• Korean journal of applied entomology
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• v.31 no.2
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• pp.182-189
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• 1992

The influnces of 9 kinds of solvents on the toxicities against several insect species, phytotoxicity and solubility of compounds were evaluated by means of leaf dipping and spray methods. In case of the spray application, density and vapor pressure seemed to be a contributing factor to lethal toxicity against brown planthopper and diamond-back moth, respectively; the bigger the property of density and the smaller the vapor pressure gave the stronger toxicity. It appeared that the toxicity of solvents was not correlated with anyone of physical properties such as boiling point, dipole moment, dielectric constant, surface tension and viscosity. Spray treatment gave more toxicity to insects than leaf dipping treatment. Although dielectric constant and dipole moment seemed to be contributing factors to phytotoxic damage to rice seedling and bean plants, respectively, no general correlation between phytoxicity and the other physical properties was found. Leaf dipping application caused stronger phytotoxicity than spray application. It is concluded that 5% acetone solution may be most suitable to test chemicals because of its favorable solubility of compounds, lower toxicity to insects, and lower phytotoxicity.

• 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 the Korean Wood Science and Technology
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• v.41 no.1
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• pp.19-32
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• 2013

In this study, outstanding white rot fungi for biodegradation of organosolv lignin were selected on the basis of their ligninolytic enzyme system. Fifteen white rot fungi were evaluated for their ability to decolorize Remazol Brilliant Blue R (RBBR) in SSC and MEB medium, respectively. Six white rot fungi (Ceriporiopsis subvermispora, Ceriporia lacerate, Fomitopsis insularis, Phanerochaete chrysosporium, Polyporus brumalis, and Stereum hirsutum) decolorized RBBR rapidly in SSC medium within 3 days. The protein contents as well as the activities of manganese peroxidase (MnP) and laccase for 6 selected fungi were determined on the SSC medium with and without organosolv lignin. Interestingly, extracellular protein concentrations were determined to relative higher for S. hirsutum and P. chrysosporium in the presence of organosolv lignin than others. On the other hands, each fungus showed a different ligninolytic enzyme pattern. Among them, F. insularis resulted the highest ligninolytic enzyme activities on incubation day 6, indicating of 1,545 U/mg of MnP activity and 1,259 U/mg of laccase activity. In conclusion, $STH^*$ and FOI were considered as outstanding fungi for biodegradation of organosolv lignin, because $STH^*$ showed high extracellular protein contents and ligninolytic enzyme activities over all, and ligninolytic enzyme activities of FOI were the highest among white rot fungi used in this study.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.253-256
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• 2001

$3{\sim}5$ types of proteins were expressed by toluene and heat during $30{\sim}60$min. Generally it is reported that proteins below 10kDa function as transcription factor. In this study we certified that 7kDa was induced by organic solvent and the rate of expression was 2 folds at $30{\sim}45$min.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.2
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• pp.114-119
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• 2003

This study is to remove several organic pollutants from wastewater by non-dispersive membrane solvent extraction technique. The distribution coefficients of several solvents were determined and the experimental system was operated counter-currently and cocurrently with respect to the aqueous phase and solvent. In these experiments, as the flow rate of aqueous solution inclosed, due to being shortened contact time to solvent, the rate of removal of organic pollutants decreased and as the flow rate of solvent increased, the rate of removal increased. Meanwhile, the rate of removal of organic pollutants for the countercurrent flow system was higher than that for the occurrent flow system.

• KSBB Journal
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• v.22 no.3
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• pp.174-178
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• 2007

The aim of this study was to identifyisothiocyanates (ITCs) from wasabi (Wasabi japonica Matsum) using supercritical carbon dioxide ($SCO_2$) and to compare the composition in the extracts between $SCO_2$ and organic solvents extraction. A semi-continuous high pressure apparatus was used to extract wasabi (roots, stems and leaves) at following conditions pressure 80$\sim$120 bar, temperature $40\sim50^{\circ}C$. Ether, ethanol, chloroform and dichloromethane were used as organic solvents. The ITCs extracted by means of both separation technologies were analyzed by a gas chromatography system. As the results of study, AITC and ITCs were highly extracted at 40$^{\circ}C$ and 80 bar. To extract AITC from wasabi, $SCO_2$ extraction is more effective than organic solvents extraction, resulted in thermal degeneration and remaining of organic solvents.

