In this article, the authors consider the main aspects of maintaining the temperature and relative humidity of the premises of library collections and archive repositories using specialized engineering equipment. The preservation and preservation of material assets is designated as one of the priority tasks of preserving the cultural heritage of Russia. Conservation includes all types of activities and engineering support to guarantee the physical safety of any objects intended for long-term storage, such as library and museum. Currently, both the national program for the preservation of cultural values and the strategy for the development of librarianship have been adopted, including engineering methods for maintaining microclimate parameters for storage facilities and archives of various types: library, museum and federal purposes. Previously, the authors studied the reports provided on the preservation of library collections in Russia and abroad. It has been revealed that in a significant number of cases, the conditions for the preservation of both paper and other funds intended for storage and use as necessary to work with them are not provided. The authors conducted a study and analyzed changes in microclimate parameters when using central air conditioners of various configurations serving two separate sections of one library storage, which is a single-tier room type. The disadvantages of using a simplified basic modification of the central air conditioner based on the results of temperature and relative humidity control in each of the rooms, performed daily from January to June 2022, were confirmed. Variants of changing the configuration of engineering equipment with insufficient functionality with a limited area of the ventilation chamber are proposed.

Keywords: library, engineering equipment, central air conditioning, preservation of funds, conservation, microclimate, storage

The article deals with the distribution of air flow velocities for cities of compact configuration on the example of the city of Stavropol. The verification of the implementation of Weibull's law for different wind flow velocities in its various directions has been carried out.

Keywords: wind flow direction and velocity, atmospheric air, distribution law, Weibull's law, mixed Gaussian distribution, change in air flow velocities, time of day, compact city

Results of field tests of mobile dust meters of the AirExpert series based on optical sensors (OPC-R1 / OPC-N3) at the stationary air monitoring station "Shabolovka" State Environmental Budgetary Institution (GPBU) "Mosekomonitoring", Moscow, equipped with a dust analyzer (TEOM) series 1405 , showed that the measurement accuracy meets the requirements for instruments for measuring the quality of atmospheric air in populated areas. Mapping of atmospheric air pollution in certain areas of the cities of Obninsk, Dubna, St. Petersburg, Kursk, Moscow, Volgograd (2019-2024) was carried out, which made it possible to quickly assess the environmental situation in the study area in real time, thereby detailing the data from stationary monitoring posts.

Keywords: mobile dust meters, monitoring, reference device, measurement accuracy, pollution mapping, hyperlocal monitoring

Issues of environmental protection, in particular atmospheric air, protection of the population from the effects of pollutants living near the deployed construction works are relevant, as the volume of construction and commissioning of new buildings and structures increases, and there is a continuous development of equipment and technologies in construction production. In order to study the degree of air pollution of the construction site during 2020-2023, air pollution with fine dust particles PM2.5 and PM10 was monitored, namely the volume of dust emissions, their chemical composition to assess pollution from construction processes and equipment that produce these construction processes, taking into account the factors of background dustiness of the air environment of the territory, affecting on the health of construction workers and the population. Based on the results of the work carried out, it was determined that the highest concentration of dust and the volume of dust emissions are shown by earthworks. The results of this work, with practical accuracy.

Keywords: environmental safety, environmental monitoring, atmospheric air protection, ecology in construction, dust suppression, feasibility study, dust collection systems, labor protection in construction

This article highlights the theoretical results of analytical research in the field of the use of tethered balloons as carriers of barrier networks, which can be used as passive protection of particularly important civil and industrial facilities from unmanned aerial vehicles and other low-flying means of air attack. A diagram of an aerostatic barrier system, theoretically capable of countering air attack means, is presented. The elements of the methodology for determining the probability of damage to aircraft from cable type air barriers are presented.

Keywords: aerostatic air barrier system, unmanned aerial vehicles, tethered balloons, aerial protection of ground objects

At the present stage of increasing competition, the increased level of threats to the economic condition of business entities in any sector of the economy requires special attention. Enterprises of this industry annually emit aerosols of various composition and origin into the atmosphere: iron, vanadium, aluminum oxides, manganese oxides and other heavy metals. One of the components of safety is environmental safety and ensuring safe working conditions. The chemical composition of the dust-gas-air mixture of metallurgy enterprises is considered in the article, and the dispersed composition of aerosol emissions is determined. The data of the results of microscopic analysis of the fractional composition of dust based on the data of integral dependences of the density of distribution by equivalent sizes (diameters) D for the ingredients accepted for the study allowed us to determine the average median values of equivalent dust diameters.

