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  • GaInAsBi epitaxial films based on indium arsenide - a new material for infrared lighting technology

    The results of a theoretical and experimental study of the synthesis of GaInAsBi thin-film structures formed on InAs substrates in the field of a temperature gradient are discussed. The features of interfacial interaction in the In-As-Sb system in the presence of isovalent solvents (In, Bi) have been studied. The values ​​of the interaction parameters and the distribution coefficients of the system components are determined. Optimal technological modes for obtaining InAs-based heterostructures are presented. The properties of the surface of epitaxial layers are studied experimentally. It was found that the main control parameters are the temperature of thermomigration and its gradient. It is shown that the synthesized semiconductor materials can be effectively used in electronic devices of a new generation - electro-optical modulators and supersensitive sensor elements.

    Keywords: epitaxial structure, crystallization, recrystallization, melt, segregation coefficient, organometallic compound, voltage sensitivity, near infrared range, solid solution, optical characteristic

  • Analysis of the technical and economic efficiency of low-rise construction based on Canadian technology

    The article discusses several types of wood frame house construction technology, primarily "Canadian technology". The rate of increase in construction in Russia is estimated. The structural materials of external enclosing structures used in frame housing construction are compared with the most commonly used components for construction. A comparative assessment of heat losses in percentage ratio during the operation of wooden frame houses and traditional ones is given. The pros and cons of frame housing construction are considered. A detailed analysis of the costs of construction and operation of wooden frame houses was made.

    Keywords: frame house construction; Canadian technology; building materials; dynamics of price changes

  • Influence of ground slag of steelmaking production on the properties of a composite slag-alkaline binder

    The hardening of steel-making slags is slow and the strength properties of the cement stone do not provide the specified operational properties. By creating an optimal composition (steelmaking slag + blast furnace) and chemical activation, a composite material with high strength is obtained. The compressive strength of concrete samples at the age of 28 days of hardening in a normal hardening chamber is 28 to 54 MPa. Caustic soda and sodium silicate were used as a chemical activator of hardening. The greatest strength is provided by the ratio of chemicals as NaOH: Na2 SiO3 × nH2O = 1: 1 and at a dosage of 8% of the mass of the composite slag-alkali binder. The optimum ratio of ground granulated blast furnace slag and steelmaking slag is 3: 1 to obtain high compressive strength and minimum water absorption in the early stages of hardening.

    Keywords: steelmaking slag, blast furnace slag, homogenization, hardening activator, hydration, strength

  • Application of tensor methodology for the design of mathematical models of electromagnetic drives

    When creating a model of a nonlinear electrical system based on differential equations, it is important to keep in mind that ordinary differentiation does not give an adequate mathematical idea of ​​the nonlinear physical processes taking place. Even in the simplest case of a conductor with a current, the construction of an adequate model is only possible if the tensor approach is applied. From this point of view, any electrical system is an object of tensor methodology. A typical example of a non-linear electrical system is an AC electromagnetic drive. The nonlinear nature of the processes in such devices is due to a number of reasons. The main reasons are: current displacement in the winding of the AC electromagnetic drive and saturation of the steel of the magnetic circuit in the process of magnetization. Both phenomena admit tensor description, which is confirmed by the research presented in the article.

    Keywords: dynamic characteristic of magnetization, electromagnet, mathematical model, tensor methodology

  • Information system of a research organization

    Nowadays, it is often necessary to create effective tools for collecting, analyzing and processing information related to taking into account the activities of universities. There is also a need to develop information systems that provide automation of educational process management functions, which would reduce the cost of organizing educational process management in an educational institution. One of the primary tasks of the university is the implementation of research work by students, graduate students and research workers on the basis of research organizational structures. In this regard, an additional burden is placed on the employees of a research organization, which implies the performance of routine operations, as a result of which mistakes can be made. You can avoid possible mistakes, as well as increase the efficiency of employees by creating an information system, which is described in this article.

    Keywords: information system, science, university, information services

  • Automated non-destructive testing in the monitoring system of the technological process of bearing production

    The issues of ensuring the reliable operation of bearing production on the basis of the organization of the process monitoring system (SMTP), based on the introduction of effective automated control and diagnostics of technological equipment, including processing modes and technical condition, active control of product quality in the manufacturing process, output characteristics of rings processed by the eddy current method, as well as making decisions on timely maintenance of equipment. The results of the inspection are stored in a report file generated in the eddy current device computer: information about each checked part is stored: the time of inspection, the type of part, the surface to be monitored, the number of the machine on which the part was processed. The results of eddy current control serve as the basis for monitoring the dynamic characteristics of the equipment by vibroacoustic vibrations. Based on the results of the control within the framework of the SMTP, a decision is made on the quality management of processing. The introduction of SMTP provided a significant reduction in ring defects in terms of grinding quality up to 2-3 % and increased operational reliability of bearings.

