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The sizes and rise velocity of bubbles in a stationary liquid in an inclined channel with a circular cross-section at various gas flow rates through a capillary were determined (3.0÷5. ml/min). The sizes and velocity of gas bubbles was studied by shadow photography. It is shown that in the range of channel inclination angles 40÷60°, the formation of stable bubble structures-clusters consisting of bubbles of the same size (1.5÷1.8 mm) - can be formed. In modes without the formation of chain clusters, the average diameter of gas bubbles increased (2.0÷2.2 mm) due to their coalescence.

Direct numerical modeling is used to study the effect of wall heating on the characteristics of reverse wall flow that occurs during turbulent flow of various coolants in a channel with a square cross-section. The temperature field is considered both in the passive impurity approximation and in the low Mach number approximation. Qualitative and quantitative results were obtained characterizing the probability of the occurrence of reverse wall flows in all considered cases at the Reynolds number Re = 3150, calculated from the average flow velocity and half-height of the channel. It has been established that in the considered cases, heating of the walls leads to an increase in the probability of the formation of reverse wall flows by an average of 2-3 times.

Using previously obtained analytical formulas for the natural frequencies and vibration modes of inhomogeneous rods with a variable cross-section (corset shape), the geometric and elastic characteristics of the samples were determined, and the amplitudes of axial stresses obtained during experimental studies of the fatigue strength of metal alloys under high-frequency cyclic loading were assessed. Based on a three-mode model of fatigue failure, a numerical method is proposed for calculating the kinetics of damage under high-frequency cyclic tensile-compression loading of corset-shaped specimens at different values of the cycle asymmetry coefficient. The results of calculations using the proposed model are compared with the results of experiments on corset-shaped samples made of titanium alloy. The proposed model and calculation method make it possible to construct fatigue curves with sufficient accuracy for various cyclic loading modes and cycle asymmetry coefficients. To do this, it is enough to know the base points of the bimodal fatigue curve for the reverse cycle.

Nonlinear vibrations, buckling, and aeroelasticity of a thin nonlinear orthotropic composite plate have been analyzed. The types of symmetric and antisymmetric sheet layering, the number of layers, the fiber angle ranging from 0 to 90°, the effect of constant and variable thermal loads, the temperature dependence of the specific heat coefficient and the elastic modulus of the material, along with the local geometrical defects have been investigated. Using Galerkin's weighted residual theory, partial differential equations have been transformed into nonlinear ordinary differential equations, which are solved by the Runge-Kutta method.

The heat conduction equation of the coupled dynamic theory of thermoelasticity is considered. An assessment is made of the connectivity in the heat conduction equation for a space with a constant initial temperature, containing a flat semi-infinite crack moving at a constant speed, on the sides of which a constant temperature is instantly established, less than the initial one (thermal shock). The movement of a crack and thermal shock on its shores determine dynamic effects that must be taken into account to assess connectivity in the thermal conductivity equation. It is shown that, under real conditions of thermal impact on massive bodies with cracks, dynamic effects and cohesion for materials that satisfy certain conditions imposed on their thermomechanical constants can be neglected, which makes it possible to significantly simplify the solution of problems of thermoelasticity for such bodies.

The problem of forced bending vibrations of a rod-strip with two consoles and a fixed section of finite length on one of the front surfaces is solved. To describe the processes of deformation of consoles, the Timoshenko model is used without taking into account transverse compression and a fixed section - the same deformation model taking into account transverse compression, modified by taking into account the presence of a fixed fixed section. The conditions for the kinematic coupling of the consoles and the fixed section are formulated. Based on the Hamilton-Ostrogradsky variational principle, the equations of motion and boundary conditions, as well as the force conditions for the coupling of sections of the rod, are formulated. Exact analytical solutions of the equations of motion under the influence of a harmonic transverse force at the end of one of the rod consoles are obtained. Numerical experiments were carried out in which the passage of resonant vibrations through a fixed section of finite length in rods made of duralumin and fiber composite was studied, with and without taking into account the transverse compression of the fixed section. A significant increase in the vibration amplitude of the end of the unloaded cantilever of a duralumin rod was discovered due to transverse compression of the fixed section. For a composite rod, the vibration amplitude increased slightly.

