• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.456-460
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• 1999

The YHB radial distribution functions of a linear gas molecule CO were calculated by a computer within the Stockmayer molecular potential molel, which assumed thc CO molecule as a simple dipolar molecule. To examine the validity of the obtained YHB radial distribution of CO gas molecule, the density dependent pressures of CO at several temperatures were also calculated. The calculated pressures showed a good agreement with literially known experimental CO pressure data. The temperatures examined were 273, 298, and 373 K and the densities were up to $0.013/{\AA}^3$ (maximum pressure = 1000 atm). Since the calculated pressures showed a good agreement with the experimental values, the obtained YHB radial distribution functions of CO molecule seemed good enough to obtain and predict various equilibrium physical and chemical quantities of CO molecule sensitive to density such as pressure. It was also found that in CO gas system the dipole-dipole interaction is effective up to approximately 2.5 molecular diameter.

• Journal of the Korean Wood Science and Technology
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• v.25 no.3
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• pp.37-42
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• 1997

This study was carried out to track the heated-air flows within the tree disk through measuring the distribution of wood temperatures during explosing the 7.5mm-thick Japanese cedar disk and to investigate the effects of the time for the first explosion cycle and the number of explosion cycles on the improvement of permeability of tree disk. If the tree disk are explosed when the temperatures of the shell and core of it are not equilibrium yet, all of the inflated airs in the shell after explosion don't flow out toward the autoclave and some of them flow into the core of which the air pressures are lower than those of the shell. It is very effective for the improvement of permeability of tree disk to make the first explosion cycle when the temperatures of the shell and the core equilibrate at the setting temperature of steam in the autoclave. The more tree disks were explosed under the same conditions of first explosion, the more their permeabilities were improved.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.230-236
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• 2017

Solubility data of carbon dioxide ($CO_2$) in poly(ethylene glycol) dimethyl ether (PEGDME) are presented at pressures up to about 50 bar and at temperatures between 303 K and 343 K. The solubilities of $CO_2$ were determined by measuring the bubble point pressures of the $CO_2+PEGDME$ mixtures with various compositions using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. To observe the effect of the PEGDME molecular weight on the $CO_2$ solubility, the $CO_2$ solubilities in PEGDME with two kinds of molecular weight were compared. As the equilibrium pressure increased, the $CO_2$ solubility in PEGDME increased. On the other hand, the $CO_2$ solubility decreased with increasing temperature. When compared at the same temperature and pressure, the PEGDME with a higher molecular weight gave smaller $CO_2$ solubility on a mass fraction and molality basis, but gave greater $CO_2$ solubilities on a mole fraction basis.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E1
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• pp.10-15
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• 2007

The gas hydrates are probably most sensitive to climate change since they are stable only under specific conditions of high pressure and low temperature. One of the main factors responsible for formation of gas hydrates is the saturation of the gases with water vapor. Quantitative phase equilibrium data and understanding of the roles of water component in the phase behavior of the heterogeneous water-hydrocarbon-hydrate mixture are of importance and of engineering value. In this study, the water content of ethylene gas in equilibrium with hydrate and water phases were analyzed by theoretical and experimental methods at temperatures between 274.15 up to 291.75 K and pressures between 593.99 to 8,443.18 kPa. The experimental and theoretical enhancement factors (EF) for the water content of ethylene gas and the fugacity coefficients of water and ethylene in gas phase were determined and compared with each other over the entire range of pressure carried out in this experiment. In order to get the theoretical enhancement factors, the modified Redlich-Kwong equation of state was used. The Peng-Robinson equations and modified Redlich-Kwong equations of state were used to get the fugacity coefficients for ethylene and water in the gas phase. The results predicted by both equations agree very well with the experimental values for the fugacity coefficients of the compressed ethylene gas containing small amount of water, whereas, those of water vapor do not in the ethylene rich gas at high temperature for hydrate formation locus.

• Clean Technology
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• v.13 no.3
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• pp.173-179
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• 2007

In this study the amount of equilibrium sorption of C.I. Disperse Yellow 54 dye in the polymeric textiles such as PTT (poly(trimethylene terephthalate)) and PET (poly(ethylene terephthalate)) textiles was measured in the presence of supercritical carbon dioxide at different temperatures, pressures, and time. The amount of dye sorption increased with temperature and pressure in both PTT and PET textiles, but the increasing rate decreased with pressure. The PTT textile has much larger dye sorption than PET textile. The increasing rate of dye sorption decreased with time at same temperature and pressure for both PTT and PET textiles.

