Generalized equation for transient-wave propagation in continuous inhomogeneous rigid-frame porous materials at low frequencies

A wave model for rigid-frame porous materials using lumped parameter concepts

The work presented in this paper concerns the behaviour of porous media when exposed to a normal incidence sound field. A propagating wave model based on lumped parameter concepts of acoustic mass, stiffness and damping is used to investigate the absorption phenomena due to the wave propagation in the layer(s) and interference effects due to the wave reflection–transmission at the interfaces of...

A Parabolic Equation for Wave Propagation over Porous Structures

Continuous-wave light modulation at molecular frequencies

By using continuous-wave (CW)–stimulated Raman scattering inside a high-finesse cavity, we generate three CW spectral components covering about one octave of optical bandwidth. We investigate the mutual coherence of these three beams by studying phase-dependent second harmonic generation. From the high contrast of the observed interference fringes, we infer very good phase coherence across the ...

Reconfigurable antennas and radio wave propagation at millimeter-wave frequencies

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Vasilii Semkin Name of the doctoral dissertation Reconfigurable antennas and radio wave propagation at millimeter-wave frequencies Publisher School of Electrical Engineering Unit Department of Radio Science and Engineering Series Aalto University publication series DOCTORAL DISSERTATIONS 151/2016 Field of research Radio Engine...

Wave Propagation in Mixture of Generalized Thermoelastic Solids Half-Space

This paper concentrates on the reflection of plane waves in the mixture of generalized thermo elastic solid half-space. There exists quasi dilatational waves i.e. qP1, qP2, qT and two rotational waves S1, S2 in a two dimensional model of the solid. The boundary conditions are solved to obtain a system of five non-homogeneous equations for amplitude ratios. These amplitude ratios are found to de...