Pub Date : 2005-09-06DOI: 10.1109/MIA.2005.1502475
E. S. Thomas, R. A. Barber, J. Dagenhart, A. Clapp
The most common medium voltage electric distribution system in the United States is multigrounded wye using a common neutral for both primary and secondary systems. The effective interconnection of the multigrounded wye neutral conductor with the earth ground reference is very important for safe and effective operation of these systems. Areas of concern include: public safety, operating personnel safety, system reliability, power quality, customer surge protection. This paper is intended to address how grounding system effectiveness affects each of these goals.
{"title":"Distribution system grounding fundamentals","authors":"E. S. Thomas, R. A. Barber, J. Dagenhart, A. Clapp","doi":"10.1109/MIA.2005.1502475","DOIUrl":"https://doi.org/10.1109/MIA.2005.1502475","url":null,"abstract":"The most common medium voltage electric distribution system in the United States is multigrounded wye using a common neutral for both primary and secondary systems. The effective interconnection of the multigrounded wye neutral conductor with the earth ground reference is very important for safe and effective operation of these systems. Areas of concern include: public safety, operating personnel safety, system reliability, power quality, customer surge protection. This paper is intended to address how grounding system effectiveness affects each of these goals.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130699536","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307041
J. Josken, D. Wareham
Mineral oil has been the preferred insulating fluid in power electrical equipment for more than 100 years. Undesirable characteristics of mineral oil, such as lower fire point, environmental concerns and degradation of insulation paper, has spurred the industry to develop alternative insulating systems. Recently developed seed based oils have been proven to provide better performance in all of the objectionable categories of mineral oil. This paper will provide an introduction to these new oils and explain the advantages of using this fluid in new transformer and as a retrofill alternative.
{"title":"Seed based oil as an alternative to mineral oil","authors":"J. Josken, D. Wareham","doi":"10.1109/REPCON.2004.1307041","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307041","url":null,"abstract":"Mineral oil has been the preferred insulating fluid in power electrical equipment for more than 100 years. Undesirable characteristics of mineral oil, such as lower fire point, environmental concerns and degradation of insulation paper, has spurred the industry to develop alternative insulating systems. Recently developed seed based oils have been proven to provide better performance in all of the objectionable categories of mineral oil. This paper will provide an introduction to these new oils and explain the advantages of using this fluid in new transformer and as a retrofill alternative.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"288 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122781081","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307067
D. Farmer, M. Marshall
Many utilities are faced with the problem of shrinking budgets while continuing to maintain or improve the level of service to their customers. Customer expectations have changed and, as a result, maintaining or improving reliability can be very expensive and elusive. It is not easy to define what the customer expectations are in many cases. Reliability programs and initiatives have been in place at many utilities for a number of years and, as a result, much of the low hanging fruit has been picked. All of this leads to a need for developing more detailed methods for analyzing system improvements to determine which are the most effective. This paper addresses how to define the benefit of reliability improvement techniques, how to perform a basic cost benefit analysis, and a process for prioritizing work based on reliability and cost impact. Although the amount of available funding will vary greatly between utilities, budget limitations are a fact of life for all, regardless of the source of capital funding. The challenge is to maintain an acceptable level of reliability within that budget. It's a basic truth that if you don't invest in the system, service availability and reliability will ultimately degrade.
{"title":"Getting the most from your reliability budget","authors":"D. Farmer, M. Marshall","doi":"10.1109/REPCON.2004.1307067","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307067","url":null,"abstract":"Many utilities are faced with the problem of shrinking budgets while continuing to maintain or improve the level of service to their customers. Customer expectations have changed and, as a result, maintaining or improving reliability can be very expensive and elusive. It is not easy to define what the customer expectations are in many cases. Reliability programs and initiatives have been in place at many utilities for a number of years and, as a result, much of the low hanging fruit has been picked. All of this leads to a need for developing more detailed methods for analyzing system improvements to determine which are the most effective. This paper addresses how to define the benefit of reliability improvement techniques, how to perform a basic cost benefit analysis, and a process for prioritizing work based on reliability and cost impact. Although the amount of available funding will vary greatly between utilities, budget limitations are a fact of life for all, regardless of the source of capital funding. The challenge is to maintain an acceptable level of reliability within that budget. It's a basic truth that if you don't invest in the system, service availability and reliability will ultimately degrade.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114579392","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307046
R. Harness, E. Walters
A number of methods have been tried to control woodpeckers from damaging utility poles. Decoys (e.g. owls and snakes) and load noises may have some effect initially but woodpeckers soon acclimate to these and return to their previous activities. Most birds do not hear in the ultrasonic frequency so ultrasonic or high frequency sound-producing devices are ineffective. Creating artificial nesting cavities is not likely to be effective in the long-term as cavity creating is a critical part of the breeding ritual and very few woodpecker species use nest boxes. To date, no chemical repellents have been developed that have proven to be both significantly effective and environmentally friendly, however the approach still holds promise as a cost-effective means to successfully mitigate woodpecker damage. Wire mesh is the most widely used barrier to prevent damage. When selecting a barrier, it is critical to know what woodpecker species are damaging poles. The most commonly used mesh is 19 gauge-galvanized wire in a 1/4-inch mesh pattern. Larger species such as the Pileated woodpecker can penetrate 19-gauge wire so a heavier gauge wire is required. It is becoming common for utilities to repair woodpecker cavities in wood poles with fillers in an effort to extend the pole's useful life. There are a variety of tools to calculate damage and determine if a pole can be repaired or must be replaced. A number of repair products are discussed in this paper.
