Журнал Сибирского федерального университета. Серия: Техника и технологии @technologies-sfu
Статьи журнала - Журнал Сибирского федерального университета. Серия: Техника и технологии
Все статьи: 1471
The influence of thallium additives on the kinetics of oxidation of the Zn22Al alloy
Статья научная
The article presents the results of a thermogravimetrical study of the effect of thallium alloying additives on the oxidation kinetics of the Zn22Al alloy. Established in the temperature range of 473-623 K the kinetic and energy parameters of the oxidation of alloys. The oxidation of alloys proceeds according to the hyperbolic mechanism and has the order of 10-4 kg∙m-2∙sec-1. Higher activation energies indicate that the oxidation of these alloy samples results in the formation of oxide films with good protective properties. Additives of thallium in amounts of 0.01-1.0 wt.% contribute to a decrease in the oxidizability of the Zn22Al alloy. The resulting products during the oxidation of the studied alloys consist of a mixture of oxides ZnO, ZnAl2O4, Al2O3, Tl2O3.
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Статья научная
The automated laboratory equipment for efficient interrupting electrocontact materials testing with respect to their general functional properties during their development and/or improvement is presented. The equipment for estimating erosion resistance, transient resistance of loaded pair contacts and also welding resistance during on-off cycles by break force measurement (380/220 V, current is 15-30 А, power factor φ=0.8, frequency of on-off cycles is 0.01-10 Hz, controlled duty cycle). The equipment control, monitoring, recording and primary processing of parameters taken from the detecting device are performed using specialized software. The equipment was tested on two type contact materials, Ag and Ag/(15%CdO). The results and appropriate correlation are presented in this article.
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Статья научная
The polyzonal mathematical model of heat transfer in the furnace with a liquid bath of Vanyukov smelting energotechnological complex has been improved and its design-theoretical analysis has been made. The paper gives quantitative estimation of influence on thermal condition of furnaces design characteristics: shapes and size of over layer space, the situation of uptake and place of charge load.
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Статья научная
The task of developing a method and information presentation algorithm for the exchange of complex hierarchical management system in terms of information overload. The criteria of inclusion of information aggregation algorithm. Finding of fact overload the system asked to carry out by comparing the distances between aircraft objects with preset thresholds, the amount of air objects in the processing system of the automated control system components and for each region of space, covert interference - the operator of the complex automation.
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Статья научная
The paper proposed an effective model of management of fuel and energy enterprises, developed on the basis of fuzzy logic, allowing to minimize the risks associated with incorrect forecasting of energy consumption, allowing to consider not only quantitative but also qualitative indicators of the enterprise.
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The numerical probabilistic approach to the processing and presentation of remote monitoring data
Статья научная
The paper deals with a numerical probabilistic analysis as a method of processing and presentation of remote monitoring for the aggregation large amounts of data. For the aggregation we used histograms, polygons and splines. On the basis of aggregated data to identify relationships between the input and output characteristics are studied the theoretical and the practical aspects of regression modeling. On the basis of numerical examples we demonstrated the effi ciency and reliability of the proposed methods.
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The performance of classifiers in the task of thematic processing of hyperspectral images
Статья научная
The performance of the spectral classification methods is analyzed for the problem of hyperspectral remote sensing of soil and vegetation. The characteristic features of metric classifi ers, parametric Bayesian classifiers and multiclass support vector machines are discussed. The results of classifi cation of hyperspectral airborne images by using the specifi ed above methods and comparative analysis are demonstrated. The advantages of the use of nonlinear classifiers are shown. It is also shown, the similarity of the results of some modifications of support vector machines and Bayesian classifi cation.
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Статья научная
The article considers the issue for development of the computer-aided program designed for determining optimal location of installation of symmetry facilities in 0.4 kV power supply systems with the motor-drive load in conditions of imbalance of voltages. The program is aimed at making electrotechnical calculations during designing, modernization and operation of electrical grids with available motor drive load. It ensures plotting of schematic circuits for 0.4 kV power supply system sections with installed symmetry facilities. The software program provides for calculating different symmetry options and selecting the most economically feasible one. Using the program in motor- drive load power supply systems will enhance the asynchronous motor reliability and efficiency. The program is of interest during development of the power supply system projects for the regions with available non-linear loads.
