TY - GEN. T1 - Analysis of multiple scattering effects in optical Doppler tomography. AU - Yura, H.T.. AU - Thrane, L.. AU - Andersen, Peter E.. PY - 2005. Y1 - 2005. N2 - Optical Doppler tomography (ODT) combines Doppler velocimetry and optical coherence tomography (OCT) to obtain high-resolution cross-sectional imaging of particle flow velocity in scattering media such as the human retina and skin. Here, we present the results of a theoretical analysis of ODT where multiple scattering effects are included. The purpose of this analysis is to determine how multiple scattering affects the estimation of the depth-resolved localized flow velocity. Depth-resolved velocity estimates are obtained directly from the corresponding mean or standard deviation of the observed Doppler frequency spectrum. Thus, in the present analysis, the dependence of the mean and standard deviation of the Doppler shift on the scattering properties of the flowing medium are obtained. Taking the multiple scattering effects ...

A swept source based Fourier domain optical Doppler tomography (FDODT) system was developed. The technique is based on a phase-resolved method where phase information was retrieved from the reconstructed complex fringe signals. The aliasing effects and artifacts caused by lateral scanning and sample movement were removed with a signal processing technique. The standard deviation of the phase shift of the system was reduced from 49 to 1.8 degrees with the signal processing method employed. Structural, Doppler and Doppler variance images of fluid flow through glass channels were quantified, and blood flow through vessels of chick chorioallantoic membrane (CAM) was demonstrated in vivo.. ©2005 Optical Society of America. Full Article , PDF Article ...

This report describes a novel, non-invasive and label-free optical imaging technique, speckle variance optical coherence tomography (svOCT), for visualising blood flow within human retinal capillary networks. This imaging system uses a custom-built swept source OCT system operating at a line rate of 100 kHz. Real-time processing and visualisation is implemented on a consumer grade graphics processing unit. To investigate the quality of microvascular detail acquired with this device we compared images of human capillary networks acquired with svOCT and fluorescein angiography. We found that the density of capillary microvasculature acquired with this svOCT device was visibly greater than fluorescein angiography. We also found that this svOCT device had the capacity to generate en face images of distinct capillary networks that are morphologically comparable with previously published histological studies. Finally, we found that this svOCT device has the ability to non-invasively illustrate the ...

We introduce a novel contrast mechanism for imaging blood flow by use of magnetomotive optical Doppler tomography (MM-ODT), which combines an externally applied temporally oscillating high-strength magnetic field with ODT to detect erythrocytes moving according to the field gradient. Hemoglobin contrast was demonstrated in a capillary tube filled with moving blood by imaging the Doppler frequency shift, which was observed independently of blood flow rate and direction. Results suggest that MM-ODT may be a promising technique with which to image blood flow.. © 2006 Optical Society of America. Full Article , PDF Article ...

With the Doppler Effect Buzzer Demonstration Kit for physical science and physics, easily demonstrate the Doppler effect and fundamental principles of sounds. Clearly hear the sounds of the moving buzzer.

The article reveals the physiological parameters and the possibility of the new direction of magnetic therapy - bio-resonance or structural resonance electromagnetic therapy - in the curative and preventive medicine. The use of structural resonance electromagnetic therapy in the range of physiologic frequencies of the body can restore optimum rhythms, positively affecting the body as a whole through the normalization of the neuro-humoral and energy system of regulation. The most proven effects of structural resonance therapy is a sedative, hypotensive, anti-inflammatory, anti-swelling, analgesic, trophic and regenerative action, hypocoagulation effect, improved microcirculation and regional blood flow. There is also a proven beneficial effect of structural resonance electromagnetic therapy on immunoreactive and neuro-vegetative processes, which make this technique unique for the treatment and prevention of a number of inflammatory diseases of metabolic and posttraumatic genesis. Spectrum of used

A passive acoustic method to locate moving sound sources is applied to maneuvering aircraft. The advantages of the method are that it is suitable for all kinds of aircraft, not only propeller-driven, and is not restricted to low height above the ground. Its applicability could be, for instance, to supplement aircraft noise monitoring systems or to supervise small airports activities. The method is based on the relation between the relative Doppler effect observed from a set of at least seven microphone receivers, distributed in the airport surroundings, and the aircraft position and speed. The method requires knowledge of the position of the aircraft at the start of takeoff. The ambiguity function is used to calculate the relative Doppler stretch of the spectrum of the sound between pairs of microphones. The results of applying the ambiguity function are the inputs to a system of equations that relates the aircraft position and speed to the relative Doppler frequency stretches. This system of ...

