브레이징 온도 변화에 따른 ZrO2와 Ti-6Al-4V의 접합 특성

기세호,박상윤,허영구,정재필,김원중 大韓齒科補綴學會 2012 대한치과보철학회지 Vol.50 No.3

Purpose: In this study, brazing characteristics of ZrO2 and Ti-6Al-4V brazed joints with increasing temperature were investigated. Materials and methods: The sample size of the ZrO2 was 3 mm × 3 mm × 3 mm (thickness), and Ti-6Al-4V was 10 mm (diameter) × 5 mm (thickness). The filler metal consisted of Ag-Cu-Sn-Ti was prepared in powder form. The brazing sample was heated in a vacuum furnace under 5 × 10-6 torr atmosphere, while the brazing temperature was changed from 700 to 800℃ for 30 min. Results: The experimental results shows that brazed joint of ZrO2 and Ti-6Al-4V occurred at 700 - 800℃. Brazed joint consisted of Ag-rich matrix and Cu-rich phase. A Cu-Ti intermetallic compounds and a Ti-Sn-Cu-Ag alloy were produced along the Ti-6Al-4V bonded interface. Thickness of the reacted layer along the Ti-6Al-4V bonded interface was increased with brazing temperature. Defect ratios of ZrO2 and Ti-6Al-4V bonded interfaces decreased with brazing temperature. Conclusion: Thickness and defect ratio of brazed joints were decreased with increasing temperature. Zirconia was not wetting with filler metal, because the reaction between ZrO2 and Ti did not occur enough. 연구 목적: 온도 변화에 따른 ZrO2와 Ti-6Al-4V의 접합 특성에 대해 알아보기 위하여 새로운 브레이징 합금을 제조하고, 브레이징 온도가 접합 특성에 미치는 영향에 대하여 조사하고자 하였다. 연구 재료 및 방법: 본 연구에서 사용된 시편으로는 실험용 ZrO2 모재(ZirBlank-PS, Acucera, Inc., Gyeonggi-do, Korea)는 소결 전의 블록형태(65 mm × 36 mm × 12 mm (t))이며, 이를 잘라 사포(#2400)로 표면연마 후 소결하였다. 소결된 ZrO2 시편의 크기는 3 mm × 3 mm × 3 mm (t) 이다. Ti-6Al-4V 모재(Ti 6Al 4V ELI CG Bar, TMS, Washington, USA)는 직경 10 mm × 5 mm (t)를 사용하였다. 소결된 ZrO2와 Ti-6Al-4V의 접합을 위하여 브레이징 합금을 제조하였다. 시편을 3군으로 나누어A군은 700℃에서, B군은 750℃에서, C군은 800℃에서 각각 브레이징 하였다. 브레이징 부의 두께와 결함율의 측정은 각 군당 하나의 시편으로 각 시편 당 5회씩 반복 측정하여 평균값을 취하였다. 결과: 브레이징 합금을 사용하여 진공 브레이징을 수행한 결과 ZrO2 와 Ti-6Al-4V 는 700℃ - 800℃에서 양호한 접합을 보였다. 브레이징 후 브레이징 온도 변화에 따른 브레이징 부의 두께 및 결함율의 변화는SEM을 사용하여 측정하였다. 브레이징 온도가 700℃에서 800℃로 증가함에 따라 CuTi 금속간 화합물 층 및 Ti-Sn-Cu-Ag계 화합물 층의 두께는 각각 4.5 ㎛에서 10.3 ㎛로, 3.1 ㎛에서 5.0 ㎛로 증가되었다. 또한 브레이징 온도가 700℃에서 800℃로 증가함에 따라 브레이징 접합계면의 결함율은 ZrO2 및 Ti-6Al-4V 계면에서 각각25%에서 16.3%, 5%에서 1.5%로 감소되었다. 결론: 브레이징 온도가 700℃에서 800℃로 증가됨에 따라, 브레이징 접합계면의 결함율은 ZrO2 및 Ti-6Al-4V 계면에서 모두 감소되었다. 이는 결함부에서 ZrO2와 활성원소인 Ti과의 반응이 충분히 일어나지 않아서 브레이징 합금이 ZrO2에 웨팅되지 않은 것이 원인이라고 사료된다.

