Effect of Cooling Rate on Mechanical and Electrical Properties of Cu-TiB₂ by Turbulent In-Situ Mixing Process

Park, J.S.,Yun, J.H,Park, Young Do,Park, Yong Ho,Cho, Kyung Mok,Park, Ik Min Scitec Publications Ltd. 2007 Solid State Phenomena Vol.119 No.-

<P>A copper matrix composite reinforced with in situ TiB2 nanoparticle was successfully fabricated by tubulent in-situ mixing process. The microstructure, mechanical and electrical properties of the in situ composite were investigated. The results showed that the in situ formed TiB2 particles, in which size varying from about 50nm to 200nm, exhibited a homogenous dispersion in the copper matrix. It is shown that the interface between the nanoscale particles and the matrix was clean without a transitional layer. Because of the reinforcement, the hardness and Young’s Modulus of the composite improved with increment of cooling rate. Moreover, the in situ Cu-TiB2 composite exhibited higher electrical conductivity with increasing of cooling rate.</P>

作文 硏究의 最近 動向과 展望

朴泳穆 弘益大學校 敎育硏究所 1995 敎育硏究論叢 Vol.- No.12

The purpose of this study is to trace the emergence of composition studies as one partof a more general intellectual history concerning the problems of meaning in discourse, and to summarize the trends and perspectives of composition studies. The study of rhetoric generated not only an elaborate system for investigating language practices but also theoretical questions about the relationship of language to knowledge. The system of classical rhetoric was too powerful to be limited to to the few forms of public speaaking to which it was originally applied, and the questions about language ans knowledge rasied by classical rhetoricians were never to be put to rest. After the classical rhetoric period, all forms fo discourse ans symbolic communication can be reduced within its scope. The history of rhetoric is the story of long struggle to understand the relationship between discourse and knowledge, communication and its effects, language and experience. Recent developments in composition studies as well as both critical and linguistic theories have parraled each other in fundamental ways. The 1950s were largely a period of formalism. In compositon, learning to write meant learning to avoid text errors. Formalis assumed an objectivity of text elements, contending that all important issues about text and text meaning could be adressed through analysis of text elements and their inter-relationship. Evidence concerning language processes such as writing, reading, and thinking was held to be unobjective, unreliable, and spurious. In the late 1960, formalist conceptions of composition came under attack and began to wane, and scholars began to think of writing not in terms of text or products but rather in terms of the cognitive processes of writing. This view of language as a cognitive, constructive process motivated writing scholars to reconceptualize writing as dynamic processes of constructing meaning. In this constructivist view, language orders and gives shape and meaning to experience. The meaning were said to be generated and then stored as mental representation. In the 1980s, the cognitive studies supplemented by social analysis that proved the character of interpretive and discourse communities and investigated the dialogical nature of written communication. This social reorientation of the field demanded that composition scholars reevaluate sorne pet of cognitivist assumptions that had virtually swept the field by the early 1980s. Thus writing scholars began to interprete the different genres of academic writing ain terms of didcourse communities to describe the social and historical nature of writing. They suggest that individual writers compose not in isolation but as members of communities whose discourse practices constrain the way they structure meaning. Thus the problem students face in writing could be explained by their lack opf familiarity with the forms and conventions of academic discourses.

개에서 직장탈의 수술적 치료 1례

박정희,김영실,신영지,박창식,전무형,김명철,정성목 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

A 3-year old, male Jindo dog was referred with history of tenesmus, dyschezia and recurrent rectal prolapse. On the physical examination, the rectum was prolapsed about 10 em, congested and necrotized. Fecal incontinence and pain were observed. Complete blood count revealed a mild leukocytosis and there were no remarkable abnormalities in serum biochemistry profiles. It was diagnosed as a rectal prolapse. Rectal resection and anastomosis was performed for necrotic tissue removal. On postoperative fecal smear, protothecosis was observed. Amphotericin B was administered. There has been no evidence of recurrence of rectal prolapse for ten months.

개에서 피지선 과형성의 진단 및 치료 증례

박희서,손화영,정성목,송근호,조종기,이영원,신상태,김명철,김덕환,박성준 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

An eleven year old castrated male Maltese was presented to the Veterinary Medical Teaching Hospital of Chungnam National University. In physical examination, approximately 0.5 cm round mass was observed on tail base. This small elevated mass has also shown alopecic and firm configuration. It was differentially diagnosed as sebaceous adenoma and hyperplasia by fine needle aspiration. After surgical removal, the sample was diagnosed as sebaceous hyperplasia by histopathological examination. It has not yet shown any signs of recurrence and prognosis has teen good.

