Vestnik IGEU最新文献

{"title":"Simulation study of 6–10 kV overhead transmission lines to research single phase to earth fault location algorithms","authors":"Y. Kutumov, N. Kuzmina, V. Lebedev","doi":"10.17588/2072-2672.2023.2.036-043","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.036-043","url":null,"abstract":"As part of evolution of single phase to earth faults protection methods and tools in 6–10 kV networks the development of simulation study methods of these networks and their components becomes relevant. A significant direction in this area is upgrading of sensors installed directly on the wires and electrical transmission towers. These sensors are installed in the conditions of an electromagnetic field acting on them and dynamically changes both in time and space, especially during emergency modes including single phase to earth faults. Application of modern software offers a challenge for complex simulation study of electromagnetic fields distribution at the location of the measuring transducers in continuously variable electromagnetic environment. The above-noted statement determines the relevance of the research goal, which is the development of a simulation study method of 6–10 kV overhead power lines, the model of which is designed to study existing and create new single phase to earth fault location algorithms and devices. To solve the tasks set the methods of simulation study of overhead transmission lines and corresponding medium voltage networks in PSCAD and COMSOL Multiphysics software have been used. The general concept of design of a 6–10 kV network and an overhead transmission line simulation model is formulated. The geometrical parameters of the section of the model of an overhead power transmission line to simulate electromagnetic transients are selected, considering the frequency dependence of the line parameters (inductance and active resistance). The proposed model of the overhead transmission line is verified, and recommendations for its application are given. The developed “inductive” component of the proposed overhead transmission line model allows to provide high accuracy of calculation of transient components of currents and voltages during single phase to earth faults. It makes possible to use this model for the development and research of single phase to earth fault location algorithms. The developed approach to simulation study of an overhead transmission line is the field of interest for further research, as it makes it possible to calculate the components of the electric field which are observed during single phase to earth faults.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82775632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of air parameters during drying of large-block metal structures in a tent-type drying chamber","authors":"I. Prosvirina, P. Yakovlev","doi":"10.17588/2072-2672.2023.2.013-018","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.013-018","url":null,"abstract":"One of the stages in the manufacture of large-block metal structures is their coloring followed by drying. A feature of this process is the need to maintain a temperature determined by the characteristics of the paint, which is difficult at low ambient temperatures. The solution of the problem is the use of a tent-type mobile drying chamber at the stage of drying the painted part at the place of its assembly. At the same time, the drying process can be controlled by changing the location of the fan heater and exhaust ventilation, changing the performance of the heater fan and the temperature of the supplied air. The solution of this technological problem is the goal of the study. The study uses the methods of numerical modeling and experimental studies. As a modeling tool, the SOLIDWORKS software package and office packages for statistical data processing have been used. It is found out that the distribution of temperatures in the shelter depends on the thermal resistance of the walls of the drying chamber, the main characteristic of the heater fan, the dimensions of the chamber and the painted module, the gaps between the walls, the ambient temperature and the air coming from the heater, the fan parameters, the fan placement methods and draft ventilation. The calculation considers the aerodynamic resistance of the drying chamber with the part placed in it, the influence of free convection, heat loss and features of air distribution inside the shelter. Based on the results obtained, the authors proposed a calculation method that allows determining the temperature decrease inside the chamber relative to the temperature of the air coming from the heater. To automate the calculation results, a program has been developed to determine the parameters of air after heating with a fan heater. The results obtained makes it possible to solve an important practical problem of ensuring high quality of painting works in a tent-type shelters under various climatic conditions, including negative ambient temperatures due to a reliable forecast of the uneven temperature field in the painting chamber. The developed technique is designed for the rapid selection of heaters, including the supply of a fan, the power of the heating element, and the air temperature at the outlet of the heater depending on the ambient temperature, the permissible range of temperature changes of the paint, the geometric parameters of the tent shelter and the painted product. The scientific value of the study is the results of the study of mixed convection in the tent shelter, the revealed essential regularities of the process and the obtained criterion equation to calculate the temperature range of the paint coating of the product in the chamber. The obtained results have determined the ways to further increase of energy efficiency and to improve the design of tent shelters.