• Title/Summary/Keyword: Gas Discharge

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A Study on the Effect of Pressure upon A.C Partial Discharge in Insulating Oil (제어유의 문류품분효전에 미치는 형력의 영향)

  • Sang-Hoon Kook
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.7
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    • pp.227-233
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    • 1983
  • Noticing that action of gaseous phase in insulating oil concerns to the discharging characteristics, I investigated the smalness pressure effects on quantity of the partial discharge and discharging pulse frequency. Tests are carried out between the niddle points in insulating oil at pressure being changed by gradual charge of inert gas Ar. At pressure as low as of 0.1-0.5 torr pulse frequency and maximum partial discharge reach peak while at pressure haigher than 20 torr no pulse is observed. The fact that pulse frequency has peak value at certain presure, which is changed either by charging Ar or by adding oil, implies that the action of gaseous phase depends on pressure. Test results are that partial discharge pulse are governed by pressure of Ar-charged oil, and less partial discharge pulses correspond to smaller bubbles whereas more partial descharge pulses correspond to larger bubbles.

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Measurement of a Threshold Initiation Carrier Density for a Reduction in Gas Breakdown Voltage

  • Park, Hyunho;Kim, Youngmin
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2421-2424
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    • 2018
  • A direct measurement of an initiation carrier injection for a low voltage discharge is presented. A self-sustained pulsed discharge is utilized to characterize electrical responses of a glow discharge for varying amounts of injected initiation carriers. It is clearly demonstrated that the initiation carrier injection affects the ignition time and the breakdown voltage of the primary discharge. An abrupt reduction in the breakdown voltage for a $300{\mu}m$ gap pin-plate discharge is observed when a threshold carrier density of $3{\times}10^{11}cm^{-3}$ is injected and the breakdown voltage continues to decrease to 250 V with increasing the initiation carrier injection beyond the threshold density.

Increase in Color Depth of Black Dyed PET Fabrics Treated by Sputter Etching (Sputter etching에 의한 PET직물의 심색성 향상)

  • Shim, Yu Bong;Lee, Mun Cheul
    • Textile Coloration and Finishing
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    • v.9 no.1
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    • pp.15-22
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    • 1997
  • The alkali treated and black dyed PET fabrics were sputter etched under Ar gas atmosphere. The color depth of PET fabrics were increased with sputter etching time only under some limits of discharge power. And above that limits of discharge power the color depth of PET fabrics was decreased by increasing discharge power and treatment time. Minute cracks were made by sputter etching in the whole surface of fabrics to the direction of perpendicular to the longitudinal side of yarns. The fineness and density of minute crack were increased with lowering discharge power. And the size of crack was far smaller than that of microcrater which was obtained by alkali treatment. It is considered that the increase of color depth is related to the minute crack. The water permeation time of sputter etched fabrics was increased with increasing discharge power and treating time. The increase of color depth attained by sputter etching was fully kept through repeated laundering.

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The characteristics study of discharge lamp type ozonizer using pulse power source (펄스 전원을 활용한 방전관형 오존발생기의 특성 연구)

  • Song, Hyun-Jig;Kim, Min-Huei;Park, Chan-Gyu;Cho, Kyu-Pan;Yoon, Dae-Hee;Jee, Seung-Wook
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.350-352
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    • 2007
  • This paper describes the discharge and ozone generation characteristics with variation of the applied voltage, the number of ozonizer, the quantity of flowing material gas. The important conclusions are as follows. The discharge voltage and current values are proportional to the applied voltage. The ozone concentration and generation are proportional to the applied voltage and the number of ozonizer. As the maximum value of ozone concentration and generation of silent discharge type ozonizer using discharge lamp can be obtained 890[ppm] and 59.7[mg/h] respectively.

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Diffusion Modelling of Cold Discharge on Coastal waters (연안역의 냉배수 확산모델링)

  • Kim, Jong-Kyu;Kim, Jong-Hwa
    • Journal of Fisheries and Marine Sciences Education
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    • v.13 no.2
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    • pp.132-145
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    • 2001
  • The cold discharge from LNG(liquefied natural gas) terminal makes the water temperature around the terminal fall down. This temperature reduction may result in serious changes on marine ecosystem of the coastal area. The numerical model experiments of material transport and tidal circulation in the inner bay, Chinhae Bay are investigated in the dispersion of cold discharge from LNG terminal. The condition of ambient water is exposed to tide, tidal current and cold discharge temperature. Simple numerical model experiments highlight the importance of tidal circulation and cold discharge at each case and some results are discussed. The results of this study can be used as the guideline for the site selection of LNG terminals and long-term marine environmental impact assessment.

