Home – Home – Jornals – Atmospheric and Oceanic Optics 2024 number 2

The Aeronian clastic sediments in the Gorny Altai area bear signatures of past seismic effects (paleo-seismites). Sedimentary structures produced by brittle deformation (breccias) span the level of the upper convolutus graptolite zone and the lower sedgwicki zone. They coexist with soft-sediment deformation structures (SSDS), such as turbated and rolled layers, bumpy layer boundaries, etc. At the final deposition stage, the rocks were deformed during seismically-triggered landsliding and were shed into a submarine canyon, with formation of rolls (pseudo-conglomerate).

Studies of the mineral-petrographic and geochemical compositions of high-potassic lamprophyric dikes of the Tobuk complex, manifested at the Ryabinovyi plutonic massif (Central Aldan Mesozoic magmatic province, Russia), have shown that these dikes compose a single fractionation series formed from a high-Mg lamproitic parental melt in an intermediate chamber. The composition of the rocks ranges from olivine-diopside-phlogopite and diopside-phlogopite lamproites through minettes to microsyenites and syenite-porphyry. Early crystallization of high-Mg olivine and chromite in an intermediate chamber could produce cumulative dunites similar to those of the Inagli intrusion. Crystallization of olivine and chromite was followed by cotectic crystallization of olivine and clinopyroxene, then that of clinopyroxene and phlogopite, and, finally, eutectic crystallization of Na-rich clinopyroxene, phlogopite, and K-feldspar. Crystallization and gravitational differentiation of lamproitic melt was complicated by silicate-carbonate immiscibility, which is texturally manifested in minettes as carbonate-silicate globules and interstitial calcium and magnesium carbonates. Furthermore, compositional zoning of Sr in apatite and Ba in phlogopite and K-feldspar is considered to have resulted from the immiscibility. Separation of the carbonate-fluorite melt fraction might have led to formation of the carbonatite and fluorite-carbonatite schlieren and gangues which have been described in drill cores from the Ryabinovyi massif. In most of the geochemical and mineralogic features, the Ryabinovyi massif lamproites are similar to the low-Ti lamproites of the Mediterranean postcollisional belt and northern Vietnam and differ from typical high-Ti within-plate lamproites.

The best source of information about the specific features of magmatism in collision zones is the late collisional tectono-magmatic stage, which is associated with the largest volume and diversity of the resulting magmatic associations. In this paper, granitoid and mafic late collisional magmatism is considered using the example of Early Caledonian igneous complexes of Western Sangilen (Tuva-Mongolian massif). Results of geochronological, petrographic, petrogeochemical, and mineralogical studies of the rocks of the Saizyral mingling dike and salic dikes are presented. Approximately ~485 Ma, high-potassium granitoid massifs formed simultaneously with the intrusion and occurrence of a complex of granitoid and mingling dikes. The Saizyral mingling dike resulted from the joint intrusion and mixing of basic and silicic magmas in a low-pressure region within the Erzin shear zone at a middle crust depth level. Interaction of contrasting magmas is comprised of two stages. The first stage occurs during the transport of a contrast mixture and comes down to intensive mechanical mixing and the introduction of LIL and HFS elements, as well as Th and U from granitoids into the mafic rocks. This changes the geochemical characteristics of the mafic rocks. The second stage is when the joint crystallization of magmas is accompanied by gravitational sedimentation of denser mafic magmas and the formation of narrow zones of intermediate composition at the contact of contrasting rocks.

The results of comprehensive studies of terrigenous rocks of the Khabarovsk Sikhote-Alin accretionary complex are presented. It is established that the fragments of Jurassic and Permian-Triassic sandstones are dominated by poorly rounded and poorly separated material mainly from local provenance areas. The detrital part of the rocks is mainly represented by quartz, in a smaller amount by feldspar and rock fragments. Sandstones are characterized by high silica content, moderate alumina content, low concentrations of femic elements and calcium, moderate alkali content with significant varia-tions in the K/Na ratio. Both Jurassic and Permian-Triassic rocks are typically characterized by reduced contents of LILLE, REE, to a lesser extent HFSE and negative values of the ɛ_Nd(T) parameter - compared to PAAS. The model Nd age of Jurassic sandstones varies from 1.36 to 1.71 Ga, Permian-Triassic - from 1.14 to 1.35 Ga. Most of the detrital zircon population is of late Paleozoic-early Mesozoic age, approximately 25% are older (pre-Paleoproterozoic). The studied sandstones are mainly rocks of the first cycle of weathering (petrogenic), formed during the erosion of igneous rocks of felsic composition. The synthesis of the obtained data suggests that the main source of the cluster material for the Mesozoic sedimentary rocks was the geological formations of the northern part of the Bureya-Khanka superterrane (Bureya and Malokhingan blocks), as well as, possibly, the east-ern part of the Mongol-Okhotsk belt. The Khabarovsk terrane has not drifted significantly along the Tan Lu stike-slip system and is an “autochthonous” block in the present-day struc-ture of Sikhote-Alin.

