Pub Date : 1985-09-01DOI: 10.1109/ISE.1985.7341571
H. Baumgartner, F. Loffler, H. Umhauer
Deep-bed electret filters are used to separate fine particles (diameters < 10μm) from gas flows. Compared with conventional deep-bed filters having similiar pressure losses, they operate with substantially higher collection efficiencies. In this paper, two experimental methods allowing the charge characteristics of single electret fibres to be determined, are presented and discussed. Furthermore, the results of the investigated fractional efficiency measurements are given for experiments conducted on two different filter materials, for a particle size range of 10 nm to 10 μm, and at a filter face velocity of 10 cm/s.
{"title":"The collection performance of deep-bed electret filters","authors":"H. Baumgartner, F. Loffler, H. Umhauer","doi":"10.1109/ISE.1985.7341571","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341571","url":null,"abstract":"Deep-bed electret filters are used to separate fine particles (diameters < 10μm) from gas flows. Compared with conventional deep-bed filters having similiar pressure losses, they operate with substantially higher collection efficiencies. In this paper, two experimental methods allowing the charge characteristics of single electret fibres to be determined, are presented and discussed. Furthermore, the results of the investigated fractional efficiency measurements are given for experiments conducted on two different filter materials, for a particle size range of 10 nm to 10 μm, and at a filter face velocity of 10 cm/s.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"23 1","pages":"772-777"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72772613","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341463
J. Sworakowski, M. Samoć
Transport of charge carriers in one-dimensional systems is considered. Kinetic equations describing trapping and release of carriers are discussed. It is shown that the equilibrium occupancy of traps in one-dimensional systems differs from that in three-dimensional ones. Particular cases of isothermal and non-isothermal carrier transport are presented.
{"title":"Isothermal and non-isothermal transport of charge carriers in one-dimensional insulators","authors":"J. Sworakowski, M. Samoć","doi":"10.1109/ISE.1985.7341463","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341463","url":null,"abstract":"Transport of charge carriers in one-dimensional systems is considered. Kinetic equations describing trapping and release of carriers are discussed. It is shown that the equilibrium occupancy of traps in one-dimensional systems differs from that in three-dimensional ones. Particular cases of isothermal and non-isothermal carrier transport are presented.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"118 1","pages":"94-99"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86830047","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341553
Edson Rodrigues
An exact solution using the ionic model for the d.c. conduction of electricity in insulating liquids is obtained in the case of equal mobilities of the carriers and absence of diffusion effects. The potential profile in the conductivity cell is derived and the well known characteristic conduction curves with its two regions explained with theoretical expressions for the conductivities. Potential profile and characteristic conduction experimental curves may be analized graphically to give the rate generation of carriers, the recombination coefficient. conductivities and ionic mobility. Computed curves using the equations de rived show excellent agreement with experimental curves obtained with liquid hydrocarbons and liquefied gases such as nitrogen and helium.
{"title":"Electrical conduction in insulating liquids under the action of ionizing radiation: Theory and comparison with experiments","authors":"Edson Rodrigues","doi":"10.1109/ISE.1985.7341553","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341553","url":null,"abstract":"An exact solution using the ionic model for the d.c. conduction of electricity in insulating liquids is obtained in the case of equal mobilities of the carriers and absence of diffusion effects. The potential profile in the conductivity cell is derived and the well known characteristic conduction curves with its two regions explained with theoretical expressions for the conductivities. Potential profile and characteristic conduction experimental curves may be analized graphically to give the rate generation of carriers, the recombination coefficient. conductivities and ionic mobility. Computed curves using the equations de rived show excellent agreement with experimental curves obtained with liquid hydrocarbons and liquefied gases such as nitrogen and helium.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"43 1","pages":"659-665"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91105231","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341490
D. Senatra, C. Gambi
Isotropic w/o microemulsions as well as the liquid crystalline phase that develops in the former upon water addition, were investigated as a function of increasing water concentration (mass fraction), in the interval 0.024–0.8 with the thermally stimulated depolarization method (TSD). The different structures that develop in isotropic microemulsions as water is added, were analyzed. The features that characterize the different amphiphile-association structures against water addition are reported.
