• Title/Summary/Keyword: Cathode electrode

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Improvement of Cathode Reaction of a Mediatorless Microbial Fuel Cell

  • Pham, The-Hai;Jang, Jae-Kyung;Chang, In-Seop;Kim, Byung-Hong
    • Journal of Microbiology and Biotechnology
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    • v.14 no.2
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    • pp.324-329
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    • 2004
  • Oxygen diffuses through the cation-specific membrane, reducing the coulomb yield of the fuel cell. In the present study, attempts were made to enhance current generation from the fuel cell by lowering the oxygen diffusion, including the uses of ferricyanide as a cathode mediator and of a platinum-coated graphite electrode. Ferricyanide did not act as a mediator as expected, but as an oxidant in the cathode compartment of the microbial fuel cell. The microbial fuel cell with platinum-coated graphite cathode generated a maximum current 3-4 times higher than the control fuel cell with graphite cathode, and the critical oxygen concentration of the former was 2.0 mg $1^{-1}$, whilst that of the latter was 6.6 mg $1^{-1}$. Based on these results, it was concluded that inexpensive electrodes are adequate for the construction of an economically feasible microbial fuel cell with better performance as a novel wastewater treatment process.

Study on Plasma Treatment of electrode for CCFL (CCFL 전극의 플라즈마 처리에 관한 연구)

  • Park, Hyun-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.3
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    • pp.1308-1312
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    • 2011
  • CCFL(Cold Cathode Fluorescent Lamp)for BLU of LCD and special lighting has been widely utilized. The removal of oxide film formed on electrode of CCFL in manufacturing process is required. In this pape Plasma treatment was carried out to remove the oxide film. To ensure the optimum process, the analysis of sheet resistance, XRD, AFM and solder test was conducted. A minimum sheet resistance and the maximum percentage of the solder coverage ratio were measured in optimal process conditions such as plasma power consumption 600W and processing time of 70 seconds. As the plasma treatment is confirmed to be due to removal of copper oxide, this process is expected to be used as a treatment of electrode for CCFL.

Fabrication of EDM Electrodes by Localized Electrochemical Deposition

  • Habib, Mohammad Ahsan;Gan, Sze Wei;Lim, Han-Seok;Rahman, Mustafizur
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.2
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    • pp.75-80
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    • 2008
  • The fabrication of complex three-dimensional electrodes for micro electrical discharge machining (micro-EDM) is an important issue in the field of micromachining Localized electrochemical deposition (LECD) is a simple and inexpensive technique for fabricating micro-EDM electrodes. This study presents a new process for manufacturing electrodes with complex cross-sections using masks of different shapes, In this process, a non-conductive mask is placed between an anode and cathode that are immersed in a plating solution of acidified copper sulfate. The LECD is achieved by applying a pulsed voltage between the anode and cathode, which are separated by a small distance. In this setup, the cathode is placed above the anode and the mask, so that the deposited electrode can be used directly for EDM without changing the tool orientation. We found that the microstructure of the deposited electrode is influenced by the concentration of the plating solution and organic additives. Moreover, the values of the voltage, frequency, and duty cycle of the pulsed input have significant effects on the microstructure of the fabricated electrode. Finally, the optimum values of the voltage, frequency, and duty cycle were determined for the most effective fabrication of complex-shaped electrodes.

The Back-Bias Effect on the Breakdown Voltage of SOI Device (Back-bias 효과에 의한 SOI소자의 항복전압 특성.)

  • Kim, Han-Soo;Choi, Yearn-Ik;Han, Min-Koo
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.178-180
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    • 1993
  • The back bias effect on the breakdown voltage of SOI $p^+$-n diode is investigated. The breakdown voltage of the SOI $p^+$-n diode increases with the applied back bias. When the cathode electrode is used as a back bias, it is necessary to put the dielectric material between the Si-substrate and the bottom cathode electrode.

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Study on Composite Cathode for YSZ Electrolyte in SOFC (SOFC의 YSZ 전해질에 대한 혼합공기극 연구)

  • Lee, Chang-Bo;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.1 s.256
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    • pp.62-67
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    • 2007
  • Optimization of cathode properties for intermediate temperature-operating SOFC (IT-SOFC) is carried out by using composite-type electrode structure in this study. Composite cathode may lower cathode overpotential by enhancing mixed ionic-electronic conductivity. In this study, particularly, LSM/YSZ, LSF/YSZ, LSCF/CGO, and PSC/CGO were selected as cathode materials. LSM/YSZ composite cathode showed the best performance of about 0.9${\Omega}cm^2$ at $700^{\circ}C$. It is inferred that the resistance is mainly affected by the reactivity between cathode and electrolyte which can cause the formation of resistive phases. Area specific resistance (ASR) characteristics were not changed significantly with decreasing sintering temperature of cathode, because reaction sites were increased even with worse adhesion of cathode on electrolytes.

