Home – Home – Jornals – Region: Economics and Sociology 2025 number 3

Due to degradation of laser beam properties on atmospheric paths, the maximum length of communication lines is limited. In this regard, it is of interest to evaluate the possibility of detecting the topological charge of a vortex beam disturbed by atmospheric fluctuations using wave front sensors. The problem of measuring the wavefront tilts of a vortex laser beam propagating along a path in a turbulent atmosphere by a Shack-Hartmann sensor is considered. Estimates are obtained for the change in the angles of local tilts of wavefront associated with the solenoidal component of the Poynting vector and the influence of turbulent fluctuations of the refractive index of the atmosphere. Using several specific models of the Shack-Hartmann sensor as an example, the possibility of calculating the value of the topological charge of a vortex Laguerre-Gaussian beam from the measured angles of local wavefront tilts is investigated.

Based on the representation of the solution of the stochastic Helmholtz equation in the form of a path integral (Samelsohn G., Mazar R. Phys. Rev. E. 1996. V. 54, N 5) for the Kolmogorov model of the turbulence spectrum, an expression for the spatial coherence function of a spherical wave propagating in a turbulent atmosphere is derived under the assumption that the geometric-optical approximation is valid for a random phase incursion in the path integral. Estimates of the corrections to this approximation by order of magnitude are found. The obtained formula has no restrictions on the wavelength and the angle between the observation points that arise when using the parabolic and Markov approximations. The error in estimating the radius of spatial coherence in the parabolic approximation, arising from the sphericity of the wave front with an increase in the angular separation of the observation points, is calculated. It is shown that the error increases with the wavelength, and for millimeter and longer waves it can lead to an overestimation of the scale of spatial coherence of a spherical wave by few times.

Water vapor is a significant component of the Earth's atmosphere. Assessing the contribution of water vapor to the Earth's radiation balance has remained a topical issue for decades. In this work, the water vapor self- and foreign-continuum spectra have been retrieved at temperatures of 310, 325, and 340 K in the 1600 cm^-1 absorption band for the first time based on earlier Fourier-measurements of water vapor absorption under self-broadening and broadening by air at 296-340 K within this absorption band with the use of HITRAN2020 spectroscopic database. The retrieved spectra show characteristic for self- and foreign-continuum spectral and temperature dependences. The spectra we retrieved are compared with the MT_CKD semi-empirical continuum model and the semi-empirical dimer-based continuum model ( Simonova A.A., Ptashnik I.V., Shine K.P. Semi-empirical water dimer model of the water vapour self-continuum within the IR absorption bands // J. Quant. Spectrosc. Radiat. Transfer. 2024. V. 329. P. 109198-1-19. DOI: 10.1016/j.jqsrt.2024.109198). The results are important from both fundamental, within the molecular spectroscopy, and practical point of view, in problems of atmospheric modeling and remote sensing.

Ergodic theorems are important when comparing measurement results with theoretical conclusions. Compilation of a “statistical ensemble" requires numerous experiments under similar conditions, which is practically impossible. Therefore, average values are necessarily derived from the measurement data of a single experiment by averaging the empirical data over a certain time range or spatial region. The question of how close such empirical averages are to probability averages is answered by so-called ergodic theorems. An ergodic theorem for stationary processes was proved by G. Taylor in 1922. In this work, we have proved an ergodic theorem for the case of non-stationary random processes. The proof confirms the ideas of O. Reynolds (1894), according to which the time averaging interval should be large compared to the characteristic periods of a pulsation field, but small compared to the periods of the averaged field. The cause of the drift of the mean value, which consists in the dependence of the average values of hydrodynamic fields on averaging interval length and significantly complicates the determination of empirical average values, is found. An approximate measure for quantitative assessments of this phenomenon is suggested; the existence of an averaging time at which the influence of this phenomenon is minimal is shown. The results are important for studies of atmospheric turbulence, where all hydrodynamic elements are non-stationary and show pronounced daily and annual variations.

Aerosol turbidity of the atmosphere over Antarctica is the lowest on the planet. However, it shows regional peculiarities in the temporal variability. In this paper, the main features of the interannual and seasonal variations in the aerosol optical depth (AOD) are revealed on the basis of the analysis of its long-term measurements at Mirny Station. Pronounced variations with a period of 5-6 years and amplitude of 0.005 relative to the average level of 0.023 in the interannual variability of AOD (0,5 mm) are shown. The annual variation in AOD of fine aerosol is characterized by spring and summer maxima (October and February), and that of coarse aerosol is characterized by one summer maximum. Approximation formulas are proposed that make it possible to estimate the monthly average values of spectral AOD in the wavelength range 0.34-2.14 mm.

