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Modern Techniques and Technologies, 2003. MTT 2003. Proceedings of the 9th International Scientific and Practical Conference of Students, Post-graduates and Young Scientists

Date 7-11 April 2003

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Displaying Results 1 - 25 of 126
  • Microstructure of spark-plasma sintered TiB2-Cu nanocomposites

    Page(s): 167 - 169
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (345 KB) |  | HTML iconHTML  

    The goal of this study is to investigate the evolution of microstructure of TiB2 -60 wt.% Cu nanocomposite and titanium diboride nanoparticles behavior during spark-plasma sintering. One of the current problems facing material science is the production of bulk materials with fine nano-level microstructure. Methods of mechanical alloying and mechanical treatment are widespread and well known for making it possible producing a great variety of composite powders with nano-level grains or inclusions. Ti-B-Cu powder mixtures were mechanically treated in high-energy planetary ball mill AGO-2 with stainless steel balls and vials. Balls of 5 mm diameter were used. The powder/balls weight ratio was 1/20 in all experiments. Before milling the vials were pumped and filled with argon to prevent oxidation during processing. To study the connectivity between TiB2 particles we removed copper matrix from the surface of SPS-compacts by electrochemical etching and formed a layer. X-ray phase analysis shows that this layer consists of titanium diboride as the major phase with small amounts of TiBO3 probably formed as a result of electrochemical reaction. View full abstract»

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  • Development of the energy-saving circuit for compressed air cooling in compressor unit

    Page(s): 42 - 44
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (293 KB) |  | HTML iconHTML  

    To decrease energy expenditures for air compression, it is necessary to keep the air temperature constant and as low as possible, thereby bringing the compression process near to isothermal when the compression reaches its minimal value. If the air is not cooled up to the temperature of the outdoor air, then the overexpenditure of the electric energy becomes more significant. As the need to use water as coolant is limited by the freezing temperature, the available energy reserve is not used. This paper shows that the possibility of energy savings during air compression depends largely on the use of the environment potential in winter on the air temperature. It also shows the energy overexpenditure for compression with the corresponding temperatures of the environment. View full abstract»

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  • Automated system of academic activities monitoring

    Page(s): 247 - 249
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (318 KB) |  | HTML iconHTML  

    It is important not only assess the quality of knowledge but be able to apply the method of total education quality control as the interaction of time, subject, a student, a group of students and a teacher; in other words, the method of analytical analysis of quality monitoring outcomes. In order to fully investigate the effectiveness of teaching, Institute for International Education has worked out the automated system of monitoring the academic activities, counting on current and final knowledge assessment for the subjects listed in the curriculum. Monitoring in terms of "teacher-student" system means the combination of controlling and diagnosing actions necessary for the goal oriented education process and prediction of gradual but dynamic obtaining the material for studying and its correction. View full abstract»

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  • Error estimation of the heat conductivity coefficient determination when sample heated with the radiant flux

    Page(s): 56 - 58
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (264 KB) |  | HTML iconHTML  

    This paper describes a method for determining the heat conductivity coefficient based on solving the quasi-inverse multivariate problem of the heat conductivity in cylinder, which is heated with the radiant flux from the face and radiates freely with the constant temperature from all sides into the medium. A sample radiant heating can be carried out by different methods, e.g. by means of optical furnace, laser or high temperature furnace. To determine the heat conductivity coefficient and the error estimation with the radiation flux the mathematical simulation was carried out. At first the direct problem of heat conductivity was solved. The calculation resulted in determination of the total heat flow departing from the low surface of the sample. Accuracy assurance of solving is the convergence of heat balance. Then the inverse problem was solved by means of which the heat conductivity coefficient was determined by the known density of incoming heat flow and the total heat flow. View full abstract»

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  • On resistive grounding of neutral point of APP network

    Page(s): 27 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (341 KB) |  | HTML iconHTML  

    In this paper, the results of atomic power plant (APP) house system operation modes analysis, the selection of the optimal value of the neutral point grounding resistance of the network, the selection of the place for the special neutrals assignment transformer installation, to which the resistors are connected as well as the capabilities of parallel connection of ground-fault neutralizers and resistors are considered. By installing high ohmic resistors of 500 ohms into the neutrals assignment transformers, the currents of the single-phase ground amount to 10 to 20 A, lower than those with the installation of low ohmic resistors of 100 ohms. Resistors of 500 ohms are not disconnected in processes tracking the single-phase ground and the single-phase arc ground. View full abstract»

