打擊速度 및 溫度變化가 豫크랙을 가진 衝擊試驗片의 動的破壞靭性에 미치는 影響

兪在煥,李敬奉,金重吉,李致雨,吳世旭 慶南大學校 附設 工業技術硏究所 1989 硏究論文集 Vol.7 No.-

計裝化衝擊試驗에서 打擊速度와 溫度의 變化가 豫크랙을 揷入한 衝擊試驗片의 動的破壞靭性에 미치는 影響을 考察한 結果 다음을 알 수 있었다. 豫크랙을 揷入한 試驗片이 V-노치 試驗片에 比하여 實驗値의 分散度가 적으며 0℃以下의 溫度領域에서 動的破壞靭性의 有效性이 있었다. 또한 打擊速度와 實驗溫度의 影響은 溫度가 速度보다 훨씬 上廻하는 傾向이었다. The effect of various impact velocity and temperature on dynamic fracture toughness is tested with precracked Charpy specimen, and conclude following results. Precracked specimen has less dispersion of test results than V-notched specimen, unstable crack initiation load didn't agreed to maximum load at room temperature but at 0℃ below, thus, the availability of dynamic fracture toughness is relatively high. Comparing V-notched specimen, the precracked Charpy specimen represented lower shelf of temperature different. But, at this time, the absorbed energy is estimated equivalently. With the decrease of temperature, the reduction of fracture toughness was obvious, but the effect of impact velocity didn't appear.

Streptozotocin 유도 당뇨백서의 구강점막과 신장에서 Proliferating cell nuclear antigen 발현에 관한 연구

유정택,김경욱 단국대학교 치의학연구소 1996 논문집 Vol.8 No.1

Streptozotocin induced diabetes mellitus revealed a chronic disorder of carbohydrate, fat, and protein metabolism characterized by an absolute or relative insulin deficiency, fasting hyperglycemia, glycosuria, a striking tendency toward development of atrherosclerosis, microangiopathy, nephropathy, neuropathy, and destrution of some vital organs in body. PCNA(Proliferating Cell Nuclear Antigen) revealed DNA polymerase auxilliary factor, which was expressed on late G1 phase and early S phase in cell cycle. The purpose of this study was to assess proliferation activity and histopathologic changes of oral mucosa and kidney in experimental induced diabetic rats through hematoxylin & eosin staining and immunohistochemical staining by PCNA. The results wer obtained as follows: 1. The first week after DM induction, some vacuolized blood vessel cells of veins were seen in oral mucosa. 2. In the control group of oral mucosa, many PCNA positive cells were experssed at the basal and parabasal cell layer. 3. The third day after DM induction, PCNA positive cells were not expressed, but expressed in the fourth week, and then increased in the sixth week after DM induction. 4. In the experimental group of kidney, eosinophilic cytoplasms and ruptured capillaries in the glomerulus increased periodically. Some congestions and plasma organizations were seen in the fourth and sixth week after DM induction and hyaline materials in the proximal convoluted tubules increased in the first week after DM induction. 5. PCNA positive cells were weakly expressed on the tubule cells of kidney in the control group, but not in the whole experimental groups. From the above results, proliferating cells of oral mucosa and convoluted tubules in kidney were prevented by streptozotocin induced diabetes mellitus, but recovered periodically in oral mucosa. Destruction of glomerulus, convoluted tubules and vessels in kidney increased periodically.

P.C.를 이용한 作業管理시스팀(Ⅰ)

姜鎬郁,金炅模,徐有振 慶尙大學校 工科大學 附屬 生産技術硏究所 1986 生産技術硏究所論文集 Vol.2 No.-

The object of this research is to develop a personnel-computer program for THERBLIG analysis and FLOW-PROCESS analysis which are kinds of work methods design. All programs are written in BASIC language. The results of this research can be extended to other work methods design and reduce 50% in clerical effort.

街路建築物에서의 公開空地에 관한 硏究

송경욱,이석주,유창균,조용준 朝鮮大學校 建設技術硏究所 1999 建設技術硏究 Vol.19 No.3

The city is the social space with a lot of people having the various and different background and positions. That the city is the social space of high density means it is the space for convenient and comfortable life with the sense of community in frequent activities by overcrowded people and for this, intentional human behaviors within the city. From such a viewpoint, this research is to examine and analyze the publicity of external space of buildings with open space which is the important factor in improving the quality of city and the results of the research are as follows. It is found that the installation of open space has been made at the place where urban development is actively performed from the center of city with many users, but the open space which secures the comfort of the city and then attracts the people is not secured and is in the stage of legal restriction and the conversion of building owner's consciousness is needed. It is analyzed that most of open space are located at the front, but in fact there is no device which intercepts the eyes of pedestrian and open space users and since each space is divided by merely ground border, it is difficult to find the hierarchy or territory of two spaces and more considerations should be given for users. It is shown that the obligatory installations of open space such as bench are not equipped. Since the open space in urban area should be prepared in the side of publicity for users as well as for the urban comport, it is considered that the conversion of building owner's consciousness and institutional supports like incentive system should be followed. Moreover, open space have an influence on the diversification of architectural design, architects must consider the diversification of location, form and components of open space to make it an attractive space for users.

급성 뇌경색 환자에서 경색 위치가 심근 효소치 상승에 미치는 영향

윤경호,박현영,박성욱,장혁,김요식,조광호,유남진,김남호,오석규,정진원 圓光大學校 醫科學硏究所 2003 圓光醫科學 Vol.18 No.2

계장화충격시험에 의한 복합조직강의 파괴인성에 관한 연구

오세욱,유재환,박원조,이경봉 동아대학교 공과대학 부설 한국자원개발연구소 1989 硏究報告 Vol.13 No.1

The dynamic fracture toughness (K_(Id)) is measured using the precracked standard Charpy specimen with an instrumented impact machine. The value of K_(Id) is determined as a function of yield strength and microstructure, and correlations are established between K_(Id) and both energy of initial fracture and total energy of fracture. Since the K_(Id) values of the precracted impact specimens are in accordance with their theoretical ones, this test method is sufficiently practical.

