This paper reports on the results obtained on the diagnostics of a steam pipeline of a thermal power plant; it analyzes the effect of thermal fatigue on the structure and properties of the 12Kh1MF steel and possible reasons for the emergency destruction of steam pipeline elements before the exhaustion of economic life. Ultrasonic testing and additional heat treatment are proposed to be used for the detection and elimination of structural inhomogeneity in the metal. The applicability of statistical technique to analyzing data on the loading history of a steam pipeline is studied, which enables us to evaluate the damaging effects of loading cycles and to develop a plan of preventive measures, as well as to increase the accuracy of predicting the residual life of steam pipeline elements.

Keywords: metallic structure, diagnostics, degradation, steam pipeline, thermal fatigue, microstructure, mechanical properties, residual life

Reducing energy consumption in the design, installation and operation of engineering networks is implemented in the process of implementing investment construction projects. An energy service contract, like any economic agreement, requires a feasibility study. When strengthening the thermal protection of a building, it is necessary to determine both the design of the fences and translucent structures, and the payback period of the investment. The objective of the research is to develop and analyze a mathematical model of heat losses depending on the characteristics of the resistance to heat transfer of walls, windows and balcony doors. Classical dependencies do not allow applying standard mathematical analysis procedures. It is proposed to use a power function that assumes the availability of differentiation. The paper substantiates the form of such a function and provides an extended analysis of the effect of changes in the resistance to heat transfer of building structures on the transmission heat losses of a building, which allows arguing for the adoption of optimal technical and economic decisions.

Keywords: energy-saving construction project, thermal protection of buildings, indifference curves, mathematical model of heat loss

Practice shows that today the main trend in the development of the modern construction industry is associated with the expansion of the use of cast-in-situ reinforced concrete. In many cases, cast-in-situ reinforced concrete has better construction and technological properties (compared to precast concrete, metal) and allows you to freely implement a variety of architectural solutions with economic benefits. In turn, modern advances in the technology of concrete work would not be possible without the appropriate technical base. This article analyzes the use of construction machines in the construction of a cast-in-situ reinforced concrete skeleton of civil buildings on the example of objects realized in Yekaterinburg. A study was conducted, according to the results of which the manufacturers of construction equipment were identified, as well as the technologies prevailing in monolithic housing construction in the city. According to the terms and cost of construction, which are the defining elements of the construction sector, one indicator was allocated for a technical and economic comparison, the results of which determined the need to develop a comprehensive feasibility study of the use of construction machines in the construction of cast-in-situ load-bearing reinforced concrete structures, as well as the development of methods for selecting machines, which in the future will reduce the construction time of the cast-in-situ skeleton of the building, increase the payback of monolithic civil housing construction and the efficiency of construction from cast-in-situ reinforced concrete.

Keywords: civiс building, cast-in-situ reinforced concrete,construction machine, load-bearing structure, technical and economic comparison, concrete mix, building skeleton, construction machine, construction, civil engineering

Suspended ceilings constructions can improve the sound insulation of air and impact noise in civil buildings. To minimize the volume of the room, two types of suspended acoustic ceilings are most often used. They are: with the attachment of the structural shell of the ceiling close to the floor slab, and at a low suspension height. The influence of the slab's surface density on the correction to the sound insulation, which is created by the suspended ceiling, both in the first and in the second type, is considered. A method for a correction calculation for the sound insulation due to a suspended ceiling in these cases is given. At a minimum height the method is based on taking into account acoustic power's radiation coefficient of the shell. While for the low suspension height the method deals with the vibration's transmission from the floor slab to the ceiling's shell through the air layer and through the metal fasteners, that in this case become acoustic bridges. As a result, the formula of frequency response for sound pressure lowering, due to the sustained ceiling structure, is obtained. The influence of plasterboard suspended ceiling's perforation on the sound insulation of the entire floor structure is evaluated.

