Статьи журнала - Журнал Сибирского федерального университета. Серия: Техника и технологии
Все статьи: 1367
Статья научная
The article is dedicated to end users (decision makers) of information support technique in the process of agricultural lands’ (AL) remote monitoring with the use of Earth remote sensing (ERS) data. The model of spatial object has been developed, which considers its spatial structure and allows to estimate its state in accordance with preset plan of object development with time.
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Статья научная
Were presented a description of the innovative new technologies of production of a small cross-sectional products made from non-ferrous metals and alloys with using combined methods of casting and metal forming. Sets out the technical and technological solutions, allowing obtaining semi-fi nished products from compact and non-compact billets from different non-ferrous metals and alloys.
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Interaction of PbO-based oxide melts with crucible materials
Статья научная
Contact interaction of PbO-GeO2 melts with crucible materials (Au, Ag, Al2O3, BeO) was investigated by sessile drop method. It was found that the contamination of PbO-GeO2 oxides by the components of these crucibles depended on the initial composition of melts.
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Investigation of electric characteristics of contact assemblages with a powder damping interlayer
Статья научная
In our work there were investigated thermal electrophysical characteristics of coaxial contact assemblages, made of a steel current carrying rod, steel or cermet sleeve and filled with an iron or nichrome powder. As a result of heating up to 950 ºС the iron powder was shown to be sintered and develop a highly conductive and damping medium that can be used for making contact junctions of materials having very different linear expansion coefficients.
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Investigation of electrical characteristics of high temperature ceramic-metal contact assemblages
Статья научная
There was carried out research work on electrical technical characteristics of contact assemblages made of materials with very diverse linear expansion coefficients (LECs) at temperatures up to 900°С and current loads of long-durations up to 100 hours. Foam nickel was employed as a conductive damping material. After being subjected to long current and heat loads contact junctions between the foam nickel and contact assemblage materials were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis.
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Статья научная
Coating deposition on many industrial components with good microstructural, mechanical properties and better wear resistance is always a challenge for the thermal spray community. A number of thermal spray methods are used to develop such promising coatings for many industrial applications; viz. arc spray, flame spray, plasma, and HVOF. All these processes have their own limitations to achieve porous free, very dense, high performance wear resistant coatings. In this study, an attempt has been made to overcome this limitation. Molybdenum coatings were deposited on steel substrates using Wire flame. As-sprayed coatings were analyzed for phase using x-ray diffraction (XRD), and for microstructural using scanning electron microscopy (SEM), also the micro-hardness of coatings are measured. Results show that the coatings have good performance in terms of microstructural, mechanical properties.
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Investigation of physical-mechanical and electric properties of conducting SnO2-based ceramics
Статья научная
In our paper there are presented results of the investigation of physical-mechanical and electric properties of conducting ceramics based on SnO2-Sb2O3-CuO-system with superdispersed additives of metal oxides produced by pyrolysis of their water-soluble salts.
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Large size metal-clad ingots rolling process analysis using finite elements method
Статья научная
Under real rolling conditions, plastic strain is accompanied by inevitable uneven distribution of the metal movement velocities, strains and stresses both in height and width of the actual deformation zone of the rolled metal. With the simultaneous plastic strain of various metals, there is still a layered inhomogeneous strain, which is caused by the fact that at the same time in a plastic zone there are metals possessing different mechanical properties. The inhomogeneity of layered strain is one of the most important and complex problems of the theory of simultaneous plastic strain. A considerable number of works, has been devoted to the investigation of this problem, but many of the issues that we should deal with when developing the technology for the production of clad products remain unclear. In this article, the authors carried out a study of the process of rolling high cross-section ingots with cladding plates, using finite element modeling in the DEFORM software. Relationships are determined to take into account the strain inhomogeneity and the influence of various parameters on the depth of strain penetration into ingot.
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Lazar continuous carbon baking - the future is now
Статья научная
The Lazar Continuous Carbon Baking Furnace (CCBF) presents a groundbreaking new process for the baking of carbon anodes. A static thermal profile provides a consistent heat-up rate across distinct temperature zones, eliminating thermal cycling. Complete PAH destruction, combined with the lack of thermal cycling, eliminates refractory maintenance requirements and allows for tighter tolerances in pollution-control systems, leading to a significant decrease in operating costs. Costs to build a Lazar CCBF are estimated to be 35 to 45 % less than conventional ring-type furnaces, with operating costs estimated to be approximately 60 % less.
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Low-toxic core sands for mould cores pattern - making in a heated rig
Статья научная
The innovative method of physical and chemical analysis was first used for core sand research that, unlike the method of tests and errors, radically shortens the scope of an experimental work in order to find the optimal core sands compoundings. Some results of the investigations based on the physical and chemical analysis for obtaining the compoundings of low - toxic core sands using hot hardening of a new generation without containing resins are presented. Such compoundings impart more advanced technical, economical and ecological indicators to the process of cores moulding using a heated rig. The development of such mixtures relies on low - toxic technical lignosulphonates (LTTLS) binders containing a modifier. The mixture of vat residues of organic synthesis in water having volume relationship in the proportion of 6:1 was used as a modifier. The search of technological additions set increasing LTTLS binder properties was conducted. To put into practice the declared purpose we investigated the additions of marshalit, boric acid and iron minium influences on the mixtures properties. It was demonstrated that only the joint use of the above - mentioned three technological additions may result in an effective influence of each of them on mixtures properties. An additional introduction of «KO» solution in kerosene turned out to be effective, as well. The given research results lie in presenting mixtures compoundings based on LTTLS having physical and mechanical indicators usually characterizing resins mixtures. Some mixtures containing the additions of a wasted zinc - chromium catalyst having good ecological properties and being applicable to the cores molding of a wide range of pig iron and steel castings were elaborated.
