• Title/Summary/Keyword: Red Shift

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Structure Control of Merocyanine LB Films by Optical Absorption Spectra (광 흡수 Sepectra 에 의한 메로시아닌 LB막의 구조제어)

  • 신훈규;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.401-404
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    • 1996
  • Optical absorption were performed on LB films of binary mixtures of three kinds of merocyanine dyes [DO], [DS], and [6Me-DS], where [DS] and [6Me-DS] from J-like aggregates but not [DO] in single component films. The observed optical absorption spectra of mixed films were markedly dependent on the combination of dyes. [DS]$_{1-x}$ [DO]$_{x}$ LB films show a sharp red shift J-like band peak in the while concentration range. We found the formation of J-aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye [DO], in a single component case. Further investigations on the present and other mixed dye films will be needed to clarify these points.ts.

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Photocatalyst Effect of Polyester Fabrics Treated with Visible-light Responsive Photocatalyst

  • Choi, Sei Young
    • Elastomers and Composites
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    • v.51 no.1
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    • pp.31-37
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    • 2016
  • In this study, we studied the photocatalytic functionality such as deodorant, antibacterial, antistatic of polyester fabrics treated with visible-light responsive photocatalyst. According to UV/visible spectrometry result, the UV-visible peak of visible-light responsive photocatalyst was found to be red shift at 420 nm sensitive in the visible light region. Also, the deodorizing and antimicrobial performance were shown to be retained more than 99% both before washing and even after 25 times washing. According to washing durability of polyester fabrics treated with visible-light responsive photocatalyst, the reduction effects for gas such as ammonia, trimethylamine, formaldehyde and toluene after 25 times washing appeared to be retained as much as before washing. At both before washing and after 25 times washing, antistatic property showed frictional voltage of approximately 250V.

A Study on the Reduction of VOCs Generated from Vehicle Interior Parts and Materials Using Visible-light Responsive Photocatalyst (가시광촉매를 이용한 자동차 내장재로부터 발생하는 VOCs의 저감연구)

  • Choi, Sei-Young;Yang, Seung-Gi
    • Elastomers and Composites
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    • v.48 no.3
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    • pp.209-215
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    • 2013
  • On this study, visible-light responsive photocatalyst prepared by sol-gel method was evaluated the effect of the reduction of volatile organic compounds (VOCs) occurred in vehicle interior and its property was examined. According to UV/visible result, visible-light responsive photocatalyst was found that the UV-visible peak is red shift at 420nm, is sensitive in the visible light region. With vehicle interior parts and materials coated visible-light responsive photocatalyst, VOCs was measured by GC/MS. Measuring the VOCs generated from vehicle interior parts and materials, the reduction of VOCs was confirmed.

Magnetic and Photo-catalytic Properties of Nanocrystalline Fe Doped $TiO_2$ Powder Synthesized by Mechanical Alloying

  • Uhm, Y.R.;Woo, S.H.;Lee, M.K.;Rhee, C.K.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.955-956
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    • 2006
  • Fe-doped $TiO_2$ nanopowders were prepared by mechanical alloying (MA) varying Fe contents up to 8.0 wt.%. The UV-vis absorption showed that the UV absorption for the Fe-doped powder shifted to a longer wavelength (red shift). The absorption threshold depends on the concentration of nano-size Fe dopant. As the Fe concentration increased up to 4 wt.%, the UV-vis absorption and the magnetization were increased. The benefical effect of Fe doping for photocatalysis and ferromagnetism had the critical dopant concentration of 4 wt.%. Based on the UV absorption and magnetization, the dopant level is localized to the valence band of $TiO_2$.

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Biosensor Based on Distributed Bragg Reflector Photonic Crystals for the Detection of Protein A

  • Jung, Daehyuk
    • Journal of Integrative Natural Science
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    • v.3 no.1
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    • pp.33-37
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    • 2010
  • The functionalized photonic crystals of porous silicon biosensor was prepared for the application as a label-free biosensor based on distributed Bragg reflector interferometer. Prepared distributed Bragg reflector of porous silicon biosensor displayed sharp reflection in the optical reflective spectra. The mean of construction of molecular architectures on distributed Bragg reflector of porous silicon surfaces was investigated for the step-by-step binding interaction with amines, biotin, avidin, and biotinylated protein A. The subsequent introduction of avidin, and biotinylated protein A resulted in the reflectivity shifted to longer wavelengths, indicative of a change in refractive indices induced by binding of biomolecules.

