• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.3
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• pp.287-297
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• 2019

This study was carried out to evaluate the antioxidant, anti-inflammation, and whitening effect of Hordeum vulgare L. extracts and their fractions. Total polyphenol and flavonoid contents in fractions were varied from 13.58 to 40.06 mg GAE/g and 7.67 ~ 13.67 mg CE/g, respectively. Among the three fractions(chloroform, hexane, and water), $400{\mu}g/mL$ of the chroloform fraction showed similar antioxidant activity to ascorbic acid ($30{\mu}M$) against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The chloroform and hexane fractions inhibited the NO production of RAW 264.7 cells similar to quercetin ($15{\mu}M$) and the chloroform fraction of $100{\mu}g/mL$ significantly reduced IL-6, iNOS and COX2 gene expression. Additionally, the chloroform fraction inhibited ${\beta}$-hexosaminidase degranulation, IL-4, and IL-13 gene expression in RBL-2H3 cells. All of the fractions inhibited tyrosinase activity in a concentration-dependent manner, and the hexane fraction at $50{\mu}g/mL$ and the chloroform fraction at $100{\mu}g/mL$ significantly inhibited melanin production of B16F10 cells. These results indicated that H. vulgare L. can be used as an effective cosmetic ingredient having anti-inflammation and whitening activity.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.425-435
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• 2020

Numerous chemical modifications on activated carbon such as acidic conditioning, thermal treatment and metal impregnation have been investigated to enhance adsorption capacities of micropollutants in water treatment plants. In this study, chemical modification including acidic, alkaline treatment, and iron-impregnation was evaluated for adsorption of 2,4-dichlorophenol (2,4-DCP). For Fe-impregnation, three concentrations of ferric chloride solutions, i.e., 0.2 M, 0.4 M, and 0.8 M, were used and ion-exchange (MIX) of iron and subsequent thermal treatment (MTH) were also applied. Surface properties of the modified carbons were analyzed by active surface area, pore volume, three-dimensional images, and chemical characteristics. The acidic and alkaline treatment changed the pore structures but yielded little improvement of adsorption capacities. As Fe concentrations were increased during impregnation, the active adsorption areas were decreased and the compositional ratios of Fe were increased. Adsorption capacities of modified ACs were evaluated using Langmuir isotherm. The MIX modification was not efficient to enhance 2,4-DCP adsorption and the MES treatment showed increases in adsorption capacities of 2,4-DCP, compared to the original activated carbon. These results implied a possibility of chemical impregnation modification for improvement of adsorption of 2,4-DCP, if a proper modification procedure is sought.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.1-7
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• 2004

Fenoxaprop-p-ethyl[Ethyl (R)-2-{4-(6-chloro-1,3-benzoxazol-2-yloxy)phenoxy}propionate] is well known as a herbicide for its specific activity against the weed grasses. This compound was synthesized by the reaction of 4-(6-chloro-1,3-benzoxazol-2-yloxy)phenol and ethyl (S)-O-(p-toluenesulfonyl)lactate in good yields with high optical pure(optical purity: 99.9% up). In this process Walden inversion occurs, whereby the S-configuration of the propionic acid derivative is converted to the R-configuration of the final product. 4-(6-Chloro-l,3-benzoxazol-2-yloxy)phenol was obtained by 5 step reactions in over-all 70% yields using inexpensive raw materials.

• Analytical Science and Technology
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• v.14 no.1
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• pp.72-79
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• 2001

Oxidative decomposition of 2, 4, 6-trichlorophenol(TCP) was studied in aqueous solution. Iron and manganese protoporphyrin [or tetrakis(p-carboxyphenylporphyrin)] and their polymer supported derivatives were used as catalysts, and $KHSO_5$ and tert-butyldroperoxide(TBHP) as oxidants. Metalloporphyrin itself shows very poor catalytic activity in oxidative decomposition of TCP with oxidant. However, very high catalytic activity was observed when metalloporphyrin was chemically bound to newly synthesized polymers or XAD2 resin. Additionally, it revealed much higher catalytic activity in the presence of water-soluble polymers having a electron-donating axial ligand such as pyridine and immidazole. Maleic acid and chloromaleic acid were found in the resulting solution by ESI-MS. Especially, XAD2-supported metalloporphyrins can be reused as catalysts due to insolubility to solvent, and stability against oxidant.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.1
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• pp.31-40
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• 1997

This study was conducted to investigate the biodegradation of gaseous trichloroethylene (TCE) and tetrachloroethylene (PCE) in an activated carbon biofilter inoculated with phenol-oxidizing microorganisms and to study the effect of surfactant concentration below its critical micelle concentration (CMC) on the re-moval efficiency of TCE or PCE. The investigation was conducted using two specially built stainless steel biofilters, one for TCE and the other for PCE, at residence times of 1.5~7 min. The removal efficiency of gaseous TCE was 100％ at a residence time of 7 min and its average inlet concentration of 85 ppm. For gaseous PCE, 100％ removal efficiency was obtained at residence times of 4~7 min and its average concentrations of 47~84 ppm. It was found that adsorption by GAC was a minor mechanism for TCE and PCE removal in the activated carbon biofilters. Transformation yields of gaseous TCE and PCE were about 8~48 g of TCE/g of phenol and 6~25g of PCE/g of phenol, according to residence times. This values showed one or two orders of magnitude less than aqueous TCE degradation. The TCE and PCE activated carbon biofilter performances were observed to be a little enhanced but not significantly, when the surfactant was introduced at concentrations of 5~50 mg/L.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.111-118
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• 1992