View Notes - 53_doppler from PHYSICS 235 at Rutgers. Lesson 53: Doppler Effect Youve probably noticed that when an ambulance passes you with its siren going, or a plane flies overhead, you can hear

At first glance the season five Formula E car looked to our design team like an EV-powered supersonic bird in flight. Naturally this initial reaction from the team started us on a path that captured a sense of a form breaking free of resistance and gravity. Formula E racers are virtually silent, with explosive speed bursts thus naturally we turned to Doppler when designing the livery. The combination of the sonic pulse of the Doppler effect and the released power of a sonic boom inspired our celebration of EV Racing!. ...

Today we will be learning about the Doppler Effect. Watch the video tutorials below and complete the notes part of the package as well as the example problems. In class we will do a quick recap of the lesson, talk about applications of this (doppler radar, the big bang, police radar, etc.) and work on the problems. ...

Define Doppler effect Deduce the apparent frequency of sound in case of: (i) Source is in rest and observer is moving toward source. (ii) Observer is in rest and source is moving away from observer.

The Doppler effect is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a car with a siren approaches, passes and goes away from the observer. The received frequency is higher during the approach, it is identical at the instant of passing by, and it is lower during the recession. ...

The Doppler effect is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a car with a siren approaches, passes and goes away from the observer. The received frequency is higher during the approach, it is identical at the instant of passing by, and it is lower during the recession. ...

The Doppler effect suggests that sound waves are relative to the observer. You know if an object is coming or going from the sound it makes. Light wa...

An F1 car is loud even when stationary -- loud enough to hurt your ears if you are too close. The Doppler effect means that as the car is driving towards you that loud, painful sound arrives as lots of closely spaced sound waves yet once it has passed you by the sound waves are spaced much further apart. This explains why at a clockwise circuit such as Silverstone your right ear will be sorer than your left as the cars tend to approach you from the right. Of course if you went to watch a race in Brazil (or any other anti-clockwise circuit) then your left ear would be sorer than your right. The only people with sore left ears at Silverstone would be those on the inside of the circuit and given how much they would have had to pay for their seat or how much money they would have to make to be a guest of one of the teams then I dont have much sympathy for their left ears ...

The Doppler effect is the occurring change in wavelength and frequency when an observer moves relative to the source. Learn more on the blog

Second part of elementary, nonmathematical discussion of the Doppler effect and its application, discusses the effect as applied to sound and light; part of an educational web site on astronomy, mechanics, and space

This barcode costume is a funny geek costume idea. It also works perfectly as a doppler effect costume, although you might have to explain to people what that is.

От:shuba ([email protected]). Тема:Re: Classical transverse Doppler effect Группы новостей:sci.physics.relativity. Дата:2005-04-13 15:34:20 PST Sergey Karavashkin wrote:. , *Abstract*. , On the basis of complete solution of Doppler shift of frequency. , received by moving receiver, noting non-central motion of receiver as. , to the source, we compare the properties of longitudinal and. , transverse Doppler effect predicted by classical and relativistic. , formalism. We show that complete statement of problem predicts the. , transverse Doppler effect in frames of classical formalism, but its. , properties considerably differ from relativistic predictions. In. , particular, the sign of effect predicted by classical conception is. , opposite to that relativistic. While just the classical approach is. , most fully consistent with the phenomenology of effect, while the. , relativistic approach is essentially problematic both in description. , of phenomenon and in ...

As discussed in the chapter on sound, if a source of sound and a listener are moving farther apart, the listener encounters fewer cycles of a wave in each second, and therefore lower frequency, than if their separation remains constant. For the same reason, the listener detects a higher frequency if the source and listener are getting closer. The resulting Doppler shift in detected frequency occurs for any form of wave. For sound waves, however, the equations for the Doppler shift differ markedly depending on whether it is the source, the observer, or the air, which is moving. Light requires no medium, and the Doppler shift for light traveling in vacuum depends only on the relative speed of the observer and source.. ...

Fetal doppler or fetal heart rate monitor is a handheld device which is used to listen to the babys heartbeat inside the womb of the mother. Fetal doppler works on the principle of Doppler effect, discovered in 1842 by a famous Austrian mathematician and physicist Christian Doppler (1803-53). Doppler discovered that when high-frequency sound waves are reflected from a moving object, their frequency change and this can be analyzed.. Each fetal doppler contains a transducer or a probe which sends out short pulses of ultrasound sound waves into the directed area of the body. When these sound waves are reflected from the babys beating heart, their frequency change. When this echo is received by the fetal doppler, it converts this signal into the babys heartbeat. Normally a speaker or an auxiliary jack of earphones is connected to the doppler through which one can hear the heartbeat.. Fetal doppler and Ultrasound machine used by doctors work on the same doppler effect. The main difference between ...

