• Title/Summary/Keyword: high resolution spectra

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Analysis of Ellerman Bomb Spectra Observed by FISS

  • Seo, Minju;Chae, Jongchul;Lee, Jeongwoo
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.61.3-61.3
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    • 2017
  • We have studied the high-resolution $H{\alpha}$ and Ca II $8542{\AA}$ line profiles of Ellerman Bombs (EBs) obtained with the Fast Imaging Solar Spectrograph (FISS) installed on the 1.6m Goode Solar Telescope (GST) in Big Bear Solar Observatory (BBSO). The FISS spectra of EBs are compared with synthetic profiles computed using RH non-LTE radiative transfer code and a set of 1D atmospheric models with local transient heating, the latter of which is modeled by varying local temperature enhancement in magnitude and height. We could reproduce each of the observed $H{\alpha}$ and Ca II line profiles separately with different atmospheric models, but not with a single atmospheric model. To fit the observed $H{\alpha}$ lines we often need much higher temperature enhancements than those needed for fitting Ca II lines. Possible causes for this temperature mismatch are briefly discussed.

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Identification and Determination of Oil Pollutants Based on 3-D Fluorescence Spectrum Combined with Self-weighted Alternating Trilinear Decomposition Algorithm

  • Cheng, Pengfei;Wang, Yutian;Chen, Zhikun;Yang, Zhe
    • Journal of the Optical Society of Korea
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    • v.20 no.1
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    • pp.204-211
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    • 2016
  • Oil pollution seriously endangers the biological environment and human health. Due to the diversity of oils and the complexity of oil composition, it is of great significance to identify the oil contaminants. The 3-D fluorescence spectrum combined with a second order correction algorithm was adopted to measure an oil mixture with overlapped fluorescence spectra. The self-weighted alternating trilinear decomposition (SWATLD) is a kind of second order correction, which has developed rapidly in recent years. Micellar solutions of #0 diesel, #93 gasoline and ordinary kerosene in different concentrations were made up. The 3-D fluorescence spectra of the mixed oil solutions were measured by a FLS920 fluorescence spectrometer. The SWATLD algorithm was applied to decompose the spectrum data. The predict concentration and recovery rate obtained by the experiment show that the SWATLD algorithm has advantages of insensitivity to component number and high resolution for mixed oils.

Structure and Photoluminescence Properties of SnO2/Zn Core-shell Nanowires

  • Kim, Hyoun Woo;Na, Han Gil;Kwon, Yong Jung;Cho, Hong Yeon
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.241-241
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    • 2014
  • $SnO_2-core/Zn-shell$ heteronanowires were fabricated by a two-step process: thermal evaporation of Sn powders and employing a sputtering technique with a Zn target. X-ray diffraction, high-resolution transmission electron microscopy, and EDX spectra coincidentally indicated that the shell layer comprised the Zn phase. From Gaussian deconvolution studies, we observed that photoluminescence (PL) spectra consisted of yellow, green, and ultraviolet (UV) emission bands, regardless of shell-coating. We speculated the possible mechanisms of these emission peaks.

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Physical parameters of the detached eclipsing binary KIC3858884

  • Lee, Chung-Uk;Kim, Seung-Lee;Lee, Jae-Woo
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.141.2-141.2
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    • 2011
  • We present physical parameters of the detached eclipsing binary KIC3858884, which has a d-Scuti type pulsating secondary component. To derive orbital elements from radial-velocity curve, high-resolution Echelle spectra were obtained at the Bohyunsan Optical Astronomy Observatory in Korea. The BOES spectra and Kepler photometric data were analyzed with JKTEBOP and Wilson-Devinney model for eclipsing light-curve synthesis and Period04 for pulsation frequency analysis. After the iterative curve fitting, we determined physical parameters of KIC3858884 as $M_1=2.02{\pm}0.23M_{\odot}$, $M_2=2.02{\pm}0.16M_{\odot}$, $R_1=3.61{\pm}0.12R_{\odot}$, $R_2=2.84{\pm}0.10R_{\odot}$, respectively.

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Application of Clustering Methods for Interpretation of Petroleum Spectra from Negative-Mode ESI FT-ICR MS

  • Yeo, In-Joon;Lee, Jae-Won;Kim, Sung-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3151-3155
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    • 2010
  • This study was performed to develop analytical methods to better understand the properties and reactivity of petroleum, which is a highly complex organic mixture, using high-resolution mass spectrometry and statistical analysis. Ten crude oil samples were analyzed using negative-mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Clustering methods, including principle component analysis (PCA), hierarchical clustering analysis (HCA), and k-means clustering, were used to comparatively interpret the spectra. All the methods were consistent and showed that oxygen and sulfur-containing heteroatom species played important roles in clustering samples or peaks. The oxygen-containing samples had higher acidity than the other samples, and the clustering results were linked to properties of the crude oils. This study demonstrated that clustering methods provide a simple and effective way to interpret complex petroleomic data.