Keywords: suspended ceiling, impact noise isolation, airborne noise isolation, acoustic radiation power, limit frequency, acoustic bridge, acoustic impedance, vibration velocity level, porous and fibrous material, perforated plasterboard

The possibility of using nonlinear effects in hydroacoustic systems with parametric radiation mode for profiling the bottom and bottom sediments attracts the attention of both domestic and foreign specialists. The use of parametric antennas in hydroacoustic equipment allows, due to their high directivity and low side field level, to increase the information content and accuracy in detecting and determining the coordinates of underwater objects, and to obtain additional features for recognition. The efficiency of using a parametric profiler for solving problems that require high resolution is justified. A block diagram of a parametric profiler for studying the layered structure is developed. The features of the signal generator and the amplification unit are considered. The characteristics of the radiating antenna were measured under laboratory conditions. It is shown that the directivity characteristic is constant in the operating frequency range and the acoustic power at the output makes it possible to solve the tasks of sounding up to 10 m into the ground. A record of the soil profile was obtained, confirming the operability of the system. In the future, the results will be used in full-scale conditions with the use of cepstral echo processing.

Keywords: profilograph, parametric antenna, kepstr, block diagram, signal generator, power amplifier, directional pattern, amplitude-frequency response, pump antenna, ground profile

In this work, a survey of the hot water supply system from the boiler house No. 2 of Energoservice LLC was carried out. The daily schedule of hot water released for sanitary needs is given. The existing scheme of the boiler burner on-off control system is considered. A method for stabilizing the hot water preparation process by increasing the burner shut-off settings at the hour of the highest water consumption is found and described, and their values are found experimentally. A scheme has been developed, assembled and tested that allows you to adjust the operating mode of boilers at a strictly specified time of day. The proposed measure allowed us to solve the problem of selling hot water to consumers of a given quality during the maximum water intake period. In addition, the reduction in the generation of thermal energy for heating hot water at night and on weekends allowed for a 13.87% reduction in natural gas consumption in 2020.

Keywords: hot water supply, fuel consumption, pumping station, circulation line, conditional fuel, mode, boiler unit

The article discusses the natural factors that should be taken into account when designing highways. The following factors have a significant impact on the design of roads: terrain, engineering-geological and hydrogeological structure, climate, etc. The variety of natural factors is taken into account comprehensively in the design. They also take into account the negative impact of road construction on the environment. The terrain has an impact on fundamental engineering decisions, the volume of construction work, and ultimately not only on the construction cost of the highway and transport operating costs. In relation to the design of roads, there are five categories of terrain according to the complexity of road construction. Depending on the geological conditions, sometimes an extension of the highway route is used or expensive engineering measures are provided. It should be borne in mind that the use of the latest materials, road structures and new techniques for the production of construction areas is becoming less and the problems of seasonality of road reconstruction are becoming less relevant.

Keywords: highways, terrain, climate, slope, natural factors, engineering and geological process, surveys, tortuosity, lengthening of the route, road clothing

The article is devoted to the possibility of applying the methods of successive approximations in the analysis of the instantaneous scheme of the traction network. The described approach allows to improve the accuracy of modeling dynamic modes of operation of traction power supply sections, and also allows to significantly improve the process of modeling diagnostics and control systems of electric rolling stock at the design stage based on a more accurate model of dynamically changing input parameters of the traction network, depending on their required level.

Keywords: traction network, instantaneous circuit, diagnostics, simulation, recruitment model

The methodology of numerical experiment of laying with closed method by methods of horizontal-directional drilling, brown-screw drilling, forcing, microtonneling has been developed. Some features of the construction of cases for penetration by collectors under existing highways, including general information about the used materials of the cases, are given. A selection of controlled factors and experiment planning, system stability check, results reliability analysis was performed.