Bio-optical parameters of seas of the Far East region obtained from the MODIS/AQUA radiometer data are analyzed. The results of two main atmospheric correction algorithms based on the following assumptions are compared: the absence of water-leaving radiance in the near-infrared spectral bands and the stability of the sea water spectral shape in this range (MUMM). Verification was carried out using data of Japanese and Korean AERONET-OC stations. An approach to improving the results of MUMM atmospheric correction by using a regional adjustment of the color indices is considered. The MUMM correction after adjustment is not inferior to NIR correction in terms of the calculation accuracy of chlorophyll- a concentration. It was found that the recommended NIR correction leads to negative reflectivity coefficients Rrs at a wavelength of 412 nm in 10% of cases. These cases correspond to highly trophic waters and are accompanied by an overestimation of the chlorophyll-a concentration by an average of 1.8 times. The proposed correction of the color indices does not lead to negative values of Rrs; the color indices in the blue spectral range have significantly lower errors than those of the NIR algorithm. The proposed approach ensures more reliable estimates of bio-optical parameters of the sea based on satellite data.

Wind Doppler lidars have proven themselves as an effective means of evaluating wind turbulence in aircraft measurements. However, existing methods of sounding from aboard an aircraft assume the presence of a complex scanning system. In this work, we test possibility of evaluating turbulence parameters and wind convective flows using the second version of the lidar created in the Laboratory of Wave Propagation of IAO SB RAS during nadir sounding from aboard a flying aircraft. Based on the analysis of experimental data, we retrieved vertical profiles of estimates of vertical wind velocity (VWV) dispersion and turbulent kinetic energy dissipation rate up to altitudes of 1250-1600 m. During the analysis of sounding data near clouds, we recorded VWV shear according to one lidar signal spectrum, which contained two Doppler peaks. The results of this work can be useful in creating new methods for evaluating turbulence and wind shear.

Characteristics of a convective cloud with heavy rainfall over Saint-Petersburg and Leningrad region on 1st of July, 2023, are considered. The analysis was based on data of the weather radar DMRL-C, weighing precipitation gauges Pluvio² 200, and two lightning detection networks. The appearance and development of Cb under study was a result of merging two convective clouds. During their development the clouds slowly converged moving towards Saint-Petersburg from the southwest. Measurements have shown that the cloud merging led to explosive growth of the cloud top, which reached an altitude of 13.4 km; significant increase in the maximal reflectivity up to 69 dBZ, in volume of the cloud supercooled part with high reflectivity, volumes of the cloud with graupel and hail, precipitation intensity up to 140 mm/h, and lightning rate. The appearance of “the cloud bridge” was recorded. It has been shown that it consisted of graupel and wet snow particles.

Correct assessments of greenhouse gas fluxes and the global carbon cycle require well-provided data on greenhouse gas sources and sinks in the surface - atmosphere system at various natural sites. The article summarizes the results of shipboard measurements of carbon dioxide concentration in surface water throughout the water area of Lake Baikal received in eight spring campaigns of Limnological Institute, Siberian Branch, Russian Academy of Sciences. Spring period is of particular interest for research, since due to the large geographical extent of the lake from south to north, after the opening of the ice cover, the water gradually warms up. This makes it possible to take measurements in relatively different “seasons" during a time-limited expedition. Against the background of a noticeable interannual variability in the spatial distribution of CO₂ concentration in surface water in spring, its decrease from the Southern to the Northern basins of the lake is pronounced. While moving away from the coastal zone to the central part of the water area (to depths of more than 200 m), the concentration of dissolved carbon dioxide increases. The results of the study are of interest to specialists in climate issues and biologists, since carbon dioxide is one of the integral components of the carbon cycle during photosynthesis of aquatic plankton in the Baikal water.

The work is devoted to the study of the effect of aerosols on various processes in the atmosphere, in particular, the formation of convective clouds and their electrification. The special cases of thunderstorms in the Krasnoyarsk Territory during wildfires are considered. This region is characterized by the highest risk of increased wildfires due to the climate change among Russian regions. The thunderstorm events were selected based on the analysis of lightning activity in the selected area from 2015 to 2022 in comparison with wildfire data. A series of numerical experiments on simulating thunderstorms in the WRF model with different aerosol concentrations in the atmosphere have been performed. Based on the simulation results, electrical parameters of clouds have been calculated. To find correlations between the density of lightning discharges and the parameters of convective systems we suggest methods for estimating lightning activity based on the volume of thunderstorm cells with a certain radar reflectivity and the area of high electrical potential. We have revealed that an increase in the aerosol load in the atmosphere increases the time of convection development, as well as a significant effect of aerosol concentration on electric potential maximum at near constant radar reflectivity maximum. The results can be used to develop fundamental ideas about the relationship between lightning activity and wildfires and to improve methods for predicting lightning activity.

The problem of atmospheric emission source identification using remote sensing data is considered. An algorithm is proposed for a three-dimensional model of atmospheric pollutant transport and a nonlinear measurement model represented as a “differentiable black box". The algorithm is based on sensitivity operators and ensembles of adjoint equations solutions. It was tested on a realistic scenario for identifying soot sources for the Baikal region with synthetic satellite measurements of the Terra/MODIS platform, which showed its applicability. Additionally, the measurement data decomposition modification of the algorithm is proposed, which made it possible to reduce the relative error of retrieving the source function by 12% compared to the version without decomposition. The results can be used in the development of remote sensing data processing systems.

