• Food Science and Preservation
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• v.15 no.3
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• pp.411-420
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• 2008

This study was performed to examine the effect of $\gamma$-irradiation on the volatile organic compounds in Houttuynia cordata Thunb.(H. cordata). 1be volatile compounds of non-irradiated and 10 kGy $\gamma$-irradiated H. cordata were isolated using SDE apparatus and analyzed by GC/MS. For each treatment the number of volatile compounds were detected at 83 and 85, respectively, 1be predominant functional groups of volatile organic compounds from H. cordata were identified as alcohols and ketones. H. cordata was mainly composed of hexahydrofarnesyl acetone (12.81 %), phytol, decanoic acid, dodecanoic acid, octadecanol, caryophyllene oxide, 2-undecanone and menthol. Houttuynum which is characteristic compound of H. cordata was found in all samples and there was no significant difference with irradiation doses. Consequently, $\gamma$-irradiation of H. cordata would be an effective process for sanitation and to increase extraction efficiency.

• Food Science and Preservation
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• v.14 no.3
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• pp.308-314
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• 2007

To investigate effects of fermentation on volatile components, we analyzed volatile organic compounds of raw and fermented Rhus verniciflua S. bark. A 50%(w/v) sugar solution was used for fermentation. Volatile organic compounds of raw and fermented Rhus verniciflua S. were extracted by the simultaneous steam distillation and extraction(SDE) method, with a mixture of n-pentane and diethylether(1:1, v/v) and analyzed by gas chromatograph-mass spectrometer. A total of 51 and 27 volatile organic compounds were detected in raw and fermented samples, respectively, and were mainly alcohols. Compounds such as ethyl acetate, 2-methyl-3-buten-2-ol, 3-methylbutanal, 1-octen-3-o1, 3-methyl-2-butanone, hexanal and pentanal were detected as the primary compounds in the raw sample. The fermented sample showed sour different volatile compounds, such as ethanol, ethyl acetate, ethyl lactate and 3-methylbutanol. Thus, a number of volatile organic compounds were synthesized after fermentation of Rhus verniciflua S. bark.

• Food Science and Preservation
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• v.23 no.7
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• pp.977-988
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• 2016

The volatile flavor compounds in five Jeju citrus fruit varieties (Cheonhyehyang, Hallabong, Jinjihyang, Hwanggeum hyang and Redhyang) were extracted by simultaneous distillation-extraction (SDE) using solvent mixture of n-pentane and diethyl ether (1:1, v/v) and analyzed by using gas chromatography-mass spectrometry (GC-MS). The number of aroma compounds were identified with : 104 (4,939.77 mg/kg) in Cheonhyehyang, 98 (3,286.38 mg/kg) in Hallabong, 105 (3,317.56 mg/kg) in Jinjihyang, 102 (4,293.39 mg/kg) in Hwanggeumhyang, and 108 (4,049.94 mg/kg) in Redhyang. The detected main volatile compounds were; limonene, sabinene, ${\beta}$-myrcene, ${\alpha}$-pinene, ${\beta}$-pinene, linalool, 4-terpineol, ${\alpha}$-terpineol, (E)-${\beta}$-ocimene and ${\gamma}$-terpinene. Among the identified volatiles compounds, ethyl-benzene, nonanol, 1-p-menthen-9-al, (E)-isocarveol, methyl salicylate, ${\alpha}$-terpinen-7-al, perilla alcohol, and ethyl-dodecanoate were detected in Cheonhyehyang. only Furthermore, ${\beta}$-chamigrene and ${\alpha}$-selinene were in Hallabong only; 3-hydroxybutanal, (E)-2-nonenal, isoborneol, octyl acetate, (E)-2-undecenal, ${\beta}$-ylangene and guaia-6,9-diene in Jinjihyang. ${\rho}$-Cymenene, ${\beta}$-thujone, selina-4,11-diene and (E,E)-2,6-farnesol in Hwanggeumhyang only; and ${\rho}$-cymen-8-ol, bornyl acetate, carvacrol, bicycloelemene, ${\alpha}$-cubebene and 7-epi-${\alpha}$-selinene in Redhyang only. This study confirmed the differences in composition and content of volatile aroma components in five varieties of Jeju citrus fruits.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1495-1502
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• 1999