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  • Possibilities of renewable energy system in the Tomsk region

    Page(s): 25 - 27
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (343 KB) |  | HTML iconHTML  

    This paper discusses the possibility of using solar, geothermal, water, and wind energies in the Tomsk region. The basis of the research in the field of possibilities of renewable energy sources in the Tomsk region is annual climatologically data. In this paper, renewable sources were investigated as the possible energy resources with particular qualities and preconditions. Renewable resources depend on the seasonal variations, therefore they could be put into operation as small decentralized sources of energy to support central energy supply. Energy supply reliability is provided by the complex use of different energy plants in combination with conventional power plants. View full abstract»

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  • Use of connection between metal "S-N"-curve parameters for its forecasting

    Page(s): 181 - 183
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (285 KB) |  | HTML iconHTML  

    This article discusses the forecasting of metal fatigue parameters, particularly the high cycle "S-N"-curve parameters. A qualitative connection between a corner of an inclination of the left branch of the fatigue curve to the N-axis of "S-N"-curve and limit of loading was established. The results of the study were used to examine the influence of different factors on the fatigue parameters in case of transition to their transformed forms. The method of transformation is based on the use of a reduction procedure. During reduction, the transformation of high cycle loading fatigue curve parameters is carried out. This transformation involves recalculating the break point coordinates of the high cycle loading part of the fatigue curve in accordance with the fatigue curve conditional parameters. This could be obtained using the result of crossing logarithmic coordinate axes by the left branch of the high cycle loading part of the fatigue curve. View full abstract»

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  • Methods for misalignment determination of wheel pair shaft in truck

    Page(s): 77 - 79
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    This paper describes a method to control axle misalignment in the wheel pair shaft of trucks and examines the influence of the misalignment on the tribological situation of railing-wheel wear. The paper shows that there is a connection between misalignment and wear when the structure of engine running gear is considered. All units are subjected to static and dynamic loads that results in wear. Among them the wheel pairs take special place. View full abstract»

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  • Measuring equipment for eddy current converters studying

    Page(s): 75 - 77
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (294 KB) |  | HTML iconHTML  

    This paper describes a measuring equipment that is specifically designed to study eddy current converters (ECC). The equipment measures the induced voltages of ECC and their dependence on the affecting parameters for transformer converters of any construction. The equipment simplifies the process of obtaining ECC characteristics, decreases the measurement errors and provides information for further analysis. View full abstract»

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  • Analysis of controlled-velocity electric drive and its application in housing and communal services

    Page(s): 131 - 133
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (321 KB) |  | HTML iconHTML  

    The given paper is aimed at analyzing controlled-velocity electric drives and their application in housing and communal services where the problems of energy saving and energy costs decrease are very important. Analysis of the controlled-velocity electric drives in housing and communal services showed that usage of the frequency controlled-velocity electric drives based on asynchronous motors with the short circuit rotor are preferred due to their reliability, service simplicity, control fluency, low cost and mass and dimension indications. Analysis also showed the advisability of application of the methods of the rotation frequency control by changing the value of the primary voltage of frequency. View full abstract»

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  • Criterion parameter determination with the technological adaptation of fixed butt welding of pipelines

    Page(s): 107 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (290 KB) |  | HTML iconHTML  

    To carry out fixed butt welding, it is necessary to provide for the directed transfer of the electrode metal into the weldpool and to keep the pool for the welded metal in position different from the bottom one. To automate this process using the pulse feed of the welding arc, a criterion parameter is needed to make it possible to provide for stable transfer and weld forming. While the voltage on the arc can provide useful information, the velocity of voltage change on arc during break should be used as a criterion parameter to fix the oscillations of weldpool and especially the velocity of the liquid metal displacement. Feedback introduction by the velocity of the voltage change during the break gives a series of positive moments. View full abstract»

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  • The future of tpu depends on innovation

    Page(s): 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (209 KB) |  | HTML iconHTML  

