선(禪)으로 읽는 월리스 스티븐스 후기 시

윤종국 신영어영문학회 2005 신영어영문학회 학술발표회 자료집 Vol.2005 No.2

유기 금속 화학 증착법에 의한 $(Ba_{1-x},\;Sr_x)TiO_3$ 박막의 제조 및 전기적 특성

윤종국,윤순길,Yun, Jong-Guk,Yun, Sun-Gil 한국재료학회 1995 한국재료학회지 Vol.5 No.7

저압 유기금속 화학 증탁법에 의하여 Pt/Ti/SiO$_2$/Si 기판위에 (Ba$_{1-x}$ , Sr$_{x}$)TiO/$_3$박막이 제조 되었다. 제조된 BST 박막의 결정화도는 증착온도가 증가함에 따라 (100)방향으로 우선 성장하였다. 90$0^{\circ}C$에서 증착한 BST 박막은 100kHz의 주파수에서 유전상수가 365, 유전손실이 0.052를 나타내었다. 인가전계에 따라 축전용량의 변화가 작은 상유전 특성을 보였으며 0.2MV/cm인가 전계에서 축적 전하 밀도(charge storage density)는 60fC/$\mu\textrm{m}$$^2$을, 0.15MV/cm인가 전계 영역에서 누설 전류밀도(leakage current density)는 20nA/$\textrm{cm}^2$을 나타냈다.냈다. (Ba$_{1-x}$ , Sr$_{x}$)TiO/$_3$thin films on Pt/Ti/SiO$_2$/Si substrates were prepared by LP MOCVD(Low Pressure Metal-Organic Chemical Vapor Deposition). The crystalinity of BST deposit had a (100) preferred orientation with increasing deposition temperature due to surface diffusion. BST films deposited at 90$0^{\circ}C$ showed a dielectric constant of 365 and a dissipation factor of 0.052 at a frequency of 100kHz. The chance of capacitance of the films with applied voltage was small, showing paraelectric properties. BST film deposited at 90$0^{\circ}C$ had a charge storage density of 60 fc/${\mu}{\textrm}{m}$$^2$at a field of 0.2MV/cm and the leakage current density of 20 nA/$\textrm{cm}^2$ at a field of 0.15 MV/cm.cm.

Effect of Dietary Monascus Pigment on the Liver Damage Induced with CCI₄in Rats

윤종국,--,--,--,-- THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 2003 Journal of biomedical laboratory sciences Vol.9 No.3

In the biological world, there are a number of ecological fights for survival between each organism such as plants, animals and microorganism. In such events, an organism can use its natural bioactive products as defence agent against other organism. Furthermore, natural bioactive products can be utilized for medicine or functional food. Recently, we investigate the effect of Monascus pigment extracted from a fungus, Monascus anke, on the alcohol metabolism and blood lipid profile. In the present study, it is observed that Monascus pigment supplemented dietary may have a hepatoprotective effect on rat's liver damage induced with CCl₄. By treatment with CCl₄(3 times, I.P), liver damage was reduced more in the rats fed 2% Monascus pigment extract supplemented diet than those fed standard diet, based on the serum levels of alanine aminotransferase, microsomal glucose-6-phosphatse activity and hepaic malondialdehyde content. On the other hand, oxygen free radical generating enzymes, hepatic P-450 dependent aniline hydroxylase, xanthine oxidase, and oxygen free radical scavenging enzymes, hepatic glutathione S-transferase, catalase, superoxide dismutase activities were generally higher both in CCl₄, treated group and control fed 2% Monascus pigment extract supplemented diet than those fed standard diet. In conclusion, the rats fed 2% Monascus pigment extract supplemented diet showed more reduced liver damage than those fed standard diet, which may be due to the acceleration of oxygen free radical metabolism.

