• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.252-256
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• 2008

We investigated phase separation by adding different concentrations of MTBE, to the mixtures of naphtha, ethanol and water. The phase separation temperatures of the Naphtha-Ethanol-Water solutions have dropped when the concentration of MTBE increases more. When adding IPA and IBA to the solutions of Gasoline-Ethanol and Gasoline base-Ethanol individually, IBA shows lower temperatures of phase separation than IPA, and it shows synergistic effect when mixtures of IPA and IBA is applied.

• Elastomers and Composites
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• v.43 no.3
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• pp.191-198
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• 2008

It is said that polymer modified asphalt using polyethylene as modifier would show phase separation due to density difference and incompatibility between asphalt and polyethylene. In this study, to prevent coalescence of polyethylene in asphalt, we employed peroxides as phase separation inhibitor. On microscope, peroxides (dicumyl peroxide, lauroyl peroxide) with waste vinyl (comprising low density polyethylene) did not show phase separation, however, rheometer test showed phase separation at molecular level, i.e., polyethylene and asphalt are immiscible ultimately. Mechanical properties (tensile strength, Marshall stability, dynamic stability) showed waste vinyl-modified asphalts are highly resistant to plastic deformation and these properties are even better than those of Superphalt.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.473-479
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• 1998

Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.457-462
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• 2015

Hemicellulosic hydrolysates contain not only sugars but also several kinds of ethanol fermentation inhibitory substances such as carboxylic acids, furans and phenolic compounds. In this work, emulsion liquid membrane (ELM) was chosen as a separation technology to remove the inhibitors. A basic simulated hemicellulosic hydrolysate was composed of xylose as sugar, dilute sulfuric acid solution as solvent, and acetic acid as carboxylic acid, and furfural as furan derivative or p-hydroxybenzoic acid(HBA) as phenolic compound was added to the hydrolysate when necessary. Acetic acid and HBA as weak acid could be selectively removed from the hydrolysates in all the ELM systems considered here, but furfural as aldehyde was quite hard to remove. Also, when HBA was added to the basic simulated hemicellulosic hydrolysate, both of acetic acid and HBA in the feed phase could be selectively removed up to 99% in an ELM system with tributyl phosphate as extractant.