• 제목/요약/키워드: Atomic spectroscopy

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ESR spectroscopy에 의한 감마선 조사된 수입 향신료의 검지 (Detection of Gamma-Irradiation Treatment in Imported Spices by ESR Spectroscopy)

  • 한정은;이은정;양재승
    • 한국식품과학회지
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    • 제35권6호
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    • pp.1060-1063
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    • 2003
  • ESR spectroscopy를 이용하여 방사선 조사된 수입산 향신료 3종에서 생성된 ESR 신호 크기에 조사선량과 저장기간이 미치는 영향을 조사하였다. 수입산 향신료 3종(겨자, 오레가노, 월계수)를 0, 1, 5 및 10kGy의 Co-60 감마선을 조사한 후, 이를 시료로 Bruker-EPR spectrometer를 이용하여 ESR 신호를 측정하였다. 실험결과 조사 직후 감마선 조사된 겨자와 월계수는 조사시료에서 특유의 신호를 나타내어 비조사시료와 뚜렷이 구별할 수 있었고 오레가노는 비조사시료에서 single- line을 보였으나 조사시료와 비교하여 신호 크기가 매우 커서 비조사시료와 쉽게 구별할 수 있었다. 모든 적용선량$(1{\sim}10kGy)$의 범위에서 조사선량이 증가함에 따라 ESR 신호 크기가 증가하였으며, 조사선량과 생성된 ESR 신호 크기와의 상관계수인 $R^2$ 값은 $0.9939{\sim}0.9993$의 높은 값을 나타내었다. 또 상온에서 12주 후에도 ESR spectroscopy를 이용하여 방사선 조사의 여부를 확인할 수 있었다.

원자층 증착법과 스퍼터링을 이용한 고체산화물 연료전지용 YSZ 전해질에 관한 연구 (Comparison of Yittria Stabilized Zirconia Electrolytes(YSZ) for Thin Film Solid Oxide Fuel Cell by Atomic Layer Deposition and Sputtering)

  • 탄비르 와카스하산;하승범;지상훈;차석원
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.84.2-84.2
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    • 2011
  • In this research, two thin film deposition techniques, Atomic Layer Deposition and Sputtering are carried out for the fabrication of Yittria Stabilized Zirconia electrolyte for thin film Solid Oxide Fuel Cell. Zirconium to Yittrium ratio for both cases is about 1/8. Scanning Electron Microscope(SEM) image shows that the growth rate per hour for Atomic Layer Deposition is faster than for sputtering. X-ray Photo-electron Spectroscopy(XPS) shows that the peaks of both Zirconia and Yittria shift towards higher bending energy for the case of Atomic Layer deposition and thus are more strongly attached to the substrate. Later, Nyquist plot was used to compare the conductivity of Yittria Stabilized Electrolyte for both cases. The conductivity at $300^{\circ}C$ for Atomic Layer Deposited Yittria Stabilized Zirconia is found to be $5{\times}10^{-4}S/cm$ while that for sputtered Yittria Stabilized Zirconia is $2{\times}10^{-5}S/cm$ at the same temperature. The reason for better performance for Atomic Layered YSZ is believed to be the Nano-structured layer fabrication that aids in along the plane conduction as compared to the columnarly structured Sputtered YSZ.

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The Application of a Laser to the Chemical Characterization of Radionuclides

  • Park, Y.J.;Park, K.K.;M/Y. Suh;S.K. Yoon;Park, Y.S.;Kim, D.Y.;Kim, W.H.
    • Nuclear Engineering and Technology
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    • 제32권5호
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    • pp.446-456
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    • 2000
  • Laser induced photoacoustic, fluorescence, and photon correlation spectroscopies were applied to the chemical characterization of radionuclides in connection with the radiowaste treatment and disposal. Their measuring principles and systems were briefly described together with their advantages over conventional spectroscopies. Also, other applications of lasers are introduced. Laser induced photoacoustic spectra were measured for a P $r^{3+}$ solution with a very low molar absorptivity. The detection sensitivity was 4.3 $\times$10$^{-5}$ c $m^{1}$ and was 100 times better than that of a UV/VIS spectrophotometer. The Eu(III) excitation spectra($^{7}$ $F_{0}$ longrightarrow $^{5}$ $D_{0}$ transition) were measured for Eu(III)-phthalate complexes using laser fluorescence spectroscopy, showing that only two species, 1:1 and 1:2 complexes, are present in the Eu(III)-phthalic acid system. The size and size distribution for colloidal humic acids and Eu(III)-humate colloids was determined using photon correlation spectroscopy. The presence of Eu(III) enhanced the aggregation of humic acids.s.

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Study in Background Reduction for the Neutron Induced Prompt Gamma-ray Spectroscopy

  • Song, Byoung-Chul;Jee, Kwang-Yong;Park, Yong-Joon
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2004년도 학술논문집
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    • pp.433-433
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    • 2004
  • Neutron induced prompt gamma-ray spectroscopy (NIPS) system measures the prompt gamma-ray, emitting by the interaction of a neutron with various materials. This system will be of great benefit to scientists worldwide, since it provides the non-destructive measurement of many elements in either solid or liquid wastes. A NIPS facility has been developed in Nuclear Chemistry Research Division, at Korea Atomic Energy Research Institute (KAERI) with the aim of analyzing the major component elements in both aqueous and solid samples.(omitted)

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원자층 증착법으로 성장된 ZnO 박막의 질소 도핑에 대한 연구 (Nitrogen Doping Characterization of ZnO Prepared by Atomic Layer Deposition)

  • 김도영
    • 한국전기전자재료학회논문지
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    • 제27권10호
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    • pp.642-647
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    • 2014
  • For feasible study of opto-electrical application regarding to oxide semiconductor, we implemented the N doped ZnO growth using a atomic layer deposition technique. The p-type ZnO deposition, necessary for ZnO-based optoelectronics, has considered to be very difficulty due to sufficiently deep acceptor location and self-compensating process on doping. Various sources of N such as $N_2$, $NH_3$, NO, and $NO_2$ and deposition techniques have been used to fabricate p-type ZnO. Hall measurement showed that p-type ZnO was prepared in condition with low deposition temperature and dopant concentration. From the evaluation of photoluminescence spectroscopy, we could observe defect formation formed by N dopant. In this paper, we exhibited the electrical and optical properties of N-doped ZnO thin films grown by atomic layer deposition with $NH_3OH$ doping source.