scholarly journals Investigation of the effect of ultrasonic radiation on varnished and compounded impregnating compositions with an innovative method of dismantling electric motor windings

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (4) ◽  
pp. 354-363
Author(s):  
A. E. Nemirovsky ◽  
A. I. Kashin
Keyword(s):  
Experimental Studies ◽  
Point Of View ◽  
Electric Motors ◽  
Optimal Parameters ◽  
Environmental Friendliness ◽  
Stator Windings ◽  
Innovative Method ◽  
Working Solution ◽  
Insulation Systems ◽  
Scientific Results

For the purposes of energy efficiency, ecology and less time for the cycle of repairing electric motors in the part of the excavation of the stator winding, an innovative method for dismantling ultrasound-based windings has been investigated. From a technical point of view the method has shown to be more optimal in comparison with existing methods of removing the winding. The paper is a continuation of fundamental research on the development of an innovative method of repairing electric motors. It is in this article that the main emphasis is placed on the material from which the insulation of windings is made. Lacquer and compound insulations have been considered being the main types of insulation of industrial electric motors in our country. The analysis of impregnating electrical insulation compositions of motor stator windings has been carried out; the ultrasound effect during the dismantling of motor windings at different levels of influencing factors has been studied, namely duration and power of ultrasonic action, concentration and temperature of the working solution. The validity of the scientific results obtained in the work is confirmed by the correctness of the applied mathematical apparatus and the methods of mathematical modeling, the convergence of the results of numerical modeling and full-scale experiments. A system of equations has been simulated and models of the effect of useful factors relative to each other have been built, the results obtained have been optimized during the experiment and the optimal parameters of both lacquer and compound insulation systems have been identified. The optimal parameters of the types of insulation under study have shown encouraging results on many important points compared to the existing ones: duration, energy consumption, and environmental friendliness. The validity of the conclusions regarding the adequacy of the mathematical models used has been confirmed by the results of experimental studies conducted in the framework of this work of the process of depolymerization of the electric motors' stator windings.

scholarly journals Analysis of depolymerization of insulating compositions of electric motor windings based on ultrasonic radiation

Vestnik MGTU ◽  
2021 ◽  
Vol 24 (4) ◽  
pp. 361-371
Author(s):  
A. I. Kashin ◽  
A. E. Nemirovsky
Keyword(s):  
Electric Motor ◽  
Software Systems ◽  
Electric Motors ◽  
Optimal Parameters ◽  
Fundamental Study ◽  
Environmental Friendliness ◽  
Stator Windings ◽  
Working Solution ◽  
Insulation Systems ◽  
Winding Insulation

This work is a continuation of the fundamental study on implementing an innovative method of repairing electric motors using ultrasound. A study of the method of dismantling windings based on ultrasound has been carried out for the purpose of energy efficiency, environmental friendliness and less time spent on the repair cycle of electric motors in terms of removing the stator winding. The investigated dismantling method is optimal for a number of technical issues in comparison with the existing methods for dismantling electric motor windings. In the work, the main focus is on the material of the winding insulation. Lacquer and compound types of insulation of industrial electric motors, which are the main ones everywhere, have been analyzed. The analysis of the impregnating electrical insulating compositions of the stator windings of electric motors and the influence of ultrasound on them during dismantling of the windings of electric motors at different levels of influence of forcing factors: duration and power of ultrasonic action, concentration and temperature of the working solution. The applied mathematical software systems for calculation and modeling guarantee the reliability and rationality of the results of the experiments obtained during the work. A system of equations has been modeled and models of the effect of useful factors relative to each other have been constructed, the results obtained have been optimized and the optimal parameters of both varnish and compound insulation systems have been identified. The optimal parameters of the investigated types of insulation show encouraging results on many important points: duration, energy consumption, environmental friendliness.

scholarly journals Optimization of plastic foam composition for insulation systems

2019 ◽  
Vol 91 ◽  
pp. 02017 ◽  
Author(s):  
Anton Pilipenko ◽  
Ekaterina Bobrova ◽  
Alexey Zhukov
Keyword(s):  
Heat Loss ◽  
Experimental Studies ◽  
Point Of View ◽  
Structural Safety ◽  
Vapor Permeability ◽  
Building Structures ◽  
Polystyrene Foam ◽  
Building Systems ◽  
Insulation Systems ◽  
Extruded Polystyrene Foam

