Numerical physical-topological modeling is carried out to optimize the thickness of perovskite solar cells on the basis of the heterostructure TiO2 / CH3CN3PbI3-xClx / Spiro-OMeTAD. The results of the conducted studies showed that the optimum values ​​of the thicknesses of TiO2 and CH3CN3PbI3-xClx heterostructure films, which make it possible to obtain a high coefficient of efficiency of the solar cell, lie in relatively narrow limits. The carried out researches have shown the possibility of effective use of numerical physical-topological modeling for the development of perovskite solar cells, taking into account the features of photogeneration, recombination and transport of charge carriers in real heterostructures.

Keywords: Solar cell, perovskite, titanium dioxide, heterostructure, numerical simulation.

In this work, a study was made of the efficiency of the heat sink surface of a volumetric body with an internal heat source. An electrostatic analog of the distribution of the thermal field is chosen. A model of the convective flow is proposed, under certain initial and boundary conditions, the thermal conductivity of the medium transforming into heat removal. The conclusion is made about the ineffectiveness of the heat-conducting surface in the form of whip, finned and other designs of existing heat sinks, increasing only the mass, technological complexity of manufacture, thermal resistance and temperature of the heat-loaded element.

Keywords: Temperature field, convective heat transfer, effective heat sink area, electrostatic analog, similarity theory

The article discusses the technological capabilities of application of vibratory mechanical hard lubricant coatings on the basis of MоS2 to improve the surface quality and operational properties of parts made of aluminum with an oxide coating.

Keywords: vibration treatment, the vibration mechano-chemical coating of solid lubricant, combined methods of treatment

The loops of the dielectric hysteresis of a soft ceramics based on PZT with Curie temperature TC=210℃ are investigated. The studies were carried out at a frequency of 50 Hz in two modes. In the first of them, the field was switched on by 0.07 seconds, in the second - it operated continuously. The amplitude of the field E_m varied from 2.5 to 25 kV / cm and switched stepwise with an interval of 15 minutes. The coercive field EC and the switchable polarization P_m were determined. The switching polarity in the saturation region turns out to be no more, in contrast to BaTiO3 and other materials, but less than the corresponding values obtained with short-term switching.

Keywords: piezoceramics, piezoelectric material, hot pressing, dielectric hysteresis

The short analysis the direct-current motor running with the help of regulating resistors and thermostatic resistors is made. A fixed range of thermistor resistors can be obtained by optimizing the current. There are some graphical dependence of the load moment influences on the engine acceleration through the semiconductor rheostat. The authors give some warning to combine starting rheostats.

Keywords: thermistor, starting rheostat, direct-current motor, motor starting current line graph, combined starting resistance

This article is devoted to the review of production methods for determining the rigidity of technological systems based on metal cutting machines. A description of each method, its characteristics, describes the principle of the appearance of elastic strains of technological systems and the possibility of their measurement. For each method, the limits of its applicability and the possibility of using it in different production situations are given. The mathematical dependences are given which can allow the process engineer to estimate the value of the elastic deformations of the technological system and make appropriate adjustments even at the stage of production preparation (for example, to change the trajectory of the tool when writing the control program for CNC machines). A statistical method for determining the rigidity of technological systems is described, the graphical dependence of elastic deformations on cutting forces is given.

Keywords: Rigidity of the technological system, elastic deformation, technological system, cutting force, production method for determining rigidity

The paper contains an analysis of the results of experiments on obtaining radiative structures based on gallium antimonide, formed by the method of thermal melt migration in a semiconductor matrix. The epitaxial process modes within the selected range were optimized for such parameters as the wavelength corresponding to the fundamental transition, a small lattice discrepancy, a small discrepancy in the coefficients of thermal expansion of the growing TP and the matrix. An original effect is described - an increase in the solubility of the Bi content in solid solutions, isoperiodic binary compounds A3B5 under conditions of a gradient temperature field. This effect allows a wide variation in the optical parameters of the element base of instruments based on solid solutions of GaSbBi / GaSb. The mechanisms of the generation of dislocations in a crystallized solid solution and the features of electrophysical and photoelectric parameters are analyzed. A structural solution of a light-emitting diode with strip geometry is proposed.

Keywords: thermomigration, solid solutions, gradient epitaxy, diode with fine mes, gallium antimonide, fundamental transition, photoluminescence spectra

