A method for measuring the magnetic characteristics of high-coercive permanent magnets made of rare-earth materials, such as neodymium-iron-boron and samarium-cobalt, is proposed. The essence of the method is as follows: the data on the measured supply voltage and the characteristics of the magnetizing installation base a mathematical model; the measured shape of the magnetizing current pulse is fed into the mathematical model and compared with the simulated current pulse in the comparison device; further, if the difference in current characteristics does not satisfy the measurement accuracy, then adjustments are made to the mathematical model. Thus, the mathematical model determines the magnetic characteristics of a permanent high-coercive magnet. The method is developed based on full-scale model tests using a multiphysical computer model. The implementation of the measurement method is based on modern IT solutions, the multiphysical model is built in the COMSOL Multiphysics software package.

Keywords: magnet, magnetic parameter, multiphysical model, magnetization, highly coercive material, neodymium, wavelet, Fourier analysis, COMSOL

Actuator drives are widely used both in consumer electronics and in industrial systems: as all kinds of locks, couplings; as part of valves that control the flow of liquids or gases; in robotics; alarm systems, etc. In the event of a failure of the actuator drive, it is not typical for it to restore the operating mode. As a consequence, predicting reliability plays an important role. The article discusses the development of a method for processing the weber-ampere characteristics of actuator drives. Weber-ampere characteristics are converted into ampere-weber ones, reflected by the maximum flux linkage value, and interpolated by the current values ​​that are the same for all characteristics. The characteristics obtained in this way are transformed by the method of principal components and are represented by a point in three-dimensional space. By the location of the points of the center of mass and the dispersion of the groups of characteristics of one electromagnetic drive, a forecast is made about its state by the time of the next check according to the regulations. This method was applied to the characteristics of 10 actuator drives, each of which was subjected to mechanical resistance during operation. The characteristics transferred into the space of the principal components forms a figure resembling a boomerang. The movement of points from the upper edge of the "boomerang" through the center to the lower edge reflects the deterioration of its working properties.

Keywords: prediction, reliability, actuator drive, weber-ampere characteristic, principal components, flux linkage, data processing, duty cycle, malfunction, Statistica, points cloud, performance data

In modern times due to the growth of mass production of electronic devices, it becomes necessary to quickly and accurately verify their characteristics. At the same time, device testing, as a rule, includes a set of different types of checks performed at different stages of the production process. In particular, the analog signature analysis method is used for these purposes. It allows you to quickly detect faults at the component level, which makes it useful in various stages of production, such as incoming inspection, testing printed circuit boards or repairing faulty devices. This article discusses the basic principles of the method, as well as the features of its application.

Keywords: analog signature analysis, component level testing, current-voltage characteristic, fault localization

The main results of studies of the anodic behavior and chemical composition of the surface layer of the aluminum film before and after implantation of silicon ions (20 keV), conducted using the method of measuring potentiostatic polarization curves, are presented. The decrease in the anode polarization currents and the expansion of the passivation region depending on the dose of the introduced ions, due to the formation of oxide compounds with the implanted silicon impurity, are shown.

Keywords: ion implantation, films, aluminum, polarization curves, potentiostat, anode behavior, auger electron spectra, electrolyte, silicon ions

The article deals with the issues related to the design of control devices for technological equipment based on artificial neural networks. The algorithm of the neural network training process based on the Widrow-Hoff method is developed, designed for computer-aided design of artificial neural networks operating in the environment of a microprocessor system or a personal computer. The authors perform a software implementation of the algorithm for training a three-layer neural network using the C# programming language on the platform Microsoft.NET. The program uses a neural network training algorithm with a "teacher". The article shows the interface of interaction of the developed program with the "teacher" (designer of neural networks). An example is given of the development of an artificial neural network that performs the function of a binary number adder. The results of the research can be further used in the development of a computer-aided design system for artificial neural networks, and can also be used in the development of software for microprocessor control systems for technological equipment.

Keywords: artificial neural network, training, algorithm, programming language, neuron bias, adder, input signals, output signals, synaptic connections, neurons

The results of theoretical research and analysis of methods that will significantly reduce the weight of the gravity oil platform are presented. At the same time, its static, dynamic, and shear stability will remain under the influence of wind, wave, ice load and current load. In order to reduce the weight and overall dimensions, it is proposed to outline the lower part of the platform base with a metal sheet pile wall. As a result of theoretical studies, the dependence of the shear force under the influence of external forces acting on the platform during operation on the physical and mechanical properties of the soil and the size of the sheet pile wall is found, which will significantly reduce the weight of the platform and the cost of its construction.

Keywords: gravity oil platform, shear stability, tongue-and-groove wall, external forces acting on the platform, rollover stability

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

Arched constructions of the roofs of span-type buildings are very cost-effective in comparison with beam and frame systems. In many cases, the high architectural qualities of arch structures allow one to obtain expressive interiors of large halls. At the same time, the construction of long span buildings is always associated with high risks, high security requirements for such buildings, and, consequently, increased requirements for reliability to load-bearing structures, including possible local destructions. Actual becomes the issue of ensuring the survivability of building structures in general, and the construction of roofs for long span buildings in particular. To analyze the survivability properties of shallow arched coverings, a number of constructive solutions of arched constructions of various types are considered. The work of arch structures of various types with possible local caving of a number of elements is considered. Five design schemes of arched constructions are presented, and work of each of them is considered at exclusion of the most loaded elements. In particular, the work of the arch structure with fan-shaped tie system with a split upper belt is considered. A comparative analysis of the survivability properties of the constructive solutions under consideration is presented.

