• Composites Research
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• 제16권3호
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• pp.9-17
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• 2003

타이어 벨트층내의 코드간 균열연결 및 층간균열진전을 모사하기 위해 자유단을 갖는 2층 고무/코드 적층시험편에 대한 4~11mm 변위제어 실험을 수행하였다. 자유단의 코드간 균열연결시의 폭방향 균열진전량은 45$^{\circ}$ 경사진 코드들간 길이의 절반에 도달할 때의 측정값으로 하였으며, 이는 탐침법에 의해 측정되었다 또한, 자유단에서 코드들간 균열연결을 모사하기위해 2차원의 이상화된 모델링 기법을 고안하였다. 이론수명은 테어링에너지(균열파단면의 단위면적당 방출에너지)를 이용하여 코드간 균열연결수명(임계값)과 이후 최종파손까지의 수명으로 구분하였으며, 이들을 각기 실험값과 비교하였다. 임계값까지의 수명예측은 실험과 비교하여 약 20%, 최종파손까지 약 65%의 오차가 발생하였다. 따라서, 전체 이론수명은 실험과 비교하여 약 45%의 오차를 발생하였다.

• 한국식품조리과학회지
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• 제31권5호
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• pp.515-523
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• 2015

In the study reported here, the antimicrobial and antioxidant activities of the ethanol leaf extract of Dendropanax morbiferus Lev. from Jeju Island was investigated. Of the 14 strains of 12 species of microorganisms tested, the extract exhibited antimicrobial activity observed against seven Gram-positive bacteria of four species, but not against six Gram-negative bacteria and a yeast strain. Using the disc diffusion method, the diameter of the inhibition zone increased with application of the extract with every strain and the highest growth inhibition was exhibited with Staphylococcus aureus KCTC 1916 at 5 mg/ml. The minimal inhibitory concentration of the extract (MIC) by turbidity was 2.5 mg/ml against Bacillus cereus KACC 12672 and 15 mg/ml when with Enterococcus faecalis KCTC 3206. The minimum bacterial concentration (MBC) values defined as being $${\geq_-}99.9%$$ reduction in viable cells against the tested strains was higher than the MIC values. Time killing curves using the optimum MIC were performed on seven strains incubated for 48 hr. The growth of B. cereus KACC 12672 was detected after 12 hr and no significant growth was found in the others strains after 48 hr (p<0.05). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of the ethanol leaf extract was similar to that of butylated hydroxyanisole (BHA) at the same concentration. These results indicate that leaf extract of D. morbiferus Lev. can be utilized as a natural preservative and an antioxidant.

• 대한금속재료학회지
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• 제48권9호
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• pp.791-797
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• 2010

The creep crack growth rate (da/dt) of the Cr-Mo steels tested by pre-crack and the voltage (or resistance) variables were related into fracture parameter (Ct), crack growth coefficient (H), and an exponent (q) in the parts of Base, weld and HAZ. The fracture parameter (Ct) has various variables relating to the specimen and crack shape, applied stress, and creep strain curve. The H and q was inferred by OLS regression (ordinary least square method), and the H values were solved in statistics and probability assessment, which were attained fromPDF's distributions (probability density function). The HAZ part has the highest value of q by OLS regression and the widest distribution of H by PDF of WEIBULL, which means that the crack sensitivity of HAZ should be cautioned against the creep crack growth and failure.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.110.3-111
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• 2003

The effect of biological control on the severity of hot pepper wilt disease was evaluated in the vinyl house with plants cultivated in the nursery soil containing chitin and chitinolytic microorganisms. The chitinolytic microorganisms, Trichoderma harzianum and Chromobacterium sp. strain C-61, were well survived in the nursery soil containing chitin. The hot pepper damping-off was markedly suppressed in the nursery soil containing chitin and chitinolytic microorganisms. The survival of chitinolytic microorganisms and suppression of damping-off were superior as the amounts of chitin added to the nursery soil increased, but growth of hot pepper was inhibited in the 10％ (w/w) chitin treatment. When the plants cultivated in the nursery soil containing 1％ chitin and chitinolytic microorganisms were transplanted in the vinyl house, the vegetative growth increased and the wilt disease was reduced as comparison with those of control.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.110.2-110
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• 2003

The effect of biological control on the severity of hot pepper wilt disease was evaluated in the vinyl house with plants cultivated in the nursery soil containing chitin and chitinolytic microorganisms. The chitinolytic microorganisms, Trichoderma harzianum and Chromobacterium sp. strain C-61, were well survived in the nursery soil containing chitin. The hot pepper damping-off was markedly suppressed in the nursery soil containing chitin and chitinolytic microorganisms. The survival of chitinolytic microorganisms and suppression of damping-off were superior as the amounts of chitin added to the nursery soil increased, but growth of hot pepper was inhibited in the 10％ (w/w) chitin treatment. When the plants cultivated in the nursery soil containing 1％ chitin and chitinolytic microorganisms were transplanted in the vinyl house, the vegetative growth increased and the wilt disease was reduced as comparison with those of control.