Keywords: collector, numerical experiment methodology, microtonneling, horizontal directional drilling, brown-screw drilling, puncture, forcing, motorway, case, reinforced concrete, metal pipes

The paper discusses approach to voice recognition, that allows to use tools of Google Cloud Speech platform for editing source code for programs, using audioprocessing, editing distances and substitution tables. The paper discusses issues of editing source code on mobile devices and the issues, which does not allow using tools from Google Cloud Speech platform directly, like not recognizing certain keywords. The paper suggests new method, which combines substitution tables and editing distances for solving the issues. This approach can be used for editing source code for programs, using mobile devices. The paper offers a prototypr of web-application, which allows to edit source code and uses this approach and, also, allows to submit changes to Github source code hosting platform and a popular instant messenger Telegram.

Keywords: voice recognition, mobile devices, source code analysis, formal languages, editing distances

This article discusses the theoretical order and practical solution of the problem of calculating the transverse vibrations of a thermosetting polymer self-supporting shell pipe " Furanflex».Сalculation scheme with a finite number of degrees of freedom.The pipe is evenly fixed in height.The procedure for creating a universal calculation algorithm for determining the natural frequencies of pipe vibrations is considered in detail.When creating an algorithm and calculating natural frequencies, determining coefficients, plotting plots, the Mathcad software package is used.When creating an algorithm and calculating natural frequencies, determining coefficients, plotting plots, the Mathcad software package is used. The article may be of interest to design engineers, specialists in calculating the dynamics and strength of structures and specialists of heat-generating companies and thermal power plants, teachers and students of universities in the construction industry.

Keywords: eigenvalues, polymer tube "furanflex", eigenvalues of the matrix

An experimental study of a quartz generator of the GK380-P-7VS-450M-3.3 s type was carried out.A description of the scheme and design is given. The results of the experiment are presented, including the frequency run-out, the frequency dependence on the supply voltage, and the output signal spectra for three different viewing bands. The following parameters of the output signal were obtained: the operating frequency of 450 MHz, the amplitude of the sinusoidal signal of 210 mV, the frequency run - out in 20 minutes of 550 Hz, frequency instability when the supply voltage changes 230 Hz, suppression of the second and third harmonics of at least 30 dB.

Keywords: quartz oscillator, frequency instability, frequency run-out, the amplitude of the sinusoidal signal, the spectrum of the output signal

This article discusses the theoretical order and practical solution of the problem of calculating the beam by the initial parameters method using the Mathcad calculation complex. The article describes in Detail and proposes the procedure for creating a universal calculation algorithm and program for any combination of vertical load. . Программа автоматизировано создает эпюры. The program automatically creates diagrams of internal force factors, displacements, rotation angles of beam sections.The article may be of interest to design engineers, specialists in calculating the dynamics and strength of structures, teachers and students of engineering Universities and the construction industry.

Keywords: method of initial parameters, beams, diagrams of internal force factors, beam movement, angles of rotation of sections

The paper is focused on research of an access control system based on the analysis of the thermal radiation of the user's palms using common components, it is shown that the use of multifactor biometric authentication based on the thermal image of the palms and infrared images of the user's veins allows to reduce the errors of the first and second kind during biometric authentication.

Keywords: biometric authentication, thermal palm print, access control system, infrared vein imaging

For the statically indeterminate systems under consideration, there is an optimal ratio between the load-bearing capacity of stretched and out-of-center compressed elements, in which the required reliability will be provided at the lowest value of the mathematical expectation of an external destructive load. It should also be noted that for statically indeterminate systems, the beginning of rebar fluidity is not a sign of destruction, but only indicates the beginning of an intensive redistribution of forces in it. Therefore, the values of C, do not refer to the beginning of the rebar flow, but to the complete exhaustion of the load-bearing capacity. The reliability of statically undetectable systems, including prestressed trusses, is always higher, all other things being equal, than that of statically definable systems.

Keywords: reinforced concrete, reinforced concrete structures, statically indeterminate systems, reliability