The application of the gas-dynamic method with the use of nonlinear dynamics to the calculation of an underground structure built into the lower floor on the impact of an air shock wave is considered, taking into account the collapse of the above-ground part of the building. It is known that one of the impacts on built-in underground structures designed to protect the population and territory from natural and man-made emergencies is the impact of a possible collapse or blockage from a higher building when exposed to an air shock wave. This task is relevant because the current methods are based on linear static calculation methods and involve certain assumptions, including when calculating for collapse, and all this can lead to difficult to estimate errors in the calculation results. Therefore, when solving these problems, which are highly non-linear and the processes under consideration themselves are fast, it is necessary to consider the use of more adequate and accurate methods based on more rigorous formulations, which is the gas-dynamic method using nonlinear dynamics.

Keywords: emergency explosive effects, air shock wave, impulse effects, non-linear gas dynamics, compression phase, rarefaction phase, underground structures, “Ambient” elements, Eulerian grids, progressive collapse, collapse of structures, destruction of structure

This article is devoted to the study of the effect of photocatalytic oxidation together with successive layers of sorbents (shungite, celite) on the efficiency of cleaning the supply air of premises from pollutants of motor vehicles. The studies were carried out with the help of a developed supply ventilation valve with air purification.

Keywords: intensity of ultraviolet radiation, shungite, zeolite, titanium dioxide, adsorption limit, supply air, ventilation valve

The article presents the results of the study of the ventilation device. A system of automatic control of the process of regulating air exchange in a residential area has been developed, which allows you to control an element of the actuator, which increases the productivity and efficiency of the ventilation device. An automated module of the process of regulating air exchange in residential buildings has been developed, designed to control the regulation of air exchange and its determination in residential buildings in different periods of the year. The software module implements recalculation of the main heat and humidity parameters of the air.

Keywords: air exchange, automated module, automatic control, ventilation device

Many sources of environmental pollution affect human health. The concentration of harmful substances constantly changes during the day when the weather conditions change in different parts of the territory. Residents can repeatedly enter and leave areas of increased pollution without noticing it with their senses when moving around the city. The authors analyzed the existing solutions for monitoring the quality of atmospheric air, as well as key sources of pollution and their distribution in the air. The interrelation of distribution of pollutants with weather conditions is noted. Preparation of data on the presence of harmful substances on the example of the city of Volgograd has been carried out. A method for organizing monitoring of harmful substances in the atmosphere using a software and hardware complex is proposed. The developed method was applied to create a specialized web application. The implemented solution allows to monitor the state of the environment using sensors and build routes around areas with a high concentration of harmful substances.

Keywords: environment, air quality, air pollution, ecology, monitoring, web application, eco-route, spatial data, route building, cartographic visualization

This article discusses the problems of determining the organs of air respiration on computed tomography images using convolutional neural networks of the U-NET architecture. The prospects of using neural networks in the analysis of medical images, as well as the use of the U-NET architecture for semantic segmentation of images are described. The structure of an artificial neural network based on the U-NET architecture is being formed. The structure of the layers of this network is visualized and the components of this structure are described. Special attention is paid to the description and implementation of the convolution process. The formula for determining the weight coefficients of the separation boundary is presented. Algorithms for the formation of an artificial neural network model and an algorithm for constructing layers are proposed. A method of increasing data for a training sample of images of medical images is considered. The image of the result of the determination of the chest organs and the corresponding mask are presented.

Keywords: convolutional neural networks, U-NET architecture, deep learning, image recognition, machine learning

The problem of atmospheric air pollution in the regions is considered. Attention is paid to the development and implementation of automated air pollution control systems. The developed information and analytical system has a two-level system and consists of two subsystems: a city information system and a regional information system. The proposed software allows you to perform calculations of surface concentrations of pollutants with the formation of a data bank, as well as the construction of maps of pollution in the region and histograms of the distribution of the level of adverse effects of atmospheric pollution on humans.

Keywords: atmospheric air, pollution, monitoring, information and analytical system, maps of the pollution of the region

The article provides a solution to the problem of optimizing air ducts with a rectangular cross-section for ventilation and air conditioning systems. Based on the use of the methodology for optimizing air ducts according to the above costs, the optimal proportions of the sides of the rectangular cross-section of the duct are determined, depending on the amount of material costs for the duct device and the cost indicators of its operation. The obtained optimal aspect ratios of the cross sections of the ducts are universal and do not depend on the location of the duct relative to the system fan. These conditions allow, at the design stage of the ventilation system, to assess the degree of optimality of the decisions made on the choice of the dimensions of the cross-sections of the ducts and, if necessary, to make appropriate changes to the design solutions of the ventilation system. The obtained optimality conditions allow them to be included in the calculation programs of the air.

Keywords: fan, air heater, ventilation system, heating and ventilation system, energy, power, energy efficiency, energy conversion, mechanical power flow, thermodynamic system

This article presents the results of a research work devoted to the use of ultrafiltration membranes in the technology of purification of natural waters and wash waters of a contact clarifier unit, as well as design proposals developed on their basis for the reconstruction of existing water treatment plants.

