Exact solutions of the one‐dimensional acoustic wave equations for several new velocity profiles: Transmission and reflection coefficients

1982 ◽  
Vol 71 (6) ◽  
pp. 1391-1399 ◽  
Author(s):  
P. B. Abraham ◽  
H. E. Moses
Author(s):  
Erdogan S. Suhubi ◽  
Alan Jeffrey

SYNOPSISThis paper investigates the one-dimensional propagation of weak discontinuities, that is acceleration waves, in a homogeneous and isotropic half-space composed of an arbitrary number of non-linearly hyperelastic layers. The transmission and reflection coefficients are evaluated in terms of the initial condition at the boundary, and the steepening of the waves to form a shock is discussed. The results are specialised to the case of periodic layering.


1979 ◽  
Vol 57 (11) ◽  
pp. 1952-1958 ◽  
Author(s):  
W. van Dijk ◽  
M. Razavy

A model for one-dimensional many-channel scattering of a particle from a composite system is considered. It is assumed that the target cannot break up. Using Bellman's method of invariant embedding, a system of non-linear first-order differential equations with one-point boundary conditions is obtained for the transmission and reflection coefficients. These equations have stable numerical solutions. An alternative invariant embedding with the approximation of no reflection at any stage of the scattering process yields the Glauber approximation for the transmission coefficients. These formulations are used to compare the exact and the Glauber amplitudes for a projectile scattering from a bound two-particle system. It is found that unlike the inelastic Glauber amplitudes, the elastic Glauber amplitudes are very good approximations to the exact results.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3499
Author(s):  
Anatoly B. Rinkevich ◽  
Dmitry V. Perov ◽  
Yuriy I. Ryabkov

The microwave properties of a composite material containing flakes of finemet-type nanocrystalline alloy placed in the epoxy matrix have been investigated. Two compositions have been studied: with 15% and 30% flakes. Frequency dependences of transmission and reflection coefficients are measured in the frequency range from 12 to 38 GHz. The dielectric permittivity and magnetic permeability are obtained, and the microwave losses are calculated. The dependences of transmission and reflection coefficients have been drawn as functions of wave frequency and thickness of the composite material, taking into account the frequency dependences of permittivity and permeability. The regions of maximal and minimal microwave absorption have been defined. The influence of wave interference on the frequency dependence of microwave absorption is studied.


Author(s):  
O. Langueur ◽  
M. Merad ◽  
A. Rassoul

In this paper, we study the Duffin–Kemmer–Petiau (DKP) equation in the presence of a smooth barrier in dimensions space–time (1+1) dimensions. The eigenfunctions are determined in terms of the confluent hypergeometric function [Formula: see text]. The transmission and reflection coefficients are calculated, special cases as a rectangular barrier and step potential are analyzed. A numerical study is presented for the transmission and reflection coefficients graphs for some values of the parameters [Formula: see text] are plotted.


Author(s):  
Hironori Tohmyoh

Abstract This paper presents the materials evaluation and environmental monitoring techniques utilizing the acoustic resonance, which have been developed by the authors. When the ultrasound passes through thin layer, the transmission and reflection coefficients take their maximum and the minimum values at the resonant frequency. We call this acoustic resonance. The acoustic properties of a polymer film, e.g., the acoustic impedance, ultrasonic velocity, and density, can be determined by observing the acoustic resonance, which occurs at the water/film/reflection plate interface. Acoustic resonance occurs at the reflection plate/film/outer environment interface sensitively changes depending on the outer environment. With use of this, the temperature of the water as an outer environment is tried to be monitored.


2019 ◽  
Vol 34 (16) ◽  
pp. 1950087 ◽  
Author(s):  
Luis Puente ◽  
Carlos Cocha ◽  
Clara Rojas

We present a new potential barrier that presents the phenomenon of superradiance when the reflection coefficient [Formula: see text] is greater than one. We calculated the transmission and reflection coefficients for three different regions. The results are compared with those obtained for the hyperbolic tangent potential barrier and the step potential barrier. We also present the solution of the Klein–Gordon equation with the Lambert-[Formula: see text] potential barrier in terms of the Heun Confluent functions.


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