• Title/Summary/Keyword: 변색

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Electrospinning for Smart Acid-Sensitive Fiber Webs (지능형 산-감응 섬유웹을 위한 전기 방사)

  • 소정현;이선화;정재윤;윤기종;조재환
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.259-260
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    • 2003
  • Smart 재료는 외부의 환경에 따라 재료 스스로 주어진 자극을 판단하여 응답할 수 있는 재료를 말한다. 기존의 재료들이 갖는 수동적 응답 기능을 넘어서 생물체처럼 환경에 반응한다는 점에서 뛰어난 특성을 가질 수 있다. 변색성 염료도 이러한 smart 재료 중의 하나로 광, 온도, 화학물질, 전기장 등의 외부 환경 조건의 변화에 따라 색상이 바뀌게 할 수 있다. 대부분의 변색성 염료는 마이크로 캡슐화하여 섬유나 필름에 부착하는 방법을 사용하는데, 이는 항상 내구성이나 안정성 등에서 문제점을 갖고 있다. (중략)

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Responses of Castanea crenata to Injection Wound for Oxytetracycline(OTC) (옥시테트라사이크린(OTC) 수간주입 상처에 대한 밤나무의 반응)

  • Cha, Byeong-Jin;Yun, Jeong-Koo
    • Korean Journal of Environmental Agriculture
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    • v.15 no.1
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    • pp.77-85
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    • 1996
  • Chestnut(Castanea crenata) were trunk-injected by two methods to check the changes around the injection wound. In September 1993, high concentration of oxytetracycline(OTC) was injected through the injection wound of 1cm diameter and low concentration of OTC through 0.5cm diameter. Trunk diameter of injected trees ranged from 10cm to 20cm. All trees were in their vigorous conditions. Tree reaction was examined in June, 1994. None of them showed any sign of decay by the time. However, under the bark, sapwood was remarkably discolored. But, more severe discoloration was found in 1cm-injection wound than in 0.5cm one. Sapwood of some trees split from the injection wound, and the split was longer in 1cm-injection wounded trees than in 0.5cm trees. From the split, callus grew out and the split was closing. In this kind of trunk injection, the damage was more severe in 1cm-injection wound than in 0.5cm-injection wound.

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An Experimental Study of Metal Polishes Applied on Surface Cleaning of Silver Metal Archival Objects (은제 행정박물의 표면 클리닝에 적용되는 금속광택제 실험연구)

  • Cho, Ha Nui;Cho, Nam Chul
    • Journal of Conservation Science
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    • v.30 no.2
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    • pp.157-168
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    • 2014
  • This study, by selecting 3 kinds(Polish T, H, C) of metal polish being frequently used for silver archival objects treatment at present, a polish having excellent conservative property that minimizes damage of silver surface while effectively removing its yellow discolored layer by each using tool was intended to be discovered by comparing performance of tarnish inhibitor, corrosion inhibitor contained in each polish. As a result of analysis, it was confirmed that specimen that was cleaned with cotton swab and lint-free wipe by using Polish C provides not only uniformed surface expression and minimum damage but also removal function of corrosion layer. In addition, even though tarnish inhibition film should be formed after polish treatment, discolored phenomenon is unable to be prevented but among those polishes, Polish C was represented to be most stable against UV and yellowing and it showed relatively better features than that of Polish H and T in terms of hydrophobic, dispersive property. Through this, it is confirmed that Polish C would show the most excellent performance among polishes being used for conserving silver archival objects.