Keywords: membrane technology, ultrafiltration, membrane module, natural water treatment technology, flushing water treatment technologywater treatment facilities, patent research

This article gives an overview of the operation of dehumidification plants located in indoor ice arenas. Since at the moment the operation of such facilities does not include control of such parameters as CO2 content, the possibility of implementing this task using the existing equipment is considered. A method of setting the automatics of maintaining the CO2 level in the set parameters is given. The principle of dehumidifier operation and problems of CO2 level control are considered. The method of tuning the control loops is also described. The use of CO2 controlled dehumidifier equipment will create comfortable conditions for the occupants of the ice arena, which in turn will lead to a reduction in energy and heat consumption.

Keywords: automatic control system, control loop, control object, process stabilisation, air drying, air drying plant

The article raises an urgent problem for large cities - the fight against the negative consequences of road transport. The importance of urban planning measures to reduce the accumulation of emissions, as well as green spaces to reduce the concentration of dust content of harmful substances in urban areas is considered. The data of CO concentration near the mainline territories in 95 studied points were analyzed.

Keywords: road transport, dust, gas-protected green areas, leaves, green spaces

Monitoring of aerosols in the atmospheric air of residential areas of settlements ensures their environmental safety. Aerosol particles are capable of adsorbing various compounds, including metals, on their surface. It is known that heavy metals from the environment can penetrate into the human body and contribute to the development of various diseases. In this connection, their monitoring is relevant to ensure the environmental safety of residential areas of settlements. The purpose of the study was to study the indicators of the number and mass fraction of particles in the Sredneakhtuba district (Sredneakhtuba district, Volgograd region) for the spring-summer of 2019 in comparison with the conditionally clean zone. The material of the study was the leaves of Prunus armeniaca with aerosol particles. Leaves of Prunus armeniaca were placed in a glass container with 250 ml of distilled water, stirred for several minutes with a glass rod to wash particles from the surface of the leaves. As a result, aerosol suspensions were obtained, which were studied in terms of the number of particles and their mass fraction. The results obtained indicate almost the same amount of aerosol particles (PM10) in both territories. In terms of the mass fraction of aerosol particles (PM10), there is a significant excess of them in the experimental area. This fact may indicate the presence of metallic impurities in the aerosols of the residential area of ​​Srednyaya Akhtuba. At the same time, it should be noted that the high values ​​of the number of aerosol particles in the conditionally clean zone cast doubt on its status as a clean zone, since within a radius of 25 km. there is no anthropogenic load on it. The detected values ​​of aerosol particles give grounds to assume the action of a random factor (the introduction of aerosol pollution by transit air), or the action of an unknown natural source of pollution, which requires further research and study of the territory of a conditionally clean zone in combination with geochemical studies, etc.

Keywords: environmental monitoring, environmental risks, aerosols; number and mass fraction of particles

Porous media can be used as heat transfer intensifiers in the petrochemical, refrigeration, food, energy, and other industries. In this paper, heat transfer in a porous medium with a pulsating flow is studied numerically. The simulation was carried out in the AnsysFluent software product. The porous medium was represented as a two-dimensional channel with square tubes. The working medium was air and water. The heat transfer and hydraulic resistance of a porous medium in a pulsating flow are determined for different porosity and fiber diameter depending on the Reynolds number, Prandtl number, frequency and amplitude of pulsations. It is shown that with an increase in the intensity of pulsations, an increase in heat transfer occurs. Heat transfer intensification essentially depends on regime and geometrical parameters. Several empirical correlation are proposed for calculating heat transfer and the degree of heat transfer intensification for symmetric and asymmetric flow pulsations. The thermal-hydraulic efficiency is determined for the same Reynolds numbers and powers for pumping the heat carrier in a porous medium with symmetric and asymmetric flow pulsations.

Keywords: heat transfer, pulsation flow, porous media, mathematical modeling, thermal-hydraulic efficiency

This article is devoted to the study of indoor air quality in a higher education institution: assessment of the distribution patterns of suspended solids by equivalent diameters (RM0.5, RM1, RM2.5, RM5 and RM10).

Keywords: indoor air, indoor air quality, air pollution, dust, solid suspended particles, PM2.5, PM10

Refrigerating machines are designed to cover peak heat generation in public buildings. At the same time, peak loads are often short-term and most of the time the refrigerating machines operate at 40-60% of their maximum capacity. The article deals with the issues of uneven cold consumption on the example of a sports complex located in Volgograd. When designing the air conditioning system of the games hall, a cooling system with the use of "chiller-fan coils"is used. An effective solution to reduce costs is to include a cold storage battery in the cooling station circuit. The use of a cold storage battery allows you to reduce operating costs.

Keywords: cooling system, air conditioning system, refrigeration machine, cold storage, energy consumption, peak loads, variable energy consumption

The results of studies of the kinetics of the iron-catalytic oxidation of hydrogen sulfide by atmospheric oxygen in a reactor with a membrane separator are presented. The studies were carried out on a laboratory experimental complex. The dependences were obtained experimentally showing the effect of the catalyst dose - Fe (OH) 3¬, the pH of the medium, and the contact time of the water being purified with the reaction medium on the effect of water purification from hydrogen sulfide.

Keywords: hydrogen sulfide, iron catalytic oxidation, air oxygen, iron hydroxide, membrane separation, ultrafiltration