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      • 전자코를 이용한 대추의 산지판별

        조연수,한기영,김정호,노정수 서울여자대학교 자연과학연구소 2001 자연과학연구논문집 Vol.13 No.-

        대추에 내포한 특이한 향기성분을 토대로 수입산 또는 국내산인지의 여부를 아무런 전처리없이 전자코로 분석하였다. 주성분 분석결과 제1주성분 값의 기여율은 0.624이었고, 제2주성분의 기여율은 0.161, 제3주성분 값은 0.132이었다. 제1주성분 값과 제3주성분 값을 이용한 그래프가 제1주성분 값과 제2주성분 값의 그래프보다 국산과 수입산 대추를 더 잘 구별할 수 있었다. 84종의 국내산 대추를 국내산으로 판별한경우는 60종으로 71.42%의 확률로 판별하였으며 48종의 외국산 대추를 외국산으로 판별한 경우는 42종으로 87.50%의 확률로 구별할 수 있었다. 일부 시료의 판별은 어려운 상태이나 전반적으로 수입산과 국내산의 판별이 가능하였다. The discrimination of the agricultural origin of jujubes, cspecially locally produced or the imported products such as jujube was investigated by using electronic nose. Volatile components from these products were able to be distinguished by six metal oxide sensors without any pretreatment. Pattern recognition leas carried out. Principal component analysis showed the difference between imported jujubes and locally produced ones. The number of 60 from 84 species of local jujubes was recognized as locally produced one (71.42%) and 42 from 48 foreign species one was done (87.50%) by discrimination analysis.

      • 레이저 경화면의 형상특징 해석을 위한 프랙탈 차원의 적용

        옥철호,조연상,배춘익,박흥식,전태옥 동아대학교 생산기술연구소 2000 生産技術硏究所硏究論文集 Vol.5 No.2

        The determination of surface topography is believed to be extremely important in the areas of contact mechanics, adhesion and friction. In order to describe topography of various frictional surface, the harding test was carried out under different experimental conditions in dry friction. And fractal descriptors was applied to frictional surface of laser modified steel with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. Topography of frictional surface can be effectively obtained by fractal dimensions.

      • 자동차 수동 트랜스미션 기어의 손상과정 예측

        베효준,조연상,김동호,서영백,박흥식 동아대학교 생산기술연구소 2000 生産技術硏究所硏究論文集 Vol.5 No.2

        The wear particles is released from the moving surfaces in gear systems of transmission and its morphology is directly related to the damage and failure to gear systems from which the particles originated. It is the effective method to diagnosis damage process of gear systems of automobile transmission to observe wear particle in gear oil. We tested with new transmission and took out gear oil according to drive distance. To be applied to damage diagnosis of gear system in transmission of automobile, 4 shape parameters of wear particles in gear oil were calculated and wear volume were presumed with the image processing system.

      • Fractal 차원에 의한 표면경화면과 마찰면의 형태해석

        문병주,조연상,옥철호,박흥식,전태옥 동아대학교 생산기술연구소 2001 生産技術硏究所硏究論文集 Vol.6 No.1

        The determination of surface middleography is believed to be extremely important in the areas of contact mechanics, adhesion and friction. In order to describe middleography of various rubbed and hardened surface, the wear test was carried out under different experimental conditions in dry friction. And fractal descriptors was applied to rubbed and hardened surface of laser modified steel with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. middleography of rubbed and hardened surface can be effectively obtained by fractal dimensions.

      • KCI등재후보

        유압구동 습동재의 마찰면 형상특징 해석에 관한 연구

        전성재,조연상,김동호,박흥식 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.1

        It is known that fractal theory has recently been used as a useful in the characterization of surface texture and the understanding of tribological phenomena such as friction, wear and lubrication. The fractal-based method for describing the rubbed surface texture has roused great interest. In this paper, the fractal descriptors was applied to rubbed surface of hydraulic driving material with image processing system in order to describe morphology of the rubbed surface. The results showed that the fractal dimension can be determined by sum of intensity difference of surface pixel. The two step size to get fractal dimension is similar to surface roughness Ra. Fractal dimensions of the rubbed surfaces increase with an increase of applied load. Morphology of the rubbed surface driving in lubricant can be effectively obtained by fractal dimensions.

