• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.490-494
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• 1985

The effect of organic solvents on the stability and catalytic activity of the microbial lipase from Rhizopus arrhizus for interesterification of fats and oils has been examined. The reaction system used was nonaqueous solvent system (two phase system). The solvents examined were 5 hydrocarbons (n-hexane, n-heptane, n-octane, isooctane, and cyclohexane) and 3 ethers (diethylether, diisopropylether, di-n-butylether). The results revealed that diisopropylether and isooctane are superior to the other solvents examined for interesterification of fats and oils in two phase systems.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2941-2944
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• 2014

The electrical and mechanical properties of the plasma polymerized low dielectric constant SiCOH films were investigated. The SiCOH films were produced with tetrakis(trimethylsilyloxy)silane and cyclohexane as precursors by using a plasma enhanced chemical vapor deposition. When the deposition plasma powers were changed from 10 to 50 W, the relative dielectric constant of the SiCOH film increased from 2.09 to 2.76 and their hardness and elastic modulus were changed from 1.6 to 5.6 GPa and from 16 to 44 GPa, respectively. After thermal annealing at $500^{\circ}C$, the annealed SiCOH films showed relative dielectric constants of 1.80-2.97, a hardness of 0.45-0.6 GPa and an elastic modulus of 6-7 GPa. And then, the chemical structures of as-deposited and annealed SiCOH films were analyzed by using Fourier transform infrared spectroscopy.

• Journal of the Korean Chemical Society
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• v.27 no.4
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• pp.255-261
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• 1983

Several new $[Pd(L)X_2]$ complexes have been prepared with aminophosphines (L) such as trans-1,2-bis[diphenylphosphino)amino]cyclohexane and 1,2-bis[(diphenylphosphino) amino] propane that contain phosphorus atom as ${\pi}$-electron acceptor, and the bond character of complexes have been investigated by means of infrared and electronic spectroscopy. It was found that thiocyanate ions are N-coordinated possibly due to the steric and electronic influence of the phosphorus atom in aminophosphines that formed seven-membered chelate rings, and that spectrochemical series that is derived from the electronic spectra of the complexes is $NCS^- > Cl^- > Br^- > I^-$

• Polymer(Korea)
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• v.39 no.2
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• pp.287-292
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• 2015

Characterization of a series of bio-based terpolymers containing various amounts of ethylene glycol, 1,4-cyclohexylene dimethanol, and isosorbide units were studied by $^1H$ NMR and $^{13}C$ NMR. The NMR results revealed that they had all random microstructures and that their sequence distribution was affected by the content of isosorbide. From DSC data for the terpolymer series investigated, it was observed that the glass transition temperature increased mainly as the content of isosorbide increased. The glass transition temperatures of terpolymers were estimated from the composition by extended Fox equation.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.663-678
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• 2018

Refractive index and speeds of sound for the binary mixture of isomer of butanol (1) + cyclohexane, benzene and toluene (2) were measured at 308.15 K. The measured data were used to calculate deviation in refractive index ${\Delta}n$, ultrasonic speed ${\Delta}u$, isentropic compressibility $K_s^E$, available volume $V_a$, excess intermolecular free length $L_f$ and molecular association $M_A$. All the derived properties were correlated with polynomial equation. Ultrasonic speed data were predicted using various empirical correlations like Nomoto, van Dael, impedance dependence and theoretically with Schaaff's collision factor theory (CFT). Jacobson free length theory (FLT) was used to calculate $L_f$. The measured refractive index was also correlated with various mixing rules. The deviation in refractive index Δn and ultrasonic speed ${\Delta}u$ was used to determine the intermolecular interactions.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.998-1002
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• 1997

