Pub Date : 2012-10-01DOI: 10.1017/S0022377812000244
E. Rostomyan
Beam-plasma interaction in waveguide with spatially separated plasma and electron beam is investigated in limit of weak coupling. It is shown that in this case the instability is caused by growing of negative energy beam wave. Dissipation leads to a new type of dissipative beam instability with inverse proportional dependence on dissipation. Growth rate of this instability is obtained for arbitrary level of dissipation.
{"title":"Dissipative instability under weak beam-plasma coupling","authors":"E. Rostomyan","doi":"10.1017/S0022377812000244","DOIUrl":"https://doi.org/10.1017/S0022377812000244","url":null,"abstract":"Beam-plasma interaction in waveguide with spatially separated plasma and electron beam is investigated in limit of weak coupling. It is shown that in this case the instability is caused by growing of negative energy beam wave. Dissipation leads to a new type of dissipative beam instability with inverse proportional dependence on dissipation. Growth rate of this instability is obtained for arbitrary level of dissipation.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"143 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125133425","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 : 2011-08-12DOI: 10.1109/TDEI.2011.5976137
D. Wetz, D. Surls, D. Landen, S. Satapathy, M. Crawford
In any high-energy pulsed power experiment, the metallic conductors are expected to heat up significantly due to resistive losses. In the pulsed case, the effects of local heat transfer are decreased due to limited thermal diffusion, so the process is considered to be adiabatic rather than isothermal. Experimental evidence from electron beam heating indicates that high-temperature mechanical properties significantly depend on the rapidity and duration of heat deposition. With this in mind, it is important to understand the mechanical properties of metals when heated rapidly so that the correct mechanical properties are considered when designing high-energy experiments such as railguns, where both thermal and mechanical stresses are high. An expanding ring experiment, similar to the one originally designed by Gourdin et al. [1,2] has been set up at the Institute for Advanced Technology (IAT) to test such mechanical properties [3]. The experiment uses a primary coil driven with current pulse from a near critically damped RLC circuit that causes a thin specimen ring to expand and fragment due to the induced electromagnetic forces. In order to determine material properties at elevated temperatures, an inductive heating source has been developed to rapidly heat the ring specimen to temperatures as high as the melting temperature in a few milliseconds, immediately prior to the application of electromagnetic expansion forces. The source employs a microprocessor-controlled pumped LC tank circuit with a resonant frequency of roughly 25 kHz to induce a current into the ring. The current in the primary and secondary coils are measured using Pearson and Rogowski coils. A VISAR is used to measure the expansion speed of the ring, and a high-speed camera is used to capture the dynamic fragmentation of the ring. The data generated will quantify the rate of heating sensitivity of material properties in commonly used materials for development and validation of appropriate constitutive equations.
{"title":"Inductive heating of materials for the study of high-temperature mechanical properties.","authors":"D. Wetz, D. Surls, D. Landen, S. Satapathy, M. Crawford","doi":"10.1109/TDEI.2011.5976137","DOIUrl":"https://doi.org/10.1109/TDEI.2011.5976137","url":null,"abstract":"In any high-energy pulsed power experiment, the metallic conductors are expected to heat up significantly due to resistive losses. In the pulsed case, the effects of local heat transfer are decreased due to limited thermal diffusion, so the process is considered to be adiabatic rather than isothermal. Experimental evidence from electron beam heating indicates that high-temperature mechanical properties significantly depend on the rapidity and duration of heat deposition. With this in mind, it is important to understand the mechanical properties of metals when heated rapidly so that the correct mechanical properties are considered when designing high-energy experiments such as railguns, where both thermal and mechanical stresses are high. An expanding ring experiment, similar to the one originally designed by Gourdin et al. [1,2] has been set up at the Institute for Advanced Technology (IAT) to test such mechanical properties [3]. The experiment uses a primary coil driven with current pulse from a near critically damped RLC circuit that causes a thin specimen ring to expand and fragment due to the induced electromagnetic forces. In order to determine material properties at elevated temperatures, an inductive heating source has been developed to rapidly heat the ring specimen to temperatures as high as the melting temperature in a few milliseconds, immediately prior to the application of electromagnetic expansion forces. The source employs a microprocessor-controlled pumped LC tank circuit with a resonant frequency of roughly 25 kHz to induce a current into the ring. The current in the primary and secondary coils are measured using Pearson and Rogowski coils. A VISAR is used to measure the expansion speed of the ring, and a high-speed camera is used to capture the dynamic fragmentation of the ring. The data generated will quantify the rate of heating sensitivity of material properties in commonly used materials for development and validation of appropriate constitutive equations.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115762675","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}
Hydrogen has the best recovery property compared with other gases such as N2 and SF6, which has a potential application on the multi-pulse and high repetitive pulse modulator. This paper introduced a high pressure hydrogen gas switch with two cylindrical structures. The stress of the switch under high pressure is analyzed theoretically, and the pressure of hydrogen gas in the switch was hydrostatically tested up to 30atm. Such a switch was employed on high power pulse modulator with water dielectric PFL (Pulse Forming Line). At the switch breakdown voltage of 520kV and the pressure of hydrogen 12atm, a 230kV, 31kA and 60ns during time electron beam is obtained at the field-emission diode. Furthermore, when the switch was filled in different gases such as H2, N2, SF6, the rise times of diode voltage of modulator have been compared at the switch breakdown voltage 400kV. The results show that the rise times of diode voltage is reduced obviously when hydrogen is used as the dielectric of spark gap switch.
