• Korean Journal of Pharmacognosy
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• v.20 no.1
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• pp.43-47
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• 1989

An attempt was made to increase the yield of extraction of ginkgoflavonglycosides from leaves of Ginkgo biloba by treatments of with Cellulase C and macerating enzymes. The yield of dried extract and its contents of ginkgoflavonols, when treated only with cellulase C, were analyzed to be 1. 99% and 0. 38%, respectively. The contents of ginkgoflavonglycosides in the dried extracts were calculated to be 25. 28%. By the treatment with a mixture of three enzymes, cellulase C: cellulase NC and macerosin (1 : 1 : 2), the yield of the dried extract, ginkgoflavonols as well as their glycosides were determined to be 2. 48%, 0. 48% and 24. 16%, respectively.

• Current Photovoltaic Research
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• v.7 no.1
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• pp.21-27
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• 2019

Lifetime of Si photovoltaics modules are about 25 years and a large amount of waste modules are expected to be discharged in the near future. Therefore, the extraction and collection of valuable metals out of discharged Si modules will be one of the important technologies. In this study, we demonstrated that supercritical $CO_2$ extraction method can be effectively used to remove Cu, one of the abundant elements in the module, as well as its oxide form, $Cu_2O$. Especially, we proved that the addition of hexane as co-solvent is effective for the removal of both materials. The optimal ratio of $CO_2$ and hexane was 4:1 at a fixed temperature and pressure of $250^{\circ}C$ and 250 bar, respectively. In addition, it was proven that the removal of $Cu_2O$ was preceded via reduction of $Cu_2O$ to Cu.

• Food Engineering Progress
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• v.15 no.2
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• pp.175-181
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• 2011

By using supercritical carbon dioxide fluid, an attempt was made to extract surface-active substances from defatted rice bran. Extraction was carried out according to D-optimal design and results were analyzed by response surface methodology to establish optimum condition. It was found that pressure, temperature and co-solvent (ethanol) influenced in a different extent on the extraction efficiency (i.e., yield and interfacial tension) of surface-active substances. Among them, co-solvent was found to be a major influencing factor, where maximum yield (2.62%) was observed at the highest content (250 g). In addition, it also affected most on the interfacial tension at the oil-water interface but in this case the lowest interfacial tension value (9.51 mN/m) was found when added lowest (50 g). In conclusion, it was estimated that the optimum extraction condition was to be pressure 350bar, temperature $62^{\circ}C$ and co-solvent content 50 g in this study, where extraction yield was 0.69% and interfacial tension to be 10.1 mN/m.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.689-695
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• 1999

Supercritical fluid extraction (SFE), ultrasonic extraction (USE), and accelerated solvent extraction (ASE) were compared with the well known Soxhlet extraction for the extraction of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins(PCDDs) from the XAD-2 resin which was used to adsorb PCDDs in the atmosphere. XAD-2 resin spiked with five PCDDs was chosen as a sample. The optimum conditions for the extraction of PCDDs by SFE were turned out to be the use of CO2 modified with 10% toluene at 100 ℃ and 350 atm, with 5 min static extraction followed by 20 min dynamic extraction. SFE gave a good extraction rate with good reproducibility for PCDDs ranging from 68 to 98%. The ultrasonic extraction of PCDDs from XAD-2 was investigated and compared with other extractions. A probe type method was compared with a bath type. Two extraction solvents, toluene and acetone were compared with their mixture. The use of their mixture in probe type, with 9 minutes of extraction time, was found to be the optimum condition. The average recovery of the five PCDDs for USE was 82-93%. Accelerated solvent extraction (ASE) with a liquid solvent, a new technique for sample preparation, was performed under elevated temperatures and pressures. The effect of tem-perature on the efficiency of ASE was investigated. The extraction time for a 10 g sample was less than 15 min, when the organic solvent was n-hexaneacetone mixture (1 : 1, v/v). Using ASE, the average recoveries of five PCDDs ranged from 90 to 103%. SFE, USE, and ASE were faster and less laborious than Soxhlet extraction. The former three methods required less solvent than Soxhlet extraction. SFE required no concentration of the solvent extracts. SFE and ASE failed to perform simultaneous parallel extractions because of instrumental limitations.

• 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.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.316.1-316
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• 2002

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.12 no.1
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• pp.105-113
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• 1982

Because of the development of rampant caries, osteomyelitis and osteoradionecrosis that occur after radiation therapy of oral cancers, extraction of teeth at or near the malignant lesion has been done in the past. Few, however, have studied the radiation effect on the healing of extraction wounds. This study is concerned with the effect of Co-60 irradiation on the healing process of extraction wounds in rats. Fifty six, male, Spraque-Dawley rats are used. The right first molar of the mandible is extracted from all animals. They are divided into three experimental groups of 14 each and a control group of 14. Three experimental groups are irradiated respectively with 200 rad, 400 rad and 600 rad and a pair of rats in each group are killed on days 1, 3, 5, 7, 14, 21 and 28 after irradiation. Two animals from the control group are killed on the day when the experimental rats are killed. The irradiated hemimandibles are fixed in 10% neutral formalin, decalcified in 5% trichloroacetic acid, embedded in paraffin and sectioned. The sections are stained in hematoxylin and eosin, van Gieson, Masson's trichrome or silver nitrate. Results show that in general radiation effects on healing extraction wounds are dose dependent; i.e., the higher is the dose, the greater is the histologic changes observed: 1. Irradiation tends to retard blood clot organization and epithelial regeneration. 2. An increase in the number of giant cells and osteoclasts is noted after irradiation. 3. Formation of regenerating connective tissues around and within the extraction site is com- promised, and a clear reduction of primitive mesenchymal type connective cells is noted. 4. The healing process begins along the lateral aspect of the extraction socket in the control, while irregular histologic appearances of the brabecular pattern is present in the experimental rats.

• KSBB Journal
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• v.16 no.1
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• pp.95-98
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• 2001

Various factors affecting the supercritical carbon dioxide extraction of daidzein from soybean were studied. Daidzein was not extracted with pure supercritical carbon dioxide. The ethanol was an efficient modifier for supercritical carbon dioxide to extract daidzein. The extraction efficiency increased as the pressure increased up to 300 bar. At $35^{\circ}C$ and 300 bar, 93% of daidzein was extracted with supercritical carbon dioxide modified with 15% of ethanol.

• Journal of the Mineralogical Society of Korea
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• v.25 no.2
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• pp.117-122
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• 2012

The leaching of Li from fly ashes was studied. The fly ash produced from the Taean electric power plant of the Korea Western Power Co., Ltd. was used for this study. The Li leaching was observed according to the changes in solid:solution ratio, solution types (seawater or deionized water), and the $CO_2$ condition in the atmosphere. The results showed that the Li concentrations in the solution increased continuously as the solid:solution ratio increased. The Li leaching per unit mass of fly ash was greater when the deionized water was used for the experiment and when the $CO_2$ dissolution is limited during the reaction because the precipitation of $CaCO_3$ is suppressed under those conditions. At high solid:solution ratio, $Mg^{2+}$, the ion preventing the Li extraction from seawater by adsorption, was effectively removed from the seawater.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.386.1-386.1
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• 2003