Sonography can be enhanced with Doppler measurements, which employ the Doppler effect to assess whether structures (usually blood) are moving towards or away from the probe, and its relative velocity. By calculating the frequency shift of a particular sample volume, for example a jet of blood flow over a heart valve, its speed and direction can be determined and visualised. This is particularly useful in cardiovascular studies (sonography of the vasculature system and heart) and essential in many areas such as determining reverse blood flow in the liver vasculature in portal hypertension. The Doppler information is displayed graphically using spectral Doppler, or as an image using color Doppler (directional Doppler) or power Doppler (non directional Doppler). This Doppler shift falls in the audible range and is often presented audibly using stereo speakers: this produces a very distinctive, although synthetic, pulsing sound. Strictly speaking, most modern sonographic machines do not use the ...

I have read that, the light from a distant moving object is tested for doppler shift to calculate its velocity. My question is, we can only lay our hands on...

There is no such thing as the INTRINSIC frequency of a photon. The energy of the photon is frame dependent. The energy of a photon and thus its frequency as measured by someone at rest with respect to the source will be different than that it would be for some one moving with respect to the source. Put another way, there is no measurable difference between a red photon emit by a source at rest with respect to you and a red photon that has undergone Doppler shift ...

Doctors and specialists all around the world use the Doppler technique to successfully cure and diagnose diseases and problems from our body.

The vibrationally resolved X-ray photoelectron spectra of X-2 Sigma(+)(g)(3 sigma(-1)(g)) and B-2 Sigma(+)(u)(2 sigma(-1)(u)) states of N-2(+) were recorded for different photon energies and orientations of the polarization vector. Clear dependencies of the spectral line widths on the X-ray polarization as well as on the symmetry of the final electronic states are observed. Contrary to the translational Doppler, the rotational Doppler broadening is sensitive to the photoelectron emission anisotropy. On the basis of theoretical modeling, we suggest that the different rotational Doppler broadenings observed for gerade and ungerade final states result from a Youngs double-slit interference phenomenon.. ...

Tuesday, December 8th, 2015 @ 5:30 pm Round Table Pizza, 4330 Redondo Beach Blvd, Torrance Radar and the Doppler Effect, Counter-measures & Counter-Counter-Measures The Doppler effect is used in Radar to accurately measure the velocity of a target. It can also be used to spoof an enemy radar, or to figure out if the enemy is … Continue reading. ...

An age-old debate that has persisted among scientists is related to the question, Is light a wave or a stream of particles? Very noteworthy and distinguished physicists have taken up each side of the argument, providing a wealth of evidence for each side. The fact is that light exhibits behaviors that are characteristic of both waves and particles. In this unit of The Physics Classroom Tutorial, the focus will be on the wavelike nature of light.. Light exhibits certain behaviors that are characteristic of any wave and would be difficult to explain with a purely particle-view. Light reflects in the same manner that any wave would reflect. Light refracts in the same manner that any wave would refract. Light diffracts in the same manner that any wave would diffract. Light undergoes interference in the same manner that any wave would interfere. And light exhibits the Doppler effect just as any wave would exhibit the Doppler effect. Light behaves in a way that is consistent with our conceptual and ...

This work analyses the effect of the receiver movement on the detection by pulse compression of different families of codes characterizing the emissions of an Ultrasonic Local Positioning System. Three families of codes have been compared: Kasami, Complementary Sets of Sequences and Loosely Synchronous, considering in all cases three different lengths close to 64, 256 and 1,024 bits. This comparison is first carried out by using a system model in order to obtain a set of results that are then experimentally validated with the help of an electric slider that provides radial speeds up to 2 m/s. The performance of the codes under analysis has been characterized by means of the auto-correlation and cross-correlation bounds. The results derived from this study should be of interest to anyone performing matched filtering of ultrasonic signals with a moving emitter/receiver.

In strict adherence to the proposition that light does not take on the speed of the source, the leading edge of the light wave propagates outward in all directions at speed c from the SF point of emission depicted as point s in the illustration. The leading edge of the wave can therefore be represent as sphere S1 centered over point s in the SF as it expands in all directions at speed c relative to that SF point. Whereas for the initial wavelength shown as the small triangle enclosed in the larger triangle, the radius of the initial sphere S1 was defined as c, the new expanded radius is defined as xc where the variable x is a whole number as will be explained shortly. Since the source had moved to point e in the SF at the instant the trailing edge of the wave, synonymous here with the leading edge of the next wave, would then be propagated, there will be a later emitted wave represented by the smaller sphere S2 centered over point e in the SF. In other words, as the source continues its motion ...

A familiar law to astronomers is that the apparent brightness of an object decreases with increasing distance (as the inverse square of the distance). The farther away an object is, the darker is it. This relation, along with more sophisticated techniques described in the second lecture Expansion of the Universe, is used to determine relative distances of similar objects. Distance, however, is only part of the picture. It is also important to know the velocity of an object. To determine this, astrophysicists rely on a phenomenon known as the Doppler effect . As most individuals have experienced, sound waves emitted from an approaching object have an increased apparent frequency to stationary observers. One common example is that of a rapidly approaching train--its sound is much higher in pitch on its approach than on its departure (see note 1). Although the sonic Doppler effect is caused by compression of sonic wavefronts, the effect can be generalized to all wavelike phenomena in particular ...