{"title":"Application of a self-breakdown hydrogen spark gap switch on high power pulse modulator","authors":"J.L. Liu, Y. Yin, T. Zhan, J.H. Feng, H. Zhong","doi":"10.1063/1.3005902","DOIUrl":"https://doi.org/10.1063/1.3005902","url":null,"abstract":"Hydrogen has the best recovery property compared with other gases such as N2 and SF6, which has a potential application on the multi-pulse and high repetitive pulse modulator. This paper introduced a high pressure hydrogen gas switch with two cylindrical structures. The stress of the switch under high pressure is analyzed theoretically, and the pressure of hydrogen gas in the switch was hydrostatically tested up to 30atm. Such a switch was employed on high power pulse modulator with water dielectric PFL (Pulse Forming Line). At the switch breakdown voltage of 520kV and the pressure of hydrogen 12atm, a 230kV, 31kA and 60ns during time electron beam is obtained at the field-emission diode. Furthermore, when the switch was filled in different gases such as H2, N2, SF6, the rise times of diode voltage of modulator have been compared at the switch breakdown voltage 400kV. The results show that the rise times of diode voltage is reduced obviously when hydrogen is used as the dielectric of spark gap switch.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132118956","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}
Generation time of supeshort avalanche electron beam (SAEB) with respect to discharge current front has been established at nanosecond breakdown of air under atmospheric pressure in non-uniform electric field and volume discharge formation. It has been shown that SAEB current maximum is registered at the leading edge of the discharge current before the peak of discharge current of the gas diode capacitance, advancing such peak by ∼100 ps. The amplitude of bias current above 1 kA has been registered. The amplitude of bias current is increased due to capacitor charging, formed by the dense plasma, expanding from the cathode, and the flat metallic anode.
{"title":"Discharge current and current of supershort avalanche E-beam at volume nanosecond discharge in non-uniform electric field","authors":"V. Tarasenko, D. Rybka, E. H. Baksht, M. Lomaev","doi":"10.1117/12.785633","DOIUrl":"https://doi.org/10.1117/12.785633","url":null,"abstract":"Generation time of supeshort avalanche electron beam (SAEB) with respect to discharge current front has been established at nanosecond breakdown of air under atmospheric pressure in non-uniform electric field and volume discharge formation. It has been shown that SAEB current maximum is registered at the leading edge of the discharge current before the peak of discharge current of the gas diode capacitance, advancing such peak by ∼100 ps. The amplitude of bias current above 1 kA has been registered. The amplitude of bias current is increased due to capacitor charging, formed by the dense plasma, expanding from the cathode, and the flat metallic anode.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129919740","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 : 2007-07-23DOI: 10.1109/ppps.2007.4652490
J. Carmona-Reyes, J. Schmoke, M. Cook, Jie Kong, T. Hyde
Dusty plasmas have generated a large amount of interest since the discovery of ordered structure (crystal) formation in experimentally generated complex plasmas in 1994. Dust particles within the plasma sheath generated in these complex plasmas can form vertical chains due to the streaming ion wakefield. For the simplest of these configurations (a two particle chain), the particle closest to the lower electrode will generally remain in the shadow of the particle farthest from the lower electrode. These results in the two particles feeling differing ion drag forces: the top particle is acted on by the ion drag force directed from the plasma to the lower electrode, while the bottom particle is acted upon by the resulting ‘wakefield’ produced by the interaction of the upper particle with the ion drag force. This dynamic situation currently provides the best known experimental environment for examining the physics behind the ion drag force and its interaction with the plasma sheath. An experimental method for investigating the interaction between pair-particle chains based on modulating the bias on the lower electrode employing a DC bias modulation technique will be presented.
