• Title/Summary/Keyword: gas-discharge

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Determination of the initial cross-sections for the $C_4F_6$ molecule from the electron drift velocity ($C_4F_6$-Ar혼합기체에서의 Plasma Discharge Simulation을 위한 $C_4F_6$ 초기단면적 결정)

  • Lee, Kyung-Yeob;Jeon, Byung-Hoon
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1544-1545
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    • 2011
  • For quantitative understanding of gas discharge phenomena, we should know electron collision cross section. Processing plasma etching of semiconductor, and research are being used in the etching source $C_4F_6$ gas may be used by itself and mixed with other gases are also used. However, the molecular gas $C_4F_6$ study on the characteristics of the electron transport and the cross-sectional area of the decision is still lacking. Therefore, we understand the electron transport characteristics and analysed the electron transport coefficients. And to understand and interpret physical properties of the ionization coefficient ${\alpha}$/N, and the attachment coefficient ${\eta}$/N in $C_4F_6$ gas.

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Gas Detector for Hydrogen Dissolved in Transformer Oil

  • Seo Ho-Joon;Hwang Kyu-Hyun;Rhie Dong-Hee
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.2
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    • pp.72-75
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    • 2005
  • In oil-filled equipment such as transformers, partial discharge or local overheating will precede a final shutdown. Accompanied with such problems is a decomposition of insulating material into gases, which are dissolved into the transformer oil. The gases dissolved in oil can be separated with some membranes based on the differences in permeability of membranes to different gases. This paper discuss the permeability characteristics of several membranes for separation hydrogen gas in oil. With result of this paper, it may become possible to detect fault-related gases from transformer oil and predict incipient failures in the

A Study on the Effective Methods of Using Agricultural Resources Aimed to Facilitate Sustainable Agriculture (지속가능한 농업을 위한 농업자원의 유효이용 방안 -기후변화협약에 따른 영향 및 대책-)

  • 윤성이
    • Korean Journal of Organic Agriculture
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    • v.9 no.3
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    • pp.23-44
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    • 2001
  • To address complex solutions to tack1e the cost rise with the increasing of the prices of crude oil, and to lower warming gas discharge in agricultural sector in line with the framework Convention on Climate Change, we need to net only develop the methods of simply reducing energy use ratio, but also effectively energize resources discharged in the course of agricultural production aimed at enabling repealed farming, and develop systems to reinvest such energy into agricultural production and apply them to actual farming. To that end, specifically, we need to reduce the energy cost in agricultural production, and produce and harness bio gas that makes it possible to stabilize the continued supply of energy. Thus, in this research, we seek to discuss energy use volume and warming gas discharge, and the characteristics of bio gas and its use methods alike, in agricultural sector, and thus present methods for environment-friendly and continual development in agriculture.

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The Analysis of the He-Ne-Xe Gas Discharge Characteristics in an AC Plasma Display Panel by Two Dimensional Simulation

  • Seo, Jeong-Hyun;Chung, Woo-Joon;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.27-28
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    • 2000
  • We examined ($He_x-Ne_{l-x}$)-Xe gas discharge in an AC PDP cell by computer simulation to understand the gas mixing effects. The breakdown and sustain voltage were significantly lowered with the addition of Ne into He-Xe. The luminance and efficiency in ($He_x-Ne_{l-x}$)-Xe also improved when compared with the He-Xe or Ne-Xe gas mixture. The luminance is maximum around $30{\sim}40%$ He addition, while the efficiency shows peak values at 70% He. Two-dimensional numerical simulation was done to explain these results.

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The effect of vibration of the water surface for hydrogen gas generation by plasma electrical discharge (비열플라즈마에 의한 수소가스발생에 미치는 수표면 진통효과)

  • Kim, Jong-Seog;Park, Jae-Yoon;Jung, Jang-Gun;Kim, Tae-Yong;Lee, Jae-Dong;Koh, Hee-Seog;Lee, Hyun-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05b
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    • pp.115-119
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    • 2004
  • This paper is investigated about the effect of vibration of the water surface for hydrogen gas generation by non-thermal plasma. The vibration of the water surface is more powerful with increasing applied voltage. In this experimental reactor which is made of multi-needle and plate, the maximum acquired hydrogen production rate is about 6.8[ml/sec]. Although the generation of hydrogen gas is increased with elevating time, it is saturated after specific time due to the volume of reactor and the saturation of taylor cone.

