05.00.00 Technical science
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Description
At the nodes of the various machines, we use plain bimetal bearings: a steel base - antifriction cladding layer. Bimetal bearings have increased performance. One of the ways of making such bearings is the way of centrifugal bimetallization with heating of the independent electric arc. An important requirement of this technology is a uniform heating of the workpiece along the entire length until the formation of a continuous layer of the molten cladding material. The process of bimetallization require temperature control, since within the movement of the electric arc, low heat or high heat are possible due to heat dissipation from the ends of the workpiece in the installation and from the outer surface of the workpiece to the environment. A viable option the temperature control of the heat process of bimetallization for industrial conditions is to control the temperature of the outer surface of the steel base. It is necessary to solve the heat problem of the relationship between the temperature on the surface of the workpiece with the temperature on the boundary layers. For this purpose the numerical solution of the mathematical model of the thermal process, which includes the heat transmitting equation of Fourier and heat transfer at the ends of the sleeve according to Newton's law. The equivalent coefficients of heat transfer are obtained based on calculated and experimental thermograms. This is a time-consuming work. To minimize the time of fixing the boundary value problem of the thermal process of bimetallization, in this work we present the preliminary modeling based on the analytical solution of the thermal task of bi-metallization
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Description
The mechanical activation allows creating a active state in a solid, opening the prospect for holding and accelerating the chemical reactions between solids and getting materials in a nonequilibrium state. As a result of mechanical activation of the powder compositions of the active phase transformations occur in them, which lead to the formation of solid solutions and various intermediate connections, providing dispersion and dispersion hardening of materials included in the composition. The results of the study of the granulometric composition, the phase transformations and structure evolution in multiphase materials with SME Ni-30%at.Ti-20%at.Hf and Ni-33%at.Ti- 18%at.Zr at different stages of the process of mechanical activation carried out in planetary ball mill the centrifugal type is represented in the article. During mechanical activation, a composite mix is assimilated by the particles of processed material input of mechanical energy in the form of new interfaces, defects of the crystal lattice. At collision of particles and grinding bodies in contact high local temperature and pressure occur, which in some cases can lead to melting of the most fusible components. When a local increase in temperature between the particles of titanium, hafnium, zirconium and carbon solid-phase reactions become possible due to diffusion of atoms of one component into the crystal lattice of the other. Experimental studies have shown that the use of mechanical activation allows creating an effective technology of preparation of the starting material for high-speed flame spraying
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THE FINISHING CLEANUP AND STRENGTHENING PROCESSING OF AGRICULTURAL PURPOSE CARS DETAILS
DescriptionResults of engineering and scientific search of improvement of resource-saving machine technologies of finishing and cleanup processing of cars details, development of new camps and technologies are presented. The possibility of low-frequency fluctuations with big amplitude can be implemented due to assembling flat or curvilinear elements on external surfaces of the relative screw reel. The use of computer modeling enabled us to obtain a relative screw drum that provides not only giving movement to loading masses with a big fluctuations amplitude, but also compression of loading masses in the process of their motion from loading to unloading. In such machines increase in processing efficiency is reached not only due to achievement of great movement amplitudes values of the loading masses, but also at the cost of compression of loading masses in processing and intensity increase of their mixing. The scheme of the machine for continuous processing with mechanization of separation of details from working environments particles is provided. Results of researches of quality and surfaces micro hardness change processed in the offered machines designs show that details processing time makes 3-6 min
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Description
The article formulates and solves the task of discrete control in the thermophilic stage of the composting process. It is shown that considering the relay control entity to maintain specified process conditions requires the organization of the sliding mode. We have solved the problem of minimizing the temperature deviation of the substrate from the set values and the deviation of the oxygen concentration in the gas phase of the bioreactor from the specified values. The article shows the algorithm to compute the discrete control of the composting process in the thermophilic stage. This work was prepared in the framework of the scientific project 16-48-230441 a(R) "Mathematical modeling of the processes occurring in the automated installation for year-round production of organic fertilizers in the conditions of the Krasnodar region", financed by RFBR and the administration of the Krasnodar region
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SOURCES OF ELECTRICAL ENERGY OF AIRCRAFT ELECTRIC POWER SUPPLY SYSTEMS: CONDITION AND PERSPECTIVES
DescriptionAccording to its operating principles, generators of aircraft electric power supply systems do not differ from the similar generators of transporting and stationary systems, but have range of peculiarities: low weight and dimensions, high density of armature current, compulsory cooling (air and liquid), high frequency of rotor spinning. The article considers main requirements, imposed to generators of flight vehicle and the construction peculiarities and main physical and operational characteristics of generators applied in modern flight vehicles. It is suggested to use noncontact electrical machines as sources of electrical energy in the aircraft electric power supply systems: synchronous generators with impulses from permanent magnets and asynchronous generators with capacitive impulse. To improve physical and operational characteristics of generators and aircraft electric power supply systems it is suggested to refuse from permanent frequency spinning drivers which have low converters as stabilizer of voltage and frequency current of electrical energy source. The peculiarities of its operation are considered, its advantages and disadvantages. It is possible to improve characteristics of aircraft electric power supply systems by means of study of the electromagnetic compatibility of the main functional system elements and by means of application of non-contact electrical devices, applied in the guard and control systems, made on the basis of power and electronic devices
