• Title/Summary/Keyword: near-IR

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A bipolar IR feature near the center of $\gamma$-ray SNR G353.6-0.7

  • Kim, Il-Joong;Seon, Kwang-Il;Koo, Bon-Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.70.1-70.1
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    • 2010
  • 최근에 새롭게 발견된 초신성잔해 G353.6-0.7은 $\gamma$-ray source로부터 발견된 최초의 초신성 잔해이다. 이 초신성잔해의 중앙에서는 밝은 X-ray compact source, XMMU J173203.3-344518이 발견되었다. 우리는 위 X-ray compact source 근처에 IR source, IRAS 17287-3443이 매우 가까이 있음을 발견하고, Spitzer data를 이용하여 이 IR source에 대하여 자세히 분석한다. 24 um image에서 IR source는 bipolar feature를 보이며, 매우 강한 중앙지역은 8 um 에서도 extended feature를 보여준다. Spitzer IRS spectrum에서는 [Ne II] 12.88 um 방출선이 강하게 나오는 것이 특징이며, 우리는 또한 이 IR source에 embedded 된 것으로 의심되는 point source를 분석한다.

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On the UV and IR Spectra of Dioxane Lignin from Bamboo Culm (죽재(竹材) Dioxane Lignin의 UV, IR Spectrum에 대하여)

  • Moon, Chang-Kuck;Jo, Jong-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.15 no.4
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    • pp.26-31
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    • 1987
  • The ultraviolet and infrared spectra of dioxane lignin from bamboo were investigated. 1. Spectrum curve type considerably resembled that of wood lignin. There were 3 absorption peak positions at 210nm(max. peak), at 260-270nm(shallow mini. peak), at 280nm(lower max. peak) as in the wood lignin spectra. 2. The lower minimum peak near at 280 nm is the typical peak of lignin. This peak does not exist exactly at 280 nm but from 282nm to 285nm in this bamboo UV spectra. The absorption intensities are equal in this region and the peak is not sharp. 3. The absorption band of aromatic nucleus is near at wave number $1550cm^{-1}$ in the IR spectra of bamboo lignin. The intensity at about 1040-$1130cm^{-1}$ and at about 1230-$1275cm^{-1}$ were similar in the hardwood lignin but reverse to that of softwood lignin spectrum.

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Study on the MTTF of Multi Wave Lengths IR and NIR LEDs Module (다파장 IR과 NIR 모듈의 평균 수명 예측에 관한 연구)

  • Kim, Dong Pyo;Kim, Kyung Seob
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.34 no.1
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    • pp.44-49
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    • 2021
  • Recently, infrared (IR) and near-infrared (NIR) light-emitting diodes (LEDs) were widely used for home medical applications owing to its low output power and wide exposed area for curing. For deep penetration of the light under the skin, multiple LEDs with wavelengths of 700~10,000 nm were located on a flexible printed circuit board. When multiple wavelengths of LEDs were soldered on a circuit board, the lifetime of LED module highly depends on LEDs with a short lifetime. The mean time to failure (MTTF) was able to calculate with the experimental results under high temperature and the Arrhenius model. The results of this study could help companies to approve the warranty of LED modules and its product.

Photophysical and Photochemical Property of ATX-S10

  • Ito, Toshiaki;Okazaki, Shigetoshi;Kageyama, Kazumi;Hirohata, Toru;Kohno, Eiji;Hirano, Toru
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.527-529
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    • 2002
  • Photodynamic therapy (PDT) is a medical treatment using laser and photosensitizing drug taken up to destroy cancer cells. Singlet oxygen ($^1$0$_2$) generation is strongly related to this treatment. We have built a direct detection system monitoring feeble luminescence, in the near IR region, from $^1$0$_2$, We have comparatively studied the photophysical and photochemical properties in solution of a newly developed drug ATX-S10 and Photofrin already investigated clinically. We demonstrdted that ATX-S10 was capable of efficiently yielding $^1$0$_2$, which may lead to highly efficient PDT treatment. Successive laser excitation photobleached ATX -S10 readily in a dose-dependent manner. This result shows that ATX -S10 is useful in setting up suitable medical treatment conditions to minimize side effects.

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Near-IR Radiative Transfer Process for the Hazy Atmosphere of Titan

  • Kim, Sang-Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.44.2-44.2
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    • 2015
  • Radiative transfer programs have been developed to simulate near-IR spectra of Titan. The formalism of the radiative transfer calculations includes the absorption and emission lines of $CH_4$, $C_2H_2$, $C_2H_6$, and HCN, and continua produced by Titanian haze particles. Absorption and scattering of sunlight by haze particles are considered by employing a two-stream approximation and a spherical-shell model for the atmospheric layers of Titan. Various constraints on the radiative transfer calculations for generating synthetic spectra will be discussed and presented. Several examples of comparisons between the synthetic spectra and recent spectral observations of Titan will also be presented.

