Home – Home – Jornals – Thermophysics and Aeromechanics 2021 number 3

This article offers an approach to forecasting long-term options for the social and economic development of Russia’s eastern regions that covers goal setting, mobilizing resources, and selecting mechanisms to achieve the set goals, on a systematic basis. We develop a methodology to coordinate the conditions for regional development at different hierarchical levels, in particular, to ensure that the key macroeconomic determinants of economic growth in the Russian Federation are correctly translated to the regions. We also suggest an evaluation plan to assess the impact of investment on increasing gross regional product (GRP) for the region, the country, and its eastern part. The plan is based on analyzing the “investment - fixed assets - GRP - investment" cycle, changes in fixed asset age composition, and ROA ratios. The article substantiates the maximin criterion of GRP resource distribution aimed at reducing the gap between the performance of regional economic sectors and the improvement of infrastructure, social services, and household incomes in the regions. Newly drafted algorithms describe sharing the proposed methods inside a set of simulation regional macro-models. Here we propose a three-stage systemic forecasting plan, where the stages of top-down and bottom-up calculations are complemented with their mutual convergence. We study the characteristics of the social and economic situation in the Russian East. Finally, we conduct experimental regional development calculations until 2035 under a moderately optimistic scenario in relation to the key economic factor levels (the population, household incomes, a growing share of investment in GRP, etc.) and analyze their results.

The article deals with minimizing social losses associated with the inability to achieve all the set goals amid limited economic policy instruments that managers of the socio-economic system can actually use. We give a critique of the currently available approaches to minimizing the social loss function. Then we provide an example of how economic policy instruments were implemented nationwide in Russia between 2018 and 2019. It was a period when the Bank of Russia’s application of monetary policy instruments aimed at achieving a single goal only, the one related to inflation, had not been coordinated with an increase in VAT by the Ministry of Finance. Using the AD-AS model, we show a negative impact of these decisions on both economic and investment growth rates, which in their turn have a long-term effect on economic growth. The problem discussed in this paper is relevant at the regional level: when establishing regional development roadmaps, it is essential to achieve an optimal combination of short-term and long-term goals. The authors present a model for minimizing the social loss function (SLF) as a mathematical programming problem. Within this proposed problem, we outline an approach to finding the optimal solution that provides the maximum approximation to achieving not only short-term but also long-term goals of economic policy for a particular time with consideration to the restrictions on the use of its tools. Since minimizing the social loss function is carried out for an interval, the article introduces a concept of “bliss trajectory" in contrast to the “bliss point" category used in the theory of economic policy for solving static optimization problems. We also describe how to solve such a problem with the conditional gradient method and give a step-by-step algorithm for this kind of solution.

The article is devoted to studying differences in regional economic growth models identified with the shift-share technique to decompose growth structurally, which allows explaining a regional growth rate deviation (“shift") from the expected values under the assumption that all regions have identical sectoral structures. As required by the original formulation of this analysis method, such a shift is decomposed into sectoral (compositional) and regional (competitive) components. We divide the regional shift into components defined by the effects of potential spatial spillover and local competitiveness through a spatial approach. The economic activity indicators are gross value added and average annual employment in the fourteen-sector nomenclature across the constituent entities of the Russian Federation. We carry out the analysis in a dynamic setting over the period between 2004 and 2019. According to its results, the decisive contribution to regional differentiation in growth rates has been an inherent competitive effect, measured by a regional shift and arising from the same industry performing dissimilarly in several regions. The spatial decomposition of regional growth rates has separated the contribution of the region’s inherent competitiveness from that of its local environment. The first factor dominates, meaning that the regional (competitive) shift in most regions, regardless of its sign, has resulted from a local competitive effect rather than the spatial spillover of economic growth.

A tenth of the world’s forest resources are concentrated in the Asian part of Russia, but the efficiency of their use is not high. The forest industry in the Asian part of Russia has vast development potential. However, it is also characterized by raw material export orientation, low value-added production, insufficient reforestation measures, and underdeveloped forest infrastructure. This article analyzes the main trends and prospects for the forest industry development in the Asian part of Russia. By analyzing statistical indicators, official program documents, and media materials, we arrive to the following conclusion: the factors mentioned above, together with the lack of a systematic government policy aimed at supporting producers, carrying out measures to protect and restore the ecological situation in the regions and regulate forest relations severely impede the development of the forest industry. It is necessary to establish a new national industrial policy for the industry’s effective functioning and intensification.

