• Proceedings of the Korean Vacuum Society Conference
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• 2001.07a
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• pp.139-139
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• 2001

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.1
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• pp.3-18
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• 1997

This study was conducted to evaluate desorption efficiencies by types of desorption solvent for polar and non-polar organic compounds collected on activated charcoal tubes. Analytes tested were toluene, m-xylene, isobutyl alcohol, n-butyl alcohol, cellosolve acetate, and butyl cellosolve. Three different concentration levels of spiked sample were made. Types of cosolvent mixed with the main solvent, $CS_2$, were methanol, pentanol, and dimethylformamide (DMF) and the cosolvent for methylenechloride was methanol. The amounts of cosolvent added to the main solvent were 1, 5, and 10% by volume (v/v%), respectively. The results were as follows: 1. For all mixed solvents except 1% methanol and 1% pentanol with $CS_2$, desorption efficiency significantly increased, compared with that of $CS_2$ alone. 2. Desorption efficiency increased by increasing analyte loading on charcoal tube regardless of mixed solvents used and the material polarity. 3. For all cosolvents mixed with $CS_2$ by 1% and 5% volume, desorption efficiency for non-polar compound was significantly higher than that of polar compound. For the 10% mixed solvents and the methylenechloride mixed with methanol, the results were opposite. 4. The lowest mean percent bias of 4.79% was obtained from the 5% DMF-$CS_2$ mixed solvent, followed by 4.82% from the 10% DMF-$CS_2$ solvent while the highest bias of 23.26% was from the solvent of $CS_2$ alone. Based on the results of this study, in order to increase desorption efficiency, it is recommended to add such cosolvents as methanol, pentanol, and DMF to $CS_2$, preferably 5% by volume for analyzing polar compounds collected in charcoal tubes.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.124-128
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• 1999

TK6 was able to produce NAD+ dependent cyclohexanol dehydrogenase(CDH). The production of CDH was increased rapidly at the logarithmic phase and maintained constantly after that. In order to investigate the inductive production of CDH by various substrates, the bacteria were grown in the media containing alicyclic hydrocarbons and various alcohols as a sole crabon souce. CDH was induced most actively by cyclohexanol. Cyclohexanone and cyclohexane-1,2-diol also induced remarkable amount of CDH but it was induced weakly by 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 2-propanol, and 2-methyl-1-propanol. The dehydrogenase of the bacteria grown in the media containing cyclohexanol were weakly active for various alcohols, but the dehydrogenase activity for cyclohexane-1,2-diol was twice as much as that for cyclohexanol. Activity staining on PAGE of the cell free extract of Rhodococcus sp. TK6 grown in the media containing cyclohexanol reveals at least sever isozyme bands of CDH and we nominated the four major activity bands as CDH I, II, III, and IV. CDH I was strongly induced by cyclohexanol, cyclohexane-1,2-diok, but its activity was specific to cyclohexane-1,2-diol and 1-pentanol. CDH IV was strongly induced by cyclohexanol and cyclohexane-1,2-diol, and its activity was very specific to cyclohexane-1,2-diol.

• Journal of Pharmaceutical Investigation
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• v.27 no.3
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• pp.233-239
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• 1997

Glibenclamide is a second generation sulfonylurea that is orally active as a hypoglycemic drug. It exists as a crystalline powder which is sparingly soluble in water. It was investigated that the potential of glibenclamide to exhibit polymorphism. Three polymorphic modifications (form 1, form 2 and form 3) and three pseudopolymorphic modifications (form 4, form 5 and form 6) were obtained by crystallization from different organic solvents. The isolated crystal forms were characterized by differential scanning calorimetry(DSC), thermogravimetric analysis(TGA) and X-ray crystallography powder diffraction studies. Form 1 was the most stable and melt at $175.4^{\circ}C$. Form 2 was metastable and melt at $151.0^{\circ}C$. Form 3 was a new polymorphic modification because it was different from form 1 and form 2 in X-ray crystallography powder diffraction data. Form 4 was a 1 : 7(toluene : glibenclamide) toluene solvate; form 5 was a 1 : 5(toluene : glibenclamide) toluene solvate; form 6 was a 3 : 8(pentanol : glibenclamide) pentanol solvate. All forms were stable in 3-month storage under 0% or 100% humidity condition. The dissolution rate of form 4 was highest; those of form 2, form 3, form 1, form 5 and form 6 followed.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.767-772
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• 2023

In this study, combustion experiments were conducted at various engine speeds under full-load conditions using a single-cylinder diesel engine by blending butanol, pentanol, and octanol with diesel at a volume ratio of 10%. Experimental results revealed that higher alcohol-diesel blends resulted in lower brake torque and brake power than pure diesel due to the lower calorific value and the cooling effect during evaporation. An evident improvement in the brake thermal efficiency of the blended fuels was observed at engine speeds below 2,000 rpm, with the butanol blend exhibiting the highest thermal efficiency overall. Furthermore, the brake-specific fuel consumption of the higher alcohol-diesel blends was lower than that of pure diesel at speeds below 2,200 rpm. When using blended fuels, the exhaust gas temperature decreased under lean mixture conditions due to heat loss to the air and the cooling effect from fuel evaporation.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.118-124
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• 2000