Textbook solution for College Physics 11th Edition Raymond A. Serway Chapter 14 Problem 25P. We have step-by-step solutions for your textbooks written by Bartleby experts!

In this lesson, students will be introduced to how the Doppler effect changes our perception of wavelengths of sound (pitch) and light (color). Students will model how astronomers use the line spectra of stars to identify elements in the stars and... (View More) the speeds of galaxies in the universe. Requires some special equipment for spectral analysis and a darkened room for viewing spectra. Suggestions are included for introducing the Doppler Effect for students unfamiliar with this concept. This activity is part of the Cosmic Times teachers guide and is intended to be used in conjunction with the 1929 Cosmic Times Poster. (View Less). ...

After discussing the Langevin equation and its computer simulation, today we are going to introduce a completely different approach to the stochastic dynamics. Using Taylor expansion, we will show that a stochastic ODE could actually be transformed into a deterministic PDE. The corresponding PDE of Langevin equation is called Fokker-Planck equation. 在討論了朗之萬方程和他的電腦模擬之後３我們今天要來介紹另一種處理隨機微分方程的方式》利用對朗之萬方程進行泰勒展開３我們可以把具有隨機性的一個常微分方程轉換成一個不具有隨機性的偏微分方程３而這個偏微分方程我們就稱之為福克-普朗克方程》 Derivation of Fokker-Planck equation 福克-普朗克方程的推導 Consider the Langevin equation in its general form: 考慮一個朗之萬方程如下４ in which η is a white noise with unit variance. 其中 η 是一個變異數為1的白雜訊３這我們在前幾集都已經討論過很多次》 In ...

Help protect yourself from getting and spreading pink eye conjunctivitis text equivalent pink eye kyneton is extremely findlay common. Doppler effect: the doppler effect is the change in frequency or redding pitch of the sound received by an roma observer. The occasion aimed to raise calais awareness of diabetes, its prevention and complications and the care that people with the condition osceola need. Dietary sources are in the kotzebue form of either vitamin trenton d 2 or d singles meet up tonight 3, both of which are converted in the liver to hydroxyvitamin d, the major circulating metabolite. Worth to mention that when finding terminal newcastle upon tyne value, growth rate used should be average predicted gdp growth rate of manitoba that country in accordance to the mean reversion theory. There are many toggles or widgets of different catholic senior online dating site tasks that you can install derbyshire dales from cydia. In, over 50, park highland park fishing permits were issued to ...

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Copyright The Student Room 2017 all rights reserved. The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.. Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE. ...

JILA is a joint physics institute of the University of Colorado at Boulder and the National Institute of Standards and Technology. We support an eclectic and innovative research program that fosters creative collaborations among our scientists. Collaborations play a key role in the pioneering research JILA and the JILA Physics Frontier Center are known for around the world. To learn more, visit our About JILA page.. ...

I have over 50 years of theoretical, experimental, and observational experience as a scientist especially interested in scientific philosophy. Although I have produced over 500 scientific reports, including journal articles, chapters, books, consulting reports, and computer programs, the best by far is my book, The Scientific Worldview: Beyond Newton and Einstein. It introduced univironmental determinism as the universal mechanism of evolution and the proper basis for scientific philosophy. It challenges the current, wildly popular, though absurd claim that the universe is finite and that it exploded out of nothing. This theme was developed in detail in my recent book, Infinite Universe Theory. Both books are completely logical from beginning to end in support of infinite universe theory as a replacement for the Big Bang Theory. The switch from the assumption of finity to the assumption infinity will result in the Last Cosmological Revolution ...

A combination of non-invasive tests consisting of Doppler ultrasound carotid velocity assessment carotid phono-angiography and directional Doppler supra-orbital flow evaluation was used to , detect internal Carotid stenosis of 50% or more in patients with symptoms suggestive of cerebrovascular disease.

We have shown that the Doppler variance method is not sensitive to bulk-motion and the method can be used without correcting the bulk-motion when the sample-movement-induced velocity changes gradually 42. Curr Opin Oncol 2005;17140в146. In our series.

Stars around us are moving with respect to our solar system. Some are moving away from us and some are moving toward us. The movement of stars affects the wavelengths of light that we receive from them, much like the high pitched sound from a fire truck siren gets lower as the truck moves past you. This phenomenon is called the Doppler effect. By measuring the stars spectrum and comparing it to the spectrum of a standard lamp, then the amount of the Doppler shift can be measured. The amount of the Doppler shift tells us how fast the star is moving relative to us. In addition, the direction of the Doppler shift can tell us the direction of the stars movement. If the spectrum of a star is shifted to the blue end, then the star is moving toward us; if the spectrum is shifted to the red end, then the star is moving away from us. Likewise if a star is spinning on its axis, the Doppler shift of its spectrum can be used to measure its rate of rotation. ...

