연료전지의 인산전해질 함유를 위한 Marix 제조에 관한 연구

이승훈,설용건,이태희 연세대학교 산업기술연구소 1992 논문집 Vol.24 No.2

The matrix used for the electrolyte of fuel cell was fabricated by using the powder of having different particle size SiC(Silicon Carbide). About the above fabricated matrix, the pore structure and acid absorbancy were measured, and the performance was finally tested at On-Cell. In making matrix, teflon was used as its binder, and in the case of adding 10w/o, matrix could be made in the form of the sheet of 0.2~0.3mm in width. As the result of having made matrix, in the case of 1μm of it, its porosity of 61% was highest; the smaller the size of its particle was, the more increasing pore volume became; the more increasing the content of teflon got, the more decreasing pore volume became. The acid absorbancy of matrix became saturated with acid after six hours, and in the case of 1 μm matrix its acid absorbancy was highest. The highest performance of the matrix with 1μm particle resulted from the measurement of the performance of the On-Cell also the current density of 75mA/cm2at 700mV.

정상 혈압쥐와 본태성 고혈압쥐 노화 적혈수에서의 Na, K-ATPase에 관한 연구

정성훈,박창길,허강민,석정호,이재흔 충남대학교 의과대학 지역사회의학연구소 1992 충남의대잡지 Vol.19 No.1

To study the change of Na, K-ATPase of aged erythrocytes in the normotensive and hypertensive rats, the young and aged erythrocytes of Sprague-Dawley rats or spontaneously hypertensive rats were fractionized by density gradient, and ouabain sensitive Rb-uptake and [^3H] ouabain binding sites were measured. 1. In the spontaneously hypertensive rats, blood pressure was significantly increased to 151.5/110.0mmHg(systolic/diastolic). Mean corpuscular volume and membrane protein(mg/10^9 RBC) were decreased and hemoglobin content was increased in the aged erythrocytes. 2. In the normotensive rats, ouabain sensitive Rb-uptake of young erythrocyte was increased as increase of Rb concentration from 4 mM to 8 or 16 mM in the reaction medium, but that of aged erythrocyte was lower than that of young erythrocyte. 3. In the spontaneously hypertensive rats, ouabain sensitive Rb-uptake of young erythrocyte was also increased as increase of Rb concentration in the medium, but lower than that of young erythrocyte of normotensive rats, and that of aged erythrocyte was also decreased compared to that of young erythrocyte and that of aged erythrougte of normotensive ratc. 4. [^3H] ouabain binding sites of aged erythrocyte of normotensive rats and young or aged erythrocyte of spontaneously hypertensive rats were lower than that of young erythrocyte of normotensive rats. From the above results, it is suggested that the decreased activity of Na, K-ATPase in the aged erythrocyte of normotensive and spontaneously hypertensive rats may due to the decreased numbers of enzymes, and these enzymes in the erythrocytes of spontaneously hypertensive rats would changed from the younger erythrocytes than those of normotensive rats or one-kidney Goldblatt hypertensive rats.

