• 한국결정성장학회지
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• 제11권4호
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• pp.166-169
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• 2001

6H-SiC bulk crystals were grown by sublimation method with different conditions in term of gaseous pressures ad source temperatures. In order to optimize the growth rate, pressure at growth period and source and substrate temperatures were investigated as experimental variables. the results were compared with each other and finally the optimum growth conditions were discussed. Furthermore the relation of the growth steps and defects formation was evaluates in the point of reducing the micropipes. Subsequently the growth steps and defects formation was evaluated in the point of reducing the micropipes. Subsequently the growth steps were observed leading to the lower step height with the lower growth rate.

• 미생물학회지
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• 제8권3호
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• pp.103-106
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• 1970

The cultural conditions of the osmophilic red color yeasts (Strain L${1$, $L_2$, $L_3$ and $L_4$) isolated and identified in the previous report were examined and the results obtained were as follows ; 1. The optimum medium for growth of these osmophilic red color yeasts was soy sauce medium. 2. These strains were grown exceedingly well on the medium containing 3 percent of NaCl but somewhat restrained on the medium containing 6% or more. 3. The optimum temperautre for growth of these strains was $25^{\circ}C$ and their lethal temperature was $68^{\circ}C$(treatment for 5 minutes). 4. The optimum pH for growth of these strains was 6.0.

• 수산경영론집
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• 제38권1호
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• pp.1-17
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• 2007

This study is aimed at investigating optimum level of payments in the direct payment program for aquaculture extruded pellets both theoretically and practically by analyzing the effects on production and income in accordance with Green Box conditions of WTO Agreement on Agriculture. In particular, by analyzing both effects on production and income, it evaluates and compares payments affecting to the level of production and income, respectively. Analysis results indicate that the optimum level of payments in the direct payment program for aquaculture extruded pellets is determined by the growth rate of farmed fish, farming period, price and volume of extruded pellets, and additional amount of cost increase and decrease. Suppose that growth rates of farmed fish by extruded pellets(EP) and raw fish - based moist pellets(MP) are the same, it reveals the optimum level of payment should be lowered from the current level of payment. However, when the growth rate of farmed fish by EP is lower than that by MP, the optimum level of payment should be raised from the current level and total amount of payments by area should be increased as well.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.781-787
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• 2014

2-Ketogluconic acid production by Klebsiella pneumoniae is a pH-dependent process, strictly proceeding under acidic conditions. Unfortunately, cell growth is inhibited by acidic conditions, resulting in low productivity of 2-ketogluconic acid. To overcome this deficiency, a two-stage fermentation strategy was exploited in the current study. During the first stage, the culture was maintained at neutral pH, favoring cell growth. During the second stage, the culture pH was switched to acidic conditions favoring 2-ketogluconic acid accumulation. Culture parameters, including switching time, dissolved oxygen levels, pH, and temperature were optimized for the fed-batch fermentation. Characteristics of glucose dehydrogenase and gluconate dehydrogenase were revealed in vitro, and the optimal pHs of the two enzymes coincided with the optimum culture pH. Under optimum conditions, a total of 186 g/l 2-ketogluconic acid was produced at 26 h, and the conversion ratio was 0.98 mol/mol. This fermentation strategy has successfully overcome the mismatch between optimum parameters required for cell growth and 2-ketogluconic acid accumulation, and this result has the highest productivity and conversion ratio of 2-ketogluconic and produced by microorganism.

• 한국균학회지
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• 제32권2호
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• pp.134-137
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• 2004

항암 능력이 높다고 알려진 진흙버섯속(Phellinus)은 단 다년생인 백색부후균이며 여기에 속하는 10개 균주의 최적 배양조건을 조사하였다. 그 결과 진흙버섯속 균사체 배양에 적절한 영양원으로는 $25^{\circ}C$ 배양상에서 PDA 배지였으며, 최적 pH는 $6.0{\sim}8.0$로 조사되었고 pH 4.0에서는 모든 균주가 느린 생장속도를 나타냈다. 배양온도는 $25{\sim}30^{\circ}C$에서 대부분의 균주가 양호한 생장을 보여주었다. Phellinus biscuspidatus는 실험 균주 중 가장 빠른 생장속도를 나타냈으며 pH 5.0에서 최적의 성장속도를 보여주었으나 pH $6{\sim}8$에서도 양호한 생장을 한 것과 균사밀도를 고려했을 때 최적pH는 $6.0{\sim}7.0$이라 할 수 있겠다. P. biscuspidatus, P. johnsonianus와 P. lloydii는 $30^{\circ}C$와 $35^{\circ}C$ 사이에서 균사생장이 활발한 고온성 균임을 알 수 있다.

