Pub Date : 1989-10-29DOI: 10.1109/CEIDP.1989.69546
R. Fouracre, H. M. Banford, D. Tedford, W. Huiming, X. Cao
Changes in the electrical properties of insulators exposed to high levels of ionizing radiation can have a significant effect on the lifetime of equipment incorporating such material. In order to obtain a knowledge of the processes involved, a series of experiments were undertaken on the effects of gamma irradiation, at dose levels up to a few megagrays (MGy), on the DC conductivity and the thermally stimulated discharge current (TSDC) spectra of two epoxy resin samples and a polyimide. Among other findings it is shown that the curves for DC conductivity can be used to measure the glass transition temperature T/sub G/. Initial differential scanning calorimetry measurements had shown that the T/sub G/ of the as-produced resin was 189 degrees C. Irradiation to 1 MGy reduced this value to 90 degrees C, and this was little changed by annealing. The activation energy below T/sub G/ decreased as a sequence of irradiation, but increased after annealing of the sample. Comparison with the TSDC spectra shows that the T/sub G/ of the system is lowered by the irradiation process, and it has also been shown that annealing increases the T/sub G/, although at this dose level it does not return to its original value. Measurements on polyimide indicate that there is a change in conduction mechanism after irradiation.<>
{"title":"Gamma irradiation effects in two epoxy resins and a polyimide","authors":"R. Fouracre, H. M. Banford, D. Tedford, W. Huiming, X. Cao","doi":"10.1109/CEIDP.1989.69546","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69546","url":null,"abstract":"Changes in the electrical properties of insulators exposed to high levels of ionizing radiation can have a significant effect on the lifetime of equipment incorporating such material. In order to obtain a knowledge of the processes involved, a series of experiments were undertaken on the effects of gamma irradiation, at dose levels up to a few megagrays (MGy), on the DC conductivity and the thermally stimulated discharge current (TSDC) spectra of two epoxy resin samples and a polyimide. Among other findings it is shown that the curves for DC conductivity can be used to measure the glass transition temperature T/sub G/. Initial differential scanning calorimetry measurements had shown that the T/sub G/ of the as-produced resin was 189 degrees C. Irradiation to 1 MGy reduced this value to 90 degrees C, and this was little changed by annealing. The activation energy below T/sub G/ decreased as a sequence of irradiation, but increased after annealing of the sample. Comparison with the TSDC spectra shows that the T/sub G/ of the system is lowered by the irradiation process, and it has also been shown that annealing increases the T/sub G/, although at this dose level it does not return to its original value. Measurements on polyimide indicate that there is a change in conduction mechanism after irradiation.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"6 1","pages":"198-203"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85481030","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69571
A. Ebe, N. Iijima, M. Sone, H. Mitsui
The state of water in liquid dielectric was analyzed by Fourier transform infrared spectroscopy during a conduction test. The liquid dielectric used was di-octyl-phthalate (DOP) with different proportions of water. The free water in DOP is shown to contribute to the conduction. The states of the free water or weakly bound water are shown to change under stress.<>
{"title":"Effect of dissolved water on electrical conduction in liquid dielectrics","authors":"A. Ebe, N. Iijima, M. Sone, H. Mitsui","doi":"10.1109/CEIDP.1989.69571","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69571","url":null,"abstract":"The state of water in liquid dielectric was analyzed by Fourier transform infrared spectroscopy during a conduction test. The liquid dielectric used was di-octyl-phthalate (DOP) with different proportions of water. The free water in DOP is shown to contribute to the conduction. The states of the free water or weakly bound water are shown to change under stress.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"44 1","pages":"352-357"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90880433","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69573
D.H. Ren, A. Watson
It has been shown that, compared with dimethyl siloxane, transformer oil has similar reproducible current characteristics as a function of ramped voltage applied up to a high prebreakdown electric stress, where it obeys the equation I varies as V/sup s/. Moreover, at a very high electric stress, the displacement current component apparently reverses, which was not previously observed in silicone oil. This abnormal phenomenon is very dependent upon the conditions. From an earlier study in silicone oil, the average current response to the rising and falling voltage appears on a log-log scale with two linear portions which are sharply divided. Transformer oil has similar characteristics under similar testing conditions, but with increasing voltage amplitude of the applied ramp the slopes of the linear portions are changed. These two lines may become one if the maximum voltage and ramp rate are very high. This is true for copper and aluminum electrodes at differing gap separations.<>