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Статья научная
One of the sources of environmental pollution with hazardous substances, primarily heavy metals, is the electroplating industry. The prevention of pollution of water bodies with wastewater containing heavy metal ions is closely related to reducing the consumption of fresh water for the technological needs of production and to reducing the amount of effluent. One of the solutions to this problem is to create low-waste and waste-free environmentally safe technological processes of wastewater treatment using treated effluents in the recirculation system, which reduces the negative impact on the environment. The results of studying the sorption properties of the natural modified mineral Akdolit-Gran prove a high efficiency of this sorption filling when conditioning electroplating shop effluents contaminated with a complex of heavy metals. Taking into account a relatively low cost of this natural mineral, Akdolit-Gran has the advantages in terms of its economic feasibility, plus the high degree of extraction of metals using this sorbent together with its low consumption allows designing recirculation systems for industrial enterprises meeting the requirements for physical and chemical parameters of service water.
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Статья научная
The article presents a reasonable method of calculating the angles of elevation of short radio waves with the influence of regular and random inhomogeneities of the ionosphere. The method calculates short radio waves (HF) through the horizontal inhomogeneous scattering ionosphere. The technique is based on application of the law of refraction of Snell’s for well-known models of the ionosphere and its evolution in the irregular parts. The description of the program to calculate the angles of radiation and reception HF is presented. The results of calculating the angles of arrival are compared with measurements of angles of arrival of HF. We obtained the best agreement between the experimental and the calculated resultsl of arrival angles of HF than for the regular ionosphere. The use of techniques is discussed in the article.
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The speed electromagnetic wave propagation in the snow-ice underlying surface
Статья научная
The results calculations the electromagnetic wave propagation velocity in the snow-ice cover depending on the density, the proportion liquid water content, and the propagation speeds the electromagnetic wave in dry snow, dry firn, and dry ice vary very markedly depending on the proportion liquid water content, the preferred orientation, and the shape ice and air structure are presented. The inclusions in the snow.The performed estimates the complex relative permittivity the medium that determines the speed propagation electromagnetic waves show a noticeable influence the density, the proportion liquid water content and the structure the underlying surface (snow, firn, ice), which allows identifying the layers the underlying surface in order to remotely determine the possibility landing a helicopter-type aircraft on an unprepared site with snow-ice cover.Shown, when the portion the water content in the medium is equal to zero, which is typical for negative temperatures, the speed propagation electromagnetic waves in the medium will depend on the density the medium and structure the dry ice in a small range of 1 m/µs temperature. In dry snow, vertically and horizontally elongated or spherical inclusions make a significant contribution to the change in the speed propagation the electromagnetic wave. At zero temperature, in the frequency range of 2 ... 8 GHz, the share water content in the medium, the density and structure the medium will play a determining role in the speed propagation an electromagnetic wave in the medium.The purpose this article is to determine the change ranges speed propagation electromagnetic waves in snow-ice the underlying surface depending on the density, structure, water content to restore the structure the snow and ice according to radar sensing, a more accurate determination the depth snow and thickness ice cover used in the assessment the possibility the safe landing an aircraft the helicopter type on an unprepared ground with snow-ice cover.
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The structure and magnetic properties of Fe-Mn-C alloy
Статья научная
The structure of intergranular borders in Fe-Mn-C alloy has been investigated. Importance of Fe-Mn-C alloys researches connecting with their wide use in machine industry as constructional materials. In this work an attempt to find out the physical nature of high shock viscosity of Fe-Mn-C alloy, mechanical and magnetic properties, calculation of intergranular borders electronic structure is made.
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Статья научная
The aim of the work is to develop techniques for detecting weediness in agricultural crops based on the use of the VARI vegetation index, calculated from the PlanetScope satellite data. The territories of the Krasnoyarsk Agricultural Research Institute of the Federal Research Center of the Krasnoyarsk Science Center of SB RAS near the village Minino (Central Siberia, Krasnoyarsk Region) were used as the object of the research. To calculate the vegetation index VARI of grain crops, the algorithm for receiving and processing PlanetScope satellite data was developed. On its basis, a map of the spatial distribution of the VARI index for wheat crops with various degrees of weediness was made. According to the satellite data of PlanetScope (VARI), possibility to interpret the areas of wheat sowing with a high and low degree of weediness during the growing season is shown. It was revealed that the VARI value of wheat crops with a low degree of infestation is greater than the VARI value of wheat crops with a high degree of infestation.