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A Study on the Electrochemical Hydrogenation Reaction Mechanism of the Laves Phase Hydrogen Storage Alloys (Laves phase계 수소저장합금의 전기화학적 수소화 반응 매카니즘에 관한 연구)

  • Lee, Ji-Youl;Kim, Chan-Jung;Kim, Dai-Ryong
    • Journal of Hydrogen and New Energy
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    • v.8 no.1
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    • pp.31-41
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    • 1997
  • In order to investigate the mechanism of electrochemical hydrogenation reaction on Zr-based Laves phase hydrogen storage alloy electrodes, electrochemical charge/discharge characteristics, potentiostatic/dynamic polarizations and electrocehmical impedance spectroscopy(EIS) of Zr-Ti-Mn-Ni and Zr-Ti-Mn-Ni-M(M=Fe, Co, Al) alloys were examined. Electrochemical discharge capacities of the alloys were quite different with gas charge capacities. Therefore, it was considered that discharge capacities of the alloys depend on electrochemical kinetic factors rather then thermodynamic ones. Discharge efficiencies were increased linearly with exchange current densities. The results of potentiostatic/dynamic polarization measurements showed that electrochemical charge and discharge reaction of Zr-based Laves phase hydrogen storage alloys is controlled by charge transfer process at the electrode surface. The EIS measurements also confirmed this result.

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Sound Measurements of the Discharge Break Down Using Fabry-Perot Sensor Array (Fabry-Perot형 광섬유 배열센서의 방전 음압 계측)

  • Lee, Jong-Kil;Lee, June-Ho;Lee, Jin-Woo
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.770-773
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    • 2003
  • To measure discharge breakdown acoustic signal, Fabry-Perot interferometer fiber optic sensor is used. Fiber optic sensor array can measure the partial discharge acoustic signal caused by defect of power facilities such as power cables, transformers and gas insulation. Fabry-Perot interferometer is selected as an fiber optic sensor array. It is shown that Fabry-Perot fiber optic sensor array detected discharge breakdown acoustic signal, effectively.

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Ultra-fast meseurement of partial discharge current due to conducting particle in Gas-insulated System (GIS) (가스절연기기 내부의 금속 이물질에 의한 초고속 부분방전량 및 전류 측정)

  • Park, Ki-Jun;Goo, Sun-Geun;Yoon, Jin-Yul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.160-164
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    • 2002
  • A special discharge cell containing a free conducting particle was used to generate the discharges in $SF_6$. The analog bandwidth of the measurement system exceeded 5 GHz. The measured signals were processed to compensate for the response of the measurement system. The discharge current rise time was in the range of 70 ps, while its full-width half-maximum was 120 ps. Single and double current pulses of positive and negative polarities were measured. Likewise, these pulses were compared with the measurement obtained using a conventional partial discharge detector of the IEC60270 type

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Measurement of Optogalvanic Signal in Hollow Cathode Discharge Tube (Hollow cathode discharge tube에서의 광검류 신호 측정)

  • 이준회;정기주
    • Journal of the Korean Vacuum Society
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    • v.11 no.2
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    • pp.119-126
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    • 2002
  • The optogalvanic signals were measured using hollow cathode discharge tube with argon as buffer gas at change of discharge currents. A change of ionization rate due to electron collision causes an increase or decrease of the electric conductivity, This change in electric conductivity generates the optogalvanic signal. We conclude that optogalvanic signal has close relation with change of the lowest metastable atoms density at low current.

The Characteristics of Showering Discharge Type Ozonizer (Showering Discharge형 오존발생장치의 특성)

  • Kim, Keum-Yeung;Mun, Kyung-Su;Song, Hyun-Jig;Lee, Kwang-Sik;Lee, Dong-In;Jeon, Young-Ju
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2248-2250
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    • 1999
  • In this paper, showering discharge type ozonizer has been designed and manufactured. The ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode) of cylinder shape. This paper describes the following two characteristics: (1) The characteristics of discharge with variation of output voltage of AC H.V source, flux of oxygen supplied gas and discharge voltage. (2) The characteristics of ozone generation by varying flux and discharge power.

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