• Title/Summary/Keyword: Near-infrared Absorption

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AKARI near Infrared spectroscopy of luminous infrared galaxies

  • Lee, Jong-Chul;Hwang, Ho-Seong;Lee, Myung-Gyoon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.50.2-50.2
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    • 2012
  • We present the results of near infrared (2.5-5 micron) spectroscopy of nearby luminous infrared galaxies (LIRGs) using AKARI. The LIRG catalog is constructed from the cross-correlation between the Infrared Astronomical Satellite and the Sloan Digital Sky Survey data, and optically non-Seyfert type LIRGs are selected for main targets. We search for optically elusive active galactic nuclei (AGNs), based on the strengths of 3.3 micron polycyclic aromatic hydrocarbon emission and dust absorption features at 3-4 micron. We investigate the hidden AGN fraction as a function of the infrared luminosity and correlation between optical and near infrared star formation indicators.

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A PRELIMINARY STUDY ON THE CHARACTERIZATION OF HONEY BY NEAR INFRARED SPECTROSCOPY

  • Davies, Anthony M.C.;Radovic, Branka;Fearn, Tom;Anklam, Elke
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1052-1052
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    • 2001
  • Hear infrared (NIR) spectra were measured, at five temperatures, for forty-eight samples of honey, from a variety of geographical and botanical sources, and the data has been used to explore the possibility of using NIR spectroscopy for testing label claims concerning the geographical and botanical source of honey being offered for sale to the public. These results demonstrate that the successful characterization of the botanical source of a honey may be obtained by NIR spectroscopy. Further work with large numbers of samples and groups will be required to realized this potential. Additional analysis of these data suggest that research into new ways of obtaining information on the change of absorption with temperature might be beneficial for a range of technologies.

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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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Synthesis of a Novel Near-Infrared Fluorescent Dye: Applications for Fluorescence Imaging in Living Cells and Animals

  • Chen, Tongbin;Lai, Yijun;Huang, Suisheng
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2937-2941
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    • 2013
  • Fluorescence imaging is considered as one of the most powerful techniques for monitoring biomolecule activities in living systems. Near-infrared (NIR) light is advantageous for minimum photodamage, deep tissue penetration, and minimum background autofluorescence interference. Herein, we have developed a new NIR fluorescent dye, namely, RB-1, based on the Rhodamine B scaffold. RB-1 exhibits excellent photophysical properties including large absorption extinction coefficients, high fluorescence quantum yields, and high photostability. In particular, RB-1 displays both absorption and emission in the NIR region of the "biological window" (650-900 nm) for imaging in biological samples. RB-1 shows absorption maximum at 614 nm (500-725 nm) and emission maximum at 712 nm (650-825 nm) in ethanol, which is superior to those of traditional rhodamine B in the selected spectral region. Furthermore, applications of RB-1 for fluorescence imaging in living cells and small animals were investigated using confocal fluorescence microscopy and in vivo imaging system with a high signal-to-noise ratio (SNR = 10.1).

High-resolution Near-infrared Spectroscopy of IRAS 16316-1540: Evidence of Accretion Burst

  • Yoon, Sung-Yong;Lee, Jeong-Eun;Park, Sunkyung;Lee, Seokho;Herczeg, Gregory J.;Mace, Gregory;Lee, Jae-Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.42.3-42.3
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    • 2019
  • The high-resolution near-infrared (NIR) spectroscopy can reveal the evidence of the accretion burst (e.g., the broadened absorption features produced by the Keplerian disk motion) although the moment of the outburst was not caught. The embedded protostar IRAS 16316-1540 observed with the Immersion Grating Infrared Spectrograph (IGRINS, $R={\Delta}{\lambda}/{\lambda}{\sim}45000$) shows the broad absorption features in atomic and CO transitions, as seen in FU Orionis objects (FUors), indicative of an outburst event. We examine whether the spectra of IRAS 16316-1540 arise from the rotating inner hot gaseous disk. Using the IGRINS spectral library, we show that the line profiles of IRAS 16316-1540 are more consistent with an M1.5 V template spectrum convolved with a disk rotation profile than the protostellar photosphere absorption features with a high stellar rotation velocity. We also note that the absorption features deviated from the expected line profile of the accretion disk model can be explained by a turbulence motion generated in the disk atmosphere. From previous observations that show the complex environment and the misaligned outflow axes in IRAS 16316-1540, we suggest that an impact of infalling clumpy envelope material against the disk induces the disk precession, causing the accretion burst from the inner disk to the protostar.

