Introduction. The state of the population health depends on the ecological and hygienic well-being of the territory. In places with developed oil production, there is a long-term impact of pollutants on the human body and, as a result, corresponding diseases develop. This is evidenced by numerous domestic and foreign studies, but the territory of the Irkutsk region is not covered by such studies. Therefore, the work objective is to assess the impact of oil production processes on the incidence of the population of oil-producing regions of the Irkutsk region.

Materials and Methods. The source materials were the statistical indicators of overall and primary disease incidence of the population of the regions of the Irkutsk region for the period from 2016 to 2019, posted on the website of medical statistics of the Irkutsk region. For the calculation of the non-carcinogenic risk, we have used environmental monitoring data from an oil-producing company based on average daily concentrations of pollutants in oil-producing areas.

Results. It is shown that oil-producing areas are characterized by extremely high incidence rates for such groups of diseases as respiratory diseases, diseases of the circulatory system, diseases of the musculoskeletal system, diseases of the digestive system, diseases of the genitourinary system, as well as deviations in pregnancy, childbirth and the postpartum period. Infant mortality rates in these territories are up to 4 times higher than the corresponding average indicators for the Irkutsk region as a whole. The calculation of non-carcinogenic risk showed an excess over the permissible values accepted in Russia.

Discussion and Conclusions. The results of the analysis testify to the unfavorable medical and demographic situation in the territories under discussion. The pronounced excess of the incidence rate for the presented groups of diseases in the oilfield areas in comparison with the territories taken for comparison reflects the possible impact of environmental pollution on the health of the population. A connection between the growth of infant mortality in the territories under consideration and the beginning of the industrial development of hydrocarbon deposits in these places has been revealed. The contribution of oil companies to the socio-economic development of the regions, including co-financing of medical care for the population, could partially offset the negative impact of industrial processes.

Introduction. In the study of the problem of the impact of negative factors from explosions at gas stations on people and the infrastructure of settlements, a probabilistic approach is often used. The limitation of this approach is that when it is implemented, the concept of clutter of the surrounding space does not reflect the relationship between the area occupied by buildings and the total area affected by the shock wave. Therefore, this article is devoted to the development and justification of an approach to assessing the consequences of explosions of fuel-air mixtures (FA), taking into account the peculiarities of the development of settlements. The work objective is to develop an approach for assessing the consequences of explosions of fuel-air mixtures, taking into account the development features. The solution to this problem will facilitate decision-making for the development of effective protective measures for surrounding objects.

Materials and Methods. The authors have conducted an analytical review of the research results in the field of study and the existing approaches to assessing the consequences of explosions at filling stations (FS) and gas stations (GS), based on the specific conditions of their location on the territory of settlements.

Results. An approach has been developed to assess the consequences of explosions of fuel-air mixtures, taking into account the development features. The main causes, types of accidents with an explosion at a gas station and the scale of their consequences have been identified. Along with the theoretical justification of the issue under consideration, the authors provide a detailed description of the applied research methodology, as well as the characteristics of the objects of research, taking into account their location. When calculating the consequences of explosions of fuel-air mixtures, it was proposed for the first time to use a development density factor equal to the ratio of the area of the existing facilities to the total area of the territory affected by the shock wave. This approach justifies the need to apply additional protective measures in the areas where gas stations are located. The methods of analysis used are described in detail with justification of the reliability of the measurement results.

Discussion and Conclusion. The application of the approach proposed in the article for calculating the consequences of an explosion of fuel-air mixtures, taking into account the development density, makes it possible to control the location and the level of risk from possible explosions at gas stations in a real situation. The proposed approach for calculating the consequences allows you to quickly assess possible risks in real time and plan specific measures to minimize them in accordance with the existing situation in the area of the gas station.

Introduction. Recently, much attention has been paid to the issues of long-term development of specialized fire and rescue units of the Federal Fire Service of the State Fire Service. In this regard, there is a need to develop criteria to justify the use of a particular service as part of specialized fire and rescue units. Therefore, the objective of this study is to develop a mathematical model to justify the need to use radiation and chemical protection services as part of specialized fire and rescue units in the subjects of the Russian Federation.

Materials and Methods. Justification of the need to use radiation and chemical protection services as part of specialized fire and rescue units has been carried out using the theory of fuzzy sets. The mathematical model takes into account the climatic and geographical features of the subjects, indicators of social, technical and economic development, and the risks of emergencies and fires. It also takes into account the availability of forces and means of a Unified State system for the prevention and liquidation of emergency situations in each subject of the Russian Federation. In total, 15 indicators were selected that characterize the need to use radiation and chemical protection services as part of specialized fire and rescue units. A desirability function is defined for each indicator, which shows which values of the indicator are the most acceptable from the point of view of the need to use radiation and chemical protection services as part of specialized fire and rescue units.

