• Title/Summary/Keyword: IR absorption

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Calibrating the stellar velocity dispersion in near-IR

  • Kang, Wol-Rang;Woo, Jong-Hak
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.52.2-52.2
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    • 2011
  • The correlation between black hole mass and galaxy stellar velocity dispersion gives an important clue on the black hole growth and galaxy evolution. In the case of AGN, however, it is extremely difficult to measure stellar velocity dispersions in the optical spectra since AGN continuum dilutes stellar absorption features. In contrast, stellar velocity dispersions of active galaxies can be measured in the near-IR, where AGN-to-star flux ratio is much smaller, particularly with the laser-guide-star adaptive optics. However, it is crucial to test whether the stellar velocity dispersion measured from the near-IR spectra is consistent with that measured from the optical spectra. Using the TripleSpec at the Palomar 5-m Telescope, we obtained high quality spectra ranging from 1 to 2.4 micron for a sample of 35 nearby galaxies, for which dynamical black hole masses and optical stellar velocity dispersion measurements are available, in order to calibrate the stellar velocity dispersion in the near-IR. In this poster, we present the initial results based on 10 galaxies, with the stellar velocity dispersion measured in the H-band.

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Preparation, Reactions and Catalytic Activities of Water Soluble Iridium-Sulfonated Triphenylphosphine Complex

  • 진종식;장원태;양서균;주광석
    • Bulletin of the Korean Chemical Society
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    • v.18 no.3
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    • pp.324-327
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    • 1997
  • Water soluble iridium complex, IrCl(CO)(TPPTS)2·χH2O (1) (TPPTS=m-trisulfonated triphenylphosphine) has been prepared from the reaction of a water soluble complex, IrCl(COD)(TPPTS)2·6H2O (COD=l,5-cyclooctadiene) with CO and unambiguously characterized by electronic absorption, 31P NMR, 13C NMR and IR spectral data. Complex 1 catalyzes the hydration of terminal alkynes to give ketones in aqueous solutions at room temperature. The rate of PhC≡CH hydration dramatically increases with addition of MeOH to the reaction mixture in H2O, which is understood in terms of i) the excellent miscibility between H2O and MeOH and ii) the assumed catalytic hydration pathway involving the initial formation of (alkyne)IrCl(CO)(TPPTS)2.

A Study on the Infrared Radiation Properties for SiO$_2$/Fe$_2$O$_3$Films Coated on aluminum (알루미늄에 코팅된 SiO$_2$/Fe$_2$O$_3$막의 적외선 복사특성에 관한 연구)

  • 강병철;김기호
    • Journal of the Korean institute of surface engineering
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    • v.36 no.5
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    • pp.406-412
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    • 2003
  • FT-IR and thermography were used to investigate the infrared radiation characteristic of SiO$_2$ film and SiO$_2$/Fe$_2$O$_3$film coated on aluminum. Through FT-TR spectrum, SiO$_2$film showed high infrared absorption in accordance with the stretching vibration of Si-O-Si, and as$ Fe_2$$O_3$was mixed additional absorption band appeared resulting from the stretching vibration of Fe-O at $590cm^{-1}$ and the bond of Si-O-Fe at $900 cm^{-1}$ The two kinds of film measured by the integration method and the reflective method coincided with each other in the wavelength area of infrared absorption and radiation, and corresponded well with Kirchhoff's law as the infrared emissivity is high in wavelength where infrared absorption rate is high. The emissivity of $SiO_2$ film was 0.65 and that of $SiO_2$/Fe$_2$$O_3$film was 0.77, so the addition of$ Fe_2$$O_3$ raised the infrared emissivity by approximately 13%.$ SiO_2$$Fe_2$$O_3$ film is efficient as an infrared radiator at below $100^{\circ}C$. The temperature of heat radiation after 7 minutes was 117$^{\circ}C$ in aluminum plate and $155^{\circ}C$ in $SiO_2$$Fe_2$$O_3$ film, $38^{\circ}C$ higher than the former.