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NEAR INFRARED BIO-SPECTROSCOPY : APPROACHES FOR MEASUREMENTS IN CRITICAL CARE

  • Burns, David
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.2102-2102
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    • 2001
  • Near infrared, diffuse reflectance spectroscopy has shown significant potential for in vitro and in vivo assessment of metabolic status. However, the complexity of living samples can lead to ambiguous results. This presentation will focus on methods that provide controls for scattering and absorption estimation in tissue. For robust estimations, normalization procedures will be shown which can greatly improve interpretability of results. Normalization based on time, location and spectral property will be shown with data from models, tissue phantoms and in vivo measurements. In particular, interpretation of NIR spectra associated with major respiratory constituents will be examined. Measurement of constituents such as hemoglobin, myoglobin, tissue edema, and lactate will be shown. Results suggest that NIR may provide a valuable tool for physiological monitoring in critical care research and practice.

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Spectral Characteristics Visible and Near-infrared of Metamorphic Rocks (변성암의 분광특성)

  • 조민조;강필종;이봉주
    • Korean Journal of Remote Sensing
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    • v.8 no.1
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    • pp.1-13
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    • 1992
  • The study is to analize the spectral characteristics of metamorphic rocks by their spectral reflectance curves obtained from CARY 17-D Spectrophotometer. Coarse grained rocks generally show strong absorption at 1.4 and 1.9 $\mu\textrm{m}$ due to preserved water inclusion in quartz of feldspar. The basic rocks show a broad absorption due to Fe$^{++}$ ion rich in mafic minerals. Strong absorption near 2.0$^+\mu\textrm{m}$ suggests existence of carbonate or clay minerals.

Optical Property Measurements of Optical Phantoms and Honan Tissues Using Frequency-Domain Diffuse Optical Tomography (주파수 영역 확산광 단층촬영 장치를 이용한 광 팬텀 및 인체조직의 광 계수 측정)

  • Ho, Dong-Su;Kwon, Ki-Woon;Eom, Gi-Yun;Lee, Seung-Duk;Kim, Beop-Min
    • Journal of Biomedical Engineering Research
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    • v.28 no.2
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    • pp.229-234
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    • 2007
  • Diffuse optical tomography (DOT) is a relatively new medical imaging modality which uses near infrared light to image large-sized tissues noninvasively. We constructed a frequency-domain DOT system to measure the optical properties of optical phantoms and human tissues. The FD-DOT uses the intensity-modulated infrared light source that illuminates the biological tissues. The phase shift and modulation changes at each detector site are separately processed to measure the optical properties. The absorption and scattering coefficients are separately estimated using inverse algorithms.

Plasmon-enhanced Infrared Spectroscopy Based on Metasurface Absorber with Vertical Nanogap

  • Hwang, Inyong;Lee, Jongwon;Jung, Joo-Yun
    • Journal of Sensor Science and Technology
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    • v.27 no.5
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    • pp.275-279
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    • 2018
  • In this study, we introduce a sensing platform based on a plasmonic metasurface absorber (MA) with a vertical nanogap for the ultrasensitive detection of monolayer molecules. The vertical nanogap of the MA, where the extremely high near-field is uniformly distributed and exposed to the external environment, is formed by an under-cut structure between a metallic cross nanoantenna and the mirror layer. The accessible sensing area and the enhanced near-field of the MA further enhance the sensitivity of surface-enhanced infrared absorption for the target molecule of 1-octadecanethiol. To provide strong coupling between the molecular vibrations and plasmonic resonance, the design parameters of the MA with a vertical nanogap are numerically designed.