Home – Home – Jornals – Numerical Analysis and Applications 2021 number 1

The paper discusses the results of calculation of heat fluxes (kinematic temperature fluxes) in the surface air layer from experimental data on variations in the air temperature and wind vector components on different scales. The fluxes along three coordinate axes of the “stationary” and “accompanying” Cartesian coordinate systems are compared. Estimates of the heat fluxes for the territory with natural landscape (at two altitudes in the surface layer) and the urban territory are considered. The analysis of experimental data has led us to the conclusion that the heat fluxes on the local scale should be taken into account along with the heat fluxes on the turbulent scale when predicting the state of the atmosphere using models of high spatial resolution.

The variability of the characteristics of cyclones and anticyclones (number, pressure at the center (hPa), and duration (days)) and their trajectories is studied for Siberia (50-70 N, 60-110 E) in different seasons throughout the climatically significant time interval 1976-2018 on the basis of surface synoptic maps. It is found that the number of baric formations has increased, the pressure at the centers of cyclones has decreased and at the centers of anticyclones increased, and the duration of cyclones and anticyclones has decreased during the period under study. These trends in the behavior of the characteristics of cyclones and anticyclones are especially pronounced at the end of the period. During the year, the anticyclonic weather was observed more often than cyclonic in Siberia.

The propagation velocity of plasma plumes in the presence of an external electric field was measured in air, at a pressure corresponding to the altitudes of the middle atmosphere transient luminous events. Based on the results, a hypothesis is formulated that the transient type starting from the thundercloud dome (blue jet, starter, gigantic jet) depends on the intensity of intracloud lightings and the ratio of the positive charge of the dome top and the negative charge of the outer layer.

Results of measurements of the amount of precipitation with an OPTIOS optical precipitation gauge together with a standard Tretyakov O-1 gauge during three summer months of 2020 are presented; a good agreement between the measurement results is shown. The comparison of the OPTIOS readings with the readings of a similar optical rain gauge mounted at a distance of 3 km, as well as with related data of the Tomsk weather station of the Roshydromet network located at a distance of 6 km, shows significant spatial variations in the characteristics of atmospheric precipitation. A possibility of using OPTIOS both as an automated gauge within a weather station and as a component of an observation precipitation gauge network is shown.

A supersonic flow in a channel with a variable cross section is numerically simulated in the case of ethylene injection along the channel under the action of a jet generating a throttling effect. The averaged Navier-Stokes equations closed by the k-e turbulence model are solved. Ethylene combustion is modeled with the use of one reaction. The results are compared with experimental data on the pressure distribution over the channel wall. It is found that gas-dynamic pulses produce an irreversible effect on the flow structure. The formation of a transonic flow region and its structure are described.

The influence of thermal nonequilibrium on the laminar-turbulent transition is studied with the use of the e^N -method for two widespread flow regimes in a supersonic boundary layer at the Mach number M = 4.5. The set of the actual frequencies of spatial disturbances is determined on the basis of the neutral curves for temporal disturbances. Families of the curves of N-factors are calculated for selected frequencies. Then, based on the envelopes of these curves, the transition Reynolds number Re_δT for a given transition factor NT is determined. The calculations show that the transition region in the case with NT = 8 and vibrational excitation level below the dissociation limit is located 12-14% downstream as compared to the transition region in a perfect gas.

Solutions to a nonlinear parabolic convection-diffusion equation are constructed in the form of a diffusion wave that propagates over a zero background with a finite velocity. The theorem of existence and uniqueness of the solution is proven. The solution is constructed in the form of a characteristic series whose coefficients are determined using a recurrent procedure. Exact solutions of the considered type and their characteristics, including the domain of existence, are found, and the behavior of these solutions on its boundaries is studied. The boundary element method and the dual reciprocity method are used to develop, implement, and test an algorithm for constructing approximate solutions.

In the space of self-similar variables, two-dimensional flows of a polytropic gas are constructed in the form of solutions of the corresponding characteristic Cauchy problems of the standard type, which can be represented in the form of endless series. The convergence of the series is proved, and a procedure for constructing the coefficients of the series is described. It is found that in one particular case, the series breaks off and coincides with the well-known analytical solution that was used by V. A. Suchkov to describe gas flow from an oblique wall into vacuum and by A. F. Sidorov to describe unlimited compression of prismatic gas volumes. It is shown that unlimited compression of the gas flow is by impermeable pistons moving according to different laws possible, and the gas-dynamic flow parameters are studied. Highly nonuniform pressure distribution during compression of prismatic targets was obtained.

