a circuit into the Sky Tower.
Woodchips can be reprocessed into an extremely effective playground surfacing material, or impact-attenuation surface. When used as playground surfacing (soft fall, cushion fall, or play chip, as it is sometimes known), woodchips can be very effective in lessening the impact of falls from playground equipment. When spread to depths of one foot (30 centimetres) playground woodchips can be effective at reducing impacts in falls up to 11 feet (3 meters). Playground woodchips are also an environmentally friendly alternative to rubber-type playground surfaces.
In 2007, the American National Standards Institute published a new standard for noise reduction ratings for hearing protectors, ANSI S12.68-2007. Using the real ear attenuation at threshold data collected by a laboratory test prescribed in ANSI S12.6-2008, the noise reduction statistic for A-weighted noise (NRSA) is computed using a set of 100 noises listed in the standard.ANSI S12.68 (2007). American National Standard Methods of Estimating Effective A-Weighted Sound Pressure Levels When Hearing Protectors, are Worn, American National Standards Institute, New York.
The Bessel filter has a maximally flat time- delay (group delay) over its passband. This gives the filter a linear phase response and results in it passing waveforms with minimal distortion. The Bessel filter has minimal distortion in the time domain due to the phase response with frequency as opposed to the Butterworth filter which has minimal distortion in the frequency domain due to the attenuation response with frequency. The Bessel filter is named after Friedrich Bessel and the transfer function is based on Bessel polynomials.
The surface wave is also very dependent upon the nature of the ground over which the signal travels. Ground conductivity, terrain roughness and the dielectric constant all affect the signal attenuation. In addition to this the ground penetration varies, becoming greater at lower frequencies, and this means that it is not just the surface conductivity that is of interest. At the higher frequencies this is not of great importance, but at lower frequencies penetration means that ground straight down to 100 meters may have an effect.
The principle of the squeezing resonator is the following: The medium parametrically attenuates the electric field inside the resonator to such a value that perfect destructive interference is achieved outside the resonator for the attenuated field quadrature. The optimum field attenuation factor inside the resonator is slightly below 2, depending on the reflectivity of the resonator mirror. This principle also works for electric field uncertainties. Inside the resonator, the squeeze factor is always less than 6 dB, but outside the resonator it can be arbitrarily high.
Transparent fluorescent materials can work as an optical filter, with an absorption spectrum, and also as a light source, with an emission spectrum. Also in general, light which is not transmitted is absorbed; for intense light, that can cause significant heating of the filter. However, the optical term absorbance refers to the attenuation of the incident light, regardless of the mechanism by which it is attenuated. Some filters, like mirrors, interference filters, or metal meshes, reflect or scatter much of the non-transmitted light.
For instance, it may be required to filter one band with the sharpest possible cut-off, but in another to minimise phase distortion while still achieving some attenuation. If the form is identical at each transition from passband to stopband the filter will be the same as an m-type filter (k-type filter in the limiting case of m=1). If they are different, then the general case described here pertains. The k-type filter acts as a prototype for producing the general mn designs.
Bioremediation can occur on its own as natural attenuation or intrinsic bioremediation or can be encouraged by the addition of fertilizers, a strategy called biostimulation. Nutrient bioextraction is bioremediation involving cultured plants and animals. Nutrient bioextraction or bioharvesting is the practice of farming and harvesting shellfish and seaweed for the purpose of removing nitrogen and other nutrients from natural water bodies. It has been suggested that nitrogen removal by oyster reefs could generate net benefits for sources facing nitrogen emission restrictions, similar to other nutrient trading scenarios.
Chart of Attenuation ISAB is only a factor in the period of the day where radio signals travel through the portion of the ionosphere facing the sun. The solar wind and radiation cause the ionosphere to become charged with electrons in the first place. At night, the atmosphere becomes drained of its charge, and radio signals can go much farther with less loss of signal. In particular, low frequency signals that would be attenuated to nothing during the day will be received much farther away at night.
Single-shot multi-contrast x-ray imaging is an efficient and a robust x-ray imaging technique which is used to obtain three different and complementary types of information, i.e. absorption, scattering, and phase contrast from a single exposure of x-rays on a detector subsequently utilizing Fourier analysis/technique. Absorption is mainly due to the attenuation and Compton scattering from the object, while phase contrast corresponds to phase shift of x-rays. The technique obtain images from the biological and non-biological objects.
A recent development in live-attenuated HSV vaccine design is the production of replicative vaccines that are ablated for nervous system infection. These vaccines infect the respiratory mucosa where their replication and localized spread provoke a robust immune response. The safety of these vaccines is based on their inability to invade the nervous system and establish life-long latent infections, as opposed to a general attenuation. Unlike other live-attenuated designs, these vaccines are cleared from the body once the immune response from vaccination has matured.
Again, keep in mind that bulls can sometimes remain carriers for life once they become infected; they are unable to clear the infection like cows can. Cows can be treated by being left alone for around three months to allow them time to shed the vaginal and uterine lining that is affected. Semen can also be treated successfully with dimetridazole and then used for artificial insemination. Commercially available vaccines (TrichGuard, Tricovac) cannot prevent infection, but confer disease attenuation and some level of protection against complications.
The efficiency of detection of a G–M tube varies with the type of incident radiation. Tubes with thin end windows have very high efficiencies (can be nearly 100%) for high energy beta, though this drops off as the beta energy decreases due to attenuation by the window material. Alpha particles are also attenuated by the window. As alpha particles have a maximum range of less than 50 mm in air, the detection window should be as close as possible to the source of radiation.
Presbycusis is the leading cause of SNHL and is progressive and nonpreventable, and at this time, we do not have either somatic or gene therapy to counter heredity-related SNHL. But other causes of acquired SNHL are largely preventable, especially nosocusis type causes. This would involve avoiding environmental noise, and traumatic noise such as rock concerts and nightclubs with loud music. Use of noise attenuation measures like ear plugs is an alternative, as well as learning about the noise levels one is exposed to.
The description of raindrop shape has some rather practical uses. Understanding rain is particularly important with regard to the propagation of electromagnetic signals. A portion of atmosphere that has rain in it, or a rain cell, has the characteristic of attenuating and de-polarizing EM signals that pass through it. The attenuation of such a signal is approximately proportional to the square of the frequency of the signal, and the de-polarization is proportional to the shape distribution of raindrops in the rain cell.
The US system was located in Wisconsin and the Upper Peninsula of Michigan over the Laurentian Shield formation, for that reason. Such ELF transmitters cannot be installed on submarines, because of the size of the antenna and high power requirements. So ELF communication is one-way, with a receiver in the submarine receiving orders from a shore station, but unable to reply. The low attenuation of ELF waves with distance allows a single ELF station to send messages to submarines all over the world.
See also: Digital variance angiography The diagnostic value of radiographic images is limited by image quality, which can be measured through signal-to-noise ratio (SNR) calculations. The higher the value of SNR, the better the image. The SNR can be increased initially by enhancing the "signal" or "contrast", which is the intensity difference between the object of interest and the background. This is usually done by adding contrast medium to increase the attenuation values of the object, while holding the background values constant.
An example of a transmission line modeled by this circuit would be a balanced transmission line such as a telephone line. The impedances Z(s), the voltage dependent current sources (VDCSs) and the difference amplifiers (the triangle with the number "1") account for the interaction of the transmission line with the external circuit. The T(s) blocks account for delay, attenuation, dispersion and whatever happens to the signal in transit. One of the T(s) blocks carries the forward wave and the other carries the backward wave.
Hand injuries, meanwhile, were more likely to be caused by struggling prey. Stress fractures in dinosaur bones can be identified by looking for bulges on the shafts of bones that face toward the front of the animal. When x-rayed, these bulges often show lines of clear space where the x-rays have a harder time traveling through the bone. Rothschild and the other researchers noted that this "zone of attenuation" seen under the x-ray typically cannot be seen with the naked eye.
These instruments work by sending a short pulsed signal into the cable and measuring how long the reflection takes to return. If only reflection magnitudes are desired, however, and exact fault locations are not required, VSWR bridges perform a similar but lesser function for RF cables. The combination of the effects of signal attenuation and impedance discontinuities on a communications link is called insertion loss. Proper network operation depends on constant characteristic impedance in all cables and connectors, with no impedance discontinuities in the entire cable system.
In invertebrates, just as in Drosophila, the binding of Hedgehog to PTCH leads to internalisation and sequestration of the ligand. Consequently, in vivo the passage of hedgehog over a receptive field that expresses the receptor leads to attenuation of the signal, an effect called ligand-dependent antagonism (LDA). In contrast to Drosophila, vertebrates possess another level of hedgehog regulation through LDA mediated by Hh- interacting protein 1 (HHIP1). HHIP1 also sequesters hedgehog ligands, but unlike PTCH, it has no effect on the activity of SMO.
It does so by binding to caspase 1 (or ICE – interleukin-1 converting enzyme) which is under normal circumstances activated by the formation of inflammasome. SPI-2 expression also inhibits the apoptotic pathway activated by Fas-ligand and TNFα. Deletion of SPI-2 leads to virus attenuation in vivo (observed in mice model after intranasal infection) but without any remarkable influence on the host immune response. That was one of the reasons this gene was targeted during search for more safe and efficient vaccine against smallpox.
In more severe cases, the vulva may become discolored, developing dark purple bruising (ecchymosis), bleeding, scarring, attenuation of the labia minora, and fissures and bleeding affecting the posterior fourchette. Its cause is unknown, but likely genetic or autoimmune, and it is unconnected to malignancy in children. If the skin changes are not obvious on visual inspection, a biopsy of the skin may be performed to acquire an exact diagnosis. Treatment for vulvar lichen sclerosus may consist of topical hydrocortisone in mild cases, or stronger topical steroids (e.g.
Cluster of Differentiation 86 (also known as CD86 and B7-2) is a protein expressed on dendritic cells, macrophages, B-cells, and other antigen- presenting cells. Along with CD80, CD86 provides costimulatory signals necessary for T-cell activation and survival. Depending on the ligand bound, CD86 can be used to signal for self-regulation and cell-cell association, or for attenuation of regulation and cell-cell disassociation. The CD86 gene encodes a type I membrane protein that is a member of the immunoglobulin superfamily.
The attenuation coefficient is compiled from all the cross sections of the interactions that are happening in the material. The three most important inelastic interactions with X-rays at those energy levels are the photoelectric effect, compton scattering and pair production. After having crossed the object, the photons are captured by a detector, such as a silver halide film, a phosphor plate or flat panel detector. When an object is too thick, too dense, or its effective atomic number is too high, a linac can be used.
Intrinsic Immunity combines aspects of the two traditional branches of the immune system - adaptive and innate immunity – but is mechanistically distinct. Innate cellular immunity recognizes viral infection using toll-like receptors (TLRs), or pattern recognition receptors, which sense Pathogen- associated molecular patterns (PAMPs), triggering the expression of nonspecific antiviral proteins. Intrinsic immune proteins, however, are specific both in virus recognition and their mechanism of viral attenuation. Like innate immunity, however, the intrinsic immune system does not respond differently upon repeat infection by the same pathogen.
Some musical VCFs offer a variable slope which determines the rate of attenuation outside the bandpass, often at 6dB/octave, 12dB/octave, 18dB/octave or 24dB/octave (one-, two-, three- and four-pole filters, respectively). In modular analog synthesizers, VCFs receive signal input from signal sources, including oscillators and noise, or the output of other processors. By varying the cutoff frequency, the filter passes or attenuates partials of the input signal. In some popular electronic music styles, "filter sweeps" have become a common effect.
Haeco-CSG technology works on the basis of phase cancellation. When two waves that are not in phase are mixed, the resulting waveform has an attenuation in accordance to the degree of shift. For example, two waves which are 180 degrees out of phase will entirely cancel out when mixed together whereas two waves which are entirely in phase will double in amplitude. A difference in phase between 180 and 0 degrees results in a partial cancellation, which is the effect Haeco-CSG takes advantage of.
The linear attenuation coefficients can hence be expanded as In contrast-enhanced imaging, high-atomic-number contrast agents with K absorption edges in the diagnostic energy range may be present in the body. K-edge energies are material specific, which means that the energy dependence of the photo-electric effect is no longer separable from the material properties, and an additional term can be added to Eq. () according to where a_K and f_K are the material coefficient and energy dependency of contrast- agent material K.
Mensah worked at Air Products and Chemicals from 1980 to 1983. In 1983, Mensah joined Corning Glass Works, working in fiber optics research at Sullivan Park, New York. Researchers at Corning had previously developed optical fiber with loss below the crucial attenuation limit of 20 dB/km, but the fibers could not be manufactured at rates higher than 2 meters per second. Mensah improved the manufacturing process through a series of innovations, raising the speed of manufacture to 20 meters per second by 1985.
Nodes of Ranvier (also known as myelin sheath gaps) are short unmyelinated segments of a myelinated axon, which are found periodically interspersed between segments of the myelin sheath. Therefore, at the point of the node of Ranvier, the axon is reduced in diameter. These nodes are areas where action potentials can be generated. In saltatory conduction, electrical currents produced at each node of Ranvier are conducted with little attenuation to the next node in line, where they remain strong enough to generate another action potential.