Keywords: metallurgy, aerosol, electric steelmaking shop, dust-gas-air mixture, dispersion analysis, average median diameter, dh 50

The effectiveness of air purification with the following sorbents has been studied: crushed expanded clay with granule sizes up to 2-3 mm, zeolite with granule sizes up to 1-3 mm, activated carbon with granules up to 3 mm, the natural mineral pyrolusite as a catalyst, Portland cement prepared using various methods: with the addition of a 6% solution of table salt, with soaking of granules in 26%, 31% and 36% solutions of diethanolamine. Studies have shown that the most effective (98%) use of pyrolusite granules, Portland cement granules obtained after mixing Portland cement with a 6% sodium chloride solution, soaked in 31% diethanolamine and then drying the granules at a temperature of 125 0C.

Keywords: crushed expanded clay, portland cement, purification, supply air, sulfur dioxide, carbon monoxide, formaldehyde, granules

Models of open-loop and closed-loop systems for automatic control of air supply to a steam boiler are constructed. An open-loop system is modeled and, on its basis, a closed-loop system with a PI controller tuned to the optimum modulo is developed. The introduction of a frequency converter into the control system for more economical and gentle operation of the fan electric drive is considered. The developed system consists of models of a controller, a frequency converter, an asynchronous motor and a blower fan. The simulation results are presented, demonstrating the operability of the resulting system in compliance with the requirements for stability and speed. The modernized closed system has a number of advantages over the existing open one, and the described method of its construction can be applied when implemented at enterprises using air blowers.

Keywords: automatic pressure control system, automatic control system, closed system, open system, PI controller, modular optimum

An original approach to describe airflow in the thin conic diffusor is suggested. It is based on approximate analytic solution of continuity equation. In addition simplified model of turbulence is combined. Reliability of derived formula is confirmed by comparison with finite-element solution for designed experimental setup. The elaboration is intended to direct computer simulation of multiphase flow.

Keywords: dust-air mixture, aspiration systems, turbulence, finite element modeling, separation diffuser, digital twin

The purpose of author's researches - assessment of level of pollution by fine particles (PM10, PM5, PM2.5, PM1, PM0.5) of atmospheric air in territories of parks in Volgograd. Due to the fact that the parks operate year-round, research was carried out in the winter, spring-autumn and summer periods of the year. Research, in particular, was carried out in two parks located in the central part of Volgograd, where there are no industrial enterprises, and are adjacent to one of the largest city highways. Analysis of the particulate composition and mass concentration of fine dust in atmospheric air was performed using microscopic analysis and using Handheld 3016. At the same time, the temperature and relative humidity of the air, wind speed and atmospheric pressure were measured. Measurements were made in places with the largest concentration of visitors to the park at an altitude of 0.5 m, 1 m and 1.5 m, i.e. in the breathing zone of children, adolescents and adults. In the air environment on the territory of the surveyed park zones of Volgograd, there is no excess of the MPC in the atmospheric air for suspended matter RI2.5 observed, but there are cases of significant excess of the average annual and average daily MPC for RM10 particles.

Keywords: atmospheric air, park area, fine dust, maximum permissible concentration (MAC), dispersed composition

The problem of atmospheric air pollution by dust particles, along with the formation of greenhouse gases, covers many countries of the world. To monitor the state of atmospheric air, expensive and cumbersome monitoring stations are traditionally used, for which state organizations are responsible. The use of inexpensive sensor particle sensors that will allow real-time measurements at the border of the sanitary protection zone of industrial enterprises and on the territory of the residential zone opens up new prospects in the field of atmospheric air research. Currently, about 10 thousand inexpensive sensors operate on the territory of 75 countries of the world, which causes the involvement of citizens in the collection of data on the state of atmospheric air. The presented technology for monitoring the concentration of fine particulate matter can replace the traditional measurement method, but the question remains of the value of the data obtained in terms of their accuracy. This article discusses the factor influencing the deviation of the readings of the inexpensive Nova SDS011 solid particle sensor. To do this, the sensor was tested in real environmental conditions, experimental dependences of the concentration of dust particles of no more than 2.5 micrometers depending on humidity were obtained.