National Aids Council (Nac) public health officer, Dr. Blessing Mutede, said authorities were concerned about the high rate of infection among the circumcised. He said it was largely a result of risk compensation behaviors. Most men, after circumcision, harbour the false impression that they have been equipped with an invisible condom, he added. It is a worrying development that at a time when we are promoting male circumcision as a preventive measure to combat HIV, we are recording a high prevalence rate amongst the group that has been circumcised largely due to uninformed risky compensation behaviors. He continued, Most people forget that being circumcised will only safeguard a person from contracting HIV up to a certain percentage and they are still at a 40 percent risk of contracting the virus. What we encourage everyone, circumcised or [intact], is to practise safe sex all the time ...

Purpose: : Doppler optical coherence tomography enables non-invasive vasculature imaging of the human posterior eye. However, its low flow sensitivity limits the imaging quality and speed. Fast and high quality vasculature imaging is demonstrated with high-speed, high-sensitive Doppler optical coherence tomography. Methods: : Newly developed spectral-domain OCT with double probing beams is used. Doppler frequency shift is obtained from the phase shift between two OCT signals acquired from each probing beam at the same location, but the different time position. These two probing beams are horizontally separated on the retina, and scan the same position sequentially with a time difference. The time difference is proportional to flow sensitivity and can be long without sacrificing the scanning speed, hence high-speed, high-sensitive Doppler flow imaging is achieved. This system is operated at 27,000 axial scans per second. Three-dimensional blood flow imaging has been applied for a healthy ...

To improve the scan quality of Doppler Optical coherence tomography for blood flow measurement, we investigate how to improve the Doppler signal for all vessels around optic disc. Doppler signal is depending on the Doppler angle, which is defined as angle between OCT beams and normal direction vessel. In this examination, we test the effect of different OCT beam direction on Doppler angles of all veins. We also test maximizing the Doppler angle by combining scans with different OCT beams direction. Three criteria were used to evaluate the overall quality, average Doppler angle, the percentage of vessels with Doppler angle larger than the optimize value, the percentage of vessel with Coefficient variance of Doppler angle less than the optimize value. The result showed that the best protocol is to maximize the Doppler angle from one scan with OCT beam through supranasal portion of pupil and other scan with OCT beam through infranasal portion of pupil ...

The present invention provides a kind of ultrasonic communication system.The ultrasonic communication system can suppress the influence of environment noise, the influence of Doppler effect (doppler effect) and avoid allowing mobilephone terminal user to hear the sound that need not be listened to.After the encryption of store information is performed, the beacon (5) being arranged in sales territory (3) will control carrier wave, first carrier and the second carrier wave to be combined by following manner, so that the beacon message of a channel comprising store information is sent in the form of ultrasonic wave in sales territory (3).The mode refers to：During carrier signal is controlled, first carrier signal and the second carrier signal correspond to store information and exported for several times, also, under the form that the state of the carrier signal of at least one party is maintained in output first carrier signal and the second carrier signal.

Our universe could be such an expanding universe. When first formulated Garmow theory predicted that there must be a signature in the form of low radiation caused the by Big Bang. He calculated the temperature of the explosion, it took into account the loss due to expansion of the universe, and reached a figure of 5 Kelvin. In 1961 Arno Penzias and Robert Wilson detected a background noise while trying to improve communications with microwave and concluded that it comes from space, having previously removed all land sources. What they found is nothing but the remaining primary radiation from the Big Bang. They were rewarded with the Nobel Prize for their discovery. ...

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Color Doppler optical coherence tomography (CDOCT) is a noninvasive optical imaging technique for micro-meter-scale physiological flow mapping simultaneously with morphological optical coherence tomography imaging. We have developed a novel CDOCT signal-processing strategy capable of imaging physiological flow rates at 8 frames/s. Our new strategy features hardware-implemented digital autocorrelation across subsequent scans, permitting us to measure 300-Hz-8-kHz Doppler shifts upon signals of 0.6-MHz bandwidth. The performance of the CDOCT system was demonstrated in a flow phantom and in vivo in Xenopus laevis.. © 2002 Optical Society of America. Full Article , PDF Article ...