This paper presents the results of experimental and computational studies of instability development and mixing at the interfaces between gases of different densities. It is shown that instability and mixing at two interfaces of a three-layer gas systems arise after the interfaces are pass by a shock wave with a Mach number M = 1.3 which is formed on the left end and moves along the tube. Two experiments were carried out, in the first of which the central layer was filled with a heavy gas (SF6 gas), and in the second experiment, it was filled with a light gas (helium). On the left and right of the central layer is air at atmospheric pressure. The results obtained are compared.

The influence of the smoothly changing beam height on delamination in multilayered inhomogeneous beam configurations consisting of longitudinal vertical layers is investigated. A solution to the strain energy release rate is obtained for a delamination crack located arbitrarily between the layers, assuming a linear change in the height over the beam length. The solution obtained is verified by considering the energy balance. The strain energy release rate is also analyzed for the cases of parabolic and tangent changes in the height over the beam length.

A method is proposed for determining the volume concentration of the gas phase in gas-liquid flow using an ultrasonic flow meter. The method is based on the experimental determination of the transparency coefficient of the gas-liquid flow to the ultrasonic pulses used in the flow meter to measure the flow rate. The transparency coefficient is determined as the ratio of the number of reliable ultrasonic pulses to the number of emitted pulses, and it is shown that due to the scattering of probing pulses, the presence of the phase in the form of gas bubbles leads to a decrease in the transparency coefficient. The ultrasonic flow meter was calibrated in air-water flow at volumetric air concentrations in the flow of 0-19%. The results show that the proposed method can be used to measure the volumetric concentration of the gas phase in gas-liquid flow up to values of the order of 30%.

In this study, a numerical simulation is used to show the physics of a coupled forced perturbation and liquid jet in the presence of a low-velocity coaxial gas flow. The volume of fluid (VOF) approach is employed to capture the liquid-gas interface. A sinusoidal velocity with a finite frequency and amplitude is applied at the liquid jet inlet to define a forced perturbation. An annular gas flow with a velocity lower than that of the liquid jet is imposed to examine its influence on the liquid jet breakup mechanism. The annular gas flow is modulated by the sinusoidal velocity inlet, and the effect of this flow on the liquid jet breakup mechanism is analyzed. Different ratios of the gas velocity to liquid velocity are studied. The results indicate that the low-velocity gas flow can considerably affect the behavior of the liquid jet, and this effect becomes more significant as the amplitude of the forced perturbation increases.

In the current paper, a modified algebraic method (MAGM) is proposed as an effective semi-analytical technique for solving nonlinear damped oscillatory systems. A polynomial is supposed as the trial solution, and its unknown coefficients are easily determined through the algebraic method (AGM). In order to improve the solution, the Laplace transformation is applied to the series solution, and then the Padé approximants of the resultant equation are constructed. Finally, the inverse Laplace transformation is adopted to obtain a periodic solution for the nonlinear problem under consideration. The proposed method is then applied for obtaining approximate analytical solutions of a damped rotatory oscillator as well as nonlinear vibrations of a flexible beam excited by an axial force. The results are compared with those obtained by the fourth-order Runge-Kutta method, and good agreement is observed.

A method for determining the background parameters of weakly dispersing media is formulated within the framework of the theory of low-intensity wave bores in such media. An analytical model of an undular (cnoidal) bore on a pycnocline of a stratified shallow sea is used to obtain expressions for calculating the coefficients of the extended Korteweg-de Vries equation: the velocities of linear internal waves, high-frequency dispersion, quadratic and cubic nonlinearities, i.e., the parameters characterizing the hydrophysical background over which the bore propagates. These parameters are calculated from data of direct measurements of bore characteristics: their waveforms, nonlinear velocity, mass and amplitude of leading solitons, as well as the frequencies of the waves that close the region in which the bore propagates. The efficiency of the proposed method is confirmed by the results of numerical simulation.

