• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.19-23
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• 2003

The optimum extraction condition of pungent component from Zanthoxylum piperitum D.C pericarps by using supercritical fluid extraction(SFE) was investigated. The optimum condition of SFE was $300kg/cm^2$ of pressure, $60\;^{\circ}C$ of extraction temperature, 80% of $CO_2$ fluid, 20% of modifier(methanol) volume and 20 min of extraction time. The extraction efficiency between the classical solvent extraction method and SFE was studied. About 40% of extraction efficiency was improved when SFE was applied.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.393.1-393
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• 2002

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3107-3110
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• 2014

• Resources Recycling
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• v.29 no.5
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• pp.55-63
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• 2020

In order to investigate the separation of Co(II) and Ni(II) by ionic liquids from weak hydrochloric acid solutions, extraction experiments were performed by changing the type and concentration of ionic liquids and the initial pH of the aqueous phase. Two kinds of ionic liquids based on Aliquat 336 were employed in this work; one was synthesized by reacting organophosphorus acids(D2EHPA, PC88A, Cyanex 272, Cyanex 301) with Aliquat 336 and the other was prepared by exchanging the chloride ion of Aliquat 336 with SCN^-. The three types of ionic liquids (ALi-D2, ALi-PC, and ALi-CY272) showed better extraction of Co(II) than Ni(II), and the equilibrium pH was higher than the initial pH. In the case of ALi-CY301, the selectivity of Co(II) and Ni(II) depended on the extraction conditions. In addition, the effect of the addition of TBP to the ionic liquid on the extraction of two metals was also investigated. Employment of ALi-SCN as an extractant resulted in selective extraction of Co(II) and complete separation of the two metal ions was possible.

• ETRI Journal
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• v.25 no.2
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• pp.101-108
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• 2003

This paper proposes an improved vascular pattern extraction algorithm for person verification applications. The proposed direction-based vascular pattern extraction (DBVPE) algorithm is based on the directional information of vascular patterns. It applies two different filters to the input images: row vascular pattern extraction filter (RVPEF) for effective extraction of the abscissa vascular patterns and column vascular pattern extraction filter (CVPEF) for effective extraction of the ordinate vascular patterns. We use the combined output of both filters to obtain the final hand vascular patterns. Unlike the conventional hand vascular pattern extraction algorithm, the directional extraction approach prevents loss of the vascular pattern connectivity. To validate the DBVPE algorithm, we used a prototype system with a DSP processor. The prototype system shows approximately a three-times better false acceptance rate (FAR) than the conventional single filter algorithm.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.321-326
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• 2008

In order to improve the market competitiveness of the processed products of Undaria pinnatifida, various extraction conditions of Undaria pinnatifida were examined to determine the optimal conditions for the extraction of its valuable components. The highest level of alginic acid content was detected after 90 min of typical extraction or after 20 min of pressure extraction, after which the levels decreased slightly. The concentrations of reducing sugar and crude protein were also high after 90 min of typical extraction. Both alginic acid and reducing sugar were extracted in greater amounts using pressure extraction. The reducing sugar content was $2.8{\sim}3.2$ times higher using pressure extraction rather than typical extraction. Furthermore, the extraction results were superior with the, pressure extraction method. The appropriate temperature and duration of extraction were found to be $120^{\circ}C$ for 20 min. The use of a single enzyme yielded better results during extraction compared to the use of a mixture of enzymes. 20 min of pressure extraction followed by the addition of 0.1% pectinase and 2 hr of further extraction at $50^{\circ}C$ yielded high contents of alginic acid and reducing sugar from Undaria pinnatifida.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.2
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• pp.123-132
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• 2007

