Статьи журнала - Журнал Сибирского федерального университета. Серия: Техника и технологии

Все статьи: 1122

1’000’000 amperes deram cell

1’000’000 amperes deram cell

Kaenel Rene V., Antille Jacques, Bugnion Louis, Kaenel Laure V.

Статья научная

The aluminum industry is constantly looking at reducing the production cost. During the last three decades it has mainly been achieved by the economy of scale consisting in increasing the cell dimensions allowing for higher current and therefore increasing the plant production and productivity. This paper presents under which conditions a step change can be achieved without increasing the shell dimensions. The design of a cell of the future is discussed in term of voltage distribution, heat loss, energy saving, productivity and environmental consequences.

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A game based energy sensitive spectrum auction model and bid learning process for cognitive radio systems

A game based energy sensitive spectrum auction model and bid learning process for cognitive radio systems

Oloyede Abdulkarim Ayopo

Статья научная

An auction based bid learning process for cognitive radio networks, where the users and the service providers are learning about each other to maximise each other’s utility is examined. A game model is formulated to allow players to learn depending on their priority. This enables users to learn different parameters such as the best offered bid price and the appropriate time to participate in the auction process. The performance of the system is examined based on the developed utility function. The results show that the blocking probability, utility function and the energy consumed is better with the learning users when compared to the non-learning users. Results also show that provided learning is taking place in the system, Nash Equilibrium can be established.

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A simple method for determination of switched capacitor bank in power distribution systems

A simple method for determination of switched capacitor bank in power distribution systems

Dowlatshahi Milad, Pahlavan Davood

Статья научная

This paper proposes an efficient and novel technique for assessment of the direction of switched capacitor bank as well as estimating its distance from the monitoring location in real distribution systems. At first, the proposed method determines the direction of switched capacitor banks based on the slope of the voltage and current space vectors immediately after the capacitor switching instant. Afterward, the exact location of switched capacitor from the monitoring location is determined by estimating the feeder line inductance using first sample magnitude of voltage and current space vector after the switching instant. The discrete wavelet transform (DWT) is also used to detect the exact instant of switching as well as the exact values of voltage and current caused by switching. In this paper, the capabilities of the proposed method are evaluated in various state of switching (normal, Back-To-Back), presence of stochastic nonlinear load and different sampling rate. The effectiveness of the proposed technique is demonstrated with system data obtained from IEEE-13 bus feeders modelled in PSCAD/EMTDC. Simulation results demonstrate the validity and effectiveness of the proposed method considering accepTable error in locating the switched capacitor bank in distribution systems.

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A study of ozone anomaly of 2011 in the Northern hemisphere based on Aura satellite data

A study of ozone anomaly of 2011 in the Northern hemisphere based on Aura satellite data

Kashkin Valentine B., Rubleva Tatiana V.

Статья научная

In this work we have studied the appearance of analogue of the Antarctic ozone hole in the Northern hemisphere in March 2011. Possible reasons of this phenomenon were the low temperature in the polar region and intense solar flares. The solar activity led to changes in the atmospheric circulation. As a result, in the stratosphere for a while have any rotating circumpolar vortex in the form of a ring in mid-latitudes and low ozone content in the polar region. Our studies revealed a redistribution of ozone mass between the inner and outer part of the vortex with decreasing the total ozone content in the inner part and increases in the outer. A model of the formation of the circumpolar vortex based on atmospheric physics is proposed.

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Abnormal geophysical events in the northern hemisphere in 2010 and 2011

Abnormal geophysical events in the northern hemisphere in 2010 and 2011

Kashkin Valentine B., Rubleva Tatyana V., Odintsov Roman V.

Статья научная

Based on ATOVS satellite data, temperature-pressure vertical profiles at different levels have been constructed for the epicenter of the Japan earthquake that occurred on March 11, 2011 for the “undisturbed” and seismically disturbed atmosphere (December 2010 - January-April 2011). In the undisturbed atmosphere over the focal zone, the coefficient of correlation between the time series of the temperature at levels of 200 gPa and 450 gPa was positive, reaching 0.4-0.6; in the disturbed atmosphere, there were intensive internal gravity waves, and the correlation coefficient was negative, reaching -0.86. The large wave in the atmosphere observed over the focal zone before the earthquake could have triggered it. A rare event occurred almost simultaneously with the earthquake: an ozone anomaly similar to the Antarctic ozone hole was formed in the Northern Hemisphere between March 5 and April 4, 2011. That event was preceded by a dramatic temperature drop in the lower stratosphere. In 2010, Europe experienced an unprecedented hot summer, and the winter of 2010-2011 was exceptionally cold. Those events could have a common cause. That could be an oil spill in the Gulf of Mexico in spring-summer of 2010, which changed the direction of the Gulf Stream, leading to changes in atmospheric circulation and generation of intensive atmospheric waves.