    First Page of the Article
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  • Usage of OLAP-means of the system "analytics" for the problem of health protection

    Page(s): 150 - 152
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (310 KB) |  | HTML iconHTML  

    The health care sector has been experiencing some difficulty as a result of the implementation of some new principles in planning and management and the continuous accumulation of electronic information. To help ease the situation, the use of an analytical modeling software, called OLAP (online analytical processing), is suggested. With the aid of OLAP, the capability of business analysis is significantly improved in terms of increased operation speed, presentation of the results and operative design of analytical reports. View full abstract»

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  • Thermo physical properties of protective coatings used in arc welding by melting

    Page(s): 105 - 107
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    The paper investigates the thermophysical properties of protective coatings used in arc welding by melting and their effect on the value of the residual welding stress. Based on the performed investigations, it was established that the usage of protective coatings provide a decrease of the residual stresses after welding. This is due to the slower cooling of the welded joint metal than after welding without protective coating. In this case, the less factor of thermal diffusivity of protective coating, the lower residual stress after welding. Hence, in developing new protective coatings it is necessary to aim at obtaining composition with the lowest factor of thermal diffusivity. View full abstract»

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  • Specifications correction algorithm by the position of multicoordinate servo drive

    Page(s): 212 - 214
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (291 KB) |  | HTML iconHTML  

    In this paper, mathematical computations for the positioning of a manipulator are presented. Under real conditions of the functioning of the industrial mechanisms, it becomes necessary to correct the velocity of the specifying signals and their values reading as the function of the coordinates equality of the initial and final points of the displacement of the calculated and the required trajectories of the mechanism operation unit motion as well as dynamic capabilities of the executive drive. The suggested method for forming specific trajectories of the drive motion is universal and can be used in designing the position systems of different control mechanisms. View full abstract»

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  • Pressure control devices with the microprocessor error correction

    Page(s): 64 - 66
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (300 KB) |  | HTML iconHTML  

    The use of microprocessors in pressure control devices is necessary to improve its accuracy, provide long-term stability, and satisfy modern requirements when the digital signal protocol needs reprogramming. By using complementary MOS structure microprocessors and decreasing the working frequency, the electronic module power consumption may be decreased. Nevertheless, the reduced processor speed allows doing the full cycle of design-measuring procedures 3-5 times per second and correcting DAC with the same speed. Microprocessor pressure control devices have some common procedures: the calibration procedure, resulting in the form of the sensitive element mathematical model characteristic and some adjustments of the device; the characteristic approximation procedure on base of the sensitive element error correction mathematical model; the measurement result-engineering unit transformation procedure; the forming of analog digital signals of interface. View full abstract»

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  • Distant education courses

    Page(s): 253 - 255
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (346 KB) |  | HTML iconHTML  

    The Power Supply Department of the Power Engineering Faculty at Yakutsk State University has been organizing distant educational courses for engineering and special disciplines which have the hypertext structure and can be installed in a Web server. The distant courses can be used not only for distant teaching but also as reference for internal students. The courses can generate interest in study and make the teaching process more active as well as improve the student's cognitive activity. They also ensure objectivity in estimating and self-evaluating student's knowledge level and improve the computer skills of the operator. Distant courses can be used not only by the students of higher educational institutions but also in educational centers of enterprises of power engineering, and can be useful for workers engaged in exploitation and design of objects in power engineering. View full abstract»

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  • Synchronization of heterogeneous components within the hybrid expert system

    Page(s): 207 - 210
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    The hybrid approaches to knowledge representation provides several important advantages. First, it allows the use of various kinds of expert knowledge inside the intelligent system. Second, it makes it possible to organize an interchange of knowledge between various parts of the intelligent system (including interchange between parts that use connectionist and symbolic paradigms for representation of experts' knowledge). This article describes hybrid systems whose knowledge base contains heterogeneous modules actively coupled by shared memory. Such framework is also called loosely coupled architecture. View full abstract»

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  • Ways of analysis operational characterizations increase of the polishing wheels

    Page(s): 102 - 103
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (234 KB) |  | HTML iconHTML  