AZD 1305 also acts on voltage gated sodium channels (Nav1.5) by attenuating the peak (INapeak) and late sodium current (INalate), though the latter current is more potently inhibited. Attenuation of INalate by AZD1305 is concentration-dependent and decreases the slope of depolarization and delays repolarization. INalate blockade by AZD1305 depressed the threshold of sodium channel excitation and prolongs APD. Blockade of IKr may lead to excessive prolongation of APD and repolarization instability, which may promote arrhythmic conditions in the heart, including EAD and Torsade de Pointes (TdP).
Comparison of the iPhone 4 (GSM) antenna placement (top) with that of the (bottom). Notice the repositioning of the antennas which forms the perimeter around the phone; the iPhone 4 antenna is on the top of the phone while on the iPhone 4S, the antennas are on the sides. This side antenna placement meant a benefit of cellular signal attenuation and was used in later models like the iPhone 5. The has a stainless steel, dual cellular antenna design, identical to iPhone 4 CDMA.
Vehicle noise is predominantly from the engine at low vehicle speeds and from tires and the air flowing past the vehicle at higher speeds. Electric motors are quieter than internal combustion engines. Thrust-producing engines, such as turbofans, turbojets and rockets emit the greatest amount of noise due to the way their thrust-producing, high-velocity exhaust streams interact with the surrounding stationary air. Noise reduction technology includes intake and exhaust system mufflers (silencers) on gasoline and diesel engines and noise attenuation liners in turbofan inlets.
The mid grating forms Fourier images of the first grating. These images beat with the 3rd grating to produce broad moiré fringes on the detector at the appropriate distance. Phase shifts and de-coherence of the wavefront by the object cause fringe shifts and attenuation of the fringe contrast. The grating fabrication challenge was eased by the discovery of a phase moiré effect which provides an all-phase- grating interferometer that works with compact sources, called the polychromatic far-field interferometer (see figure on the right).
For example, OTO Melara's new lightweight 120 mm L/45 gun has achieved a recoil force of 25 t by using a longer recoil mechanism (550 mm) and a pepperpot muzzle brake.Hilmes, Arming Future MBTs, p.79 Reduction in recoil can also be achieved through mass attenuation of the thermal sleeve. The ability of ETC technology to be applied to existing gun designs means that for future gun upgrades there's no longer the necessity to redesign the turret to include a larger breech or caliber gun barrel.
Schematic diagram of the so called "Ultimate Transmatch"Originally, the Ultimate Transmatch was promoted as a way to make the components more manageable at the lowest frequencies of interest and also to get some harmonic attenuation. A version of McCoy's Ultimate Transmatch network is shown in the illustration to the right. It is now considered obsolete; the design goals were better realized using identical parts by the Series-Parallel Capacitor (SPC) network, shown above, which was designed after the name Ultimate had already been used.
A passive oscilloscope probe with a switch in the probe handle that selects 1× or 10× attenuation To minimize loading, attenuator probes (e.g., 10× probes) are used. A typical probe uses a 9 megohm series resistor shunted by a low-value capacitor to make an RC compensated divider with the cable capacitance and scope input. The RC time constants are adjusted to match. For example, the 9 megohm series resistor is shunted by a 12.2 pF capacitor for a time constant of 110 microseconds.
Hull's experiments showed the reality of some classical phenomena such as mentally induced pain reduction and apparent inhibition of memory recall. However, Clark's work made clear that these effects could be achieved without hypnosis being seen as a distinct state, but rather as a result of suggestion and motivation, which was a forerunner of the behavioural approach to hypnosis. Similarly, moderate increases in certain physical capacities and changes to the threshold of sensory stimulation could be induced psychologically; attenuation effects could be especially dramatic.
Schematic of a Geiger counter using an "end window" tube for low penetration radiation. A loudspeaker is also used for indication Proportional counters and end-window Geiger-Muller tubes have a very high efficiency for all ionising particles that reach the fill gas. Nearly every initial ionising event in the gas will result in Townsend avalanches, and thereby an output signal. However the overall detector efficiency is largely affected by attenuation due to the window or tube body through which particles have to pass.
Mechanical systems are elevator systems, boilers, refrigeration or air conditioning systems, generators and trash compactors. Since many of these sounds are inherently loud, the principle of regulation is to require the wall or ceiling assembly to meet certain performance standards (typically Sound Transmission Class of 50), which allows considerable attenuation of the sound level reaching occupants. The second type of interior sound is called Impact Insulation Class (IIC) transmission. This effect arises not from airborne transmission, but rather from transmission of sound through the building itself.
Shorter wavelengths are useful for smaller particles, but the signal is more quickly attenuated. Thus 10 cm (S-band) radar is preferred but is more expensive than a 5 cm C-band system. 3 cm X-band radar is used only for short-range units, and 1 cm Ka-band weather radar is used only for research on small-particle phenomena such as drizzle and fog. W band weather radar systems have seen limited university use, but due to quicker attenuation, most data are not operational.
Pixels in an image obtained by CT scanning are displayed in terms of relative radiodensity. The pixel itself is displayed according to the mean attenuation of the tissue(s) that it corresponds to on a scale from +3,071 (most attenuating) to −1,024 (least attenuating) on the Hounsfield scale. Pixel is a two dimensional unit based on the matrix size and the field of view. When the CT slice thickness is also factored in, the unit is known as a Voxel, which is a three-dimensional unit.
The main applications of acoustic levitation are likely to be scientific and industrial. 376x376pxThe contactless manipulation of droplets has gained significant interest as it promises small scale contactless chemistry. There is particular interest in the mixing of multiple droplets using PATs so that chemical reactions can be studied in isolation from containers. There is also interest in using levitation to suspend protein droplets for use of X-ray diffraction imaging without containers, which attenuation the beam and reduce the quality of the diffraction data provided.
At Pouilly-le-Fort, Pasteur used a vaccine attenuated by potassium dichromate, employing a process similar to Toussaint's, who had published a means of attenuation by another antiseptic, carbolic acid. Pasteur never gave proper credit to Toussaint and his discovery. Pasteur's nephew, bacteriologist Adrien Loir (1862-1941) was aware of Toussaint's work with the vaccine, of which he documented in the 1938 treatise, A l'ombre de Pasteur ("In the Shadow of Pasteur"). From 1881, Toussaint was in declining health, reportedly from a nerve-related disease.
The main components of an NDIR sensor are an infrared (IR) source (lamp), a sample chamber or light tube, a light filter and an infrared detector. The IR light is directed through the sample chamber towards the detector. In parallel there is another chamber with an enclosed reference gas, typically nitrogen. The gas in the sample chamber causes absorption of specific wavelengths according to the Beer–Lambert law, and the attenuation of these wavelengths is measured by the detector to determine the gas concentration.
Ubiquitin and ubiquitin-like molecules extensively regulate immune signal transduction pathways at virtually all stages, including steady-state repression, activation during infection, and attenuation upon clearance. Without this regulation, immune activation against pathogens may be defective, resulting in chronic disease or death. Alternatively, the immune system may become hyperactivated and organs and tissues may be subjected to autoimmune damage. On the other hand, viruses must block or redirect host cell processes including immunity to effectively replicate, yet many viruses relevant to disease have informationally limited genomes.
Metal fiber sintered porous sheets are used as a sound attenuation medium in the aircraft cabin, reducing HVAC sounds, and auxiliary power unit noise. Technical textiles Metal fibers can serve as antistatic fibers for textiles, which can be used in, amongst others, electrical protective clothing or antistatic big bags. Not only antistatic, but also shielding from electromagnetic interference (EMI) can be achieved by metal fiber textiles. Stainless steel fiber textiles can be heated by applying electrical current and can also be used for cut resistant clothing (gloves).
As is now well known the independent variables are frequency/wavelength, distance, surface conductivity. The latter variable is particularly troublesome varying greatly with the type of the ground (rock, soil, clay or sand), its depth profile, cover and moisture content; almost impossible to measure directly. A further complication is that the type of ground will itself vary over large distances of the order of hundreds of kilometres. Today effective ground conductivity is mostly calculated from measurement of the actual attenuation of radio waves propagating over that surface.
However, the level of attenuation required for safe use in sheep and goats is not sufficient for cattle. For this reason the sheeppox and goatpox vaccines are restricted to countries where sheeppox or goatpox is already endemic since the live vaccines could provide a source of infection for the susceptible sheep and goat populations. In order to ensure adequate protection against LSDV, susceptible adult cattle should be vaccinated annually. Approximately, 50% of cattle develop swelling (10–20 mm in diameter) at the site of inoculation.
This method first has the subject listen to tones with headphones and "match" loudness between both ears until tones sound equally loud on both sides. Then an earplug is placed in one ear while the baseline procedure is repeated to match loudness in both ears, then the procedure is repeated a third time so both ears are tested individually with earplugs. This calculates a personal attenuation rating based on the loudness of the sound delivered to the unprotected ear when it matches the protected ear.
During the summer months, specifically in Poland Lemna bloom occurs that reduces light attenuation which reduces photosynthesis efficiency of the Chlorella algae, this influences the asexual behavior. Even though during the beginning of the mating season for the Hydra, all the individuals are sexually active, asexual reproduction is the main strategy for reproduction. This behavior of interference of asexual and sexual reproduction allows population growth to continue throughout all conditions. When the Hydra reproduces asexually, buds will be produced that attach to the body wall.
Growth attenuation is an elective medical treatment which involves administering estrogen to cause closure of the epiphyses of the bones (Epiphyseal plates), resulting in a reduced adult height. Since the 1960s this treatment has been performed primarily on children growing toward an adult height considered unacceptably excessive by their parents and doctors. The cultural consensus of what is considered an excessive height justifying treatment has differed in Europe and North America and has risen over the last 4 decades.Joyce M. Lee and Joel D. Howell.
The thyroid gland is encapsulated by the middle layer of deep cervical fascia and is part of the visceral space in the infrahyoid neck. It wraps around the trachea and is separated from the oesophagus by the tracheoesophageal groove on each side, which houses the recurrent laryngeal nerves. The thyroid has variable lymphatic drainage to the internal jugular chain, para-tracheal region, mediastinum, and retropharyngeal area. It has homogeneous high attenuation values on a CT scan, as compared to adjacent muscles, due to its high iodine concentration.
For the El Chichón cloud, the optical depth has been measured to be around 0.3 around mid-visible wavelengths. The imaginary part of the refractive index, describing the attenuation of radiation for the 80 km sample, varies between 0.004 at 300 nm and 0.001 at 700 nm. Based on these results, the real part of the refractive index of the stratospheric El Chichon ash is estimated around 1.52, while the imaginary part is expected to be slightly less than the one measured for the ground samples.
The law was discovered by Pierre Bouguer before 1729, while looking at red wine, during a brief vacation in Alentejo, Portugal. It is often attributed to Johann Heinrich Lambert, who cited Bouguer's Essai d'optique sur la gradation de la lumière (Claude Jombert, Paris, 1729)—and even quoted from it—in his Photometria in 1760. Lambert's law stated that the loss of light intensity when it propagates in a medium is directly proportional to intensity and path length. Much later, August Beer discovered another attenuation relation in 1852.
Roadway geometrics and surrounding terrain are interrelated, since the propagation of sound is sensitive to the overall geometry and must consider diffraction (bending of sound waves around obstacles), reflection, ground wave attenuation, spreading loss and refraction. A simple discussion indicates that sound will be diminished when the path of sound is blocked by terrain, or will be enhanced if the roadway is elevated so as to broadcast; however, the complexities of variable interaction are so great, that there are many exceptions to this simple argument.
Seismic activity is still ongoing at the edge of the Puna, indicating thrusting. The crust beneath the CVZ is thick. A steepening of the subduction zone during the Late Miocene has been linked to an increase in volcanic activity and its westward migration, but it is unlikely that the pattern of activity in the southern Puna next to the Toro fault zone can be explained through this alone. A large low velocity and low seismic attenuation anomaly is found between 20 and 24° latitude south.
Depending on the application, this may require one or more of the following: a simple proportion (gain or attenuation), an integral (low pass filter) and/or derivative (high pass filter). Loop parameters commonly examined for this are the loop's gain margin and phase margin. Common concepts in control theory including the PID controller are used to design this function. The second common consideration is limiting the amount of reference frequency energy (ripple) appearing at the phase detector output that is then applied to the VCO control input.
Using both ear muffs (whether passive or active) and earplugs simultaneously results in maximum protection, but the efficacy of such combined protection relative to preventing permanent ear damage is inconclusive, with evidence indicating that a combined noise reduction ratio (NRR) of only 36 dB (C-weighted) is the maximum possible using ear muffs and earplugs simultaneously, equating to only a 36 - 7 = 29 dB(A) protection. Some high-end, passive, custom-molded earplugs also have a mechanical filter inserted into the center of the earmolded plug, with a small opening facing to the outside; this design permits being able to hear range commands at a gun range, while still having full rating impulse noise protection. Such custom molded earplugs with low pass filter and mechanical valve typically have a +85 dB(A) mechanical clamp, in addition to having a lowpass filter response, thereby providing typically 30-31 dB attenuation to loud impulse noises, with only a 21 dB reduction under low noise conditions across the human voice audible frequency range (300–4000 Hz) (thereby providing low attenuation between shots being fired), to permit hearing range commands. Similar functions are also available in standardized earplugs that are not custom molded.
