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The paper considers a dispersive geological medium (seismically turbid medium, as defined by A.V. Nikolaev), which is in a stress–strain state. Results of studies on the joint monitoring of seismic effects and radon emanation in various geological environments are presented. It is concluded that the turbidity of the medium, as a statistical characteristic, can be generalized in terms of other media parameters, such as permeability. A stable connection between radon emanation and dynamic processes occurring in a geological environment and caused by external influences has been established. The concentration of radon can also reflect the degree of enrichment of the environment by underground fractures. Consequently, saturation of the environment with radon provides information about the presence of disturbances in a geological environment in the form of cracks and a stress–strain state of the medium before and after seismic loadings. Radon observations make it possible to assess a continuity of the environment and the possibility of leaching in natural conditions. Therefore, it could be efficiently used for underground leaching efficiency assessment. [ABSTRACT FROM AUTHOR]

Electric vehicles are the most innovative and promising area of the automotive industry. The efficiency of a traction battery is an important factor in the performance of an electric vehicle. This paper presents a mathematical model of an electric truck, including modules for the traction battery to determine the depth of battery discharge during the operation of the electric truck, a traction electric system for the electric truck and a system for calculating traction forces on the shaft in electric motors. As a result of the modelling, the charging and discharging currents of an accumulator battery in a real cycle of movement in peak and nominal modes of operation in electric motors and at different voltages of the accumulator battery are determined. A functional scheme of a generalized model of the electric vehicle traction electrical equipment system is developed. An experimental battery charge degree, torques of asynchronous electric motors, temperature of electric motors and inverters, battery voltage and the speed of electric motors have been measured and analysed. The developed complex mathematical model of an electric vehicle including a traction battery, two inverters and two asynchronous electric motors integrated into an electric portal bridge allowed us to obtain and study the load parameters of the battery in real driving cycles. Data were verified by comparing simulation results with the data obtained during driving. [ABSTRACT FROM AUTHOR]

From a commercial viewpoint, mine methane is the most promising object in the field of reducing emissions of climate-active gases due to circular waste management. Therefore, the task of this research is to estimate the technogenic reservoirs resources of mine methane when implementing the circular waste management concept. The novelty of the authors' approach lies in reconstructing the response space for the dynamics of methane release from the front and cross projections: CH4 = ƒ(S; t) and CH4 = ƒ(S; L), respectively. The research established a polynomial dependence of nonlinear changes in methane concentrations in the mixture extracted by type 4 wells when a massif is undermined as a result of mining in a full-retreat panel. And the distance from the face to the start of mining the panel is reduced by 220 m. For this reason, the emission of mine methane, in case of degasification network disruption in 15 days, can amount to more than 660 thousand m3 only for wells of type no. 4. [ABSTRACT FROM AUTHOR]

Artificial neural networks are successfully used to solve a wide variety of scientific and technical problems. The purpose of the study is to increase the efficiency of distributed solutions for problems involving structural-parametric synthesis of neural network models of complex systems based on GRID (geographically disperse computing resources) technology through the integrated application of the apparatus of evolutionary optimization and queuing theory. During the course of the research, the following was obtained: (i) New mathematical models for assessing the performance and reliability of GRID systems; (ii) A new multi-criteria optimization model for designing GRID systems to solve high-resource computing problems; and (iii) A new decision support system for the design of GRID systems using a multi-criteria genetic algorithm. Fonseca and Fleming's genetic algorithm with a dynamic penalty function was used as a method for solving the stated multi-constrained optimization problem. The developed program system was used to solve the problem of choosing an effective structure of a centralized GRID system that was configured to solve the problem of structural-parametric synthesis of neural network models. To test the proposed approach, a Pareto-optimal configuration of the GRID system was built with the following characteristics: average performance–103.483 GFLOPS, cost–500 rubles per day, availability rate–99.92%, and minimum performance–51 GFLOPS. [ABSTRACT FROM AUTHOR]

The urban transport network involves complex processes, operating 24 h a day and 365 days a year. The sustainable development of the urban transport network using electric buses and trolleybuses that run autonomously is an urgent task since the transport network performs integral social functions and is the transport artery of any urban center. The social and economic life of a city as a whole depends on the reliability of the transportation network. A theory is proposed for the technical and economic evaluation of reliability improvement in electric buses and trolleybuses running autonomously, which enables the determination of the reliability parameters of electric buses and forecasts for the future from the point of view of optimal economic costs for the operation of electric equipment in electric buses. As a result of the application of the proposed theory, it was found that increasing the reliability of the transportation fleet can lead to a decrease in both specific operating costs and capital investments in the development of the fleet. This is achieved as a result of increasing the annual productivity of vehicles by reducing the time they are out of service to eliminate the consequences of failures and carry out maintenance and repair. The conducted experiments confirmed that the theory and methodology of optimal reliability level selection not only enable the rational use of the material resources of the urban transport network but also the release of funds for its scientific and technical development by reducing the number of failures in the electrical equipment of transport systems by 14%. [ABSTRACT FROM AUTHOR]

