• Analytical Science and Technology
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• v.28 no.5
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• pp.341-346
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• 2015

In order to understand the counter anionic effects in a non-aqueous vanadium redox flow battery (VRFB), we synthesized four types of electrolyte salts (1-ethyltriethamine tertafluoroborate, [E-TEDA]⁺[BF₄]⁻, 1-ethyltriethamine hexafluorophosphate, [E-TEDA]⁺[PF₆]⁻, 1-butyltriethylamine tertafluoroborate, [B-TEDA]⁺[BF₄]⁻, and 1-buthyltriethamine hexafluorophosphate [B-TEDA]⁺[PF₆]⁻) by counter anion exchange reaction after the SN₂ reaction. We confirmed the successful synthesis of the electrolyte salts [E-TEDA]⁺[Br]⁻ and [B-TEDA]⁺[Br]⁻ via ¹H-NMR spectroscopy and GC-mass analysis before the counter anion exchange reaction. The electric potential of the vanadium acetylacetonate, V(acac)₃, as an energy storage chemical was shown to be 2.2 V in the acetonitrile solvent with each of the [E-TEDA]⁺[BF₄]⁻, [E-TEDA]⁺[PF₆]⁻, [B-TEDA]⁺[BF₄]⁻, and [B-TEDA]⁺[PF₆]⁻ electrolyte salts. In a non-aqueous VRFB with a commercial Neosepta AFN membrane, the maximum voltages reached 1.0 V and 1.5 V under a fixed current value of 0.1 mA in acetonitrile with the [E-TEDA]⁺[BF₄]⁻ and [E-TEDA]⁺[PF₆]⁻ electrolyte salts, respectively. The maximum voltage was 0.8 V and 1.1 V under a fixed current value of 0.1 mA in acetonitrile with the [B-TEDA]⁺[BF₄]⁻ and [B-TEDA]⁺[PF₆]⁻ electrolyte salts, respectively. From these results, we concluded that in the non-aqueous VRFB more of the [PF₆]⁻ counter anion than the [BF₄]⁻ counter anion was transported onto the commercial Neosepta AFN anion exchange membrane.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.104-114
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• 2014

Scale insects heavily damaged many agricultural crops and trees in urban and forest areas. This study was conducted to carry out alternative control methods for environmentally friendly control of scale insects. Hot water extract of Quisquali indica produced high mortality against the black pine bast scale, Matsucoccus thunbergianae in previously experiment. Methanol extract obtained from fruit of Q. indica was successively fractionated using hexane, chloroform, ethyl acetate, buthanol and water which were examined by exposing for their insecticidal activity against four Cocoidea species (Eriococcus lagerstroemiae, Ceroplastes japonicus, Crisicoccus pini and Planococcus citri) in laboratory. Hexane fraction gave the highest insecticidal activity against scale insect pest. GC-mass analysis confirmed that the main compounds of Q. indica were alpha-pinene, methyl palmitate, eugenol, methyl myristate, phthalic acid mono(2-ethylhexyl)ester and palmitic acid. Among those compounds, ${\alpha}$-pinene was included 10 hexane subfractions. $LC_{50}$ of ${\alpha}$-pinene was 0.0114 ppm against 2nd instar of E. lagerstroemiae. These results suggest that Q. indica extracts might be used as an alternative control agent of scale insects.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1532-1539
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• 2012

The ${\alpha}$-galactosidase-coding gene agaAJB13 was cloned from Sphingomonas sp. JB13 showing 16S rDNA (1,343 bp) identities of ${\leq}97.2%$ with other identified Sphingomonas strains. agaAJB13 (2,217 bp; 64.9% GC content) encodes a 738-residue polypeptide (AgaAJB13) with a calculated mass of 82.3 kDa. AgaAJB13 showed the highest identity of 61.4% with the putative glycosyl hydrolase family 36 ${\alpha}$-galactosidase from Granulicella mallensis MP5ACTX8 (EFI56085). AgaAJB13 also showed <37% identities with reported protease-resistant or Sphingomonas ${\alpha}$-galactosidases. A sequence analysis revealed different catalytic motifs between reported Sphingomonas ${\alpha}$-galactosidases (KXD and RXXXD) and AgaAJB13 (KWD and SDXXDXXXR). Recombinant AgaAJB13 (rAgaAJB13) was expressed in Escherichia coli BL21 (DE3). The purified rAgaAJB13 was characterized using p-nitrophenyl-${\alpha}$-D-galactopyranoside as the substrate and showed an apparent optimum at pH 5.0 and $60^{\circ}C$ and strong resistance to trypsin and proteinase K digestion. Compared with reported proteaseresistant ${\alpha}$-galactosidases showing thermolability at $50^{\circ}C$ or $60^{\circ}C$ and specific activities of <71 U/mg with or without protease treatments, rAgaAJB13 exhibited a better thermal stability (half-life of >60 min at $60^{\circ}C$) and higher specific activities (225.0-256.5 U/mg). These sequence and enzymatic properties suggest AgaAJB13 is the first identified and characterized Sphingomonas ${\alpha}$-galactosidase, and shows novel protease resistance with a potential value for basic research and industrial applications.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.1-11
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• 2013