• Journal of Life Science
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• v.25 no.3
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• pp.345-348
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• 2015

An organic solvent stable lipase from solvent-tolerant Pseudomonas sp. BCNU 171 had an optimal pH of 8 and an optimal temperature of 37℃. This crude extracellular lipase from BCNU 171 exhibited increased stability in the presence of various types of solvents at high concentrations (25%, v/v). The lipase stability was found to be highest in the presence of xylene (137%), followed by toluene (131%), octane (130%), and butanol (104%). Overall, BCNU 171 lipase tended to be more stable than immobilized commercial lipase (Novozyme435) in the presence of organic solvents. Furthermore, BCNU 171 lipase maintained about 90% of its enzyme original activity in the presence of NH₄⁺, Na⁺, Ba²⁺, Hg²⁺, Ni²⁺, Cu²⁺, and Ca²⁺ion and significantly increased its enzyme activity in the presence of various emulsifying agents. Thus, the organic solvent stable lipase from Pseudomonas sp. BCNU 171 could be usable as a potential whole cell biocatalyst and for synthetic applications of enzymes for industrial chemical processes in organic solvents without using immobilization.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.203-213
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• 1996

In physical and reactive extraction system using equilibrium extraction equipment, the effects of extractants, concentration of extractant, and solvent on the degree of extraction were investigated. The organic acids used were acrylic acid and metacrylic acid. Extractants were n-octylamine(OA), di-n-octylamine(DOA), tri-n-octylamine(TOA) and tri-octylmetyl ammonium chloride(TOMAC ; Aliquat 336). We found that the degree of extraction for reactive extraction was 2~9 times than that for physical extraction and that effect of extractants on the degree of extraction of organic acid was the order of OA

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.210-210
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• 2010

저항 구조를 가진 유기 쌍안정성 소자는 비휘발성 기억 소자 중에서 구조가 간단하고 제작비용이 저렴하며 플렉시블이 용이한 장점 때문에 많은 연구가 진행되고 있다. 유기물/무기물 복합재료를 사용한 유기 쌍안정성 소자 제작에 대한 연구는 많이 진행되어 왔지만, 넓은 에너지 밴드 갭을 가진 $SnO_2$ 나노 입자가 삽입된 고분자 박막을 기반으로 제작한 유기 쌍안정성 소자에 대한 연구는 상대적으로 미흡하다. 본 연구에서는 Poly(methyl methacrylate) (PMMA) 박막 안에 분산된 $SnO_2$ 나노 입자를 사용하여 제작한 유기 쌍안정성 소자의 전기적인 특성을 관찰하였다. 소자를 제작하기 위해 나노 입자의 전구체인 Tin 2-ethylhexanoate (95%) 2.4 mmol을 dibutyl ether (99.3%) 10 ml에 용해시킨 후, 용매열 화학적 방법을 사용하여 용매 안에서 $SnO_2$ 나노 입자를 합성하였다. 용매 안에 들어있는 1 wt%의 $SnO_2$ 나노 입자와 100 mg의 PMMA를 2 ml의 클로로벤젠에 용해하여 고분자 용액을 제작하였다. 하부 전극 역할을 하는 indium tin oxide가 증착된 유리 기판 위에 고분자 용액을 스핀 코팅하고, 열을 가해 용매를 제거하여 $SnO_2$ 나노 입자가 분산되어 있는 PMMA 박막을 형성하였다. 그 위에 Al 전극을 증착하여 기억 소자를 완성하였다. 제작된 유기 쌍안정성 소자의 전류-전압 (I-V) 측정 결과에서는 동일한 전압에서 서로 크기가 다른 전류가 흐르는 I-V 곡선의 히스테리시스 특성이 나타났다. 그러나 $SnO_2$ 나노 입자가 없는 PMMA 박막으로 형성된 유기 쌍안정성 소자에서는 I-V 곡선의 히스테리시스 특성이 나타나지 않았다. 따라서 PMMA 박막 안에 삽입된 $SnO_2$ 나노 입자가 유기 쌍안정성 소자의 메모리 효과에 결정적인 영향을 준 것을 알 수 있었다. 전류-시간 측정 결과에서는 소자의 ON/OFF 비율이 시간에 따라 큰 변화 이 없이 1000 사이클 이상 지속적으로 유지 하고 있음을 보여 줌으로써 유기 쌍안정성 소자를 장시간 사용할 수 있음을 나타내 주었다.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.183-187
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• 1997

The analytical conditions of 1,3-dichloro-2-propanol (DCP) and 3-chloro-1,2-propanediol (MCPD) by solid phase extraction were optimized to improve recovery. Selected-ion monitoring technique which was used for GC-MS analysis of both compounds gave substantially higher sensitivity. The detection limits of DCP and MCPD were 25 and 50 ppb, respectively. The effects of extraction column type, elution solvent and salt concentration on recovery were examined. A normal phase column was better than a reverse phase column in solid phase extraction of DCP and MCPD. It was explained in terms of polarity relationship of solvent-solute-solid phase. A maximum recovery was obtained at the salt concentration of 20% (w/v). Water-immiscible and chloropropanol-soluble solvents such as chloroform, diethyl ether, hexane and ethyl acetate were tested for elution solvent. Hexane and ethyl acetate were the most suitable solvents for the extraction of DCP and MCPD, respectively. High recovery better than 95% was obtained with the selected solvents.