Home – Home – Jornals – Russian Geology and Geophysics 2021 number 11

The basic software package of a JXA-8230 microanalyzer, like its predecessor JXA-8100, uses the long-established ZAF correction method (with some differences) for a quantitative analysis: Calculation of mass absorption coefficients is based on Chantler’s theoretical data. The core of this method is quantum-mechanical calculation of the cross section of the interaction between an X-ray photon and atomic electrons. This innovation has had a positive influence on the trueness of X-ray microanalysis. Control tests on specimens where the absorption effect is dominant have demonstrated that the results of this analysis are slightly lower (by less than 2%) independently of the matrix absorption interval in which the analytical line is located. As a consequence, the selection of comparison specimens becomes easier: It is sufficient that the specimen under study and the comparison specimen belong to the same isomorphic series and that the intensity of the analytical line of the comparison specimen allows for the measurement with the required accuracy.

We study the relations between several selected elements present in the Sin Quyen IOCG deposit, Lào Cai, North Vietnam, and interpret the obtained correlations, especially with a coefficient higher than 0.7. The correlations with high coefficients are mainly observed for the elements belonging to the chalcophile group (Cu, Ag, Au, Te, and Bi) and for the relation between uranium and Ag, Au, Cu, Pb, and Bi. Although the S-, Fe-, and REE-bearing minerals are predominant in the studied deposit, no strong correlation between them and the other elements was observed, even with Cu. The phenomena are primarily explained based on the geochemical properties of the mentioned elements and the characteristics of IOCG deposits.

Two spectra of the ¹⁸O-enriched ozone were recorded at the Fourier spectrometer of Reims in the range 3400-5600 cm^-1. The experimental centers of 12 vibrational-rotational bands of the ¹⁶O¹⁶O¹⁸O isotopologue were determined from the analysis of the spectra. They were compared with theoretical calculations based on the potential energy surface of the molecule.

Water vapor continuum absorption in the H₂O-N₂ mixture is examined on the basis of the CKD model and using the line shape with parameters found from fitting the calculated absorption coefficients to the CRDS data in the 4000-5100 cm^-1 window. Differences of these two definitions are analyzed as applied to the IR region. It is shown that the CKD continuum includes the absorption due to excess of the line contour over the Lorentzian one at distances less than 10 cm^-1 from the line centers. The possibility is examined of extracting the absorption by additional objects (like water dimers) when calculating the Н₂О-N₂ continuum absorption on the basis of the ATLW approach.

A combined experiment aimed at the study of the air composition over all the seas of the Russian Arctic was carried out in September 2020 with the Optik Tu-134 flying laboratory. The experiment included sampling the atmospheric aerosol in a layer of 200 to 9000 m above the sea level and determining the concentration of saturated hydrocarbons ( n -alkanes) in aerosol particles. Saturated hydrocarbon compounds С₉Н₂₀-С₂₇Н₅₆ were detected. The main mass of this class of organic compounds is concentrated in the narrower range С₁₀Н₂₂-С₂₀Н₄₂. The concentrations of n -alkanes in aerosol over all the seas were low (9.3-12.6 ng/m³). The only exception was the Chukchi Sea, over which the concentrations reached 37.7 ng/m³.

According to monitoring data at AERONET stations in Beijing region in the 21th century, the aerosol optical depth can attain 4.0-4.5 during a dust haze. The optical and microphysical characteristic of the tropospheric aerosol are determined by the coarse mode, with a modal radius of particles of ~ 2-4 mm and a mass content of dust aerosol of 11-12 g/m². In accordance with monitoring data at the Beijing and Xinglong stations in April 2006 and at the Beijing-CAMS station in March 2021, the imaginary part of the refractive index of dust aerosol in an optically dense dust haze was comparatively small, from 0.0005 to 0.003, with the detection probability 54 and 77% at the Beijing and Xinglong stations, respectively. The spatial distribution of the aerosol optical depth and the wind field reanalysis data are analyzed. The analysis has shown the long-range dust aerosol transport from Takla-Makan desert to Northern China Plain in April 2006. The aerosol radiative forcing at the top and bottom of the atmosphere are calculated for the period of dust haze propagation in China. Its efficiency is shown to be 85 W/m² at the top of the atmosphere and attains 135-140 W/m² at the bottom in the Beijing region. Using the wind field reanalysis data, aerosol optical depth monitoring data, and retrievals of the optical and microphysical characteristics of the tropospheric aerosol, the dust aerosol mass flux from Takla-Makan desert to Northern China Plain and the daily total dust aerosol mass transport are estimated to be ~ 1.5 ton/s and 1.5 million tons, respectively.