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"40 1-2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85657861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinctive features of modeling 110–750 kV overhead transmission lines and cables in phase domain","authors":"D.Yu. Vikharev, I. Ivanov, A. Murzin, N. A. Rodin, D.I. Gandzhaev, A.S. Lifshits","doi":"10.17588/2072-2672.2023.2.051-060","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.051-060","url":null,"abstract":"Power system steady state and transient analysis require correct modeling of overhead transmission lines and cables operating at 110–750 kV. The key difficulties to model sections of overhead and cable lines are caused by complex conductor geometry, their transposition, as well as grounding schemes of ground wires of overhead lines and screens of underground cables. The paper covers various aspects of 110–750 overhead line and cable modeling that must be taken into consideration to obtain a reliable mathematical model in a phase domain. Modern software does not provide a universal solution to determine line parameters. The 110–500 kV cable line modeling issues have not been worked out properly and require careful analysis of specialized foreign literature. Thus, the task to develop the algorithms of calculating the parameters of overhead and cable power lines is relevant, taking into account the various configuration options of these lines which are possible in operational practice. To derive overhead transmission line and cable line models, electric circuit theory and matrix algebra methods have been used. The ATP/ATPDraw and MATLAB/Simulink software environment has been used to investigate what tools are available to determine line parameters, as well as to verify some of the calculation results. Analysis has been carried out to reveal the options available in the ATP/ATPDraw and MATLAB/Simulink software to compute line parameters in a phase domain. An algorithm has been developed and verified to calculate overhead line parameters regardless of the number of parallel circuits. The key features of the calculation of the matrix of linear resistances of overhead power transmission lines are outlined. The main features of modern cable lines operating at 110–500 kV are also described. The paper presents various cable layouts possible in real-field conditions, as well as provides expressions that allow obtaining correct impedances and admittances for a system of cable line conductors. Study of the options of various software tools dedicated to overhead line parameter calculation in a phase domain has revealed that these tools cannot be deemed universal to represent an overhead line of whatever configuration. However, the developed algorithm is universal as it allows computing line parameters regardless the ground wire grounding approach. The expressions presented in this paper consider various layouts of 110–500 kV cable lines that could be encountered in the Russian power system.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72723277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method for reducing time of backup power supply in power supply systems with motor load","authors":"S. Derkachev","doi":"10.17588/2072-2672.2023.2.044-050","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.044-050","url":null,"abstract":"Nowadays fast-acting automatic transfer equipment is commonly applied in power supply systems with a motor load since it ensures uninterrupted power supply of critical consumers. However, their application requires the use of high-speed breakers. The implementation of a “high-speed” transfer to a backup power source when using vacuum switches may not be possible due to the long turn-on and turn-off times. Therefore, the purpose of the paper is relevant. The aim of the paper is to study the possibility to reduce the backup power supply time by improving the algorithm to control the vacuum switches of the main and backup power sources in the modes “high-speed” switching by the fast-acting automatic device in case of short circuits in the external power supply network. To achieve this purpose, computer modeling methods are used. They are based on mathematical models of electrical network elements written using systems of differential equations. The authors have defined the regularities of the transient processes in synchronous and induction motors when switching to a backup power source by the fast-acting automatic device in case of short circuits in the external power supply network. It makes possible to set the limit value of the mismatch angle between the residual voltage vectors on the section of the main power source and the voltage of the backup power source, at which the level of the self-starting current does not exceed the values of the starting currents. Also, it makes possible to develop an algorithm to control breakers. The proposed algorithm is based on changing the operation order of the switches of the main and backup power sources. The obtained results show that implementation of the proposed algorithm to control breakers of the main and backup power sources in fast-acting automatic devices in case of short circuits in the external power supply network of the main power source makes it possible to reduce the backup power supply time and decrease the level of self-starting currents that do not exceed the level of starting currents of electric motors without use of high-speed switches.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83849941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transmitted power limit of controlled high voltage transmission line for modes on steady-state stability boundary","authors":"V. Golov, D. Kormilitsyn, O. Sukhanova","doi":"10.17588/2072-2672.2023.2.028-035","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.028-035","url":null,"abstract":"The use of series compensation devices is one of the methods to increase the capacity of a power transmission line. In addition, the use of controlled series compensation devices affects the steady-state stability of the electric power system. It is also widely known that automatic excitation control of generators has a positive effect on the stability of the system. Thus, it is reasonable to analyze the influence of the adjustable parameters of the controlled series compensation device on the line capacity when considering modes at the boundaries of the stability regions, taking into account automatic excitation controllers on synchronous generators of the power plant. Methods of mathematical modeling of the electric power system, the theory of long-distance power lines and electromechanical transients, methods of analyzing the stability of electric power systems are used. The original software in the C ++ programming language is used as a modeling tool. The authors have selected the regulation laws parameters of controlled series compensation device and automatic excitation controller, provided that steady-state stability is maintained. The stability regions of the electric power-engineering system under study are constructed depending on the tuning parameters of the considered devices. A technique is proposed to select the coefficients of complex regulation of the devices to increase the capacity of a high-voltage power transmission line. The proposed method of the complex selection of regulation coefficients of controlled devices provides the possibility of obtaining their optimal values in a controlled electric power system to ensure stability.