Introduction. Understanding the epidemic curve and spatiotemporal dynamics of SARS-CoV-2 virus is of fundamental importance for the work of the health system during epidemic and pandemic periods. Firstly, the data obtained allow us to assess the epidemiological characteristics of the virus. Secondly, it becomes possible to develop and coordinate measures to counter the spread of COVID-19, to allocate resources reasonably.

   The work objective is to create and initialize a mathematical model of the epidemic process, which makes it possible to explain the observed dynamics, to predict its development and to assess the reliability of such forecasts.
   Materials and Methods. Scientific research was based on the statistical data analysis. A hierarchy of mathematical models describing the dynamics of the spread of a new coronavirus infection (COVID-19) and the mortality of COVID-positive patients from 12.02.2020 to 22.09.2021 has been constructed. The incidence submodel reflects regular (aperiodic and periodic), as well as random components. To study and predict the processes, the classical technique of time series research, correlation and Fourier analysis were used. This approach allowed using the method of moments to identify the statistical properties of the scientific research object, and then visualize the stages and algorithm of work.
   Results. An optimistic, pessimistic and intermediate scenario of infection spread has been mathematically investigated. Their strengths and weaknesses are noted. Numerical characteristics of the trend model and the model of fluctuations in the incidence of COVID-19 are systematized in the form of tables. Based on these data, a conclusion is formulated about the optimality of the pessimistic model: after the highest possible indicators, the infection curve reaches a plateau, and the virus remains in the population. It has been established that the spread of a new coronavirus infection has a pronounced seasonal character with a period of 1/3 of the year. Mathematical analysis and modeling of the mortality dynamics of COVID-positive patients revealed weekly fluctuations in the level of deaths. At the same time, it turned out that the maximum risk corresponds to the 15th and 22nd day of infection. According to the hypothesis proposed by the authors, this virus will be characteristic of the human population. The mortality rate is expected to be 1.75 %. The calculations have shown that the influence of random components of morbidity and mortality will correspond to seasonal fluctuations.
   Discussion and Conclusion. The probable frequency of the epidemic has been established — three times a year. The potential mortality rate is determined as constant. It is caused by epidemiological and organizational reasons, i. e. the work of medical institutions and authorities. Taking into account the features of the new coronavirus strain (omicron), it is possible to predict the further dynamics of the pandemic and make recommendations regarding its prevention. The authors believe that vaccination should be carried out three times a year. Optimal periods of vaccination campaigns:
05. 02–15. 02, 17. 05–28. 05, 24. 09–5. 10.

   Introduction. The paper considers the influence of radiation forest and peat fires on the spread of radioactive contamination, which affects the well-being of thousands of people. The state of the environment in vast territories is deteriorating; negative socio-economic processes are developing. This is a serious problem of two states: the Russian Federation and the Republic of Belarus.