The results of experimental study of the condensation activity of particles of different size carried out in October 2020 till June 2021 with use of an AZ-10 optical counter, equipped with a system for artificial humidification of atmospheric aerosol collected, are considered. Hygrograms of the total aerosol scattering coefficient were simultaneously measured with a M903 integral nephelometer. The atmospheric conditions and aerosol characteristics during the measurement period were typical, which was confirmed from the comparison with long-term series of the condensation activity parameter for the scattering coefficient at an angle of 45°.

In a Large aerosol chamber of the IAO SB RAS, experiments were carried out to simulate the smoke aerosol formed as a result of burning pine wood, with different ratios of smoldering and flame combustion modes. The variability of the chemical composition of mixed smokes at the stage of their formation and during 2-day aging under UV irradiation and dark aging was revealed. The dependence of the mass concentrations of light-absorbing carbon-containing particles on the mixing parameter of smoldering and flame combustion modes is considered.

Multiple scattering in cirrus clouds occurring in lidar sensing of the atmosphere is studied in Monte-Carlo simulation with the use of model phase functions appropriate to crystal cloud particles of 20-100 mm in size. Critical analysis of some common methods for multiple scattering correction in cirrus clouds is presented. Sensing of cirrus clouds and stratosphere aerosol from the Earth surface with signal calibration at 30 km is numerically simulated. A significant deformation of the altitude profile of the backscattering coefficient at cirrus clouds and above without multiple scattering correction is shown, meanwhile the error in the optical depth of clouds is small. An iteration multiple scattering correction procedure is suggested and verified in numerical simulations. The comparison between the simulation and experimental data is performed.

The results are presented of atmospheric experiments on compensation for the artificially introduced initial aberrations of the wavefront of a focused laser beam using the aperture sounding method based on an atmospheric backscatter signal from an additional source at a different wavelength. It is shown that adaptive compensation can reduce the amount of wavefront distortions, increase the backscatter signal, and restore the focusing of the main laser beam

The sequence of appearance of various atmospheric discharges (lightning, elve, and blue jet) shown on video from the International Space Station is analyzed. For comparison, experimental data on the formation of diffuse, corona, and apokampic discharges with participation of cylindrical and spherical streamers are used. It is assumed that the formation of the elve filmed from the space is initiated by extensive discharges in clouds with subsequent formation of lightning closed to the Earth in this area. In this case, the lightning reaches the positively charged upper cloud layer. The dense plasma of the upper part of the lightning initiates the development of a blue jet, consisting of cylindrical streamers of the ionization wave.

The operation of an anti-jamming modem for wireless remote communication with deep-sea vehicles using ELF radio signals with quadrature intrapulse phase modulation (QIPPM) is described. In QIPPM, the signals quadrature are manipulated by mutually orthogonal binary sequences, which allows a radio anti-jamming pulse to transmit various code combinations, which are control and communication commands. It is shown that the technique for transmitting control commands by QIPPM gives an energy gain of about 3 dB over the method of transmitting information using phase shift signals. Therefore, the maximum transmission depth of control commands to underwater objects increases by up to 2 times.

The dynamic (temporal) characteristics of adaptive optics systems operating through a turbulent atmosphere are analyzed. An analytical calculation of the Strehl parameter is used based on the results of the theory of optical wave propagation in randomly inhomogeneous media. The analysis uses a model of the active correcting mirror. A traditional adaptive optics system with a finite response time is described as a dynamic constant lag system. In such a system, the admissible time delay turns out to be comparable with the time of transport of turbulent inhomogeneities through the radius of coherence by the average wind speed. An expression is derived which connects all the most important parameters of the system: the accuracy and frequency of the wavefront sensor, the size of the aperture of the optical system, the parameters of the atmosphere: the Fried parameter and the wind speed with an achievable level by the Strehl parameter. Differences between open and closed loops in AO systems are analyzed. The possibilities of the "predictive" algorithm for adaptive correction are shown.