In atmospheric remote sensing, particularly in the interpretation of lidar signals from cirrus clouds, the accuracy of light scattering modeling on non-spherical randomly oriented ice particles plays a crucial role. Although the physical optics approximation is commonly used due to its computational efficiency, it does not always provide sufficient accuracy, especially when particle sizes are comparable to the wavelength of incident radiation. This introduces systematic errors into scattering matrix databases used for solving inverse problems. This study employs the discrete dipole approximation to verify the validity of the physical optics approximation. The primary focus is on comparing results obtained at wavelengths of 0.532 and 1.064 mm for particles of various shapes and sizes from 2 to 8 wavelengths. It is shown that in this size range, the physical optics approximation leads to relative errors of up to 20% in the linear depolarization ratio and reduces the backscattering intensity by half. The findings enable a more precise estimation of the applicability limits of the physical optics approximation and provide corrections for existing scattering matrix databases. This, in turn, will improve the accuracy of lidar data interpretation and enhance the quality of microphysical retrievals for cirrus clouds.

Highly directional supercontinuum (HDSC) is a unique source of broadband coherent radiation. To create such a source, it is necessary to know the parameters and conditions of its occurrence. The article presents the results of experimental study of the conditions for HDSC generation in gaseous nitrogen pumped by a radiation pulse with wavelength of 950 nm, duration of 70 fs, and energy of 3-6 mJ. The pump radiation was focused into a gas chamber by a spherical mirror with F = 75 cm under aberration conditions (the angle of incidence of the radiation on the mirror was 15°). It is shown that there is optimal pump energy of 4.5 mJ and gas pressure of 3-4 atm. The spectral composition of the HDSC covers the range from 350 to 1000 nm. The divergence of HDSC radiation is diffraction-limited and its greatest value (the diameter of the white spot in the far zone) corresponds to a wavelength of 780 nm. The maximal HDSC energy was 17 μJ. The results are useful for understanding the physical mechanisms underlying the emergence of HDSC, as well as for developing broadband coherent radiation sources.

In 2024, the head of the Ministry for the Economic Development of the Russian Far East stated: “The main challenge in the development of the Far East and the Arctic is retaining the population" (https://roscongress.org/materials/aleksey-chekunkov-v-novoy-globalnoy-sisteme-koordinat-rol-dalnego-vostoka-budet-vozrastat/). This phrase entered the vocabulary of politicians and publicists and came to mean not a ban on moving to a new place of residence, but, firstly, various ways of encouraging the local population to stay and work in their region and, secondly, preferences for those who decide to move to work and live in areas of particular importance to the state. The article reviews examples of such territories in pre-revolutionary Russia, the USSR, and the Russian Federation, the legitimacy of their status, and preferential regimes. It systematically analyzes the reasons creating two huge megaregions of special state significance - the Far East and the Russian Arctic - whose ambitious development plans require additional labor resources. The article examines the list and adequacy of measures used to “retain the population," the objective difficulties in implementing state personnel policy, and possible ways to overcome them.

Improving the energy efficiency of the constituent parts of the Russian Federation in the context of their sustainable development is fully in line with the global “green agenda " and, due to the adopted domestic regulatory documents, represents a state task. Sustainable development is subject to a number of conditions and factors, including the availability of regions’ own energy resources. Energy self-sufficiency in the general energy sense implies the self-sufficiency of regions not only in terms of electricity, but also in terms of other fuel and energy resources (coal, gas, oil, etc.). However, this article focuses on the issue of regional self-sufficiency in electricity. In this regard, the aim of the article is to construct typological groups of regions depending on the degree of influence on their sustainable development of such indicators as the region’s energy security and the share of energy losses in power grids. The study covers 85 constituent entities of the Russian Federation based on data for 2022 and is based on a methodology developed by the author, which first involves assessing the country’s regions according to the analyzed indicators and then typologizing them. As a result, quantitative and qualitative parameters made it possible to form four groups of regions, differing in terms of sustainable development characteristics. In order to increase the level of sustainable development and energy efficiency of regions, authorities should adopt not typical but typological decisions for each identified group, taking into account the impact of the region’s energy self-sufficiency and energy losses on the gross regional product and gross regional product per capita. This study contributes theoretically to solving the scientific and practical problem of levelling energy imbalances in regional electricity production and consumption models. The practical significance of the study lies in the fact that the results obtained can be used by regional authorities in implementing energy policy in the region, and the proposed tools and mechanisms can be directly applied in their practical activities.

