• Title/Summary/Keyword: Self-Absorption

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Isolation and Structural Determination of a Complete Set of Intact Bacteriochlorophyll-d Homologs and Isomers from Green Sulfur Bacterium Chlorobium vibrioforme and Their Aggregation Properties in Hydrophobic Solvents

  • Mizoguchi, Tadashi;Saga, Yoshitaka;Tamiaki, Hitoshi
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.344-346
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    • 2002
  • Eight intact bacteriochlorophyll (BChl)-d homologs and isomers were isolated from a strain of green sulfur bacterium Chlorobium vibrioforme. All the molecular structures of the BChl-d components were fully determined by a combination of mass spectrometry and $^1$H-NMR spectroscopy. The aggregation behavior of the isomerically pure BChls-d in hydrophobic organic solvents was examined with respect to the stereoisomeric configuration at the C3$^1$ position as well as the bulkiness of the C8 and C12 side-chains by using electronic- absorption spectroscopy.

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Thermal denaturation analysis of protein

  • Miyazawa, Mitsuhiro
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1628-1628
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    • 2001
  • Near infrared (NIR) spectroscopy is a powerful technique for non-destructive analysis that can be obtained in a wide range of environments. Recently, NIR measurements have been utilized as probe for quantitative analysis in agricultural, industrial, and medical sciences. In addition, it is also possible to make practical application on NIR for molecular structural analysis. In this work, Fourier transform near infrared (FT-NIR) measurements were carried out to utilize extensively in the relative amounts of different secondary structures were employed, such as Iysozyme, concanavalin A, silk fibroin and so on. Several broad NIR bands due to the protein absorption were observed between 4000 and $5000\;^{-1}$. In order to obtain more structural information from these featureless bands, second derivative and Fourier-self-deconvolution procedures were performed. Significant band separation was observed near the feature at $4610\;^{-1}$ ,. Particularly the peak intensity at $4525\;^{-1}$ shows a characteristic change with thermal denaturation of fibroin. The structural information can be also obtained by mid-IR and CD spectral. Correlation of NIR spectra with protein structure is discussed.

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A Study on the Waterproof Properties of Cement Mortar with the Addition Rate of the Inorganic Admixture and Zinc Stearate (무기질 혼화재 및 금속비누의 혼입률 변화에 따른 시멘트 모르터의 방수 특성에 관한 연구)

  • Choi, Hoon;Jiang, Yi-Long;Han, Min-Cheol;Ryu, Hyun-Ki;Han, Cheon-Goo
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.139-144
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    • 1998
  • This study is intended to devolop the self waterproof agents for high performance concrete by analyzing the properties of fresh and hardened mortar with various addition ratios of the inorganic admixture and zinc stearate. As the results of the test, the flow and air content increase with the addition of expansive additives. When the replacement rate of silica fume increases, the flow decreases for the increased viscidity. And the flow and sir content decrease with the addition of zinc stearate. At hardened state, the compressive strength, tensile strength and flexual strength decrease with the addition of expansive additives and zinc stearate. With the increase of silica fume's replacement, they show a little decrease at early age and then increase gradually. Also, absorption and permeability show a steep decrease when zinc stearate is added, and a slack decrease with the replacement of silica fume.

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An Experimental Study on the Mixing and Mechanical Properties of Artificial Lightweight Aggregate(ALA) Concrete (인공경량골재 콘크리트의 배합과 역학적 성상에 관한 실험적 연구)

  • 김화중;김태섭;전명훈;안상건
    • Proceedings of the Korea Concrete Institute Conference
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    • 1991.04a
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    • pp.99-104
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    • 1991
  • It is necessary to generalize the use for structural ALA Concrete in our country, as increasing in the need for the development of ALA and the use of ALA Concrete which is related with the diminution of the self load and foundation section of structure responding to the realistic requirement against the decrease of natural aggregate and the high-rising and large-sizing of structures. This little study, therefore intended to help in the mixing design of concrete by considering the fundamental properties of ALA Concrete used with expanded clay, which is considered by acopting the experimental factors such as unit cement content, water cement ratio and the rate of fine aggregate. By considering the results of this experiment, it has difficulty in getting expected slump with the unit water content of normal concrete because of the large absorption of lightweight aggregate, and because the weight of unit volume and specific gravity ALA Concrete are small it appears that the strength and Elastic Modulus of that are small too and that it is more ductile than normal concrete.

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Atomic Layer Deposition of $Sb_2S_3$ Thin Films on Mesoporous $TiO_2$

  • Han, Gyu-Seok;Jeong, Jin-Won;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.282-282
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    • 2013
  • The antimony sulfide ($Sb_2S_3$) thin films were deposited using the gas phase method which known as atomic layer deposition (ALD) on mesoporous micro-films. Tris (dimethylamido) antimony (III[$(Me_2N)_3Sb$] and hydrogensulfide ($H_2S$) were used as precursors to deposit $Sb_2S_3$. Self-terminating nature of $(Me_2N)_3Sb$ and $H_2S$ reaction were demonstrated by growth rate saturation versus precursors dosing time. Absorption spectra and extinction coefficient were investigated by UV-VIS spectroscopy. Scanning electron microscopic analysis and X-ray photoelectron spectroscopy (XPS) depth profile were employed to determine the conformal deposition.

