• Textile Coloration and Finishing
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• v.15 no.6
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• pp.47-54
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• 2003

To be dyed with cationic Berberine, the cotton fiber was modified with reactive anionic agent. The Berberine, a natural cationic colorant of pure yellow, is the major component of Amur Cork tree extract and also can be employed as a natural antimicrobial agent due to its characteristic of cationic quaternary ammonium salt. By LC/MS analysis, it became obvious that the Berberine was contained in Amur Cork tree extract as a major color component. The adsorption of the Berberine on the cotton fabrics pretreated with the anionic agent was greatly increased comparing to that of untreated fabric. Because the anionic agent was colorless, it did not cause unintended color change of the dyeings. The dyed fabric with the Berberine has strong antimicrobial activity showing 99.5% of reduction of bacteria against Staphylococcu aureus.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.231-236
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• 1998

In general, the drying shrinkage of polymer-modified mortars using redispersible polymer powders is much higher than that of unmodified mortar. The purpose of this study is to reduce the drying shringkage of polymer-modified mortars using a redispersible poly(ethylene-vinyl acetate) (EVA) powder, which is widely used for the manufacture of prepackaged-type polymer-modified mortar products at present. Polymer-modified mortars using the redispersible EVA powder with powdered shrinkage-reducing agent were prepared with various polymer-cement ratios and shrinkage-reducing agent contents, and tested for drying shrinkage and strength. From the test results, the drying shrinkage of the redispersible EVA powder-modified mortars with a powdered shrinkage agent is remarkably reduced with increasing shrinkage-reducing agent content, and becomes approximately a half of that of the redispersible EVA powder-modified mortars with the same polymer-cement ratios and without the shrinkage-reducing agent at a shrinkage-reducing agent content of 6%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.9-10
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• 2017

In case of the concrete is poured into the HPC(Hollow Precast Concrete) column, the shrinkage condition of the HPC surface and the infilled concrete may be different, causing an interfacial space and deteriorating the integration performance. In this study, manufacturing HPC column mold and and the drying shrinkage properties with the charging concrete were examined. As a result, case of the shrinkage reducing agent showed the best drying shrinkage reduction effect. In the case of the expansive agent, the length change was lower than that of plain, but the difference from the shrinkage reducing agent was large, so it is considered that mixing condition of expansion mixing condition should be improved.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.32-33
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• 2017

In order to improve the flow performance of high performance concrete, use of high performance water reducing agent and low viscosity type water reducing agent is a study of suitable range of use due to side effects. in this study, we aimed at reducing viscosity and yield value using high performance water reducing agent and low viscosity type water reducing agent, and this was evaluated using a rheometer. as a result of analysis of viscosity and yield value, it was found that the high performance water reducing agent has higher reduction effect than the low viscosity type water reducing agent. however, the larger the viscosity lowering effect is, the lower the usable range is, compared to general high performance water reducing agents, and it was found that sufficient consideration for this judgment of appropriate quantity is necessary.

• Journal of the Korean Ceramic Society
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• v.31 no.8
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• pp.893-901
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• 1994

In this study, AlN powder of fine particle size and of high purity was synthesized by the carbothermal reduction-nitridation of monodisperse, spherical Al(OH)3 which had been prepared by sol-gel method using Al(O-sec-C4H9)3 as the starting material. Depending on the mixing order and kinds of reducing agents, the optimum condition for the preparation of AlN was determined as follows. AlN single-phase was produced by the carbothermal reduction-nitridation of (1) Benzene-washed Al(OH)3 and the reducing agent, carbon, which was mixed in a ball mill: for 5 hours at 140$0^{\circ}C$ under NH3 atmosphere; (2) The mixture prepared by hydrolysis of alkoxide solution into which carbon had been dispersed beforehand: for 5 hours at 135$0^{\circ}C$ ; (3) Al(OH)3 Poly(furfuryl alcohol) composite powder: for 2.5 hours at 135$0^{\circ}C$; (4) The mixture of Al(OH)3 and polyacrylonitrile: for 5 hours at 140$0^{\circ}C$. Addition of CaF2 increased the nitridation rate when carbon or polyacrylonitrile was used as the reducing agent; but it had no effect on the nitridation rate when furfuryl alcohol was used as the reducing agent.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.577-585
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• 2001

