In article results of the analysis of method of calculation of flat plates of girderless floors are considered on breakdown according to the Russian and foreign design codes are considered. The analysis of the received results demonstrates that in the considered calculation procedures on breakdown similar settlement models are used and identical power factors are considered. Namely the pressing-through effort and the bending moments operating in two planes. Taking note of the moments in various techniques is carried out in two ways. The first way – tangent tension is entered into settlement model. And each technique offers the form of an epyura of tangent tension. The second way – introduction to a condition of durability of the empirical coefficient considering influence of the bending moments. Approach to purpose of geometrical parameters of a settlement (critical) contour is not identical. Contours of different techniques differ in a form and the sizes. And the difference of the sizes is very considerable. It is established that work of knot of interface of girderless flag with a column is studied yet not fully and additional researches on generalization of calculation procedures are required.
Keywords: reinforced concrete, girderless floor, breakdown, working height of section, transversal armature, pyramid of breakdown
The main disadvantages of the methods of diagnosing the cylinder-piston group used at present are indicated in the article. Mathematical dependencies and the technique of technical diagnosing of a cylinder-piston group of diesel engines with a cold starting cranking of a cranked shaft developed on their basis are offered.
Keywords: engine, cylinder-piston group, compression,diagnosis, cold idle cranking of the crankshaft
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
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
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
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
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
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
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
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
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
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
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 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
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