Reflecting the common use of the MMPI-2 to provide diagnostic considerations, computer-based test interpretations (CBTIs) also typically offer diagnostic suggestions. However, these diagnostic suggestions can sometimes be shown to vary widely across different CBTI programs even for identical MMPI-2 profiles. The present study evaluated the diagnostic reliability of 6 commercially available CBTIs using a 20-item Q-sort task developed for this study. Four raters each sorted diagnostic classifications based on these 6 CBTI reports for 20 MMPI-2 profiles. Two questions were addressed. First, do users of CBTIs understand the diagnostic information contained within the reports similarly? Overall, diagnostic sorts of the CBTIs showed moderate inter-interpreter diagnostic reliability (mean r = .56), with sorts for the 1/2/3 profile showing the highest inter-interpreter diagnostic reliability (mean r = .67). Second, do different CBTIs programs vary with respect to diagnostic suggestions? It was found that

We report on laser Doppler perfusion imaging of human retinas using digital holography with near infrared light. The optical signal is obtained by exploiting the Doppler frequency shifts of cross-polarized light. A polarization beam splitter is used to illuminate the retina with a given linear polarization and collect cross-polarized light. The interference pattern is sampled using two detection channels: a 40 Hz sCMOS camera for real-time monitoring, and a 39 kHz CMOS camera to properly sample the Doppler broadened spectrum of the light backscattered by the retina. The holograms are numerically reconstructed by angular spectrum propagation and then processed on sliding windows of 512 images. For each short-time window, the Fourier transformation along the temporal dimension is computed, and the Doppler signal is drawn from the first moment of the high-pass filtered Fourier transformation. In the resulting images, the contrast is derived from the tissue perfusion which is related to both the ...

New look at relativity: Electrons cant exceed the speed of light -- thanks to light itself, says biologist: Any space with a temperature above absolute zero consists of photons. As a result of the Doppler effect, the moving electron experiences the photons crashing into the front of it as being blue-shifted, and the photons colliding with the back of it as being red-shifted. Since blue-shifted photons exert more momentum than red-shifted photons, the photons themselves exert a counterforce on the moving electron, just as the cytoplasm in a cell exerts a viscous force on the moving organelles. The viscous force that arises from the Doppler-shifted photons prevents electrons from exceeding the speed of light, according to Randy Wayne, associate professor of plant biology ...

Weather guys have it, planes have it, the police have it, even cars have it now Its radar! But how does it work? Well discuss the behavior of electromagnetic waves and how they can be used to determine the distance, direction, and speed of an object. Its the Doppler Effect! Watch online: Oklahoma Road Trip: Doppler from What s the Deal?. On demand, streaming video from Oklahoma Educational Television Authority

The MWS-DP-3 Microwave Solids Flow Sensor, available from Allpronix, detects moving solids utilizing microwave high penetrability and the Doppler effect. The sensing head transmits microwaves toward the target material. A portion of the microwaves are reflected back to the sensing head and analysed as to whether they are from a moving or stationary object.. The highly-penetrable microwave passes through a build-up on the head and even through pipe made of non-conducting materials such as plastics. It is best suited for detecting such materials as powders, granules, etc, moving through a vacuum pipeline.. Special Features include blocked chute detection; equipped with a filter for screening unnecessary incoming Doppler signals; and equipped with a sensitivity margin indicator.. Application Example: Flow/Non Flow ...

Microsoft Research took motion detection to new levels this week when it unveiled a new gesture recognition system for laptops.. Called SoundWave, the rig utilises the Doppler effect, picking up subtle changes in sound wave frequencies to calculate how a users hand is moving in front of a laptop. Its said to work even in noisy environments.. SoundWave works by emitting an inaudible tone between 18 and 22kHz. As these waves reflect off an object, the frequency is changed slightly. The changes are detected by the computers array of microphones.. ...

Gravity wave models for the horizontal wave number spectra of atmospheric velocity and density fluctuations are derived by assuming that both saturated and unsaturated waves obey the polarization and dispersion relations and that the joint $(m{,}\omega)$ spectrum is separable. The models show that the joint $(k, l, m)$ and $(k, l, \omega$) spectra are not separable. The one-dimensional horizontal wave number spectra models are consistent with existing observations of horizontal wave number spectra in the lower stratosphere and upper mesosphere. The gravity wave models are used to analyze the effects of Doppler shifting caused by the mean wind field on the separability of gravity wave spectra. If the intrinsic joint $(m,\omega)$ spectrum is separable, Doppler effects associated with even small mean winds will destroy separability of the observed joint $(m,\omega\sb{\rm o})$ spectrum, particularly at high vertical wave numbers. Vertical and horizontal wave number spectra of density perturbations ...

Contains 13 historical, archaic, and unusual functions. They are: Versine (VERS(X); 1 - cos x), Coversine (COVERS(X); 1 - sin x), Haversine (HAV(X); sin(x/2)^2), Normalized Sampling (NSINC(X); sin(π * x)/(π * x)), Exsecant (EXSEC(X); sec x - 1), Gundermannian (GD(X); atan(sinh x)), Inverse Gundermannian (INVGD(X); asinh(tan x)), Dilogarithm (DILN(X); ∫ (ln t / (t - 1) dt, 1, x)), Exponential Polynomial (EPOLY(N, X); Σ(x^j / j!, j, 0, n)), Hypotenuse of a Right Triangle (HYPER(A,B); √(a^2 + b^2)), Langevin Function (LANGEVIN(X); 1/tanh x - 1/x), General Mean Function (GENMEAN(N,A,B), N = 1, arithmetic mean, N = 2, root mean square, N = -1, harmonic mean, (a^n + b^n) / 2)^(1/n)), and Logarithmic Integral (Li(X); Ei(LN(x ...

