• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.773-783
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• 2008

In this paper, data collected from 22 different rural watersheds during stormflow conditions were analyzed. Those watersheds consisted of forest and cultivated land. EMC data analysis indicates that as agricultural land use increases, EMC values of TSS, COD and TN clearly tends to increase, but TP does not show a significant increase. Pattern of the pollutographs mostly has a similarity in hydrograph shape except nitrogen which inherently shows a variability and complication. The fraction of soluble reactive-P to TP increases as cultivated land use increases while mobile-nitrogen portion was higher in the runoff from forested watersheds than agricultural areas. During stormflow, pollutograph of the nitrogen was determined mainly by change in Particle-TKN as other pollutants but its effect is thought to be masked by decrease of dissolved form of nitrogen due to the dilution.

• Journal of the Korean Applied Science and Technology
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• v.17 no.4
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• pp.273-278
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• 2000

Cellulose tosylate(CT) was prepared by reaction of cellulose with p- toluenesulfonylchloride in DMAc/LiCl homogeneous system. In order to study a reversible photoisomerization of disperse red 1(DR-1) attached on natural polymer, cellulose tosylate containing DR-1(DR-1/CT adduct) was prepared at $110^{\circ}C$ in DMAc, and the changes of UV/Vis spectra of its solutions and thick film were investigated by alternate irradiation technique. Form the UV/Vis spectra of DR-1/CT adduct dissolved in cosolvents, such as DMAc, DMAc/THF, DMAc/benzene, and DMAc/chloroform and irradiated with 360 nm and 450 nm ligths, we found out changes of UV/Vis spectra were reversible in all solvents systems and we found out changes of UV/Vis spectra were reversible at thick film, also.

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.126-129
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• 1991

In order to produce ${\gamma}-linolenic$ acid by Mucor sp. KCTC 8405P. the fungus was cultivated in fed-batch culture with two phases. i.e., growth in yeast-like form and induction to hyphal growth by pH shift of the culture medium during cultivation. The synchronous growth of the fungus into the appropriate sizes was important for the high density cell culture of this dimorphic fungus. Dissolved oxygen concentration in the medium did not affect degree of unsaturation of fatty acids and ${\gamma}-linolenic$ acid content. Under the culture conditions applied in this experiment. the fungus was found to produce 100 g/l dry mycelia containing 40% of the lipids, where ${\gamma}-linolenic$ acid comprised about 9% of the total extractable fatty acids.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.191-196
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• 1996

The bacteriolytic enzyme produced from Bacillus subtilis SH-1 was purified and characterized, and its molecular weight was determined. The bacteriolytic enzyme activity was increased about 66.5 times via purification with recovery yield of 18.5%. The optimum pH and temperature of this enzyme were 9.0 and 50$\circ$C. The enzyme was stable within a pH range of 6.0-10.0 and unstable above 60 . The molecular weight of the enzyme was estimated to be 23,000 dalton in a form of monomer with no other subunits. Effect of the enzyme on the lysis of bacteria engaged in food posion was tested. The lysis degree was below 31% against Gram negative bacteria and above 48% in Gram positive bacteria. The values higher than 73% were obtained against Vibrio sp. and Listeria sp. As the turbidity of dissolved peptidoglycan clecreases, the free amino group levels were increased. And, based on hydrolysis of casein, this enzyme was thought to be an endopeptidase.

• Applied Biological Chemistry
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• v.24 no.3
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• pp.194-199
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• 1981

In order to compare Kimchi fermentability of Chinese cabbage cultivars, five cultivars grown in Korea were fermented in 3% NaCl. The measurements were done for both the fermenting properties: bacterial growth, $CO_2$ generation, acid production, dissolved oxygen, pH changes in the fermenting broth and extractable sugars form the cabbage tissue and salt solution, respectively. The measured values were scorized to evaluate the cultivar's fitness to Kimchi processing. The most rapid cultivar is Naeseu Baekno and the lowest one is Mussang.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.153-161
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• 2002