作文 能力 伸張 方案 硏究

朴泳穆 弘益大學校 敎育硏究所 1994 敎育硏究論叢 Vol.- No.10

The Purpose of this study is to summarize the knowledge acquired from writing research and to draw implication for writing instruction. Recently, composition theorists are pointing out the need to consider the role of academic disciplines in writing. The use of writing in specific academic settings is usually a function of a teacher and the construct this teacher has of the writing purpose and context. the writing acroos the curriculum movement has come from a growing body of theory linking writing to learning. This theory argues that writing is ideally suited for the discovery, formulation, and expression of ideas. Academic discipline, whose instructional goals are to teach students a body of knowledge while also helping them to acquire the communication skills, thinking skills, and positive emotions of professionals in the field, emphasize on writing as a mode of learning. Composition theorists are pointing out the need to consider the role of the situation in writing. Writing does not occur in a vacum. It always occurs in some kind contexts. A piece of writing comes into existence as the result of a response to a situation that often demands immediate attention. A writing situation consists of the complex interrelations of persons, events, and objects which the writer must take into account in order to bring about a change in the sistuation. A writing situation must take into account the reader, the writer, the subject of writing, and the writer's purpose. Research on composing has exploded that the composing process has much in common with the problem solving processes people use every day. The experts in their fields are characterized by two things: a great deal of knowledge about their topics and a large repertory of powerful strategies for attacking their problems. Good Writers share these qualities. They are people who have developed better ways to entertain the problems of writing. The problem solving strategies of the experts writers can give them the enormous power of conscious choice - the power to guide, test, and alter their own problem solving process.

이산화질소, 암모니아 및 수분의 기상반응에 의한 이산화질소 제거 거동에 관한 연구

목영선,장경룡,박태성,김경숙,남인식 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.1

암모니아 첨가 저혼 플라즈마 공정이나 전자빔 공정에서 NO의 산화반응을 통해 생성되는 NO_2를 효과적으로 제거하기 위한 조건을 도출하기 위하여, 문헌의 반응속도에 기초한 반응기 모델링을 통해 NO_2 저감에 미치는 여러 가지 운전변수의 영향을 살펴보았다. 본 연구에서 운전변수로 선정한 것은 수분함량, 초기 NO_2 농도, 반응온도 그리고 암모니아 농도이며, 각각의 운전변수에 대한 적정 범위를 결정하였다. NO_2를 효율적으로 제거하기 위해서는 배기가스의 수분함량이 4-6%(v/v)이상은 되어야 하나, 수분함량을 더 증가시키는 것은 큰 이득이 없는 것으로 나타났다. 초기 NO_2 농도가 100ppm 이하로 작을 때는 원하는 제거효율을 달성에 필요한 체류시간이 급격히 증가하며, 반응온도는 낮을수록 NO_2제거에 유리한 것으로 나타났다. NO_2 저감 속도는 암모니아 농도이며, 각각의 운전변수에 대한 적정 범위를 결정하였다. NO_2를 효율적으로 제거하기 위해서는 배기가스의 수분함량이 4-6%(v/v)이상은 되어야 하나, 수분함량을 더 증가시키는 것은 큰 이득이 없는 것으로 나타났다. 초기 NO_2 농도가 100ppm 이하로 작을 때는 원하는 제거효율 달성에 필요한 체류시간이 급격히 증가하며, 반응온도는 낮을수록 NO_2 제거에 유리한 것으로 나타났다. NO_2 저감 속도는 암모니아의 농도에 크게 의존하지 않는 것으로 평가되었다. This study reports a simple reactor modeling utilizing chemical kinetic data of the gas phase reaction between nitrogen dioxide, ammonia and water vapor in order to estimate the influences of several operating variables on the removal of NO_2 which is generated from NO by the oxidation process in a non-thermal plasma reactor or an electron-beam irradiation reactor. The operating variables chosen are water vapro content, initial concentration of NO_2, reaction temperature and ammonia concentration and the appropriate ranges of such variables were suggested. The gas phase reaction for the removal of NO_2 takes place effectively at the water vapor content higher than 4-6%(v/v), but further increase in the water vapor content does not significantly enhance the removal. The residence of NO_2 is less than 100ppm. Since the removal rate of NO_2 is in inverse proportion to the reaction temperature, lower temperature is favorable to promote the reaction. The effect of ammonia concentration on the removal of NO_2 was estimated to be negligible.

