Simulation of Convective Flow of an Electrically Conducting Fluid in a Cavity

A new quasi-hydrodynamic algorithm is proposed for numerical analysis of convective flows in the presence of a homogeneous external magnetic field. The Marangoni convection problem in a square cross-section cavity is solved.     

Tests for extremality in a problem for quasiconformal mappings

Mathematical Notes -     

Teikhmyuller problem for one class of open Riemannian surfaces

A particular solution is given to the Teikhmyuller problem on minimizing the deviation K[f] in the homotopic classa, preserving the orientation of the quasiconformal homeomorphism h: S₀ S, where S₀ and S are open Riemannian surfaces of infinite kind. Some properties of the complex characteristic of the solution are studied.Translated from Matematicheskie Zametki, Vol. 7, No. 5, pp. 605–615, May, 1970.     

Anomalous thermopower in the metalliclike phase of a 2D hole system

We report very low temperature ( T) thermopower and resistivity ( rho) measurements on variable-density, two-dimensional hole systems confined to GaAs quantum wells. As the hole density is lowered from 1.49x10(11) cm(-2) to 0.14x10(11) cm(-2), the system crosses from an insulating ( drho / dT less, similar0) to a metallic regime ( drho / dT>0) and finally displays insulating behavior ( drho / dT<0). Diffusion thermopower shows a striking sign reversal in a narrow range of density in the metallic regime, suggesting a qualitative change in the conduction or the scattering mechanism.     

A monopole mass filter with a hyperbolic V-shaped electrode

In this article we compare the classical monopole mass filter of von Zahn and the monopole mass filter with a hyperbolic V-shaped electrode. The experimental results and those of computer simulation for both mass spectrometers are presented. We show that the replacement of a conventional 90 degrees V-shaped electrode by an electrode with a hyperbolic profile substantially improves the peak shape of any given mass, and increases the mass resolution by a factor of 3-4 and the abundance sensitivity by a factor of 100. The potential of high analytical performance combined with electroforming techniques for electrode manufacture indicate future practical uses of such instruments. Copyright 1999 John Wiley & Sons, Ltd.     

Computation of convective flows using the quasihydrodynamic equations

We discuss the results of numerical modeling of problems of gravitational and thermocapillary convection in rectangular cavities with small Prandtl numbers. The results are obtained using the quasihydrodynamic system of equations and compared with the results of computations using the Navier-Stokes system. Three tables, 12 figures. Bibliography: 19 titles. Translated fromProblemy Matematicheskoi Fiziki, 1998, pp. 193–208.