Today, Russia, while adapting to strategic challenges primarily related to the changing world order, is creating its own model of a sovereign national economy. One of the important considerations for achieving this goal is the development of interregional interaction within the country as a tool for fulfilling the potential of its territories. This article studies the problem of structural and technological proximity (STP) of regions as a significant factor in activating economic ties between the subjects of the Russian Federation through the example of the Kemerovo Oblast - Kuzbass. The methodological toolkit for assessing the STP of regions is tested. In order to measure it, the official data of Rosstat for 2022 were used. According to the calculations, the subjects of the Russian Federation, which currently have the strongest positions for the development of cooperation with Kuzbass, were identified. They represent the main macro-regions of the country. Within the framework of a possible partnership with the participants of this group of territories, the Kemerovo Oblast is able to act as both a supplier and a recipient of not only capital, but also knowledge and technology. The latter is especially important in the situation of reforming the resource (raw material) model of Kuzbass performance. The findings can be used to update the strategic planning documents of the Kemerovo Oblast, develop programs and projects aimed at strengthening the processes of its integration and cooperation with other Russian regions through the development of intellectual resources and capital exchange channels.

The article considers the factors of competitiveness of creative industries in Russian regions with a focus on the role of personal branding as a tool for promotion and self-fulfillment of the creative class. The subject of the study embraces the practices of creating and promoting personal brands in the conditions of digital environment and high information saturation. The aim of research is to identify the key strategies ofpersonal brand formation in the creative sector and evaluate their effectiveness to improve the competitiveness of professionals and regions as a whole. The hypothesis is analyzed that successful development of the creative economy requires not only state support, but also natural market mechanisms, including competition, networking and personal brands. The research was conducted by a survey of384 representatives of creative industries in Krasnoyarsk Krai (February-April 2024), the sample was formed by river-sample technology. The respondents represented such spheres as art industry, design, music, theater, cinema, education, media and others, according to the UNESCO classification and the Concept of Creative Industries Development in Russia. The results showed that 42.6% of the participants are purposefully working on their personal brand, and another 36.4% plan to do so. Respondents consider positioning and awareness to be the main attributes of a personal brand. The most popular promotion tool was social networks (27.8%), as they correspond to the logic of the attention economy. More than a third of respondents noted a tangible effect of branding: invitations to projects, new clients, recommendations as a professional and networking. The obtained results can be used to improve the state policy of supporting creative industries, develop the methodological basis for personal branding research and improve the efficiency of professional activity in the creative sphere. The article demonstrates that personal brand is an important resource of competitiveness in the creative economy and requires further study and system support.

The prospects for scientific, technological and innovative development at the level of individual territories depend on many regional characteristics, including the size and balance of accumulated scientific and technological capabilities. The proposed approach to assessing such balance is based on the ideas of innovation and absorption capacities accumulated in a certain territory. The study proposes a typology and positioning of the RF subjects based on the comparison of the highlighted characteristics. The share of people employed in research and development in the total labor force in the region is used as an indicator of innovation capacity. Absorption capacity reflects the localization coefficient of high-tech business. Leading and follower regions are identified for 2016 and 2022. Data from Rosstat and SPARK-Interfax database were used as an empirical basis. The authors performed factor and cluster analyses on indicators describing the state of the region’s economy, its research and technological potential, human resources and digital technologies, as well as the quality of institutions in the field of innovation policy, and identified groups of similar territories. The study identified characteristics that affect the level of innovation and absorptive capacities at the regional level, contribute to their balanced combination, ensuring socio-economic growth and technological independence. These include significant expenditures on research and development, high level of digital technology development, advanced innovation policy. The structure of the economy should be relatively balanced, provide an external environment favorable for the development of new technologies and the production of innovative goods.

The article reviews over long intervals the transition that took place during the Soviet period from an expanded to a narrowed regime of reproduction of the population in Russia, which inevitably leads to depopulation, first latently, and then openly. It is shown that a widespread practice of abortion, which has significantly reduced the number of newborns for a long time, has become the most important factor contributing to the general decreasing trend in the total fertility rate below the threshold level of simple reproduction. In the early 1960s, there was a rapid increase in the number of artificial abortions, accompanied by a drop in fertility. The peak number of abortions recorded in 1965 coincided exactly with the start of the latent phase of depopulation in Russia. In the post-Soviet period, despite a considerable reduction in the number of abortions, both in absolute and relative terms, their number is still high. This has a significant impact on fertility decline, although in recent years the official statistics indicate that there is now less than one abortion for every two births. The article briefly describes the century-old history of legalized abortion in Russia. Its extremely important role in reducing fertility and depopulation in our country is revealed. The long-term and widespread abortive practices, reflecting the reluctance to procreate, systematically undermined the demographic potential and caused enormous damage to demographic security in several important areas for many decades. The authors cite the dynamics of the number of abortions per 100 births in the federal districts in the post-Soviet period, as well as the differentiation of this indicator at the level of federation subjects. The eastern territories consistently show the worst results: the Ural, Siberian and Far Eastern Federal Districts. In recent years, the Siberian Federal District has been ranked first in the country in terms of the number of abortions per 100 births. Among the Siberian regions, the Novosibirsk Oblast stands out, which for many years has been the district leader in this indicator. It is concluded that prevention and minimization of the number of abortions while conducting a well-thought-out and balanced demographic and socio-economic policy aimed at strengthening the family as a pillar of society and improving its financial situation could become a counter-force for increasing the birth rate, especially significant in the context of a prolonged decline in the number of reproductive female populations. The results obtained during the study can be used by federal and regional authorities to make managerial decisions aimed at preventing and reducing the number of abortions, as well as in developing new demographic policy measures and improving socio-economic development strategies in order to create moral and material conditions in society favorable for birth and upbringing of children.

