• 한국응용과학기술학회지
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• 제9권1호
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• pp.15-23
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• 1992

This study was aimed to observe dose-response effects of squid liver oil enriched in n3 polyunsaturated fatty acids(n-3 PUFA) on the metabolism of streptozotocint(STZ)-induced diabetic rats. In this experiment, 24 STZ-induced diabetic male rats of Sprague Dawley strain were divided into 4 groups and fed for 4 weeks with basal diet(0%). 33%,67% and 100% squid liver oil(SLO) of total fat content, and 6 normal rats were fed with 0% SLO diet at the same time. The results obtained were as follows: 1. Rat group fed with 33% SLO diet showed the least body weight loss and changes in blood glucose, while ones of 100% SLO diet showed the highest level. 2. Serum total protein and ratio of albumin to globulin of all the groups were below the standard level, but did not show significantly different among diet groups. 3. Serum creatinine concentration of all the groups were stayed whthin normal range, but BUN were 3 to 4 times higher than normal rats. BUN concentration of rats fed with 0% and 33% SLO diet was significantly lower than those of others. 4. Total-cholesterol level of serum increased in all the groups except 33% SLO diet, but since HDL-chol, levels and TG concentration went up with an incerase of SLO in the diets, the ratio of HDL-chol. to total-chol, of rats fed with 67% and 100% SLO diet showed higher than those with 0%, and 33% SLO, and TG concentration of rats fed with 67% and 100% SLO diet decreased significantly.

• 미생물학회지
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• 제43권3호
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• pp.217-221
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• 2007

거봉 포도로부터 분리하여 동정한 야생효모 Saccharomyces cerevisiae IJ850을 이용, 국내산 캠벨얼리와 거봉포도를 발효시켜 적포도주를 제조하고, 이의 발효특성을 분석함으로서 포도주제조용 발효균주로서의 가능성을 알아보고자 하였다. 야생발효균주의 분리를 위하여 안성지역 거봉포도와 캠벨얼리 포도즙을 실온에서 6일 동안 스타터의 첨가없이 자연발효시켜 우세균주를 분리하였다. 거봉에서 분리된 효모의 발효능이 캠벨얼리에서 분리된 효모보다 1.8배정도 높았다. 거봉에서 분리한 발효균주를 분자 생물학적 인 방법 인 26S rDNA 염기서열에 근거하여 동정한 결과, Saccharomyces cerevisiae와 99.7%의 유사성을 나타내어 Saccharomyces cerevisiae IJ850으로 동정되었다. 분리균주를 이용한 포도주의 제조에서는 캠벨얼리와 거봉포도즙의 최종 당도를 $25^{\circ}Brix$로 포도당을 이용하여 보당하고, 이산화탄소를 발효조에 채우고, 실온에서 10일간 발효시켰다. 포도주의 수율은 캠벨얼리가 75%, 거봉이 85%였고 최종 알코올 도수는 캠벨얼리가 11.0%, 거봉이 13.0%이었다. 산업용발효균주인 S. cerevisiae EC-1118과 비교한 결과 총산도는 캠벨얼리와 거봉포도주 모두에서 산업용 발효균주인 EC-1118에 비하여 분리한 S. cerevisiae IJ850에서 낮은 수치를 보였다. 포도주의 pH와 색도 분석에서는 S. cerevisiae IJ850과 S. cerevisiae EC-1118로 제조한 포도주모두에서 비슷한 수치를 보여주었으나, 페놀 성분분석에서는 S. cerevisiae EC-1118로 제조한 캠벨얼리 포도주에서 125 mg/L의 함량을, S. cerevisiae IJ850으로 제조한 거봉포도주에서 75 mg/L의 함량을 나타내었다. 따라서 국내 거봉포도로부터 분리한 S. cerevesiae IJ850는 포도주 생산에 사용될 수 있는 균주로써 그 가능성을 보여주었다.