Gamma-irradiated beef and chicken at the dose levels of 0.5 to 10 kGy were subjected to the detection of radiation-induced 2-alkylcyclobutanones whether irradiated or not. Radiation-induced 2-alkylcyclobutanones were extracted from beef and chicken fats, separated by florisil column chromatography and identified with GC/MS method by selected ion monitoring(SIM). When beef and chicken were irradiated, 2-dodecylcyclobutanone, 2-tetradecylcyclobutanone and 2-(5'-tetradecenyl)cyclobutanone were formed from palmitic, stearic and oleic acids. Concentrations of 2-alkylcyclobutanones were linearly increased with the dose levels of irradiation and depended upon the composition of fatty acids in beef and chicken. Radiation-induced 2-alkylcyclobutanones in irradiated beef and chicken were remarkably detected at 1 kGy and over, while these compounds were not detected in non-irradiated samples. The concentrations of radiationinduced 2-alkylcyclobutanones were relatively constant during 6 months.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.743-748
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• 2013

The purposes of this study are to prepare Hanji fiber-filter sheets using replacement liquid in water-swollen fiber with non-polar solvent such as ethanol, methanol and pentane. The experiments were studied on the selection of optimal non-polar solvent and the optimal drying method for wetted fiber and then were to know physicochemical characteristics of prepared Hanji fiber-filter sheet. The Ethanol as liquid changer in water-swollen fiber was excellent solvent and the optimal drying method for them was freeze drying served with vacuum pump. The bulk density and porosity of prepared fiber sheet from freeze dryer were 0.11-0.13 g/mL, half of natural dried fiber sheet, and 90%, respectively. The results of SEM observation for the fiber sheet prepared with natural drying or heating drying were shown very close structure of fiber wall in dry state. However, the freeze drying sheet were shown the open structure. So, the head loss of freeze drying sheet was very lower than natural drying and heating drying sheets. From the results of BTEX removal experiments, the sheets dried at water wetted condition was shown more higher efficiency than the fiber sheets dried at solvent wetted condition.

• Food Science and Preservation
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• v.12 no.4
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• pp.372-378
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• 2005

Compare with volatile organic compounds from unirradiated and irradiated dried-red pepper that is representative spice of korea. Volatile compounds from unirradiated and irradiated dried-red pepper were extracted using simultaneous distillation-extraction(SDE) apparatus and analyzed by Gas chromatography/mass spectrometer (GC/MS). A total of 61 and 62 compounds were identified from unirradiated and irradiated dried red pepper at dose of 10 kGy. These compounds included alcohols, aldehydes, furans, hydrocarbons, ketones, N-containing compounds, terpenes and micellaneous compounds. Furfural, benzaldehyde, linalool, nerolidol, ${\alpha}$-curcumene, ${\alpha}$-zingibirene were detected as the major volatile compounds from dried-red pepper. Specially, 1,3-bis[1,1-dimethylethyl]-benzene was confirmed as a marker of irradiated dried-red pepper because is not detected in unirraiatied dried-red pepper.

• Tribology and Lubricants
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• v.37 no.6
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• pp.232-239
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• 2021

Petroleum is the most consumed energy source in Korea with a usage rate of 38.7% among the available primary energy sources. The price of liquid petroleum products in Korea includes taxes such as transportation·environment·energy tax. Thus, illegal production and distribution of liquid petroleum is widespread because of its huge price difference from that of the normal product and its tax-free nature. Generally, the illegal petroleum product is produced by mixing liquid petroleum with other similar petroleum alternatives. The two kinds of gasoline, common gasoline and premium gasoline, are being distributed in Korea. The premium gasoline is often adulterated with cheaper common gasoline that lowers the octane number of gasoline. It is possible to distinguish them with their color difference, green and yellow for different grade gasoline. However, when small volume of common gasoline is added to premium gasoline, it is difficult to determine whether premium gasoline contained common grade or not. In this study, we inspect gasoline, which is illegally produced by mixing common gasoline to premium gasoline. When the ratio of mixing common gasoline is increased, premium gasoline shows decreasing absorbance at 600 nm and 650 nm under UV-Vis spectrometer. Moreover, the detected intensity (mV·s) of green dye in high performance liquid chromatography (HPLC) was decreased by common gasoline under 0.99 correlation value. The more the common gasoline is mixed, the more olefin and naphthene are detected by gas chromatography. In addition, trimethyl pentane as octane improver, paraffin and toluene are decreased by common gasoline mixing. The findings of this study suggests that illegal petroleum can be identified by analysis of components and simulated samples.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.377-384
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• 2010