At present, the assessment of the standard of living of the working segments of the population is of particular relevance. The purpose of the study is to adapt the traditional methodology of the HDI approach to assessing the standard of living of the working population in the regions of the Volga Federal District (PFD). The methodology proposed by the authors for calculating the human development index (HDI) of the working population, called “HDI-labor”, includes the following components: 1) the index of median wages, correlated with the cost of a fixed set of consumer goods and services (salary purchasing power index); 2) the index of viability of the working-age population; 3) the index of education, based on the number of students of secondary specialized and higher educational institutions per 10 thousand people of the population. A rating of the regions of the Russian Federation supported by calculations of the new HDI-labor indicator based on data for 2013, 2015, 2017, 2019 and 2021 indicates that the Republic of Bashkortostan in 2021 dropped two positions compared to 2013, taking 35th place. The article also provides comparisons of HDI-labor with HDI-region as a whole and by their components. In 2021, the value of HDI-labor in the Republic of Bashkortostan was 0.375, including the purchasing power index of the median wage - 0.359, the vitality index - 0.311, the education index - 0.454. The value of obtained results is to complement the methodology for assessing the standard of living of the working population based on the HDI approach. This methodology for assessing the standard of living of the working population based on an integral indicator is suggested for use while developing recommendations for improving the standard of living of the working population in the regions of the Russian Federation.

A study of hydrogen oxidation in the presence of sulfur dioxide was conducted in an oscillatory mode. It was found that this process occurs via a degenerate chain mechanism, with sulfur oxide (SO), the primary product of sulfur dioxide conversion, playing a significant role. It was shown that the hydrogen oxidation reaction in the presence of sulfur dioxide in the autoignition region under certain conditions (pressure, temperature, gas mixture composition, contact time) proceeds explosively and is accompanied by light emission. A comparison of experimental data on hydrogen oxidation in the presence of sulfur dioxide with the results of calculations using the proposed model of the process under study revealed good agreement. Based on the calculation results, the effective activation energy of the reaction was determined to be 9 200 J/mol.

The paper presents the results of experimental determination of the flammability concentration limits of methane--air--water vapor, methane--hydrogen--air--water vapor mixtures with a methane to hydrogen volume ratio of 1:2 and 2:1, and carbon monoxide--hydrogen--air--water vapor mixtures with a hydrogen to carbon monoxide volume ratio of 4:1 at an initial temperature of 150 °C and a pressure of 101 kPa. The water vapor content varied in the range of 0 ÷ 60 vol. %. The experiments were conducted in a spherical chamber with a volume of 100 dm3. The presence of mixture ignition and flame propagation were recorded using infrared imaging. The flammability limits of the methane--air--water vapor mixture obtained in the experiments are in agreement with the data available in the literature. The flame propagation mode in hydrogen-containing mixtures near the lower concentration limit was recorded in the form of a spherical flame turning into a toroidal vortex.

The effect of chemical nonequilibrium in the combustion process of a diffusion methane-air flame at moderate pressures and temperatures of the initial reactants on the reduction of nitrogen oxide in reactions known as NO reburn was studied. Based on the detailed mechanism of chemical kinetics of methane oxidation GRI-Mech 3.0, an analysis was performed of the distribution of the main NO-reducing substances (CH, CH₂, CH₃, HCCO) in reburn reactions, as well as the initial substances forming NO in Zeldovich reactions, across the thickness of a diffusion laminar flame based on a numerical solution of the Peters-Kuznetsov system of equations using the thin flame front model (flamlet model). In the flame representation as a chain of isolated ideally mixed reactors distributed across the flame thickness, the NO concentration was estimated using a precise analytical formula representing the rates of reburn reactions in accordance with three detailed kinetic mechanisms: GRI-Mech 3.0, Glarborg, and Miller---Bowman. A comparative assessment of the efficiency of these mechanisms for reducing NO concentration was performed; the maximum reduction was 13.3, 23, and 30.4%, respectively. An assessment of the influence of diffusion showed a change in the relative concentration of NO profiles by no more than 0.06%. It was also shown that, as the chemical equilibrium deviates, reburn reactions gradually begin to occur on the "lean" side of the flame (as fuel radicals diffuse across the stoichiometric boundary), and the region of reburn reactions in terms of the composition of the gas mixture expands more than twofold. The contribution of reburn reactions on the lean side of the flame increases steadily and can reach 56% of the total reburn efficiency, which is of practical significance in systems with a high degree of combustion nonequilibrium. The main contributions to NO reduction on the lean side of the flame are reactions with CH (up to 75% via the GRI-Mech 3.0 mechanism) and reactions with HCCO (up to 80% via the Glarborg mechanism).