A group of experts has studied and codified 160 scientific articles published in Russian from 2015 till 2020 that mention the Spatial Development Strategy of the Russian Federation (SDS). Each is defined and assigned to one of four groups: 1) with suggestions for the SDS (23% of the articles); 2) critical of the SDS with suggestions for it (19%); 3) purely critical of the SDS (18%); and 4) neutral or laudatory (40%). This study points out 22 thematic motifs, or themes, found in articles and related to the SDS semantic core. For each article, we have compiled a digital code vector that marks the theme’s presence (code 0) and the author’s critical demeanor toward its interpretation in the SDS: from code 1 (meaning “full support") to 5 (meaning “strong resentment"). The following themes have been addressed most often: 1) the need for the SDS as a state planning document. Its design requirements in terms of form, content, and the period of validity (90 articles); 2) goals, timetables, and resources for implementation (45); 3) macro-regions and their allocation principles (44); 4) agglomerations and their identification adequacy (43); 5) prospective effective specialization of regions (43); 6) tools and methods to implement the strategy (35). For all the themes, the number of critical statements is significantly larger than that of neutral or favorable references. The greatest resentment is shown toward the following: the principles of determining priorities; quantitative indicators of implementation; institutional conditions for implementation; geostrategic territories; peripheral and degrading territories; regional imbalances

The article considers trends in the spatial development and regional policy of the Russian Federation in the last five years against the background of global trends, external challenges, and threats. It reveals the features of the “eastern vector" of Russia’s spatial development as a new element of its spatial policy and an important area of cross-border interactions. We show that the state support for Far Eastern investment projects and territories of priority development has dominated its implementation so far, whereas Siberia and its regions are practically excluded from this strategic initiative. Here we also examine the trends in national, inter-regional, and regional strategizing (as exemplified by the Strategy for the Spatial Development of Russia, the Strategy for Socio-Economic Development of the Angara-Yenisei Macroregion, as well as various growth and governance strategies and models for Novosibirsk and Kemerovo oblasts). By analyzing the statements of senior government officials, this paper gives an overview of recent strategic initiatives in public administration of spatial development processes. The conclusion justifies that, notwithstanding the extremely difficult growth conditions Russia underwent over the past five years, new strategic initiatives and trends gradually began to emerge, which have given grounds for cautious optimism about modernizing the country’s regional policy and spatial development.

The article presents new instrumental concepts for a class of the Gran- berg-type multiregional models, designated for studying how the three key features of an interregional system-equilibrium state, coalition stability, and openness-interdepend. Our computations illustrate fundamental differences in the properties of a closed interregional system and an open one.

The article analyzes the development of Moscow’s industrial sector. Despite the changes since the beginning of market reforms, the capital still hosts a significant industrial segment important not only to the city but the national economy at large, which makes selecting development vectors for this metropolis even more significant. We show that the existing competitive advantages in the form of concentrated production, financial, and intellectual resources are not exploited in their entirety. The article considers Moscow’s experience in pursuing an industrial policy based on the following combination: system-wide measures aimed at improving the investment attractiveness of the city with measures to support industrial sectors and certain economic activities, as well as to encourage investment in priority areas of industrial development, taking into account the established industrial potential, local social and economic needs, and promising technological trends. It is noted that the development of modern high-tech industrial sectors could contribute to the innovative growth potential being actualized by forming both demand for innovative products and their supply. We also examine the prospects of individual economic activities of an industrial kind for the city, their competitive advantages, limitations, and risks that may hinder investment in industries. Using the example of Moscow, we highlight several general principles that should be considered when preparing appropriate measures for the regions.