Dyeing properties of the colorants extracted from pomegranate hull on cotton fabric were investigated. Effects of dyeing conditions and mordanting on dye uptake, color change and colorfastness were explored. Cationic agent treatment was done for cotton to improve low dyeability in natural dyeing. In addition antimicrobial activity of the cotton fabrics dyed with pomegranate colorants was examined by the shake flask method. Pomegranate colorants showed low affinity to cotton fiber and its adsorption isotherm was Freundlich type. Therefore, hydrogen bonding was involved in the adsorption of pomegranate colorants onto cotton fiber. Mordants did not significantly increase dye adsorption. Pomegranate colorants produced mainly yellow color on cotton fabric. In order to improve dye uptake, cotton was cationized by treating with Cationon UK(quarterly ammonium salt) and chitosan. The cationized cotton with Cationon UK showed higher dye uptake and shorter dyeing time, compared with the untreated cotton. Chitosan treated cotton also showed high dye uptake, but chitosan was less effective compared with Cationon UK. Fastness to washing, perspiration, and rubbing was not improved by mordanting and cationizing treatment, but light fastness was increased by all mordants and cationic agent. As dye concentration increased, bacterial reduction rate was increased and mordants did not significantly increase bacterial reduction rate.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.117-122
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• 2013

This study is aimed to develop LNT(Lean NOx Trap) aftertreatment system for DME engine. Modified DME engine, which was changed from diesel to current DME engine, is used for this research and is equipped with common rail type injector and fuel supplying system. LNT system has reductant injector. DME is also used as reduction agent. For this research, reduction agent injection time width and interval were varied. And also, swirler was used to improve homogeneity of reducing agent in exhaust pipe. The reduction rate of NOx by LNT was increased by longer injection width, short interval and swirler. The maximum diminution of NOx by LNT was over 85%.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.389-393
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• 1991

A convenient method for the synthesis of indobufen, which is a potent antiinflammatory agent, was described. Ethyl 2-phenylbutyrate(4) was prepared by Friedel-Crafts reaction of benzene with ethyl $\alpha$-chloro-$\alpha$-(methylthio)acetate(l) followed by ethylation and desulfurization of the resultant ethyl 2-(methylthio)phenylacetate(2). Ethyl 2-(p-aminophenyl)butyrate(6) was prepared by nitration of (4) and successive reduction of ethyl 2-(p-nitrophenyl) butyrate(5). Indobufen was obtained by condensation reaction of (6) with phthalic anhydride followed by reduction and hydrolysis of the resultant ethyl 2-[p-(1, 3-dioxo-2-isoindolinyl)phenyl]butyrate(7).

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.505-509
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• 2013

A low temperature ($65^{\circ}C$) thermal deposition process was developed for depositing a silver coating on thermally sensitive polymeric substrates. This low temperature deposition was achieved by chemical reduction of a silver alkylcarbamate complex with latent reducing agent. The effects of acetol as a latent reducing agent for the silver 2-ethylhexylcarbamate (Ag-EHCB) complex and their blend solutions were investigated in terms of reducing mechanism, and the size and shape of silver nanoparticles (Ag-NPs) as a function of reduced temperature and time, and PVP stabilizer concentration were determined. Low temperature deposition was achieved by combining chemical reduction with thermal heating at $65^{\circ}C$. A range of polymer film, sheet and molding product was coated with silver at thicknesses of 100 nm. The effect of process parameters and heat treatment on the properties of silver coatings was investigated.

• Textile Coloration and Finishing
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• v.8 no.5
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• pp.1-6
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• 1996

To obtain the basic data of the effect of antimicrobic finishing on chrome-tanned leather for apparel, it was studied that the specimens given from each step of manufacturing process, that is, steps before and after neutralization and after fixation were treated with Si-QAC as a antimicrobic finishing agent, and the antimicrobic activity was evaluated. The results were as follows: 1. The bacterial reduction of the specimens finished antimicrobically were 100% and 94.4% before and after neutralization respectively, however, the specimens carried out successive process after antimicrobic finishing exhibited the reduction of 16.5% and 14.8%. It was assumed that the antimicrobic agent was washed off by the successive process. 2. When the antimicrobic finishing was carried out on the specimens after fixation the bacterial reduction was 95.0% and then the specimen carried out successive process was 97.3%. This result indicates that antimicrobic finishing on the leather would be given after fixation rather than before and after neutralization.