{"title":"Woodpeckers and utility pole damage","authors":"R. Harness, E. Walters","doi":"10.1109/REPCON.2004.1307046","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307046","url":null,"abstract":"A number of methods have been tried to control woodpeckers from damaging utility poles. Decoys (e.g. owls and snakes) and load noises may have some effect initially but woodpeckers soon acclimate to these and return to their previous activities. Most birds do not hear in the ultrasonic frequency so ultrasonic or high frequency sound-producing devices are ineffective. Creating artificial nesting cavities is not likely to be effective in the long-term as cavity creating is a critical part of the breeding ritual and very few woodpecker species use nest boxes. To date, no chemical repellents have been developed that have proven to be both significantly effective and environmentally friendly, however the approach still holds promise as a cost-effective means to successfully mitigate woodpecker damage. Wire mesh is the most widely used barrier to prevent damage. When selecting a barrier, it is critical to know what woodpecker species are damaging poles. The most commonly used mesh is 19 gauge-galvanized wire in a 1/4-inch mesh pattern. Larger species such as the Pileated woodpecker can penetrate 19-gauge wire so a heavier gauge wire is required. It is becoming common for utilities to repair woodpecker cavities in wood poles with fillers in an effort to extend the pole's useful life. There are a variety of tools to calculate damage and determine if a pole can be repaired or must be replaced. A number of repair products are discussed in this paper.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132795447","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307056
J. Smith, J. Taylor, D. Brooks, R. Dugan
This paper is an overview of the various types of studies required for the interconnection of wind generation to the utility power system. While the emphasis is on distributed wind applications connected to the distribution system, both bulk wind and distributed wind generation are discussed. Each has its own set of challenges and different analysis requirements. Wind generators are frequently installed in remote geographic locations where the power system is weak. This compounds issues associated with the variable and somewhat unpredictable nature of the energy resource. This paper describes procedures for wind farm interconnection studies, advances in model development for system dynamics studies, and operating impact studies. Voltage regulation and overcurrent protection studies for distributed wind applications are also described.
{"title":"Interconnection studies for wind generation","authors":"J. Smith, J. Taylor, D. Brooks, R. Dugan","doi":"10.1109/REPCON.2004.1307056","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307056","url":null,"abstract":"This paper is an overview of the various types of studies required for the interconnection of wind generation to the utility power system. While the emphasis is on distributed wind applications connected to the distribution system, both bulk wind and distributed wind generation are discussed. Each has its own set of challenges and different analysis requirements. Wind generators are frequently installed in remote geographic locations where the power system is weak. This compounds issues associated with the variable and somewhat unpredictable nature of the energy resource. This paper describes procedures for wind farm interconnection studies, advances in model development for system dynamics studies, and operating impact studies. Voltage regulation and overcurrent protection studies for distributed wind applications are also described.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131189624","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307053
M. Hennes, B. J. Schmidt
Minnkota Power Cooperative (MPC) is a generation and transmission utility providing electric power to 11 distribution cooperatives and 12 municipal power agencies in eastern North Dakota and northwestern Minnesota. Cass County Electric Cooperative (CCEC) is a distribution cooperative member of MPC. In the mid 80's, MPC created a program whereby its member cooperatives could market electric heating energy without a demand charge in order to utilize excess energy production. As energy supplies have tightened up, this program was discontinued. The distribution cooperatives had to find a means to offset the electrical demand created by the heating loads which were added under this program and not included in the MPC load management program. In a joint effort, MPC and CCEC have worked to install ten diesel powered generation modules at the distribution level totaling 18.25 MW of peak electrical capacity. These units will he operated synchronously with the grid system during periods of peak electrical demand to offset the non-managed load created by the demand waiver heating program. This paper will detail some of the electrical and mechanical design and installation challenges and solutions for this project. Of special consideration for the project are the cold-weather climate conditions, design aspects for the interconnection, joint monitoring and control requirements, and operational guidelines incorporated into the completed project.