Carbon materials are promising for use as electrodes for supercapacitors and lithium–ion batteries due to a number of properties, such as non-toxicity, high specific surface area, good electronic conductivity, chemical inertness, and a wide operating temperature range. Carbon-based electrodes, with their characteristic high specific power and good cyclic stability, can be used for a new generation of consumer electronics, biomedical devices and hybrid electric vehicles. However, most carbon materials, due to their low electrical conductivity and insufficient diffusion of electrolyte ions in complex micropores, have energy density limitations in these devices due to insufficient number of pores for electrolyte diffusion. This work focuses on the optimization of a hybrid material based on porous carbon and carbon nanotubes by mechanical mixing. The purpose of this work is to gain new knowledge about the effect of hybrid material composition on its specific capacitance. The material for the study is taken on the basis of porous carbon and carbon nanotubes. Electrodes made of this hybrid material were taken as an object of research. Porous carbon or nitrogen-containing porous carbon (combined with single-, double-, or multi-layer carbon nanotubes (single-layer carbon nanotubes, bilayer carbon nanotubes or multilayer carbon nanotubes) were used to create the hybrid material. The effect of catalytic chemical vapor deposition synthesis parameters, such as flow rate and methane-to-hydrogen ratio, as well as the type of catalytic system on the multilayer carbon nanotubes structure was investigated. Two types of catalysts based on Mo12O28 (μ2-OH)12{Co(H2O)3}4 were prepared for the synthesis of multilayer carbon nanotubes by precipitation and combustion. The resulting carbon materials were tested as electrodes for supercapacitors and lithium ion intercalation. Electrodes based on nitrogen-containing porous carbon/carbon nanotubes 95:5% were found to be the most efficient compared to nitrogen-doped porous carbon by 10%. Carbon nanotubes, bilayer carbon nanotubes and multilayer carbon nanotubes synthesized using the catalyst obtained by deposition were selected as additives for the hybrid material. The hybrid materials were obtained by mechanical mixing and dispersion in an aqueous solution followed by lyophilization to remove water. When optimizing the ratio of the hybrid material components, the most effective porous carbon:carbon nanotubes component ratio was determined. [ABSTRACT FROM AUTHOR]

In world practice, the role of reproduction of raw material base of oil production by implementing modern methods of oil recovery enhancement (thermal, gas, chemical, microbiological) on the basis of innovative techniques and technologies is rapidly growing and is becoming more important. It is concluded that at present, the priority of increasing oil reserves in world oil production is the development and industrial introduction of modern integrated methods of enhanced oil recovery, which can provide a synergistic effect in the development of new and developed oil fields. This article presents a review and comparative analysis of theoretical and practical methods of improving oil recovery of conventional and unconventional reservoirs. The paper examines in detail methods of improving oil recovery, taking into account the factors of enhanced oil recovery of oil reservoirs. Considered the main methods and technologies currently used to develop oil fields and recommendations for their effective use, taking into account the variety of external factors of oil production: the geological structure of the reservoir, its volume, and properties of oils. It is shown that there is no universal method of oil reservoir development, and it must be chosen after a thorough feasibility study among several proposed models. When describing the methods of enhanced oil recovery, special attention is also paid to the physical processes that occur as a result of applying the technology. In conclusion, the positive and negative characteristics of the presented methods included in EOR are presented, and recommendations that may influence the choice of practical solutions for engineers and oil producers are given. Conclusions are made that development systems, placement and choice of operating mode of wells essentially depend on the geological structure of the reservoir, its volume and properties of oils. An important role in this is the construction of a geological model of the production facility. The used hydrodynamic models of development are based on physical laws, about which oil producers sometimes don't even suspect, and the authors of the models are not always able to convey it to the real producers. The authors consider it reasonable to make a logical generalizing conclusion that understanding processes occurring in the reservoir and taking appropriate measures for optimization and intensification of oil production will allow making oil production as effective as possible. [ABSTRACT FROM AUTHOR]

