• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1967-1971
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• 2013

Aim of our study is finding adsorbents suitable for pre-concentration of chemical warfare agents (CWAs). We considered Tenax, bare silica and polydimethylsiloxane (PDMS)-coated silica as adsorbents for dimethyl methylphosphonate (DMMP) and dipropylene glycol methyl ether (DPGME). Tenax showed lower thermal stability, and therefore, desorption of CWA simulants and decomposition of Tenax took place simultaneously. Silica-based adsorbents showed higher thermal stabilities than Tenax. A drawback of silica was that adsorption of CWA simulant (DMMP) was significantly reduced by pre-treatment of the adsorbents with humid air. In the case of PDMS-coated silica, influence of humidity for CWA simulant adsorption was less pronounced due to the hydrophobic nature of PDMS-coating. We propose that PDMS-coated silica can be of potential importance as adsorbent of CWAs for their pre-concentration, which can facilitate detection of these CWAs.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.147-150
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• 2002

The cure kinetics of blends of epoxy (DGEBA:diglycidyl ether of bisphenol A)/anhydride (NMA:nadic methyl anhydride) resin with synthesized amino terminated polyetherimide (AT-PEI) were studied using differential scanning calorimetry (DSC) and Dynamic Mechanical Analysizer(DMA) under isothermal condition to determine the reaction parameters and gel-vitrification behavior. The fracture toughness of AT-PEI 20phr/epoxy resin system was improved over 224% and 42.5% more than neat epoxy resin and commercial PEI/Epoxy Resin System.

• Natural Product Sciences
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• v.19 no.2
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• pp.160-165
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• 2013

The 12 compounds were isolated from MeOH extract of Magnolia biondii and their structures were identified as seven lignans, two phenolics, one coumarin, and two flavonoid compounds, respectively. Among these constituents, tiliroside (3), kaempferol-7-methyl ether (4), 4-hydroxybenzoic acid (5), vanilic acid (6), and scopoletin (9) were isolated from Magnolia biondii for the first time.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.354-357
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• 2004

The addition of oxygenates to diesel fuel can significantly reduce particulate emissions. Dibutyl maleate (DBM) and tripropylene glycol methyl ether (TGME) have been identified as possible additives based on their physicochemical characteristics and performance in engine test. However, their potential environmental impacts are unknown. therefore, practical considerations in the selection of an oxygenate additives should include cost, availability, compatibility with engines and fuel, and, particularly, its overall environmental impact. This study was investigated to determine optimal condition for the analysis of potential diesel oxygenates using SPME technique with GC-FID. Four fibers were compared and CAR/PDMS fiber was found to be the most sensitive when used direct-sampling. An absorption time of 30min and a desorption time of 5min provided to be the most sensitivity. The effects of experimental parameters such as the addition of salts, agitation, absorption time, compositon on the analysis were investigated. Analytical parameter such as linearity was also evaluated.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.493-498
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• 1998

An attempt was in this to analyzer volatile flavor components of sancho(Zanthoxylum schinfolium). Essential oils in sancho tree and fruit isolated by a simulataneous steam distillation (SDE) methods using n-pentane/diethyl ether as solvent. A total of 57 and 44 components were identified by gas chromatography(GC) and combined gas chromatography spectrometry (GC-MS), respectively. Granyl acetate(29.23%) geraniol (6.80%, p-isopropyl-2-chclohexenone(5.53%), phellandral (4.10%) in sancho fruit and 4, 6, 6-trimethyl-bicyclo(7.47%), T-carvelo(4.60%, ${\alpha}$-cypernone(3.58%) in sancho tree were found to be major volatile flavor. 22 compnents including myrcene, limonene, 1, 8-cinol in sancho fruit and 10 components including 4-(1-methylethyl)-cyclohexanol, methyl undecyl ketone in sancho tree were identified. The contents of unsaturated fatty acids of palmitic acid(24.34%), myristic acid(3,68%) in sancho tree was higher than that of the sancho fruit.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.285-285
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• 1996

Cyclosporin A (CyA) is widely used in the inhibition of graft rejection in organ transplantation. However, the bioavailability of CyA after oral administration is very low due to its poor solubility and dispersability hi water. To improve the solubility of CyA, microemulsion systems were developed and its physicochemical characteristics were evaluated by phase studies, solubility and dispersability tests. Phase studies on the systems composed of ethyl oleate (EO), PPG-20 methyl glucose ether (GP-20), poloxamer 123 (PL) and water U) were carried out to make stable w/o emulsions. Besides, based on CyA solubility test in various compositions of surfactant systems, a reasonable surfactant composition (GP-20/PL=4/1) was selected to enhance its solubility.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.289-295
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• 2004

The objective of this study is to delineate removal efficiency of the MTBE in solution by $TiO_2$ photocatalytic degradation as a function of the following different experimental conditions: Initial concentration of MTBE, air flow rate in solution, $H_2O_2$ dosage and pH of the solution. Photodegradation rate was increased with decreasing initial concentration of MTBE. The removal efficiency was 82% after 180 min in the case of MTBE concentration of 100 mg/L but 100% after 180 min in the case of 20 mg/L. Removal efficiency was increased with increasing pH, $H_2O_2$ dosage and air flow rate in solution.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.110-113
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• 2008

최근 가시광선에서 응답하는 광촉매를 이용하여 저농도의 일반적인 실내 대기 오염물질 제어를 위한 적용가능성에 대해 많은 평가가 있어왔다. 가시광선에서 활성을 보이는 질소 원소가 도핑된 TiO$_2$광촉매를 이용하여 대표적인 휘발성유기화합물질들 중에 하나인 MTBE의 분해율에 대한 실험을 실시하였다. 본 연구에서 여러 가지 변수들 중에 농도와 상대습도에 따라 MTBE의 분해율에 대하여 실험하였으며, 본 연구의 실험조건하에서 질소가 도핑된 TiO$_2$ 광촉매를 통해서 효과적으로 MTBE가 제거됨을 확인 할 수 있었다.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.57-62
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• 2000

By bioassay-guided fractionation followed by chromatographic separation of the MeOH extract of Alpinia Rhizome, five COX-2 inhibitors were isolated and characterized as pinocembrin, galangin 3-methyl ether, galangin, kaempferid, and 5-hydroxy-7-(4'-hydroxy-3'-methoxyphenyl)-1-phenyl-3-heptanone.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.92-95
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• 2000

A mixed bacterial culture capable of mineralizing methyl tort-butyl ether (MTBE), other fuel oxygenates ethers, tertiary carbon alcohols, benzene and toluene was used to inoculate batch reactor and sequence batch reactor (SBR) to treat gasoline contaminated ground water containing about 60 mg/L MTBE, 5 mg/L benzene, 5 mg/L toluene, and low concentrations of several other aromatic and aliphatic hydrocarbons. Respirometery studies showed that MTBE degrading mixed culture could treat MTBE contaminated ground water with addition of nitrogen and phosphate. SBR was operated to demonstrate the feasibility of using suspended growth activated system for the treatment of ground water and to confirm that the respirometry derived kinetics and stoichiometric coefficients were useful for predicting reactor performance. Theoretical performance of the reactor was predicted using mathematical models calibrated with biokinetic parameters derived from respirometry studies.