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The velocity measurement of phase objects
Opto-electronics, 1972Conventional laser velocimeters rely upon small contaminant dust particles to scatter the laser light. A technique is described which requires no contaminant particles but relies upon minute refractive index variations in the fluid. By placing the detector far from the measuring region a set of shadow bands is produced which is convected with the fluid.
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Relativistic phase velocity transformation
American Journal of Physics, 1989By utilizing the appropriate Doppler formulas, it is shown that phase velocities in both Galilean and relativistic kinematics transform according to rules different from the ordinary velocity addition laws. As corollaries, it is demonstrated that (i) phase velocities parallel to the inertial frames’ relative velocity transform according to the Lorentz ...
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Phase, Group, and Signal Velocity
American Journal of Physics, 1954Phase, group, and signal velocity are defined. Simple examples are given in which the phase and group velocities exceed the velocity of light, in which the phase velocity is a function of distance, and in which the group velocity is equal to the signal velocity.
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On the phase velocity of the quantal waves
Il Nuovo Cimento A, 1995As a consequence of the theory of the characteristics of the partial differential equations the law of motion of the wave front of a quantal wave moving in electrostatic and magnetostatic fields is formally identical with the corresponding law for zero magnetic fields.
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Negative Phase-Velocity Mediums
2009Isotropic dielectric-magnetic mediums wherein the phase velocity vector and the time-averaged Poynting vector of propagating plane waves are oppositely directed have recently become the focus of research on microwave composite materials. The purpose of this overview is to illuminate the background of rapidly occurring developments, to present a clear ...
Akhlesh Lakhtakia +2 more
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Demonstrating Phase Velocity and Group Velocity
American Journal of Physics, 1969openaire +1 more source
Jaw phasings and velocity profiles in arabic
3rd European Conference on Speech Communication and Technology (Eurospeech 1993), 1993Mounir Jomaa, Christian Abry
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The measurement of Lamb wave phase velocity using analytic cross-correlation method
Mechanical Systems and Signal Processing, 2021Liang Zeng, Xuwei Cao
exaly