• 대한기계학회논문집A
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• 제41권8호
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• pp.765-770
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• 2017

Ni기 초내열합금인 GTD111 DS는 가스터빈 블레이드에 사용된다. 본 논문에서는 실제 운전조건과 유사한 조건을 설정하여 GTD111 DS의 저주기 피로시험을 실시하였다 상온, $760^{\circ}C$, $870^{\circ}C$의 온도범위와 다양한 변형률에서 저주기 피로시험을 수행하였다. 실험결과 총 변형률이 증가함에 따라 피로수명은 감소하였다. 상온 및 $760^{\circ}C$에서는 주기적 경화반응이 나타났으며 $870^{\circ}C$에서는 주기적 연화반응이 나타났다. $870^{\circ}C$에서 응력완화 현상은 유지시간에 따른 크리프의 영향으로 나타났다. 피로수명과 총 변형률의 관계는 Coffin-Manson 식을 통해 얻었다. 파단면은 SEM을 통해 초기균열 및 피로진전지역을 관찰하였다.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1591-1597
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• 2007

The production of carotenoids, lipid content, and fatty acid composition were all studied in a strain of Sporobolomyces ruberrimus when using different concentrations of technical glycerol as the carbon source and ammonium sulfate as the nitrogen source. The total lipids represented an average of 13% of the dry weight, and the maximum lipids were obtained when using 65.5 g/l technical glycerol (133.63 mg/g). The optimal conditions for fatty acid production were at $27^{\circ}C$ using 20 g of ammonium sulfate and a pH range from 6 to 7, which produced a fatty acid yield of $32.5{\pm}1\;mg/g$, including $1.27{\pm}0.15\;mg$ of linolenic acid (LNA), $7.50{\pm}0.45\;mg$ of linoleic acid (LLA), $5.50{\pm}0.35\;mg$ of palmitic acid (PA), $0.60{\pm}0.03\;mg$ of palmitoleic acid (PAL), $1.28{\pm}0.11\;mg$ of stearic acid (SA), $9.09{\pm}0.22\;mg$ of oleic acid, $2.50{\pm}0.10\;mg$ of erucic acid (EA), and $4.25{\pm}0.20\;mg$ of lignoceric acid (LCA), where the palmitic, oleic, and linoleic acids combined formed about 37% of the total fatty acids. The concentration of total carotenoids was 2.80 mg/g when using 20 g of ammonium sulfate, and consisted of torularhodin (2.70 mg/g) and $\beta$-carotene (0.10 mg/g), at $23^{\circ}C$ and pH 6. However, the highest amount with the maximum specific growth rate was obtained (${\mu}_{max}=0.096\;h^{-1}$) with an ammonium sulfate concentration of 30 g/l.

• 대한가정학회지
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• 제40권11호
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• pp.193-205
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• 2002

To evaluate farmers' workload during harvesting grapes in summer, this study investigated farmers' physiological, psychological responses, work postures and thermal environment around in the field. This field study was conducted in the Anseong County of Kyonggi Province at the end of August. Five career farmers (1 male, 4 females) volunteered as subjects. Three of them were over their sixties. During harvesting grapes in the field, physiological responses were monitored continuously. 1. Air temperature (T/sub a/), air humidity(H/sub a/), black globe temperature(T/sub g/), air velocity and WBGT around the grape field were 26.9℃, 77.7%RH, 32.8℃, 0.08㎧ and 26.3℃, respectively. Because farmers started the harvesting task in early morning, thermal environments weren't conditions to give farmers severe heat strain. 2. The percentage of the work postures was larger in order of standing, walking, and bending one's back posture. Particularly, the percentage of standing posture with raising both arms above shoulder of two farmers was up to 29% and 61% of the total work duration. 3. Rectal temperature (T/sub re/), mean skin temperature (T/sub sk/), clothing microclimate temperature (T/sub cl/) on the chest and the back, heart rate (HR) and energy expenditure (EE) were 37.2℃, 33.1℃, 32.0℃, 32.4℃, 88bpm and 1.3 Kca1/㎡/min respectively. In the point of these physiological results, we evaluated that the harvesting task was a moderate work. 4. All farmers expressed‘hard, hot, humid and slightly uncomfortable’ at the end of works for each subjective questionnaire. The grape harvesting tasks were not evaluated as a very hard work in the point of physiological work standards. But we considered 1) inappropriate work posture (standing posture with raising both arms above shoulder) and 2) farmers' age as burden factors. These findings suggest that adding adequate protective clothing/equipments for farmers may contribute to maintain their body temperature within the normal range, stabilize HR and decrease psychological strain.