{"title":"Thermally-stimulated effects in water in oil microemulsions","authors":"D. Senatra, C. Gambi","doi":"10.1109/ISE.1985.7341490","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341490","url":null,"abstract":"Isotropic w/o microemulsions as well as the liquid crystalline phase that develops in the former upon water addition, were investigated as a function of increasing water concentration (mass fraction), in the interval 0.024–0.8 with the thermally stimulated depolarization method (TSD). The different structures that develop in isotropic microemulsions as water is added, were analyzed. The features that characterize the different amphiphile-association structures against water addition are reported.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"53 1","pages":"259-264"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91329723","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341580
M. Neubert, R. Bakule, J. Nedbal
The dielectric spectrum of DNA was observed in the frequency range from 10 mHz to 100 kHz-Several dielectric absorption regions were found and their dependence on temperature and humidity was studied-There seems to be a conformational transition near 290 K and a collective behaviour of the whole system DNA-water-ions at low temperatures as if there were a glass transition near 238 K. Mechanisms of all dispersion regions are discussed and special attention is paid to the model of the jump-like movement of the DNA counter-ions accompanied by water rearrangement.
{"title":"Temperature and humidity dependence of the dielectric spectrum of Na DNA in solid state","authors":"M. Neubert, R. Bakule, J. Nedbal","doi":"10.1109/ISE.1985.7341580","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341580","url":null,"abstract":"The dielectric spectrum of DNA was observed in the frequency range from 10 mHz to 100 kHz-Several dielectric absorption regions were found and their dependence on temperature and humidity was studied-There seems to be a conformational transition near 290 K and a collective behaviour of the whole system DNA-water-ions at low temperatures as if there were a glass transition near 238 K. Mechanisms of all dispersion regions are discussed and special attention is paid to the model of the jump-like movement of the DNA counter-ions accompanied by water rearrangement.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"68 1","pages":"825-830"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84158532","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341467
P. Pillai, A. Tripathi, A. Tripathi, T. C. Goel
Thermoelectrets of solution cast films of PVC and PVC containing mica were prepared. Thermal depolarization current of these electrets has been measured to study the effect of polymer filler interface on the behaviour of carrier transport mechanism. A single dipolar peak has been observed in PVC around 90 °C, while two peaks (around 95 °C and 60 °C) are found in mica containing PVC, The peak around 95 °C in mica loaded PVC has been attributed to inter-facial phenomena which is confirmed by dielectric measurements as well as by TSC of electrets formed under a.c. fields using disimilar electrodes and blocking contacts.
{"title":"“TSC study on interfacial phenomena in micaloaded poly vinyl chloride (PVC) films”","authors":"P. Pillai, A. Tripathi, A. Tripathi, T. C. Goel","doi":"10.1109/ISE.1985.7341467","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341467","url":null,"abstract":"Thermoelectrets of solution cast films of PVC and PVC containing mica were prepared. Thermal depolarization current of these electrets has been measured to study the effect of polymer filler interface on the behaviour of carrier transport mechanism. A single dipolar peak has been observed in PVC around 90 °C, while two peaks (around 95 °C and 60 °C) are found in mica containing PVC, The peak around 95 °C in mica loaded PVC has been attributed to inter-facial phenomena which is confirmed by dielectric measurements as well as by TSC of electrets formed under a.c. fields using disimilar electrodes and blocking contacts.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"10 1","pages":"117-125"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81846276","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}
A new method for measuring the spatial distribution of combined polarization and space charge in poled polymer electrets has been developed. The technique, called the Laser Intensity Modulation Method (LIMM), is based upon measurement o-f the pyroelectric current generated by the electret when it is heated with a laser beam which is intensity-modulated at frequencies varying from 200 to 2500 Hz. A special analytical technique is used to trans-form the current-frequency measurements to spatial distributions. The advantages and limitations of LIMM are illustrated by means of calculations based upon simulated data. Experimental results on laboratory-poled samples are presented.
