• Title/Summary/Keyword: Gas Discharge

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SUPERLUBRICITY IN CARBON FILMS

  • Erdemir, Ali
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.163-164
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    • 2002
  • This paper describes a new carbon film that afford superlubricity (i.e, friction coefficients of 0.001- 0.005) and superlow wear rates (i.e., $10^{-11}-10^{-10}mm^3/N.m$) to sliding metallic and ceramic surfaces, when tested in inert test environments. The wear life of these films are more than 1000 km even under very high contact pressures (i.e., 1-3 GPa) and at a wide range of sliding velocities (i.e., 0.1 to 2 m/s). They are produced in a plasma enhanced chemical vapor deposition system at room temperature using highly hydrogenated gas discharge plasmas. Extensive research has shown that films grown in highly hydrogenated gas discharge plasmas (i.e., hydrogen-to-carbon ratio of 6 and above) provide superlow friction and wear coefficients. In full paper, specific conditions under which superlubricity can be achieved in carbon films will be discussed.and a mechanistic model will be proposed to explain the superlubricity of new carbon films.

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Mechanisms of $Cl_2$ Molecules Dissociation in a Gas Discharge Plasma in Mixtures with Ar, $O_2.N_2$

  • Efremov, A.M.;Kwon, Kwang-Ho
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.4
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    • pp.197-201
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    • 2001
  • The influence of argon, oxygen, and nitrogen admixtures on the dissociation of $Cl_2$ molecules in a glow discharge low-temperature plasma under the constant pressure conditions was investigated. For $Cl_2/Ar$ and $Cl_2/O_2$mixtures, the concentration of chlorine atoms was observed to be a practically constant at argon or oxygen concentrations up to 50%. This invariability is a most pro bably explained by relative increase in rate of $Cl_2$ direct electron impact dissociation due to the changes in electrophysical parameters of plasma such as EEDF, electron drift rate and mean energy. For all the considered mixtures, the contribution of stepwise dissociation involving active species from gas additives (metastable atoms and molecules, vibrationally excited molecules) was found to be negligible.

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A Study on the TiC Coating Using Hollow Cathode Discharge Ion Plating (HCD 이온 플레이팅 방법을 이용한 TiC 코팅에 관한 연구)

  • Kim, In-Cheol;Seo, Yong-Woon;Whang, Ki-Whoong
    • Proceedings of the KIEE Conference
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    • 1991.11a
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    • pp.261-264
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    • 1991
  • Titanium carbide(TiC) films were deposited on stainless-steel sheets using HCD(Hollow Cathode Discharge) reactive ion plating. Acetylene gas was used as the reactant gas. The characteristics of TiC films were examined by X-Ray diffraction, $\alpha$-step, ESCA(Electron Spectroscopy for Chemical Analysis), and, AES(Auger Electron Spectroscopy). The results were discussed with regard to various deposition conditions(bias voltage, acetylene flow rate, temperature).

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A Study on the Supply Gas Temperature Characteristics of Silent Discharge Type Ozonizer by Applying Radio Frequency Voltage (고주파 전압인가에 의한 무성방전형 오존발생기의 원료가스 온도특성에 관한 연구)

  • 이상근;전병준;박용권;박원주;이광식;권혁한;송현직;박중협
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.5
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    • pp.46-54
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    • 2001
  • In this paper, a co-axial cylinder type ozonizer using silent discharge applying radio frequency voltage known as an ozone generation was designed and fabricated. A cooling system was installed to investigate the characteristics of ozone generation in accordance with temperature change of the supplied gas known as an important factor. The characteristics of ozone generation were investigated in accordance with the change of cooling temperature.

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An Address Voltage Stabilization Circuit for the Single-Side Driving Method of AC Plasma Display Panels

  • Kim, Tae-Hyung;Kang, Jung-Won;Lee, Jun-Young
    • Journal of Power Electronics
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    • v.9 no.6
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    • pp.884-891
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    • 2009
  • An address voltage stabilization circuit for the single-side driving (SSD) method for AC plasma display panels (PDP) is proposed. The single-side driving method, which eliminates a common sustaining driver, uses only two electrodes in a three electrode AC PDP structure. The high-impedance (Hi-Z) mode operation of the data drive ICs during the sustaining period is needed for surface gas-discharge without misfiring in the SSD method but it produces the problem that the address voltage increases up to the breakdown voltage. The proposed circuit based on a flyback converter can stabilize the address voltage under the breakdown voltage and provide better surface gas-discharge performance without any misfiring in the SSD scheme.

