A mathematical model for lifetime prediction of lacquer-paint coatings in sea water

Main features of the mechanism of lacquer-paint coatings destruction in sea water have been revealed. On this basis, a mathematical model has been developed and boundary value problems of mathematical physics have been formulated to calculate the determining processes on characteristic stages of coatings in sea water. The theoretical evaluation of coatings longevity depending on physical characteristics of the system has been made. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Exact Solution of the Heat Transfer Problem for a Rotating Disk under Uniform Jet Impingement

An exact solution of the heat transfer problem for a uniform air stream impinging on a rotating disk is found. By introducing self-similar radial velocity and temperature profiles, the problem is reduced to a system of ordinary differential equations which are solved numerically. The Nusselt numbers are calculated for Prandtl numbers equal to 1 and 0.71 and various ratios of the free-stream velocity to the disk rotation velocity. The limits of the flow regime in which the heat transfer is determined solely by the impact jet parameters are found. The results are compared with experimental data for the stagnation point.     

Effect of the porous structure of sodium chloride granules on their physicochemical properties

The effect of porous structure on the strength characteristics of compacted potassium chloride granules and also on their moisture absorption and caking was studied.     

Computation of the lifetime of metal cathode coatings

We propose a method of computing the service time of protective coatings as functions of the geometric and physical characteristics of the aggressive medium-coating-base system. The method is based on representing the destruction process as a series of successive time stages. We analyze the possibility of loss of protective properties of a metallic cathode covering both as a consequence of mechanical failure and as a result of flaking.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 35, 1992, pp. 24–34.     

Properties of blends of methyl cellulose and carboxymethyl cellulose with different degrees of ionization in solutions and solids

The rheological properties of dilute and moderately concentrated aqueous solutions of methyl cellulose with carboxymethyl cellulose having different degrees of ionization, were examined. The solvent vapor sorption method was applied to examine the compatibility of the polymers in the solid state and elucidate how the amount of nonionized carboxy groups in carboxymethyl cellulose affects its compatibility with methyl cellulose.