• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.813-824
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• 1988

Use of a plasma arc as the source of energy for penetration welding of thin plates gives rise to a cylindrical hole surrounded by the molten metal. Material moves from the front to the rear of the hole by flowing around the hole as the workpiece is translated relatively to the arc. Based on the finite difference method, three different computer models have been proposed for the steady state, two dimensional heat and mass flow during the plasma arc welding. In the formulation energy equation was derived by the energy blance method through the cell control volume, and all the governing equations derived for the fixed coordinates was translated for the moving coordinate system. The driving force for fluid flow being considered was only electromagnetic force. The calculated and measured molten poon and HAZ width were compared and better agreement was obtained for the models considering the keyhole effect.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1387-1388
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• 1997

The MCFC has conspicuous feature and high potential in being used as an energy converter of various fuel to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at $650^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti alloys has been done in (62+38)mol% (Li+K)CO3 melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.157-159
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• 2001

The molten carbonate fuel cell has conspicuous feature and high potential in being used as an energy converter of various fuel to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at 650$^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti alloys has been done in (62+38)mol% (Li+K)CO$_3$ melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method. And, The research and development for the solid oxide fuel cell have been promoted rapidly and extensively in recent years, because of their high efficiency and future potential. Therefore this paper describes the manufacturing method and characteristics of anode electrode for SOFC, by the way, Ni-YSZ materials are used as anode of SOFC widely. So in this experiments, we investigated the optimum content of Ni, by the impedance characteristics, overvoltage. As a result, the performance of Ni-YSZ anode(47vo1%) was bettor excellent than the others.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.927-933
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• 2000

The molten carbonate fuel cell has conspicuous feature and high potential in being used as an energy converter of various fuel to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at 650$^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti alloys has been done in (62+38)mol% (Li+K)CO3 melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method. And, The research and development for the solid oxide fuel cell have been promoted rapidly and extensively in recent years, because of their high efficiency and future potential. Therefore this paper describes the manufacturing method and characteristics of anode electrode for SOFC, by the way , Ni-YSZ materials are used as anode of SOFC widely. So in this experiments, we investigated the optimum content of Ni, by the impedance characteristics, overvoltage. As a results, the performance of Ni-YSZ anode(40vo1%) was better excellent than the others.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.14-19
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• 1998

Increasing demand for high modulus high strength polymeric materials have drawn considerable interest in industry. Thermotropic liquid crystal polymers (TLCP), differing from lyotropic liquid crystal polymers, have excellent melt processability and mechanical property resulting from the high degree of molecular orientation under a shear flow field in the molten state with relatively low viscosity$\^$1,2/.(omitted)

• Journal of the Korean Ceramic Society
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• v.21 no.3
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• pp.271-277
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• 1984

To study interface between crystals grown and molten state in the crusible. Pulling and rotating rate of the shaft were varied in LiF crystal growth by Czochralski method. Lower speed of the pulling and rotating rate increased the degree of convexity in solid-liquid interface and higher speed of the pulling and rotating rate decreased it. Optimum condition of LiF crystal growth obtained as pulling rate was 6.5cm/h when it rotated as 46rpm.

• 한국전기화학회:학술대회논문집
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• 2003.11a
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• pp.153-168
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• 2003

Polymer electrolytes - solid polymeric membranes with dissolved salts - are being intensively studied for use in all-solid-state lithium-metal-polymer consumer electronic device. The low ionic conductivity at room temperature of existing polymer electrolytes, however, has seriously hindered the development of such batteries for many applications. The incorporation of salts molten at room temperature (room temperature ionic liquids or RTILs) into polymer electrolytes may be the necessary solution to overcoming the inherent ionic conductivity limitations of 'dry' polymer electrolytes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.346-348
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• 1996

The MCFC has conspicuous features and high potential in being used as an energy converter of various fuels to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at 650[$^{\circ}C$] have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti alloys has been done in (62+38)㏖ % (Li+K)CO$_3$ melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method.

• Journal of the Korean Electrochemical Society
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• v.13 no.1
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• pp.34-39
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• 2010

This work investigated the effect of anode thickness on the anodic overpotential with $100\;cm^2$ class MCFC single cells. The hydrogen oxidation rate in the molten carbonate is sufficiently high, which may lead to weak relation of overpotential with anode geometrical area. The relation of anode surface area and overpotential was analysed in terms of anode thickness in this work. Steady state polarization, inert gas step addition (ISA), and reactant gas addition (RA) methods were employed to the two cells with 0.77 mm and 0.36 mm thickness of anode. The result represented that the anodic overpotential at the cells were identical. It implied that the anodic overpotential was independent on the electrode thickness within the tested range.

• Journal of Electrochemical Science and Technology
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• v.7 no.3
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• pp.234-240
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• 2016

The effect of initial electrolyte loading (IEL) on cell performance in a coin-type molten carbonate fuel cell (MCFC) was investigated in this work. Since the material of MCFC depends on the manufacturer, optimisation requires experimental investigation. In total, four IEL values, 1.5, 2.0, 3.0, and 4.0 g, were used, corresponding to a pore filling ratio (PFR) of 38, 51, 77, and 102%, respectively. The cell performance with respect to the PFR was analysed via steady-state polarisation, step-chronopotentiomtery, and impedance methods. The electrochemical analyses revealed that internal resistance and overpotential of the cell decreased with increasing PFR, and a large overpotential was observed when the PFR was 102%, probably due to the flooding phenomenon. After operation, cross-section of the cell was analysed via surface analysis of SEM and EDS methods, and the remaining electrolyte was estimated by dissolution of the cell in 10 wt% acetic acid. A linear relationship between IEL and the weight reduction ratio by dissolution was obtained. Thus, the remaining amount of electrolyte could be measured after operation. The results of SEM and EDS showed that a PFR of 38 and 102% showed a lack and flooding of electrolytes at the cell, respectively, which led to a large overpotential. This work reports that MCFC performance is allowed only in the narrow range of PFR.