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A mathematical model is proposed and analytical solutions are constructed for the problem of the growth of a hydrate layer during contact of gas and water for two limiting regimes of gas hydrate formation, determined by mass transfer and heat transfer. Critical values are obtained for thermal parameters and for parameters that determine the flow properties of the hydrate layer (diffusion coefficient and permeability), on which the hydrate formation regime depend.

The interaction of a shock wave with turbulent flow has been experimentally investigated. The case where the shock wave formed on one end of the tube, passed through the interface between two resting gases with different densities (air-CO₂ or air-Ar), reflected from the end of the tube and interacted with turbulent mixing zone formed at the contact boundary. The Mach number of the shock wave incident on the interface in air was M ≈ 2.37-2.57. The flow field was recorded using schlieren method and high-speed video recording. It is found that after passing the mixing zone, the shock-wave front is deformed and becomes unstable.

The accuracies of measurement of the velocity field using clinical and research magnetic resonance scanners were compared. The flow velocity was measured for a fluid simulating blood in the carotid artery model connected to a programmable pump. Using phase-contrast magnetic resonance tomography, velocity distributions in the carotid artery model and were obtained and compared with the analytical solution for viscous liquid flow in a cylindrical tube (Poiseuille flow). It is established that the accuracy of the velocity measurement does not depend on the field induction and spatial resolution of the scanners.

This study is focused on the heat and mass transfer effects in a magnetohydrodynamic (MHD) flow of a viscous nanofluid saturating a porous medium past an exponentially radiating stretching sheet. The governing differential equations are transformed to a system of nonlinear ordinary differential equations by suitable transformations. It is noted that stratification affects the local Nusselt and Sherwood numbers.

An attempt is made to study a steady two-dimensional flow of a viscous incompressible fluid incident at some angle onto a plate lubricated with a thin layer of a power-law fluid. Similar and nonsimilar solutions of the governing partial differential equations are obtained numerically by imposing the continuity of velocity and shear stress at the interface layer between the fluid and the lubricant. The Keller box method is applied to obtain the solutions. The limiting cases for full and no-slip conditions are compared

An unsteady double diffusive mixed convection boundary layer flow over a vertically stretching sheet in the presence of suction/injection is investigated in this paper. The governing partial differential equations are reduced by applying suitable transformations to a set of nonlinear ordinary differential equations, which is solved by the Keller box method. The influence of various flow parameters on the velocity, temperature, and species concentration profiles of the fluid is studied. The effect of some problem parameters on the skin friction coefficient in the presence of suction/injection is considered

Numerical simulation was performed to study convective structures in a thin silicone oil layer heated from below, whose free surface is exposed to air flow, generating a drift current. Transformation of the basic equations to a form suitable for spectral methods is proposed. The steady flow velocity profile obtained under laboratory experiment conditions is calculated. It is shown that increasing the Reynolds number leads to the transition from the polygonal convective cells to longitudinal (elongated along the flow) rolls. The dependence of the transitional Reynolds number on the temperature on the lower boundary of the layer is obtained. The calculation results are compared with experimental data.

The research was conducted in the southern part of the forest-steppe zone of West Siberia (Novosibirsk oblast’). The spatial-temporal structure of the spider community was studied at the continuous chain of habitats (180 m long) from the central part of small birch-aspen forest to the center of meadow site. We applied two sampling methods which completed each other: pitfall trapping and hand separating soil samples. Over 5000 specimens of spiders from 83 species and 14 families were collected during 2007-2008. Spiders are most abundant in June and less abundant in July. Representatives of different families are maximally abundant in different sites: Lycosidae and Gnaphosidae mainly in the forest, and Philodromidae - in the solonetz meadow. The distribution of diversity and abundance of spiders and carabids through the habitat gradient is generally similar. This is controversial compared to the spatial interactions of these two groups of predatory arthropods in extreme ecosystems: in Arctic and near saline lakes. Niche distinguishing between carabid and spider species is not only topical. It includes use of different strata of vegetation, various seasonal activity and trophic specialization.

The following biomarkers of oxidative stress: catalase (CAT), glutathione-S-transferase (GST), glutathione and reductase (GR) activities as well as malondialdehyde and reduced glutathione content and heavy metal concentrations (HM) were studied in Dreissenа polymorpha tissues. Mussels were collected on three sites located in the Rybinsk reservoir differing in the levels of anthropogenic load: more polluted sites 1 and 2 and relatively clean site 3. Mussels from sites 1 and 2 had higher concentrations of HM and their response to pollutants’ action was manifested in increased processes of LPO, activation of CAT and elevated level of GHS.

The distribution of bioorganic components and compounds of anthropogenic and mixed origin in the sediments of freshwater lake Black and salt one Tus (Khakasiya) was studied by the method of gas chromatography-mass spectrometry. The contribution of major sources of organic matter to the bottom sediments was evaluated. It was found that the formation of the composition of the bottom sediments was mainly due to compounds of biogenic and mixed origin. The sites with high concentration of contaminants: pyrogenic and oil hydrocarbons and izoalkilbenzols - possible products of surfactants degradation were revealed.