• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.650-654
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• 1998

Aggregations of 1,1'-diethyl-2,2'-carbocyanine iodide (DCI) and 1,1'-diethyl-2,2'-dicarbocyanine iodide (DDT) in aqueous solution have been investigated by the steady-state absorption spectroscopy. The equilibrium constants for dimerization of DCI and DDT are found to be $(9.8{\pm}0.5){\times}10^4 \;and\; (1.6{\pm}0.5){\times}10^5\; M^{-1}$, respectively, at 293 K. The enthalpy changes for the dimerization of DCI and DDT are -6.7±0.7 and -7.7±0.8 kcal/mol, respectively. The results show that the dispersion force plays an important role in the aggregation of DCI and DDT in aqueous solution. The absorption bandwidth of DCI/ethanol system has been measured as a function of temperature, providing the evidence for no strong interaction between DCI and solvent molecules. The participation of hydrophobic force in driving the aggregation is suggested. For the first time, DCI in aqueous solution is found to form a new aggregate which has both J- and H- bands.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.474-481
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• 2005

In this study, modeling and optimization work were performed to obtain nearly pure anhydrous ethanol from aqueous ethanol mixtures using benzene as an entrainer. NRTL liquid activity coefficient model was adopted for phase equilibrium calculations and PRO/II with PROVISION 6.01, a commercial process simulator, was used to simulate the azeotropic distillation process. We used the total reboiler heat duties as an objective function and the concentration of ethanol at concentrator top as a manipulated variable. As a result, 76 mole percent of ethanol at concentrator top gave an optimum value which minimized the total reboiler heat duties of three distillation columns.

• Journal of the Korean Chemical Society
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• v.10 no.3
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• pp.114-118
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• 1966

The glass electrode was empirically calibrated in dioxane-and ethanol-water mixed solvents, by means of which the pH-meter reading could be converted to stoichiometric hydrogen ion concentration. By the potentiometric titration method, the thermodynamic dissociation constants of hydrogen cupferrate (HCup) with variations of ionic concentration in aqueous solution were determined, and by the extrapolation of the constants the new thermodynamic $pK_a$ value, 3.980${\pm}$0.006, at zero ional concentration was obtained. The thermodynamic dissociation constants of HCup in dioxane-and ethanol-water solution were also potentiometrically determined with the changes in composition of organic solvents at 0.01 and 0.05 of the ionic strength(${mu}$) and 25 $^{\circ}C$. The empirical formula of the constants with mole fraction(n) of the organic solvent are as follow: Dioxane-water solution. $pK_a$= 12.96n + 4.10 at ${\mu}$ = 0.01, n = 0.0228∼0.171 $pK_a$= 12.05n + 4.23 at ${\mu}$ = 0.05, n= 0.0228∼0.171 Ethanol-water solution, $pK_a$= 4.0ln + 4.26 at ${\mu}$= 0.01, n= 0.0395∼0.262 $pK_a$= 3.83n + 4.34 at ${\mu}$= 0.05, n= 0.0395∼0.262

• Fire Science and Engineering
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• v.29 no.2
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• pp.39-43
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• 2015

The flash point is the major property to characterize fire and explosion hazard of liquid mixtures. The flash point is the lowest temperature at which a liquid gives off enough vapor to form a flammable air-vapor mixture. The flash points of two aqueous mixtures, water-methanol and water-ethanol, were measured using Seta flash closed cup tester. A prediction method based on activity coefficient models, Wilson and UNIQUAC equations, was used to calculate the flash point. The calculated flash points were compared to the results by the calculating method using Raoult's law. The calculated values based on activity coefficients models were found to be better than those based on the Raoult's law.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.185-192
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• 1999

Four different parts of Hovenia dulcis $T_{HUNB}$; fruit, bark, vessel area, fruit coat were extracted with water and ethanol. The ethanol extracts of bark, fruit coat and fruit were fractionized into diethyl ether, chloroform and aqueous partitions. Ethanol extract of fruit coat increased the activity of cathepsin B up to 55 %, which can enhance the alcohol dehydration in the liver. The ethanol extracts was more effective than water extracts against the growth of Hep3B, MCF7. The ethanol extracts of bark (0.5mg/ml) inhibited 90% the growth of MCF7. Each extracts and fractions (0.5mg/ml) did not show considerable cytotoxicity on HEL299. In overall, most of the fractions had similar effects to ethanol extracts; however, diethyl ether and chloroform fractions had higher bioactivity than ethanol extracts, but aqueous fraction.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.172-175
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• 1999

