급성기 중대뇌동맥부 허혈성 뇌졸중의 초기 CT 소견에 관한 연구

최낙천,이광호,정진상 대한신경과학회 1996 대한신경과학회지 Vol.14 No.4

발전기 고정자 권선용 마이카/에폭시 수지의 표면 및 구조분석

이상교,심재선,정의남,송우창,박하용,심상흥,임윤희,박종국,심낙순 三陟大學校 1998 論文集 Vol.31 No.1

The purpose of this study is to determine the ageing mechanism of Mica/Epoxy composite material for large generator stator windings in order to estimate remaining life of generator. X-ray analysis is performed to investigate the position and structure of mica crystal in insulation materials. The phase change of aged and sound specimen under each atmosphere isn't observed. Surface analysis of insulation materials by optical microscope also show that the sound and aged specimen, sliding phenomenon by shear and thermal stress is observed both interface between mica and epoxy.

모기지론 활성화의 기대효과와 과제

이정도,여낙상 慶北大學校出版部 2004 經商論集 Vol.32 No.1

The activation of mortgage loans by the Korea Housing Finance Corporation is considered first to make a great contribution to the stabilization of the money market. It is analyzed to reduce the risk of short-term housing loans, to stabilize the money market by absorbing floating funds, and to improve the soundness and the income structure of financial institutions. In particular, the reorganization of the housing loan market into long-term fixed interest rates is expected to reinforce the stability of the housing loan market against the fluctuation of market interest rates and house prices, and the reduction of financial institutions' risk-weighted assets to improve the BIS-based ratio of net worth to total assets base, and the rapid progress of the standardization of mortgage-backed securities to enhance the soundness of home loan assets. In addition, the expansion of asset securitization income, etc. will provide an opportunity for domestic banks to have advanced income structure, and the activation of MBS issued by the Korea Housing Finance Corporation will significantly contribute to the activation of the long-term loan market by complementing the government bond market. Considering domestic financial institutions' ability to manage assets and debts that has limitations in converting maturity structure, the inconsistence of maturities due to lack of long-term loans is considered to remove a severe obstacle to the stability of the macroscopic money market. Lastly, the advancement of the housing loan market is analyzed to expand opportunities for ordinary people to buy their own houses. In order for the policy of activating mortgage loans through the Korea Housing Finance Corporation to overcome problems in the domestic money market and to be successful, the following tasks should be carried out first. First, for the successful settlement of the mortage loan system, it is required to resolve the competitive relationship and develop a cooperative relationship between financial institutions, which should play the role of selling and supplying mortgage loans, and the Korea Housing Finance Corporation. Second, it is necessary to reduce difference between long-term and short-term interest rates. Third, it is required to increase the capital of the Korea Housing Finance Corporation as soon as possible.

p-Nitrostyrylphenylsulfone 基質에 對한 L-Cysteine의 反應

李天培,成洛道,明平根 충남대학교 자연과학연구소 1980 學術硏究誌 Vol.7 No.1

The kinetics and mechanism of nucleophilic addition of L-Cysteine to P-nitrostyrlphenyl-sulfone substrate over wide pH range was presented and analyzed in detail. The rate constants were determined by ultra-violet spectrophotometry in 50% methanol water mixed solvent at 25℃ and the following rate equation which can be applied over wide pH range was obtained. i.e kt = ko + kp [OH^(-)] =(1.92×10^(-3)+3.71×10^(3)[OH^(-)]/8.94×10^(-2)+1.03×10^(5)[OH^(-)]) +4.56×10^(2)OH^(-)] From the rate equation, the following mechanism were proposed; above pH 10. 50, the reaction proceed by the attack of L-Cy-S^(-) on the activated carbon-carbon double bind of substrate. Below pH 8.50, the reaction proceed by addition of L-Cysteine to p-nitrostyrl phenylsulfone substrate. And in the range of pH 8.50-10.50, these two reaction occur competitively.