The main objective of this research is to identify which regional-level environment factors affect the emergence of high-tech companies and assess this impact’s orientation. As an empirical basis, the research uses the indicators of high-tech and knowledge-intensive companies by regions available in the SPARK Database of Russian Companies, regional economic development indicators issued by Rosstat, and public information provided by government authorities. We have evaluated how new companies form by the number of firms under three years of lifespan with non-zero revenues. Another factor analyzed was the ratio of this number to total employment in the region. Regional environment factors were considered in five sets: innovation potential, human resources potential, general characteristics of industrial production, state support of innovation activity, and partnerships among innovation companies. We paid special attention to the last two. Analyzing the general characteristics of the sample formed has proved that young companies are exceptionally unevenly distributed over the country, with 47.8% operating in five regions only. Of all firms, 96% belong to the category of microenterprises. The results of econometric calculations have revealed that the federal funding of innovation activity at the regional level is positively significant in general, as well as organizations being involved in joint R&D projects. Meanwhile, regional budget participation and channeling of federal resources to support innovative infrastructure for SMEs, similarly to whether regional firms are part of clusters and technology parks, do not yet have a noticeable impact on the emergence of new high-tech enterprises.

COVID-19 has led to significant changes around the globe. Many studies have already identified the factors influencing the disease spread and mortality, both at regional and national scales. The consistently large number of people infected and newly discovered strains show that these studies are as relevant as ever. Judging from global and domestic practices, we see the increasing use of digital technologies to combat the pandemic and its consequences. These can include technologies that facilitate detecting infected people, contact tracing, prediction, diagnosis and treatment, promoting public awareness, as well as helping to comply with social distancing, self-isolation rules, and transitioning to remote operations. Such technologies are better developed in smart cities due to the availability of suitable infrastructure, although they can be applied in any location. This study assesses what smart technologies and comfortable urban environments contribute to controlling coronavirus infection. The paper proposes a negative correlation between the smart urban environment and the number of deaths, which is tested with statistical methods. According to our findings, a developed urban infrastructure does reduce excess mortality, consisting not only of those who die directly from infection but also from its consequences. Its other benefits include reducing healthcare overload, difficulties with routine check-ups and planned operations, etc. At the same time, the degree of urban environment digitalization has no considerable impact on mortality.

This article aims to assess mortality by cause of death before the COVID-19 pandemic in Russia. The database consists of Rosstat data for the period from 1990 to 2019 characterized by multidirectional dynamics of life expectancy in the Russian population. We have found a significant increase in the degree and share of mortality from diseases of the digestive system, observed recently amid a decline in overall mortality, as well as from infectious and parasitic diseases. Other observations include an increase in mortality from neoplasms with its share reduced and a marked decrease in the degree and share of mortality from respiratory diseases, external causes, and circulatory diseases. As a result of countertrends, the main causes of death regrouped twice in 2006. The share of mortality from other causes, where neurodegenerative diseases play a major role in the aging society, has tripled; since 2016, it has been second only to mortality from cardiovascular diseases. Here we assess the gender peculiarities of mortality by cause of death and disparities between urban and rural areas. The study results can be used to improve the demographic policy in terms of mortality.

This article is devoted to the issues of modeling and forecasting mortality rates in the regions of the Russian Federation. The analysis showed that 2020 was characterized by a significant deterioration in the demographic situation and that the key reason was an increase in the number of deaths by 18%. Although excess mortality was also observed in most other countries, the authors do not set the task of assessing the impact of such an atypical situation as the coronavirus pandemic. The primary task is to develop measures to reduce the death rate under so-called “normal conditions”. Ensuring a high quality of life, in a sense, would alone be a factor to reduce the consequences of unforeseen situations. Our hypothesis is that the level of social infrastructure advancement largely determines the regional mortality and life expectancy. The goal is to develop an approach to modeling this impact and forming appropriate forward-looking estimates for the medium term. For that, we use methods of comparative, factor, correlation, and regression analysis, grouping methods, and scenario forecasting. As a result, we have formed a set of econometric models which describe the relationship between the death rate, life expectancy, the level of social infrastructure advancement, and how well the region’s potential benefits are actualized. The obtained forecast shows that the baseline scenario allows a decrease in the death rate in most Russian regions by 1.0-2.5% compared to 2019 and an increase in the average life expectancy up to 74.7 years. However, one needs to consider the law of diminishing marginal utility, which states that resources required to increase life expectancy will ever grow. Part of such resources will be allocated to developing social infrastructure. These results can be applied by public authorities to draft demographic policy measures.

