• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.285-288
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• 2020

The demand for coating technology on electric power equipment that has arisen from such issues regarding the attaching of illegal advertisements and posters to electric power distribution boxes such as TR, SW, etc. in down town areas seeks to produce functional coating surfaces using polymers and nano-materials that will result in improvements in self-cleaning performance and greater stability even under harsh environmental conditions. KEPCO-coatings consist of copolymerized acrylic resin and methacryl-modified reactive silicone that are able to chemically combine, which results in performance improvement without any leakage of of silicone, thus contributing to its properties of high-stability. Thus, the research team has also started long-term on-site testing on 9 electric power distribution spots around a city center in cooperation with the KEPCO Daeduck-yusung branch. The KEPCO-coating technology could advance the best coating materials and processes to meet appropriate circumstances for a variety of outdoor damage environment. It is also predicted that KEPCO could be possible to expand international electric maintenance markets and to arrange business platforms if KEPCO would achieve its original technology (IPs) by the means of upgrading in self-cleaning coating technology and obtaining long-term on-site test records from nationwide electric facilities.

• Journal of Adhesion and Interface
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• v.24 no.4
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• pp.124-130
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• 2023

For automotive coating agents that require little change in characteristics due to changes in external temperature, changes in noise characteristics due to changes in the external environment are very important. Therefore, soft polyurethane with excellent cold resistance, weather resistance, and abrasion resistance, and polysiloxane whose -OH terminated and side chains are modified with amines, are widely used. In this study, coating agents was prepared by adding water-born polyurethane, polysiloxane, ultra high molecular weight polypropylene (UHMWPP) powder, carbon black, and a matting agent to determine the effect of each resin component on noise. To study the effect of each resin component on noise, a coating agent was prepared by adding water-born polyurethane, polysiloxane, UHMWPP powder, carbon black, and a matting agent. The hard/soft segment ratio of water-born polyurethane, the main component of the coating, was 27.1%/72.9%, and the ratio of amino siloxanes to hydroxy-terminated polysiloxane was 2:7, which produced the least noise. The difference in friction coefficient was large when the friction body moves at high speed. When UHMWPP powder replaced SiO₂, noise decreased and gloss also decreased.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.13-24
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• 2000

UV-curable resin has the properties of quick-drying, high productivity at low temperature, energy, space saving, solventless, non-polluting and low-stinking, and thus, UV-curing system has been widely used in the fields of printing inks, adhesives, paints and coating agents. This study has been executed to develop a new functionnal material by the polymerization induced phase separation. The results obtained were as follows. As for the curing properties of the monomer/prepolymer/alkyd resin blends, it was found out that there was a peak by the polymerization induced phase separation when measuring the changes of viscosity and elasticity. It was also found out that such polymerization phase separation occurred in case that the alkyd resin contents were 20wt% and 30wt% and not found at the contents of 40wt%. Therefore, it would be desirable to maintain the contents of alkyd resin at less than 30wt% in order to use the polymerization induced phase separation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.467-469
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• 2001

KAM200 which can be used electroluminescence binder is cyano material. In this study, we have fabricated KAM200 thin film by Spin-Coating method. And we have studied the electical properties of KAM200 thin films. In the I-V characteristics, the current decreases as the voltage overflow definite voltage immediately. And that definite voltage depend on thickness of KAM200 material. In the case of thickness is 1.9[$\mu\textrm{m}$], definite voltage is 7[V]. And that's electrical field 3.86[MV/m]. The dielectric properties of KAM200 thin film is investigated by measuring dielectric dispersion and absorption. KAM200's Relative dielectric constant is 10.25, and it has high permittivity compared with different materials.

• Journal of the Korean Ceramic Society
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• v.30 no.7
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• pp.549-556
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• 1993

Interfacial shear strength plays an important role in determining the mechanical properties of a fiber-reinforced ceramic composites. In this study, the effect ofinterlayer thickness on mechanical properties of Nicalon-fiber-reinforced SiC composites fabricated via polymer solution infiltration/chemical vapor infiltration (PSI/CVI) was studied. It was found that the flexural strength and fracture toughness of the composites were increased with the interlayer thickness and showed maximum value at the interlayer thickness of 0.66${\mu}{\textrm}{m}$. Typical flexural strength and fracture toughness of Nicalon-fiber-reinforced SiC composites with interlayer thickness of 0.66${\mu}{\textrm}{m}$ were 391.7$\pm$34.6MPa and 15.1$\pm$1.8MPa.m1/2, respectively.

