• Membrane Journal
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• v.6 no.3
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• pp.173-181
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• 1996

Common volatile organic compounds(VOCs) such as toluene and methanol were removed successfully from N$_{2}$ using a novel silicone-coated hollow fiber membrane module. This novel membrane is a thin film composite(TFC) and was highly efficient in removing VOCs selectively from a N$_{2}$ stream. This membrane had some innate advantages over other silicone-based membrane in that the selective barrier was ultrathin(~1 $\mu$m) and the porosity of the polypropylene substrate was high which leads to a low permeation resistance. The substram was very strongly bonded to the coating layer by plasma polymerization and can withstand a very high pressure. A small hollow fiber module having a length of 25cm and 50 fibers could remove 96~99% of toluene as well as methanol vapors when the feed flow rate was up to 60cc/min. The percent removal of VOCs were even higher when the feed inlet concentration was higher. This process is especially suitable for treating streams having a low flow rate and high VOCs concentration. The permeances of VOCs through this membrane was in the range of $4~30 \times 10^{-9}gmol/sec \cdot cm^{2}\cdot cmHg$ for both toluene and methanol, and nitrogen permeance was between $3~9 \times 10^{-10}gmol/sec \cdot cm^{2} \cdot cmHg$. High separation factor between 10~55 for toluene/N$_{2}$ and 15~125 for methanol/N$_{2}$ were obtained depending on the feed flow rate ranges and feed VOCs concentration levels.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.451-459
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• 2010

The fluorescence detection of intracellular metal ions are high interest in the fields of organic molecular chemistry and cellular biology. This study was purposed to detection for mercury and zinc in the cell using fluorescent chemosensor (FS). FS exhibits a weak fluorescence, but emits strong fluorescence upon Zn$^{2+}$ complexation. The increased fluorescence of the 2FS/Zn$^{2+}$ can be quenched completely by addition of only 1 equiv of Hg$^{2+}$ with the formation of complex FS-Hg$^{2+}$. Four cell lines (LLC-MK2, Hela, HT29 and AMC-HN3) were used for fluorescence imaging by confocal microscope. The cell viability MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was evaluated after cell treatment of FS, Zn$^{2+}$, FS-Zn$^{2+}$, Hg$^{2+}$ on LLC-MK2 cell line. The cytotoxicity of FS was showed to viability over 80%. This study has shown that FS can be detected for selective imaging of Zn$^{2+}$ and Hg$^{2+}$ in living cells.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.490-494
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• 2011

Rice stripe virus (RSV) has been the main viral disease of rice plant in western coastal region of Korea since 2000. The control of the vector insect, small brown planthopper (Laodelphax striatellus), is the most effective management method of the persistently-transmitted viral disease. Thus, ecological study between RSV and the vector insect was needed and investigated in order to make effective control plan, especially about study on the feeding and transmission of the virus by the vector insect. Each larval stage of vector insect differed in vector competence; larvae over 4th stage were shown as higher transmission after feeding on RSV-infected rice plant. These 4th and 5th larvae had higher transmission rates, 69.2% and 67.9% respectively, than 44.8% of the adult stage. The vector competence, however, was changed according to temperature; the highest transmission rate was 93.3% on $30^{\circ}C$ in comparison to 70.6% on $25^{\circ}C$ and 43.8% on $20^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.208-217
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• 2011

The effects of pH and temperature on the removal of two dyes (neutral red; NR and malachite green oxalates; MG) from aqueous effluents using Maghnia montmorillonite clay in a batch adsorption process were investigated. The results showed the stability of the optical properties of MG in aqueous solution and adsorbed onto clay under wide range of pH 3-9. However, the interaction of NR dye with clay is accompanied by a red shift of the main absorption bands of monomer cations under pH range of 3-5, whereas, those of neutral form remains nearly constant over the pH range of 8-12. The optimal pH for favorable adsorption of the dyes, i.e. ${\geq}$90% has been achieved in aqueous solutions at 6 and 7 for NR and VM respectively. The most suitable adsorption temperatures were 298 and 318 K with maximum adsorption capacities of 465.13mg/g for NR and 459.89 mg/g for MG. The adsorption equilibrium results for both dyes follow Langmuir, Freundlich isotherms. The numerical values of the mean free energy $E_a$ of 4.472-5.559 kj/mol and 2.000-2.886 kj/mol for NR and MG respectively indicated physical adsorption. Various thermodynamic parameters, such as ${\Delta}H^{\circ}$, ${\Delta}S^{\circ}$, ${\Delta}G^{\circ}$ and Ea have been calculated. The data showed that the adsorption process is spontaneous and endothermic. The sticking probability model was further used to assess the potential feasibility of the clay mineral as an alternative adsorbent for organic ion pollutants in aqueous solution.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.409-414
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• 2004

Kojic acid is well known for its anti-pigmentation effect with tyrosinase inhibition activity. However, kojic acid is a unstable compound. In order to improve stability, kojic acid derivative, kojic acid $6-O-2',3',4',6'-tetraacetyl-{\beta}-D-glucopy-ranoside\;(KTGP)$, was synthesized with $O-pentaacetyl-{\beta}-D-glucose$ through the regio- and stereo-selective glycosylation of 6-OH group of kojic acid. High yield $(80\%)$ was obtained by the use of Lewis acid and organic base in nonpolar solvent. Hydrolysis of KTGP with the aid of sodium methoxide in methanol afforded kojic acid $6-O-{\beta}-D-glucopyranoside$ (KGP), which was confirmed by $^1H-NMR\;and\;^{13}C-NMR$ KGP is freely soluble in water and soluble in methanol and ethanol. Inhibition activity of KGP for tyrosinase was investigated by measuring the activity of mushroom tyrosinase compared with those of ascorbic acid, kojic acid, and arbutin. The free radical-scavenger activity was determined by the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) assay. In toxicity assay, KGP was much less toxic than kojic acid and arbutin, Therefore, glycosylation of kojic acid may be useful for the development of stable kojic acid derivatives.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.574-578
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• 2005