The possibility of using jet fluid flows in the presence of an artificial cavity with a negative cavitation number to generate periodic pulsed jets is studied. Flow in a line consisting of a cavitator, an artificial gas cavity, and a converging nozzle through which liquid and gas flow into the atmosphere is investigated. Regimes in which the liquid flow is close to intermittent are experimentally found. For such flow regimes, a one-dimensional model for estimating the flow rate of liquid portions from the nozzle is proposed.

Equations of non-isothermal two-phase filtration are used to solve the problem of motion of water and air in melting snow. The investigated mathematical model is verified using experimental data.

Dynamic properties of low-carbon steel are investigated using the Kolsky method (the split Hopkinson pressure bar method). Changes in the properties of the steel after 50 years of storage are determined, and the destroyed samples are subjected to metallographic studies. The fractal dimension of the fracture contours is determined. It is shown that, the long-term storage of steel introduces no significant changes in its properties.

Data of an experiment to determine the ultimate strength of frozen soil under uniaxial compression in the range of deformation rate values 400-2700 s-1 are presented. Final expressions are obtained for the coefficients of the quadratic approximation that depend on the impact velocity of the stress normal to the surface of the striker and the experimentally determined physical and mechanical parameters of the soil - shock adiabat and the dynamic strength in compression. The obtained formulas are verified on the basis of comparison with the known data of experiments on the introduction of a steel conical striker into frozen sandy soil. It is shown that the difference between the results of bilateral evaluations and experiments does not exceed 15.

Primary (unsteady) and secondary (steady) regimes of creep deformation of a rotating disk made of an Al-SiC functionally graded material (FGM) is investigated using the generalized differential quadrature (GDQ) method. The disk is subjected to three different types of the temperature gradient in the radial direction, and a temperature dependence of the material properties is assumed. The primary and secondary creep is described by Norton's law in which the creep parameters depend on the volume fraction distribution of SiC reinforcement particles, temperature, and particle size. It is shown that the creep rates are strongly dependent on the temperature gradient type, prevailing temperature, and content of reinforcing particles at any point of the disk.

Transverse vibrations of a double-layered viscoelastic orthotropic graphene sheet system are investigated. The two sheets in the system are coupled by the visco-Pasternak medium. General governing equations for free and forced vibrations of the double-layered graphene sheet system with a high-order surface stress effect are formulated. Theoretical solutions for the damped vibrational frequency, damping ratio, and relative deflection of the two sheets with simply supported boundary conditions are obtained. The effects of the high-order surface stress on the damped frequency and damping ratio of the system for in-phase and out-of-phase free vibrations are discussed. The impacts of the high-order surface stress, structural damping, medium damping, Winkler modulus, and shear modulus of the medium on the relative deflection of the two sheets for forced vibrations are investigated. It is demonstrated that the high-order surface stress effects on the vibrational properties of the system are more significant than those of the conventional surface stress.

Experimental data on the motion parameters of a steel spherical impactor with a diameter of 13.5 mm that moves in a sandy medium at a velocity of 1470 m/s are presented. Induction sensors and the PIV (particle image velocimetry) method are used to record the motion of the impactor near a sandy obstacle and in a sandy medium, which allow one to visualize a surface wave via high-speed video recording of the sand surface. The values of the parameters characterizing the impactor motion in the sandy medium and the surface wave propagation are obtained.

Experimental data on the failure and deformation of various materials are considered from the viewpoint of the kinetic concept of fracture as thermodynamic processes occurring over time. Mathematical modeling of the general and local plastic flows in materials is based on rheological models of a solid with due allowance for damage accumulation. The prediction of the longevity of materials under constant or variable temperature and force conditions is performed by time steps, including situations with changes in the material structure. A single fracture criterion is used, which implies that fracture occurs after reaching a threshold damage concentration (concentration criterion) in a certain volume of the solid body.

This paper describes a solution to the problem of determining the elastic and plastic deformation regions arising in a plate that is under tension and weakened by two circular holes in the case of a plane stress state. A method for solving the problem is based on the use of conservation laws.

Load on the structure from the side of the onboard equipment at the moment of the aircraft impact on it is investigated. The estimation of the correctness and applicability of the model of the aircraft, presented in the form of a rigid-plastic rod (Riera's approach), is carried out when studying the effect of onboard equipment. To simulate this impact, we used volumetric perforated aluminum alloy samples. Calculations were carried out using the proposed model in a one-dimensional approximation, as well as direct three-dimensional modeling of the impact by the finite element method using the LS-DYNA package. Both of these approaches make it possible to study the process of loading a rigid wall. The quantitative and qualitative differences between these approaches and Riera's approach are shown.

