Self-similar axisymmetric thermal in a variable-density medium

A model of a turbulent axisymmetric thermal rising in a medium whose density varies with height is proposed. An analytic solution describing the self-similar stage of ascent of the thermal is constructed. The effect of the density stratification of the atmosphere on the structure of the thermal during its motion is analyzed, and relations describing the characteristic points of the thermal and the smearing of its leading edge are obtained.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 45–53, July–August, 1991.     

Sedimentation of a cloud of a bidispersed aerosol onto a flat horizontal surface

Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, No. 2, pp. 101–108, March–April, 1992.     

Entrainment of dispersed impurities into the atmosphere by a rising thermal

The ascent of a dusty turbulent thermal in a nonuniform compressible atmosphere is numerically investigated. The dispersed phase is described in the one-velocity and one-temperature approximation. A comparative calculation of the entrainment of active and passive impurities into the stratosphere is made, the vertical aerosol density distribution in the hanging cloud is obtained, and the maximum amount of active impurity that can be carried beyond the tropopause by a thermal of given energy is determined. The ascent of a thermal formed in an air blast is contrasted with that of a thermal formed in a surface blast, and the results of the calculations are compared with previously published data.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1, pp. 123–130, January–February, 1990.     

Heat Transfer of a Cylindrical Body with Catalytic Surface in Subsonic Nonequilibrium Air Plasma Flow

Fluid Dynamics - Steady-state subsonic flows of nonequilibrium air plasma past a cylindrical body with plane face and heat transfer are investigated under the conditions characteristic of testing...     

Calculation of the thermondynamic values of alkylthiazoles from the Kovats retention indices on the basis of the non-linear additivity principle

Summary Retention indices and their energy equivalents were determined for ten alkylthiazoles analysed on the stationary phases Apiezon L, Triton X-305 and Carbowax 1000. It was found that the energy contributions of identical alkyl groups to the partial molar free energy of sorption of a molecule are not equivalent. Smaller energy contribututions are due to the α-position of alkyl groups with respect to the heteroatoms in the thiazole ring (α-effect). This effect was most pronounced for 2-alkylthiazoles. Higher sorption energies were found for dimethylthiazoles with two methylgroups in a vicinal position. The retention indices were predicted for ten other di- and tri-substituted methyl, ethyl and propyl thiazoles on the basis of the so-called α- and ortho-effects. The predicted values are in good agreement with the experimentally determined values. Dedicated to Prof. Dr. E. sz. Kováts (Ecole Polytechnique Fédérale de Lausanne) on the occasion of his sixtieth birthday.     

Proximate Composition,Antioxidant Properties,and Hepatoprotective Activity of Three Species of Shellfish of the Pacific Coast of Russia

The objective of the present study was to investigate the proximate composition, antiradical properties and hepatoprotective activity of three species of shellfish, Corbicula japonica, Spisula sachalinensis, and Anadara broughtonii, from the coastal areas of Far East Russia. Biologically active peptides such as taurine (3.74 g/100 g protein) and ornithine (2.12 g/100 g protein) have been found in the tissues of A. broughtonii. C. japonica contains a high amount of ornithine (5.57 g/100 g protein) and taurine (0.85 g/100 g protein). The maximum DPPH and ABTS radical scavenging activity (36.0 µg ascorbic acid/g protein and 0.68 µmol/Trolox equiv/g protein, respectively) was determined for the tissue of C. japonica. The protein and peptide molecular weight distribution of the shellfish tissue water extracts was investigated using HPLC. It was found that the amount of low molecular weight proteins and peptides were significantly and positively correlated with radical scavenging activity (Pearson’s correlation coefficient = 0.96), while the amount of high molecular weight proteins negatively correlated with radical scavenging activity (Pearson’s correlation coefficient = −0.86). Hepatoprotective activity, measured by the survival rate of HepG2 hepatocytes after cotreatment with t-BHP, was detected for C. japonica. The highest protection (95.3 ± 2.4%) was achieved by the cold water extract of C. japonica at the concentration of 200 mg/mL. Moreover, oral administration of hot water extract of C. japonica to rats before the treatment with CCl₄ exhibited a markedly protective effect by lowering serum levels of ALT and AST, inhibiting the changes in biochemical parameters of functional state of rat liver, including MDA, SOD, GSH and GST.     

Calculation of retention indexes of alkyloxazoles and alkylthiazoles in capillary chromatography

The retention indexes of 41 alkyloxazoles and alkylthiazoles have been determined at 110°C on capillary columns with OV-101/KF, Triton X-305/KF, and PEG-40M/KF, and the contributions calculated to the retention indexes of the methyl, ethyl, and propyl groups at different positions in the rings. The magnitude of the contribution for each alkyl group depends on its position in the ring; this has been used in the calculation schemes to predict the retention indexes of di- and trisubstituted oxazoles and thiazoles with different alkyl radicals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1338–1344, June, 1990.     

A new method for the Lebedev-Ufliand integral equation for contact problems of elasticity

Let a circular flat punch penetrate a finitely thick slab resting on a rigid foundation. Lebedev and Ufliand showed that the determination of the stresses and displacements can be reduced to solving the Fredholm integral equation{ie181-1}We show how to reduce this integral equation to a Cauchy system in which plays the role of the time-like variable. Numerical experiments show the computational efficacy.

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Zusammenfassung Man lasse einen flachen, kreisrunden Durchschlag in eine auf einer steifen Unterlage ruhenden Platte von endlicher Dicke eindringen. Lebedeff und Ufliand haben gezeigt wie das Bestimmen der Drücke und Verschiebungen zurückgeführt werden kann auf die Losung der Integralgleichung von Fredholm,{ie181-1}Wir zeigen, wie man dieses Problem auf ein Cauchysystem reduziert, worin der Parameter t die Rolle der Zeit spielt. Ein numerisches Beispiel illustriert die digitale Lösbarkeit.

     

Circulation instability of steady falling of a flat layer of fine dispersed particles

A numerical investigation has been made of the linear instability of the steady falling under gravity of an infinite horizontal layer of fine dispersed particles in an incompressible atmosphere. The layer has an inhomogeneous vertical distribution of the dispersed phase and a small volume concentration of the particles, the hydrodynamic interaction between which occurs solely through the carrier phase. It is shown that steady falling is unstable and that the layer of particles breaks up into individual convective cells with a characteristic scale of the order of the thickness of the layer.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1, pp. 78–83, January–February, 1991.