• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.13-19
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• 2012

The long-lived fission products $^{79}Se$ and $^{99}Tc$ have been considered as the major concern nuclides for the disposal of radioactive waste because of their high solubilities and the existence of anionic species in natural water. In this study, the solubilities of $FeSe_2(s)$ and $TcO_2(s)$, known as respective Solubility Limiting Solid Phase (SLSP) of selenium and technetium, were measured in the KURT (KAERI Underground Research Tunnel) groundwater under various pH and redox conditions. And their solubilities and major species were also calculated using geochemical codes under conditions similar to experimental solutions. Experimental results and calculation for $FeSe_2$ show that the solubility of selenium was found to be below $1{\times}10^{-6}mol/L$ under the condition of pH 8~9.5 and Eh=-0.3~-0.4 V while the dominant species was identified as $HSe^-$. For $TcO_2$, the solubility of technetium was found to be $5{\times}10^{-8}{\sim}1{\times}10^{-9}mol/L$ in the solutions of pH 6~9.5 and Eh<-0.1 V, while the dominant species was $TcO(OH)_2$. However, when the Eh of the solution is -0.35 V, $TcO(OH)_3^-$ and $TcO_4^-$ are calculated as the dominant species at pH 10.5~12 and pH>12, respectively.

• Journal of Industrial Technology
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• v.11
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• pp.3-16
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• 1991

The lattice-fluid theory are adopted for modeling the phese equilibria in supercritical fluids, In order to investigate effects of the nonrandom distribution of holes in mixtures on the phase equilibria, the equation of state and the chemical potential of the binary miture are formulated with taking into account nonrandomness of holes distributions in the fluid mixture. The relations of phase equilibria formulated in this work are tested through predictions of solubility of heavy solids in supercritical fluids and predictions of high pressure phase equilibria of binary mixtures. Results obtained exhibit that the lattice fluid model with assumptions of nonrandomness of hole distributions is successful in quantatively mideling the phase equilibria of mixtures of molecules of dissimilar sizes, specifically solids-supercritical fluid mixtures.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.206-212
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• 2016

Experimental data are reported on the phase equilibrium of propoxylated neopentyl glycol diacrylate in supercritical carbon dioxide. Phase equilibria data were measured in static method at a temperature of (313.2, 333.2, 353.2, 373.2 and 393.2) K and at pressures up to 27.82 MPa. At a constant pressure, the solubility of propoxylated neopentyl glycol diacrylate for the (carbon dioxide + propoxylated neopentyl glycol diacrylate) system increases as temperature increases. The (carbon dioxide + propoxylated neopentyl glycol diacrylate) system exhibits type-I phase behavior. The experimental result for the (carbon dioxide + propoxylated neopentyl glycol diacrylate) system is correlated with Peng-Robinson equation of state using mixing rule. The critical property of propoxylated neopentyl glycol diacrylate is predicted with Joback and Lyderson method.

• Journal of Pharmaceutical Investigation
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• v.34 no.1
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• pp.35-42
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• 2004

Ibuprofen (IBU), is a non-steroidal anti-inflammatory drug, used to treat rheumatoid arthritis, removal of fever and mild to moderate pain. Because of small dosage and very low accumulation in the body, IBU has been used to heal children's fever. However, IBU was very low solubility in a low pH and water (in water $0.03{\sim}2.5$ mg/ml). A nanoemulsion containing IBU by means of self-microemulsion drug delver system (SMEDDS) was prepared in order to enhance the solubility of IBU. The SMEDDS was composed of cosurfactant, oil and surfactant The solubility of IBU in various components such as cosurfactant, oil and surfactant was examined. $Carbitol^{\circledR}\;(386.99{\pm}20.5\;mg/ml)$ as a cosurfactant, $Labrafil^{\circledR}$　 M1944CS $(90.16{\pm}1.60mg/ml)$ as an oil and $Cremopher^{\circledR}$　 RH-40 $(239.01{\pm}2.8\;mg/ml)$ as a surfactant were used in this study for preparing SMEDDS. Optimized formulation of SMEDDS was obtained by phase diagram which express the section of nanoemulsion formation. The SMEDDS containing IBU had higher dissolution rate than conventional IBU sirups. Thus the SMEDDS was a potential candidate of stable conventional and effective oral dosage form for IBU.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.1
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• pp.13-21
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• 2016