Geochemical studies of Inikan Formation rocks from the coastal outcrops of the Yudoma River were carried out. All analyzed lithological varieties are characterized by significant enrichment in B, Ni, Mo, Ag, Sb, U (redox-sensitive trace metals and elements associated with biodeposition). The source of the elements was sea water that leached them from the eolian material. It was found that the deposits accumulated in anoxic environments with periods of both euxinic (probably, in the bottom water mass) and suboxic conditions. Such anoxic and euxinic conditions developed due to the stable stratification of the ocean that existed in the early-middle Cambrian in this part of the basin. In addition, the long-term accumulation of organic-rich sediment under conditions of anoxia, periodic euxinia, and stable stratification indicates the presence of a geomorphologically isolated depression in this part of the basin. CIA-Kcorr ranges from 68 to 95. The low values of the CIA may be related to the height of the relief in the sedimentary source area.

This study presents a comprehensive analysis of the Balkassar oilfield in the Potwar Basin, Pakistan. It integrates seismic reflection data, a 3D subsurface horizon model, and geochemical and petrophysical data. Evaluating the Lockhart Formation’s geochemical properties using well cuttings reveals consistent patterns of relatively low to fair total organic carbon (TOC). S2 values suggest a fair generation potential with a mixed Type II-III kerogen composition. Seismic facies analysis identifies five distinct categories with parallel attributes. Horizons from lower Permian to Eocene show varying amplitudes and prevalent parallel to wavy internal configurations. Geometries, mainly sheet-to-wedge, enhance stratigraphic understanding. The 3D seismic interpretation reveals the Lockhart Formation’s structural traits, with pronounced northwest dip and gentler southeast inclination. Faults flanking the formation truncate its limbs. A significant contour closure in the northwest, confined by fault boundaries, signifies attractive hydrocarbon potential. Petrophysical analysis indicates an average 9.17% porosity. Dominated by limestone, the formation shows average water saturation of around 25.29% and hydrocarbon saturation of roughly 74.71%, indicating favorable reservoir properties. The Lockhart Formation holds promise as a reservoir rock within the Potwar Basin, though its source rock suitability is limited. This study enhances understanding of Balkassar’s geological complexities and contributes to knowledge of hydrocarbon exploration in the Potwar Basin.

Different approaches to tectonic zoning and different types (complexes) of used data, on the basis of which the zoning is performed, cause the plurality of tectonic schemes of Kamchatka and the Kamchatka region previously obtained by different authors. In this work, a joint analysis of gravity field anomalies, gravity field and relief transforms, magnetic field and modern seismotomographic models of velocity anomalies was used to study spatial relationships of tectonic manifestations of geological processes. As a result of this study, a linear-block type tectonic scheme was constructed. The obtained linear structural elements are in good agreement with the data of potential fields, results and previously published materials. The productivity of the presented method of complex analysis of geophysical fields for revealing their spatial relations and block structures of the environment is shown. The analysis outcomes can be used to establish spatial constraints for gravity field sources when solving inverse problems, potential field separation problems and their detailed geological interpretation.

Weather conditions are a natural limitation of the use of remote lidar sensing methods of the atmosphere, while the direct method based on an aerological aerosol backscattersonde has no such limitations, and these methods are close in physical principles of measurement. The creation of an all-weather stratospheric aerosol monitoring system can be based on the combination of direct and remote observation methods; however, their consistency should be experimentally confirmed. The results of a lidar-aerological experiment on atmospheric sounding at altitudes of 7-50 and 0-30 km using a ground-based lidar and an aerosol backscattersonde (AZOR), respectively, are presented. The experiment was conducted in Tomsk on March 15-16, 2023. Vertical profiles of backscattering coefficients of radiation from sources with close wavelengths were measured: ground-based 532 nm (in lidar) and balloon-based 528 nm (in AZOR). The obtained consistency of lidar and balloon measurements indicates the possibility of using AZOR as a mobile tool to complement lidar measurements in the case of clouds. The combination of direct and remote sensing of the atmosphere with the aim of improving the quality of measurements in studies of the aerosol composition of the atmosphere is discussed. The possibility of extending two wave (355 and 532 nm) lidar observations by direct measurements of AZOR with an additional set of wavelengths (470, 528, 850, and 940 nm) is shown.