Effects of different yeast strains on physicochemical characteristics of Bokbunja (Rubus coreanus Miq.) fruits alcohol fermentation were investigated. Bokbusnja fruit must was inoculated with Saccharomyces cerevisiae KCCM 12224 (Sc-24), wild-type Bokbunja yeast (Bok-3), Saccharomyces coreanus (Yak-7), and Sc-24+Yak-7. Ethanol contents of Sc-24, Bok-3, Yak-7, and Sc-24+Yak-7 were 11.08, 10.62, 10.18, and 10.26%, respectively after 10 days fermentation. Addition of pectinase (500 ppm) increased ethanol content by 0.1-1.5%. Organic acids of Bokbunja wine were citric, malic, shikimic, formic, and oxalic acids. Citric and malic acid contents remarkably decreased, whereas that of acid increased by fermentation. Total acidity of Bokbunja wine was dependent on citric acid content. Sc-24, Yak-7, and Bok-3+ pectinase were more efficient for improvement of wine-color, although color values of Bokbunja wine significantly decreased during early stage of fermentation. Sc-24 and Bok-3+500 ppm of pectinase, and 8-10 days of fermentation could enhance quality of Bokbunja wine.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.104-110
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• 2004

This study was carried out to survey the pollution of bisphenol A(BPA) and total organic carbon(TOC) in surface sediments around Gwangyang bay. BPA is suspected chemicals as endocrine disruption. Gwangyang bay Is located on the mid south coast of Korea. It is a semi-closed bay which Yeosu petrochemical industrial complex, POSCO(Pohang Steel Company) and Gwangyang container harbor are located. The surface sediments were collected at 15 stations with gravity corer at October, 1999, February, May and August, 2000. Also, the stream and intertidal sediment were collected at 5 sites at August, 2000. Concentrations of BPA in surface sediments were in the range of 0.46 to 24.59 ng/g dry wt.. Seasonal range(mean value) of BPA are 0.59 to 9.00(1.88) ng/g dry wt. at October, 0.99 to 2.97(1.57) ng/g dry wt. at February, 0.46 to 24.59(2.53)ng/g dry wt. at May and 0.54 to 2.46 (1.29)ng/g dry wt. at August. BPA was seasonally fluctuated, and the highest mean value and range were detected at May, 2000. BPA was highly distributed in the inner part of Kwangyang bay than Yosu sound. Concentrations of BPA in stream and intertidal sediments showed the highest value in downstream near Yochon petrochemical industrial complex and Yondung stream. It suggests that the source of BPA are industrial wastewater and municipal sewage. TOC in surface sediments were in the range of 0.09∼1.22%. There was no any correlation between the BPA and TOC.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.1-6
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• 2002

To elucidate the effect of soil addition and subsoil plowing on the change of sell chemical properties and the reduction of root-knot nematode, this experiment carried out in continuous cropping field of protected oriental melon (Cucumis melo L.). Soil addition reduced electric conductivity (E. C.) from 4.3 to 1.8 dS/m (58%), available $P_2O_5$ from 406 to 182 mg/kg (55%) and organic matter content from 16 to 11 g/kg (31%). Population densities of root-knot nematode in soil reduced as much as 89%, 84%, and 69% at first year, third years, and of five years later, respectively The effects of subsoil plowing were similar to that of soil addition. E. C. and phosphate were reduced from 4.30 to 1.98 dS/m (54%) and phosphate from 406 to 329 mg/kg (19%), respectively. Population densities of root-knot nematode reduced as much as 71%, 67%, and 42% after 1, 3, and 5 years, respectively Subsoil plowing reduced nematode densities only for three years.

• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.277-283
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• 2015

This study was conducted to investigate the selected chemical properties of soils in Saururus chinensis Baill (Chinese lizard's tail) cultivation fields to provide optimal fertilizer application rates and to examine the growth and pharmaco-consitituents of Saururus chinensis Baill as influenced by different amounts of nitrogen (N) fertilizer applications. Based on the results of selected soil chemical properties in 37 cultivation sites of the plant, soil pH, organic matter content, and exchangeable $K^{+}$ concentration were lower than optimal values for cultivating general medicinal crops even though relatively high standard deviations were found in some of the values. At the harvesting stage of the plant aerial parts, soil pH, electrical conductivity (EC), available $P_2O_5$, and exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$ decreased as comparing with those before transplanting the plant, whereas the concentration of exchangeable $K^{+}$ increased in the plot treated with N 100% and compost. Fresh weight of the plant aerial parts were highest, 492.5kg/10, in the N 100% treatment plot. Correlation equation between N levels treated (X) and yield of the plant aerial parts (Y) presented as $Y=-2.1609X^2+30.082X+344.12$($R^2= 0.7113$) and the optimal rate of N fertilizer application for the plant was 6.6kg/10a. Carbon concentrations in the plant were not different among the different N levels applied. N and K concentrations in the plant were highest in the plot of N 100% with compost applications, the highest P concentration was in N 100% plot, and the highest Ca and S concentrations were in N 200% plot. Quercetin and quercitrin were highest in the N 150% plot and tannin was highest in N 100% or N 100% with compost application plot.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.591-596
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• 2011

The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.