In practice, no bandpass filter is ideal. The filter does not attenuate all frequencies outside the desired frequency range completely; in particular, there is a region just outside the intended passband where frequencies are attenuated, but not rejected. This is known as the filter roll-off, and it is usually expressed in dB of attenuation per octave or decade of frequency. Generally, the design of a filter seeks to make the roll-off as narrow as possible, thus allowing the filter to perform as close as possible to its intended design.
The impression is sent to a laboratory to be checked and made into a hearing protector. Formed in place uses the same process to make an impression of the ear canal and outer ear and then turns that impression into the protector. Both types of custom molded earplugs are non-disposable with the laboratory made typically lasting for 3 – 5 years and the formed in place lasting for 1 – 2 years. For the best attenuation and proper fit, the impressions for custom molds must meet a desired criteria by the manufacturer of the mold.
When external sounds exceed an established threshold (typically 82 dBA SPL), the amplification of the electronic circuit is reduced. At very high levels, the amplification is turned off automatically and you receive the full attenuation of the earplug just as if it were turned off and seated in the ear canal. This protects hearing, but allows one to hear normally when sounds are in safe ranges – for example, have a normal conversation in a low-noise situation, but be protected from sudden loud noises, for example at a construction site or a while hunting.
A Chebyshev filter has a faster cut-off transition than a Butterworth, but at the expense of there being ripples in the frequency response of the passband. There is a compromise to be had between the maximum allowed attenuation in the passband and the steepness of the cut-off response. This is also sometimes called a type I Chebyshev, the type 2 being a filter with no ripple in the passband but ripples in the stopband. The filter is named after Pafnuty Chebyshev whose Chebyshev polynomials are used in the derivation of the transfer function.
Australia and New Zealand have different standards for protector ratings yielding a quantity SLC80 (Sound Level Class for the 80th percentile). Canada implements a class system for rating the performance of protectors. Gauger and Berger have reviewed the merits of several different rating methods and developed a rating system that is the basis of a new American National Standard, ANSI S12.68-2007 The various methods have slightly different interpretations, but each method has a percentile associated with the rating. That percent of the users should be able to achieve the rated attenuation.
Common static filter attenuation levels are 9, 15, and 25 dB. This type of plug is quite popular among audio engineers who can safely listen to loud mixes for extended periods of time. However, they can be quite costly, being intended for constant re-use unlike simple earplugs which are disposable. Custom earplugs worn by professional musicians Lead singer of the metal band Sepultura Derrick Green wearing a custom earplug Alternately, musicians may use in-ear monitors, which are essentially headphones that also serve as earplugs by attenuating surrounding sound.
The advantage of TEE over TTE is usually clearer images, especially of structures that are difficult to view transthoracically (through the chest wall). The explanation for this is that the heart rests directly upon the esophagus leaving only millimeters that the ultrasound beam has to travel. This reduces the attenuation (weakening) of the ultrasound signal, generating a stronger return signal, ultimately enhancing image and Doppler quality. Comparatively, transthoracic ultrasound must first traverse skin, fat, ribs and lungs before reflecting off the heart and back to the probe before an image can be created.
Though SeaWiFS was designed primarily to monitor ocean concentrations from space, it also collected many other parameters that are freely available to the public for research and educational purposes. These parameters aside from include reflectance, the diffuse attenuation coefficient, particulate organic carbon concentration (POC), particulate inorganic carbon concentration (PIC), colored dissolved organic matter (CDOM) index, photosynthetically active radiation (PAR), and normalized fluorescence line height (NFLH). In addition, despite being designed to measure ocean chlorophyll, SeaWiFS also estimates Normalized Difference Vegetation Index (NDVI), which is a measure of photosynthesis on land.
Mechanical systems are elevator systems, boilers, refrigeration or air conditioning systems, generators and trash compactors. Aerodynamic sources include fans, pneumatics, and combustion. Noise control for aerodynamic sources include quiet air nozzles, pneumatic silencers and quiet fan technology. Since many mechanical sounds are inherently loud, the principal design element is to require the wall or ceiling assembly to meet certain performance standards,Cyril M. Harris, Noise Control in Buildings: A Practical Guide for Architects and Engineers (1994) (typically Sound transmission class of 50), which allows considerable attenuation of the sound level reaching occupants.
Frequencies more than 1.5 GHz are well suited for FBAR devices. Because FBARs on a silicon substrate can be manufactured in high volumes and is supported by all development of semiconductor device fabrication methods. Future requirements of new applications like filtering bandwidth with steep stopband attenuation have effects on resonator performance and show development steps needed. FBARs can be used by oscillators and synchronizers to replace a crystal/crystals in applications where frequencies more than 100 MHz and/or very low jitter is one of the performance targets.
The formal process of Ylem is notated verbally . It requires a great deal of imagination from performers but is very simple in conception, consisting of the very slow attenuation and compression of a galaxy of musical points (Maconie 2005, 348). At the beginning, ten of the mobile performers stand close to the piano. After an initial explosive sound (on E and A in the London version) these ten players move out into the hall, playing all the while, and take up positions around the audience, while the other players remain on the stage.
If the pulse hits gases or solids, the density difference is so great that most of the acoustic energy is reflected and it becomes impossible to see deeper. The frequencies used for medical imaging are generally in the range of 1 to 18 MHz. Higher frequencies have a correspondingly smaller wavelength, and can be used to make sonograms with smaller details. However, the attenuation of the sound wave is increased at higher frequencies, so in order to have better penetration of deeper tissues, a lower frequency (3–5 MHz) is used.
Consequently, there are other adjustments for completing the compensation.; Tek claims 300 MHz resistive coax at 30 pF per meter; schematic has 5 adjustments. Probes with 10:1 attenuation are by far the most common; for large signals (and slightly-less capacitive loading), 100:1 probes may be used. There are also probes that contain switches to select 10:1 or direct (1:1) ratios, but the latter setting has significant capacitance (tens of pF) at the probe tip, because the whole cable's capacitance is then directly connected.
Ten Commandments, HarperCollins Bible Dictionary, 1996, Achtemeier Paul J., ed., New York:HarperCollins Publishers, , p.1109; Names of God in the OT: Attenuation of the Divine Name, in The Anchor Bible Dictionary, Freedman, D.N., editor-in-chief, New York: Doubleday, 1992, , p. 1010 Hebrew Bible passages also refer to God's name being profaned by hypocritical behavior of people and false representation of God's words or character.See for examples Leviticus 18:21, 20:3, 21:6; Isaiah 48:1–2; Jeremiah 5:1–2, 7:9–15; Matthew Henry's Commentary on the Whole Bible, Vol.
Observe that the atmosphere comes between the radiation source and the target, and between the target and the sensor. Depending on the type of radiation and sensor in use, the atmosphere can have little interfering effect, or have a tremendous effect requiring extensive engineering to overcome. First, the atmosphere may absorb part of the energy passing through it. This is bad enough for sensing if all wavelengths are affected evenly, but it becomes much more complex when the radiation is of multiple wavelengths, and the attenuation differs among wavelengths.
The flow of the river has decreased in power in recent years, partly because of surface run-off in the upper catchment of the Hazel Brook, especially from the large retail centre at Cribbs Causeway. The run-off sends a good deal of silt into the system, slowing the flow and creating a risk of flooding downstream. This problem has now been partially alleviated by the construction of the Catbrain attenuation reservoir near Cribbs Causeway. Measurements of pollution by the city council show the water to be relatively clean.
Note that the steeper green and red regression estimates are more consistent with smaller errors in the y-axis variable. In the case when some regressors have been measured with errors, estimation based on the standard assumption leads to inconsistent estimates, meaning that the parameter estimates do not tend to the true values even in very large samples. For simple linear regression the effect is an underestimate of the coefficient, known as the attenuation bias. In non-linear models the direction of the bias is likely to be more complicated.
In 1977, Jöbsis reported that brain tissue transparency to NIR light allowed a non-invasive and continuous method of tissue oxygen saturation using transillumination in neonates. Transillumination (forward-scattering) was of limited utility in adults because of light attenuation and was quickly replaced by reflectance-mode based techniques - resulting in development of NIRS systems proceeding rapidly. Then, by 1985, the first studies on cerebral oxygenation were conducted by M. Ferrari. Later, in 1989, following work with David Delpy at University College London, Hamamatsu developed the first commercial NIRS system: NIR-1000 Cerebral Oxygenation Monitor.
The purpose of XP is provide an on-orbit cross-calibration for the X123: the sum of the X123 spectrum should be approximately equal to the XP measurement. SPS is a fine sun sensor with 2.4 arcsec precision that consists of a planar quad-diode observing visible light, whose purpose is to provide fine knowledge of the solar position with respect to the X123 and XP optical axes to correct for any off-axis signal attenuation. All instruments were calibrated at the National Institute of Standards and Technology's Synchrotron Ultraviolet Radiation Facility (SURF III).
Below the Altiplano, low-velocity zones indicate the presence of large amounts of partial melts that correlate with volcanic zones south of 21° S, whereas north of 21° S thicker lithospheric layers may prevent the formation of melts. Next to the Eastern Cordillera, low-velocity zones extend farther north to 18.5° S. A thermally weakened zone, evidenced by strong attenuation, in the crust is associated with the APVC. This indicates the presence of melts in the crust. A layer of low velocity (shear speed of ) thick is assumed to host the APVC magma body.
This energy, while given off quite early, does not usually cause damage. It is also the ElarmS that are responsible for roughly estimating the geographical location and size of the earthquake. Following these Elarms, empirical attenuation relations estimate how much the earth will shake in the specified region of the quake. In December 2014, $5 million was added to the USGS budget for ShakeAlert development. This enabled USGS to purchase $1 million in seismic instrumentation and award $4 million in funding to the project partners to make current "ShakeAlert" demonstration system more robust.
B. bruxellensis plays a key role in the production of the typical Belgian beer styles such as Lambic, Flanders red ales, Gueuze, Kriek, and Orval, and is part of spontaneous fermentation biota. It is naturally found in the brewery environment living within oak barrels that are used for the storage of beer during the secondary conditioning stage. Here it completes the long slow fermentation or super-attenuation of beer, often in symbiosis with Pediococcus sp. Macroscopically visible colonies look whitish and show a dome-shaped aspect, depending on the age and size.
In principle, by avoiding attenuation of HSV replication in the mucosa while removing the capacity to infect the nervous system, non-invasive vaccines have the potential to break the safety-efficacy dilemma by producing the strongest possible immune response while maintaining a high degree of safety. The VC2 non-invasive vaccine was developed by Dr. Gus Kousoulas at Louisiana State University. VC2 encodes two attenuating mutations that together reduce HSV entry into neurons. The establishment of latency is prevented in animal models such as mice, guinea pig, and rhesus monkeys.
Gamma spectroscopy yields results that are conceptually equivalent to alpha-particle spectroscopy, however, can result in sharper peaks due to reduced attenuation of energy. Some radionuclides produce discrete γ-rays that produce energy between a few KeV to 10 MeV which can be measured with a gamma-ray spectrometer. This can be accomplished without destroying the sample. The most common gamma-ray detector is a semiconductor germanium detector which allow for a greater energy resolution than alpha-particle spectroscopy, however gamma spectroscopy only has an efficiency of a few percent.
A tester and analyzer for twisted pair and fiber optic cables. BNC and twisted pair cabling A cable tester is an electronic device used to verify the electrical connections in a signal cable or other wired assembly. Basic cable testers are continuity testers that verify the existence of a conductive path between ends of the cable, and verify the correct wiring of connectors on the cable. More advanced cable testers can measure the signal transmission properties of the cable such as its resistance, signal attenuation, noise and interference.
More powerful cable testers can measure the properties of the cable relevant to signal transmission. These include the DC resistance of the cable, the loss of signal strength (attenuation) of a signal at one or more frequencies, and a measure of the isolation between multiple pairs of a multi-pair cable or crosstalk. While these instruments are several times the cost and complexity of basic continuity testers, these measurements may be required to certify that a cable installation meets the technical standards required for its use, for example, in local area network cabling.
In radiology, the halo sign is a finding of a dark halo around the arterial lumen on ultrasound that suggests the diagnosis of temporal arteritis. The standard diagnostic test for temporal arteritis is biopsy; however, ultrasound and MRI show promise for replacing it. The halo sign of temporal arteritis should not be confused with Deuel's halo sign, which is a sign of fetal death. The halo sign is also understood as a region of ground-glass attenuation surrounding a pulmonary nodule on an X-ray computed tomography (CT scan) of the chest.
