• Culinary science and hospitality research
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• v.17 no.1
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• pp.208-217
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• 2011

This study explores the antioxidant activity of solvent extracts from Vitis coignetiea skins, and the result is as follows. Total phenolic compound and flavonoids contents were the highest in ethyl acetate extract, $53.4{\pm}1.2\;mg$/100 g and $644.7{\pm}3.7\;mg$/100 g, respectively. Electron donating abilities of solvent extracts from Vitis coignetiea skin were proportionally increased with concentration and ethyl acetate extract ($80.93{\pm}0.58%$) showed the higher activity than BHT($63.21{\pm}0.72%$) at concentration of $50\;{\mu}l$/mL. Reducing power of solvent extracts from Vitis coignetiea skin was the highest in ethyl acetate extract(1.769) at concentration of $1,000\;{\mu}l$/mL. TBARS of ethyl acetate extract was higher than ascorbic acid. Nitrite scavenging ability of solvent extracts from Vitis coignetiea skin(pH 1.2, $1,000\;{\mu}l$/mL) was the highest in ethyl acetate extract($92.5{\pm}2.4%$).

• Journal of Environmental Science International
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• v.23 no.7
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• pp.1289-1297
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• 2014

In this study, PVC-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with poly vinyl chloride (PVC) diluted in dioxane solvent. XRD and SEM analysis confirmed that LMO was immobilized well in PVC-LMO beads. The diameter of PVC-LMO beads prepared by dioxane solvent was about 2 mm. The adsorption experiments of lithium ions by PVC-LMO beads were conducted batchwise. The optimum pH was pH 10. The adsorption characteristics of lithium ions by PVC-LMO beads was well described by the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from Langmuir model was 24.25 mg/g. The thermodynamic parameters such as ${\Delta}H^{\circ}$, ${\Delta}S^{\circ}$ and ${\Delta}G^{\circ}$ were evaluated. The calculated ${\Delta}G^{\circ}$ was between -6.16 and -4.14 kJ/mol (below zero), indicating the spontaneous nature of $Li^+$ adsorption on PVC-LMO beads. Also, the results showed that PVC-LMO beads prepared in this study could be used for the removal of lithium ions from seawater containing coexisting ions such as $Na^+$, $K^+$, $Mg^{2+}$ and $Ca^{2+}$.

• Journal of Life Science
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• v.26 no.5
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• pp.603-607
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• 2016

A crude extracellular lipase from solvent-tolerant bacterium Pseudomonas sp. BCNU 106 was highly stable in the broad pH range of 4-10 and at temperature of 37℃. Crude lipase of BCNU 106 exhibited enhanced stability in 25% organic solvents such as xylene (121.85%), hexane (120.35%), octane (120.41 %), toluene (118.14%), chloroform (103.66%) and dodecane (102.94%) and showed excellent stability comparable with the commercial immobilized enzyme. In addition, the stability of BCNU 106 lipase retained above 110% of its enzyme activity in the presence of Cu²⁺, Hg²⁺, Zn²⁺ and Mn²⁺, whereas Fe²⁺ strongly inhibited its stability. The detergents including tween 80, triton X-100 and SDS were positive signals for lipase stability. Because of its stability in multiple organic solvents, cations and surfactants, the Pseudomonas sp. BCNU 106 lipase could be considered as a potential biocatalyst in the industrial chemical processes without using immobilization.

• Journal of Pharmaceutical Investigation
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• v.10 no.3
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• pp.14-19
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• 1980

The dissociation constant of erythrosine in the mixed solvent systems of water-alcohols and water-acetone at various pH and in concentration media were determined by spectrophotometric method. Methanol, ethanol, and acetone were employed as solvents and studied the changes of pK values of erythrosine according to the kind and change of concentration of organic solvent which is mixed into water solution. The effect of organic solvent on pK is negligible at 40% while in the case of above 40% mixing, it is not negligible.