• Journal of the Korean Ceramic Society
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• v.23 no.2
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• pp.31-37
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• 1986

The effect of dehydration temperature on the reduction process of silica-coated hematite was invest-igated The particle shape and magnetic properties of the products reduced from hematite at various conditions and the oxidation resistance of silica-coated iron powder were examined. It was revealed that single phase iron powder obtained over 45$0^{\circ}C$ had good magnetic properties. The iron powder manufactured between 45$0^{\circ}C$ and 50$0^{\circ}C$ displayed the maximum coercive force as a result of maintaining its acicular shaped. However the coercive force of iron powder reduced over 50$0^{\circ}C$ was decreased. The oxidation resistance of silica-coated iron powder in air was very good up to 11$0^{\circ}C$ and for 12 days.

• Journal of the Korean Society of Clothing and Textiles
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• v.9 no.2
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• pp.35-43
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• 1985

The purpose of this study was to analyse the characteristics and the problems of commercial zippers such as polyester coil zippers, plastic zippers and brass zippers by testing their properties. The sizes of the samples used for this were $\sharp$3, $\sharp$5 and $\sharp$8($\sharp$7 only in case of brass zippers), and all of them were selected in the same lot and collected from 4 different domestic companies. Original samples and another samples laundered 1, 3, 5 and 10 times were measured in terms of colorfastness, durability of coating of zipper, longitudinal dimensional change, operability of zipper, strength of zipper chain crosswise, and reciprocating movement of zipper. In conclusion, the properties of the zippers were revealed differently according to their kinds. Therefore, it was recommended that the present test standard should be modified, in order to improve them in quality.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.4 s.112
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• pp.26-31
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• 2005

The purpose of this study was to confirm paper strengthening properties with recently commercialized polyvinylamine. Because of its high cationic charge density, polyvinylamine has been investigated as a size retention and surface coating aids. In this study, we tried to confirm polyvinylamine as wet-end additives to improve dry and wet strength using LBKP and BCTMP pulps. As a result, we found improvement of dry and wet tensile properties of polyvinylamine with BCTMP were much better than LBKP condition. This phenomena could be explained that ionic bonding of cationic charge of polyvinylamine with abundant anionic substances of BCTMP was a very important factor to improve dry and wet strength of paper.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.3
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• pp.210-217
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• 2009

Insulated methods of compact bus duct has been applied a way of coating Epoxy powder. The problem which is caused by degradation during operation is very important in severe environment. Therefore, this study compared and verified many kind of properties ; electrical breakdown by thermal and water aging, v-t characteristic, arc discharge, mechanical properties, bending test and cross cut. Sample D was stable before the $T_g$ to be about $7{\sim}10 %$ decrease in the breakdown test according to temperature change. In case of V-t and arc discharge, it had been kept up suitable characteristic. Also, in case of electrical and mechanical characteristic, both sample D and A have excellent capacity.

• Journal of Surface Science and Engineering
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• v.49 no.5
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• pp.461-466
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• 2016

Nanocrystalline vanadium nitride (VN) coatings were deposited using asymmetric bipolar pulsed dc sputtering to further understand the influence of the pulsed plasmas on the crystal structure, microstructure and mechanical properties. Properties of VN coatings were investigated with FE-SEM, XRD and nanoindentation. The results show that, with the increasing pulse frequency and decreasing duty cycle, the coating morphology changed from a porous columnar to a dense structure, with finer grains. Asymmetric bipolar pulsed dc sputtered VN coatings showed higher hardness, elastic modulus and residual compressive stress than dc sputtered VN coatings. The results suggest that asymmetric bipolar pulsed dc sputtering technique is very beneficial for the reactive sputtering deposition of VN coatings.