흰쥐의 발치와에 이식한 단계별 치아싹의 발육 과정

정희훈,정한성,김성오,최형준,이제호,최병재 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.2

The purpose of this study is to evaluate at which stage of tooth germ would develop into normal calcification and hence to increase the success rate of transplantation. Therefore, tooth germs on the 15th, 17th embryonic day and the 3rd day of birth were separated for allotransplantation into maxilla of adult rat of 11 weeks. Calcification processes were analyzed radiographically and histopathologically at 4 weeks and 8 weeks after allotransplantation. The results are as follows: 1. Allotransplanted tooth germ at 4 weeks and 8 weeks showed delayed calcification compared to that of normal odontogenesis. 2. At 4 weeks, abnormal calcified tissue, such as odontoma and ankylosis of osteodentin with surrounding alveolar bone were observed. 3. At 8 weeks, allotransplanted tooth germs of the 15th and 17th embryonic day showed calcification and osteodentin surrounded by periodontal ligament. 4. At 8 weeks, allotransplanted tooth germs of the 3rd day of birth showed calcification composed of cementum and osteodentin. In this study, we observed small sized and amorphous calcified tissue from allotropic allotransplantation of tooth germs. Since these calcified tissue were underdeveloped and shaped irregularly, for calcification into normal tooth form, further study needs consideration about the reduction of surgical trauma, developmental stage of transplanted tooth germ, blood supply from recipient site, fixation method in transplanted site and period of transplantation. 외상이나 치주 질환,유전적 결함 등에 의하여 치아가 상실되었을 경우,보철 수복이나 임플란트로 치료하고 있다. 그러나 보철 수복이나 임플란트는 자연치가 아닌 인공치를 이용한 치료로서 기능성과 섬미성 등에서 자연치에 비하여 한계 가 있으므로 자연치를 이용한 이식 방법에 관심이 증가하고 있으며 치아 이식의 성공률을 높이기 위한 이식 치아의 발육과 성장에 대한 연구가 진행 중이다. 이 연구는 세 가지 단계의 치아싹을 발치와에 동종 이식하고 치아싹이 발육하여 석회화가 이루어지는지 평가하기 위하여 임선 15일과 17일,출생 후 3일 된 흰쥐의 치아싹을 분리하여 11주 된 흰쥐의 발치와에 이식하고 4주와 8주 후 방사 선학적 그리고 병리조직학적으로 석회화 과정을 관찰하여 다음과 같은 결과를 얻었다. 1. 발치와에 이식된 임신 15일과 17일,출생 후 3일 된 치아싹에서 4주와 8주 후 석회화된 조직이 형성되었다. 2. 임신 15일과 17일,출생 후 3일 된 치아싹을 발치와에 이식하고 4주 후 치아종 같은 비정상적인 석회화 조직과 인접 치조골과 유착된 골양상아질이 관찰되었다. 3. 임신 15일과 17일 된 치아싹을 발치와에 이식하고 8주 후 골양상아질이 보였으며 치주인대로 둘러싸인 것도 관찰되었다. 4. 출생 후 3일 된 치아싹을 발치와에 이식하고 8주 후 골양상아질과 백악질이 형성되었다. 이 연구는 치아싹을 흰쥐의 발치와에 이식한 후 치아싹의 발육을 관찰한 것으로 이식 조직에서 크기가 작고 무정형의 석회화 조직이 형성되었다. 정상적인 치아보다 형태가 불규칙하고 발육이 늦었으므로 이식된 치아싹이 정상적인 치아 형태로 석회화되도록 하기 위해서는 이식 조직의 발육 정도와 이식 조직을 절제할 때 외과적 손상의 감소,치아싹으로의 풍부한 혈류 공급,이삭 기간,이식 조직의 고정을 고려하여 더 많은 연구가 필요할 것으로 생각된다.

소록도 나환자의 이비인후과 질환의 분류에 관한 고찰

박승훈,장혁순 순천향대학교 1984 논문집 Vol.7 No.4

Leprosy is a chronic disease of man, caused by Mycobacterium leprae. It manifests itself in the development of specific granulomatous or neutrophic lesions in the skin, mucous membrane, nerves, bone and viscera. The disease was known as early as 2000 B.C. in Egypt and has been present throughout the ages in most parts of the world and continuous to afflict more than 12 million people world wide and perhaps more than 50 thousand people in Korea. This study was carried out 2300 leprosy patients at National Leprosy Hospital for otorhinolaryngologic classification of the leprosy patient.

單一反射音의 最適遲延時間

강성훈,임광호,차일환 연세대학교 산업기술연구소 1983 논문집 Vol.15 No.2

Subjective preference tests with a simulated single reflection in an anechoic chamber were performed in order to find the preferred delay time of the first reflection in the musical sound field. The preferred time delay gap between the direct sound and the first reflection can be determined by the interval of coherence of music and the amplitude of the reflection. The scale value of subjective preference is formulated in terms of the 1.2 power of the normalized parameter which is expressed in the logarithm. This observation is taken into consideration in the design stage of concert halls and in selecting music to be performed in a given concert hall.

고주파수대역에 적용되는 Fe-( BN, Si₃N₄)박막의 미세구조와 자기적특성에 관한 연구

申東勳,張勝彦,李宰源,南勝義 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

We have investigated the magnetic properties of FeBN thin films deposited by using RF magnetron sputtering and Fe-BN composite target. It was investigated that the area fraction of BN chips on the Fe target and partial pressure of nitrogen was the main factors influencing the soft magnetic properties and resistivity of FeBN thin film. The low addition of N₂increases significantly the soft magnetic properties and electrical resistivity. The good soft magnetic properties are obtained at N₂partial pressure of 5%, but futher increase in N₂ partial pressure degrade the soft magnetic properties due to formation of nitrides such as Fe₄N, Fe₂∼₃N. In a sputtering process, as the area fraction of BN increases, FeBN thin films fabricated at the area fraction of 0.25 exhibt soft magnetic properties (Bs∼17kG, Hc∼10e, μ∼1000).

