Recognition of radiation from celestial bodies by technical means is an important task in the orientation of spacecraft. For a device that is part of the Earth orientation device, a variant of modeling an electronic signal amplifier received from a pyroelectric sensor is studied. On the recommendation of the developers, the properties of trans-impedance operational amplifiers were studied, and suitable coefficients for the negative feedback circuit were selected. The type of output signal of the model is studied in comparison with the recording of values taken from a real photodetector. The preferred design of the model in the Matlab Simulink environment is shown – a model defined by an electrical circuit using the Simscape Electrical library.

Keywords: simulation of electric circuits, space orientation, photodetecting device, transimpedance amplifier, optoelectronic devices, space instrumentation

Lignin is a natural polymer material, one of the main components of wood and is a renewable resource. The current trends concerning the methods of oxidation of hydrolysis lignins and the use of oxidation products are considered. Lignin oxidation processes are mainly aimed at obtaining macromonomers with a high content of functional groups and at obtaining low molecular weight oxidation products. A significant group of research is associated with the development of processes for the production of polyols used for the synthesis of polyurethane foams. In view of the insolubility of hydrolysis lignins in acidic media, the reactions of their modification to obtain highly reactive polymeric ingredients are expediently carried out in acids. Electrochemical oxidation in acidic environments allows for multiple use of electrolytes and is energy-consuming to young.

Keywords: renewable resource, industrial waste, hydrolysis lignin, oxidized lignin, hydroxyl groups, macromonomers, low molecular weight products, chemical oxidation, catalysis, electrochemical method, resource saving

The paper argues for the relevance of using volumetric modular units (VMU) in construction, especially in building temporary field camps. Despite a high installation technology intensity, the use of VMUs is said to demonstrate a low technology intensity in terms of transport operations. In order to ensure a high transport flexibility for temporary settlements, collapsible volumetric modular units are suggested as a potent solution.

Keywords: modular construction, assembly and transport adaptability, collapsible construction

This article presents the results of studies of modes of regulation of heat energy supply to the network. Analysis of the existing (traditional) mode of weather regulation of heat supply to the network revealed a number of shortcomings, incl. low period of operation of boilers in effective modes. The proposed mode of supply of heat energy from the network will ensure a long-term efficient operation of the boiler units. It optimizes the consumption of heat energy for auxiliary needs by significantly reducing the number of starts of boiler units.

Keywords: boiler unit, temperature schedule, specific gas consumption, heat output, weather regulation

The article investigates the physical and mechanical properties of fine-grained fiber-reinforced concrete with metal, polypropylene and polyamide fibers, using Portland cement, hyperplasticizer. Comparison of strength characteristics of fiber-reinforced concrete made using metal fiber, polypropylene and polyamide fibers is carried out. A technical and economic comparison of the efficiency of using fibers of various origins has been made. According to the cost calculations, the use of polyamide fibers is cost-effective, since the cost of materials is lower than the cost of fiber-reinforced concrete materials based on polypropylene fibers of this composition.

Keywords: fiber concrete, hyperplasticizer, fiber, microsilica, tensile strength, nature of destruction, mechanical property, polypropylene fiber, polyamide fiber, cement, reinforcement, adhesion, monolithic structure, cost

This article presents the results of the analysis of factors influencing the burner device of heat generators, as well as methods for their selection. The results of an experimental study of the dependence of the efficiency of heat generators on the operating power of burners are presented. Recommendations have been developed for choosing a heat generator and a burner.

Keywords: heat generator, burner device, Gorenje mode, operating power, heat balance

The article proposes a thermodynamic approach that allows us to more accurately represent the flow modes of quasi-stationary gas through a long step gas pipeline . It takes into account the peculiarities of the operation of side gas venting devices of small-caliber automatic guns on the principle of automatic operation. We use a combination of the main characteristics that represent the operation of such systems under difficult loading conditions and high temperatures. These are mainly gas consumption, heat transfer losses, gas flow rate, improvement of the approach to the solution of ensuring the appropriate parameters to ensure the reliable operation of the relevant technical systems with the possibility of recommendations after appropriate tests of such products.

Keywords: step gas pipeline, side gas outlet device, gas flow, thermodynamic parameters, heat loss, filling period, gas consumption, automatic weapons systems

In modern conditions, internal combustion engines (ice) are the most popular power plant for a number of transport vehicles: cars, tractors, locomotives, river and sea transport vessels. Strict requirements of modern Euro-standards to the degree of "smokiness" of exhaust gases of diesel internal combustion engines and their toxicity contribute to the emergence of a dead end situation. It is almost impossible, using obvious technical solutions, to comply with the requirements of Euro-5 and Euro-6 standards while maintaining the acceptable growth in economic costs, internal combustion engines (ice) emit a significant amount of exhaust gases into the atmosphere, which is an environmental threat. The article considers the method of SHS technology and its advantages.

