• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.357-362
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• 2010

Electricity can be directly generated from organic matter even wastewaters using a microbial fuel cell. To achieve high power in MFCs, finding factors decreasing activation and Ohmic losses is very important. In this study we determined activation loss at the anode and cathode and Ohmic loss using the current interruption technique in a H-type MFC. Activation loss at the cathode was four times higher that that of anode activation loss even if pt-coated carbon (0.5 $mg/cm^2$;10%Pt) was used as the cathode. Ohmic loss determined using current interruption technique (1146 ${\Omega}$) was almost same as the internal resistance (1167 ${\Omega}$) measured using AC impedance. The sum of activation losses at the anode and cathode was the same as the value of activation loss of the cell.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.99-100
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• 2007

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.563-567
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• 1998

5M 이상의 질산 매질에 있는 Ag(Ⅰ) 이온을 전착회수하기 위하여 질산 농도에 따른 전착특성을 cyclic voltammetry 방법으로 조사하였다. Ag(Ⅰ) 이온의 전착은 질산 매질의 농도에 크게 영향을 받았으며 질산 농도가 3M 이하인 경우에는 백금을 전극에서 Ag(Ⅰ) 이온이 쉽게 전착될 수 있음을 알 수 있었다. 질산농도가 5M 이상에서는 질산 자체의 환원이 활발하게 일어나 Ag(Ⅰ) 이온의 전착을 억제하였으나 용액을 혼합시킬 경우 질산 환원의 영향을 크게 감소시킬 수 있었다

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.325-329
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• 2013

The membrane and electrode were degraded coincidentally at real PEMFC(Proton Exchange Membrane Fuel Cells) operation condition. But the interaction membrane degradation between electrode degradation has not been studied. The effect of membrane degradation on electrode degradation was studied in this work. We compared electrode degradation after membrane degradation and electrode degradation without membrane degradation. I-V performance, hydrogen crossover current, impedance and TEM were measured after and before degradation of MEA. Membrane degradation enhanced hydrogen crossover, and then Pt particle growth rate was reduced. Increase of hydrogen crossover by membrane degradation reduced the electrode degradation rate.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.352-352
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• 2004

산화물 형태의 사용후핵연료를 고온 용융염계에서 금속 형태로 전환하는 전기화학적 금속전환 공정 개발의 일환으로 $U_3O_8$ 분말로 충전된 다공성 마그네시아 용기 및 스테인레스강 고체전극으로 구성된 일체형 음극과 $SnO_2$ 재질의 양극을 사용하여 5kg $U_3O_8$/batch 규모의 mock-up 시험을 수행하였다. 백금 재질의 양극을 사용하였을 때 99% 이상의 금속전환율을 보인 동일한 전하량을 공급하고 실험을 중단한 결과 X-선 회절분석(XRD) 및 열중량 분석(TG)으로부터 스테인레스강 고체전극 부분에서는 거의 금속으로 전환되었으나 다공성 마그네시아 용기 부분에서는 비교적 금속전환율이 낮은 경향을 나타내었다.(중략)

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.419-421
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• 2008

Sputter deposition on a Pt counter electrode was studied using RF plasma as the improvement of conversion efficiency for dye-sensitized solar cells (DSC). The effects of the sputtering thickness and incident angle on a Pt counter electrode for DSC was scrutinized. We conducted the experiment to get the optimal sputtering time for the performance of the DSC. Under the sputtering time condition of 120 seconds, we varied the incident angles of substrate from $0^{\circ}$ to $60^{\circ}$. Under standard test condition (AM 1.5, 100mW/$cm^2$), we obtained the maximum efficiency of 4.61% at the incident angle of $40^{\circ}$ with an active cell area of $1cm^2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.255-255
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• 2010

Metal-Insulator-Metal 구조의 $Al_2O_3$ ReRAM 소자를 플라스틱 기판 위에 제작하였다. $Al_2O_3$ 박막은 원자층 증착 방법으로 $150^{\circ}C$의 저온 공정에서 15nm 두께로 증착하였으며, 하부와 상부의 전극으로는 DC 스퍼터링 방법으로 증착된 백금전극을 이용하였다. 플라스틱 기판위에 제작된 $Al_2O_3$ ReRAM 소자는 unipolar 메모리 특성을 보였다.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.78-83
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• 2014