Irradiation of tert-butyl 9-anthroate and furan through a Uranium glass filter gave the [4+4] cyclodimer (21.8%) of tert-butyl 9-anthroate and furan and the 1,4-10',9' cyclodimer (4.2%) of tert-butyl 9-anthroate as well as the 9,10-10',9' cyclodimer (65.7%) of tert-butyl 9-anthroate. The [4+4] cyclodimer of tert-butyl 9-anthroate and furan was found to be thermally dissociated into their unit components with the activation enthalpy of 35.6 kcal/mole and the activation entropy of 7.6 eu, and photochemically dissociated to produce excited tert-butyl 9-anthroate. Quantum yields for the photodissociation to tert-butyl 9-anthroate and the formation of excited tert-butyl 9-anthroate in cyclohexane at room temperature were determined to be 0.56 and 0.19, respectively. The 1,4-10',9' cyclodimer of tert-butyl 9-anthroate in DMF was thermally dissociated into tert-butyl 9-anthroate with the activation enthalpy of 34.8 kcal/mole and the activation entropy of 16.4 eu. Upon irradiation, the [4+4] cyclodimers of tert-butyl 9-anthroate and the [4+4] cyclodimers of methyl 9-anthroate were quantitatively dissociated. However, no adiabatic photoreversion was observed from any of the cyclodimers. Quantum yields for the photodissociation in cyclohexane at room temperature were measured and compared.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.593-599
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• 2007

In this study, we examined the volatile flavor components in the mashes of takju prepared using different yeasts such as Saccharomyces coreanus, S. ellipsoideus, S. carlsbergensis, S. cerevisiae (Baker's yeast), and S, rouxii by GC and GC-MS. Fourteen alcohols, 13 esters, 5 acids, 3 aldehydes, 7 amines, and 2 other compounds were identified in the mash after 6 days of fermentation. On day 6, the takju fermented by S. coreanus had the greatest variety of volatile flavor components. Fifteen flavor components, including ethanol, isobutyl alcohol, isoamyl alcohol, methyl pentanol, 1,3-butanediol, 3-methylthio-1-propanol, benzeneethanol, ethyl lactate, acetic acid, acetaldehyde, and 1,3-cyclohexane diamine, were typically detected in all the treatments. The relative peak areas of the volatile components were as follows: alcohols (96.758-99.387%), esters (0.081-0.968%), acids (0.040-0.640%), aldehydes (0.266-0.959%), and amines (0.011-0.047%). In particular, 1-propanol, isobutyl alcohol, 3-methyl-1-butanol, 2,3-butanediol, trimethyl benzylalcohol, heptene-2,4-diol, ethyl lactate, diethyl succinate, ethyl nonanoate, methyl hexadecanoate, linoleic acid, hexadecanoic acid, and acetaldehyde were hish in the takju made by S. coreanus. Also, ethyl stearate was high in the takju made by S. carlsbergensis, and hexanoic acid was high in the takju made by S. cerevisiae. Finally, methyl pentanol, 1,3-butanediol, 3-methylthio-1-propanol, benzene ethanol, ethyl octadecanoate, acetic acid, pentanal, and 1,3-cyclohexane diamine were high in the takju made by S. rouxii.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.573-579
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• 1994

1-O-oleoyl glycerol, 2-O-oleoyl myo-inositol and methyl 2-O-oleoyl-${\alpha}$-D-glucopyranoside were used as surfactants in this study. The solution properties and solubilization process of those nonionic surfactants were examined by the phase equilibria. As a result of this study, we have found that phase behavior of two component systems of surfactants/$H_2O$/cyclohexane depends on temperature respectively. The three phase regions of three component systems appeared in the temperature range of $27^{\circ}C{\sim}32^{\circ}C$, $36^{\circ}C{\sim}45^{\circ}C$ and $38^{\circ}C{\sim}52^{\circ}C$ and solubilization of water and oil was high in those three phase ranged As the temperature was varied in the two component systems, liquid crystals of hexagonal were observed to in the case of 1-O-oleoyl glycerol, and liquid crystal of lamella types were observed in the case of 2-O-oleoyl myo-inositol and methyl 2-O-oleoyl-${\alpha}$-D-glucopyranoside.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.163-164
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• 2004

• Journal of the Korean Chemical Society
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• v.42 no.5
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• pp.579-583
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• 1998