{"title":"Distributed generation as a solution for demand waiver heating loads","authors":"M. Hennes, B. J. Schmidt","doi":"10.1109/REPCON.2004.1307053","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307053","url":null,"abstract":"Minnkota Power Cooperative (MPC) is a generation and transmission utility providing electric power to 11 distribution cooperatives and 12 municipal power agencies in eastern North Dakota and northwestern Minnesota. Cass County Electric Cooperative (CCEC) is a distribution cooperative member of MPC. In the mid 80's, MPC created a program whereby its member cooperatives could market electric heating energy without a demand charge in order to utilize excess energy production. As energy supplies have tightened up, this program was discontinued. The distribution cooperatives had to find a means to offset the electrical demand created by the heating loads which were added under this program and not included in the MPC load management program. In a joint effort, MPC and CCEC have worked to install ten diesel powered generation modules at the distribution level totaling 18.25 MW of peak electrical capacity. These units will he operated synchronously with the grid system during periods of peak electrical demand to offset the non-managed load created by the demand waiver heating program. This paper will detail some of the electrical and mechanical design and installation challenges and solutions for this project. Of special consideration for the project are the cold-weather climate conditions, design aspects for the interconnection, joint monitoring and control requirements, and operational guidelines incorporated into the completed project.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127911600","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307030
S. Collier
Ubiquitous broadband Internet access is desirable, maybe even essential for acceptable quality of life and productivity of business in the future. The new BPL technologies may prove to be feasible and result in a viable, sustainable industry. There are substantial, but not insurmountable technical, regulatory, organizational and economic challenges for the industry and electric utilities to overcome. There are special challenges for rural areas. BPL will not likely be feasible for many rural distribution systems for years to come.
{"title":"Delivering broad band Internet over power lines: what you should know","authors":"S. Collier","doi":"10.1109/REPCON.2004.1307030","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307030","url":null,"abstract":"Ubiquitous broadband Internet access is desirable, maybe even essential for acceptable quality of life and productivity of business in the future. The new BPL technologies may prove to be feasible and result in a viable, sustainable industry. There are substantial, but not insurmountable technical, regulatory, organizational and economic challenges for the industry and electric utilities to overcome. There are special challenges for rural areas. BPL will not likely be feasible for many rural distribution systems for years to come.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134403858","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307044
D. R. Joens, T. Weir
Until recently, one of the only viable rural or suburban feeder protection schemes beyond the loading limits of the 70-amp hydraulic Automatic Circuit Recloser (recloser) involved the use of a three phase electronic recloser with phase and ground curve settings. The three phase reclosers could only operate as three phase or single phase reclose and three phase lockout. On feeders that connected many single phase customers, this three phase operating characteristic proved to be costly with respect to reliability and, more specifically, to the number of customers experiencing an outage. The fault on one conductor of the three phase line from a substation would affect the other two phases until a crew could isolate the fault and reenergize the recloser. This report summarizes the investigation of using single phase sectionalizers on the load side of the three phase reclosers to provide sectionalizing of the faulted phase while leaving the other two phases energized.