   The objectives of the presented work are to study the radiation situation in forests and peat bogs located in the border areas of the Bryansk region, as well as to study the possibility of transferring radioactive materials during forest and peat fires.
   Materials and Methods. The facts that clarified the theoretical basis of the presented research are highlighted in the scientific literature. The authors took into account, in particular, that: – the activity of radionuclides in the soil decreases in direct proportion to the depth; – a peat fire is an uncontrolled burning; – emissions of caesium-137 fractions (¹³⁷Cs) during a fire can reach 3–4 %. We know the areas of forests in radiation-contaminated territories (RCT) of the Bryansk region from the applied literature and official sources. The most problematic areas from this point of view have been identified.
A mobile radiometric laboratory, a scintillation gamma-ray spectrometer MKS-AT6101S were involved in the expedition research. The results of field gamma-ray spectrometry were recorded in three localities. The calculations for a hypothetical fire were carried out using the SAUR AIUS RSCHS 2030 software tool.
   Results. The consequences of large and prolonged fires in the exclusion zone of the Chernobyl nuclear power plant are analyzed. It is established that the incidents did not lead to dangerous consequences for the population. The total effective dose of inhalations was ~0.003 % of the permissible level of irradiation. It is noted, however, that the forest soil of the Bryansk region has received significant damage from ¹³⁷Cs pollution. The density of such pollution exceeded 5 Ci/km² in 40 % of the affected forests. Of these, an indicator of 15-40 Ci/km² and more was recorded in 16 %, in some quarters — up to 200 Ci/km². It is established that zones with a high contamination density (40 Ci/km²⁾ will remain in the region until 2026. Five districts are particularly problematic: Gordeevsky, Zlynkovsky, Klintsovsky, Krasnogorsky and Novozybkovsky. When fixing and predicting harm, the authors of the presented work proceeded from the following fact: during fires, the combustion products (forest litter, grass and undergrowth) contain more radioactive substances than the crowns of trees. In this regard, measurements were not made at a significant height. The field study route was chosen based on the available data on the maximum level of radioactive contamination. The ambient dose equivalent rate (ADER) of gamma radiation recorded at 2,757 points did not exceed 1.2 μSv/h (with an average value of 0.2-0.3 μSv/h). Measurements in the marshes did not reveal traces of 137Cs at a depth of more than 40 cm. The maximum activity of ¹³⁷Cs was observed in the upper (0–4 cm) soil layer (up to 65 %). Taking into account the data obtained, the possibility of radioactive containation in the event of a forest fire was assessed. According to the calculations in the software environment, radioactive contamination will spread to 348 hectares. The density of radioactive contamination of the area may increase by 5–10 % (from the initial one). 33 people will suffer; there is a threat of death of 1 person. It has been established that a burning peat bog is the most powerful and long-term source of radioactive contamination, therefore it is important to prevent peat and forest fires. This will reduce the transfer of radionuclides and emissions of radioactive fumes. Remote and surface radiation monitoring facilities should be developed.

   Discussion and Conclusion. The registered ADER is not dangerous for the health of the population of the Bryansk region. However, frequent fires significantly increase the likelihood of transferring active ¹³⁷Cs to residential areas. In this sense, timely monitoring and forecasting of fires is relevant. The authors formulated proposals to improve the technical and technological components of the solution of the considered problem.
   1. To clarify the radiation situation, all-terrain vehicles should be equipped with: – means of registering the radiation situation; – software and hardware complex for automatic collection, analysis of information and its fixation in databases.
   2. There should be a reliable cellular communication between all rapid response units in the emergency zone.

   Further research is focused on the creation of fast-deployable radiation monitoring modules and mobile aerial photography complexes using drones in the emergency zone.

   Introduction. Electric machines, diesel installations, pumping units and fans, as well as working bodies of dredgers (pipelines, scoops, rippers, etc.) are the main sources of noise and vibration on watercrafts. Moreover, the main harmful factors in the operation of floating cranes and dredgers are both the vibration itself and the accompanying phenomena of infrasound and structural noise. One of the most urgent tasks for the introduction of technosphere safety methods on watercrafts is to reduce the harmful effects of vibroacoustic factors on the health of personnel.

   The research objective is to improve the working conditions of watercrafts drivers by introducing the method of designing vibration protection systems proposed by the authors, taking into account both the external factors (ambient temperature) and the dynamic characteristics of vibration damping materials.

