Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982最新文献

{"title":"Biological dielectrophoresis: Applications to the determination of the dielectric properties of cells, to cell sorting, and to fusion","authors":"H. A. Pohl","doi":"10.1109/CEIDP.1982.7726515","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726515","url":null,"abstract":"Dielectrophoresis (DEP), the motion of neutral bodies induced by nonuniform electric fields, is widely applicable in biological problems. The DEP force, and hence the relative polarizability of all cells in aqueous media varies strongly with the applied frequency. This gives rise to DEP spectra which we find to be unique even for individual cells. For example, single cells can be readily ‘levitated’ by ac fields to balance against gravitational force, so as to provide precise spectra of the dielectric properties. In other apparatus to be described, streams of cells are subjected to nonuniform ac fields and their deflection into or out of the regions of high field intensity are measured to provide dielectric spectra and comparisons of cell types or normalcy. Moreover, such apparatus is readily arranged to provide cell sorting based upon intrinsic dielectric properties of the passing cells Finally, the DEP phenomenon can be applied “in reverse” so to speak, and used to probe the ac fields generated by the cells themselves. Here, the DEP effect exerted by the nonuniform ac field of a cell is studied with the aid of tiny polarizable particles (Micro-Dielectrophoresis), Again, the application of external rf fields is found to evoke cellular spinning at sharply resonant frequencies. Using both micro-DEP and cellular spin resonance, natural rf oscillations are found in a wide range of cell types, from bacteria to mammalian, indicating that it is “universal”. DEP is also useful in evoking cell fusion. Biological particles such as cells or their parts can be made to move simply by applying a nonuniform electric field. This motion occurs even though the cells or their parts are electrically neutral, and by its means we can control cells so as to sort them, to fuse them together, and to even assess their electrical nature. The fundamental phenomenon concerned is “dielectrophoresis”. Dielectrophoresis, hereafter abbreviated to DEP, is defined as the motion of neutral, polarizable matter produced by a nonuniform (ac or dc) field. DEP should be distinguished from electrophoresis, which is the motion of charged particles in a static electric field. The DEP of many particle types has been examined, resulting in numerous applications. Aerosols, glasses, minerals, polymer molecules, living cells, organelles, and virus particles were made to respond with DEP. Among the numerous applications developed are agglomeration, orientation, sorting or separations, dielectric characterization, levitation, and materials handling such as pumping, precipitation and filtration [1]. The effects of DEP are easily produced, and large particles especially respond in many useful ways. DEP, which is a gentle effect, can how-ever be observed on particles ranging in size even down to the molecular level under special conditions. Sincethermal (Brownian motion) effects tend to disrupt ordering by gentle actions such as that of DEP, a practical lower limit of particle size in normal usage ","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129653568","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}

{"title":"Molecular aspects of the dielectric relaxation of solid polymers","authors":"Graham Williams","doi":"10.1109/CEIDP.1982.7726508","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726508","url":null,"abstract":"Whilst the discovery and development of manmade polymer materials dates from the pioneering works of Goodyear (vulcanized rubber) and Hyatt (celluloid plastics) in the mid-nineteenth century, and to Baekeland (phenol-formaldehyde resins) at the beginning of this century, the remarkable growth of the synthetic fibre, rubber and plastics industries followed the preparative achievements of the I.C.I. group in Cheshire (polyethylene), Carothers at du Pont, Wilmington (linear polyesters and nylons) and the German chemists (polyvinyl halides) in the 1930's, and the U.S. Government Synthetic Rubber Program during World War II. The ability to vary chemical structure and composition (e.g. for copolymers) and physical structure (by fillers, plasticizers, thermal and mechanical treatments, processing methods) made it possible to create materials which could be tailor-made for a particular application. Thus the industries grew to the dominant positions they hold today.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130760017","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}

{"title":"The stability of flow-improver additives in transformer oils under oxidation and electrical discharges","authors":"M. Duval, S. Lamothe, D. Cauchon, Y. Giguere","doi":"10.1109/CEIDP.1982.7726564","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726564","url":null,"abstract":"Transformer oils used in the northern part of the United States and Canada must have low pour-point temperatures in order to maintain good flow characteristics under the sometimes arctic conditions encountered during the winter months. The naphthenic oils presently used meet this requirement, but they are not expected to be available any longer, as the corresponding crude oil bases are now depleted. The paraffinic oils proposed as alternatives by the oil industry have much higher pour points, which must be artificially lowered by incorporating relatively large amounts of pour depressants. The eventual use of paraffinic oils in cold climates therefore relies heavily on the quality of such additives and their stability under actual service conditions. Flow improver additives used in transformer oils are generally large molecules or polymers of the aromatic type, with long paraffinic side chains preventing the formation of crystals in oil on cooling [1]. Their resistance to oxidation, corona discharges and arcing have been examined in the present study.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130249571","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}