Decarbonization of the mining industry on the basis of closing the energy generation, on the basis of cogeneration of coal mine methane, and on the internal consumption of the mine is a promising direction in ensuring sustainable development. Known problems of deep underground mining do not allow for realizing the potential of man-made gas reservoirs due to the deterioration of the conditions of development of reserves of georesources. The aim of the work was to improve recommendations for the substantiation of drilling parameters for undermined drainage boreholes for increasing methane production from unconventional coal-gas collectors. The authors' approach innovation lies in the possibility of using the established patterns of better natural stability of undermined boreholes to optimize them as spatial orientation parameters in an existing drilling passport for the improvement of methane extraction productivity. For this purpose, smoothing (LOESS) of the experimental data of two similar types of wells was used; then deterministic interpolation methods in combination with a three-dimensional representation of the response function in "gnuplot" were used. As a result, it was found that the increase in the inclination angle from 40° to 60° leads to a significant transformation of the model of the studied process, accompanied by a decline in the dynamics of methane emission and a decrease in the distance of the productive work zone of this type of well from 13 to 5 m before the roof landing, which then is replaced by a sharp increase in the productive work zone up to 35 m ahead of the longwall face. This allows under specific conditions for recommending increasing the productivity of methane capex from technogenic disturbed coal-gas reservoir replacement of wells with a smaller angle of rise to the transition to a more frequent grid of clusters from wells #4. [ABSTRACT FROM AUTHOR]

The increase in the share of physical and technical processing methods in the arsenal of deburring technologies used in modern production is associated both with the use of difficult-to-machine materials, such as beryllium bronze and the 29 NK alloy, and with the need to solve technological problems for the production of small-sized products with hard-to-reach surfaces. The aim of the study is to improve the processes of blade processing of small-sized parts made of beryllium bronze and the 29 NK alloy to provide rational conditions for thermal pulse deburring. Surface samples were experimentally obtained after turning in different modes on a CITIZEN CINCOM K16E-VII automatic lathe equipped with an Applitec micromechanics tool. The surface quality and burr characteristics were examined using a JEOL JIB-Z4500 electron microscope and a ContourGT-K optical profilometer. The program Statistica 6 allowed processing of the results. The relationship between the parameters of the turning mode and the thickness of the root of the burrs formed on the machined surface, the limitation of which is one of the conditions for the application of the thermal pulse method, was established. The obtained empirical regression dependencies establish a rational range of cutting mode parameters, and the implementation of the formulated recommendations for setting blade modes ensures deburring by the thermal pulse method in compliance with the requirements of drawing under maximum processing performance. [ABSTRACT FROM AUTHOR]

The results of studying the morphological peculiarities of polycrystalline CdS1−xSex films, obtained by screen printing, with well-formed grain boundaries of high structural quality are presented here. The developed method for screen printing provides the formation of polycrystalline films of a specified area per cycle, provided that there is a possibility for varying their thickness from tens of microns to units, which allows reducing the solar cell's thickness and facilitating the process of its connection with the substrate. Therefore, the application of the films to a sitall substrate by screen printing contributes to reducing the product weight and facilitating the process of joining sheet materials intended for solar panels, namely attaching the lasing element to the substrate. The purpose of this work is to study the morphological peculiarities of polycrystalline CdS1−xSex films obtained by an optimized screen-printing method and to create a model of their formation process. The structural and morphological peculiarities of the samples were studied using electron microscopy, AFM, XPA, and XFS. As a result of the work, based on the obtained experimental data, a model of the film formation process was developed. The model validity is justified by the conformity of the data of the experiment performed on its basis. [ABSTRACT FROM AUTHOR]

Purpose: The goal of this work is to reduce the effect of dynamic loads on the mine timbering through the use of the elastic devices contained in the monorail suspension and to justify their parameters. Methods and materials: The article considers the developed mathematical model of vertical oscillations of the monorail track, which allows setting the interconnection between the rolling stock parameters and dynamic loads in the suspension. At vertical oscillations of the monorail and under the effect of harmonic disturbing force caused by the movement of the suspension, the system of the monorail suspension can be represented in the form of a dual-mass system. Results: As a result, the equations for oscillation amplitudes of the monorail elements were obtained and damping coefficient of suspension was defined. The obtained results suggest setting reasonable parameters of the monorail fastening, which offers the possibility to decrease dynamic loads occurring during the operation of the mine suspended monorail tracks. The proposed monorail suspension makes it possible to reduce the dynamic loads formed during the movement of the rolling stock by 30–40% and can be used to modernize existing mine suspended monorails. Discussion: Analysis of the obtained results shows that in order to reduce the vibration amplitudes of a suspended monorail mine, it is appropriate to use suspension systems for rolling stock and a monorail track, consisting of elastic elements. The parameters required for this can be determined using the proposed method, and required rigidity of the monorail track is provided by embedding elastic supports into its suspension system. Conclusions: The obtained results allow setting reasonable parameters of the monorail fastening of the mine suspended monorail tracks. The proposed monorail suspension makes it possible to minimize the dynamic loads formed during the movement of rolling stock and can be used to modernize existing mine suspension monorails. [ABSTRACT FROM AUTHOR]