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TECHNICAL SOLUTIONS OF AN ENERGY SUPPLYING COMPLEX OF APIARY BASED ON A SOLAR PLANT
DescriptionWe have presented technical solutions of an energy supplying complex of apiary based on a solar plant, which ensure its functioning in the winter. Various aspects of the influence of the snow cover on the functioning of the complex are considered in the article. The favorable effect of the snow cover includes increasing the diffuse insolation, improving the thermal insulation of the building for placement of bees, which protects bee families from fluctuating external temperature. The negative effect of the snow cover includes adherence of snow to the receiving surfaces of solar energy converters, which can lead to decreasing the efficiency of using of photovoltaic modules and solar collectors. Both active and passive methods of combating snow sticking are suggested in article. Passive methods include installation of solar energy converters at an angle close to 90°, as well as their placement on the windward side. The simulation of the functioning of the complex based on a solar plant was conducted for climatic conditions of the Republic of Mari El (the time interval – from 14 October to 14 April, a photovoltaic module area – 1,3 m 2 with installation angles of 72˚ and 88˚). Because of the simulation, we obtained graphs of the changing the power of the photovoltaic module. Active methods include air injection onto the receiving surfaces of solar energy converters and using of heating elements
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FILTRATION-WAVE HEATING OF THE OIL POOL
DescriptionWe have developed a mathematical model of thermodynamic processes at oscillatory movement of liquids in porous environment with consideration of heat interaction of an oil layer with surrounding breeds and phase transitions caused by dissolution of paraffin’s dissolution. We have received analytical dependences of temperatures on time, distances to well and depth, that proves an opportunity to increase of oilrecavery when influenced by periodic fields of pressure. We have suggested a bartering effect to increase the temperature in zones far from the well formation. The mathematical model is based on the equation of heat balance, taking into account the contribution of phase transitions due to paraffinization in the case when the motion of the mixture takes place in a homogeneous isotropic porous medium with constant porosity and constant density. In the work we have developed a theory of bartering effect upon oscillatory movement of fluids in porous media considering thermal interaction between the oil reservoir and surrounding rocks and phase transitions due to the dissolution of paraffins. Comparison of theoretical and experimental data has confirmed the possibility of using the first approximation for the calculation of real thermodynamic processes in the filtration-wave fields. The developed process model allows the calculation of the temperature field in the practical conditions
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THE IMPLEMENTATION OF THE CONCEPT OF "ELECTRONIC GOVERNMENT" IN HIGHER EDUCATION
DescriptionThe article describes the current state of the transition to paperless exchange of documented information. The general trend of application of information technologies in the field of document management is linked to the concepts of "electronic government" and "information society". The article gives an overview of the legal and regulatory framework the concept of "electronic government" in Russia. We present the dynamics of modern forms of communication and creating unified information space to ensure efficient, effective interaction of society and the state, including the transition to work with documents in electronic form, on education and science. The author has conducted a detailed analysis of the functioning of the module of "Interaction" between the Ministry of education and science and its subordinate organizations; we have also identified technological features of exchange document information. Based on the analysis, we give the evaluation of the implementation of the module of "Interaction"; we emphasize the urgency and high efficiency of information exchange, as well as comfort for users
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Description
The technique relates to the area of distribution of key information in cryptographic communication systems. The purpose of the work was to solve the problem of increasing the speed of distribution of key information for special bodies of federal bodies of critical facilities in the conditions of network-centric management and creating alternative options for the distribution of key information when key documents are compromised to special equipment. By applying the methodology, a solution to this problem is achieved by applying a key distribution method based on asymmetric cryptography using symmetric polynomials
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METHODIC OF KNOWLEDGE ASSESSMENT WITHIN THE FRAMEWORK OF THE AUTOMATED TESTING SYSTEM
DescriptionIn this article, we consider approaches to the transfer of knowledge to students and an objective semiautomatic assessment of knowledge. The characteristic features of the application and the possibility of using cognitive training methodologies and complex systems for testing skills and the theoretical base of trainees are analyzed. The problems of development of this direction and possible ways of their solution are described. The basic concepts are introduced and the existing methods of calculating the average score for checking the student's knowledge are considered, and a new approach to solving this problem is proposed. Based on the conducted researches it is offered to use the complex system of testing of end users, which includes testing, monitoring, collecting, analyzing and displaying the results of students/groups/ course. The main requirements for the creation of such a complex and the rules to be followed are formulated for a more objective assessment of knowledge. A model of an integrated modular system for objective semi-automatic testing of knowledge through testing is described