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Near-IR Polarimetry Survey of the Large Magellanic Cloud : Photometric Reliability Test

  • Kim, Jae-Yeong;Pak, Soo-Jong
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.78.1-78.1
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    • 2012
  • We present near-IR imaging polarimetry of the 5${\times}$9 fields (-39'${\times}$69') centered at 30 Doradus in the Large Magellanic Cloud (LMC), using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL in 2008 December and 2011 December. We measured Stokes parameters of point-like sources to derive the degree of polarization and the polarization position angle. Since our results are suffered from non-photometric weather, we compare the polarization results from 2008 and those from 2011, and examine the photometric reliabilities between the two runs. Our survey data will be compared with molecular and dust maps to reveal the large-scale magnetic field properties in the star-forming clouds.

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Near-IR Polarimetry of Star-Forming Regions around 30 Doradus

  • Kim, Jae-Yeong;Pak, Soo-Jong;Choi, Min-Ho;Kwon, Jung-Mi;Kandori, Ryo;Nakajima, Yasushi;Tamura, M.;Nagata, T.;Sato, S.
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.59.1-59.1
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    • 2010
  • We present wide-field near-IR imaging polarimetry of 30 Doradus, using the InfraRed Survey Facility(IRSF) 1.4 m telescope at the South African Astronomical Observatory. We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL. 30 Doradus is located in the Large Magellanic Cloud(LMC) and it is the most active starburst region known in the Local group of galaxies. 30 Doradus is one of the best field to examine the behavior of the interstellar medium and star-formation mechanism under different conditions. We will investigate the structure of magnetic field in 30 Doradus region.

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Near-IR Polarimetry around 30 Doradus - II. Polarization Structure of the Expanded Survey Field

  • Kim, Jae-Yeong;Pak, Soo-Jong;Kang, Won-Seok
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.111.1-111.1
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    • 2011
  • We present near-IR imaging polarimetry of the observed $5{\times}9$ fields (${\sim}39'{\times}69'$) in the Large Magellanic Cloud (LMC), using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL. We measured Stokes parameters of point-like sources to derive the degree of polarization and the polarization position angle. We show a polarization vector map in the reduced 45 fields and the statistical distribution of the polarization degrees and angles. This poster presents the preliminary results to show the physical properties of the magnetic field in the observed LMC regions.

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Near-IR Polarimetry Survey of the Large Magellanic Cloud: Relationship between the polarization degree and the color

  • Kim, Jaeyeong;Pak, Soojong;Kang, Wonseok;Choi, Minho
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.100.2-100.2
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    • 2012
  • We performed near-IR imaging polarimetry of the $5{\times}9$ fields (${\sim}39^{\prime}{\times}69^{\prime}$) around 30 Doradus in the Large Magellanic Cloud (LMC), using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in the J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL in 2008 December and 2011 December. With the reliable LMC field data which were selected using a bad-data-rejection algorithm, we measured Stokes parameters of point-like sources to derive the degree of polarization and the polarization position angle. We present physical relationship between the three bands using the photometric and the polarimetric properties of the sources.

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A Study on Electronic Interaction in Dimetallic Complexes with Conjugated Chain (공액사슬로 연결된 이핵금속착체의 전자적 상호작용에 관한 연구)

  • Chung, Min-Chul;Munetaka Akita
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.6
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    • pp.652-660
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    • 2004
  • The cis-hex-3-ene-1,5-diynyl-bridged diiron compound 3, [(η$^{5}$ - $C_{5}$ M $e_{5}$ ) Fe(dppe)]$_2$($\mu$-C≡C-CH=CH-C≡C), have been prepared and characterized by cyclic voltammetry(CV), and electronic spectroscopy (UV-VIS and near-IR, NMR). From the results, compound 3 show two well resolved, single-electron, reversible oxidation waves by CV, and comproportionation constant(Kc) calculated from the CV data for compound 3. The Mixed-valence (MV) radical cation 3$^{+}$ show strong absorptions in the near IR, 1586 nm, and this band is more readily assigned as MV $\pi$-$\pi$ band of delocalized complex (Robin-Day Mixed-valence Class III), and the $H_{ab}$ , effective coupling parameter are most consistent with electronic delocalization.