Changes in the total weight of live clams Pisidium amnicum and weight of their shells were studied by comparing uninfected clams with clams infected with trematods Allocreadium crassum, Phyllodistomum folium and Bunodera spp. Mean total and shell weights of clams infected with A. crassum were significantly lower than those of uninfected clams. Characteristics of clams infected with P. folium and Bunodera spp. were not different from the control with the exception of the weight of clams infected with Bunodera spp. Clams infected with mature metacercariae of A. crassum possessed light and fragile shells that weighed on average 3 times less than those of uninfected clams (25.6 vs 74.1 g.). The weight of shells of clams with immature metacercariae was not different from that of uninfected clams. The obtained results were analyzed from the viewpoint of the hypothesis of adaptive manipulation of the host phenotype.

In course of many years of research on assessing the state of pine forests polluted by emissions from the Bratsk aluminum smelter, a large array of data of different sizes has been accumulated, and when generalized and structured, two groups of representative indicators were identified. The first group includes indicators with a high degree of reliability characterizing a state of the assimilating phytomass and growth processes of polluted trees: percentage of green needles in the tree crown, mass of needles on the shoots, total content of chlorophyll in the needles of the shoot, ratio of protein and non-protein nitrogen in the needles, value of the ratio F_v / F_m . The second group included indicators reflecting the efficiency of the antioxidant system: content of low-molecular metabolites (proline, catechin, total glutathione digetogulonic acid), as well as the activity of peroxidase enzyme. Based on these parameters, integral indices were calculated. The regression dependences between the indices and a level of pollutant elements accumulation in needles were used to develop a scale for assessing the vital state of forest stands under conditions of technogenic pollution by emissions from a large aluminum smelter. Applying this scale, it is possible to identify changes at the earliest stages, when the external signs of tree weakening are not yet manifested or are minimally expressed. A schematic map has been compiled, reflecting the distribution of pine forests of varying degrees of oppression. It has been established that the maximum weakening in the state of forest stands (more than 70 %) is observed in local areas in the industrial zone of BrAZ, strong (within 50-69 %) is found in different directions from the smelter at a distance of up to 10 km, average (by 31-49 %) - typical for forest stands at a distance of up to 40 km, weak (by 11-30 %) - at a distance of 40-60, less often 80 km from BrA Z. In the rest of the surveyed area, changes in the vital state of pine stands are minimal, which makes it possible to characterize the stands as healthy (background).

The size and shape variability of three bones of the river perch from two adjacent reservoirs in the upper reaches of the river Techa (the Southern Urals) - Techa storage reservoir cascade of liquid radioactive wastes contaminated with technogenic pollution (over 50 years) (TRC) and control lake Irtyash was studied using geometric morphometrics methods. Perch bones in adjacent populations differed in shape and characterized by similar growth rates. The range of sex variability of the bone shape was on average 5.4 times less than the intergroup differences of perch population. It was found out that with age the frontal bone growth has slows down, the praeoperculum growth does not change, and the cleithrum growth increases. The sexual dimorphism in bone sizes of older age fish and low level of sex differences in the shape of frontal bone and praeoperculum in the Techa cascade population was revealed. The obtained data characterize a high degree of phenotypic plasticity of the perch and adaptive restructuring of its morphogenesis associated with local environment of technogenic reservoirs.

The environmental heterogeneity can significantly modify the rate of species extinction with an increase in anthropogenic load and the rate of recolonization of disturbed territories after decrease in load, but this issue is currently poorly understood. The distribution of fourteen species of the herb-dwarf shrub layer of forests on area of 1734 km² in two natural regions of the eastern and western macroslope of the Urals during the periods of high (1995-1998) and low (2014-2016) emissions from the Middle Ural Copper Smelter has been analyzed. With an increase/decrease in load, the pattern of dynamics and the magnitude responses were species-specific, significantly depend on habitat conditions, but the main contribution to the space-temporal dynamics of species affected the load level. During the period of high emissions, the environmental heterogeneity slowed down the rate of decrease of area species distribution along a load gradient, but under very heavy pollution, the distribution has been decreased despite of habitats or species. After the reduction of emissions, the distribution of most species in the heavily polluted areas has changed little for 19 years, elimination and reduction in the distribution of the most sensitive species continued. Positive shifts have been revealed mainly in less polluted areas; the rates of recolonization varied in different habitats. Depending on habitat conditions, species response to increase/decrease in pressure can be "fast" (relatively high rates of change) and "slow" (lower rates of change and even continued decline in distribution despite of reductions in pressure).