수계형 아크릴 점착제의 제조

곽윤철,조주익,신기석,박은석,함현식 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - Removable protective adhesives for automobiles were synthesized by the emulsion polymerization of monomers, such as n-butyl acrylate(BA), n-butyl methacrylate(BMA), acrylonitrile(AN), acrylic acid(AA) and 2-hydroxyethyl methacrylate(2-HEMA), in which AA and 2-HEMA were functional monomers. Emulsion polymerization was conducted with a semi-batch type reactor. Tensile strength, extension, peel strength, viscosity and solid content of the synthesized adhesives were measured. In addition, acid resistance, alkali resistance and smoke resistance were also examined. As a result, with 0,43 mol of BA, 0,57mol of AN and 0.14~0.21 mol of BMA, the tensile strength, extension and peel strength of the synthesized adhesives satisfied the standard of removable protective adhesives for automobiles.

송전선로 뇌섬락률 계산 알고리즘 개선을 위한 기초연구

곽주식(Joo-Sik Kwak),김태훈(Tae-Hoon Kim),정재승(Jae-Seung Jung) 대한전기학회 2015 대한전기학회 학술대회 논문집 Vol.2015 No.7

과전압 분석 결과와 고장특성을 고려한 기설 송전선로의 절연보강 방법에 관한 연구

곽주식(Joo-Sik Kwak),우정욱(Jung-Woog Woo),구교선(Kyo-Sun Koo),김경탁(Kyung-Tak Kim),권동진(Dong-Jin Kweon) 한국조명·전기설비학회 2009 조명·전기설비학회논문지 Vol.23 No.12

본 논문은 이미 표준 절연설계 값으로 건설되어 운전중인 송전선로의 절연거리를 과전압분석결과, 뇌사고 및 오손 고장 확률과 특성을 고려하여 재설계하고 소요 애자수량을 결정하기 위하여 수행된 연구결과이다. 송전선로의 절연성능을 훼손하지 않으면서 적절한 절연거리를 확보하기 위하여 EMTP 모델을 이용하여 선로에서 발생 가능한 최대 과전압을 계산하고, 뇌 고장실적 및 뇌사고율 예측계산결과와 오손 고장 확률을 조사 분석하였다. 분석결과로부터 고장 특성을 고려한 소요 애자수량의 결정방법을 제시한다. This paper describes a study that is to redesign insulation of transmission lines and determine required the numbers of insulators in order to enhance the insulation performance of existing transmission lines which were constructed with standard insulation design, considering overvoltage analysis results, probabilities and characteristics of faults. To ensure proper insulation distance without deteriorating the required performance, EMTP model is established to calculate maximum overvoltage in the line. The fault records and predicted outage rates due to lightning and contamination in the line were investigated and analyzed respectively. It presents a method to determine the numbers of insulators considering the probability and the characteristic of fault.

축전지 충전기용 전압형 컨버터

곽주식(Joo-Sik Kwak),김제홍(Je-Hong Kim),최재호(Jae-Ho Choi) 대한전기학회 1995 대한전기학회 학술대회 논문집 Vol.1995 No.7

보조접지선 시공에 의한 송전선로의 내뢰성 향상효과 모의

곽주식(Kwak Joo-sik),심정운(Shim Jeong-woon),심응보(Shim Eung-bo),최종기(Choi Jong-gi) 대한전기학회 1997 대한전기학회 학술대회 논문집 Vol.1997 No.7

X-線 照射에 의한 肺彈力組織의 超微形態學的 變化

朱亮求,郭精植,孫泰重 慶北大學校 醫科大學 1988 慶北醫大誌 Vol.29 No.2

This study was carried out to investigate the early ultrastructural changes of elastic fibers of the lungs after X-ray irradiation and its pathogenesis. The rabbits averaging 2.0㎏ in weight were irradiated 2000 rad in dose of X-ray for 15 minutes on the chest. Irradiation was carried out 100 ㎝ in distance from 6 MV linear acceleraor with 20×20㎠ in covering areas. The lungs were examined 1, 2, and 4 days after irradiation by light and electron microscopy. Kajikawa stain was performed for demonstration of the elastic fibers. The results were as follows: On light microscopy, congestion and mild infiltration of alveolar macrophages and neutrophils appeared after irradiation. On electron microscopy, partial fragmentation of elastin was developed after 2 days of irradiation. Small elastin having microfilaments appeared 4 days after irradiation. And also was infiltraion of alveolar macrophages and neutrophils. These findings suggest that the earliest changes of the elastic fibers after irradiation is fragmentation of fibers. Synthesis of elastin is possible in the early period, and damage of elastin is caused by free radicals produced by X-ray irradiation.