Construction insulation systems should provide solutions to the problems of creation of suitable conditions of load-bearing construction elements and whole construction, reduction of heat loss through thermal insulation layer, and creation of living comfort in buildings. The article presents the results of experimental studies, the purpose of which is to optimize the composition of extruded polystyrene foam, the formation of methods for selecting its composition and the development of systems for the use of products based on extruded polystyrene foam. Main provisions of the method of analytical optimization, which allows significantly reducing the material and time costs for processing the experimental results, are also provided. Aspects of the implementation of building systems using extruded polystyrene foam both from the point of view of minimizing heat loss through contact areas and the degree of influence of vapor permeability of building structures on the temperature and humidity conditions of premises are studied. Mandatory criteria for construction with the use of building systems are safety conditions, including both structural safety (including maintenance-free cycle) and fire safety.

scholarly journals Trial using of ultrasonic cavitation in cottonization processes of hemp fibers

ScienceRise ◽  
2021 ◽  
pp. 24-31
Author(s):  
Olha Hych ◽  
Oksana Zakora ◽  
Mariia Rastorhuieva ◽  
Andrii Zilinskyi
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Structural Features ◽  
Ultrasonic Cavitation ◽  
Hemp Fiber ◽  
Environmental Friendliness ◽  
Hemp Fibers ◽  
Textile Materials ◽  
Scientific Results ◽  
Technological Product

The object of research: ultrasonic processing technology of textile materials. Investigated problem: increasing the degree of splitting of complex hemp fibers due to the effect of the mechanism of ultrasonic cavitation on them. The main scientific results: The article shows the potential of textile production to ensure the environmental friendliness of textile products, and the development and implementation of new eco-technologies of physical and mechanical cottonization of hemp fiber is important in this. Analysis of existing methods of cottonization and structural features of hemp fibers has led to the conclusion that the destruction of cellulose satellites in complex fiber can be considered as a process of purification from impurities, since the technologies for purification of substances in the aquatic environment by ultrasound now are widely used. Therefore the process of cottonization of hemp by technology of ultrasonic treatment was used in this investigation for the first time. The basic principle effect on the textile material what placed in the liquid are the hydroacoustic effects formed by the collapse of cavitation bubbles in the contact zone "liquid-material". Experimental studies of the geometric characteristics of the obtained hemp cottonine were carried out, and the effectiveness of the effect of ultrasonic vibrations on the change of the structure of hemp fiber was confirmed. Due to the removal of inlaid substances under the action of cavitation, the complex fibers of hemp were split, as a result of which the range of variation and the absolute value of their length and linear density were decreased. The scope of practical use of the research results: textile enterprises of deep processing of bast raw materials into technical and household yarns. Innovation technological product: technology of ultrasonic cottonization of hemp fibers. The scope of using the innovation technological product: manufacturing of textile hemp products for general use.

Calculation And Experimental Substantiation Of Optimal Design Of The Welded Joint Of Plates On Соver Plates

2020 ◽  
pp. 17-24
Keyword(s):  
Welded Joint ◽  
Experimental Studies ◽  
Engineering Calculation ◽  
Tensile Tests ◽  
Physical Nonlinearity ◽  
Steel Plates ◽  
Optimal Parameters ◽  
Actual Problem ◽  
Numerical Research ◽  
Cover Plates

The article is devoted to the actual problem of assigning optimal parameters for connecting steel plates on cover plates with angular welds that are widely used in construction practice. The article presents the results of a comprehensive study of operation of a welded assembly of the plates connection on cover plates. An algorithm is proposed for determining the optimal parameters of a welded joint with fillet welds on the cover plates, which makes it possible to obtain a strength balanced connection. The results of full-scale tensile tests of models were presented. These results confirmed the correctness of the assumed design assumptions, and made it possible to obtain a form of destruction, not characteristic and not described in the normative literature, expressed by cutting the main elements along the length of the overlap in the joint. The possibility of such a form of destruction was confirmed by the results of numerical research in a nonlinear formulation. The optimal parameters of the nodal welded joint determined by engineering calculation are confirmed by experimental studies, as well as by the results of numerical experiments on models of calculation schemes, taking into account the physical nonlinearity of the material operation. The obtained dependence for determining the bearing capacity of the joint by the cut-off mechanism and the expression for limiting the overlap length of the cover plates will make it possible to predict the nature of the fracture and design equally strong joints.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