The paper presents an algorithm based on a convolutional neural network with a modified U-Net architecture for detecting cloud formations in satellite images. Multispectral satellite images obtained from the MSU-GS instrument installed at Arktika-M No 1 satellite are used as input data. The accuracy of the algorithm was evaluated using machine learning metrics and comparing the results with reference masks compiled by manual decryption of the satellite images by an experienced decoder specialist. In addition, a comparison with similar products based on data of the SEVIRI and VIIRS instruments was conducted. For areas illuminated by the sun, the cloud mask obtained by the proposed algorithm has an accuracy of 92% compared to the reference mask, and for areas not illuminated by the sun, the accuracy is 89%.

To improve the accuracy of weather and climate forecasts, a deeper understanding of atmospheric processes and phenomena, which are determined, among other things, by high-level clouds (HLCs), is required. The experimental results on polarization laser sensing of high-level clouds are presented. The data of systematic (from December 2009 to present) lidar measurements performed with the high-altitude matrix polarization lidar developed at the Tomsk State University are combined. Optical (backscattering phase matrix, optical depth, and scattering ratio) and geometric (lower and upper boundary altitudes and vertical thickness) characteristics of clouds are determined from the lidar measurements. The dataset is supplemented with corresponding vertical profiles of meteorological quantities (temperature, relative and specific humidity, and wind direction and speed) obtained from radiosonde observations and ERA5 reanalysis. The frequency of lidar detection of HLCs and those of them which are characterized by the preferred horizontal orientation of non-spherical ice particles is estimated. The results were combined into a database and used to create a software product based on neural networks to retrieve the dependencies between the atmospheric meteorological parameters and HLC optical characteristics. The database can be used for various training options in solving problems of atmospheric optics including independent ones.

We present the results of trajectory analysis of multi-year measurements of organic (OC) and elemental (EC) carbon in aerosols sampled on quartz filters from a height of 300 m at ZOTTO station. The EC and OC concentrations were determined by the thermo-optical method. The obtained time series were supplemented with the HYSPLIT backward trajectories. As a result the CWT and PSCF functions were calculated on a grid of 150 ´ 250 cells covering the geographical area 30 ´ 20° with the center in Zotino. These functions characterize the intensity of potential sources of carbon-containing aerosols for a given cell. The results allow us to identify the areas with the strongest organic and elemental carbon emissions and to estimate the seasonal variability of these emissions. In particular, in summer, the main sources of OC and EC are located to the east of Zotino, in the Podkamennaya Tunguska River region, and are most likely associated with forest fires. During the cold seasons, the sources of aerosol carbon dominate in the southwestern part of the geographical area under study, where large cities are located and the bulk of the population is concentrated. It is shown that regression analysis of CWT functions of organic and elemental carbon allows one in some cases to determine the dominant type of sources of carbonaceous aerosols. Our results can be used for estimation of aerosol radiative forcing in Siberia.

Using data from experimental studies in a desertified area and in a wind channel, patterns of vertical distribution of saltating particles in a wind-sand flux have been established, which are necessary for understanding the dynamic and electrical processes in a wind-sand flux. Investigation of the influence of wind velocity in the surface air layer on the vertical distribution of saltating particles in a windsand flux in a desertified area has been carried out. A piecewise exponential approximation of vertical particle concentration profiles with a wind speed-independent height scale and a logarithmic concentration gradient in the lower saltation layer is proposed. Using measurements in the wind channel of saltation particle flux profiles, the dependences of the thickness of the lower saltation layer and the height scale for the mass flux of particles in the lower saltation layer on the size of the saltation particles in the range from 100 to 800 mm are obtained. It is shown that the results of determining the parameters of the windsand flux in the desertified area and in the wind channel are consistent with each other. Our results can be used for modeling the dynamics of wind-sand flux.

