Статьи журнала - Журнал Сибирского федерального университета. Серия: Техника и технологии
Все статьи: 1404
Smart materials in materials science
Статья научная
The basic categories of materials which form the row in order of complication of their performance such as simple–multifunctional–adaptive–active–smart are considered. Energy aspects of external effects upon materials, and behavior of materials response to the stimuli of physical, chemical and biological nature, are examined. A model of smart material is proposed as the atom-molecular structure provided with a feedback system which corrects the primary reaction of material upon effect of surroundings via optimal usage of its energy.
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Статья научная
The article presents the results of software development for predictive maps modeling of the earth’s surface processes based on time-varying satellite data using the probabilistic and spatial characteristics of various types of the earth’s surface in the image. The analysis of existing methods for the assessment and modeling of the state of landscapes of various territories using satellite Earth monitoring data is presented. The review of existing systems of the earth’s surface dynamics analysis and their main advantages and disadvantages is given. The cellular automata method was used to implement the forecast. This method allows complex systems modeling using a simple set of rules and is the most convenient and accurate method for working with a space images. Algorithms and basic modeling parameters for using this method are described. The developed software makes it possible to forecast the state of the surface of the territories under consideration based on a series of time-varying data, and also to specify various modeling parameters in order to improve the accuracy of forecast maps. The results of the developed software testing with MODIS and Landsat data are presented, the accuracy of the forecast and the influence of simulation parameters on the result were estimated.
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Solution of the problem of flow past a wing profile near the interface
Статья научная
In this paper presente some approaches to solving the problems of flow past a wing profile near the interface. Studies on the flow in the vicinity of separation boundaries (solid walls and free surfaces) show that in a confined flow liquid turns into a bubble mixture of liquid and gas. This complicates the flow analysis and introduces additional losses resulting in impaired energy performance of the concerned mechanisms. In a general case the problem of a two-phase compressible flow around various types of vane mechanisms is substantially nonlinear (even under no-vortex flow assumption).
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Sorption cleaning of galvanic wastewater from Fe ions (II), (III) and reuse of sorbent IPI-T
Статья научная
The sorption method of wastewater cleaning from ions of Fe (II) and (III) using carbon sorbent IPI-T synthesized in the Irkutsk State Technical University. Particular attention is paid to the regeneration of the carbon sorbent saturated with ions of Fe (II) and (III),by the chemical treatment method. Was studied the reuse of the sorbent for the purification of galvanic wastewater.
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Статья научная
The purpose of this work is to assess the long-term changes in the state of forest vegetation on the territory of the Nature Reserve “Stolby” for the period 2000-2018. An algorithm has been developed for this and a map of the spatial distribution of the average annual NDVI trends of forest vegetation according to MODIS satellite data has been created (May - September as averaging period). In the work, a map of vegetation cover was used according to the electronic ecological atlas of the Nature Reserve “Stolby”. The analysis of the distribution of the number of pixels on the values of the average annual NDVI trend revealed that for the class of coniferous vegetation negative values of the linear trend prevail (by 30%). For the deciduous vegetation class, the number of pixels with negative values of linear trend slope is 3.1% higher than with positive ones. In general, for most types of forest vegetation negative trends NDVI prevail. The negative NDVI trend slope of vegetation indicates degradation processes. The reasons for this are the changes of climatic factors, anthropogenic impact, fires, aging and forest vegetation diseases.
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Статья научная
The objective of the study is to assess the state of agricultural seeds (level of weediness) on the territory of the Krasnoyarsk Agricultural Research Institute of Federal Research Center «Krasnoyarsk Science Center of the SB RAS» near the village Minino according to satellite data. For this purpose, an algorithm for obtaining and processing PlaneScope satellite data for calculating the NDVI vegetation index of agricultural seeds has been developed. On its basis a map of the spatial distribution of NDVI wheat seeds with different levels of weediness has been created. According to PlanetScope satellite data, an opportunity to interpret areas of wheat seeds with high and low levels of weediness has been shown. It has been found that the NDVI value of pure plantation of wheat with a low level of weediness is greater than the NDVI value of wheat seeds with a high level of weediness.