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A Study on the Two-Phase Flow Transition and Atomization Characteristics in Effervescent Injectors (기체주입식 분사기의 이상유동 변화와 분무특성에 관한 연구)

  • Lee, Kangyeong;Jung, Hadong;Kang, Cheolwoong;Ahn, Kyubok
    • Journal of ILASS-Korea
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    • v.27 no.3
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    • pp.144-154
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    • 2022
  • Gas injection is a technique applied to improve throttling in liquid rocket engines and atomization in effervescent injectors. When a gas is injected into a liquid, it creates a two-phase flow inside the injector. The changes (bubbly flow, slug flow, annular flow, etc.) in the two-phase flow affect the injector's spray characteristics. In this study, cold-flow tests were performed by using three injectors with different orifice diameters and four aerators with different gas injection hole diameters. The experiments were done by changing the thrust ratio (liquid mass flow rate ratio) and gas-liquid mass flow rate ratio. Two-phase flow transition, breakup length, and discharge coefficient according to the injector/aerator design and flow conditions were investigated in detail.

Optical Gain Measuring System in the Laser Discharge using Feedback Light (귀환광을 이용한 레이저방전내의 광이득 측정시스템)

  • Choi, Sang-Tae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.7
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    • pp.9-14
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    • 2011
  • A spectroscopic measuring system was developed in order to determine optical gain of gas laser discharge for any optical transitions between 190[nm] and 800[nm] without laser resonator. With an image optical system and a feedback optical system emission light of laser discharge are entered in a monochromator and received at a photomultiplier. Subsequently optical gain and line intensity are measured.

Measurement of Optogalvanic Signal in Hollow Cathode Discharge Tube (Hollow Cathode Discharge Tube에서의 광검류 신호 측정)

  • Lee, Jun-Hoi;Yoon, Man-Young;Kim, Song-Kang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.874-877
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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 the lowest metastable atoms density at low current.

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A study of the hollow cathode discharge (HOLLOW CATHODE DISCHARGE의 방전 특성 연구)

  • Cho, S.M.;Seo, Y.W.;Kim, M.J.;Whang, K.W.
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.139-141
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    • 1989
  • The characteristics of the hollow cathode discharge were investigated. Temperature distribution of the hollow cathode was investigated and I-V curves of the hollow cathode discharge were obtained. In this paper variables are chamber pressure, Ar gas flow rate injected through the cathode tube and the gap distance between cathode and anode. The inter electrode electron temperature and density were measured by Langmuir probe.

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Magnetic Properties and Microstructure of Co Thin Films by RF-diode Sputtering Method (RF-diode Sputtering법으로 제작한 Co박막의 자기특성과 미세구조)

  • Han, Chang-Suk;Kim, Sang-Wook
    • Korean Journal of Materials Research
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    • v.28 no.3
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    • pp.159-165
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    • 2018
  • In order to increase the efficiency of the sputtering method widely used in thin film fabrication, a dc sputtering apparatus which supplies both high frequency and magnetic field from the outside was fabricated, and cobalt thin film was fabricated using this apparatus. The apparatus can independently control the applied voltage, the target-substrate distance, and the target current, which are important parameters in the sputtering method, so that a stable glow discharge is obtained even at a low gas pressure of $10^{-3}$ Torr. The fabrication conditions using the sputtering method were mainly performed in $Ar+O_2$ mixed gas containing about 0.6 % oxygen gas under various Ar gas pressures of 1 to 30 mTorr. The microstructure of Co thin films deposited using this apparatus was examined by electron diffraction pattern and X-ray techniques. The magnetic properties were investigated by measuring the magnetization curves. The microstructure and magnetic properties of Co thin films depend on the discharge gas pressure. The thin film fabricated at high gas pressure showed a columnar structure containing a large amount of the third phase in the boundary region and the thin film formed at low gas pressure showed little or no columnar structure. The coercivity in the plane was slightly larger than that in the latter case.