{"title":"Acoustic emission spectrum signatures from capacitors under AC and transient conditions","authors":"R. Harrold","doi":"10.1109/CEIDP.1982.7726542","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726542","url":null,"abstract":"In order to improve diagnostic∗ testing, the acoustic emission spectrum signatures from model and full-size power capacitors were examined under ac and transient conditions. Acoustic emissions were monitored from the foil and insulation structure, poor electrical contacts and from partial discharge or corona activity. It was found that noise apparently associated with the aluminum foil occurs at a frequency near 27 kHz, and that it is generally best to monitor the acoustic emissions from both contact arcing and partial discharges or corona at a frequency of ∼80 kHz.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131335371","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}

{"title":"Breakdown voltage characteristics in a narrow gap","authors":"S. Hong","doi":"10.1109/CEIDP.1982.7726573","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726573","url":null,"abstract":"Static breakdown in most gases is in accordance with the Paschen's law for pressures up to a few atmospheres, at normal temperatures and uniform-field. However, departures from Paschen's law are observed notably for very small spacing or high pressure. Studies have indicated that the deviation is associated with high electric field, usually greater than 105 V/cm.1,2 For gaps of 2–3 mils, the electric field strength at static breakdown is close to 105 V/cm. Under impulse surge conditions, voltage rise rates of ≥ 100 V/μs, the electric field strength can be higher. In the following sections, an experimental arrangement to measure breakdown voltage at different rates of voltage rise (600 V/S and 100 V/μS) in a narrow gap (0.8 to 6 mils) will be described. Studies were made with carbon coated copper electrodes in a gas at pressures from 400 to 1000 torr at room temperature. Data will be presented for argon, argon-neon mixtures, neon, nitrogen and air.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"141 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122268271","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}

{"title":"Light emission from polyethylene subjected to highly divergent fields","authors":"S. Bamji, A. Bulinski, J. Densley, N. Shimizu","doi":"10.1109/CEIDP.1982.7726584","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726584","url":null,"abstract":"It is well known that polymers such as polyethylene can deteriorate under high electrical stress. This deterioration is usually in the form of electrical trees when the polymer is dry or water or electro-chemical trees in a wet environment. The tree initiation, before the tree becomes visible, is not fully understood. There is evidence that light is emitted during the electrical tree initiation process at both cryogenic and room temperatures [1,2]. Light has also claimed to have been detected during the growth of water trees [3]. This light has been attributed to electroluminescence or partial discharges ocurring in small voids near the needle tip. Previous studies have not attempted to detect partial discharges while measuring the light. This paper describes initial results of tests to measure simultaneously the light and partial discharge characteristics from a needle/plane electrode system in polyethylene.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121248858","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}

{"title":"Streamer propagation in water","authors":"R. Hebner, R. Mcknight","doi":"10.1109/CEIDP.1982.7726575","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726575","url":null,"abstract":"Prebreakdown events in water have been photographed for selected electrode geometries. From these measurements, the modes of propagation were identified and the propagation velocities were estimated. Streamers propagating from the anode were an order of magnitude faster than the initial cathode propagation mode. The measurement results are compared with similar results obtained in hydrocarbon and silicon oils. Knowledge of streamer propagation phenomena is required to predict and control switching behavior.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127813478","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}

{"title":"Radiation effects on spacecraft dielectrics","authors":"F. Bouquet, C. Maag","doi":"10.1109/CEIDP.1982.7726535","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726535","url":null,"abstract":"Applications of dielectrics that are being applied to present and future spacecraft are treated in this paper. One of these, Galileo (Figure 1) is scheduled to be launched in 1985 and will photograph the detailed changes in the giant red spot and other atmospheric phenomena in 1989–1990. Dielectrics are to be used on other applications also. In this paper, some of the applications simulated test results and results of space phenomena from Shuttle 3 are treated. The radiation aspects will be emphasized.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"311 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133208374","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}

{"title":"High-temperature conductivity of PI films","authors":"H. Chang, W. Shen, J. Yu","doi":"10.1109/CEIDP.1982.7726520","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726520","url":null,"abstract":"In polyimide films, there occur breaks in the reciprocal-temperature dependence of the log-electrical conductivities. It indicates that the multiple transitions and relaxations of the polyimide films are reflected in the above mentioned relationship. This presents us the possibility to determine the rule of variations of the electrical conductivities of the polymer with temperatures and is of interest to all working in the insulation field, especially in the semi-rigid chain polymer field.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134422782","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}

{"title":"Separation of conduction and displacement currents by direct electric field measurement by using an acoustic transducer","authors":"T. Takada, T. Sakai","doi":"10.1109/CEIDP.1982.7726510","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726510","url":null,"abstract":"A newly developed technique using an electro-acoustic transducer embedded in an electrode is used to measure the normal electric field as a function of time at the electrode surface of a plane-parallel capacitor enclosing thin film polymeric dielectrics. The displacement current Idisp is then obtained from the product of the dielectric Eonstant ε, electrode area A, and the time derivative of measured electric field E. With the total terminal current Iter measured by a pico-ammeter in series with the test capacitor and voltage source, the conduction current Icond, is obtained by taking the difference Iter-Icond This paper reports that the measured values of Idisp for a step applied voltage varied strongly with the type of polymer film insulation, PE(polyethylene) and PET(polyethylene-terephthalate), and exhibits a dependence on the magnitude and duration of the applied dc voltage, indicating space charge effects.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129491438","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}