Based on simulations performed with the CHIMERE chemistry transport model and WRF meteorological model, we analyzed the processes responsible for the formation of the semi-direct radiative effect (SDRE) of smoke from Siberian fires over snow-ice surfaces in the Arctic. Within the framework of the analysis, time and space averaged changes in the radiative fluxes, cloud parameters in different cloud layers, and some meteorological characteristics associated with cloud formation processes due to the radiative impact of Siberian biomass burning aerosol (SBBA) have been considered. The results show that the scattering of the solar radiation by SBBA particles increases the static stability of the atmosphere at altitudes of 2-4 km and suppresses vertical turbulent motions, which decreases the rate of water condensation, the optical thickness of clouds, and the ratio of the mixture of condensed water in the mid-level and partially low-level clouds. The decrease in the optical thickness of the clouds, in turn, causes the appearance of a positive SDRE of SBBA at the top and bottom of the atmosphere. Absorption of radiation by SBBA particles does not play a fundamental role in these processes, although it causes addition changes in the meteorological characteristics.

The purpose of the present investigation is to evaluate the effect of tropical oscillations on the polar stratosphere. The influence of the quasi-biennial oscillation (QBO) of the zonal wind in the equatorial stratosphere and the El Niño Southern Oscillation (ENSO) on the dynamic state of the stratosphere in winter and the evolvement of sudden stratospheric warming (SSW) is studied. A number of numerical experiments were carried out using the nonlinear general circulation model of the middle and upper atmosphere (MUAM) for the winter conditions of the Northern Hemisphere (January-February). They made it possible to estimate the sensitivity of the fields of zonal wind, temperature, and geopotential to taking into account certain ENSO and QBO phases in the model. Depending on the combination of phases, the statistics of observed SSWs and their evolution differ. For example, the largest number of SSWs is observed under the combination of El Niño and the easterly QBO phase, while major SSWs are not reproduced by the model under the combination of La Niña and the westerly QBO phase. For combinations of El Niño/easterly QBO, El Niño/westerly QBO, La Niña/easterly QBO, the fields of hydrodynamic parameters were averaged to investigate the characteristic features of the model “climatic" SSWs. It is shown that the largest temperature increase in the stratosphere and cooling in the mesosphere are modeled under El Niño conditions and the eastern phase of QBO, but the wind weakening is maxumal during El Niño and the western phase of QBO. The largest amplitudes of planetary waves are modeled during the QBO eastern phase regardless of the ENSO phase. The results can be used in climate forecasting on time scales from one month to decades.

The paper is devoted to thermodynamic and chemical processes inside the stratospheric polar vortex, leading to a decrease in ozone content in this region. The winter-spring seasons in the Arctic with the strongest stratospheric vortices and, as a result, the greatest ozone losses are considered. To study the ozone variations and ozone-active components averaged over the vortex, we used an ensemble of backward trajectories inside the vortex and M2-SCREAM stratospheric reanalysis data, which includes some chemical components that affect the ozone concentration. It is shown that the record ozone depletion in the winter of 2020 was due to not only the long-lived stable stratospheric polar vortex, but also the earlier transformation of chlorine reservoirs into the active form and stronger denitrification and dehydration of air masses. The proposed approach can be used to analyze processes in the polar stratosphere over the past winters, as well as to validate chemical-climate models.

Problem of developing algorithm based upon neutral networks and machine learning to find clouds on hyperspectral images are under consideration. It is required that the network is not a "black box," but allows an analysis of the reasons for decision making and classification results. Presented hybrid model includes decision tree trained to overcast recognition (model 1) on pre-selected features of an image in combination with convolutional neural network (model 2). Model 2 uses the result of model 1 and brightness in a selected band of an image. Model 1 finds cloud cores, and model 2 finds cloud edges. Results of testing the hybrid model on data of HYPERION sensor are presented. Data obtained over three surface types (ocean, plant, and urban region) are considered. Overall accuracy, as well as commission and omission errors are assessed. It is shown that the hybrid model can find 85% cloud pixels, only if the neural network is trained on an image where the contrast attains a maximum in the same spectral band. The results of this work can be applied to solve the general problem of analyzing and processing multispectral satellite images and further in environmental science and monitoring of changes in vegetation, ocean and glaciers.

To estimate the relative contribution of the main chemical and physical processes to the observed variability of climate and atmospheric gas composition in 1980-2020, numerical experiments were conducted with the chemical and climatic model (CMC) SOCOLv3. The following factors of changes in ozone content and atmospheric temperature were studied: changes in the content of ozone-depleting substances; changes in greenhouse gas concentrations, ocean surface temperature and sea ice area; variations in solar activity, and changes in atmospheric aerosol content. To estimate the relative role of these factors, calculations were carried out on scenarios taking into account each factor separately and all factors together. According to the results of numerical experiments, the relative contribution of various factors to changes in the temperature of the troposphere and the lower stratosphere, as well as the ozone content was revealed for the period from 1980 to 2020. The model results have been compared with the satellite SBUV data.