AM broadcasting stations use ground waves to cover their listening areas. As the frequency gets lower, the attenuation with distance decreases, so very low frequency (VLF) and extremely low frequency (ELF) ground waves can be used to communicate worldwide. VLF and ELF waves can penetrate significant distances through water and earth, and these frequencies are used for mine communication and military communication with submerged submarines. At medium wave and shortwave frequencies (MF and HF bands) radio waves can refract from a layer of charged particles (ions) high in the atmosphere, called the ionosphere.
The presented plots of image impedance, attenuation and phase change correspond to a low-pass prototype filter section. The prototype has a cut-off frequency of ωc = 1 rad/s and a nominal impedance k = 1 Ω. This is produced by a filter half-section with inductance L = 1 henry and capacitance C = 1 farad. This prototype can be impedance scaled and frequency scaled to the desired values. The low-pass prototype can also be transformed into high-pass, band-pass or band-stop types by application of suitable frequency transformations.
Elimination or reduction of the source of noise or chemical exposure is ideal, but when that is not possible or adequate, wearing personal protective equipment (PPE) such as earplugs or earmuffs can help reduce the risk of hearing loss due to noise exposure. PPE should be a last resort and not be used in substitution for engineering or administrative controls. It is important that workers are properly trained on the use of PPE to ensure proper protection. A personal attenuation rating can be objectively measured through a hearing protection fit-testing system.
Optical tomography relies on the object under study being at least partially light-transmitting or translucent, so it works best on soft tissue, such as breast and brain tissue. The high scatter-based attenuation involved is generally dealt with by using intense, often pulsed or intensity modulated, light sources, and highly sensitive light sensors, and the use of infrared light at frequencies where body tissues are most transmissive. Soft tissues are highly scattering but weakly absorbing in the near-infrared and red parts of the spectrum, so that this is the wavelength range usually used.
Tracts of wild flowers and grassed areas close to the building act as supplementary 'coolants' for fresh air being drawn in at basement level during the summer; and for fuel for The Hive's biomass boiler, a large plantation of willows has been established alongside the building. To act as flood attenuation, two water meadows are situated along the western elevation of the new building. These have been planted with a range of native wildflower species, based on communities found locally in traditional lammas meadows. Worcestershire’s county flower, the cowslip, is planted throughout.
In physics, absorption of electromagnetic radiation is the way by which the energy of a photon is taken up by matter, typically the electrons of an atom. Thus, the electromagnetic energy is transformed to other forms of energy, for example, to heat. The absorption of light during wave propagation is often called attenuation. Usually, the absorption of waves does not depend on their intensity (linear absorption), although in certain conditions (usually, in optics), the medium changes its transparency dependently on the intensity of waves going through, and the Saturable absorption (or nonlinear absorption) occurs.
Because of the photon nature of X-rays, intensity measurements inevitably contain shot noise, which follows a Poisson distribution. Other types of noise, like detector noise or electrical noise can also contribute to fluctuations of the measured X-ray signal but do not provide information about the studied sample. In comparison, X-ray intensity changes arising from the alteration of attenuation carry important motion information. Statistical analysis of the data allows correction for the known noise sources to ascertain changes that result from movements within the sample or patient.
Beams may encounter losses as they travel through materials which will cause attenuation of the beam intensity. A property common to non- diffracting (or propagation-invariant) beams, such as the Airy beam and Bessel beam, is the ability to control the longitudinal intensity envelope of the beam without significantly altering the other characteristics of the beam. This can be used to create Bessel beams which grow in intensity as they travel and can be used to counteract losses, therefore maintaining a beam of constant intensity as it propagates.
In this way, the Near Infrared (NIR) band is mostly used in fiber optic telecommunication systems since silica (SiO2) provides a low attenuation losses medium for the infrared, whilst the Short Wave Infrared (SWIR) band allows to work on long-distance telecommunications (remote sensing) using a combinations of detector materials. The Medium Wavelength Infrared (MWIR) and the Long Wavelength Infrared (LWIR) bands find applications in Infrared Thermography for military or civil applications, e.g. target signature identification, surveillance, NonDestructive Evaluation, etc. The Very Long Wavelength Infrared (VLWIR) band is used in spectroscopy and astronomy.
Brain MRI is the mainstay of initial investigation pointing to limbic lobe pathology revealing increased T2 signal involving one or both temporal lobes in most cases. Serial MRI in LE starts as an acute disease with uni- or bilateral swollen temporomesial structures that are hyperintense on fluid attenuation inversion recovery and T2-weighted sequences. Swelling and hyperintensity may persist over months to years, but in most cases progressive temporomesial atrophy develops. PET-CT is not an essential investigation but can help in suspected cases with MRI negative for early diagnosis.
There Braude continued work on radio-location equipment, particularly the Rubin, a further improvement of the Zenit. He also continued his studies under Slutskin, being awarded the higher D.Sc. degree in 1943. He was given the title of Professor in 1944. The preliminary testing of Rubin turned up a previously unreported phenomena in radio-signal propagation, later called surface or atmospheric ducting, resulting in a major decrease in signal attenuation; Braude initiated studies in this area. Following the war, the LEMO returned to Kharkiv in mid-1945, remaining independent of the UPTI.
Throughout the early and late 1990s, several mobile radar concepts came to be, often involving high frequency X-band radars which suffer significant attenuation, and often lack in range. Ideally, these radars would serve as research and observation platforms, covering regions scarcely covered by the NEXRAD network as a whole. One such concept later went on to become the Doppler On Wheels, now a fleet of 3 operational vehicles. In order to counteract the problems previously described with high frequency radars, two decommissioned WSR-74 radars, originally used for local warnings, were acquired by TAMU.
The dose rate measured from 10mm away will be two orders of magnitude lower than the measured surface dose rate. Given that the half-value thickness of 10 keV photon radiation in water is about 0.14 cm, the attenuation provided by tissue overlaying blood-forming organs is considerable. The primary danger from tritium arises if it is inhaled, ingested, injected, or absorbed into the body. This results in the absorption of the emitted radiation in a relatively small region of the body, again due to the low penetration depth.
If the signal passes through a capacitor, or has a path to ground through an inductor, then the filter presents less attenuation to high-frequency signals than low-frequency signals and therefore is a high-pass filter. Resistors on their own have no frequency- selective properties, but are added to inductors and capacitors to determine the time-constants of the circuit, and therefore the frequencies to which it responds. The inductors and capacitors are the reactive elements of the filter. The number of elements determines the order of the filter.
MSOT provides anatomical, dynamic and molecular information, but quantifying the features of MSOT images is not straightforward because constituents of the target tissue absorb and scatter the illuminating light. As a result, the illuminating light is attenuated as one moves deeper into the tissue, and the extent of attenuation depends on wavelength. The measured spectral signature of photoabsorbers inside tissue may therefore differ from the absorption spectrum of the same molecule measured inside the cuvette of a spectrophotometer. This discrepancy, termed "spectral coloring", depends on the number and types of photoabsorbers in the propagation path.
Modern digital telephone systems have less trouble in the voice frequency range as only the local line to the subscriber now remains in analog format, but DSL circuits operating in the MHz range on those same wires may suffer severe attenuation distortion, which is dealt with by automatic equalization or by abandoning the worst frequencies. Picturephone circuits also had equalizers. In digital communications, the equalizer's purpose is to reduce intersymbol interference to allow recovery of the transmit symbols. It may be a simple linear filter or a complex algorithm.
Unenhanced CT or MRI usually does not show the difference in intensity between the FNH and surrounding liver except when there is marked liver steatosis that reduces the attenuation of the liver, causing FNH to be hyperattenuating when compared with the surrounding liver. In the arterial phase CT or MRI, there is a strong enhancement not followed by washout. The lesion presents a slight hyperintensity or isodensity on portal venous phase or delayed phase images. There is also a presence of a central scar and absence of a capsule for the FNH.
More over, the ribosome is proposed to only block about 10 nts downstream, thus ribosome stalling in either the upstream Gly or further downstream Thr do not seem to affect the formation of the termination hairpin. The end result is that the operon will be transcribed only when tryptophan is unavailable for the ribosome, while the trpL transcript is constitutively expressed. This attenuation mechanism is experimentally supported. First, the translation of the leader peptide and ribosomal stalling are directly evidenced to be necessary for inhibiting the transcription termination.
DNA strand breaks accumulate in long term hematopoietic stem cells during aging. This accumulation is associated with a broad attenuation of DNA repair and response pathways that depends on HSC quiescence. Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. NHEJ is referred to as "non-homologous" because the break ends are directly ligated without the need for a homologous template. The NHEJ pathway depends on several proteins including ligase 4, DNA polymerase mu and NHEJ factor 1 (NHEJ1, also known as Cernunnos or XLF).
One incarnation of Bode's filter as a low-pass filter. Another variation on the m-type filter was described by Hendrik Bode. This filter uses as a prototype a mid-series m-derived filter and transforms this into a bridged-T topology with the addition of a bridging resistor. This section has the advantage of being able to place the pole of attenuation much closer to the cut-off frequency than the Zobel filter, which starts to fail to work properly with very small values of m because of inductor resistance.
A seismic metamaterial, is a metamaterial that is designed to counteract the adverse effects of seismic waves on artificial structures, which exist on or near the surface of the earth. Current designs of seismic metamaterials utilize configurations of boreholes, trees or proposed underground resonators to act as a large scale material. Experiments have observed both reflections and bandgap attenuation from artificially induced seismic waves. These are the first experiments to verify that seismic metamaterials can be measured for frequencies below 100 Hz, where damage from Rayleigh waves is the most harmful to artificial structures.
MPEG Surround coding uses our capacity to perceive sound in the 3D and captures that perception in a compact set of parameters. Spatial perception is primarily attributed to three parameters, or cues, describing how humans localize sound in the horizontal plane: Interaural level difference (ILD), Interaural time difference (ITD) and Interaural coherence (IC). This three concepts are illustrated in next image. Direct, or first-arrival, waveforms from the source hit the left ear at time, while direct sound received by the right ear is diffracted around the head, with time delay and level attenuation, associated.
Spinning wool is a different process as the variable lengths of the individual fibres means that they are unsuitable for attenuation by roller drafting. For this reason, woolen fibres are carded using condenser cards which rub the carded fibres together rather than drafting them. They are then spun on mule-type machines which have no roller drafting, but create the draft by the spindles receding from the delivery rollers whilst that latter, having paid out a short length of roving, are held stationary. Such mules are often complex involving multiple spindles speeds, receding motions, etc.
The layer principal overcomes any acoustic or sound transfer issues. In Stadthaus an economic layering strategy of stud walls, floating floor build-ups and suspended ceilings, gave sound attenuation far in excess of building regulations (58 - 60db). In a fire, a solid wall of timber benefits from the protection of a charred layer and therefore does not combust in the same way as a single stud. In Stadthaus, five-layer cross-laminated timber panels are used to obtain a fire protection that allows the structure to retain its integrity for at least 90 minutes.
The microelectrodes used by Katz and his contemporaries pale in comparison to the technologically advanced recording techniques available today. Spatial summation began to receive a lot of research attention when techniques were developed that allowed the simultaneous recording of multiple loci on a dendritic tree. A lot of experiments involve the use of sensory neurons, especially optical neurons, because they are constantly incorporating a ranging frequency of both inhibitory and excitatory inputs. Modern studies of neural summation focus on the attenuation of postsynaptic potentials on the dendrites and the cell body of a neuron.
These interactions are said to be nonlinear, because the response is less than the sum of the individual responses. Sometimes this can be due to a phenomenon caused by inhibition called shunting, which is the decreased conductance of excitatory postsynaptic potentials. Shunting inhibition is exhibited in the work of Michael Ariel and Naoki Kogo, who experimented with whole cell recording on the turtle basal optic nucleus. Their work showed that spatial summation of excitatory and inhibitory postsynaptic potentials caused attenuation of the excitatory response during the inhibitory response most of the time.
Hull's experiments showed the reality of some classical phenomena such as mentally induced pain reduction and apparent inhibition of memory recall. However, Hull's work indicated that these effects could be achieved without hypnosis being considered as a distinct state, but rather as a result of suggestion and motivation, which was a forerunner of the behavioral study of hypnosis. Similarly, moderate increases of certain physical capacities and changes to the threshold of sensory stimulation could be induced psychologically; attenuation effects could be especially dramatic. After moving to Yale, his work in hypnosis quickly encountered resistance.
Fiber-optics allow for fast data speeds and large bandwidth, they suffer relatively little attenuation, allowing them to cover long distances with few repeaters, and they are also immune to crosstalk and other forms of electromagnetic interference which plague electrical transmission. The real-time routing protocols and redundancy built into the backbone is also able to reroute traffic in case of a failure. The data rates of backbone lines have increased over time. In 1998, all of the United States' backbone networks had utilized the slowest data rate of 45 Mbit/s.
Hardware mixing is a performance feature of computer audio hardware which enables sound cards to receive multiple audio streams and play them all at the same time. Hardware mixing improves performance by offloading audio mixing operations from the CPU and performing them on dedicated hardware. In addition to mixing, the hardware performs related operations such as sample rate conversion (SRC), attenuation, and, optionally, 3D processing that would otherwise need to be performed in software. On Microsoft Windows, hardware mixing is also referred to as hardware buffering or as DirectSound hardware acceleration.
