• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.763-770
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• 1997

The separation of benzene-cyclohexane mixture using (O/W)/O emulsion liquid membrane was studied. The operating parameters which can affect the selectivity, benzene yield, and emulsion size distribution were examined and determined by the batch type operation. The unsteady state and steady state extraction behavior in continuous pulse stirred reactor(CPSR) were verified. The optimum conditions for benzene selectivity and yield in batch operation were as follows; emulsion mixing intensity 4000 rpm, Tween 80 concentration 0.4%, volume ratio of membrane phase to internal phase 0.75, volume ratio of dispersed phase to continuous phase 0.5, and permeation time 10 minutes, As impeller speed increased and the microdrop holdup decreased, the Sauter mean diameter decreased. Turbulence damping parameter of modified Calabrease correlation considering microdrop holdup was 2.28. The optimum conditions of continuous operation were as follows; agitation speed 300 rpm, pulse frequence 2 times/sec, flow rate of continuous phase 30ml/min, and flow rate of emulsion phase 12.0ml/min.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.451-455
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• 2006

An efficient pilot scale (10 ton) three-stage methane fermentation system to digest food waste has been developed in this laboratory. This system consisted of three stages: semianaerobic hydrolysis, anaerobic acidogenesis and strictly anaerobic methanogenesis. From the secondary acidogenesis reactor, a novel strain KA4 responsible for alcohol fermentation was isolated and characterized. The cell was oval and its dimension was $5.5-6.5{\times}3.5-4.5\;{\mu}m$. This strain was identified as Saccharomyces cerevisiae KA4 by 26S rDNA D1/D2 rDNA sequence. Optimal culture temperature was $30-35^{\circ}C$. Cells were tolerant to 5% (v/v) ethanol concentration, however, were inhibited significantly by higher ethanol concentration up to 7%. The strain could grow well up to 50% (w/v) initial glucose concentration in the YM liquid medium, however, optimal concentration for ethanol fermentation was 10%. It could produce ethanol in a broad initial pH range from 4 to 10, and optimal pH was 6. In this condition, the strain converted 10% glucose to 7.4% ethanol during 24 hr, and ethanol yield was estimated to be 2.87 moi EtOH/mol glucose.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.333-341
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• 1983

Tannase of Aspergillus sp. AN-11 isolated from contaminated acorns was purified by a procedure involving ammonium sulfate precipitation, DEAE-cellulose column chromatography and Sephadex G-200 gel filtration. Physiochemical properties of the purified tannase was investigated. Tannase was purified about 37 folds with the yield of 49% from the culture broth of Aspergillus sp. AN-11. The purified tannase was homogeneous on polyacrylamide gel disc electrophoresis and was dissociable into two identical subunits on SDS-polyacrylamide gel electrophoresis. The molecular weight of the tannase was determined to be 200,000 by gel filtration on Sephadex G-200. The purified tannase showed a typical protein ultraviolet spectrum. The enzyme had a optimum pH 5.5 and optimum temperature at 30 to $40^{\circ}C$. The enzyme was stable at a pH range from 5.0 to 6.5 and at the temperature below $30^{\circ}C$. The enzyme was inactivated remarkably by $CuCl_2$ and $ZnCl_2. The Km value of the enzyme was $7.58{\times}10^{-4}\;M$.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.185-191
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• 1976

This study was conducted to evaluate the performance of 2,4-D amine salt (2,4-dichlorophenoxy acetic acid) 40EC in broadleaf weeds control under diverse conditions of rate and time of application and soil type in fall barley field. The results obtained were summarized as follows: 1) At the rate of 70cc prod./10a, 2,4-D amine salt treated during the fully tillered stage of barley was effective for the control of most broadleaf weeds without crop injury. 2) The fully tillered stage was a optimun time lot the application of 2,4-D amine salt in fall barley. Earlier(zero-to four-leaf stage) or late. (boot stage to flowering) application than this stage caused a crop injury and resulted in yield reduction. 3) It was possible to safely use 2,4-D amine salt in fall barley regardless of soil types if applied the rate of 70cc prod./10a at the fully tillered stage.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.22-30
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• 1985

Protoplasts of Pisum sativum L. were isolated and cultured from leaf mesophyll tissue. The successful yield of protoplast was obtained in an enzyme solution of 2% 'Onozuka R-10' and 2 % 'Macerozyme R-10' contained 6mM $CaCl_2{\cdot}2H_2O$ within 4 hours. They were divided in B5 culture medium supplemented with 2mg/l kinetin, 1mg/l 2, 4-D and 0.2% Difcobacto agar. Divisions of the protoplasts were continued and led to colony formation for 1 months. The colony from protoplasts of pea mesophyll tissue was formed to callus after subculture in a medium contained macronutrients and amino acids of BII medium and micronutrients and vitamins of B5 medium, and also supplemented with 2mg/l kinetin 2mg/l NAA.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.315-321
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• 1994