GOAL SETTING AND ITS ACHIEVEMENT AS A CRITERION OF SCIENTIFIC RESEARCH IN THE FIELD OF CIVIL LAW

2021 ◽  
Vol 3 (3) ◽  
pp. 96-123
Author(s):  
L.V. Shchennikova
Keyword(s):  
Goal Setting ◽  
Social Relations ◽  
Civil Law ◽  
Scientific Research ◽  
Scientific Work ◽  
Point Of View ◽  
Existing Problems ◽  
The Creation ◽  
Scientific Results ◽  
Definition Of

Introduction: the article deals with the methodological problem of the meaning of the goal of civil law research. The author analyzes the dissertation abstracts from the point of view of goal setting, which were completed in different periods of the development of Russian civil law science, identifies the qualitative characteristics of the stages, and proves the connection of the achieved results with the researcher’s knowledge of the methodological methods of goal setting. Purpose: to show the value of goal setting in scientific research in general and in civil research in particular; to consider the relationship of goal setting with the achievement of specific scientific results on the examples of dissertations defended in the specialty 12.00.03; to justify the need to set as goals the fundamental problems associated with the identification of patterns of development of relations that are part of the subject of civil law regulation and the creation of effective mechanisms that mediate them. Methods: system-structural, system-functional, generalization, abstraction, analogy, logical, statistical, classification, legal modeling, comparative legal, forecasting, formal legal, historical. Results: civil methodology should take into account the importance of the goal in the organization of scientific work. Only a competent possession of goal setting skills can ultimately ensure the creation of scientifically-based mechanisms for effective impact of civil law norms on regulated social relations. Conclusions: 1) any science, including the science of civil law, is not only designed to study and describe existing problems, including legislative, doctrinal, and law enforcement. Research, in order to meet the criterion of scientific character, must attempt to identify the laws of development, both regulated relations and mechanisms that mediate them; 2) the significance of the goal in the development of science has been proven by outstanding philosophers. In addition, the very definition of science indicates that goal setting is one of its essential characteristics; 3) the analysis of the author’s abstracts of leading Russian tsivilists showed how the skilful setting of research goals helped to achieve them consistently, as well as to create a high-quality categorical apparatus of civil law science; 4) the analysis of modern dissertations showed that not all young researchers see the value of goal-setting and this methodological disadvantage is important for the author to eliminate.

INFLUENCE OF TECHNOLOGICAL FACTORS ON THE EFFICIENCY OF REMOVAL OF SCALE FROM FLATS FOR HOLLOW BALLS

2021 ◽  
pp. 143-147
Author(s):  
А.В. Панфилова ◽  
А.В. Королев ◽  
О.П. Решетникова ◽  
Б.М. Изнаиров ◽  
А.Н. Васин
Keyword(s):  
Rotation Speed ◽  
Experimental Studies ◽  
Surface Cleaning ◽  
Point Of View ◽  
Design Parameters ◽  
Technological Factors ◽  
Proportional Relationship ◽  
Sheet Products ◽  
Process Factors ◽  
Rolled Surface