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Study on the Application of Domestic Artificial Sands for the Self-hardening Molding Process by Using Furan Resin (후란자경성(自硬性) 주형용(鑄型用) 국산인조규사(國産人造硅砂)의 활용(活用)에 관(關)한 연구(硏究))

  • Choi, Chang-Ock;Lee, Sang-Yun
    • Journal of Korea Foundry Society
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    • v.1 no.3
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    • pp.19-29
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    • 1981
  • An emphasis has been placed on the importance of selecting a sand for furan sand process, which ie affected by the properties of sand. Investigations have been carried out to use the domestic artificial sands for the furan sand process. For laboratory investigations, the sands have been prepared and tested for chemical analysis, loss on ignition, sieve analysis, AFS grain fineness number, grain shape, PH value, acid demand, surface shape, theoretical surface area, moisture absorption, crushing durability and compressive strength and S. S. I. of molding sands. Most commercial sands have been found to be able to be used. The main requirement of the sands has been shown to be that 3 or 4 screen sands, AFS no.40-70 (or 100), of low acid demand, good surface area and good grain shape require less resin and catalyst to give an adequate strength.

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What we have learned about Gamma-ray bright AGNs using the iMOGABA program

  • Lee, Sang-Sung
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.45.1-45.1
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    • 2017
  • A Korean VLBI Network Key Science Program, the Interferometric Monitoring of Gamma-ray Bright AGNs (iMOGABA) program continues to aim at revealing the origins of the gamma-ray flares that are often detected in active galactic nuclei (AGNs). Here in this presentation, we would like to present what we have learned about the Gamma-ray bright AGNs based on the recent results of the Korean VLBI Network Key Science Program: the iMGOABA. The results will include a) the source properties of the whole samples obtained from a single-epoch observation, and b) some of scientific highlights for the iMOGAGBA on specific sources. From those highlighted works, we find that the Gamma-ray bright AGNs become fainter at higher frequencies, yielding optically thin spectra at mm wavelengths. Based on the studies on specific sources, taking into account the synchrotron self-absorption model of the relativistic jet, we estimated the magnetic field strength in the mas emission region during the observing period.

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An Influence through the Mediating of Flows Play about the Attraction and Emotions Absorption of the Website (웹사이트의 매력성과 고객의 정서적 몰입에 대한 플로우의 매개적 영향 - 인터넷 쇼핑몰에서의 의류구매행동을 중심으로 -)

  • Kang, Sung-Ju
    • International Commerce and Information Review
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    • v.10 no.2
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    • pp.63-87
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    • 2008
  • This study investigates the relationship between perceived system characteristics of Internet shopping mall and loyalty, and examines how perceived website attractiveness and flow play mediating roles between perceived system characteristics of Internet shopping mall and affective commitment in the context of Internet clothing shopping mall. For these purposes, the author developed a structural model which consists of several variables. In this model, perceived system characteristics of Internet shopping mall that consist of such as familiarity, reputation, uniqueness, positive emotion, self-efficacy, and interactivity were proposed to affect the website attractiveness and flow, and in turn, result in higher affective commitment. Thus, perceived website attractiveness and flow were proposed as core mediating variables between perceived mobile service characteristics and affective commitment. To test unidimensionality and nomological validity of the measures of each construct, the author employed scale refinement procedure. The results of reliability test with Cronbach's, and confirmatory factor analysis warranted unidimensionality of the measures for each construct. In addition, nomological validity of the measures was warranted from the result of correlation analysis.

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Fabrication of Conducting Polymer Thin Films Using Molecular Layer Deposition

  • Han, Gyu-Seok;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.289-289
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    • 2011
  • The conducting polymer thin films were deposited using the gas phase method which known as molecular layer deposition (MLD). Terephthalaldehyde (TPA) and p-phenylenediamine (PD) were used as monomers to deposit conducting polymer. Self-terminating nature of TPA and PD reaction were demonstrated by growth rate saturation versus precursors dosing time. Infrared spectroscopic and X-ray photoelectron spectroscopy were employed to determine the chemical composition and state of conducting polymer thin films. Layer by layer growth and polymerization of thin films can be showed by shifting of absorption edge using UV-VIS spectroscopy. This conducting polymer fabricated by using MLD method gives the opportunity to develop new hybrid materials by combining inorganic materials in nanoscale.

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Molecular Layer Deposition of Titanium Nitride Cross-linked Benzene Using Titaniumchloride and 1,4-Phenylenediamine

  • Han, Gyu-Seok;Yang, Da-Som;Kim, Se-Jun;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.305-305
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    • 2012
  • The organic-inorganic hybrid polymer thin films were deposited using the gas phase method which known as molecular layer deposition (MLD). Titaniumchloride (TiCl4) and 1,4-phenylenediamine (PD) were used as monomers to deposit hybrid polymer. Self-terminating nature of TiCl4 and PD reaction were demonstrated by growth rate saturation versus precursors dosing time. Infrared spectroscopic and X-ray photoelectron spectroscopy were employed to determine the chemical composition and state of hybrid polymer thin films. Layer by layer growth was showed by increasing UV-VIS absorption peak of hybrid polymer thin films.

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