{"title":"Vertical dust particle chains - mass and charge measurements","authors":"J. Carmona-Reyes, J. Schmoke, M. Cook, Jie Kong, T. Hyde","doi":"10.1109/ppps.2007.4652490","DOIUrl":"https://doi.org/10.1109/ppps.2007.4652490","url":null,"abstract":"Dusty plasmas have generated a large amount of interest since the discovery of ordered structure (crystal) formation in experimentally generated complex plasmas in 1994. Dust particles within the plasma sheath generated in these complex plasmas can form vertical chains due to the streaming ion wakefield. For the simplest of these configurations (a two particle chain), the particle closest to the lower electrode will generally remain in the shadow of the particle farthest from the lower electrode. These results in the two particles feeling differing ion drag forces: the top particle is acted on by the ion drag force directed from the plasma to the lower electrode, while the bottom particle is acted upon by the resulting ‘wakefield’ produced by the interaction of the upper particle with the ion drag force. This dynamic situation currently provides the best known experimental environment for examining the physics behind the ion drag force and its interaction with the plasma sheath. An experimental method for investigating the interaction between pair-particle chains based on modulating the bias on the lower electrode employing a DC bias modulation technique will be presented.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129844709","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4345913
G. Shvetsov, A. Matrosov, S. Fedorov, A. Babkin, S. Ladov
The present paper considers the possibility of using magnetic fields for the antiterrorist protection of various objects against shaped-charge action by means of their magnetic screening — the creation of a magnetic field in the space ahead of the object being protected from attack. The results of an experimental and numerical investigation of the effect of the magnetic field generated in a shaped-charge liner on the structure of the shaped charge jets and penetration into a target are presented. It is shown that a considerable decrease in the depth of penetration of shaped- charge jets into the target can be achieved at moderate magnetic fields of a few tenths of a tesla.
{"title":"Magnetic screening against shaped-charge action","authors":"G. Shvetsov, A. Matrosov, S. Fedorov, A. Babkin, S. Ladov","doi":"10.1109/PPPS.2007.4345913","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345913","url":null,"abstract":"The present paper considers the possibility of using magnetic fields for the antiterrorist protection of various objects against shaped-charge action by means of their magnetic screening — the creation of a magnetic field in the space ahead of the object being protected from attack. The results of an experimental and numerical investigation of the effect of the magnetic field generated in a shaped-charge liner on the structure of the shaped charge jets and penetration into a target are presented. It is shown that a considerable decrease in the depth of penetration of shaped- charge jets into the target can be achieved at moderate magnetic fields of a few tenths of a tesla.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115665431","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4651808
S. Macgregor, I. Timoshkin, M. Given, R. Fouracre, J. Lehr, L. Warne
Multi-electrode spark switches can be used for switching applications at elevated voltages or for command triggering. Symmetrical field graded electrodes allow the electrical stress across individual gaps to be controlled, thus maximising the hold off voltage and reducing switch pre-fire. The paper considers some aspects of multielectrode switch design and their influence on switching behavior. Non-symmetrical, uni-directional electrode topologies can be employed with advantages over traditional symmetrical design. The choice of working gas and gas pressure can influence switching performance in terms of delay-time and jitter. Transient analysis of switch characteristics has been undertaken in order to understand multi-electrode switching.
{"title":"Factors affecting the operation of laser-triggered gas switch (LTGS) with multi-electrode spark gap","authors":"S. Macgregor, I. Timoshkin, M. Given, R. Fouracre, J. Lehr, L. Warne","doi":"10.1109/PPPS.2007.4651808","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4651808","url":null,"abstract":"Multi-electrode spark switches can be used for switching applications at elevated voltages or for command triggering. Symmetrical field graded electrodes allow the electrical stress across individual gaps to be controlled, thus maximising the hold off voltage and reducing switch pre-fire. The paper considers some aspects of multielectrode switch design and their influence on switching behavior. Non-symmetrical, uni-directional electrode topologies can be employed with advantages over traditional symmetrical design. The choice of working gas and gas pressure can influence switching performance in terms of delay-time and jitter. Transient analysis of switch characteristics has been undertaken in order to understand multi-electrode switching.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121008019","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4346103
A. Akimov, P. Logachev, V. Bochkov, D. Bochkov, V. Dyagilev, V. G. Ushich
The circuit of modulator, serving to supply inductive-resistive load in double-pulse mode with currents up to 10 kA and pulse duration of 300 ns, is described. As switching components thyratrons (pseudospark switches) designated as TPI1-10k/50 with anode voltage up to 50 kV have been used. TPI-thyratrons are capable of operating in circuits with grounded cathode, which allows obtaining higher performance reliability and longer service lifetime in contrast to other known designs of pseudospark switches, operating with grounded grid. The thyratrons can be considered as alternative to present switches, including hot cathode hydrogen thyratrons and up-to-date power solid state devices, especially for switching of high-currents with sub-nanosecond jitter, turn-on time of 3÷5 ns and average current up to 0.3 A. The results of tests, confirming possibility of reverse dielectric strength recovery within some microseconds after switching of 10 kA forward anode current, are presented. Basic electrical parameters, effecting thyratron operation in the indicated mode, are analyzed. To clarify prospects of further development of TPI-thyratrons, pentode version of the thyratron, serving to reduce recovery time, is designed.
