• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.8-13
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• 1998

Animal cells in culture typically convert most of the glucose they consume into lactate. The accumulation of lactate, however, is commonly cited as one of the factors that inhibit cell growth and limit the maximum cell concentration that can be achieved in culture. The specific production of lactate and the amount of glucose converted to lactate can be reduced when cells are grown in a fed-batch culture in which the residual glucose concentration is maintained at low levels. Such a fed-batch culture was used to grow and adapt hybridoma cells into a low-lactate-producing state before changing into continuous culture. The cells reached and maintained a high viable cell concentration at steady state. In a similar manner, cells that were initially grown in batch culture and a glucose-rich environment reached a steady state with a cell concentration that is much lower. The feed composition and dilution rates for both cultures were similar, suggesting steady state multiplicity. From a processing perspective the desired steady state among those is the one with the least metabolite production. At such seady state nutrient concentration in the feed can be further increased to increase cell and product concentrations without causing the metabolite inhibitory effect typically seen in a cell culture. Controlling cell metabolism in a continuous culture to reduce or eliminate waste metabolite production may significantly improve the productivity of mammalian cell culture processes.

• 한국광물학회지
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• 제9권1호
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• pp.7-16
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• 1996

Partially sericitized tourmaline from a pegmatite, Black Hills, South Dakota, U.S.A., was investigated using high-resolution transmission electron microscopy (HRTEM). Muscovite occurs as the only alteration product of tourmaline, and it is developed extensively as narrow veinlets along the {110} and {100} cleavage directions of tourmaline, indicating that a cleavage-controlled alteration mechanism was dominant. Muscovite was characterized mainly as two-layer polytypes with minor stacking disorder, but tourmaline is almost free of structural defects. HRTEM images of tourmaline-muscovite interfaces revealed that the interfaces between two minerals are composed of well-defined {110} and {100} boundaries of tourmaline. The (001) of muscovite is in general parallel to the c-axis of tourmaline, but tourmaline and replacing muscovite do not show specific crystallographic orientation relationship; muscovite consists of numerous 100-1000$\AA$ thick subparallel packets, and the angles between the (001) of muscovite and (110) of tourmaline is highly variable. Al/Si ratios of both minerals suggest that tourmaline to muscovite alteration by late magnetic fluids has been facilitated by their similar Al/Si ratio in the incipient alteration stage, in that the hydration reaction with preservation of Al and Si would require only addition of K+ and H2O. Aluminous minerals other than muscovite were not characterized as the alteration products of tourmaline, indicating that tourmaline reacted directly to muscovite; the tourmaline alteration apparently occurred by the presence of residual fluids in which K+ is available and silica was not undersaturated.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.7-11
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• 2015

The influence of spice (cinnamon, allspice, black pepper)-oil extract on canned seafood quality was studied. During the processing of canned seafood, the substitution of spice-oil extract for vegetable oil (refined sunflower, corn, soybean and olive oil) resulted in a decrease in the heat resistance of spore microorganisms, making it possible to reduce the duration of sterilization for canned food to 5-10 min at $115^{\circ}C$. This reduction in the sterilization duration of canned seafood with spice-oil extract inhibited residual microflora in the product, thus reducing the deleterious effect of heating on the main food compounds while preserving protein digestibility.

• 한국소음진동공학회논문집
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• 제17권11호
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• pp.1056-1063
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• 2007

Recently, there has been a growing consumer interest in the amount of noise produced by household electrical appliances. The designer of the product must identify the source of the noise, in order to reduce the noise. In the case of a household electric appliance such as the washing machine, there is consumer's complaint about the noise that is generated during the dehydrating condition. Because of several noise sources combined each other. It is difficult to identify the noise sources that contribute to the noise output. Multi-Dimensional Spectral Analysis (MDSA) is a method that can remove the correlation between different noise sources, and it expresses the key contributing factor as a unique output. This study utilized MDSA to analyze the contribution of each input in the noise output during the dehydrating condition.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.501-503
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• 2003

Soil-gas radon level and other atmospheric factors have been measured at residual soil profiles that overlie granite bedrock which consists of major geology in Korea for 6 months from November, 2000 to April, 2001. Seasonal variations of soil-gas radon concentration are generally of greater magnitude than day-to-day fluctuations. The highest radon concentrations of 5,131 pCi/L measured during winter season and the lowest radon concentrations of 107 pCi/L during spring season. Two study areas, Bongcheon-dong(granite bedrock) and Seongnam-Yongin(gneiss bedrock) were investigated to assess the radon potential according to their field survey and emanation tests. The mean values of radon decrease in sequentially from Suji-A(813 pCi/L)>Suji-B(757 pCi/L)>Bundang-B(691 pCi/L)>Bundang-A(643 pCi/L)>Bongcheon-dong(513 pCi/L). Estimated soil-gas radon potential using maximum radon emanation ratios of each study area decreases in the order of Bongcheondong(950 pCi/L)>Suji-B(524 pCi/L)>Bundang-A(437 pCi/)>Bundang-B(259 pCi/L)>Suji-A(230 pCi/L) areas. The values of indoor radon and its daughter product concentrations in Bongcheon-dong area show that indoor basement rooms in poor ventilation condition could be classified as extremely high radon risk location of more than 4 pCi/L Rn and 0.02 WL.

