• 제목/요약/키워드: near IR

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A Study of Heat Transfer in Supersonic Flow Field on a Sharp Fin Shape (Sharp Fin에 의한 초음속 유동장내 열전달 변화 연구)

  • Song, Ji-Woon;Yu, Man-Sun;Cho, Hyung-Hee
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.11a
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    • pp.371-374
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    • 2006
  • Heat transfer characteristic near a sharp fin in a supersonic flow was studied. Infra-red thermography was used to obtain the variation of surface heat transfer coefficient distribution. The attack angle of fin is ranged from $10^{\circ}\;to\;20^{\circ}$ and the oil flow method was also conducted to understand a flow field near a sharp fin.

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HIGH RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASAR, PG1426+015

  • Le, Huynh Anh Nguyen;Pak, Soo-Jong;Im, Myung-Shin;Ho, Luis C.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.51.1-51.1
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    • 2012
  • We observed low-z quasar PG1426+015 (z=0.086), using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. Using an Adoptive Optics system, the full width at half maximum of the point spread function was about 0.3 arcsec, which can effectively separate the quasar spectra from the host galaxy spectra. We also maximize the total exposure time up to several hours per target, and develop data reduction methods to increase the signal-to-noise ratios. This poster presents the data reduction processes and sample spectra from the quasar and its host galaxy. These spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bugle of the host galaxy.

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Near-Infrared Spectra of Super Star Clusters in M82

  • Nguyen, Kim Ngan N.;Pak, Soo-Jong;Im, Myung-Shin;Ho, Luis C.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.61.2-61.2
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    • 2012
  • We observed selected super cluster regions in M82 with 5'5 arcsec field-of-view using near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The slit width of 0.15 arcsec makes the high resolution (R ${\approx}$ 20,000) spectra in the H and K bands. In this poster, we present sample spectra of [FeII] lines and ro-vibration lines of $H_2$ which trace ionic shocks in the intercloud regions and molecular shocks. The line widths of $Br{\gamma}$ line are also measured to derive the velocity dispersion within the super star clusters.

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A Study on the Characteristics of near IR lights for non-restrained Biotelemetry (생체 신호의 무구속 측정을 위한 근 적외선 특성 연구)

  • 허수진;정찬수
    • Journal of Biomedical Engineering Research
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    • v.13 no.2
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    • pp.141-146
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    • 1992
  • The propagation, reflection and scattering characteristics of the near Infra-red lights were experimented in order to check the feasibility of non-restrained biotelemetry using indirect transmitted light. The results of the experiments show that 3 kinds of walls examined are not specular reflectors but almost perfect diffuse surfaces with slight directivity and that light in a local point is spread out and fills the room uniformly by repeating the reflection and scattering at walls, ceiling, floor. These results also explain the fact that the diffusely reflected light can be utilized as the carrier of biotelemetry even after several scattering and reflections.

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NEAR-INFRARED PHOTOMETRY OF METAL RICH GLOBULAR CLUSTER M71

  • 경재만;변용익;천문석
    • Journal of Astronomy and Space Sciences
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    • v.14 no.2
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    • pp.194-201
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    • 1997
  • We have carried out JK near-infrared photometry for the central region of the metal rich globular cluster M71, whose (K, J - K) color-magnitude diagram is presented here. Using two independent methods we derive the distance modulus to M71, 12.89 and 12.86 $pm0.12$ respectively. The former is derived using the HB luminosity $M_{Ko}$(HB) = -1.15 for globular clusters having metallicity between -1.0 to -0.3 (Kuchinski et al. 1995). The latter is derived through a comparison with IR photometry of stars in the similar metallicity cluster 47 Tuc. We also estimate the reddening to M71, E(J - K) = 0.13, based on E(B - V) = 0.04 of 47 Tuc.

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A Study on the Dyeing Properties of Natural Indigo Complex Powder and Synthetic Indigo with Natural Fiber (쪽풀로부터 제조한 고형쪽과 합성인디고의 염색성에 관한 연구)

  • 정영진;이명환;최해욱;이언필
    • Textile Coloration and Finishing
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    • v.12 no.3
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    • pp.174-182
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    • 2000
  • We prepared natural indigo/calcium hydroxide complex powder from tinctoria's leaf, according to the demand of developing new dyeing technique of natural fibre with natural indigo. FT- IR and UV/Visible spectra were operated to find the dyeing properties of synthetic indigo and natural indigo powder. Cotton, flax and silk fabrics were dyed with different pH, dye concentration and dyeing time. The colour yield of indigo dye was quite sensitive to dye bath pH and fabric. In synthetic indigo, the highest K/S value of dyed silk fabric was shown at near pH 9.0, and which of flax and cotton fabric were shown at pH 11.0. In other hand, in the case of natural indigo complex powder, the highest K/S value of dyed silk fabric was shown at near pH 8.0, and which of flax and cotton fabric were shown at pH 9.5∼pH 10. Mercerized cotton fabric dyed with natural indigo powder has a little antimicrobial activity.