복강경하 대장절제술을 시행 받는 환자에서 라모세트론과 온단세트론외 술 후 오심 및 구토 예방 효과 비교

김효중;어전영;어근무;어정한;엄세훈;조광래;김명훈 인제대학교 2011 仁濟醫學 Vol.32 No.-

Objectives : We evaluated the efficacy of ramosetron and ondansetron for preventing postoperative nausea and vomiting (PONV) in laparoscopic colectomy. Methods and Materials : Eighty patients who received laparoscopic colectomy were randomly divided into two groups: R group (ramosetron 0.1mg PO) and O group (ondansetron 4mg twice IV). Injection or oral medication was administered before the induction of anesthesia in each group. Injection was administered at the end of surgery in O group. General anesthesia was induced using propofol and rocuronium, and maintained with sevoflurane, remifentanil and air (FiO2 0.5), We investigated the incidences of PONV in each group by the Rhodes index of nausea, vomiting and retching (RINVR) at postoperative 6 and 24 hours. Results : The incidence of PONV was not different between group at each time points after surgery (at postoperative 6 hours: 20% in group R, 17.5% in group 0, at postoperative 24 hours; 12.5% in group R, 7.5% in group 0). There was no difference in the severity of PONV, satisfaction, rescue drug usage. Conclusion : Prophylactic therapy with ramosetron is as effective as conventional prophylactic therapy with ondansetron for preventing PONV in general anesthesia for laparoscopic colectomy.

지구과학 학습용 Computer program 연구 : 고등학교 지구과학Ⅰ 제1단원을 중심으로 Centering around the First Unit of Highschool Earth Science Textbook Ⅰ

尹世重,金在炫,崔錫源 공주대학교 사범대학 과학교육연구소 1984 과학교육연구 Vol.16 No.1

A Computer program which could be used for teaching material in new curriculum of highschool earth science course was programed with Goldstar Co. model FC-100 personal computer in BASIC language. The main contents of this program are calculation of radius, mass, average density, the acceleration of gravity of earth and evidences for rotation of earth etc. All these substances are explained with Korean or English and by means of derivation of formula, calculation or dynamic graphs.

師範大學 科學科 實驗實習敎育의 模型硏究

尹世重,李聖瑞,徐廷穆,崔鎬亨,蘇鮮燮 공주대학교 사범대학 과학교육연구소 1984 과학교육연구 Vol.16 No.1

師範大學의 生物 實驗 敎育의 改善 方向을 강구하기 위하여 전국 15개 師範大學의 生物敎育科에서 敎育하고 있는 실험 실습을 학점을 중심으로 조사하였고 아울러 20개 非師範系 대학의 생물 실험실습 학점도 조사하여 비교하고, 분석 하므로서 다음과 같은 몇 가지 결과를 얻게 되었다. 1) 師範系 生物 敎育科의 전공 학과중 實驗 實習 배정시간 및 학점수를 늘려 나가야 하겠다. 2) 探究學習 지도 能力을 保有할 수 있도록 實驗 實習 指導 改善 方法을 강구해야겠다. 3) 基礎 共通科目은 3과목 모두를 최소한 1학기는 이수토록 해야 하고 반드시 실험 실습을 竝行 하여야 하겠다. A study for the model of the laboratory experiment curriculum in teacher's college seience was done. Because of individual characteristics in each field in department sc-ience education, the model was not necessarily unique. However, the common elements of frame in this model were suggested as follows : 1. The ratio of laboratory experiment's credits and total major credits. 2. The ratio of basic common laboratory experiment's credits (basic physics, basic chemistry, basic biology, and basic earth science) and total laboratory experiment's credits. 3. Credits and course name of laboratory experiments charactoristic for the science education in teacher's college. 4. Suggestion of the experimental guide for an inquiry learning.

질량 명사와 가산 명사의 전환에 따른 영어 관사 용법

김세중 단국대학교 1998 論文集 Vol.33 No.-

The aim of this dissertation is to answer the following questions so often asked by adult language learners of English: (a) in which case do we use the? (b) in which case do we use a(n)? (c) in which case do we use Φ­­before nouns. This dissertation deals with what are the signals for the occurrence of the articles ―a(n), the, Φ―before nouns. This study discusses sho to distinguish count couns from mass ones and what makers an NP definite and what makes it indefinite. It also discusses the generic use of the English articles. This dissertation puts great emphasis on the best way to convert a mass noun into a count noun and vice versa. Five principles are presented for mass/count conversion. The best plausible signals for the English articles are found to be existence, uniqueness and familiarity Subtle differences among the generic use of the, a(n) and Φ are discussed and their respective distributions and restrictions are suggested. An over-all system of article usage is presented for learners of English as a foreign language.