The article examines the factors that determine the risks and depth of poverty for households with disabled people. The empirical basis of this study is the 2018 Comprehensive Survey of Living Conditions. The study findings show that when one working-age adult is disabled, poverty risks increase for the entire household, whereas having a child or elderly person with a disability does not significantly affect poverty risks compared to households without disabilities. Residing in rural areas or small towns, managing large dwellings, and having children, especially of preschool age, increase the risk of poverty for such households. To reduce the risks, it is necessary to shift the focus from the individual recipient in need of assistance to the household as an economic unit, and to switch from the categorical principle of social protection of vulnerable groups to targeted social support based on an individual assessed need. This change will make it possible to consider the diversity of living circumstances in households that include people with disabilities.

The article discusses the theoretical, methodological, and applied aspects of ensuring that the results of discontinuous surveys at the national, regional, and municipal levels are representative. It reviews the principles, methods, forms, and technologies of sample observations implemented by state and public institutions when various mass sample surveys are arranged and conducted. We also define the problem of obtaining non-random samples in the survey process and assess the practice of spreading their results to the general population. Without the basis for a general population (i.e., a unit listing), researchers must solve the inverse problem of the sampling method; this circumstance does not allow obtaining random samples, and besides, often there is no reasoning for the representativeness of the data obtained. Viewing these problems with adequate statistical inference allows us to find an acceptable solution. We have developed and tested an algorithm to generate representative non-random samples on a wide range of surveys. The proposed methodology is used in arranging and conducting a sociological survey on enforcing the critical provisions of several federal laws. Ensuring the representativeness of the obtained non-random sample has made it possible to assess the level and degree of differentiation of citizens’ satisfaction with the measures taken to regulate public relations in the studied laws across federal districts and constituent entities of the Russian Federation.

The practices of the social and economic development of the south of Tyumen Oblast (STO, federal constituent entity, without autonomous okrugs) since the mid-2000s exemplify generally successful economic growth. The STO industry’s build-up was largely associated with the extraction of hydrocarbons (primarily oil) and their processing (petrochemistry and oil refining). But these growth drivers are losing their meaning. Today, the potential for further growth due to the expansion of hydrocarbon production and processing is close to being exhausted. The region needs to search for new sources of economic growth. They can be related to the knowledge economy and interregional ties, which includes manufacturing high-tech equipment and providing high-tech services not only for STO but also for the oil and gas sector throughout Western Siberia. It is advisable to pursue activities in this regard within the newly established oil cluster, whose successful functioning has all the necessary prerequisites in STO. Its generation and development must be carried out considering the peculiarities of transforming the main assets of the oil and gas sector, Western Siberian mineral reserves.

November 5, 1921, is an important date in the history of Russian-Mongolian cooperation. On that day, the People’s Government of Mongolia and the Government of the RSFSR signed the agreement to establish friendly relations. This document set the stage for nearly seventy years of alliance between the first two countries in the world to choose the socialist path. The 100th anniversary of the establishment of Mongolia-Russia diplomatic relations provides a significant opportunity to review the history of their strategic partnership and assess the current state and the short-term outlook of economic cooperation. The article considers the results of the Soviet-Mongolian cooperation, draws attention to the “big debt" problem, analyzes the Russian-Mongolian economic relations and the prospects for their further intensification within the China - Mongolia - Russia Economic Corridor Program.

The authors discuss the numerical and field research findings on seismic radiation of water flow in a fracture. The flow parameters can be remotely controlled using the amplitude-versus-frequency response of the vibrations recorded. It is recommended to include the infra-low frequency control in the seismic monitoring in hydrodynamically hazardous mines.

3D discrete-element modeling is used to analyze passive pressure applied by dense soil to a retaining wall. The soil particles have spherical shapes with the radii selected from the normal distribution. The calculation of tangential forces between the particles takes into account the sliding friction and rolling resistance. The surface roughness of the retaining wall has influence on localization of shear strains in the granular medium and on the pressure applied to the wall by the granular material. The calculation results are compared with the classical solution of the limit state theory.

