The article is devoted to the problem of theoretical research and development of perovskite-based solar cells to optimize their design and increase efficiency. The paper presents a numerical simulation of the transfer and accumulation of charge carriers in the planar p – i – n heterostructure of a solar cell. The simulation is based on a stationary physico-topological model based on the diffusion-drift system of semiconductor equations. The efficiency of solar cells for different perovskite film thickness was obtained. It has been established that the maximum efficiency of the optimized design of a solar cell is about 27% with a perovskite film thickness of 500-700 nm and a defect concentration in it of the order of 1012 cm-3.

Keywords: Numerical simulation, solar cell, perovskite, film thickness, defect concentration, current-voltage characteristic

It has been established that the concentration of cholesterol mesogenic esters in lubricants ambiguously affects the microrelief parameters and the tribotechnical characteristics of a steel 45 – steel 45 friction pair. %, the best indicators of friction and wear of metals, on the contrary, are realized with an increase in the concentration of cholesterol esters in lubricating compositions.

Keywords: lubricant, cholesteric liquid crystal, microrelief on friction surface, coefficient of friction

The aim of the article is to analyze the existing methods for constructing a model of random errors in micromechanical sensors. A comparison of different methods for determining the parameters of a random process model is presented: autocorrelation, power spectral density analysis, time domain analysis, and Allan variation analysis. This direction is also supplemented by considering the effect of sensor errors on the error of inertial navigation systems. In conclusion, the synthesis of forming filters for various random errors in micromechanical sensors and the results of simulation are given.

Keywords: mems gyroscope; noise analysis; stochastic drift; error modelling

When developing any technology of repair it is necessary to conduct research mikrolitrazhnyh worn parts of assemblies using metrological equipment. At the moment to improve the accuracy of research the repair company should use the latest measuring system, allowing to carry out a full complex of works on profileration surfaces of worn parts. Such devices include for example profilograph profilometer English company "Taylor Hobson", which allowed to determine the amount of allowance for machining the body of the power steering distributor. As a result, using the data obtained, the technology of repairing the power steering of KAMAZ vehicles was developed.

Keywords: metrological equipment, profilograph-profilometer, micrometer, power steering, repair technology, recovery, wear, distributor, shaft

The paper considers an adaptive on-off regulator. A block diagram of this device is given, and the sequence of operation of the blocks is also described. Simulation modeling of various types of on-off regulators was carried out in order to identify their effectiveness.

Keywords: automation, adaptive regulation, regulators, simulation

Currently, one of the main problems of our time is to improve the ecology of the regions. Green areas can contribute to this, however, the southern region of Russia is caused by a dry summer period. In this regard, there is the task of ensuring high-quality irrigation, which is often carried out by automated systems. However, without feedback, it is extremely difficult to bring the process to the proper level of quality. To do this, use humidity sensors, the price of which inevitably leads to a strong appreciation of the system. This article discusses the possibility and feasibility of developing and implementing its own moisture sensor that would meet such positive criteria as low cost, high accuracy and wide range of measurements, high corrosion resistance, versatility of application.

Keywords: soil moisture sensor, automation, irrigation, capacitive measurement method, microcontroller, Southern Federal District

Economic-probabilistic method assesses the feasibility of tactics for MAINTENANCE and operating time and technical condition for buses equipped with electronic control units. The scheme of determination of limit values of diagnostic parameters is proved. It is shown that the implementation of the STATE is appropriate when the economic costs associated with the cost of diagnosing and forecasting the technical condition of the buses are not decisive.

Keywords: strategy, tactics, method, parameter, maintenance, repair, cost, reliability, operation, technical condition

On the basis of the mathematical apparatus of Queuing, a mathematical model for the diagnosis of the technical condition of vehicles with electronic control units. The developed mathematical model of vehicle diagnostics in the framework of discrete-event paradigm. Numerical experiments to assess the effectiveness of diagnostics are carried out.

Keywords: cars, electronic control unit, diagnostics, Queuing system, efficiency, operating costs

The article is devoted to the actual problem of overcoming the restrictions imposed by the IP Protocol and network technologies used in conjunction with it, in particular, address translation, on the structure of computer networks and the availability of its individual nodes. It proposes a method of building virtual network tunnels based on the principles of steganography using service network protocols, briefly describes the shortcomings of existing technologies of tunneling. The paper describes in detail the proposed method of steganographic encapsulation of network packets, describes the principles of formation of packet headers, provides examples of protocols for encapsulation. The material of the article is presented consistently, competently and meets the generally accepted requirements for scientific works. The presented approach to solving the problem of building virtual tunnels has scientific novelty and has practical value.

