Vol 11, No 1 (2021)

The article presents a brief overview of the life path of the Swiss mathematician and mechanic Leonard Euler, considers the history of the emergence of the formula for calculating stability, shows options for taking into account the fl exibility of an element in the calculations of reinforced concrete structures, the disadvantages of the Euler curve and the features of its application in relation to structures made of high-strength concrete and concrete hardening under pressure. An example of the result of using a non-linear deformation model in the calculations of eccentrically compressed reinforced concrete elements with the introduction into the algorithm for calculating a coeffi cient that takes into account the eff ect of buckling (defl ection) of an element on its bearing capacity is given.

One of the options for optimization in the activities of the construction industry plants is the improvement of the composition of concrete mixtures, which requires control measures to assess indicators that ensure the reliability of operation of concrete and reinforced concrete structures. The strength of concrete in standard control cubes is at the same time the dominant parameter that determines the prospects of changes in production. The presented work presents the results of a comprehensive assessment of experimental concrete on cubes, prisms and reinforced concrete beams.

This article discusses the issue of determining the value the average wall temperature of the plate of a recuperative heat exchanger type “air-to-air” with a corrugated mesh insert based on the results processing the data of a physical experiment to determine the thermohydraulic characteristics such heat exchange surfaces. It has been established that the temperature fi eld of heat exchange surfaces of this type is nonuniform, depends on the conditions of heat exchange and hydraulic regimes of air fl ow. Therefore, the adoption of the arithmetic means value of the measured surface temperatures as the calculated average temperature of the heat exchanger wall entails signifi cant errors in the subsequent processing of experimental data and fi nal the values of the heat transfer coeffi cients, the values the Nusselt criterion and the criterion equations of heat transfer. It is proposed to determine the average value the wall temperature of the heat exchanger based on the results of measurements the wall’s temperatures, the estimate of the coordinates the center of distribution the results of measurements the wall temperatures, the equations of heat balance and heat transfer.

Currently, the Strategy for the development of the fi shery sector of the Russian Federation for the period up to 2030 has been approved. To implement this strategy, the construction of new and reconstruction of existing enterprises is planned. Wastewater from fi sh processing contains a large amount of scales, remnants of entrails (liver, intestines, ovaries), proteins and lipids. Therefore, when developing a treatment technology, it is necessary to pay increased att ention to mechanical and physicochemical pre-treatment of effl uents. This article summarizes the experience of foreign and domestic research on mechanical and physical-chemical wastewater treatment. Also presented are the results of studies on wastewater treatment of two fi sh processing enterprises. The use of Al2(SO4)3 at a dose of 50 mg/l for Al2O3 gave the best results in a laboratory experiment.

The preservation of the historical, urban planning and architectural heritage of the central territories of St. Petersburg requires a special approach to solving the problems of reconstruction and renovation of the historical urban environment. The modern period, characterized by active reconstruction of the historical center, puts forward new requirements for the preservation of cultural heritage sites. The att itude to history as an experience, on which modern practice should be based, presupposes the disclosure of historical architectural and urban planning processes on the basis of systematization of existing and fi lling in missing information. This allows us to analyze the spatial and temporal transformations that the city underwent in the course of its development. Revealing the internal laws of the genesis of these processes is of great importance. The article analyzes the state of urban landscapes within the boundaries of the historical territories of the Petrogradsky district of St. Petersburg.

The article is devoted to the problem of adaptation of the living environment of the population of large and largest cities to the vital and dangerous challenges of the new coronavirus pandemic. The author suggests that historically developed cities in their traditional hypostasis have a certain” anti-epidemic “ potential of morphotypological genesis, which must be taken into account, it is advisable to use and it is desirable to increase in the extreme situation of the global COVID-19 epidemic. The working hypothesis of the study is formulated on the basis of the results of monitoring the data of the offi cial St. Petersburg statistics, which refl ect the dynamics of the incidence of new coronavirus infection among citizens, starting from March 2020. According to these results, the most stable epidemiological situation persists in the historical suburbs of the” northern capital “ and its central administrative districts. The center of St. Petersburg was originally developed as a “conglomerate of sett lements” - pre-industrial and proto- industrial urban planning morphotypes that have been inherent in the Russian urban planning culture since ancient times. Urban sett lements, which preserved their planning characteristics in the course of a historically predetermined morphotypological transformation, became the basis for the formation of a set of spatial loci in the structure of a megalopolis - separate components of the urban landscape, within which, if necessary, the introduction of stringent control measures and epidemiological situation in St. Petersburg, it is possible to protect “idealizations” quality of urban life and where work most eff ectively medicareinsurance “antipandemic” sliders “disaggregation”, “distancing”, “disinfection”.

The article for the fi rst time carried out a comprehensive analysis of the architecture of rural houses of clergymen in the middle Volga region and the Southern Urals in the 19th - early 20th century. The materials of construction, planning, composition and stylistic features of the architecture of these buildings in the region have been studied. Houses made by local carpenters and designed in St. Petersburg are considered. Changes in the architecture of such buildings over time have been revealed. Examples and descriptions of the architecture of diff erent types of wooden houses of clergymen are given. The most detailed complex of buildings at the church of Nicholas the Wonderworker in the village of Epifanovka. The features of the interweaving of “red-brick” and neo-Russian architectural styles in the decoration of the buildings of this complex have been analyzed.

The article is devoted to the work of Irving John Gill during his heyday, and then in conditions when the principles of modernism discovered by him, due to the lack of society’s need for new architecture in the United States, were not needed in this country - from 1909 until his death in 1936. New technologies used by Gill in the construction of public and residential buildings from concrete are described as well as his unsuccessful participation in the Panama-California World Exhibition of 1915-191, the construction near Los Angeles of the “ideal” city of Torrance and end-of-life projects. The reasons why Gill did not become the leader of the American and one of the leaders of world architecture are discussed, and his work is still controversial.

The article is devoted to the concept of an associative landscape and the phenomenon of the visual nature of its perception. The aim of the work is to study the sign-symbolic images of nature on the example of a cultural landscape and their visualization of graphic design. The article examines the features of associative landscapes, the semiotic concept of the cultural landscape and its semantic reading as a text, the concept of semiosphere and noosphere. The object of the research is the associative landscape as a special type of space perception based on a visual-semiotic language. The subject of the research is the cultural landscape as a visual-spatial category, expressed in sign-symbolic images and directly related to the natural environment.