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  • Title/Summary/Keyword: charge distribution

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The dependence of the electrical characteristics of MgO on temperature in an AC PDP

  • Ha, Chang-Hoon;Jeong, Dong-Chul;Kim, Joong-Kyun;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.714-716
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    • 2005
  • We studied the dependence of the electrical characteristics of MgO protecting layer on temperature in an AC PDP cell. Careful measurements of the surface resistance of MgO were performed for the temperature range from room temperature to 100C with and without the VUV illumination. Experimental results show that the resistivity is affected by not only the temperature but also VUV irradiation. The measurement of wall charge distribution and the address discharge delay time as to the temperature show that the resistivity change of MgO may affect the wall voltage and consequently the discharge delay time.

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Mechanism of Striation in Plasma Display Panel Cell

  • Yang, Sung-Soo;Iza, Felipe;Kim, Hyun-Chul;Lee, Jae-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.167-170
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    • 2005
  • The mechanism of striation in the coplanar- and matrix-type plasma display panel (PDP) cells has been studied using the particle-in-cell Monte-Carlo Collision (PIC-MCC) model. The striation formation is related to the ionization energy of neutral atoms and the well-like deformation of space potential by space charge distribution. Negative wall charge accumulation by electrons on the MgO surface of the anode region is also one of the key factors for the formation of striation. The clearness of the striation phenomenon in PIC-MCC code in comparison with fluid code can be explained by using nonlocal electron kinetic effect.

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Approach to Characterization of a Diode Type Corona Charger for Aerosol Size Measurement

  • Intra Panich;Tippayawong Nakorn
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.5
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    • pp.196-203
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    • 2005
  • A semi-empirical method to determine the electrostatic characteristics of a diode type corona aerosol charger based on ion current measurement and electrostatic charging theory was presented. Results from mathematical model were in agreement with those from experimental investigation of the charger. Current-voltage characteristics, Nit product and charge distribution against aerosol size were obtained. It was shown that the space charge was significant and must be taken into account at high ion number concentration and low flow rate. Additionally, significant particle loss was evident for particles smaller than 20 nm in diameter where their electrical mobility was high. Increase in charging efficiency may be achieved by introducing surrounding sheath flow and applying AC high voltage. Overall, the approach was found to be useful in characterizing the aerosol charger.

Calculation of Power Frequency Electromagnetic Field Around the Kyeongbu High Speed Railways (경부고속철도 주변의 60 Hz 전자계 분포 예측에 관한 연구경부고속철도)

  • Kim, E.S.;Myung, S.H.;Lee, B.Y.;Han, I.S.;Park, J.K.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1648-1650
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    • 1997
  • The effects of power frequency electric and magnetic fields have been a source of concern for many years. Electromagnetic fields can pose a theat to both signal system of electrified railways and human body around railways. It is believed that, though the electromagnetic fields do no serious harm to human health, they do induce biological effects. This paper estimates the electromagnetic fields near Kyeongbu high speed railways with numerical data. The charge simulation method and surface charge method are used to calculate the electric field of 2 dimensional power distribution lines and rails and magnetic field is calculated on the base of Biot-Sarart's law.

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Physical Properties of Glass Fiber Reinforced Nylon 6,6 and lonomer Blends (Glass Fiber로 강화된 Nylon 6,6 / Ionomer 블렌드의 물리적 특성)

  • 박광석;서광석
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.536-539
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    • 1999
  • Physical properties of glass fiber-reinforced nylon 6,6 and ionomer blends were investigated in variation of ionomer and glass fiber content. With the increase of ionomer content, tensile strength, impact strength and flexural strength decreased, whereas increasing glass fiber content, these properties were improves. Both permittivity and tan δ remain unchanged. Space charge distribution was investigated by PEA (Pulsed electroacoustic) method. Heterocharge was found in nylon 6,6 and 히ass fiber composites, whereas composites, whereas when ionomer is blended.