In this study, we investigated chemical characteristics of solid residues obtained from inorganic acid hydrolysis of hybrid poplar (Populus alba ${\times}$ glandulosa). Different concentration (72, 36, 18%) of sulfuric acid and hydrochloric acid were used for first hydrolysis step and second hydrolysis step were carried out after equally dilution to 4%. Solid residues after consecutive two step hydrolysis were named to RS72 (Residue from Sulfuric acid 72%), RS36, RS18, as well as RC36 (Residue from hydroChloric acid 36%) and RC18, respectively. The yield of RS decreased from 71.2% to 21.4% with increasing sulfuric acid concentration in the first hydrolysis step, whereas that of RC showed little difference (67.0% to 65.0%), irrespective of hydrochloric acid concentration. The lignin content in solid residue was 23.6% for both of RS36 and RS18, 25.6% for RC36 and 27.3% for RC18, respectively. The results of pyrolyzer-GC/MS showed that 24 cellulose derivatives (Levoglucosan, Furfural) and 21 lignin derivatives (Guaiacol, Syringol) were detected. Thermogravimetric analysis indicated that the yield of char increased and maximum wieght loss rate decreased with increasing lignin portion of solid residue. Therefore, structure of lignin was condensed effectively by sulfuric acid and by high concentration of acid.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.318-324
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• 2010

The aim of this study is to examine feeding habits of the Korean water deer(Hydropotes inermis argyropus) from its rumen contents using a PCR-DGGE method. For this study, rumen contents were collected from water deer causalities by natural death or road-kill in two different sites(Cheorwon, Gangwon province and the Eastern part of Jeonnam province). DNA was extracted from rumen contents of a total of 44 individuals. Two primers, rbcLZ1aF(GC) and rbcL19bR, were used for PCR amplifications of ribulose-1,5-bisphosphate carboxylase large subunit (rbcL) gene. Among 44 samples, twenty-nine samples were successfully amplified by PCRs. The 29 PCR products of partial rbcL gene were applied for PCR-DGGE. Totally, six families of plants were detected from the diet analyses. Five families of plants were found in Cheorwon, Gangwon province, but only three families of plants were found in the Eastern part of Jeonnam province. The PCR-DGGE method will provide us with a potential tool to study feeding habits of ungulates including water deer, even though our results failed to identify the prey plants at the level of species.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.561-567
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• 1996

A method for the simultaneous analysis of 31 residual organic chloride pesticides was studied using gas chromatography. Prepared analytical samples were injected to gas chromatography (HP 5890 Series II plus) on the Ultra-2 column with ECD. The packing materials for column were changed as the following reagents ; florisil and alumina N, The residual solution was loaded to column and was elected pith erection solvents ; ether : benzene (2 : 8) solution, hexane : benzene (1 : 1) solution, dichloromethane, acetone, and methanol. The analytical results showed that 6 kinds of organic chlorides were not detected when florisil (first condition) was used as the column packing material. The nondetected 6 kinds of organic chlorides in the first analytical condition were detected and the recoveries of thrin-pesticides were increased, in particular, captan and captafol, but the recoveries of benzene hexachloride compounds were decreased when dichloromethane and methanol were added as elution solvents (pac'king material was florisil as in the first condition). The recoveries of dichlornuanid, chlorofenvinfos, folpet, and dicofol were increased and that of aldrin was increased, but those of captan and captafol were not good when alumina N was used as the packing material. To detect simultaneously thrin-pesticides, captan, and captafol, florisil and alumina N were used as the packing materials. The elution result showed that captan and captafol were not detected. This was because the column was activated insufficiently. The analytical method was the best (31 kinds of organic chlorides in the residual pesticides were detected sharply and showed high sensitivity) when the column (packing materials were florisil and alumina N: together) was fuliy activated and the impurities were removed using various elution solvents.