The results of a study examining the effect of a weak electric field on a Bunsen burner flame are presented, including the combustion of an aerosol consisting of water microdroplets in an air-methane mixture. Analysis of velocity fields obtained using a PIV system revealed changes in the laminar flame front propagation velocity when exposed to a weak electric field. Moreover, over a significant portion of the combustion front, the laminar front propagation velocity can be considered constant. The existence of an ion wind caused by the drift of negative charge carriers is confirmed. The introduction of water microdroplets into the fuel reduces the charge carrier concentration, indirectly evidenced by the fact that the effect of an electric field on combustion in this case leads to smaller changes in the flow structure ahead of the flame front.

The lower temperature limits for flame propagation of mixtures of oil vapor with oxygen and nitrogen in the presence of liquid oil were determined. Experiments showed that the lower temperature limit differs significantly from that expected for oxygen. One reason for this discrepancy is that, in the presence of an ignition source and a large amount of oxygen in the gas phase, diffusion combustion of the liquid oil film present on the inner surfaces of the vessel can initiate. The flame propagates along this film to the bulk of the oil. As the oil continues to diffuse, a pressure increase significantly exceeds that expected for flame propagation through the gas phase.

The gas-dynamic, kinetic, and energy parameters of detonation in dual-fuel methane-hydrogen systems are presented: a) stoichiometric methane-oxygen and hydrogen-oxygen mixtures in various ratios; b) stoichiometric methane-oxygen mixture with added hydrogen in various ratios; c) stoichiometric hydrogen-oxygen mixture with added methane in various ratios; d) lean hydrogen-oxygen mixture with added methane in various ratios; e) enriched hydrogen-oxygen mixture with added methane in various ratios. The main behavioral patterns of such systems are discussed.

A study was conducted to determine the effect of sample length fixation and mechanical activation of the mixture on the combustion rate and elongation of the samples during synthesis, as well as on the phase composition and morphology of the combustion products in the Ti + C system. After activation for 9 min in an AGO-2 mill with an acceleration of 90g using 9 mm diameter steel balls in air, partial mechanochemical synthesis occurred in the mixture, with the TiC product present in addition to the initial Ti and C components. With activation lasting 9 min, the mixture became pyrophoric and, in some cases, ignited upon removal from the activator drum. After mechanical activation lasting less than 9 min, the combustion rate of the mixture increased and the particle size decreased compared to the combustion rate and particle size of the original mixture. With an increase in activation time in the range of up to 9 min, the amount of impurity gases in the mixture increased, which led to an increase in elongation, and at longer times, to the dispersion of the product samples during synthesis. Fixing the sample length significantly increased their combustion rate, but, like mechanical activation of the mixture, did not affect the phase composition of the synthesis products.

A study was conducted on the macrokinetic combustion of a granulated Zr + 0.5C mixture under nitrogen flow conditions. It was shown that the combustion rate increases nonlinearly with increasing gas flow rate, with the combustion process accompanied by sample shrinkage of up to 26%. Experimental data were analyzed using conductive and convective combustion models. Calculations showed that combustion in a nitrogen flow at gas flow rates exceeding 500 l/h occurs via the convective mechanism. It was established that longitudinal sample shrinkage is due to the presence of a significant amount of zirconium melt during combustion. According to X-ray diffraction analysis, the synthesis products are a mixture of zirconium carbonitrides ZrC_xN_y of variable composition. Chemical analysis of the synthesis products revealed that the degree of nitridation of the granulated mixtures is higher than that of the powder mixtures and increases with increasing nitrogen flow through the sample.

To improve inherent safety and reduce energy consumption in industrial explosives production, the water-soluble compound hexamethylenetetramine is being used to replace the traditionally used insoluble fuel oil in ammonium nitrate-based explosives. This oxidizer and fuel, combined in water, create an intermolecular explosive called an ammonium amine explosive. The effect of pH in the range of 4.0 to 5.8 on the density of this explosive, crosslinking time, microbubble formation, detonation velocity, and water resistance was determined. The studies were conducted using density measurements, a digital viscometer, an optical microscope, detonation velocity tests, and a conductivity meter. The results show that ammonium amine-based explosives prepared at various pH levels form numerous chemically sensitized microbubbles, the average diameter of which decreases as the pH decreases. Lower pH values are associated with higher foaming rates and shorter crosslinking and foaming times. The detonation velocity of ammonium amine-based explosives is 3,500-4,200 m/s, slightly lower than that of conventional emulsion explosives. Furthermore, a comparison of the water resistance of ammonium amine-based explosives with crosslinking times of 1 and 24 hours yields contrasting results. A pH of approximately 5.2 sets the boundary between in-situ mixed and packaged ammonium amine-based explosives. Packaged explosives show significant advantages at pH values above 5.2, while in-situ mixed explosives are more advantageous at lower pH values. These results provide a theoretical basis for improving the performance of this new water-resistant nitrated substance and simplify its industrial application.