   The possibility of choosing the most rational vibration damping material based on the engineering calculation of the required vibration insulation is shown.
   Materials and Methods. A passive method of vibration control has been applied, in which elastic elements and vibration damping material are used in the watercraft design. The sources of noise and vibration have been identified, and their actual exposure levels have been determined. The analysis of dynamic characteristics and properties of vibration damping materials is carried out. The factors influencing the efficiency of vibration damping are revealed.
   Results. A design scheme of the vibration damping model at the workplace of the watercraft driver has been developed. An analytical database of dynamic characteristics and properties of vibration damping materials has been created. An engineering method for calculating the effectiveness of vibration insulation has been adapted to watercrafts. The calculations of the effectiveness of vibration insulation using various vibration damping materials of different thicknesses have been performed, on the basis of which the advantages of vibration damping flooring made of elastomeric plate VEP20 have been proved.
   Discussion and Conclusion. The engineering methodology developed in Excel for calculating the effectiveness of vibration insulation is automated and has a user-friendly interface. This allows you to calculate and reasonably select multilayer structures taking into account the ambient temperature, as well as the dynamic characteristics of vibration damping materials depending on the spectrum of noise and vibration. The results obtained can be used in the design of vibration protection systems for watercraft drivers.

   Introduction. Noise and vibration in railway transport is a dangerous type of pollution for both the workers and the environment. It is important to carry out a comprehensive analysis of the effects of noise and vibration pollution on railway transport workers, the environment, and to consider available methods to minimize harmful effects created during the movement of trains. Safety can be achieved by ensuring regulatory noise and vibration levels.

   The work objective is to assess the safety of work during the operation of railway transport by improving the system of vibration damping pads and rail plates.
   Materials and Methods. In the course of the study, an analysis of the occurrence of noise and vibration, an assessment of their negative impact on railway transport workers and the environment was carried out. The available methods of noise pollution minimization are considered, the classification of noise and vibration control methods is described. The methods and means required by the regulatory documents on labor safety during the operation of railway transport were used in the work.
   Results. Based on the results of the study, it follows that there is a need to strengthen measures for comprehensive protection and minimization of harmful factors. The result of the study was the proposal to improve one of the applied methods of noise minimization — the installation of a vibration damping pad, for the production of which secondary raw materials in the form of rubber crumbs are used. The paper calculates the economic efficiency of one of the proposed methods of minimizing noise pollution and describes the positive effect after its application, considers available options for improving the sound absorption of rails.
   Discussion and Conclusion. Based on the results of the study, the positive economic effect of one of the proposed ways to improve the noise minimization method was revealed.

    Introduction. The relevance of this study is determined by the increasing need to ensure reliable protection of steppe and agricultural territories from possible fires with the help of innovative monitoring methods, the use of fire equipment, fire water supply systems and modern fire extinguishing means. Despite the introduction of new, modern and safe for the environment and people technical solutions aimed at preventing and extinguishing fires, there is still a need to improve the technologies used in the field of fire safety, which is a serious problem for the country.

   The work objective is to assess the technical feasibility of effective application of geo-positioning technologies and monitoring based on a set of special devices, model calculation of conditions for reliable fire blocking on steppe and agricultural territories, in particular, in fields with grain areas.
   Materials and Methods. The main research methods are the analysis of sources of normative-methodological and scientific-technical information, mathematical modeling, extrapolation to computational and graphic materials, physical experiment.
   Results. The data are presented for the development and implementation in the practical activities of fire departments of new technical solutions and technologies for monitoring and extinguishing steppe fires and fires in grain areas, the creation and development of material, technical, methodological and information base for the system of blocking geoecological fires.
   Discussion and Conclusion. The analysis of the causes of fires in steppe and agricultural territories allowed us to outline the main methods of their monitoring. Based on the study of prototypes, changes in the technical and layout characteristics of the main elements, a rational solution (know-how) for extinguishing fires in steppe and grain areas is proposed — a tractor-soil-thrower-fire-break maker. At the same time, it is concluded that it is also possible to increase the efficiency of multifunctional tracked or wheeled robotic complexes due to elements of navigation systems (geo-positioning) and monitoring using automatic process control systems.