Fabrication and Characterization of Silole and Biotin-functionalized Rugate Porous Silicon

  • Kwon, Hyungjun
    • Journal of Integrative Natural Science
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    • v.3 no.1
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    • pp.24-27
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    • 2010
  • Multi-functionalized rugate porous silicon (PSi) for biosensor was developed by hydrosilylation with silole and its further reaction with biotin groups. PSi was generated by an electrochemical etching of silicon wafer in aqueous ethanolic HF solution PSi prepared by using etching conditions showed that many sharp spectral lines can be obtained in the optical reflectivity spectrum. 1,1-hydrovinyl-2,3,4,5-tetraphenylsilole was obtained from the reaction of 1,1-dilithio-2,3,4,5-tetraphenyl-1,3-butadiene with dichlorovinylsilane. Multi-functionalized PSi with silole and biotin groups was characterized by UV-vis absorption spectroscopy, Ocean optics 2000 spectrometer, and fluorescence spectroscopy. Optical characteristics such as reflectivity and photoluminescence (PL) were observed. An increase of the reflection wavelength in the reflectivity spectrum by 20 nm was observed, indicative of a change in refractive indices induced by hydrosilylation of the silole and biotin groups to the rugate PSi. This red-shift was attributed to the replacement of some of the Si-H group of fresh rugate PSi with silole and biotin group.

Design of Camera for QUasars in EArly uNiverse II

  • Choi, Nahyun;Pak, Soojong;Oh, Young-Seok;Lee, Hyein;Choi, Changsu;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.72.1-72.1
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    • 2013
  • Camera for QUasars in EArly uNiverse (CQUEAN) is an optical CCD camera, developed by Center for Exploration of Origin of the Universe (CEOU), which is now searching for high red shift quasar candidates. It has been operated since 2010, attached to the 2.1m Otto Struve telescope at the McDonald Observatory, USA. Based on the previous operation experiences, we present CQUEAN II system design which has a new filter wheel allowing with 20 narrow band filters. In addition, the auto guiding system will be rearranged and the interfacing units between the telescope and the instrument will become stabilized.

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New generation polydiacetylenes: Thermo-optical properties as active materials of thermally actuated display devices

  • Yarimaga, Oktay;Lee, Su-Mi;Kim, Jong-Man;Choi, Yang-Kyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.457-460
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    • 2009
  • The thermo-optical characteristics of new generation fully reversible diacetylene vesicles, DCDDA-mono-mBzA and DCDDA-bis-mCPE, and their solid film composites are utilized as thermochromic display materials. Conspicuous color intensity of their solid films and blue-to-red color shift with non-fluorescent to fluorescent switching at $100^{\circ}C$ make them promising materials for dual color thermally actuated display devices of the near future.

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A design of constant current driving circuit for LED stage light (LED 무대조명용 정전류 구동회로의 설계)

  • Jung, Kwang-Hyun;Kim, Pyung-Moo;Park, Chong-Yeun
    • Journal of Industrial Technology
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    • v.31 no.A
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    • pp.95-101
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    • 2011
  • According to recent technological developments in high-power LEDs, the stage lighting is one of most important areas to apply power LED system. Moving light for color rendering of stage uses the RGBW(red, green, blue, white) color mixing method. LED moving light system needs to have a wide range of dimming control as enough to operate at very low power. Also LED dimming system should not be induced color-shift and flicker in camera. This paper is experimentally verified the LED Moving Light driving circuit of 200Watt level designed to satisfy the above characteristics which applied the DC current-controlled and PWM mixed dimming method.

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Substitution Effect on Electronic Transition of Bi-substituted Benzyl-type Radicals: Symmetric Substitution

  • Ahn, Hyeon-Geun;Lee, Gi-Woo;Kim, Tae-Kyu;Lee, Sang-Kuk
    • Bulletin of the Korean Chemical Society
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    • v.28 no.11
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    • pp.1993-1995
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    • 2007
  • A substitution effect on the electronic transition of bi-substituted benzyl-type radicals was discovered. The origin of the electronic D1 → D0 transition of benzyl-type radicals was red-shifted upon substitution to the benzene ring. For symmetric bi-substituted benzyl-type radicals, it was found that the predicted shift obtained from mono-substituted benzyl-type radicals agreed well with the observation. The reason for this agreement is believed that the substituent contributes independently to the electronic energy. The substitution effect was applied to the symmetric bi-substituted difluoro-, dichloro- and dimethylbenzyl radicals.