This study was performed to evaluate the co- and mutual separation for Am, Cm and RE elements from the simulated multi-component solution equivalent to real HLW level by a Zr-DEHPA(di-(2-ethylhexyl) phosphoric acid containing Zirconium)/$NDD(n-dodecane)-HNO_3$ extraction system. Zr-DEHPA was self-synthesized and the optimal condition of (15g/L Zr-1M DEHPA)/NDD-1M $HNO_3$ was selected taking into consideration of prevention of the third phase, and effects of concentration of DEHPA, nitric acid and impregnant amount of Zr on the co-extraction of Am, Cm and RE. In that condition, the extraction yields were 81% (Am), 85% (Cm), more than 80% (RE elements), 98% (Mo), 85% (Fe), 98% (U), 73% (Np), and less than 5% (other elements) so that the system developed for the co-extraction of Am-Cm/RE was proved to be available. For that, however, U, Np, Mo and Fe was elucidated to have to be removed in advance, and Zr inducing the third phase formation was found to be practically excluded. The co-extracted Am-Cm/RE were sequentially separated in an order of Am-Cm (stripping agent : 0.05 M DTPA-1M Lactic acid of pH 3.6)${\rightarrow}RE$ (stripping agent : 5M $HNO_3$), and then their separation factors were evaluated. At above conditions, Am of 65.4%, Cm of 63.9%, RE (except for Y) of more than 85% were stripped.

• Clean Technology
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• v.25 no.4
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• pp.275-282
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• 2019

In this study, the extraction of Conger myriaster oil by using supercritical carbon dioxide (SC-CO₂) and organic solvent was investigated. The extraction conditions conducted for SC-CO₂ varied for pressure (25, 30 MPa) and temperature (45, 55 ℃), while the SC-CO₂ flow rate was kept constant during the experiment (27 g min^-1) and hexane was used as a conventional organic solvent. The extraction yield indicated that the best extraction condition would be SC-CO₂ at 55 ℃ and 30 MPa, resulting in the highest yield of 37.73 ± 0.14%. The oils were characterized for their fatty acid (FAs) composition using gas chromatography, while it was revealed that the major FAs were mystric acid, palmitoleic acid, oleic acid, electroosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The oxidation stability of the extracted C. myriaster oil was evaluated by measuring the acid value, peroxide value, and free fatty acid. The best oxidative stability was obtained from SC-CO₂ extracted oil at 30 MPa and 55 ℃. There was a significant difference in the color properties of the SC-CO₂ and hexane extracted oils, with the SC-CO₂ extracted oil showing better chromaticity than the oil extracted using hexane. Extracting oils from C. myriaster with SC-CO₂ could bring better economic benefits than using organic solvents. When supercritical carbon dioxide was used, there was no post-treatment process; thus, it was confirmed that this is a more environmentally friendly oil extraction method.

• Journal of Soil and Groundwater Environment
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• v.23 no.4
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• pp.48-59
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• 2018

Beryllium (Be), cobalt (Co), thallium (Tl) and vanadium (V) are candidates of 21 priority soil pollutants in Korea. The distribution of their concentration in soils from three contamination sources including industrial, roadside and mining areas was investigated. Concentrations of the metals were evaluated quantitatively using pollution indices and the fractionation of metals was conducted using modified SM&T (Standards Measurements and Testing programme) sequential extraction. Concentrations of the metals for all samples from industrial and roadside soils were within the range of natural background levels, while some of Be in soils from abandoned mines exceeded that the range. Enrichment Factor (EF) and Nemerow Integrated Pollution Index (NIPI) for Be, Co, Tl and V showed that there are effects or possibilities of anthropogenic activities. Pollution Load Index (PLI) analyses indicated all investigated sites needed further monitoring. The results of sequential extractions indicated mobile fractions (F1+F2) of Be, Tl and V were below 30% except some of Co in soil, which implies their low mobility to neighboring environment media. Variable tools like sequential extraction, comparison with background/actual concentration and pollution indices, as well as aqua regia extraction should be considered when evaluating Be, Co, Tl, V in soil.

• Journal of Life Science
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• v.13 no.5
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• pp.569-575
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• 2003

Supercritical $CO_2$ extraction was applied to extraction of the valuable compound for benign prostatic hyperplasia from saw palmitto. Three levels of parameters, temperature $(35^{\circ}C,\; 60^<\circ}C)$, pressure 22∼30 Mpa and ethanol modified solvent concentration, were used as the independent variables of central composite to rotate the design. The extracting pressure and temperature interaction was significantly affected the extraction of valuable compounds. The ethanol was an efficient modifier to extract valuable compound by supercritical carbon dioxide. The optimal processing conditions were extracting pressure, 30 Mpa, extracting temperature, $60^<\circ}C$, ethanol modifier, 15% for extracts of the valuable compounds from saw palmitto. In conclusion, it was found that supercritical $CO_2$ extraction can successfully be applied to extract high quality extracts from saw palmitto.