Home – Home – Jornals – Journal of Applied Mechanics and Technical Physics 2026 number 4

The results of magnetotelluric studies on the Medvetskoye–Toguchin settlement profile, located in the interface zone of the southern margin of the West Siberian Plate and its mountain-folded rim, the Altai-Sayan folded region, are considered. The profile intersects elements of three large tectonic structures: the Salair cover-folded structure, Gorlovskiy trough, and Doroninskaya Depression. The main differences in the geoelectric structure of these structures, as well as the blocks isolated within them, are shown. The conductive heterogeneity identified in the Earth's crust of the Salair ore zone is considered as a promising area with the highest probability of detecting indigenous deposits of endogenous genesis. The areas of increased electrical resistivity (3*10³ ohms·m) detected at a depth of about 1000 m in the territory of East Salair are interpreted as granitoid intrusions of the Zhernovsky complex. They are located on the continuation in the northern direction of the axis of the roof projections of a large batholith of the Zhernovsky complex of Late Permian age. In spatial connection with these granitoids, manifestations of geochemical anomalies of tin, lead, zinc and other elements are found.

Andrey Alekseevich Trofimuk is a patriarch of Russian oil and gas geology, a talented scientist, one of the founders of the Siberian Branch of the USSR Academy of Sciences, and the organizer and permanent director of the Institute of Geology and Geophysics, Siberian Branch of the USSR Academy of Sciences, for three decades. He made a significant contribution to strengthening the resource base of the Russian oil and gas industry. During the Great Patriotic War, A.A. Trofimuk and his colleagues discovered large oil fields in Bashkiria, thereby laying the foundation for a new oil base in the Ural-Volga region. A.A. Trofimuk carried the character traits he developed during the war years—a scientifically sound approach to assigned work, optimism, a tremendous will to achieve goals, integrity, and courage—throughout his life. He participated in the scientific substantiation and discovery of the West Siberian and East Siberian oil and gas provinces. Vladislav Stanislavovich Vyshemirsky is a renowned Russian scientist, a prominent representative of the Siberian school of petroleum geochemists, and a specialist in the theory of naphthidogenesis and the conditions of oil deposit formation. His primary works focus on theoretical issues of petroleum and coal geology and assessing the oil and gas potential of Siberian sedimentary deposits. In 1985, he established a new research direction on direct gas-geochemical methods for hydrocarbon deposit exploration. V.S. Vyshemirsky was the first head of the Laboratory of Fossil Fuel Geochemistry at the Institute of Geology and Geophysics of the Siberian Branch of the USSR Academy of Sciences and one of the founders of the Department of Oil and Gas Field Geology at Novosibirsk State University.

This study investigates allochthonous chloroform rock extracts (allochthonous bitumoids) of Carboniferous-Lower Permian deposits and crude oils from the Anabara-Khatanga oil and gas region. The main geochemical parameters in the Lower Permian bitumoids show a clear correlation with marine organic matter of the Lower Kozhevnikov and Tustakh formations. The distribution of biomarkers in crude oils and allochthonous bitumoids located within the Nordvik and South Tigyan fields suggests their genetic relation. The specific features of the molecular composition of the studied samples indicate the organic matter accumulation in a sedimentary basin with high water mineralization, which suggests conditions for the formation of carbonate-evaporite deposits typical of the Devonian. However, due to the very limited information on the organic matter geochemistry from Devonian source rocks, the issue of genetic correlations «oil/ allochthonous bitumoids - source rock organic matter» remains open.

The article discusses the postulates underlying the phenomenological theory of the induced electrical polarization (IP) in geological materials. According to one of these, polarization currents are always directed opposite the polarizing currents generated by the current source. Furthermore, it is claimed that the electric field in a polarizing material is equal to the sum of the primary and IP fields. Time-domain measurements demonstrate that these assumptions are inconsistent with electrical circuit theory and do not provide a correct explanation for the IP manifestation. An alternative explanation, taking into account electrical circuit theory and based on the fact that electrical resistivity of polarizing media depends on time/frequency, is free from this inconsistency.

This paper examines the design of algorithms that minimize the localization time of an unknown signal source that manifests itself by generating ultrashort (essentially instantaneous) pulses at random moments. The source being searched for is random in two respects: first, its position within the search interval is unknown, and second, the source generates pulses at random moments. The source is localized using a detector receiver capable of arbitrarily changing its viewing window at any moment in time. Optimal search algorithms are constructed for the case where the a priori probability density function of the source distribution is a two-level piecewise constant function. The optimal parameters of these algorithms are determined, including the expected execution time for each of them. It is proven that an optimal algorithm that takes into account a priori information about the intensity of the source being searched for is always more efficient than an algorithm for which this intensity is unknown.