Рассматриваются результаты проведения экспериментальных исследований способа удаления окалины с поверхности стального листового проката. Предложен новый способ и устройство для очистки поверхности листового проката от окалины режущими пластинами, вращающимися вокруг оси, перемещающейся поступательно вдоль обрабатываемой поверхности. Пластины наклонены в направлении вектора вращения на угол до 10 градусов и упруго поджимаются к обрабатываемой поверхности. Это обеспечивает возможность в процессе очистки поверхности воспроизводить макронеровности листового проката. Приведены результаты экспериментальных исследований, построены математические и графические зависимости, описывающие влияние факторов процесса на эффективность очистки поверхности проката. Показано, что наиболее значимое влияние на параметр оптимизации оказывает сила воздействия инструмента на поверхность заготовки. Причем это влияние реализуется в прямо пропорциональной зависимости. Другие исследованные факторы, а именно: угол наклона пластины, скорость ее вращения и подача, оказывают значительно меньшее влияние на степень очистки проката. Эти исследования были необходимы с точки зрения определения конструктивных параметров силовых элементов как технологической оснастки, реализующей указанный способ, так и технологической установки в целом. План эксперимента был принят, исходя из реальных производственных возможностей индустриального партнера, и соответствовал классическим представлениям теории резания. Описанные результаты дают возможность планировать дальнейшие эксперименты по изучению направлений использования данного способа Here we consider the results of experimental studies of the method of removing scale from the surface of steel sheet products. We propose a new method and device for cleaning the surface of rolled sheets from scale by cutting plates rotating around an axis moving translationally along the treated surface. The plates are tilted in the direction of the rotation vector at an angle of up to 10 degrees and are elastically pressed to the treated surface. This makes it possible to reproduce the macro-dimensions of sheet metal during the surface cleaning process. We present the results of experimental studies. We constructed mathematical and graphical dependences describing the influence of process factors on the efficiency of cleaning the rolled surface. We show that the most significant influence on the optimization parameter is exerted by the force of the tool's impact on the surface of the workpiece. Moreover, this influence is realized in a directly proportional relationship. Other factors studied, namely the angle of inclination of the plate, its rotation speed and feed, have a much smaller impact on the degree of cleaning of rolled products. These studies were necessary from the point of view of determining the design parameters of the power elements of both the technological equipment implementing this method and the technological installation as a whole. We adopted the experimental plan based on the real production capabilities of the industrial partner and corresponded to the classical concepts of the cutting theory. The described results make it possible to plan further experiments to study the directions of using the method

scholarly journals The study on decreasing of nitrogen oxides emission carried out on DKVR 10-13 industrial heating boilers

2018 ◽  
Vol 44 ◽  
pp. 00056 ◽  
Author(s):  
Sylwia Janta-Lipińska ◽  
Alexander Shkarovskiy
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxides ◽  
Experimental Studies ◽  
Steam Injection ◽  
Reference Level ◽  
Optimal Parameters ◽  
End Caps ◽  
Atmosphere Pollution ◽  
Industrial Heating ◽  
Study Plan

Nitrogen oxides are considered to be much more toxic than, for example, carbon monoxide. For this reason, the Authors developed and implemented a method for decrease of NOX emission into the atmosphere from DKVR 10-13 boilers. As an effective method for boilers propose injection of steam into the combustion zone. After series of experimental studies an optimal design of the head for steam injection was developed, according to the proprietary technology. The injector head was kept unchanged while the spraying end caps were modified (Fig. 2). Three levels of possible impact of emissions from boiler on the atmosphere pollution were taken into account during studies. After the analysis, it was assumed that the level of the real maximum emission should be taken as the reference level in relation to which the decrease of NOX emission should be determined. The results obtained by the Authors calculated into mass emission and as objective values of nitrogen oxides concentration calculated into α = 1 (Figures 3 and 4). Realization of the study plan, assumed by the Authors, allowed to determine the optimal parameters of the NOx emission decrease method, assuming the expected 30% level of emission decrease at a limited consumption of injected.

Recurrent Neural Networks with Small Weights Implement Definite Memory Machines

2003 ◽  
Vol 15 (8) ◽  
pp. 1897-1929 ◽  
Author(s):  
Barbara Hammer ◽  
Peter Tiňo
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Experimental Studies ◽  
Activation Function ◽  
Transition Function ◽  
Recurrent Network ◽  
Point Of View ◽  
Recurrent Networks ◽  
Contraction Parameter ◽  
Arbitrary Precision

Recent experimental studies indicate that recurrent neural networks initialized with “small” weights are inherently biased toward definite memory machines (Tiňno, Čerňanský, & Beňušková, 2002a, 2002b). This article establishes a theoretical counterpart: transition function of recurrent network with small weights and squashing activation function is a contraction. We prove that recurrent networks with contractive transition function can be approximated arbitrarily well on input sequences of unbounded length by a definite memory machine. Conversely, every definite memory machine can be simulated by a recurrent network with contractive transition function. Hence, initialization with small weights induces an architectural bias into learning with recurrent neural networks. This bias might have benefits from the point of view of statistical learning theory: it emphasizes one possible region of the weight space where generalization ability can be formally proved. It is well known that standard recurrent neural networks are not distribution independent learnable in the probably approximately correct (PAC) sense if arbitrary precision and inputs are considered. We prove that recurrent networks with contractive transition function with a fixed contraction parameter fulfill the so-called distribution independent uniform convergence of empirical distances property and hence, unlike general recurrent networks, are distribution independent PAC learnable.

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