We study dynamic processes in liquid crystals using a simplified mathematical model in which a liquid crystal is considered as a finely dispersed continuous medium with rotating particles which has elastic resistance to volume deformation and viscoelastic resistance to relative rotation of the particles. The oscillatory regime of rotational motion described by the Klein-Gordon equation for tangential stress is studied. Moment interactions of particles due to the inhomogeneity of the rotation field are taken into account. The dispersion properties of a subsystem of two equations for tangential stress and angular velocity are investigated. These equations are used to numerically analyze the rotation field in the liquid crystal under the action of tangential stress caused by the thermal expansion of a metal plate at the boundary. We consider the problem of perturbation of an extended layer of a 5CB liquid crystal by means of an electric field generated by charges on capacitor plates located periodically along the layer. Singularities of the electric potential at the ends of the capacitor plates are selected explicitly. Some results of computations simulating the Fréedericksz effect in the liquid crystal layer are presented.

We consider linear schemes with several degrees of freedom (DOFs) for the transport equation with a constant coefficient. The Fourier transform decomposes the scheme into a number of finite systems of ODEs, the number of equations in each system being equal to the number of OFs. The matrix of these systems is an analytical function of the wave vector. Generally such a matrix is not diagonalizable and, if it is, the diagonal form can be non-smooth. We show that in a 1D case for L₂-stable schemes the matrix can be locally transformed to a block-diagonal form preserving the analytical dependence on the wave number.

In this paper, optimal methods of approximation of some geophysical fields involving gravitational and heat fields are considered. A review of results on this problem is presented. We have developed the algorithm of approximation of multidimensional heat fields which are described by heat equation with constant coefficients. In order to do that, we introduce classes of functions that include solutions of heat equations, and continuous splines uniformly approximating the functions from these classes in the whole domain of definition. We give the upper bounds for the Kolmogorov diameters of the introduced classes of functions. For a wider class of the introduced classes of functions, the Kolmogorov diameters is estimated from below.

To enhance oil recovery and limit water inflow in the fields with a low reservoir temperature (20-23 ºC), a new low-temperature nanostructured composition with two gel-forming components (polymer and inorganic) with improved rheological characteristics was developed at the Institute of Petroleum Chemistry SB RAS. Laboratory studies of gelation kinetics, rheological and filtration characteristics in the system polyvinyl alcohol (PVA) - boric acid - aluminium salt - carbamide - hexamethylene tetramine (HMTA) - polyol - water are presented. At a temperature of 20-23 ºC, this system forms coherently dispersed nanoscale structures of gel-in-gel type, with viscosity 2.4-6.8 times higher and elasticity 1.4-2.3 times higher than those of the gels with only one gel-forming component. The formation of gel directly in the reservoir leads to a selective water shutoff, a change in the direction of filtration flows, a decrease in water cut, and a limitation of breakthroughs of the injected working agent into production wells. Laboratory studies demonstrated the high efficiency of the composition for flow redistribution and additional displacement of oil from the channels with very high permeability. The composition is applicable to reduce water cut and to limit water inflow in cold wells, which allows us to recommend it for use on cold producing and injection wells with complicated geological structure of the formation, with highly permeable faults, cracks and washed channels, in particular, to limit water inflow and enhance oil recovery in the Permian-Carboniferous deposits of high-viscosity oil of the Usinsk field with the natural operating mode of development. Expected result: enhancement in the oil recovery factor (ORF), a decrease in the water cut of the product, and intensification of oil production.