The paper solves the problem of deriving the relationship between the variability of statistical characteristics of atmospheric parameters measured by GNSS receivers and the characteristics of convective processes according to the monitoring data near the Kazan city for 2013-2021. The results of GNSS monitoring are compared with the convective indices for the observation period. To assess convective processes, we used physical and statistical parameters of instability calculated from ERA5 reanalysis: Upward Vertical Velocity, Vortex Generation Parameter, and WMAXSHEAR. Statistical characteristics of the zenith tropospheric delay’s horizontal gradient significantly change under conditions of deep convection. The results of the work can be used to develop a methodology for sub-satellite monitoring of convective processes in the tasks of operational forecasting of severe weather phenomena.

Possibilities of astronomical millimeter and submillimeter observations strongly depend on the precipitable water vapor (PWV), which determines the radiation absorption. The precise determination of PWV within large regions is one of key astroclimate problems. In this work, we refine estimates of PWV content for different sites based on processing ERA5 reanalysis and radiosounding data and test the previously proposed technique for correcting PWV values taking into account the characteristic water vapor vertical scale and relative altitude difference of grid nodes. In addition, the spatial distribution of the nighttime atmospheric optical thickness at a wavelength of 3 mm averaged over December - February 2013-2022 was derived for the first time for Russia and the adjacent territory. Our results can serve the basis for selecting an astronomic site for a new large millimeter telescope within the Eurasian Sub-Millimeter and Millimeter Telescope Project.

The characteristics of the combustion process of liquid (diesel) fuel in a high-speed jet of superheated water vapor in the combustion chamber of a hot water boiler are studied at a thermal power of the burner device approximately equal to 40 kW. It is shown that the burner device, created on the basis of the technology of fuel atomization with a steam jet, meets modern technical and environmental standards and has a number of advantages over analogues. It has been established that the addition of steam makes it possible to reduce the concentration of CO and NO_x in combustion products several times. At the same time, the volume of emissions of carbon monoxide and nitrogen oxides when using the burner design under study is significantly (2.5 and 1.4 times, respectively) less than when using a serial analogue of the Weishaupt burner device. Recommendations for optimizing the operation of such devices are presented.

This paper presents the results of an experimental study of the breakup of a jet consisting of two coaxial jets of immiscible liquids with varying phase flow rates. Distilled water and a mixture of polymethylsiloxanes were used as working liquids. The regimes of jet breakup, the types of capsules formed, and the sizes of single-chamber capsules formed under the influence of capillary instability were determined. The natural frequencies of surface instability were measured.

Results of tensile and low-cycle fatigue testing of samples made of an aluminum-lithium alloy of the Al-Mg-Li system obtained by plasma-assisted laser cutting performed by a pulsed CO₂ laser in an argon jet with the laser beam and optical discharge plasma simultaneously affecting the material are reported. Low-cycle fatigue tests show that the number of loading cycles survived by the sample obtained by plasma-assisted laser cutting is more than twice greater than the number of cycles survived by the samples obtained by conventional laser cutting with continuous radiation.

This paper presents a solution of the two-dimensional non-stationary problem of the development of wave motion in a two-layer liquid of finite depth under ice cover modeled by a thin elastic plate taking into account longitudinal compression forces. The cases are considered where, in the unperturbed state, one of the layers is at rest and in the other (top or bottom) layer, the horizontal flow velocity varies linearly in thickness. Dispersion dependences were determined for three wave modes arising in the presence of shear flow. The vertical deflections of the ice cover due to a pulsating source of disturbances located in an initially motionless layer of liquid were calculated. A special case is also considered where the liquid is bounded at the top by a solid lid. The problem is considered in a linear formulation, and the liquid is assumed to be ideal and incompressible.