Results. Using the developed model, the subjects of the Russian Federation are identified in which the need for radiation and chemical protection service as part of specialized fire and rescue units is the highest. It is proposed to create a radiation and chemical protection service of the 1st category in the Moscow, Sverdlovsk and Rostov regions, in the Krasnoyarsk and Primorsky Territories and in St. Petersburg. In 21 subjects it is proposed to use the radiation and chemical protection service of the 2nd category. In other subjects, it is proposed to assign the 3rd category to the radiation and chemical protection service.

Discussion and Conclusion. The mathematical model developed using the theory of fuzzy sets will allow a more differentiated approach to the creation of a radiation and chemical protection service as part of specialized fire and rescue units and increase the efficiency of the functioning of this service and specialized fire and rescue units as a whole. The presented model can be applied to justify the need to use other services and groups as part of specialized fire and rescue units.

Introduction. The paper considers the problem of fire resistance assessment of building structures with intumescent fire protection. For the results reliability, a fire test should be carried out only when the intumescent coating at the facility is ready, which will make it possible to detect hidden factors of violation of its quality and prevent collapse in case of a possible fire. The work objective is to test the express analysis of intumescent coatings in comparison with standard methods for fire resistance assessment.

Materials and Methods. The elements of building structures covered with fire-resistant intumescent paint Defender M Solvent with different diluent content were studied. The fire resistance of the coatings was determined by two methods. The first one is an express analysis. The following indicators were recorded:

– general appearance of the coked cellular material (CCM);

– swelling coefficient;

– CCM compressive and shear-tear strength of the boundary layer.

The second one is a standard approach according to the requirements of ISO 834-75 (GOST 30247.0-94). The indicators were:

– time to reach the critical temperature;

– critical deflection during heating.

Results. In addition to the above indicators, testing also took into account the amount of diluent. The CCM swelling coefficient, CCM compression force, tensile strength and density were considered. The revealed patterns are systematized in a table. The obtained indicators were compared with the technical requirements for the material. The period during which the steel substrate of the sample reaches a critical temperature is recorded. It is established that with an increase in this time, the coefficient of swelling of the protective layer (CCM) and its shear-tear strength increases. At the same time, the values of compressive strength and CCM density decrease. When the intumescent paint is diluted beyond the norm, the fire protection parameters deteriorate and the fire resistance limit R45 is not reached. The research results are visualized in the form of diagrams. They confirm that the express analysis makes it possible to reasonably judge the suitability or unsuitability of the paint for fire protection, if the required fire resistance limit is R45.

Discussion and Conclusions. In comparison with the results of the application of standard techniques, the effectiveness of the express analysis technique and the correctness of the results of the assessment of intumescent fire protection were confirmed. In construction conditions, an express CCM analysis will be sufficient to determine the quality of an intumescent fire retardant coating.

Introduction. Ensuring safe and comfortable working conditions is one of the most important tasks in the organization of modern production processes that have a direct impact on employee productivity, injuries and occupational diseases. Despite all the efforts made both at the state and departmental levels, the current state of occupational safety and health of industrial workers in the Republic of Kazakhstan continues to remain at an insufficiently high level. The main cause of occupational injuries and occupational diseases is the impact on working personnel of dangerous and harmful production factors, one of which is an increased level of noise and vibration from production equipment. The authors analyze statistical data on the number of cases of injuries, their types and causes of occurrence in workers by sectors of the economy of the republic. The influence of noise and vibration on the health of workers is considered. It is found that an increased level of noise and vibration effects causes injuries to a lesser extent, and occupational diseases to a greater extent. The work objective is instrumental measurement of noise and vibration levels in the workplaces of production sites of a machine-building enterprise and assessment of working conditions there to develop effective measures to reduce the harmful effects on the health of workers.

Materials and Methods. Statistical data on occupational injuries and occupational diseases were used as basic information, as well as the results of instrumental measurements of the level of noise and vibration effects on workers using the methods set out in GOST ISO 9612-2016 and GOST 31319-2006, taking into account Order of the Minister of Health of the Republic of Kazakhstan of February 16, 2022 № KR DSM-15 «On approval of hygienic standards to physical factors that have an impact on a person».

Results. The results of the conducted research allowed us to conclude that about 22.6% of workplaces at production sites are characterized by harmful and dangerous working conditions in terms of noise and vibration effects on workers.

Discussion and Conclusion. Based on the results of the study, a plan of priority measures was developed to reduce the harmful effects of increased noise and vibration in the workplace. The authors also recommend a special working regime, benefits and additional payments to employees for working conditions that do not meet safety requirements.