Hydrothermal Synthesis of Metal-doped BiVO4 Powder and its Thermochromic Properties (금속이 도핑된 BiVO4 분말의 수열 합성 및 이의 열 변색 특성)

  • Wu, Guan Zhu;Son, Dae Hee;Jin, Young Eup;Lee, Gun-Dae;Park, Seong Soo
    • Applied Chemistry for Engineering
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    • v.26 no.6
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    • pp.681-685
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    • 2015
  • In this study, pure $BiVO_4$ powder and metal-doped $M-BiVO_4$ (M = Mg, Cu) powder, well known as thermochromic materials, were prepared from a mixed aqueous solution of bismuth nitrate ($Bi(NO_3)_3$) and ammonium vanadate ($NH_4VO_3$) in autoclave by hydrothermal method. The crystal structure, microstructure, and thermochromic property of samples were analyzed using FE-SEM, FT-IR, XRD, DSC, UV-Vis-NIR spectroscopy and colorimeter. When heating samples above phase transition temperature, the color of $M-BiVO_4$ (M = Mg, Cu) sample was thermally changed more clearly than that of using only pure $BiVO_4$ sample.

Material and Deterioration Characteristic Analysis for Stone Sculptures in Gyeongbokgung Royal Palace, Seoul (경복궁 석조조형물의 재질 및 손상특성 분석)

  • Kim, Jiyoung;Jo, Young Hoon;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.29 no.4
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    • pp.407-420
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    • 2013
  • The stone sculptures in Gyeongbokgung Royal Palace are mainly composed of granite (884 sculptures, 96.7%) and marble (25 sculptures, 2.7%) that originated in several different quarries. Main deterioration forms are crack (24%), break-out (21%), exfoliation (36%), granular disintegration (9%) and blackening (20%). Crack and break-out are dominant contributors to high physical deterioration degree, and blackening is major weathering form of intensive discoloration. The Gyeonghoeru, Geunjeongjeon and Pumgyeseok areas require urgent and high conservation maintenance with short-term periodic monitoring since proportions of 3-grade deterioration were calculated higher than others as 55% for Gyeonghoeru, 29% for Geunjeongjeon, 11% for Pumgyeseok area. The Pumgyeseok (officials' rank stone), especially, needs intervention for protective facility due to its material vulnerability to weathering in outdoor environment.

Damage Factor Interpretation and Conservational Environment Assessment by Microclimatic Analysis of Hyeonpung Seokbinggo (Ice-storing Stone Warehouse), Korea (현풍석빙고의 미기후 분석을 통한 손상요인 해석과 보존환경 평가)

  • Kim, Ji-Young;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.26 no.4
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    • pp.385-395
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    • 2010
  • This study aimed to identify weathering factors and to assess the conservation environment through microclimatic analysis of Hyeonpung Seokbinggo (ice-storing stone warehouse). The stone blocks inside Seokbinggo suffered crack, displacement, break-out, exfoliation, efflorescence, brown and black discoloration, and biological colonization. Biological colonization represented the maximum deterioration rate(24%) among those weathering forms. The indoor microclimate showed parallel patterns with outdoor one, but the indoor temperature and relative humidity ranged far narrower than outdoor and remained steady. The environmental characteristics resulted from blocking-out of outdoor heat by the closed entrance and surrounding microtopography. This prevented water condensation and freezing effects, so that it reduced physical deterioration of rock, and maximized ice-storing effect for long time. However, contrary to positive effect, extremely high relative humidity over 99% accelerated biological colonization inside the Seokbinggo.

Effect of Blanching on the Prevention of Discoloration in the Thermal-treated Chestnut Powder (밤 가루의 변색 방지를 위한 Blanching 효과)

  • Cho, Sung-Hwan;Sung, Nack-Kie;Ki, Woo-Kung;Hur, Jong-Hwa;Shim, Ki-Hwan;Chung, Duck-Hwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.17 no.3
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    • pp.211-214
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    • 1988
  • The thermal drying of chestnut powder showed a distinct discoloration from yellow to reddish brown color and resulted in a decrease in lysine content of chestnut protein. Chanted powders were blanched in hot solutions of 0.1% sodium bisulfate, 0.2% alum, 0.05% vitamin C and 0.1% citric acid and dried for 7 days in $50^{\cire}C$ of heatine drier. The color difference values in contrast with the original chestnut powder were 1.05, 1.24, 3.47 and 3.34, respectively. In particular, the effect of 0.1% potassium metabisulfide was distinguished. Under the blanching conditions used, a blanching period of 3 min resulted in the most favorable color of chestnut powder.

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