• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1358-1360
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• 1997

In this paper, the performance of Pt/$WO_3$ and Pt-$WO_3$ electrodes was studied for the direct methanol fuel cell. The characteristics of Pt/$WO_3$ electrode which was prepared by using electrodeposition method was tested with half-cell experiment. The characteristics of Pt-$WO_3$/C electrode which was Prepared by using freeze-drying method was tested with a single cell experiment. The performance of DMFC single cell which was prepared by Pt-$WO_3/C$ and Pt/C showed a current density of $32mA/cm^2$ at $110^{\circ}C$ & 0.3V(0.5mg Pt/$cm^2$).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.1
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• pp.30-34
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• 2010

$CoSb_3$-based skutterudite compounds are promising candidates as thermoelectric (TE) materials used in intermediate temperature region. In this study, sintering of $CoSb_3$ powder and joining of $CoSb_3$ to copper-molybdenum electrode have been simultaneously performed by spark plasma sintering technique. The Ti foil was used for preventing the diffusion of copper into $CoSb_3$ and the Cu : Mo = 3 : 7 Vol. ratio composition was selected by the consideration of thermal expansion coefficients. The insertion of Ti interlayer between Cu-Mo and $CoSb_3$ was effective to join $CoSb_3$ to Cu-Mo by forming an intermediate layer of $TiSb_2$ at the Ti-$CoSb_3$ boundary. However, the formation of TiSb and TiCoSb intermediate layers deteriorated the joining properties by the generation of cracks in the interface of intermediate layer/$CoSb_3$ and intermediate/intermediate layers.

• The Inventors News
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• no.23
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• pp.3-4
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• 2004

5월 `발명의 달` 맞아 다양한 발명행사 갖다 - `2004 대한민국 특허기술이전 박람회` 개최 - LG전자 & 일본 노스 양산기술 주고 특허기술 받는다 - `2004 여성용품 및 발명품 박람회` 열다 - `제10회 여성발명 우수사례 발표회` 성황리에 마치다 - `특허기술 사업화 성공사례 발표회` 통해 성공 사례 듣다 - 무해하면서도 더 효율적인 `전극` 발명

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.461-464
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• 2001

본 연구에서는 생체 임피던스를 이용하여 3채널 상지(upper arm) 운동 분석 시스템을 제작하였다. 각 채널은 상지의 외전(supination)과 내전(pronation), 팔꿈치(elbow)의 폄과 굽힘, 손목(wrist)의 평과 굽힘에 따른 각 관절의 임피던스 변화를 얻을 수 있도록 설계되었다. 상체 임피던스는 전극의 부착위치에 의존하므로 정밀한 감지를 위해 상지 운동에 대한 임피던스의 변화와 각도계(goniometer)의 각도 변화와의 상관관계를 통하여 상관 관계가 높고, 변화량이 가장 크고 다른 관절의 움직임에 따른 영향이 최소인 곳을 찾아 이를 최적의 전극 위치로 정하였다. 그리고, 선정된 최적의 전극 위치에서 임피던스 변화를 얻어 상지 운동을 분석해 보았다. 최적의 전극 위치에서 손목과 팔꿈치의 각도 변화와 임피던스 변화의 상관 계수는 각각 0.94, -0.97로 아주 높은 상관 관계를 보였다. 또한 이전의 다른 연구에서 임피던스 방법으로 구현해 본적이 없는 팔의 회전(rotation)도 분석이 가능하였다. 이 시스템은 피검자의 동작에 거의 제한을 주지 않고, 가벼우며, 장시간 측정이 용이할 뿐만 아니라 시스템 구성이 영상 분석기에 비해서 단순하다는 장점을 가지고 있다. 본 연구에서 제안하는 방법은 재활과 생체역학, 로봇의 원격 제어, 그리고 가상 현실에서의 동작 구현 등에 활용 할 수 있을 것으로 사료된다.

• Nuclear Engineering and Technology
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• v.26 no.3
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• pp.425-432
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• 1994

Voltammogram analysis of U(VI) reduction at electrochemically non-pretreated/pretreated Ti electrodes in nitric acid and hydrazine($N_2$H$_4$)/protonated hydrazine($N_2$H$_{5}$$^{＋}$) media was done in order to determine the effect of hydrazine form and Ti electrode condition on the reduction of U(VI) in nitric acid. In the case of non-pretreated Ti electrode, the reduction in nitric acid and hydrazine mono-hydrate solution needed a high activation overpotential and was affected by the ratio of hydrazine to nitric acid rather than by only absolute amount of hydrazine because of the decrease of solution conductivity and increase of iR drop, which were caused by proton consumption in the solution by the hydrazine. In the case of pretreated Ti electrode in nitric acid and protonated hydrazine solution, the reduction current peaks of U(VI) were clearer and higher enough to perform a kinetic analysis, compared with the case with the non-pretreated Ti electrode at the same potential, and the behavior was strongly affected by nitric acid. The presence of hydrazine was important in the reduction of U(VI) at the pretreated Ti electrode for preventing the reoxidation of U(IV), but the concentration of protonated hydrazine was not.t.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.7-11
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• 2011

