• Title/Summary/Keyword: Electrodes

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Three-dimensional Molecular Director Simulation within a Unit Pixel of TFT-LCDs including Floating Electrodes

  • Jung, Sung-Min;Park, Woo-Sang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1151-1154
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    • 2004
  • In this study, we presented a novel method to calculate unknown voltages on the floating electrodes introduced in a unit pixel of TFT-LCDs using three-dimensional molecular director simulation. For the simulation of the potential distribution profiles generated under the influence of the floating electrodes, we used the floating boundary condition on the surface enclosing the floating electrodes. The constraint for the floating boundary condition was derived from the charge neutrality condition about the floating electrodes disconnected from voltage sources. For the pixel with the floating electrodes patterned between the pixel and the data electrodes, we simulated the molecular director and the potential distribution in three-dimension, and then observed the location of the disclination lines around the edge of the pixel electrode. As a result, it was revealed that the floating electrodes significantly affect the electro-optical characteristics such as the location of the disclination line.

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Development of a Non-contacting Capacitive Sensor Based on Thompson-Lampard Theorem for Measurement of ${\mu}m-order$ Displacements (Thompson-Lampard 정리를 적용한 마이크로미터 변위 측정을 위한 비접촉식 전기용량 센서 개발)

  • Kim, Han-Jun;Kang, Jeon-Hong;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.9
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    • pp.443-448
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    • 2006
  • Non-contacting capacitive sensor based on Thompson-Lampard theorem have been fabricated and characterized for measuring of 때 order displacements. To overcome disadvantages of the existed capacitive sensors of parallel plate type with 2-electrodes and 3-electrodes, the developed new sensor was designed to have 4-electrodes with a constant gap of 0.2mm between the electrodes. Two of the electrodes were used as a high potential electrode and a low one, the other two electrodes were used as guard electrodes. These electrodes were made from copper using RF sputtering system on a sapphire plate with diameter 17 mm and thickness 0.7 mm. This sensor can be used for measuring the distance not only between the sensor and metallic target connected to ground potential but also non-metallic target without ground connection.

Interference Coefficient of X axis for Electrodes using Variation of Plural Earth Electrodes (복수접지극의 변화에 따른 전극의 X축 간섭계수)

  • Kim Sung Sam;Kim Ju Chan;Song Won Pyo;Koh Hee Seog
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.449-451
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    • 2004
  • In the building, there are a lot of electricity, electrodes, and communication equipment. Many of those equipment needs to earthing. Naturally, the earth electrodes are constructed in the site of a building. In such a situation, when electric current flows into a certain earthing system the potential of other earthing systems rises. That is, the potential interference will take place between the earth electrodes. The conventional study has been considered by only the relation of the distance between the earth electrodes using the potential distribution formula of earth surface. However, it is necessary to inquire strictly, taking the surface potential of electrodes by electrode form into consideration. In this paper, basic formula is deduced on the basis of both electrodes surface potential of earth electrode as a source of the potential interference and earth electrode which receives the potential interference.

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Electrochemical Determination of As(III) at Nanoporous Gold Electrodes with Controlled Surface Area

  • Seo, Min Ji;Kastro, Kanido Camerun;Kim, Jongwon
    • Journal of the Korean Chemical Society
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    • v.63 no.1
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    • pp.45-50
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    • 2019
  • Because arsenic (As) is a chemical substance toxic to humans, there have been extensive investigations on the development of As detection methods. In this study, the electrochemical determination of As on nanoporous gold (NPG) electrodes was investigated using anodic stripping voltammetry. The electrochemical surface area of the NPG electrodes was controlled by changing the reaction times during the anodization of Au for NPG preparation, and its effect on the electrochemical behavior during As detection was examined. The detection efficiency of the NPG electrodes improved as the roughness factor of the NPG electrodes increased up to around 100. A further increase in the surface area of the NPG electrodes resulted in a decrease of the detection efficiency due to high background current levels. The most efficient As detection efficiency was obtained on the NPG electrodes prepared with an anodization time of 50 s. The effects of the detection parameters and of the Cu interference in As detection were investigated and the NPG electrode was compared to flat Au electrodes.

Study on Mechanism and Electro-Optical Characteristics of Liquid Crystal Alignment Employing ZnO:Al Electrode

  • Kim, Mi-Jung;Oh, Byeong-Yun;Kim, Byoung-Yong;Kang, Dong-Hun;Park, Hong-Gyu;Lee, Kang-Min;Moon, Hyun-Chan;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.433-433
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    • 2007
  • In this paper, we investigated the feasibility of applying ZnO:Al films to display devices as transparent electrodes, and reported the electro-optical (EO) characteristics of VA cells using ZnO:Al electrodes and compared them with those of VA cells using ITO electrodes. The experiment results show that a uniform vertical LC alignment and a large pretilt angle were achieved. Also, the good voltage-transmittance curve, response time, and capacitance-voltage characteristics were observed for the rubbing aligned VA-LCD using ZnO:Al electrodes m comparison with ITO electrodes. In other words, the vertical alignment mode based on the ZnO:Al electrodes showed appropriate electro-optical characteristics and high transparency in comparison with that based on the ITO electrodes. These results indicated that the transparent ZnO:Al electrodes of the liquid crystal displays could substitute the ITO electrodes.