Underground mining, including underground coal mining, is accompanied by accidents and fire hazards that pose a threat to the life safety of miners. The fire hazard increases with an increase in the mining depth. Currently, most accidents in coal mines are mine fires. The cost of eliminating mine fires is 80–95% of the cost of eliminating all accidents occurring at mining enterprises. Therefore, the problem of developing a new methodology for modeling the ventilation network parameters of the mine to increase the reliability of controlling the aerogas mode at the excavation site is very relevant. The comprehensive analysis and assessment of gas-dynamic processes in coalmines under study were carried out using the methods of probability theory and mathematical statistics. Spatial data were processed using spline interpolation in "gnuplot". As a result, a generalized expression for the transfer functions of coalmine objects, taking into account delays, was developed, including the description of dynamic properties of mining sites under various operating modes. The principal possibility of using a graphical method for estimating additional parameters of the sections of the ventilation system branches has been proved due to the alignment of their profiles at an equivalent distance relative to an arbitrary analogue. The improved method of spatial modeling was used to determine the gas-dynamic characteristics through additive gas-dynamic processes. The studies have been carried out and the method for managing the process of changing connections between devices (controllers–switches) of the technical system was developed in order to obtain greater reliability for safe mining. In subsequent studies, there is an issue of more detailed clarification of the peculiarities concerning the interrelations between the studied parameters in several projections of the response space. [ABSTRACT FROM AUTHOR]

An analysis of the results of rail operation shows that up to a third of all rail breaks in the railway line and up to 12.9% of all withdrawn acute defective rails are associated with welded joints. This is largely explained by the formation of structures with martensite sections in the welded joints of rails and the formation of burns. This work presents the results of studying welded joints, obtained under three welding modes (continuous flash welding, pulsating flash welding and combined flash welding). The conducted studies have shown that the flash welding mode significantly influences both the cooling rate value and the very nature of the thermal cycle of the welded joint as a whole. Changes in the cooling rate under different modes exert a significant influence on the structure and properties of the weld. Resistance welding of rails from the steel grade E76HGF by pulsating flash welding can result in the appearance of needle martensite areas, which is the reason for increased embrittlement of the weld and a decrease in its properties. The conducted field experiments have reliably shown that in the conditions of the combined welding mode it becomes possible to avoid these problems. Moreover, a slight increase in the mechanical properties of the weld in the range of 2–4% has been experimentally recorded, and the destructive load of the welded joint of the rail increases by 2–3% at high values of the bending deflection. In turn, these factors allow a significant reduction in the number of cases of rail welded-joint failures in real conditions of their operation. [ABSTRACT FROM AUTHOR]

The present study is focused on improving the technology for deep oil sludge processing by pyrolysis methods, considered to be the most promising technology for their environmentally friendly utilization, in which a significant yield of fuel products is expected. The technology developed by the authors of this study is a two-stage process. The first stage, pyrolysis of oil sludge, was investigated in previous papers. A significant yield of non-condensable gases was obtained. This paper presents a study of the second stage of complex deep processing technology—pyrolysis of non-condensable gases (purified propane) using a stirrer with the help of the developed experimental setup. The expected benefit of using the stirrer is improved heat transfer due to circumferential and radial-axial circulation of the gas flow. The effect of a stirrer on the yield of final target decomposition products—H2-containing mixtures and H2 generated during non-catalytic (medium-temperature) and catalytic pyrolysis of non-condensable gases obtained by pyrolysis of oil sludge are estimated. Ni catalyst was used for catalytic pyrolysis. The study shows that the application of the stirrer leads to increasing in H2-containing mixtures and H2 concentrations. In particular, during the whole reaction time (10 h), the average H2 concentration in pyrolysis gas during catalytic pyrolysis increased by ~5.3%. In this case, the optimum reaction time to produce H2 was 4 h. The peak H2 concentration in the pyrolysis gas at reaction temperature 590 ± 10 °C was: 66.5 vol. % with the stirrer versus 62 vol. % without the stirrer with an error of ±0.4 %. A further increase in reaction time is cost-effective in order to obtain H2-containing mixtures. [ABSTRACT FROM AUTHOR]

