• Title, Summary, Keyword: Electrode

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Influence on Relative Electrode Wear by Material and Size of Electrode (전극의 재료와 크기가 전극소모에 미치는 영향)

  • 전언찬
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.5
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    • pp.671-677
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    • 1999
  • This study has been performed to investigate REW(relative electrode wear) in condition of vari-ous pulse-on duration using the copper and graphite electrode with change of the electrode size on the heat treated STD11 which is extensively used for metallic molding steel with the EDM. The results obtained are as follows; a) Graphite has much benefits than copper electrode when rapid machining is done without electrode wear, b) Neative REW result from the electrode that is very liable attach to decomposition carbide c)Increasing of machining time cause to increase wear length of the copper electrode and decrease wear length of the graphite electorde d)The more pulse-on duration copper electrode has the less REW. e) The edge portion of the electorde wears remarkably at the beginning of machining,.

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Micro Electrochemical Machining Using a Multi-Function Electrode (복합기능 전극을 이용한 미세 전해가공)

  • Shin, Hong-Shik;Kim, Bo-Hyun;Kim, Gyu-Man;Chung, Do-Kwan;Chu, Chong-Nam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.5
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    • pp.496-501
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    • 2009
  • In micro electrochemical machining(micro-ECM), it is important to measure and control the potential of a tool electrode and a workpiece electrode because electrochemical reaction rate depends on the potential of the electrodes. When the electrode potential was measured against a reference electrode, the error of measured electrode potential could be minimized by proper tool electrode design. In this paper, multi-function electrodes consisting of a tool electrode and a reference electrode was fabricated by micro fabrication techniques. The machining conditions in micro-ECM using multi-function electrodes, such as pulse voltage parameters and electrode potential, were investigated.

Effect of Electrochemical Redox Reaction on Biochemical Ammonium Oxidation and Chemical Nitrite Oxidation

  • Jeon, Bo-Young;Seo, Ha-Na;Kang, Seung-Won;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.485-493
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    • 2010
  • A modified graphite felt electrode with neutral red (NR-electrode) was shown to catalyze the chemical oxidation of nitrite to nitrate under aerobic conditions. The electrochemically oxidized NR-electrode (EO-NR-electrode) and reduced NR-electrode (ER-NR-electrode) catalyzed the oxidation of $1,094{\pm}39$ mg/l and $382{\pm}45$ mg/l of nitrite, respectively, for 24 h. The electrically uncharged NR-electrode (EU-NR-electrode) catalyzed the oxidation of $345{\pm}47$ mg/l of nitrite for 24 h. The aerobic bacterial community immobilized in the EO-NR-electrode did not oxidize ammonium to nitrite; however, the aerobic bacterial community immobilized in the ER-NR-electrode bioelectrochemically oxidized $1,412{\pm}39$ mg/l of ammonium for 48 h. Meanwhile, the aerobic bacterial community immobilized on the EU-NR-electrode biochemically oxidized $449{\pm}22$ mg/l of ammonium for 48 h. In the continuous culture system, the aerobic bacterial community immobilized on the ER-NR-electrode bioelectrochemically oxidized a minimal $1,337{\pm}38$ mg/l to a maximal $1,480{\pm}38$ mg/l of ammonium to nitrate, and the community immobilized on the EU-NR-electrode biochemically oxidized a minimal $327{\pm}23$ mg/l to a maximal $412{\pm}26$ mg/l of ammonium to nitrate every two days. The bacterial communities cultivated in the ER-NR-electrode and EU-NR-electrode in the continuous culture system were analyzed by TGGE on the $20^{th}$ and $50^{th}$ days of incubation. Some ammonium-oxidizing bacteria were enriched on the ER-NR-electrode, but not on the EU-NR-electrode.

Half spherical electrode machining in micro EDM (미세 방전 가공을 이용한 반구형 전극 제작)

  • 김기현;주종남
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1080-1084
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    • 2001
  • In manufacturing a micro die with half spherical cavity by MEDM, it is necessary to prepare an electrode with the same shape. This paper suggests a simple method to manufacture a half spherical electrode based on tool wear. The tool wears more rapidly at the edge of a cylindrical electrode. In order to make a half spherical micro electrode, cylindrical electrode was fed into the workpiece by the distance of its radius. The d/R(depth/Radius) value varied with respect to capacitance and electrode diameter. The smaller the size of electrode was, the closer the electrode tip geometry approached to a half sphere.

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The Effects of Electric Field Variation by The Third Electrode on Water Electrophysicochemical Characteristics (제3전극에 의한 전계변화가 수중 전기물리화학적 특성에 미치는 영향)

  • Kim, Jin-Gyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.9
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    • pp.136-141
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    • 2010
  • In this paper, after the third electrode type oxidant generator which could format non-uniform electric field in water had been manufactured and installed, by direct electrolysis, the effects of the hydrogen potential and oxidation reduction potential characteristics attendant upon electric field change on a higher concentration oxidant generation characteristics were investigated. Consequently, as the third electrode was installed in the middle of two slit electrodes and the polarity of applied power was changed, it was observed that the third electrode system with the positive electrode can generate a higher concentration oxidant, hydrogen potential and oxidation reduction potential as compared with that of the negative electrode. It is because the positive electrode was bombarded mostly energetic electrons and the negative electrode was bombarded mainly by less energetic positive ions.