Assessing the big data informativity is a topical area of research related to realizing the potential of big data technology for solving problems of automated monitoring, forecasting, decision-making, and machine learning in economic sectors. This article analyzes modern approaches and methods defining the concept of informativity and allowing for assessing the informativity in the context of the pragmatic and relativity of information, its value, and usefulness. The specifics of processing distributed and streaming big data and determining the minimum information space are considered. Assessing the big data informativity for problems of feature generation and selection, design, and data-driven management are discussed in detail.

A method for visualizing translucent objects with subsurface light scattering in real time is proposed. An analytical model is described that takes into account the directivity of the incident light, providing images that are more realistic compared to those generated using known analytical models. A sampling scheme based on the optical properties of the material is considered. A directional dipole using a rendering pipeline on a GPU is presented.

Statistical characteristics of the envelope ratios of two non-Gaussian signals and a mixture of two random processes with given distribution laws were determined. One-dimensional Density of Probability Distribution (DPD) for the ratio of envelopes of two independent non-Gaussian signals during incoherent processing, joint DPD of envelopes and their derivatives, as well as the average number of outliers were found. It is shown that one-dimensional DPD depends on the parameters characterizing the shape, scale and center of distribution of signal envelopes. Special cases of DPD calculations for Rayleigh and Rice distributions are given. Statistical characteristics of the polarization parameters of the signal, such as the DPD and the average number of emissions of the ellipticity coefficient, are obtained. Statistical characteristics are defined for the mixture ratio of two random processes with a normal distribution law and with a generalized non-Gaussian distribution. In particular, expressions were obtained for determining the DPD of a mixture of the two above processes, v-initial moments and an integral distribution function of the mixture of processes were found. The expressions DPD of the envelope of the useful signal in the presence of normal interference, DPD of the ratio of two statistically independent mixtures, DPD of the polarization phasor module, joint DPD of the mixture of two independent stationary processes and the average number of emissions are obtained.

Universal analytical expressions are proposed for calculating the quality factor (Q-factor) of optical amplitude-phase channel signals for data centerinterconnection (DCI) using Coherent Orthogonal Frequency Division Multiplexing (CO-OFDM). A single-span fiber-optic transmission system with an optical amplifier located at the receiving end and using polarization multiplexing for transmitting OFDM signals is considered. The resulting formulas take into account the simultaneous effects of nonlinear phase distortions occurring in the fiber and amplified spontaneous emission noise. These formulas enable the noise immunity of individual signal points in the M-QAM constellation to be estimated depending on the transmission system parameters, without resorting to resource-intensive simulation modeling. Calculations of the noise immunity of polarization-multiplexed 16-QAM channel signals showed the possibility of organizing a connection between Data Centers over a standard single-mode fiber over a distance of 80 km with a total data transfer rate of 32 Tbit/s.

The charge traps formation was studied in SiO₂ films implanted with In⁺ and As⁺ ions during subsequent annealing at temperatures T = 800-1100 °C. It was found, as the annealing temperature increased, the flat band voltage shifted non -monotonous and reached its maximum at the temperature 900 °C. At the same time, the hysteresis observed in the high-frequency C-V-characteristics was minimal. As the annealing temperature grew to 1000-1100 ^oC, the hysteresis window increased by an order of magnitude. From the obtained C-V-characteristics, the density of the fixed charge and the density of rechargeable charge carrier traps in the oxide was estimated. From the C-V and G-V-characteristics as a function of frequency, the surface state density was estimated, which was practically independent of the annealing temperature and was about 2×10¹¹ cm^-2eV^-1. The nature of the fixed charge in the dielectric was related to the oxygen vacancies In-As in the SiO₂ matrix. The increase in the hysteresis of the C-V-characteristics as a function of the annealing temperature was explained by a change in the energy spectrum of deep levels.

