• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.193-197
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• 2014

Si-carbon composites as anode materials for lithium rechargeable batteries were prepared simply by mixing Si nanoparticles with carbon black and/or graphite through a solution process. Si nanoparticles were well dispersed and deposited on the surface of the carbon in a tetrahydrofuran solution. Si-carbon composites showed more than 700 mAh/g of initial capacity under less than 20% loading of Si nanoparticle in the composites. While the electrode with only Si nanoparticles showed fast capacity fading during continuous cycling, Si-carbon composite electrodes showed higher capacities. The cycle performances of Si nanoparticles in composites containing graphite were improved due to the role of the graphite as a matrix.

• Journal of the Korean Applied Science and Technology
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• v.17 no.3
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• pp.192-197
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• 2000

Rosin moeity-containing monomer was prepared by the reaction of abietic acid with 2-hydroxyethyl methacrylate in tetrahydrofuran(THF) using diethyl azodicarboxylate as a catalyst. This new monomer was photo-polymerized to give thin films in the presence of a radical type initiator. The rate of photo-polymerization and amount of cured polymer were determined using the residual yield method. A thermogravimetric analysis of the cured polymer showed that the film was stable up to 170oC, at which point the polymer film has lost 10 wt % of its weight.

• Journal of Nutrition and Health
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• v.15 no.1
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• pp.15-21
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• 1982

In this work, the quantitative estimation of fatty acids in sesame and perilla oil by high performance liquid chromatography (HPLC) was investigated. The analysis of fatty acids were separated by HPLC using a differential refractometer as a detector. With micro Bondapak $C_{18}FFAA$ column and acetonitril, chloroform and tetrahydrofuran mixture as a solvent. In the fatty acid compositions, sesame oil was composed mainly of linoleic and oleic acids 49.6 % and 34.7%. In perilla oil, the amounts of oleic, linoleic and linolenic acids were 13.6%, 14.5% and 63.8%, respectively.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.344-344
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• 2006

Poly(n-hexyl-(S)-3-methylpentylsilane) aggregates confined in microcapsules to keep the aggregation number and ranging in average polymer mass in a microcapsule from $2{\Box}10^{-16}\;to\;2{\Box}10^{-14}g$. were studied by circular dichroism measurements in ethanol (a non solvent) and tetrahydrofuran (an associative solvent at low temperature) at varioustemperatures. The size of each aggregate did not affect the optical activity because the circular dichroism was proportional to the aggregation number at the same condition. Moreover, the circular dichroism appreciably reflected the prepared method, i.e. temperature and solvent.

• YAKHAK HOEJI
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• v.32 no.4
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• pp.251-257
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• 1988

A simple and sensitive HPLC method was developed for the simultaneous determination of ten kinds of active ingredients formulated in commercial cough-cold mixtures. A group of Pseudoephedrine HCl, dl-Methylephedrine HCl, Noscapine, Chlorophenylamine maleate, Dextromethorphan HBr and Phenylpropanolamine HCl were determined at 254nm using a Novapak $C_{18}$ column with mobile phase consisting of a mixture of methanol-acetonitrile-1, 4dioxane-tetrahydrofuran-water(12 : 20 : 20 : 5 : 43, pH4.7) containing 0.013M-dioctyl sodium sulfosuccinate. The another group of Acetoaminophen, Caffeine, Guaifenesin and Ethenzamide were also determined at 254nm using a Novapak $C_{18}$ column as the stationary phase, and a mixture of methanol-1% aqueous acetic acid (3 : 7). The results indicate that these methods are accurate and precise with relative standard deviation of not more than 1% (n=5) for the above active ingredients.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.343-350
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• 2008

The fate of two cyclic ethers, THF(Tetrahydrofuran) and 1,4-Dioxane, in conventional biological wastewater treatment plants was investigated using sequential activated sludge process. Removal efficiency of THF were about 86% in average, which was greater than that of 1,4-Dioxane, 30%. However, it was not clear whether the removal of cyclic ethers in biological system was caused by microbial activity or not. Thus treatability tests were conducted by batch experiments. The effects of mixing, aeration and the addition of activated sludge on the removal of cyclic ethers were investigated in batch experiments. THF was totally removed by mixing and aeration in 24 hours while removal ratio of 1,4-Dioxane was at most 30% for the same period. This results could be ascribed to the differences in Henry's law constants between the two chemicals. In addition, biological degradation including biosorption was not obviously observed in these batch tests.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.159-167
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• 2018

Here we designed and synthesized new zinc phthalocyanines and structures were fully confirmed by spectral and elemental analysis. All phthalocyanines have a very good solubility in industrial solvents like chloroform, dichloromethane, dimethyl sulfoxide, N,N-dimethyl formamide, propylene glycol monomethyl ether acetate (PGMEA), acetone, tetrahydrofuran and acetonitrile. UV-Visible absorption and transmittance in PGMEA showed that these dyes have suitable spectral properties for LCD color filters. By Triton X surfactant study, we confirmed that these dyes are not showing any aggregation in PGMEA. We dissolved the all phthalocyanines in LCD fabricating solvent (PGMEA), and all phthalocyanines showed more than 8 wt% of solubility. Finally, all of these results concluded that PCK1, PCK2 and PCK3 are fit for LCD green color filter.

• Korean Journal of Pharmacognosy
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• v.44 no.1
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• pp.6-9
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• 2013

Two fraxinellone-based hydrogenated derivatives were prepared from fraxinellone, a well-known degraded limonin, via catalytic hydrogenation in the presence of $PtO_2$ in HOAc. Their structures were confirmed as (3S,3aR,3'R)-3a,7-dimethyl-3-(tetrahydrofuran-3-yl)-3a,4,5,6-tetrahydroisobenzofuran-1(3H)-one and (3S,3aR,2'R)-3-((R)-1-hydroxybutan-2-yl)-3a,7-dimethyl-3a,4,5,6-tetrahydroisobenzofuran-1(3H)-one on the basis of 2D NMR assignments. The $^{13}C$ NMR assignments of two quaternary carbons in the ${\alpha}$,${\beta}$-unsaturated carbonyl moiety of ${\gamma}$-butyrolactone core of fraxinellone should be revised.

• International Journal of Safety
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• v.9 no.1
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• pp.43-46
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• 2010

In the recycle process of organic solvent, the atmospheric oxygen can cause autoxidation and product peroxide. The time-saving method to evaluate the hazards has been required. In this study, oxygen pressure monitoring experiment was proposed as a new method to evaluate autoxidative resistances of solvents. Some of organic solvents were pressurized by oxygen and kept under isothermal condition. At the same time, the pressure in the vessel tracked. Iodometrical titration, thermal analysis and spectroscopic analysis were performed to measure peroxide concentration, the heat of reaction and chemical bonding change. From the results that THF has larger oxygen consumption rate than CPME, it is considered that autoxidative resistance of THF is lower than that of CPME. This method enables to obtain results in shorter time than other methods. These experimental results were consistent with the previous research with longer test durations [1-2].

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.429-437
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• 2008

The p-dioxanone can be used to make a variety of commercially useful products particularly where biodegradability is desired, such as fibers, sutures, molded articles, containers, medical devices and surgical clips, film and compostable trash bags. The mole fraction solubility of p-dioxanone in various solvents such as acetone, ethylacetate, tetrahydrofuran, methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol were measured over the temperature range from 263.05 K to 288.45 K. The solubility of p-dioxanone increases with increasing polarity of the solvents.