• 신재생에너지
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• 제5권1호
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• pp.18-25
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• 2009

PEMFC (Proton Exchange Membrane Fuel Cell) is a low temperature fuel cells which are high efficient and clean energy. But it has many problems like economical efficiency or durability. Because of this reason, many researchers challenge various view points. One of challenge is the flow channel design and many researchers develop new flow channel design. In addition to most of them have the anode and cathode's flow channel overlapped almost perfectly. In this case, the electrochemical reaction is almost done by the inertial force of flow. So we study on the effect of the anode and cathode's flow channel which aren't overlapped perfectly, have more diffusion effect, to PEMFC performance using CFD.

• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1206-1211
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• 2014

This study has been conducted to confirm the effect of sacrificial anode cathodic protection system for 90 days to protect corrosion on pier that is located in Korea. The cathodically protected structure was a slab and a pile cap. Before the construction of cathodic protection system, the macrography was carried out. As a result of the macrography, many corrosion traces were confirmed in this structure. The trace was mainly focused on joint and zones that concrete cover was eliminated. To apply the cathodic protection system, many onsite techniques have been adopted. In addition, to confirm the inner state of steel in concrete properly, a corrosion monitoring sensor (DMS-100, Conclinic Co. Ltd) has been applied. Test factors were corrosion & cathodic protection potential, 4 hour depolarization potential, resistivity and current density. After 90 days from the installation of cathodic protection system, it could confirm that proper corrosion protection effect was obtained by considering the result of tests.

• 한국표면공학회지
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• 제42권4호
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• pp.179-185
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• 2009

Diamond-like carbon(DLC) films were deposited by linear ion source(LIS)-physical vapor deposition method changing the anode voltages from 800 V to 1800 V, and characteristics of the films were investigated using residual stress tester, nano-indentation, micro raman spectroscopy, scratch tester and Field Emission Scanning Electron Microscope(FE-SEM). The results showed that the residual stress and hardness increased with increasing the ion energy up to anode voltage of 1400 V. It was also found that the content of $SP^3$ carbon increased with increasing the anode voltage $SP^3/SP^2$ ratio through investigation of $SP^3/SP^2$ ratio by the micro-raman analysis. From these results, it can be concluded that the physical properties of DLC films such as residual stress and hardness are increased with increasing the anode voltage. These results can be explained that 3-dimensional cross-links between carbon atoms and Dangling bond are enhanced and the internal compressive stress also increased with increasing the anode voltage. The optimal anode voltage is considered to be around 1400 V in these experimental conditions.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.82.1-82.1
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• 2010

Recently, Molten carbonate fuel cells(MCFCs) have been developing to get a good durability and economic feasibility for commercialization. To achieve these objectives, the cost of nickel based electrodes should be reduced. Regular anode thickness used in MCFCs is normally 0.7mm. Thus, in our study, the purpose was to reduce anode thickness up to 0.3 mm keeping MCFC performance on standard levels. In-situ sintering has been used, with 2 different fabrication methods (method A and B) and 2 different supports (support 1 and 2). Voltage losses at different temperature (600,620,640,$650^{\circ}C$) and after 1000 hours showed the higher performance that can be obtained using method B and support 2. After single cell test, an open-circuit voltage(OCV) of 1.075 V and a closed-circuit voltage(CCV) of 0.829V were obtained, at current density of $150mV/cm^2$. Also the voltage loss ratio at different cell temperature was lower in the case of method B and support 2. According to these results, the cost of anode fabrication can be reduced in the future, contributing for the economical feasibility of MCFCs.

• 전기화학회지
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• 제6권1호
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• pp.53-58
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• 2003

음극지지형 고체산화물 연료전지의 전극성분은 연료전지 성능의 주된 감쇄요인으로 지적되고 있는 분극저항을 줄이기 위해 높은 전기전도도와 가스투과도등이 요구되어지고 있다. 본 연구에서는 SOFC음극의 성능에 영향을 주는 음극의 미세구조, 특히 음극의 기공구조를 다르게 형성시키기 위해 두 가지 서로 다른 과립형성 방법을 이용하여 음극을 제조하고 이에 따라 기판의 기공구조가 어떻게 바뀌는지 또 그로 인해 기판의 미세구조 및 전기전도도가 어떠한 영향을 받는지 관찰하였다 또한 미세구조에 대한 정량적인 화상분석을 통해 기판의 미세구조적인 인자들과 전극특성간의 상관관계를 분석하였다.