The potential of a method for determining protein concentration in biological fluids using Raman spectra of the dry residue after water evaporation is investigated. The method is used when the protein content in the liquid is low compared to non-protein components. To suppress contributions to the Raman spectrum from non-protein organic substances, protein precipitation with trichloroacetic acid (TCA) in the liquid before obtaining the dry residue is proposed. To obtain a quantitative value for the mass fraction of protein, it is proposed to add lysozyme, a protein with unique Raman spectral properties, to the liquid. It is shown that analysis of the Raman spectra of the dry residue with lysozyme precipitated with TCA allows determination of the mass fraction of protein in the range of 0.03 mg/ml and higher. The method is also tested using conditioned fluids after culturing corneal fibroblasts and myofibroblasts, demonstrating the feasibility of obtaining reliable protein concentration values.

Surface-enhanced infrared absorption (SEIRA) spectroscopy, which is based on the enhancement of the infrared response of an analyte in the vicinity of plasmonic nanoantennas, is a promising technique for highly sensitive molecular detection. The development of approaches to further improve the sensitivity of this technique remains an important challenge in modern sensor technology. In this work, arrays of linear gold nanoantennas fabricated on a silicon substrate were used to detect the characteristic vibrations of monolayer coatings. 1-Octadecanethiol (ODT) was employed as a model analyte, and a layer-by-layer coating procedure based on the Langmuir-Blodgett method was implemented. Two ODT monolayers were sequentially deposited onto the Au nanoantennas, allowing the absorption enhancement factor of the ODT vibrational band at approximately 1470 cm⁻¹, assigned to the bending vibrations of CH_₂ groups, to be estimated as 3×10⁵. The obtained results demonstrate the potential of plasmonic nanoantennas for the development of mid-infrared sensors.

A three-channel static polarimeter scheme designed for distributing spatial phase light modulators based on liquid crystals is presented. The interaction of light reflected from the modulator with the device's optical elements is calculated, and analytical expressions for the light intensity in each channel are obtained. A solution to the inverse problem of determining phase transitions on the matrix elements is presented. Experimental results demonstrating the transformation of a control signal into a phase transition are obtained.

Three metrological indicators are analyzed, the experimentally recorded values of which turned out to be inconsistent with the requirements of the three basic goniometry methods that formed the basis for the implementation of the selected measurement procedures.It is shown that the efficiency of the process of filtering the harmonics of the instrumental error in the reference sensor of the angular comparator, implementing one of the variants of the multi-combination method, turned out to be an order of magnitude lower than its theoretical value.It was shown that the results of calibration of the precision encoder RON-905, implemented using the mentioned comparator, were not in accordance with the requirements of the EDA method of the goniometry. It is also shown that the calibration results of one of the reading heads of the reference sensor of this comparator are distorted by the action of harmonics, the presence of which does not correspond to the original prescriptions of the self-calibration method.

The widespread use of carbon dioxide (CO₂) lasers in material processing, polymer welding, and lithography has led to a significant reduction in their cost, enabling their applications in new areas. In this work, we characterized the pulsed operation mode of a commercial Reci W2 sealed CO₂ laser tube that generates mid-infrared (mid-IR) radiation with an average power above 100 W. By combining pulse energy measurements with time-resolved FTIR spectroscopy, we examined the temporal profiles of the emitted radiation in the 10-1000 µs range and analyzed the spectral dynamics. Complementary measurements of current and voltage provided additional information on the discharge behavior and its temporal relationship with the optical output, offering a more complete picture of pulse formation. Two distinct modes of pulsed operation was demonstrated: 1) a transient high-peak-power regime achieved with relatively short 50-150 μs laser pulses, 2) a stable-generation regime observed for 150-1000 μs and longer laser pulses. The results show that inexpensive sealed CO₂ laser tubes can operate as convenient mid-IR pulsed sources with characteristics suitable for a range of spectroscopic measurements, materials research, and instrumentation development.

The work solves the problem of quantitative modeling of the semantic structure of text, which is formulated as the inverse problem of wave optics. Based on the established operational analogy between semantic dynamics and the propagation of coherent radiation in an inhomogeneous environment, geometrization of text in Minkowski space is proposed. Within this analogy, the concept of "semantic refractive index" is introduced, and the text is considered as a field of complex amplitude. The key result is to demonstrate the applicability of numerical methods of computer optics - the Finite-Difference Time-Domain (FDTD) method for direct modeling of the propagation of the semantic front and iterative phase recovery algorithms (Gershberg-Saxton) for reconstructing the latent thematic structure by the distribution of the "intensity" of embeddings. Experimental testing on a scientific text confirmed that the proposed approach makes it possible to visualize thematic clusters as a mode structure of a waveguide beam and quantify the coherence of discourse through a coefficient similar to the degree of spatial coherence. The work expands the scope of computer optics methods to the problems of analyzing complex semantic systems.

