• Title/Summary/Keyword: Spectroscopic method

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The Weatherproof Detection System of Sea Fog by Remote Sensing and its Applications

  • Bao, Xianwen;Wang, Xin;Sun, Litan;Zhou, Faxiu
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1380-1382
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    • 2003
  • Detection of sea fog by remote sensing with spectroscopic analysis method and structural analysis method is introduced in this paper. On this base, designing principles and frame of weatherproof detection system of sea fog by remote sensing are systemically explained. Using GMS5 and NOAA visible and infrared channel data, progresses of sea fog on yellow sea on April 17,18, 2001 is monitored which accord with the observing.

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A Simple Laboratory Monochromator Controller (실험실용 간이 분광기 구동장치)

  • Sung, Hakje;Kim, Taesam
    • Analytical Science and Technology
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    • v.6 no.3
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    • pp.345-348
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    • 1993
  • A monchromator controller has been built to drive directly by a personal computer. This controller gives better conveniency and accuracy on spectroscopic experiment when a monochromator has deficient driver. This controller consists with simple electronic circuit and control program. The original spectroscopic precision is retained by using stepper motor. The rate changing method is adopted for short slew time. And the scanning is synchronized with spectrum recording device. Because the controller includes electronic counting ciruit, other program can be executed on personal computer during monochromator scanning.

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High resolution spectroscopic study of the peculiar globular cluster M22 (NGC 6656)

  • Kim, Hyeong-Jun;Lee, Jae-Woo
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.65.1-65.1
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    • 2017
  • We present the high-resolution spectroscopic study of the red-giant branch (RGB) stars in the peculiar globular cluster M22 (NGC 6656). We obtained high-resolution spectra of 55 RGB stars using the CTIO 4-m telescope and the HYDRA multi-object spectrograph. By employing an improved LTE analysis method, we measured accurate elemental abundances. In this talk, we will discuss the differences in the chemical composition between the two stellar populations in the context of the formation of M22.

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Determination of optical constants and thickness of organic electroluminescence thin films using variable angle spectroscopic ellipsometry (가변입사각 분광타원 법을 이용한 유기 발광 박막의 광학상수 및 두께 결정)

  • 김상열;류장위;김동현;정혜인
    • Korean Journal of Optics and Photonics
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    • v.12 no.6
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    • pp.472-478
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    • 2001
  • We determined the optical constants and thickness of organic electroluminescence thin films using variable angle spectroscopic ellipsometry. Using the measured transmittance spectra and the spectroscopic ellipsomeoy data of the organic films on glass substrates in the optically transparent region, we determined the effective thickness and the refractive indices of organic thin films. Then by applying a numerical inversion method to variable angle spectro-ellipsometry data, we determined the complex refractive index at each wavelength including the optically absorbing region, as well as the thickness and surface micro-roughness of the organic thin films. The calculated transmittance spectra showed a tight agreement with the measured ones, confining the validity of the present model analysis.

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Study of Stray-light Analysis and Suppression Methods for the Spectroscopic System of a Solar-radiation Observer Instrument

  • Zheng, Ru;Liu, Bo;Wang, Lingyun;Gao, Yue;Li, Guangxi;Li, Changyu
    • Current Optics and Photonics
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    • v.5 no.3
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    • pp.220-228
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    • 2021
  • To improve the measurement accuracy of a solar-radiation observer instrument, aiming at the problem of multiorder-stray-light interference caused by the diffraction of the flat-field concave grating in the spectroscopic system, straylight suppression methods for different forms of optical traps are studied. According to the grating surface-scattering distribution-function model, the bidirectional scattering distribution function (BSDF) of a dust-polluted surface and the flat-field concave grating's transition area of the spectroscopic system is calculated, and a Lyot stop with blade baffle is designed to suppress this kind of stray light. For diffraction multiorder stray light, based on the theory of light-energy transmission, a design for precise positioning of the trench optical trap is proposed. The superiority of the method is verified through simulation and actual measurement. The simulation results show that in a spectroscopic system approximately 160 mm × 140 mm × 80 mm in size, the energy of the stray light is reduced by one order of magnitude by means of the trench optical trap and Lyot stop, and the number of beams is reduced from 5664 to 1040. The actual measurements show that the stray-light-suppression efficiency is about 69.4%, which is effective reduction of the amount of stray light.

