No abstract

Design proposals usually contemplate the corrosion protection of all metal elements of hydraulic structures by varnish and paint coatings. The large metal elements of the spillway gates, the maintenance gates for the hydraulic turbines, and the trashracks are installed and painted at the construction sites. Repair of the varnish and paint coatings is carried out every 3-4 years. The restoration of such coatings requires a large expenditure of labor and funds in the carrying out of all the auxiliary work connected with the disassembly of the gates and trashracks, installation of the maintenance barriers in the grooves, transportation of the disassembled gates to the maintenance areas, and installation of these gates in special jigs.The maintenance and painting costs for the spillway gates and trashracks atthe 22nd CPSU Congress Volga hydroelectric plant were of the order of 365,000 rubies per year. In order to develop a corrosion protection method having a long service life, the plant operators and the Gipromorneft' Institute carried out investigations on the possibility of using for this purpose a metallic coating made from aluminum. During 1967During -1970, tests on a metallic zinc-aluminum coating for the spillway gates were carried out under operating conditions at the plant. At three zones (above water, in the variable level zone, and under water), tests were conducted on samples measuring 100 x 150 ram, with a 50-~-thick zinc coating followed by a second 150-1~-thick aluminum coating. Simultaneously with the samples having the zinc--aluminum coatings, tests were carried out on the same samples with two additional types of polymer coatings applied on them: ethynyl varnish, and varnish made from gD-6 epoxy resin.The samples were coated twice with varnish: with solutions having viscosities* of 12 and 20 see. The thickness of the surface layer of the composition did not exceed 50~t.

Introduction. The reasons for the formation of an increased amount of condensate in the exhaust system of a car at a low ambient temperature are considered. Since the speed of the vehicle is one of the factors that determine the heating of the exhaust system and the formation of condensation, an experimental study was carried out to determine the temperature of the elements of the exhaust system at various vehicle speeds.The purpose of this study: to establish the features of the temperature change of individual elements of the exhaust system, depending on time at different vehicle speedsMaterials and methods. The sequence of the experimental study consisted of starting the “cold” engine, accelerating the car and then moving the car at a constant speed for 20 minutes. Simultaneously with the start of the engine, the temperature of the elements of the exhaust system was recorded. In this study, thermocouples were used to measure the surface temperature of the exhaust system. Experimental studies were carried out on a Toyota Camry with a gasoline engine in the climatic conditions of the Perm Territory.Results. The dependences of the temperature of the exhaust system elements on time were obtained at different speeds. In an experimental study, it was found that the temperature of the elements of the exhaust system is established within 8-12 minutes from the start of the vehicle at a constant speed; the rear muffler has the least surface heating, and therefore the greatest probability of the formation and accumulation of condensate.Discussion and conclusion. The analysis of the peculiarities of the change in the temperature of the exhaust system during the movement of the vehicle in conditions of low ambient temperature is carried out. The established patterns can be used to obtain information on the processes of condensate accumulation in the exhaust system and are aimed at predicting the amount of condensate accumulation in the exhaust system; to develop new solutions to ensure reliable operation of the exhaust system.

Currently operation of cars in large cities in winter is the most unfavorable from the point of view of the risk of blocking the exhaust system by condensate accumulated in it. Frequent starts during relatively short period of time, or the cycle of start-up – short run – and subsequent long-term parking at low temperatures are dangerous because the exhaust system does not have time to warm up and remove the accumulated condensate. Daily operation in such modes contributes to rapid accumulation of condensate, and subsequent long-term parking at ambient temperatures below 0˚C are equally dangerous because, depending on the design features of the exhaust system elements, condensation may occur and freeze in the exhaust system, icing can occur inside it or at its exit, causing inability to start the engine. Given that most of the territory of Russia is located in the areas of moderate and cold climate, the relevance of studies, aimed at identifying the patterns of condensate formation and accumulation in the exhaust system, at adjusting on this basis the frequency of condensate removal from the exhaust system, as well as at optimizing the design parameters of the exhaust systems, is quite evident. The objectives of this study were: to identify the features of changes in temperature of the elements of the exhaust system when the automobile engine warms up at low ambient temperature, the effect of various modes of the heater operation on the temperature of the elements of the exhaust system, as well as the features of the temperature change of individual elements of the exhaust system depending on time for various ambient temperatures. To achieve those objectives a series of experiments has been conducted to study the process of starting the «cold» engine, and of its warming up in idle mode. The found dependencies can be used to develop methodology to adjust the recommended periodicity of warming up of the exhaust system, as well as a model of a device that will ensure the absence of condensate in exhaust systems during the operation of cars in large cities during winter period.

Government designated the development of cities and urban agglomerations among measures in the field of regional development. In this regard, it should be understood how to evaluate the results of policies for the development of cities and urban agglomerations, what effects can be expected and predicted. The article considers the features of agglomeration development assessment methods. The topic of agglomerations is currently relevant – in the strategic planning documents of Russian regions, agglomerations are increasingly present every year. Federal, regional and municipal authorities speak about their development. The article presents methods for assessing the development of agglomeration in Russia. A hypothesis was put forward that there is no unified methodology for assessing agglomeration growth in Russia. We considered the following methods: the indices used in the research of PricewaterhouseCoopers consulting agency, the Institute for Urban Economics and the urban environment index, created as part of the implementation of the May decree on the strategic development of the Russian Federation until 2024 and the national project Housing and Urban Environment. Based on the results of testing the hypothesis, conclusions are drawn and possible ways to achieve positive changes are considered.