Methods to incorporate the effect of ambient currents in the prediction of nearshore wave transformation are developed. This is accomplished through the construction of a finite-element coastal/harbor wave model based on an extended mild-slope wave–current equation that includes wave breaking. Improved boundary conditions are used to provide more accurate forcing and to minimize spurious wave r...

This paper studies a Boltzmann transport equation with several electronphonon scattering mechanisms, which describes the charge transport in semiconductors. The electric field is coupled to the electron distribution function via Poisson’s equation. Both the parabolic and the quasi-parabolic band approximations are considered. The steady state behaviour of the electron distribution function is i...

We study travelling-wave solutions for a reaction-diffusion system arising as a model for host-tissue degradation by bacteria. This system consists of a parabolic equation coupled with an ordinary differential equation. For large values of the ‘degradation-rate parameter’ solutions are well approximated by solutions of a Stefan-like free boundary problem, for which travelling-wave solutions can...

Computational aspects of EM pulse propagation along the nonuniform earth surface are considered. For ultrawide-band pulses without carrier, the exact wave equation in a narrow vicinity of the wave front is reduced to a time-domain version of the LeontovichFock parabolic equation. To solve it by finite differences, we introduce a time-domain analog of the impedance BC and a nonlocal BC of transp...

Description of waves that propagate through the turbulent atmosphere is a fundamental problem, for instance from the point of view of applications to communication and remote sensing. Yet, so far, very little is known about how the wave field interacts with the turbulent or multiscale nature of the refractive index which derives from the multiscale nature of the temperature fluctuations. The pa...

The interference of the direct wave from the point source to the receiver and the wave reflected from the impedance ground in a turbulent atmosphere is studied. A parabolic equation approach for calculating the sound pressure p at the receiver is formulated. Then, the parabolic equation is solved by the Rytov method yielding expressions for the complex phases of direct and ground-reflected wave...