• KSBB Journal
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• v.9 no.2
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• pp.104-107
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• 1994

A cone-type tower fermentor packed with Sacchromyces uvarum was employed to examine the continuous ethanol fermentation process. The maximum yeast concentration in the cone-type tower fermentor was 37.5-39.5g/$\ell$, the maximum ethanol productivity at the dilution rate of $hr^{-1}$ was 16.3g/$\ell$ . hr and the average ethanol yield was 0.48g EtOH/g glucose, which was 94% of the maximum theoretical yield. It was concluded that a cone-type tower fermentor might offer better perspectives for continuous ethanol fermentation.

• Kyungpook Mathematical Journal
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• v.51 no.3
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• pp.323-338
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• 2011

In this paper, we introduce ($$\tilde{g}$$, s)-continuous functions between topological spaces, study some of its basic properties and discuss its relationships with other topological functions.

• Journal of applied mathematics & informatics
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• v.40 no.3_4
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• pp.669-674
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• 2022

In this paper, we shall consider some properties of the metric projection as a set valued mapping. For a set G in a metric space E, the mapping 𝜋_G; x → 𝜋_G(x) of E into 2^G is called set valued metric projection of E onto G. We investigated the properties related to the projection P_S(·)(·) and 𝜋_S(·)(·) as one-sided best simultaneous approximations.

• KSBB Journal
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• v.25 no.5
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• pp.471-477
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• 2010

In order to improve bio-ethanol productivity by various cultivation methods in this paper, the culture modes using food wastes, such as batch culture, high-cell-density fermentation, SSF (simultaneous saccharification and fermentation) by fill & draw, continuous culture by fill & draw were performed and their productivities were compared. SSFs by fill & draw were performed by continuous decompression using 1 L evaporator system, and by 10 L bioreactor without decompression. In addition, the continuous cultures by fill & draw mode using SFW (saccharafied food wastes) medium were performed by changes of 40% culture broth with intervals of 12 h (0.03 $h^{-1}$), 6 h (0.07 $h^{-1}$), 3 h (0.13 $h^{-1}$). Consequently, productivities of bio-ethanol were 2.52 g/L-h and 1.30 g/L-h in batch culture and high- cell-density fermentation, respectively. The productivities of SSF by fill & draw showed 2.24 g/L-h and 2.03 g/L-h in continuous decompression with 1 L evaporator and 10 L bioreactor without decompression, respectively. Also, the productivities in continuous culture by fill & draw modes showed 2.02 g/L-h, 4.07 g/L-h and 6.25 g/L-h by medium change with intervals of 12 h, 6 h, and 3 h, respectively. In conclusion, the highest ethanol productivity was obtained in the continuous culture mode by fill & draw with dilution rate of 0.13 $h^{-1}$.

• Korean Journal of Mathematics
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• v.29 no.2
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• pp.355-360
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• 2021

In this paper, we introduce the definition of sequentially g-connected components and sequentially locally g-connected by using sequentially g-closed sets. Moreover, we investigate some characterization of sequentially g-connected components and sequentially locally g-connected.

• Korean Journal of Mathematics
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• v.8 no.1
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• pp.91-96
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• 2000

• East Asian mathematical journal
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• v.24 no.4
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• pp.329-338
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• 2008

The aim of this paper is to introduce a new generalization of fuzzy faintly continuous functions called fuzzy faintly pre-continuous functions and also we have introduced and studied weakly fuzzy pre-continuous functions. Several characterizations of fuzzy faintly pre-continuous functions are given and some interesting properties of the above functions are discussed.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.374-380
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• 2006

In this study, glucose, sucrose, and dextrin were found to be better carbon sources for the production of pullulan by Aureobasidium pullulans HP-2001. Maximal production of pullulan with 200 g/l sucrose as a carbon source was 54.2 g/l. The highest yield of pullulan from sucrose was 0.40, when the sugar concentration was 100 g/1. Optimal conditions for the continuous production of pullulan by A. pullulans HP-2001 in a 7-1 bioreactor were determined by studying the effects of composition of feed solution, dilution rate, and concentration of sucrose in the feed solution. Pullulan concentration and productivity with 100 g/l glucose and 2.5 g/l yeast extract were 38.1 g/l and 0.53 g/l h for 72 h, respectively, in a batch culture of A. pullulans HP-2001. When the substituted medium contained 100 g/l sucrose, 2.5 g/l yeast extract, and mineral salts, which is the same composition as the medium for the production of pullulan, the pullulan concentration and productivity were 74.9 g/l and 0.55 g/l h for 120 h, respectively. The production of pullulan at the steady state increased with a dilution rate up to 0.015/h, and its concentration was 78.4 g/l with a weight average molecular weight ($M_w$) of $4.0{\times}10^5$. Unlike a batch culture, however, the decline of the $M_w$ and the number average molecular weight ($M_n$) of pullulan was not found in the continuous culture of A. pullulans HP-2001. When the concentration of sucrose in the feed solution was 200 g/l, 113.5 g/l of pullulan was obtained at the steady state. The steady state was maintained longer in the continuous culture fed with the feed solution containing 200 g/l sucrose than when fed with the feed solutions containing either 100 or 150 g/l sucrose.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.497-503
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• 1991

The catalytic activities of immobilized gIucoamylase in a packed bed column and a continuous stirred tank reactor have been compared. Rapid production of glucose from liquefied starch have been studied through, the continuous liquefaction and saccharification using settling chamber. The immobilized glucoamylase with chitin gave the saccharification yield of 20% with the dextrin concentration of 100 g/l in a residence of 20 min. in a packed bed column. The half-life of immobilized glucoamylase with chitin was 19 days. The glucoamyalse immobilized in chitin and encapsulated with Ca-alginate gave the saccharification yield of 6% with the dextrin concentration of 50 g/l in a residence of 20 min. in a packed bed column. The Ca-alginate encapsulated and chitin immobilized glucomylase had a half-life of 25 days, which is 6 day larger than that of the immobilized glucoamylase with chitin only. In continuous liquefaction and saccharification, the glucose yield was 17% for the liquefied starch with naked barley concentration of 50gA in a residence of 20 min.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.398-404
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• 1991

- Ethanol production by calcium alginate-immobilized baker's yeast was studied in the continuous shaked-flask reactor (CSFR) using glucose medium as a feed. Immobilized cells were stable at 30~$37^{\circ}C$ and pH 4~8. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration employed were 50, 100 and 150 g/l, respectively. It was investigated that the influent glucose concentration and the dilution rate have an influence on the ethanol fermentation characteristics at steady state in continuous culture of immobilized baker's yeast. The optimum conditions for high ethanol productivity and low residual glucose output in ethanol prodution were shown to be 0.2 h ' for the dilution rate and 150 g/l for the influent glucose concentration. The maximum ethanol productivity, ethanol yield, specific growth rate and glucose conversion rate were around 7.12 g/$l\cdot h$, 0.23, 0.366 g/$l\cdot h$ and 78.43, respectively.