An image system and surface singularity solutions for potential flow past an elliptical cylinder

The Milne-Thomson circle theorem is extended to give a simplegeneral expression for the image system in an elliptical cylinderintroduced into an otherwise specified unbounded potential flowwhich contains no singularities in the region to be occupiedby the ellipse. This image system is used to obtain an expressionfor the corresponding source-sink surface singularity distributionon the ellipse, thus providing new benchmark test cases forsource-sink solutions as obtained numerically by a panel method.Several typical examples are given to illustrate the generaltheoretical approach.     

TiO<Subscript>2</Subscript> Photocatalytic Oxidation: II. Gas-Phase Processes

The results of studies on the TiO₂ photocatalytic oxidation of model air pollutants are summarized. The kinetics of photocatalytic oxidation of CO and the vapors of a number of simple organic substances was studied in detail. It was found that, in the course of reaction, all of the test substances underwent complete mineralization. Gaseous substrates were converted with the participation of several types of reaction centers. The photocatalytic oxidation of sulfur- and phosphorus-containing substances resulted in gradual deactivation of the photocatalyst; however, its activity can be restored by washing the photocatalyst with water. It was found that, along with oxidation, the steps of hydrolysis play an important role in the photocatalytic degradation of air pollutants, such as dimethyl methylphosphonate and 2-chloroethyl sulfide.__________Translated from Kinetika i Kataliz, Vol. 46, No. 3, 2005, pp. 450–465.Original Russian Text Copyright © 2005 by Vorontsov, Kozlov, Smirniotis, Parmon.