• Title/Summary/Keyword: 변색

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Development of Energy Harvesting Hybrid system consisted of Electrochromic Device and Dye-Sensitized Solar Cell using Nano Particle Deposition System (나노 입자 적층 시스템(NPDS)을 이용한 염료 감응 태양전지 - 전기 변색 통합 소자 및 에너지 하베스팅 시스템에 대한 연구)

  • Kim, Kwangmin;Kim, Hyungsub;Choi, Dahyun;Lee, Minji;Park, Yunchan;Chu, Wonshik;Chun, Dooman;Lee, Caroline Sunyong
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.2
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    • pp.65-71
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    • 2016
  • In this study, Antimony Tin Oxide (ATO) ion storage layer and $TiO_2$ working electrode were fabricated using Nano Particle Deposition System. NPDS is the cutting-edge technology among the dry deposition methods. Accelerated particles are deposited on the substrate through the nozzle using NPDS. The thicknesses for coated layers were measured and layer's morphology was acquired using SEM. The fabricated electrochromic cell's transmittance was measured using UV-Visible spectrometer and power source at 630 nm. As a result, the integrated electrochromic/DSSC hybrid system was successfully fabricated as an energy harvesting system. The fabricated electrochromic cell was self-operated using DSSC as a power source. In conclusion, the electrochromic cell was operated for 500 cycles, with 49% of maximum transmittance change. Also the photovoltaic efficiency for DSSC was measured to be 2.55% while the electrochromic cell on the integrated system had resulted in 26% of maximum transmittance change.

Green Teeth Associated Hyperbilirubinemia in Primary Dentition (유치열에서의 고빌리루빈혈증과 연관된 초록색 변색)

  • Park, Min Kyung;Sun, Yeji;Kang, Chung-Min;Lee, Hyo-Seol;Song, Je Seon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.44 no.3
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    • pp.378-383
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    • 2017
  • There are many reasons for tooth discoloration. An increase in the bilirubin level may cause tooth discolorations. Such cases are rare, but most involve tooth discoloration with a greenish hue. The purpose of this case report is to describe green discoloration of the primary dentition in the presence of neonatal hyperbilirubinemia. 2 boys aged 16 and 22-months presented with chief complaints of erupting teeth of abnormal color. Their primary teeth exhibited a greenish discoloration along enamel hypoplasia. Both patients were born prematurely with a low birth weight and had been diagnosed with neonatal hyperbilirubinemia. Systematic diseases can affect the hard tissue of teeth during their formation and result in changes in tooth color. Periodic follow-ups are required for establishing a normal dental condition and meeting the esthetic needs of patients. A pediatric dentist may be the first person to observe patients with discoloration in their primary dentition. In such cases the dentist can deduce the systematic disease responsible for this discoloration.

Applicability of Colormetric Method for Estimation of Chloride Penetration in Concrete Structures (콘크리트 구조물의 염화물 침투 특성 파악을 위한 변색법의 적용성)

  • Yang Eun-Ik;Kim Myung-Yu;Leem Young-Moon;Park Hae-Geun
    • Journal of the Korea Concrete Institute
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    • v.17 no.6 s.90
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    • pp.931-938
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    • 2005
  • When concrete structures are exposed under marine condition for a long time, the steel in concrete is corroded due to the ingression of chlorides in the seawater. Because the damages of corrosion resulting from the chloride ion are very serious, many researches have been performed. Silver nitrate colormetric method that can measure easily penetration depth of chloride ion has been executed, recent)y. However, characteristics of silver nitrate colormetric method were not fully examined. Therefore, the objective of this paper Is to study the applicability of colormetric method. For the purpose of this, effect factors and reaction mechanism of colormetric method were investigated, and the colormetric method is applied for marine concrete structures. According to the results of silver nitrate colored method, two reactions such as white reaction of AgCl and brown reaction of AgOH were shown when $AgNO_3$ was sprayed in splited section. And velocity constant ratio(K) of two reactions appeared that white reaction, AgCl reacts with the fast speed by 3240. When the colormetric method was applied in concrete, it is reasonable that $AgNO_3$ solution more than 0.05N concentration was sprayed. It is confirmed that the colormetric method is useful tool for estimating the chloride of concrete structures in situ. The average chloride amount of colored parts indicates $0.9kg/m^3$ per concrete unit weight.

