• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.11a
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• pp.231-232
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• 2004

PCBs를 분석한 결과 낙동강 유역 4개 전 지점에서 검출되었으며, $4\~6$염소 PCBs가 주로 검출되었다.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.79-79
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• 2002

• Proceedings of the Korea Crystallographic Association Conference
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• 2005.11a
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• pp.20-20
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• 2005

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.3 no.2
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• pp.1-7
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• 2007

This paper is concerned with the selection of proper working fluids for medium temperature range heat pipe. The heat pipe which is made of SUS 316L has a total length of 700 mm as well as an outside diameter of 27.2 mm and a thickness of 2.1 mm respectively. Working fluids used in this study were Naphthalene, Biphenyl and Dowtherm A. Their charge amounts were about 40% of the inside volume of evaporator section. Experimental results shows that the Dowtherm A is good for $200^{\circ}C{\sim}300^{\circ}C$temperature range, while the Naphthalene is proper for $300^{\circ}C{\sim}430^{\circ}C$. In the case of the Naphthalene heat pipe, the heat transfer rate reaches 1500 W along with a vapor temperature of $430^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1531-1536
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• 2006

Microsomal prostaglandin $E_2$ synthase (mPGES-1) is an enzyme that is associated with inflammation, pain, fever and cancer. Hologram quantitative structure activity relationship (HQSAR) was conducted on the series of MK-886 compounds acting as mPGES-1 inhibitors. A training set with 24 compounds was used to establish the HQSAR model. The best model was chosen based on the cross-validated correlation coefficient ($q^2$=0.884) and the correlation coefficient($r^2$=0.976). The model was utilized to predict the activity of the eight-test set of compounds giving the predictive $r^2$ value of 0.845. The descriptors of the model are based on fragment distinction (atoms, bond and connectivity) and fragment size (2-5 atoms). The atomic contribution maps generated from HQSAR were useful in identifying the important structural features responsible for the inhibitory activity of MK-886 inhibitors. Based on the generated model, the presence of hydrophobic biphenyl group seems to enhance inhibition of mPGES-1 that is in agreement with the previous experiments. In addition, it seems important for a halogen to be substituted to the biphenyl ring and for an acyl group to be attached to the indole moiety for enhanced activity.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1142-1146
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• 2004

The synthetic route and physical properties for three-ring derivatives, trans-2,3,2',3'-tetrafluoro-4-alkyl-4'-(4-alkyl-cyclohexyl)-biphenyl and 4-alkyl-cyclohexane carboxylic acid 2,3,2',3',4'-pentafluoro-biphenyl-4-yl ester are presented. They exhibit broad range nematic phases exceeding 30K and low viscosity of nematic liquid crystal mixtures containing these materials. Their viscosity is compared with that of homologues with a lateral isothiocyanate group and show large negative dielectric anisotropies. The threshold voltage $V_{th}$ was low enough to be operated at a driving voltage of 5V. Our novel LC compounds are suitable materials for the improvement of dielectric anisotropy of vertical align liquid crystal displays (VA-LDCs).

• Journal of Microbiology
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• v.40 no.4
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• pp.340-343
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• 2002

A PCB degrader, Ralstonia eutropha H850 was shown to induce bphC gene encoding 2,3-dihydroxy-biphenyl-1,2-dioxygenase in a carvone-amended pure culture in our previous study (Park et al.,1999). The present study was carried out to examine how plant terpenes, as natural substrates, would cause an expression of a PCB degradative gene in soil that was amended with terpenes. The population of Ralstonia eutropha H850 was maintained at least around 10$\^$8/ (CFU/g fresh soil) in the soil amended with carvone or limonene in the presence of succinate as a growth substrate at 50 th day. The gene expression was monitored by RT-PCR using total RNA directly extracted from each soil and bphC gene primers. The bphC gene expression of the seeded strain H850 was observed in the soil amended with biphenyl (4 days) but not with succinate, carvone and limonene. These results indicate that terpenes widely distributed in nature could be a potential inducing substrate for effective PCB biodegration in the soil but their bioavailability and specific induction behavior should be taken into account before PCB bioremediation implementation.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.97-97
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• 1995

