• Journal of Adhesion and Interface
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• v.12 no.1
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• pp.34-42
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• 2011

The roll coating process is well-known for completely replacement coating system with an existing wet paint process for automotive which has low productivity and is not environment-friendly process. It is very important to evaluate the curing behavior, corrosion resistance and processing property as well as rheological behavior in order to realize a film flexibility and hardness simultaneously. In this study, we have synthesized the polyester resin modified with hydroxyl values and molecular weight to apply the pre-painted system, and then evaluated the curing behavior, deep drawing, tensile strength and rheological properties. It was observed that N-0375-40 of 40 (mg KOH/mol) hydroxyl values showed the most suitable for flexibility, film hardness, and curing behavior.

• Corrosion Science and Technology
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• v.9 no.4
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• pp.153-158
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• 2010

Electrical appliances such as audiovisual equipment and personal computers have recently had heat and electromagnetic problems. In order to solve those problems, 'High heat absorbing pre-painted steel sheet (hereinafter referred to as PSS)', 'High electromagnetic shielding PSS' and 'High heat absorbing and high electromagnetic shielding PSS' have been developed. In this paper, the heat characteristics and electromagnetic shielding properties of PSS are investigated by methods that use enclosures and their mechanisms are discussed. It was found that 'High heat absorbing PSS' and 'High heat absorbing and high electromagnetic shielding PSS'could reduce the heat problem. The mechanism of the heat characteristics was presumed for the high heat absorptivity of the back coating inside the enclosure. And it was also found that 'High electromagnetic shielding PSS' and 'High heat absorbing and high electromagnetic shielding PSS' could shield electromagnetic waves well. The mechanism of the electromagnetic shielding properties was considered for the low transfer impedance of the back coating inside the enclosure. 'High heat absorbing PSS' and 'High electromagnetic shielding PSS' have been adopted as materials for electrical appliances and 'High electromagnetic shielding and high heat absorbing PSS' have been tested for that purpose.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.45-45
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• 2014

The importance of magnesium alloys has significantly increased due to their low density, high strength/weight ratio, very good electromagnetic shielding features and good recyclability. However, unfortunately, Mg alloys are very susceptible to corrosion due to their high chemically activities (= -2.356 V vs. NHE at $25^{\circ}C$), hence, most commercial Mg alloys require corrosion protective coatings. Organic coating such as painting, powder coating and electrophoretic deposition of paint (E-paint) is typically used in the final stages of the coating process of Mg alloys. In this study, effect of pre-immersion time on the deposition of E-paint on AZ31 Mg alloy was investigated. It was found that during pre-immersion time, AZ31 Mg alloy rapidly reacts with E-paint solution and paint can be self-deposited on the AZ31 surface without applying of electric current. The pore size on the E-painted AZ31 Mg alloy increased with increasing pre-immersion time from 0 to 5 min. Both adhesion and corrosion resistance of E-painted AZ31 Mg alloy decreased with increasing pre-immersion time. The best E-paint AZ31 Mg alloy, which showed stronger adhesion after water immersion test and good corrosion resistance, was started to deposit after 5 s of pre-immersion time.

• Elastomers and Composites
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• v.49 no.2
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• pp.160-166
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• 2014

The formulation of six basecoats was designed using aluminium pastes for the per-painted system in the automotive. The aluminium pastes contain pancake type metallic pigment, #501, #801, #601 and cornflake type metallic pigment, #750, #770, #790. The relative cure density of the basecoat increased in order of #501, #801, #601, #750, #770, #790. T-bending, impact resistance, and taping adhesion showed increment with increasing cure density. In the appearance( combined factor) test on cornflake type pigment, The basecoat including the smallest particle size pigment, #790 resulted in the best combined factor compared to other two systems(#750, #770).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.187-187
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• 2015

Polyvinylidene fluoride (PVDF) 코팅은 뛰어난 내후성으로 인해 Pre-painted metal에 많이 응용되며 주로 고가의 건축물 외장재에 적용되고 있는데, 수지의 열가소성 특성으로 인해 도막경화시 Baking 온도 및 냉각속도가 도막의 결정화도에 영향을 주어 가공특성이 상이하게 변함을 확인 하였다.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.49-55
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• 2011

With the development of pre-painted steel sheets for automotive body application, a new joining method is required such as hybrid joining with combination of adhesive bonding and mechanical joining. The objective of this study is to investigate the effect of pre- and post-baking of adhesive bonding on failure mode and strength of hybrid joining of automotive steel sheets. Experiments show that the hybrid joining exhibits better bonding strength and displacement than conventional adhesive joining and mechanical fastening each. Comparison of pre- and post-baked hybrid joining results suggested that baking at $160^{\circ}C$ after mechanical joining was found to have higher joining properties than pre-baking condition. The prebaking condition changed its fracture mode from interfacial to button fracture. The changes in fracture mode with post-baking of hybrid joining was attributed to variation in neck thickness and undercut of joint.

