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  • Research of the thyristor regulator of the booster voltage harmonic composition with longitudinal-transverse regulation of the output voltage

    The article is devoted to the study of the thyristor regulator of the booster voltage harmonic composition in the mode of longitudinal-transverse regulation. The results of the harmonic analysis of thyristor regulator output voltage , obtained using simulation in the Simulink package, are presented.

    Keywords: longitudinal-transverse regulation, thyristor regulator, regulating characteristics, modeling, harmonic analysis, Matlab Simulink

  • Formation of diagnostic signs for security systems

    The application of the parameters of the modes of signal allocated using the extremal filtering algorithm is considered. The use and disadvantages of amplitude detectors are described. Use of attenuation are described and shows how to reduce the effect of ""overshoots"". It is proposed to use a combined sign for a more contrast extracting of detection areas. A method for reducing the labor intensity is presented, which consists in applying filtering directly to a number of extrema, without calculating the smoothed components.A method was chosen that allows the signal analysis algorithm to be adapted to work in real time.

    Keywords: Security system, diagnostic signs, extreme filtering, mods, real time

  • Development of a highly efficient design of a sulfuric acid alkylation jet reactor

    The article discusses the process of sulfuric acid alkylation used to produce high-octane gasoline, as well as the design of jet reactors, their advantages and disadvantages. Based on the existing drawbacks of jet reactors, the development of a new high-efficiency jet reactor design has been proposed.

    Keywords: reactor, sulfuric acid alkylation, isosurface, isocontours, gasoline, fractions, jet type, industry, oil refining

  • Prescription and technological aspects of obtaining high-quality centrifuged concrete

    The possibility of creating centrifuged products of an annular cross section with a variotropic structure due to the introduction of a porous aggregate is considered. Various methods of introducing coarse aggregate have been studied in order to increase the uniformity of the physicomechanical properties of centrifuged products. The study examines the effect of various types of fiber fibers on the physicomechanical properties of centrifuged concrete. The results of physical and mechanical tests of fiber-reinforced concrete showed that the greatest effect on compressive strength is achieved with the introduction of a metal fiber into the composition. At the same time, shrinkage deformations are lower by 20% in the composition with basalt fiber as compared with the control fiber. Studied recipe-technological techniques have proven their effectiveness and can be successfully applied in construction practice.

    Keywords: centrifuged concrete, fiber, fiber concrete, coarse aggregate, porous aggregate, variotropic structure

  • Estimation of the impact of disperse reinforcement on coefficient of structural quality of vibrated and centrifuged heavy concrete on granite rubble

    The article presents and studies the theoretical foundations of vibration and centrifugal compaction of heavy concrete in the production technology of building products and structures. Attention is paid to such a technique as vibropressing. The physical entity is described, the phenomena of the processes occurring during the molding of such products and structures are disclosed. The influence of dispersed reinforcement of vibrated and centrifuged concretes by various types of fiber fibers on their coefficient of structural quality is considered and evaluated.

    Keywords: vibrated concrete, centrifuged concrete, dispersed reinforcement, coefficient of structural quality, vibropressing

  • Modernization of a standard gasoline engine, which uses a gas-air mixture as fuel

    The article proposes a scheme of modernization of the gasoline engine to work on a gas-air mixture. This article discusses the technical characteristics of the engine on gasoline which is recommended by the manufacturer. The characteristics of the engine operation on the gas-air mixture without alterations, and the characteristics that the engine shows when working on the gas-air mixture with the already made changes are also given.

    Keywords: car, gas equipment, intake valve, compression ratio, mixture pressure

  • Innovative developments in the field of constructive and architectural solutions for translucent roofs of airports from glass materials

    the paper presents the characteristics of the leading on the market types of structures and types of materials used in the construction of translucent roofs of glass-filled airports , based on the analysis of which the technology is promising. Also are described innovative developments applicable in the field of study.

    Keywords: translucent roof, triplex, tempered glass, airport, single-chamber double-glazed window, long-span coating, roofing, coating, translucent construction, glass roofing, panoramic roofing, glass coating

  • The efficiency evaluation of stabilization circuits of operation modes of the input stages of the differential and multidifferential operational amplifiers under the influence of ionizing radiation and temperature. Part 2. Current feedback

    This paper presents a radiation hardened by design of differential stages using dynamic loads. The efficiency of proposed design methods to improve the scheme qualitative indicators can be assessed by some evaluation. The theoretical results of the evaluation of the self-compensation circuit effect of parasitic impedance of the output transistor closed collector in the dynamic loads of classical differential stages, which is realized on the base of current feedbacks, are presented. It is shown that the introduction of the current feedbacks allows to reduce the effect of transistors small-signal parameters instabilities of the dynamic load under the influence of ionizing radiation and temperature on it's quality and the parameters of the differential stages. The efficiency evaluation of the circuit solutions in differential stages of modern operational and multidifferential amplifiers is given. The theoretical results of the evaluation of the self-compensation circuit effect of parasitic impedance of the output transistor closed collector in the dynamic loads of classical differential stages, which is realized on the base of current feedbacks, are presented. It is shown that the introduction of the current feedbacks allows to reduce the effect of transistors small-signal parameters instabilities of the dynamic load under the influence of ionizing radiation and temperature on it's quality and the parameters of the differential stages. For the organization of feedback circuits in the structure of dynamic loads, additional current amplifiers based on transistors are introduced into the circuit. It is shown that this approach can increase the output resistance of the dynamic load and increase the gain coefficient of the differential stage under the influence of ionizing radiation and temperature. The efficiency evaluation of the circuit solutions in differential stages of modern operational and multidifferential amplifiers is given. The efficiency evaluation method is based on the construction of a mathematical model of the scheme expressed through low-signal differential h-parameters of the scheme transistors. Thus, the calculation of the main qualitative indicators of the scheme can be carried out by mathematical modeling. The obtained simulation results confirm the efficiency of the proposed circuit design.