• Proceedings of the Korean Society of Potoscience Conference
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• spring
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• pp.79-80
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• 1999

• Resources Recycling
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• v.27 no.4
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• pp.16-22
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• 2018

Inconel713C which of a commercial Ni super alloy have the compositions of 70 wt.% Ni, 12 wt.% Cr, 6 wt.% Al and 4 wt.% Mo. In this study, solvent extraction has been performed to separate Mo from the synthetic leaching solution, formation of Inconel713C alloy similarly and is found the optimum conditions of recovery of Mo from the leaching solution. The effects of some variables, such as the nature and concentration of the extractants, $H_2SO_4$ concentrations, and the presence of impurities were investigated. The extraction percentage of Mo by Cyanex272 is 96% in the condition of pH 1 and 4% of concentration of Cyanex272 but Alamine336 is 99% in the condition of the range of pH 1 to 4 and 1 wt.% of concentration of Alamine336. In the case of Alamine336, the extraction percentage of Mo is increased by increasing of the concentration of Alamine336. The optimum condition of this experiment is pH 1 in aqueous phase, 1% concentration of Alamine336 and activation ratio of $H_2SO_4$ 1:0.5.

• Resources Recycling
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• v.23 no.1
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• pp.17-24
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• 2014

Solvent extraction experiments have been performed to separate Nd and Pr from chloride leaching solution of monazite sand using PC88A and D2EHPA. For this purpose, the effect of the saponification of PC88A and D2EHPA on the extraction and separation of the two metals were studied by varying the pH of aqueous solution. In the experimental ranges conducted in this study, the distribution coefficients of Nd were higher than those of Pr and separation factor value increased with the increase of solution pH. Saponification of PC88A enhanced the distribution coefficients of Nd and Pr as well as the separation factor. Saponification of D2EHPA had some effect on the extraction of the two metals but little effect on the separation factor.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.53-57
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• 2013

For the purpose of development of the extraction process of lithium ion from concentrated water eliminated from desalination process, an experimental research on the solvent extraction of lithium ion from aqueous solutions was performed. The effects of operating parameters, such as concentration of extractant, ratio of extracting solution/aqueous solution, pH of aqueous solution, were examined. The effect of sodium chloride, the major component of sea water, was also examined. Lithium ion in aqueous solutions of pH=10.2~10.6 adjusted by ammonia solution was most effectively extracted by extracting solution composed of 0.02 M TTA and 0.04 M TOPO in kerosine. The addition of sodium chloride in lithium aqueous solution significantly interfered the extraction of lithium ion.

• Resources Recycling
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• v.25 no.1
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• pp.16-23
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• 2016

The separation behaviour of Mo and W from sulfuric acid solution by solvent extraction with Alamine 336 was investigated as a function of solution pH and extractant concentration. Selective extraction of Mo over W by Alamine 336 was obtained in the pH range of 3-5 with low amine concentration. The mixture of Alamine 336 and acidic extractants improved the separation factor between Mo and W and was in the following order: D2EPHA > PC88A > Decanol > Versatic acid. The stripping efficiency of Mo and W from the loaded mixture of Alamine 336 and D2EHPA was very poor, while complete stripping of Mo and W was possible from the mixture of Alamine 336 and Decanol by using a mixture of $NH_4OH$ and $NH_4Cl$.

• Journal of the Mineralogical Society of Korea
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• v.30 no.4
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• pp.205-217
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• 2017

Mineral carbonation by indirect method has been studied by serpentinite as cation source. Through the carbonation of $CO_2$ and alkaline earth ions (calcium and magnesium) from serpentinite, the pure carbonates including $MgCO_3$ and $CaCO_3$ were synthesized. The extraction solvent used to extract magnesium (Mg) was ammonium sulfate ($(NH_4)_2SO_4$), and the investigated experimental factors were the concentration of $(NH_4)_2SO_4$, reaction temperature, and ratio of serpentinite to the extraction solvent. From this study, the Mg extraction efficiency of approximately 80 wt% was obtained under the conditions of 2 M $(NH_4)_2SO_4$, $300^{\circ}C$, and a ratio of 5 g of serpentinite/75 mL of extraction solvent. The Mg extraction efficiency was proportional to the concentration and reaction temperature. $NH_3$ produced from the Mg extraction of serpentinite was used as a pH swing agent for carbonation to increase the pH value. About 1.78 M of $NH_3$ as the form of $NH_4{^+}$ was recovered after Mg extraction from serpentinite. And, the main step in Mg extraction process of serpentinite was estimated by geochemical modeling.