Keywords: Encapsulation, Internet protocols, multilevel network models, steganography, steganographic packet encapsulation, tunneling

The method of layer-by-layer build-up of the material allows creating parts of complex configuration.To expand the field of application of such parts in the industry, it is necessary to know the properties of products obtained by this wayvery well. Currently, the literature sources do not provide enough information about the properties of products obtained by 3D printing on FDM-technologies.This is due to the variety of materials used and printing modes.Data on mechanical properties, such as tensile strength, bending, compression, shrinkage, specific weight of the material, will allow designing and creating real structures using 3D printing.The article considers the extrusion method of 3D printing, describes the study of tension, compression, bending, specific weight, shrinkage of samples with different structures obtained from ABS plastic.It is found that the deformation of the material during its tension depends on the number of filaments on the shell of the surface layer and reaches the highest values for samples containing eight and ten filaments. The calculation of the specific weight of the samples shows that the density of the samples with a tetrahedral structure is higher compared to the hexahedral structure at the same printing and filling modes. In determining the ultimate compressive strength of the samples, it is revealed: the higher the percentage of sample filling material, the more the sample withstands compressive stress. Experimental data on material shrinkage show that when filling the model with material from 20 to 80% shrinkage is 1%, and at 100% filling - 0.78%.

Keywords: additive manufacturing, 3D extrusion printing, mechanical property, FDM technologies, ABS plastic

Executed system analysis of the types of damage to logging machines and damage them in the manufacture. It is found that defects in material, shape and size of the part have a significant impact on the reliability of the equipment. The main attention is paid to the effect of crack-like defects. If as a measure of damage to take the length of the crack and apply the methods of fracture mechanics in the calculations, it will be obvious the relationship of operational and industrial damage. It is established that the main cause of failures of logging machine details of domestic production is not enough high quality of their production. It is recommended to use more widely such as characteristic of materials as fracture toughness to assess the reliability of the design.

Keywords: Logging machine, reliability, damage, manufacturing defects, fracture toughness

There are represented scheme and design of duplexer for the 300-344 MHz radio station. Simulation of duplexer was implemented in Microwave Office environment. Experimental research was executed on the complex transmission coefficient measuring instrument such as “Obzor-103”. There are shown amplitude-frecuency characteristic of receive and transmission channels. Comparison of the simulations results with natural experiment proving the identical.

Keywords: Filter, duplexer, amplitude-frequency characteristics, receive channel, transmission channel

The analysis of the used algorithms for the search of unstructured information was carried out, during which it was established that they do not take into account the thematic orientation of the specialized collection of documents. It is proposed to use an annealing simulation algorithm to obtain numerical coefficients used in the information retrieval ranking algorithm system. The results of the standard and modified search algorithm and ranking search results unstructured information. As a result, the value of quality metrics failed improve by an average of 8%, and the average error decreased by 29%

Keywords: information retrieval, ranking, model, quality metrics, relevance, unstructured information

Offers on the rational organization of control of durability of concrete according to GOST 18105 for modular products, commodity concrete mix and monolithic designs are presented. The concept of "moving analyzed period"is introduced. It is shown that it is not reasonable to use the control scheme for the control of the indirect indicators and the development of rapid methods for assessing the strength of concrete in the control of commercial concrete mixtures. The rational organization of concrete strength control of monolithic structures using direct and indirect methods is proposed. The groundlessness of application of statistical methods of control at control of durability of concrete of monolithic designs is shown.

Keywords: control of the concrete strength, the analyzed period, the control scheme, the actual concrete strength

A study of the directional coupler range 1-4GHz. The description of the construction on a symmetrical strip line with a lateral connection is given. The amplitude-frequency characteristics were simulated using the Microwave Office package. The model of the directional coupler is experimentally investigated, the following results are obtained: the working attenuation does not exceed 1.7 dB, the transient attenuation does not exceed 10 dB.

Keywords: Directional coupler, frequency response, flatness, symmetric stripline