{"title":"Ramped voltage testing of transformer oil","authors":"D.H. Ren, A. Watson","doi":"10.1109/CEIDP.1989.69573","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69573","url":null,"abstract":"It has been shown that, compared with dimethyl siloxane, transformer oil has similar reproducible current characteristics as a function of ramped voltage applied up to a high prebreakdown electric stress, where it obeys the equation I varies as V/sup s/. Moreover, at a very high electric stress, the displacement current component apparently reverses, which was not previously observed in silicone oil. This abnormal phenomenon is very dependent upon the conditions. From an earlier study in silicone oil, the average current response to the rising and falling voltage appears on a log-log scale with two linear portions which are sharply divided. Transformer oil has similar characteristics under similar testing conditions, but with increasing voltage amplitude of the applied ramp the slopes of the linear portions are changed. These two lines may become one if the maximum voltage and ramp rate are very high. This is true for copper and aluminum electrodes at differing gap separations.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"54 1","pages":"363-368"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74178775","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69545
A. Kumar
The effect of nuclear radiation in space on dielectric material used in microstrip and dielectric antennas is described. It has been shown that the primary effect of nuclear radiation on materials based on PTFE (polytetrafluoroethylene) is the reduction of molecular weight by breaking the large polymer molecule into smaller parts. There is an increase in brittleness, and this reaction is maximized in the presence of air. The degree to which PTFE is affected is essentially a function of the amount of energy absorbed regardless of the nature of the radiation. The susceptibility of electronic dielectric materials as a function of the total nuclear radiation dose is shown. Usually, the dose rate of 10 rad/h is quoted for the Van Allen belt. At this rate PTFE could operate for more than five years before a threshold level of damage would be detectable electrically and mechanically. Space-proven dielectric antennas are briefly discussed, with particular emphasis on the GTE GSTAR satellite reflector antenna which is fed by a dielectric loaded horn array. The elongation loss caused by radiation on a number of polyimide materials is shown.<>
{"title":"Effect of nuclear radiation on microstrip and dielectric antennas in space","authors":"A. Kumar","doi":"10.1109/CEIDP.1989.69545","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69545","url":null,"abstract":"The effect of nuclear radiation in space on dielectric material used in microstrip and dielectric antennas is described. It has been shown that the primary effect of nuclear radiation on materials based on PTFE (polytetrafluoroethylene) is the reduction of molecular weight by breaking the large polymer molecule into smaller parts. There is an increase in brittleness, and this reaction is maximized in the presence of air. The degree to which PTFE is affected is essentially a function of the amount of energy absorbed regardless of the nature of the radiation. The susceptibility of electronic dielectric materials as a function of the total nuclear radiation dose is shown. Usually, the dose rate of 10 rad/h is quoted for the Van Allen belt. At this rate PTFE could operate for more than five years before a threshold level of damage would be detectable electrically and mechanically. Space-proven dielectric antennas are briefly discussed, with particular emphasis on the GTE GSTAR satellite reflector antenna which is fed by a dielectric loaded horn array. The elongation loss caused by radiation on a number of polyimide materials is shown.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"19 1","pages":"192-197"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75802782","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69589
A. Hammoud, I. Myers
Four candidate materials were evaluated for use as high-temperature capacitor dielectrics. The materials investigated were polybenzimidazole polymer and three aramid papers. The samples were characterized with and without heat treatment in terms of their dielectric constant and loss. These properties of the heat-treated samples were also evaluated in a temperature range of 20 to 250 degrees C in the presence of electrical stress of 60 Hz, 50 V/mil. The AC and DC breakdown strengths of both dry and impregnated samples were determined at ambient conditions. The preliminary data indicate that heat treatment of the materials tested improves their dielectric properties and breakdown voltages. The AC and DC dielectric strengths are further improved upon impregnation with a suitable liquid.<>