    Keywords: grinding process monitoring, bearing rings, dynamic machine quality, active control, eddy current control, ring quality

  • Application of a magnetic shunt to increase the sensitivity of a device for testing samples of magnetostrictive materials

    This article discusses one of the parts of the development of a device for testing samples of magnetostrictive materials. A study of various designs and an analysis of the sensitivity of the measuring system are presented. The substantiation of the use of a magnetic shunt to increase the sensitivity is given, which is confirmed in field experiments.

    Keywords: magnetostrictive materials, basic magnetization curve, magnetic shunt, magnetic flux

  • Automation and control of technological processes of a promising checkpoint

    The restraining setting for customs administration at the border of the Russian Federation is the insufficient equipment and technological equipment of checkpoints. The current uniform requirements for equipment and material and technical equipment of buildings, premises and pass structures do not provide for the introduction of high new technological solutions that have appeared in recent years. Proposals are presented to improve the control system at checkpoints based on advanced technologies of Technet technologies and subtechnologies of end-to-end digital technology "Artificial Intelligence and Neurotechnologies".

    Keywords: customs, automation, end-to-end digital technologies, checkpoint

  • Existing Ways to Formalize Fuzzies in Transport Processes

    The lack of information about the conditions for the implementation of transport processes does not allow building mathematical models that operate with extremely accurate input data. Therefore, methods are being developed that formalize input uncertainties for constructing mathematical models of transport processes. To describe uncertainties, along with static, stochastic and interval approaches, methods based on fuzzy sets are actively used. The generalization of the belonging of the element, presented by Zadeh, allowed blurring the boundaries of the set. The blurring of the boundaries of the sets allows one to formalize insufficiently complete, in an informational sense, judgments and facts for the purpose of the subsequent use of this information in the construction of mathematical models. To identify formal approaches to working with uncertainties, an analysis of foreign periodicals in recent years has been carried out and two well-known approaches have been identified. The first is based on the theory of fuzzy sets - the generalized concept of belonging of an element to a set, leading to blurring of the boundaries of the set. The second approach involves describing fuzziness using a hierarchy - a family of ordered crisp sets [1]. Within the framework of the first approach, the authors have identified five ways of formalization. The first includes fuzzy sets (numbers) with different n-gonal forms of the membership function. The second consists of intuitionistic fuzzy sets (numbers) with n-gonal membership functions. The third contains heterogeneous fuzzy sets of type 2. The fourth represents non-standard fuzzy sets (oscillating, Pythagorean, etc.). The fifth method is a combination of spaced fuzzy numbers, intuitionistic spaced fuzzy numbers, and the like. References are given to sources containing a description of formalization methods and their application in solving some fuzzy transport problems, possible directions of research on the considered topics are formulated.

    Keywords: fuzzy transport routing problem, optimization, fuzzy methods, fuzzy numbers, fuzzy sets, heuristic algorithms, hybrid algorithms, transport processes

  • Managing the life cycle of a construction investment project taking into account the importance of environmental factors

    This article considers the assessment of the life cycle costs of investment and construction projects, taking into account the costs aimed at reducing the level of pollution into the environment. Financial calculation tools used to analyze investment decisions and calculate the cost of the life cycle of an object (LCC life cycle costs, also life cycle costs) are closely related methods of evaluating investments, including equipment, installation, construction work and various infrastructure investments necessary to maintain and develop the construction sector in the country's economy. For environmental management, this analysis allows the construction company to assess the financial benefits of alternative strategies or compare such strategies with the current state of affairs. The calculation of investments in terms of costs, cost savings and the potential to reduce the risk of environmental responsibility is the basis on which construction organizations should base their long-term strategies. The article is aimed at highlighting the issues of rational calculation of investment decisions in construction to maintain a favorable environmental situation in the territory where the construction production will be located.

    Keywords: environmental safety, environmental monitoring, project management, ecology in construction, dust suppression, life cycle costs, dust collection systems, investments in construction

  • Club "Planet" as a unique building in Rostov-on-Don

    Club architecture of the XX century has a significant role in the history of architecture development both in Rostov-on-Don and in Russia as a whole. This is due to the presence of a number of tasks, which clubs were solved in the formation of Soviet society. The change of socio-economic formation, the nihilism connected with the oblivion of some tendencies in the Soviet architecture as something alien, exposed the problem of the study of architectural form - the clubs of 1960-1980. The study, which previously did not pay due attention. As a consequence, the formed "gap" in the architectural history of the unique form of clubs, the lack of emphasis on the need for their study and conservation can lead to an irretrievable loss of structures which have compositional and artistic value. One of such objects is a club of tourists and climbers "Planet", located in the park named after N. Ostrovsky in Rostov. N. Ostrovsky Park in Rostov-on-Don. The relevance of the study of its architecture for history and local history prompted the writing of this article. The peculiarities of the club are discussed, the analysis of urban planning and volume composition of the building is carried out, it reveals the uniqueness of the building. Determined the architectural and artistic features of the building on the basis of field research and the study of preserved historical and graphic materials. The value of the object (wall of basalt stone), as a structure reflecting the main directions of the club of tourism and mountaineering is revealed, its current state is recorded.

