• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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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.

• 대한화학회지
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• 제40권9호
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• pp.615-622
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• 1996

1-(Benzotriazol-1-yl)-1-benzenesulfonylmethane 1a에 LDA 및 methyl iodide를 작용시켜 1-(Benzotriazol-1-yl)-1-benzenesulfonylmethane 2a와 2-(Benzotriazol-1-yl)-2-benzenesulfonylpropane 2b를 각각 얻었다. 같은 방법으로 1-(Benzotriazol-1-yl)-1-benzenesulfonylmethane 1b로부터 1-(Benzotriazol-1-yl)-1-benzenesulfonylpropane 3a와 3-(Benzotriazol-1-yl)-3-benzenesulfonylpentane 3b를 얻었다. 한편, 1, 1-di(benzotriazol-1-yl)-1-arylmethane 4를 butyl lithiym과 diphenyl disulfide로 처리하여 1, 1-di(benzotriazol-1-yl)-1-aryl-1-thiophenoxymethane 5를 합성하였다. 1, 1-di(benzotriazol-1-yl)methane 8을 butyl lithiym과 diphenyl disulfide로 처리하여 1, 1-di(benzotriazol-1-yl)-1-thiophenoxymethane 9a와 1, 1-di(benzotriazol-1-yl)-1, 1-dithiophenoxymethane 9b를 각각 얻었다. 화합물 9a를 m-CPBA로 산화시켜 1, 1-di(benzotriazol-1-yl)-1-benzenesulfoxymethane 10a와 1, 1-di(benzotriazol-1-yl)-1-benzenesulfonylmethane 10b를 얻었다. 한편, 화합물 3b를 170.deg.C 에서 열분해시켜 3-toluenesulfonyl-2-pentene 11ㅇ르 얻었으며, 150.deg.C의 강철봄베속에서 3b를 과량의 물로 가수분해 시켰더니 sulfone의 C-N 및 C-S 결합 모두가 절단된 diethyl ketone 13a가 생성됨을 확인하였다.

• Journal of Magnetics
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• 제18권3호
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• pp.331-338
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• 2013

We present a few significant advances in methods and concepts of magnetic measurements, aimed both at providing novel routes in the characterization of hard and soft magnetic materials and at improving our basic knowledge of the magnetization process. We discuss, in particular, investigation methods and experimental arrangements that have been developed in recent times for: 1) Hysteresis loop determination in extra-hard magnets by means of Pulsed Field Magnetometry; 2) Broadband observation of domain wall dynamics by highspeed stroboscopical Kerr techniques; 3) Entropy measurements in magnetocaloric materials by calorimetry in magnetic field. While pertaining to somewhat independent fields of investigation, all these measuring techniques have in common a solid approach to the underlying physical phenomenology and have a potential for further developments.

• 대한화학회지
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• 제53권4호
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• pp.422-426
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• 2009

Indion 190 수지의 존재하에서 di-tert-butoxypyrocarbonate $(Boc)_{2}O$를 이용한 아민의 N-Boc protection의 효과적인, 화학적 선택성적인, 실용적인 실험안. 수지는 반응혼합물로부터 쉽게 분리되었고 활성의 감소 없이 재사용되었다. 간단한 workup, 온화한 조건, 짧은 반응시간, 높은 수율은 이 방법의 두드러진 특색들이다.

• Bulletin of the Korean Chemical Society
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• 제28권4호
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• pp.547-552
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• 2007

This study examined the thermal reactions of 2,4-dibromophenol (diBP), 2,6-diBP and 2,4,6-triBP. The products obtained under pyrolytic conditions were analyzed by gas chromatography/mass spectrometry (GC/MS). 2,7-dibromodibenzo-p-dioxin (diBDD) was the major compound produced from the thermal reaction of 2,4-diBP. In addition, monoBDD and triBDDs were obtained through a process of debromination and bromination, respectively. The pyrolysis of 2,6-diBP and 2,4,6-triBP produced two major brominated dioxin isomers through direct condensation and a Smiles rearrangement. The two ortho-Brs in 2,6-diBP and 2,4,6-triBP mainly led to the production of dioxins, whereas in addition to 2,7-diBDD, 2,4-diBP produced two furans as minor products, 2,8-dibromodibenzofuran (diBDF) and 2,4,8-triBDF, through the intermediate dihydroxybiphenyl (DOHB). The maximum yield of the major dioxins was obtained at 400 oC, and decomposition by debromination at 500 oC resulted in less substituted bromodioxins.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.247-256
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• 1999

