• Korean Journal of Metals and Materials
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• v.47 no.7
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• pp.454-459
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• 2009

In order to commercialize Polymer Electrolyte Fuel Cell (PEFC), the cathode catalyst such as Platinum supported Carbon (Pt/C) need to have a high activity of Oxygen Reduction Reaction (ORR). In this study, the 20% Pt/C was synthesized using the chemical reduction method while the crystallinity of Platinum (Pt) particles were controlled under heat treatment conditions. The activity of synthesized Pt catalysts was evaluated using electrochemical measurement. Compared with the $i_{ORR}$ at 0.8 V of 20% Pt/C heat-treated at $500^{\circ}C$ and the 20% Pt/C that were not heated and commercial 20% Pt/C, the $i_{ORR}$ at 0.8 V of 20% Pt/C heattreated at $500^{\circ}C$ was 9.5 and 1.7 times higher than those of the 20% Pt/C and commercial 20% Pt/C that were not heated. It was considered that the crystallinity and particle size affect the ORR activity of the Pt/C catalysts.

• Progress in Superconductivity
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• v.9 no.2
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• pp.127-135
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• 2008

We study the effects of phonon interaction on the superconducting pairing in the high $T_c$ superconductors (HTSC). Using coupled BCS gap equations, we found that phonon interaction can induce a s-wave component to the d-wave gap, mediated by Antiferromagnetic (AFM) spin fluctuations, in the (D+iS) form. However, $T_c$ is not enhanced compared to the pure d-wave pairing without phonon interaction. On the other hand, anisotropic phonon interaction can dramatically enhance the d-wave pairing and $T_c$ itself, together with the AFM spin fluctuation interaction. This ($D_{AFM}+D_{ph}$) type pairing exhibits strongly reduced isotope coefficient despite the large enhancement of $T_c$ by phonon interaction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.353-356
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• 2004

This paper discribes the analysis of the I-V characteristics of 4H-SiC DiMOSFET with single epi-layer Silicon Carbide has been around for over a century. However, only in the past two to three decades has its semiconducting properties been sufficently studied and applied, especially for high-power and high frequency devices. We present a numerical simulation-based optimization of DiMOSFET using the general-purpose device simulator MINIMIS-NT. For simulation, a loin thick drift layer with doping concentration of $5{\times}10^{15}/cm^3$ was chosen for 1000V blocking voltage design. The simulation results were used to calculate Baliga's figure of Merit (BFOM) as the criterion structure optimization and comparison.

• Korean Journal of Medicinal Crop Science
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• v.17 no.2
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• pp.139-144
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• 2009

This study was conducted to evaluate the vegetation, distribution and growth pattern of Glehnia littoralis community by the DCA ordination method in eastern coast of Korea. The number of plant species growth with G. littoralis in natural habitat was found 51 taxa, and species of high frequency among 51 taxa was Ixeris repens, Calystegia soldanella, Carex kobomugi, Elymus mollis, Lathyrus japonica and Zoysia macrostachya. Indicator species of Z. macrostachya, Linaria japonica, C. soldanella, I. repens, Carex pumila, Artemisia capillaris, Oenothera biennis, L. japonica and E. mollis in G. littoralis community was differential species of syntaxonomy. C. kobomugi, Z. macrostachya, E. mollis, Cynodon dactylon and L. japonica was the distribution in dryness sand and moisture sandyloam, I. repens, C. soldanella, L. japonica and C. pumila was the distribution in dryness sand. In coastal dune, I. repens, C. soldanella, Salsola komarovi and G. littoralis combined strength of the distribution, and sand of coast was typical of the habitat.

• Advances in Traditional Medicine
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• v.8 no.4
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• pp.380-385
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• 2008

Ethanolic extracts of T. cordifolia and C. asiatica were evaluated for immunostimulatory effect in mice against sheep RBCs as antigen by three models viz. delayed type hypersensitivity reaction, ercent change in neutrophil count and haemagglutination titre. Immunostimulatory effect in the presence of immunosuppressant agent, cyclophosphamide (100 mg/kg, i.p.) was also investigated. T. cordifolia and C. asiatica significantly (p < 0.001, p < 0.05 respectively) enhanced foot pad thickness when measured after 24 hours of sheep RBC antigen challenge. Both the plant materials increased foot pad thickness even after being subjected to immunosuppressant exposure. T. cordifolia revealed enhanced neutrophil counts, while C. asiatica had no significant effect on neutrophil counts. T. cordifolia exhibited significantly (P < 0.01) elevated neutrophil levels even in the presence of cyclophosphamide administration. Both the plants exhibited humoral antibody response, as haemagglutination titre values were significantly high as compared to control. T. cordifolia and C. asiatica could combat immunosuppressant effect of cyclophosphamide (P < 0.01). This suggests that T. cordifolia and C. asiatica can be regarded as biological response modifiers and can be utilized for the development of immunostimulating agent among plant sources.

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.78-82
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• 2000

The influence of daily water temperature changes on chemiluminescent (CL) response of phagocytes, plasma glucose level and mortality in cultured gray mullet (Mugil cephalus) was investigated. Among three experimental temperature groups, the fish in group I and group II were maintained constantly at $27^{\circ}C$ and $29^{\circ}C$, respectively, and those in group III were suffered daily elevation of water temperature from $27^{\circ}C$ to $29^{\circ}C$ for 5 hours, then restored again to $27^{\circ}C$. After 1 week of maintaining at each experimental tank, the fish in group III showed significantly lower CL peak value (p < 0.01) and higher plasma glucose levels (p < 0.05) than those in group I and group II. The cumulative mortality of group III was $86.9\%$ within 3 days after being subjected to acute handling stress. On the other hand, the cumulative mortalities of group I and group II were $12.5\%$ and $19.2\%$, respectively. In conclusion, gray mullet farms, especially, in the vicinity of thermoelectric power plants should avoid stressing the fish during periods of high water temperature.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.170-171
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.485-486
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.23-24
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• 2009

• YAKHAK HOEJI
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• v.41 no.3
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• pp.352-358
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• 1997

The study was carried out on the biochemical characters of Cd-BP(I) after isolation and purification of the protein from the liver of rat injected intraperitoneally with Cd. A c ontinued study has been doing whether Cd-BP(I) could be induced by Cd or by other metals such as Zn and Cu. Antisera were made against the Cd-BP(I) from NewZealand white rabbits. Carried out were ${\gamma}$-globulin purification, then Ouchterlony test adn gel immunodiffusion test. Cd-BP(I) was also found in normal tissues of rat. It was induced up to a considerable level by Cd, whose induced level was higher than that of Cu or Zn treatment. The level of induction by Cu or Zn pretreatment plus Cd treatment was lower than that by simple treatment of Cu or Zn. Such a result was presumably related to the Cd toxicity.