• Journal of the Korean Chemical Society
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• v.27 no.1
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• pp.9-17
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• 1983

The effect of pressures and temperatures on the stabilities of the durene-iodine charge transfer complex have been investigated through ultraviolet spectrophotometric measurements in n-hexane. The stabilities of complexes were measured at 25, 40 and $60^{\circ}C$ under $1{\sim}1600$ bars. The equilibrium constant of the complex was increased with pressure and decreased with temperature raising. The absorption coefficient was increased with both pressure and temperature. Changes of volume, enthalpy, free energy and entropy for the formation of complexes were obtained from the equilibrium constants. The red-shift observed at a higher pressure, the blue-shift at a higher temperature, and the relation between pressure and oscillator strength were discussed by means of thermodynamic functions.

• Journal of the Korean Chemical Society
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• v.24 no.6
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• pp.405-412
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• 1980

The effect of pressures and temperatures on the stabilities of the mesitylene-iodine charge transfer complex have been investigated through ultraviolet spectrophotometric measurements in n-hexane. The stabilities of complexes were measured at 25, 40 and $60^{\circ}C$ under 1∼1600 bars. The equilibrium constant of the complex was increased with pressure and decreased with temperature raising. The absorption coefficient was increased with both pressure and temperature. Changes of volume, enthalpy, free energy and entropy for the formation of complexes were obtained from the equilibrium constants. The red-shift observed a higher pressure, the blue-shift at a higher temperature and the relation between pressure and oscillator strength were discussed by means of thermodynamic functions.

• Journal of the Korean Chemical Society
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• v.22 no.4
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• pp.245-253
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• 1978

The effect of pressures and temperatures on the stabilities of the p-xylene-iodine charge transfer complex have been investigated through ultraviolet spectrophotometric measurements in n-hexane. The stabilities of complexes were measured at 25, 40 and $60^{\circ}C$ under 1∼1,600 bars. The equilibrium constant of the complex was increased with pressure and decreased with temperature raising. The absorption coefficient was increased with both pressure and temperature. Changes of volume, enthalpy, free energy and entropy for the formation of complexes were obtained from the equilibrium constants. The red-shift observed a higher pressure, the blue-shift at a higher temperature and the relation between pressure and oscillator strength were discussed by means of thermodynamic functions.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.105-114
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• 2004

This study investigated the thermal behavior of the nuclear graphite waste generated from the decommissioning of the Korean nuclear research reactor, The first part study investigated the decomposition rate of the nuclear graphite waste up to $1000^{\circ}C$ under various oxygen partial pressures using a thermo-gravimetric analyzer (TGA). Tested graphite waste sample not easily destroyed in the oxygen-deficient condition. However, the gas-solid oxidation reaction was found to be very effective in the presence of oxygen. No significant amount of the product of incomplete combustion was formed even in the limited oxygen concentration of 4% $O_2$. The influence of temperature and oxygen partial pressure was evaluated by the theoretical model analysis of the thermo-gravimetric data. The activation energy and the reaction order of graphite oxidation were evaluated as 128 kJ/mole and 1.1, respectively. The second part of this study investigated the behavior of radioactive elements under graphite oxidation atmosphere using thermodynamic equilibrium model. $^{22}Na$, $^{134}Cs$ and $^{137}Cs$ were found be the semi-volatile elements. Since volatile uranium species can be formulated at high temperatures above $1050^{\circ}C$, the temperature of incinerator furnace should be minimized. Other corrosion/activation products, fission products and uranium were found to be the non-volatile species.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.529-541
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• 1996

The granitic rocks, so called Masanite, characterized by the micrographic, mylmekitic and perthitic textures, and zonal structure of the plagioclase in the Masan, Changwon and Jinhae areas belong to normal granite and granodiorite based on the modal analysis. These petrographic features strongly suggest the shallow emplacement of the plutons which are defined a typical calc-alkaline suite and I-type granitoids. The pressures of emplacement of the granitic plutons using the amphibole geobarometer were calculated to be 1.2kbar in the Masan area and 1.4kbar in the Changwon area. Their amphibole-plagioclase equilibrium temperatures were obtained to be $638^{\circ}C$ for the former ones and $724^{\circ}C$ for the latter. Homogenization temperatures and salinities for the type HI and IV fluid inclusions in quartz range from 298 to $541^{\circ}C$ (av. $425^{\circ}C$), and 10.5 to 34.6 wt.% NaCl (av. 28.2 wt.% NaCl), respectively. Gas compositions of the granitic rocks with fairly high $CO_2$ concentration relative to CH, correspond to the magnetite series granite of the mantle source. The terminology of the Masanite is not recommended usage. Because it is hard to discriminate in terms of petrological and petrogenetical characteristics between the Masanite and the Bulguksa granites in the Kyeongsang basin.