흰쥐에 사염화탄소 투여가 혈청 Acid Phosphatase활성에 미치는 영향

윤종국,신중규,차상은 한국환경보건학회 1991 한국환경보건학회지 Vol.17 No.2

To clarify a cause of increased serum level of acid phosphatase in CCl$_{4}$-treated rats, the acid phosphatase activity of liver was compared with that serum. Concomitantly, the serum and liver acid phosphatase activity of CCl$_{4}$-treated rats were compared with that of CCl$_{4}$-treated rats pretreated with prednisolone or actinomycin D. In CCl$_{4}$-treated rats, the activity of serum acid phosphatase was significiantly increased whereas that of liver acid phosphatase was rather slightly decreased. the pretreatment of prednisolone led to the decreased activity of serum and liver acid phosphatase in CCl$_{4}$-treated rats. But the pretreatment of actinomycin D rather increased the activity of liver and serum enzyme. In conclusion, it is likely the increased activity of serum acid phosphatase is based on the excess leaking of acid phosphatase into blood by the increased membrane permeability of both liver cell and lysosome in it.

흰쥐에 toluene 투여가 백혈구 xanthine oxidase 및 superoxide dismutase 활성에 미치는 영향

윤종국,이혜자,최미애 한국독성학회 1995 Toxicological Research Vol.11 No.2

This study was designed to observe the effect of tohiene pretreatment on leukocyte variation in whole blood and the oxygen free radical generating, scavenging enzyme activities in neutrophil of bacteria infected rats. Toluene was administered 7 times intraperitoneally at levels of 9.45 mM/kg body weight to the rats and then infected with S. aureus $2\times10^7$ cfu/ml. The toluene treated-rats showed the significantly decreased numbers of lymphocyte and monocytes, but the similiar numbers of neutrophils with the control. Furthermore the increased neutrophils in blood of bacteria infected rats were reduced by the toluene pretreatment. Concomitantly the increased activities of xanthine oxidase and superoxide dismutase in neutrophil of bacteria infected rats were also decreased by the toluene pretreatment. On the other hand, injection of benzaldehyde to rats also led to similiar results in the count of leukocytes, xanthine oxidase and superoxide dismutase activities of neutrophil with those of toluene treated rats. These data suggest that toluene and its intermediate metabolite, benzaldehyde influence on the phagocytosis and defence mechanism of neutrophil.

Fabrication of Ozone Bubble Cleaning System and its Application to Clean Silicon Wafers of a Solar Cell

윤종국,이상헌 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

Ozone micro-bubble cleaning system was designed, and made to develop a uniquetechnique to clean wafers by using ozone micro-bubbles. The ozone micro-bubble cleaning systemconsisted of loading, cleaning, rinsing, drying and un-loading zones, respectively. In case of thecleaning the silicon wafers of a solar cell, more than 99 % of cleaning efficiency was obtained bydipping the wafers at 10 ppm of ozone for 10 minutes. Both of long cleaning time and high ozoneconcentration in the wet-solution with ozone micro-bubbles reduced cleaning efficiency because of there-sorption of debris. The cleaning technique by ozone micro-bubbles can be also applied to variouswafers for an ingot and LED as an eco-friendly method.

철강용접자의 크롬 및 망간 노출평가와 산업위생관리 대책에 관한 연구

윤종국,이영세,박종안,이송권,채종홍,김억수 한국산업위생학회 2000 한국산업보건학회지 Vol.10 No.1

Results of environmental monitoring for 35 steel industry welders exposed to manganese and chromium fume were evaluated. Efficiency of respiratory protectors, welding face shields and local exhaust ventilation were also evaluated to establish more efficient preventive measures that can protect welders from occupational disease as related to welding fume. The results are as follows; 1. Total fume from CO₂ arc welding with mild steel occurred 1.5 to 2.2 times more than that from shielded meta arc welding. Chromium and nickel fume from welding with stainless steel occurred 27 to 59 times and 18 to 30 times, respectively, than those with mild steel. 2. Proportions of water-soluble chromium(VI) and insoluble chromium(VI) Compare to total chromium occurring from CC₂ arc welding with stainless steel were 10.5% and 8.7%, respectively, while those with mild steel were 57.1 to 63.2% and 31.6 to 38.1%, respectively. 3. The efficiencies of 4 types of respiratory protectors to reduce welding fume exposure were evaluated as 54.4 to 64.4%. 4. The reducing effect of head type welding face shield was 67.6%, and that of hand type welding face shield was 58.5%. The highest reducing effect was shown in air supply welding face shield as 99.2%, although it is not convenient to wear. 5. When welding face shield and respiratory protectors were worn together, the reducing efficiency increased to 79.0 to 87.5%. 6. When local exhaust ventilation was installed in workplace, the reducing efficiencies varied from 31.5 to 73.1% according to the types of welding.

