Pub Date : 2015-05-04DOI: 10.1080/08929882.2015.1039343
D. Coblentz, F. Pabian
An evaluation of terrain characteristics provides a way to make geologic interpretations for denied-access sites. This contribution illustrates the utility of this approach by developing a revised geologic map of the North Korean test site through reconnaissance-based geomorphometrics (defined as the science of quantitative land surface analysis) and geospatial investigation. This study provides a way to quantify the geologic differences at the test site and suggests that geologic factors contributed to the prompt release of detected radionuclides associated with the 2006 nuclear test event compared to the 2009 and 2013 events. This method is relevant for test monitoring by providing: 1) A better understanding of host rock integrity and geologic coupling characteristics; 2) A means to facilitate a more accurate determination of explosive yields; 3) A better understanding of event containment and the likelihood of venting, and 4) An enhanced understanding of potential radionuclide transport mechanisms that might assist in future monitoring and verification of clandestine tests.
{"title":"Revised Geologic Site Characterization of the North Korean Test Site at Punggye-ri","authors":"D. Coblentz, F. Pabian","doi":"10.1080/08929882.2015.1039343","DOIUrl":"https://doi.org/10.1080/08929882.2015.1039343","url":null,"abstract":"An evaluation of terrain characteristics provides a way to make geologic interpretations for denied-access sites. This contribution illustrates the utility of this approach by developing a revised geologic map of the North Korean test site through reconnaissance-based geomorphometrics (defined as the science of quantitative land surface analysis) and geospatial investigation. This study provides a way to quantify the geologic differences at the test site and suggests that geologic factors contributed to the prompt release of detected radionuclides associated with the 2006 nuclear test event compared to the 2009 and 2013 events. This method is relevant for test monitoring by providing: 1) A better understanding of host rock integrity and geologic coupling characteristics; 2) A means to facilitate a more accurate determination of explosive yields; 3) A better understanding of event containment and the likelihood of venting, and 4) An enhanced understanding of potential radionuclide transport mechanisms that might assist in future monitoring and verification of clandestine tests.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"22 1","pages":"101 - 120"},"PeriodicalIF":0.7,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88221337","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 : 2015-05-04DOI: 10.1080/08929882.2015.1039431
J. Bistline, David M. Blum, C. Rinaldi, Gabriel, Shields-Estrada, S. Hecker, M. Elisabeth, Paté-Cornell
This article presents a model to estimate North Korea's uranium enrichment capacity and to identify probable bottlenecks for scaling up that capacity. Expert assessment is used to identify and estimate the size of key centrifuge materials and component stockpiles. Bayesian probability networks are used to characterize uncertainties in these stockpiles and a deterministic optimization model to estimate the capacity of North Korea's uranium enrichment program given the assumed components and materials constraints. A Monte Carlo simulation model is used to propagate uncertainties through the optimization model. An illustration of this approach, based on the opinions of three experts, suggests that North Korea was likely (about 80 percent chance) to have a larger uranium enrichment capacity than what was displayed to visitors to the Yongbyon nuclear complex in 2010. The three most important bottlenecks to increases in enrichment capacity are the availability of pivot bearings, maraging steel, and high-strength aluminum. The nature of the model allows it to be easily updated as new information becomes available about centrifuge materials and component stockpiles.
