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In a dispersive medium, the phase speed itself depends upon the frequency of the wave, making the relationship between wavelength and frequency nonlinear.
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dispersive and medium
Otherwise, when the phase velocity varies with frequency, velocities differ and the medium is called dispersive.
Due to the Kramers – Kronig relations, a linear medium with dispersion also exhibits loss, so the sine wave propagating in a dispersive medium is attenuated in certain frequency ranges that depend upon the medium.
A dispersion-limited operation is an operation of a communications link in which signal waveform degradation attributable to the dispersive effects of the communications medium is the dominant mechanism that limits link performance.
Solitons are caused by a cancellation of nonlinear and dispersive effects in the medium.
But air does contain a small amount of CO < sub > 2 </ sub > which is a dispersive medium, and it introduces dispersion to air at ultrasonic frequencies (> 28 kHz ).
In a dispersive medium sound speed is a function of sound frequency, through the dispersion relation.
This was inconsistent with dispersive replication, which would have resulted in a single density, lower than the intermediate density of the one-generation cells, but still higher than cells grown only in < sup > 14 </ sup > N DNA medium, as the original < sup > 15 </ sup > N DNA would have been split evenly among all DNA strands.
In fluid theory, in which the plasma is modeled as a dispersive dielectric medium, the energy of Langmuir waves is known: field energy multiplied by the Brillouin factor.
We consider the propagation for the SVEA of the electric field in a homogeneous dispersive nonistropic medium.
Because of the dispersive nature of the interstellar plasma, lower-frequency radio waves travel through the medium slower than higher-frequency radio waves.
As a result, water with a free surface is generally considered to be a dispersive medium.
dispersive and phase
Because waves at different frequencies propagate at differing phase velocities in dispersive media, for a large frequency range ( a narrow envelope in space ) the observed pulse would change shape while traveling, making group velocity an unclear or useless quantity.
To model dispersive wave phenomena, those in which the speed of wave propagation varies with the frequency of the wave, the constant c is replaced by the phase velocity:
A wave in which the group and phase velocities differ is called dispersive.
* group velocity, the propagation velocity for the envelope of wave groups and often of wave energy, different from the phase velocity for dispersive waves
This is commonly called the dispersive phase of the life cycle.
First order corrections to frequency dispersive antennas such as log periodic can be handled by phase correcting the received signal.
Examples of dispersive targets include RF absorbers in which the absorption depth is a function of frequency and various antenna in which the phase center position is frequency dependent.
dispersive and speed
( The term " dispersive effects " refers to a property of certain systems where the speed of the waves varies according to frequency.
dispersive and depends
The waveguide is dispersive, which means that their group velocity depends on frequency.
dispersive and frequency
** Fading model, for example Rayleigh fading, Ricean fading, log-normal shadow fading and frequency selective ( dispersive ) fading
Equations such as NLS, having solutions whose velocities depend on frequency are called dispersive.
Experimentally, the frequency shifts in Brillouin scattering are detected with an interferometer, while Raman setup can be based on either interferometer or dispersive ( grating ) spectrometer.
Classically, in analog systems, it is passed to a dispersive delay line ( often a SAW device ) that has the property of varying velocity of propagation based on frequency.
Like negative index materials, SNGs are innately dispersive, so their ε, µ, and refraction index n, will alter with changes in frequency.
dispersive and wave
An impression of the dispersive behaviour of this wave packet is obtained by looking at
It is evident that this dispersive wave packet, while moving with constant group velocity k < sub > 0 </ sub >, has a width increasing with time as.
Control and guidance of phonon-polariton propagation may also be achieved by guided wave, reflective, diffractive, and dispersive elements, as well as photonic and effective index crystals that can be integrated directly into the host crystal.
This dispersive arrivals of swells, long periods first with a reduction in the peak wave period over time, can be used to tell the distance at which swells were generated.
dispersive and between
This is usually achieved using costly fluoro-crown glasses, abnormal flint glasses, and even optically transparent liquids with highly unusual dispersive properties in the thin spaces between glass elements.
In dispersive adhesion, also known as physisorption, two materials are held together by van der Waals forces: the attraction between two molecules, each of which has a region of slight positive and negative charge.
The contact angle of the three-phase system is a function not only of dispersive adhesion ( interaction between the molecules in the liquid and the molecules in the solid ) but also cohesion ( interaction between the liquid molecules themselves ).
Because of these attractive dispersive forces between the PDMS and the smooth substrate, the elevated surface – or “ roof ” – collapses down onto the substrate without any external force aside from the van der Waals attraction.
If a dispersive element, such as a prism, is introduced into the optical cavity, tilting of the cavity's mirrors can cause tuning of the laser as it " hops " between different laser lines.
For a given distance between the dispersive elements, prisms generate much less dispersion than gratings.
dispersive and wavelength
X-rays, which are produced by the interaction of electrons with the sample, may also be detected in an SEM equipped for energy-dispersive X-ray spectroscopy or wavelength dispersive X-ray spectroscopy.
The directions of these beams depend on the spacing of the grating and the wavelength of the light so that the grating acts as the dispersive element.
The wavelength dependence in the grating equation shows that the grating separates an incident polychromatic beam into its constituent wavelength components, i. e., it is dispersive.
In wavelength dispersive analysis, the fluorescent X-rays emitted by the material sample are directed into a diffraction grating monochromator.
In wavelength dispersive analysis, the single-wavelength radiation produced by the monochromator is passed into a photomultiplier, a detector similar to a Geiger counter, which counts individual photons as they pass through.
Figure 6: Schematic arrangement of wavelength dispersive spectrometer
In wavelength dispersive spectrometers ( WDX or WDS ), the photons are separated by diffraction on a single crystal before being detected.
Although wavelength dispersive spectrometers are occasionally used to scan a wide range of wavelengths, producing a spectrum plot as in EDS, they are usually set up to make measurements only at the wavelength of the emission lines of the elements of interest.
The velocity of these waves varies with wavelength, so they are said to be dispersive and the shape of the wavetrain varies with distance.
The Wavelength dispersive X-ray spectroscopy ( WDXRF or WDS ) is a method used to count the number of X-rays of a specific wavelength diffracted by a crystal.
Unlike the related technique of Energy dispersive X-ray spectroscopy ( EDS ) WDS reads or counts only the x-rays of a single wavelength at time, not producing a broad spectrum of wavelengths or energies simultaneously.
EDS is often contrasted with its spectroscopic counterpart, WDS ( wavelength dispersive X-ray spectroscopy ).
In a wavelength dispersive X-ray spectrometer the single crystal diffracts the photons ( Bragg's law ) which are collected by a detector.
Specific X-ray wavelengths are selected and counted, either by wavelength dispersive X-ray spectroscopy ( WDS ) or energy dispersive X-ray spectroscopy ( EDS ).
EBSD when used together with other in-SEM techniques such as cathodoluminescence ( CL ), wavelength dispersive X-ray spectroscopy ( WDS ) and / or energy dispersive X-ray spectroscopy ( EDS ) can provide a deeper insight into the specimen's properties.
Angle dispersive ( fixed wavelength ) instruments typically have a battery of individual detectors arranged in a cylindrical fashion around the sample holder, and can therefore collect scattered intensity simultaneously on a large 2θ range.
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