      • SCOPUSKCI등재
      • SCOPUSKCI등재

        Bacillus licheniformis KFB-C14가 생산하는 내열성 Chitinase의 정체 및 특성

        홍범식,윤호근,신동훈,조홍연 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

        Bacillus licheniformis KFB-C14가 생산하는 내열성 chitinase를 30~70% ammonium sulfate fractionation, DEAE-Toyopearl 650M, Butyl-Toyopearl 650M, TSK-Gel Toyopearl HW-55F에 의해 정제도 66배, 수율 21%로 전기영동적으로 균일하게 정제하였다. 정제 단백질은 gel permeation chromatography에 의해 86,000±2,000의 분자량을 나타내었으며, SDS 전기영동에 의해 밝혀진 본 효소의 subunit 구조는 monomer였다. 효소 단백질의 안정성을 검토한 결과 80℃에서 30분 열처리에 의해 56%, 37℃에서 20분간 40% ethanol과 ethyl acetate, 단백질 변성제 등의 처리시에도 50% 이상의 잔존활성을 나타냄으로써 공업적으로 유용성이 높은 안정한 단백질로 판명되었다. 효소반응의 최적 pH와 온도는 pH 6.0과 60℃이었고 Mn^2+ 이온에 의해 효소 활성이 저해되었으나 EDTA, N-ethylmaleimide, p-chloromercuribenzoate 등에 의한 활성감소는 관찰되지 않음으로써 금속효소 또는 thiol계 효소에 속하지 않음을 알 수 있었다. 본 효소는 colloidal chitin, 시판용 chitin에는 반응성이 높았으나 exo형 chitinase의 대표적인 기질인 p-nitrophenyl-2-aectamido-2deoxy-β-glucopyranoside, NN'-diacetylchitobiose에는 전혀 반응성을 보이지 않는 전형적인 endo형의 chitinase였다. 본 효소는 colloidal chitin으로부터 주로 (GlcNAc)_2를, 반응시간 경과에 따라 (GlcNAc)_1과 (GlcNAc)_3을 생성하는 반응성을 보였다. Chitinase (EC 3.2.1.14) from culture fluid of Bacillus licheniformis KFB-C14 was purified 66-folds to homogenity in overall yield of 21% by ammonium sulfate fractionation, DEAE-Toyopearl, Butyl-Toyopearl and TSK-Gel HW-55F column chromatography. The enzyme protein had a molecular weight of about 86,000 and was composed of one subunit. The enzyme was significantly stable not only at high temperature but also on treatment with organic solvents and protein denaturants such as SDS, urea and guanidine·HCl. The optimum temperature and pH for reaction was 60℃ and 6.0,respectively. The enzyme activity was inhibited by only Mn^2+ ion, but not inhibited by EDTA, N-ethylmaleimide and pCMB. The enzyme had high activity with colloidal chitin (V_max: 421) and commercial chitin (V_max :480), but not with typical substrates of exo type chitinase. The thermostable chitinase had an useful reactivity for producing functional chitooligosaccharide, showing the production of (GlcNAc)_1, (GlcNAc)_3, and (GlcNAc)_2 as major product.

      • 위암종과 Epstein-Barr 바이러스와의 연관성에 대한 연구

        심광용,김호영,김효열,백순구,권상옥,조미연,이창훈,이종인 건국대학교 의과학연구소 2004 건국의과학학술지 Vol.14 No.-

        Objectives: Epstein-Barr virus (EBV) has been known to be linked to a spectrum of neoplastic conditions, including nasopharyngeal carcinoma, Burkitt's lymphoma, peripheral T-cell lymphoma and Hodgkin's disease. This study aims to investigate the association of EBV with gastric carcinoma in Korea. Methods: Fifty-three cases of gastric adenocarcinoma were studied for evidence of EBV infection by EBV-encoded small RNA (EBER) in situ hybridization (ISH) on the paraffin sections and amplifying the EBV genome encoding envelop glycoprotein (gp220) with polymerase chain reaction (PCR) in fresh gastric cancer specimens. Results: EBER was detected in 7 (13.2%) of 53 gastric carcinomas and all cases were male. In 6 (85.7%) of 7 EBER-positive cases, the tumors were located in the upper and middle part of the stomach. EBER ISH study showed strong positivity in all the tumor cells, but negativity in surrouning lymphocytes, stromal cells and normal gastric mucosa. DNA PCR was positive in 23 (43.4%) of 53 gastric carcinomas, including all of 7 EBER-positive cases. Conclusion: We could observe some association of EBV with gastric carcinoma, and our findings about the charateristics of EBV-positive gastric cancers involving sex, site and histological type are similar to those in Japan. However, EBV-positive rate of gastric cancer is higher than in Japan and lower than in Western countries. Further studies to elucidate oncogenic mechanism of EBV in gastric cancer should be performed.

      • SCOPUSKCI등재

        내열성 Chitinase 생산균주의 분리 및 효소생산 특성

        홍범식,윤호근,신동훈,조홍연 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

        자연계 고온환경으로부터 내열성 chitinase 우수하고 반응산물로 N-acetyl-D-glucosamine 이량체(GlcNAc)_2를 생산하는 균주를 분리 선별하고 Bacillus licheniformis KFB-C14로 동정하였다. 선별균주의 효소생산 특성은 탄소원으로서 효소기질인 colloidal chitin이 첨가될 때만이 생합성이 유도되었으며 유도제의 첨가시기에 의해 효소생산이 크게 영향을 받았다. 각종 무기, 유기태 질소원 중 yeast extract가 활성과 비활성을 각각 약 2배 증가시켰으며 높은 친화도를 나타내었다. 균의 최대생육과 효소의 최대생산온도는 55℃이었다. 본 균주의 내열성 chitinase 생산에 미치는 최적배양조건은 1.2% colloidal chitin, 0.15% K_2HPO_4, 0.05% KH_2PO_4 0.01% MgSO_4·7H_2O, 0.1% yeast extract, pH 6.5의 배지를 55℃, 150rpm에서 40시간 회전진탕배양 하였을 때로 3.89 units/ml의 효소활성과 7.4 units/mg의 비활성을 나타내었다. A strain capable of producing thermostable chitinase suitable for chitooligosaccharide production was isolated from high temperature environment and identified as Bacillus licheniformis. The chitinase from Bacillus licheniformis KFB-C14 was only induced by addition of colloidal chitin into the basal medium as carbon source, showing the decrease of the chitinase production by supplemental addition of other carbon sources into the medium containing 1.0% colloidal chitin. Among organic and inorganic nitrogen sources, yeast extract was the most effective for the increase of total activity and specific activity, and had high affinity for the enzyme production. The optimum temperature of cell growth and thermostable chitinase production was 55℃. The optimum culture medium was composed of 1.2% colloidal chitin, 0.15% K_2HPO_4, 0.05% KH_2PO_4 0.01% MgSO_4·7H_2O, 0.1% yeast extract (pH 6.5). Bacillus licheniformis KFB-C14 produced the thermostable chitinase of 3.89 units per culture fluid and 7.4 units per mg protein under rotary shaking at 150 rpm for 40 hr.

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