The article exams the shadow economy in public passenger transport across Russian regions. The goal of this research is to assess the effect of a newly established cashless system on the size of declared revenues by domestic transport organizations. The research relevancy is expressed in quantitative evaluations of how the cashless system, along with discounts for cashless payments, helps combat the concealment of revenues by transport organizations. We use an econometric analysis of panel data for the period between 2014 and 2019. The Fixed effects model is chosen as the best among others. The econometric model considers heteroscedasticity and endogeneity of the average bus fares. The obtained data indicate that the cashless system with payments by debit and credit cards leads to increased transport organizations’ declared revenues. In contrast, the same cashless system with payments by transport cards does not lead to such an increase. In 2019, cashless payments were spread more in municipal and public transport rather than in commercial vehicles.

Modern Russia is characterized by a frequent discrepancy between the places of employment and the residence of the able-bodied population. Combined with the new opportunities for its spatial mobility, this has led to the development of intra-Russian and intraregional labor migrations. Among them, a significant place is occupied by pendulum migration (daily departure to the place of work in another locality) and shift labor organization (departure to a new place of work for a long time due to the irrationality of daily return to the place of permanent residence). The phenomenon of shift work historically grew out of the pre-revolutionary otkhodnichestvo, which does not fully coincide with that of seasonal work. Our contemporaries are increasingly using the term “otkhodnichestvo" finding direct parallels with shift work. Such work is becoming one of the most dominant areas of labor migration and an active factor of spatially mediated depopulation, analyzed in the article published in the previous issue of this journal. Unfortunately, statistics do not allow us to obtain objective information about the shift labor phenomenon, and therefore its estimates by different researchers differ significantly. Legally, shift work in Russia is regulated only from the point of view of this employment relationship between the employer and the employee. However, the article shows that this work situation determines not only the special organization of labor but also the special order of organizing the lives of millions of Russian citizens and the spatial organization of economic and social activities in the regions and municipalities of Russia. The concentration of shift work is noted in Moscow and several other large cities, and in poorly populated areas of Russia, it is localized in stationary shift settlements. They are proposed to be considered as a kind of components of the settlement system with the legal establishment of relations with local self-government bodies.

The article presents an analysis of studies by Russian and foreign scientists, which demonstrated the relevance of the problems of social inequality at the regional level. The purpose of this study is to develop an approach for dividing Russian regions into groups based on the level of socio-economic development and development of the educational system. Another goal is to scientifically substantiate the importance of the social elevator “Education " (in relation to school education), not only at the level of an individual gifted person but also at the regional level. A desk study was carried out using an adapted model of multivariate ABC analysis. The integral parameter proposed by the authors is based on such factors as the results of the unified state exam, the region’s performance in the All-Russian Olympiad for schoolchildren, and the project competition Big Challenges, as well as the presence of highly rated schools. As a result, three enlarged groups were identified among the regions of the Russian Federation, which make it possible to assess the possibilities and potential of the provided social elevator “Education " in certain regions for the development of gifted individuals. The article presents recommendations for improving the effectiveness of regional education policy for regions losing high-quality human capital. The results of the analysis can be used to form regional programs for the strategic development of the education system and social elevators for gifted individuals in the context of interregional inequality. In the future, it is possible to research the intercountry mobility of gifted individuals, as well as a quantitative analysis of migration flows associated with the choice of the next level of education and the volume of the “reverse of talents."

This article examines the background and conditions for China’s Belt and Road Initiative, how it is perceived and reacted to in the world. We also present the results of the agreements reached by the Heads of State of Russia, Mongolia, and China. The article classifies 32 projects within the economic corridor, highlighting the most priority ones. A review of research done by scientists from these three countries in infrastructure development, regional integration, and interstate cooperation made it possible to determine the states’ potential and development levels in terms of financial and natural resource possession. In addition, we analyze and compare each party’s strategic interests and benefits from the economic corridor to be built, identify their peculiarities, and assess the existing mechanisms for trilateral cooperation. This work proves the need to work on interstate coordination mechanisms. Particular attention is paid to describing the essence, goals, and objectives of Mongolia’s Steppe Road national program, later renamed Path for Development, and the results of measures taken by the Mongolian government to create road transport infrastructure as part of the economic corridor. Examples of such measures are several road construction projects under the Path for Development, and the Tavan-Tolgoi - Gashuunsukhait and Tavan-Tolgoi - Zuunbayan railways. The problems of road transport infrastructure are related to the financial difficulties in refinancing the profits coming from the Ulaanbaatar Railbus, the lack of investment from the Asian Infrastructure Investment Bank and the Silk Road Fund, despite these financial institutions having decided to participate in financing road transport projects. There is criticism toward the fact that Chinese companies act as the principal contractors in the Mongolian-based projects financed by grant aid and a concessional loan from the Chinese government, while Mongolian ones are only involved as subcontractors. The Mongolian side has taken the initiative to attract investment from countries outside the set contracts or international financial institutions, which the other two parties, Russia and China, find disagreeable.