Hubbles law is considered the first and most cited observational basis for the Big Bang (BB) theory. Hubble, relying on observations made by him and by others, postulated that galaxies are receding from each other at a velocity that is linear to their relative distances. He used the Doppler effect for finding the receding velocity. He claimed that there is a linear relation between the galaxys receding velocity and the measured redshift of the galaxy. These observations led to acceptance of the BB theory. The linear relation seemed valid for galaxies relatively close to the Milky Way with small redshifts. However, later measurements done on distant galaxies with high redshift show that the linear graph curves up. These later observations led to the theory that the universe is expanding at an ever-accelerating rate and subsequently to the theory of Dark Energy to account for this accelerated expansion. These new theories related to the accelerated expanding universe has raised controversies ...

Transmitted and received signals involving rotorcrafts are subject to inter-modulations caused by the rotor blades. The statistical characteristics of the wireless communication link between a rotorcraft transmitter and a receiver on the ground are developed. Both the scattering and Doppler effects.... Full description. ...

Johannes Stark (1874 - 1957) received the Nobel Prize for Physics in 1919 for his discovery of the Doppler effect in canal rays and of the splitting of spectral lines in electric fields.. ...

This week, Richmond was named the Ultimate craft beer destination in Southeast America by The Beer Travel Guide, with a note that good ol RVA has the best craft beer east of the Mississippi (cant argue with that). According to the travel guide, we not only have a rich number of breweries, but also have some of the nations most elite right here in the city limits. They report: Any serious beer trader has a few Richmond breweries on his or her In Search Of list. One could easily spend a weekend in Richmond doing nothing but drink craft beer and *still* feel like there wasnt enough time to get everything done. Aint that the truth. Since RVA is just so-damn-great, we actually get two parts to our chunk of the countrys guide, all to ourselves. They released Part 1 this week, and some of our favorites made the list. Final Gravity Brewing Company came in at #3 for its world-class IPAs (with The Doppler Effect recently ranking as the 12th-best IPA in the country). Up next was The Answer ...

Hourglass (17) Exstacy (17) Doppler Effect (21) Circuit Breaker (22) Just Hot (23) More Monkey Than Funkey (21) Red Column (15) Sands of Time (19 R) Gnasher (19) Question of Balance (21 ...

In the present study, a commercially available LSFG system (LSFG-NAVI; Softcare Co., Ltd., Fukuoka, Japan) was used to quantify perfusion in a custom-built flow phantom and in retinal vessels in vivo. The principles of LSFG have previously been outlined in detail.20-24 The LSFG device used in this study consisted of a fundus camera supplied with an 830-nm diode laser and a digital charge-coupled device camera (750 × 360 pixels). The fundamental output parameter of LSFG is mean blur rate (MBR). This parameter constitutes a measurement of relative blood flow velocity and is expressed in arbitrary units (au). During one LSFG scan, a total of 118 images are continuously captured at a rate of 30 frames per second over a time period of approximately 4 s. The device is equipped with dedicated analysis software (LSFG Analyzer version 3.1.58; Softcare), which synchronizes and mathematically averages all 118 acquired images to produce a so-called composite map depicting the distribution of perfusion in ...

The |i|Journal of Biomedical Optics|/i| (JBO) publishes peer-reviewed papers on the use of novel optical systems and techniques for improved health care and biomedical research.

Non-invasive diagnosis of fetal lung immaturity. Ultrasound gray level histogram width (GLHW) tissue characterization was studied in fetal lung. GLHW ratio of fetal lung ..

1] This paper presents an altimetric method for ocean monitoring by remote sensing. It uses carrier observations of reflected GNSS signals. The method is illustrated in a simulation study and applied to a long term experiment yielding an ocean tide spectrum. The altimetric concept is based on residual observations of Doppler frequency. A linear relation between Doppler residuals f0 and height departures ΔHfrom the surface level is derived. In contrast to existing phase-based methods which are constrained by smooth ocean conditions, the frequency-based retrieval here described holds good for rougher ocean conditions. Two retrievals of Doppler residuals are distinguished: Tracking Retrieval and Spectral Retrieval. A simulation study investigates the performance of Spectral Retrieval for a rough ocean surface with a noise-like sea level deviationξ(t). Simulation settings were adjusted to reflection events in coastal experiments with an elevation range of [5…15] deg. In this range Tracking ...