    This paper describes a method for increasing the operational effectiveness of polishing instruments by adjusting the ordering position of the abrasive grain forms. This can be achieved by either sorting the free abrasive grains to some parts, each with its own same form and geometry, or producing abrasive grains with special planning forms. Experimental results show significant improvements in the instrument's cutting ability, steadfastness, polishing coefficient as well as reduced roughness. View full abstract»

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  • Stand for the study of the resonance vibration impact mechanism

    Page(s): 117 - 119
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (238 KB) |  | HTML iconHTML  

    This paper considers a new approach to the study of the energy input in vibration impact mechanism circuits with a switched structure under resonance condition. By studying the transient conditions in such a system with a switched structure using optimization, a vibration impact mechanism with improved mass and dimension characteristics can be created. View full abstract»

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  • Mathematical formulation of a optimization task of the local computer network of a building structure

    Page(s): 210 - 211
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (237 KB) |  | HTML iconHTML  

    Using the local computer network of a building as model for an optimization task, this paper examines a network constructed on a family of Ethernet network technologies since these networks are the most widespread network used. As an estimation of an optimality of the project, criterion of cost was chosen. With the aid of mathematical programming methods and special heuristic algorithms, the least structure of outgoing of the local computer network of a building that satisfies the given characteristics may be determined. View full abstract»

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  • Pulsed power supply unit for microcontroller

    Page(s): 86 - 87
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (227 KB) |  | HTML iconHTML  

    Magnitogorsk State University has developed a power supply unit for the MK-A/D-01 specialized microcontroller used in the design monitoring systems of complex technological objects. The power supply unit has three output voltages, +5V, +15V, and -15V. Maximum admissible continuous current at the output +5V, -2A, ∓15V. with 0.7A. The integrated chip TOP203 forms the basis of the power supply unit. View full abstract»

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  • Studying plastic deformation on mesoscale level of steel 15NZMA boride samples with thin hardened layers

    Page(s): 186 - 188
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (314 KB) |  | HTML iconHTML  

    Results of experimental investigations of the behavior of materials with homogeneous hardened layers on the surface with plain boundary showed that with active tension, the system of cross cracks quasiperiodically arranged occurs. This paper aims to study the plastic deformation of the samples with thin hardened layers characterized by complex form of the boundary under pressing. It shows the curves of the flow of the nonhardened and hardened samples of the steel 15NZMA. Based on the results, it was concluded that thin boride layers increase the deformation resistance, hence the samples strength of the steel 15NZMA. Also, great difference of strength characteristics of the matrix and coating materials as well as the non-planar boundary form between substrate and boride layer formed on the steel 15NZMA result in strong localization of the deformation of the boundary with loading. View full abstract»

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  • Choice of optimal combination of interturn insulation components

    Page(s): 137 - 139
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    In designing and manufacturing insulation of electrical machines the problem of right choice of electric insulating materials for the interturn insulation is very important. This problem is brought to the match of the interturn insulation consisting of the enamel composition and the impregnating compound film allowing for their properties, manufacturability as well as the compatibility of the chosen components. Determination of the values of the internal strains and the adhesion in the system of the interturn insulation allows one to estimate the advisability of the joint usage of the interturn insulation components. The value of the adhesion between the impregnating compound and the enamel insulation depends on a series of factors: temperature, contact time, adhesive viscosity, area of the contacting surfaces, number of connections deter-mining adhesion and power, value and time of the force action directed onto the break of the adhesion interaction, state of the substrate surface. View full abstract»

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  • Time-of-flight test bench for the determination of speed ability of atomized fuel

    Page(s): 93 - 95
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (285 KB) |  | HTML iconHTML  

    Altai State Univeristy has developed a time-of-flight test bench that measures the optical density of fuel flow developing through two sections arranged in series. Passing through the flow, the light intensity changes according to the flow density and the signal from the photodiode intensifies and is converted to digital form, which is analyzed by a computer. The relative mass of the fuel flow having passed through the chosen optical section can be calculated, and the mass can be compared and normalized, and the time of delay of the fuel mass transport from the first up to the second section can be determined. By determining the speed of the fuel movement, it is possible to forecast the location of the main area of fuel flow at the characteristic moment of the fuel ignition and burning that determines the process of burning and cracking. View full abstract»

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