• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.3
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• pp.334-342
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• 1998

In this experimental study, methanol was chosen as a system material for a long -distance heat transportation. Not only transition metals but also noble metals were investigated as an active component, and several metal oxides, such as ${\gamma}$-$Al_2$,$O_3$, $SiO_2$, etc. as a support. In general, transition metal catalysts absorbed more heat than noble metal catalysts. The amount of heat absorption and CO selectivity depends on temperature and methanol partial pressure, and 25$0^{\circ}C$ Ni/$SiO_2$ catalyst showed the best result for methanol decomposition reaction.

• Journal of Energy Engineering
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• v.19 no.3
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• pp.195-202
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• 2010

A third of primary energy is lost as a waste heat. To improve this inefficient use of energy, systems using chemical reaction have been suggested and studied. In this study, methanol decomposition/synthesis reaction as a chemical reaction was selected for long time heat storage and long distance heat transport system because of safe, cheap and gaseous product. The purpose of this study is to find the optimal conditions in the methanol decomposition and synthesis reactions for long distance heat transport. Several parameters such as reaction temperature, pressure, $H_2$/CO ratio, space velocity, catalyst particle size were tested to find the effects on the reaction rates for the methanol synthesis. And the reaction temperature, space velocity, catalyst particle size were tested to find the effects on the production concentration for the methanol decomposition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.116-124
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• 2011

In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.65-71
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• 1996

Decomposition reaction of methanol was conducted on Ni-Cu/SiO$_2$catalysts with several variables. Variables used in this study are S.V(Space Velocity), partial pressure of methanol, reaction temperature, and composition rate of Ni-Cu. The range of S.V is 10,000-30,000h$\^$-1/, the temperature range is 150-400$^{\circ}C$ and values of Cu/(Ni＋Cu) are 0, 0.25, 0.5, 0.75, and 1. Over Ni/SiO$_2$, and Ni-Cu/SiO$_2$, the conversion rate of decomposition reaction of methanol arrived at 100% with increasing of temperature. At this time the selectivity of CO on Ni/SiO$_2$, was suddenly decreased, but on Ni-Cu/SiO$_2$, it was still sustained highly. The main products of reaction were CO and H$_2$, and by-products were CO$_2$ and CH$_4$mainly.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.216-220
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• 2006

Thermophillic fungus Thermoascus aurantiacus showed excellent growth and produced high amount of alcohol oxidase and catalase in a pectin medium. Besides, the strain produced enzymes which related with pectin or alcohol decomposition. We detected extracellular pectin esterase (EC 3.1.1.11) activity and, both intracellular and extracellular pectinase (EC 4.2.2.10) activity, as pectinolytic enzymes produced by T. aurantiacus. The production of methanol decomposition enzymes, such as alcohol oxidase (AOD, EC 1.1.3.13), alcohol dehydrogenase (ADH, EC 1.1.1.1), formaldehyde dehydrogenase (FADH, EC 1.2.1.1) and formate dehydrogenase (FDH, EC 1.2.1.2) follows by pectin esterase reaction which is converted to methanol. We concluded that T. aurantiacus has pectinolytic and alcohol - oxidative enzymological mechanism which produced carbon dioxide as a final material, started from pectin.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1286-1291
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• 2017

In this study, Pyracantha angustifolia (Franch.) C. K. Schneid was extracted with 70% methanol at room temperature for 48 hrs and concentrated under reduced pressure to measure its total polyphenol contents; furthermore, the effect of electron donating ability was examined. Methylene chloride, ethyl acetate, and methanol were used to fractionate the extract to testify total polyphenol contents, electron donating abilities, the removal abilities of superoxide radical as well as hydrogen peroxide. The total polyphenol contents were $2007.30{\pm}109.28{\mu}g\;GAE/mL$ in 70% methanol extract, $273.39{\pm}10.19{\mu}g\;GAE/mL$ in methylene chloride fraction, $80.57{\pm}0.64{\mu}g\;GAE/mL$ in ethyl acetate fraction, and $1,160.87{\pm}44.71{\mu}g\;GAE/mL$ in methanol fraction. The total polyphenol contents showed significant differences (p<0.05) between the solvents. The electron donating ability was $79.07{\pm}7.31%$ for 70% methanol extract, $22.34{\pm}0.64%$ for methylene chloride fraction, $5.33{\pm}0.28%$ for ethyl acetate fraction, and $32.26{\pm}1.10%$ for methanol fraction. The electron donating abilities were significantly different(p<0.05) between the solvents. The removal ability of superoxide radical was $0.018{\pm}0.003$ for 70% methanol extract, $0.007{\pm}0.002$ for methylene chloride fraction, $0.0147{\pm}0.003$ for ethyl acetate fraction, and nothing for methanol fraction. The measurement of hydrogen peroxide decomposition was $0.022{\pm}0.0046$ for 70% methanol extract, $0.0027{\pm}0.0015$ for methylene chloride fraction, $0.0037{\pm}0.0012$ for ethyl acetate fraction, and $0.0009{\pm}0.0001$ for methanol fraction.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2657-2662
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• 2013