Effect of Various ${\prod}$Type Metal Electrode in the AC PDP (AC PDP에서 다양한 형태의 ${\prod}$형 금속방전유지 전극의 효과)

  • Yoo, Su-Bok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.3
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    • pp.586-590
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    • 2009
  • Recently, an AC Plasma Display Panels(PDP) with the metal sustain electrodes have been reported in order to reduce the manufacturing cost of the AC PDP. However, the luminance and efficacy of the AC PDP with metal electrodes are worse than those of the AC PDP with ITO electrodes. In this paper, various ${\prod}$type metal electrodes are suggested, in order to improve the electro-optical characteristics of the AC PDP with metal electrodes. Among the suggested electrode types, luminance of Hump electrode structure is higher by $40\;cd/m^2$ and discharge current of Asymmetry electrode structure is lower by 5% than those of Pi electrode structure, respectively. Moreover, $T_1$ of Hump electrode structure is reduced to 10% as compared with Pi electrode structure in address period for ADS driving scheme. In all aspects, the characteristics of Hump and Asymmetry electrode structure show best performance.

A Study on the Characteristics of Electrode Fabrication for Micro Hole-making (미세 구멍가공을 위한 전극성형 가공특성에 관한 연구)

  • Lee, Ju-Kyoung;Lee, Jong-Hang;Park, Cheol-Woo;Cho, Woong-Sick
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.11
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    • pp.1053-1058
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    • 2007
  • Micro-EDM technology (or the manufacture of miniature parts is used to make a micro hole. Two electrode shaping methods, mechanical electrode grinding and WEDG technique, have been studied. In this study, an electrode shaping method by using previously machined hole is introduced in order to obtain an optimal hole-making condition. Key factors such as applied voltage, capacitance, feedrate, and hole-dimension have an influence on the fabricating error of electrode shaping, which are taper ratio of a hole, electrode form accuracy, and electrode surface. Therefore, we try to investigate the optimal fabricating of electrode shaping from various experiments. Results from experiments, it was able to minimize the electrode fabricating error as voltage increases, and also applied feedrate and capacitance decreases.

Effect of a Cylindrical Third Electrode of a Point-Plate Type Plasma Reactor on Corona Discharge and Ozone Generation Characteristics (침대 평판형 플라즈마장치의 코로나 방전 및 오존발생 특성에 미치는 원통형 3전극의 영향)

  • Moon, Jae-Duk;Jung, Ho-Jun;Jung, Jae-Seung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.5
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    • pp.933-937
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    • 2007
  • A point plate type nonthermal plasma reactor, with a grounded cylindrical third electrode which closely- encompasses the needle point, have been investigated with an emphasis on the role of the third electrode. It was found that the point plate airgap, with the grounded third electrode, had a switching characteristic on its I V characteristics for negative and positive discharges, which is very different from that of a conventional point plate airgap without a third electrode. The corona discharge and ozone generation characteristics of the plasma reactor with the grounded cylindrical third electrode, such as the corona onset voltage. the breakdown voltage. the corona current. and the amount of output ozone, were influenced significantly by the height of the third electrode. and these characteristics can be controlled by adjusting the height of the third electrode.

Preparation and Characterization of a Surface Renewable Solid State Hg/HgO Reference Electrode Utilizing Gold Amalgam

  • Kim, Won;Park, Jong-Man
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.439-442
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    • 2007
  • A solid state Hg(Au)/HgO reference electrode was prepared utilizing gold amalgam solid particles. Solid fine powder of the gold amalgam was prepared by chemical reduction of Au(III) with NaBH4 followed by reduction of Hg(II) in the presence of gold fine particles. The solid content in the suspension of the gold amalgam particles and fine mercury oxide particles in DMF containing PVC was precipitated by the addition of a large amount of water to give solid Hg(Au)/HgO/PVC mixture. After drying, the mixture was pressure-molded to a physically stable Hg(Au)/HgO composite reference electrode material. The electrochemical characteristics of the electrode as a reference electrode were very similar to an ordinary Hg/HgO reference electrode. The electrode material can be molded and fabricated in any desired shape and size. The surface can be renewed by a simple polishing process whenever contaminated or deactivated. The applicability of the electrode in the electrochemical detection of carbohydrates after anion exchange separation was evaluated.

A New Measurement Method of Dielectric Constants Applied the Principles of Cross Capacitance (Cross Capacitance 원리를 작용한 새로운 유전상수 측정방법 제안)

  • Kim, Han-Jun;Lee, Rae-Duk;Kang, Jeon-Hong;Yu, Kwang-Min;Han, Sang-Ok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.1084-1087
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    • 2002
  • The guard-ring type 3-terminal parallel plate electrodes proposed by ASTM D 150-81 and IEC 250 have been widely used for measurement of dielectric constants of solid dielectrics. However the method using this electrodes causes many uncertainty associated with the measurement errors of the diameter of the guarded electrode. the gap between guarded and guard-ring electrode. the distance of two active electrodes(the thickness of specimen), the roughness and contamination of surface of electrode and specimen. close adherence grade of electrode and specimen. In this paper. a new electrode system of cross capacitance type based on Thompson-Lampard theorem is designed and is employed for the measurement of dielectric constant. The results of simulation of guard-ring electrode and cross capacitance electrode using FEM program show that distance measurement between two electrodes in guard-ring electrode produces large uncertainty. on the other hand this effect in cross capacitance electrode is negligible. Furthermore. the air gap effects in the cross capacitance electrode is 5.6 times less sensitive than that in guard-ring electrode by assuming air gap of $50{\mu}m$.

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