LC50 Determination of tert-Butyl Acetate using a Nose Only Inhalation Exposure in Rats

양영수,Jinsoo Lee,Soonjin Kwon,Heung-Sik Seo,최성진,Hee-Jin Yu,송정아,Kyuhong Lee,Byoung-Seok Lee,Jeong-Doo Heo,Kyu-Hyuk Cho,송창우 한국독성학회 2010 Toxicological Research Vol.26 No.4

tert-Butyl acetate (TBAc) is an organic solvent, which is commonly used in architectural coatings and industrial solvents. It has recently been exempted from the definition of a volatile organic compound (VOC) by the Air Resources Board (ARB). Since the use of TBAc as a substitute for other VOCs has increased, thus its potential risk in humans has also increased. However, its inhalation toxicity data in the literature are very limited. Hence, inhalation exposure to TBAc was carried out to investigate its toxic effects in this study. Adult male rats were exposed to TBAc for 4 h for 1 day by using a nose-only inhalation exposure chamber (low dose, 2370 mg/m3 (500 ppm); high dose, 9482 mg/m3 (2000 ppm)). Shamtreated control rats were exposed to clean air in the inhalation chamber for the same period. The animals were killed at 2, 7, and 15 days after exposure. At each time point, body weight measurement, ronchoalveolar lavage fluid (BALF) analysis, histopathological examination, and biochemical assay were performed. No treatment-related abnormal effects were observed in any group according to time course. Based on those findings, the median lethal concentration (LC50) of TBAc was over 9482 mg/m3 in this study. According to the MSDS, the 4 h LC50 for TBAc for rats is over 2230 mg/m3. We suggested that this value is changed and these findings may be applied in the risk assessment of TBAc which could be beneficial in a sub-acute study.

용융금속 액적의 고체표면 충돌거동

양영수,손광재,강대현 대한용접접합학회 2000 대한용접·접합학회지 Vol.18 No.4

This paper presents a study of the solder bumping process. The theoretical model, based on the variational principle instead of solving the Navier-Stokes equation with moving boundaries, was developed to considered the energy dissipation in semi-solid phase and the approximate solidification time of the molten metal droplet. The simulation results revealed that the developed model could reasonably describe the collision behavior of molten metal with solid surface. Simulations were made with variation of initial droplet temperature, substrate metal and initial substrate temerature.

자동 요소 생성법을 이용한 대형 용접구조물의 해석

양영수,이세환 대한용접접합학회 1998 대한용접·접합학회지 Vol.16 No.1

The accuracy of the finite element method depends upon the mesh that is used in the analysis. The temperature around the arc is higher than the melting point of the materials, and it drops sharply in the regions just away from the arc. This requires an extremely fine mesh in the confined high temperature region to predict the temperature accurately in that region. But the computational time increases with the fineness of mesh. Since fine mesh is required only around the arc source, adaptivity of the input mesh according to the position of the arc source is efficient. The remeshing technique gives a fine mesh in the high temperature region around the arc and a coarse mesh in other region at any time step. With this it is possible to achieve desired accuracy with less computation time. In this study a transient adaptive mesh, remeshing technique, is developed and calculated temperature for a sample problem.

파이프 용접에서 기계적 잔류응력 이완법에 관한 연구

양영수 대한용접접합학회 1996 대한용접·접합학회지 Vol.14 No.1

The heat transfer and thermal stress-distribution were numerically determined by using the finite element method for a butt-welded pipe. A mechanical stress relieving(MSR) treatment which has been frequently used in the fabrication of pressure vessels instead of the post weld heat treatment (PWHT) was also simulated to investigate its effect of reducing the residual stress in the welded zone by a mechanical loading.