Physiological and Spectroscopic Changes of Rice by Nitrogen Fertilization Conditions

  • Jung-Il Cho;Dongwon Kwon;Hoejeong Jeong;Wan-Gyu Sang;Sungyul Chang;Jae-Kyeong Baek
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.106-106
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    • 2022
  • An appropriate amount of nitrogen fertilizer input during rice cultivation is essential for rice growth, quality control, and reduction of greenhouse gases in paddy fields. Therefore, it is necessary to develop a technology that can check whether an appropriate amount of fertilizer is applied in paddy fields. In this study, we tried to derive a method for diagnosing nitrogen fertilization level using spectroscopic diagnosis, physiological analysis, and molecular indicator genes. Nitrogen fertilization treatment was performed in a greenhouse by dividing into five treatment conditions: no fertilization (N0), low fertilization (N0.5), standard fertilization (N1.0), excessive fertilization (N1.5), and double fertilization (N2.0), respectively. Growth characteristics analysis was investigated by nitrogen fertilization conditions and growth stages, and the height of the canopy was analyzed using a laser scanner. Physiological and spectroscopic analyses were performed by analyzing chlorophyll and sugar contents and measuring SPAD and leaf spectrometer on rice leaves. In addition, real-time PCR experiment was performed to check the relative expression levels of several known nitrogen metabolism related genes. These results suggest that spectroscopic techniques can be helpful in diagnosing the level of nitrogen fertilization in rice paddy fields.

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Integral Field Spectroscopic Data Reduction Method for High Resolution Infrared Observation

  • Lee, Sung-Ho;Pak, Soo-Jong;Choi, Min-Ho
    • Journal of Astronomy and Space Sciences
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    • v.27 no.4
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    • pp.309-318
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    • 2010
  • We introduce a technical approach for reducing three-dimensional infrared (IR) spectroscopic data generated by integral field spectroscopy or slit-scanning observations. The first part of data reduction using IRAF presents a guideline for processing spectral images from long-slit IR spectroscopy. Multichannel image reconstruction, Image Analysis and Display (MIRIAD) is used in the later part to construct and analyze the data cubes which contain spatial and kinematic information of the objects. This technic has been applied to a sample data set of diffuse 2.1218 ${\mu}m$ $H_2$ 1-0 S(1) emission features observed by slit-scanning around Sgr A East in the Galactic center. Details of image processing for the high-dispersion infrared data are described to suggest a sequence of contamination cleaning and distortion correction. Practical solutions for handling data cubes are presented for survey observations with various configurations of slit positioning.

Ab initio MRCI+Q Investigations of Spectroscopic Properties of Several Low-lying Electronic States of S2+ Cation

  • Li, Rui;Zhai, Zhen;Zhang, Xiaomei;Liu, Tao;Jin, Mingxing;Xu, Haifeng;Yan, Bing
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1397-1402
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    • 2014
  • The complete active space self-consist field method followed by the internally contracted multireference configuration interaction method has been used to compute the potential energy curves of $X^2\prod_g$, $a^4\prod_u$, $A^2\prod_u$, $b^4\sum_{g}^{-}$, and $B^2\sum_{g}^{-}$ states of $S{_2}^+$ cation with large correlation-consistent basis sets. Utilizing the potential energy curves computed with different basis sets, the spectroscopic parameters of these states were evaluated. Finally, the transition dipole moment and the Franck-Condon factors of the transition from $A^2\prod_u$ to $X^2\prod_g$ were evaluated. The radiative lifetime of $A^2\prod_u$ is calculated to be 887 ns, which is in good agreement with experimental value of $805{\pm}10$ ns.

Rapid Determination of Seed and Stem Content in Red Pepper Powder by Near-Infrared Reflectance Spectroscopic Analysis (근적외 분광분석법에 의한 분말고추중의 씨앗 및 꼭지혼입량의 신속한 측정)

  • Cho, Rae-Kwang;Sohn, Mi-Ryeong;Ann, Jae-Jin
    • Korean Journal of Food Science and Technology
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    • v.23 no.4
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    • pp.447-451
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    • 1991
  • Red pepper peels stored with seeds or stems in the powder state at $30^{\circ}C$ resulted in decrease of quality components such as capsanthin, capsaicin and total sugars. The effect of seeds on the quality deterioration was larger than stems. A near-infrared reflectance spectroscopic(NIRS) method was evaluated for the determination of seed and stem contents in red pepper peels. The standard error of prediction was 1.76% in seeds and 0.43% in stems. It is concluded that the NIRS method is suitable for the determination of seen and stem contents in red pepper powder.

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