   Introduction. Currently, the technical condition of ropes of cable-working machines is evaluated periodically according to regulatory documentation. At the same time, methods of visual and instrumental control are used, which depend on the skills and physical capabilities (vision) of the personnel performing the work. There is no unified system of continuous assessment of the technical condition based on a set of factors that does not depend on the human factor. As a result, emergencies occur even when all routine maintenance is carried out on time. To correct this situation, it is proposed to use a computer vision system and neural networks, which allows determining its suitability for further operation by risk levels based on the totality of detected and identified defects, with the interpretation of their results in the color scheme: green — acceptable, yellow — increased, red — high.

   The work objective is to propose an integral method for risk assessment of operating machines with rope traction when defects and their combinations are detected in a steel rope using computer vision while excluding the influence of the human factor.
   Materials and Methods. Training of the neural network was carried out on the basis of statistical data of defects obtained from the results of technical inspections of machines with rope traction, on sections of the rope, multiples of its six and thirty nominal diameters according to GOST 33 718. Indexing of risks in the color scheme was carried out according to GOST 55 234.3 to develop a strategy for steel ropes maintenance. A certificate of registration of a computer program was obtained for the neural network program code. The neural network processes visual and measurement control data based on computer vision.
   Results. An integrated risk assessment system has been created for the diagnosis of steel ropes using computer vision, which allows you to detect defects in steel ropes timely, assess the existing risk of further operation and give recommendations to specialists of operating organizations in real time. This will dramatically reduce the risk of accidents, injury and death of people at facilities using steel ropes.
   Discussion and Conclusion. The proposed integrated risk assessment system can be applied in any facility that uses rope traction. These are elevators for various purposes, funiculars, cable cars, cranes and many other machines. It should be noted that the estimated commercial cost of the system is low; therefore, the system is available to a wide range of consumers.

   Introduction. At present, great success has been achieved in the field of creating effective protective materials. Various non-metallic, metal-ceramic, and also composite materials act as armor elements. However, most of the armor elements of vehicles and personal protective equipment (PPE) are steels that, along with high ballistic resistance, have a high mass. In this regard, the relevance of the article is related to the possibility of lightening typical protective elements when using a material that has a structural organization like a natural ferrite-martensite composite (NFMC).

   The work objective is to evaluate the prospects of using steel with an oriented structure as an effective protective material when exposed to high-speed concentrated impact of high power in comparison with the steel materials used.
   Materials and Methods. The features and disadvantages of effective armor steels are revealed, a comparative analysis is carried out with steel oriented as NFMC. The assessment of 14G2 steel microstructure state with different hardening temperatures (730 °C and 760 °C) was carried out by the method of microstructural analysis. In relation to the topic of the study, the prospects for the use of low-carbon ferritic-martensitic steel were shown based on the laws of fracture mechanics and their comparison with the experimental data obtained on a sample of 14G2 steel with dimensions of 150 × 44 × 7 mm after testing for bullet resistance by cartridges with a steel core and armor-piercing cartridges with a tungsten core made of SVD rifles and AK-74 assault rifles of 7.62 mm and 5.45 mm caliber, respectively.
   Results. The possibilities of resistance to fracture of steel with an oriented ferritic-martensitic structure are evaluated in comparison with typical homogeneous and heterogeneous steel materials. The resistance of such steel is related to the nature of the development of fracture, expressed in the deceleration of the crack during delamination at the ferrite-martensite boundaries. When a delamination is formed, a crack expends energy on delamination and changes its direction, which subsequently leads to a complete stop of the fracture process.
   Discussion and Conclusion. The disadvantages of armor elements made of homogeneous and heterogeneous steel materials, associated with a high effective thickness of the protective element and the laborious process of obtaining a steel sandwich, respectively, can be solved by using oriented ferritic-martensitic steel. The data presented indicate a higher fracture resistance due to a special crack propagation mechanism, which is relevant in the development of armored vehicles. This makes it possible to reduce the total mass of combat vehicles associated with a decrease in the effective thickness of protective elements while maintaining the required class of resistance to high-speed impact loading, which will increase their mobility and reduce fuel consumption.