This article is a compilation of interdisciplinary studies aimed at ensuring the environmental, political, and economic sustainability of oil and gas-producing countries with a focus on areas with many years of permafrost. One of the main concepts adopted in this research was the desire to show that confronting various energy lobbies is not mandatory and that it is necessary to find compromises by finding and introducing innovative technologies for integrated development for the benefit of society, industry, and the state. This is particularly relevant due to the increasing share of hard-to-recover hydrocarbon reserves, widely represented in the fields of the Eastern Siberian Arctic, and because Russia is the leader in flare emissions. We thus present the relevance of using these gases as industrial waste while reducing the carbon footprint. The technology of biofuel production based on the use of supercritical liquid extraction in a well extractor is presented as a result of the development of the presented experimental devices representing the investigation of the processes of extraction in wells and reactors for the distillation of hydrocarbons from heavy oil components. The obtained yield of the desired product (hydrogen) of the thermocatalytic pyrolysis of the test extract was in the range of 44 to 118 L/h, depending on the catalyst. This information can help inform the direction of future ecological engineering activities in the Eastern Siberian Arctic region. [ABSTRACT FROM AUTHOR]

The quality of operation of neural networks in solving application problems is determined by the success of the stage of their training. The task of learning neural networks is a complex optimization task. Traditional learning algorithms have a number of disadvantages, such as «sticking» in local minimums and a low convergence rate. Modern approaches are based on solving the problems of adjusting the weights of neural networks using metaheuristic algorithms. Therefore, the problem of selecting the optimal set of values of algorithm parameters is important for solving application problems with symmetry properties. This paper studies the application of a new metaheuristic optimization algorithm for weights adjustment—the algorithm of the spiders-cycle, developed by the authors of this article. The approbation of the proposed approach is carried out to adjust the weights of recurrent neural networks used to solve the time series forecasting problem on the example of three different datasets. The results are compared with the results of neural networks trained by the algorithm of the reverse propagation of the error, as well as three other metaheuristic algorithms: particle swarm optimization, bats, and differential evolution. As performance criteria for the comparison of algorithms of global optimization, in this work, descriptive statistics for metrics of the estimation of quality of predictive models, as well as the number of calculations of the target function, are used. The values of the MSE and MAE metrics on the studied datasets were obtained by adjusting the weights of the neural networks using the cycling spider algorithm at 1.32, 25.48, 8.34 and 0.38, 2.18, 1.36, respectively. Compared to the inverse error propagation algorithm, the cycling spider algorithm reduced the value of the error metrics. According to the results of the study, it is concluded that the developed algorithm showed high results and, in the assessment of performance, was not inferior to the existing algorithm. [ABSTRACT FROM AUTHOR]

The aim of this work is to develop an intelligent method for controlling the induction soldering process of spacecraft's thin-walled aluminum waveguide tracks. This new control method is based on the use of intelligent data analysis in order to determine the optimal control algorithms for product heating and the workpiece motion control with optimal coefficients based on the operational data of the induction soldering technological process. The paper presents a mathematical formulation of the intelligent control problem. As part of this work, such intellectual methods have been chosen for comparison as a method based on a fuzzy logic, artificial neural networks, and a neuro-fuzzy controller. Based on experimental data on real technological processes of induction soldering, a comparative analysis of the effectiveness of the proposed approach has been carried out. The results of experimental studies have shown that the control method of the induction soldering technological process based on artificial neural networks has the highest efficiency. In addition, based on experimental data of real technological processes, the most effective structure of an artificial neural network has been determined. The highest recognition accuracy has been provided by an artificial neural network with five artificial neurons on each one of five hidden layers. Experimental quality control of the obtained artificial neural network has been carried out on three different waveguide tracks assemblies with different tube thicknesses: 58×25 mm, 35×15 mm, 19×9.5 mm. The results of the experimental verification have showed that for all the three waveguide tracks assemblies high-quality soldered joints have been obtained. The integrated application of intelligent technologies for controlling the technological process of induction soldering of thin-walled aluminum waveguide tracks could significantly improve the quality of permanently formed connections, as well as eliminate errors associated with human factor. Further research will focus on the intellectualization of other technological processes for creating permanent connections, such as electron beam welding, diffusion welding, etc. The results of this work clearly show the effectiveness of the proposed concept of intellectualization, so it is advisable to extend it to a wider range of technological processes. [ABSTRACT FROM AUTHOR]