PCBs have been measured using GC-ECD, GC-MS, GC-ELCD, HPLC, TLC, NMR and Immunoassay. The analysis of PCBs using GC-ECD include the peak pattern method as none derivatization and the Perchlorination method as derivatization. This study was conducted to establish the perchlorination method with Sbcls from PCBs to decachlorinated biphenyl(DCB). The aroclor 1242 of PCBs was chlorinated and then, converted into the DCB which showed a single peak in GC-ECD chromatogram. The detection limit of DCB was 2pg. The quantification detection concentration of PCBs extracted with soxhlet was 0.5ng/g in the soil. PCBs were not detected in the suburban soil, but 174ng/g in the soil of industrial complex. Mean PCBs concentration of Shinchun stream at Kumho river and Jinchun stream at Nakdong river was calculated average 낙ngjg in 각e sediment. PCBs concentration in the sediment of Kumho river near 2-7km from conjunction with Nakdong river was average 154ng/g. PCBs concentration in the sediment of Nakdong river near conjunction with Kumho river was average 159ng/g.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.249-258
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• 1995

PCBs have been measured using GC-ECD, GC-MS, GC-ELCD, HPLC, TLC, NMR and Immunoassay. The analysis of PCBs using GC-ECD include the peak pattern method as none derivatization and the Perchlorination method as derivatization. This study was conducted to establish the perchlorination method with Sbcls from PCBs to decachlorinated biphenyl(DCB). The aroclor 1242 of PCBs was chlorinated and then, converted into the DCB which showed a single peak in GC-ECD chromatogram. The detection limit of DCB was 2pg. The quantification detection concentration of PCBs extracted with soxhlet was 0.5ng/g in the soil. PCBs were not detected in the suburban soil, but 174ng/g in the soil of industrial complex. Mean PCBs concentration of Shinchun stream at Kumho river and Jinchun stream at Nakdong river was calculated average 낙ngjg in 각e sediment. PCBs concentration in the sediment of Kumho river near 2-7km from conjunction with Nakdong river was average 154ng/g. PCBs concentration in the sediment of Nakdong river near conjunction with Kumho river was average 159ng/g.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.499-499
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• 2013

유기 발광 소자는 낮은 구동전압, 낮은 소비전력, 높은 명암비, 넓은 시야각 및 빠른 응답속도의 장점을 가지고 있기 때문에 전색 디스플레이에서 각광을 받고 있다. 고효율의 청색 유기 발광 소자를 제작하기 위해서 다양한 구조를 제작하고 있지만, 적색 및 녹색 유기 발광 소자에 비해 낮은 효율, 색 순도의 저하 및 짧은 수명으로 인한 문제점을 갖고 있기 때문에 이를 해결하기 위한 연구가 필요하다. 본 연구에서는 발광층내에 호스트 물질로 1.3-Bis(carbazol-9-yl) benzene (mCP)와 2-t-butyl-9,10-di-2-naphthylanthracene (TBADN)을 혼합하였고, 형광 도펀트인 4,40-Bis[4-(diphenylamino)styryl]biphenyl (BDAVBi) 또는 인광 도펀트인 bis(3,5-difluoro-2-(2-pyridyl) phenyl-(2-carboxypyridyl)iridium III (FIrpic)을 혼합한 발광층을 사용한 유기 발광 소자를 제작하여 전기적인 특성과 발광 효율을 관찰하였다. 유기 발광 소자의 정공 수송층 N,N,'-bis-(1-naphthyl)-N,N'-diphenyl1-1'-biphenyl-4,4'-diamine (NPB)와 정공 저지층 3-Benzidino-6-(4-chlorophenyl) pyridazine (BCP) 사이에 호스트 mCP와 도펀트 TBADN：BDAVBi를 혼합한 발광층의 혼합비율을 최적화 할 때 구동전압이 낮고, 발광효율이 증가됨을 확인하였다. 호스트 mCP에 도펀트를 혼합한 발광층에서는 호스트로 mCP 또는 TBADN만 사용하였을 때보다 전계발광 스펙트럼의 최대치가 청색 영역에서 나타남을 확인하였다. Commission Internationale de l'Eclairage (CIE) 측정을 통해, 호스트 mCP와 도펀트 TBADN : BDAVBi의 최적화된 혼합비에서 전압의 변동에 따른 CIE 값이 매우 안정적임을 확인하였다.