{"title":"A Bayesian Model to Assess the Size of North Korea's Uranium Enrichment Program","authors":"J. Bistline, David M. Blum, C. Rinaldi, Gabriel, Shields-Estrada, S. Hecker, M. Elisabeth, Paté-Cornell","doi":"10.1080/08929882.2015.1039431","DOIUrl":"https://doi.org/10.1080/08929882.2015.1039431","url":null,"abstract":"This article presents a model to estimate North Korea's uranium enrichment capacity and to identify probable bottlenecks for scaling up that capacity. Expert assessment is used to identify and estimate the size of key centrifuge materials and component stockpiles. Bayesian probability networks are used to characterize uncertainties in these stockpiles and a deterministic optimization model to estimate the capacity of North Korea's uranium enrichment program given the assumed components and materials constraints. A Monte Carlo simulation model is used to propagate uncertainties through the optimization model. An illustration of this approach, based on the opinions of three experts, suggests that North Korea was likely (about 80 percent chance) to have a larger uranium enrichment capacity than what was displayed to visitors to the Yongbyon nuclear complex in 2010. The three most important bottlenecks to increases in enrichment capacity are the availability of pivot bearings, maraging steel, and high-strength aluminum. The nature of the model allows it to be easily updated as new information becomes available about centrifuge materials and component stockpiles.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"14 1","pages":"100 - 71"},"PeriodicalIF":0.7,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91055814","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 : 2015-01-02DOI: 10.1080/08929882.2015.996079
S. Chirayath, Jeremy M. Osborn, T. M. Coles
The growing concern about nuclear terrorism threats has enhanced the need to develop fast and accurate nuclear forensics analysis techniques for nuclear material source attribution and to create a credible nuclear deterrence. Plutonium produced as a by-product in nuclear reactor fuel, especially in fuel discharged at low burn-up (1 to 2 MWd/kg), is potentially weapons usable material. In the event of plutonium interdiction from a smuggling act, its origin has to be established through nuclear forensics attribution methods before any response is initiated against this malicious act. The characteristics of separated plutonium from discharged reactor fuel and the associated fission product traces depend on factors such as the reactor type (thermal or fast reactor), fuel burn-up, irradiation history, and the chemical process used to separate plutonium. A new methodology of using trace fission product to plutonium ratios for nuclear forensics attribution of plutonium to the type of reactor used for its production is presented along with results obtained for case studies of a fast neutron spectrum breeder reactor and a thermal neutron spectrum reactor using open literature design information of these two types of nuclear reactors.
{"title":"Trace Fission Product Ratios for Nuclear Forensics Attribution of Weapons-Grade Plutonium from Fast and Thermal Reactors","authors":"S. Chirayath, Jeremy M. Osborn, T. M. Coles","doi":"10.1080/08929882.2015.996079","DOIUrl":"https://doi.org/10.1080/08929882.2015.996079","url":null,"abstract":"The growing concern about nuclear terrorism threats has enhanced the need to develop fast and accurate nuclear forensics analysis techniques for nuclear material source attribution and to create a credible nuclear deterrence. Plutonium produced as a by-product in nuclear reactor fuel, especially in fuel discharged at low burn-up (1 to 2 MWd/kg), is potentially weapons usable material. In the event of plutonium interdiction from a smuggling act, its origin has to be established through nuclear forensics attribution methods before any response is initiated against this malicious act. The characteristics of separated plutonium from discharged reactor fuel and the associated fission product traces depend on factors such as the reactor type (thermal or fast reactor), fuel burn-up, irradiation history, and the chemical process used to separate plutonium. A new methodology of using trace fission product to plutonium ratios for nuclear forensics attribution of plutonium to the type of reactor used for its production is presented along with results obtained for case studies of a fast neutron spectrum breeder reactor and a thermal neutron spectrum reactor using open literature design information of these two types of nuclear reactors.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"20 1","pages":"48 - 67"},"PeriodicalIF":0.7,"publicationDate":"2015-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77169173","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 : 2015-01-02DOI: 10.1080/08929882.2015.996076
E. Christensen, P. Huber, P. Jaffke
In this article a case study of the application of antineutrino safeguards to a real-world scenario, the North Korean nuclear crisis in 1994, is presented. Detection limits to a partial or full core discharge in 1989 based on actual IAEA safeguards access are derived and it is found that two independent methods would have yielded positive evidence for a second core with very high confidence. To generalize these results, detailed estimates for the sensitivity to the plutonium content of various types of reactors, including most types of plutonium production reactors, are presented, based on detailed reactor simulations. A key finding of this study is that a wide class of reactors with a thermal power of 0.1–1 gigawatt can be safeguarded achieving IAEA goals for quantitative sensitivity and timeliness with antineutrino detectors adjacent to the reactor building. Antineutrino reactor monitoring does not rely on the continuity of knowledge and provides information about core inventory and power status in a timely fashion. The necessary detection systems do not exist yet but are expected to become available within two to five years.
