• Title/Summary/Keyword: Raman Scattering

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Tip Enhanced Nano Raman Scattering in Graphene

  • Mun, Seok Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.87.2-87.2
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    • 2016
  • As an era of nano science approaches, the understanding on the shape and optical properties of various materials in a nanoscale range is getting important more seriously than ever. Accordingly the development of high spatial-temporal-spectral resolution measurement tools for characterization of nanomaterials/structures is highly required. Generally, the various properties of sample can be measured independently, e.g. to observe the structural property of sample, we use the scanning electron microscopy or atomic force microscopy, and to observe optical property, we have to use another independent measurement tool such as photoluminescence spectroscopy or Raman spectroscopy. In the case of nano-materials, however, it is very difficult to find out the same position of sample at every different measurement processes, and the condition of sample can be changed by the influence of first measurement. The tip enhanced Raman scattering(TERS), which can simultaneously measure the two or more information of sample with nanoscale spatial resolution, is one of solutions of this problem. In this talk, I will present our recent nano Raman scattering data of graphene that measured by TERS and optimized tip fabrication method for efficient experiment.

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A Study on Quantitative Measurements of Equivalence Ratio in Constant Volume Chamber Using UV Laser Raman Scattering (UV Laser Raman Scattering을 이용한 정적 연소기내 분사된 연료의 정량적 당량비 측정에 관한 연구)

  • Jin, S.H.;Heo, H.S.;Kim, G.S.;Park, K.S.
    • Journal of ILASS-Korea
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    • v.3 no.4
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    • pp.35-42
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    • 1998
  • Laser Raman scattering method has been applied to measure equivalence ratio of methane/air and propane/air mixture in constant volume combustion chamber. We used high power KrF excimer laser$(\lambda=248nm)$ and a high gain ICCD camera to capture low intensity Raman signal. Raman shifts and Ram cross-sections of $H_2,\;O_2,\;N_2,\;CO_2,\;CH_4\;and\;C_3H_8$ were measured precisely. Our results showed an excellent agreement with other groups. Mole fraction measurement of $O_2\;and\;N_2$ from air showed that $O_2\;:\;N_2$ = 0.206 : 0.794. We used constant volume combustion chamber and gas injector which is operated at $5\sim10barg$. Methane and propane are used as a fuel. 50 Raman signal are obtained and ensemble averaged for measurement of equivalence ratio. Our measured results showed that the equivalence ratio of fuel/air mixture is reasonable at ${\pm}5%$ error range.

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Raman Scattering Characteristics with Varying Liquid Water Temperature (유체온도 변화에 따른 Raman 산란 특성)

  • An, Jeongsoo;Yang, Sunkyu;Chun, Seyoung;Chung, Moonki;Choi, Youngdon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.5
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    • pp.621-627
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    • 1999
  • This paper presents Raman scattering of liquid water to obtain the characteristics with variation of temperature. Very clear Stokes-Raman signals were observed, which shows H-O vibration stretching and H-O-H vibration bending. The obtained spectrum were processed by FFT filter to extract the noise and base. The spectral shape of the H-O stretching provided a various sensitive signature which allowed temperature to be determined by a curve-fitting technique. Those are Maximum Intensity, Maximum Wave Length, FWHM(Full Width at Half Maximum), PMCR(Polymer Monomer Concentration Ratio) and TSIR(Temperature Sensitive Intensity Ratio). TSIR method shows the highest accuracy of $0.1^{\circ}C$ in mean error and $0.32^{\circ}C$ In maximum error.

Explicit matrix elements for Raman scattering blueward of H gamma

  • Lee, Hee-Won
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.50.2-50.2
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    • 2010
  • We present the explicit expressions for the matrix elements associated with the interaction of photons with atomic hydrogen. These expressions are applied to compute the scattering cross section for the Raman scattering operating blueward of Lyman epsilon and H gamma. A brief discussion that re relevant to some symbiotic stars and young planetary nebulae is also presented.

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Chitosan-gold Nano Composite for Dopamine Analysis using Raman Scattering

  • Lim, Jae-Wook;Kang, Ik-Joong
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.237-242
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    • 2013
  • This experiment was conducted for the purpose of developing such a sensor that can quickly sense dopamine concentration by using chitosan-gold nanoshell. Chitosan nano particles were reacted with gold nano particles so as to synthesize chitosan-gold nanoshell, and the size of the synthesized product was about 150 nm. When dopamine was reacted with chitosan-gold nanoshell, the size of it was not definitely changed, but dopamine was well reacted with chitosan-gold nanoshell, and it generated SERS (surface-enhanced Raman scattering), which led to a clear difference in the intensity of Raman scattering within the range of dopamine concentration (1 mM-10 mM). When Raman scattering was intensity marked on chitosan-gold nanoshell by employing a calibration curve according to dopamine concentration, a straight line whose margin of error was narrow was earned.

Polarized Raman Spectroscopic Studies of Syndiotactic Polypropylene (편광 Raman 분광법을 이용한 Syndiotactic Polypropylene에 관한 연구)

  • 진정희;임현주;김성수;송기국
    • Polymer(Korea)
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    • v.26 no.6
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    • pp.745-751
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    • 2002
  • The anisotropic Raman scattering properties of oriented syndiotactic poly propylene have been investigated using FT-Raman spectrometer in which the fluore scent problem of polymer samples can be removed. To assign the observed Raman bands to their respective symmetry species, the anisotropic scattering results for four different combinations of incident and scattered polarization were compared with those predicted by normal coordinate analysis and infrared dichroism measurement data.

Characteristics of Raman scattering spectroscopy for $ZnS_{1-x}Te_x$ alloy semi- conductor ($ZnS_{1-x}Te_x$ 삼원 화합물 반도체의 라만 산란 특성)

    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.5
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    • pp.223-228
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    • 2002
  • We have studied the characteristics of Raman scattering spectroscopy from $_ZnS{1-x}Te_x$ alloys in the whole range of Te composition x. The Raman spectra showed two-mode behaviors for those alloys. The Raman line shape showed the changes of an asymmetry and broadening of that with Te composition x. The asymmetric broadening of the line shape could be explained with a spatial correlation model.