제주와 중국 및 그리스 신화의 비교

양영수 제주대학교 동아시아연구소 2000 東아시아硏究論叢 Vol.11 No.-

This comparative study tries to find similar and different points among Cheju, Chinese, and Greek mythologies, and the comparative examination in this paper in made in two aspects, i.e. the relation between human and divine entities and the one among divine entities. As for the fires aspect, the supreme purpose of the divine entities in Chejuian and Chinese mythologies is to help to enhance the well­being of human beings, Difference between these two mythologies is that Chejuian god's help centers on the individual person's fortunes, while Chinese god's help centers on the universal establishment of natural order. This kind of difference seems to come from the face that Cheju mythology is mostly shamanistic, while Chinese mythology derives mostly from the art of ruling which is the more effectively practiced by propagating some plausible order of the world. The supreme purpose of Greek gods is to satisfy their own desires, not the human beings' prayer, and so the interests on the part of men must be pursued by their own struggle with ruling gods. As for the second aspect, the relation among Chejuian gods is Characterized by the principle of peace, sine they are showing to antagonistic conflicts among themselves: the relation among Chinese gods by the principle of pacification, since their power struggles, if any, are reduced to the state of peace by the ruling supreme god: the relation among Greek gods by the principle of struggle, since they are pursuing endless struggle either in governing the world or in amorous affairs. Greek gods' tendency of struggling disposition seemingly gives rise to the dynamic structure of their character, which has been used as prolific materials of artistic creation in literary and visual representation of the humanity.

과정신학적 관점에서 본 죠지 엘리어트의 신앙편력

양영수 제주대학교 사범대학 2001 백록논총 Vol.3 No.1

Changes of religious experience in George Eliot's own life resembles, in a way, the evolutionary process of Christianity in the Western Culture. The unconditional belief in her early years in the Anglican Church and then in the Evangelical Puritanism corresponds to the simple belief of the Early Period Church. Her sceptical attitude and refusal to go to church in her early twenties (enlightened by free thinkers such as C. C. Hennel, D. F. Strauss, and Ludwig Feuerbach) corresponds to the negation of the revealed Christianity by the Enlightened Thinkers or materialistic scientists. Her com - promise with her family and community in refusing the belief but accepting the custom and morality of Christianity is similar to unbelieving eclecticistic church-goers in the Christian-oriented society. She didn't return to dogmatic Christianity, but she saw in it the highest expression of moral sentiment. When she agreed with Feuerbach to identify God with the essence of man, she felt like thereby paying god the highest possible honor. This paper tries to interpret George Eliot's change of religious attitude in terms of evolutionary concepts and process thought as proposed by Alfred N. Whitehead. According to process theology, God is influenced by the world, and divine love is equal to supremely sympathetic participation in the world process. This way of thinking leads us to accept the model of god as communicator of information, who distributes pieces of information for mankind and makes for more truthful worship in the process of bringing to light the Providence or the order of the Nature. Hence comes up a position where both the Christian creationism and scientific evolutionism come to getting together instead of conflicting. George Eliot tried to find out a new kind of moral standard which would replace Christianity to serve unbelievers' conscience in the modern times. We can sympathize with her when she reached the idea of "sympathetic imagination" as a useful source of morality in place of a revealed religion, because she herself lived a life which needed just this sympathetic imagination on the part of her own family and her contemporary fellow citizens.

유도가열을 이용한 강판성형공정에서 유도코일 형상의 효과

양영수,배강열,신희윤,Yang, Young-Soo,Bae, Kang-Yul,Shin, Hee-Yun 대한용접접합학회 2008 대한용접·접합학회지 Vol.26 No.4

Because of high intensity and easy controllability of the heat source, high frequency induction heating has been concerned and studied for the steel forming process in the ship building industry. However, the heating and forming characteristics have to be further properly modelled and analyzed for the process to be utilized with its optimal working parameters. In this study, a modelling with thermo-elasto-plastic analysis is performed using the FEM to study heat flow and deformation of the steel plate during the forming process with the electro-magnetic induction heating. The numerical model is then used to study the effect of the inductor shape on the magnitude of angular deformation of the plate during the forming process. It is revealed that the square shape of inductor induces the largest deformation among the rectangular inductors.