LCC형 고주파 공진 인버터의 특성해석에 관한 연구

이경호,심상홍,심낙순,원재선 三陟大學校 2001 論文集 Vol.34 No.1

This paper describes characteristics and operating principles of inverter according to the variable capacitance of the DC voltage source separated capacitor use in the conventional HB type high frequency resonant inverter. In the case of variable capacitance of the DC voltage source separated capacitor, the analysis of inverter circuit has generally described by using normalized parameter and operating characteristics has been evaluated in term of switching frequency and parameters. According to the calculated characteristics value, a method of the circuit designs and operation characteristics of the inverter is proposed. Also, We performed an experiment to prove the validity of the characteristics analysis of proposed inverter. The theoretical results are in good agreement with the experimental ones. In the future, this proposed inverter shows that it can be practically used as a power source system for the lighting equipment of discharge lamp. DC-DC converter etc.

Pectolytic Enzyme에 關한 硏究 (第一報) : 分離細菌 ??가 生産하는 Macerating Enzyme와 Pectolytic Enzymes에 關하여 Ⅰ. Macerating Enzyme and Pectolytic Enzymes Produced by Isolated Bacteria (??)

李千洙,金鍾奎,奇宇京,成洛癸 慶尙大學校 1972 論文集 Vol.11 No.-

고구마 軟腐病所에서 分離한 細菌 ??가 生産하는 酵素中에서 macerating acton을 하는 酵素를 究明하기 위한 資料로 쓰기 위해 macerating enzyme의 生成에 미치는 pectin의 影響과 生成한 macerating enzyme와 pectolytic enzymes의 一般전 性質을 조사한 결과는 다음과 같다. 1. 細菌 ??는 酵素生成培地(wheat bran media)에 pectin을 加하므로써 macerating enzyme을 效果的으로 生産했다. 2. pectic acid liquefying activity, pectin liquefying activity, pectin esterase,와 macerating enzyme은 各各 1) 最適作用 pH가 7.2∼7.8, 7.2, 6.0, 6.5∼7.5 2) 最適作用溫度는 50℃, 50℃, 60℃, 50℃ 3) pH 安定性은 3.0∼8.0, 5.0∼8.0, 3.0∼8.0, 및 3.0∼8.0이었다. The influence of pectin on production of macerating enzyme by isolated bacterial ?? and the enzymological properties of its macerating enzyme produced and pectolytic enzymes were studed. The results obtained were summarized as follows: 1. Macerating enzyme was effectively produced in the media adding pectin. 2. The optimum pH of pectic acid liquefying activity, pectin liquefying activity, pectin esterase and macerating enzyme were 7.2∼7.8, 7.2, 6.0 and 6.5∼7.5 respectively. 3. The optimum temperature of pectic acid liquefying activity, pectin liquefying activity and macerating enzyme were 50℃., and that of pectin esterase was 60℃. 4. The pH stability of pectic acid liquefying activity, pectin esterase and macerating enzyme were 3.0∼8.0, and that of pectin liquefying activity was 5.0∼8.0.

달맞이꽃(Oenothera odorata Jacquin) 뿌리에서 추출한 항균성분의 특성

신성진,권순경,이권행,성낙도,최우영 충남대학교 농업과학연구소 1994 농업과학연구 Vol.21 No.1

An antibacterial component was isolated from the roots of evening primrose (Oenothera odorata Jacquin). The component was purified by repeated preparative TLC of the chloroform-extract with solvent system of toluene(7): ethyl acetate(4) : formic acid(O.8). NMR spectrum indicated that it is a steroid compound containing radical(-C=C-C=0) and aromatic structures. Its antibacterial activity against strains of the genus Streptococcus was relatively high, the MIC value was 50 according to the Hoechst Manual-345, as compared with the other genera such as Staphylococcus and Escherichia.