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83544364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method to determine effective thermal conductivity coefficient of porous material based on minimum surface Schoen's I-WP(R) type","authors":"D. Bragin, A. Eremin, A. Popov, A. Shulga","doi":"10.17588/2072-2672.2023.2.061-068","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.061-068","url":null,"abstract":"Currently, to develop the materials with predictable properties at the macrostructural level, triply periodic minimum surfaces (TPMS) are used. The production of materials with an ordered structure of TPMS has become available due to the active development of additive technologies. Such materials have high strength-weight ratio, which is important in many structural problems. The study of the thermophysical properties of materials is necessary for the further design of various types of thermal insulation, heat exchangers, etc. In this regard, the study of the thermophysical properties of materials with an ordered structure based on TPMS is a topical issue. The paper proposes to study the thermophysical properties of materials with an ordered structure of Schoen’s I-WP(R) TPMS. Using the ANSYS software package (Steady-State Thermal module), numerical simulation of the heat transfer process in the material under study is carried out. The study is carried out for a material common in additive technologies, that is PETG plastic. The article presents the results of a study of the thermophysical properties of a material with an ordered macrostructure based on Schoen’s I-WP(R) triply periodic minimal energy surfaces. Based on the simulation results, graphical and analytical dependences of the heat flux density and effective thermal conductivity of the material are obtained. The results of the heat flux density are obtained in different directions with variable geometric parameters of the structure (the thickness of the cell wall and the length of the edge of the cube in which the cell is inscribed). Using the ANSYS software package, numerical simulation of the heat transfer process in the material under study is performed. The calculation results show a linear dependence of the effective thermal conductivity of the homogenized material on the wall thickness of the unit cell. It is shown that the intensity of heat transfer depends not only on the wall thickness and unit cell size, but also on the direction of the heat flux. The obtained results of the study can be used to create materials with predictable thermal conductivity by changing the dimensions (cell wall thickness and cube edge length) and high strength-weight ratio. The production of the material is possible with the help of additive technologies.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"125 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84803779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of placement of transformer substations in urban neighborhoods using genetic algorithm and pathfinding of electric power transmission lines on the map","authors":"E. G. Kozlov, S. Kosyakov","doi":"10.17588/2072-2672.2023.2.069-075","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.069-075","url":null,"abstract":"To define the placement of electric substations when designing power supply schemes in urban neighborhood is a challenging task since it is necessary to consider spatial restrictions when choosing routes for electric power lines. Thus, the selection of the substation distribution is usually limited by comparison of several variants. In the scientific literature, problems of optimization are usually considered without taking into account real environmental restrictions for the electric power transmission lines. And it significantly reduces the adequacy of the models used. Thus, the study of the possibilities to use both combinatorial optimization methods and the construction of minimum cost routes in the GIS environment to select the optimal layout of electrical substations when designing power supply schemes for urban neighborhood is relevant. The methods to determine the shortest paths on the graphs and the genetic algorithm search are used for the research. The map of the electric lines of Ivanovo city has been used as base data for calculation. A new method has been developed to determine the optimal number and placement of transformer substations to power a lot of buildings on the digital city map. A wave algorithm of cost surfaces is used to estimate the cost of laying cable electric power transmission lines from the consumer to any location of the transformer substation. A genetic algorithm is used to select the network structure. The research results have confirmed the possibility to determine the best transformer substation distribution using GIS with given spatial restrictions.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78945052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of efficiency of pyrolysis processing of municipal solid waste","authors":"R. Gabitov, O. Kolibaba, D. Dolinin, M.M. Chizhikova","doi":"10.17588/2072-2672.2023.2.019-027","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.2.019-027","url":null,"abstract":"The disposal of waste by direct combustion method is prohibited in the Russian Federation due to the negative impact on the environment. An alternative option is solid waste pyrolysis technology, which allows not only to significantly reduce the amount of waste that requires disposal, but also to obtain various types of energy carriers. Existing installations allow recycling waste with humidity up to 30–35 %. An increase of humidity over 40 % requires additional energy sources for the drying process. To increase the efficiency of waste recycling by pyrolysis, it is necessary to improve the