• 한국표면공학회지
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• 제29권5호
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• pp.519-524
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• 1996

We synthesized semiconducting Sn-doped diamondlike carbon films by rf plasma-enhanced chemical vapor deposition using an organotin compound as a dopung gas source. XPS quan-titative analysis for the deposited films after 60 s argon ion etching revealed that Sn concen-tration increased with the partial pressure of the organotin compound in the reactant gas. In C 1s spectra, there was a component due to C-Su bond which had a negative chemical shift. C 1s spectra also indicated that the deposited films were relatively $sp^2$ rich. The chemical shift of the Sn-C bond in Sn $3d_{5/2}$ spectra was about +1.7 eV. The electrical resistivity and the optical transmittance were also investigated.

• 한국재료학회지
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• 제14권4호
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• pp.265-269
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• 2004

Plasma nitrocarburising and post oxidation were performed on SCM435 steel by a pulsed plasma ion nitriding system. Plasma oxidation resulted in the formation of a very thin ferritic oxide layer 1-2 $\mu\textrm{m}$ thick on top of a 15～25 $\mu\textrm{m}$ $\varepsilon$-F $e_{2-3}$(N,C) nitrocarburized compound layer. The growth rate of oxide layer increased with the treatment temperature and time. However, the oxide layer was easily spalled from the compound layer either for both oxidation temperatures above $450^{\circ}C$, or for oxidation time more than 2 hrs at oxidation temperature $400^{\circ}C$. It was confirmed that the relative amount of $Fe_2$$O_3$, compared with $e_3$$O_4$, increased rapidly with the oxidation temperature. The amounts of ${\gamma}$'-$Fe_4$(N,C) and $\theta$-$Fe_3$C, generated from dissociation from $\varepsilon$-$Fe_{2-3}$ /(N,C) phase during $O_2$ plasma sputtering, were also increased with the oxidation temperature.e.

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.989-993
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• 2014

The molecular structures of 2,6-diaza-1,3,5,7-tetraoxaspiro[3,3]heptane (1) and its dinitro derivative, 2,6-dinitro-2,6-diaza-1,3,5,7-tetraoxaspiro[3,3]heptane (2), were fully optimized without symmetry constraints at $HF/6-31G^*$ level of theory. A bisected conformation with respect to the ring is preferred with a $C_2$ symmetric structure. The density of each molecule in the crystalline state was estimated to 1.12 and 2.36 $g/cm^3$ using PM3/VSTO-3G calculations from the molecular volume. The heat of formation was calculated for two compounds at the CBS-4M level of theory. The detonation parameters were computed using the EXPLO5 software: D = 6282 m/s, $P_{C-J}$ = 127 kbar for compound 1, D = 7871 m/s, $P_{C-J}$ = 307 kbar for compound 2, and D = 6975 m/s, $P_{C-J}$ = 170 kbar for 60% compound 2 with 40% TNT. Specific impulse of compound 1 in aluminized formulation when used as monopropellants was very similar to that of the conventional ammonium perchlorate in the same formulation of aluminum.

• 한국재료학회지
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• 제19권4호
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• pp.207-211
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• 2009

In this study, we attempted to develop a convenient aluminizing process, using Al-Ti mixed slurry as an aluminum source, to control the Al content of the aluminized layer as a result of a one-step process and can be widely adopted for coating complex-shaped components. The aluminizing process was carried out by the heat treatment on disc and rod shaped S45C steel substrates with Al-Ti mixed slurries that were composed of various mixed ratios (wt%) of Al and Ti powders. The surface of the resultant aluminized layer was relatively smooth with no obvious cracks. The aluminized layers mainly contain an Fe-Al compound as the bulk phase. However, the Al concentration and the thickness of the aluminized layer gradually decrease as the Ti proportion among Al-Ti mixed slurries increases. It has also been shown that the Al-Ti compound layer, which formed on the substrate during heat treatment, easily separates from the substrate. In addition, the incorporation of Ti into the substrate surface during heat treatment was not observed.

• Food Science and Biotechnology
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• 제15권3호
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• pp.363-368
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• 2006

Twenty-four different natural food materials extracted with 80% methanol were used to investigate the inhibition of cell-mediated immediate type allergic reactions induced by compound 48/80 in rat peritoneal mast cells (RPMCs). Nine 80% methanol extracts screened at a concentration of $10\;{\mu}g/mL$ inhibited histamine release from RPMCs induced by compound 48/80. Of these, two materials (Ulmus parvifolia and Liriope platyphylla Wang et Tang) were extracted and fractionated into four different solvent types (chloroform, ethylacetate, butanol, and water), and the fractions with major anti-allergic effects were assessed. The chloroform fraction of U. parvifolia (UP) at $5\;{\mu}g/mL$ and the ethylacetate fraction of L. platyphylla Wang et Tang (LPWT) at $1\;{\mu}g/mL$ showed the greatest inhibition of histamine release induced by compound 48/80. The chloroform fraction of UP and the ethylacetate fraction of LPWT in combination showed a greater inhibition of histamine release than either fraction alone. The cAMP levels in RPMCs treated with UP and LPWT were significantly greater than in cells treated with compound 48/80 alone. Our studies suggest that extracts from UP and LPWT may alleviate immediate type hypersensitivity reactions through the increase of cAMP levels in the mast cells.

• 한국산학기술학회논문지
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• 제18권9호
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• pp.127-135
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• 2017

인삼은 약용으로 수 천년 동안 소중하게 사용되어 왔으며 근대에 들어와 단일 성분의 분리와 각 성분에 대한 효능의 과학적인 연구가 활발히 이어져 오고 있다. 최근에는 인삼 성분 중에 Rg3, compound K 등이 주목 받고 있으며 기능성을 갖는 다양한 소재들이 연구 개발되어 제품화 되고 있다. 본 연구에서는 전통 장류에서 유래한 효모균 (Saccharomyces servazzii, GB-07)을 이용하여 인삼 추출물을 발효하여 compound K를 생산하고 기능성을 확인하여 상업적 이용 가능성을 확인하였다. Compound K 함유 ($20{\mu}g/g$ 함유) 인삼 발효 추출물을 이용하여 항산화 및 항염증 활성을 측정하였다. 발효 인삼추출물은 자유 라디칼 DPPH (di(phenyl) -(2,4,6-trinitrophenyl)를 농도 의존적으로 소거하였으며. macrophage(RAW 264.7 cell)에서 ROS의 생성을 농도 의존적으로 억제하였다. 또한 LPS에 의해 유도된 염증 사이토카인 $IL-1{\beta}$와 IL-6 그리고 $TNF-{\alpha}$의 생성을 억제하는 것으로 나타났다. 본 연구 결과는 향후 공정개발과 다양한 효능 시험을 통해 compound K를 함유한 제품의 개발을 통한 산업화의 가능성 시사하고 있다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2008년도 추계학술발표대회 및 제15회 신소재 심포지엄
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• pp.34.2-34.2
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• 2008

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 춘계 학술발표강연 및 논문개요집
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• pp.155-155
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• 2002

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.63-63
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• 1994

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.144-145
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• 1994