• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.9-18
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• 2010

In this study, Solid-phase micro-extraction (SPME) with Gas Chromatograph using Flame Ionization Detector (GC/FID) was studied as a possible alternative to liquid-liquid extraction for the analysis of Methyl tert-butyl ether (MTBE) and Tertiary-butyl ether (TBA) in water and an optimization condition of trace analysis of MTBE and TBA using the design of experiment (DOE) was described. The aim of our research was to apply experimental design methodology in the optimization condition of trace analysis of fuel oxygenated compounds in soil-phase microextraction with GC/FID. The reactions of SPME were mathematically described as a function of parameters of Temp ($X_1$), Volume ($X_2$), Time ($X_3$) and Salt ($X_4$) being modeled by the use of the partial factorial designs, which was used for fitting 2nd order response surface models and was alternative to central composite designs. The model predicted agreed with the experimentally observed result ($Y_1$(MTBE, $R^2$ = 0.96, $Y_2$ (TBA, $R^2$ = 0.98)). The estimated ridge of the expected maximum responses and optimal conditions for MTBE and TBA were 278.13 and (Temp ($X_1$) = $48.40^{\circ}C$, Volume ($X_2$) = 73.04 mL, Time ($X_3$) = 11.51 min and Salt ($X_4$) = 12,50 mg/L), and 127.89 and (Temp ($X_1$) = $52.12^{\circ}C$, Volume ($X_2$) = 88.88mL, Time ($X_3$) = 65.40 min and Salt ($X_4$) = 12,50 mg/L), respectively.

• KSBB Journal
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• v.13 no.1
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• pp.77-82
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• 1998

Glutathione(L-$\gamma$ -glutamyl-L-cysteinylglycine, GSH) produced by microbial enzymes was separated by a liquid chromatography. In order to select a resin which would bind GSH efficiently, a batch adsorption experiment was carried out with GSH solution and various resins at pH 8.0 GSH bound to Q-sepharose and QAE-sephadex among anion exchange resins, but the latter was found not to be suitable because of the reduction of resin volume at high salt concentration. Preliminary experiments using a standard solution were carried out to separate GSH. GSH and $\gamma$ -glutamylcysteine were separated from the other constituents by applying step gradient of salt(NaCl) concentration. GSH was successfully separated from $\gamma$ -glutamylcysteine by applying Tris buffer containing 35mM NaCl. Chromatographic separation behaviors for the enzymatic product was similar to that for the standard solution. Separation yields of GSH from the standard solution and enzymatic product solution were 72.6% and 84.4%, respectively.

• Journal of the Korean Dietetic Association
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• v.15 no.1
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• pp.69-76
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• 2009

To determine the salinity of packaged Kimchi, bulk Kimchi and other common foods, we collected samples of foods from the Gyeonggi province area in October 2006 and determined the salinity levels in one serving portion. The average salinity of all foods was 0.226${\pm}$0.212%. The average salinity of all Kimchi samples was 0.401${\pm}$0.260. The average salinities of soups, stews, protein containing side dishes, vegetable side dishes and drinks were 0.153${\pm}$0.085%, 0.691${\pm}$0.213%, 0.151${\pm}$0.102%, 0.209${\pm}$0.121% and 0.080${\pm}$0.016%, respectively. The average salt intake of one serving of Kimchi was 0.125${\pm}$0.041 g, while the average salt intakes of one serving of the soups, stews, protein containing side dishes, vegetable side dishes and drinks were 0.306${\pm}$0.170 g, 1.382${\pm}$0.426 g, 0.094${\pm}$0.061 g, 0.146${\pm}$0.089 g, and 0.159${\pm}$0.152 g, respectively. The salinity of packaged Kimchi was significantly higher than the salinity of the bulk Kimchi (p < 0.01). In addition, the salinity of the liquid and solid stem portions of the packaged Kimchi was significantly higher than the salinity of the same sized portions of the bulk Kimehi (p<0.01). Furthermore, the salinity in the liquid and solid stern portions of the packaged mustard leaf Kimchi were significantly higher than the salinities of other types of Kimchi (p < 0.0001). The salinity of all Kimchi is higher than that of soup, protein containing side dishes, vegetable side dishes or drinks, but the salt content of one serving of Kimchi is lower than those of the soups or stews or vegetable side dishes or drinks (because one serving size of Kimchi is usually smaller than that of the other foods).

