• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.570-572
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• 1990

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.156-158
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• 1993

• Bulletin of the Society of Naval Architects of Korea
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• v.58 no.1
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• pp.8-13
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• 2021

• Journal of Soil and Groundwater Environment
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• v.12 no.2
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• pp.20-26
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• 2007

The microbial community properties of groundwater samples contaminated with landfill leachates were examined using Ecoplate including 31 sole carbon sources. The samples were KSG1-12 (leachate), KSG1-16 (treated leachate), KSG1-07 (contaminated groundwater), KSG1-08 (contaminated groundwater), and KSG1-13 (uncontaminated groundwater). Among the carbon sources used as substrates, 2-hydroxy benzoic acid, D,L-$\alpha$-glycerol phosphate, and D-malic acid were not utilized in any sample, while D-xylose, D-galacturonic acid, L-aspargine, tween 80, and L-serine were utilized in all 5 samples. The rest of substrates showed very different patterns among the samples. Average well color development (AWCD) analysis demonstrated that the potential activity on 31 substrates was in the order of KSG1-16 > KSG1-12 > KSG1-07 > KSG-08 > KSG1-13, which generally agrees with the degree of pollution, except KSG1-16. Principal component analysis (PCA) on similarity between samples showed two groups (KSG1-12, -07 and -08 vs KSG1-16 and -13), coinciding with contaminated and uncontaminated groups. Shannon index showed that the microbial diversities were similar among the samples.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.13-13
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• 2007

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1997.04a
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• pp.13-13
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• 1997

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.113-118
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• 2017

BACKGROUND: The carbon (C) isotope ratio (${\delta}^{13}C$) of dissolved organic C (DOC) is an indicator of water pollution source. In this study, the potential use of two pre-treatments for the ${\delta}^{13}C$ analysis, alkaline persulfate oxidation coupled with carbonate precipitation (precipitation) and freeze drying (drying), were compared to suggest a more feasible pre-treatment method. METHODS AND RESULTS: Two reference materials with different ${\delta}^{13}C$ values were used for the experiments; chemical grade glucose ($-12.0{\pm}0.02$‰) and pig manure compost extract ($-23.3{\pm}0.04$‰). In the precipitation method, the measured ${\delta}^{13}C$ values were consistently lower than the theoretically calculated values as dissolved $CO_2$ could not be removed due to the alkaline property of the reagents and the dissolution of air $CO_2$ into the alkaline solution. The drying method also resulted in more negative ${\delta}^{13}C$ than the calculated ${\delta}^{13}C$; however, the difference was systematic ($3.9{\pm}0.3$‰) and there was a strong correlation (${\delta}^{13}C_{calculated}=0.87{\times}{\delta}^{13}C_{measured}-0.624$, $r^2=0.98$) between the calculated and measured ${\delta}^{13}C$. Calibration of ${\delta}^{13}C$ using the relationship between the calculated and the measured ${\delta}^{13}C$ values produced reliable and accurate ${\delta}^{13}C$ values. CONCLUSION: Our results suggest that the drying method is more accurate pre-treatment method to minimize the influence of air $CO_2$ compared to the precipitation method for the determination of ${\delta}^{13}C$ of DOC.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.201-209
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• 2006

Various desorption methods were investigated for an activated carbon and zeolite 13X packed bed after benzene adsorption. Desorption experiments using hot steam, purge gas, and evacuation were performed. As a result, the desorption with hot steam showed the best performance. Hot steam makes the temperature in the adsorption column increase and gives arise to the desorption. Drying process should be accompanied to increase the efficiency because steam vapor prevents the adsorption later. The vacuum desorption showed poor performance and it reveals that temperature swing operation is more effective than pressure swing operation. In the purge gas desorption, good performance was achieved using evacuation.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.709-714
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• 1993

The cetane number is a measure of ignition quality, specifically ignition delay, of diesel fuel. It is an engine measure of kinetic phenomena. The ignition quality such as kinetic behavior does correlate with the molecular structure, the carbon type structural composition. In fact, we use the group additivity rule to dissect the molecular structures and predict cetane number. In this study, the use of $^{13}C-Nuclear$ Magnetic Resonance spectroscopic measuring the molecular structure and group additivity rule at different diesel fuels, whose cetane numbers were determined on a number of standard cetane rating engines is proposed to predict cetane numbers that relate the carbon type structural composition. The effect of the molecular structures on the cetane numbers has been studied.

• Journal of Ginseng Research
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• v.19 no.3
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• pp.225-230
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• 1995

The effect of long-term ginseng (Panax ginseng C.A. Meyer) administration on the clearance of carboxyhemoglobin (CO-Hb) and the property of blood gases was investigated in rats. Rats were received ginseng water extract (0.025% in drinking water) for 42 weeks starting at the age of 6 weeks. They were exposed to the diluted mainstream smoke generated from 15 filter cigarettes for 20 min in a round polycarbonate chamber (D37 cmXH13 cm). Under this condition, the mean CO-Hb content of control and the ginseng-treated rats immediately after the exposure was nearly the same as 13.8$\pm$2.9 f) and 13.9$\pm$1.6%, respectively. However, CO-Hb was more rapidly removed from blood in the ginseng treated rats than in untreatEd control with the laps of time, namely, its biological half life In the former was 36.9$\pm$1.5 min and in the latter was 56.9$\pm$13.2 min. Although long-term ginseng treatment did not affect the content of hemoglobin and blood pH of rats, it slightly increased blood oxygen content and its partial pressure value, and decreased levels of carbon dioxide and bicarbonate. These results suggest that long-term administration of rats with ginseng extract accelerate the elimination of CO from the blood. This effect seems to be related to the enhancement of oxygen consumption of the rat by a certain action of ginseng components as previously reported.