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About safety during landing aircraft of the helicopter type on unprepared ground

About safety during landing aircraft of the helicopter type on unprepared ground

Mashkov Viktor G., Malyshev Vladimir A.

Статья научная

In the article the peculiarities landing a helicopter on a snowy (dusty) area and analysis the security when boarding an aircraft of the helicopter type on unprepared ground. Conditions insufficient visibility when landing in this way are one of the key problems. Since when landing on snow-covered or dry ground because the air jet from the rotor of the helicopter rises solid suspension, which critically reduces the horizontal and vertical visibility and can lead to an incorrect assessment by the crew the spatial position of the helicopter relative to the ground, in addition, unnoticed can remain obstacles in the landing zone (large stones, movable and stationary objects). In addition, when there is insufficient light or adverse weather conditions in the landing zone can be buildings, structures, masts power lines, trees, bushes, etc. Security analysis showed that the aircraft landing helicopters on unprepared ground is a serious problem. The solutions in the field synthetic vision technologies, for the safe landing of the helicopter, which allow to form a three-dimensional image the landing zone through a snow or dusty vortex, lidar (laser location), W-band radars and other developments, are outlined. The materials the article are practical value to specialists dealing with the issues of helicopter landing in remote forest, mountainous areas, the Arctic zone, etc.

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About some properties and features of differential and integrated representations in the theory of thermodynamic functions

About some properties and features of differential and integrated representations in the theory of thermodynamic functions

Zhakatayev Toksan A., Sakipov Kamalkhan E., Kakimova Klara Sh., Аytmagambetova Maralgul B.

Статья научная

In article the comparative analysis of differential and integrated consideration of thermodynamic process is carried out. It is shown that use of the rule of replacement of variables of integration leads to correct output of main thermodynamic functions (an enthalpy, Helmholtz's function and Gibbs's function). It occurs through integrated consideration of thermodynamic process when parameters change in fi nal (limited) intervals. It is established that Integrated consideration of the law of energy conservation in general view for the moving fi nal volume of liquid or gas leads to «expanded» option of formula for the fi rst law of thermodynamics. At the same time the equations recorded in differential form taking into account different types of technical work. Communications between the work of pushing through of some volume of gas and work connected with pressure at expansion of gas volume are shown.

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About the possibility of the bulk thermo gradient effect use for the creation of the effective thermobattery

About the possibility of the bulk thermo gradient effect use for the creation of the effective thermobattery

Zhakatayev Toksan A.

Статья научная

The theoretical basis has been developed and the idea of practical production and testing the semiconductor electric generator (thermobattery) of a new type acting on the basis of a metal - semiconductor system has been offered. It is shown that the thermobattery will work on the basis of the use of a bulk thermogradient effect. Such effect allows to gain a sufficient level of generated power from one unit of the whole volume of a semiconductor material. When using the semiconductor thermobattery together with solar and wind electric generators, it is possible to simplify significantly constructional and technological features of these installations.

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Accelerated phase-lock-loop frequency control methods of users equipment in perspective radio navigation systems

Accelerated phase-lock-loop frequency control methods of users equipment in perspective radio navigation systems

Kuzmin Evgeny V.

Статья научная

This paper investigates noise-immunity of accelerated phase-lock-loop frequency control algorithms of user equipment in perspective ground-based radio navigation systems. Three algorithms of accelerated phase-lock-loop frequency control are suggested and described. Statistic simulations of signal processing in involved system are given.

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Access matrix as a passive element in the protection of information resources

Access matrix as a passive element in the protection of information resources

Krasnov Igor Z.

Статья научная

In this work the author considers a problem of management of access to information resources of the enterprises. Formulates the purposes of a control system of access. Defines interrelation of the purposes of information security and available threats of safety. Suggests to use an access matrix as a passive element of protection of information resources. Formulates tasks which need to be solved in any control system of access. Sets a task of a redundancy exception when carrying out measures of information resources protection. Offers a formation technique of an access matrix. Describes procedure of information categorization, risk groups identification, formation of access profi les, fi xing of access rights in organization regulating documents.