• The Korean Journal of Ecology
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• v.28 no.3
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• pp.135-139
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• 2005

This study was carried out to find the allelopathic effect of volatile materials released from Eupatorium rugosum. The GC method was employed for analysis of volatile materials from E. rugosum and 49 chemical substances were identified such as $\beta$-caryophyllene, $\alpha$-terpinenol, chamazulene, bornyl acetate, $\alpha$-pinene, etc. including unidentified three chemicals. Germination test in Phaseolus radiatus was done to find the inhibition effect of volatile materials using some chemicals which were proved to be important component or much amounts ones in E. rugosum. It was strongly inhibited by linalool and terpinen-4-ol. Seedling elongation and radicle growth of that were proportionally inhibited by the concentration of the essential oil, especially $\alpha$-pinene and bornyl acetate. Biomass of receptor plant was slightly decreased more than 58 ${\mu}l$ of the extract in case of $\alpha$-pinene, while it was decreased more than 19 ${\mu}l$ of that in bornyl acetate but it was shown non-significant. From the above results, it was found that volatile materials from E. rugosum showed a allelopathic effect and also $\alpha$-pinene, bornyl acetate, linalool and terpinen-4-ol used in bioassay were some of major allelochemicals in germination inhibition and especially linalool and terpinen-4-ol are prominent effect on growth inhibition of other plant.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1407-1421
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• 2010

This study was carried out to elucidate the relation between water quality and structure of the aquatic ecosystem in the agriculture reservoir Otae-ji from January to December in 2009. The proportion of forest was 46.98%, which means that non-point sources are major contributor of water pollution in this area. The annual mean COD(Chemical Oxygen Demand) in Otae-ji was $3.6mgL^{-1}$, indicating, level II of environmental standards and the trophic state was mesotrophic. Although total phosporus concentration in the reservoir was high in August due to large inflow of nutrients from outside the reservoir during monsoon season, there was no break out of significant algal bloom in the summer. The seasonal succession of phytoplankton showed that the dinophyta dominated in the the spring, chlorophyta in the summer, chrysophyta and chlorophyta in the autumn and chrysophyta in the winter. In case of zooplankton, rotifers dominated in the most seasons, but cladoceran(Bosmina longirostris) dominated in June and copepod(Nauplii) in August. The macrophyte plants showed diverse species compositon consisted of 3 varieties, 24 species, 23 genera, 15 families and 14 orders. The macroinvertebrates also showed various FFG(Functional Feeding Groups) such as GC(Gathering-Collector), P(Predator), SH(Shedder), FC(Filter-Collector) and PP(Plant-Piercer). Ecosystem stability analysis using aquatic insects was classified as Group I, which has high resilience and resistance indices. A total of 14 species of fish was collected but exotic species such as Lepomis macrochirus and Micropterus salmoides were not found in Otae-ji. In conclusion, the preservation of healthy food wed in the reservoir ecosystem is closely related to water quality management as well as effective prevention of algal bloom by helping good material circulation in aquatic ecosystems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.255-261
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• 2013

This study investigated changes in the physicochemical characteristics and coffee flavors of coffee beans under different roasting conditions. Four different kinds of roasted coffees were analyzed using a headspace gas chromatographic technique. The moisture content and total acidity of roasted coffee decreased whereas the pH and weight loss (%) increased, as coffee beans were roasted at higher temperatures. The Hunter's color values of the roasted coffee (indicating L (lightness) and b (yellowness)) decreased as the roasting temperature of the coffee beans increased, but a (redness) value only increased with light roasting. We also noted that the color of the Arabica coffee was darker than that of the Robusta coffee. The aroma compounds, acetaldehyde, acetone, 2-methylfuran, 2-methylbutanol, 2-methylpyrazine, furfural, 2-propanone, furfuryl alcohol, 2,5-dimethylpyrazine and furfuryl acetate were mainly analyzed. A sensory evaluation of all light-roasted coffees had flavor and sourness and those of all medium-roasted coffees had heaviness and finishness.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.321-328
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• 2014

This study was conducted to investigate volatile organic compounds (VOCs) of persimmon (Diospyros kaki Thunb) flower. VOCs of persimmon flower was collected via SPE (solid phase micro extraction) and determined by GC-MS according to tree age and organs such as flower and calyx. The ratio of early bloom was higher in more than 15 year old tree than other trees showing tree age was related with flowering rate. Major VOCs of persimmon flower was a-pinene, butane, caryophyllene, cubebene, lavandulol, D-limoneneylangene, ylangene, mainly included green, fruit, and floral flavors. The number of VOCs in persimmon flower was 30 compounds in 5-9 years old tree, 24 compounds in 10-14 years old tree, and 32 compounds in more than 15 years old tree. In comparison with VOCs in organs of sweet persimmon 'Fuyu' cultivar, flower has 10 compounds of VOCs and 26.35% of relative peak area, while calyx has 14 compounds and 46.28%, respectively. In astringent persimmon, flower has 6 compounds of VOCs and 17.58% of relative peak area, while calyx has 9 compounds and 50.27%, showing calyx of both cultivars has various volatile compounds. This study will contribute to provide a basic data for the fragrance industry to use the flavor of persimmon flower.