Effect of Deposition Parameter on Ionic Conductivity of RF Magnetron Sputtered Li$_2$O-B$_2$O$_3$-SiO$_2$ Solid Electroiyte Films (RF 마그네트론 스퍼터링법으로 증착된 Li$_2$O-B$_2$O$_3$-SiO$_2$ 계 비정질 박막 고체전해질의 증착변수에 따른 이온전도 특성에 관한 연구)

  • 노남석;권혁상
    • Journal of the Korean institute of surface engineering
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    • v.27 no.2
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    • pp.65-73
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    • 1994
  • Effects of deposition parameter on the ionic conductivity and structural change of the Lithium borosili-cate solid electrolyte films, prepared by rf sputtering using 7$LI_2O-3B_2O_3-1SiO_2$ single phase target and also a mosaic target enriched with $LI_2O$, were analyzed by measuring AC impedance and IR absorption spectra for the films. Thed solid electrolyte film deposited from the single phase target exhibited very low ionic conductivi-ty of $10^{-10}{\Omega}^{-1}cm{-1}$ at room temperature, a result of low $Li^+$ ion content(7.52 at%) in the film. The $Li^+$ con-ductivity for the films deposited from the mosaic target, however, significantly increased to $10^{-7}{\Omega}^{-1}cm{-1}$ due to both an increased $Li^+$content (14.75 at %) and a structural change of the films. The increased ionic conduc-tivity of the film appears to be associated with an easiness of ionic mobility by structural change of glassy film from a some close packed network structure to a open one. These structural changes of film were found to be closely related to the increase in the peak intensity at~$960cm^{-1}$ of IR absorption spectra for the glassy films. With increasing either argon pressure from 3 to 21 mtorr or rf power from 2 to 3 W/$cm^2$, the $Li^+$ conduc-tivity for the films significantly increased to an order of $10^{-6}{\Omega}^{-1}cm{-1}$ due to an increase in openness of film structure, as confirmed by both an increase in the IR absorption peak intensity at ~$960cm^{-1}$ and a resultant reduction of activation energy for mobility of $Li^+$ ion.

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Chemical Modification of Japanese Cedar with 2-Methacryloyloxyethyl Isocyanate (2-메타크릴로일옥시에틸 이소시아네이트에 의한 삼나무재의 화학처리)

  • Han, Gyu-Seong;Setoyama, Kouichi
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.1
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    • pp.36-41
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    • 2000
  • This study was carried out to introduce functional groups onto wood by reacting with 2-methacryloyloxyethyl isocyanate(MOI). The effects of the catalyst and the reaction conditions(temperature and time) on the treatment were investigated. The evidence of bonding between wood and MOI were examined by infrared(IR) spectroscopy. The change in surface characteristics of MOI treated wood was examined by water contact angle measurement and X-ray photoelectron spectroscopy(XPS). Wood reacted quickly with MOI in the presence of di-n-butiltin dilaurate catalyst. Especially, the increase in weight percent gain(WPG) with increasing in reaction time was remarkable at the reaction temperature of over $50^{\circ}C$. The IR spectrum of wood reacted with MOI showed a strong urethane absorption(1715 $cm^{-1}$) but no isocyanate(2235 $cm^{-1}$) absorption. It also showed a sharp olefinic C=C double bond absorption at 1635 $cm^{-1}$. This means that an introduced methacrylate group becomes the starting point of further graft copolymerization with another vinyl monomers. The wood modified with MOI showed a gradual increase in contact angle with increasing in WPG, which means that the hydrophilic wood surface become quite hydrophobic. Also, it was cleared that most parts of the wood surface were modified with MOI by XPS analysis.

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Characterization of Glycine Metal Salts for $CO_2$ Absorption (이산화탄소 흡수를 위한 글리신 금속염의 특성 연구)

  • Lim, Yun-Hui;Park, Young Koo;Jo, Young-Min
    • Applied Chemistry for Engineering
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    • v.23 no.3
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    • pp.284-288
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    • 2012
  • This work deals with the chemical characterization of glycine aqueous solution in $CO_2$ absorption. Three alkali elements were impregnated into the glycine in order to facilitate the formation of amino functionalities. The analysis by IR revealed the transformation of ammonium ions to the amino group. In addition, the NMR analysis showed that the substitution of metal cations to the chemical shift of hydrogen and carbon atoms in glycine; in order of lithium glycinate, sodium glycinate and potassium glycinate depending on the electro negativity. Meanwhile, the $CO_2$ absorption at room temperature was the highest in primary amine solution, but at the increasing temperature sodium glycinate could capture more $CO_2$ than that of the pure amine solution.