The article examines the current state and eco-economic development of the Arctic zone of the Russian Federation, using the example of one of the Arctic regions of the European North of Russia, Arctic Karelia. The purpose of the article is to identify the key problems and contradictions of the ecological and economic development of Arctic Karelia in the perception of the region’s population. In the context of limited statistical information on these issues, the main emphasis is on the use of sociological research methods. The principal methods applied in the study are dialectical, sociological analysis (questionnaire survey), and statistical analysis. Based on the results of an empirical study, the Arctic Karelian population estimated the state of the natural environment and its dynamics in the world, Russia, the Arctic, the region of residence, and the immediate place of residence. We received the residents’ detailed assessment of the natural environment for the following components: air quality, surface water quality, noise level, state of forests and parks, and the level of domestic pollution. These data were obtained and analyzed, including in a breakdown by regions, making it possible to use the research results to draft differentiated regulatory measures both at the level of regional government and in creating software tools for Arctic Karelia’s development and establishing a special economic regime in the Russian Arctic. These results are scientifically significant due to the unique nature of our research object. The region of Arctic Karelia, formed in July 2020, has not been previously studied, firstly, as a separate territorial entity, and secondly, as thoroughly as it was in this work. The study is of practical importance to federal authorities as an information base for carrying out administrative tasks, as well as to regional and municipal authorities, e.g., in preparing strategic and program documents for the development of the Arctic region and establishing a special economic regime in the Russian Arctic.

Results of an experimental study of the local structure of the mean and fluctuating flow in a near-wall gas jet injected through inclined cylindrical holes along a smooth surface and in the case of injection in a transverse trench are reported. The local structure of the near-wall jet is measured by means of the particle image velocimetry. Injection of the secondary near-wall air jet into the main turbulent flow leads to a significant deformation of the streamwise velocity profile of the gas in both test cases. In the case of injection through the holes in the trench, the streamwise velocity of the gas displays a noticeably smoother profile with no clearly expressed maximum behind the cross section of the transverse trench exit. The streamwise velocity of the gas in the near-wall region has a smaller value than that in the case of injection without the trench. The transverse component of the gas velocity in the case of injection without the trench is greater than the corresponding value in the case of injection through the holes in the transverse trench after the gas leaves the trench.

The influence of external vortex disturbances on the position of the laminar-turbulent transition in boundary layers on swept wings at the Mach number M = 2 is experimentally studied. The experiments are performed with two wing models; the sweep angles of the leading edges are 45° and 72°. The vortex disturbances are generated by a wire placed ahead of the nozzles in the subsonic part of the flow. It is found that such disturbances increase the amplitude and change the spectral composition of oscillations in the boundary layer; moreover, they can induce earlier turbulization of the flow.

The paper presents a study of a supersonic boundary layer while heat supply to the layer’s narrow internal region. Calculations were performed for a flow with Mach number M = 2 and the dimensionless temperature (normalized to the temperature at a layer boundary edge T_w = 3.9 (630 K). It was demonstrated that heat supply causes a two-fold increase in the 2D disturbance increments, while the frequency range expands by factor of three with a heat-insulated plate (zero heat input) taken as a reference. For a heated plate (with T_w = 3.9), the heat input into this layer delays the disturbance growth; that is, this facilitates the boundary layer stabilization and the disturbance increments reduce by almost four times. Along with 2D waves, the oblique waves were investigated in this paper. It was found that for low-frequency disturbance, we observe an intense growth of 3D (oblique) waves. Meanwhile, 2D disturbances enhance for a high-frequency range. These facts comply with the numerous data on boundary layer stability. However, these factors for boundary layer stability become less significant in the case of heat input to the supersonic boundary layer (compared with the zero heat input). The study also observes the longitudinal structures with a downstream decay. The heat supply makes these structures decrement lower in the supersonic boundary layer (meaning a slower decay). The results for the study of boundary layer disturbance are compared to similar data for the flow with M << 1.

