• Title/Summary/Keyword: Electrode Size

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A Study on the Saturation of Grain Size in Pb(Zr, Ti)$O_3$ Thin Films (Pb(Zr, Ti)$O_3$ 박막에서 결정립 크기 포화 현상에 관한 연구)

  • 이장식;김찬수;주승기
    • Journal of the Korean Ceramic Society
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    • v.37 no.6
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    • pp.530-536
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    • 2000
  • During the grain growth of the PZT thin films by selective nucleation method using PZT seed, it was found that the grain size was saturated with the annealing temperature. The saturation of grain size was analyzed by the interfacial energy which appeared during the crystallization. The factors affecting the saturation of grain size were found to be the interfacial energy between perovskite phase and pyrochlore phase, and PZT thin film and the bottom Pt electrode. When the ion damage was introduced to the grain-size saturated PZT thin films, further lateral growth was observed. Pt bottom electrode thickness was changed to control the interfacial energy between the PZT thin film and the Pt bottom electrode. When Pt thickness was increased, the grain size was also increased, because the lattice parameter of Pt films was increased with the thickness of the Pt films. The incubation time of nucleation was increased with the amount of the ion damage on the Pt films.

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Screen-printed carbonaceous matrrials for photocapacitor electrode (스크린 프린터에 의한 광캐패시터용 카본 전극 제작)

  • Choi, Woo-Jin;Kwak, Dong-Joo;Sung, Youl-Moon;Ha, Soon-Ho
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.411-414
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    • 2009
  • Photo-capacitor electrodes are attracting great attention because of their high capacitance and potential applications in electronic devices. Carbon capacitor, active carbon capacitor and its combination will be fabricated using simple sandwich capacitor electrode method as carbonaceous material on each type of capacitor electrodes with 20 ${\times}$ 15 mm cell size. Carbon/active carbon cell was fabricated using sol-gel process with 120oC dry temperature in l hour and using sintering process with 500oC in 2 hour. The effect of sintering temperature on carbon properties was also investigated with X-ray diffraction technique to get the best sintering temperature. The detail of fabrication process will be explained. Elemental composition in electrode material can be measured using quantitative spectroscopic as and a cyclic voltammetric technique was used to study the combined effects of electrode material and effect of annealing temperature and also time on the capacitance of thermally treated in capacitor electrode. In this work, characterization impedance technique is used to measurement of capacitance and giving complementary results. Active carbon as carbonaceous material has a better capacitance in charge/discharge process with mean thickness $32{\mu}m$ and with particle size $1{\mu}m$ to $4.5{\mu}m$ in 20 ${\times}$ 15 mm sample size of capacitor electrode.

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Effects of Tungsten Particle Size and Nickel Addition in DC arc Resistance of Cu-W Electrode

  • Kim, Bong-Seo;Jeong, Hyun-Uk;Lee, Hee-Woong
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.2
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    • pp.68-72
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    • 2004
  • The performance of copper-tungsten for electrodes used in an ultra high voltage interruption system was evaluated by means of an interruption test, which requires a large-scale apparatus and high cost. In this study, prior to the interruption test, the characteristics of a Cu-W electrode were estimated through the DC arc test, which is a simple, low cost procedure. The DC arc characteristics of a 20wt%Cu-80wt%W electrode were investigated with the change of tungsten powder size distribution and the addition of nickel. In specimens containing a high volume fraction of large sized tungsten particles, the relative density and hardness of sintered Cu-W electrodes increased while the electrical conductivity and the DC arc resistance decreased. Furthermore, the relative density became enhanced with the increase of the amount of nickel while the hardness and electrical conductivity diminished and the DC arc resistance worsened.

A Basic Study on Developing an Electrocharged Scrubber (전기하전식 세정집진장치 개발에 관한 기초 연구)

  • 김종호
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.1
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    • pp.33-39
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    • 1999
  • This study has been performed to develop an efficient electrocharged scrubber. To improve collection efficiency of the scrubber, electric-charger was installed at the forefront of the packed crossflow scrubbers, and an experiment of changing discharge electrode shape and fluctuating electric field strength was undertaken. After using a light-oil boiler for generation of particles in the about 80% weight of submicron size particles was exhausted. Collection characteristics of the electrocharged scrubber were similar to those of two-stage electrostatic precipitator. In this study the collection efficiency of submicron size particles has been much improved, compared with the previous ones. In an experiment of changing discharge electrode and electric field strength, a needle-spike shape wire electrode showed a higher collection efficiency than round shape wire. The collection efficiency becomes increased with an increase of electric field strength.

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Optimization of Current Distributions of Electroplating on Patterned Substrates with the Auxiliary Electrode (보조 전극을 이용한 패턴된 전극에서의 전류 밀도 분포의 최적화)

  • 김남석;모화동;강탁
    • Journal of the Korean institute of surface engineering
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    • v.28 no.3
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    • pp.164-173
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    • 1995
  • Based on the potential-theory model for secondary current distribution, we could predict the thickness distributions of electroplating on patterned substrates with the different size of the auxiliary electrode. The substrates contain lithographic patterns at each sample geometry. Each sample geometry had different current distribution at the same condition except the size of the auxiliary electrodes. The size effect of the auxiliary electrode on thickness distribution of electrodeposition on patterned electrode was investigated in a series of experiments. Copper was galvanostatically deposited from an acid-sulfate solution in a reciprocating paddle cell. The thickness distributions of the workpiece scale measured by profilometry across the specimen were in good agreement with the current distribution predicted by boundary element method.

