폴리아닐린/폴리이미드 혼합막의 제조와 기체분리특성

이형록,이광석,김진환 한국공업화학회 2003 응용화학 Vol.7 No.1

Polyaniline(PAN)/Polyimide(PI) blended membernes were prepared and the effect of mixing ration of PANI and PI on the stuctural properties and the gas transportproerties was studied. The polyamic acid(PAA) solution was prepared from 6FDAand ODA in NMP solvent. The PANI/PI blended membranes were obtained bymixing PAA solution and PANI solution. The gas permeation experiments with H_2,He, O_2,N_2,CO_2, and CH_4 were carried out by variable pressure method at 30℃ and5atm. For all gases tested, the permeability coefficient of OANI/PI blended membranes was higher relative to that of polyamiline and the separation factors for the blended were comparable to polyaniline.

정형회과영역에서의 Cefmetazole(Cefmetazon^(�)) 임상적 효과

이정웅,문형석,안상로,이준규,이광진,윤승호 최신의학사 1988 最新醫學 Vol.31 No.5

혈관 반응성에 대한 Cyclooxygenase 억제제 효과와 Cyclooxygenase 발현 변화

이기영,박진우,엄은아,강영진,이광윤,최형철 영남대학교 의과대학 2006 Yeungnam University Journal of Medicine Vol.23 No.1

진통과 해열작용을 가진 NSAIDs는 소화기계에 대한 부작용 때문에 COX-2 선택성 억제제로 대체되고 있다. 그러나 COX-2 선택적 억제제는 심혈관계에 대한 부작용이 보고되고 있어 혈관 평활근에 대한 직접적인 연구가 필요하다. 이에 본 연구에서는 혈관 반응성에 미치는 celecoxib와 aspirin, indomethacin의 영향을 비교 분석하였다. 또한 COX-1, COX-2 단백질 발현에 대한 indomethacin과 NO 공여제의 영향을 조사하였다. Phenylephrine 유발 수축반응에서 전처치 된 celecoxib, indometacin, aspirin 순서로 혈관 반응성을 증가시켜, cyclooxygenase를 억제하면 혈관 수축성물질에 대한 반응성이 커질 수 있음을 나타낸다. 이중 cyclooxygenase에 대해 비가역적으로 강한 억제를 나타내는 aspirin이 제일 강한 효과를 나타내어 여기에 대한 연구는 더 필요할 것으로 생각된다. 혈관평활근 세포의 COX-2 단백질 발현은 indomethacin과 SNP, NOR-3 처치에 의해 증가되었으며, LPS를 이용하여 혈관염증을 유발시키는 경우 혈관평활근 세포의 COX-2 단백질 발현이 증가되었고, 이 상태에서 SNP 100μM 전처치로 COX-2 단백질 발현을 감소되었으며, NOR-3 100 μM은 COX-2 단백질 발현을 증가시켰다. LPS 유도 nitrite 생성에서 NOR-3는 SNP 보다 더 많은 nitrite를 생성시켰다. 이는 혈관의 수축반응에서 aspirin은 강한 상승작용을 유발하고, 혈관평활근 세포의 COX-2 발현은 NO 공여제, 혈관염증 유무에 따라 차이가 있는 것을 나타낸다. Background: There is controversy regarding whether COX-2 specific inhibitors are associated with elevation of blood pressure. We compared the effects of aspirin, indomethacin, and celecoxib for vascular reactivity induced by phenylephrine. We also tested the effects of indomethacin and NO donor on COX-1 and COX-2 protein expression, as well as nitrite production in culture medium of vascular smooth muscle cells. Materials and Methods: In this experiment, we used the isometric tension study for vascular reactivity. After 45 minutes of pretreatment with aspirin, indomethacin, celecoxib, and phenylephrine induced contractions were tested. COX-1 and COX-2 protein expressions were analyzed by Western blot and nitrite production by the Griess reaction. Results: Although celecoxib pretreatment caused enhanced arterial contraction, aspirin pretreatment induced more potent arterial contraction than celecoxib in the isometric tension study of rabbit femoral artery. COX-1 protein expression was unchanged by indomethacin, SNP and NOR-3; COX-2 protein expression was increased by the addition of indomethacin, SNP, and NOR-3. Especially, NOR-3, a NO donor, significantly increased COX-2 protein expression with unstimulated conditions as well as LPS stimulation. Induction of nitrite production was higher with NOR-3 treatment than SNP treatment with LPS stimulation. Conclusion: These results suggest that aspirin caused more potent vascular contraction than celecoxib and indomethacin. COX-2 expression in VSMC depended on the types of NO donor and LPS stimulation.

Compocasting 법에 의한 AZ91D/SiC_pMMCs(metal matrix composites)제조

이경태,김세광,구형찬,김달식,김영직 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.2

Metal matrix composites have toughness, machinability and heat conductivity, which can be obtained in metals, as well as hardness, high temperature stability, which can be obtained in ceramics. The purpose of this study is to find the optimum production condition of a compocasting method which is composed of stirring SiC particles inside a matrix which is presented as a solid or liquid state. During the compocasting method. SiC particles are mechanically incorporated into the matrix. From this study, sound AZ91D/SiC_p composites were obtained when stirring the matrix for 60minutes between 583-588℃.

