• Membrane Journal
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• v.20 no.4
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• pp.312-319
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• 2010

Carbon membrane materials have received considerable attention for the gas separation including hydrocarbon mixture of ingredients of the volatile organic compounds(VOCs) because they possess their higher selectivity, permeability, and thermal stability than the polymeric membranes. The use of activated carbon membranes makes it possible to separate continuously the VOCs mixture by the selective adsorption-diffusion mechanism which the condensable components are preferentially adsorbed in to the micropores of the membrane. The activated carbon hollow fiber membranes with uniform adsorptive micropores on the wall of open pores and the surface of the membranes have been fabricated by the carbonization of a thin film of phenolic resin deposited on porous alumina hollow fiber membrane. Oxidation, carbonization, and activation processing variables were controlled under different conditions in order to improve the separation characteristics of the activated carbon membrane. Properties of activated carbon hollow fiber membranes and the characterization of a gas permeation by pyrolysis conditions were studied. As the result, the activated carbon hollow fiber membranes with good separation capabilities by the molecular size mechanism as well as selective adsorption on the pores surface followed by surface diffusion effective in the recovery hydrocarbons have been obtained. Therefore, these activated carbon membranes prepared in this study are shown as promising candidate membrane for separation of VOCs.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.118-128
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• 2016

As the interest on the air-pollution is gradually rising up at home and abroad, automotive and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward two main issues : exhaust emission and PM (particulate matter) particle emissions of gasoline vehicle. Exhaust emission and PM particle of automotive had many problem that cause of ambient pollution, health effects. In addition, researcher studied the environment problems of the MTBE contained in the fuel as oxygenate additives. The researchers have many data about the health effects of ingestion of MTBE. However, the data support the conclusion that MTBE is a potential human carcinogen at high doses. Based on the oxygenated fuel additive types (MTBE, Bio-ETBE, Bio-ethanol, Bio-butanol), this paper discussed the influence of oxygen contents on gasoline fuel properties and evaporative emission characteristics. Also, this paper assessed the acceleration and power performance of gasoline vehicle for the fuel property.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.201-208
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• 2007

Functional oils (FOs) were produced from commercial diacylglycerol oil and red yeast rice extracts from 80% ethanol for 1 hr in a shaking water bath at $35^{\circ}C$ and 175 rpm. FOs contained (A) 600, (B) 1200, (C) 1800, and (D) 2280 ppm of red yeast-rice extracts, respectively. The Hunter a value and b value were risen whereas L value was reduced along with the increase of extract concentration. Content of monacolin K and total phenolic compounds in FOs significantly increased according to the increase of extract concentration. The oxidation stability of FOs was observed by Rancimat at $98^{\circ}C$. Induction time decreased according to the increase of extract concentration. The major volatile compounds of FOs were compared using the electronic nose (EN) system and solid phase microextraction (SPME) method combined with gas chromatograph/mass spectrometry (GC/MS). EN was composed of 12 different metal oxide sensors. Sensitivities (Rgas/Rair) of sensors from EN were analyzed by principal component analysis (PCA), whose proportion was 99.66%. For qualitative or quantitative analysis of volatile compounds by SPME-GC/MS, the divinylbenzene/carboxene/polydimethyl-siloxane fiber and sampling temperature of $50^{\circ}C$ were applied.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.85-90
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• 1987

This experiment was carried out to study the preparations of red pepper oleoresin, the effects of pH and heat treatment on the stabilities of capsanthin and capsaicin in oleoresin state, and the interacting effects of ascorbic acid, metal salts and EDTA on the stabilities of capsanthin in the oleoresin-linoleate aqueous model system. The results were as follows: 1. Acetone was the most effective solvent to extract capsanthin and capsaicin from red pepper powder. The yield of oleoresin extracted with acetone was 14.27%. 2. Capsaicin was more stable at high temperature than capsanthin in oleoresin state. Capsanthin and capsaicin in oleoresin state were comparatively stable in the range (ron) pH 3 to pH 8. 3. Ascorbic acid acted as a prooxidant on the capsanthin oxidation reaction at concentrations up to $10^{-3}M$, but acted as an antioxidant at $10^{-1}M$. 4. The addition of $Cu^{+2}M$ and $Fe^{+3}M$ ions at all concentration increased the prooxidant activity on the degradation of capsanthin in oleoresin state. 5. EDTA showed a strong antioxidation the stability of capsanthin in oleoresin state.

• Analytical Science and Technology
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• v.9 no.1
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• pp.43-51
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• 1996

We have discussed on the deintercalation process of Li-EaGICs and Li-EGICs synthesized under pressure and temperature by spontaneous oxidation reaction of those compounds based on the results of X-ray diffraction, thermal analysis and electrical specific resistivity analysis. According to the results of the X-ray analysis for the intercalation process, we have found that the stage 1 for Li-EaGICs and Li-EGICs were not completly formed, but their lower stages were formed mainly. And from this results of the deintercalation process, we have found that the deintercalation process did not occur any more after 4 weeks, and the Li-EGDICs have more residual lithium metals than LiEaGDICs between the graphite interlayers. According to the thermal decomposition analysis, Li-two compounds had included very hard exothermic reaction. And we have found that these compounds did not occrurred deintercalation reaction above $400^{\circ}C$. According to the results of the electrical specific resistivity measurements, Li-EGDICs have relatively lower electrical specific resistivity than Li-EaGDICs, and Li-EaGDICs showed a formation of the ideal curve. From these results, we can suggest that Li-EaGDICs have a better properties as an anode material secondary than Li-EGICs.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.802-810
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• 2018