Stable polyaniline-dodecylbenzenesulfonic acid(PANI-DBSA) fully dissolved in toluene was obtained by a direct one-step emulsion polymerization technique. By using the proper molar ratio of APS/aniline monomer and DBSA/aniline monomer, the highest conductivity(7 S/cm) of PANI was obtained. The UV-Vis absorption spectrum of PANI confirmed PANI is emeraldine salt form. PANI/styrene polymers (polystyrene and styrene-butadiene copolymer) blends were prepared by mixing PANI solution with polymers in toluene. These blends exhibited the conductivity of 10$\^$-4/-10$\^$-3/ S/cm at 1 wt. % of PANI content. The mechanical property of conducting blend was decreased and TGA thermograms of conducting blends were similar to that of PANI. It had been checked that the flatness of coating layers of conducting blends decreased with increasing conducting components. It was also found that the morphology of blends was setting closer to that of PANI at higher conducting component contents.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.147-154
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• 1990

A sensitive method for the determination of total selenium in aerosol particles is described. The method involves dissolution of aerosol particles by $HNO_3-HClO_4$ mixed acids, pre-reduction of Se (VI) to Se (IV) by boiling hydrochloric acid, and hydride generation followed by atomic absorption detection. Dissolved Se (IV) in 4M hydrochloric acid is reacted with $NaBH_4$ to form $H_2Se$, which is subsequently collected in an U-tube cooled in liquid nitrogen. Upon the completion of $H_2Se$ generation, the collected $H_2Se$ is rapidly vaporized into a quartz cuvette burner by removing the U-tube from liquid nitrogen, atomized, and then detected by an atomic absorption spectrophotometer. The absolute sensitivity of the method is 0.49 ng/0.0044 Abs. The accuracy of the method evaluated by analyzing standard reference materials for urban aerosol is better than 10%. Analytical results for urban and rural aerosol particles are reported.

• Journal of the Korean Chemical Society
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• v.10 no.1
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• pp.4-10
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• 1966

A new method of cobalt determination has been developed by employing ethylenediamine tetrabutyl acetate(EDTA-butyl ester) synthesized from EDTA and Butyl alcohol. The synthesized EDTA ester dissolved in butyl alcohol extracts various metal ions from aqueous solutions. Cobaltous ion extracted into organic phase containing EDTA ester to form Co (II)-EDTA butyl ester complex is back extracted into alkaline aqueous phase forming a stable pink colored complex of Co (III). The optimum condition for spectrophotometric determination of cobalt via the new complex has been established. The absorption peak occurs at 540$m{\mu}$ and Beer's law was obeyed over the concentration range of 0∼50 ${\mu}g/ml$ of cobalt.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.189-192
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• 1998

This paper presents the basis for the need of feed-water deaerator installation in nuclear power plant and has been conducting reviews to understand the mechanism of dissolved oxygen(DO) formation as well as removal. DO is produced by feedwater make-up, air inleakage in vacuum system and condensation in condenser, etc. and removed by mechanical method and chemical method. DO has an influence on S/G in the form of denting, pitting, fretting, etc. DO control by deaerator has an great effect on the integrity of S/G in nuclear power plant.

• Korean Journal of Biological Psychiatry
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• v.3 no.1
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• pp.83-87
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• 1996

The effects of disulfiram implantation therapy have three components : placebo, pharmacological, and psychological effects, However, considering the fact that there is no reported DER(disulfiram-ethanol reaction) in placebo implanted patients and the absorption of implanted disulfiram is not sufficient to produce DER, the major effect of disulfiram implantation is psychological rather than placebo and pharmacological one, Recently, there have been great efforts to develop a new farm of disulfiram which could exert a real pharmacological effect through the heightened bioavailability, To illustrate several examples, there are copolymer consisting of disulfiram and polymer such as polyethylene glycol and PLGA(polyglycolic-co-L-lactic acid) and depot in which disulfiram is dissolved into saline solution containing 5% w/v carboxymethylcellulose or 0.1% polysorbate 80. On the other hand, there has been a continuous research about Me-DTC, an active metabolite of disulfiram, which inhibit ALDH (acetaldehyde dehydrogenase) more potently even at a smaller amount than disulfiram. In the future. In is hoped to develop a new form of disulfiram with high bioavailability at a small amount.