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Speciality of sulfide minerals alteration of copper-nickel ores
Статья научная
Grain-size class redistribution of non-ferrous, precious metals and iron in copper-nickel ores tailings from Norilsk industrial region was after artificial weathering investigated. Possible mechanisms of metal redistribution were suggested.
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Статья научная
The paper presents the results of the analysis on measured parameters of harmonics at the node of the high-voltage network. The measurements were made at the node connecting the pulp-and-paper mill to the 220 kV supply network. This load is nonlinear and has a large capacity. Particular attention is paid to the distributions of the current and voltage harmonics. The paper clearly shows probabilistic properties of the measured parameters of harmonics.
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Статья научная
The design of active hydrostatic radial bearing with smooth cylindrical surfaces and lubricant output flow restrictors in the form of movable rings on membrane suspension is presented. The device is several times less power-consuming compared with known devices of flow control. The bearing has a negative and zero compliance (infinite stiffness), and therefore can be used in machine tools to suppress the negative influence of elastic system deformation on the accuracy of processing. On the basis of two-dimensional model of lubricant flow developed a mathematical model, method and procedure for calculating the bearing load capacity and flow rate. It is established, that the calculation of static characteristics of bearing in the entire range of operating loads can be correctly performed only on the base of two-dimensional model. For small eccentricities the characteristic of zero and negative compliance can be calculated with sufficient accuracy by the simplified method, based on one-dimensional motion of lubricant flow. Bearing of zero or negative compliance have load capacity range, which is 20 - 50% more than conventional bearings of the same overall dimensions. The setting of input throttling slits resistance decisive influence on the optimal static characteristics of the bearing. The optimal values of its resistance for conventional and active bearing are practically identical.
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Statistical regularities of chronology of astronautics
Статья научная
In article chronological anomaly of astronautics is described and investigated by methods of mathematical statistics. The binomial law of distribution of number of chronological coincidence is proved. It is shown, that the probability of casual occurrence of considered coincidence is rather small.
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Stochastic simulation of covariance matrix and power load curves in electric distribution networks
Статья научная
An algorithm of stochastic simulation of covariance matrix and nodal power load curves is developed for electric distribution networks based on factor analysis. Statistical stability of factor power load model is confirmed. Application of this model is able to identify a general regularity of nodal power changing, and to simplify the analysis of multivariate operating conditions in operational problems of electric distribution networks and their optimization.
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Статья научная
Work is devoted research of features of structure formation processes in the contact zone of limited solubility bimetals and alloys subjected to plastic deformation. It is established, that the plastic deformation of limited solubility metals (Al-Ti, Al-Ni), can significantly broaden the scope of their mutual solubility. The appearance of zones of local tensile and compressive stresses (curvature crystal lattice zones) leads to increased solubility, emergence of new phases and redistribution of their composition, reorientation of granular structure.
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Structural topological analysis of cardiac conduction system
Статья научная
In this paper the method of structural-topological analysis of cardiac conduction system based on wavelet analysis of electrocardio signal reflecting conductive network of heart topology has been considered.
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Статья научная
The purpose of this work was to study the chemical changes, taking place during the initial stage of the interaction of butadiene rubber and its vulcanized product with nitric acid by means of the differential IR spectroscopy. Thus some mechanistic knowledge, associated with the complex nature of this process could be obtained.