{"title":"Application of single phase sectionalizers with three-phase reclosers to increase reliability","authors":"D. R. Joens, T. Weir","doi":"10.1109/REPCON.2004.1307044","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307044","url":null,"abstract":"Until recently, one of the only viable rural or suburban feeder protection schemes beyond the loading limits of the 70-amp hydraulic Automatic Circuit Recloser (recloser) involved the use of a three phase electronic recloser with phase and ground curve settings. The three phase reclosers could only operate as three phase or single phase reclose and three phase lockout. On feeders that connected many single phase customers, this three phase operating characteristic proved to be costly with respect to reliability and, more specifically, to the number of customers experiencing an outage. The fault on one conductor of the three phase line from a substation would affect the other two phases until a crew could isolate the fault and reenergize the recloser. This report summarizes the investigation of using single phase sectionalizers on the load side of the three phase reclosers to provide sectionalizing of the faulted phase while leaving the other two phases energized.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124935878","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307059
T. Wilson, D. Bell
In 2002, two Pacific Northwest Utilities placed new distribution automation technology solutions into service at four substations with a total of ten distribution feeders. These solutions use commercial-off-the-shelf control technology to closely control distribution voltages to reduce energy usage and control demand. The first system at Inland Power and Light Company, a cooperative in Eastern Washington, went into service in April 2002, and the other three at Clatskanie PUD in Oregon went into service in November 2002. Avista Utilities is installing this new technology at the time of this writing. This paper presents the results of the ongoing operation and tests at these four rural substations. It will also describe the results that other utilities could expect when this technology is used to implement demand control, load management and conservation voltage regulation.
2002年，两家太平洋西北公用事业公司将新的配电自动化技术解决方案投入到四个变电站的服务中，总共有十个配电馈线。这些解决方案使用商业现成的控制技术来密切控制配电电压，以减少能源使用和控制需求。位于华盛顿州东部的内陆电力和照明公司(Inland Power and Light Company)的第一个系统于2002年4月投入使用，俄勒冈州克拉茨科尼电力公司(Clatskanie PUD)的另外三个系统于2002年11月投入使用。在撰写本文时，Avista Utilities正在安装这项新技术。本文介绍了这四个农村变电站正在进行的运行和测试的结果。它还将描述当该技术用于实施需求控制、负载管理和保护电压调节时，其他公用事业公司可能期望的结果。
{"title":"Energy conservation and demand control using distribution automation technologies","authors":"T. Wilson, D. Bell","doi":"10.1109/REPCON.2004.1307059","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307059","url":null,"abstract":"In 2002, two Pacific Northwest Utilities placed new distribution automation technology solutions into service at four substations with a total of ten distribution feeders. These solutions use commercial-off-the-shelf control technology to closely control distribution voltages to reduce energy usage and control demand. The first system at Inland Power and Light Company, a cooperative in Eastern Washington, went into service in April 2002, and the other three at Clatskanie PUD in Oregon went into service in November 2002. Avista Utilities is installing this new technology at the time of this writing. This paper presents the results of the ongoing operation and tests at these four rural substations. It will also describe the results that other utilities could expect when this technology is used to implement demand control, load management and conservation voltage regulation.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134491745","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}
Pub Date : 2004-05-23DOI: 10.1109/REPCON.2004.1307069
C. Warren, B. Saint
The new IEEE "Guide for Electric Power Distribution Reliability Indices" (1366-2001) has been approved and should be released in early 2004. Among the changes from the previous Guide is a new method to calculate Major Event Days (MED). The Working Group on System Design developed a statistically based methodology that classifies reliability data into day-to-day and major event days. This newly developed methodology, the "Beta Method", utilizes daily SAIDI values in a-log-normal distribution. There have been questions of the effect of this calculation on small utilities where days with no outages are not uncommon. This has previously been unknown because of lack of data from small utilities. Recently, data has been obtained from several co-ops ranging in size from 1400 customers to 72,000 customers. This paper discusses the results of the evaluation of small utility data and encourages more utilities to use this methodology to determine MEDs and submit the data to the working group.
{"title":"IEEE Reliability Indices Standards - Major Event Day calculations and how it effects small utilities","authors":"C. Warren, B. Saint","doi":"10.1109/REPCON.2004.1307069","DOIUrl":"https://doi.org/10.1109/REPCON.2004.1307069","url":null,"abstract":"The new IEEE \"Guide for Electric Power Distribution Reliability Indices\" (1366-2001) has been approved and should be released in early 2004. Among the changes from the previous Guide is a new method to calculate Major Event Days (MED). The Working Group on System Design developed a statistically based methodology that classifies reliability data into day-to-day and major event days. This newly developed methodology, the \"Beta Method\", utilizes daily SAIDI values in a-log-normal distribution. There have been questions of the effect of this calculation on small utilities where days with no outages are not uncommon. This has previously been unknown because of lack of data from small utilities. Recently, data has been obtained from several co-ops ranging in size from 1400 customers to 72,000 customers. This paper discusses the results of the evaluation of small utility data and encourages more utilities to use this methodology to determine MEDs and submit the data to the working group.","PeriodicalId":401769,"journal":{"name":"Rural Electric Power Conference, 2004","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123158548","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}
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