Keywords: arched covers, arch structure with fan-shaped tie system, survivability, local destruction, constructive solutions, long span roofs, progressive collapse

The article is devoted to the importance and relevance of the development of underground space, today in large cities there is an acute shortage of areas free from development, as well as the high traffic congestion with personal cars, these and many other problems can be solved through the integrated development of underground space. The classification of underground structures is given. The organizational and technical problems of construction below the zero cycle are indicated. Examples of competent use of underground space in the world are considered. Benefits of construction below zero cycle are also noted. The objects, the construction of which is promising underground, are described. Attention is drawn to the climatic and anthropogenic factors taken into account during construction. In conclusion, the measures that need to be taken for the development of the underground space of our cities are considered.

Keywords: development of underground space urban studies, organization of construction of underground structures, urban space, cramped urban development, organizational and technical problems

This article discusses a hardware and software complex for the study of aerodynamics and electromechanical characteristics of wind turbines (WPP) with a vertical axis of rotation. The created laboratory stand makes it possible to carry out experimental studies of the developed wind power plants, to obtain the dependences of the angular speed of rotation of the rotor and the consumed electric power on the wind speed. To demonstrate the efficiency of the considered vortex-type wind turbine, the corresponding prototypes of wind turbines with a power of 0.2 kW and 1.2 kW were designed and assembled, and their full-scale tests were carried out. The developed software makes it possible to carry out numerical simulation of the motion of a wind turbine with an unsteady undisturbed wind flow, taking into account the mass-inertial characteristics of the installation and the nature of the moment of resistance to the rotation of its rotor. Experimental and numerical results obtained using the developed hardware-software complex are presented and compared. These results indicate the possibility of using such a complex as an effective tool for the development of wind turbines with a vertical axis of rotation.

Keywords: wind power plant, experimental research, software and hardware complex, numerical modeling, numerical methods of dynamics of continuous media

The problem of digitalization of the data accounting system and the problem of managing the technical condition of equipment at thermal power plants are considered. The performance of the entire thermal power plant depends on the operation of the boiler units. If the equipment fails and the necessary measures to resolve the emergency are not taken in time, then the probability of a decrease in the plant's performance up to the suspension of work increases. Thus, the issue of monitoring the technical condition of all operating equipment is relevant. The developed software for automation of the data recording system and visualization of technical parameters of the reliability of boiler and turbine equipment is described. The software has a methodology for determining the technical condition index of equipment. The software was developed using the JavaScript programming language, the React.js library. Digital technologies have been introduced into the process of recording data on the technical condition of equipment, where for the first time the software includes a method for automatic calculation of the technical condition index of boiler units. The software ensures that equipment downtime is reduced, as well as the likelihood of failure or critical breakdown of boilers. Thus, the operation of the software makes it possible to reduce the likelihood of an emergency state of the main equipment of power plants.

Keywords: thermal power plant, boiler and turbine equipment, software, technical condition, reliability, repairn

The water recreation industry is actively developing. An individual pool at home is also not uncommon for a long time, because everyone wants to live in comfortable conditions. Modern country houses place the pool on the ground floor of the premises on the plot next to the house. Despite the financial costs and time for maintenance, the health benefits of the pool, as well as the variety of leisure activities through taking water procedures or playing with children, are a very powerful argument in order to arrange a pool at home.The number of pools is increasing and the number of pools built with defects is also increasing. it may be because use low-quality construction materials and reduce their volumes, perform work by unskilled employees, violate the requirements of construction documents of the project. therefore it is necessary to carry out construction and technical examination.

Keywords: construction, swimming pool, construction and technical expertise, regulatory documentation, defects

Urbanization and increased production have led to the fact that every year the world generates a large amount of plastic waste, which pollutes the environment. Using them in the construction industry will help solve this problem, as well as get profitable solutions in the production of building materials and mixtures.

Keywords: plastic waste, environment, construction, construction materials

Currently, in the design and manufacture of steel products operating in conditions of heavy impact-abrasive wear, not only material is given, but also the structure of the product itself. One such detail is the friction wedge of a freight wagon trolley. In the presented work, a new design of the friction wedge of the vibration damping unit is presented; technical calculations are carried out on the strength of the presented design. The safety factors of spring suspension are calculated. All calculations were performed according to the standards for the calculation and design of new and modernized railroad cars of the Ministry of Railways 1520 mm gauge. The performed calculations indicate the high performance of the developed design, the obtained values ​​fully satisfy the requirements for such products. The result of the work on creating a new design of the friction wedge of the vibration damping unit is to obtain a patent for utility model No. 194823, a drawing has also been developed (KI-000.00.00.001) and terms of reference for experimental design work (KI-000.00.00.001 TK).

Keywords: friction wedge, vibration damping unit, freight car truck, strength, reliability, durability, calculation of spring suspension, static deflection of spring suspension, coefficient of structural margin of deflection, coefficient of relative friction

hydroxyapatite, non-collagenous protein, implant, quantum-chemical analysis, molecular model, one-electron spectrum, vibrational mode, osseointegration.

Keywords: hydroxyapatite, non-collagenous protein, implant, quantum-chemical analysis, molecular model, one-electron spectrum, vibrational mode, osseointegration