• Title/Summary/Keyword: Spectroscopic studies

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Spectroscopic studies of the high-pressure di-atomic sulfur vapor excited in an optical cavity by microwave discharges (마이크로파 방전에 의한 광학적 공동 안에서 고압 2-원자 황 증71의 분광학적 특성 연구)

  • 김진중;고정태;원동호;홍성호;김정원
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.114-115
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    • 2002
  • 마이크로파 방전에 의한 고압 2-원자 황증기 (high-pressure di-atomic sulfur vapor)는 고효율(high luminous efficacy) 및 고연색성 (high color rendering index)의 백색 광원 (source of white light)으로 높이 평가되고 있다 [1]. 소위 무전극 황전등 (elec출odeless sulfur lamp, ESL)으로 알려진 이 발광원은 최고 효율이 173 lm/w 까지 시연되어 알려진 모든 인조 광원 중에서 가장 높은 효율을 보인 혁신적인 광원이다 [2]. (중략)

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Spectroscopic Studies of Gas Hydrates (가스 하이드레이트의 분광학적 연구)

  • Kim, Do-Youn;Lee, Heun;Seo, Yu-taek
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.615-617
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    • 2005
  • [ $^{13}C$ ] NMR spectra were obtained for pure $CH_4$ hydrate in order to identify hydrate structure and cage occupancy of guest molecule. The NMR technique can provide both qualitative and quantitative hydrate characteristics. The moles of methane captured into pure $CH_4$ hydrate per mole of water were found to be similar to the full occupancy value. The overall results drawn from this study can be usefully applied to storage and transportation of natural gas.

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Microbial Metabolism of trans-2-Dodecenal

  • Kim, Hyun-Jung;Park, Hae-Suk;Lee, Ik-Soo
    • Natural Product Sciences
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    • v.17 no.1
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    • pp.19-22
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    • 2011
  • Microbial metabolism of trans-2-dodecenal (1) was studied. Screening studies have revealed a number of microorganisms that are capable of metabolizing trans-2-dodecenal (1). Scale-up fermentation with Penicillium chrysogenum resulted in the production of two microbial metabolites. These metabolites were identified using spectroscopic methods as trans-2-dodecenol (2) and trans-3-dodecenoic acid (3).

Studies of process measurement technology for manufacturing advanced nano devices (첨단 나노소자 공정제어용 측정기술 연구)

  • Cho, Yong Jai
    • Vacuum Magazine
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    • v.2 no.3
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    • pp.4-10
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    • 2015
  • We developed a real-time three-polarizer spectroscopic ellipsometer based on a new data acquisition algorithm and a general data reduction (the process of extracting the ellipsometric sample parameters from the Fourier coefficients). The data acquisition algorithm measures Fourier coefficients of radiant flux waveform accurately and precisely. The general data reduction is introduced to represent the analytic functions of the standard uncertainties of the ellipsometric sample parameters, and the extracted theoretical values closely agree with the corresponding experimental data. Our approach can be used for optimization of measurement conditions, instrumentation, simulation, standardization, laboratory accreditation, and metrology.

HISTORY OF STAR FORMATION OF EARLY TYPE GALAXIES FROM INTEGRATED LIGHT: STELLAR AGES AND ABUNDANCES

  • Schiavon, Ricardo P.
    • Publications of The Korean Astronomical Society
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    • v.25 no.3
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    • pp.83-90
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    • 2010
  • I briefly review what has been learned from determinations of mean stellar ages and abundances from integrated light studies of early-type galaxies, and discuss some new questions posed by recent data. A short discussion of spectroscopic ages is presented, but the main focus of this review is on the abundances of Fe, Mg, Ca, N, and C, obtained from comparisons of measurements taken in integrated spectra of galaxies with predictions from stellar population synthesis models.

Rare 2-Phenoxychromones from Ononis serrata Growing in Egypt

  • Amer, Masouda E.;Kassem, Fahima F.;Abdel-Kader, Maged S.
    • Natural Product Sciences
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    • v.10 no.1
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    • pp.32-34
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    • 2004
  • Two 2-phenoxychromones; a rare group of natural products, were isolated from the combined ethylacetate and chloroform fractions of the ethanolic extract of Ononis serrata frossk (Leguminosae) growing in Egypt. Structures were elucidated by chemical, spectroscopic methods as well as single X-ray diffraction analyses. The cytotoxic and antimicrobial effects of the two compounds were examined. It is worth to mention that this is the first report on the isolation of 2-phenoxychromones from the family Leguminosae.

Studies on the Constituents of Impatiens noli-tangere L. (노랑물봉선의 성분에 관한 연구)

  • Choi, Bok-Ja;Kim, Chong-Won
    • Korean Journal of Pharmacognosy
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    • v.33 no.4 s.131
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    • pp.263-266
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    • 2002
  • From the herbs of this plant, six compounds were isolated and their structures were characterized as dieicosyl ether (1), scopoletin (2), ${\alpha}-spinasterol-3-O-{\beta}-D-glucopyranoside$ (3), kaempferol (4), quercetin (5), and quercetin 7, 3', 4'-trimethylether-3-O-rutinoside (6) by chemical and spectroscopic evidences. These compounds were isolated for the first time from this plant and compound 6 was first isolated from nature.

NMR Techniques for the Structure Elucidation and Conformational Analysis of Natural Products

  • Cordell, Geoffrey A.
    • Korean Journal of Pharmacognosy
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    • v.19 no.3
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    • pp.153-169
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    • 1988
  • The combined use of the J-modulated selective INEPT and CSCM 1DNMR techniques is described for the structure elucidation of several new classes of compound including prionitin, the loureirins and larreantin, and for the regiosubstitution of the furanonaphthoquinones. Spectroscopic studies on the conformation of the cytotoxic agent savinin are also described, together with the NMR assignments and preliminary biosynthetic experiments on the antitumor antibiotic staurosporine.

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Studies on the Components of the Seeds of Phaseolus radiatus (녹두의 성분연구)

  • Shin, Soon-Hee;Kang, Sam-Sik;Kwon, Kyung-Sook
    • YAKHAK HOEJI
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    • v.34 no.4
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    • pp.282-286
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    • 1990
  • An hydrocarbon alcohol and steroids were isolated from the hexane fraction of the extract from the seeds of Phaseolus radiatus L. And also a flavonoid was identified from the ethyl acetate and butanol fraction. The structure of the obtained compound were elucidated by spectroscopic methods (UV, IR, mass and NMR) and their physicochemical properties. As the results, triacontanol, stigmasterol, ${\beta}-sitosterol$ and vitexin were identified.

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