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Статья научная
There is studied the possibility of increasing the quality of cryptocrystalline graphite which is connected with searching for more complete opening, the aggregates of graphite and ash admixtures. To achieve this purpose, there was used mechanoactivation and microbiological processing. The developed technology including mechanoactivation, sintering, chemical and microbiological processing, allows to reduce the ash content of cryptocrystalline graphite from 20-25 down to 1-10 % depending on the initial quality and the area of using graphite
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Статья научная
A description and capabilities developed computer models on research of methods developed high-precision navigation used in the software and hardware complex modeling processes positioning and measurement of the spatial orientation of the spacecraft at the low orbit and the GSO.
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Статья научная
The effect of hydrorefining of heavy coal semicoking tar on its composition and efficiency for bituminous coal dissolution was studied. It was found that the concentration of the oxygen-bearing compounds decreased as a result of catalytic hydrotreating with hydrogen or with hydrogen donors. This resulted in improved dissolving power. However, best result in coal dissolution was achieved when heavy semicoking tar was blended with the anthracene oil. The products obtained represented at ambient temperature solid pitch-like matter with the softening points of 124 to 138 °С (“ring and ball” method). It was composed of mainly bi- and three-cyclic aromatics, the content of quinoline-insolubles being less than 6 %, and the ash content less than 0.5 %.
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Thermodynamic stability of intermetallic compounds in technical aluminum
Статья научная
For the following systems Al-Ti, Al-Ni, Al-Zr, Al-Cr, Al-Fe, Al-V the wide range of intermetallic compounds based on aluminum was considered. Thermodynamic parameters such as Gibbs energy and formation enthalpy characterizing the properties of resulting intermetallic compounds were calculated. The relations of these two characteristics versus temperature were established in a wide range. On the basis of the obtained relations the comparative assessment of the compound stability for each binary system was carried out. The level of each intermetallic compound stability was revealed on the ground of the affinity with aluminum. The possibilities of practical application of obtained data for actual metallurgical tasks were defi ned.
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Thin magnetic film magnetometer
Статья научная
This paper presents a novel design of a dual resonator broadband sensor for weak magnetic fields based on thin magnetic films. Such sensors are widely used in various fields, e.g. in geological exploration. The magnetic field of the feedback coil in the sensor is orthogonal to the plane of the printed circuit board with the microwave oscillator. This makes it possible to extend the frequency bandwidth of the measured magnetic fields in the sensors based on thin magnetic films. This is achieved by reducing the effect of the electromagnetic shielding covering the microwave oscillator in the device.
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Time deviations of physical properties of natural minerals
Статья научная
The opportunity of inversion the spin is shown at the several of configuration of defects in the second coordination of sphere. The principle of calculation of energy of cationic vacancies is offered. The condition of splitting of single levels of cationic vacancies in the power zone is certain. It is proved, that inversion the spin - result of transition of vacancy on an extrinsic level.
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Статья научная
trace elements in agate from Permian volcanics (Nowy Kościoł, Poland) in low concentrations and with high spatial resolution. The used LA-ICP-MS system consists of a DUV 193 laser ablation system linked to a Thermo Finnigan Element 2 mass spectrometer. The use of a 193 nm ArF excimer laser (50-200 mJ energy output) and the standards NIST 611 and NIST 612 enables to produce and analyse small crater diameters down to 5 μm. Trace-element profiles have been analyzed for the elements Ti, Ge, Al, Fe, Mn, U, Th, Ba, Sr, Rb, Cs, and Y in the ppm- and sub-ppm level. The concentrations of the REE are sometimes below the detection limit of the method. Almost all elements (except Cu) display higher contents in chalcedony than in the macrocrystalline quartz. Fe, for instance, shows a 100 times higher concentration in agate bands compared to quartz, which may be due to finely distributed iron oxide particles in the chalcedony which probably act as colour pigments. The trace elements in agate are released simultaneously with Si during alteration of the surrounding volcanic rocks. Oxygen isotope data indicate that silica accumulation and agate formation took place at temperatures below 120°C. The characteristic trace-element distribution patterns in agate result from a self-purification process during crystallization of chalcedony and quartz from a silica gel.
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