고농도의 연폭로근로자들에서 혈중연량과 Dithiothreitio로 처리된 δ-aminolevulinic acid dehydratase 활성비(ALAD Ratio)와의 상관관계

김형아,이원철,이광묵 가톨릭대학산업의학센타 산업의학연구소 1992 韓國의 産業醫學 Vol.31 No.4

The ??-aminolevulinic acid dehydratase activity(??-ALAD) and the ratio of activated to inactivated ??-ALAD treated with dithiothreitol of whole blood was measured to evaluate the correlation between the ratio and blood lead level. Zinc protoporphyrin(ZPP), the indices most widely used in screening of lead absorption and blood lead were also measured. These parameters indicative of lead exposure were measured in whole blood from 57 highly lead exposed workers(most of them, ZPP was higher than 100ug/100ml), and from a group of 15 control subjects not exposed to undue environmental lead. We found that the correlation coefficient between the ratio and the blood lead level(r=0.58) was slightly greater than the correlation cofficient between the log inactivated ??-ALAD and the blood lead level(r=-0.51) among 57 highly lead exposed workers.

특수일 전력수요예측을 위한 신경회로망 시스템의 개발

윤형선,김광호,이철희 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

Conventional short-term load forecasting techniques have limitation in their use on holidays due to dissimilar load behaviors of holidays and insufficiency of pattern data. Thus, a new short-term load forecasting method for special days in anomalous load conditions is proposed in this paper. The proposed method uses two Artificial Neural Networks(ANN); one is for the estimation of load curve, and the other is for the estimation of minimum and maximum value of load. The forecasting procedure is as follows. First, the normalized load curve is estimated by ANN. At next step, minimum and maximum values of load in a special day is obtained by combining these two outputs of ANNs. The proposed method shows a good performance, and it may be effectively applied to the practical situations.

동하중 측정 신호처리의 개발에 관한 연구

신영균,이영준,박찬원,신형재,안광희 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

A high speed and stable A/D conversion data process is required to weigh a mass on moving conveyer weighing platter. The paper presents a new method to obtain stable and fast automatic weighing A/D conversion data process. Dynamic weighting system which is constructed with dual load cell is realized by the stable A/D conversion data preocess algorithm using DSP. The proposed memthod is applied to the real design, and that experimental results showed good performances of the weighing stability.

학습 평가 분석을 이용한 웹기반 코스 스케쥴링 멀티 에이전트 시스템

박재표,이광형,이종희,전문석 한국컴퓨터교육학회 2004 컴퓨터교육학회 논문지 Vol.7 No.1

최근 학습자의 요구에 맞는 코스웨어의 주문이 증가하고 있는 추세이며 그에 따라 웹 기반 교육 시스템에 효율적이고 자동화된 교육 에이전트의 필요성이 인식되고 있다. 본 논문에서는 취약성 분석 알고리즘을 이용한 학습자 중심의 코스 스케쥴링 멀티 에이전트 시스템을 제안한다. 제안한 시스템은 먼저 학습자의 학습 평가 결과를 분석하고 학습자의 학습 성취도를 계산하며, 이 성취도를 에이전트의 스케줄에 적응하여 학습자에게 적합한 코스를 제공하고, 학습자는 이러한 코스에 따라 능력에 맞는 반복된 학습을 통하여 적극적인 완전학습을 수행하게 된다. Recently, the demand for the customized courseware which is required from the learners is increased. Therefore the needs of the efficient and automated education agents in the web-based instruction are recognized. In this paper we propose a multi-agent system for course scheduling of learner-oriented using weakness analysis algorithm. At first proposed system analyze learner’s result of evaluation and calculates learning accomplishment. From this accomplishment the multi-agent schedules the suitable course for the learner. The learner achieves an active and complete learning from the repeated and suitable course.

Alloxan 유도 당뇨병상태에서 과산화지질생성에 미치는 Brazilin의 효과

안영수,길이룡,소동수,창동신,김진형,박광식,문창규 한국환경독성학회 1996 환경독성보건학회지 Vol.11 No.2

Brazilin was tested for its ability to inhibit alloxan induced lipidperoxidation. Lipid peroxide contents in liver, kidney and serum were measured by the TBA method. ICR mice receiving alloxan at a dose of 43mg/kg via the tail vein after a 24hrs starvation showed significantly increased lipid peroxide contents as compared to untreated control. Lipid peroxide contents in liver, kidney and serum of alloxan-induced diabetic mice were dose-dependently decreased by the treatment of brazilin at a dose of 10mg/kg, 50mg/kg, 100 mg/kg for 5 days.

Fosfomycin의 항균효과 및 capillary electrophoresis에 의한 측정법에 관한 연구

윤효인,박승춘,이규승,권진욱,조준형,신광순,김무열,허강준,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

Fosfomycin, a low molecular antibiotic, is to be easily synthesized, therefore to be possibly used in veterinary sectors due to econimic reasons. In this study, we determined the antibacterial activities of fosfomycin against some domestic animal-origin pathogens, and its combined effects with some important antibacterials available. We also compared detection methods of fosfomycin from various measuring instruments. The results obtained through this experiment were as follows: 1. Antibacterial activities of fosfomycin against the pathogens used in this experiment were appeared fairly low. We found the antobacterial activities depanded on the kinds of media and the addition of some material thereins, which suggests the importance of appropriate medium so as to judge the antibacterial activity of fosfomycin. 2. Fosfomycin showed varying antibacterial effects in combination with other antibacterials, which should be taken into consideration when combining other antobacterials especially in the clinical settings. Of the combined antivacterials, fosfomycin had synergistic effects in combination with amoxicillin but antagonistic effects with oxytetracyline. 3. Conventional detection methods using HPLC, GC and spectrophotometer were not appropriate to measure fosfomycin. Capillary electrophoresis by the way of the indirect ultraviolet detection method was good enough to detect fosfomycin in the range of expected concentration in tissues, with the limit of quantitation (LOQ) of 1.25 ㎍/㎖. We recommend the eletrophoresis method could be used to detect fosfomycin, thereby being able to set the optimal dosage for animals and providing the measures in relation with the residual concentration in the meat.