There is also a weak pulse in the veins . In contrast to the arterial pulse, which is mainly caused by changes in pressure, the pulsation of the veins is mainly caused by changes in their filling state and causes a so-called volume pulse. However, the vein flow depends on several factors, in particular on breathing, body position and body activity and not so much on the bimodal venous pulse, which is caused by changing pressure conditions in the right atrium of the heart. The venous pulse used to be recorded as a jugular vein pulse curve and can now be derived relatively easily with a Doppler device at various regions of the body. To do this, however, the Doppler frequency must be switched to the low flow velocities in the venous system. The typical vein pulse curve shows two distinctive valleys that correspond to the systolic and diastolic influx to the heart. Only in a short phase is there a brief return flow into the veins, which manifests itself as a small mountain in the vein pulse curve. ...

An embodiment of the present invention includes a GPS receiver capable of concurrently tracking up to eight GPS satellites. The GPS receiver comprises computer-implemented methods for parallel search, split search and precomputation. The parallel search method causes the apparent Doppler frequency spectrum to be sectioned into several segments and a first GPS satellite signal is searched for in parallel in each of the segments. When the first GPS fix is not found after a predetermined time has expired, a split search is begun.

In this paper, we consider the serial concatenation of linear time-varying (LTV) systems and its impact on the discrete-time modeling of wide-sense stationary uncorrelated scattering (WSSUS) fading channels. By deriving an expression for the composite impulse response of the overall concatenated system, we find that unlike the time-invariant case, the concatenation of LTV systems is not commutative, i. e., the order of arrangement affects the overall impulse response. This has significant impact when a digital transmission over a time-varying fading channel, which is an LTV channel, is represented by an equivalent discrete-time model that incorporates both transmitter and receiver filters. We further show that if the maximum Doppler frequency is much smaller than the system bandwidth, the concatenation of LTV systems is approximately commutative, then a convenient and efficient representation in the discrete-time domain for WSSUS fading channels is obtainable.

In order to investigate whether a lip-reed instruments material of manufacture plays a significant role in determining the timbre of the notes it produces, tests have been conducted on five post horns. These post horns have identical geometry but are manufactured from different copper alloys. Using a laser Doppler vibrometer, the structural resonances of each instrument have been established and the wall vibrations induced in each instrument when artificially blown have been measured. In this paper, these measurements are compared with findings from a series of blindfold playing tests carried out using professional musicians and with listening tests comprising notes produced by the different instruments.. ...

Condition: This item is in good shape cosmetically. There are a few minor scratches, scuffs, and/or markings here and there from normal use. Please see pictures for more details ...

The purpose of this work is to introduce a technology that has great potential for non-invasive flow imaging in the human retina - both quantitatively as well as for microvascular contrast imaging - based on Doppler Optical Coherence Tomography (DOCT).. Traditional DOCT is highly sensitive to motion artifacts due to the dependence on the angle between the vessel and the illumination direction, limiting its accuracy in clinical practice. To overcome this limitation, we use a bidirectional dual beam platform with flexible aligning of the incidence plane allowing reconstruction of the true flow velocity in the range of 5 to 500mm/s. The system operates at a longer wavelength of 1060nm than traditional ophthalmic OCT systems which allows for better penetration beyond the retinal pigment layer, with improved contrast for the important choroidal capillaries and vessels.. The angle independent quantitative flow dynamics are extracted from specific vessel cross-sections of arteries and veins, acquired ...

V. Kavvadias, G. Epitropou, N. Georgiou, F. Grozou, M. Paschopoulos and C. Balas A Novel Endoscopic Spectral Imaging Platform Integrating K-Means Clustering for Early and non-Invasive Diagnosis of Endometrial Pathology, at the 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC13) Osaka, Japan on July 3-7, ...

Instrument for automatic analysis and recognition (through a software/algorithm) of pulmonary sounds acquired through an electronic stethoscope.

Novel Biomarkers Located at 3p22.1 And 10q22.3 Offer a Non-Invasive Diagnosis of Lung Cancer in Induced Sputum Samples by Combination of Cytology and Fluorescence in Situ Hybridization (FISH) ...

The cosmic microwave background is the radiation left over from the big bang. Its very uniform, 2.725 Kelvin everywhere. Were moving with respect to it, so theres a doppler shift, and we see that as a dipole moment in the Temperature. When we subtract that out, we see variations on the order of 30 microKelvins!…. ...

I am a 45 year old white male about 40 pounds overweight. Family history is significant for hypertension, diabetes, but no significant coronary history per say. My parents are both still living. I s...

WHY ISNT EVERYONE WAKING UP? OR ARE WE? IS THIS LIFE A TRAINING SIMULATION? IS EACH CIRCUMSTANCE TAILOR MADE FOR US TO WAKE UP? LETS REFLECT TOGETHER OUR CHOICES DETERMINE THE STORY WE LIVE. IS WHAT WE ARE GOING TO DO NEXT ALREADY HAPPENED? WERE WE IN THE FUTURE BEFORE WE ARRIVED HERE? I SPEAK…