    Keywords: efficiency evaluation, circuit design, differential stage, dynamic load, destabilizing factors, low-signal parameters

  • About some features of the layout of dust cleaning systems with vortex inertial devices with counter-swirling flows

    Based on the results of theoretical and experimental studies, the necessity of taking into account the “overshoot effect of large particles” in inertial devices with small diameters is justified when assembling dust collection systems with devices of different sizes.

    Keywords: vortex inertial dust collector with counter-swirling flows (CTF), suction from the bunker, differently polluted flows, aerodynamic resistance, overshoot

  • Analysis of the reconstruction of residential buildings, taking into account their life cycle

    Over time, residential buildings under the influence of physical deterioration, as well as moral degradation need to be transformed. Experience in the redevelopment of residential buildings of the 1960s – 1990s. built in the Republic of Belarus, as well as in other countries of the former USSR, testifies to the significant resource intensity of this process, which is due to a certain “rigidity” of the structural and technical characteristics of the reconstructed buildings. Given that during the life cycle global housing redevelopment measures may be needed every 30–35 years, questions of reducing resource intensity during this type of work are an important factor in optimizing the process of operating the housing complex as a whole.

    Keywords: operation and reconstruction, design, life cycle, architecture, urban planning, construction

  • Principles of saving metal in reinforced concrete structures

    The question of economy of metal at production of building designs is considered. Measures for the organization of effective production in the current projects of high-rise and long-span buildings are proposed. Measures of increase of efficiency of construction are considered

    Keywords: organization of construction; economy of construction, production of building materials

  • The effect of modifying additives on the properties of the supported cobalt catalyst

    The physical and chemical properties of cobalt catalysts for Fischer-Tropsch synthesis have been studied. The effect of copper and iron oxides on the specific surface, pore volume and dimensions, and the degree of reduction of metallic cobalt on the surface of the Co-Al2O3 / SiO2 catalyst have been studied.

    Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, cobalt, promoter, carrier, specific surface, porous structure, catalytic activity, reduction degree

  • Modification of the generalized algorithm for processing weakly formalized information

    A modification of the generalized algorithm for processing weakly formalized information is considered. It is assumed that in the processing of weakly formalized information it is important to consider external and internal factors. External factors are determined by the characteristics of the incoming information. Internal factors are determined by goals, objectives, methods, etc. The importance of taking into account the latter is that if goals are clear, tasks are set, methods for solving problems and achieving goals are known, then the volume of information being processed is significantly less and the speed of achieving goals is significantly greater. The increase in the speed of processing incoming information is achieved due to the fact that the information processing system adapts to the purpose of information processing. The dominant state of the information processing system is formed taking into account the goals of information processing and the characteristics of the incoming information (the dominant of A. A. Ukhtomsky). Thus, the processing of weakly formalized information from various technical systems allows, taking into account the dominant of A. A. Ukhtomsky, to take into account in the dynamics not only the external impact of the incoming information on the system processing information, but also the state of the information processing system. This system adjusts to the goals of information processing and taking into account the purpose of information processing and the characteristics of the incoming information, the dominant state of the information processing system (dominant) is formed. This allows you to reduce the processing time of incoming information due to the fact that the dominant formed means that the information processing system knows how to process information that has not yet arrived, but it is expected that it will soon go to the sensors of technical systems. In the process of processing the system of processing of weakly formalized information, the dominant may change over time. These changes may be due to changes in both the purpose of collecting the information and the characteristics of the incoming information. Such an approach, which takes into account the dominant of A. A. Ukhtomsky, allows processing large volumes of information in real time and can be used in the development of control systems.

    Keywords: information processing, weakly formalized information, algorithm, dominant of A. A. Ukhtomsky, lack of information, control

  • Human activities as the principle of formation of social and functional of carcases in the spatially-geometrical properties of the urban environment

    The article deals with the human activity that is carried out in the spatial-geometrical conditions of the city. The main interest presents the distribution of forms an activity on the territory of the urban area. The allocation identified the social and functional frames or carcases, which characterized by the consolidation of properties, density, sparsity, and scattering. The skeletons set the degree of mixed use and diversity activities, and track the social and functional processes of their dynamics and changes in the spatial and geometrical properties of the urban environment.

    Keywords: Human activities, spatial and geometric conditions, distribution activities, social and functional carcases, consolidation and diversity of activities

  • Investigation of the influence of the parameters of the Gunn diode and the inhomogeneity of doping on its operating modes with the help of a physico-topological model

    When modeling the transport of hot carriers in strong electric fields and using various mathematical relationships describing these processes, usually do not take into account inhomogeneities of impurity doping, which affect the field distribution and the density of the output current. In this paper, we calculated the field distribution along the length of the diode chip. In this case, a one-dimensional model and a phenomenological approach to the description of carrier behavior were used. The results obtained allow one to estimate the influence of the inhomogeneity on the operating modes of the Gunn diode and can be used to create models of higher orders.

    Keywords: Gunn diode, numerical modeling, heterogeneity doping physical topological model