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Optimization of insulation of walling of building walls is proposed, taking into account the relationship of structural, heat engineering, operating parameters and economic indicators. The purpose of research is to determine the optimal value of the thickness of the insulation with the heat-insulating material of the object, taking into account the thermal energy released to it. The study used methods of mathematical modeling of heat transfer, an optimization problem. The results of the study of the influence of the thickness of the insulating material on the technical and economic efficiency of the building's consumption of energy resources and material costs are presented. The results showed a decrease in heat losses through the building envelope, consumption of heat and electric energy for the heating, ventilation system and reduced costs.

The article discusses the issues of using the technology of replacing inventory rails with rail lashes of a jointless track. For the production of works on the replacement of rail lashes, excavators on a combined course have been selected as the leading machines, which in recent years have been widely used in the production of works for the current maintenance and repair of the railway track. The paper presents the results of a comparative assessment of the use of rail lash replacement technology using attachments and using a pair of trolleys. In order to select the best technology for the production of works on the replacement of rail lashes, a methodology for assessing the economic efficiency of using a particular technology has been developed. The main indicator in the calculations were the given operating costs, taking into account the cost of the machine per unit of work, the cost of relocating the machine, the delay of trains, the wages of track fitters and the discharge of rail lashes. According to the results of the calculation, it was found that it is economically advantageous to replace rail lashes at the front of work up to 4 km using technology using a pair of trolleys, at the front of work more than 4 km, it is advisable to replace rail lashes using technology using attachments. The maximum economic effect when using technology with the use of attachments is achieved with a work front of 10 km. A comparison of the results of work on two technologies gives grounds to conclude that with a three-hour «window», the volume of work performed on the technology with the use of attachments is 1,7 times higher than the volume of work performed on the technology with the use of a pair of trolleys.