The paper presents the results of numerical simulation of three-dimensional turbulent flow around a hydraulic turbine guide vane at the angle of attack of 9º with the aspect ratio of the foil equal to 0.8. The influence of turbulence modeling variants on 3D flow effects is analyzed. The 3D boundary layer separation at the vane-sidewall junctions and the flow separation near the trailing edge influence the flow pattern. The study considered various approaches for modeling of a turbulent flow, such as the k-ω SST turbulent viscosity model and several variants of the differential and algebraic Reynolds stress models. At the given angle of attack, the k-ω SST model shows a significant separation zone in the corners between the wall and the vane, while no separation of the flow in the central plane is observed. Both differential and algebraic Reynolds stress models reproduce the secondary vortex flow at the corners and suppress the flow separation near the central cross section.

A problem is formulated and solved on the motion of a viscous liquid in a gravity field. The liquid is in contact with curvilinear walls and is exposed by oscillatory influences which have no predominant direction in space. The problem formulation includes the equation of Navier-Stokes, the equation of continuity, and the conditions at the solid boundaries of the liquid. In particular, the new hydro-mechanical effect is revealed which consists in that the liquid behaves paradoxically that is performs a steady “down up” motion (at a background of oscillations).

The paper presents the results of numerical simulation of a submerged jet flowing from a circular hole in a wall with introduction of various types of perturbations. Active methods of flow control, including imposition of axial and helical harmonic oscillations on the inlet profile of the jet velocity, vibration of the jet nozzle, as well as their combinations, are considered. It is found that the external forcing leads to the effects of jet splitting at Reynolds number Re ≥ 1000 in wide ranges of perturbation frequencies and amplitudes, as it is shown in the studies of other authors. The mechanisms of interaction of vortex structures during jet bifurcation are investigated, and the angle of flow expansion in the bifurcation plane, which demonstrates an increase with a growing Re, is estimated. Calculations at 500 ≤ Re <1000 show that in order to obtain and enhance the above effects, it is necessary to optimize the forcing parameters, in particular, the type, frequency, and amplitude of perturbation. It is concluded that mechanical vibrations of the nozzle appear to be a more efficient way to control the flow than helical excitation of the inlet velocity profile.

This paper studies approaches to numerical modeling of the transfer of harmful gas emission from low sources in the vicinity of the highways. A model problem of ethane injection through a system of low sources located on a flat plate imitating a road is considered in accordance with experimental data of. The influence of the turbulent Schmidt number on the processes of turbulent mixing of gases in the vicinity of a system of bluff bodies is investigated. Within the framework of numerical modeling, various configurations of baffles location in the vicinity of highways are considered and the most effective configurations are estimated in terms of air quality in pedestrian zones. A qualitative and quantitative comparison with experimental data on the profiles of ethane concentration in characteristic locations is carried out.

This paper presents the linear stability analysis of laminar mixed convection flow combined to thermocapillary effect in a horizontal infinite channel heated uniformly from below. Pure water and water-based nanofluid containing various volume fractions of Al₂O₃ and Ag nanoparticles are considered. The results are presented for volume fractions up to 3 %. A spectral collocation method based on Chebyshev polynomials is implemented and the obtained algebraic eigenvalue problem is solved. In this study, the thresholds of the onset of the convective instability in the form of longitudinal and transverse rolls are determined numerically. The comparison between the pure water and the nanofluid flows allows to investigate the nanoparticles effects on the critical parameters for the onset of convective rolls. The combination of buoyancy and thermocapillary effects on the flow instability is studied and showing the competition between these two effects to make the flow more unstable in pure water and nanofluids. Critical wave numbers that describe the size of convective cells, in nanofluid flow are also presented, analysed, and compared with those of the pure water flow without nanoparticles. Besides, the effects of the type and the volume fraction of nanoparticles on the stability of the system are investigated.