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The Use of Artificial Neural Networks in the Monitoring of Spot Weld Quality (인공신경회로망을 이용한 저항 점용접의 품질감시)

  • 임태균;조형석;장희석
    • Journal of Welding and Joining
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    • v.11 no.2
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    • pp.27-41
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    • 1993
  • The estimation of nugget sizes was attempted by utilizing the artificial neural networks method. Artificial neural networks is a highly simplified model of the biological nervous system. Artificial neural networks is composed of a large number of elemental processors connected like biological neurons. Although the elemental processors have only simple computation functions, because they are connected massively, they can describe any complex functional relationship between an input-output pair in an autonomous manner. The electrode head movement signal, which is a good indicator of corresponding nugget size was determined by measuring the each test specimen. The sampled electrode movement data and the corresponding nugget sizes were fed into the artificial neural networks as input-output pairs to train the networks. In the training phase for the networks, the artificial neural networks constructs a fuctional relationship between the input-output pairs autonomusly by adjusting the set of weights. In the production(estimation) phase when new inputs are sampled and presented, the artificial neural networks produces appropriate outputs(the estimates of the nugget size) based upon the transfer characteristics learned during the training mode. Experimental verification of the proposed estimation method using artificial neural networks was done by actual destructive testing of welds. The predicted result by the artifficial neural networks were found to be in a good agreement with the actual nugget size. The results are quite promising in that the real-time estimation of the invisible nugget size can be achieved by analyzing the process variable without any conventional destructive testing of welds.

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Synthesis of Electrode Catalyst for Polymer Electrolyte Membrane Fuel Cells Using Colloidal Method (콜로이드법을 이용한 고분자전해질 연료전지용 백금전극 촉매의 제조)

  • Park, Jin-Nam
    • Clean Technology
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    • v.19 no.1
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    • pp.59-64
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    • 2013
  • Pt/carbon Electrode catalysts for PEMFC were synthesized using colloidal method. PSA (platinum sulfite acid) was used as a Pt precursor and CPA (chloroplatinic acid) was also used to replace relatively expensive PSA. Electrode catalysts prepared using PSA showed Pt particle size less than 3.5 nm and Pt yield higher than 90% in 10~40 wt% Pt loading. Electrode catalysts prepared using CPA also showed Pt particle size less than 4.4 nm and Pt yield higher than 80% in 10~40 wt% Pt loading. The MEA (membrane electrode assembly) using 20 wt% Pt/VXC72 showed equivalent I-V curve comparing with commercial electrode catalyst in single cell test.

Implementation of Wireless ECG Measurement System Attaching in Chair for Ubiquitous Health Care Environment (유비쿼터스 헬스 케어 적용을 위한 의자 부착형 무선 심전도 측정 시스템 구현)

  • Ye, Soo-Young;Baik, Seong-Wan;Kim, Jee-Chul;Jeon, Gye-Rok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.8
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    • pp.776-781
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    • 2008
  • In this study, ubiquitous health care system attaching in chair to monitor ECG for health care was developed at the unconsciousness state. The system conveniently and simple measured ECG at non-consciousness. We measured the contact impedance to skin-electrode of metal mesh electrodes of the system. Contact impedance enable the electrode to use for ECG measurement. The results are that the impedance of the metal mesh electrodes according to sizes is low when the size is 4$cm^2$. As the result, when the size of the metal mesh electrode is 4$cm^2$, the electrode is fit for ECG measurement. We can acquired by positing the arm on the metal mesh electrode. The ECG signal was detected using a high-input-impedance bio-amplifier, and then passed filter circuitry. The measured signal transmitted to a PC through the bluetooth wireless communication and monitored. Data of the non-constrained ECG system attaching in chair is noise-data when comparing metal mesh electrode with the Ag/Agcl electrode but the data is significant to monitor ECG for check the body state.

Distortion of the Bottom Surface in Micro Cavity Machining Using MEDM (미세 캐비티 방전 가공에서 바닥면 형상 왜곡)

  • 임종훈;류시형;제성욱;주종남
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.12
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    • pp.191-197
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    • 2003
  • As mechanical components are miniaturized, the demand on micro die and mold is increasing. Micro mechanical components usually have high hardness and good conductivity. So micro electrical discharge machining (MEDM) is an effective way to machine those components. In micro cavity fabrication using MEDM, it is observed that the bottom surface of cavity is distorted. Electric charges tend to be concentrated at the sharp edge. At the center of the bottom surface, debris can not be drawn off easily. These two phenomena make the bottom surface of the electrode and workpiece distort. As machining depth increases, the distorted shape of electrode approaches hemisphere. This process is affected by capacitance and the size of electrode. By using a smaller electrode than the desired cavity size and appropriate tool movement, bottom shape distortion can be prevented.

Distortion of the Bottom Surface in Micro Cavity Machining Using MEDM

  • Lim Jong Hoon;Je Sung Uk;Ryu Shi Hyoung;Chu Chong Nam
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.4
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    • pp.44-48
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    • 2005
  • As mechanical components are miniaturized, the demands on micro die/mold are increasing. Micro mechanical components usually have high hardness and good conductivity. Micro electrical discharge machining (MEDM) can thus be an effective way to machine those components. In micro cavity fabrication using MEDM, it is observed that the bottom surface of the cavity is distorted. Electric charges tend to be concentrated at the sharp edge, and debris cannot be drawn off easily at the center of the bottom surface. These two phenomena make the bottom surface of electrode and workpiece distort. As machining depth increases, the distorted shape of the electrode approaches hemisphere. This process is affected by both capacitance and the size of electrode. By using a smaller electrode than the desired cavity size and appropriate tool movement, bottom shape distortion can be prevented.