{"title":"Evaluation of high temperature capacitor dielectrics","authors":"A. Hammoud, I. Myers","doi":"10.1109/CEIDP.1989.69589","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69589","url":null,"abstract":"Four candidate materials were evaluated for use as high-temperature capacitor dielectrics. The materials investigated were polybenzimidazole polymer and three aramid papers. The samples were characterized with and without heat treatment in terms of their dielectric constant and loss. These properties of the heat-treated samples were also evaluated in a temperature range of 20 to 250 degrees C in the presence of electrical stress of 60 Hz, 50 V/mil. The AC and DC breakdown strengths of both dry and impregnated samples were determined at ambient conditions. The preliminary data indicate that heat treatment of the materials tested improves their dielectric properties and breakdown voltages. The AC and DC dielectric strengths are further improved upon impregnation with a suitable liquid.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"47 1","pages":"459-464"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90580146","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69553
G. Gagnon, S. Pélissou, M. Wertheimer
It has been shown in a previous study (P. Rohl, 1982) that the breakdown strength of polyethylene increases with increasing oxidation levels. The purpose of the research reported here is to verify this somewhat surprising result. Unlike the earlier work, cross-linked polyethylene (XLPE), the principal insulation used in extruded cables, is utilized. The authors correlate dielectric breakdown measurements with oxidation, monitored by Fourier transform infrared (FTIR) spectroscopy, and the results are interpreted using the modified free-volume theory. It is found that the breakdown strength E/sub b/ indeed shows a slight tendency to increase with the oxidation level. In particular, the authors found a correlation between E/sub b/ and the degree of oxidation, expressed in terms of the carbonyl band (1741 cm/sup -1/) absorption. The exact reasons for this behavior are not clear at this time, but appear to be compatible with the modified free-volume theory breakdown.<>
{"title":"Oxidation dependence of breakdown strength of XLPE","authors":"G. Gagnon, S. Pélissou, M. Wertheimer","doi":"10.1109/CEIDP.1989.69553","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69553","url":null,"abstract":"It has been shown in a previous study (P. Rohl, 1982) that the breakdown strength of polyethylene increases with increasing oxidation levels. The purpose of the research reported here is to verify this somewhat surprising result. Unlike the earlier work, cross-linked polyethylene (XLPE), the principal insulation used in extruded cables, is utilized. The authors correlate dielectric breakdown measurements with oxidation, monitored by Fourier transform infrared (FTIR) spectroscopy, and the results are interpreted using the modified free-volume theory. It is found that the breakdown strength E/sub b/ indeed shows a slight tendency to increase with the oxidation level. In particular, the authors found a correlation between E/sub b/ and the degree of oxidation, expressed in terms of the carbonyl band (1741 cm/sup -1/) absorption. The exact reasons for this behavior are not clear at this time, but appear to be compatible with the modified free-volume theory breakdown.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"118 1","pages":"241-246"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77584904","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69580
A. Kumar
The absorption of microwaves in a composite containing a random distribution of iron-oxide particles embedded in fiberglass composites is considered. Generally, iron-oxide particles in the form of spheres or cylinders are held together by a binder such as fiberglass. Since weight and structural integrity of the composite are also of concern in many applications, it is desirable to choose the optimum volume fraction of iron-oxide particles and adjust the shape, size, and distribution of particles to obtain the required mass density and microwave absorbing properties. A short review of mixture theories is given. Results are shown for spherical conducting particles in a pure dielectric host medium and are compared with experimental data. Results (real and imaginary parts of the permittivity and permeability, loss tangent, reflection coefficient, and attenuation per unit length) on iron-oxide impregnated fiberglass composites in the frequency range of 1 to 12 GHz are reported.<>
{"title":"Ferrite-impregnated fibre-glass composites as microwave absorbers","authors":"A. Kumar","doi":"10.1109/CEIDP.1989.69580","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69580","url":null,"abstract":"The absorption of microwaves in a composite containing a random distribution of iron-oxide particles embedded in fiberglass composites is considered. Generally, iron-oxide particles in the form of spheres or cylinders are held together by a binder such as fiberglass. Since weight and structural integrity of the composite are also of concern in many applications, it is desirable to choose the optimum volume fraction of iron-oxide particles and adjust the shape, size, and distribution of particles to obtain the required mass density and microwave absorbing properties. A short review of mixture theories is given. Results are shown for spherical conducting particles in a pure dielectric host medium and are compared with experimental data. Results (real and imaginary parts of the permittivity and permeability, loss tangent, reflection coefficient, and attenuation per unit length) on iron-oxide impregnated fiberglass composites in the frequency range of 1 to 12 GHz are reported.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"1 1","pages":"403-408"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82307250","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69551