A method is proposed for estimating the energy expenditure associated with air injection through a cylindrical section of a finely perforated surface on a high-aspect-ratio body of revolution at zero angle of attack in an incompressible flow. The method is based on the premise that the power required for injection is independent of both the power of the propulsion engine and the motion regime of the body. For a Reynolds number Re₁ = 1.666 × 10⁶ m^-1, numerical simulations demonstrate that distributed air injection into the turbulent boundary layer of the body of revolution can yield power savings of 11 to 19 %, depending on the size of the computational domain.

Results of an experimental investigation of coherent structures in a shear layer, obtained using different approaches, are presented. Characteristic length scales are determined via combined processing of data from single-wire and surface hot-film anemometers and PIV measurements. The combined PIV and surface anemometry approach allows one to identify regions where the flow parameters correlate with the readings of the surface sensors. The joint analysis of data from the surface sensors and PIV enabled determination of the optimal location of the surface sensors relative to the separation region for the development of active closed-loop flow control techniques.

We investigate the superposition of two unsteady one-dimensional shear flows of a homogeneous Newtonian viscous fluid in a half-space with a boundary that translationally moves parallel to itself. Exact solutions are expressed in terms of Stieltjes integrals in a quasi-self-similar form characteristic of diffusion-vortex processes. A linearized perturbation problem is formulated in terms of velocity and pressure variations, assuming the motion of the boundary plane remains unperturbed. This problem is analyzed using the method of integral relations. The method employs quadratic functionals and yields integral estimates sufficient to ensure that perturbations do not grow over an infinite time interval. The case in which both boundary velocity components are monotonically nondecreasing functions of time is examined analytically.

A numerical study of the effect of mixer configuration on the flow structure and mixing quality of a rheologically complex fluid in a mixing apparatus is performed in a two-dimensional formulation. Three mixer configurations are considered: paddle, anchor, and anchor with rotation. The non-Newtonian behavior of the fluid is described using the power-law model. The solution is obtained using the finite-volume method with the SIMPLE pressure-correction procedure, implemented on an unstructured triangular mesh. The flow structure is characterized by the formation of circulation zones near the blades and a shear-flow region along the solid wall of the apparatus. The redistribution of an ensemble of marker particles over time is also simulated to enable a qualitative assessment of the mixing process. A quantitative assessment is performed using a measure of marker distribution inhomogeneity.

The problem of surface wave propagation in the presence of a thick rectangular block floating above an infinite step is studied within the framework of linear theory. The block is located entirely in the region of finite depth. An eigenfunction expansion method is used to construct the velocity potential describing the fluid motion in the finite- and infinite-depth regions. From the pressure continuity conditions in the gaps above the step corner and below the two corners of the block, three integral equations of the first kind are derived for the horizontal velocity components in these gaps. The integral equations are solved using the Galerkin method, the basis functions are chosen as simple polynomials multiplied by exponentially decaying functions, and the weight functions are determined taking into account the edge conditions. We perform the numerical calculations of the hydrodynamic characteristics-the reflection and transmission coefficients and the components of the wave force acting on the block. The dependences on the wave number are obtained and analyzed.

A new microcapsule design for targeted drug delivery is proposed and investigated. The design consists of a spherical liquid cell (drug solution) containing a nanobubble, encapsulated in a polymer shell. The effect of low- and high-frequency ultrasound on the cavitation bubble dynamics in a confined liquid volume and the resulting elastic tangential (circumferential) stresses in the polymer shell is analyzed. It is found that a relatively weak external ultrasound stimulus can be significantly amplified inside the microcapsule due to explosive cavitation growth of the bubble. The most significant amplification and, consequently, the maximum tangential stresses in the shell are achieved using low-frequency (approximately 20 kHz) ultrasound and a thin shell. It is shown that, in the presence of a cavitation bubble, the mechanical stresses in the shell are many times greater than in a capsule filled with liquid alone.