Fogging phenomenon in computerized tomography (CT) scanning of the head is vanishing signs of an infarct on the serial CT imaging in a patient with a recent stroke. It is a reversal of the hypodensity on the CT after an acute ischemic stroke. This happens as a result of re-nourishment of the infarcted area in subacute phase about one to three weeks after the stroke. In fact, resolution of the edema, which was caused by the accident, leads to increased attenuation of infarcted area that may regain near-normal density and mask the stroke.
The IEEE K band is a portion of the radio spectrum in the microwave range of frequencies from 18 to 27 gigahertz (GHz). The range of frequencies in the center of the K band between 18 and 26.5 GHz is absorbed by water vapor in the atmosphere due to its resonance peak at 22.24 GHz, 1.35 cm. Therefore these frequencies experience high atmospheric attenuation and cannot be used for long distance applications. For this reason the original K band has been split into three bands, Ka band, K-band, and Ku band as detailed below.
The River Nene flows past the village close by to the north, through an old, narrow bridge - narrow, that is, for both vehicles and the river which frequently floods. The most recent serious incident in 1998 caused flood damage to several houses in the village. Some flood attenuation work has since been carried out but it remains to be seen if this proves adequate. The village carries heavy traffic being on a route to the larger village of Bugbrooke with the large Campion Secondary School which serves the village and a large catchment area around.
This comes at the cost of sensitivity. For example, distinguishing iron from argon requires a resolving power of about 10,000, which may reduce the iron sensitivity by around 99%. A single collector ICP-MS may use a multiplier in pulse counting mode to amplify very low signals, an attenuation grid or a multiplier in analogue mode to detect medium signals, and a Faraday cup/bucket to detect larger signals. A multi-collector ICP-MS may have more than one of any of these, normally Faraday buckets which are much less expensive.
Lattice filter topology A lattice phase equaliser or lattice filter is an example of an all-pass filter. That is, the attenuation of the filter is constant at all frequencies but the relative phase between input and output varies with frequency. The lattice filter topology has the particular property of being a constant-resistance network and for this reason is often used in combination with other constant resistance filters such as bridge-T equalisers. The topology of a lattice filter, also called an X-section is identical to bridge topology.
A single frame from a real-time MRI (rt-MRI) movie of a human heart. a) direct reconstruction b) iterative (nonlinear inverse) reconstruction The advantages of the iterative approach include improved insensitivity to noise and capability of reconstructing an optimal image in the case of incomplete data. The method has been applied in emission tomography modalities like SPECT and PET, where there is significant attenuation along ray paths and noise statistics are relatively poor. Statistical, likelihood-based approaches: Statistical, likelihood-based iterative expectation-maximization algorithms are now the preferred method of reconstruction.
The gas stream (frequently ambient air) passes through a filter material which traps the suspended particulates, creating a deposit of increasing density. A light beam projected through the deposit is attenuated by those particles which are absorbing (‘black’) rather than scattering (‘white’). Measurements are made at successive regular time intervals. The increase in attenuation from one measurement to the next is proportional to the increase in the density of optically absorbing material on the filter: which, in turn, is proportional to the concentration of the material in the sampled air stream.
The Dynamic Insertion loss of a sound attenuator is the amount of attenuation, in decibels, provided by the silencer under flow conditions. While flow conditions in typical low velocity duct systems rarely exceed 2000-3000 ft/min, sound attenuators for steam vents must withstand airflow velocities in the 15,000-20,000 ft/min. range. The acoustic performance of a sound attenuator is tested over a range of airflow velocities, and for forward and reverse flow conditions. Forward flow is when the air and sound waves propagate in the same direction.
Where sound attenuator dimensions differ from surrounding duct dimensions, transitions to and from the sound attenuator should be smooth and gradual. Abrupt transitions cause the pressure drop and regenerated noise to significantly increase. The pressure drop through a sound attenuator is typically higher than the pressure drop for an equivalent length of lined duct. However, significantly longer lengths of lined duct are required to achieve equal attenuation, at which point the pressure drop of large extents of lined duct is significantly greater than incurred through a single sound attenuator.
He earned a BSE in engineering physics in 1949 and an MS in physics in 1950 from the University of Michigan. He was author or co-author of over one hundred publications including the "Radiation Physics" article in the 2002 Encyclopedia of Physical Science and Technology. He was past editor of Applied Radiation and Isotopes and consulting editor of Radiation Physics and Chemistry. In the scientific community, Mr. Hubbell is known for his evaluations, computations and compilations of photon cross sections and attenuation (and energy-absorption) coefficients used in medicine, engineering and other disciplines.
This gamma LET has little relation to the attenuation rate of the beam, but it may have some correlation to the microscopic defects produced in the absorber. It must be noted that even a monoenergetic gamma beam will produce a spectrum of electrons, and each secondary electron will have a variable LET as it slows down, as discussed above. The "gamma LET" is therefore an average. The transfer of energy from an uncharged primary particle to charged secondary particles can also be described by using the mass energy-transfer coefficient.
One of the important results of the work on loading coils was that the loading caused a cut-off at a definite frequency in the line response, whose value could be predicted with a knowledge of the line capacitance and coil inductance and the spacing between coils. An unloaded continuous line has no such behavior, the attenuation simply steadily increased with frequency. This behavior, and the lumped-element networks being used to create artificial lines for test purposes, suggested to Campbell a possible topology for a filter with similar characteristics.Brittain, p.
During the above-mentioned motion (that is pivoting around the object(1)) of parallel beam irradiation optical system, the collimated X-ray source (2) emits transmission beam (4) which are effectively “parallel rays” in a geometrical optical sense. The traveling direction of each ray of the transmission beam (4) is parallel to the t-axis. The transmission beam (4), emitted by the X-ray source (2), penetrates the object and reaches the screen (3) after attenuation due to absorption by the object. Optical transmission can be presumed to occur ideally.
Apple redesigned the antenna in the CDMA after some original iPhone 4 users reported cellular signal attenuation problems as a result of holding the phone in certain positions. The improved cellular radio in the phone can switch between two antennas, depending on which is sending/receiving the best signal. These two antennas are incorporated into the distinctive stainless steel band that wraps around the sides of the . The bands on the iPhone 4S are divided into two antennas: cellular and Global Positioning System GPS, with Bluetooth and Wi-Fi reliant on an internal antenna.
From 5% to 20% of rain fade or satellite signal attenuation may also be caused by rain, snow, or ice on the uplink or downlink antenna reflector, radome, or feed horn. Rain fade is not limited to satellite uplinks or downlinks, as it can also affect terrestrial point-to-point microwave links (those on the earth's surface). Rain fade is usually estimated experimentally and also can be calculated theoretically using scattering theory of rain drops. Raindrop size distribution (DSD) is an important consideration for studying rain fade characteristics.
2, Macmillan and Co, NY, second edition, 1896, first edition, 1878. There have been hundreds of papers studying ultrasound propagation through fluid particulates in the 20th century.Dukhin, A. S. and Goetz, P. J. Characterization of liquids, nano- and micro- particulates and porous bodies using Ultrasound, Elsevier, 2017 It turns out that instead of measuring scattered energy versus angle, as with light, in the case of ultrasound, measuring the transmitted energy versus frequency is a better choice. The resulting ultrasound attenuation frequency spectra are the raw data for calculating particle size distribution.
It can be measured for any fluid system with no dilution or other sample preparation. This is a big advantage of this method. Calculation of particle size distribution is based on theoretical models that are well verified for up to 50% by volume of dispersed particles on micron and nanometer scales. However, as concentration increases and the particle sizes approach the nanoscale, conventional modelling gives way to the necessity to include shear-wave re-conversion effects in order for the models to accurately reflect the real attenuation spectra.
The attenuation of ELF waves is so low that they can travel completely around the Earth several times before decaying to negligible amplitude, and thus waves radiated from a source in opposite directions circumnavigating the Earth on a great circle path interfere with each other.Barr, et al (2000) ELF and VLF radio waves, p. 1700-1701 At certain frequencies these oppositely directed waves are in phase and add (reinforce), causing standing waves. In other words, the closed spherical Earth-ionosphere cavity acts as a huge cavity resonator, enhancing ELF radiation at its resonant frequencies.
Aug 12, 2013,Park Electrochemical Corp introduced its new NL9000 RF/Microwave electronics materials products with a dissipation factor (“Df”) of 0.0017 at 10 GHz using stripline testing methodology and a 0.5dB/cm attenuation loss at 77 GHz for microstrip automotive radar applications. The new series meets UL 94V-0 and IPC-4103 specifications and are RoHS compliant. July 22, 2013, After its successful applications of SIGMA STRUT, Park introduced ALPHA STRUT, new proprietary composite strut design for aircraft and other aerospace applications. These two technologies improve weight savings and load carrying reliability.
A nuclear level gauge or gamma ray gauge measures level by the attenuation of gamma rays passing through a process vessel. The technique is used to regulate the level of molten steel in a continuous casting process of steelmaking. The water-cooled mold is arranged with a source of radiation, such as cobalt-60 or caesium-137, on one side and a sensitive detector such as a scintillation counter on the other. As the level of molten steel rises in the mold, less of the gamma radiation is detected by the sensor.
The metal layers are grounded to dissipate any electric currents generated from external or internal electromagnetic fields, and thus they block a large amount of the electromagnetic interference. See also electromagnetic shielding. They provide less attenuation of outgoing transmissions than incoming: they can block EMP waves from natural phenomena very effectively, but a tracking device, especially in upper frequencies, may be able to penetrate from within the cage (e.g., some cell phones operate at various radio frequencies so while one cell phone may not work, another one will).
In NTSC and PAL transmissions, the color TV signal can be represented as: :E(t) = E_y(t)+ a_1\cdot(E_b(t)-E_y(t))\cdot \sin(\omega t)+ a_2\cdot(E_r(t)-E_y(t))\cdot \cos(\omega t) In this equation a_1 and a_2 are attenuation factors, E_y is the luminance signal, (E_b-E_y) and (E_r-E_y) are the so-called color difference signals and \omega is the angular frequency of the color carrier. \omega is within the luminance bandwidth.For more complete equation see Reference Data for Radio Engineers, Howard W. Sams Co, , pp. 30–14.
VDSL is capable of supporting applications such as high- definition television, as well as telephone services (voice over IP) and general Internet access, over a single physical connection. VDSL2 (ITU-T G.993.2) is a second-generation version and an enhancement of VDSL. Approved in February 2006, it is able to provide data rates exceeding 100 Mbit/s simultaneously in both the upstream and downstream directions. However, the maximum data rate is achieved at a range of about 300 meters and performance degrades as distance and loop attenuation increases.
ASTM Standard E336 Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings is used to conduct field measurements of STL. Standard methodology, laboratory precision and accuracy, and manufacturing standards have changed over the years. Therefore, the STL and STC ratings cited in past publications may not accurately represent the sound isolation performance of products and assemblies today. Basing expectations of STL and STC performance on current test data is necessary because building designers and engineers rely on this information to meet building code and other requirements.
Ground waves must be vertically polarized (the electric field is vertical while the magnetic field is horizontal), so vertical monopole antennas are used for transmitting. The attenuation of signal strength with distance by absorption in the ground is lower than at higher frequencies. Low frequency ground waves can be received up to from the transmitting antenna. Low frequency waves can also occasionally travel long distances by reflecting from the ionosphere (the actual mechanism is one of refraction), although this method, called skywave or "skip" propagation, is not as common as at higher frequencies.
Following the decision Smith threatened to close Charlotte Motor Speedway and build a track elsewhere in Metrolina. When asked if he would go through with the threat Smith replied "I am deadly serious". After a month of negotiations, the issue was settled and, instead of the speedway closing, Smith announced $200 million worth of improvements including road and highway improvements, as well as noise attenuation for the drag strip. The drag strip officially opened on August 20, 2008, and a public open house was held a few days later.
Although radiographs provide higher spatial resolution, CT can detect more subtle variations in attenuation of X-rays (higher contrast resolution). CT exposes the patient to significantly more ionizing radiation than a radiograph. Spiral multidetector CT uses 16, 64, 254 or more detectors during continuous motion of the patient through the radiation beam to obtain fine detail images in a short exam time. With rapid administration of intravenous contrast during the CT scan, these fine detail images can be reconstructed into three-dimensional (3D) images of carotid, cerebral, coronary or other arteries.
During this process (electron transport chain) the electron donor is oxidized and the electron acceptor is reduced. Petroleum hydrocarbons, less chlorinated solvents like vinyl chloride, soil organic matter, and reduced inorganic compounds are all compounds that can act as electron donors. These reactions are of interest not only because they allow organisms to obtain energy, but also because they are involved in the natural biodegradation of organic contaminants. When clean-up professionals use monitored natural attenuation to clean up contaminated sites, biodegradation is one of the major contributing processes.