technology and to design an energy-efficient waste disposal plant. The use of the heat of combustion products in the heat exchanger to heat the air going into the drying chamber will increase the range of processing of wet waste. To determine the efficiency of the furnace for thermal waste disposal, the method of material and thermal balance is used. It allows determining the efficiency of the installation and selecting its operating mode with its maximum value. The paper proposes a new design of a waste disposal furnace with separate drying and pyrolysis chambers, as well as a mathematical model based on the equations of thermal and material balance. The design feature of the installation allows you to organize the controlled drying of wet waste and reduce losses with combustion products by using a heat exchanger for air heating. The proposed installation allows the waste recycling process to be carried out at a relative humidity of 0 to 60 % without additional energy sources. The efficiency of the waste varies from 61,5 to 80 % when the plant is operating on dry waste and from 42 to 62 % when operating on wet waste.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78814668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method of simultaneous equations of material and energy balances when calculating actual data of thermal efficiency of gas turbine plants","authors":"A.S. Zinovieva, S. D. Gorshenin, G. V. Ledukhovsky, V. Zhukov","doi":"10.17588/2072-2672.2023.1.005-010","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.1.005-010","url":null,"abstract":"Reconciliation of material and energy balances according to data received from systems of technical and commercial record keeping is a mandatory step to calculate thermal efficiency indicators of thermal power plant (TPP) equipment. At the same time, the methodology to draw the balance is not regulated by regulatory documents for gas turbine plants. Appropriate approaches to solve the issue under consideration have not been worked out. There is no data on the impact of the balancing on the results of calculating the actual values of the gross efficiency of gas turbine plants. Thus, it is relevant to develop a methodology of simultaneous equations of the material and energy balances of gas turbine plants. The problem of simultaneous equations of the material and energy balances of a gas turbine plant in a scalar value is formulated within the framework of the concept of solving ill-posed problems based on Tikhonov's regularization. The concept allows one to obtain an analytical solution. When conducting calculations, data from the automated process control system of the operated GTX-100 gas turbine plant have been used. The method of simultaneous equations of the material and energy balances when calculating the actual indicators of the thermal efficiency of gas turbine plants is proposed. The influence of the balancing procedure on the results of calculating the actual values of the thermal efficiency indicators of a gas turbine plant is shown. The authors have determined the maximum deviations of the actual gross efficiency values when adjusting the results of measuring the controlled parameters using the example of GTX-100 gas turbine plant. The developed technique makes it possible to consider the maximum allowable total discrepancy between mass and energy balances, as well as the maximum deviation of the parameter values adjusted according to the balancing results, due to the standardized metrological characteristics of measuring instruments.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78449779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and Calculation of Heat and Mass Transfer Process in Multistage Multiflow Flash Evaporators","authors":"V. Zhukov, I. A. Kokulin, V. Vinogradov","doi":"10.17588/2072-2672.2023.1.071-078","DOIUrl":"https://doi.org/10.17588/2072-2672.2023.1.071-078","url":null,"abstract":"Thermal methods that have several environmental and economic advantages are widely applied for water treatment at thermal (TTP) and nuclear power plants (NPP) along with chemical methods. Multistage flash evaporation plants are important in case of use of thermal methods for desalinated water treatment as they can use low-temperature steam of thermal power plants. Despite the considerable number of scientific papers on this issue, the effective performance and improvement of the heat and mass transfer process in evaporator plants remains an urgent task, especially with variable operating modes of the technological equipment of TPPs and NPPs. On the one hand, it is due to the need to match the variable parameters of steam and the variable flow rates of make-up water for the process needs of the station. On the other hand, it is due to the lack of universal methods to calculate and design the equipment. Thus, the development of new methods to model and improve heat and mass transfer processes in thermal water treatment plants of thermal power plants and nuclear power plants is an urgent task for the power energy industry and related ones. To solve the problems of modeling heat and mass transfer processes in flash evaporation plants, models based on the mass and energy balance equations have been used. The obtained differential and linear equations are solved by analytical methods and methods of mathematical programming. A matrix model of the process of heat and mass transfer in a multi-stage multi-flow evaporative flash installation has been developed, considering evaporation of part of the water when it enters the low-pressure region. The steady-state pressure distribution over the stages and the performance of each stage of the evaporative installation have been found. Comparison of the calculated and known results have shown an adequate description by means of the model of the real process of heat and mass transfer in flash evaporation plants. It makes possible to set and solve problems to choose the optimal design and operating parameters of equipment for multi-flow evaporation plants. The proposed method to solve the problem of modeling heat and mass transfer provides the possibility of simultaneously search for acceptable values of design and operating parameters of multistage evaporative plants for various purposes.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88182743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}