Acoustic Absorption Coefficients at High Frequencies

Electrothermal transport coefficients at finite frequencies

We review a recently developed formalism for computing thermoelectric coefficients in correlated matter. The usual difficulties of such a calculation are circumvented by a careful generalization of the transport formalism to finite frequencies, from which one can extract the high frequency objects. The technical parallel between the Hall constant and the Seebeck coefficient is explored and used...

Zn-doped GaSb epitaxial film absorption coefficients at terahertz frequencies and detector applications

The reflectance measurements of p-type GaSb:Zn epitaxial films with different hole concentrations, grown by metalorganic vapor-phase epitaxy, have been investigated in the 3–30-THz frequency region. The experimental spectra were fitted using a classical harmonic Lorentz oscillator and the Drude model, illustrating that the hole effective mass and the mobility change with the carrier concentrati...

Reflection and absorption coefficients for use in room acoustic simulations

Study of the effect of shape on acoustic performance of micro perforated absorbent at low frequencies

Introduction: Micro-perforated absorbents are one of the structures that are widely used nowadays. The sound absorption mechanism is performed by viscous energy losses in the cavities on the plate. In this study, the acoustic properties of non-flat perforated panels in oblique angle was investigated in numerical method. Material and Methods: This paper examined the effect of the surface shape ...

A High Order Approximation of the Two Dimensional Acoustic Wave Equation with Discontinuous Coefficients

This paper concerns with the modeling and construction of a fifth order method for two dimensional acoustic wave equation in heterogenous media. The method is based on a standard discretization of the problem on smooth regions and a nonstandard method for nonsmooth regions. The construction of the nonstandard method is based on the special treatment of the interface using suitable jump conditio...