The territories of discharge of ascending deep thermal waters are a unique object for studying the mineral composition of vegetation and soils under strong exposure to endogenous factors. The aim of this work was to determine the peculiarities of the accumulation of 25 chemical elements by Potentilla anserina L. in the impact zone of Kuchiger hydrotherms (Barguzin Depression, the Buryat Republic, Russia). The concentrations of Ca, K, Mg, P, S, and Zn in P. anserina plants did not vary significantly in the surveyed territory. In the zone of subaquatic discharge of ascending deep thermal waters, plants accumulated more Na, Sr, Li (near the discharge of high-temperature gryphons) and W, Mo (near the discharge of low-temperature gryphons). The maximum concentrations of Al, Mn, Ti, Cr, Ni, Co, La, and Y in the plants were found on the coastal diapir shaft with extremely high ascent activity of gas-hydrothermal mud fluids. Concentration of several elements in plant ash exceeded the clarke values for plants: Ca ( K_с = 2.0-3.6), Na ( K_с = 2.4-4.8), Sr ( K_с = 3.5-9.5), Ba ( K_с = 2.7-6.6), Li ( K_с = 6.0-17.0), Sc ( K_с = 6.0-21.0). The intensity of biological absorption was characterized by the biological absorption factor (BAF) . The highest coefficients were found for P and S (BAF = 22.4-69.2). The elements of strong accumulation are Ca, Na, K, Mg, Mn, Sr, Zn, Cu, Li, Ni, Mo (BAF = 1.5-10.5); the rest elements were very weakly accumulated by plants (BAF = 0.1-0.9). The change in the intensity of element accumulation by plants under different conditions leads to a violation of the ratios between Fe/Mn, Fe/Zn, Cu/Mo, Ca/Sr, Ca/Ba, K/Ba, Sr/Ba.

The physicochemical properties and structure of biosurfactants produced by oil destructor microorganisms represented by three strains - Rhodococcus 108, Acinetobacter 112, Acinetobacter 114 - are investigated. It is shown that all these microorganisms are capable of synthesizing both cell-bound and extracellular biosurfactants. The amount of free biosurfactants produced by Rhodococcus 108 strain is higher than the amount produced by the bacteria belonging to Acinetobacter genus. All the studied compounds contain carbohydrate and lipid components. According to the data of IR spectroscopy, the biosurfactant isolated from the Rhodococcus 108 strain is a compound bearing long-chain aliphatic hydrocarbons, ester bonds, carbonyl and OH groups, while lipopolysaccharide isolated from Acinetobacter 114 strain consists of a trisaccharide skeleton, to which the residues of fatty acids are added (С₁₀-С₂₂) via ester and amide bonds.

The process of calcium carbonate (calcite and vaterite modifications) crystallization from the solutions containing bile is investigated. It was found that calcite is formed in an uncontaminated environment and in the presence of 1 mass % bile, while an increase in bile concentration in the initial solution from 5 to 100 mass % promotes the crystallization of vaterite. It is shown that the mass of the solid phase increases in proportion to an increase in the bile concentration in the initial solution. The dissolution of the synthesized samples in 0.9 mass % NaCl and 0.05 mol/L EDTA was studied. It was revealed that the presence of bile components in the composition of solid samples reduces their dissolution rate.

The possibilities of new approaches to assessing the physiological adequacy of drinking water using biotesting methods are disclosed. Biotesting of waters, both depleted and enriched with potassium, sodium, calcium and magnesium, was carried out according to the indicators of acute water toxicity on freshwater fish Brachydanio rerio , genotoxicity on its blood cells, and chronic toxicity on Ceriodaphnia affinis . It was found that water samples with the optimal content of K⁺, Na⁺, Ca²⁺, Mg²⁺ do not exhibit toxicity, while in the samples in which the content of these elements is outside the range of optimal concentrations, chronic toxic and genotoxic effects are found.

The set and levels of phenolic compounds in water-ethanol extracts from the leaves of Spiraea betulifolia subsp. aemiliana (Schneid.) Hara (Rosaceae) were studied under natural conditions and after introduction into the environment of Novosibirsk (Russia). The samples were collected in two natural coenopopulations (Kunashir Island) and in the Introduction Division of CSBG SB RAS (Novosibirsk) in 2016-2019. Flavonoids and phenolcarboxylic acids were found in the extracts. Using high-performance liquid chromatography, we detected 19 phenolic compounds in the water-ethanol extracts from plant leaves of the natural populations and 26 in the introduced population. Thus, differences in high-performance liquid-chromatography profiles of phenolic compounds were found between the natural populations and the introduced population. Five new phenolic acids and one flavonol were discovered in the leaves of the introduced plant population. Additionally, the levels of some phenolic compounds in the leaves of S. betulifolia subsp. aemiliana changed as a result of the transfer from the wild to the new environment. Hyperoside (3.36-9.99 mg/g) is the major phenolic compound in the leaves of the natural populations, while quercetin (1.23-5.07 mg/g) is the major phenolic compound in the leaves of the introduced population. The differences in the leaf concentrations of quercetin and hyperoside between the natural and introduced populations were statistically significant ( P ≥ 0.05). Concentrations of taxifolin, isoquercitrin, rutin, avicularin, astragalin, kaempferol, and chlorogenic, p -coumaric, and cinnamic acids in the leaf extracts were found to be similar between the introduced and natural (Kunashir Island, Lake Kipyashcheye shore) populations. Across plant development phases, inhomogeneous distributions of individual phenolic compounds were revealed in the leaf extracts from the introduced S. betulifolia subsp. aemiliana .