The primary objective is balancing the frequency content of near and far stacks, while correcting for the effect of the attenuation over the overburden. AVO is used to detect the existence of oil reservoirs because of the anomaly evident in oil reservoirs where AVO rising is prominent in oil-rich sediments. It is not as useful in defining the rock formations and permeability properties to improve sweep efficiency. Furthermore, not all oil reservoirs manifest the same anomalies associated with hydrocarbon oil reservoirs since they are sometimes caused by residual hydrocarbons from breached columns of gas.
Scuba diver with bifocal lenses fitted to a mask Underwater, things are less visible because of lower levels of natural illumination caused by rapid attenuation of light with distance passed through the water. They are also blurred by scattering of light between the object and the viewer, also resulting in lower contrast. These effects vary with wavelength of the light, and color and turbidity of the water. The vertebrate eye is usually either optimised for underwater vision or air vision, as is the case in the human eye.
Example: let Kr = 0.5 for a set of surfaces. Then from the first surface the maximum contribution is 0.5, for the reflection from the second: 0.5 × 0.5 = 0.25, the third: 0.25 × 0.5 = 0.125, the fourth: 0.125 × 0.5 = 0.0625, the fifth: 0.0625 × 0.5 = 0.03125, etc. In addition we might implement a distance attenuation factor such as 1/D2, which would also decrease the intensity contribution. For a transmitted ray we could do something similar but in that case the distance traveled through the object would cause even faster intensity decrease.
The physical (PHY) layer in 802.11af is based on the orthogonal frequency division multiplexing (OFDM) scheme specified in 802.11ac.Broadcast TV&Radio;(DVB-T, Digital Radio Mondiale) also uses OFDM in this band. The propagation path loss as well as the attenuation by materials such as brick and concrete is lower in the UHF and VHF bands than in the 2.4 and 5 GHz bands, which increases the possible range compared to 802.11 a/b/g/n/ac. The frequency channels are 6 to 8 MHz wide, depending on the regulatory domain.
APR is commonly measured using the pulsed echo technique at high sound frequencies of the order 100 MHz – 100 GHz. Two opposite sides of a studied crystal are mirror polished and made parallel to each other, and a piezoelectric crystal is attached to one side. It generates an ultrasound wave which is detected after multiple bouncing between the flat sides, and the signal attenuation serves as the measure of the resonant absorption. The crystal is located inside the magnet capable of providing static field corresponding to the applied frequency.
However, it should be stressed that the addition of late arterial phase images is only indicated if one of these tumors is suspected, or if there is a need for further characterization of a hepatic mass, since the large majority of patients will not benefit from the addition of this phase. In addition, if there is a need to definitively characterize a hepatic mass, MRI is generally more sensitive and specific, with no associated radiation dose. Transient hepatic attenuation differences in the arterial phase may mimic diseases of the liver.
In the United States, frequencies from 31.0 through 31.3 GHz are also considered LMDS frequencies. Throughput capacity and reliable distance of the link depends on common radio link constraints and the modulation method used - either phase-shift keying or amplitude modulation. Distance is typically limited to about due to rain fade attenuation constraints. Deployment links of up to 5 miles (8 km) from the base station are possible in some circumstances such as in point-to-point systems that can reach slightly farther distances due to increased antenna gain.
These radars will subdivide the large area of the NEXRAD into smaller domains to look at altitudes below its lowest angle. These will give details not currently available. Using 3 cm radars, the antenna of each radar is small (about 1 meter diameter) but the resolution is similar at short distance to that of NEXRAD. The attenuation is significant due to the wavelength used but each point in the coverage area is seen by many radars, each viewing from a different direction and compensating for data lost from others.
Radio amateurs in some countries have been granted permission (or have assumed permission) to operate at frequencies below 8.3 kHz. Radiated power from amateur stations is very small, ranging from 1 μW to 100 μW for fixed base station antennas, and up to 10 mW from kite or balloon antennas. Despite the low power, stable propagation with low attenuation in the earth- ionosphere cavity enable very narrow bandwidths to be used to reach distances up to several thousand km. The modes used are QRSS, MFSK, and coherent BPSK.
The characteristics of the traveling ultrasound energy greatly depend on the medium that it is traveling through. While ultrasound waves propagate through a medium, the amplitude of the wave is continually reduced or weakened with the distance it travels. This is known as attenuation and is due to the scattering or deflecting of energy signals as the wave propagates and the conversion of some of the energy to heat energy within the medium. A medium that changes the mechanical energy from the vibrations of the ultrasound energy into thermal or heat energy is called viscoelastic.
Pidilizumab (formerly CT-011) is a monoclonal antibody being developed by Medivation for the treatment of cancer and infectious diseases.Statement On A Nonproprietary Name Adopted By The USAN Council - Pidilizumab, American Medical Association- needs login. Pidilizumab was originally thought to bind to the PD-1 immune checkpoint molecule, however, recent evidence suggests that Delta-like 1 (DLL1) is its primary binding target while binding to PD-1 is secondary and restricted to non-glycosylated and hypoglycosylated forms of this molecule. Pidilizumab causes in the attenuation of apoptotic processes in lymphocytes, primarily effector/memory T cells.
Gratification is a pleasurable reaction in response to a communication of the cause of unwanted mood. This type of gratification can be a reward for the participant in releasing the tension carried by the cause of the mood and a feeling of relief. Spending time with someone and engaging in an emotional activity are also considered to be forms of social support. These forms of social support allow for an individual to become distracted from the cause of the issue and allow for time to go by and allow for a process of mood attenuation.
Acoustic plaster is plaster which contains fibres or aggregate so that it absorbs sound. Early plasters contained asbestos, but newer ones consist of a base layer of absorptive substrate panels, which are typically mineral wool, or a non-combustible inorganic blow-glass granulate. A first finishing layer is then applied on top of the substrate panels, and sometimes a second finishing layer is added for greater sound attenuation. Pre-made acoustic panels are more commonly used, but acoustic plaster provides a smooth and seamless appearance, and greater flexibility for readjustment.
Moreover, since ubiquitination functions to tightly regulate the cellular level of cyclins, its misregulation is expected to have severe impacts. First evidence of the importance of the ubiquitin/proteasome pathway in oncogenic processes was observed due to the high antitumor activity of proteasome inhibitors. Various studies have shown that defects or alterations in ubiquitination processes are commonly associated with or present in human carcinoma. Malignancies could be developed through loss of function mutation directly at the tumor suppressor gene, increased activity of ubiquitination, and/or indirect attenuation of ubiquitination due to mutation in related proteins.
At this time Thames Transit introduced two new branded routes, The Wood Farm Woodman and The Marston Pony, in direct competition with long-established City of Oxford routes. Both routes were unsuccessful – partly because they used tired vehicles but also because they failed to run frequently enough given the attenuation of staffing under the pressure of the bus war with City of Oxford. The bus war ended in autumn 1996, with both firms withdrawing from routes and increasing fares. Thames Transit withdrew its Park & Ride service and the Wood Farm Woodman and Marston Pony routes.
By introducing more energy thresholds above the low-energy threshold, a PCD can be divided into several discrete energy bins. Each registered photon is thus assigned to a specific bin depending on its energy, such that each pixel measures a histogram of the incident X-ray spectrum. This spectral information provides several advantages over the integrated deposited energy of an EID. First, it makes it possible to quantitatively determine the material composition of each pixel in the reconstructed CT image, as opposed to the estimated average linear attenuation coefficient obtained in a conventional CT scan.
From an organizational perspective, it has been suggested that mobbing behavior can be curtailed by acknowledging behaviors as mobbing behaviors and that such behaviors result in harm and/or negative consequences. Precise definitions of such traits are critical due to ambiguity of unacceptable and acceptable behaviors potentially leading to unintentional mobbing behavior. Attenuation of mobbing behavior can further be enhanced by developing policies that explicitly address specific behaviors that are culturally accepted to result in harm or negative affect. This provides a framework from which mobbing victims can respond to mobbing.
Usually, the IRU can be considered to be a physical asset, which can be resold, traded or used as collateral. For regulatory reasons, generally only licensed carriers are allowed access to support structures, and to municipal rights of way. The IRU contract defines detailed technical and performance specifications for the IRU fibers. More specifically, it includes dark fiber acceptance and testing procedures, the description of the dark fiber physical route, operating specifications for the dark fiber infrastructure, performance specifications (attenuation, Chromatic Dispersion, Polarization Mode Dispersion, Optical Return Loss), maintenance and restoration terms.
To overcome many of these drawbacks, cortical cooling devices may be used instead of ablation. While allowing a range of tissue areas to be cooled (small with cryotips to very large if using multiple cryoloops or a cooling plate), using cooling devices is a reversible method that enables control of the period of inactivation and, when turned off, takes only minutes for the animal to recover full function. These advantages hold even when deactivations are repeated over long periods of time, from months to years, with no evidence of attenuation.
For a single grain of mineral, the dose rate (D_R) can be determined by measuring the concentrations of uranium, potassium and thorium by direct mass spectrometric analysis of quartz or feldspar grains. Ge-Gamma, INAA, X-ray flourescnce and ICP-MS or ICP-OES are spectrometers that can could be used. Other methods for the determination the dose rate include: (1) overburden cosmic dose rate estimation, (2) water content attenuation method, and (3) disequilibrium dose rate correction method. An average dose rate is usually calculated as representative of the dose rate.
Brucella suis is a Gram-negative, facultative, intracellular coccobacillus, capable of growing and reproducing inside of host cells, specifically phagocytic cells. They are also not spore-forming, capsulated, or motile. Flagellar genes, however, are present in the B. suis genome, but are thought to be cryptic remnants because some were truncated and others were missing crucial components of the flagellar apparatus. In mouse models, the flagellum is essential for a normal infectious cycle, where the inability to assemble a complete flagellum leads to severe attenuation of the bacteria.
Feustel's Ph.D. thesis investigated seismic wave attenuation in underground mines and measurement techniques and applications to site characterization. For three years, Feustel worked as a geophysicist for the Engineering Seismology Group, Kingston, Ontario, Canada, installing and operating microseismic monitoring equipment in underground mines throughout Eastern Canada and the United States. In 1997, he began working for the Exxon Exploration Company (now ExxonMobil Exploration Company), Houston, Texas, as an exploration geophysicist designing and providing operational oversight of land, marine, and borehole seismic programs worldwide. He worked in industry for five years before joining NASA.
Conditioned place preference protocol As in Pavlovian conditioning, an initially neutral stimulus, in this case environmental cues, is repeatedly paired with an unconditioned stimulus that naturally produces a response prior to conditioning (the unconditioned response). Over time and pairings the neutral stimulus will come to elicit responses similar to the unconditioned response. In conditioned place preference the unconditioned stimulus could be any number of things including food pellets,Spyraki C, Fibiger HC, Phillips AG (1982) Attenuation by haloperidol of place preference conditioning using food reinforcement. Psychopharmacology 77:379–382.
The ER UPR is induced by a variety of cellular stressors that inhibit protein folding or exit of the ER. Within the ER GRP78, an ER lumen chaperone, is bound to ER menbrane proteins. When unfolded proteins build up, it dissociates to from the membrane to aid in protein folding. GRP78 dissociation triggers the UPRER that restores protein homeostasis via three pathways (IRE1, PERK, and ATF6). The UPRER restores proteostasis by selectively attenuation protein translation, upregulating protein folding chaperones, and degrading excess misfoleded proteins via ER associated protein degradation (ERAD).
The plots shown of image impedance, attenuation and phase change are the plots of a low-pass prototype filter section. The prototype has a cut-off frequency of ωc = 1 rad/s and a nominal impedance R0 = 1 Ω. This is produced by a filter half-section where L = 1 henry and C = 1 farad. This prototype can be impedance scaled and frequency scaled to the desired values. The low-pass prototype can also be transformed into high-pass, band-pass or band-stop types by application of suitable frequency transformations.
Scuba diver with bifocal lenses fitted to a mask Underwater, things are less visible because of lower levels of natural illumination caused by rapid attenuation of light with distance passed through the water. They are also blurred by scattering of light between the object and the viewer, also resulting in lower contrast. These effects vary with wavelength of the light, and color and turbidity of the water. The vertebrate eye is usually either optimised for underwater vision or air vision, as is the case in the human eye.
The second circuit is a filter which removes (as much as practical) the fundamental frequency. This can be a notch filter, one which passes all but the fundamental, with negligible attenuation at other frequencies (including whatever harmonics might be present). Alternatively, if the distortion products are at higher frequencies, a highpass filter can be used if its cutoff rate is sufficiently steep to not affect the expected distortion products. The output of the filter is measured as a percentage of the fundamental, and the reported value will be the distortion value.
The electrical coaxial cable (with RCA jacks) or optical fibre (TOSLINK). Note that there are no differences in the signals transmitted over optical or coaxial S/PDIF connectors—both carry exactly the same information. Selection of one over the other rests mainly on the availability of appropriate connectors on the chosen equipment and the preference and convenience of the user. Connections longer than 6 meters or so, or those requiring tight bends, should use coaxial cable, since the high light signal attenuation of TOSLINK cables limits its effective range.