Keywords: atmospheric air, PM2.5, Nova SDS011 sensor, dust particle concentration, monitoring stations, relative humidity

Construction control at the stage of preparation for the commissioning of the object requires checking the quality of external enclosing structures according to the air permeability parameter. The GOST 31167 methodology available to specialists, as well as other similar methods, is based on the principle of creating and maintaining the required pressure drop in the room and beyond its boundary for a long time while simultaneously determining the flow rate of the air supplied for testing. The essence of this method is that it limits the possibility of quantifying the values of air permeability through specific sections of external enclosing structures and allows you to determine only complex indicators for one room or a group of rooms without specifying specific values of defects in various types of exterior walls, window fillings, door openings, and abutments. The proposed method of qualitative and quantitative assessment of air permeability is based on an additional analysis of the temperature fields of the internal surfaces of external enclosing structures while ensuring a given difference in pressure and temperature of the indoor and outdoor air entering the room by creating a vacuum. Conducting field studies is necessarily complemented by the results of numerical modeling of structures in undisturbed and defective states.

Keywords: non-stationary heat transfer, numerical modeling, calculation of temperatures in the defect region, analysis of temperature fields, air permeability resistance, experimental evaluation of air permeability

The article considers examples of atmospheric air monitoring in linear and compact cities. The issues of atmospheric air pollution are considered, examples of components of pollutants coming from stationary and mobile sources are given. The analysis of the monitoring system of cities with different urban planning is carried out.

Keywords: linear city, compact city, highway, pollution, monitoring, monitoring posts, motor transport, gas pollution, exhaust gases

The article assesses the impact of road transport on air pollution of roadside areas of a major transport highway in Volgograd. The road-car complex makes a significant contribution to air pollution by solid particles, significantly exceeding the background value. One of the criteria for assessing the impact of dust particles on the air environment according to the World Health Organization is the mass content of particles with a diameter of less than 10 microns (PM10) and 2.5 microns (PM2.5) in atmospheric air, which is normalized in the territory of the Russian Federation by hygienic standards. The fractional composition of dust particles entering the atmospheric air was assessed by the Microtrac S3500 laser particle analyzer, the concentration by the Lighthouse 3016-IAQ particle counter. The results of the dispersion analysis are presented in the form of the Rosin–Rammler–Sperling–Bennett function of the volume distribution of particles over diameters.

Keywords: dust, particle, dispersed composition, concentration, road transport, atmospheric air, transport highway

Air pollution in urban areas contributes to the development of various diseases among the population. In this connection, its environmental monitoring is relevant. Goals and objectives. The aim of the study was to study the redox potential of aerosols in the residential area of the village. Kuporosny (Volgograd, Sovetsky district) (experimental area) in comparison with the conditionally clean zone. The objectives of the study were to select aerosol particles in the leaves of apricot trees (Prunus armeniaca L.); preparation of aerosol suspensions from the leaves of apricot trees; study of the ORP of aerosol suspensions when they are infused for 5 minutes in distilled water; discussion of the obtained results. Methods. Leaves of apricot trees (Prunus armeniaca L.) in the amount of 10 pcs. placed in a glass dish, added 100 ml. distilled water, stirred them for several minutes with a glass rod to wash the particles from the surface of the leaves. As a result, aerosol suspensions were obtained, in which the ORP was studied. The ORP value was measured using electrochemical equipment (SevenCompact pH meter S220, manufacturer: Mettler-Toledo GmbH, Switzerland). Results. Established air pollution residential area in the village. Vitriol based on low values of the redox potential (Eh=30.03+0.27 (mV)) compared to the conditionally clean zone (Eh=140.83+0.81 (mV)). Conclusion. The results obtained indicate the predominance of recovery processes in the atmosphere of the residential zone of the village. Vitriol, the deterioration of its oxygen regime and the development of environmental risks for the population living there. In this connection, it is required to establish sources of pollution and develop appropriate environmental measures.

Keywords: aerosols, redox potential, environmental monitoring, residential areas, atmospheric air pollution