• 제목/요약/키워드: Fluorescent probe

검색결과 172건 처리시간 0.03초

A Study on Emission Characteristics of Ar Gas Using a Single Langmuir Probe Method in Radio-Frequency Inductively Coupled Plasma (13.56MHz ICP에서 단일 탐침법에 의한 Ar 가스의 발광특성 연구)

  • Jo, Ju-Ung;Choi, Yong-Sung;Kim, Yong-Kab;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.611-615
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    • 2004
  • In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, Electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The electrodeless fluorescent lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, electron temperature and electron density were measured in a radio-frequency inductively coupled plasma using a Langmuir probe method for emission characteristics. Measurement was conducted in an argon discharge for pressure from 10 [mTorr] and input RF power 100 [W] to 150 [W]. As for the electron density, a electron temperature was more distinguished for a emission characteristic. The results of ideal may contribute to systematic understanding of a electrodeless fluorescent lamps of emission characteristics.

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Turn-On Type Fluorogenic and Chromogenic Probe for the Detection of Trace Amount of Nitrite Ion in Water

  • Saleem, Muhammad;Abdullah, Razack;Hong, In Seok;Lee, Ki-Hwan
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.389-393
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    • 2013
  • A rhodamine B-based fluorescent probe for nitrite ion ($NO{_2}^-$) has been designed, synthesized, characterized and its properties for recognition of $NO{_2}^-$ were studied. Nearly non fluorescent probe upon reaction with nitrite ion significantly triggered the fluorescence. Fluorescence response is based on ring opening of the spirolactam of rhodamine B phenyl hydrazide showing maximum absorbance at 552 nm and maximum emission at 584 nm. Probe 3 exhibited high sensitivity and extreme selectivity for nitrite ion over other common ions and oxidants ($Cl^-$, $ClO^-$, $ClO{_2}^-$, $ClO{_3}^-$, $ClO{_4}^-$, $SO{_4}^{2-}$, $SiO{_3}^{2-}$, $NO{_3}^{2-}$, $CO{_3}^{2-}$) examined in methanol water (1:1, v/v) at pH 7.0. The probe might be a new efficient tool for detection of nitrite ion in natural water and biological system.

The Effect of Cure History on the Fluorescence Behavior of an Unsaturated Polyester Resin with A Fluorescence Probe

  • Donghwan Cho;Yun, Suk-Hyang;Bang, Dae-Suk;Park, Il-Hyun
    • Macromolecular Research
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    • 제12권3호
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    • pp.282-289
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    • 2004
  • We have extensively characterized the fluorescence behavior of unsaturated polyester (UP) resin in the absence and presence of a 1,3-bis-(l-pyrenyl)propane (BPP) fluorescent probe at various dynamic and isothermal cure histories by means of a steady-state fluorescence technique using a front-face illumination equipment. In addition, we explored the effect of the fluorescence intensity on the relaxation of the fluorescent probe in the UP resin by resting the dynamically and isothermally cured resin at ambient temperature and pressure for 24 h. The monomer fluorescence intensity, which has two characteristic peaks at 376 and 396nm, changed noticeably depending on the cure temperature and time and provided important information with respect to the molecular and photophysical responses upon curing. The result of the fluorescence study indicates that the increased local viscosity and restricted molecular mobility of the UP resin surrounding the BPP probe after curing are both responsible for the enhancement of the monomer fluorescence intensity. Our results also demonstrate that once the BPP probe has enough time to rearrange and become isolated prior to fluorescence, a sufficient amount of fluorescence is emitted. Therefore, we note that the fluorescence behavior of this UP resin system is influenced strongly by the relaxation process of the fluorescent probe in the resin as well as process used to cure the resin.

