• Membrane Journal
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• v.17 no.4
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• pp.359-368
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• 2007

The copolymer membranes, poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) were prepared by phase inversion method using as an additive with N,N-dimethylformamid as a solvent. The pores are generated during the solvent and non-solvent exchange process in the coagulation bath filled with non-solvent (distilled water). The highest porosity of the membrane was 60%. The surface and cross-section of the membranes was observed with a scanning electron microscopy (SEM). The mechanical property of the membrane was determined by using an universal testing machine (UTM). Tensile strength of measured membranes is presented the maximum 6.57 MPa at 30 wt% of PVdF-HFP.

• Membrane Journal
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• v.7 no.4
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• pp.191-198
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• 1997

Membrane formation mechanism by the phase inversion has been investigated in order to control the membrane morphology. It was found that finger-like structures were obtained when the heat of mixing between the solvent and non-solvent is exothermic, while sponge-like structures were obtained when they are endothermic in polystyrenes as well as in polyimides (Torlon and polyimide made frorn 3,3'4,4'-benzophenontetracarboxylic diahmydride and 1,4-phenylene diarnine) membranes. This concept was applied to control the morphology of polysulfone membranes simply by adding a solvent additive by adjusting the heat of mixing. A crude, but simple, relationship between the heat of mixing and the exchange rate of the solvent with non-solvent has been also developed.

• KSBB Journal
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• v.18 no.4
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• pp.301-305
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• 2003

The study of pancreatin extraction was investigated by supercritical fluid process. Using supercritical carbon dioxide extraction with entrainer the purification of pancreatin was possible to remove lipids from Hog pancreas. To observe the optimum conditions different experimental variables were changed as pressure, temperature, flow rate of solvent and 0.25 mm of sample size were evaluated for effective removal of lipids. Ethanol and n-hexane were used as an entrainer with 5 mL/min. Increasing pressure at constant temperature the efficiency of the lipid removal in Hog pancreas was improved and the protein was concentrated without denaturalization, compared that of the control Hog pancreas. The most efficient conditions of lipid elimination were 17 MPa of pressure and 35$^{\circ}C$ of temperature and 0.25 mm of sample size.

• Resources Recycling
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• v.24 no.3
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• pp.3-10
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• 2015

A study has been made on the recovery & separation of cobalt and copper from organic acid leaching solution by solvent extraction. The experimental parameters such as the equilibrium pH, concentration of extractant and phase ratio were observed. Copper was extracted using LIX 84 and Cobalt was extracted using cyanex 272 and versatic acid 10. Experimental results showed that extraction percent of copper was 99% at above eq. pH 2.0 and then more than 90% of cobalt were extracted by cyanex 272 in eq. pH 6.0 and versatic acid 10 in eq. pH 7.5. Stripping of copper and cobalt from the loaded organic phases can be accomplished by sulfuric acid as a stripping reagent and 120 ~ 150 g/L of $H_2SO_4$ was effective for the stripping of copper and cobalt respectively. Finially, the basic optimal process for recovery of copper and cobalt from the bio-leaching solution was proposed.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.256-261
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• 1991

To isolate new antioxidants from twelve edible seaweeds, mixed methanol and chloroform extract of marine algae was fractionated into several subfractions and their antioxidant activities were measured by using AOM and 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Especially the aqueous-methanol soluble fractions of brown and red algae showed a considerable antioxidant effect. Their antioxidant activities were stronger than synthetic antioxidants such as BHA, BHT, under the same concentration. Further fractionation of the aqueous-methanol soluble fractions using silica gel column chromatography yielded five subfractions. Among them methanol fraction exhibited high DPPH quenching activities. Also, it was confirmed to be benzene-derivative substances of two compounds by UV, HPLC, GC/MS analysis. Its each molecular weight was about 181, 238. These results suggested the existence of two effective natural antioxidant compounds in three edible marine algae.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.490-494
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• 1985

The effect of organic solvents on the stability and catalytic activity of the microbial lipase from Rhizopus arrhizus for interesterification of fats and oils has been examined. The reaction system used was nonaqueous solvent system (two phase system). The solvents examined were 5 hydrocarbons (n-hexane, n-heptane, n-octane, isooctane, and cyclohexane) and 3 ethers (diethylether, diisopropylether, di-n-butylether). The results revealed that diisopropylether and isooctane are superior to the other solvents examined for interesterification of fats and oils in two phase systems.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.98-99
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• 2000

최근 유전자 공학의 급속한 발전으로 인하여 유전자 조작을 통한 생화합물의 대량 생산, 세포배양에 의한 생화학제품(아미노산, 단백질, 핵산)의 생산이 크게 진보하고 있으나, 이에 비해 생화학제품을 효율적으로 분리 및 정제하는 기술은 상대적으로 발전하지 못했다. 생화합물의 분리 방법은 전통적으로 유기용매에 의한 침전법, 염석법, 탈염법, 크로마토그래피법, 전기영동법, 흡착제를 이용한 흡착법등을 사용하는데 이 방법들은 소규모 및 회분식 공정으로 이루어져 대형화에 따른 분리 공정의 효율이 감소하는 어려움이 있었다. 따라서 연속공정으로서 대형화가 쉽고, 효율적인 생물분리공정의 개발이 요구되고 있다. (중략)

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.323-327
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• 2001

• Proceedings of the Membrane Society of Korea Conference
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• 1999.04a
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• pp.69-72
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• 1999

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.262.2-263
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• 1998