{"title":"Antineutrino Reactor Safeguards: A Case Study of the DPRK 1994 Nuclear Crisis","authors":"E. Christensen, P. Huber, P. Jaffke","doi":"10.1080/08929882.2015.996076","DOIUrl":"https://doi.org/10.1080/08929882.2015.996076","url":null,"abstract":"In this article a case study of the application of antineutrino safeguards to a real-world scenario, the North Korean nuclear crisis in 1994, is presented. Detection limits to a partial or full core discharge in 1989 based on actual IAEA safeguards access are derived and it is found that two independent methods would have yielded positive evidence for a second core with very high confidence. To generalize these results, detailed estimates for the sensitivity to the plutonium content of various types of reactors, including most types of plutonium production reactors, are presented, based on detailed reactor simulations. A key finding of this study is that a wide class of reactors with a thermal power of 0.1–1 gigawatt can be safeguarded achieving IAEA goals for quantitative sensitivity and timeliness with antineutrino detectors adjacent to the reactor building. Antineutrino reactor monitoring does not rely on the continuity of knowledge and provides information about core inventory and power status in a timely fashion. The necessary detection systems do not exist yet but are expected to become available within two to five years.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"34 1","pages":"20 - 47"},"PeriodicalIF":0.7,"publicationDate":"2015-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79497038","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 : 2015-01-02DOI: 10.1080/08929882.2015.996074
Ali Ahmad, A. Glaser
This article examines possible modifications of Iran’s IR-40 (Arak) heavy-water reactor that would limit its plutonium production without compromising its usefulness for civilian purposes. The proposed modifications only involve the fuel composition, avoid changes to the fuel and core geometry, and therefore have the advantage of minimizing the overall complexity and cost of conversion as well as shortening the time period required to implement these modifications. The suggested changes would significantly reduce the reactor’s production of plutonium from 7–9 kilograms to less than 1 kilogram per year. The article also examines key safety parameters, medical isotope production rates, and uranium resource requirements for all modifications considered. The analysis is relevant beyond the case of Iran’s Arak reactor and may provide some future guidance for converting other heavy-water reactors that continue to operate today.
{"title":"A Conversion Proposal for Iran’s IR-40 Reactor with Reduced Plutonium Production","authors":"Ali Ahmad, A. Glaser","doi":"10.1080/08929882.2015.996074","DOIUrl":"https://doi.org/10.1080/08929882.2015.996074","url":null,"abstract":"This article examines possible modifications of Iran’s IR-40 (Arak) heavy-water reactor that would limit its plutonium production without compromising its usefulness for civilian purposes. The proposed modifications only involve the fuel composition, avoid changes to the fuel and core geometry, and therefore have the advantage of minimizing the overall complexity and cost of conversion as well as shortening the time period required to implement these modifications. The suggested changes would significantly reduce the reactor’s production of plutonium from 7–9 kilograms to less than 1 kilogram per year. The article also examines key safety parameters, medical isotope production rates, and uranium resource requirements for all modifications considered. The analysis is relevant beyond the case of Iran’s Arak reactor and may provide some future guidance for converting other heavy-water reactors that continue to operate today.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"64 1","pages":"19 - 3"},"PeriodicalIF":0.7,"publicationDate":"2015-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85608073","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 : 2014-09-02DOI: 10.1080/08929882.2014.952970
{"title":"EOV Ed board","authors":"","doi":"10.1080/08929882.2014.952970","DOIUrl":"https://doi.org/10.1080/08929882.2014.952970","url":null,"abstract":"","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"51 1","pages":"ebi - ebi"},"PeriodicalIF":0.7,"publicationDate":"2014-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73236006","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 : 2014-09-02DOI: 10.1080/08929882.2014.952581
M. Schoeppner, W. Plastino
Radioxenon is an important atmospheric tracer to detect underground nuclear explosions. The International Monitoring System is designed to provide worldwide continuous physical monitoring and detection of nuclear explosions and incorporates 40 noble gas monitoring stations. They are constantly sampling the atmosphere for concentrations of radioxenon. This work analyses how effectively the network of stations is able to detect unusual xenon-133 concentrations in the atmosphere. A large multitude of nuclear explosions, evenly distributed in space and time, is simulated and the detection rate is calculated. Atmospheric transport modelling is applied to calculate the source-receptor-sensitivities for each monitoring station. The approach includes the anthropogenic radioxenon background, station-specific detection criteria, different scenarios for surface and subsurface nuclear explosions, and a spatial as well as a time dependent analysis. Recommendations are drawn for the improvement of the detection capability.