Multiwalled carbon nanotube (MWCNT)-g-poly (aniline-co-2,5-diaminobenzenesulfonic acid) (DABSA) reinforced Nafion$^{(R)}$ nanocomposite membranes were prepared and characterized for direct methanol fuel cells (DMFCs). The nanocomposite membranes with approximately $90{\mu}m$ thickness were prepared by the water assisted solution casting method. To evaluate the properties of nanocomposite membranes for DMFC applications, the nanocomposite membranes were characterized by methanol and water uptake, thermal stability, and ion exchange capacity (IEC). Furthermore, oxidative stability measurements in terms of the hydrogen peroxide decomposition rate that represent the oxidative stability of the membranes were examined. The methanol uptake values of the nanocomposite membranes were dramatically decreased compared to the cast Nafion$^{(R)}$ membranes. The IEC values of the nanocomposite membranes were increased about 30% compared to the cast Nafion$^{(R)}$ membrane.

• The Korean Journal of Food And Nutrition
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• v.31 no.4
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• pp.543-548
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• 2018

This study was conducted to investigated the antioxidant activities of extract for Megmoondong fruit. Liriope platyphylla L. was extracted with 70% methanol at room temperature for 48 hr and concentrated under reduced pressure to measure its total polyphenol contents and electron donating ability. The total polyphenol contents were $7,253.50{\pm}335.43{\mu}g\;GAE/mL$ in 70% methanol extract, $1,239.77{\pm}9.30{\mu}g\;GAE/mL$ in methylene chloride fraction, $919.30{\pm}50.83{\mu}g\;GAE/mL$ in methanol fraction, $105.44{\pm}2.04{\mu}g\;GAE/mL$ in ethyl acetate fraction. The total polyphenol contents showed significant differences (p<0.05) between the solvents. The electron donating ability was $69.17{\pm}12.61%$ for 70% methanol extract, $33.11{\pm}1.77%$ for methylene chloride fraction, $5.19{\pm}2.59%$ for ethyl acetate fraction, and $20.16{\pm}1.04%$ for methanol fraction. The electron donating abilities were significantly different (p<0.05) between the solvents. The removal ability of superoxide radical was $0.0174{\pm}0.0007$ for 70% methanol extract, $0.0164{\pm}0.0007$ for methylene chloride fraction, $0.0172{\pm}0.0007$ for ethyl acetate fraction, and nothing for methanol fraction. The measurement of hydrogen peroxide decomposition was $0.0985{\pm}0.1021$ for 70% methanol extract, $0.0896{\pm}0.0893$ for methylene chloride fraction, $0.0115{\pm}0.0085$ for ethyl acetate fraction, and $0.0170{\pm}0.0180$ for methanol fraction. The Liriope platyphylla L. extracts obtained from methylene chloride showed significantly relevant results in the total polyphenol contents and electron donating ability, which was higher than the original extract.

• Bulletin of the Korean Chemical Society
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• v.9 no.1
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• pp.55-59
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• 1988

The gaseous carbon dioxide has been irradiated with Co-60 gamma-radiation in the presence and absence of various alcohols, and the radiolysis products analyzed by gas chromatography. Experimental results indicate that no detectable amount of carbon monoxide is formed when pure carbon dioxide is irradiated. By adding small quantities of alcohols to carbon dioxide, however, considerable amount of carbon monoxide, ketones, alcohols and other organic products have been detected. By adding 0.1% of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-l-propanol, 2-butanol, and 2-methyl-2-propanol, G(CO) values obtained are 4.4, 4.5, 5.2, 4.4, 5.2, 5.0, 4.7 and 4.1, respectively. These high yields of carbon monoxide suggest that the oxidation reactions of carbon monoxide may be suppressed by scavenging oxygen atom with the alcohols. The main radiolytic decomposition reactions of the alcohols present in small quantity in carbon dioxide may be supposed to be the reactions with the oxygen atom produced by the radiolysis of carbon dioxide. The decomposition reactions seems to follow pseudo-first order kinetics with respect to the alcohols. The decomposition rate measured with 2-propanol is the fastest and that with 2-methyl-2-propanol the slowest. The mechanisms of the radiolytic decomposition reactions of the alcohols present in carbon dioxide are discussed on the basis of the experimental results of the present study.

• Carbon letters
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• v.25
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• pp.33-42
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• 2018

Activated carbon (AC) was modified by ammonium persulphate or nitric acid, respectively. AC and the modified materials were used as catalyst supports. The oxygen groups were introduced in the supports during the modifications. All the supports were characterized by $N_2$-physisorption, Raman, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis. Methanol synthesis catalysts were prepared through wet impregnation of copper nitrate and zinc nitrate on the supports followed by thermal decomposition. These catalysts were measured by the means of $N_2$-physisorption, X-ray diffraction, XPS, temperature programmed reduction and TEM tests. The catalytic performances of the prepared catalysts were compared with a commercial catalyst (CZA) in this work. The results showed that the methanol production rate of AC-CZ ($23mmol-CH_3OH/(g-Cu{\cdot}h)$) was higher, on Cu loading basis, than that of CZA ($9mmol-CH_3OH/(g-Cu{\cdot}h)$). We also found that the modification methods produced strong metal-support interactions leading to poor catalytic performance. AC without any modification can prompt the catalytic performance of the resulted catalyst.