Absorption of SO2 at High Temperatures by Ionic Liquids and the Absorption Mechanism

  • Tian, Shidong;Hou, Yucui;Wu, Weize;Ren, Shuhang;Qian, Jianguo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2791-2796
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    • 2014
  • The capture of $SO_2$ at or close to the temperatures of real flue gas is much more attractive in application. In this work, two kinds of ionic liquids (ILs) based on lactate anion were used to absorb $SO_2$ at high temperatures from 100 to $120^{\circ}C$. The ILs show high absorption capacities of over one mol $SO_2$ per mol IL at $110^{\circ}C$. The absorption of $SO_2$ by the ILs based on lactate anion is reversible and the ILs can be reused for the capture of $SO_2$ at high temperatures with high absorption capacity and thermal stability. Furthermore, the absorption mechanism of $SO_2$ by the ILs was studied by FT-IR, $^1H$ NMR and $^{13}C$ NMR spectra. It has been found that there are strong chemical interactions between the ILs and $SO_2$. Also the absorption mechanism is different when there is water present in ILs compared to when there is not.

Characteristics of Tissue Dose of High Dose Rate Ir-192 Source Substitution for Co-60 Brachytherapy Source (코발트-60 선원 대체용 고선량률 Ir-192 선원의 조직선량특성)

  • 최태진;이호준;김옥배
    • Progress in Medical Physics
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    • v.9 no.4
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    • pp.259-266
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    • 1998
  • To achieve the 2D dose distribution around the designed high dose rate Ir-192 source substitution for Co-60 brachytherapy source, we determined the exposure rate constant and tissue attenuation factors as a large depth as a 20 cm from source center. The exposure rate constant is used for apparent activity in designed source with self-absorption and encapsulation steel wall. The tissue dose delivered from the 4401 segments of 2.5 mm in a diameter and 2.5 mm height of disk-type source layer. In the experiments, the tissue attenuation factors include the tissue attenuation and multiple scattering in a medium surrounding the source. The fitted the polynomial regression with 4th order for the tissue attenuation factors are very closed to the experimental measurement data within ${\pm}$1% discrepancy. The Meisberger's constant showed the large uncertainty in large distance from source. The exposure rate constant 4.69 Rcm$^2$/mCi-hr was currently used for determination of apparent activity of source and air kerma strength was obtained 0.973 for tissue absorbed dose from the energy spectrum of Ir-192 source. In our experiments with designed high dose rate brachytherapy source, the apparent activity of Ir-192 source was delivered from the 54.6 % of actual physical source activity through the self-absorption and encapsulation wall attenuations. This paper provides the 2-dimensional dose tabulation from unit apparent activity in a water medium for dose planning includes the multiple scattering, source anisotropy effect and geometric factors.

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Antimicrobial Activity and Physical Properties of Acrylic Acid Grafted Nylon 6 (아크릴산 그라프트 Nylon 6의 항균성 및 물성)

  • 김수미;송화순
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.5
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    • pp.686-695
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    • 2000
  • Recently, with a growing interest of health and environment, chitosan which was good in no harmful effect to human body and environment, has been watched as the finish treatment of hygiene and pleasantness. The purpose of this study is to develop multifunctional fabric that was improved antimicrobial activity and deodorization rate, water absorption, static voltage and dye absorption by treatment of nylon 6 grafted with acrylic acid added in chitosan. FT-IR spectra of the grafted with acrylic acid added in chitosan shows peaks of COOH and NH2. Antimicrobial activity and deodorization rate of chitosan and grafted with acrylic acid added in chitosan were increased greatly than the control, durability of laundry of grafted with acrylic acid added in chitosan was good. In case of chitosan was dyed acid dyes and grafted with acrylic acid added in chitosan was dyed basic dyes, dye absorption of them were increased than the control. Moisture regain, absorption time and tensile strength of grafted with acrylic acid added in chitosan was increased greatly than the control.

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Microwave-assisted Solvent-free Synthesis of Some Dimethine Cyanine Dyes, Spectral Properties and TD-DFT/PCM Calculations

  • Zhang, Xiang-Han;Wang, Lan-Ying;Zhai, Gao-Hong;Wen, Zhen-Yi;Zhang, Zu-Xun
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2382-2388
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    • 2007
  • A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.