• 터널과지하공간
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• 제11권2호
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• pp.96-108
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• 2001

NATM 터널의 콘크리트라이닝은 계획, 지반조사, 지반-라이닝 상호작용해석, 시공, 관찰, 시공중 수정 등의 과정을 거쳐 시공된다. 따라서, 설계자는 라이닝의 여러 기능, 시공과정, 지반조건 등을 고려하여야 한다. NATM 터널 콘크리트라이닝 설계시 지반조건이 열악하거나 숏크리트의 부식 등으로 1차 지보재가 지보능력을 상실할 경우에 대비하여야 한다. 그러나, 암반이완하중과 잔류수압의 크기, 형태 및 산정방법이 설계자에 따라 다양하게 적용되고 있는것이 현실이다. 본 논문에서는 NATM 터널 콘크리트라이닝 설계시 적용할 수 있는 암반이완하중 산정 법들에 대하여 고찰하고, 설계시 국내에서 주로 적용하는 다양한 암반하중과 잔류수압모델을 조합하여 구조해석을 실시한 후 콘크리트라이닝에 발생 하는 부재력의 크기를 비교하였으며, 적절한 하중조합을 제시하였다.

• 펄프종이기술
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• 제38권3호
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• pp.72-78
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• 2006

The extraction properties of the biological waste originated from the Tobacco industry were evaluated. The biological waste have been recycled and transformed into a valuable material, so called a reconstituted tobacco sheet(Recon) by the papermaking process. In this process, The mechanical extraction process, which divides the mixed raw material slurry into the soluble stock and the insoluble stock, could affect not only the quality of final Recon product but also the productivity of whole Recon making process. This study investigated the effects of the extraction process on the slurry properties in detail. In order to quantify the amounts of the solubles which resided in the insoluble fibers, the washing treatment of the stock before and after squeezing process was applied. The amounts of the residual solubles showed little changes according to each stage of the extraction process. The fractionation of the slurry showed the difference in the amount of soluble in the stock depending on the size of the biological waste. After the extraction process, the bigger size fiber portion contained about 19%(by weight) in soluble after pressing but the smaller size fiber portion 9% in soluble. The fractionation ratio of the stocks also was changed by the screw press process, which could demonstrate the physical effects of the mechanical extraction.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.74-80
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• 1999

Work roll wear in the cold rolling of mild steel strip is strongly affected by rolling materials, rolling conditions such as roll arrangement in the cold rolling mill and lubrication. The tests were performed to find the effects of roll arrangement n the cold rolling mill on the work roll wear under the same lubricating conditions. The obtained results are as follows:If the distance of cold rolling is about 60km, the surface roughness of its was reduced by half(Ra 0.49${\mu}{\textrm}{m}$) and Pc(peak count) also was decreased to 60 ea/cm.It is easier for CC(Continuous casting) to make a slip on rolling than IC(Ingot casting). It is due to surface mirror in which first residual product appears and iron powder included Al2O3 is sticked. Because bending degree of 4Hi-rolling mill is higher than 6Hi-rolling mill, the first surface mirror was occurred to its center-point which is loaded strongly. 6Hi-rolling mill shape-controlled by intermediate roll doesn't need the initial crown to work roll. Therefore, fatigue and wear would appear a little bit.

• 한국지역사회생활과학회지
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• 제14권3호
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• pp.53-58
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• 2003

This study on the processing of noodles was carried out to increase utilization of Allium fistulosum L., In the areas of total solids in residual liquid, swelling volume, and water absorption, a mixture of 10.0% dried Allium fistulosum L. flour and wheat flour, and a mixture of 25.0% raw Allium fistulosum L. flour and wheat flour both perform similarly to noodles made with just wheat flour. In the area of texture- the gumminess, cutting factor, and chewiness increase as the percentage of dried Allium fistulosum L. flour increases. There is no great difference in these factors between the 10.0% dried and the 25.0% raw mixtures. The color of the noodles with a mixed Allium fistulosum L. flour is green-yellow. As the quantity of Allium fistulosum L. flour increases the color gets darker The over all perception of the noodles made with a mixed Allium fistulosum L. flour was rated higher in color, taste, and smell than regular noodles. This study shows that mixing wheat flour with 10.0% dried Allium fistulosum L. flour or 25.0% raw Allium fistulosum L. flour produces a better noodle product.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.197-203
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• 1992

Studies of the pretreatment of chitin and its subsequent hydrolysis by Aspergillus carneus chitinase are reported. Ball milling was found to be the most effective way among the pretreatment methods tested. Data are presented describing the effect of enzyme and substrate concentrations on the rate and extent of the hydrolysis process. It was found that the successive addition of enzyme improved the saccharification yield. Significant product inhibition of the chitinase was observed when N-acetylglucosamine concentration was 3.6％ or higher. Adsorption of enzymes to the substrate occurred during a 24 hr hydrolysis period. An initial rapid and extensive adsorption occurred, followed by gradual desorption which increased during the time of reaction. Intermediate removal of the hydrolyzate and continuation of the hydrolysis by adsorbed enzyme on the residual chitin was also investigated. A total of 75.4 g/l reducing sugars, corresponding to 69.2％ saccharificaton yield (as N-acetylglucosamine) was obtained. In addition an increase in the amount of recoverable enzymes was observed under these conditions. Evidence presented here suggests that the technique, whereby the free enzymes in the recovered hydrolyzate are re-adsorbed onto the new substrate, may provide a means of recirculating the dissolved enzymes.