• Title/Summary/Keyword: Plasma Discharge

Search Result 1,424, Processing Time 0.038 seconds

Analysis of flat fluorescent lamp discharges for LCD backlight unit by using two-dimensional fluid simulation code

  • Yoon, Hyun-Jin;Ha, Chang-Seung;Lee, Hae-June
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2007.08b
    • /
    • pp.1569-1572
    • /
    • 2007
  • A two-dimensional fluid simulation code has been developed in order to investigate discharge phenomena and to improve plasma luminous efficiency in a Hg flat fluorescent lamp (FFL) for an LCD backlight unit. In this study, the method of a two-dimensional fluid simulation for FFL is explained and the simulation results of Hg-Ar-Ne mixture gas are presented for the enhancement of the luminance efficiency. The effects of various parameters, such as driving voltage, frequency, and gas mixture ratio, are investigated. The luminance efficiency increased with increasing fraction of mercury but the increasing fraction of argon did not affect the efficiency much.

  • PDF

Characteristics of Electron Beam Extraction in Large Area Electron Beam Generator

  • Woo, Sung-Hun;Lee, Hong-Sik
    • KIEE International Transactions on Electrophysics and Applications
    • /
    • v.4C no.1
    • /
    • pp.10-14
    • /
    • 2004
  • A large area electron beam generator has been developed for industrial applications, for example, waste water cleaning, flue gas treatment, and food pasteurization. The operational principle is based on the emission of secondary electrons from the cathode when ions in the plasma contact the cathode, which are accelerated toward the exit window by the gradient of the electric potential. Conventional electron beam generators require an electron beam scanning mechanism because a small area thermal electron emitter is used. The electron beam of the large area electron beam generator does not need to be scanned over target material because the beam area is considerable. We have fabricated a large area electron beam generator with peak energy of 200keV, and a beam diameter of 200mm. The electron beam current has been investigated as a function of accelerating voltage and distance from the extracting window while its radial distribution in front of the extracting window has been also measured.

NOx removal in cylinder type reactor and Packed-bed type reactor (원통형과 packed-bed형 반응기에서 NOx제거특성)

  • 박재윤;박상현;이경호;하상태;송원섭;황보국
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.07a
    • /
    • pp.499-502
    • /
    • 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 and packed-bed 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]. Ac voltage to discharge the gases was supplied. In the result, NOx removal rate in packed bed reactor is higher than that in cylinder type reactor. it is thought that plasma density in contact point of BaTiO$_3$ is significantly higher than that in cylinder reactor.

  • PDF

Surface Modification of Polydimethylsiloxane using Nd:YAG Laser (Nd:YAG 레이저를 이용한 PDMS 표면개질)

  • Shin Sung-Kwon;Song Hyun-Seung;Lee Cheon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.19 no.2
    • /
    • pp.181-184
    • /
    • 2006
  • Nd:YAG($\lambda$=266 nm, pulse) laser beam was irradiated on the PDMS surface to improve its chemical reaction, wettability, adhesive property. The various surface modification methods of PDMS were already studied using oxygen plasma, ozone and corona discharge. The surface modification using laser has the advantage of the simple experiment that only directly irradiated laser beam on the PDMS surface in the air. After the laser treatment, the PDMS surface was investigated using a contact angle measuring instrument. The contact angle was decreased with a increase of the surface oxygen content. In conclusion, the wettability of PDMS surface was improved by the laser treatment without changing of its bulk characteristics.

Effect of Working Gas Pressure on Misfirng of ac PDP at High Ambient Temperature

  • Ryu, Jae-Hwa;Choi, Joon-Young;Kim, Dong-Hyun;Kim, Joong-Kyun;Kim, Young-Kee;Lee, Ho-Jun;Park, Chung-Hoo
    • Journal of Information Display
    • /
    • v.4 no.4
    • /
    • pp.25-32
    • /
    • 2003
  • One of the important problems in ac PDP in recent years is the misfiring of ac PDP at high ambient temperatures which consequently degrades the image quality of the ac PDP. This may be due to the change of working gas pressure and/or MgO surface characteristics at high ambient temperatures. This paper deals with the effect of working gas pressure on the misfiring of ac PDP at high ambient temperature. From this study, we found that the main cause of the misfiring at high ambient temperature is the increase in discharge firing voltage induced by increased working gas pressure

Plasma discharge characteristics of MgO protection layer deposited by using targets made of single crystals, and nano powders

  • Yang, Choong-Jin;Park, Eun-Byeong;Lee, Ho-Sang;Park, Jung-Hoo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2008.10a
    • /
    • pp.157-160
    • /
    • 2008
  • Improved properties of second electron emission was evaluated by assemble of 4 inch PDP panel. MgO protection layers were deposited and examined by using both pellets made of extremely pure MgO single crystals and sintered pellets using MgO nano powders. $\gamma$ coefficients higher than 0.11 were obtained from the panel by adopting dopant-controlled MgO single crystals. Especially the MgO layer deposited by sintered pellets made of nano powders showed the higher $\gamma$ coefficients at the operating voltage above 200 volts.