Lipoxygenase(LOX) in soybeans is responsible for beany flavors which limit the wide utilization of soybeans to foods. This study was conducted to analyze beany flavor compounds of the normal Hwagkeumkong and LOX-deficient soybean cultivars, Jinpumkong which lacks L-2, L-3, and Jinpumkong 2 which lacks all L-1, L-2, L-3. Using the combination of dynamic headspace sampling and gas chromatography-mass selective detector(DHS-GC-MSD) for analyzing volatile compounds, hexanal and hexanol were identified in whole soy flour of all three soybena cultivars. Hwangkeumkong had more volatile compounds than Jinpumkong and Jinpumkong 2 in defatted soy flour. Hexanal and acetic acid were identified in soy milk of all three soybean cultivars but Hwangkeumkong had more volatile compounds than Jinpumkong 2. From the analysis with a static headspace sampling(SHS) and GC-MSD the major compounds were hexanal, acetic acid, 1-hexanol, and 1-octen-3-ol. The content of acetic acid was similar among three cultivars. But contents of hexanal and pentanal in Jinpumkong 2 were less than that of Jinpumkong and Hwangkeumkong. Using GC-FID, Jinpumkong 2 had less contents of hexanal and pentanol than Hwangkeumkong in whole soy flour and defatted soy flour. In this study, LOX-deficient soybean cultivars showed less hexanal, pentanol and other compounds than the normal Hwangkeumkong. However quite amount of beany flavor compounds were identified in Jinpumkong and Jinpumkong 2. So further studies are required to characterize LOX isozymes, to understand the mechanisms of beany flavors production, and to develop some other methods for removing beany flavor.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.3
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• pp.43-48
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• 1991

Activation energies of alcohol fuels have been determined through droplet combustion and extinction experiments using droplet suspension technique in a low pressure environment to minimize the effect of buoyance. Results show that the activation energies determined are 41.4 kcal/mol for ethanol, 47.6 for 1-propanol, 48.4 for 1-butanol, 40.0 for 2-butanol, 48.0 for 1- pentanol, 50.8 for 1-hexanol and 51.7 for 1-decanol.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.299-305
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• 1991

Volatile aroma concentrates of four oyster mushrooms cultivated in Korea were obtained by the simultaneous distillation-extraction method. The volatile components were identified by the combined capillary gas chromatography-mass spectrometry and compared with the of retention data on GC of those authentic compounds. About 54 volatile compounds were identified in each of the four edible oyster mushrooms. The main compounds in Pleurotus ostreatus ASI 201 were 1-octen-3-ol, 3-octanone, 3-octanol, in Pleurotus sajor-caju, 1-octen-3-ol, 3-octanone, 1,5-octadien-3-one, 3-octanol, in Pleurotus florida-ostreatus-ostreatus, 1-octen-3-ol, n-hexanol, 3-octanone, 3-octanol, phenol, and in Pleurotus ostreatus (Ae-Neutari), 1-octen-3-ol, n-pentanal, n-hexanol, n-pentanol, 3-octanone, 3-octanol, 1,5-octadien-3-one, respectively. The mushrooms worked were rich in an alcohols and carbonyl compounds containing $C_8$ compounds. The peak area ratio of $C_8$ compounds in aroma concentrates were 56.60% in Pleurotus ostreatus ASI 201, 72.46% in Pleurotus sajor-caju, 54.84% in Pleurotus florida-ostreatus-ostreatus and 35.85% in Pleurotus ostreatus (Ae-Neutari ), respectively.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.52-56
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• 1993

Flavor compounds formed in the ramyon fried in palm oil at $148-150^{\circ}C$ for 1 minute during storage at $65^{\circ}C$ were isolated and identified by gas chromatography-mass spectrometry. Their changes in the amount when the ramyon was stored at 20, 40 and $65^{\circ}C$ were also studied by using static headspace gas chromatography. Pentane, hexane, butanal, heptane, 1-pentanol, hexanal, and octane were formed during $65^{\circ}C$ storage of the ramyon and they were thought to be from linoleic and oleic acid present in ramyon. Formation of the flavor compounds was shown to increase with the storage temperature and/or storage time. Hexanal showed the highest correlation with the sensory score(r=0.87).

• Applied Biological Chemistry
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• v.27 no.1
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• pp.14-20
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• 1984

Volatiles from Mallus pumila Miller Var. Fuji, Ralls Janet and Jonathan during maturity were examined. The volatiles of apples were collected by the headspace trapping method using. Tenax GC and identified by gas liquid chromatography and GC-mass spectrometry. Among over 34 GLC peaks, 23 esters, 9 alcohols and 2 aldehydes were identified. The quantity of volatiles produced was increased in proportion to the degree of maturity, and 1-butanol, isobutyl butyrate, 2-pentanol, ethyl valerate and hexanal were major.