Fe₃O ₄-Al₂O ₃-CaO系 鑛球의 還元에 關한 硏究

양훈영,이승원,김진호,은일상 연세대학교 산업기술연구소 1975 논문집 Vol.6 No.1

Reduction of coke mixed magnetite ore pellets containing alumina and/or lime has been carried out in a fixed bed with coke powder in the temperature range of 1,100-1,250℃. Degree of metallization of the reduced pellets was obtained from the chemical analysis, and volume change of the reduced pellets was evaluated by measuring pellet diameter before and after reduction. Phase change during the reduction was also investigated by microscopic observation. The results obtained are summurized as follows. (1) As the Al₂O ₃content increases, degree of metallization of the ore pellets decreases and shrinkage of the reduced pellets also decreases. (2) Addition of 5% CaO to the 5% Al₂O ₃ pellets improves the degree of metallization and increases shrinkage of the reduced pellets, especially within the temperature range of 1,200-1,250℃. In the case of 10% CaO addition to the same pellets, however, both degree of metallization and shrinkage decrease. (3) CaO addition to the 10% Al₂O ₃ pellets showed the similar effect to that of 5% Al₂O ₃ pellets on the degree of metallization and shrinkage, showing no conspicuous effect of lime addition. (4) While Al₂O ₃ in the pellets is inhibitive to the reducibility as well as agglomeration, CaO is promotive to the above properties.

Staphyloccus aureus에 대해 gentamicin의 MIC측정을 위한 firefly Iuciferase assay의 응용

이승배,최상훈,이동만 건국대학교 1987 論文集 Vol.24 No.1

Susceptibllity of Staphyloccus aureus (ATCC 14492) to gentamicine was determined by minium inhibitory concentration(MIC) test and firefly bioluminescence assay of bacterial adenosine triphosphate(ATP). ATP content extracted Staphyloccus aureus was proportional to the number of bacterial, ATP content in a bacteria was 3.1fmol. The patterns of growth curves for Staphyloccus aureus look very similar, when the bacterial growth was monitored by ATP content and viable cell count. The MIC of gentamicine for Staphyloccus aureus measured both firefly bioluminescence assay and MIC test was 0.5ug. Determinent of intrcellular ATP in culture of Staphyloccus aureus exposed to gentamicin seem to be suitable for reliable determination of MIC within 3 hours of incubation. It gave very good correlation(r=0.97), when firefly bioluminescence and MIC test were compared.

hCG에 대한 단일클론 항체 생산과 그 이용에 관한 연구

崔尙勳,李丙哲,李承培 건국대학교 1987 論文集 Vol.25 No.1

This study was carried out to produce monoclonal antibody against hCG secreted by the tr-ophoblast of developing embryo. Produced monoclonal antibody to hCG was regarded as IgG class since it had a strong affinity for a protein A. The concentration of monoclonal antibody in cell culture supernatant and in mouse ascitic fluid was 250㎍ and 30mg perml, respectively. The titer of antibody in mouse ascitic fluid was about 1 : 106~107 on ELISA

다이아몬드휠을 사용한 WC-Co재의 고능률적 평면 연삭 가공에 관한 연구

김원일,허성중,강재훈,이재경 慶南大學校 附設 工業技術硏究所 1992 硏究論文集 Vol.10 No.-

WC-Co재는 금형 제작용으로 근래 그 사용이 급증하고 있다. 본 논문은 WC-Co재의 고능률 최적 연삭조건을 정립하기 위하여 연삭저항과 연삭비를 중심으로 실험적 연구를 행한 결과 다음과 같은 결론을 얻을 수 있었다. 1)WC-Co재의 가공에 대한 연삭저항은 연삭 깊이가 증가하고 다이야 몬드 연삭 숫돌의 주속도가 느릴수록, 공작물 연삭 속도가 감소할 수록 증가하였다. 2)WC-Co재의 경우, 연삭비는 테이블 이송 속도등의 증가와 더불어 감소함을 나타내었다. Recently, the making of WC-Co materials which are used for metallic mould is growing very rapidly. This investigation examines the grinding force and grinding ratio caused by experimental machining of WC-Co for research high efficiently optimal grinding condition. From the result of experiments obtained hear are summarized as follows and so forth. 1) For working WC-Co materials, the grinding force increases according to increase of depth of cut, decrease of surface velocity of diamond abrasive wheel and increase of surface velocity of work. 2) In case of WC-Co materials, grinding ratio is decrease according to increase of table feed rate et, al.