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Acoustic control method of quality characteristics of new transformer oil

Acoustic control method of quality characteristics of new transformer oil

Krekhova Anastasiia V., Bezborodov Yuriy N., Batrak Andrey P.

Статья научная

Power transformers are the most expensive and strategically important components of any power generation and transmission system. Diagnostics methods result from the necessity to provide the operational reliability of power equipment and extend its operation time. Acoustic method is one of the perspective methods to determine transformer oil quality. In comparison with standard methods the acoustic method have follow important advantages: low labor intensity, need lack of the difficult expensive equipment, carrying out researches in vitro frames and high qualification of researches. This study represents results of impurity influence investigation (water and cellulose) on an acoustic range of new transformer oil.

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Adaptation of method combined rolling-extruding for production of semi-finished products from graded waste chip of aluminum alloys

Adaptation of method combined rolling-extruding for production of semi-finished products from graded waste chip of aluminum alloys

Zagirov Nikolai N., Sidelnikov Sergey B., Bespalov Vadim M., Burmistrov Konstantin V.

Статья научная

Was proposed a device for obtaining deformed semi-finished products from chip of aluminum alloys with use combined methods of treatment. Carried experiments to obtain rods and receipted data about their mechanical properties.

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Aerodynamic separation of fly ashes of selective sampling from pulverized combustion of coals of different ranks

Aerodynamic separation of fly ashes of selective sampling from pulverized combustion of coals of different ranks

Sharonova Olga M., Oreshkina Natalia A., Kurteeva Larisa I., Anshits Alexander G.

Статья научная

This paper reports on the results of the investigation of fly ashes from pulverized combustion of coals of two ranks, i.e., the B2 (sub C) rank, which is taken from Fields 1−4 of the electrostatic precipitators at the BSDPS -1 (the Bfa series), and the T (sa) rank, which is taken from Fields 1 and 2 of the electrostatic precipitators at the MPP-22 (the Mfa series). It has been shown that fly ashes of the Bfa series have a lower bulk density and a higher dispersity and a unimodal particle size distribution. The size of particles increases along the gas-and-dust flow, in particular from the Field 1 to the Field 2 of the electrostatic precipitators. Fly ashes of the Mfa series are characterized by a higher density, a substantially lower dispersity, a bimodal particle size distribution and have rather close size characteristics for ashes from the Fields 1 and 2 of the electrostatic precipitators. The use of the aerodynamic separation has made it possible to obtain three products from fly ashes of both series which differ significantly in the bulk density and size of particles. Combination of selective sampling and aerodynamic separation of fly ashes from pulverized combustion of coals are promising techniques for manufacturing ash products with a controlled density and dispersity.

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Aluminum busbar connection parts of the cell «flexible cathode descent – cathode bus»

Aluminum busbar connection parts of the cell «flexible cathode descent – cathode bus»

Kirko Vladimir I., Galemov Takhir T., Petrov Alexandr M.

Статья научная

In the given article we present our results of research of aluminum joint parts of «cathodic flexible swith a cathode bus». Basing on the theoretical analysis and experimental researches, we present the method of molding of joint assembles in the casting mould, with an overheated fusion. The suggested method let us produce a high-quality junction without loss of electrolysers'series productivity and it also allows decreasing the operational expenditures.

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An improved multi-objective BPSO-based method for radial distribution networks reconfiguration

An improved multi-objective BPSO-based method for radial distribution networks reconfiguration

Ghandehari Ebrahim, Shojaeian Shahrokh, Pourabadeh Javad

Статья научная

The present paper will introduce an improved BPSO algorithm for radial distribution networks reconfiguration. In this regard PSO algorithm has extensively been used in many of the previous literatures; however, here a new method will be introduced in order to update swarm position which is not only simple and fast but also has high accuracy. The objective function has four weighted components representing load balancing, total losses of network, voltage deviation and system reliability. The test network is a standard distribution system with 3 feeder and 16 switches. Accuracy and speed of proposed method are compared with three other well-known algorithms to ensure its efficiency.