• Journal of Nutrition and Health
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• 제20권2호
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• pp.83-89
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• 1987

This study was conducted to investigate the effect of repeated blood collection on the amount of vitamin E in serum and liver of the rats fed standard diet. Rats (Sprague Dawley strain) were fed standard were fed standard diet for several weeks. Blood was collected with on improved cardiac puncture method at regular intervals . The amount of vitamin E analogs were measured by the HPLC. 1) The growth curve of all groups was normal, but bodyweight gains of group II were significantly decreased in case of 7 week- rats whose blood was collected at intervals of two weeks. 2) The amount of vitamin E analogs in serum of rats during growth increased, but continuos blood collection could not affect on the amount of vitamin E in serum. Especially, in the group I serum vitamin E equivalent were significantly higher in case of 7 weeks than first week. 3) The amount of liver vitamin E analogs were changed irregularly, and especially, $\alpha$-Tocopherol equivalent were significantly higher in group II then other groups.

• 한국식품위생안전성학회지
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• 제12권3호
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• pp.205-209
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• 1997

Alcohol treatment was applied to ginseng powder for the improving hygienic quality of ginseng powder. A bacterial strain designated as GT5 was isolated from ginseng powder contaminated and was identified as Escherichia coli species by IMVIC test method. Ethanol used as alcohol, inhibited strongly the growth of coliforms in ginseng powder at the concentrations of 50 to 90%. Ethanol treatment also decreased numbers of total bacteria at the same concentrations. There was not significant changes in saponin of ginseng powder after treated with ethanol. However, ethanol treatment caused a decrease in Hunter's color L value and an increase in a and b values of ginseng powder. As a hygienic quality control of ginseng powder, ethanol treatment could be cosidered as an effective means for decontaminating microorganisms in ginseng powder.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.177-182
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• 1996

The objective of this thesis is to investigate the influence of welding residual stresses on the fatigue growth behavior of welding residual stresses on the fatigue growth behavior of cracks located transverse to the weld bead. For this purpose, G.T.A. (Gas Tungsten Arc) welding was performed on the Al. Alloy 1100-0 plate and the same initial crack is made on HAZ(Heat Affected Zone), weld metal and base metal respectively. C.T.(Compact Tension) specimens were used as experimental material. Initial welding residual stresses were measured by using strain gage sectioning method. All specimens were tested under constant amplitude load with stress ratio R=0.1

• 미생물학회지
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• 제52권1호
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• pp.32-39
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• 2016

독도에 자생하는 번행초의 뿌리로부터 순수 분리하여 형태적으로 상이한 17개의 내생균류를 선별하였다. 또한 분리된 균류들에 대하여 각각의 염농도와 pH 농도 구배에 따라 생장 시험을 확인하였다. 내생균류에 대해 각각 난장이벼의 유묘에 식물생장활성시험을 진행하였고, 그 결과 YH103 균주가 가장 높은 활성을 나타내었다. 계통분석은 Maximum likelihood 방법을 활용하여 결합된 ITS영역, beta-tubulin 및 calmodulin 유전자 염기서열을 분석하여 분리된 균주의 유연관계를 분석하였다. YH103 균주의 배양여과액을 HPLC와 GC/MS SIM을 이용하여 분석한 결과 식물호르몬인 지베렐린 $GA_4$, $GA_7$, $GA_8$ 및 $GA_{19}$가 확인되었다. 최종적으로 YH103 균주의 형태학적 관찰 및 결합된 유전자 염기서열의 분자적 분석을 통해 GA를 생산하는 새로운 Aspergillus tubingensis로 동정되었다.

• 한국축산식품학회지
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• 제31권3호
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• pp.413-419
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• 2011

The antimicrobial effects of the natural flavonoids kaempferol, quercetin, apigenin, and naringenin as well as a novel flavonoid 7-O-butyl naringenin against the growth of four meat-born Staphylococcus aureus strains were evaluated. First, the flavonoids were screened for inhibitory effects against the growth of each strain using the paper disc diffusion method. Second, the growth inhibitory effects of flavonoids that showed antimicrobial activity were measured using the microplate method. Third, the bactericidal effects of flavonoids were evaluated in a 0.8% (w/v) NaCl solution. All flavonoids showed bacteriostatic effects at >20 mM. Among the flavonoids studied, quercetin was more effective than the others tested. However, the inhibitory effect of 7-O-butyl naringenin on growth of S. aureus KCCM 32395 was greater than that of quercetin at the same concentration. Additionally, 7-O-butyl naringenin exhibited significant bactericidal effects at >25 ${\mu}M$. When bacterial cells were examined using scanning electron microscopy, it appeared that the S. aureus membranes were damaged or morphologically changed when treated with quercetin and 7-O-butyl naringenin at 200 ${\mu}M$.