• KSBB Journal
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• v.19 no.6 s.89
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• pp.421-426
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• 2004

The extraction and separation of isoflavones from Korean soybean were peformed by various mechanical and chemical extraction methods. They included solvent extraction, stirring, supersonification and sub/supercritical water extraction. From the experimental results of the variation of solvent extraction by change in composition, the increase in extraction of a specific compound by stirring or supersonic energy, and the application of supercritical fluid with superior solvating power over solvents, the sonification was the most desirable extraction method in extracting aglycone isoflavones, daidzein and genistein from Korean soybean.

• Journal of Mechanical Science and Technology
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• v.14 no.9
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• pp.985-996
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• 2000

The issue of quench is related to safety operation of large-scale superconducting magnet system fabricated by cable-in-conduit conductor. A numerical method is presented to simulate the thermal hydraulic quench characteristics in the superconducting Tokamak magnet system, One-dimensional fluid dynamic equations for supercritical helium and the equation of heat conduction for the conduit are used to describe the thermal hydraulic characteristics in the cable-in-conduit conductor. The high heat transfer approximation between supercritical helium and superconducting strands is taken into account due to strong heating induced flow of supercritical helium. The fully implicit time integration of upwind scheme for finite volume method is utilized to discretize the equations on the staggered mesh. The scheme of a new adaptive mesh is proposed for the moving boundary problem and the time term is discretized by the-implicit scheme. It remarkably reduces the CPU time by local linearization of coefficient and the compressible storage of the large sparse matrix of discretized equations. The discretized equations are solved by the IMSL. The numerical implement is discussed in detail. The validation of this method is demonstrated by comparison of the numerical results with those of the SARUMAN and the QUENCHER and experimental measurements.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.85.1-85
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• 2003

• Clean Technology
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• v.15 no.4
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• pp.233-238
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• 2009

Supercritical fluid processes have gained great attention as a new and environmentally-benign method of preparing the microparticles of energetic materials like explosives and propellants. In this work, RDX (cyclotrimethylenetrinitramine) was selected as a target explosive. The microparticle formation of RDX using supercritical anti-solvent (SAS) recrystallization process was performed and the effect of operating variables on the size and morphology of prepared particles was observed. N,N-Dimethylformamide was used as organic solvent for dissolving the RDX. The size of the RDX particles decreased remarkably up to less than $10\;{\mu}m$ by SAS recrystallization. In the range of operating conditions of the SAS process studied in this work, the finest RDX particles were obtained at 313.15K, 150 bar, and 15wt% RDX concentration in feed solution.

• KSBB Journal
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• v.14 no.1
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• pp.109-113
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• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• 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.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.566-569
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• 2002

In general, Pb-based complex perovskite powders have not been directly prepared because pyrochlore that is secondary phase appears. In this study, we tried to prepare Pb(Fe$_{1}$2/Nb$_{1}$2/)O$_3$ which was used to the electronic multicomponent by supercitical fluid method in order to fabricate very active powder not through pyrochlore.

• Journal of the Korean Applied Science and Technology
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• v.14 no.2
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• pp.49-55
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• 1997

It was tested the possibility that EPA and DHA could be separated from fish oil fatty acid ethyl ester(FAEE) in the supercritical carbon dioxide rectification method. Experiments were carried out in the 1800mm tall and temperature gradient packed rectification column at the pressure of 100bar and carbon dioxide flow rate of 52.43NL/min. Experimental results showed that this method was useful to separate the FAEE by the relative volatility of the components. The maximum attainable concentration of EPA, DHA and both of them in product were 41%, 43% and 57% respectively in this rectification column using raw fish oil feed.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.197-201
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• 2001

Extraction efficiency of ${\beta}-ecdysone$ in Achyranthis radix was investigated using the methods of solvent extraction and supercritical fluid extraction (SFE). The optimum SFE conditions for the analysis of ${\beta}-ecdysone$ in A. radix were 300 atm, $80^{\circ}C$, 100 ml of extraction volume, and 20% ratio of modifier(methanol). As revealed through SFE, detection limit of ${\beta}-ecdysone$ in A. radix was 5 ng and recoveries of ${\beta}-ecdysone$ in A. radix shoots and root were $90.7{\sim}93.5%$ and $77.8{\sim}81.9%$, respectively. Recoveries of ${\beta}-ecdysone$ in A. radix shoots and root through solvent extraction were $76.4{\sim}93.0%$ and $80.6{\sim}93.1%$, respectively. ${\beta}-Ecdysone$ content was determined to be highest at 654.9 ppm in the first year A. radix roots harvested in August.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1691-1695
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• 2016

The objective of this study was to determine the antioxidant activities of rice bran extracts by three different extraction methods. Rice bran was extracted by solvent extraction, saponification extraction, and supercritical fluid extraction. The antioxidant activities of the rice bran extracts were determined based on ABTS and DPPH radical scavenging activities, reducing power, and lipid peroxidation inhibitory activity. The unsaponifiable matter (USM) extracted by the saponification method showed higher ABTS (671.7 mg Trolox equivalent antioxidant capacity (TEAC)/g) and DPPH (330.7 mg TEAC/g) radical scavenging activities as well as reducing power ($A_{700}=1.14$) than those of the solvent extract (ME) and supercritical fluid extract (SFE). Inhibitory effect on lipid peroxidation was higher in USM (68.7%) and SFE (75.4%) compared to ME (47.8%). USM indicated relatively higher antioxidant activities compared with those of SFE and ME. These results show that the saponification method for extraction of USM from rice bran extracted was the most effective method for enhancement of antioxidant activity. In addition, these extracts from rice bran could be used as functional ingredients in the food industry.