The mechanical strength of unreinforced abrasive wheels is determined by centrifugal and bending forces, but their distribution during reinforcement is unknown. It was assumed that the stresses are distributed evenly, but a comparison of calculations on the theory of elasticity and real characteristics on a special stand showed complete discrepancy. Tensile tests of the wheels made it possible to compare the stresses results in the circumferential and radial directions. Was found that the reinforced wheel is an anisotropic body. Anisotropy can be reduced by displacing one reinforcement mesh relatively to the other by angle of 45°. In this paper, a mathematical model of the stress-strain state of the abrasive reinforced wheel was developed, taking into account the anisotropy of its properties. To determine the centrifugal forces, the theory of elasticity for an orthotropic body is applied. The bending forces that arise in the working wheel were determined during solving the problem of the distribution of deformations in the anisotropic annular plate rigidly fixed along the inner contour. As a result of experimental studies, it was found that stresses reach 8...23 MPa, which can be compared with the ultimate strength of the wheel matrix. The elastic module of the wheel matrix is noticeably greater than the elastic module of the reinforcing mesh, which practically does not perceive the load at the initial stage. The developed mathematical model of the strength indicators for abrasive reinforced wheels makes it possible to predict their reliability and safe operation.

Today, a very urgent task is to analyze the water supply and quality of drinking water in Ukraine, the development of new normative documents, the improvement of existing water treatment technologies with the approximation of the standards of European countries.We based on the example of Kyiv conducted a preliminary analysis of the quality of water used for centralized water supply. The paper summarizes real hydrological information on surface water supply sources over a five-year period (the Kyiv Reservoir and the Desna River), data on the qualitative assessment of surface waters (ecological index, water pollution index), cause-and-effect relationships of environmental equilibrium, primary sources of pollution and pollutants, an analysis of the dynamics of water pollution, as well as the characteristics and volumes of discharges of pollutants Dnieper and Desnyanskaya water stations.

While conducting the ecological estimation of the hydro ecosystems (HE) condition of Tisza water basin, engineering ecological indices and their parameters are used. The system-basin research approach of the water basin based on systematization and data processing of the eco-logical monitoring for a long-term period is used. Such period allowed to set scientific regu-larities of naturally-anthropogenic hydro ecosystems development in the conditions of con-stant anthropogenic load on them.

No abstract

The problem of global climate change is one of the most important problems of society. Such relevance is due to the fact that the change in climatic parameters has a significant impact on the economic sphere, the ecological situation, social and political life, and the construction industry. The change in the parameters of climate systems has long been beyond doubt. In recent years, due to the perceived threat of global climate warming, interest in long-term interannual climate fluctuations has increased significantly. Therefore, one of the unquestionably relevant tasks is the monitoring of trends in changes in climatic indicators at the local (regional) level. It is these observations on a regional scale that allow us to detect cyclical fluctuations in meteorological values and further judge the change in the Earth's climate in general. When building urban quarters in difficult natural and climatic conditions, along with urban planning and architectural and planning methods of organizing residential structures, one of the key points is the correct selection of fencing materials and structures. Special attention should be paid to their physical properties, thermal conductivity, specific resistance, optical reflectivity, etc. It is also necessary to take into account the location of the construction site, because due to macro- and micro-scale climate-forming factors (radiation conditions, wind regime, form of meso- and microrelief, vegetation, soil, close proximity to the sea, surrounding buildings, etc.) and their due to joint influence in different areas of the city, the difference in temperature and humidity can be significant. The article examines the peculiarities of the manifestation of climatic changes for the city of Kyiv in the context of engineering and construction adaptation and the selection of building materials to create more comfortable living conditions for the residents of the metropolis. It was established that during the last decades in the city the average annual air temperature increased by 0.7–1.2°С, compared to the climatic norm. The most significant increase in the average monthly air temperature in the modern period in the city is observed in the winter and summer months. According to calculations, the average annual temperature will rise gradually and increase by an average of 2.0–2.5°С. On the basis of this, the necessity of conducting further research, creating scientific and practical recommendations, especially in the conditions of modern megacities, which are a factor in climate formation, has been proven. The article analyzes the impact of changes in climatic factors on the life cycle of buildings.