The note is concerned with a time-delayed reaction–diffusion equation with nonlocality for the population dynamics of single species. For the critical speed of traveling waves, we give a detailed analysis on its location and asymptotic behavior with respect to the parameters of the diffusion rate and mature age, respectively. c © 2006 Elsevier Ltd. All rights reserved.

We report uniform Type-II GaInAsSb/InP UTC-PDs, and compare their performance to devices fabricated with GaAsSb graded (composition doping) absorbers of the same thickness. The quaternary UTC-PDs show a transit limited bandwidth 274 GHz in contrast 107 185 for absorber UTC-PDs. Because ternary only differ material, findings conclusively demonstrate enhanced transport GaInAsSb. Performance compa...

State transitions in the nervous system often take shape as traveling waves, whereby one neural state is replaced by another across space in a wave-like manner. In visual perception, transitions between the two mutually exclusive percepts that alternate when the two eyes view conflicting stimuli (binocular rivalry) may also take shape as traveling waves. The properties of these waves point to a...

Unstable concentration gradients inherent in traveling chemical waves can give rise to buoyancy-driven convection, altering the speed of the wave. When an excitable Belousov– Zhabotinsky reaction system is confined within a sufficiently narrow, vertical two-dimensional channel, convection arises at a symmetry-breaking bifurcation point. The observed linear rate of change of wave speed with the ...

is investigated, where f is a bi-stable reaction-term and D(v) is a diffusion coefficient with changing sign, modeling aggregating-diffusing processes. We provide necessary and sufficient conditions for the existence of traveling wave solutions and classify them according to how or if they attain their equilibria at finite times. We also show that the dynamics can exhibit the phenomena of finit...

In this paper, we investigate a nonlocal periodic reaction-diffusion population model with stage structure. In the case of unbounded spatial domain, we establish the existence of the asymptotic speed of spread and show that it coincides with the minimal wave speed for monotone periodic traveling waves. In the case of bounded spatial domain, we obtain a threshold result on the global attractivit...

For a large class of nonlinear Schrödinger equations with nonzero conditions at infinity and for any speed c less than the sound velocity, we prove the existence of finite energy traveling waves moving with speed c in any space dimension N ≥ 3. Our results are valid as well for the Gross-Pitaevskii equation and for NLS with cubic-quintic nonlinearity. AMS subject classifications. 35Q51, 35Q55, ...

A wave traveling upward through a particle bed is observed to steepen and form a shock as the surface is approached. This steepening is due to the increase in the local speed of sound that is induced by the local pressure increase in the upward moving phase of the wave behind the wave front. The pressure increase leads to an increase in the local coordination number which in turn increases the ...