• Title/Summary/Keyword: Laboratory spectroscopy

Search Result 676, Processing Time 0.029 seconds

Measurement of excited Xe atoms density in accordance with various barrier ribs in AC-PDP by laser absorption spectroscopy

  • Jeong, Se-Hoon;Oh, P.Y.;Hong, Y.J.;Lee, S.B.;Moon, M.W.;Song, K.B.;Lee, H.J.;Yoo, N.L.;Son, C.G.;Han, Y.G.;Jeong, S.J.;Kim, J.H.;Park, E.Y.;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.949-952
    • /
    • 2006
  • We have measured the excited Xe atoms density in the $1s_5$ metastable states by laser absorption spectroscopy in accordance with various barrier ribs. In this experiment, the average density of one cell in the panel with stripe barrier rib has been measured to be $1.8{\times}10^{12}cm^{-3}$. The panel with close type barrier rib has been measured to be $5.1{\times}10^{12}cm^{-3}$.

  • PDF

Investigation of the Electronic Structure of Mn12 Molecular Magnet Using Synchrotron Radiation

  • Kang, J.S.;Kim, J. H.;Kim, Yoo-Jin;Jeon, Won-Suk;Jung, Duk-Young;Han, S.W.;Kim, K.H.;Kim, K.J.;Kim, B.S.;Shim, J.H.;Min, B.I.
    • Journal of Magnetics
    • /
    • v.8 no.4
    • /
    • pp.149-152
    • /
    • 2003
  • The electronic structure of Mn12-Ac molecular magnet has been investigated using synchrotron radiation. The valence-band photoemission spectroscopy (PES) measurement reveals that Mn 3d states are located near the top of the valence band. The trend in the measured valence-band PES spectra is found to be consistent with that in the calculated local density of states. The Mn 2p x-ray absorption spectroscopy (XAS) measurement provides evidence for the Mn$^{3+}$-Mn$^{4+}$ mixed-valent states.

CORROSION BEHAVIOR OF AUSTENITIC AND FERRITIC STEELS IN SUPERCRITICAL WATER

  • Luo, Xin;Tang, Rui;Long, Chongsheng;Miao, Zhi;Peng, Qian;Li, Cong
    • Nuclear Engineering and Technology
    • /
    • v.40 no.2
    • /
    • pp.147-154
    • /
    • 2008
  • The general corrosion behavior of austenitic and ferritic steels(316L, 304, N controlled 304L, and 410) in supercritical water is investigated in this paper. After exposure to deaerated supercritical water at $480^{\circ}C$/25 MPa for up to 500 h, the four steels studied were characterized using gravimetry, scanning electron microscopy/energy dispersive X-ray spectroscopy(SEM/EDS), X-ray photoelectron spectroscopy(XPS), and X-ray diffraction(XRD). The results show that the 316L steel with a higher Cr and Ni content has the best corrosion-resistance performance among the steels tested. In addition to the oxide layer mixed with $Fe_{3}O_{4}$ and $(Fe,Cr)_{3}O_{4}$ that formed on all the samples, a $Fe_{3}O_{4}$ loose outer layer was observed on the 410 steel. The corrosion mechanism of stainless steels in supercritical water is discussed based on the above results.

Synthesis of LaMnO3-Diamond Composites and Their Photocatalytic Activity in the Degradation of Weak Acid Red C-3GN

  • Huang, Hao;Lu, Benqian;Liu, Yuanyuan;Wang, Xeuqian;Hu, Jie
    • Nano
    • /
    • v.13 no.10
    • /
    • pp.1850121.1-1850121.11
    • /
    • 2018
  • In this study, a series of $LaMnO_3$-diamond composites with varied $LaMnO_3$ mass contents supported on micro-diamond have been synthesized using a sol-gel method. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and the Fourier transform infrared spectra (FTIR). Meanwhile, the photocatalytic performances were also tested by photoluminescence (PL) spectroscopy, ultraviolet-visible diffuse reflection spectra (UV-Vis DRS) and the degradation of weak acid red C-3GN (RC-3GN). Results show that the peak position of $LaMnO_3$ is shifted to low angle after the introduction of diamond, and perovskite particles uniformly distributed on the surface of diamond, forming a network structure, which can increase the active sites and the absorption of dye molecules. When the mass ratio of $LaMnO_3$ and diamond is 1:2 (LMO-Dia-2), the composite shows the most excellent photocatalytic activity. This result offers a sample route to enlarge the range of the application of micro-diamond and provide a new carrier for perovskite photocatalysts.