The damage to the surrounding rock under the adjacent explosive load generally manifests as fracture growth. In order to in-depth understand the fracture growth law and mechanism, fracture growth process in the surrounding rock with a nearby adjacent tunnel under the explosive load is studied using the dynamic caustics method. Test results indicate that the original fracture growth process can be divided into two stages, demarcated when the main fracture penetrates the original fracture. The original fracture grows in the vertical direction due to the free surface of the tunnel in the first stage. The main fracture from the explosive source plays a dominant role in the growth direction of the original fracture in the second stage, and the original fracture deflects and grows parallel to the main fracture. Based on kinematic and energy analysis, the penetration process is companied by energy transfer and superposition. The neglected back-facing side also contains fracture on the lower side. The fracture growth direction changes after the original fracture penetrates the free surface of tunnel under the combined effect of the original fracture and unloading wave.

The authors asses water hazard and select methods to prevent it in the areas that are saturated with water and subjected to intensive drainage in the Upper Silesian Coal Basin. The research is important in the areas adjacent to the mines that are closed owing to flooding of roadways and hence is significant for the assessment of the influence of secondary saturation of the rock mass with water on the rock mass mined in an active mine. Changes to the occurrence conditions of the geodynamic phenomena of rock bursts are discussed in the context of the processes of restructuring mines and the associated processes of water inflow and flooding closed mines. The propensity of the rock mass to rock bursts in the border areas between active and closed mines is assessed.

The rational mine support system designs for underground excavations in backfill are discussed. The current mine support technology applied in excavations in backfill in Artemievsk and Orlovsky mines is examined. The strength and deformation characteristics of backfill samples are tested on a laboratory scale. The FEM-based stress-strain analysis of ore body and backfill is described with the assessment of their stability. The probable failure zones in backfill and ore body during to-downward slice mining are determined. The rational support design is validated for backfill having stability category I, II and III. The pilot test data on the load-bearing capacity of friction-anchored rock bolts in backfill are assessed. The economic efficiency of the mixed-type support composed of steel frame and friction-anchored rock bolts in backfill is demonstrated.

The article proposes an integrated approach to safety evaluation in underground mining of rare, noble and nonferrous metals. The approach includes joint assessment of variable rock properties, zoning of mineral deposits and ranking of the integrity criterion of natural arch span. The authors validate geotechnical stability in sublevel stoping as a case-study of the Shokpak-Kamyshovoe deposit. The feasibility of mining of isolated and thin bodies without backfilling or with induced caving of enclosing rocks is determined.

Depletion of available mineral resources in the metallurgy industry, as well as the growing internal and external demand for the high-quality iron products necessitates development of new iron ore fields in Siberia. This article offers description of climate, geology and hydrology in the area of the Bakchar oolitic ironstone deposit in the Tomsk Region as a promising subsoil use object. The literature and engineering solutions on this matter are reviewed. The mining risks in the conditions of high environmental standards and market uncertainty are described. The basic requirements are formulated for the potential geotechnologies, and the conceptual framework is proposed for the environmentally sound and resource-saving mining with smart usage of natural and manmade resources in the iron ore production cycle.

Safety of open pit mining in complicated geological conditions can be improved using the multilevel geomechanical monitoring of pitwall and adjacent rock mass. The domestic and foreign practices of pitwall stability monitoring are reviewed. The proposed approach need the operating mines to be equipped with advanced control equipment, procedures and services in order to jointly expand essentially the geomechanical monitoring possibilities.

The recommendations are given for conical pick patterns to prevent growing forces on neighbor picks of a failed pick. It is proposed to detect promptly pick failures by analyzing the burden variation in the transmission system of the cutting head. According to the theoretical calculations, when a pick fails, the relative growth of the feed force is not higher than the relative growth of the cutting force as against the increase in the burden as a consequence of change in the cut rock strength. This hypothesis was tested and proved during shafting at Talitsky site of the Upper Kama Potash-Magnesium Ore Deposit using shaft cutting machine 1SPKV-8.0.