The influence of the jet pressure ratio ( n =1.18÷3.35) in a nonisobaric supersonic jet of a vibrationally excited gas SF6 exhausting from a convergent axisymmetric nozzle 0.25 mm in diameter is studied numerically and experimentally. The experiments aimed at studying the gas-dynamic structure of the jets are performed in a specially designed jet setup of the Khristianovich Institute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Sciences. The numerical simulations are performed by solving two-dimensional Navier-Stokes equations within the framework of the ANSYS Fluent software and the thermally perfect gas model. The influence of excitation of vibrational degrees of freedom of the SF6 gas is studied in both an equilibrium gas and vibrationally nonequilibrium gas. The nonequilibrium state of vibrational degrees of freedom is simulated with the use of a two-temperature model of relaxation flows. It is shown that the jet pressure ratio of the SF6 gas affects the length of the wave structure cells, which is responsible for the change in the vibrational relaxation rate. The coefficient of density amplitude reduction in gas-dynamic cells is derived as a function of the jet pressure ratio.

The movement of dissolved salt in melting snow is considered based on the equations of non-isothermal two-phase filtration. The thermal conductivity of snow and dependence of the water freezing temperature on salinity were verified against available experimental data. The influence of the presence of dissolved salt on the phase transition was evaluated by numerical experiments.

The influence of the amplitude of deflectors introduced into a laminar jet flow on the coefficient of linear change in the radial component of a stationary disturbance is investigated. The method for introducing disturbances and the method for measuring them are described. It is shown that a decrease in the amplitude of the deflectors does not lead to a change in the flow pattern, does not prevent the occurrence of an algebraic growth mechanism, and causes a proportional decrease in the radial component of the stationary velocity disturbance. The transition to the turbulent regime occurs after reaching a certain value of the radial expansion, which does not depend on the initial amplitude of the introduced disturbance.

The paper presents the results of an experimental study of the influence of distributed engines mounted downstream of the trailing edge on the structure of a separated flow around a trapezoidal model of a flying wing in a subsonic wind tunnel. Visualization patterns of the near-wall flow on the leeward side of the model are obtained in the modes of blocked engines and for the rotational speed of the impeller of 32800 rpm in the range of angles of attack of the wing α = 5÷20°. The studies also take into account the location of distributed propulsion relative to the level of the trailing edge, where the axis of rotation of the engine impeller coincided with the continuation of the wing chord line or is higher than that. The possibility of controlling a separated flow by using sources of stationary disturbances in the form of cones and ribs locally mounted at singular points on the wing surface is studied.

The efficiency of fluid atomization by an atomizer is studied as a function of the spray energy. The dependence of the maximum values of energy on the fluid flow rate is analyzed. A linear dependence is obtained for flow rates smaller than 80 g/s, which testifies to a high efficiency of fluid atomization. For flow rates greater than 80 g/s, the droplet energy is seen to decrease drastically, leading to an increase in the spray droplet size, which testified that the atomization quality is deteriorated. This behavior is observed in all regimes considered in the study.

The local flow structure in a turbulent gas-droplet flow behind a single obstacle has been studied numerically for different initial mass concentrations and diameters of dispersed particles. The effect of evaporating droplets flowing around a single square obstacle on the local averaged and pulsating flow structure and the dispersed phase propagation process has been analyzed. The profiles of averaged longitudinal velocity components of the gas and dispersed phases are similar to those for the single-phase flow regime. The gas velocity in the gas-droplet flow is insignificantly (less than 3%) higher than the corresponding value in the single-phase flow. The turbulence kinetic energy increases in approaching the obstacle. Maximum gas-phase turbulence was obtained on an obstacle of height h at x / h = -1÷0, and it is more than 50% higher than the turbulence kinetic energy before and after the obstacle.

An approach is proposed to model hemodynamics in an arteriovenous malformation and its vascular environment during neurosurgical embolization. This approach is based on a combination of the filtration model of blood flow and the embolic agent in the malformation with a hydraulic approach for the vessels surrounding the malformation. The model is described mathematically by a system of integrodifferential hyperbolic equations. The parameters and functions included in the model are determined using real clinical data from patients. Based on the model, the problem of optimal control of multistage embolization was formulated and studied numerically. Optimal embolization regimens were found for which there is good agreement between the calculated and clinical data. The proposed approach can be used to develop preoperative recommendations about the optimal tactics of surgical intervention.

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.

The results of experimental measurements of the flame temperature in the presence of an impact surface and a liquid phase added to the flow are presented. Methods based on laser-induced fluorescence were used to measure temperature. For a flame of a pre-mixed methane-air mixture with values of the stoichiometric coefficient Φ = 0.92 and Reynolds number Re = 1000, a reverse flow zone was detected near the impact surface in the case when this surface is located at a distance from the nozzle exit equal to three calibers. The temperature field of a gas-droplet flame was measured using the laser-induced fluorescence method

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).