• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.170-180
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• 2018

Background: To obtain useful cosmetic resources, this study aimed to determine the non-saponin fatty acid and inhibitory activities of collagenase and elastase by treatment of Saccharomyces cerevisiae in supercritical fluid extracted oil of the adventitious root culture of wild mountain ginseng. Methods and Results: We performed supercritical fluid extraction at various conditions such as pressure, temperature, time, and use of co-solvents, unlike the n-hexane extraction for the adventitious roots culture of wild mountain ginseng. The non-saponin-fatty acid obtained from the oil of the adventitious roots culture was incresed by treatment with S. cerevisiae. The supercritical fluid extraction was conducted using gas chromatography. Non-saponin-fatty acid content, in the oil of adventitious roots culture of wild mountain ginseng treated with S. cerevisiae for 2 days were three times higher than that in the control. In addition, the oil of the adventitious roots culture treated with S. cerevisiae was investigated for the anti-wrinkle effect by using collagenase and elastase. The oil of adventitious roots culture treated with S. cerevisiae exhibited higher collagenase and elastase inhibitory activities than those in the control. Conclusions: Supercritical fluid extracted oil of the adventitious roots culture of wild mountain ginseng treated with S. cerevisiae was found to have decreased ratio of saturated fatty acids and incresed ratio and content of unsaturated fatty acids increased. Furthermore, it showed anti-wrinkle effects in vitro.

• Nuclear Engineering and Technology
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• v.41 no.7
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• pp.907-920
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• 2009

This study was performed to evaluate the prediction capability of a commercial CFD code and to investigate the effects of different geometries such as a 4.4 mm tube and an 8/10 mm annular channel on the detailed flow structures. A numerical simulation was performed for the conditions, at which the experimental data was produced by the test facility SPHINX. A 2-dimensional axisymmetric steady flow was assumed for computational simplicity. The RNG $\kappa-\varepsilon$ turbulence model (RNG) with an enhanced wall treatment option, SST $\kappa-\omega$ (SST) and low Reynolds Abid turbulence model (ABD) were employed and the numerical predictions were compared with the experimental data generated from the experiment. The effects of the geometry on heat transfer were investigated. The flow and temperature fields were also examined in order to investigate the mechanism of heat transfer near the wall. The local heat transfer coefficient predicted by the RNG model is very close to the measurement result for the tube. In contrast, the local heat transfer coefficient predicted by the SST and ABD models is closer to the measurement for the annular channel.

• Journal of the Korean Electrochemical Society
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• v.16 no.3
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• pp.151-156
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• 2013

As the cathode material for li-ion battery, $LiNi_{0.5}Mn_{0.3}Co_{0.2}O_2$ were synthesized by supercritical hydrothermal method and calcined $850^{\circ}C$ and $900^{\circ}C$ for 10hrs in air. The effect of temperature in the heat treatment on the powder and its performance were studied of xray diffraction pattern, SEM-image, physical properties and electrochemical behaviors. As a result, calcined at $900^{\circ}C$ material particle size more increase than calcined at $850^{\circ}C$ material, especially shows excellent electrochemical performance with initial reversible specific capacity of 163.84 mAh/g (0.1C/2.0-4.3V), 186.87 mAh/g (0.1C/2.0-4.5V) and good capacity retention of 91.49% (0.2C/2.0-4.3V) and 90.36% (0.2C/2.0-4.5V) after 50th charge/discharge cycle.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.59-65
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• 2014

We measured the reductions in size and solubility of mackerel muscle that was freeze-dried, deoiled by supercritical carbon dioxide (SC-$CO_2$), or roasted. The percent size reduction and solubility were high in SC-$CO_2$-treated muscle compared with freeze-dried and roasted muscle. We used oil-free residues to test for heavy metals and determine microbial safety. The SC-$CO_2$, hexane, and ethanol were used to separate oil from muscle. The concentrations of cadmium (Cd) in all treated muscles were less than the values reported in the literature, as were the concentrations of lead in SC-$CO_2$- and hexane- treated muscle. In contrast, concentrations of arsenic and mercury in muscles were greater than the reported values regardless of treatment. Zinc and iron, which are beneficial for health, were found in high levels after all treatments of muscle tissue. After 6 months of storage at different temperatures, SC-$CO_2$-and ethanol-treated muscle showed few bacterial colonies, and none were found after 4 months of storage at $-20^{\circ}C$. These results will be useful to food-processing industries for maintaining high-quality, safe mackerel muscle.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.649-656
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• 2006

The proposed head-space supercritical fluid extraction (SFE) methodology as an alternative to an existing conventional procedure was explored for the determination of organochlorine compounds in aqueous matrix. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were utilized as target analytes. To enhance the recovery efficiency, the factors such as the $CO _2$ density, the extraction time, and the extraction mode were investigated. Furthermore, the analytical procedures and the results obtained were compared with those provided by the conventional method (the U.S. EPA method 8080). Under the optimized conditions, i.e., a combination of static with dynamic SFE mode at 2,000 psi and 40 ${^{\circ}C}$, the head-space SFE methodology gave equivalent or better to the conventional method in recovery efficiencies with clear advantages such as simple sample treatment and fast analysis time as well as reduced solvent and reagent consumption.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.790-795
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• 1996

Citrus juice was treated with supercritical carbon dioxide $(SC-CO_{2})$ as an alternative to heat for pectinesterase (PE) inactivation to minimize undesirable changes in flavor, color and ascorbic acid loss caused by the current heat treatment, and the effect of temperature $(40,\;50,\;60^{\circ}C)$, pressure (138, 276 bar) and process time $(5{\sim}130\;min) $ on PE activity was determined. PE in temperature control samples was inactivated by 54% at $40^{\circ}C$ after 130 min, 84% at 50% after 60 min and 83% at $60^{\circ}C$ after 30 min treatment compared to the original juice. PE inactivation in $(SC-CO_{2})$ treated samples at 138 bar was 83% at $40^{\circ}C$ after 130 min, 88% at $50^{\circ}C$ after 20 min and 87% at $60^{\circ}C$ after 10 min. %PE inactivation due to pressure was higher at low temperature and lower at high temperature. Higher temperature, Pressure and longer process time resulted in higher %PE inactivation. Nonlinearity in the curves of PE inactivation at different temperatures and pressures indicated that at least two forms of PE existed in citrus juice with different stabilities.