{"title":"Determination of the Global Coverage of the IMS Xenon-133 Component for the Detection of Nuclear Explosions","authors":"M. Schoeppner, W. Plastino","doi":"10.1080/08929882.2014.952581","DOIUrl":"https://doi.org/10.1080/08929882.2014.952581","url":null,"abstract":"Radioxenon is an important atmospheric tracer to detect underground nuclear explosions. The International Monitoring System is designed to provide worldwide continuous physical monitoring and detection of nuclear explosions and incorporates 40 noble gas monitoring stations. They are constantly sampling the atmosphere for concentrations of radioxenon. This work analyses how effectively the network of stations is able to detect unusual xenon-133 concentrations in the atmosphere. A large multitude of nuclear explosions, evenly distributed in space and time, is simulated and the detection rate is calculated. Atmospheric transport modelling is applied to calculate the source-receptor-sensitivities for each monitoring station. The approach includes the anthropogenic radioxenon background, station-specific detection criteria, different scenarios for surface and subsurface nuclear explosions, and a spatial as well as a time dependent analysis. Recommendations are drawn for the improvement of the detection capability.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"30 1","pages":"209 - 234"},"PeriodicalIF":0.7,"publicationDate":"2014-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81643160","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 : 2014-09-02DOI: 10.1080/08929882.2014.952578
M. Kütt, F. Frieß, M. Englert
According to the Plutonium Management and Disposition Agreement, which was signed in 2000 and amended in 2010, Russia and the United States agree to dispose of 34 tons of excess weapon plutonium each. Russia plans to use the plutonium as fuel in its sodium-cooled fast reactors BN-600 and BN-800. This article analyzes BN-800 core models with and without breeding blankets for the plutonium isotopic vector in spent fuel, plutonium production in breeding blankets, breeding ratios for different plutonium concentrations in fuel, and possible annual material throughput. It finds that any spent fuel in the core contains less than 90 wt% plutonium-239, but using breeding blankets the reactor can be configured to be a net producer of plutonium, even with a breeding ratio below one, and that plutonium produced in blankets will be weapon-grade.