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Machine learning approach to simulation of continuous seeded crystallization of gibbsite
Статья научная
Continuous seeded crystallization is characterized by oscillations of particle size distribution (PSD) and liquor productivity. To describe these oscillations using analytical methods is a complicated task due to non-linearity and slow response of the process. This paper uses a statistical approach to the preparation of initial data, determination of the significant factors and arrangement of the said factors by their impact on the dynamics of crystal population development. Various methods of machine learning were analyzed to develop a model capable of forecasting the time series of particle size distribution and composition of the final solution. The paper proposes to use deep learning methods for predicting the distribution of crystals by grades and liquor productivity. Such approach has never been used for these purposes before. The study shows that models based on long short-term memory (LSTM) cells provide for better accuracy with less trainable parameters as compared with other multilayer neural networks. Training of the models and the assessment of their quality are performed using the historical data collected in the hydrate crystallization area at the operating alumina refinery.
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Magnetization of a pyrrhotite of composition Fe0.847S in area of a Curie point
Статья научная
The x-ray, Mossbauer and termomagnetic researches of pyrrhotites possessing high-temperature λ - peak (Тλ = 310 C) on curve dependence of magnetization on temperature - I (Т) are lead. The chemical compound and conditions of formation of such pyrrhotites is determined. It is established, that samples with λ - peak possessed the raised maintenance of sulfur in comparison with pyrrhotites Fe7S8 and corresponded to structure Fe1-nS (n=0.153). As has shown experiment, these pyrrhotites are in a metastable phase condition and in due course (samples were observed during 29 years) pass in a pyrite and a pyrrhotite of structure Fe7S8 (at the presence of an atmosphere the Goethite and a szomolnokit was formed also). Because of quantum-mechanical calculations of dependence of specific magnetization from temperature for various underlattices with various integral of exchange interaction good conformity of a settlement curve with experimental is received. Calculations were made within the framework of model of a molecular field for a two-sublattice ferrimagnetic.
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Статья научная
This article present main characteristics of aluminum alloys with high dispersion ability of phase of alloying elements. Examined future development in the field of obtaining heat-resistant and high-strength aluminium alloys, as well as alloys for special purposes.
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Статья научная
This study employed an algorithm of vegetation cover mapping based on a spatial analysis of Landsat OLI satellite imagery, a digital elevation model (DEM) and field data using geographic information systems (GIS) and expert knowledge. Applying this algorithm, maps of vegetation types and vegetation growth conditions were built for the test site in the northern part of near-Yenisei Siberia (Krasnoyarsk region). The spatial analysis of these two maps with field samples were used for the extrapolation and mapping of soil carbon stock volumes (kgC/m2).
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Статья научная
This article covers the use of analytical technique of solutions for flexural and longitudinal oscillations of the bearing framework of a railcar body frame in the form of an elastic core of variable section with a variable weight, flexural and longitudinal rigidity. The calculation is performed for the modernization of the body frame of emergency and repair rail service car, taking into account the variability of section, mass, longitudinal and bending stiffness along the length to prolong the service life of their useful operation.
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Статья научная
Peculiarities of geometry elements synthesis of wave transmission with a rolling (cog) rack, its kinematics and simulation interaction of discrete wedge pushers with rolling rack are considered here. Principles of drive creation and systems of microprocessor control of the mechatronical module of the translation by using wave transmission with the rolling rack as well as the main appraches in design-technological preparation of its making are presented.
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Статья научная
Proposed new ways of obtaining rods-modifiers from aluminum and aluminum alloys. Were researched of their modifying ability and tested in industrial conditions modification technology in the production of aluminum alloy ingots.
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Method and device for compression of the non stationary signals
Статья научная
In the report a new method and the operation of the device of statistical compression of non-stationary pulse signals are described. The pulse signals are characterized by, first of all, weak irregular period of signal, e.g. electro cardio signals (ECS). It is shown that construction and processing the ECS histogram provide high value of the compression.
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Статья научная
This article is devoted to development of a method for assessing NDVI dynamics in northern territories and analysis of NDVI dynamics of vegetation on the territory of the Krasnoyarsk region using MODIS/Terra satellite data for the period (2000-2020). Spatial distribution map of average annual vegetation index NDVI has been made, indicating five latitudinal sections through the territory of the Krasnoyarsk region: the coordinates (latitude from 52˚ N to 76˚ N, longitude from 91˚ E to 95˚ E). Latitudinal variability of NDVI index for 20 years of measurements has been studied. Heterogeneity of long-term dynamics of vegetation has been discovered depending on the latitude of the studied territories. Efficiency of the suggested method for identifying long-term NDVI trends has been shown. A positive NDVI response of the vegetation cover of northern territories of the Krasnoyarsk region to climatic changes over the last 5 years has been revealed.
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Methodology to optimize the anode performance
Статья научная
An aluminium smelter operating its pots with Soederberg technology has experienced a period with a very high number of anode problems, mainly occurring as spikes, hanging anode ends, leak in stud holes, vertical cracks and dusting. The anode problems hindered a planned amperage increase. This paper describes the methodology that was applied to identify the root causes of the problems and to solve them systematically. This methodology includes the following main steps: Initial plant audit; Revamping of equipment causing bottlenecks; Plant capability test; Dynamic process optimization DPO; Validation of improved anode quality and pot performance. By applying this methodology, the anode problems of the smelter could virtually be eliminated. As a consequence the key plant performance figures (current efficiency, carbon consumption, energy consumption and bubble noise) could be improved substantially. This allowed to increase the line current by 7 %.
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