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Sensitized Near IR Luminescence of Er(Ⅲ) Ion in Lanthanide Complexes Based on Diketone Derivatives: Synthesis and Photophysical Behaviors

  • Baek, Nam-Seob;Kwak, Bong-Kyu;Kim, Yong-Hee;Kim, Hwan-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.28 no.8
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    • pp.1256-1260
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    • 2007
  • Two β-diketone derivatives bearing triphenylene (1-naphthalene-2-yl-3-triphenylen-2-yl-propane-1,3-dione (NTPD)) and naphthalene (1,3-di-naphthalene-2-yl-propane-1,3-dione (DNPD)) and their Ln(III) complexes (Ln = Er or Gd) were synthesized and their photophysical properties were investigated. The sensitized emission of Er3+ ion in Er3+-[NTPD]3(terpy) and Er3+-[DNPD]3(terpy) was observed upon excitation at absorption maximum of ligands. Their photophysical studies indicate the sensitization of Er3+ luminescence by energy transfer through the excited triplet state of β-diketone ligand. The energy transfer rate through the excited triplet state of β-diketone ligand to Er3+ ion occurs faster than that of the oxygen quenching rate.

Near-IR Spectral Features of Haze Particles in the Atmosphere of Titan

  • Kim, Sang Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.62.1-62.1
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    • 2013
  • The Cassini/Visual Infrared Mapping Spectrometer (VIMS) observed the sun through the atmosphere of Titan, and provided vertically-resolved 63 spectra from 49 km to 987 km for the 1 - 5 micron range (Bellucci, 2008). Bellucci et al. (2009) analyzed selected spectral ranges where the band absorptions of $CH_4$ and CO are strong by constructing synthetic spectra including $CH_4$ and CO lines, but without including haze absorptions in their synthetic spectra. Kim et al. (2011) and Sim et al. (2013) were able to extract detailed spectral features of fundamental (Dv = 1) and overtone (Dv = 2) bands of the haze from the VIMS spectra by excluding the adjacent influences of strong $CH_4$ absorptions using a radiative transfer program, which includes effects of absorption and emission of lines of these molecules, and absorption and scattering of haze particles. In this presentation, we extend our detailed analyses to other remaining wavelengths in order to provide the spectral characteristics of the Titanian haze for the entire 1 - 5 micron range and to identify any additional haze spectral features and an unidentified feature near 4.3 microns reported by Bellucci et al. (2009).

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MEDIUM RESOLUTION SPECTRAL LIBRARY OF LATE-TYPE STELLAR TEMPLATES IN NEAR-INFRARED BAND

  • Nguyen, Huynh Anh Le;Pak, Soo-Jong;Im, Myung-Shin;Kang, Won-Seok;Lee, Sang-Gak;Ho, Luis C.;Pyo, Tae-Soo;Jaffe, Daniel T.
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.69.2-69.2
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    • 2011
  • We present medium resolution spectra in the near-infrared (IR) band 1.4-1.8 microns at a resolving power of R = 5000-10000 of template stars in G, K, and M types with luminosity classes of III observed by the echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. Identification of lines in the template star spectra has been completed base on the reference of Arcturus spectrum. We measured equivalent width (EW) of the lines, and analyze the trends of EW through the stellar spectral types.

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The Near Infrared Spectroscopic Studies of the Hydrogen Bonding Between Thioacetamide and Azines in Nonaqueous Solutions

  • 이상현;박정희;윤창주;최영상
    • Bulletin of the Korean Chemical Society
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    • v.16 no.9
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    • pp.831-834
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    • 1995
  • The nature of hydrogen bonding between thioacetamide and azines has been thoroughly investigated using near IR absorption spectroscopy. The νN-H + amide II combination band in thioacetamide (TA) has been analyzed to determine the thermodynamic constants for the formation of hydrogen bonded 1:1 TA:azine complexes in CCl4 and CHCl3 solutions. The relative stabilities of TA-azine complexes (pyridine->1,2-diazine->1,3-diazine->1,4-diazine-TA) are in good agreement with the relative proton affinities of azines in the gas phase. The results serve as a basis for analyzing the factors which influence the hydrogen bonding formation of TA in nonaqueous solutions.