{"title":"Application of TPI1-10k/50 thyratrons for building a modulator, intended for supply of inductive-resistive load in double-pulse mode","authors":"A. Akimov, P. Logachev, V. Bochkov, D. Bochkov, V. Dyagilev, V. G. Ushich","doi":"10.1109/PPPS.2007.4346103","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346103","url":null,"abstract":"The circuit of modulator, serving to supply inductive-resistive load in double-pulse mode with currents up to 10 kA and pulse duration of 300 ns, is described. As switching components thyratrons (pseudospark switches) designated as TPI1-10k/50 with anode voltage up to 50 kV have been used. TPI-thyratrons are capable of operating in circuits with grounded cathode, which allows obtaining higher performance reliability and longer service lifetime in contrast to other known designs of pseudospark switches, operating with grounded grid. The thyratrons can be considered as alternative to present switches, including hot cathode hydrogen thyratrons and up-to-date power solid state devices, especially for switching of high-currents with sub-nanosecond jitter, turn-on time of 3÷5 ns and average current up to 0.3 A. The results of tests, confirming possibility of reverse dielectric strength recovery within some microseconds after switching of 10 kA forward anode current, are presented. Basic electrical parameters, effecting thyratron operation in the indicated mode, are analyzed. To clarify prospects of further development of TPI-thyratrons, pentode version of the thyratron, serving to reduce recovery time, is designed.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123246613","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4651785
M. Given, I. Timoshkin, M. Wilson, S. Macgregor, J. Lehr
The dynamic behaviour of the resistance of a circuit consisting of a capacitive pulse power supply with a load consisting of a plasma channel formed in an underwater gap has been determined from the current transients measured during the breakdown of the gap.
{"title":"Analysis of the current waveforms observed in underwater spark discharges","authors":"M. Given, I. Timoshkin, M. Wilson, S. Macgregor, J. Lehr","doi":"10.1109/PPPS.2007.4651785","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4651785","url":null,"abstract":"The dynamic behaviour of the resistance of a circuit consisting of a capacitive pulse power supply with a load consisting of a plasma channel formed in an underwater gap has been determined from the current transients measured during the breakdown of the gap.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116571134","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4651859
G. Zhao, Ravindra P. Joshi, H. Hjalmarson
Time-dependent, two-dimensional simulations based on random Voronoi networks have been developed to study the internal heating and related breakdown effects in ZnO varistors in response to high-voltage pulsing. The focus is on internal grain-size variations and relative disorder. Our results predict that parameters such as the device hold-off voltage, the average internal temperature, and average dissipated energy density would be higher with more uniform grains. This uniformity is also predicted to produce lower thermal stresses and to allow for the application of longer duration pulses. Finally, it is shown that the principle failure mechanism arises from internal localized melting, while thermal stresses are well below the thresholds for cracking.
{"title":"Electro-thermal simulation studies for pulsed voltage failures in microstructured ZNO varistors","authors":"G. Zhao, Ravindra P. Joshi, H. Hjalmarson","doi":"10.1109/PPPS.2007.4651859","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4651859","url":null,"abstract":"Time-dependent, two-dimensional simulations based on random Voronoi networks have been developed to study the internal heating and related breakdown effects in ZnO varistors in response to high-voltage pulsing. The focus is on internal grain-size variations and relative disorder. Our results predict that parameters such as the device hold-off voltage, the average internal temperature, and average dissipated energy density would be higher with more uniform grains. This uniformity is also predicted to produce lower thermal stresses and to allow for the application of longer duration pulses. Finally, it is shown that the principle failure mechanism arises from internal localized melting, while thermal stresses are well below the thresholds for cracking.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117042637","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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