• 한국환경보건학회지
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• 제29권2호
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• pp.94-102
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• 2003

This study was carried out to investigated the distribution and characteristics of Vibrio spp. isolated from fish and shellfish, seawater and brackish water samples collected from Pohang, Uljin, Yeongduk and Gyeongju in Gyeongbuk Province from April 2000 to October 2000. Total 155 strains of genus Vibrio were isolated from 439 collected samples, and numbers of isolated strains of V. parahaemolyticus and V. vulnificus were 140 and 15, respectively. The isolation rate from the samples collected in Pohang was the highest as 41.5% (76 strains), and wat the highest as 71.4% (30 strains) in brackish water, and was the highest as 55.7% (34 strains) in August. And the optimal pH, temperature, and NaCl concentration for growth of V. parahaemolyticus and V. cholerae were 8.0, 3$0^{\circ}C$ and 2.0％, respectively. In a resistance test for environmental factors, heat and cold resistants of V. parahaemolyticus were higher than those of V. vulnificus, withstanding for 15 minutes at 6$0^{\circ}C$ and 6 days at -18$^{\circ}C$. The pH range for existence of V. parahaemolyticus and V. vulnificus were 4.5~l1.0 and 4.5~10.0, showing the similar resistance to pH. V. parahaemolyticus and V. vulnificus could grow in media containing up to 10.0% and 7.0% NaCl, respectively, Salt-tolerance of V. parahaemolyticus was higher than that of V. vulnificus. In an antibiotics sensitivity test against 16 strains of V. parahaemolyticus, twelve strains were resistant to ampicillin, eight strains were resistant to cephalothin. one strain was resistant to streptomycin, and one strain was resistant to ticarcillin.

• 한국식품저장유통학회지
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• 제18권4호
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• pp.559-566
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• 2011

국산 포도로부터 분리 된 Saccharomyces cerevisiae MM10, SS89 그리고 SS812 균주를 전체원료의 15%에서 배양하여 얻은 균체를 24 $^{\circ}Brix$로 동결농축한 사과액에 접종하여 무가당 사과주를 양조하였다. 발효 중 환원당은 대조균주와 비교 시 완만한 감소를 나타내었고, 총산은 모든 효모군에서 알코올 발효가 진행될수록 증가하였다. 최종 알코올 함량은 모든 효모군에서 12~13%의 함량을 나타내었다. 사과주의 유기산 함량의 범위는 2.43~2.92%이었으며, 유리당 조성은 약간의 과당이 검출된 SS89 균주를 제외한 모든 효모군에서 솔비톨만이 검출되었다. 메탄올은 검출되지 않거나 아주 극미량이 존재하였고, 알데히드는 107.68~114.27 ppm을 나타내었다. 퓨젤유에 있어서 propanol은 극미량 존재하였고, ethyl acetate는 55.27~69.54 ppm을 나타내었다. Isobutanol과 butanol은 각각 40.49~54.65 ppm과 25.47~27.73 ppm의 함량을 나타내었다. 그리고 isoamy1 alcohol은 108.88~217.26 ppm을 나타내었다. 총 페놀성 화합물 함량은 0.01~0.16%를 나타내었으며, hue 값은 1.40~2.01, intensity는 0.30~0.45의 범위를 나타내었다 명도는 91.78~98.19의 범위를 보였고, 적색도는 적색과 녹색의 중간색의 양상을 보였으며, 황색도는 2.38~7.7의 범위를 나타내었다. 관능검사 결과 색은 SS812 사과주, 향기는 SS889 사과주, 종합적인 기호도는 SS812 사과주가 가장 좋은 것으로 나타났다. 맛은 모든 선발균주가 동일하게 대조균주보다 높은 점수를 얻었다.