Decolorization of a Rhodamine B Using Ru-graphite Electrode (Ru-흑연 전극을 이용한 Rhodamine B의 색 제거)

  • Park, Young-Seek
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.547-553
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    • 2008
  • For the RhB removal from the wastewater, electrochemical method was adapted to this study. Three dimensionally stable anode (Pt, Ir and Ru) and graphite and Ru cathode were used. In order to identify decolorization, the effects of electrode, current density, electrolyte and air flow rate were investigated. The effects of electrode material, current, electrolyte concentration and air flow rate were investigated on the decolorization of RhB. Electro-Fenton's reaction was evaluated by added $Fe^{2+}$ and $H_2O_2$ generated by the graphite cathode. Performance for RhB decolorization of the four electrode systems lay in: Ru-graphite > Ru-Ru > Ir-graphite > Pt-graphite. A complete color removal was obtained for RhB (30 mg/L) at the end of 30 min of electrolysis under optimum operations of 2 g/L NaCl concentration and 2 A current. $Fe^{2+}$ addition increased initial reaction and decreased final RhB concentration. However the effect was not high.

A Study on Uniformity of Current Distribution in Hull Cell (Hull Cell에서 전류분포의 균일화에 관한 연구)

  • 여운관
    • Journal of the Korean institute of surface engineering
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    • v.27 no.6
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    • pp.340-346
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    • 1994
  • The method of uniforming current distribution in Hull cell are studied by using auxiliary anode, current shield bipolar electrode, and combinings bipolar electrode with current shield in order to find a way of uni-form deposition. The current density distributions are measured by each ammeter of the same inner resistance connected to divided cathode pannel respectively. The current density distributions of cathode electrode divided into five sections with 5mm width have a tendency of linear inclination, and that of twenty sections have a tendency of smoother curve than the curve of original Hull cell pannel. Their results showed lower value on the high current density portion and higher value on the low portion than that original Hull cell pannel. The current distribution in Hull cell is able to unify by using auxiliary anode, or combining bipo-lar electrode with current shield, but not efficient in using one of both individually.

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A Study on the Electrode formation of an Organic EL Devices using the RF Plasma (RF 플라즈마를 이용한 유기 EL 소자의 전극형성에 관한 연구)

  • 이은학
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.2
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    • pp.228-235
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    • 2004
  • In this thesis, it is designed efficient electrode formation on the organic luminescent device. ITO electrode is treated with $O_2$plasma. In order to inject hole efficiently, there is proposed the shape of anode that inserted plasma polymerized films as buffer layer between anode and organic layer using thiophene monomer. It is realized efficiently electron injection to aluminum due to introduce the quantum well in cathode. In the case of device inserted the buffer layer by using the plasma poiymerization after $O_2$plasma processing for ITO transparent electrode, since it forms the stable interface and reduce the moving speed of hole, the recombination of hole and electronic ate made in the omitting layer. Compared with the devices without buffer layer, the turn-on voltage was lowered by 1.0(V) doc to the introduction of buffer layer Since the quantum well structure is formed in front of cathode to optimize the tunneling effect, there is improved the power efficiency more than two times.

Simultaneous measurement of oxygen permeability by using of multi-functional oxygen electrode (다기능 산소전극에 의한 산소투과특성 동시측정)

  • 이동희;정진휘;유형풍;김태진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.532-535
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    • 2000
  • We have fabricated a sensor system for on-line monitoring the oxygen permeability and diffusivity of six different polymer films using the miniaturized 6 cathode(Ag)-single anode(Ag/AgCl) type hexagonal oxygen electrode. This system consists of multiple input front-end electronics, signal conditioning circuit using the embedded microcontroller 80C196KC, PC interface circuit and PC with the OS for microcontroller and the operating program for this system. The digital low-[ass filter was programmed and the simulated filter characteristics were enough to eliminate the noise from sensor signal. According to the experimental results, the linearity coefficients of the output voltage to oxygen partial pressure for each sensor electrode of six cathode type oxygen sensor are 0.998, 0.997, 0.998, 0.997, 0.997, 0.997 respectively, and the response times are all within 4 minutes.

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Laterally Encapsulated Cathode Structure for DC Plasma Display Panels

  • Esfahani, M.Mokhlespour;Mohajerzadeh, S.;Goodarzi, A.;Rouhi, N.;Tarighat, R.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1233-1236
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    • 2005
  • We report a novel approach for encapsulating of cathode electrodes in DC plasma pixels. Anode and cathode electrodes are laterally placed on a single substrate. The encapsulated electrode minimizes the sputtering of the cathode without significantly altering the turn-on voltage-pressure characteristics. An abnormal glow in current-voltage characteristics is also observed.

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