Aluminum diboride (AlB₂) microcapsules coated with polyvinylidene difluoride (PVDF), fabricated by a simple rotary evaporation method, were studied. According to the morphology study, PVDF forms an intact outer shell on the surface of each individual AlB₂ particle. Compared with uncoated AlB₂, the AlB₂@PVDF microcapsule has a shorter ignition time, more intense combustion, and faster pressure build-up. At an appropriate PVDF content, the measured heat of combustion is higher than that of the composition with unencapsulated AlB₂, due to a higher heat release efficiency during combustion --- 92.3% (the efficiency of the composition with unencapsulated AlB₂ is 85.2%). Mechanistic study shows that the PVDF decomposition product likely accelerates the oxidation of AlB₂ at several reaction stages, providing higher reactivity of the AlB₂@PVDF microcapsules. The use of AlB₂@PVDF in explosives increases density, detonation velocity, and heat release with good component compatibility, while maintaining acceptable mechanical sensitivity. Therefore, AlB₂@PVDF microcapsules are a promising metallic fuel in composite energetic materials.

Using the molecular dynamics method, numerical experiments were conducted to study the dependence of the melting temperature of various materials (copper, silver, titanium, and silicon carbide) on the nanostructure size. Analysis of the obtained data showed that for all materials, starting from a certain nanostructure size, the melting temperature decreases with decreasing nanostructure size.

The problem of measuring particle size distribution in shock-induced flows is discussed. The design of a mobile holographic system developed by the authors, which implements the method of axial pulse holography, is presented. The system enables the acquisition of holograms with a field of view of approximately 20 mm in diameter and a depth of over 20 mm, and the recording of flows of lead particles ≥3-5 μm in size, moving at velocities up to approximately 2 km/s. Examples of shock-induced flows moving in a vacuum, recorded using the mobile holographic system, are presented. These flows consist of both individual particles 5-100 μm in size and, predominantly, filamentary formations 3-10 μm thick. Methods of analog and digital recording and reconstruction of holograms are discussed, as well as the problem of identifying particles in images reconstructed from recorded holograms.

A new type of ammonium nitrate-based explosive is presented, prepared by replacing diesel fuel with liquid coal fuel (coal atomized in water). Experimental results show that the higher the calorific value of the raw coal, the higher the detonation velocity of the new liquid explosive. For example, with a liquid coal fuel content of approximately 9-12% and a calorific value of 5,500 kcal/kg, the efficiency of the new explosive is relatively stable and achieves improved parameters: velocity equals 2,800-3,000 m/s, brisance increased by approximately 7-10%, and the work performed increased by approximately 8-24% compared to an explosive made from ammonium nitrate and diesel fuel. Minimal changes in the physical and chemical properties were observed during 30-day storage. At the same time, the blast efficiency of this explosive was significantly improved by adding composite additives consisting of a new coal-based fuel, diesel fuel, and an emulsifier. Blast tests under industrial production conditions were conducted at the Heidaigou open pit mine. The test results showed that the new explosive exhibits significantly improved brisance and greater work-producing capacity compared to ammonium nitrate- and diesel-based explosives.

Using the electric contact method, the influence of sample porosity, dispersion, and diameter on the detonation velocity of the individual low-sensitivity explosive triaminotrinitrobenzene (TATB) was studied. Data on the detonation wave front curvature were obtained. The results show that, under identical initiation conditions, the detonation process of TATB is complete after the detonation wave travels a distance equal to 3.5 times the explosive sample diameter and is independent of the porosity, dispersion, and diameter of the samples.

To study the effect of initial ambient pressure on the explosion parameters of thermobaric explosives (HE), static explosion experiments were conducted using trinitrotoluene (TNT) as a reference at both low and high initial ambient pressures. Various grades of thermobaric explosives were tested, and a correlation model was proposed for analyzing the overpressure and momentum of the blast shock wave in different initial environments, taking into account atmospheric pressure. Analysis of the pressure data showed that the general propagation and attenuation characteristics of blast shock waves from TNT and thermobaric explosives are essentially the same at different initial ambient pressures. As the initial ambient pressure decreases, both the shock wave overpressure and momentum decrease. The explosion propagation velocity also decreases with decreasing initial ambient pressure. Furthermore, as the explosive mass increases, the reduction in overpressure and momentum decreases for both thermobaric explosives and TNT, and the difference in the shock wave propagation velocities from these two types of explosives also decreases. A comparison of the correlation model results with experimental data yielded average maximum relative errors of 12.3% for TNT and 8.8% for thermobaric explosives in low-pressure environments relative to the shock wave overpressure. Momentum errors were 12% for TNT and 13.7% for thermobaric explosives. These results demonstrate the high accuracy of the correlation model. This correlation model allows one to determine the shock wave overpressure and momentum of an explosion at various initial ambient pressures, and to estimate the shock wave power generated by thermobaric explosives.