Numerical studied on consequenses of the ion pumping effect in helicon plasmas (헬리콘 플라즈마에서 이온 펌핑 효과의 영향에 대한 수치적 해석 연구)

  • 조수원;박인호;최성을;권명회
    • Journal of the Korean Vacuum Society
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    • v.8 no.3B
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    • pp.353-360
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    • 1999
  • The global balance model is applied to investigate the transient behavior of the electron density and temperature in helicon plasmas. The power absorption calculated from the solutions of the Maxwell equations is used in solving the power balance equation. A balance model for the neutral gas is also considered to fins its density self-consistently. It is turned out that the numerical results reasonably explain consequences of the ion pumping effect including the occurrence of two distinct modes of pulsed helicon discharge which have been observed experimentally. The behavior of the discharge parameters are fond to be primarily dependent on the power absorption and the gas flow rate, but the pressure controls the electron density and temperature of the final steady state as well as the transient state even with the same flow rate. Finally, it is shown that the electron density virtually the linear relationship between the density and the magnetic field is retained for a higher pressure when the effect of the ion pumping is negligible.

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Two-Dimensional Simulation of Hg Flat Fluorescent Lamps for an LCD Backlight unit (액정디스플레이 후판광원용 평판형 수은 형광램프의 2차원 시뮬레이션 연구)

  • Yoon, Hyun-Jin;Lee, Hae-June
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.7
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    • pp.1275-1281
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    • 2007
  • The discharge phenomena in a flat fluorescent lamp for the backlight unit of liquid crystal displays are simulated by sung a two-dimensional fluid model. The numerical methods for the calculation of plasma dynamics and the radiation transport are introduced for the discharge simulation and for the transmission of the vacuum ultraviolet lights. The simulation results are presented to compare the luminance and the luminance efficacy with the variation of gas pressure, gas mixture ratio, driving voltage, and frequency.

Emission Characteristics of Flat Fluorescent Lamp for LCD Backlight Using Inert Gas Mixture

  • Heo, Sung-Taek;Lee, Yang-Kyu;Kang, Jong-Hyun;Yoon, Seung-Il;Oh, Myung-Hoon;Lee, Dong-Gu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1522-1525
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    • 2007
  • In this study, flat fluorescent lamps (FFLs) having surface discharge structures was fabricated by screen printing technique and were studied using spectraradiometer and square pulse power supply. Two types of FFLs having different shapes of electrodes (crosstype and line-type structure) were compared with variation of discharge shape and mixed gas ratio.

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Characterization of PDP Performance Prepared by Vacuum In-line Sealing Technology

  • Kwon, Sang-Jik;Kim, Jee-Hoon;Whang, Ki-Woong
    • Journal of Information Display
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    • v.4 no.4
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    • pp.19-24
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    • 2003
  • By using vacuum in-line driving and photoluminescence measuring system, we have examined the electrical and optical characteristics of plasma display panel produced by vacuum in-line sealing technology. In addition, the relationship between luminous efficiency and base vacuum level before filling discharge gas was analyzed. In the case of base vacuum level of $1.33{\times}10^{-1}$ Pa, the firing voltage of a 2-inch diagonal PDP panel was ranged from 312 to 343 V depending on the discharge gas pressure of $2.667{\times}10^4$ to $4{\times}10^4$ Pa at room temperature, Whereas in the case of $1.33{\times}10^{-4}$ Pa, the firing voltage was reduced by 40 V and luminescence was improved slightly.

Catalistic effect of sludge on $NO_x$ removal in cylinder type reactor (원통형 플라즈마 반응기에서 $NO_x$ 제거에 미치는 슬러지의 촉매효과)

  • Park, Jae-Yoon;Lee, Kyung-Ho;Park, Sang-Hyun;Kim, Hyung-Man;Kim, Jong-Suk;Ha, Hyun-Jin
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1777-1779
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    • 2001
  • In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using cylinder type reactor. An experimental investigation has been conducted for NO concentration of 50[ppm], 100[ppm], 200[ppm] balanced with air. a gas flow rate of 5[1/min]. Cylinder type reactor is at upstream of system for corona discharge and packed bed type reactor filled with sludge pellets ate put at downstream of Cylinder type reactor for catalystic effect. And AC voltage to discharge the gases was supplied. In the result, NO removal with magnetic field is higher than that without magnetic field, when packed-bed reactor with sludge pellet is installed at downstream of cylinder reactor NO, $NO_2$ removal rate increased and $O_3$ is not generated.

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