A review of methods for calculating microclimate parameters is performed. The possibility of using existing mathematical models to describe the aerodynamic characteristics of ventilation valves and optimize their performance indicators: productivity, hydraulic resistance, density, response time and other parameters that form their efficiency is considered. In order to assess the correspondence of the obtained mathematical dependencies, a physical experiment was conducted. The adequacy of the mathematical model was verified by comparing the results of calculating the parameters of the internal environment in the SolidWorks software and computing complex with experimental data.
Keywords: microclimate parameters, heat and mass transfer, mathematical modeling, heat transfer resistance, experimental study of microclimate, air mobility, valve
In the past few years, such objects have begun to be taken outside the city limits and rebuilt in new, undeveloped territories. And on the vacated territory, a new development begins with the intensive development of underground space. The strategic innovative approach to the implementation of projects for the development of the modern city released by the industrial territory is an urgent answer to the question of a completely new understanding of the comfortable environment, in which everything is involved: zoning of the development territory, laying new roads (city streets), underground structures and communications, transport accessibility, environmental friendliness of construction. Without understanding that the problem of forming a living space is complex, in the end, comfortable conditions of human existence will not be obtained. Various modern green building standards are based on this.
Keywords: redevelopment, green standard, BREEAM, industrial territories, industrial facilities, reconstruction, renovation, complex development of the territory, certificate
The article is a review, devoted to the instruments used for the experimental study of the stress-strain state of the soil base, and methods of their use. The authors considered two types of mesdoses, analyzed the possible advantages of their different designs. General cases of operation and loss of bearing capacity of shallow foundations are described.
Keywords: Foundation, construction, shallow foundation, soil mechanics, building structures, soil stress measuring device
The problem of studying the peculiarities of sound propagation in shallow seas is an urgent task of hydroacoustics, since it is associated with human production activities in coastal zones and waters of shallow seas. A shallow sea for a sound field is a waveguide in which certain modes propagate. Features such as "extinction" modes and dispersion distort the picture of the sound field. There is also a complex interference situation due to reverberation interference and multiple re-reflections. To avoid information loss, it is proposed to use narrowly directed parametric radiation without side lobes. The issues of equipment selection are considered, the law of temporary automatic gain control (TAGC) for the study of bottom layers is calculated. The results of the analysis of echograms for depths of 1-2 m are presented. The possibility of identifying layers and anomalies is shown.
Keywords: shallow sea, sound propagation, modality, waveguide, TAGC's law, structure data, layers, profilograph, anomalies
This publication is devoted to the method of applying coatings from various materials to carbide cutting tools by the method of electrospark alloying, as well as the experience of using this method in practice. The formation of the surface layer, its structure were studied, and cutting tests were carried out. It has been found that nickel and aluminum coatings are more resistant than copper and zinc coatings.
Keywords: coating, carbide, cutting tool, wear, electrospark alloying, roughness, hardness
The effect of a zeolite support on the physicochemical properties of cobalt catalysts prepared by the precipitation method and calcined at 400°C was studied. The values of the specific surface of the catalysts, the degree of cobalt reduction, and the dispersion of the metal were determined, and the presence of functional groups on the surface of the catalysts was determined by BET, TPV, TPD-H2, and IR spectroscopy.
Keywords: catalyst, cobalt oxide, hydrocarbons, dispersion, active surface
A semiconductor quantum wire (QW) containing an impurity center described in the framework of a hydrogen-like model is considered. The possibility of using InSb QW in photodetectors of infrared optical radiation is discussed. The QW is modeled as a geometrically symmetric cylinder, on the axis of which an impurity center is located at an arbitrary point, with which the origin of the cylindrical coordinate system is associated, in which calculations are performed. It is assumed that the magnetic length is much smaller than the effective Bohr radius - the case of a strong magnetic field. This approximation made it possible to make the impurity potential effectively one-dimensional and obtain analytically accurate calculation results. In the effective mass approximation, in the dipole approximation, an expression is obtained for the matrix elements of the optical transitions of an electron from the impurity ground state to the size-quantized QW states for the case of transverse light polarization and the Kane dispersion law of charge carriers.
