The issues of optimization of ribbed reinforced concrete slabs with prestressing of reinforcement, taking into account geometric, strength and cost indicators, are considered. The study was car-ried out on the basis of an analysis of the sales market for building materials, the basics of rein-forced concrete resistance and the provisions of regulatory documents, design activities in the Russian Federation, as well as the works of domestic and foreign scientists. The research method is structural-analytical analysis taking into account the relationships of the factors under study. Analytical and graphic materials are presented, revealing the regularities between the geometric dimensions and the cost of components. The proposed method for determining the efficiency of a structure, taking into account the cost indicators of materials, indicates the feasibility of its ap-plication in design practice. Recommendations for design are given to ensure that structures of the minimum cost are obtained and that meet the requirements of strength and durability.

Keywords: reinforced concrete, strength, structure, reinforcement, diameter, price, cost, efficiency, dimen-sions, analysis, element

The article presents the results of an experimental research on the effect of the pulsating mode a capacitive heat exchanger with an active pipe part on the convective processes heated fluid. Described dignity capacitive heat exchangers. The research was conducted using a thermal imaging surveys. Compares two modes: stationary and pulsating. The method of experimental data processing, based on the analysis of fluid layers. A regression analysis allows to determine the dependence of the relative distribution of the temperature difference between the layers of fluid in the studied mode. The obtained regression equations were presented in the form of an exponential function and harmonic. The effect of pulsing regime on the process of convection in the upper quarter of the heating zone in a capacitive heat exchanger. The study showed the advantage of the capacitive heat exchanger with an active pipe part is often compared with the classical heat exchanger in part the speed of convective processes in the fluid to be heated.

Keywords: capacitive heat exchanger with an active pipe part, pulse heating system, convective process