Under conditions consistent with the temperature in the human body, multiple stem loops are predicted to occur in the 5' UTR, the coding region of the protein, and in the 3' UTR. The stem loops direct RNA folding, protect structural stability for mRNA, provide recognition sites for RNA binding proteins, and serve as a substrate for enzymatic reactions. There is an interior loop and a stem loop in the mRNA near AUG on the 5' UTR. These structures are often bound by proteins or cause the attenuation of a transcript in order to regulate translation.
Haze causes issues in the area of terrestrial photography, where the penetration of large amounts of dense atmosphere may be necessary to image distant subjects. This results in the visual effect of a loss of contrast in the subject, due to the effect of light scattering through the haze particles. For these reasons, sunrise and sunset colors appear subdued on hazy days, and stars may be obscured at night. In some cases, attenuation by haze is so great that, toward sunset, the sun disappears altogether before reaching the horizon.
Derelict soils occur where industrial contamination or other development activity damages the soil to such a degree that the land cannot be used safely or productively. Remediation of derelict soil uses principles of geology, physics, chemistry and biology to degrade, attenuate, isolate or remove soil contaminants to restore soil functions and values. Techniques include leaching, air sparging, soil conditioners, phytoremediation, bioremediation and Monitored Natural Attenuation (MNA). An example of diffuse pollution with contaminants is copper accumulation in vineyards and orchards to which fungicides are repeatedly applied, even in organic farming.
Polarization-maintaining optical fibers are used in special applications, such as in fiber optic sensing, interferometry and quantum key distribution. They are also commonly used in telecommunications for the connection between a source laser and a modulator, since the modulator requires polarized light as input. They are rarely used for long-distance transmission, because PM fiber is expensive and has higher attenuation than singlemode fiber. The output of a PM fiber is typically characterized by its polarization extinction ratio (PER)—the ratio of correctly to incorrectly polarized light, expressed in decibels.
The term propagation constant or propagation function is applied to filters and other two-port networks used for signal processing. In these cases, however, the attenuation and phase coefficients are expressed in terms of nepers and radians per network section rather than per unit length. Some authorsMatthaei et al, p49 make a distinction between per unit length measures (for which "constant" is used) and per section measures (for which "function" is used). The propagation constant is a useful concept in filter design which invariably uses a cascaded section topology.
Encyclopedia of Laser Physics and Technology - Q factor, quality factor, cavity, resonator, oscillator, frequency standards A beam reflects a large number of times with little attenuation—therefore the frequency line width of the beam is small compared to the frequency of the laser. Additional optical resonances are guided-mode resonances and surface plasmon resonance, which result in anomalous reflection and high evanescent fields at resonance. In this case, the resonant modes are guided modes of a waveguide or surface plasmon modes of a dielectric-metallic interface. These modes are usually excited by a subwavelength grating.
In telecommunication, a transmission level point (TLP) is a physical test point in an electronic circuit, typically a transmission channel, where a test signal may be inserted or measured.Whitham R. Reeve (1992) Subscriber Loop Signaling and Transmission Handbook—Analog, IEEE Press, p.229 Typically, various parameters, such as the power of the signal, noise, or test tones inserted are specified or measured at the TLP. The nominal transmission level at a TLP is a function of system design and is an expression of the design gain or attenuation (loss).
AM broadcasting stations use ground waves to cover their listening areas. As the frequency gets lower, the attenuation with distance decreases, so very low frequency (VLF) and extremely low frequency (ELF) ground waves can be used to communicate worldwide. VLF and ELF waves can penetrate significant distances through water and earth, and these frequencies are used for mine communication and military communication with submerged submarines. At medium wave and shortwave frequencies (MF and HF bands) radio waves can refract from a layer of charged particles (ions) high in the atmosphere, called the ionosphere.
Optical attenuators are commonly used in fiber optic communications, either to test power level margins by temporarily adding a calibrated amount of signal loss, or installed permanently to properly match transmitter and receiver levels. Sharp bends stress optic fibers and can cause losses. If a received signal is too strong a temporary fix is to wrap the cable around a pencil until the desired level of attenuation is achieved.Using Attenuators With Fiber Optic Data Links However, such arrangements are unreliable, since the stressed fiber tends to break over time.
Pupin's design of loading coil Michael Pupin, inventor and Serbian immigrant to the USA, also played a part in the story of loading coils. Pupin filed a rival patent to the one of Campbell's.Pupin, M, Art of Reducing Attenuation of Electrical Waves and Apparatus Therefor, US patent 0 652 230, filed 14 December 1899, issued 19 June 1900. This patent of Pupin's dates from 1899. There is an earlier patentPupin, M, Apparatus for Telegraphic of Telephonic Transmission, US patent 0 519 346, filed 14 December 1893, issued 8 May 1894.
In telecommunication, de-emphasis is the complement of pre-emphasis, in the antinoise system called emphasis. De-emphasis is a system process designed to decrease, (within a band of frequencies), the magnitude of some (usually higher) frequencies with respect to the magnitude of other (usually lower) frequencies in order to improve the overall signal-to-noise ratio by minimizing the adverse effects of such phenomena as attenuation distortion or saturation of recording media in subsequent parts of the system. Special time constants dictate the frequency response curve, from which one can calculate the cutoff frequency.
On the customer side, the DSL transceiver, or ATU-R, or more commonly known as a DSL modem, is hooked up to a phone line. The telephone company connects the other end of the line to a DSLAM, which concentrates a large number of individual DSL connections into a single box. The location of the DSLAM depends on the telco, but it cannot be located too far from the user because of attenuation between the DSLAM and the user's DSL modem. It is common for a few residential blocks to be connected to one DSLAM.
In a single-mode optical fiber, the zero-dispersion wavelength is the wavelength or wavelengths at which material dispersion and waveguide dispersion cancel one another. In all silica-based optical fibers, minimum material dispersion occurs naturally at a wavelength of approximately 1300 nm. Single-mode fibers may be made of silica-based glasses containing dopants that shift the material-dispersion wavelength, and thus, the zero-dispersion wavelength, toward the minimum-loss window at approximately 1550 nm. The engineering tradeoff is a slight increase in the minimum attenuation coefficient.
Competing manufacturers began to bring the Dugan algorithm directly to their product designs. In 1993, Travis M. Sims, Jr. of Lectrosonics (Rio Rancho, New Mexico) was granted a patent for a sound system with rate controlled, variable attenuation of microphone inputs, including the Dugan algorithm as well as loudspeaker zone attenuation when in close proximity to an active microphone. The loudspeaker zone part of the patent cited a 1985 patent for proportional amplification by Eugene R. Griffith, Jr. of LVW Systems of Colorado Springs, a commercial audio contractor. In 1995, Sims and Lectrosonics gained another patent for an "Adaptive proportional gain audio mixing system" which incorporated a number of ideas including the Dugan algorithm for maintaining a constant total gain of all the inputs. In 1996, Dugan came out with the Model D-1, a speech-only economy model that did not offer the music system of the Model D. In 1997, John H. Roberts of Peavey Electronics was granted a patent for an automatic mixer priority circuit, enabling a hierarchy of logic weighting that allowed selected signals to push forward in the mix when they are in use, while still maintaining the useful constant unity, gain-sharing relationship first described by Dugan.
Similar to a noise reduction rating (NRR) required on hearing protection devices in the United States, a personal attenuation rating (PAR) can be obtained through a hearing protection fit-testing system. The PAR is subtracted from the measured noise exposure to estimate the total noise exposure an individual is receiving when wearing hearing protection. The PAR is regarded as more accurate than the NRR because it is calculated per individual and per hearing protection device, while NRR is a generalized estimate of potential sound reduction based on the protection provided to a small population of people.
Ground Wave propagation is a method of radio wave propagation that uses the area between the surface of the earth and the ionosphere for transmission. The ground wave can propagate a considerable distance over the earth's surface particularly in the low frequency and medium frequency portion of the radio spectrum. Ground wave radio signal propagation is ideal for relatively short distance propagation on these frequencies during the daytime. Sky-wave ionospheric propagation is not possible during the day because of the attenuation of the signals on these frequencies caused by the D region in the ionosphere.
The type of headgear affects noise sensitivity and noise hazard depending on whether transmission is wet or dry. Human hearing underwater is less sensitive with wet ears than in air, and a neoprene hood causes substantial attenuation. When wearing a helmet, hearing sensitivity is similar to that in surface air, as it is not greatly affected by the breathing gas or chamber atmosphere composition or pressure. Because sound travels faster in heliox than in air, voice formants are raised, making divers' speech high-pitched and distorted, and hard to understand for people not used to it.
The group velocity of a wave may also exceed c in some circumstances. In such cases, which typically at the same time involve rapid attenuation of the intensity, the maximum of the envelope of a pulse may travel with a velocity above c. However, even this situation does not imply the propagation of signals with a velocity above c, even though one may be tempted to associate pulse maxima with signals. The latter association has been shown to be misleading, because the information on the arrival of a pulse can be obtained before the pulse maximum arrives.
When Colostrinin was administered to the cells after treatment with Vitamin D3, no attenuation of the differentiation/maturation process of the HL-60 cells was observed. Therefore, Colostrinin may regulate in this way the inflammatory processes in which these cells participate. Another study in day-old domestic chicks showed enhancement of long-term memory retention. A study conducted at the University of Texas Medical Branch and published online in March 2008 in the International Archives of Allergy and Immunology showed that Colostrinin is non-allergenic and can prevent allergic inflammation due to common indoor and outdoor allergens.
Work began to develop energy absorbing seats to reduce the chance of spinal injuriesThe Evolution of Energy Absorption Systems for Crashworthy Helicopter Seats by Stan Desjardins, paper at 59th AHS Forum during training and combat in Vietnam. Heavy research was conducted into human tolerance, energy attenuation and structural designs that would protect the occupants of military helicopters.Human Tolerance and Crash Survival - Shanahan (NATO) The primary reason is that ejection or exiting a helicopter is impractical given the rotor system and typical altitude at which Army helicopters fly. In the late 1960s the Army published the Aircraft Crash Survival Design Guide.
Spielberg reflected he "was attracted to the idea that this was a death of innocence, not an attenuation of childhood, which by my own admission and everybody's impression of me is what my life has been. This was the opposite of Peter Pan. This was a boy who had grown up too quickly." Other topics that Spielberg previously dealt with, and are presented in Empire of the Sun, include a child being separated from his parents (The Sugarland Express, E.T. the Extra-Terrestrial, Close Encounters of the Third Kind and Poltergeist) and World War II (1941, and Raiders of the Lost Ark).
In-situ studies have determined that the depth of DCM formation is primarily dependent on light attenuation levels, and the depth of the nutricline, although thermal stratification also plays a role. In lakes, the thickness of the DCM layer is mainly controlled by the sizes and maximum depths of lakes. The DCM forms near the nutricline and the bottom of the photic zone. Phytoplankton growth in the DCM is limited by both nutrient and light availability, therefore either increased nutrient input, or increased light availability to the DCM can in turn increase the phytoplankton growth rate.
Fig. 2. Example of the level of chlorophyll fluorescence at different water depths. Light attenuation factors have been shown to be quite predictive of the DCM depth, since the phytoplankton present in the region require sufficient sunlight for growth, resulting in a DCM that is generally found in the euphotic zone. However, if the phytoplankton population has adapted to lower light environments, the DCM can also be located in the aphotic zone. The high chlorophyll concentration at the DCM is due to the high number of phytoplankton that have adapted to functioning in low light conditions.
The two lake types also differ in light attenuation coefficients: it is lower in the transparent deeper lakes, which means more light is able to penetrate though. As such, the main difference between the two lake types that was found to contribute to the DCM community is the light climate. Shallow lakes were found to contain greater concentrations of dissolved yellow particles than the deeper lakes. As a result, for deeper lakes, maximum absorption wavelengths were mainly at the red end of the spectra, whereas shallow lakes exhibited green and blue absorption wavelengths in addition to red.
The approximation problem in network synthesis is to find functions which will produce realisable networks approximating to a prescribed function of frequency within limits arbitrarily set. The approximation problem is an important issue since the ideal function of frequency required will commonly be unachievable with rational networks. For instance, the ideal prescribed function is often taken to be the unachievable lossless transmission in the passband, infinite attenuation in the stopband and a vertical transition between the two. However, the ideal function can be approximated with a rational function, becoming ever closer to the ideal the higher the order of the polynomial.
The electroseismic method is very susceptible to electrical cultural noise, and has also the same noise sources as reflection seismic method, which include ground roll, multiples and random noise. Seismoelectrical method also has a very low signal-to-noise ratio, because the attenuation of electromagnetic waves inside the earth is 1/r^3, thus theoretically limiting its depth of exploration to three hundred meters.Thompson, A., and Gist, G., 1993, Geophysical applications of electrokinetic conversion: The Leading Edge, 12, 1169-1173 Typical electroseismic signals are at the microvolt level. The electroseismic signal is proportional to the pressure of the seismic wave.
Chief amongst these achievements was the discovery of the general factor in human intelligence, and his subsequent development of a theory of "g" and synthesis of empirical work on ability. Spearman was strongly influenced by the work of Francis Galton. Galton did pioneering work in psychology and developed correlation, the main statistical tool used by Spearman. In statistics, Spearman developed rank correlation (1904), a non-parametric version of the conventional Pearson correlation, as well as both the widely used correction for attenuation (1907), and the earliest version of a 'factor analysis' (Lovie & Lovie, 1996, p. 81).