The question of how solid rocket propellants react to fragment impacts remains relevant. Identifying potential mechanisms for propellant propellant reaction to fragment damage is crucial for assessing the safety of solid rocket motors and developing high-energy, low-sensitivity propellants. In this study, a fragment impact experiment on a propellant propellant consisting of glycidyl azide polymer, hexogen, and triethylene glycol dinitrate (GRT) was conducted using a 14.5-mm ballistic gun and a high-speed camera to obtain images of the propellant reaction time history under various ballistic behaviors. Based on the obtained images and measured ballistic data, the relationship between propellant reaction characteristics, the primary reaction mechanisms, and two ballistic limits was analyzed. The results of a 10.0 mm diameter tungsten ball impact on a GRT charge contained in a 3 mm thick cylindrical steel shell show that the threshold reaction velocity corresponds to the ballistic limit of fragment penetration into the shell. Below this ballistic limit, no propellant reaction occurs. In the case of a significant reaction delay caused by the ignition of RDX crystal hot spots rather than ammonium perchlorate particles, the propellant reaction upon complete penetration is combustion. Only when a large number of ammonium perchlorate particles and RDX crystals simultaneously ignite hot spots, and the fragment's initial velocity exceeds the charge's ballistic limit by 2.2 times, can the charge undergo reactions more intense than combustion.

The problem of viscous oxide films, which prevent the full release of energy from boron powder during combustion, was overcome using graphene fluoride (fluorographene). This chemical compound was chosen due to its high fluorine content, low hydrogen content, low surface free energy, and strong thermal conductivity. Graphene fluoride reacts with boron, releasing a large amount of heat and gaseous products during combustion, effectively removing the viscous oxide film, and preventing boron agglomeration. Graphene fluoride was synthesized by shear cutting in an emulsifier, and graphene fluoride-boron composites were fabricated by solvent evaporation. Thermal analysis and heat of combustion tests showed that the prepared thin graphene fluoride layer had an average thickness of 1.56 nm. A composite of 20% graphene fluoride and boron showed a 1.86-fold increase in heat of combustion. Moreover, the addition of 20% graphene fluoride effectively improved the heat release during combustion of boron powder, making it comparable to the heat release during combustion of high-energy composites consisting of metal and boron powders.

The results of numerical modeling of cellular detonation propagation in inhomogeneous gas suspensions of aluminum particles in a hydrogen-air mixture are presented. A physical and mathematical model of hybrid detonation is used, describing chemical reactions within the framework of the given kinetics. The model takes into account homogeneous and heterogeneous reactions with the formation of suboxides or solid aluminum oxide particles, as well as phase transitions (evaporation and decomposition of the oxide) in the reaction products. The model is consistent with known experimental data and the results of thermodynamic calculations of detonation parameters and mixture composition at equilibrium. Flows in channels with transverse gradients and discontinuities in particle concentrations are considered. Various patterns of cellular structures are obtained, allowing us to consider the spatial distribution of particles as a controlling factor in detonation processes.

Experiments show that preheating the shaped charge liner improves its penetrating power. This increase is due to the increased ultimate elongation of the formed shaped charge jet due to thermal softening of its material. The possibility of heating the jet itself in free flight by thermal radiation from a tube located in front of the shaped charge, with heat generation within it caused by a chemical reaction of self-propagating high-temperature fusion, is considered. The characteristics of shaped charge jet heating by thermal radiation are investigated using an analytical solution to a one-dimensional axisymmetric problem of unsteady heat conduction for a uniformly elongating cylindrical rod. It is shown that before plastic breakdown of copper shaped charge jets occurs, they can be radiantly heated in free flight to a temperature that allows for a slight increase in the jet's penetrating power.

Impact tests of 1565 aluminum alloy in the impactor velocity range of 242-653.7 m/s revealed that at a certain impactor velocity (626 m/s), a sharp increase in particle velocity occurs in localized regions of the target. Microstructural studies of the sample revealed traces of localized deformation. Simultaneously, material is ejected from the rear surface of the target. This phenomenon correlates with the stochastic behavior of strain carriers at the mesoscopic scale-the presence of mesoparticle velocity dispersion. To account for the influence of stochasticity on shock wave propagation, a system of equations from the continuum theory of dislocations is used, which includes a dislocation velocity distribution function. It is shown that local attenuation or acceleration of the shock wave is determined by the relationship between velocity dispersion and the flow velocity of the dislocations.