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The paper considers the influence of thermal boundary layer on the thermal conductivity coefficient of building materials. The influence of thermal boundary layer on the thermal characteristics is shown on the example of cellular materials such as foam concrete, gas silicate and vacuum-powder thermal insulation materials.New ideas about regularities and mechanism of action of such factors as pore size, thickness and composition of interstitial partitions on thermal conductivity of porous materials are proposed. The thermal characteristics of porous systems were analyzed using the theory of similarity (calculation of Grasgoff, Rayleigh, and Prandtl criteria). Calculation of these criteria showed that in cellular materials with pore diameter up to 4 mm the convective component does not influence the heat transfer coefficient. The thermal boundary layer, a low-moving thin layer of gas adsorbed on the inner surface of the pore, has a great influence on the heat transfer processes in the pore. The paper considers the structure of the thermal boundary layer from the approach of the electrical surface properties of the pore and the gas in it. It is shown that the structure of the thermal boundary layer depends on the surface charges of the solid phase and gas. In the environment of air or oxygen denser and more homogeneous in structure thermal boundary layer will have materials, which pore walls will have an effective positive charge, and the thermal boundary layer of materials with a large negative surface charge will be loose, inhomogeneous. In hydrogen medium, on the contrary, materials with an effective negative charge will have a denser and more homogeneous thermal boundary layer structure.

In this paper presents the essence of international cooperation in the higher education system, the content, opportunities, some directions and aspects of developing effective relations based on this joint cooperation relationship, and the methods of its implementation are sufficiently described on the example of the system of higher education institutions in our country. Also, research idea and implemented results aimed at interdependently harmonizing, integrating, coordinating and improving foreign cooperation relations between high education organizations of the two countries in the higher education system are highlighted. Also, the conclusions aimed at the development of educational-cooperative relations of students in foreign countries in the higher education system are stated, the results of the questionnaire survey conducted among students are highlighted, and the usability aspects of cooperative relations are proposed based on these results.

The instantaneous, average, and critical speeds of vehicles passing through the Kamchik pass were determined in this article. The law of critical speeds of safe movement of the traffic flow has been developed. The research results on determining the speed of movement of vehicles of different categories in mountain conditions are presented. To ensure safety, depending on the speed of the vehicles and the condition of the road surface on the dangerous areas of the mountain road, recommendations are given on the speed limits and road signs to be installed.