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Analysis of the Younger Dryas impact layer

Analysis of the Younger Dryas impact layer

Firestone Richard B., West Allen, Revay Zsolt, Hagstrum Jonathan T., Belgya Tamas, Smith Alan R., Que Hee shane S.

Статья научная

We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden disappearance of the megafauna and Clovis people. The distribution pattern of the Younger Dryas boundary (YDB) ejecta layer is consistent with an impact near the Great Lakes that deposited terrestrial-like ejecta near the impact site and unusual, titanium-rich projectile-like ejecta further away. High water content associated with the ejecta, up to 28 at. % hydrogen (H), suggests the impact occurred over the Laurentide Ice Sheet. YDB microspherules and magnetic grains are highly enriched in TiO2. Magnetic grains from several sites are enriched in iridium (Ir), up to 117 ppb. The TiO2/FeO, K/Th, TiO2/Zr, Al2O3/FeO+MgO, CaO/Al2O3, REE/ chondrite, FeO/MnO ratios and SiO2, Na2O, K2O, Cr2O3, Ni, Co, U, Th and other trace element abundances are inconsistent with all terrestrial and extraterrestrial (ET) sources except for KREEP, a lunar igneous rock rich in potassium (K), rare-earth elements (REE), phosphorus (P), and other incompatible elements including U and Th. Normal Fe, Ti, and 238U/235U isotopic abundances were found in the magnetic grains, but 234U was enriched over equilibrium values by 50 % in Murray Springs and by 130 % in Belgium. 40K abundance is enriched by up to 100 % in YDB sediments and Clovis chert artifacts. Highly vesicular carbon spherules containing nanodiamonds, glass-like carbon, charcoal and soot found in large quantities in the YDB layer are consistent with an impact followed by intense burning. Four holes in the Great Lakes, some deeper than Death Valley, are proposed as possible craters produced by the airburst breakup of a loosely aggregated projectile.

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Analysis of the influence of transient process during the shunt reactors commutation on insulation of substation “Zarya” auxiliaries

Analysis of the influence of transient process during the shunt reactors commutation on insulation of substation “Zarya” auxiliaries

Sizganova Evgenia U., Petukhov Roman A., Sizganov Nikita V., Nikotina Daria U.

Статья научная

The article considers the modeling and analysis of transient processes in a system of substation Zarya500 kV with different external conditions during commutation shunt reactor ROMBS-60000/500. Revealed that the high-frequency overvoltageduring switching shunt reactor of 500 kV, can be dangerous for air insulation transformers TSZ-630/15.

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Analytical and experimental research of structural organization of heat-insulating construction materials

Analytical and experimental research of structural organization of heat-insulating construction materials

Shaumarov Said S., Adilhodjayev Anvar I.

Статья научная

The article is devoted to the determination of the fractal dimension of the porous surface and further finding the relationship of the fractal dimension with the porosity of cellular concrete. A numerical experiment was carried out aimed at determining the fractal dimension of the structure of cellular concrete in order to clarify the relationship of the latter with its porous structure. An approach has been developed to assess the properties of cellular concrete based on the analysis of its image.

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Antenna arrays on surfaces of revolution

Antenna arrays on surfaces of revolution

Erokhin Alexey А., Panko Vasily S., Salomatov Yury P., Sugak Mikhail I.

Статья научная

In this paper explicit analytical expressions are derived which describe radiation pattern of multi ring antenna array and multi ring continuous radiator allocated on an arbitrary surface of revolution. Radiation patterns of semi-spherical, conical and hyperbolical antenna arrays are shown.

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Application of error - correcting coding in hydroacoustic communication channels

Application of error - correcting coding in hydroacoustic communication channels

Filippov Boris I., Chernetskiy Gennady A.

Статья научная

The paper considers the possibility of using error-correcting coding in hydroacoustic communication channels (HACC).Comparison of test results shows that errors substantially packaged, resulting in increase of error probabilities with the large multiplicity and the likelihood of receiving a code word without error. Results of comparative statistical studies of these codes on a channel model with impulse hindranceare listed. As a result of theoretical and practical studies of various structures of error protection device (EPD) to improve the noise immunity of equipment sonar communication systems (HACC) was selected the algorithm of error correction, which is based on convolutional code R = 1/2 with block, the threshold, the iterative decoding. To ensure the independence of errors at the decoder input (decorrelation of error stream), the matrix interleaver are encouraged to use in the EPD.

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