  • PDF

Characteristics of Phosphors for PDP with Frit Contents (Frit 첨가량에 따른 PDP용 형광체의 특성 연구)

  • Jung, Ah-Reum;Kim, Hyeong-Jun;Choi, Sung-Churl
    • Journal of the Korean Ceramic Society
    • /
    • v.47 no.2
    • /
    • pp.146-150
    • /
    • 2010
  • Because the plasma display panel has used red, green and blue(RGB) phosphors, it has suffer from two intrinsic problems; 1) the cell defect due to the lack of binding force between phosphor particles and 2) mis-discharge because of difference of electrical characteristics among RGB phosphors. In order to control the mechanical and electrical properties of RGB phosphors, frit with $ZnOB_2O_3-SiO_2-Al_2O_3$ system was added to RGB phosphor as sintering additive. The mechanical properties were increased by the amount of frit. The amount of frit under 5 wt% rarely affected dielectric constant. However, there was the limit of amount because of decreasing optical properties seriously; over 3 wt% in red, over 10 wt% in green and blue.

Effects of Aluminum and Silicon as Additive Materials for the Zinc Anode in Zn-Air Batteries

  • Lee, Yong-Seok;Ryu, Kwang-Sun
    • Journal of the Korean Electrochemical Society
    • /
    • v.21 no.1
    • /
    • pp.12-20
    • /
    • 2018
  • To solve low cycle efficiency of the zinc anode in Zn-air batteries by corrosion, this study examined the effects of Al as a cathodic protection additive to Zn. The Al-mixed Zn anodes were produced by mixing Zn and Al powder (1, 2, and 3 wt. %). To compare the effects of the Al additive, Si was selected under the same conditions. The morphology and elemental composition of the additives in the Zn were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductively coupled plasma - mass spectrometry. The anti-corrosion effects of the Al and Si-mixed Zn anodes were examined by linear polarization. Cyclic voltammetry and charge-discharge tests were conducted to evaluate the electrochemical performance of the Al and Si-mixed Zn anodes. As a result, the Al-mixed Zn anodes showed highest corrosion resistance and cycling performance. Among these, the 2 wt.% Al-mixed Zn anodes exhibited best electrochemical performance.

MgO Properties Depending on E-beam Evaporation Rate and Its Effects on the PDP Discharging Characteristics

  • Kwon, Sang-Jik;Kim, Yong-Jae;Li, Zhao Hui;Kim, Kwang-Ho;Lee, Dal-Ho
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.890-893
    • /
    • 2006
  • Effects of the evaporation rate of MgO films using electron beam were investigated on the MgO properties and the discharge characteristics of the plasma display panel (PDP). The evaporation rate was changed from 3 ${\AA}/sec$ to 15 ${\AA}/sec$ at a substrate temperature of $300\;^{\circ}C$. MgO properties such as crystal orientation, surface roughness, contact angle, and film structure were inspected using XPS, AFM, drop shape analysis and SEM. We also studied the relation between MgO properties and PDP discharging characteristics. The minimum firing voltage and maximum efficacy were obtained at evaporation rate of 5 ${\AA}/sec$. In the MgO film deposited at 5 ${\AA}/sec$, (200) orientation was most intensive and surface roughness was minimum.

  • PDF

Discharge Characteristic of Microdischarge Cell with Counter Sustain Electrodes and Twin Auxiliary Electrodes

  • Hashimoto, M.;OH, J.S.;Tachibana, K.;Asai, H.;Kikuchi, N.;Sakamoto, S.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.886-889
    • /
    • 2006
  • Twin Auxiliary Electrodes were applied to the counter sustain electrode structure plasma display panels for the improvement of luminous efficiency. In advanced, we investigated the spatiotemporal behaviors of excited $Xe^{\ast\ast}(2p)$ atoms in that structure unit cell with various applied voltage conditions for the auxiliary electrodes. The near-IR emissions were observed by an ICCD camera combined with narrow band pass filter. As a partial result, the intensity of IR emissions and the response time were improved with the proposed twin auxiliary electrodes.

  • PDF