The wave flow of a viscous liquid film along the lower surface of an inclined plane is investigated. Flow regimes with steadily traveling waves are identified, and their stability with respect to periodic linear perturbations with the same wavelength as in the nonlinear solution is examined. Calculations are performed using the full Navier-Stokes equations. Bifurcation lines are calculated for various inclination angles and Kapitsa numbers. Their structure is found to depend strongly on the Kapitsa number and only weakly on the inclination angle. At large inclination angles, a change in the bifurcation type from the wave-free solution occurs, and the film thickness vanishes at a certain distance from the bifurcation point. The critical angle at which film detachment occurs is determined as a function of the Kapitsa and Reynolds numbers.

An experimental study of the gas-droplet flow parameters was conducted in a small climatic wind tunnel at the ITAM SB RAS. The droplet size distribution of the liquid phase in the test section was determined using the PolisSpray optical shadowgraphy system. Shadowgraph images of droplets were obtained in various regions of the test section. An algorithm for droplet detection, based on a combination of gradient analysis and morphological operations, was developed and implemented to improve the accuracy of droplet size estimation. Droplet diameter distributions were obtained for the investigated regions of the test section and subsequently corrected for the effects of depth of field and optical blur. These parameters were estimated from the intensity gradient at the droplet image boundaries. The results were compared with those obtained using a Malvern Spraytec laser diffraction analyzer.

Results of numerical simulations of blood pumping through an elastic vessel using the vibro-volumetric method are presented. The simulations characterize blood motion in the vessel under vibro-volumetric actuation. It is shown that blood flow depends significantly on the frequency and amplitude of the driving force, as well as on the opening angle of the channel formed by the walls of the vibrating device. A qualitative analysis of the problem demonstrates the existence of a steady-state regime of blood transport along the vessel under the action of the vibrational force, with transport velocities characteristic of various perfusion pump designs. The influence of the key operating parameters of the device on the blood transport velocity is established, enabling flow rate control by varying the external excitation frequency for a given channel opening angle and driving force amplitude. The obtained dependences confirm the feasibility of perfusion and flow rate control of blood and blood-substitute solutions by adjusting the design and operating parameters of the device. A direction for further model improvement through optimization of the channel wall geometry is proposed.

The characteristics of supersonic flow in a converging rectangular channel are numerically investigated as functions of the channel aspect ratio and wall temperature. The channel consists of a converging inlet followed by a constant-cross-section region. In the inlet, a compression wedge with an angle δ _w = 13° generates a shock wave that induces boundary layer separation. Using the Navier-Stokes equations and the k-ω SST turbulence model, data on the flow structure and the characteristics of the separation zones are obtained at a Mach number M = 4.5 at the channel inlet.

The results of a study examining the effect of dimethyl ether additives on sooty ethylene/air flat flames are presented. The study was conducted using quadrupole mass spectrometry. The experimental data are compared with kinetic modeling results. It is shown that the studied dimethyl ether additives do not significantly affect the formation of the aromatic compound C₆H₆. However, with increasing dimethyl ether content, the intensity of signals from aliphatic structures increases. The impact of this effect on soot formation is analyzed.

The problem of linear modal stability of a cylindrical Chapman-Jouguet deflagration combustion front in a radially diverging subsonic flow with a low Mach number is formulated and solved, taking into account vortex velocity disturbances. Unstable oscillation modes and waves with amplitudes increasing over time are detected for the considered types of small disturbances of the main combustible mixture flow and flame front. Quasi-natural frequencies and spatial modes of oscillations and disturbance waves of the combustion front are obtained. The presence of rotating circumferential disturbance waves of the combustion front in the annular combustion chamber channel is demonstrated, and their rotation velocities are determined. The main features of accounting for vortex disturbances are presented.

Experimental data on hydrogen propagation in a room with forced ventilation are presented. The dependence of the maximum volume fraction of hydrogen on the volumetric gas flow rate for ventilation of an 8 m³ room is determined. Experiments on the ignition of a hydrogen-air mixture formed after the discharge of a jet from a high-pressure cylinder at up to 14 MPa are also conducted. The effect of the total area of the blowout windows on the magnitude of the baric loads exerted on the room walls during combustion of the hydrogen-air mixture is assessed.

The results of an experimental study of combustion and detonation wave diffraction in a poorly understood class of dual-fuel systems (using the methane/hydrogen fuel system as an example) are presented. A characteristic feature of the studied systems is the significant difference in the kinetic parameters of the individual fuel components. New data are obtained on the dynamics of combustion wave propagation, detonation cell sizes, diffracting wave velocities, critical initiation conditions, and their optimization.

