• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.106-113
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• 2004

A major problem of nuclear energy is the production of radioactive wastes. Needs for more environmentally favorable method to decontaminate radioactive contaminants make the use of liquid/Supercritical $CO_2$ as a solvent medium. In removing radioactive metallic contaminants under $CO_2$ solvent, two methods - use of chelating ligands and that of water in $CO_2$ emulsion - are possible. In the chelating ligand method, a combination of ligands that can make synergistic effects seems important. We discuss about the properties of microemulsion formed by F-AOT. By adding acid in water core, decontamination of metallic parts, soils were possible.

• Journal of Integrative Natural Science
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• v.10 no.4
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• pp.225-231
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• 2017

Cryptand resins were synthesized by mixing 1-aza-18-crown-6 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 5%, and 10% crosslink by a substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, SEM, surface area, and IR-spectrum. As the results of the effects of pH, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > calcium ($Ca^{2+}$) > neodymium ($Nd^{3+}$) ion, adsorbability of the uranium ion was the crosslink in order of 1%, 2%, 5%, and 10% and it was increased with the lower dielectric constant.

• Polymer(Korea)
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• v.38 no.4
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• pp.464-470
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• 2014

A chemo-mechanical method was used to prepare lignin-containing cellulose nanofibrils(L-CNF) from unbleached woodpulps dispersed uniformly in an organic solvent. L-CNF/PLA composites were obtained by solvent casting method. The effects of L-CNF concentration on the composite performances were characterized by tensile test machine, contact angle machine, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). The tensile test results indicated that the tensile strength and elongation-at-break increased by 50.6% and 31.8% compared with pure PLA. The contact angle of PLA composites decreased from $79.3^{\circ}$ to $68.9^{\circ}$. The FTIR analysis successfully showed that L-CNF had formed intermolecular hydrogen bonding with PLA matrix.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.73-77
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• 1993

This study was intended to investigate the effects of solvents, particle size of a sample, sample to solvent ratio, temperature and time on the extraction of garlic oleoresin. Among eleven solvents used for oleoresin extraction from garlic, the optimal solvent was methyl alcohol. The most appropriate particle size of garlic, extracting temperature and mixing ratio of garlic to methyl alcohol were 20mesh, $25^{\circ}C$ and 1 to 3(w/w), respectively. On the basis of yield in oleoresin extraction, optimum extracting time was about 4 hours. The yield of oleoresin under the above-mentioned conditions was 21.3%. "L" and "b" as color appearance were decreased, whereas "a"was increased slightly during 60 days storage at 5$^{\circ}C$, $25^{\circ}C$ and 4$0^{\circ}C$. Changes in the pyruvate content showed close relation to pH value. During storage pyruvate content of garlic oleoresin was decreased as increasing storage temperature.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.71-74
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• 2005

In this paper, the effects of the MWCNTs on the PTC characteristics of the conventional CB/polymer nanocomposites were investigated. For the uniform dispersion of the MWCNTs in the polymer matrix., nitricacid-treated MWCNTs were dispersed with the dissolved HOPE in the solvent. After evaporating solvent, the dried master batches in the oven were melt blended mixed with CB and HDPE to obtain the PTC materials. The initial resistivity of PTC materials decreased and the PTC intensity increased with the MWCNTs. During three repeated heating and cooling cycles, the PTC materials containing MWCNTs showed a great reproducibility due to the conductive network structures of CB particles and MWCNTs.

• Journal of the Korean Chemical Society
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• v.17 no.3
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• pp.213-223
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• 1973

This report has been focused on the studies of the hydraulic pressure distribution which is created by the agitation of the both liquids, dialysing solution and solvent, on either side of the dialysis membrane surface. Agitators of the both liquids have been investigated and developed which can counterbalance the hydraulic pressures. The effects of the agitation velocities on the dialysing velocity have been studied under the conditions which allow the uniform dialysis on the whole surface of the dialysis membrane. Each agitation velocity of the dialysing solution and solvent, at which the dialysis coefficient is obtained most precisely, has been determined.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2212-2216
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• 2011

An ionic liquid-based ultrasonic-assisted extraction method has been successfully applied to the effective extraction of phenolic compounds from Laminaria japonica Aresch. Three kinds of 1-alkyl-3-methyl-imidazolium with different cations and anions were evaluated for extraction efficiency. The results showed that both the characteristics of anions and cations have remarkable effects on the extraction efficiency. In addition, the ionic liquid-based ultrasonic-assisted extraction procedure was also optimized on some extraction parameters, such as ultrasonic power, extraction time and solid-liquid ratio. Compared with the conventional solvent, the optimum approach gained the highest extraction efficiency within the shortest extraction time. Average recoveries of phenolic compounds were from 75.5% to 88.3% at three concentration levels.

• Biomedical Science Letters
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• v.17 no.2
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• pp.157-165
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• 2011

In this study, we investigated the biological activities of Carthamus tinctorius including antioxidative, fibrinolytic, thrombin inhibitory, ${\alpha}$-glucosidase inhibitory and collagenase inhibitory activities. Carthamus tinctorius, hot water extract was fractionated into hexane, chloroform, ethyl acetate, butanol and water fraction. Each of these was assayed individually. The hot water extract showed high antioxidative activity and thrombin inhibitory activity at 90.17% and 97.10% respectively. In the fraction activity tests, chloroform fraction showed the highest antioxidative activity at 81.85%. The fibrinolytic activity was strong only in the butanol fraction at 0.70 plasmin units/ml. The thrombin inhibitory activities of hexane, ethyl acetate and butanol fractions were 97.35%, 86.74% and 93.18% respectively. In collagenase inhibitory activity test, hexane fraction showed the highest activity at 87.78%. In conclusion, the hot water extract and solvent fractions of Carthamus tinctorius L can be used as a material for the development of biofunctional tea and foods respectively.

• Journal of the Korean Society of Tobacco Science
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• v.25 no.2
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• pp.137-143
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• 2003

Among the most popular means of mainstream smoke collection for specific analysis are solvent traps. Determination of the carbonyl compounds as their 2,4-dinitrophenylhydrazones(DNPHs) by HPLC offers increased sensitivity and reproducibility in the analysis of mainstream cigarette smoke. In this work, the mainstream smoke of a reference cigarette(lR4F) was collected in four kinds of gas washing bottles and their effects on the analysis of carbonyl compounds were investigated. The results show that the porosity of fritted glass filter in gas washing bottles exerted profound effect on the composition of the carbonyl compounds in mainstream smoke.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.66-71
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• 1998

This study was investigated to evaluate worker exposures to organic solvents by type of print industry. Results were as follows; 1. Workers were exposed to mixture of toluene, isopropyl alcohol(IPA), methyl ethyl ketone(MEK), n-hexane, ethylacetate(EA), acetone. The components of high exposure solvents were toluene, IPA and MEK. 2. Considering additive effects of the compounds, exposure indices(Em) were calculated. The Mean of exposure indices were 1.79 for Gravere, 0.41 for Screen and 0.14 for Opset workplace. The workers of Gravere workplace were estimated to overexpose for solvents. 3. The highest overexposed solvent was toluene for a single component. The rate of overexposed level for toluene was 7.41% for some print workplace and for mixed solvent was 1.85％. 4. Local exhaust systems were inappropriate and respiratory protective devices were not supplied to the workers. 5. Sound level was over 90dB(A) in Opset print workplace and some measures should be performed to get down the sound level.