The development of the mining industry calls for an increase in the technical and economic indicators of tunneling operations. At the same time, with increasing speed of construction, intensity and productivity of drifters, the complication of mining and geological conditions exacerbates the problems associated with ensuring the integrated safety of workers in underground conditions. With an increase in the depth of the trunks, the absolute average values ​​of the duration of individual stages of work increase. The average speed of the construction of the trunks varies slightly and is lower than the normative ones. One of the main reasons for this situation is a large loss of time during the construction period and a low level of work safety. The performed studies show that it is necessary, both to increase the technical equipment of construction, and to improve the organization of work and socio-economic working conditions. The best examples from practice show that this allows you to increase labor productivity by 3 times while ensuring high work safety. At the same time, this approach is not yet widely used in modern Russian practice, where the socio-economic situation of the mining industry remains rather severe, and the level of industrial injuries is the highest in comparison with the rest of the economy. The numerical spatial model is a fragment of a rock mass with a size of 80 to 90 meters, in which the tunnel is connected by a span of 6.0 m, adjacent to the vertical trunk. The mating and trunk in the area under consideration are fixed with reinforced concrete lining 500 mm thick. A universal spatial isoparametric eight-node finite element is used to break up the model. The dimensions of the finite elements on the outer regions of the model were 2.5 - 5.0 m, on the inner - 0.25 - 0.5 m. Thus, the principle of combining dense and rarefied grids was used to reduce the amount of information describing the numerical model. The problem was solved in an elastoplastic formulation by a stepwise iteration method. As a result of calculations, all the components of the volumetric stress tensor in the finite elements of the lining and the rock mass, movement and deformation in the nodes of the finite elements were determined. With the help of the developed numerical models, a series of calculations was performed, an array of data was obtained on the stress-strain state of the lining in the zone of coupling effect, quantitative and qualitative analysis was performed. It is established that in characteristic zones of the influence of conjugations, a significant increase in the intensity of equivalent stresses is observed, which leads to a reduction in the load-bearing capacity of the lining by 2 times or more in comparison with extended sections of underground structures. To increase the efficiency of maintaining interfaces during tunnel operation, it is necessary to justify the control actions taking into account the dynamics of changes in the stress-strain state of the lining in space and time.

Keywords: tunnel, shaft, linking, stress-strain state of the rock mass, the concrete lining

In accordance with the requirements of the legislation of the Russian Federation on the basis of a complex of pros-pecting works, it is necessary to establish the rate of removal of the soil layer. The thickness of the removal of the soil layer is established on the basis of a complex of laboratory studies of soil samples taken from established soil hori-zons. The thickness of the soil horizons is currently determined using stock data based on the characteristic type of soil. However, the thickness of soil horizons in a number of cases on sections characterized by identical soil characteris-tics differ. Thus, in each specific case it is necessary to link the soil sections and boundaries of the selected soil con-tours instrumentally through ecological excavations. High saturation with soil workings can lead to a significant distur-bance of the soil cover of the surveyed area. To solve the above problem, it is proposed to use a unit for studying the power of multicomponent dynamical systems for vertical drilling of soil wells

Keywords: soil horizon, fertile layer, survey, withdrawal power, prospecting, well, drilling, capital construction, photographic fixation, deposition

The paper presents the development of a system for detecting the status of control and protection system drives (CPS) of a water-water power reactor by vibration signals using the frequency components method. Results of experimental researches at the "Izhorskiy Plant" PO are given. Spectral analysis is used to isolate the frequency ranges of the CPS diagnostic signal spectra, and to develop diagnostic standards. The work describes formation of reference diagnostic vectors (a set of diagnostic features in the form of a binary code) and their comparison with the current state. The developed standards formed the basis for the system of automatic recognition of the object state. The introduction of such a system will simplify the task of collecting, analyzing, comparing drives data during operation at nuclear power plants, as well as improving methods of testing and diagnosing CPS drives, which should positively affect the reliability and resource of equipment.

Keywords: CPS drive, technical diagnostics, spectral analysis, diagnostic vector, state recognition

The paper proposes a method for determining the leakage in the gate of an electric drive armature by sound and ultrasonic signals using the Shannon and approximation entropy indices. The results of equipment diagnostics in laboratory and industrial conditions are presented. The results indicate the possibility of using entropy indicators as sensitive diagnostic features.

Keywords: electric drive armature, ultrasonic diagnostics, Shannon entropy, approximation entropy

This paper provides an overview of the types of existing natural gas consumption meters. A comparison is made of the instruments of various manufacturers present on the market. The main characteristics of the counters are named, the definitions for each characteristic are given. The problem of temperature compensation of flow rate depending on the temperature of the working medium is considered. The error in measuring gas at temperature differences leads to difficulties in predicting the consumption of energy resources. Two existing approaches to the solution of the problem are given. The ways of solution for the task of including metering devices in unified automated energy accounting systems are also shown.

Keywords: flowmeters of natural gas, diaphragm counters, automated metering systems, energy resources, thermal correction

In the article the technique of data processing of field and laboratory research of water-dissolved gases, osnovna on the use of the developed software and databases

Keywords: Water-soluble gases, software package, database, data processing

Тhe article deals with the malfunctions of the vehicle's brake system, resulting in uneven wear of the brake pads. Illustrations of damaged pads are given. Recommendations for troubleshooting are given.

Keywords: car, brake system, brake shoe, wear pads, malfunction

The article is devoted to the development of a multicriteria transport problem solution. As criteria, the minimal cost of transportation, the minimal time of transportation, the minimal overhead charges and the maximal volume of transportations were taken. Classical methods for solving multicriteria optimization problems are modified and adapted to the transport problem specification. In Visual Studio C # programming language, is used as a software package to solve the multicriteria transport task problem by one of the methods of linear convolution, or the main criterion, or compromise method or the method of guaranteed result and to compare the results obtained. The first paragraph is devoted to the formulation and mathematical model design of four-criterial transport problem. The second paragraph contains an example the application of guaranteed result method to solve transport problem. The next paragraph describes the program realization of transport problem with four criteria.

Keywords: four-criterial transport problem, method of potentials, initial symplex table, main criterium method, compromise method, lambda-problem, liniar convolutuin method, transporat carriages, program realization, multiplicative convolution, guaranteed result me