We perform a comparative study to investigate the properties of the new energetic chain extender (AzPD). A series of poly(glycidyl azide)/poly(tetramethylene oxide)-based energetic segmented polyurethane (GAP/PTMG ESPU) with different chain extender, which is 3-azidopropane-1,2-diol (AzPD), 1,4-butane diol (1,4-BD), or 1,5 pentane diol (1,5-PD), was synthesized by solution polymerization in dimethyl formamide (DMF) and their phase behaviors were investigated. The ESPUs were characterized with Fourier transform infrared-attenuated total reflection spectroscopy (ATR FT-IR), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results of the ATR FT-IR analysis of the urethane carbonyl group region showed that the 'free' C=O fraction was higher in GAP/PTMG AzESPU (0.5) than GAP/PTMG BDESPU (0.44) and GAP/PTMG PDESPU (0.41) for 7 days samples after preparation and that it was similar in the range of 0.26~0.29 for three 60 days ESPU samples. DMA curves of the GAP/PTMG AzESPU for 7 days samples showed amorphous polymers, but GAP/PTMG BDESPU and GAP/PTMG PDESPU showed viscoelastic behaviors with rubbery plateau and the flow region. However, DMA curves of the GAP/PTMG AzESPU for 60 days samples showed viscoelastic behaviors with rubbery plateau and the flow region like GAP/PTMG PDESPU, but GAP/PTMG BDESPU did not show the flow region. From phase behaviors with ATR FT-IR, DSC and DMA analysis, GAP/PTMG AzESPU showed good phase-mixing between components. However, it represented viscoelastic behavior of TPE similar to GAP/PTMG PDESPM according to phase equilibrium progress with aging time.

• Journal of Animal Environmental Science
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• v.10 no.3
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• pp.141-154
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• 2004

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which the electrical power is not available. The average so]ar radiation energy is 3.488 kWh/($m^2{\cdot}day$) in Korea. In this study, the automatic control logic and system of the water pump driven by the radiation energy were studied, designed, assembled, tested and analyzed for realizing the solar powered water pump. The experimental system was operated automatically and the cycle was continued. The average quantity of the water pumped per cycle was about 5,320 cc. The cycle time was about 4.9 minutes. The thermal efficiency of the system was about $0.030\%$. The pressure level of the n-pentane vapour in flash tank was 150$\%$450 hPa(gauge) which was set by the computer program for the control of the vapour supply. The pressure in the condenser and air tank during cycles was maintained as about 600 hPa and 1,200 hPa respectively. The water could be pumped by the amount of 128kg/($m^2{\cdot}day$) with the efficiency of $0.1\%$ and the pumping head of 10 m for the average solar energy in Korea.

• Korean Journal of Environmental Agriculture
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• v.21 no.4
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• pp.261-268
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• 2002

Biodegradation of monochlorophenols by wood rot fungi such as Daldina concentrica, Trametes versicolor and Pleurotus ostreatus was evaluated by determining their resistance or toxic test and biodegradability. The metabolites of monochlorophenols were also analyzed. Among the three fungi, T. versicolor was the most resistant to 200 ppm of 2-, 3- and 4-chlorophenols, and did not show any inhibitory mycellium growth. But D. concentrica had a little inhibition effect at more than 100 ppm of 3- or 4-chlorophenol. Control cultures of P. ostreatus took even 14 days far the completion of mycellium growth, but the hyphal growth was improved when 2- or 3-chlorophenol were added to the culture. In biodegradation analysis, P. ostreatus showed the highest degradation of 2- or 3-chlorophenol, while T. versicolor was the most effective in 4-chlorophenol. D. concentrica and P. ostreatus slowly degraded 4-chlorophenol. However, T. versicolor had similar degradation capability in the three monochlorophenols, suggesting that the biode- gradation nude is dependent on the fungi as well as the type of monochlorophenol. Several metabolites such as 1,3,5-trihydroxyl benzene, 1-ethyl-1-hydroxyl pentane, 2-propenoicacid, methylmalonic acid and 2-methyl-4-keto-pentan-2-ol were found as products of primary oxidation of 2-, 3- and 4-chlorophenols by intact fungal cultures. fatty acids including tetradecanoic, heptadecanoic and octadecanoic acids were also detected The order of increase of mycellium weight during incubation were P. ostreatus > T. versicolor > D. concentrica. The pH in the culture was not constantly changed depending on incubation days, but the mycellium weight was slightly increased, indicating that the biodegradation of monochlorophenol might have low relationship with the mycellium growth Laccase activities of T. versicolor and P. ostreatus were continuously increased depending on the incubation days, suggesting that the ligninolytic enzyme activity play an important role in the biodegradation of monochlorophenol.