복합인식기를 이용한 무제약필기체 숫자인식

박중조,송영기,이세영 慶尙大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.13 No.-

본 논문에서는 무제약 필기체 숫자의 인식을 위한 특징추출 방법과 인식기의 성능을 개선하기위한 인식기결합방법을 제시한다. 특징추출 방법은 영역분할특징, 교차특징, 그리고 방향특징으로 구성된다. 또한 단일 신경망을 이용했을 경우의 여러가지 문제점 즉, 수렴성, 계산의 복잡성 그리고, 정확성등을 개선하기 위한 방법으로 퍼지 적분을 이용하여 신경망을 결합하는 방법을 이용하였다. 캐나다 Concordia대학의 데이터를 이용하여 인식한 결과 97.7%의 인식률을 보였으며, 제시된 특징추출방법과 인식기의 결합이 좋은 성능을 지니고 있음을 보인다.

번역의 역사를 통한 이론과 기법

金世中 단국대학교 1995 論文集 Vol.29 No.-

The purpose of this essay is to fine out a new and good approach to translation by considering the history of translation and its theory. This essay deals with the technique of practical translation through an anthology of essays from Cicero to George Steiner. I also want to introduce translation studies to the students and scholars interested in it. I have considered the history of modern Korean literary translation from 1920s to 1950s in all its chronological aspects. A lot of problems in the course of discussion on translations were found, but nobody dared to raise the question of that. The only person who did so was then Yang Zoo-Dong who was qualified for translation. The extent to which cultural extent may feasibly be reproduced in a translation is something that should concern any translator of Korean literature. The culture of Korea is ancient and deeply rooted. As a result, those who want to reproduced a Korean text in a TL text will need to have access to cultural information rather than language proficiency. Each and every country is making every effort to win in international competitiveness, but there are now few not only professional centers and institutions for translation but also programs of translation and intercultural studies in Korea. We will have to survive in the fierce competition among the world. In my opinion, the government needs to support them as soon as possible. Paul Engle, Director of the Writer's Workshop at the Univ. of Uowa(1985) summed up the socially active, politically urgent cause of translation in the contemporary world as follows. As this world shrinks together like an aging orange and all peoples in all cultures move closer together(however reluctantly and suspiciously) it may be that the crucial sentence for our remaining years on earth may be very simply : TRANSLATE or DIE. The lives of every creature on the earth may one day depend on the instant and accurate translation of on word.(Engle and Engle, 1985 : 2) The time has come for us Koreans to make our country international, global and worldwide in every aspect. We need to gather information on education, science, economy, business, etc, so as to do so. Information is based on language with signs, because information alone has no power of communication without the medium of exchange of language. communication through language underlies translation and interpretation. This essay deals with the discussion of the vague conflict between free and literal translation. The establishment of an international collaborative venture on Translation Studies seems a logical way to proceed. The discussion of all types of literary translation also be greatly advanced by a consideration of the problems of translation texts from all over the world. Translation Studies including its Theories and History is still a young discipline and still has a long way to go. There is a need for more general theoretical discussion as to the nature, history and theory of translation, particularly as to the craft and process of translation. This essays comprise a variety of aspects that provide the reader with insights into the complex process of recreating an SL text in English. The Herman's study of the metaphors used by Dutch, French and English translator in the Renaissance has provided an extensive range of ideas about translation-the translator is variously seen as following in the footsteps of the original author. By the eighteenth century, dominant metaphors are of the translation as a mirror or as a portrait, the depicted or artificial held up against the real, while in the nineteenth century the dominant metaphors involve properly and class relations. The traditional nineteenth-century notion of translation was based on the idea of a master-servant relationship paralleled in the translation process-either the translator takes over the source text and improves and civilizes it or the translator approaches it with humility and seeks to do it homage. All translators agree that the perfect translation remains an impossibility. Gregory Rabassa expresses the recognition writing : "a translation can never equal the original ; it can approach it, and its quality can only be justified as to accuracy by how close it gets." There have been a number of attempts to open up the vast field of genealogy of systematic thought about translation in different cultures and to investigate the way in which translation has played a shaping role in the formation of literary systems and the history of ideas. Translation, like criticism, is a manipulatory process. Human emotions hardly change from on culture to another ; what changes in the way on perceives these emotions and one places them within the natural environment of a country. A cultural situation-whether in the realm of social, educational, or political realities-never finds its exact equivalent in another country. Here again, translators must assess the boundaries of every individual cultural situation to define both the sameness and the differences. As in the case of word, the comparative study of cultural situations will prominently display the different ways in which we perceive and create our cultural reality. Words don't find their equivalencies in the new language, nor do cultural expressions, and the translator will never approach a text twice the same way. All acts of translation begin with a thorough investigation of reading process. Translation, by necessity, read each word and sentence at least as carefully and closely as the critic or the author. Even the smallest detail in an SL text, as Rabassa points out, be neglected. Translation is, of course, a rewriting of an original text. All rewritings, whatever their intention, reflect a cretain ideology and a poetics and such manipulate literature to function in a given society in a given way. I hope this essay will serve to aid a future study on Translation Studies and to further open the door for new, alternative approaches. Much work still needs to be done.