Due to the high risks associated with explosive experiments, modern research typically focuses on small-scale models that determine parameters such as pressure and momentum using the distance reduction principle. Due to the complexity of the physical picture of an explosion, numerical modeling in combination with experimental methods is becoming a reliable tool for studying the parameters of detonation and shock wave propagation. In this paper, a small-scale explosive experiment was calculated using CFD modeling, the effect of the computational grid size was studied, and the effectiveness of protective devices placed above the blast barrier was assessed. Additionally, the TNT equivalent was estimated and an approach to its determination based on the Chapman-Jouguet relations was proposed. The results show that the calculation accuracy can correlate with both the grid size and the reduced distance. Modeling of protective devices revealed their noticeable effect on the shock wave distribution in the air. The proposed method for estimating the TNT equivalent showed promising results for the studied explosives; However, further research is recommended to expand its scope of application, particularly for aluminized compounds and other types of explosives.

The interaction of a shock wave with a Mach number of up to 2.5 with a quasi-elliptical lean laminar flame front was studied in a vertically positioned shock tube with a square cross-section of 138 × 138 mm. The low-pressure chamber of the shock tube was filled with a combustible mixture of 8% H₂, 18.4% O₂, and 73.6% Ar to a pressure of 20 kPa, and the high-pressure chamber was filled with air or helium to a pressure of 100 or 400 kPa. Pulsed laser radiation, focused onto a point near the axis of the low-pressure chamber, ignited the combustible mixture, resulting in the formation of an isolated, slowly growing flame source-a bubble. This quasi-elliptical shape represented the contact boundary between media of different densities-light combustion products in a heavy unburned mixture. After the membrane separating the high- and low-pressure chambers was forced to rupture, a shock wave formed in the latter. Upon interaction with the flame source, it caused the development of a Richtmyer-Meshkov instability at its boundary. The unstable flow-a quasi-elliptical flame evolving into a toroidal vortex-was recorded through a pair of optical windows in opposite walls of the tube using high-speed schlieren videography at a frame rate of 50 kHz.

A study was conducted on the flammability characteristics of 0.35 and 1 mm thick glass fiber-reinforced epoxy resin plates with additives of the phosphorus-containing flame retardant DOPO-THPO, graphene, and graphene oxide. The fire resistance of the plates was determined using the oxygen index test and the UL-94 HB test. The tests revealed no significant effect of flame retardant additives on fire resistance. The mechanism of action of the flame retardants was further investigated in experiments on horizontal flame propagation towards the oxidizer flow with different oxygen concentrations. It was found that the addition of 2 wt. % graphene + 4 wt. % DOPO-THPO leads to a decrease in the flame propagation velocity of 0.35 mm thick samples. However, an increase in the concentration of DOPO-THPO additive to 6 ÷ 8 wt. % had the opposite effect. The effect of the addition of 8 wt. % graphene oxide was higher than that of the addition of a mixture of graphene and DOPO-THPO. No effect of flame retardants on flame propagation velocity was detected for 1 mm thick specimens. This is presumably due to the specimen thickness, which corresponds to the thermal limit of thickness. Furthermore, temperature profiles in the condensed and gas phases during flame propagation were determined.

The evaporation and combustion of fuel droplets have been studied since the middle of the last century. Existing spray combustion modeling is based on a simplified one-dimensional model. This model, as well as recently developed three-dimensional combustion models for single droplets, do not describe the conditions under which various droplet combustion regimes exist. In this paper, droplet evaporation and combustion are studied using hydrodynamic and experimental methods. The hydrodynamic section considers a two-dimensional axisymmetric evaporating and burning droplet. The equations of motion are solved using an integral method similar to the Karman-Pohlhausen method for calculating the boundary layer in the presence of a pressure gradient. The resulting solution yields a local evaporation rate and flame radius consistent with known experimental data. In the experimental section, the influence of relative gas velocity, pressure, and gas temperature on droplet evaporation and combustion processes is determined. Various droplet combustion regimes at different relative velocities are experimentally revealed, explaining the change in the evaporation constant with increasing relative velocity. The theoretical results are confirmed by experimental studies of suspended droplet evaporation.

A method for automating the determination of dispersed phase parameters in materials is proposed, based on digital holographic recording and deep machine learning. Numerical and field experiments were conducted on holographic recording of a cloud of particles with sizes on the order of 10 µm, and the resulting holograms were reconstructed layer-by-layer. It was demonstrated that a neural network is capable of recognizing particles in reconstructed holograms with accuracy metrics exceeding 75%, which is more than twice the accuracy of binarization and the Hough, Sobel, and Canny algorithms.