Phenyl-N-benzoylchlorothioformimidate 誘導體의 加水分解 反應 메카니즘

權奇星,金千石,李龍九,成洛道 충남대학교 기초과학연구소 1992 연구논문집 Vol.12 No.-

25℃의 30%(v/v) dioxane-물의 혼합용매 속에서 pH 변화에 따른 X와 Y-치환된 phenyl-N-benzoylchlorothioformimidates(S)들의 가수분해 반응 속도상수를 측정하여 반응속도식을 유도하고, 경계 궤도 함수 상호작용, 용매효과, 일반 염기 촉매효과, 열 역학적 활성화 파라미터, 및 가수분해반응 생성물 분석 등의 결과로부터 pH 10.0 이하의 낮은 pH에서는 azocarbocation 중간체를 지나는 S_N1형 반응, pH 11.0 이상의 높은 pH에서는 사면체 중간체를 지나는 친핵성 첨가-제거(Ad_N-E)반응 그리고 pH 10.0과 11.0 사이에서는 이들 두가지 유형의 궤도 조절 반응이 서로 경쟁적으로 일어남을 제안하였다. The rate constants of hydrolysis of phenyl-N-benzoylchlorothioformimidates were determined by UV. spectrophotometry in 30% (v/v) aqueous dioxane at 25℃. On the basis of rate equation, general base catalysis, solvent effect, substituent effect, thermodynamic parameters, frontier orbital interaction and hydrolysis product analysis, it may be concluded that the hydrolysis of phenyl-N-benzoylchlorothioformimidates proceed through S_N1 mechanism via azocarbocation intermidiate below pH 10.0, while above pH 10.00 the hydrolysis proceeds through nucleophilic addition-elimination (Ad_N-E) mechanism. In the range of pH from 10.0 to 11.0 these two reaction occur competitavely.

Ethylcinnamate에 對한 Iso-propylmercaptan의 親核性 添加反應에 關한 反應速度論的 硏究

權奇星,李天培,成洛道 圓光大學校 1977 論文集 Vol.11 No.-

ethylcinnamate에 대한 iso-propylmercaptan의 친핵성 첨가반응 속도상수를 측정하여 넓은 pH 범위에서 잘맞는 반응속도식을 얻었다. 이 식에 의하면 pH 6.5 이하에서는 iso-propylmercaptan과 iso-propylmercaptide ion의 첨가가 경쟁적으로 일어난다. pH 10이상에서는 ethylcinnamate에 iso-propylmercaptide ion의 첨가만이 일어남을 알수 있다. 그러므로 본 실험에서 구한 반응속도식으로부터 실험측정값과 계산 값(이론 값)이 여러 pH를 통하여 잘 맞기 때문에 넓은 pH범위내에서 일어나는 친핵성 첨가반은 mechanism을 잘 설명할 수 있었다. The rate constants of nucleophilic addition reaction of iso-propylmercaptan to ethylcinnamate were determined at various pH and a rate equation which can be applied overwide pH range was obtained; ?? The rate equation reveals that below pH 6.5 the reaction is initiated by addition of iso-propylmercaptan molecule, from pH 6.5 to 10.0 iso-propylmercaptan and iso-propylmercaptide ion are competitively added. Above pH 10.0 the addition reaction of iso-propylmercaptide ion occurs. From these rate equation, we found that observed data accorded satisifactorily with theoretical value over various pH range. Hence, the mechanism of nucleophilic addition reaction over wide pH range can be fully explained.

N-(benzoyl)-C-(N-methylanilino)imidoylchloride 유도체의 가수분해 반응메카니즘

權奇星,李龍九,成洛道,金千石 충남대학교 기초과학연구소 1993 연구논문집 Vol.13 No.-

25℃의 50%(v/v) 메탄올-물의 혼합용매 속에서 pH 변화에 따른 X-치환된 N-(benzoyl)-C-(N-methylanilino)imidoylchloride(s)들의 가수분해 반응속도상수를 측정하여 반응속도식, 치환기효과, 용매효과, 염효과, 열역학적 활성화 파라미터 및 가수분해반응 생성물 분석 등의 결과로부터 pH3.0∼10.0까지의 사이에서는 azocarbonium ion 중간체를 지나는 S_N1형 반응, pH3.0 이하와 pH10.0 이상의 pH에서는 사면체 중간체를 지나는 친핵성 첨가-제거반응(Ad_N-E)이 일어남을 제안하였다. Rate constants of hydrolysis of N-(benzoyl)-C-(N-methyl-anilino)imidylchlorides were determined by UV spectrophotometry in 50% (v/v) aqueous methanol at 25℃. On the basis of rate equation, substituent effect, solvent effect, salt effect, thermodynamic parameters and hydrolysis product analysis, it may be concluded that the hydrolysis of N-(benzoyl)-C-(N-methyl-anilino)imidylchlorides proceed through S_N1 mechanism via azocarbonium ion intermediate in the range of from pH 3.0 to pH 10.0, while above pH 10.0 and below pH 3.0 the hydrolysis proceeds through nucleophilic addition-elimin ation (Ad_N-E) mechanism.