In this research, we evaluated the performance and characteristics of carbon supported PtM (M = Ni and Y) alloy catalysts (PtM/Cs) synthesized by a modified polyol method. With the PtM/Cs employed as a catalyst for the oxygen reduction reaction (ORR) of cathodes in proton exchange membrane fuel cells (PEMFCs), their catalytic and ORR activities and electrical performance were investigated and compared with those of commercial Pt/C. Their particle sizes, particle distributions and electrochemically active surface areas (EAS) were measured by TEM and cyclic voltammetry (CV), while their ORR activity and electrical performance were explored using linear sweeping voltammetries with rotating disk electrodes and rotating ring-disk electrodes as well as PEMFC single cell tests. TEM and CV measurements show that PtM/Cs have the compatible particle size and EAS with Pt/C. When it comes to ORR activity, PtM/C showed the equivalent or better half-wave potential, kinetic current density, transferred electron number per oxygen molecule and $H_2O_2$ production(%) to or than commerical Pt/C. Based on results gained by the three electrode tests, when the PEMFC single cell tests were carried out, the current density measured at 0.6 V and maximum power density of PEMFC single cell adopting PtM/C catalysts were better than those adopting Pt/C catalyst. It is therefore concluded that PtM/C catalysts synthesized by modified polyol can result in the equivalent or better ORR catalytic capability and PEMFC performance to or than commercial Pt/C catalyst.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.10
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• pp.591-598
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• 2017

Power overshoot phenomenon was observed in microbial fuel cells (MFCs) used non-catalyzed graphite felt as cathode. Voltage loss in MFCs was mainly caused by cathode potential loss. Cheap stainless steel scrubber, which has high conductivity, and Pt/C coated graphite felt as cathode were used for overcoming power overshoot and reducing the cathode potential loss in MFCs. The MFCs used stainless steel scrubber showed no power overshoot even slow catholyte flow rate and produced 29% enhanced maximum current density ($23.9A/m^3$) than MFCs used non-catalyzed graphite felt while the power overshoot phenomenon was existed in Pt/C coated MFCs. Increasing catholyte flow rate resulted in disappearing power overshoot of MFCs used non-catalyzed graphite felt. In addition, maximum power density and current density of both MFCs used non-catalyzed graphite felt and stainless steel scrubber increased by 2-3.5 times. Cathode potential losses in all region of activation loss, ohmic loss, and mass transport loss were reduced according to increase of catholyte flow rate. Therefore, stainless steel scrubber has advantages that are economical materials as electrode and prevents power overshoot, leading to enhance electricity generation. In addition, increasing catholyte flux is one of great solution when power overshoot caused by cathodic overpotential is observed in MFCs.

• Journal of the Korean Chemical Society
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• v.18 no.4
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• pp.244-250
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• 1974

The mechanisms of the electrode reaction of chlorate ion were investigated, using Pt-electrode, by means of the technique of galvanostatic double pulses. For double current pulses (a cathodic pulse followed by an anodic pulse), the mechanism of the electrode reaction of chlorate ion over a current density range from 20 ma/cm2 to 25 ma/cm2 was suggested as the following: $CIO_3^-\;{\longrightarrow^{I}_{n_{1c}}\;CIO_2^-\;{\longrightarrow^{II}_{n_{2a}}\;CIO^-\;{\longrightarrow^{I'}_{n_{1a}}\;CIO_2^-\;{\longrightarrow^{II'}_{n_{2a}}\;CIO_4^-$ For a higher current density from 40 ma/cm2, it was suggested as the following: $CIO_3^-\;{\longrightarrow^{III}_{n_c}}\;CIO^-\;{\longrightarrow^{I'}_{n_{1a}}\;CIO_2^-\;{\longrightarrow^{II'}_{n_{2a}}\;CIO_4^-$ or $CIO_3^-\;{\longrightarrow_{n_c}}\;CIO^-\;{\longrightarrow_{n_a}}\;CIO_4^-$