• 한국재료학회지
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• 제14권5호
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• pp.368-373
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• 2004

To improve the conventional cathode-supported tubular solid oxide fuel cell (SOFC) from the viewpoint of low cell power density, expensive fabrication process and high operation temperature, the anode-supported tubular solid oxide fuel cell was investigated. The anode tube of Ni-8mol% $Y_2$O$_3$-stabilized $ZrO_2$ (8YSZ) was manufactured by extrusion process, and, the electrolyte of 8YSZ and the multi-layered cathode of $LaSrMnO_3$(LSM)ILSM-YSZ composite/$LaSrCoFeO_3$ were coated on the surface of the anode tube by slurry dip coating process, subsequently. Their cell performances were examined under gases of humidified hydrogen with 3% water and air. In the thermal cycle condition of heating and cooling rates with $3.33^{\circ}C$/min, the anode-supported tubular cell showed an excellent resistance as compared with the electrolyte-supported planar cell. The optimum hydrogen flow rate was evaluated and the air preheating increased the cell performance due to the increased gas temperature inside the cell. In long-term stability test, the single cell indicated a stable performance of 300 mA/$\textrm{cm}^2$ at 0.85 V for 255 hr.

• 한국표면공학회지
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• 제54권1호
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• pp.12-17
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• 2021

Among the various precious metals, silver is used in various fields because of its low price than other precious metals. However, the surface of silver remains after rain in the atmosphere containing sulfur ions and chlorine ions, causing silver corrosion and discoloration. Existing documents have developed a anode to prevent corrosion but that are concentrated on secondary batteries. This study tried to prevent corrosion and discoloration of silver by using an Al sacrificial anode. Sulfuric acid decreased the potential of silver and increased the current density at active polarization and OCP. The amount of corrosion of silver with the Al sacrificial anode was reduced from 0.5 % to 6.5%. When silver is used for decoration outside, corrosion and discoloration of silver can be suppressed by installing an Al anode.

• 한국세라믹학회지
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• 제39권1호
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• pp.86-91
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• 2002

고체 산화물 연료전지(Solid Oxide Fuel Cell; SOFC)는 무공해 청정에너지원으로서 기존의 발전방식을 대체할 차세대 에너지원으로 각광받고 있다. 고체산화물 연료전지의 구성요소는 크게 음극(anode), 양극(cathode), 전해질(electolyte)로 나뉘어 지는데 그 중 음극은 전극으로서의 역할은 물론 음극지지형인 경우 지지체 역할가지 수행해야 하기 때문에 아주 다양한 특성이 요구되어지고 있다. 그 중에서도 연료전지 성능의 최대 감쇄요인으로 지적되고 있는 분극저항을 줄이기 위해서는 높은 전기전도도와 높은 가스투과도가 요구되고있다. 본 연구에서는 음극 제조과정 중 첨가하는 기공 전구체의 종류에 따라 기판의 기공구조가 어떻게 바뀌는지 또 그로 인해 기판의 미세구조 및 전기전도도가 어떠한 영향을 받는지 관찰하였다. 결과 음극기판의 미세구조 및 전기전도도는 기공전구체의 종류에 따라 크게 달라졌으며 특히 이방성을 가지는 기공전구체의 사용은 전도성상의 단락 및 비효율적인 기공의 양산을 가져와 결과적으로 연료전지 성능을 악화시킬 것으로 예상된다.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.130.2-130
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• 2003

• 한국재료학회지
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• 제14권3호
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• pp.196-202
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• 2004

A numerical simulation based on the finite element method is used to investigate the effect of a reciprocal paddle on the uniformity of deposition rates at a patterned electrode. The calculated deposition rates agreed well with the measured values. The influences of the paddle velocity, the gap between cathodes and paddles, anode size and the distance between the anode and cathode have been studied. The optimum conditions on the paddle and geometric factors for electrodeposit uniformity could be obtained.