총담관을 결찰한 흰쥐 혈청 및 Isocitrate Dehydrogenase간의 활성도와 총담즙산의 농도

주일,곽춘식 啓明大學校 醫科大學 1999 계명의대학술지 Vol.18 No.2

A study was made on the changes of NADP+- and NAD+ dependent isocitrate dehydrogenase (NADP+-ICD, NAD+-ICD) activities in cholestatic rat liver. The cytosolic and mitochondrial NADP+-ICD and mitochondrial NAD+-ICD activities were determined in the cholestatic rat liver induced by common bile duct ligation over a period of forty two days. And the activities of NADP+- and NAD+-ICD in the serum were measured. The concentrations of total bile acids in their serum and liver cytosolic fraction were also measured. The cytosolic and mitochondrial NADP+-ICD activities of the cholestatic rat liver each showed a marked decrease between the 1st and the 42nd day and the 12th hour and the 42nd day respectively after the ligation. However, the mitochondrial NAD+-ICD activity in the cholestatic liver markedly increased between the 2nd and the 42nd day after the ligation. On the other hand, the NADP+-ICD activity of the serum markedly increased between the 12th hour and 3rd day after the ligation. That of the serum NAD+-ICD also showed a marked increase between the 1st and the 7th day after the ligation. The concentrations of total bile acids in the cholestatic liver cytosolic fraction showed a marked increase between the 12th hour and the 7th day after the ligation. That of total bile acids in the serum showed a marked increase throughout the experiments. Viewed from above results, the NADP+-ICD in the liver with cholestasis seems to be the decreasing enzyme. But the NAD+-ICD in the cholestatic liver thought to be the increasing enzyme in its activity. Especially, when the cholestasis occurred, the activities of these enzymes of serum are higher than those of the controls because of increased permeability secondary to liver cell necrosis, which causes the enzymes to leak into the blood in great quantity.

비동기 카오스 비밀통신의 변복조 기술평가

곽부동,김성곤,최희주,변건식 동아대학교 정보기술연구소 2000 情報通信硏究所論文誌 Vol.8 No.1

During the past five years, there has been tremendous interest worldwide in the possibility of exploiting chaos in wideband communication systems. Many different demodulation techniques have been proposed up to date. They can be divided into two basic categories. In the first approach, like the conventional coherent demodulation techniques, the chaotic signal has to be recovered from the received noisy signal by synchronization. However, the chaotic synchronization techniques published to data are so sensitive to the channel noise and distortion that these techniques can not be used in radio communications. In the second approach, the demodulation is carried out nonsynchronization. This paper surveys the different chaotic communication techniques that can be implemented nonsynchronization and compares the threshold and BER of the different methods. Finally, FM-DCSK is introduced the first step for apply to wideband chaos digital CDMA, where the data is not limited by the inherent nonperiodic property of the chaotic signal.

쥐 재생간에서의 Arylamine N-Methyltransferase 활성도

주일,김여희,곽춘식 啓明大學校 醫科大學 2002 계명의대학술지 Vol.21 No.1

재생간에서 AMT 활성도 변동을 알아보기 위하여 쥐의 간엽을 부분 절제한 후 각 시기의 재생간에서 이 효소의 활성도를 측정하는 한편 혈청에서 이 효소의 활성도를 측정하였다. 또한 재생간에서 이 효소의 Km치와 Vmax치도 함께 측정하였다. 쥐 재생간의 AMT 활성도는 세포질과 미토콘드리아 분획에서는 간엽 절제 후 1일 및 2일에, 마이크로솜 분획에서는 간엽 절제 후 1일부터 3일까지 통계학적으로 유의한 증가를 나타내었다. 그러나 혈청에서 이 효소의 활성도는 변동이 없었다. 간엽 절제 후 2일의 쥐 재생간에서 세포질, 미토콘드리아 및 마이크로솜의 AMT의 Km치는 변동이 없었다. 그러나 이들 분획에서 이 효소의Vmax치는 유의한 증가를 나타내었다. 이상의 결과로 보아 쥐간의 AMT는 간재생이 활발한 시기의 재생간에서는 그 합성이 증가되는 효소로 생각된다. Changes of arylamine N-methyltransferase (AMT) activity during regeneration of rat liver was studied. Cytosolic, mitochondrial and microsomal AMT activities were determined in regenerating rat livers over a period of ten days after 70% (median and left lateral lobes) partial hepatectomy. The enzyme activity in serum, and Km and Vmax values of the hepatic enzyme were also measured. The activities of cytosolic and mitochondrial AMT were found to be significantly increased between the first and the second day of regenerating rat liver, whereas microsomal AMT increased between the first and the third day after partial hepatectpmy. On the other hand, the serum AMT activity did not change. The Vmax values of the cytosolic, mitochondrial and microsomal AMT in the regenerating rat liver were significantly increased at the second day after partial hepatectomy, however, the Km values of the above hepatic enzymes did not vary in all experimental groups. Therefore, the above results indicate that the biosynthesis of AMT was increased during the regeneration of rat liver.

Thiol Methyltransferase Activity in Cholestatic Rat Liver Induced by Commom Bile Duct Ligation

곽춘식,--,-- THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 2004 Journal of biomedical laboratory sciences Vol.10 No.1

Changes of thiol methyltransferase (TMT) activity in cholestatic rat liver were studied. Hepatic subcellular and serum TMT activities were determined in cholestatic rat induced by common bile duct (CBD) ligation over a period 28 days. The mitochondrial and microsomal TMT activities in cholestatic rat liver were found to be significantly increased between the 1st and the 28th day after CBD ligation. The TMT activity in serum was significantly increased throughout the experiments. The Vmax values of the above hepatic TMT in cholestatic rat were significantly increased at the 7th day after CBD ligation. However, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results indicate that the biosynthesis of TMT was increased in cholestatic rat liver. The elevated serum TMT activity is most likely caused by increased hepatocytes membrane permeability due to cholestasis mediated liver cell necrosis.