The integrated thermodynamic calculations and spectral analyses validated concentrations of hydrophobization agents (butyl xanthate and sodium oleate) to ensure chemisorption and chemical interaction with silicate matrix of luminophore FL-530. It is found that in the optimized conditions, hydrophobization agents interact with zinc orthosilicate without volume reaction which degrades spectral characteristics of luminophore. The increased oil receptivity of luminophore FL-530 improves its ability to remain in the organic phase of emulsion and to better attach to the surface of diamonds. The UV visiometrics revealed better attachment of hydrophobic luminophore at diamonds. The optimal concentrations of solutions of butyl xanthate and sodium oleate are determined. The tests using separator Polyus-M proved efficiency of hydrophobic luminophore FL-530 which essentially enlarged amplitudes of the fast and slow signal components in X-ray fluorescence of slight florescent diamond and their recovery in separation.

The article describes the studies into sulphide extraction from ore using an integration of flotation and oxidized copper leaching in the conditions of milling with nonacid complexing agent-ammonium sulfate, and adsorption-electrolytic recovery of copper from pregnant highly mineralized copper-bearing solutions. The thermodynamic function of products of interaction of between the base copper minerals and the yield of the hydrolysis ammonium sulfate solutions. The mechanism of sulfate ammonium leaching of oxidized copper minerals in joint mechanical-thermal activation treatment is proposed. The tests on treatment of low-grade complex copper-bearing ore from stockpiles by combination of chemical and electrochemical methods and on the mixed-type flotation-hydrometallurgical processing technology of complex copper-bearing ore were carried out.

This paper aims to encapsulate the trends in the variation of speed with real-time parameters, i.e., temperature and the corresponding change in humidity thereof for the underground mine ventilation system. The purpose mentioned above is fulfilled using a precise and vigorous estimation method of the speed for the sensorless induction motor drive (IMD). The developed model reference adaptive scheme (MRAS) speed estimator can be utilized to control the IM speed for the underground mine ventilation system based on the real-time parameters. The present work is on temperature and humidity-dependent MRAS based sensorless speed estimation technique for IM used in mine ventilation drives. This methodology has been tested analytically and experimentally using MATLAB/Simulink and LabVIEW-2013 laboratory interfaces. Furthermore, a statistically validated empirical relation between the temperature, humidity of the underground mine and speed of the ventilation system has also been developed to facilitate calculations of the same. However, implementing the proposed methodology in an actual underground mine remains a thing of the future.

The air flow dynamics in a vertical mine shaft under conditions of mixed convection is theoretically studied using 3D modeling in ANSYS. The average heat-transfer coefficients are obtained at the air-lining interface depending on air-lining temperature difference and on the average air flow velocity. The threshold velocities of air flow are determined at various air-lining temperature differences. At the air flow velocities higher than the threshold, the engineering designs can neglect the influence of the heat-gravitational forces and use the formula of heat transfer in induced convection. When the air velocity is lower than the threshold, the heat-transfer coefficient should be adjusted with respects to the natural convection effect. The authors offer an empirical formula for calculating the average dimensionless heat transfer coefficient in case of prevailing natural convection.

Hot and humid mine atmosphere can produce a strain on the human body. The study of water vapor in air is known as psychrometry and psychrometric properties of mine air allows to calculate the heat and moisture content. The psychrometric conditions of mine air have a great effect on the health, safety and productivity of employees. When considering the climatic conditions of a mine, the high temperature and humidity problem must be considered. Thus, it is possible to find out the heat and moisture content of air by making psychrometric calculations. In this study, measurement studies have been carried out to determine the increase of heat and humidity in a coal mine using mechanized production method in Turkey and then, heat and moisture exchanges in mine air were calculated. At the end of the study, according to EN ISO 7243: 2017, the amount of required air flow to provide the acceptable climatic conditions was calculated.

The aim of the research is to propose that artificial neural networks be applied in the process of identification of structurally altered coal. The results suggest that the proposed methodology of classification, due to its high effectiveness exceeding 90% of correct identifications, may be successfully used as a tool supporting the observer's decisions concerning the description of coal from near-fault zones.