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Study of alternative methods for preparing the pitch binder for the anode paste
Статья научная
Aluminium smelting industry is the biggest consumer of coal tar pitch, but the use of pitch causes numerous problems because of some economic and environmental factors. Russia’s growing defi cit is covered by import deliveries, which cannot guarantee a secure future. At the same time stricter environmental sanctions related to the use of coal tar pitch as a source of cancer-inducing emissions, are supporting the search for alternative raw materials and the development of new pitch binder production techniques. Given that the known reserves of bituminous coal will be sufficient to last for 230 years at the current production rates as opposed to the oil reserves that will be enough for 40 years only, it becomes obvious that the development of a pitch binder production technique based on thermochemical processing of coals is a promising direction to follow. Investigations were carried out to dissolve coals thermo-chemically in various organic solvents at varying levels of temperature, pressure, and reaction times. It was shown how mechanic activation and ultrasonic exposure affect the degree of organic coal mass extraction. The methods of vacuum and atmospheric distillation were used to produce pitch products from coal extracts. It was demonstrated that the use of coking additives, including nano-modified carbon, helps improve the application properties of pitch products. Large-sized samples of coal tar pitch were used to produce trial lots of anode paste for Soederberg anodes.
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Статья научная
Technology for making electrical aluminum alloys with different contents of rare-earth metals and nickel was developed. Cast and deformed semi-finished products made of new alloys were obtained as a result of experimental studies. The structure and mechanical properties of metal were studied as well as electrical resistivity measurements of rods and wires were carried out. The effect of nickel and rare-earth metals on these characteristics was found out and alloy compositions with the most favorable combination of strength and electrical properties were determined.
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Study on long-term tempering on the microstructure of creep strength enhanced ferritic P92 steel
Статья научная
Present paper deal with the studies of effect of long term heating on the microstructure and mechanical properties of creep strength enhanced Cr-Mo P92 steel. Such steels are used in supercritical power plant boilers where continuous operating temperature and pressure can be as high as 650 0C and 300 bar respectively. The P92 specimens were thermally exposed at temperature of 650 0C for duration of varying from 1000 to 3000 hours. Tensile fracture and impact toughness fracture surfaces were studied by using scanning electron microscope. The fracture surface of P92 impact toughness specimen exhibited both inter lath-decohesion and ductile dimple tearing. The various phases that formed in the tempered P92 steel were analyzed by X-ray diffraction. In XRD analysis of tempered P92 it was observed that amount of precipitates increased as compared to untemperedcondition. After tempering time of 1440 h, some new precipitates such as NbC, NbCrN were also observed.
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Supercapacitor as a buffer electrical source for induction motor
Статья научная
Mathematical substitutions in the equations and the used methods have shown the adequacy and correctness of their use. Analysis of the data, obtained from simulation modeling of the developed model, showed small discrepancies with the standard block from the Simulink library. The use of the obtained mathematical equations, as well as the model assembled in Matlab Simulink, will make it possible to qualitatively evaluate the operation of an induction drive in statics and dynamics. This model will be used in future research, including the creation of a buffer power source based on a supercapacitor for an induction electric drive.
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Статья научная
In this paper, we analyzed the vehicle’s driving modes and opted for the idle mode to save fuel. The synergy of the vehicle with the traffic light depends on many factors and has been studied on the example of the information model of the “Intelligent start-stop system”. A vehicle with an “intelligent start-stop system” was saved 8.25 % of fuel during 100 km in urban conditions. In addition, emissions of harmful gases into the environment have been minimized. It was found that an average of 132 liters of fuel was saved when one vehicle traveled 20,000 km per year. Moreover, the idling time of the vehicle’s engine was characterized by a reduction of 28-32 % in 100 km of the total test distance. Also included are the concepts of order parameter and flexible parameter on the principles of synergetic by using intelligent transport systems in the local condition.
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Synergy nanostructuring carbon materials based on cavitation technologies
Статья научная
The purpose of the present paper is to obtain new physical properties and to expand a range of operational properties of various carbon-blacks by using hydrodynamic and thermophysic effects of cavitation. After the cavitation experiment the wood carbon-black has in part gained some properties of nanocomposites among which there are fullereniferous and diamond-bearing carbon-blacks. In this case cavitationally processed wood carbon-blacks can be as an efficient modifying additive in lubricants, etc
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