In this paper, numerical simulation of conjugate heat transfer of water-copper nanofluid is performed in a microchannel using two-phase lattice Boltzmann method (LBM), in which viscous dissipation is considered. In this study, the intermolecular forces such as drag, Brownian force, buoyancy, Van der Waals and Born forces are studied and analyzed. The magnitude of these forces is estimated and their degree of importance in the simulation is determined. Further, the effect of increasing the volume fraction and nanoparticles diameter on heat transfer and fluid flow is investigated. Finally, the effect of thermal conductivity of the microchannel’s wall on Nusselt numbers is investigated.

In the framework of the thermal energy scheme, the growth of a vapor bubble in a uniformly superheated zeotropic mixture of two liquids is investigated. Formulas are derived for the bubble growth modulus and the Jacob criterion, which depends on both the physical properties of the mixture and its composition. The obtained solution for the constant composition of the mixture on the interfacial surface is an asymptotic case that limits the real rate of bubble growth. The results of calculations made for a mixture of R32/R152a freons of different compositions are presented.

The paper studies evolution of size distribution for a solid-and-droplet suspension gas flow with account for velocity slippage for the flow fractions. This process is described by the Eulerean model for polydisperse gas suspension: it consists of several fractions of metal solids and fractions of polymer droplets in air. The carrier medium (air) flow is described by a system of equations for motion of viscous compressible thermal-conductive gas with account for energy and momentum transfer to the suspended particle fractions. The dynamics of each of the dispersion fraction is described by gas dynamic equations with account for momentum and energy transfer from the suspension to the carrier flow. A set of equations for the gas suspension is formulated in general curvilinear coordinates and can be solved by the predictor-corrector explicit numerical method. The method comprises splitting of a space operator by directions and a nonlinear correction scheme for every time step. The coagulation of metal particle fractions and polymer fractions is described by Smolukhovsky’s model. This model considers the pair collisions of particles and calculates the physical parameters of each fractions (mass, radius, temperature, velocity and average density) for every time step of numerical simulation. The time and spatial parameters of metal and polymer particles coalescence in a gas flow are calculated with account for velocity slippage.

Solidification of a binary aluminum alloy modified with refractory nanoparticles considered as active solid-phase nucleation centers is investigated. A mathematical model for the heterogeneous nucleation and crystallization of the melt is formulated taking into account the hydrodynamic processes in a droplet proceeding during the interaction of the droplet with the solid surface. This thermohydrodynamic problem is studied under conditions of sequential bulk crystallization of the metal. Thermal resistance on the contact surface of the melt with the substrate is taken into account. Regularities of the temperature change, and nucleation and growth, of the solid phase in a solidifying aluminum alloy are described. An estimate of the distribution of crystal-structure dispersity over the splat cross-section is reported.

The paper analyzes the methods of temperature measurements of cooling the high-temperature bodies in liquids. Experimental studies on cylindrical samples with different embedding of thermocouples have been carried out in three liquids. It is shown that even in the case of cooling in saturated liquids, external thermocouples, whose electrodes play the role of cooling fins, distort the measured temperatures significantly. Using external thermocouples, it is impossible to record correctly the rate of hot body cooling in liquid and the temperature of transition of cooling to an intensive regime. Using only a central thermocouple is permissible at low Bio numbers. However, even in this case, with intensive cooling, the difference between the temperatures of the center and the surface can reach several tens of degrees. With a decrease in the thermal conductivity of a sample and an increase in its linear dimensions, the temperature gradient increases (especially at intense cooling), and the correct physical interpretation of the process becomes impossible.

The implemented research aimed to assess the impact of open pit coal mining in Gorlovka deposit on the seismicity in the Iskitim area of the Novosibirsk Region. The seismic vibrations induced by large-scale blasting are analyzed, the seismic event potential is estimated, and the strain accumulation at a high-stress fault under seismic load is assessed. A key potential trigger was assumed as the change of the stress field parameters. Relaxation of rock mass from stresses due to formation of a pit and the extra loading of rock mass by dumps are calculated numerically and estimated analytically as two major factors of induced effect on static stresses. For the correct selection of computation parameters, the geology and the main physical/mechanical properties of rocks mass in the coal mining area are analyzed, and the main mechanical parameters of the most significant structural faults are selected.