• Art History and Visual Culture
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• no.22
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• pp.254-279
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• 2018

This essay traces the origin and the social function of medieval knights in Edwin Austin Abbey's murals ${\ll}$The Quest of the Holy Grail${\gg}$ in the Boston Public Library. Medieval knights in the Arthurian legend appeared in American novels at the end of 1850s and in political cartoons in the 1870s. They are featured in American Renaissance murals as well. ${\ll}$The Quest of the Holy Grail${\gg}$ painted in 1895 was the first of its kind. In Britain, the Pre-Raphaelites frequently painted medieval knights. Abbey fused the visual idiom of the Pre-Raphaelites and that of the Royal Academy of Arts in his depiction of knights. Unlike the Pre-Raphaelites, who usually focused on knights' activities, he emphasized their virtue. His representation of knights reflect the social and economic crises in America in the 1890s. After the Civil War, American society enjoyed economic prosperity but suffered from government corruption, economic inequality, and class conflict. Serious social problems such as poverty and inequality decayed American society. Writers and artists brought attention to these issues. This essay argues that Abbey criticized capitalists and expressed his hope for progress through the figure of Galahad as the iconic representation of civic virtue in ${\ll}$The Quest of the Holy Grail${\gg}$. Installed in the Boston Public Library, Abbey's murals performed a public function to warn the viewers of economic and social chaos resulting from government corruption. Abbey's American knights not only emphasized moral responsibility but also promoted patriotism. The artist refashioned medieval knights into American citizens, whose civic virtue became essential to an ideal leader in American society.

• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.1-5
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• 1999

Based on the development of designed technology for aluminum carbody. the prototype aluminum carbody has been constructed. All extrusion profiles required for the carbody has been produced and their quality has also been proven. For sound construction. welding technology to join aluminum extrusion profiles has been developed and jigs for precise assembly of blocks have been made. The aluminum carbody for urban subway train has been completed with the required chamber being set and the welding deformations being constrained by jigs. The safety of the carbody structure has also been proven by the static load test. And also, painting technology has been developed and the surface of the carbody has been pre-treated and painted. The developed technology to construct the aluminum carbody can be used in mass production of aluminum cars ordered by domestic and foreign customers.

• Corrosion Science and Technology
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• v.9 no.1
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• pp.29-33
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• 2010

Laser machining technique, which is used focusing pulse YAG laser beam irradiation was applied to form area ratio controlled model cut-edge on pre painted Zn coated steels. A corrosion behavior of formed model cut-edge was investigated by rest potential measurement in 1 mol $m^{-3}$ NaCl with and without 0.5 kmol $m^{-3}$ $H_3BO_4$/0.05kmol$m^{-3}$ $Na_2B_4O_7$. The rest potential showed almost constant value with fluctuations. The amplitude of fluctuations increased with exposed area of steel surface. White corrosion products of zinc oxide and simonkollite was formed after the experiments at the formed model cut-edge.

• Journal of Conservation Science
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• v.20
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• pp.9-22
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• 2007

Three kinds of natural pesticides extracted from plants which are being sold in the Korean markets, were estimated effects on materials of art of museum. Tested samples were 1) silk fabrics : undyed, dyed(amur cork tree, gallut, gallut(alum post mordancy), gallut(copperas post mordancy), gardenia, turmeric, acorn, acorn(copperas post mordancy), gromwell, madder, madder(alum post mordancy), safflower, sappanwood, sappanwood(alum pre mordancy, post mordancy), indigo, indigo+amur cork tree, indigo+sappanwood) 2) cotton fabrics : undyed, dyed(amur cork tree, gallut, gallut(alum post mordancy), gardenia, acorn, acorn(copperas post mordancy), gromwell, madder, madder(alum post mordancy), safflower, sappanwood, sappanwood(alum pre mordancy, post mordancy), indigo, indigo+sappanwood) 3) undyed ramie fabric 4) Korean papers : undyed, dyed(sappanwood, indigo, gardenia, amur cork tree, safflower) 5) pigments : azurite, malachite, red lead, litharge, orpiment, hematite, iron oxide, cinnabar, vermilion, indigo, lake indigo, kaolin, lead white, oyster shell white 6) painted plates : azurite, malachite, red lead, litharge, orpiment, hematite, iron oxide, cinnabar, vermilion, indigo, lake indigo, kaolin, lead white, oyster shell white. Conditions of tests were that after samples were exposed to 10 times of promoted concentration for 9 months in relative humidity $55{\pm}1%$ and temperature $20{\pm}2^{\circ}C$, they were compared with standards. Items of estimation were color difference(${\Delta}E^*$) and tenacity. After exposure to pesticides, undyed silk cotton ramie fabrics and Korean papers were not nearly changed in their colors, but colors of most of dyed samples were clearly changed by pesticides except for partial samples(acorn- and madder-dyed fabrics etc, gardenia-dyed samples). Especially changes of colors of turmeric-dyed silk fabrics were most distinct. And colors of pigments and painted plates containing lead, copper, arsenic, mercury and vegetable pigments, were clearly changed. Tenacities of yams of undyed silk fabrics were not nearly changed and undyed cotton fabrics were a little reduced as compared with standards. But tenacities of yams of dyed silk and cotton fabrics were clearly reduced or increased as compared with standards. Especially, madder-dyed silk fabrics were increased 10% or more and indigo-dyed silk fabrics were reduced 10% or less in all pesticides. Also madder- and sappanwood(alum post mordancy)-dyed cotton fabrics were increased 10% or more in all pesticides.