Glyoxalase I was purified 2,294-fold from Pleurotus ostreatus by S-hexylglutathione affinity chromatography, Sephadex G-150 gel filtration chromatography and DEAE-sepharose A-50 CL-6B ion exchange chromatography with an overall yield of 21.7%. The molecular mass determined by gel filtration was found to be approx. 34 kDa. SDS-PAGE revealed that the enzyme consists of two identical subunits with a molecular mass of approx. 17 kDa. The K sub(m) values of this enzyme for methylglyoxal and phenylglyoxal were 0.39 mM and 0.22 mM, respectively. And this enzyme had a strong affinity for L-xylosone and hydroxypyruvaldehyde. The enzyme showed its optimal activity at pH 6.5-7.5 and at $40^{\circ}C$. $^1H$-NMR spectroscopic analysis of enzymic reaction showed that this enzyme catalyzes intramolecular proton transfer.

• KSBB Journal
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• v.11 no.3
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• pp.303-310
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• 1996

The marine microalga Isochrysis galbana Parke was studied to optimize its growth conditions in flask culture. Important medium components studied include nitrogen source, buffer, trace elements and vitamins. Environmental conditions include pH, temperature, light intensity, mixing extent and working volume. The medium prepared from natural sea-waters gave a higher final cell density than the medium prepared from synthetic sea-water Nitrate was a better source than ammonium. In the range of 0.4∼2mM, the final cell density was proportional to the initial nitrate concentration and the cell yield was estimated to be 8.5g dry cell wt/g N. For phosphate, optimal growth was observed in 0.1∼1.0mM but a considerable variation in pH was resulted. The addition of Tris at 5mM or 7mM could stabilize the medium pH, but this significantly reduced both growth rate and final cell density, The effect of trace elements and vitamins was negligible. Optimal temperature and initial pH were $20^{\circ}C$ and 8. When the intensity of incident light was varied in the range of 400∼2100 lux, the growth rate increased from 10mL to 70mL, the final cell density decreased although the initial growth rate did not change. Optimal agitation speed was 100rpm when working volume was 30mL. With optimal conditions, the maximum specific growth rate obtained was 0.021hr-1 and the final cell density was 1.1g/L.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.479-483
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• 2006

[ ${\beta}-Glucan$ ], one of the cell wall components, is most plentiful polysaccharides in cell wall and has several advantages in immune system. In yeast ${\beta}-glucan$ is mainly contained in the yeast cell wall, and thus it is important to produce high levels of cell mass for the mass production of yeast ${\beta}-glucan$. The best carbon and nitrogen sources on cell mass production were high fructose syrup and yeast extract. Response surface methodology (RSM) was very potential tool for the optimization of process factor and medium component. It was applied to estimate the effects of medium components on the production of cell mass. Optimal concentrations of high fructose syrup and yeast extract by response surface methodology were 8.0% (v/v) and 5.2% (w/v), respectively and the cell mass predicted was $17.0\;g/{\ell}$ at 20 h of cultivation.

• Resources Recycling
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• v.15 no.3 s.71
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• pp.20-29
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• 2006

This study was carried out for to recover the purified crystalline gypsum from phosphogypsum by means of using it's crystallographical Properties. The dehydration of hydrated phosphogypsum to $\alpha$-hemihydrate is completed with the 2 hours treatment of it in $99^{\circ}C$ waterrs. The purified crystalline gypsum having the maximum size of $200{\mu}m$ was obtained by 325# wet screening after recrystallization of the $\alpha$-hemihydrate gypsum at the condition of $Na_2SO_4$ 10 wt%, slurry density 20%, $pH\;5{\sim}6,\;65^{\circ}C$ and 4hr. In this process, the yield of gypsum was 93.9% and its grade was 99%.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1648-1653
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• 1999

A strain of potential producer of fibrinolytic enzyme was isolated from shrimp Jeot-Gal, a tiny salted shrimps, and identified as Bacillus sp.. The preliminary experiment showed an enzyme yield of 18 U/mL in medium for screening. The carbon, nitrogen and salts significantly influenced the fibrinolytic enzyme production. An optimized medium containing 2% skim milk, 2% soluble starch and 3% NaCl (pH 7.5) after 72 hrs fermentation time at $37^{\circ}C$ yielded 3-fold increase in enzyme production, 62 U/mL.