This paper is devoted to study a problem of plane waves reflection at a traction-free surface of a pre-stressed functionally graded piezoelectric material (FGPM). The effects of initial stress and material gradient on the reflection of plane waves are studied in this paper. Secular equation has been derived analytically for the pre-stressed FGPM half-space and used to show the existence of two ...

It is known that the stability of finite-difference models of hyperbolic initial-boundaq value problems is connected with the propagation and reflection of parasitic waves. Here the waves point of view is applied to models containing two boundaries or interfaces, where repeated reflection of trapped wave packets is a potential new source of instability. Our analysis accounts for various known i...

localized scatterers can be expected to give rise to spatial variations in the electric field and in the current distribution. The transport equation allowing for spatial variations is solved by first considering the homogeneous transport equation which omits electric fields. The homogeneous solution gives the purely diffusive motion of current carriers and involves large space charges. The ele...

A completion problem to recover a rational matrix function which is j-unitary on the line is treated. A Dirac type system with singularities on the semiaxis is recovered explicitly by its left reflection coefficient. The close connection between these two problems is discussed.

The rapid progress in nanoelectronics showed an urgent need for microwave measurement of impedances extremely different from the 50Ω reference impedance of measurement instruments. In commonly used methods input impedance or admittance of a device under test (DUT) is derived from measured value of its reflection coefficient causing serious accuracy problems for very high and very low impedances...

We study the reflection of terahertz (THz) radiation at the end of a parallel-plate waveguide (PPWG), due to the impedance mismatch between the propagating transverse-electromagnetic mode and the free-space background. We find that, for a PPWG with uniformly spaced plates, the reflection coefficient at the output face increases as the plate separation decreases, consistent with predictions by e...

In lamprey, the supraspinal control of velocity is mainly accomplished by the reticulospinal (RS) system. During locomotion, RS neurones are rhythmically active with a cycle duration corresponding to the duration of the swim cycle. While the velocity of the muscular contraction wave changes as swimming velocity changes, the conduction velocity of RS axons remains constant. Thus, an action poten...

When very large groups have to brainstorm in smaller subgroups, meeting organizers have a choice between two options: (1) Let every subgroup start from scratch, or (2) Let every next subgroup build on the results from the previous subgroup. We refer to these options as the Decathlon and Relay modes of brainstorming respectively. During a case study we investigated which brainstorming mode would...

Third-order susceptibilities are calculated for a Doppler-broadened two-level system. The dependence of fourwave mixing on the angle 0 between the pump and signal fields is studied, and the reflection coefficient is shown to have a narrow field of view that is inversely proportional to the ratio of the Doppler width to the homogeneous linewidth. For the collinear geometry, 0 = 0°, the frequency...