Keywords: matrix elements of optical transitions, effective mass method, quantum wire, dipole approximation, size-quantized states
The article is devoted to the development of models and algorithms for calculating control (advisory) actions when training operators of technological processes (on the example of reloading processes and, in particular, portal cranes) on computer training complexes (CTC). A complex of models and algorithms is proposed, based on which control actions are calculated regarding discrete crane controls and the possibility of moving the load to a target position with minimization of oscillations at the end point is provided. These models and algorithms use variable parameters of the technological process, described by linguistic variables, and customizable characteristics of crane models and engines, which allows calculating control actions depending on the type of crane, the specifics of the technological process, the training methodology used for operators and other significant factors. Application of the advisory system based on the developed models and algorithms promotes to improve the training process for operators of reloading cranes at CTC and, as a result, to reduce the probability of emergency situations, reduce time and energy costs.
Keywords: computer simulator, reloading processes, portal crane, advisory system, control actions, mathematical modeling, fuzzy logic controller
This article describes the process of inventorying equipment in a typical IT department. A new approach to inventory is proposed, which will eliminate the "double work" and solve a number of typical problems. The relationship with an already developed product for monitoring network infrastructure is described.
Keywords: monitoring, network infrastructure, inventory, QR code, Telegram, information technology, information technology department
This paper analyzes the state of the automation level of energy facilities. The most rational method of assessing the level of automation is given: consideration of each energy facility (generating enterprises, transport companies, consumers) separately for the most effective assessment. The analysis of the level of automation of generating companies on the example of thermal power plants is given. A solution aimed at increasing the level of automation is proposed. The analysis of the level of automation of transport companies and consumers on the example of thermal energy is also given. The ways of increasing the level of their automation aimed at improving the efficiency of transmission and use of energy are proposed. The article presents a number of advantages of the introduction of automated systems at energy facilities on the example of an automated dispatch control system at power plants and substations. A number of the most promising solutions for increasing the level of automation of energy facilities are also presented.
Keywords: automation, energy facilities, automated dispatch control, energy complex
It was necessary to develop a filter design option for implementing it on an FPGA in conditions of limited FPGA resources and processing time. Options for constructing filters and sequential optimization of the structure for implementation on an FPGA were considered. Two models were built using the Matlab environment, where the results of signal processing with filters were compared for the same parameters. Simulations have shown that the filters are unique.
Keywords: DSP, FIR filter, pipeline, FPGA
The object of the research is the utilization heat exchanger. The purpose of the work is to develop a design of a heat exchanger (HA) used to recover the heat of exhaust gases from a gas turbine unit (GTU) with an increased thermal power. In the process of work, the calculation and numerical modeling of the new design of the heat exchanger was carried out. The result of the research was the design of a gas-air heat exchanger, which requires 6.5% less flow rate of the coolant (exhaust gases) compared to the prototype.
Keywords: heat exchanger, heat utilization, energy efficiency of a gas turbine unit, numerical modeling, gas-air heat exchanger
The article discusses topical issues related to modeling the physical processes in the operation of solar photovoltaic batteries. In the course of the research, the simulation of photovoltaic batteries was carried out in the MATLAB / Simulink / Simscape simulation environment. The output current of the solar cell is chosen as the main electrical parameter. The model is tested using the characteristics of the ABi-Solar P60270-D polycrystalline photo module.
Keywords: photovoltaic batteries, MATLAB / Simulink, voltage, solar energy, capacity, defects, control
The control of the fabric in the technological chain determines the structure of this very chain. The article uses a probabilistic model to assess the feasibility of re-processing fabric in finishing production.
Keywords: fabric, marriage, quality, batch, product, technological defect, reprocessing, profit, loss
The paper studies the issue of the influence of the quality of the computational triangular grid on the accuracy of calculations in various computational problems. There is a well-known example of Schwartz, which shows that the approximation of a smooth surface by a polyhedral surface can give very large errors for calculating the surface area. This is due to the quality of the constructed triangulation of the surface. Therefore, it is natural to expect that there is some connection between a certain triangulation characteristic and the accuracy of solving some computational problem. In the presented article, as such a characteristic, a value is chosen - the average value of the minimum sine of the angle of all triangles of the computational grid. In the course of numerical experiments, the Dirichlet problem for the Laplace equation in a circular ring was solved, in which the error of the approximate solution was calculated (the gradient descent method was used to find a solution to the corresponding variational problem.). For the ring, a series of triangulations was constructed with a uniform division along the angle and a non-uniform division along the radius in polar coordinates. In this example, a linear dependence of the error on was shown. The article presents both the results of the calculation with different values and the calculation of the correlation coefficient of the studied quantities.