There are large amounts of waste deposits around mines and mineral processing plants, and their instability is one of the major concerns in mining industries. One of the methods to amend the waste deposit stability is the strength enhancement. Biocement is a method for improvement of the ground using microorganisms to precipitate calcium carbonate between geomaterial particles. For this process, Sporosarcinapasteurii bacteria is used to activate the calcite precipitation to increase the strength of Angouran mine. In this research, the effect of biocementation on increasing the strength of waste is investigated. The results of laboratory tests show that wave velocity and uniaxial compressive strength were considerably increased with number of injections. Also, the compressive strength of samples under initial load is increased in comparison to unloading modes. Therefore, utilizing the proposed method promotes the mine waste stabilization.

Fracture toughness of compact samples and polymethyl methacrylate double-cantilever beams in tension is investigated experimentally and theoretically. In loading mode I, the critical loads and propagation paths of cracks in these samples differ noticeably. The theoretical model presented is based on the energy concept. It allows predicting instability of crack propagation paths. The model includes stresses in front of the crack tip and the T- stress. The theoretical model is proved using the fracture test data on a few samples with mode I cracks. The computer modeling of crack propagation is performed in the geometrically and physically nonlinear formulation. The calculation and testing data comparison shows that the crack path instability essentially depends on geometry and can be avoided by changing the sample geometry or the type of loading.

During the backfilling mining process, the strength of backfilling body is continuously affected by the temperature. Unconfined compressive strength (UCS) tests were performed on cemented tailings backfill (CTB) samples cured at different temperatures. The results show that UCS increases linearly with the increase of curing temperature during the age of 3 to 7 days, while it shows an exponential relationship with the curing temperature during the age of 7 to 28 days and the growth rate gradually slows down. As the curing temperature and age increases, the microstructure becomes denser, meanwhile, UCS becomes more sensitive to variances in age, and the failure patterns of CTB samples change from crushing failure to tensile failure. The established formula can well describe the coupling effect of curing temperature and age on UCS, which can provide a certain reference for CTB strength design and mining.

The common constraints of coal production under conditions of deeper level mining and methane release in mined-out voids in Kuzbass are described. The theoretical calculations of gas release from coal seams during multiple hydraulic fracturing are elaborated. The revised procedure of gas flow rate from coal seams, based on the data obtained in gas drainage boreholes during multiple hydraulic fracturing is theoretically and experimentally justified.

The newly presented structure of integrated monitoring includes geological and geotechnical conditions of mineral mining, peculiarities of the production and infrastructure objects, as well as specifications and manuals of measurement tools. The monitoring-embraced hazardous objects are listed and grouped. Each group of the hazardous objects is described with the common features, properties, criteria and other characteristics meant for the monitoring supervision toward efficient and faultless operation. A prototype monitoring system for instability of mine objects is implemented using mining and geological information system MINEFRAME, and the data base on the objects of monitoring is composed.

The impact of pressure fluid-air interaction on endurance of hydraulic drives is discussed. It is proposed to employ the enclosed hydraulic drive to isolate the pressure fluid from air, solid impurities and moisture. The functional flow chart of the enclosed hydraulic drive with hydraulic motors and hydraulic cylinders is designed. The design procedure is validated for an ejector pump and a hydropneumatic accumulator to ensure the boost pressure at the main pump inlet and to provide the drainage leek return to the system subjected to the excessive pressure. The new ejector design enables adjustment of the ejection factor and the total flow pressure at the pump outlet. The cavitation procedure is presented for the ejector tests at different values of the running, drainage and total flow rates.

The mathematical model of the one-way hydraulic positive-displacement system with two piston stop tools includes the design variables of the system and its interaction with rock mass, namely, dry friction in the impact facility body-piston couple, pressure losses in the hydraulic system branches and piston velocity recovery factor. The dynamic similarity criteria, which are dimensionless analogs of the listed characteristics, are determined. The numerical calculation is performed, the influence of the similarity criteria on the dynamics and integral characteristics of the test system is analyzed, and the main behavioral patterns are revealed. It is found that these criteria influence the shape of the domains of the single impact travel and back run, two-impact and multi-impact limit cycles. It is possible to reduce the difference between the system characteristics in the impact travel and back run by means of changing the piston coordinates such that the valve stations are changed.

The modification procedure for the kinetics and spectral characteristics of fluorescent diamonds using luminophores ensures the simultaneous increase in the amplitudes of the long- and short-persistent luminescence signals at a preset ratio (1:1). Abnormally and weakly fluorescent diamonds after luminophore modification have elevated amplitudes of the kinetics and spectral characteristics, and are identifiable as natural crystals with the required luminescence intensity. This approach allows the simultaneous increase of the collapse and the decay constant of X-ray luminescence signal. As a result, abnormally and weakly fluorescent diamonds acquire higher values of these characteristics, become detectable as natural diamonds and are recoverable in X-ray fluorescent separation.