    Keywords: Planet Club architecture, mountaineering and tourism, basalt rock, reconstruction, N. Ostrovsky Park, feature

  • Predicting the state of a stochastic system on electrified railways

    Stochastic systems are systems in which changes are random. In which the predicted values depend on a probability distribution. An example of a stochastic system in a power system, the operation of which is affected by many random factors, their analysis and control will allow you to control the safe cycle and reliability of operation. Currently, there are methods and mathematical tools that allow us to estimate the likelihood of any phenomenon and situation with acceptable accuracy, however, they are practically not used to solve this problem on electrified railway transport. Therefore, the work summarizes the existing methods of probabilistic forecasting, and gives recommendations on their application to solve the existing problematic of the issue. Further, the paper shows a method for determining the probability of failure of a constituent structural element of any, arbitrarily complex, stochastic system, to which the contact network of electrified railways belongs. In the conclusion of the work, an elementary method-oriented software tool with the functional purpose of automating statistical methods for solving problems of primary data processing and calculating elementary statistics in the process of risk management is proposed, as well as loading and maintaining a database that is subsequently oriented to the principles of machine learning.

    Keywords: electrified railways, stochastic systems, operational reliability, probability of failure, forecasting

  • Development of an algorithm for identifying the parameters of object models using the example of a temperature control system

    The article discusses the main stages of identification of a control system for maintaining a given temperature, which includes an actuator, a control object and a temperature sensor. The initial data were experimental values ​​obtained under various setting influences on objects of the material world. To confirm the accuracy of the calculations and the selected methods for identifying parameters, mathematical modeling of the system in the Matlab / Simulink package is presented. At the end of the article, quantitative and qualitative assessments of the obtained mathematical models are given. The identification of the parameters of the control system for maintaining the set temperature was successful. The developed algorithm for describing material objects by mathematical models showed a low error, which indicates the applicability of this approach in real technological processes of production management.

    Keywords: identification, mathematical model, control object, control system, transient response, full-scale experiment, transfer function

  • Development of an AC voltage regulator

    An urgent scientific and technical task is the development of electric energy converters with high operational and energy characteristics. The use of modern methods for the development and analysis of power electronics circuits based on the use of computer equipment allows us to successfully solve this problem. In this article, a schematic diagram of an alternating voltage regulator has been developed, in which a control system based on a microcontroller implementing an algorithm for pulse-phase regulation of the variable output voltage is used to control a power thyristor key. The control system, a power thyristor key, is synchronized with the moments of transition through zero of the supply voltage of a sinusoidal shape. The controller circuit is adapted for computer modeling in the environment of the PROTEUS software product. In the article, a block diagram is also developed and a software implementation in assembly language of the microcontroller operation algorithm is performed. As a result of computer modeling, time diagrams of voltages on the main elements of the AC voltage regulator circuit are obtained. Time diagrams explain the features of electromagnetic processes occurring in the controller circuit. The results of computer modeling, the controller circuit, the developed algorithm and the microcontroller software can be used in the development of electric energy converters for automatic control systems of electrical equipment.

    Keywords: computer simulation, thyristor regulator, alternating voltage, microcontroller operation algorithm, time diagrams, transistor switch, control system, damping circuit, power thyristor, active-inductive load

  • Investigation of the heat transfer process in a cylindrical fuel element

    the presented work is devoted to the study of the temperature state of a fuel element (fuel element) – a cylindrical solid body with an internal heat source of constant power. Using the integral method of heat balance with the introduction of an additional desired function, an approximate analytical solution of the corresponding boundary value problem of thermal conductivity is obtained. The conditions of external heat transfer at the boundary of the studied region were set according to the Newton-Richman law (a boundary condition of the third kind). When obtaining the solution, trigonometric coordinate functions were used. Their use made it possible to reduce the number of terms in the desired solution due to the a priori fulfillment of the boundary condition in the center of the fuel element. It is shown that when using only three terms in the analytical solution (the first approximation), an accuracy sufficient for engineering applications is achieved. The error of the developed method was estimated by comparing the results obtained with a numerical solution based on the finite difference method. The article presents graphs of the temperature distribution at different power values of volumetric fuel element heat sources. The developed method can be used to determine the time of the system's exit to the stationary mode, estimate the maximum fuel element temperature at various values of the dimensionless Bio and Pomerantsev numbers, and determine temperature stresses.

    Keywords: internal heat sources, boundary conditions of the third kind, additional desired function, heat balance integral, heat-generating element, approximate analytical solution, numerical solution, heat conduction problem, Bio number, Pomerantsev number