• ETRI Journal
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• v.26 no.6
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• pp.647-652
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• 2004

A new ionic liquid, 1-vinyl-3-heptylimidazolium iodide (VHpII), was synthesized and applied as a redox electrolyte for dye-sensitized solar cells. The chemical structure of the synthesized VHpII was confirmed using $^1H$ NMR. Thermogravimetric analysis showed that the VHpII was stable for thermal stress of up to $250^{\circ}C$. The energy conversion efficiencies of the VHpII-based dye-sensitized solar cells were investigated in terms of the effect of a lithium iodide addition. A solar cell containing the redox couple of VHpII and iodine showed a conversion efficiency of 2.63% under 1 sun light intensity at AM 1.5. Adding 0.4 M LiI results in a conversion efficiency of 3.63%, which was an improvement of about 40%. The increased conversion efficiency was ascribed to an increase in external quantum efficiency.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.369-372
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• 2004

Orientation of E7 liquid crystals(LCs) confined to 200 nm-diameter cylindrical cavities of Anodisc membranes are investigated by FTIR dichroism techniques. The cavity walls of the confining pores are chemically modified with different perfluorinated carboxylic acids (PCA, $C_nF_{2n+1}$COOH, n=3, 4, 5, 6). From the FTIR spectra of PCA treated alumina Anodsic membranes, we found the salt formation between -COOH group of PCA and Anodisc membrane. From the FTIR spectra of LC filled Anodisc membranes, we found abrupt alignment direction change of LC molecules between n=4 and 5 for 1 mM PCA treated Anodisc membranes, from parallel to perpendicular direction to the cavity walls. But 5mM PCA treated Anodisc membranes, alignment direction of LC molecules changed between n=3 and n=4, from parallel to perpendicular direction.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.475-477
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• 2003

Orientation of E7 liquid crystals (LCs) confined to 200 nm-diameter cylindrical cavities of Anodisc membranes are investigated by FTIR dichroism techniques. The cavity walls of the confining pores are chemically modified with different aliphatic acids ($C_nH_{2n+1}COOH$, n=5, 6, 7, 9). From the FTIR spectra of aliphatic acid treated alumina Anodsic membranes, we found the salt formation between -COOH group of aliphatic acid and Anodisc membrane. From the FTIR spectra of LC filled Anodisc membranes, we found abrupt alignment direction change of LC molecules between n=6 and 7 for 2% aliphatic acid treated Anodisc membranes, from parallel to perpendicular direction to the cavity walls. But 4% aliphatic acid treated Anodisc membranes, alignment direction of LC molecules changed between n=5 and n=6, from parallel to perpendicular direction. The same trend was observed for $^2H-NMR$ measurements.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.185-188
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• 2003

In order to enhance shoot elongation and rooting of Anthurium andreanum 'Atlanta' in vitro, 15mL of liquid media containing various concentrations of activated charcoal, sucrose and MS salts were added in same vessels after small shoots were induced from the calli on mudium supplemented with 10.0mg/L BA and 0.1mg/L 2.4-D. The post-supplying of 15mL liquid medium containing MS macro and micro elements, 30g/L sucrose and 5.0∼10.0g/L activated charcoal was significantly stimulated the shoot elongation and rooting of regenerated shoots from calli. The medium addition was also resulted in the enhanced soil survival, elongation and rooting of plantlets in cultural soil mixed with perlite and vermiculite(1 : 1)

• Nuclear Engineering and Technology
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• v.3 no.1
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• pp.33-36
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• 1971

With the use of the significant structure theory of liquid, the fusion criteria has been successfully explained. To test the theory of fusion, the excess volume upon melting has been calculated for some liquids such as simple liquids and fused salts. The results obtained show good agreements between theory and experiment. The theoretical study on the fused salt may be useful to understand the properties and structure of high temperature liquids in the atomic reactor.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.3
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• pp.175-182
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• 1992

Freezing of the binary solution ($H_2O-NaCl$) saturating a packed bed of spheres is investigated experimentally. The system is cooled through its top surface, and the bottom is maintained at a temperature above the liquidus. Experiments are performed on the hypolutectic side, and the cold wall temperature is lower than the eutectic point. The effects of initial mixture concentration, superheat and glass bead diameter on temperature and concentration distributions are investigated. Supercooling was observed only at early times of the freezing process for experiments with 5% initial salt concentration. Flow visualization experiments and mushy-liquid interface position observations revealed natural convection in the liquid region. Remelting phenomena was not observed at both the solid-mushy and mushy-liquid interfaces.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.42-47
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• 2024

The electrochemical extraction of uranium in ternary low melting LiCl-KCl-CsCl eutectic on inert and reactive electrodes via different electrochemical techniques was investigated. It was established that the electrochemical reduction process of U(III) ions on the inert W electrode was irreversible and proceeded in one stage. On reactive liquid Ga and liquid Cd electrodes the reduction of uranium ions took place with the considerable depolarization with the formation of UGa₂, UGa₃ and UCd₁₁ intermetallic compounds. Thermodynamic characteristics of uranium compounds and alloys were calculated. The conditions for the extraction of uranium from the electrolyte in the form of alloys on both liquid reactive electrodes via potentiostatic electrolysis were found.