{"title":"Laser intensity modulation method (LIMM): A technique for determination of spatial distributions of polarization and space charge in polymer electrets","authors":"S. Lang, D. Das-Gupta","doi":"10.1063/1.336352","DOIUrl":"https://doi.org/10.1063/1.336352","url":null,"abstract":"A new method for measuring the spatial distribution of combined polarization and space charge in poled polymer electrets has been developed. The technique, called the Laser Intensity Modulation Method (LIMM), is based upon measurement o-f the pyroelectric current generated by the electret when it is heated with a laser beam which is intensity-modulated at frequencies varying from 200 to 2500 Hz. A special analytical technique is used to trans-form the current-frequency measurements to spatial distributions. The advantages and limitations of LIMM are illustrated by means of calculations based upon simulated data. Experimental results on laboratory-poled samples are presented.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"76 1","pages":"444-449"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82155237","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341590
D. Schilling, K. Dransfeld
In ferroelectric switching experiments with stretched and unstretched PVDF-foils we have measured the time dependent growth of the polarization after applying a high electric field (of about 200 MV/m). These experiments were performed between 300 K and about 140 K. During the dipolar re-orientation (p=dipol moment per monomer) in the high field regime (E = electric field) the liberated energy p»E per monomer is of the same order as kT, and therefore the process of polarization in high fields is expected to be strongly influenced by the liberated energy and thus to proceed in a cooperative way. This cooperative polarization process is demonstrated in the strongly field dependent growth time of the polarization which rapidly decreases when higher fields are applied as can be best observed at temperatures above 200 K.
{"title":"Ferroelectric switching in PVDF at low temperatures and in high electric fields","authors":"D. Schilling, K. Dransfeld","doi":"10.1109/ISE.1985.7341590","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341590","url":null,"abstract":"In ferroelectric switching experiments with stretched and unstretched PVDF-foils we have measured the time dependent growth of the polarization after applying a high electric field (of about 200 MV/m). These experiments were performed between 300 K and about 140 K. During the dipolar re-orientation (p=dipol moment per monomer) in the high field regime (E = electric field) the liberated energy p»E per monomer is of the same order as kT, and therefore the process of polarization in high fields is expected to be strongly influenced by the liberated energy and thus to proceed in a cooperative way. This cooperative polarization process is demonstrated in the strongly field dependent growth time of the polarization which rapidly decreases when higher fields are applied as can be best observed at temperatures above 200 K.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"256 1","pages":"889-893"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73039363","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341479
S. Datt, Ranjit J. Singh
An anomalous thermally stimulated current (TSC) flowing in the same direction as the charging current was observed in low-density polyethylene (LD-PE) thermoelectrets polarized at temperatures 20–90°C with fields ranging from 5–25 kV/cm. However, normal TSC was observed with thermoelectrets polarized with higher fields. Anomalous TSCs were considered to be caused by the injected homo space-charge and the partial blocking of a metal-polymer contact, A close relationship between the anomalous discharge current and the anomalous TSC has been observed.
{"title":"Anomalous thermally stimulated and transient currents in low density polyethylene","authors":"S. Datt, Ranjit J. Singh","doi":"10.1109/ISE.1985.7341479","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341479","url":null,"abstract":"An anomalous thermally stimulated current (TSC) flowing in the same direction as the charging current was observed in low-density polyethylene (LD-PE) thermoelectrets polarized at temperatures 20–90°C with fields ranging from 5–25 kV/cm. However, normal TSC was observed with thermoelectrets polarized with higher fields. Anomalous TSCs were considered to be caused by the injected homo space-charge and the partial blocking of a metal-polymer contact, A close relationship between the anomalous discharge current and the anomalous TSC has been observed.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"8 1","pages":"196-201"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79189341","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 : 1985-09-01DOI: 10.1109/ISE.1985.7341559
P. Martin, M. Bernard
In a γ-radiation field, the absorbed dose at each point is a function of the ionization created in an air cavity (air-filled cavity) and at the stopping power of the secondary electrons.
在γ辐射场中，每个点的吸收剂量是空腔(充满空气的空腔)中产生的电离和次级电子的停止功率的函数。
{"title":"Comparison of the ionization in a flat electret-ionization chamber and of that resulting from a uniform polarization field","authors":"P. Martin, M. Bernard","doi":"10.1109/ISE.1985.7341559","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341559","url":null,"abstract":"In a γ-radiation field, the absorbed dose at each point is a function of the ionization created in an air cavity (air-filled cavity) and at the stopping power of the secondary electrons.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"18 1","pages":"696-701"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74170399","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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