• Journal of the Korean Chemical Society
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• v.15 no.4
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• pp.171-175
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• 1971

Significant structure theory has been applied to the viscosities of supercooled liquids with success. In the supercooled region, the effect of free volume decrease is so significant that the thermal effects on the solid-like volume must be considered properly. In addition, the two state theories proposed by Jhon and Eyring for water and Litovitz et al. for boron trioxide have been successfully applied to the structure change in the liquid state. Considered liquids are benzene, carbon tetrachloride, p-xylene, water and boron trioxide.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.477-479
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• 1987

An understanding of dielectric breakdown characteristics in cryogenic liquids is of importance in the development of various cryogenic and superconducting electrical equipments. This investigation describes measurements of pulse breakdown voltage, polarity effect, conditioning effect and time lag characteristics of cryogenic liquids.

• Proceedings of the Safety Management and Science Conference
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• 2010.04a
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• pp.247-251
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• 2010

The victims of fire are increasing steadily. Fires have been occurred by arson, spontaneous combustion and various causes. As a result of that, the damages of fire got out of hand. Especially, the fires of flammable liquids are can be spreaded easily because of high calorific value and fire loads. These rapid fire spread cause the huge losses of both life and property and the malfunction of extinguishing systems. In these studies, we examined the spread pattern of surface fire on the water surface by the reappearance experiment.

• Bulletin of the Korean Chemical Society
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• v.1 no.1
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• pp.26-28
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• 1980

The surface tensions, the chemical potentials and the densities of various liquids such as argon, nitrogen, helium, ammonia, and water are calculated using the significant structure theory of liquids. And using these calculated values, the critical supersaturation ratios and the radii of the above materials are determind according to the classical Becker-Doring and the revised Lothe-Pound theories. The results are compared with the experimental values and well agreed with the available experimental data.

• Bulletin of the Korean Chemical Society
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• v.8 no.2
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• pp.105-110
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• 1987

A theory in which the Enskog hard sphere collisional dynamics complements the hydrodynamic theory is applied to the fast modulation dephasing dynamics in liquids which leads to homogeneous line broadening in the isotropic Raman spectra. The dephasing times of several molecules in pure liquids and in trace solutions in the solvent $CCl_4$ are calculated and these are compared with experimental values. The temperature dependence of the dephasing time of liquid acetonitrile and the isothermal density dependence of the dephasing time of liquid methyl iodide are also investigated.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.345-354
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• 2006

Ionic liquids are alternative reaction media of increasing interest and are regarded as an eco-friendly alternatives, of potential use in place of the volatile organic solvents typically used in current chemical processing methods. They are emerging as the smart and excellent solvents, which are made of positive and negative ions that they are liquids near room temperature. The nucleophilic substitution reaction is one of the important method for inserting functional groups into a carbon skeleton. Many nucleophilic substitution reactions have been found with enhanced reactivity and selectivity in ionic liquid. In this review, some recent interesting results of nucleophilic substitution reactions such as hydroxylations, ether cleavages, carbon-X (X= carbon, oxygen, nitrogen, fluorine) bond forming reactions, and ring opening of epoxides in ionic liquids are discussed.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1583-1586
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• 2011

Silver nanoparticles (<10 nm) were prepared in ultrasonic vibration-induced nanodroplets of isopropyl alcohol (IPA) in combination with hydrophobic room temperature ionic liquids (RTILs). The Ag-precursor used were silver (I) complex, Ag$_2$(ehac)$_2$(eha)$_2$ (ehac = 2-ethylhexylammonium carbamate; eha = 2-ethylhexylamine), in IPA, while 1-butyl-3-methylimidazolium-based ionic liquids bearing $SbF_6^-$, $PF_6^-$ and $NTf_2^-$ as counter anions were used as RTILs. During sonication for 10-90 min at room temperature, uniform silver nanoparticles with mean sizes of 2 to 8 nm were rapidly synthesized. Transmission electron micrographs also confirmed that silver nanoparticles have a spherical shape and diverse sizes depending on the reaction time (10-90 min).

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.225-230
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• 2014

Several nitrile-functionalized ionic liquids have been prepared and characterized. An attempt was made to systematically characterize nitrile-functionalized ionic liquids on the basis of a few kinds of cations and anions. The detailed comparison of the differences in physicical characteristics such as UV-Vis spectroscopy, thermal stability, viscosity, solubility property, and electrochemical property before and after incorporation of a nitrile group were studied. The results showed that the incorporation of a nitrile group to cations could result in remarkable changes in these properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.31-39
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• 1999

A good atomization in uniform size brings the elevation of thermal efficiency in spray combustion, the beautiful painting on surfaces, and the economical sprinkling of chemicals. Ultrasonic atomization has been expected as a good uniform atomization mechanism due to its uniform size distribution. Influx, load, and physical properties of liquids are the effecting factors to atomize liquids. In this study, distilled water and city water are selected as reference liquids and gasoline, kerosene, and petroleum as fuel liquids. Characteristics and affinity to get the maximum effect for the ultrasonic atomization are observed by using the two ultrasonic transducers with 28kHz and 2MHz. Results show that the size distributions of liquid spray dorplet by the direct vibration method prevail over those by the aerosol method in uniform droplet size and as a whole, sizes of spray liquid droplets are increased slightly according to increasing influx in the direct vibration method and quantities of spray droplets in the aerosol method decreasing according to increasing liquid load h.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.14-17
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• 2012

Submicron silver particles were synthesized by chemical reduction with various room temperature ionic liquids. The size and distribution of silver particles were significantly affected by the anion type of ionic liquids and this is mainly attributed to the different abilities of the anions to coordinate with the silver particle, leading to various coagulation of silver particles. Among ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate was the most effective to synthesize submicron silver particles.