The Sulfur-Iodine thermochemical hydrogen production process (SI process) consists of the Bunsen reaction section, the $H_2SO_4$ decomposition section, and the HI decomposition section. The $HI_x$ solution ($I_2-HI-H_2O$) could be recycled to Bunsen reaction section from the HI decomposition section in the operation of the integrated SI process. The phase separation characteristic of the Bunsen reaction using the $HI_x$ solution was similar to that of $I_2-H_2O-SO_2$ system. On the other hands, the amount of produced $H_2SO_4$ phase was small. To investigate the effects of $SO_2$ solubility on Bunsen reaction, the continuous Bunsen reaction was performed at variation of the amounts of $SO_2$ gas. Also, it was carried out to make sure of the effects of partial pressure of $SO_2$ in the condition of 3bar of $SO_2-O_2$ atmosphere. As the results, the characteristic of Bunsen reaction was improved with increasing the amounts and solubility of $SO_2$ gas. The concentration of Bunsen products was changed by reverse Bunsen reaction and evaporation of HI after 12 h.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.405-409
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• 2003

The effect of substitution of Gd ions for Ca ions in the B $i_{1.84}$P $b_{0.34}$S $r_{1.91}$(C $a_{1-x}$ G $d_{x}$)$_{2.03}$ C $u_{3.06}$ $O_{ 10+{\delta}}$/ (x=0.0~0.06) was investigated by measuring x-ray diffraction patterns, lattice constants, do resistivity and Hall effect. We found the solubility limit of Gd in the 110 K phase to be x < 0.015. Within the solubility limit, the c-axis seemed to decrease with increasing x. In the region of the 110 K single phase, the critical temperature $T_{c}$ gradually decreased with an increasing the Gd concentration x, corresponding to a small change of the carrier concentration.

• Journal of Korea Foundry Society
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• v.8 no.4
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• pp.453-458
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• 1988

Al-Si alloy powder produced by the gas atomizer showed fine eutectic structure between ${\alpha}-dendrites$, that was grown by coupled growth, and there remained small amount of ${\alpha}$ in Al - 20 wt% Si alloy. The morphology of Si in the eutectic structure was largely influenced by the recalescence caused by solidification latent heat, and that was thought to be due to decrement of the surface energy of Si. In modified eutectic Si by rapid solidification, fine twin about $0.01\;{\mu}m$ was observed and growth direction of eutectic Si was <112>. This fact implied that the growth mechanism of eutectic Si in rapid solidification was related to TPRE mechanism. Due to rapid solidification Si was soluble in ${\alpha}-phase$ in Al - 12.6wt%Si alloy up to about 3.4wt%, and the solubility of Si in ${\alpha}-phase$ reaches the equilibrium solubility stare after 60min, holding when it was held isothermally at $253-296^{\circ}C$.

• Clean Technology
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• v.13 no.4
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• pp.237-243
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• 2007

Phase behavior of the ternary systems of water-insoluble simvastatin drug, which is well known to be effective drugs for hypercholesterolemia therapy, in solvent mixtures of dimethyl ether (DME) and supercritical carbon dioxide was investigated to present a guideline of establishing operating conditions in the particle formation of the drugs by a supercritical anti-solvent recrystallization process utilizing DME as a solvent and carbon dioxide as an anti-solvent. The solubilities of simvastatin in the mixtures of DME and carbon dioxide were determined as functions of temperature, pressure and solvent composition by measuring the cloud points of the ternary mixtures at various conditions using a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The solubility of the drug increased as the DME composition in solution and the system pressure increases at a fixed temperature. A lower solubility of the drug was obtained at a higher temperature.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.11-18
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• 1993

Inclusion complex of ibuprofen with $2-Hydroxypropyl-{\beta}-cyclodextrin\;(HP-{\beta}-CD)$ in aqueous solution and in the solid state was evaluated by the solubility method and the instrumental analysis such as infrared spectroscopy, thermal analysis and x-ray diffractometry. The aqueous solubility of ibuprofen was increased linearly with the increase in the concentration of $HP-{\beta}-CD$, showing an $A_L$ type phase solubility diagram. The results showed that the dissolution rate of ibuprofen was significantly increased by complexation with $HP-{\beta}-CD$. $Ibuprofen-HP-{\beta}-CD$ complex enhanced the mean plasma concentration levels and the area under plasma concentration-time curve after oral administration compared to those of the drug alone. It is concluded that the complex of ibuprofen with $HP-{\beta}-CD$ increases the dissolution rate and improves the bioavailability of the ibuprofen by the formation of a water-soluble complex.

• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1056-1061
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• 1999

Phase formation and oxygen ion conduction of La(Ba)Ga(Mg)O3-$\delta$ system was studied, BaLaGa3O7 and BaLaGaO4 formed as a secondary phase above the solubility limit of Ba2+ in La3+ sites. The oxygen ionic conductivity of La(Ba)Ga(Mg)O3-$\delta$ was 0.1 S/cm 80$0^{\circ}C$ The activation energy of the oxygen ion conduction was dependent on temperature. This value was higher at low temperature than at high temperature.