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Electrostatic Properties of N-Acetyl-Cysteine-Coated Gold Surfaces Interacting with TiO2 Surfaces

  • Park, Jin-Won
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.902-906
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    • 2009
  • It is found that that the coating N-acetyl cysteine (NAC) on gold surfaces may be used to design the distribution of either gold particle adsorbed to the TiO2 surface or vice versa by adjusting the electrostatic interactions. In this study, we investigated electrostatic properties of the NAC-coated-gold surface and the TiO2 surface. The surface forces between the surfaces were measured as a function of the salt concentration and pH value using the AFM. By applying the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to the surface forces, the surface potential and charge density of the surfaces were quantitatively acquired for each salt concentration and each pH value. The surface potential and charge density dependence on the salt concentration was explained with the law of mass action, and the pH dependence was with the ionizable groups on the surface.

Chemical Substitution Effect on Energetic and Structural Differences between Ground and First Electronically Excited States of Thiophenoxyl Radicals

  • Yoon, Jun-Ho;Lim, Jeong Sik;Woo, Kyung Chul;Kim, Myung Soo;Kim, Sang Kyu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.415-420
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    • 2013
  • Effect of chemical substitution at the para-position of the thiophenoxyl radical has been theoretically investigated in terms of energetics, structures, charge densities and orbital shapes for the ground and first electronically excited states. It is found that the adiabatic energy gap increases when CH3 or F is substituted at the para-position. This change is attributed to the stabilization of the ground state of thiophenoxyl radical through the electron-donating effect of F or CH3 group as the charge or spin of the singly-occupied molecular orbital is delocalized over the entire molecule especially in the ground state whereas in the excited state it is rather localized on sulfur and little affected by chemical substitutions. Quantitative comparison of predictions based on four different quantum-mechanical calculation methods is presented.

Analysis of Electric Fields Inside GIS with a Small Void in Spacer or with a Metal Impurity (고체 절연체 내부 공극 또는 금속 이물질 존재시의 GIS 내부의 전계 해석)

  • Min, Seok-Won;Kim, Yong-Jun;Kim, Eung-Sik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.6
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    • pp.346-353
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    • 2000
  • In this paper, we developed 3 dimensional Surface Charge Method which could calculate electric fields inside GIS with a small void in solid insulator or with a metal impurity. We find a metal impurity makes much more non-uniform electric field distribution inside GIS than a small void. We also find electric field is much more increased when a metal impurity is close to solid insulator surface at high voltage conductor.

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Cell Balancing Scheme with Series Coupling of Multiple Primary Windings for Hybrid Electric Vehicle Lithium-Ion Battery Cells

  • Park, Hong-Sun;Kim, Chong-Eun;Moon, Gun-Woo;Lee, Joong-Hui
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.347-349
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    • 2007
  • Charge equalization scheme for HEV lithium-ion battery system is proposed in this paper, where all the primary windings with in parallel bi-directional switches are coupled in series to provide the equalizing energy from the whole battery string to the specific under charged cells. Moreover, to realize minimized size of equalization circuit employing the proposed cell balancing scheme, the optimal power rating design rule according to equalization time and SOC distribution of imbalance is proposed. A prototype of HEV lithium-ion battery system of four cells shows the outstanding charge equalization performance while maintaining greatly reduced size of cell balancing circuit.

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Development of The New field Analysis System (차세대 전재해석 시스템의 개발)

  • 강종성;고광철;강형부
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.237-241
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    • 1997
  • It is necessary to know the accurate field distribution around the high power apparatus, in designing it. To calculate the field around electrodes, we use the Charge Simulation Method(CSM) among several numerical methods and develop the new \"Field Analysis System\", by which we can draw the shape of electrodes, save the drawing in ascii code and apply CSM on the data. In the Field Analysis System, we try several rules for arrangement of simulation charge on CSM and consider their accuracy. At firs we simulate the case with simple electrode geometry and consider the adequacy of the rules. With tole field Analysis System applied the rules, we simulate the main electrode of load switchgear. As a result of the simulation, equipotential line, flux line and field strength on male electrode are drawn.

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