The effect of potassium, calcium, magnesium, and iron chloride inclusions on the critical energy density of laser radiation sufficient for igniting pre-demineralized grade 2B brown coal using millisecond laser pulses with a wavelength of 1070 nm and an intensity in the range of 6.4-52 kW/cm² was studied. For minimum radiation intensities, additional calcium and magnesium concentrations of 5-7% increase the critical ignition energy density by 2-4 times. Potassium increases the critical energy density by less than 20%, while iron reduces it by approximately 2 times, with a tendency to saturate as the inclusion concentration increases to 7%. The effect of the inclusions used decreases with increasing radiation intensity and virtually ceases at a radiation intensity of 52 kW/cm².

This paper examines the problems of describing conductive and radiative heat transfer in models of aluminum nanoparticle combustion. The agreement between theoretical models of classical electrodynamics and experimental data on absorption cross sections in the IR region is analyzed. It is shown that in both the far- and near-IR regions, the models underestimate the absorption cross section of aluminum nanoparticles compared to experimental data. Models that assume a small nanoparticle size compared to the skin depth differ from experiment not only quantitatively but also qualitatively in the near-IR region. This indicates that the skin depth in the near-IR region is no greater than the size of the nanoparticles, and therefore, the dissipation of wave energy within the nanoparticles should be considered taking into account partial shielding of the wave field. A semiempirical formula for calculating the thermal radiation of nanoparticles is proposed, taking into account the partial shielding of the wave field within the nanoparticle volume.

The results of an experimental study of the detonation characteristics of the C25A model explosive composition manufactured at the V.V. Bakhirev State Research Institute of Machine Building (GosNIIMash) are presented. The following detonation parameters were determined: density, detonation velocity, pressure, and chemical spike duration; pressure, temperature, density, mass velocity, speed of sound, and the adiabatic index at the Chapman-Jouguet point. The onset time of the aluminum oxidation reaction after the passage of the detonation wave and the response time during the expansion of the explosion products in the detonation flow were estimated, and an adiabatic curve for the unloading of the detonation products was constructed. Equipment from the Lavrentyev Institute of Hydrodynamics and the Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences was used in the study.

The combustion behavior of granulated mixtures (100 - X )(Ti + C) + X(Co---Cr---Ni) at X = 0 ÷ 40 wt. %, used for the synthesis of metal ceramics, was studied for the first time. The mixture composition at which the release of impurity gases leads to a transition from the conductive to the convective combustion mode ( X = 20%) was determined by calculation, which made it possible to estimate the impurity hydrogen content in the studied mixtures. For granules of 1.7 mm in size, the filtration of impurity gases through the sample leads to the convective combustion mode at X < 20% and to the conductive one at X > 20%. The conductive combustion mode is realized in all mixtures with granules of 0.6 mm in size. The phase composition of the obtained composite samples is represented by TiC and the fcc phase of the medium-entropy CoCrNi alloy. The interphase heat transfer coefficient in granulated SHS mixtures, calculated using experimental data, is an order of magnitude higher than the theoretical values for the heat transfer coefficient in a porous medium. The proposed synthesis method from granulated mixtures in a flow reactor holds promise for the production of TiC-CoCrNi composite powders used for applying hardening coatings.

The influence of the Fe + Co + Cr + Ni + Al metallic binder content, mechanical activation and compression of the samples on the maximum combustion temperature and rate, sample elongation during synthesis, mixture yield after mechanical activation, morphology and phase composition of the combustion products in the 5Ti + 3Si + x(Fe + Co + Cr + Ni + Al) system was studied. A composite material consisting of ceramics and a high-entropy silicide was obtained using self-propagating high-temperature synthesis. A two-phase high-entropy alloy consisting of solid solutions with an fcc and bcc lattice is formed during a 5-minute activation of 5Ti + 3Si + x(Fe + Co + Cr + Ni + Al) mixtures. With an increase in the metallic binder content in the mixtures, the grain size of the ceramics in the products, the maximum combustion temperature and the mixture yield after mechanical activation decrease. Compression of the samples from the initial mixtures expanded the concentration limits of combustion for the metallic binder content. The dependence of the combustion rate on the metallic binder content shows a maximum at x = 10% by weight. Activation of the mixtures increased the combustion rate and expanded the combustion concentration range depending on the binder content.