This study estimated the effect of drone pupa meal (DPM) added as replacement of sodium nitrite (SN) and vitamin C (VC) on physico-chemical quality characteristics of emulsion-type sausages. Samples were prepared either with 150 ppm SN+200 ppm VC (control); 75 ppm SN+100 ppm VC+6.015% DPM (T1); or 12.03% DPM (T2) and then stored at $4^{\circ}C$ for 30 days. The pH value decreased (p<0.05) with increase in the levels of DPM. Moisture and protein content decreased (p<0.05) but fat and ash content increased (p<0.05) with higher levels of DPM. T1 and T2 had higher (p<0.05) saturated fatty acids content and lower (p<0.05) unsaturated and polyunsaturated fatty acids content compared to the control. Lower (p<0.05) $L^*$ and $a^*$ values and higher (p<0.05) $b^*$ and $h^{\circ}$ values were exhibited in the T1 and T2 than in the control; and $C^*$ value was the lowest (p<0.05) in T2. The TBARS content was the highest (p<0.05) in T2, especially, 2 times higher (p<0.05) than in the control. T1 and T2 had harder (p<0.05) texture compared to the control. These findings suggest that the DPM has no replacement effects against SN and VC in emulsion-type sausage, but it has negative effects on color, lipid oxidation stability, and texture.

• Journal of Environmental Science International
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• v.19 no.8
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• pp.951-960
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• 2010

Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. $0.57\;W/m^2$ Al/Graphite. Meanwhile, graphite-only electrodes produced max. $0.11\;W/m^2$ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was $0.64\;W/m^2$. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5~36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.

• Journal of the Korean Electrochemical Society
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• v.12 no.3
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• pp.263-270
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• 2009

Carbon felt surface was modified by heat or acid treatment in order to use for the electrode of a redox-flow battery. Polymers on the surface of carbon felt was removed and oxygen-containing functional group was attached after the thermal treatment of carbon felt. Thermal treatment was better for the stability of the carbon structure than the acid treatment. Oxygen-containing functional group on the thermally treated carbon felt at 500$^{\circ}C$ was confirmed by XPS and elementary analysis. BET surface area was increased from nearly zero to 96 $m^2/g$. Thermally treated carbon felt at 500$^{\circ}C$ showed lower activation polarization than the thermally treated carbon felt at 400$^{\circ}C$ and the acid-treated carbon felt in the cyclicvoltammetry and polarization experiments. The thermally treated carbon felts at 400$^{\circ}C$ and 500$^{\circ}C$ and the acid-treated carbon felt was applied for the electrode to prepare vanadium redox flow battery. Voltage efficiencies of charge/discharge were 86.6%, 89.6%, and 96.9% for the thermally treated carbon felts at 400$^{\circ}C$ and 500$^{\circ}C$ and the acid-treated carbon felt, respectively.

• KSBB Journal
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• v.9 no.3
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• pp.239-245
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• 1994

The effects of reaction temperature and the level of hydration(water activity) were studied for gas phase reactions of alcohol oxidase and alcohol dehydrogenase immobilized on DEAE-cellulose and controlled pore glass(CPG). Optimum reaction temperature zone of gas phase reaction was similar to that of aqueous phase reaction. The activity of alcohol oxidase increased dramatically and the stability decreased when the water activity was increased from 0.3 to 0.8. The apparent activation energies of the gas phase reaction decreased approaching the values obtained in the aqueous phase reaction as the water activity increased. In the both cases of alcohol oxidase and alcohol dehydrogenase, the rate constants of the gas phase reaction were lower than those of aqueous phase reaction by two orders of magnitude and these results could be correlated to the vapor-liquid equilibrium data of the substrate, ethanol.

• Economic and Environmental Geology
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• v.35 no.4
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• pp.355-368
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• 2002

The multi-storied Daewonsa stone pagoda (Treasure No. 1112) in the Sancheong, Korea was studied on the basis of deterioration and geological safety diagnosis. The stone pagoda is composed mainly of granitic gneiss, partly fine-grained granitic gneiss, leucocratic gneiss, biotite granite and ceramics. Each rock of the pagoda is highly exfoliated and fractured along the edges. Some fractures in the main body and roof stones are treated by cement mortar. This pagoda is strongly covered with yellowish to reddish brown tarnish due to the amorphous precipitates of iron hydroxides. Dark grey crust by manganese hydroxides occur Partly, and some Part coated with white grey gypsum and calcite aggregates from the reaction of cement mortar and rain. As the main body, roof and upper part of the pagoda, the rocks are developed into the radial and linear cracks. Surface of this pagoda shows partly yellowish brown, blue and green patchs because of contamination by algae, lichen, moss and bracken. Besides, wall-rocks of the Daewonsa temple and rock aggregates in the Daewonsa valley are changed reddish brown color with the same as those of the pagoda color. It suggests that the rocks around the Daewonsa temple are highly in iron and manganese concentrations compared with the normal granitic gneiss which color change is natural phenomena owing to the oxidation reaction by rain or surface water with rocks. Therefore, for the attenuation of secondary contamination, whitening and reddishness, the possible conservation treatments are needed. Consisting rocks of the pagoda would be epoxy to reinforce the fracture systems for the structural stability on the basements.