The authors have developed and justified the method to describe overall particle-size indexes of coal as a case-study of Bezymyanny and Vnutrenni seams of Prokopyevsk-Kiselevsk coal region in Kuzbass using the problem-oriented programming equipment for the yield and ash content prediction in mineral dressing. It is found that test data approximation, solely, is incapable to provide the uniformly accurate calculations of yields and ash contents in pooled size grades within the sieve mesh size range from 0 to 100 mm.

The authors find the collecting activity criteria for slack coal flotation agents. The collectability tests used kerosene, straw oil, thermal gas oil, KETGOL and FLOTEC agents. Efficiency of these agents in slack coal flotation is determined, and the velocities of their films on water surface are found. It is found that the spreading velocities of the collecting agents are correlated with the slack coal flotation performance. The article proposes a new concept of particle-bubble attachment and the floatability criteria for slack coal flotation agents.

The author offers the calculation procedure for minimum exposure time of ore and mining waste containing polymineral aggregates, as well as for sizes of grains such that limit stresses are only achieved at the grain boundaries. With regard to the calculated mechanical stresses, the ways of increasing recovery of fine valuable components of minerals are identified.

The ore from Baiyinchagan mine is typical increasingly refractory as the mine get deeper, especially the increasing lead and zinc contents, which not only detrimentally affects the product quality of copper concentrate, but also results in the loss of lead and zinc resources. In order to solve the problem, two routes were conducted: first, depress liberated lead and zinc minerals from the raw ore; second, float lead minerals from the copper concentrate. Sodium sulfide was used as detoxification, polysulfide-as copper depressant and diethyldithiocarbamate-as lead collector. The quality improvement and efficiency of copper rough concentrate were realized.

The material constitution and structure of mineral particles in fluorite ore mill waste at Yaroslavskaya Mining Company are estimated. The set of factors having influence on the efficiency of sample preparation for flotation is determined. Alongide with the complex mineralogy and structure of primary ore, dressability of mining waste is affected by mineral properties acquired in prime processing and during long-term tailings storage. It is necessary to take care when selecting the process conditions and the composition of agents for flotation. The studies into the influence exerted on flotation performance by a composiiton of carboxyl collectors with different contents of fat acids and different structures of hydrocarbon radical identified the best effective conditions. It is feasible to produce finely dispersed carbonate-fluorite concentrates from mining waste, at CaF₂ content of 95.21-95.6% and at fluorite recovery of 59.55-62.56%.

The authors review the methods of dust emission suppression at operated and abandoned tailings storages. The environmental impact of mineral dust particles and the after-effects are greatly varied. Dust suppression in surface layer of tailings ponds can use the most widely applied chemical methods, as well as mechanical and biological methods. The requirements imposed on binding agents are efficiency, dust catching, longevity and the environmental safety. Dust suppression control can utilize natural climatic events, e.g., seasonal freezing-thawing of tailing surface. The described engineering solutions concern techniques and equipment for spreading suitable chemical agents for dust suppression at overburden dumps and tailing storage facilities at mining and processing plants.

The authors have designed equipment for the stress-strain behavior assessment in granular medium and soil in shearing. The shear test machine enables investigation of stresses and dilatancy in granular materials subjected to multiple cyclical shears (tens thousands). Special sensors are designed for long-term stress and dilatancy measurements in granular media in lab-scale modeling of geomechanical processes.

In this study, the Shore hardness measurements are made on carbonate rocks using Durometer PCE-1000, Mitech MH310 Hardness Tester and C-2 type Shore Scleroscope, and the results obtained were compared. The usability of digital new generation Shore hardness test devices (Durometer PCE-1000 and Mitech MH310 Hardness Tester) to determine the Shore hardness of the rocks is investigated.

The article determines the three-level deviation correction equipment of mine conveyor belt. The experimental results show that the mine conveyor belt deviation detection system based on machine vision can effectively detect the deviation fault and control the deviation correction equipment, which has the advantages of high efficiency and fast processing speed. The mine conveyor image clarity in operation under high dustiness is greatly increased.