The results of the automated evaluation of the dynamic quality of grinding machines in the process monitoring system are presented. The transfer function of the dynamic system is analytically obtained, a formula for the frequency function is derived from it, on the basis of which models of vibration spectra are constructed, in which frequencies are present that are adequate to the real vibro-acoustic vibrations of the dynamic system of the machine when processing rings. For experimental evaluation of the dynamic quality of machine tools, integral estimates of the low-frequency components of the vibration spectrum are used, characterizing the relationship between the quality of processing bearing rings and the dynamic quality of machine tools.

Keywords: dynamic quality of the grinding machine, vibroacoustic vibrations, bearing rings, processing quality, monitoring system

Refrigerating machines are designed to cover peak heat generation in public buildings. At the same time, peak loads are often short-term and most of the time the refrigerating machines operate at 40-60% of their maximum capacity. The article deals with the issues of uneven cold consumption on the example of a sports complex located in Volgograd. When designing the air conditioning system of the games hall, a cooling system with the use of "chiller-fan coils"is used. An effective solution to reduce costs is to include a cold storage battery in the cooling station circuit. The use of a cold storage battery allows you to reduce operating costs.

Keywords: cooling system, air conditioning system, refrigeration machine, cold storage, energy consumption, peak loads, variable energy consumption

At present, despite the variety of mini-loaders in terms of purpose and type of work performed, the problems associated with the technology of snow removal from roads and adjacent areas remain relevant. Along with the continuous growth of the municipal machinery fleet, qualitative changes are constantly being made to its working equipment, aimed at increasing the productivity and efficiency of the snow removal process through the introduction of new rational and technical solutions.

Keywords: mini-loader, blade, snow removal, working equipment, snow cover, compaction, hydraulic cylinders, shock absorbers

The article describes the main technological features of strengthening subsidence soils by cementation. The features of quality control of work on strengthening arrays of subsidence soils by cementation are considered. On the example of a multi-storey residential building exposed to uneven deformations, the reasons for the violation of technologies during the strengthening of the foundation soils are analyzed. The results of laboratory and field tests of soils are analyzed as part of a re-examination of the foundations fixed by the cementation method during the construction of a multi-apartment three-section residential building. The actual results of laboratory tests are compared with the values set by the project. The diagrams of the location of pits near the building are given. The photos show the presence of cement veins. The causes of uneven deformations of the newly erected object have been established based on the results of a laboratory study of the fixed subsidence soil. It is noted that strict quality control of work on strengthening subsidence soils will allow avoiding emergency consequences during the construction and operation of buildings in the future.

Keywords: cementation of soils, subsidence soil, artificial strengthening of soils, injection, geocomposite, armoelement, drilling, testing of soils, construction control

Reducing the consumption of heat resources in construction and housing and communal services is one of the key tasks solved by design engineers. The increase in the thermal protection of buildings is determined by regulatory documents, but construction customers often require it to be strengthened without any feasibility study. The objective of the study is to develop a graphical-analytical model, the analysis of which allows you to choose the most optimal combination of heat resistances of the coating (walls) and translucent structures of a particular building object.

Keywords: energy-saving project, thermal protection of buildings, "indifference" curves, the method of the fastest descent

The article offers a solution which will enable to reduce dust pollution during earthworks in urban conditions. A special multi-functional mechanism is proposed enabling to perform several important preliminary processes simultaneously - improving an environmental situation on the site of earthworks. The ground surface damping during trench opening and soil unloading from a bucket into a disposal area will make it possible to reduce the fine dust pollution of the air surrounding a work location. The objective of the study is to develop a mechanism reducing the fine dust dispersal when performing trench and pit excavation. The novelty is that a mechanism of special construction has been proposed that can be mounted onto any machine in the construction line.

Keywords: earthworks, dispersal, technology process, trenching, single-bucket excavator, soil disposal area, trench, fine dust, air pollution, РМ 2,5, PМ 10

The results of verification of turbine and rotary gas meters used as measuring instruments in gas supply systems of industrial enterprises are presented. It was found that about 50% of calibrated meters exceed the requirements for the permissible values of the main relative error, as a rule, in the range of minimum gas flow rates. Ways to increase the service life of gas meters are proposed.

Keywords: gas flow metering, gas meter, verification, basic relative error, gas flow

The article provides the definition of a deep pit. The authors substantiated the need for fixing the walls of excavations with a depth of 3-5 meters and the development of methodological recommendations and reference data for the selection of optimal methods and structures used for enclosing the excavation. Wooden sheet pile is the most affordable and technically simple solution for fixing the walls of excavations with a depth of 3-5 meters. The authors calculated the structural characteristics of a wooden sheet pile for various soil conditions according to the method proposed by Professor E.K. Jacobi. The results are presented in a reference table, a fragment of which is given in the article. The developed reference data make it possible to assess the feasibility of using a wooden sheet pile without additional calculations. Engineers can determine the required cross-sections of the fence and struts, the immersion depth of the wooden sheet pile, the step of installing the struts according to the reference data.

Keywords: deep pit, fixing the walls of the pit, sheet pile, E.C. Jacobi method, pit collapse, pit slopes, earthworks, work safety, wooden sheet pile, accident

The issues of ensuring the reliable operation of bearing production on the basis of the organization of the process monitoring system (SMTP), based on the introduction of effective automated control and diagnostics of technological equipment, including processing modes and technical condition, active control of product quality in the manufacturing process, output characteristics of rings processed by the eddy current method, as well as making decisions on timely maintenance of equipment. The results of the inspection are stored in a report file generated in the eddy current device computer: information about each checked part is stored: the time of inspection, the type of part, the surface to be monitored, the number of the machine on which the part was processed. The results of eddy current control serve as the basis for monitoring the dynamic characteristics of the equipment by vibroacoustic vibrations. Based on the results of the control within the framework of the SMTP, a decision is made on the quality management of processing. The introduction of SMTP provided a significant reduction in ring defects in terms of grinding quality up to 2-3 % and increased operational reliability of bearings.

