• Journal of Magnetics
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• v.10 no.3
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• pp.128-132
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• 2005

We report optical ab-plane properties of the layered sodium cobaltate, $Na_xCoO_2$ for x = 0.35 and 0.75. Two samples show metallic behaviors according to dc resistivity transport. Overall temperature dependent optical conductivities of both samples are very similar to those of the high temperature superconducting underdoped cuprates. We found that the optical scattering rate of x = 0.75 sample, which is in a Curie-Weiss metallic phase, varies linearly (non-Fermi liquid) with frequency and temperature while that of x = 0.35 sample, which is in a paramagnetic metallic phase, varies quadratically (Fermi liquid) with frequency and temperature. Both x = 0.35 and 0.75 samples have an onset of scattering around $600\;cm^{-1}$ which can be attributed to the interaction of charge carriers with a bosonic collective mode in a system.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2638-2641
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• 2007

The magnetohydrodynamic(MHD) pressure drop along a liquid sodium flow was measured in a rectangular duct under a transverse magnetic field. The test section was made of a 3 mm thick stainless steel SUS304 with a $74{\times}5mm^2$ rectangular flow channel. The range of experimental parameters was roughly B=0${\sim}$0.18T and U=0${\sim}$0.9m/s at around $200^{\circ}C$. The differential pressure was measured by a diaphragm seal-type pressure transmitter filled with a high temperature silicon oil within 0.1MPa. The experimental results show a similar pressure drop with the theoretical estimation according to a change of the flow velocity and the magnetic field.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1771-1775
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• 2005

An efficient and environment friendly method has been described for the synthesis of various 2-alkyl-4-hydroxy-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxides starting from N-alkylation of sodium obenzosulfimide in an ionic liquid for the first time. Ring cleavage and ring closure of the resulting product were achieved in a single step in a cost effective solvent (methanol) followed by N-alkylation of resulting alkyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate in ionic liquid while boron triflouride was used as a catalyst along with molecular sieves in carboxamide formation step.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.1-7
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• 1999

An innovative concept for a passive reactor shutdown system, so called self-actuated shutdown system(SASS), is inevitably required for the inherent safety in liquid metal reactor, which is designed with the totally different concept from the usual reactor shutdown system in LWR. SASS using Curie point electromagnet(CPEM) was selected as the passive reactor shutdown system for KALIMER (Korea Advanced Liquid MEtal Reactor). A mock-up of the SASS was designed, fabricated and tested. From the test it was confirmed that the mockup was self-actuated at the Curie point of the temperature sensing material used in the mockup. An articulated control rod was also fabricated and assembled with the CPEM to confirm that the control rod can be inserted into core even when the control rod guide tube is deformed due to earthquake. The operability of SASS in the actual sodium environment should be confirmed in the future. All the design and test data will be applied to the KALIMER design.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.133-142
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• 1962

This study was carried out to investigate the lead-bismuth-sodium ternary system which a basis of the Dittmer method as a part of "the fundamental study of pyrometallurgical debismuthizing of lead". Thermodynamic properties of each liquid Pb-Bi, Pb-Na binaries as well as liquid Pb-Bi-Na ternary solution were measured by e.m.f. of these concentration cells, and those of each component were also determined. Furthermore, iso-activity lines including Pb rich side composition of Pb-Bi-Na ternary solution were determined. The relationship between those thermodynamic characteristics and tendency of intermetallic compound formation was discussed through the above experiments.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2797-2800
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• 2010

For the purpose of developing advanced new absorbents for carbon dioxide, ionic liquids (ILs) are considered as alternative materials due to their superior properties to conventional organic solvents. Since low $CO_2$ solubility in ionic liquids is a major concern for their application as absorbents, it is essential to focus on improving $CO_2$ absorbing capability of ILs. In this paper, strongly basic ionic liquids, namely [$C_n$-mim]OPh (n = 2, 4, 6), have been synthesized and studied over a wide range of temperature and pressure changes. [$C_n$-mim]OPh can be easily synthesized from corresponding [$C_n$-mim]Cl and sodium phenoxide and has been found to be good $CO_2$ absorbents.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.10-12
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• 1998

Pumping liquid metal in nuclear power plant application by conventional centrifugal pumps pose difficulties such as bearing wear out at high temperatures and leak proof sealing of the liquid metal. MHD machine is obtained by replacing solid conducting secondary of conventional motors with ionized gas or liquid metal. It is used for reactor cooling pump because of construction simplicity, perfect sealing and easy operation/maintenance MHD pump is complicated because it includes electromagnetic and hydrodynamic phenomena. The principle of MHD Pumps is described in this paper. We design small laboratory size Flat Linear Induction Pump(FLIP) for transferring sodium.

• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.89-94
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• 1999

Carbon dioxide reforming of methane on Ni/γ-Al2O3 catalyst was studied. A new 10 wt% Ni/γ-Al2O3 catalyst prepared by the liquid phase oxidation method (L10O) exhibited much higher activity as well as resistances to both sintering and coke formation during the reaction than the catalyst prepared by the conventional impregnation method (D10). The electrically strong attractive interaction between nickel and support during the liquid phase oxidation process and the resultant high nickel dispersion made the L10 have superior activity and stability to the D10. To elucidate the results, the experiments with nickel catalysts on the other supports as well as 7-AI203 were performed. The effect of sodium as a promoter was also studied.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.3
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• pp.425-425
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• 1995

The interaction and detergency between liquid oily soil and surfactant solution were studied by the mechanism of formation of liquid crestal(LC). Samples used were triolein as a triglyceride, oleic acid as a free fatty acid and sodium dodgily sulfate (SDS) as a surfactant. The results were as follows: In the phase diagram of SDS/oil/Water system, the area of liquid crystalline phase region were in the order of SDS/trillion/water< SDS/oleic acid/water< SDS/mixture of trillion and oleic acid/water. In the system of oleic acid alone or mixture of trillion and oleic acid contacted with SDS solution, the LC phase was formed right after or after some time with SDS concentration. But in a case of trillion alone, the LC phase was not formed although the concentration of the SDS solution was relatively high. The detergency of model oily soils were seldom changed with temperature, and the detergency of oleic acid was very high compared to that of the trillion. The detergency of mixed soil was improved with the increase of the ratio of oleic acid in the mixture.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.3
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• pp.426-433
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• 1995

The interaction and detergency between liquid oily soil and surfactant solution were studied by the mechanism of formation of liquid crestal(LC). Samples used were triolein as a triglyceride, oleic acid as a free fatty acid and sodium dodgily sulfate (SDS) as a surfactant. The results were as follows: In the phase diagram of SDS/oil/Water system, the area of liquid crystalline phase region were in the order of SDS/trillion/water< SDS/oleic acid/water< SDS/mixture of trillion and oleic acid/water. In the system of oleic acid alone or mixture of trillion and oleic acid contacted with SDS solution, the LC phase was formed right after or after some time with SDS concentration. But in a case of trillion alone, the LC phase was not formed although the concentration of the SDS solution was relatively high. The detergency of model oily soils were seldom changed with temperature, and the detergency of oleic acid was very high compared to that of the trillion. The detergency of mixed soil was improved with the increase of the ratio of oleic acid in the mixture.