• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.765-772
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• 2011

In this research, the fuel cell system model capable of generating codes in real time was developed to construct of a HIL (Hardware-In-the-Loop) for a SOFC-powered ship. Moreover, the effects of the distribution of the exhaust gas flow rates in a stack, the flow rates of fuels and temperature of air supplied on the temperature characteristics of fuels supplied to the cathode and the anode, the output power of the stack and system efficiency are examined to minimize the temperature difference between fuels supplied to the stack used in a 500kW SOFC system using methane as a fuel. As a result, the temperatures of fuels supplied to the cathode and the anode maintain at 830K when the opening factor of three-way valve located at outlet of turbine is 0.839. Also the process for optimization of methane flow rate considering the fuel cell stack and system efficiency is required to increase the temperatures of fuels supplied to the stack.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.406-413
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• 2011

Recently the fuel cell has been spotlighted as a technology to reduce greenhouse gases emission from a ship. In this research, internal reforming 500kW solid oxide fuel cell stacks fueled by methane for a ship were developed. Characteristics of power and efficiency depending on the number of cells in the stack, hydrogen conversion ratio, and active area of the cell are evaluated. Also the effects of air and methane supplying conditions on performance are analyzed. As a result, as the number of cells, hydrogen conversion ratio, active area of the cell, or supplied air flow rate increase, the stack power and efficiency increase. When the methane flow rate increases, the power increases. However the efficiency decreases. In addition, the case at the current of 976.4 A, voltage of 529.1 V, with corresponding power of 516.6 kW shows that the efficiency of fuel cell stack is 42.91%.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.582-589
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• 2011

The fuel cell technology has been considered as a technology to reduce greenhouse gases emission from a ship. In this research, internal reforming 500kW solid oxide fuel cell system fueled by methane for a ship were developed. Characteristics of gas temperature, stack power and system efficiency depending on the air flow rate, $CH_4$ flow rate, $H_2O$ flow rate, and system operation pressure are evaluated. As a result, air and $CH_4$ flow rate directly affect the temperature of inlet and outlet gas in the fuel cell stack. When the air and $H_2O$ flow rate increase, the stack power and system efficiency increases. However, the case of $CH_4$ flow rate increase, the efficiency decreases.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.101-105
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• 2016

Recently, the hydrophobic surface has been attracted because of the excellent opto-physical properties. Various processing methods such as chemical, mechanical, photolithographic and laser processing are competitively introduced for fabrication of hydrophobic surface of polymer, metal and ceramics. In this paper, we fabricated the hydrophobic surface of copper metal by simple method which irradiated 355 nm UV-pulsed laser in order to shape microgrooves and increased surface roughness through oxidation process at room temperature. Finally the contact angle is dramatically increased by maximum $45^{\circ}$, as a result of oxidation which simply created nanostructures on the microstructures without expensive chemical process.

• Journal of the Korean GEO-environmental Society
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• v.4 no.2
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• pp.39-46
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• 2003

An immobilization zone can be constructed by modifying soils in the vadose zone with surfactants, which can be used to promote retardation of organic contaminants in the subsurface. Column experiments were conducted to investigate the behavior of surfactants and organic contaminants in unsaturated and saturated conditions with different water contents (25%, 50%, 75%, 100%). Transport and sorption of surfactant (dialkylated disulfonated diphenyl oxide) in the columns containing aluminum oxide was similar under the conditions at different water contents. However, transport of a model organic compound (naphthalene) was retarded as the water content decreased by enhanced partitioning of the compound into the surfactants that were sorbed on the aluminum oxide. This suggests that the immobilization method could well be applied to vadose zone as well as to saturated zone.

• Clean Technology
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• v.20 no.1
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• pp.88-94
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• 2014

During the past decades much attention has been paid to the desulfurization of diesel oil which is important as a source for the fuel cells to prevent the sulfur poisoning of both diesel steam reforming catalyst and electrode of fuel cell. Although alternative desulfurization techniques have been investigated, desulfurization for ultra-low sulfur diesel (ULSD) is still challenged. Therefore, this research focuses on the desulfurization of commercial ULSD for the application to molten carbonate fuel cell (MCFC). Herein, the performances of several kinds of commercial adsorbents based on activated carbons, zeolites, and metal oxides for desulfurization of ULSD were screened. The results showed that metal oxides based materials can feasibly reduce sulfur concentration in ULSD to a level of 0.1 ppmw while activated carbons and zeolites did not reach this level at current conditions.

• Polymer(Korea)
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• v.35 no.6
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• pp.565-573
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• 2011

The nanocomposites containing graphene oxide (GO) were prepared in order to improve the mechanical properties of poly(methyl methacrylate)/aluminum hydroxide (PMMA/AH) composites. GO was prepared from graphite by oxidation of Hummers method followed by exfoliation with thermal treatment. The surface of GO was modified by oxygen plasma in various exposure times from 0 to 70 min to improve interfacial compatibility. Compared with PMMA/AH composites, the nanocomposites containing GO modified with oxygen plasma for the exposure time up to 50 min showed significant increases in flexural strength, flexural modulus, Rockwell hardness, Barcol hardness, and Izod impact strength. The morphology of fracture surface showed an improved interfacial adhesion between PMMA/AH composites and GO, which was properly treated with oxygen plasma. The mechanical properties of nanocomposites were deteriorated by increasing the content of GO above 0.07 phr due to the nonuniform dispersion of GO.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.249-251
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• 2014

Synthesis gas such as hydrogen and carbon monoxide was produced from $CH_4//oxygen$ mixture using two-section porous media combustor. Heat recirculation through the inner foam structure could extend the flow velocity of stable region over the laminar burning velocity. $H_2/CO$ ratio and module M from concentration of flue gas measured by Gas Chromatography was similar to those calculated by equilibrium. But it was made sure that the heat loss effect becomes more influential than heat recirculation effect as the mixture gets richer. To generate synthesis gas appropriate for methanol production, insulated pressurized porous media combustor will be designed and built in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.225-229
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• 2005

We have designed micro-fuel processor system, which consists of a steam reforming area and a PROX(preferential oxidation) area. Micro-fuel processor system generates $H_2$ rich gas from a methanol. In our experiment, we have integrated micro-fuel processor system using low temperature cofired ceramics (LTCC) process because LTCC is superior to other materials principally due to their high thermal and chemical stability, simpler fabrication processes, and lower materials cost. Therefore, we have studied and integrated micro-fuel processor system containing embedded heaters, cavities, and 3D structures of micro-channel with LTCC. Also we have optimized the LTCC process.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.84-85
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• 2012

Poly(ethylene glycol) (PEG)는 Hydrophilic하면서 독성이 없기 때문에 약물과 관련된 연구가 많이 이루어졌다. 초기 PEGylation은 약물과 관련된 연구가 주를 이루었지만, 최근에는 PEG의 non-fouling 효과 때문에 표면에 적용하여 biomedical 장비에 세포나 단백질이 붙지 않도록 하는 개질하는 방법에 많은 연구가 진행되고 있다. Native Chemical Ligation(N.C.L.)은 단백질을 합성할 때, Protecting group을 사용하지 않고 반응을 진행시킬 수 있기 때문에 많은 주목을 받고 있다. N.C.L.은 합성한 두 물질이 Thioester와 Cysteine을 갖고 있으면, mild condition에서 amide bond를 형성하면서 반응이 쉽게 진행되기 때문에 다양한 분야에 적용할 수 있다. 이 논문에서 우리는 N.C.L.을 표면에 적용시켰으며 그 중 한 예로 표면 PEGylation진행하였다.