Keywords: grinding process monitoring, bearing rings, dynamic machine quality, active control, eddy current control, ring quality

The lack of information about the conditions for the implementation of transport processes does not allow building mathematical models that operate with extremely accurate input data. Therefore, methods are being developed that formalize input uncertainties for constructing mathematical models of transport processes. To describe uncertainties, along with static, stochastic and interval approaches, methods based on fuzzy sets are actively used. The generalization of the belonging of the element, presented by Zadeh, allowed blurring the boundaries of the set. The blurring of the boundaries of the sets allows one to formalize insufficiently complete, in an informational sense, judgments and facts for the purpose of the subsequent use of this information in the construction of mathematical models. To identify formal approaches to working with uncertainties, an analysis of foreign periodicals in recent years has been carried out and two well-known approaches have been identified. The first is based on the theory of fuzzy sets - the generalized concept of belonging of an element to a set, leading to blurring of the boundaries of the set. The second approach involves describing fuzziness using a hierarchy - a family of ordered crisp sets [1]. Within the framework of the first approach, the authors have identified five ways of formalization. The first includes fuzzy sets (numbers) with different n-gonal forms of the membership function. The second consists of intuitionistic fuzzy sets (numbers) with n-gonal membership functions. The third contains heterogeneous fuzzy sets of type 2. The fourth represents non-standard fuzzy sets (oscillating, Pythagorean, etc.). The fifth method is a combination of spaced fuzzy numbers, intuitionistic spaced fuzzy numbers, and the like. References are given to sources containing a description of formalization methods and their application in solving some fuzzy transport problems, possible directions of research on the considered topics are formulated.

Keywords: fuzzy transport routing problem, optimization, fuzzy methods, fuzzy numbers, fuzzy sets, heuristic algorithms, hybrid algorithms, transport processes

The most common fittings in gas networks are investigated, such as bends with different angles of change in flow direction and equal tees. The dependences of the values of the coefficients of local resistance depending on the gas flow rate, diameter, angle of rotation and material of the product are determined. Recommendations are given for determining the coefficient of local resistance of the studied fittings.

Keywords: gas pipeline, hydraulic calculation, pressure loss, coefficient of local resistance, gas consumption, geometrical parameters

An urgent scientific and technical task is the development of electric energy converters with high operational and energy characteristics. The use of modern methods for the development and analysis of power electronics circuits based on the use of computer equipment allows us to successfully solve this problem. In this article, a schematic diagram of an alternating voltage regulator has been developed, in which a control system based on a microcontroller implementing an algorithm for pulse-phase regulation of the variable output voltage is used to control a power thyristor key. The control system, a power thyristor key, is synchronized with the moments of transition through zero of the supply voltage of a sinusoidal shape. The controller circuit is adapted for computer modeling in the environment of the PROTEUS software product. In the article, a block diagram is also developed and a software implementation in assembly language of the microcontroller operation algorithm is performed. As a result of computer modeling, time diagrams of voltages on the main elements of the AC voltage regulator circuit are obtained. Time diagrams explain the features of electromagnetic processes occurring in the controller circuit. The results of computer modeling, the controller circuit, the developed algorithm and the microcontroller software can be used in the development of electric energy converters for automatic control systems of electrical equipment.

Keywords: computer simulation, thyristor regulator, alternating voltage, microcontroller operation algorithm, time diagrams, transistor switch, control system, damping circuit, power thyristor, active-inductive load

The paper considers mathematical models obtained on the basis of experimental studies of electrical sheet steel. The models reflect the error in determining the main magnetization curve of electrical steel. The magnetic properties are determined in the center and at the edge of the cut of sheet samples with a size of 150 × 150 mm, made by cutting with guillotine shears and laser cutting. The choice of scale factors for calculating the main magnetization curve with an error of ± 5% according to the measured Weber-ampere characteristic has been substantiated. The study was carried out using a device for express control of the magnetic characteristics of electrical sheet steel. The main curve of magnetization of the sample material from sheet electrical steel was determined in an alternating magnetic field with a frequency of 50 Hz, along the direction of rolling. Investigated samples of isotropic sheet electrical steel grade 2212.

Keywords: mathematical model, electrical steel, magnetic properties, magnetization curve

This paper proposes an algorithm for automatic segmentation of subretinal fluids in the macular retinal layers of the retina. The proposed algorithm is implemented in an integrated development environment - PyCharm, a high-level general-purpose programming language (GPL) - Python was chosen. The proposed algorithm together with other methods of analysis of morphometric parameters of the human retina, which are still under development, will be used for more accurate diagnosis of the stage and degree of retinal damage in age-related macular degeneration.

Keywords: software, image processing, diagnostics, automatic segmentation, macula, retina, age-related macular degeneration, optical coherence tomography

The article provides a brief overview of the creation of the Diagrid system, describes the concept of forming this structure, its key elements and their role in creating geometrically immutable integral structures. The main directions of application in construction and the peculiarities of work on vertical and horizontal force effects are given. It also provides an overview of the materials of construction used and the main design constraints. This article will be useful for design engineers and architects engaged in the design and calculation of high-rise buildings, as well as buildings with a complex architectural form made of reinforced concrete and metal structures.

Keywords: diagrid, mesh supporting structures, reinforced concrete structures, metal structures, stability, free architectural form