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Characterization of Seawater Electrolysis of Insoluble Catalytic Electrodes Fabricated by RF Magnetron Sputtering (RF Magnetron Sputtering을 이용하여 제작한 불용성 촉매전극의 해수전기분해 특성)

  • Lee, Hyun-Seok;Kim, Sei-Ki;Seok, Hye-Won;Kim, Jin-Ho;Choi, Hun-Jin;Jung, Ha-Ik
    • Korean Journal of Materials Research
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    • v.22 no.2
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    • pp.86-90
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    • 2012
  • Insoluble catalytic electrodes were fabricated by RF magnetron sputtering of Pt on Ti substrates and the performance of seawater electrolysis was compared in these electrodes to that is DSA electrodes. The Pt-sputtered insoluble catalytic electrodes were nearly 150 nm-thick with a roughness of $0.18{\mu}m$, which is 1/660 and 1/12 of these values for the DSA (dimensionally stable anodes) electrodes. The seawater electrolysis performance levels were determined through measurements of the NaOCl concentration, which was the main reaction product after electrolysis using artificial seawater. The NaOCl concentration after 2 h of electrolysis with artificial seawater, which has 3.5% NaCl normally, at current densities of 50, 80 and 140 mA/$cm^2$ were 0.76%, 1.06%, and 2.03%, respectively. A higher current density applied through the electrodes led to higher electrolysis efficiency. The efficiency reached nearly 58% in the Pt-sputtered samples after 2 h of electrolysis. The reaction efficiency of DSA showed higher values than that of the Pt-sputtered insoluble catalytic electrodes. One plausible reason for this is the higher specific surface area of the DSA electrodes; the surface cracks of the DSAs resulted in a higher specific surface area and higher reaction sites. Upon the electrolysis process, some Mg- and Ca-hydroxides, which were minor components in the artificial seawater, were deposited onto the surface of the electrodes, resulting in an increase in the electrical resistances of the electrodes. However, the extent of the increase ranged from 4% to 7% within an electrolysis time of 720 h.

Aligning Capabilities for Vatical-Alignment (VA) Liquid Crystal Display using AZO Film

  • Oh, Yong-Cheul
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.12
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    • pp.1144-1148
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    • 2006
  • We have investigated liquid crystal (LC) aligning capabilities and electro-optical (EO) characteristics of transparent electrodes as Al-doped ZnO (AZO) substituting indium tin oxide (ITO). The experiment results show that a uniform vertical LC alignment on AZO electrodes based on a rubbed polyimide (PI) surface were achieved. A high pretilt angle of about $88^{\circ}$ was obtained. EO performances of the VA cell on rubbed PI surfaces with AZO electrodes are almost the same as that of the VA cell with ITO electrodes. These results appeared that AZO electrodes as transparent electrodes of LCDs could substitute ITO electrodes.

Effects of the Thickness and Dopant on the Photoelectro- chemical Conversion in the Polycrystalline $TiO_2$ Electrodes (광전기 화학변환에 미치는 $TiO_2$ 전극의 두께와 첨가제의 영향)

  • 윤기현;강동헌
    • Journal of the Korean Ceramic Society
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    • v.21 no.3
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    • pp.266-270
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    • 1984
  • The photoelectrochemical properties of the reduced $TiO_2$ceramic electrodes are investigated varying the thickness of the electrodes and the amounts of $Sb_2O_3$ as dopant. As the thickness of the undoped. $TiO_2$ceramic electrode increases the photocurrent tends to decrease. However for the R-F sputtered $TiO_2$ thin film electrodes the photocurrent tends to increase to about 1$\mu\textrm{m}$ thick and then decreases with increasing thickness. For the $TiO_2$ ceramic electrodes doped with $Sb_2O_3$ the photocurrent decreases with inreasing the amounts of dopant and in the case of rapid cooling in air without reduction treatment the photocurrent shows lower value. Also visible light excitation is observed at 500~550(nm) wavelength for the $TiO_2$ ceramic electrodes doped with $Sb_2O_3$comparing wtih the $TiO_2$ ceramic electrodes (~420nm)

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A STUDY ON CHARACTERISTICS OF Ac ELECTRO-OSMOTIC FLOWS IN THE MICROCHANNEL WITH COPLANAR ELECTRODES (마이크로 채널 내 동일 평면 전극에 교류인가로 인한 유동특성 연구)

  • Heo, H.S.;Kang, S.M.;Suh, Y.K.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.163-166
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    • 2006
  • This paper presents numerical results of fluid flows and mixing in a microfluidic device for AC electroosmotic flow (AC-EOF) with coplanar electrodes on top and bottom walls. Differently from previous EOF a channel which attached a couple of coplanar electrodes can be utilized to mix a target liquid with a reagent. In this study we propose a method of controlling fluid flows and mixing enhancement. To obtain the flow and mixing characteristics, numerical computations are performed by using a commercial code, CFX10. It was found that the flow near the coplanar electrodes is of 3-D complex flows and vortices between the other electrodes, and as a consequence the AC-electroosmotic flow on the electrodes plays an important role in mixing the liquid.

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Organic Photovoltaic Devices on $HNO_3$-Treated Multilayer Graphene Electrodes

  • Jung, Yong Un;Na, Seok-In;Kim, Han-Ki;Kang, Seong Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.235-235
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    • 2013
  • We reported on the characteristics of organic solar cells (OSCs) fabricated on $HNO_3$-treated multilayer graphene (MLG) transparent electrodes. MLG electrodes were prepared using a chemical vapor deposition and a multi-transfer process. Compared to organic solar cells (OSCs) on the ITO electrodes had a fill factor of 65.97%, and a power conversion efficiency (PCE) of 3.364%, OSCs on the MLG (three-layer graphene) electrodes with sheet resistance of $274{\pm}1{\Omega}$/square and transparency of 92.1% had a fill factor of 43.46%, and a power conversion efficiency (PCE) of 2.019%. However, OSCs on the HNO3-treated MLG electrodes with lower sheet resistance of $119{\pm}1{\Omega}$/square had a fill factor of 57.54%, and a PCE of 2.861%. The results would provide a promising method to improve the performance of large-area OSCs based on MLG electrodes.

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