Keywords: boundary value problem, Delaunay triangulation, calculation accuracy, Dirichlet problem, mathematical modeling, triangular mesh, minimum triangle angle, piecewise linear approximation, variational method, Laplace equation
This article considers one of the parts of the development of a device for determining the magnetic characteristics of ferromagnetic materials with a shape memory effect. A functional diagram of the device has been developed. The operation of the device was simulated and the behavior of the shape memory alloy was studied. The error in determining the magnetic characteristics of the FMSF using the magnetizing setup of the developed device did not exceed 0.25%.
Keywords: magnetostrictive materials, basic magnetization curve, magnetic shunt, magnetic flux
This article discusses the development of a magnetometer calibration device, which is controlled by a microcontroller, Arduino [1, 2], which can receive, process and transmit the necessary commands to the peripheral part of the installation using the written program code. The need for buffer circuits and elements allows you to control I / O devices. With their help, interface hardware is implemented. Structural and functional diagrams of the device were developed. And also the calculation of the parameters of the Helmholtz coils was carried out, their 3D model was built. With the help of the Gaussmeter, a full-scale experiment was carried out, which confirmed the operability of the device and its effectiveness.
Keywords: control and measuring device, induction, Helmholtz coils, gaussmeter
This article discusses the development of a digital weather station with the measurement of geomagnetic field parameters. The advantage of the developed device is the possibility of simultaneous stable and correct operation of several sensors (namely 15), measurement accuracy at long distances (up to 300 meters). Structural and functional diagrams of the device have been developed. The voltage regulator of the device is designed in the Micro-Cap circuit analysis program. Experimental studies of the finished device were carried out.
Keywords: digital weather station, geomagnetic field, magnetic sensor, Arduino
This article discusses the development of a control and measuring system for reading barcodes from printed circuit boards in the production process. A functional diagram of the device was designed. A full-scale experiment was carried out to determine the working distance and angles for reading barcodes. It was revealed that the developed system has competitive advantages over analogues in a higher barcode reading speed and work with different barcode inclination angles.
Keywords: control and measuring system, bar code, printed circuit boards, laser range finder
This article considers the development of an information-measuring system for determining the thermophysical parameters of electrical devices. The developed functional diagram of the device is presented. Experimental studies were carried out in the COMSOL program. As a result of an experimental study of the transfer of heat from one part of the electromagnet to another, namely from the magnetizing coil, through the core to the environment, it was concluded that the best location of the temperature sensors is in the upper part of the body of the electromagnet EM-34-5. The data obtained can be used to determine the thermophysical parameters, in solving problems of the theory of inverse problems of heat transfer and heat transfer.
Keywords: information-measuring system, electrical devices, thermophysical parameters, COMSOL
The article discusses the importance of using modeling to analyze the technological performance characteristics of products, identify possible defects. The paper presents the results of a study of the design of the terminal locking device, and draws conclusions about the effectiveness of using the ANSYS software in the design of mechanical engineering products.
Keywords: modeling, locking device, innovative technologies, reliability, material quality, operational characteristics, working environment, mechanical engineering
The article presents a variant of the analytical dependence of the workability factor on the time of execution of a specific operation by an employee of the transport security unit performing the function of screening passengers and baggage crossing the borders of the transport security zone using technical means of ensuring transport security. A mathematical model of the influence of the human factor on reducing the number of technological operations, as well as the quality of inspection activities during long-term monotonous and homogeneous operations is constructed. A software implementation of passenger questionnaires through the Blockchain system is presented to optimize the work of employees from the transport security units performing the functions of passenger and baggage screening in order to improve the security of transport infrastructure facilities and vehicles from acts of unlawful interference.
Keywords: blockchain, transport security, inspection, data analysis, data processing, mathematical model, workability, optimization, railway transport, transport security units