TLC 검출의 適用硏究 : 環境科學 敎材硏究 A Teaching Material of Environmental Science

尹世重 공주대학교 사범대학 과학교육연구소 1977 과학교육연구 Vol.9 No.1

微量成分을 分離하고 確認하는데 여러가지 方法이 있지만, 그 중에서도 學生實驗敎材로 적합한 것으로는 chromatography를 들 수 있다. 특히 paper partition chromatography와 thin layer chromatography(TLC)는 실험이 간편하고 活用범위가 넓고, 많은 학생들에게 일일히 실험 시킬 수 있고, 時間을 유효하게 활용할 수 있고, 또 費用이 많이 들지 않기 때문에 널리 활용될 수 있는 方法이다. TLC는 paper partition chromatography와 거이 같은 내용의 조작을 하면서도, 전展開시간이 짧고 分離가 선명하게 잘 된다는 利點이 있다. 짧은 시간에 많은 학생이 하는 實驗敎材로 아주 훌륭하다. 이 實驗은 TLC를 활용하여, 微量으로도 生理的으로 活性인 alkaloid, caffeine에 대하여 여러가지 溶媒에 따라 Rf값을 측정하여 용매와 試料사이의 상관관계를 알아보고, 각종醫藥品과 市販되는 飮料水에서 caffeine 성분을 檢出해 내는데 適用시켜 보았다. 이를 통하여 TLC 적용의 技術뿐만 아니라, 溶媒의 極性에 따르는 시료의 分配原理를 익힐 수 있도록 시도해 보았다. Thin Layer Chromatography(TLC) is an excellent method for detection and separation of trace amounts of component. Because of shorter running time, clear detection, versatile application, and inexpensiveness, it can be available for non-major students experiment in college and for major students as well. In this experiments, the Rf values were measured when run with various solvents and observed the relationship on the partition of samples against solvents. Caffeine was detected from several drugs and commercial of samples against solvents. Caffeine was detected from several drugs and commercial soft drinks. This would be a base for detection of other biological active pollutants as well as an alkaloid. The Rf value of caffeine was largest in solvent which has a intermediary polarity such as chloroform, and was smallest in solvent which has either larger polarity or nothing such as ethanol or cyclohexane. The best solvent for detection of caffeine from samples was a mixed solvent, chloroform-ethylacetate 1:1 by volume.

외국어 습득 이론과 모형 : Krashen의 이론을 중심으로

김세중 단국대학교 1998 論文集 Vol.32 No.-

This is a study on second language acquisition(SLA) and English education focusing on the theory by Krashen. This area (SLA) can be said either a very brand new beginning stage or a polemic one unlike the field of first language acquisition. Because of this context researchers tried to accept the concepts and theories directly from that of the first language acquisition theory in the past. This attitude, however, has been perceived as mainly incorrect and then they began to change their way of thinking and now they are doing their job independently. In this article I briefly take a look at the chronological aspect of English education as a second or foreign language, and then I try to collect the related theories of SLA. Krashen's theory is one of these SLA theories. I pay attention to the advantage and disadvantages of the theory and on the basis of my knowledge, insights, and teaching experience I would like to release my academic critique on the theory in order to provide a better understanding of the classroom learning and SLA process. Anyway this paper investigates the effect of Krashen's theory on the SLA.

휴대용 계산기에 의한 착물의 안정도상수의 계산

윤세중,오제직,박병빈,박성록 공주대학교 사범대학 과학교육연구소 1980 과학교육연구 Vol.12 No.1

A Pocket calcultor program(Texas Instruments TI58 or TI59) was constructed for evaluation of the Successive stability constants of Nikel-glycine complex. This program conld be used for many other systems having similar eguhibrium scheme and experimental method. TI59, this program could be extended to the calculation of ionic strength correction and high n Complexes.