• 한국세라믹학회지
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• 제46권3호
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• pp.253-262
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• 2009

The purpose of this study is to find out optimum conditions for zinc crystalline glaze under variables of firing: maximum firing temperature, crystal growth temperature, temperature increasing speed, annealing speed, holding time at maximum temperature and holding time at crystal growth temperature. Ferro Frit3110, ZnO and Quartz were used as starting materials and tested by three component system. The best result of test was selected and extended to its vicinity as five glaze formulas. And then the specimens were experimented by variable firing conditions and analyzed by crystal appearance observation, XRD, FT-IR and Raman spectroscopy. In result, main crystal was willemite in the zinc glazes. Some gahnite was detected in specimens which were fired at $1230^{\circ}C$, $1250^{\circ}C$ and $1270^{\circ}C$, however gahnite was not identified at $1300^{\circ}C$. Optimum zinc crystalline glaze was gained by following firing condition: temperature increasing speed $5^{\circ}C$/min, holding 1 h at $1270^{\circ}C$, annealing speed $3^{\circ}C$/min till $1170^{\circ}C$, holding 2 h at $1170^{\circ}C$ then naturally annealed.

• 한국균학회지
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• 제31권1호
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• pp.8-13
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• 2003

매미누꽃동충하초(Paecilomyces sinclairii)를 전라남도 백양사의 인근 숲에서 채집하여 균주를 순수 분리하고 균사의 최적 배양조건과 특성을 조사하였다. 균사생장에 적합한 pH는 $5{\sim}9$의 범위였으며 pH 8에서 가장 왕성한 균사생장을 보였고, 온도는 $25{\circ}C$가 적합하였다. 균사생장에 가장 적합한 배지는 Hamada 배지였으며 탄소 영양원은 dextrin, 질소 영양원은 glutamine인 것으로 조사되었다. 균사의 생장은 C/N비가 20:1일 때, 옥수수추출물과 우유가 혼합한 배지에서 가장 양호하였다. 자실체는 20%의 누에번데기가 첨가된 현미배지에서 500lux, $25{\circ}C$의 조건으로 배양할 때 가장 자실체 형성이 우수하였다.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.557-560
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• 1994

The optimum medium composition for the production of L-tryptophan with Klebsiella pnuemoniae pheA tyrA trpE trpR/pSC 101-trp$^{+}$ and the effect of precusors in the optimum medium were studied. The specific growth rate in the optimum medium was almost the same as that in the basal medium, the former showing 1.01 and the latter 1.07 hr $$^{-1}$, but the produced tryptophan was increased 45% in the optimum medium. The maximum amount of produced tryptophan was 159 mg/l within 14 hours. Tryptophan production was ceased by casamino acid addition over 4 g/l in medium, but cell maSS increased with its addition. Indole and anthranilate as precusors had toxic effect on growth and tryptophan production at experimented concentration range (over 20 mg/l), but L-serine had good effect on tryptophan production, resulting in 175 mg/l tryptophan within 14 hours.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.289-293
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• 2003

Schizophyllum commune의 균체 생육 및 다당체 생성에 미치는 여러 가지 배지성분의 영향을 조사하였다. 탄소원으로는 산업적인 경제성과 높은 다당체 생성량을 나타낸 glucose를 선택하였고, 무기질소원은 유기질소원에 비해 현저히 낮은 다당체 생성량을 나타내었으며, 그 결과 균체량과 다당체 생성량에서 높은 효과를 나타낸 yeast extract를 질소원으로 선택하였다.

• 동아시아식생활학회지
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• 제21권5호
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• pp.661-668
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• 2011

This study was conducted in order to determine the optimum conditions for the production of fermented grapefruit extract showing high cell growth, antioxidant activity and total flavonoid content. Five lactic acid bacterial strains - Lactobacillus plantarum KCTC3104, Lactobacillus brevis KCTC3102, Weisella cibaria KCTC3746, Leuconostoc citreum KCTC3526 and Leuconostoc mesenteroides KCTC3505 - were evaluated first in order to determine the optimum strain able to grow with high efficiency on grapefruit as a substrate and possesses higher antioxidant activity and flavonoids content. Among these strains, L. mesenteroides KCTC3505 was selected as a starter culture. To estimate the available or effective content of grapefruit in basal medium, the effects of 30%, 50%, and 70% grapefruit contents on the performance of fermentation were tested, and it was found that grapefruit can be added at 70% levels to medium. In this study, three factors of fermentation conditions - incubation time, sucrose, and glucose contents - were evaluated for their effects on fermentation performance. Taguchi experiment design was employed and the responses of experiments were calculated using signal and noise ratio calculation with larger-the-best characteristics. Finally, the optimum conditions for the manufacture of fermented grapefruit extract were as follows: grapefruit 70%, sucrose 10 g/L, glucose 10 g/L, sodium acetate 1 g/L, NaCl 1 g/L, dipotassium phosphate 0.1 g/L, magnesium sulfate 0.01 g/L and 16 hr of incubation.