하아디와 로렌스 문학에 나타난 자연주의적 성향

양영수 한국로렌스학회 2007 D.H. 로렌스 연구 Vol.15 No.1

It can be soundly said that two different elements of idiosyncratic view of the Nature, those of romanticism and naturalism, are characterizing Thomas Hardy and D. H. Lawrence The former element came from time-hornored tradition beginning with the primitive society and lies roughly in common with Christianity in terms of spiritual force immanent in the Nature The latter element was formed together with the modern scientific view of the universe, Darwinism in particular, which tends to look on human life in the light of natural law Hardy's literary world is, however, only limitedly naturalistic since it lacks strict application of scientific analysis and dispassionate reasoning while including pathetic and myterious features Hardy so often falls into sentimental imagination when he introduces the natural law of the survival of the fittest or the genetic inheritance Lawrence's literary world is situated at the intersection of the two ways naturalist-materialist reading of the universe expounded by Darwinism and the transcendentalist-vitalist reading of the romantic Nature tradition Comprehensively speaking, such points of comparison as following can be mentioned Firstly, the nature in Hardy's world looms as formidable and antagonistic to human purposes while Lawrence's nature is viewed as the sources of bountiful vitality and inspiration Secondly, enthusiastic lovers in Hardy's literature suffer from final frustration even in the heart of natural habitation, while Lawrence's loving characters meet more successful outcomes with the helping influence from the nature Thirdly, Hardy's literary characters in general undergo the climax of insignificance of life at the moment of their death, while most of the characters in Lawrence's literature go through the magnificence and reverence of life right on their deathbeds, with the former inclined to reductive meaning of life and the latter to expansive meaning of life.

곡가공에서 인공신경망을 이용한 가열선 예측 기법

양영수,배강열,Yang, Young-Soo,Nguyen, Truong-Thinh,Bae, Kang-Yul 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.4

D.H.로렌스의 『사랑하는 여인들』에 나타난 현대문명비판

양영수 제주대학교 1994 논문집 Vol.39 No.1

Most of D.H.Lawrence's novels deal with love affairs between men and women, but they can also be interpreted as criticism on the modern civilization, of which Women in Love is no exception. Two major characters in this novel, Gerald and Gudrun, can be seen as the objects of critical discussion on contemporary civilization, for they are representative of two major traits of the modern life-style shared by social and cultural leaders. Gerald, who appears as an 'industrial magnate', exemplifies the strong will to power which is the driving force of modern industrial society. He is eager to subjugate natural power to his will and to exercise complete control over the laborers of his mining company. His extraordinary ability as a mechanical leader in business goes so far as to make his existence redundant, which causes his deep frustration as a human being. He turns to Gudrun's dallying love for salvation from his feeling of futility. But Gudrun is a ruthless woman who needs no love from a man. She gradually turns on him and grows to take to Loerke, a German sculptor, for she is a self-assured woman who can sacrifice her own love for artistic creation. Gerald's despair in love drives him to nearly throttle Gudrun. He wakes up and goes into the Alps only to be snowed up. Both of them get ruined in their love just because they are overly faithful to their strong will to power or artistic creativity, which can be seen as the basic well-spring of flourishing modern society. It is rather ironic that Birkin and Ursular, two other major characters in this novel, should be able to get along comparatively well in their love affair in spite of the incipient hardships arising from the difference of their love morality, for they are free of such strong will as to participate self-assertively in the modern siciety, whether industrial or artistic. They wants to retreat completely from it, considering it quite meaningless. Their love for each other is such that they don't have misgivings over being separated from each other, or, conversely, being too close to each other because they believe in love as independent as between constellations. It is regrettable that Women in Lot'e should have been affected so negatively by the author's own dreary experiences in the course of writing it as to be a less persuasive diagnosis of malady of modern civilization. But the pictufure of Gerald and Gudrun is a vivid and plausible creation of some strong-willed characters of modern industrial society, and a symbolic manifestation of certain peculiarities in the diversity of the contemporary life-style, while Birkin and Ursular are the extreme cases of pessimistic and secluded individualism.