Study on the Discoloration Identified from the Column of Wooden house, Hyunchungsa(Shrine) - Focused on Influence of Microorganisms and Correlation with Strength - (현충사 옛집의 기둥 하부 변색에 관한 연구 - 미생물에 의한 영향 및 강도와의 상관관계를 중심으로 -)

  • Jeong, So-young;Seo, Min-seok;Hong, Jin-young;Kim, Soo-ji;Jeong, Ah-ruem;Kim, Ji-seo
    • Korean Journal of Heritage: History & Science
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    • v.47 no.4
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    • pp.58-73
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    • 2014
  • In general, it is thought discoloration on wood is frequently found in decorative wood products. So this study was conducted focusing on white rot found lower parts of columns and baseboards of a wooden house, Hyunchungsa (shrine) to know whether microorganisms have any influence on discoloration or there is correlation with strength by investigating resistograph, occurrence of microorganisms and microscopy for analysis(SEM, tissue analysis etc.). The results obtained were as follows: (1) The result of measurement of resistograph showed there are little correlation between discoloration and strength though there was a spot indicating low resistance. (2) The moisture content of discolored part was relatively higher than that of normal parts, but occurrence of microorganisms was less in discolored parts while more kinds of microorganisms were identified in normal parts with high CFU(Colony Forming Unit). (3) The result of SEM (with a magnification of 500 times) on the surface of discolored parts, it was found out there are many kinds of particles in different sizes on the surface and those were composed of elements such as C, O, Si, Ca, and a small amount of Na and Cl (weight %) were detected in part. (4) The result of tissue analysis showed discoloration occurs limitedly to the outer surface of column. As these results, it is concluded that discoloration has nothing to do with strength, damage by microorganisms and salt.

Enhanced Electrochromic Switching Performance in Nickel Hydroxide Thin Film by Ultra-Thin Ni Metal (니켈금속 박막에서 수산화 니켈 박막의 전기변색속도 개선)

  • Kim, Woo-Seong;Seong, Jeong-Sub
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.2
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    • pp.163-167
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    • 2002
  • Improved optical switching property of electrochromic nickel hydroxide/nickel glass thin film is reported. Nickel metal film was deposited on glass by e-beam evaporation before following electrochemical redox cycling to form nickel hydroxide for electrochromic activation. Without ITO (indium tin oxide) layer as electrical conductor, this electrode showed more rapid coloration rate than nickel hydroxide film on ITO substrate in the change of the electric voltage and optical transmittance. XPS analysis confirmed the existence of ultra-thin nickel metal layer (${\sim}10{\AA}$) between electrochemically grown nickel hydroxide and the glass substrate. It is concluded that the remained nickel metal nano-layer attribute to the conduction layer and the enhanced response time.

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Electrochromic Property of a Conductive Polymer Film Fabricated with Vapor Phase Polymerization (증기중합으로 제조된 전도성 고분자 박막의 전기 변색 특성)

  • Lee, Ji-Yea;Kim, Yu-Na;Kim, Eun-Kyoung
    • Membrane Journal
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    • v.20 no.1
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    • pp.8-12
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    • 2010
  • Poly(3,4-ethylenedioxythiophene) (PEDOT), which has the highest stability in conducting polymer was employed to electrochromic (EC) film and studied about electrochromic properties according to the film fabrication method. PEDOT films were coated by two different methods, electropolymerization (EP) and vapor phase polymerization (VPP). Both of PEDOT films showed dark blue color at dedoped neutral state. Spectroelectrochemistry, switching ability and stability of the devices were investigated by UV-Vis Spectrophotometer and Cyclic voltammetry. Surface morphologies of the PEDOT VPP film at oxidized and reduced state were obtained by AFM. The average surface roughness of the PEDOT-VPP film was 50 nm and more homogeneous than that of the PEDOT-EP. The EC property from the PEDOT-VPP film was improved compared to that of the PEDOT-EP film, to show a response time of 1.5 sec, transmittancechange of 49%, and coloration efficiency of 402.