Rhodamine Cyclen-based Fluorescent Chemosensor for the Detection of Cd2+

  • Shim, So-Young;Tae, Jin-Sung
    • Bulletin of the Korean Chemical Society
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    • 제32권spc8호
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    • pp.2928-2932
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    • 2011
  • A chemosensor based on a rhodamine-hydroxamate platform containing a pyridine and a cyclen binding units has been developed for the detection of $Cd^{2+}$ in aqueous solutions. The probe responds selectively toward $Cd^{2+}$ over other biologically relevant metal ions. The fluorescent probe shows 1:1 binding stoichiometry and the detection limit for $Cd^{2+}$ in water proved to be as low as 25 nM.

Detection of Near-membrane Calcium Ions in Live Tissues with a Two-Photon Fluorescent Probe

  • Shin, Yu-Na;Lim, Chang-Su;Tian, Yu Shun;Rho, Won-Young;Cho, Bong-Rae
    • Bulletin of the Korean Chemical Society
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    • 제31권3호
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    • pp.599-605
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    • 2010
  • A two-photon fluorescent probe (ACaCL) that can detect near-membrane $Ca^{2+}$ is reported. This probe can be excited by 780 nm fs pulses, shows high photostability and negligible toxicity, and can visualize near-membrane $Ca^{2+}$ in live cells and deep inside live tissues by two-photon microscopy.

Electron Density Measurement of Inductively Coupled Plasma by Ar Gas Pressure (Ar 가스 압력에 따른 유도결합형 플라즈마의 전자 밀도 측정)

  • 이영환;김광수;조주웅;박대희
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • 제52권11호
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    • pp.508-511
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    • 2003
  • In this paper, electrical characteristics of inductively coupled plasma in an electrodeless fluorescent lamp were investigated using a Langmuir probe with a variation of argon gas pressure. The RF output was applied in the range of 5 ∼ 50 (W) at 13.56 (MHz). The internal plasma voltage of the chamber and the probe current were measured while varying the supply voltage to the Langmuir probe in the range of -100 (V) ∼+100 (V). When the pressure of argon gas was increased, electric current was decreased. There was a significant electric current increase from l0W to 30 〔W〕. Also, when the RF power was increased, electron density was increase. This implies that this method can be used to find an optimal RF rower for efficient light illumination in an electrodeless fluorescent lamp.

Tune Metal Ion Selectivity by Changing Working Solvent: Fluorescent and Colorimetric Recognition of Cu2+ by a Known Hg2+ Selective Probe

  • Tang, Lijun;Guo, Jiaojiao;Huang, Zhenlong
    • Bulletin of the Korean Chemical Society
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    • 제34권4호
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    • pp.1061-1064
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    • 2013
  • A known $Hg^{2+}$ selective rhodamine B derivatised probe 1 was reinvestigated as a colorimetric and fluorescent probe for $Cu^{2+}$ through changing the applied solvent media. Probe 1 exhibited good selectivity and sensitivity to $Cu^{2+}$ in $CH_3CN-H_2O$ (7:3, v/v, HEPES 10 mM, pH 7.0) solution with a detection limit of $9.74{\times}10^{-7}$ M. The $Cu^{2+}$ sensing event was proved to be irreversible through hydrolysis of 1 to release rhodamine B.

Electron Density Measurement of Inductively Coupled Plasma Using Langmuir Probe (Langmuir Probe를 이용한 유도결합형 플라즈마의 전자 밀도 측정)

  • Lee, Young-Hwan;Jo, Ju-Ung;Kim, Kwang-Soo;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.1111-1114
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    • 2003
  • In this paper, electrical characteristics of inductively coupled plasma in an electrodeless fluorescent lamp were investigated using a Langmuir probe with a variation of argon gas pressure. The RF output was applied in the range of $5{\sim}50W$ at 13.56MHz. The internal plasma voltage of the chamber and the probe current were measured while varying the supply voltage to the Langmuir probe in the range of $-100V{\sim}+100V$. When the pressure of argon gas was increased, electric current was decreased. There was a significant electric current increase from l0W to 30W. Also, when the RF power was increased, electron density was increase. This implies that this method can be used to find an optimal RF power for efficient light illumination in an electrodeless fluorescent lamp.

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