흰쥐에 있어서 주정중독이 Toluene 대사에 미치는 영향

윤종국,윤선동,신중규 한국독성학회 1996 Toxicological Research Vol.12 No.2

To evaluate an effect of ethanol pretreatment on the toluene metabolism, toluene (50% in olive oil) was given three times at 0.2 ml/100g body weight at the interval of one day to the rats fed with 5% ethanol during two months. The ethanol pretreated rats were not identified particular liver injury by the histopathologic findings. In case of toluene treatment, the ethanol pretreatment to the rats led to more increased concentration of urinary hippuric acid than those treated with only toluene. The ethanol pretreatment to the rats led to the increased activities of hepatic aniline hydroxylase and these enzyme activities were higher both in toluene treated and those pretreated with ethanol, but no differences were found in two groups. Ethanol pretreated rats showed the more increased activities of benzylalcohol dehydrogenase than control group. Moreover, the ethanol pretreatment to the toluene treated rats led to significantly more increased activities of benzylalcohol dehydrogenase compared with those treated with toluene only. Furthermore, the alcohol pretreatment to the toluene treated rats also led to somewhat higher activities of benzaldehyde dehydrogenase than those treated with toluene. In conclusion, these results indicate that the chronic pretreatment of ethanol at not so much liver damage as normal may rather activate the toluene metabolism.

四鹽化炭素를 投與한 흰쥐에서의 肝臟및 血淸 Xanthine Oxidase活性의 變動

尹鐘國 啓明大學校 生活科學硏究所 1980 科學論集 Vol.6 No.-

This study was intended to observe the changes in liver and serum xanthine oxidase activity after administration of carbon tetrachloride (CCl₄) in rats. The microscopic investigation on the histologic changes of the liver and the determination of serum glutamic pyruvic transaminase (SGPT) in CCl₄ treated rats, were combined in this experiment for a correlation to observe that the activity of xanthine oxidase would be effected by the various degree of hepatic injury induced by CCl₄ serum levels of glutamic pyruvic transaminase being to compare with that of xanthine oxidase, as the determination of SGPT has been widely known as a method of biochemical evaluation of hepatic damage. Female rats of five groups received subcutaneous injections, at 3 days intervals for 13 days, of 0.13ml. 50% solution of CCl₄ in oil per 100g body weight. Each rat was sacrificed after one day of its last injections. The results are as follows; (1) The first group rats, which were administered only the frist dose with the amount of the above mentioned dose each, showed a rapid elevation in activity of xanthine oxidase in serum of each rat, with the continued same high levels of xanthine oxidase throughout the whole course of the experiment, presenting the indentical patterns in case of SGPT but higher proportional increase than xanthine oxidase. (2) The activity of xanthine oxidase in the liver of each rat showed a gradual increase from the first group results reaching the plateau at the third group which received the three doses in three days intervals, with the continued same high levels of xanthine oxidase throughout the whole course of the experiment. (3) In all groups, the chief histopathologic changes in the liver were severe hepatic necrosis and slightly increasing degree of fatty changes as time elapsed. In these results, it is suggested that CCl₄induced liver necrosis should cause the elevation of serum and liver xanthine oxidase activity. In other words, the determination of serum xanthine oxidase activity could be applied for the diagnosis of acute liver damage as necrotic activity in the liver tissue causing a release of abnormal quantities of enzyme into the blood.

브로티건의 『미국송어낚시』에 나타난 상상력과 전원문학전통

윤종국 서강영문학회 1991 서강영문학 Vol.3 No.-

브로티건의 「미국송어낚시」는 "한 미국의 환상"이다. 이 소설은 마크 트웨인과 어네스트 헤밍웨이의 미국전통에 뿌리를 박고 있는바, 이들의 주제는 "인간의 구원이 오로지 복잡한 도시생활을 벗어나 조용한 시골로 도피하는데 있다"는 것이다. 브로티건은 실제적으로 황야 속으로의 도피는 미국에서 불가능하지만 "상상적 도피는 아직도 가능하며 이런 생각이 본 소설의 핵심이다." 이런 환상의 상상적 세계 속으로의 도피행위가 전원적 생각의 한 부분이다.