Asymptotic stability of the numerical solution for an integrodifferential reaction-diffusion system

This paper presents the study of the numerical solution of a reaction-diffusion system involving a reaction term of integral type arising from biological models. By means of a monotone approach we introduce upper and lower solutions and then we show the existence and the asymptotic behavior of nonnegative numerical solutions. To this end, we require the positivity of the numerical scheme and so we can use some properties of positive and M-matrices. Finally we give some sufficient conditions to verify the asymptotic stability of the numerical solution.     

Electrospray deposition in vacuum

We have used the established technique of electrospray in developing a portable vacuum electrospray system which can deposit, in vacuo, dissolved molecules onto a sample which may then be analysed by UHV techniques. As an initial test of the system we have analysed silicon samples with an electrosprayed layer of poly(ethylene) oxide (PEO) using atomic force microscopy (AFM). The polymer forms different structures depending on the voltage applied to the emitter, and solution composition. The system is part of our ongoing effort to deposit other materials such as nanoparticles, and large dye molecules for developing molecular dye sensitised solar cells.     

Recent trends in optical data processing

Optical data processing is an advancing field which has received much attention in recent years. Optical techniques have already shown their applicability in target identification, advanced signal processing operations and advanced linear algebra operations. The potential capabilities of processing of data using photons instead of electrons as the carrier of information have established, beyond any doubt, that the optical techniques will be the next generation technology surpassing electronic techniques in some important areas such as air traffic control, missile guidance and remote sensing. Although great strides have been made in all the areas of optical data processing, the goal of high performance, high speed and very accurate all-optical computers would be realised only around the year 1995. The main difficulty is that the required materials for high resolution and fast spatial light modulators and optical interconnects are yet to be perfected. The present paper reviews the recent trends and the future prospects of optical data processing.     

Neutron interferometry in gravitational field with torsion

We consider the possibility of finding experimental evidence of the fifth force with the measurement of a phase shift of neutron beams via an interferometric apparatus and also a possible rotation of the polarization plane of polarized neutron beams when torsion is introduced in a gravitational field.     

On a zero equation model of turbulence

In this paper we study a widely used zero equation model of turbulence. The governing equations are derived by applying to the incompressible Navier-Stokes equations the Reynolds time averaging procedure. We achieve closure by employing the eddy viscosity concept. Using the Implicit Function Theorem we obtain an existence and uniquencess result. We also discuss the existence of nonsingular solutions. Finally, we present an algorithm for solving the modeled equations.