Keywords: environmental threat, internal combustion engines, SHS technology, waste, synthesis, filters

Rail transport plays a key role in the transport of passengers and goods. The high demand for effective means of flaw detection of high-speed rails, which is an important component of railway safety, is justified by the constantly growing number of vehicles and their speed [2]. Failure of elements of the railway infrastructure entails huge losses. In this regard, the analysis and forecasting of the state of elements of the railway infrastructure is an urgent task. This article analyzes modern methods for diagnosing the state of a rail track from a mobile bogie or a conventional locomotive. A method for diagnostics of a rail track is proposed, based on registration of vibrations near the rolling surface of rails and processing these signals using neural networks.

Keywords: rail flaw detection, wheel surface, algorithm, IMM, MEMS, control system, inertial sensor, rail defect, contactless measurement

The article presents proposals for the calculation of three-layer reinforced concrete slab structures, the outer layers of which are made of heavy concrete, the middle layer is made of lightweight expanded clay concrete. Experimental elements were calculated according to the compiled program of iterative calculation, which takes into account the concrete deformation diagram in an explicit form. The calculation program reflects a technique that allows you to determine the actual distribution of deformations in sections with a crack and in the areas between them. The results of the calculation of the prototypes indicate a close convergence of the theoretical values ​​of the breaking moments, deflections, deformations of the extreme fibers, and cracking forces with those directly recorded in experimental studies.

Keywords: concrete, reinforced concrete, expanded clay concrete, reinforcement, three-layer slab, prestressing, calculation methods, deformations, stresses, deflections

The paper studies the liquid-phase epitaxy processes of a new material of infrared optoelectronics - indium arsenide doped with bismuth using a stepwise thermal field. An analysis of the phase equilibrium during the growth of a solid solution is carried out. The possibility of the formation of a mesostructure (modulation of the composition along the growth coordinate) is shown. The problems of defect formation in composite layers grown from a melt are considered. Ways of decreasing the dislocations density in gradient layers are discussed. A relatively simple method for controlling the thermal field of temperature in the crystallization zone and a new technological procedure for the sequential crystallization of solid solutions with a mesostructure have been developed.

Keywords: solid solutions, liquid-phase epitaxy, indium arsenide, mesostructure, stepwise thermal field, dislocation generation

The problem of major repairs on the factory highway in Samara still remains unresolved, although the issue has been acute for many years. During this time, as statistics show, there were a lot of accidents and damage to vehicles. A heavy load on the roadbed leads to rapid wear of the asphalt surface, as a result, almost every year the Factory highway needs repairs. The load on the highway will increase even more when the section of road connecting the new Kirovsky bridge with the Zavodsky highway is built. The automobile road in Samara along the ZAVODSKOE highway needs major repairs for several years, but the work does not begin, and every spring its condition worsens more and more. The issue remains relevant today.

Keywords: automobile road, ZAVODSKOE highway, traffic intensity, climate zone, engineering and geological conditions, major repairs

The article discusses the problems that arise in pattern recognition related to clustering and data abstraction. Detailed typical data clustering options. The problem of data transformation by vector quantization with the least error is given. A competitive training system for an artificial neural network based on a growing neural gas is described. Using the method of growing neural gas, an improved algorithm of a self-learning artificial neural network of competitive training is proposed. The criteria for completing clustering using the adaptation criterion as a stop criterion are defined. Examples of data clustering by an artificial neural network using the method of growing neural gas are given.

Keywords: clustering, artificial neural network, computer modeling, pattern recognition, self-learning intelligent systems

The theoretical aspects of crystallization of multicomponent solid solutions are discussed. Antimonoid heterosystems in which bismuth is present are considered, a component that largely determines the photoelectric properties of the studied materials. The features of establishing the equilibrium of the liquid and solid phases in the process of crystallization of these systems are considered. The laws of the thermodynamic behavior of heterosystems in the conditions of gradient liquid-phase epitaxy are established. The results of experimental studies on the growth of solid solutions of multicomponent bismuthides on InSb substrates are presented.

Keywords: solid solutions, migrating liquid phase, indium antimonide arsenide, gallium bismuthide, binary pair, recrystallization, quasicrystalline structure

In this work, we simulated the graphene-MnO composite structure based on minimizing the electron density functional. The analysis of the processes of rearrangement of the interface surface SLG (monolayer of graphene) - MnО (111). In this case, the interface was subjected to hydrogenation. The distribution of the effective charge on graphene is investigated. A decrease in the work function of the charge carriers during hydrogenation of the interface is established.

Keywords: effective charge, graphene, passivated surface, density functional, interface, work function, energy gap, band structure