Coating을 시행한 뇌동맥류 파열환자의 예후

박종혁,석종식,목진호,박관,김영백,민병국,황성남,최덕영 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.6

In rare occasions in which aneurysmal neck clipping is nearly impossible, coating is employed. During the period from 1985 to 1992, 312 patients with aneurysm underwent surgery ; aneurysmal neck clipping were performed in 284 cases while coating only in 28. The reasons that coating was required were ; wide and broad neck in 13, perforators arising from the neck in 4, neck tearing during dissection in 3, very friable neck in 2, severe adhesion with surrounding structures in 3, and small aneurysm without enough room for clipping in 3. In twenty-three cases, cotton wisp and bioglue were used as coating materials. In another five cases, the aneurysmal wall was reinforced using Surgicel or Gelfoam. Patients were followed for 24 months on average of all the patients. Four had last contact Six died(4 due to rebleeding and 2 due to pneumonia). Fourteen were good and 4 were moderately disabled. There were no rebleeding incidences during first three months' follow-up after coating. We thus concluded that coating an aneurysm offers some protection from rebleeding, particularly when the rebleeding risk period is over.

" The Korean Journal of Chemical Engineering " 게재 논문 요약 : Processabilities & Mechanical Properties of the Biodegradable LDPE / Modified Starch Blends

Young Jin Kim,Yong Man Lee,Hyang Mok Lee,O Ok Park 한국화학공학회 1994 NICE Vol.12 No.5

N/A An investigation of the biodegradable polymers based on starch has been accomplished. Starch needs to be modified before blending with low density polyethylene(LDPE) because of its hydrophilicity. Three kinds of modification methods were applied to obtain the compatibility to starch-LDPE blends. The first one was the esterification of the hydroxyl group of starch with acetic anhydride. The second was the copolymerization of actylonitrile and styrene onto starch. The last was the esterification reaction of the hydroxyl group of starch with three kinds of ionomers. The tensile strength, % elongation, Young`s modulus, and shear viscosities of blends of the modified starch and LDPE were examined. Ionomer-treated starch showed better compatibility with LDPE to give better performances than other blends.

作文活動 過程에서의 社會認知的 意味 協商

朴泳穆 弘益大學校 敎育硏究所 2001 敎育硏究論叢 Vol.- No.18

Writing is a kind of social cognitive act. Writers construct meaning within the broader context of a social and cultural context of language and discourse conventions. And also writers construct meaning within the immediate context of general purposes, specific goals, and activated knowledge linked to the task at hand. Writers build socially shaped, individually formed meanings. In some circumstances, the processes of constructing meaning grow into an active negotiation among some of the multiple forces and conflicts that shape meaning, and writers are forced to turn conscious attention to dealing with the options, constraints, and conflicts that would shape meaning. At these points of conflict and decision, meaning can be actively negotiated. The process of constructing negotiated meaning comes into play for a writer when the process of meaning making is subject to converging constraints and conflict, and when a writer turns his/her attention at some level of awareness to negotiating the problematic cognitive and social situation. In the processes of constructing meaning, negotiation begins with acts of interpretation. After interpretation with the expectations of others, the meaning of key words in an assignment, and the recognition of his/her role as a writer, writers negotiate with some of the constraints on how they select, organize, and connect ideas. After negotiation, writers reflect not only on meaning they create, but also on their own goals, assumptions, strategies, and attitudes of making meaning. The negotiation strategies can be used as effective means for collaborative writing. The collaborative writing fits for the twenty-first century classroom because it alters the traditional teaching environment and places the student in the center. With a goal of the whole being greater than the sum of its parts, cooperation and negotiation replace working alone and competition between individuals. Throughout the collaborative writing, students would learn how to determine questions and find answers, how to share their understanding, and how to negotiate with complex problems and constraints. In the processes of collaborative writing, students need to use effective negotiation strategies to resolve conflicts and to reach their goals.

개에서 직장탈의 수술적 치료 1례

박정희,김영실,신영지,박창식,전무형,김명철,정성목 忠南大學校 獸醫科大學 動物醫科學硏究所 2005 動物醫科學硏究誌 Vol.13 No.-

A 3-year old, male Jindo dog was referred with history of tenesmus, dyschezia and recurrent rectal prolapse. On the physical examination, the rectum was prolapsed about 10 cm, congested and necrotized. Fecal incontinence and pain were observed. Complete blood count revealed a mild leukocytosis and there were no remarkable abnormalities in serum biochemistry profiles. It was diagnosed as a rectal prolapse. Rectal resection and anastomosis was performed for necrotic tissue removal. On postoperative fecal smear, protothecosis was observed. Amphotericin B was administered. There has been no evidence of recurrence of rectal prolapse for ten months.