Direct UV photolysis of the aqueous solutions of seven well-known pharmaceuticals was accomplished using a high-pressure mercury lamp. Within 30 min of irradiation, active substances of ranitidine and phthalylsulphathiazole were almost completely destructed, whereas paracetamol and novocaine were destroyed to a lesser extent. Stable organic products are not formed during the destruction of paracetamol, while the photolysis of sulphaguanidine leads to the formation of acetic acid, which was confirmed by means of ¹H NMR spectroscopy. It is concluded that UV photolysis may be used for initial wastewater treatment to remove the studied micropollutants.

The development of new two-phase aqueous systems based on surfactants for extraction requires the identification of patterns of delamination depending on the nature of the surfactant and salting-out agent. The phase equilibria in ternary aqueous delaminating systems containing a cationic surfactant - alkylbenzyldimethylammonium chloride (catamine AB) and an inorganic salting-out agent were studied. Catamine AB forms stratifying systems with chlorides (KCl, NaCl, NH₄Cl, LiCl, CaCl₂), sulphates (K₂SO₄, Na₂SO₄, (NH₄)₂SO₄), nitrates (KNO₃, NH₄NO₃, NaNO₃, Mg(NO₃)₂, LiNO₃, Al(NO₃)₃, Ca(NO₃)₂), as well as with Na₂CO₃, K₂CO₃, KHCO₃, NaBr, KSCN, NH₄F, (NH₄)₂HPO₄ and HNO₃. The influence of the nature of the salting-out agent on the process of system delamination is discussed. The best salting-out agents for catamine AB are nitrates, which have relatively low hydration energy in the series of studied anions. The phase diagram of the water - catamine AB - sodium chloride system was built up. The stratification region exists in a rather wide acidity range up to 2.4 mol/L H₂SO₄ (or HCl), and up to 2.8 mol/L NH₃ (or 4.7 mol/L NaOH). The phases remain transparent at all studied concentrations of inorganic acids and bases. The extraction ability of the water - catamine AB - sodium chloride system was evaluated. Thallium (III) is quantitatively recovered in the range of sulphuric acid concentrations from 0.5 to 2 mol/L. The range of recoverable metals may be expanded by using organic complexing agents. Quantitative extraction of lanthanum (100 μg) is observed in the system containing 2.2 g of surfactant, 2.0 g of the salting-out agent, 1 mL of 0.01 mol/L Arsenazo III solution with a total volume of 15 mL and pH ~8.

Thermodynamic modeling of hypergene processes in copper-nickel ore tailings was performed with the variations of temperature (3 and 20 ^oC) and water evaporation processes in the upper layers of tailings during summer months at low filtration coefficients. It is established that the major cations of pore solutions are magnesium, calcium, nickel and copper ions, while predominant anions are sulphate and hydrocarbonate ions. The main newly formed phases in the system are the minerals of smectite group, as well as goethite, carbonates, silica, chlorite and gypsum.