{"title":"Plutonium Disposition in the BN-800 Fast Reactor: An Assessment of Plutonium Isotopics and Breeding","authors":"M. Kütt, F. Frieß, M. Englert","doi":"10.1080/08929882.2014.952578","DOIUrl":"https://doi.org/10.1080/08929882.2014.952578","url":null,"abstract":"According to the Plutonium Management and Disposition Agreement, which was signed in 2000 and amended in 2010, Russia and the United States agree to dispose of 34 tons of excess weapon plutonium each. Russia plans to use the plutonium as fuel in its sodium-cooled fast reactors BN-600 and BN-800. This article analyzes BN-800 core models with and without breeding blankets for the plutonium isotopic vector in spent fuel, plutonium production in breeding blankets, breeding ratios for different plutonium concentrations in fuel, and possible annual material throughput. It finds that any spent fuel in the core contains less than 90 wt% plutonium-239, but using breeding blankets the reactor can be configured to be a net producer of plutonium, even with a breeding ratio below one, and that plutonium produced in blankets will be weapon-grade.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"36 1","pages":"188 - 208"},"PeriodicalIF":0.7,"publicationDate":"2014-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73236414","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 : 2014-09-02DOI: 10.1080/08929882.2014.952136
A. Diakov
The importance of converting research reactors from highly enriched uranium (HEU) fuel, with enrichment levels as high as 90–93 percent uranium-235, to low-enriched uranium (LEU) fuel, was recognized in the 1970s. Russia has developed and produced fuel enriched to below 20 percent to replace HEU-fuel for research reactors it had supplied to Hungary, Ukraine, Vietnam, the Czech Republic, Uzbekistan, Libya, Bulgaria, and North Korea, but until recently, has not given priority to the task of converting its own research reactors, despite the fact that Russia now has more HEU-fueled research reactors than any other country. In December 2010, Russia and the United States agreed to conduct a preliminary study on the possibility of converting six Russian research reactors. This article assesses the prospects for their conversion.
{"title":"Prospects for Conversion of HEU-Fueled Research Reactors in Russia","authors":"A. Diakov","doi":"10.1080/08929882.2014.952136","DOIUrl":"https://doi.org/10.1080/08929882.2014.952136","url":null,"abstract":"The importance of converting research reactors from highly enriched uranium (HEU) fuel, with enrichment levels as high as 90–93 percent uranium-235, to low-enriched uranium (LEU) fuel, was recognized in the 1970s. Russia has developed and produced fuel enriched to below 20 percent to replace HEU-fuel for research reactors it had supplied to Hungary, Ukraine, Vietnam, the Czech Republic, Uzbekistan, Libya, Bulgaria, and North Korea, but until recently, has not given priority to the task of converting its own research reactors, despite the fact that Russia now has more HEU-fueled research reactors than any other country. In December 2010, Russia and the United States agreed to conduct a preliminary study on the possibility of converting six Russian research reactors. This article assesses the prospects for their conversion.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"19 1","pages":"166 - 187"},"PeriodicalIF":0.7,"publicationDate":"2014-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80310879","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 : 2014-05-26DOI: 10.1080/08929882.2016.1127039
S. Raju
ABSTRACT Bayesian methods are used to compare the predictions of probabilistic risk assessment—the theoretical tool used by the nuclear industry to predict the frequency of nuclear accidents—with empirical data. The existing record of accidents with some simplifying assumptions regarding their probability distribution is sufficient to rule out the validity of the industry’s analyses at a very high confidence level. This conclusion is shown to be robust against any reasonable assumed variation of safety standards over time, and across regions. The debate on nuclear liability indicates that the industry has independently arrived at this conclusion. Paying special attention to the case of India, the article shows that the existing operating experience provides insufficient data to make any reliable claims about the safety of future reactors. Finally, policy implications of the article findings are briefly discussed.
{"title":"Estimating the Frequency of Nuclear Accidents","authors":"S. Raju","doi":"10.1080/08929882.2016.1127039","DOIUrl":"https://doi.org/10.1080/08929882.2016.1127039","url":null,"abstract":"ABSTRACT Bayesian methods are used to compare the predictions of probabilistic risk assessment—the theoretical tool used by the nuclear industry to predict the frequency of nuclear accidents—with empirical data. The existing record of accidents with some simplifying assumptions regarding their probability distribution is sufficient to rule out the validity of the industry’s analyses at a very high confidence level. This conclusion is shown to be robust against any reasonable assumed variation of safety standards over time, and across regions. The debate on nuclear liability indicates that the industry has independently arrived at this conclusion. Paying special attention to the case of India, the article shows that the existing operating experience provides insufficient data to make any reliable claims about the safety of future reactors. Finally, policy implications of the article findings are briefly discussed.","PeriodicalId":55952,"journal":{"name":"Science & Global Security","volume":"15 1","pages":"37 - 62"},"PeriodicalIF":0.7,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87412023","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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