Structural and component characterization of the B4C neutron conversion layer deposited by magnetron sputtering

  • Jingtao Zhu;Yang Liu;Jianrong Zhou;Zehua Yang;Hangyu Zhu;Xiaojuan Zhou;Jinhao Tan;Mingqi Cui;Zhijia Sun
    • Nuclear Engineering and Technology
    • /
    • v.55 no.9
    • /
    • pp.3121-3125
    • /
    • 2023
  • Neutron conversion detectors that use 10B-enriched boron carbide are feasible alternatives to 3He-based detectors. We prepared boron carbide films at micron-scale thickness using direct-current magnetron sputtering. The structural characteristics of natural B4C films, including density, roughness, crystallization, and purity, were analyzed using grazing incidence X-ray reflectivity, X-ray diffraction, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and scanning electron microscopy. A beam profile test was conducted to verify the practicality of the 10B-enriched B4C neutron conversion layer. A clear profile indicated the high quality of the neutron conversion of the boron carbide layer.

Detection of Gamma-Irradiated Korean Medicinal Herbs by ESR Spectroscopy (ESR Spectroscopy에 의한 감마선 조사된 한약재의 검지)

  • Lee, Eun-Jeong;Yang, Jae-Seung
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.31 no.4
    • /
    • pp.717-721
    • /
    • 2002
  • Study was carried out with electron spin resonance (ESR) spectroscopy to identify irradiated Korean medicinal herbs. Pueraria thunbergiana Benth., Angelica gigas Nakai, Agaricus blazei Murill and Astragalus membranaceus Bunge were irradiated with doses of 0, 1, 5 and 10 kGy at room temperature using a Co-60 irradiator. The irradiated Korean medicinal herbs exhibited an asymmetric absorption, which was different from the non-irradiated ones. The strength of ESR signals linearly increased by dose-dependent manner (1~10 kGy) and highly positive correlation coefficients ($R^2$=0.9428~0.9942) were obtained between the irradiation doses and the corresponding ESR signal intensities. Detection of the irradiated Korean medicinal herbs was possible even after 6 weeks of storage although the signal intensities of the irradiated samples decreased until 2 weeks at room temperature.

Optical and Dielectric Properties of Chalcogenide Glasses at Terahertz Frequencies

  • Kang, Seung-Beom;Kwak, Min-Hwan;Park, Bong-Je;Kim, Sung-Il;Ryu, Han-Cheol;Chung, Dong-Chul;Jeong, Se-Young;Kang, Dae-Won;Choi, Sang-Kuk;Paek, Mun-Cheol;Cha, Eun-Jong;Kang, Kwang-Yong
    • ETRI Journal
    • /
    • v.31 no.6
    • /
    • pp.667-674
    • /
    • 2009
  • Terahertz time-domain spectroscopy has been used to study the optical and dielectric properties of three chalcogenide glasses: $Ge_{30}As_8Ga_2Se_{60}$, $Ge_{35}Ga_5Se_{60}$, and $Ge_{10}As_{20}S_{70}$. The absorption coefficients ${\alpha}({\nu})$, complex refractive index n(${\nu}$), and complex dielectric constants ${\varepsilon}({\nu})$ were measured in a frequency range from 0.3 THz to 1.5 THz. The measured real refractive indices were fitted using a Sellmeier equation. The results show that the Sellmeier equation fits well with the data throughout the frequency range and imply that the phonon modes of glasses vary with the glass compositions. The theory of far-infrared absorption in amorphous materials is used to analyze the results and to understand the differences in THz absorption among the sample glasses.

Spatiotemporal behavior of excited Xe atoms density in Counter discharged type AC-PDP

  • Hong, Young-June;Oh, Phil-Yong;Jeong, Se-Hoon;Hong, Jong-Hwa;Kim, Jung-Hyun;Gyu, Yong;Cho, Seok-Ho;Hong, Sung-Hee;Hong, Byoung-Hee;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2007.08a
    • /
    • pp.574-577
    • /
    • 2007
  • We have measured the excited Xe atoms density in the $1s_5$ metastable states by laser absorption spectroscopy in counter discharged type AC-PDP. This experiment has shown the characteristic of the excited Xe atoms density which is relation to the visible light efficiency of PDP. The density of counter discharged AC-PDP have measured to be $9.47\;{\times}\;10^{13}\;cm{-3}$. The result has been shown to higher value than $1.45\;{\times}\;10^{13}\;cm^{-3}$ of conventional AC-PDP.

  • PDF