Introduction. At the stage of designing technical devices and performing appropriate strength calculations of metal structures, sufficiently large reserves of strength are taken, which, theoretically, exclude any failures of parts. In fact, the machines work with frequent failures. Of interest are undiagnosed failures that lead to a critical decrease in safety, especially at hazardous production facilities. It is assumed that the previously applied approaches of selective determination of the maximum (minimum) reliability value, based on point estimates of the distribution parameters of the two-parameter Weibull law, lead to an overestimation of the calculated indicators of the probability of failure-free operation, i.e. underestimation of risk. Therefore, the work objective is to consider an approach to assessing the risk of operating production facilities in a situation of accidental occurrence of dangerous and undiagnosed failures in systems.

Materials and Methods. Methods for technical devices safety assessment based on probability theory were used in the work, and the probability of machine failure was determined based on the well-known method of reliability theory. This method consists in calculating and constructing distribution functions of random variables (load-bearing capacity and loading) that influence the occurrence of failure. The level of increase in the reliability index was determined, leading to frequent unpredictable failures of technical devices (machines) and a decrease in the safety of their operation.

Results. The signs of inconsistency of strength calculations based on overestimated safety margins, which in theory exclude failures of parts and machines in general, are identified and substantiated. A new approach to risk assessment of operating production facilities in a situation of accidental occurrence of dangerous and undiagnosed failures by safety systems has been developed and implemented. An algorithm for determining the three parameters of Weibull's law for a population based on sample data has been developed. The resource distribution densities of the boom of the single-bucket excavator EK-14 are constructed. The recommendations are given to increase the probability of failure-free operation to 0.9989.

Discussion and Conclusion. The results of the conducted research allow us to substantiate a new approach to risk assessment of operating production facilities in the event of dangerous and undiagnosed failures of basic parts by safety systems, leading to negative consequences.

Introduction. The operation of lifting cranes is an integral part of the production processes. For the trouble-free operation of these mechanisms, certain knowledge, skills and abilities are required, which should also be possessed by specialists performing organizational and supervisory functions at facilities where such cranes are involved. Here there is an important problem – the lack of a reasonable connection between the level of development of professional competencies and possible emergency situations, as well as various incidents during the operation of lifting cranes. The authors of this study are trying to solve it. Their goal in this regard is to assess the probability of an emergency during the operation of lifting cranes, depending on the level of professional competence of specialists, through the use of neural networks.

Materials and Methods. The competencies of workers in the operation of lifting cranes (knowledge, skills and work responsibilities) provided for by the professional standard «Specialist in the operation of lifting structures» were used as initial data to train neural networks. Based on them, a list of possible incidents was compiled. For the purposes of training, the results of the certification of 200 conditional employees were generated. During the generation, the Monte Carlo method was used, and the data were output to Excel tables. Neural networks were trained in Python 3.10 in the PyCharm development environment. Open libraries Keras and TensorFlow, as well as auxiliary libraries for data representation and processing (Pandas, NumPy, Scikit-learn) were used for neural networks training.

Results. As a result, a tool was obtained – a neural network in the form of executable program code, which makes it possible to assess the probability of emergencies during the operation of lifting cranes by analyzing the degree of proficiency of specialists in professional competencies. It is proposed to implement artificial intelligence technologies based on neural networks in order to assess the knowledge, skills and abilities of specialists of facilities operating lifting cranes, both during the certification of employees and in the course of work.

Discussion and Conclusion. The main result of using neural networks to assess the knowledge of employees of facilities operating lifting cranes is the expected reduction in accidents, which can be ensured by timely identification of incompetent personnel at the stages of primary certification and, most importantly, during periodic tests of knowledge based on an impartial analysis and evaluation of data.

Introduction. The application of functional coatings on products, the performance properties of which are localized in the surface layer is a trend in modern mechanical engineering and materials science. The issues considered in this regard are relevant, in particular, for thermal-barrier coatings of turbine blades of steam and gas turbine engines. It is worth mentioning the materials that experience significant thermal loads during operation. In this case, the lack of reliable methods for predicting the thermophysical properties of the coating seems to be a problem. The work objective is to create a computational and analytical methodology for determining the thermal conductivity of coatings. This approach is based on experimental data and takes into account structural parameters of the material.

Materials and Methods. The experiments were carried out with the blades of a high-speed gas turbine of a locomotive engine made of heat-resistant chromium-nickel alloy Inconel 713LC. An experimental multiphase coating of the Nb-Ti-Al intermetallic system with a thickness of about 80 microns was applied using vacuum ion-plasma technology. The two-beam scanning electron microscope Zeiss CrossBeam 340 was used in the work. The thermal conductivity of the coatings was determined by an experimental technique based on the measurement of the contact potential difference (CPD). Numerical values of this difference were obtained using a mirror galvanometer with high voltage sensitivity. A special signal amplifier and a USB oscilloscope were used to record the readings.

Results. The calculation apparatus of the thermal conductivity determination technique is based on the experimental values of  ∆φ CPD:

– for the base metal (Inconel 713LC) +846 mkV;

– for the coating Nb-Ti-Al – 90 mkV.