This paper describes the results of analysis, syntheses and Roll Stability of various Di-urea greases. Di-urea greases were synthesized by reaction of 4,4'-Methylenebis(phenyl isocyanate) and various amines, such as cyclohexylamine, octylamine, stearylamine and p-toluidine with base oil at 80-180 $^{\circ}C$. The synthesized di-urea greases were analyzed by FT-R spectroscopy. The Roll Stability of synthesized di-urea greases was evaluated.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.405-406
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• 2006

Raw materials from different sources, produced by a given process and having equal chemical composition, are supposed to be equivalent. The differences in sintering behavior have been investigated on P/M steels obtained from four diffusion-bonded powders (Fe + Ni + Cu + Mo) on atomized iron base, at the same alloy contents. Two levels of carbon and two sintering conditions have been investigated. Dimensional changes, C content, hardness, microhardness pattern, universal hardness, fractal analysis, pore features, microstructure features, and rupture strength have been compared to characterize different raw materials. The results show that the claimed equivalence is not confirmed by experimental data.

• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1227-1234
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• 2008

Pseudomonas aeruginosa is an opportunistic human pathogen that produces and secretes exopolysaccharides (EPS), in which cells are embedded to form a highly organized community structure called biofilm. Here, we characterized the role of cyclic diguanylate (c-di-GMP) and EPS (PEL) overproduction in the wspF mutant phenotypes of P. aeruginosa PA14 (wrinkly appearance, hyperadherence, impaired motilities, and reduced virulence in acute infections). We confirmed that the elevated c-di-GMP level plays a key role in all the wspF mutant phenotypes listed above, as assessed by ectopic expression of a c-di-GMP-degrading phophodiesterase (PvrR) in the wspF mutant. In contrast, PEL EPS, which is overproduced in the wspF mutant, was necessary for wrinkly appearance and hyperadherence, but not for the impaired flagellar motilities and the attenuated virulence of the wspF mutant. These results suggest that c-di-GMP affects flagellar motility and virulence, independently of EPS production and surface adherence of this bacterium.

• 한국진공학회지
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• 제15권1호
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• pp.50-56
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• 2006

[ $Si(5\;5\;12)-2{\times}1$ ] 표면에 벤젠과 피리딘의 흡착구조를 80K 온도에서 주사 터널링 현미경과 density functional theory 계산 방법으로 연구했다. 벤젠 분자는 기울어진 butterfly 형태로 $Si(5\;5\;12)-2\times1$의 D2, D3 유닛에 두 개의 adatom과 강하게 결합된다. 흡착 벤젠 분자에 두 개의 C=C 이중 결합이 있으며 탄소와 Si adatom 사이에 $di-\sigma$ 결합이 있다. 피리딘 분자는 Si-N dative 결합 또는 $di-\sigma$ 형태로 D2와 D3 유닛의 adatom과 결합을 한다 질소 원자의 홀전자쌍에 의해 결합된 dative 결합은 수직 형태의 구조를 띠며 $di-\sigma$ 결합보다 더 안정한 것으로 나타났다. $Di-\sigma$ 결합은 Si-C2와 Si-C5 또는 Si-Nl와 Si-C4으로 형성된다.

• 약학회지
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• 제35권6호
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• pp.509-514
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• 1991

The effect of diacylglycerol on glucose release was studied by using 1,2-dioctanoyl-sn-glycerol ($diC_8$), a cell permeable diacylglycerol, in perfused rat liver. The glucose release was increased by $diC_8(50\;{\mu}M$), and the effect was depended on calcium ions. The increment of glucose release by $diC_8(50\;{\mu}M$) was inhibited by indomethacin ($50\;{\mu}M$); the amount of glucose release was almost the same with that of control group. Arachidonic acid($200\;{\mu}M$) also increased glucose release and the release was inhibited by indomethacin. There was no synergistic effect on glucose release by the combination of $diC_8(50\;{\mu}M$) and phenylephrine($10\;{\mu}M$).