• 대한의생명과학회지
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• 제18권3호
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• pp.268-275
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• 2012

Reference ranges of standard experimental parameters are useful for comparisons in toxicology. The aim of this study was to collect data from 4-week repeated toxicity studies in Crl:CD (SD) rats, a strain widely used for toxicity and efficacy research, for establishing domestic reference values. Data on body weight, food consumption; urinalysis, hematological, and blood biochemical parameters; and organ weights were collected from 16 toxicity studies in 220 Crl:CD (SD) rats (110 males and 110 females). The studies had been performed at a single testing facility over the last 3 years and involved animals sourced from a single breeder. The findings were collated as means, standard deviations, percentages, and ranges. Urine volume, uterus weight, eosinophil, and basophil counts, and triglyceride, total bilirubin, and gammaglutamyl transpeptidase levels showed standard deviations of 30% or more. These historical control data would help to interpret the effects of test substances in routine toxicity and efficacy studies.

• 대한조선학회지
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• 제21권1호
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• pp.35-42
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• 1984

In the present study, rotating bending fatigue tests have been carried out in three kinds of carbon steel specimens; an annealed low carbon steel, an annealed high carbon steel and quenched-tempered high carbon steel; with a small artificial surface defect that might exist in real structures. Fatigue crack lengths have been observed by a method of replication in order to investigate the growth characteristic of fatigue crack in the viewpoints of strength of materials and fracture mechanics. The main results obtained are as follows: 1) The effect of a small surface defect upon the reduction of fatigue limit is considerably large, and the rate of fatigue limit reduction grows in the following order; annealed low carbon steel(mild steel), annealed high carbon steel, quenched-tempered high carbon steel. 2) When the growth rate of surface crack length(2a) was investigated in the viewpoints of fracture mechanics based upon $ ${\Delta}K_{\varepsilon}$, the dependence of stress level and of surface defect size disappear, and there exists a linear relationships between d(2a)/dN and ${\Delta}K_{{\varepsilon}t},\;\Delta_{{\varepsilon}t}\sqrt{{\pi}a}$, on log. plot, i.e, $d(2a)/dN={C{\cdot}{\Delta}K_{\varepsilon}}^3_t$, where ${\Delta}_{{\varepsilon}t}\sqrt{{\pi}a}$ a is the cyclic total strain intensity factor range.

• Structural Engineering and Mechanics
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• 제68권2호
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• pp.237-245
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• 2018

This study proposes an empirical formulation to predict the maximum deformation of offshore blast wall structure that is subjected to impact loading caused by hydrocarbon explosion. The blast wall model is assumed to be supported by a simply-supported boundary condition and corrugated panel is modelled. In total, 1,620 cases of LS-DYNA simulations were conducted to predict the maximum deformation of blast wall, and they were then used as input data for the development of the empirical formulation by regression analysis. Stainless steel was employed as materials and the strain rate effect was also taken into account. For the development of empirical formulation, a wide range of parametric studies were conducted by considering the main design parameters for corrugated panel, such as geometric properties (corrugation angle, breadth, height and thickness) and load profiles (peak pressure and time). In the case of the blast profile, idealised triangular shape is assumed. It is expected that the obtained empirical formulation will be useful for structural designers to predict maximum deformation of blast wall installed in offshore topside structures in the early design stage.