• Food Engineering Progress
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• v.15 no.3
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• pp.203-208
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• 2011

Effects of particle size and high pressure processing on the extraction rate of oil compounds from soybean powder were evaluated by Soxhlet method using hexane and supercritical fluid extraction (SFE) using $CO_{2}$. SFE was carried out at 4,000 psi and $50^{\circ}C$ for 4 hr. The mean particle sizes were varied from 26.7 to 862.0 ${\mu}m$ by controlling milling time. Saturation solubility increased as the particle size decreased. At large particle size, high pressure processing (HPP) showed higher extraction yield in both hexane extraction and SFE, but, as the particle size decreased, the HPP was irrelevant to the extraction yield in SFE. The higher extraction rate obtained from the smaller particle size. The scanning electronic microscopy of soybean powder treated by HPP showed pores on the surface of the particle. The higher extraction rate and yield from HPP treatment might be due to the less internal resistance of transferring the solvent and miscellar in the solid matrix by collapsing of tissues.

• Economic and Environmental Geology
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• v.50 no.4
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• pp.257-266
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• 2017

Batch experiments were performed to develop the method for the pH reduction of recycled aggregate by using $scCO_2$ (supercritical $CO_2$), maintaining the pH of extraction water below 9.8. Three different aggregate types from a domestic company were used for the $scCO_2$-water-recycled aggregate reaction to investigate the low pH maintenance of aggregate during the reaction. Thirty five gram of recycled aggregate sample was mixed with 70 mL of distilled water in a Teflon beaker, which was fixed in a high pressurized stainless steel cell (150 mL of capacity). The inside of the cell was pressurized to 100 bar and each cell was located in an oven at $50^{\circ}C$ for 50 days and the pH and ion concentrations of water in the cell were measured at a different reaction time interval. The XRD and SEM-EDS analyses for the aggregate before and after the reaction were performed to identify the mineralogical change during the reaction. The extraction experiment for the aggregate was also conducted to investigate the pH change of extracted water by the $scCO_2$ treatment. The pH of the recycled aggregate without the $scCO_2$ treatment maintained over 12, but its pH dramatically decreased to below 7 after 1 hour reaction and maintained below 8 for 50 day reaction. Concentration of $Ca^{2+}$, $Si^{4+}$, $Mg^{2+}$ and $Na^+$ increased in water due to the $scCO_2$-water-recycled aggregate reaction and lots of secondary precipitates such as calcite, amorphous silicate, and hydroxide minerals were found by XRD and SEM-EDS analyses. The pH of extracted water from the recycled aggregates without the $scCO_2$ treatment maintained over 12, but the pH of extracted water with the $scCO_2$ treatment kept below 9 of pH for both of 50 day and 1 day treatment, suggesting that the recycled aggregate with the $scCO_2$ treatment can be reused in real construction sites.

• Clean Technology
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• v.16 no.3
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• pp.191-197
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• 2010

Repair reaction of plasma damaged porous methyl doped SiOCH films was carried out with silylation agents dissolved in supercritical carbon dioxide ($scCO_2$) at various reaction time, pressure, and temperature. While a decrease in the characteristic bands at $3150{\sim}3560cm^{-1}$ was detectable, the difference of methyl peaks was not identified apparently in the FT-IR spectra. The surface hydrophobicity was rapidly recovered by the silylation. In order to induce effective repair in bulk phase, the wafer was heat treated before reaction under vacuum or ambient condition. The contact angle was slightly increased after the treatment and completely recovered after the subsequent silylation. Methyl groups were decreased after the plasma damage, but their recovery was not identified apparently from the FT-IR, spectroscopic ellipsometry, and secondary ion mass spectroscopy analyses. Furthermore, Ti evaporator was performed in a vacuum chamber to evaluate the pore sealing effect. The GDS analysis revealed that the open pores in the plasma damaged films were efficiently sealed with the silylation in $scCO_2$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.423-429
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• 2009

This study was conducted to investigate the effects of pine (Pinus densiflora) needle extracts on hepatic antioxidative system in rats fed high-cholesterol diet. Eight-week old Sprague Dawley rats were divided into four groups; normal diet group (CON), 0.5% cholesterol diet group (0.5% CHOL), 0.5% cholesterol diet and pine needle extracts prepared by using hot water group (HOT water), and 0.5% cholesterol diet and pine needle extracts prepared by using sub-supercritical $CO_2$ group (Sub-supercritical). The serum ALP, AST, and ALT activities were increased by 0.5% cholesterol diet supplementation, but treatment with pine needle extracts showed decrease compared with 0.5% CHOL group. The SOD activity in liver at 0.5% cholesterol diet group was more decreased than control group while Sub-supercritical group had significantly higher SOD activity than 0.5% CHOL group. Moreover, groups with pine needle extracts supplementation had higher level of GPx in liver than 0.5% cholesterol diet group. These results suggest that pine needle extracts increased antioxidative activities.