The curing acceleration of epoxy/amine system was investigated by using differential scanning calorimeter(DSC), The epoxy, diglycidylether of bisphenol A (DGEBA) was cured with methylene dianiline (MDA) with or without accelerators. Two kinds of accelerators were tested for the study ; tris(dimethylaminomethyl)phenol (DMP - 30) and 3 - (3,4 - dichlorophenyl)-1, 1-dimethylurea (DIURON). Heats of reaction and glass transition temperatures ($T_g$) of the cured epoxy system were analyzed by DSC along with the estimation of activation energy by the dynamic DSC studies. It was found that DMP - 30 is more effective accelerator than DIURON which showed faster curing and lower activation energy.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.374-379
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• 2010

The interaction of dichlorophenol isomers with the micellar system of TTAB (tetradecyltrimethylammonium bromide) was studied by the UV/Vis spectrophotometric method. The solubilization constants ($K_s$) of dichlorophenol isomers into the micellar system have been measured with the change of temperature and the various thermodynamic parameters have been calculated and analyzed from these changes. The results show that the values of ${\Delta}G^{\circ}_s$ and ${\Delta}H^{\circ}_s$ are all negative within the measured temperature range. The effects of additives (n-butanol and NaCl) on the solubilization of dichlorophenol isomers have been also measured. There was a great change on the values of $K_s$ and CMC simultaneously with these additives. From these changes we can postulate the solubilization sites of each isomers in the micellar system of TTAB.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.90-96
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• 2019

Unripe astringent persimmon (Diospyros kaki Thunb. cv. Cheongdo-Bansi) is a by-product produced when thinning out the superfluous fruit of persimmon. We investigated whether unripe astringent persimmon has antioxidative and anti-inflammatory effects. Unripe astringent persimmon extract was fractionated sequentially in n-hexane, chloroform, ethyl acetate, n-butanol, and water. The ethyl acetate fraction had the highest total phenolic content, total flavonoid content, and antioxidant capacity compared to those of the other fractions. Pretreatment of lipopolysaccharide-stimulated RAW 264.7 macrophages with the ethyl acetate fraction reduced nitric oxide, interleukin-6, and intracellular oxidative stress in a dose-dependent manner. Ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry analysis revealed gallic acid, protocatechuic acid, 4-hydroxybenzoic acid, quercetin-3-O-glucoside, quercetin, and p-coumaric acid as the phenolic compounds of the ethyl acetate fraction. Collectively, these findings suggest that unripe astringent persimmon is a source of functional materials that can promote antioxidative and anti-inflammatory effects.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.723-730
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• 2017

The batch experiments by response surface methodology (RSM) have been applied to investigate the influences of operating parameters such as temperature, initial concentration, contact time and adsorbent dosage on 2,4-dichlorophenol (2,4-DCP) adsorption with an activated carbon prepared from waste citrus peel (WCAC). Regression equation formulated for the 2,4-DCP adsorption was represented as a function of response variables. Adequacy of the model was tested by the correlation between experimental and predicted values of the response. A fairly high value of $R^2$ (0.9921) indicated that most of the data variation was explained by the regression model. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. These results showed that the model used to fit response variables was significant and adequate to represent the relationship between the response and the independent variables. The kinetics and isotherm experiment data can be well described with the pseudo-second order model and the Langmuir isotherm model, respectively. The maximum adsorption capacity of 2,4-DCP on WCAC calculated from the Langmuir isotherm model was 345.49 mg/g. The rate controlling mechanism study revealed that film diffusion and intraparticle diffusion were simultaneously occurring during the adsorption process. The thermodynamic parameters indicated that the adsorption reaction of 2,4-DCP on WCAC was an endothermic and spontaneous process.

• Analytical Science and Technology
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• v.18 no.4
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• pp.320-328
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• 2005

The most common five chlorophenols (4-chloro-3-methylphenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol) were determined from the industrial wastewater by GC/MS. The samples were collected from the petrochemical company, textile company and leather making company. The developed analytical method was modified by USEPA Method 3510. The samples were extracted with dichloromethane under pH 2 and pH 5-6, and determined by the GC/MS with SIM mode. There were good linearities (above $R^2=0.9943$) on e ranges of the 0.1 ng/mL~10 ng/mL and 0.5 ng/mL~10 ng/mL, and the limit of detection were between 0.1 ng/mL and 0.5 ng/mL. The absolute recoveries were measured at the concentration of 1, 5, and 10 ng/mL, and the recovery was 71.6~98.9% except for PCP. The relative standard deviation (RSD) was 1.2~14.3% and it gave a good reproducibility for the assay. The bias, which shows the accuracy, was a good although it was a little high values (11.3~22.1%) at the low concentration (1 ng/mL).