Spectroscopic study of Planetary hosting star HD 20794

  • Rittipruk, Pakakaew;Yushchenko, Alexander V.;Kang, Young-Woon
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.43.4-44
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    • 2016
  • We observed the high resolution spectra of a solar-neighborhood planetary hosting star HD 20794. The analysis of spectroscopic data was performed using URAN and SYNTHE programs. These spectra allow us to determine the effective temperatures, surface gravities, microturbulent velocities and, chemical abundances. Bond et al. (2008) found chemical abundance for 11 elements, but using the Spectrum synthesis method we have so far determine about 30 elements. We have derived iron metallicity $[FeI/H]=-0.42{\pm}0.03$, $[FeII/H]=-0.43{\pm}0.012$, and surface gravity, log g = 4.48, in good agreement with values from previous investigation.

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N-type doping and band gap change of Calix adsorbed on Graphene

  • Park, Seon-Min;Yang, Se-Na;Kim, Gi-Jeong;Kim, Bong-Su;No, Gwang-Hyeon;Lee, Han-Gil
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.341-341
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    • 2010
  • Electronic structure of Calix adsorbed on epitaxial graphene (EG) was investigated using high resolution photoemission spectroscopy (HRPES). Increasing the deposition of calix molecule, we found that EG becomes n-type doping using secondary edge measurement (work function change). As we observe bonding nature of O 1s peak, we found that single O 1s peak can be clearly distinguished in the spectra indicating equivalent adsorption state. Finally, we were able to control the band gap of EG using valence band spectra as we change the amount of calix molecule. In this study, we will propose the possibility of band gap modulation of EG using calix molecule.

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High Resolution Optical Spectroscopy of mer-[Cr(dpt)(Gly-Gly)]ClO₄

  • 최종하
    • Bulletin of the Korean Chemical Society
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    • v.20 no.4
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    • pp.436-440
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    • 1999
  • The highly resolved absorption spectra of mer-[Cr(dpt)(Gly-Gly)]ClO4·H2O [dpt = di(3-aminopropyl)amine, H2Gly-Gly = glycylglycine] have been measured between 13000 cm-1 and 50000 cm-1 temperatures down to 2 K. The vibrational intervals were extracted by recording emission and far-infrared spectra. The characteristic infrared bands in meridional isomer were discussed. The four-teen electronic origins due to spin-allowed and spin-forbidden transitions were assigned. With the use of this electronic transitions, a ligand field optimization based on the exact known ligand geometry have been performed to determine more detailed bonding properties of Gly-Gly and dpt ligands. It is confirmed that the peptide nitrogen of the Gly-Gly has a weak π-donor property toward chrornium(Ⅲ) ion.

Identification of ML106 Phase 1 Metabolites in Human Liver Microsomes Using High-Resolution Quadrupole-Orbitrap Mass Spectrometry

  • Jo, Jun Hyeon;Nam, WoongShik;Kim, Sunjoo;Lee, Doohyun;Min, Kyung Hoon;Lee, Taeho;Lee, Sangkyu
    • Mass Spectrometry Letters
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    • v.7 no.3
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    • pp.69-73
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    • 2016
  • High-resolution quadrupole-Orbitrap mass spectrometry (HRMS), with high-resolution (> 10,000 at full-width at half-maximum) and accurate mass (< 5 ppm deviation) capabilities, plays an important role in the structural elucidation of drug metabolites in the pharmaceutical industry. ML106, a derivative of imidazobenzimidazole, decreased melanin content and tyrosinase activity in a dose-dependent manner. Here, we investigated the phase 1 metabolic pathway of ML106 using HRMS in human liver microsomes (HLMs) and recombinant cDNA-expressed cytochrome P450 (CYP). After the incubation of ML106 with pooled HLMs and recombinant cDNA-expressed CYP in the presence of NADPH, five phase 1 metabolites, including three mono-hydroxylated metabolites (M1-3) and two di-hydroxylated metabolites (M4 and M5), were investigated. The metabolite structures were postulated by the elucidation of protonated mass spectra using HRMS. The CYP isoforms related to the hydroxylation of ML106 were studied after incubation with recombinant cDNA-expressed CYP. Here, we identified the phase 1 metabolic pathway of ML106 induced by CYP in HLMs.

Absorbtion Spectroscopy, Molecular Dynamics Calculations, and Multivariate Curve Resolution on the Phthalocyanine Aggregation

  • Ajloo, Davood;Ghadamgahi, Maryam;Shaheri, Freshte;Zarei, Kobra
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1440-1448
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    • 2014
  • Co(II)-tetrasulfonated phthalocyanine (CoTSP) is known to be aggregated to dimer at high concentration levels in water. A study on the aggregation of CoTSP using multivariate curve resolution analysis of the visible absorbance spectra over a concentration range of 30, 40 and 50 ${\mu}M$ in the presence of dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), acetonitrile (AN) and ethanol (EtOH) in the concentration range of 0 to 3.57 M is conducted. A hard modeling-based multivariate curve resolution method was applied to determine the dissociation constants of the CoTSP aggregates at various temperatures ranging from 25, 45 and $65^{\circ}C$ and in the presence of various co-solvents. Dissociation constant for aggregation was increased and then decrease by temperature and concentration of phthalocyanine, respectively. Utilizing the vant Hoff relation, the enthalpy and entropy of the dissociation equilibriums were calculated. For the dissociation of both aggregates, the enthalpy and entropy changes were positive and negative, respectively. Molecular dynamics simulation of cosolvent effect on CoTSP aggregation was done to confirm spectroscopy results. Results of radial distribution function (RDF), root mean square deviation (RMSD) and distance curves confirmed more effect of polar solvent to decrease monomer formation.