The effect of Korean red ginseng extract on the pharmacokinetics of ethanol was examined in 14 male rats and 10 healthy male volunteers. Aqueous red ginseng extract (200 mg/kg), or an equivalent volume of water was administered orally to the rats and followed immediately by treatment with $50\%$ (v/v) ethanol orally (3.2 g/kg). The area under the curve (AVC) and elimination rate constant (Ke) of ethanol were $29.2{\pm}6.2\;g{\cdot}min{\cdot}dl^{-},\;0.51{\pm}0.06\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in ginseng-treated group and $28.0{\pm}5.6\;g{\cdot}min.{\cdot}dl^{-},0.5{\pm}0.1\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in control group. These differences were not significant. The volunteers were given orally with 3g of aqueous ginseng, or an equivalent volume of water, followed immediately by Korean alcoholic beverage, Soju (2.4 ml/kg). The AUC and Ke of ethanol for volunteers were $10.6{\pm}2.0\;g{\cdot}min.{\cdot}dl^{-}$ and $0.21{\pm}0.05\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in ginseng-treated group and $11.0{\pm}2.2\;g{\cdot}min.{\cdot}dl^{-}$ and $0.22{\pm}0.04\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in control group. These differences were not also significant. These results suggest that an application of red ginseng extract does not have any clinically significant effect on the pharmacokinetics of ethanol.

• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.245-250
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• 2003

Composition of isoflavone in cotyledon and hypocotyl of soybean were detected using HPLC. Optimum conditions for extracting isoflavone from hypocotyl were studied as well. Contents of isoflavone in soybean cotyledon and hypocotyl were 482.5 mg 100 $g^{-1}$ and 3453.3 mg 100 100 $g^{-1}$, respectively. Hypocotyl contained 7~8 times move isoflavone than corresponding cotyledon of the soybean. Malonyl glycoside accounted for move than 70% of the total isoflavone, followed by glycoside, acetyl glycoside, and aglycone. Aqueous ethanol of 60~80% was the most suitable solvent for extracting isoflavone from the hypocotyl. Optimum temperature and time was $90^{\circ}C$, 1hr. Acetic acid, NaCl, and NaOH added to 80% ethanol suppressed extraction yield of the phytochemieal.

• Advances in Traditional Medicine
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• v.1 no.1
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• pp.89-96
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• 2000

A human hepatoma cell line, Hep G2 cells are a reliable for the study of alcohol-induced hepatotoxicity. In this study, the author investigated the effect of an aqueous extract of Asparagus $cochinchinensis_{MERRIL}$ (Liliaceae) roots (ACAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. ACAE dose-dependently inhibited the EtOH-induced tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ secretion. ACAE also inhibited the EtOH and $TNF-{\alpha}-induced$ cytotoxicity. Furthermore, the author found that ACAE inhibited the $TNF-{\alpha}-induced$ apoptosis of Hep G2 cells. These results suggest that ACAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.378-382
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• 2009

Rates of solvolyses of benzhydryl chloride ($Ph_2$CHCl, 1) and benzhydryl bromide ($Ph_2$CHBr, 2) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, 2,2,2-trifluoroethanol (TFE) and acetone are reported. Solvolyses were also carried out in TFE-ethanol mixtures. Application of the extended Grunwald-Winstein equation led to l value of 1.19 (1), 1.29 (2) and m value of 1.00 (1), 0.77 (2), correlation coefficient of 0.965 (1) and 0.970 (2). Sensitivities (l = 1.19 (1), 1.29 (2) and m = 1.00 (1), 0.77 (2)) were similar to those obtained for several previously studied solvolyses, in which an $S_N$2 pathway is proposed for the solvolyses of benzhydryl halides ($Ph_2$CHX, X = Cl or Br).

• Macromolecular Research
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• v.15 no.5
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• pp.403-411
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• 2007

Monodisperse micron-sized polystyrene (PS) spheres were successfully obtained using a single stage soap-free emulsion method in aqueous media mixed with ethanol (co-solvent) containing NaCI as the electrolyte. The optimum conditions for preparing the monodisperse PS microspheres, using soap-free emulsion polymerization in a water/ethanol mixture with an electrolyte, were studied. The presence of the co-solvent and electrolyte controlled the particle dispersion stability during the polymerization. The microspheres formed using PS, with a weight-average diameter of $2.6{\mu}m$, coefficient of variation of 5.3% and zeta potential of -15.1 eV, were successfully obtained in the presence of 0.1 wt% NaCI, 10 wt% monomer, 0.1 wt% initiator and 95/5 (g/g) of a water/ethanol mixture reacted at $70^{\circ}C$ for 24 h.