In this paper, we proposed a simple and high-yield printing process for source and drain electrodes of organic thin film transistor (OTFT). The surface energy of PVP (poly 4-vinylphenol) gate dielectric was decreased from 56 $mJ/m^2$ to 45 $mJ/m^2$ by adding fluoride of 3000ppm into it. Meanwhile the surface energy of source and drain (S/D) electrodes area on the PVP was increased to 87 $mJ/m^2$ by treating the areas, which was patterned by photolithography, with oxygen plasma, maximizing the surface energy difference from the other areas. A conductive polymer, G-PEDOT:PSS, was deposited on the S/D electrode areas by brushing painting process. With such a simple process we could obtain a high yield of above 90 % in $16{\times}16$ arrays of OTFTs. The performance of OTFTs with the fluoride-added PVP was similar to that of OTFTs with the ordinary PVP without fluoride, generating the mobility of 0.1 $cm^2/V.sec$, which was sufficient enough to drive electrophoretic display (EPD) sheet. The EPD panel employing the OTFT-backpane successfully demonstrated to display some patterns on it.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.45-49
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• 2006

Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

• Investigative Magnetic Resonance Imaging
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• v.15 no.1
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• pp.11-21
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• 2011

Purpose : Localization using MRI is difficult due to susceptibility induced artifacts caused by metal electrodes. Here we took an advantage of the B0 pattern induced by the metal electrodes by using an oblique-view imaging method. Materials and Methods : Metal electrode models with various diameters and susceptibilities were simulated to understand the aspect of field distortion. We set localization criteria for a turbo spin-echo (TSE) sequence usingconventional ($90^{\circ}$ view) and $45^{\circ}$ oblique-view imaging method through simulation of images with various resolutions and validated the criteria usingphantom images acquired by a 3.0T clinical MRI system. For a gradient-refocused echo (GRE) sequence, which is relatively more sensitive to field inhomogeneity, we used phase images to find the center of electrode. Results : There was least field inhomogeneity along the $45^{\circ}$ line that penetrated the center of the electrode. Therefore, our criteria for the TSE sequence with $45^{\circ}$ oblique-view was coincided regardless of susceptibility. And with $45^{\circ}$ oblique-view angle images, pixel shifts were bidirectional so we can detect the location of electrodes even in low resolution. For the GRE sequence, the $45^{\circ}$ oblique-view anglemethod madethe lines where field polarity changes become coincident to the Cartesian grid so the localization of the center coordinates was more facilitated. Conclusion : We suggested the method for accurate localization of electrode using $45^{\circ}$ oblique-view angle imaging. It is expected to be a novelmethodto monitoring an electrophysiological brain study and brain neurosurgery.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.51-58
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• 1991

A new tubular poly(vinyl chloride) membrane type of nitrate selective electrode was prepared and its characteristics were evaluated. The response slope, detection limit, and response time (t$_{99}$) under the optimum membrane composition (5${\%}$ aliquat-NO$_3$ solution + 32${\%}$ poly(vinyl chloride) + 63${\%}$ dibutyl sebecate) of the electrode were 58.5 ${\pm}$ 0.1 mV/decade, 2.0 ${\times}$ 10$^{-5}$ M, and 25 seconds, respectively. The nitrite ion was determined by the continuous-automated method using the new electrode. 10$^{-2}$ M phosphate buffer solution (pH 7.6) was used as a recipient solution. And also hydrogen peroxide (0.3${\%}$) was added to the recipient as an oxidant. The linear response range and response range and response slope for the standard nitrite solution under the optimum condition of this electrode system were 8.0 ${\times}$ 10$^{-5}$ M ∼ 5.0 ${\times}$ 10$^{-2}$ M and 56.8 ${\pm}$ 0.2 mV/decade, respectively.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.720-725
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• 2012

Sodium hypochlorite is used worldwide as a water disinfectant and in bleaching agent. Sodium hypochlorite applied to water initially undergoes hydrolysis to form free chlorine consisting of hypochlorous acid(HOCl) and hypochlorite ion($OCl^-$). For free chlorine determination, an electrochemical method is simple due to the electroactivity of free chlorine; it measures current and is free of most reagents. Amperometric free chlorine sensor has been developed with gold (Au)-based electrode. The 3-electrode free chlorine sensor whose working and counter electrodes were Pt exhibited excellent response to HClO at +400mV vs. Ag/AgCl/sat. KCl. In addition, the use of a pH error correction algorithm provided a reliable measurement of residual free chlorine in water sample without any pretreatment in the normal pH range(pH 6~8) of municipal water supply. The free chlorine sensor installed in on-line monitoring system could be used to continually monitor the level of residual free chlorine in real samples.