The solution to the problem of the distribution of particles in a force field with a potential difference ∆φ is described by the Boltzmann distribution. Starting from the obtained result, we get:

– CPD at the boundary of the contacting metals;

– energy and thermal conductivity of the Fermi level;

– electron relaxation time.

The multidirectional influence that the dimensional differences of the particles of the second phase have on the effective thermal conductivity is considered. For this case, a dimensionless value of the effective thermal conductivity in the direction of each axis and the effective thermal conductivity of the composite are found. Porosity is taken into account according to the Maxwell – Aiken dependence and introduced into the general calculation system. The thermal conductivity of Nb-Ti-Al is established: λ_NbTiAl = 4,76 W/m∙K. Thus, the thermal barrier coating Nb-Ti-Al fully meets its functional purpose.

Discussion and Conclusion.The method of determining thermal conductivity described in the article is applicable only to conductive consolidated materials or composites with a continuous conductive matrix. The presented work completes the initial stage of creating a computational and analytical model for predicting the thermal conductivity of materials and coatings. The results of testing the model for materials with a complex structure showed its satisfactory accuracy. This indicates the expediency of using the two considered elements of the model. The first one is the instrumental measurement of the CPD. The second one is taking into account the features of the structural and phase state of the material. With the development of the model, it is expected to overcome its weaknesses:

– the impossibility of using non-conductive objects to determine the thermal conductivity;

– a significant decrease in the accuracy of determining thermal conductivity for materials and coatings with a gradient structure.

Introduction. The technology for producing hot-formed powder steel is one of the most energy-intensive in powder metallurgy, which includes a large number of operations. The study of the influence of technological modes on the final properties of the part is an urgent task. Developed by the scientific team under the leadership of Yu. G. Dorofeev at the end of the XX century, the technology of manufacturing hot-formed powder steels is currently one of the main ones in the production of high-density products. However, the use of new materials that improve the mechanical properties of products requires a modern approach to analyzing the quality of interparticle splicing of powder particles. The influence of the following technological factors on the formation of qualitative interparticle splicing was established: the blank density, the granulometric composition of the initial charge, the temperature and holding time of the blank during heating, the ratio of its dimensions, the deformation rate. The study objective is to analyze the effect of a graphite-containing component on the mechanical properties of hot-formed powder alloys due to the formation of high-quality interparticle splicing.

Materials and Methods. The work used domestic and foreign powders produced by PAO Severstal and the Swedish company Höganäs with the addition of carbon GC-1 (GOST 4404-78). Hot stamping was carried out on a crank press of the K2232 model with a maximum force of 1600 kN. The heating temperature of the workpieces varied between 800-1200 ºC.

Results. As a result of the experiments, the influence of the sintering duration on the mechanical properties of materials was established. The reason for the change in mechanical properties are local inclusions of graphite, which did not have time to homogenize as a result of prolonged sintering. Technological modes of hot stamping for steels have been developed that affect the preservation or destruction of the pre-formed contact interparticle surface.

Discussion and Conclusion. The studies have shown that additional hot plastic deformation contributes to the formation of intracrystalline fusion on the entire contact surface. The addition of graphite to the charge improves splicing for alloyed iron powder and practically does not affect the use of alloyed and unalloyed iron powder.

Introduction. Laser surface treatment of mechanical engineering products makes it possible to increase their durability. However, the laser hardening process is not good at the consistency of results, since choosing the irradiation modes and schemes of specific products, texture effects in the zones of laser exposure are not taken into account. This leads to premature wearing and even destructing the working surfaces of irradiated products. Therefore, the work objective is to study the mechanism of influence of the structure of the laser-hardened layer on the operational properties of the tool.

Materials and Methods. The materials for this study were tool steels: R6M5 and R18 (according to the EN 10027 standard tool steels: 1.3355, 1.3343). Pulsed laser irradiation was carried out at the technological device Kvant-16 with a radiation power density of 70–250 MW/m². Scanning probe and optical microscopy, X-ray diffraction and durometric methods for analyzing the steels structure were used. The values of steel strength in bending and impact strength were determined before and after laser treatment.

Results. It has been experimentally proven that it is necessary to strengthen the sections of the products working surfaces that are subject to maximum wear and are under the action of compressive stresses during operation. It is shown that textural effects in the laser treatment zones lead to a decrease in the friction coefficients and contribute to an increase in the wear and adhesion resistance of the steels surface layers.

Discussion and Conclusion. The results of the research carried out make it possible to rationally select the surface laser processing modes and schemes of products for various functional purposes and ensure their operability with a guarantee. The possibilities increasing the structural strength and properties of the tool due to laser alloying the surface layers of powder-coated steels and stabilizing tempering after laser irradiation are determined.