• 공업화학
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• 제3권2호
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• pp.256-265
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• 1992

NaCl(30wt%)/ZnO(60wt%)/${\alpha}-Al_2O_3$ 촉매상에서 메탄의 oxidative coupling 반응의 속도식을 연구하여 활성 산소종에 관하여 고찰하였다. 반응온도 $650^{\circ}C$에서 $750^{\circ}C$까지 메탄의 전화율 10%미만의 범위에서 메탄과 산소의 분압을 변화시켜 가면서 메탄의 전환속도를 측정하여 속도식을 검증하였다. 제안된 메틸라디칼의 생성반응은 Langmuir-Hinshelwood형 반응기구를 따른다. 촉매표면의 서로 다른 활성점에 흡착된 메탄분자와 산소분자가 반응하여 메틸라디칼이 생성되는 반응이 속도결정단계이며, 이때 활성화 에너지는 약 39kcal/mol이었다. 메탄의 C-H 결합의 해리에 관여하는 산소종은 표면상의 이원자 산소인 $O{_2}{^{2-}}$나 $O_2{^-}$로 제시할 수 있었다.

• 한국결정학회지
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• 제6권2호
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• pp.98-102
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• 1995

1-Ethyl-1,4-dihydro-7-methyl-1,8-naphthyridin-4-one-3-carboxylic acid [Nalicixic Acid]의 분자 및 결정구조를 X-선 회절법으로 연구하였다. 이 결정의 분자는 C12H12N2O3, 단사정계이고 공간군은 P21/c이다. 단위포상수 a=8.910(2)Å, b=13.145(3)Å, c=9.370(3)Å 이며, β=100.06(2)°, V=1080.6Å, T=293K, Z=4이다. 구조해석에 사용한 X-선은 CuKα선(λ=1.5418Å)을 사용하였다. 분자구조는 직접법으로 풀었으며 최소자승법으로 정밀화하였다. 최종 신뢰도 R값은 [F0>4σ(F0)]인 1555개의 독립회절반점에 대해 R=0.055이었다. 이 분자는 한 개의 내부수소결합 O(17)-H(17)…O(14)를 가지고 있다 [2.525(2)Å, 144.3(10)°].

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권1호
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• pp.79-84
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• 1998

The rates of absorption of carbon dioxide into aqueous solutions of 2-amino-2-methyl-1-propanol (AMP) were measured using a semibatch stirred vessel with a plane gas-liquid interface at $25^{\circ}C.$ The absorption rates under the fast reaction regime were analysed using chemical absorption theory. The reaction was found to be first order with respect to both $CO_2$ and the amine.

• 한국환경과학회지
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• 제2권1호
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• pp.79-84
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• 1993

The rates of absorption of carbon dioxide into aqueous solutions of 2-amino-2-methyl-1 propanol (AMP) were measured using a semibatch stirred vessel with a plane gas-liquid interface at $25^{\circ}C$. The absorption rates under the fast reaction regime were analysed using chemical absorption theory. The reaction was found to be first order with respect to both $CO_2$ and the amine.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.375-379
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• 2002

Methyl mercaptan oxidase was successfully induced in Thiobacillus thioparus TK-m using methyl mercaptan gas, and was purified for the detection of mercaptans. The purification procedure Involved a DEAE (diethylaminoethyl) -Sephacel, or Superose 12, column chromatography with recovery yields of 47.5 and 48.5%, and specific activities of 374 and 1240.8 units/mg-protein, respectively, The molecular weight of the purified methyl mercaptan oxidase was 66.1kDa, as determined by SDS-PAGE. The extract, from gel filtration chromatography oxidizes methyl mercaptan, producing formaldehyde, which can be easily detected by the purpald-coloring method. The optimized temperature for activity was found to be at 55$\^{C}$. This enzyme was inhibited by both NH$_4$Cl and (NH$_4$)$_2$SO$_4$, but was unaffected by either KCl or NaCl at less than 200 mM. With K$_2$SO$_4$, the activity decreased at 20 mM, but recovered at 150 mM. In the presence of methanol, full activity was maintained, but decreased in the presence of glycerin, ethanol and acetone 43, 78 and 75%, respectively.