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.
AirHop holds 20 patent applications for its eSON™ self- organizing network (SON) software. eSON enables carriers to build a 3G or 4G LTE heterogeneous network (“het-net”) to augment existing macro base stations. Many carriers are using small cells and self-organizing networks to fill in gaps in 3G and 4G networks due to signal attenuation and add capacity. The 3rd Generation Partnership Project (3GPP) defined a SON specification to allow basestations to discover each other when inserted into a network and to adjust their radio frequency (RF) signal strength to avoid overlap and interference.
The Police Field Force was also involved during the Indonesia- Malaysia confrontations. In various actions during the Confrontation, the Police Field Force detained Indonesian irregulars sent to the peninsula, with the view of running clandestine operations on Malaysian soil. Following the May 13, 1969 incident, the Malaysian government realised the importance of a mobile and independent team and more capable to the facing of public order situations. Following the disarmament of the Malayan Communist Party (MCP) on 2 December 1989, the Police Field Force was reformed with attenuation from 21 battalions to 17 battalions on 1 September 1994.
The Titans were fully configured for immediate launch in a matter of two minutes. The launch sequence included a number of test and initiation functions as well as a 20-second door opening sequence. The silo closure door weighed 780 tons and was locked down with hydraulically operated locks, and raised on hydraulic jacks. The hydraulics also operated the radial motors that pulled the door open with steel cables (four of them). Launch initiation was also accompanied with attenuation water which flowed 9000 gallons per minute for sound suppression and protection of the missile during the launch.
The shorter wavelength, which is closer to the size of a raindrop than the wavelength, is partially absorbed by precipitation. This is a serious drawback to using TDWR, as the signal can be strongly attenuated in heavy precipitation. This attenuation means that the radar cannot "see" very far through heavy rain and could miss severe weather such as strong thunderstorms which may contain the signature of a tornado, when there is heavy rain falling between the radar and that storm. When heavy rain is falling on the radome, the range of the TDWR is further limited.
Lead's high density, atomic number, and formability form the basis for use of lead as a barrier that absorbs sound, vibration, and radiation. Lead has no natural resonance frequencies; as a result, sheet-lead is used as a sound deadening layer in the walls, floors, and ceilings of sound studios. Organ pipes are often made from a lead alloy, mixed with various amounts of tin to control the tone of each pipe. Lead is an established shielding material from radiation in nuclear science and in X-ray rooms due to its denseness and high attenuation coefficient.
Sensitivity time control (STC), also known as swept-gain control, is a system used to attenuate the very strong signals returned from nearby ground clutter targets in the first few range gates of a radar receiver. Without this attenuation, the receiver would routinely saturate due to the strong signals. This is used in air traffic control systems and has an influence on the shape of the elevation pattern of the surveillance antenna. It is represented in terms of numerical value typically expressed in decibels (dB), starting from zero, indicating that there is no muting and that the radar system is accepting all returns.
Two unique strains of yeast were traditionally used; one highly flocculent strain that was responsible for most of the fermentation in the first few days, and the other, a powdery and less flocculant strain, that was slower and finished off the beer in the fermentation vats and in the bottles. Until the end of the 19th century, the breweries that produced Grodziskie used a single strain of yeast that was characterized by low attenuation and early flocculation. However, that strain was lost in the early 20th century. After World War II, yeast was imported from the Groterjan Brewery in Berlin.
A head shadow or acoustic shadow is a region of reduced amplitude of a sound because it is obstructed by the head (diffracted). Sound may have to travel through and around the head in order to reach an ear. The obstruction caused by the head can account for a significant attenuation (reduced amplitude) of overall intensity as well as cause a filtering effect. The filtering effects of head shadowing are an essential element of sound localisation—the brain weighs the relative amplitude, timbre, and phase of a sound heard by the two ears and uses the difference to interpret directional information.
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The array has been constructed on the elevation Chajnantor plateau - near the Llano de Chajnantor Observatory and the Atacama Pathfinder Experiment. This location was chosen for its high elevation and low humidity, factors which are crucial to reduce noise and decrease signal attenuation due to Earth's atmosphere. ALMA is expected to provide insight on star birth during the early Stelliferous era and detailed imaging of local star and planet formation.
Wrong assumptions on the attenuation of seismic waves may introduce errors of a factor of 3. Moderate errors, typically about 30%, can be introduced by variations of magnitude for M<8, soil conditions, and directivity of energy radiated. Other inaccuracies in data sets or input contribute errors that are negligible compared to the aforementioned uncertainties.Wyss, M., G. Trendafiloski, M. Elashvili, N. Jorjiashvili, and Z. Javakhishvili The mapping of teleseismic epicenter errors into errors in estimating casualties in real time due to earthquakes worldwide, abstract, presented at European Geosciences Union General Assembly, Vienna, EUG2011-9938, April 4, 2011.
Advanced manufacturing techniques such as pre- pregs and fiber rovings extend fiberglass's applications and the tensile strength possible with fiber-reinforced plastics. Fiberglass is also used in the telecommunications industry for shrouding antennas, due to its RF permeability and low signal attenuation properties. It may also be used to conceal other equipment where no signal permeability is required, such as equipment cabinets and steel support structures, due to the ease with which it can be molded and painted to blend with existing structures and surfaces. Other uses include sheet-form electrical insulators and structural components commonly found in power-industry products.
At moderate gain or attenuation settings noise of the core, assuming noise-free surrounding circuitry, is determined by collector current shot noise which is proportional to square root of emitter current. Thus lowest noise is attained in class AB cores with very small idle currents. Design for lowest distortion, on the contrary, require pure class A operation at the cost of higher noise. For example, in THAT Corp's ICs increase of idle current from 20 μA (class AB) to 750 μA (class A) causes a rise in no-signal noise floor by 17 dB; in dbx, Inc.
The story in the movie significantly deviates from the short story, most notably turning Johnny, not his bodyguard partner, into the primary action figure. In fact, the movie transforms Molly Millions into "Jane", as the film rights to Molly were owned by a company unaffiliated with the film's producers. Nerve Attenuation Syndrome (NAS) is a fictional disease in the film, which is not present in the short story. NAS, also called "the black shakes", is caused by an overexposure to electromagnetic radiation from omnipresent technological devices, and is presented as a raging epidemic affecting the world in the future.
Modern computed tomography (CT) scanners have AEC systems which aim to maintain image quality for patients of varying sizes, whilst keeping doses as low as reasonably practicable. The systems are also designed to maintain quality with the varying size and attenuation of an individual patient over their length. Implementations vary between manufacturers, some systems are based on a desired noise level in the image, while others are based on a specified reference output (milliampere second, mAs). CT AEC systems use the initial "scanogram", a fixed angle planning view, to determine the relative size of the patient, and variation over their length.
In 2016 PBG went out of business and sold the Tone King brand to Boutique Amps Distribution (BAD), which now manufacturers these amps in Huntington Park, California. In January 2016, Tone King introduced the new Royalist 45 Mk II amplifier, an updated version of Tone King's Royalist amplifier, known for its low-gain British sound qualities. That same month, Tone King introduced an updated version of its Ironman attenuator, the Ironman II Mini. There are 4 different amplifiers in the current lineup that all feature the Ironman compensated reactive load attenuation: Gremlin Combo, Falcon Grande Combo, Imperial Head and Combo, Sky King.
XPS detects only electrons that have actually escaped from the sample into the vacuum of the instrument. In order to escape from the sample, a photoelectron must travel through the sample. Photo-emitted electrons can undergo inelastic collisions, recombination, excitation of the sample, recapture or trapping in various excited states within the material, all of which can reduce the number of escaping photoelectrons. These effects appear as an exponential attenuation function as the depth increases, making the signals detected from analytes at the surface much stronger than the signals detected from analytes deeper below the sample surface.
Passive implementations of linear filters are based on combinations of resistors (R), inductors (L) and capacitors (C). These types are collectively known as passive filters, because they do not depend upon an external power supply and they do not contain active components such as transistors. Inductors block high-frequency signals and conduct low- frequency signals, while capacitors do the reverse. A filter in which the signal passes through an inductor, or in which a capacitor provides a path to ground, presents less attenuation to low-frequency signals than high-frequency signals and is therefore a low-pass filter.
A novel member of endothelium-specific growth factors, hepatocyte growth factor (HGF), is produced in vascular cells. In diabetic patient’s, levels of the hepatocyte growth factor (HGF) were found in high levels, thus independently associated with increased the incidence of diabetes. There is a study that indicate that HGF/c-Met signalling is essential for maternal β-cell adaptation during pregnancy and that its absence/attenuation leads to gestational diabetes mellitus.Demirci, Cem, Sara Ernst, Juan C. Alvarez-Perez, Taylor Rosa, Shelley Valle, Varsha Shridhar, Gabriella P. Casinelli, Laura C. Alonso, Rupangi C. Vasavada, and Adolfo García-Ocana.
This early demographic transition characterised by The Attenuation of Mortality Crises started in Britain in the late 18th century and on the European continent about a half century later. Still in 2002, some critics of McKeown described this demographic controversy as one of his many flaws, not understanding that 'stabilisation of mortality' followed by 'decrease in both mortality and fertility' are perfectly complementary theories, as argued by Flinn (1971) and McKeown (1988) (and as illustrated by the Figure describing the population growth, fertility and mortality rates in the Netherlands from the pre- industrial early 19th century until the present day).
It does not matter if the transition band is not very narrow, or that the stopband has poor attenuation. In fact, trying to improve the bandwidth beyond what is strictly necessary will detract from the accuracy of the impedance match. With a given number of elements in the network, narrowing the design bandwidth improves the matching and vice versa. The limitations of impedance matching networks were first investigated by American engineer and scientist Hendrik Wade Bode in 1945, and the principle that they must necessarily be filter-like was established by Italian-American computer scientist Robert Fano in 1950.
Despite a striking effect of heparin on tumor progression shown in a number of clinical trials, the use of heparin as anti-cancer agent is limited because of its risk, which might induce adverse bleeding complications. Given those reasons, development of new compounds that target P-selectin is now emerging for cancer therapy. Among them, the inhibitory activity of semisynthetic sulfated tri mannose C-C-linked dimers (STMCs) to P-selectin was shown by the attenuation of tumor metastasis in vivo animal model, indicating the inhibition of interaction between tumor cell and endothelial cell is significant for blocking tumor dissemination.
Presynaptic terminals release chemical messengers, called neurotransmitters, from compartments known as synaptic vesicles. The release of neurotransmitters relays signals between neurons and is critical for normal brain function. Although the function of alpha-synuclein is not well understood, studies suggest that it plays a role in restricting the mobility of synaptic vesicles, consequently attenuating synaptic vesicle recycling and neurotransmitter release. An alternate view is that alpha-synuclein binds to VAMP2 (a synaptobrevin) and stabilizes SNARE complexes; though recent studies indicate that alpha-synuclein–VAMP2 binding is critical for alpha-synuclein-mediated attenuation of synaptic vesicle recycling, connecting the two seemingly divergent views.
For analog signals, connections usually consist of a simple electrical bus and, especially in the case of a chain of many devices, may require the use of one or more repeaters or amplifiers within the chain to counteract attenuation (the natural loss of energy in such a system). Digital signals between devices may also travel on a simple electrical bus, in which case a bus terminator may be needed on the last device in the chain. However, unlike analog signals, because digital signals are discrete, they may also be electrically regenerated, but not modified, by any device in the chain.
The characteristic impedance of the cable (Z_0) is determined by the dielectric constant of the inner insulator and the radii of the inner and outer conductors. In radio frequency systems, where the cable length is comparable to the wavelength of the signals transmitted, a uniform cable characteristic impedance is important to minimize loss. The source and load impedances are chosen to match the impedance of the cable to ensure maximum power transfer and minimum standing wave ratio. Other important properties of coaxial cable include attenuation as a function of frequency, voltage handling capability, and shield quality.
The coaxial portion of the network connects 25–2000 homes (500 is typical) in a tree-and-branch configuration off of the node. RF amplifiers are used at intervals to overcome cable attenuation and passive losses of the electrical signals caused by splitting or "tapping" the coaxial cable. Trunk coaxial cables are connected to the optical node and form a coaxial backbone to which smaller distribution cables connect. Trunk cables also carry AC power which is added to the cable line at usually either 60 or 90 V by a power supply (with a lead acid backup battery inside) and a power inserter.
Reflection seismograms record the reflection wave along the propagation path r from the source to reflector and back to the surface. Equation (1.1) has an analytical solution given by :U(r+\bigtriangleup r,w) =U(r,w)\exp (ik\bigtriangleup r) \quad (1.2) Where k is the wave number. When the wave propagates in inhomogeneous seismic media the propagation constant k must be a complex value that includes not only an imaginary part, the frequency-dependent attenuation coefficient, but also a real part, the dispersive wavenumber. We can call this K(w) a propagation constant in line with Futterman.

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