The spherical microstructures of bismuthyl (III) fumarate with the composition (BiO)₂С₄H₂O₄ were obtained using the standard method of precipitation from solutions at 23 and 60 ºС. The composition of the reaction product and its properties were studied using a complex of physicochemical methods. At 60 ^oC, the degree of bismuth precipitation in the product is not less than 99.8 % for the molar ratio of bismuth to fumarate ion equal to 1.5. According to IR and Raman spectroscopy data, both acidic residues of fumaric acid are deprotonated in the resulting compound, while the carboxylic groups have bidentate coordination to bismuthyl cation. The effect of temperature on the morphology of obtained compounds was studied by scanning electron microscopy and small-angle laser light scattering. According to scanning electron microscopy data, (BiO)₂С₄H₂O₄ obtained at 23 ºC is composed of spherical particles about 10-12 µm in size, consisting of thin nanoplates about 0.1 μm thick. The data of sedimentation analysis of the powder indicate a symmetric particle size distribution with the average particle size equal to 11.7 μm. With an increase in precipitation temperature to 60 ^oC, particle size decreases to 3-7 µm; an asymmetric function of particle size distribution is observed, and the average size of the aggregates is 30.9 µm. A possible mechanism for the formation of (BiO)₂С₄H₂O₄ spherical microstructures is described as a process combining Ostwald ripening and self-assembling. According to the data of thermal and XRD analyses, the product of thermal decomposition of bismuthyl fumarate at a temperature of 450 ºC is a monoclinic modification of Bi₂O₃.

The current level of traffic development is characterized by a continuous increase in the intensity of cargo transport vehicles and a rise of dynamic load on road coatings. Improvement of the quality of road bitumen through the search for novel technical and technological solutions remains an urgent problem for achieving high physical-mechanical characteristics of asphaltic concrete pavements and for ensuring their long lifetime. The effect of a cation-active adhesive additive on the range of plasticity of oxidized and non-oxidized bitumen is considered. The physical and mechanical properties of asphalt-concrete mix prepared on the basis of bitumen modified with the additive in different concentrations are investigated. A technology is developed for obtaining a modified bitumen binder involving the adhesive additive. On the basis of BND 60/90 grade bitumen, an experimental lot (40 t) of bitumen modified with the designed additive was manufactured, the test region of the roadway with the total area of 7900 m² was paved in Naberezhnye Chelny (Tatarstan, Russia), construction design supervision of the state of the test road region was performed.

A number of ceramic membrane reactors (CMR) of various designs and compositions for high-temperature hydrogen sulphide decomposition were studied. Two CMR types with the layered structure were used: the first type included catalyst layer, membrane support, and membrane layer, while the second one was composed of catalyst layer, membrane support, an intermediate layer, and membrane layer. It is demonstrated that the pore structure and the thickness of the membrane layer have a significant effect on permeability for H₂ and H₂S. Due to the high H₂/H₂S separation coefficient (more than 2.5), a significant improvement of the parameters of H₂S decomposition in CMR in comparison with the flow reactor with a granulated catalyst is observed. The H₂S conversion (with the formation of H₂) reaches 87 % at 900 ºC in the CMR of the optimal composition prepared using the optimal method.

The data on the content of 20 elements determined by means of X-ray fluorescence analysis using synchrotron radiation (SRXRF) in the leaves and stems of three Syringa vulgaris cultivars ‘Nadezhda’, ‘Olimpiada Kolesnikova’, ‘Pamyat o Kirove’ growing under the conditions of transport-caused and industrial pollution in Novosibirsk and under background conditions (reference). The concentrations of Mn, Fe, Co, Cr, Br, Rb, Nb in plants increased as a result of the technogenic impact, while the concentrations of Zn and Mo decreased (in comparison with the reference). The plants of ‘Nadezhda’ cultivar were distinguished by the increased content of microelements under urban conditions. As a consequence of environmental pollution, changes in the relations between physiologically essential chemical elements were observed in the leaves and stems of the plants. The smallest changes were detected in the Fe/Mn and Zn/Cu ratios in the plants of ‘Pamyat o Kirove’ cultivar. It was determined that the K/Rb ratio decreased under technogenic load in the plants of ‘Olimpiada Kolesnikova’ and ‘Pamyat o Kirove’ cultivars due to an increase in Rb content in the leaves and stems, while, quite contrary, this ratio increased in ‘Nadezhda’ cultivar with respect to the reference. On the basis of the calculated biogeochemical transformation coefficient, the most significant changes in the microelement composition are recorded for leaves and stems of the ‘Nadezhda’ cultivar, compared to others, which indicates its lower resistance to anthropogenic pollution in comparison with other cultivars. Common lilac plants of ‘Pamyat o Kirove’ cultivar were determined to tolerant to pollution under urban conditions.