Discoloration Effects of LEDs on Painting Binder Materials (LED광원에 의한 회화 전색제의 변색 영향 연구)

  • Kim, Ji Won;Lee, Yu Jung;Kim, Kyu Lin;Lee, Hwa Soo;Kang, Dai Ill
    • Journal of Conservation Science
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    • v.34 no.2
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    • pp.77-85
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    • 2018
  • In order to understand the influence of light artifact discoloration, priority must be given to the reaction characteristics of the light the materials constituting the product. In this study, we focus on two representative medium, animal glue and linseed oil which constitute the colored layer of the painting relics. This study is based on an accelerated degradation test using two types of light emitting diods (LEDs) with different wavelength characteristics. In the experiments, discoloration appeared markedly in the animal glue and linseed oil under accelerated aging test conditions using Blue LED. Among the two types of LEDs, the degree of discoloration of the material was much higher with the Blue LED having the total radiation flux (mW). This indicates that the discoloration of painting artifacts such as animal glue and linseed oil is more significantly influenced by the total radiation flux (mW) of the light source than the total luminous flux (lm).

Preparation and Characteristics of Photochromic Plastic Lenses by Hard Coatings (하드코팅에 의한 광변색 플라스틱 렌즈의 제조 및 특성)

  • Yu, Dong-Sik;Ha, Jin-Wook;Moon, Byeong-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.7
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    • pp.1635-1641
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    • 2009
  • In this study, we have prepared plastic lenses with both photochromic and hard properties by hard coating, and evaluated their optical properties and surface characteristics. Photochromic effects could be observed on the UV spectra of the closed forms and the visible spectra of the open forms. Visible light transmittance of photochromic lenses was from 83.44% for graphite(GP) to 85.15% for blue(BL) in colourless state and from 71.10% for red(RE) to 79.98% for yellow(YE) in colour state. Red photochromic lens was higher in optical density(${\Delta}$OD) and color difference(${\Delta}$$E^{\ast}_\;{ab}$) than the others. Photochromic lenses applied by hard coating showed good adhesion, hot water resistance, chemical resistance and surface appearance. Also, compared to the uncoated lens, hardness and abrasion resistance were increased. Consequently, this coating system could impart functional properties such as photochromic and hard coating property onto ophthalmic lenses.

Extraction and Quality Characteristics of Porphyran from Laver(Porphyra yezoensis) Waste (김 부산물로부터 Porphyran의 추출 및 품질특성)

  • Kim, Seon-Jae;Ma, Seung-Jin;Jang, Yoon-Sen
    • Journal of the Korean Society of Food Culture
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    • v.20 no.4
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    • pp.446-450
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    • 2005
  • Chemical compositions such as total sugar, sulfate/total sugar, protein and 3,6-anhydrogalactose content of porphyran extracted from commercial laver, discolored laver and laver waste were measured. The total sugar contents of commercial laver, discolored laver and laver waste showed 54.5%, 45.7% and 56.2%, respectively. The total sugar of the commercial laver and laver waste were showed almost similar portion although that of discolored laver showed relatively lower level. The sulfate/total sugar contents showed 17.6%, 13.9% and 17.3%, and 3,6-anhydrogalactose contents showed 13.8%, 9.1% and 13.9% in commercial laver, discoloredlaver and laver waste respectively.