• Archives of Pharmacal Research
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• 제20권2호
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• pp.194-196
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• 1997

A C-glycosyl chromone, named as 7-O-methylaloesinol, was newly isolated from the leaf exudate of Aloe capensis and identified as $8-C-{\beta}-D-glucopyranosyl$${\beta}-2-[2-(R)-hydroxypropyl]-7-methoxy-5-methyl-4H-1-benzopyran-4-one$ by chemical and spectral evidence.

• 대한화학회지
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• 제56권3호
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• pp.328-333
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• 2012

A simple, convenient and practical green synthetic protocol for sodium bisulfite catalyzed multicomponent reaction of ethyl acetoacetate, hydrazine hydrate, malononitrile, and various aldehydes for the synthesis of 6-amino-4-phenyl-3-methyl-2,4-ihydropyrano[2,3-c]pyrazole-5-carbonitriles using ultrasound irradiations in solvent free condition. This method provides the advantage of operational simplicity, shorter reaction time and excellent yields making the protocol environment friendly and economically lucrative.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.93-102
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• 1997

Isothiazoline derivatives is widely used to food, medical drug and industrial goods, cosmetics etcs, and it makes to restrain and to sterilize a breeding of microbe as a preservative and a sterilizing agent. It differs with the raw material of paraoxybenzoic acid derivatives or imidazolydinyl urea to be in use at present, on the efficacy and effect, and has various characteristics. This synthesis makes 3,3'-dithiodipropionic chloride to add a thionyl chloride in 3,3'-dithiodipropionic acid, and 3,3'-dithiodipropionic methyl amide makes to synthesize in a reflux reaction the mono methyl amine to 3,3'-dithiodipropionic chloride. And last synthesis becomes to make chlorination-cyclization molecule doing a reflux reaction in the temperature of $90{\sim}100^{\circ}C$ to mix excessively thionyl chloride and ethylene dichloride to 3,3'-dithiodipropionic methyl amide. The last synthesis material has got in the mixture of 5-chloro-2-methyl-4-isothiazoline-3-one and 2-methyl-4-isothiazoline-3-one, and it is so-called isothiazoline derivatives. The purification of isothiazoline derivatives makes to fuse in ethyl acetate, and makes to decolorize and to deodorize in recrystallization. This experiment has been in synthesis and purification of isothiazoline derivatives, and has tried to measure on the antisepsis and sterilization function of microbe according to pH or content change.

• 대한화학회지
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• 제39권6호
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• pp.434-439
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• 1995

산소, 질소, 그리고 황 주개 원자의 이염기성 세자리 리간드로서 S-methyl-3(-2-hydroxy-x-phenyl)methylenedithiocarbazate($L^1:x=5-H$)와 그 유도체($L^2:x=5-CH_3,\;L^3:x=3CH_3O,\;L_4:x=5,6-C_4H_4\; 그리고\;x^5:ㅌ=5-NO_2$)의 6-배위 몰리브덴(V)-산소 착물, ($R_4N$)[MoO(NCS)_2L](R=CH_3,\;C_3H_5,\;n-C_4H_9)$들을 합성하고 원소분석, 몰 전도도, UV-Vis, IR, $1^H$ NMR 그리고 CV 등을 이용하여 착물의 구조와 분광학적 및 전기화학적 성질 등을 조사하였다.

• 한국산학기술학회논문지
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• 제11권6호
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• pp.2311-2316
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• 2010

디아민으로서 p-phenylene diamine, 4,4'-oxydianiline, 1,4-bis(4-aminophenoxy)benzene에 대해 이염기산으로서 terephthalic acid와 2,2'-bibenzoic acid를 혼합 사용하여, 주쇄에 Biphenyl-2,2'-diyl 구조를 갖는 copolyterephthalamide를 직접중축합법에 의해 합성하였다. 얻어진 공중합체는 $0.46{\sim}0.93dL/g$의 본성점도를 나타내었으며, 이들 대부분은 N,N-dimethylacetamide와 N-methyl-2-pyrrolidone과 같은 범용 유기용매에 용해하였고, 유리전이온도는 $239^{\circ}C$와 $326^{\circ}C$ 사이의 값을 나타냈으며, 질소기류하 10% 열분해 온도는 $410{\sim}485^{\circ}C$였다.