C. Chauvet, C. Laurent, C. Mayoux
In order to investigate the consequences of water-induced degradation on the dielectric breakdown field of polyethylene, the authors performed statistical electric breakdown strength measurements on cable slices previously aged in the presence of water. A Weibull analysis is performed on at least 40 sets of breakdown voltage data for each population, leading to a precise determination of the nominal breakdown field E/sub 0/. Comparison is made as a function of ageing time and testing conditions. Wet ageing under conditions of water tree development affects the breakdown strength of XLPE (cross-linked polyethylene) cable slices. The presence of water trees in the insulation must therefore be considered as potentially harmful.<>
{"title":"Influence of wet ageing on the electrical breakdown strength of XLPE cable slices","authors":"C. Chauvet, C. Laurent, C. Mayoux","doi":"10.1109/CEIDP.1989.69551","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69551","url":null,"abstract":"In order to investigate the consequences of water-induced degradation on the dielectric breakdown field of polyethylene, the authors performed statistical electric breakdown strength measurements on cable slices previously aged in the presence of water. A Weibull analysis is performed on at least 40 sets of breakdown voltage data for each population, leading to a precise determination of the nominal breakdown field E/sub 0/. Comparison is made as a function of ageing time and testing conditions. Wet ageing under conditions of water tree development affects the breakdown strength of XLPE (cross-linked polyethylene) cable slices. The presence of water trees in the insulation must therefore be considered as potentially harmful.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"100 1","pages":"230-234"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85697073","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69590
Y. Shao, K. Sheu, D. Damon, S. Huang, J.F. Johnson
The breakdown field strength of recessed samples of XLPE (cross-linked polyethylene) containing varying amounts of acetophenone and cumene is shown to decrease with increasing sample thickness. This thickness dependence is more complicated than previously observed. The addition of small amounts of acetophenone to XLPE produces a small increase in the dielectric strength. Small concentrations of cumene have no effect. Results from both AC ramp to failure and impulse breakdown can be fit to Weibull distributions. The characteristic values obtained from ramp to failure measurements depend on the ramp rate as suggested by theory.<>
{"title":"Dielectric strength of crosslinked polyethylene: the effects of the volatile products of the crosslinking reaction","authors":"Y. Shao, K. Sheu, D. Damon, S. Huang, J.F. Johnson","doi":"10.1109/CEIDP.1989.69590","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69590","url":null,"abstract":"The breakdown field strength of recessed samples of XLPE (cross-linked polyethylene) containing varying amounts of acetophenone and cumene is shown to decrease with increasing sample thickness. This thickness dependence is more complicated than previously observed. The addition of small amounts of acetophenone to XLPE produces a small increase in the dielectric strength. Small concentrations of cumene have no effect. Results from both AC ramp to failure and impulse breakdown can be fit to Weibull distributions. The characteristic values obtained from ramp to failure measurements depend on the ramp rate as suggested by theory.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"3 1","pages":"465-470"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87629031","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69579
S.L. Wang
The definition of capacitance in ASTM D150-81 is improved by considering the definition of complex capacitance. It is concluded that since the practical capacitor always has losses, it can be suitably represented by complex capacitance. The complex capacitance is closely related to relative complex permittivity, so that the concept of complex capacitance is very important in technology, and an accurate definition of complex capacitance is necessary for electrical engineering.<>
{"title":"Comments on the definition of AC capacitance in ASTM-D150-81","authors":"S.L. Wang","doi":"10.1109/CEIDP.1989.69579","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69579","url":null,"abstract":"The definition of capacitance in ASTM D150-81 is improved by considering the definition of complex capacitance. It is concluded that since the practical capacitor always has losses, it can be suitably represented by complex capacitance. The complex capacitance is closely related to relative complex permittivity, so that the concept of complex capacitance is very important in technology, and an accurate definition of complex capacitance is necessary for electrical engineering.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"20 1","pages":"398-402"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75277156","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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