간암세포에서 저산소증에 의해 유도되는 VEGF의 발현기작에 대한 연구

권유욱,배수경,김정애,김규원,박병채 영남대학교 약품개발연구소 1997 영남대학교 약품개발연구소 연구업적집 Vol.7 No.-

Puropse: Hepatocellular carcinoma (HCC), a typical hypervasculized tumor is very sensitive to hypoxia and vascular endothelial growth factor (VEGF) has previously been identified to be up-regulated in response to hypoxia in several cell types. However, the molecular mechanisms by which hypoxia is sensed by the cells remain enigmatic. To investigate whether calcium and AP-1 are involved in hypoxia-sensing mechanism, we performed following experiments. Materials and Methods: Hep3B cells were grown in hypoxic condition. To assess cell viability, MTT assay was performed. To investigate the effect of calcium and AP-1, northern blot analysis was performed after treatment with BAPTA/AM. Results: The expression of VEGF was significantly up-regulated by hypoxia in Hep3B, hepatocellular carcinoma cell line. The increased expression of VEGF induced by hypoxia was blocked by the addition of BAPTA/AM, a cytosolic calcium chelator to the media. In addition, we found that the expression of c-jun protooncogene was also up-regulated by hypoxia. Hypoxic increase of c-jun expression was also normalized by the treatment with BAPTA/AM. Conclusion: These results suggest that the increased expression of VEGF by hypoxia is mediated through the calcium and c-jun signalling pathway in the Hep3B human hepatoma cell lines.

관상동맥질환자에서 경흉부 도플러 심초음파를 이용한 좌심실 확장기 기능의 평가 : 좌심실 확장기 장애 형태에 따른 분류

전희경,윤호중,유기동,박지원,전두수,정욱성,채장성,김재형,최규보,홍순조 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.1

간암세포에서 저산소증에 의해 유도되는 VEGF의 발현기작에 대한 연구

권유욱,배수경,김정애,김규원,박병채 부산대학교 유전공학연구소 1997 분자생물학 연구보 Vol.13 No.-

Purpose: Hepatocellular carcinoma(HCC),a typical hypervasculized tumor is very sensitive to hypoxia and vascular endothelial growth factor(VEGF) has previously been identified to be up-regulated in response to hypoxia in several cell types. However, the molecular mechanisma by which hypoxia is sensed by the cells remain enigmatic. To investigate whether calcium and AP-1 are involved in hypoxia-sensing mechanism, we performed following eaperiments. Materials and Methods: Hep3B cells were grown in hypoxia condition. To assess cell viability, MTT assay was performed. To investigate the effect of calcium and AP-1,northern blot analysis was performed after treatment with BAPTA/AM. Results: The expression of VEGF was significantly up-regulated by hypoxia in Hep3B, hepatocellular carcinoma cell line. The increased expression of VEGF induced by hypoxia was blocked by the addition of BAPTA/AM, a cytosolic calcium chelator to the media. In addition, we found that the expression of c-jun protooncogene was also-regulated by hypoxia. Hypoxia increase of c-jun expression was also normalized by the treatment with BAPTA/AM. Conclusion: These results suggest that the increased expression of VEGF by hypoxia is mediated through the calcium and c-jun signalling pathway in the Hep3B human hepatoma cell lines.

석이로부터 분리한 페놀성 화합물의 phospholipase A_2 저해활성

김진우,송경식,유익동,장현욱,유승현,배강규,민태진 충남대학교 생물공학연구소 1997 생물공학연구지 Vol.5 No.-

호알카리성 진균 Cephalosporium sp. RYM-202가 생산하는 alkaline xylanase (CX-III)의 작용에 의해 xylan 기질로부터 생성되는 주요 가수분해 산물은 xylobiose와 중합도가 4 이상인 xylooligosaccharides이었다. 이 효소는 xylobiose에 대한 분해능을 가지고 있지 않지만 xylotriose로부터는 xylobiose를, xylotetraose로부터는 xylobiose와 xylotriose를 주산물로 형성하였다. 이러한 결과들은 CX-III가 transglycosidase 활성을 소유하는 전형적인 endo-type xylanase임을 보여준다. N-bromosuccinimide에 의한 CX-III의 화학적 변화 실험 결과 효소 1분자 당 2개의 tryptophan 잔기가 활성에 관여하는 것으로 나타났다. 그러나 iodoacetamide 및 diethylpyrocarbonate에 의한 효소활성의 저해효과는 나타나지 않음으로써 이 효소의 활성부위에 cysteine과 histidine 잔기가 필수적이지 않음이 확인되었다. The hydrolysis products formed from birchwood xylan by the action of an alkaline xylanase (CX-III) from alkalophilic Cephalosporium sp. RYM-202 were xylobiose and xylooligosaccharides polymerized with more than 4 sugar molecules. This enzyme was not active on xylobiose but readily attacked xylotriose accumulating xylobiose as a major product. The predominant end-products from xylotetraose by CX-III were xylobiose and xylotriose. These results indicate that the enzyme is typically endo-type xylanase possessing transglycosidase activity. Chemaical modification of CX-III with N-bromosuccinimide revealed that two tryptophan residues per molecule of CX-III were essential for its catalytic activity on xylan. On the other hand, iodoacetamide and diethylpyrocarbonate did not influence the activity of the enzyme, suggesting that cysteine and histidine residues are not involved in the active site of this alkaline xylanase.