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.

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.

폐자로형 평면 인덕터의 제조에 관한 연구

李昌昊,申東勳,南勝義 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.2

The purpose of this research were to develop the magnetic thin films using for high frequence range and to establish the processing technique of a meander type micro-coil in order to produce the micro magnetic device(MMD) and analyze its electrical characteristics. As magnetic thin films, we used Fe??Ta??N?? films which had nano-crystalline structure produced by a DC magnetron reactive sputtering system, magnetic properties were like these : Bs=15∼16 kG, Hc=0.12∼0.17 Oe, μ'=2800∼4000. The Cu coil produced by selective electro-plating(SEP) showed the resistivity of 2 μΩ-cm. In case of the meander type magnetic thin films inductor with 5 turns, an inductance of 229 nH which is about 4 times higher than that of air core inductor was shown, and a resonance frequency of 37 MHz and a quality factor of 1.8 at 10 MHz were also shown.

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.

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.

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).

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.

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

양식장 배출물 발효물의 어류 사료 첨가에 따른 넙치, Paralichthys olivaceus의 혈액학적 변동에 미치는 영향

강주찬,지정훈,송승엽,문상욱,강지웅,이영돈,김세재 한국어병학회 2004 한국어병학회지 Vol.17 No.1

본 연구는 우리나라 주요 양식어류인 넙치, Paralichthys olivaceus를 대상으로 육상수조식양식장 배출물 발효물의 어류 사료 첨가에 따른 혈액학적 변동에 미치는 영향을 검토하였다. 젖산균 및 효모를 사용하여 발효한 양식장 배출물의 이화학적 분석을 실시하였고, 발효물을 0.1, 0.5, 1.0 및 5.0% 농도로 8주간 투여하였다. 투여 4주째 및 8주째에 각 투여 구간별로 혈액학적 항목을 중심으로 그 차이를 확인하였다. 배출물 발효농도별 유의한 차이는 나타나지 않았지만, 분석시기에 따른 적혈구수, 혈색소 농도 및 혈색소 지수가 증가하는 경향을 나타내었으나, 주요 혈청 무기 및 유기성분은 배출 발효물 농도별로 유의한 차이는 나타나지 않았다. 또한 혈청 효소학적 조사에서는 조사시기별로 변동은 나타났지만, 동일 조시시기에서 각 구간별 유의한 차이는 나타나지 않았다. 따라서 이러한 육상 약식장 유래의 배출물 발효산물에 대한 다양한 방면의 연구가 진행되어야겠다. Effects of oral administration with fermented product from sewage in land-based seawater fish farm on haematological disturbance in the olive flounder, Paralichthys olivaceus was investigated. After 4 weeks of conditioning with a basal diet, fish were divided into 4 groups and provided experimental diet (0.1,0.5, 1.0 and 2.0%) supplement of fermented sewage for 80 days. Proximal analysis was performed for the product of sewage which was fermented by lactic acid and yeast. RBC count, hemoglobin concentration and hematocrit value were increased according to the treated periods, however, no statistical difference was observed between control and treatment groups. There were no significant difference in serum organic, inorganic compounds and enzyme activities between control and treatment groups. This study hypothesized that the supplement of fermented product from sewage in land-based seawater fish farm might be an additive sup plement for source of fish diet in view of haematological examination. Recycling of the sewage may be an economic artificial sources of diet for fish aquaculture practices.

고품위 연삭 가공기법을 이용한 알루미나 세라믹스 부품의 강도향상에 관한 연구

김원일,강재훈,이재경,허성중 경남대학교 신소재연구소 1992 論文集 Vol.2 No.-

초지립 연삭 공구인 다이아몬드 휠을 사용하여 엔지니어링 세라믹스를 제거가공함에 있어 공구의 마멸 및 가공면 상의 가공 결함 등에 의한 강도 저하 현상 등이 야기되어지고 있다. 한편, 최적 절인 형성을 위한 가공 공정상의 빈번한 재드레싱 시간 등의 소요는 생산성 향상의 측면에 있어 장애가 되고 있다. 연삭 가공중의 연속 드레싱 기구를 고려해 봄으로써 계속적인 다이아몬드 지립의 양호한 절인 상태를 유지하며 고능률적으로 제거 가공을 추진하고, 절인 마멸에 의한 가공 결함 들을 극소화시키는 효과를 얻고자 실험적으로 본 연구를 수행하였다. 굽힘 강도 시편을 가공 제작하여 기계적 특성치의 변화를 구해봄으로써 이에 대한 재고찰을 해보았으며, 고품위 연삭 기법에 의한 우수한 결과치들을 얻을 수 있었다. Engineering ceramics have some excellent properies as the material for the mechanical components. It is, however, very difficult to grind ceramics with high efficiency because of their high strength, hardness and brittleness. In this paper experiments are carried out to obtain the effect of In-process dressing to grind the engineering ceramies with high efficency. To save running time for dressing process and obtain restraint effect of diamond grain wear, In-process dressing system using WA stick type honing stone is proposed. Representative engineering ceramics, A1₂O₃, are ground with diamond wheel. Also bending strength test is carried out to check upward tendency of mecahnical properties as the result of machining defact restraint through the grinding machining method using "In- process dressing" process. Some results obtained in this study provide useful information to attain the high efficiency grinding and the high mechanical properties of engineering ceramics.