• Title/Summary/Keyword: Infrared absorption

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Analysis of Functional Characteristics of the Commercial Wood Charcoal in Korea (국내 시판용 목탄의 기능성 분석(II))

  • Lee, Dong-Young;Kim, Byung-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.6
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    • pp.480-489
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    • 2010
  • We investigated the functional characteristics of commercial wood charcoal in Korea and their application as functional raw materials. The areas of analysis were anatomical features, elementary composition, mineral composition, caloric values, anion and far-infrared ray emission, and moisture absorption capacity. Based on the analyses as above mentioned, it is considered that charcoal can be evaluated as functional raw material. In commercial wood charcoal in Korea, there were highly varied depending on manufacturing methods as black charcoal, white charcoal and mechanical charcoal and manufactures for elementary composition, mineral composition, anion emission, far infrared ray emission. Especially, black charcoal showed lower moisture absorption capacity than white charcoal and mechanical charcoal. For charcoal as functional raw material, selective usage are needed based on the analyses of anatomical features, elementary composition, mineral composition, caloric values, anion and far-infrared ray emission, and moisture absorption capacity. Specific charcoal making methods for improving specific functionality, required as functional raw material, are necessary in further research.

Studies on the Near Infrared Diffuse Reflection Spectroscopy for Meat Components (근적외선 반사분광분석법에 의한 정육 및 그 구성성분의 반사 spectra에 관한 연구)

  • Oh, Eun-Kyong;Grossklaus, Dieter
    • Korean Journal of Food Science and Technology
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    • v.24 no.5
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    • pp.404-407
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    • 1992
  • This study was conducted to determine the effect of the physical and chemical factors on the absorbance when the chemical component of food was rapidly and effectively analyzed with near infrared reflection spectrophotometer. The absorbance was measured within the wavelength range of 1100 and 2500m and at the various sample temperatures. The absorbance was greatly increased with the rising sample temperature. When the grinding time of samples prolonged, the absorbance was decreased. The absorption peaks occurring in the near infrared spectra of meat, meat protein, pork fat and water were attributed to the overtone and combination vibration of C-H, N-H, O-H or C=O bond within the macromolecules of each sample. The absorbance was lower for meat protein than other meat components. Pork fat was characterized by the ${\cdot}CH_2{\cdot}$ absorption peak at the wavelength of 1700 and 2300 nm and water by the relatively high absorption peak at the wavelength of 1450 and 1930 nm. As a result, the absorbance of near infrared reflection spectrum of meat was affected mainly by fat and water in meat.

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Non-invasive Blood Glucose Detection Sensor System Based on Near-Infrared Spectroscopy (근적외선 분광법 기반 비침습식 혈당 검출 센서 시스템)

  • Kang, Young-Man;Han, Soon-Hee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.5
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    • pp.991-1000
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    • 2021
  • Among non-invasive blood glucose detection technologies, the optical technique is a method that uses light reflection, absorption, and scattering characteristics when passing through a biological medium. It reduces pain or discomfort in measurement and has no risk of infection. So it is becoming a major flow of blood glucose detection research. Among them, near-infrared spectroscopy has a disadvantage in that the complexity increases when analyzing signals detected due to interferences between proteins and acids that share a similar absorption function with blood glucose molecules. In this study, a non-invasive sensor system with multiple near-infrared bands was designed and manufactured to alleviate the deterioration of blood glucose detection function that may occur due to skin absorption of near-infrared rays. A blood survey was conducted to verify the system, and the degree of blood glucose response in the blood was collected as spectral data, and the results of this study were quantitatively verified in terms of correlation between the data and blood glucose.

NEAR-INFRARED HIGH-RESOLUTION SPECTROSCOPY OF THE OBSCURED AGN IRAS 01250+2832

  • Shirahata, M.;Usuda, T.;Oyabu, S.;Nakagawa, T.;Yamamura, I.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.295-296
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    • 2012
  • We provide a new physical insight on the hot molecular clouds near the nucleus of the heavily obscured AGN IRAS 01250+2832, based on the results of near-infrared high-resolution spectroscopy of gaseous CO ro-vibrational absorption lines with Subaru/IRCS. The detected CO absorption lines up to highly excited rotational levels reveal that hot dense molecular clouds exist around the AGN under the peculiar physical conditions.

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.

Novel optical properties of amorphous ferric hydroxide in near infrared region

  • Kang, Tae Yeon;Chae, Weon-Sik
    • Rapid Communication in Photoscience
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    • v.4 no.2
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    • pp.34-36
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    • 2015
  • New spectroscopic characteristics of amorphous ferric hydroxide ($Fe(OH)_3$), interestingly in the near infrared (NIR) region, are presented in this study. The absorption spectrum of ferric hydroxide covers wide spectral regions from ultraviolet to NIR (200~900 nm). Unique emission bands were newly observed in the NIR regions (800~1400 nm). Several bands of this NIR emission are quiet well overlapped with the combinational vibrational absorption bands of water. From photothermal conversion study, very interestingly, temperature of aqueous mixture solution including the amorphous ferric hydroxide was significantly increased from ambient temperature to $38^{\circ}C$ for 30 minutes under irradiation of a standard helium lamp.

Cure Kinetics for the Acid Anhydride-cured Epoxy System Using a Near-infrared Reflection Spectroscopy (근적외선 분광분석을 통한 산무수물경화 에폭시 시스템의 경화 동력학)

  • 곽근호;박수진;이재락
    • Polymer(Korea)
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    • v.24 no.1
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    • pp.65-71
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    • 2000
  • The latent properties and cure kinetics of an acid anhydride-cured epoxy resin have been investigated by a near-infrared (NIR) reflection spectroscopy. The assignments of the latent properties and cure behaviors were performed by the measurements of the NIR reflectance for epoxide and hydroxyl groups at different temperatures. A comprehensive analysis of the origin, location, and shifts during reaction of all major NIR absorption peaks in the spectral range from 4000 to 7100 $cm^{-1}$ / was provided. The extent of reaction was determined from NIR absorption band at the 4530 $cm^{-1}$ / depending on epoxide concentration and cure temperature.

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Self-Assembled and Langmuir-Blodgett Arachidic Acid Monolayers on Silver: A Comparative Reflection-Absorption Fourier Transform Infrared Spectroscopic Study

  • Ahn, Sang-Jung;Mirzakhojaev, Diyas A.;Son, Dong-Hee;Kim, Kwan
    • Bulletin of the Korean Chemical Society
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    • v.15 no.5
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    • pp.369-374
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    • 1994
  • Self-assembled (SA) and Langmuir-Blodgett (LB) monolayers of arachidic acid on silver surfaces have been investigated by a reflection-absorption Fourier transform infrared spectroscopy. Arachidic acid was adsorbed on silver as carboxylate with its two oxygen atoms bound symmetrically to the surface. Although both the SA and LB monolayers consisted of fully extended trans zigzag carbon chains, a closer examination indicated that the SA monotayers should possess a more ordered crystalline structure than the LB monolayers. The infrared spectral data dictated that the extent of methyl group exposure at the air-film interface was greater in the SA monolayers than the LB monolayers, in agreement with the contact angle measurement. From a theoretical analysis, the alkyl chains in each monolayers seemed to be tilted away from the surface normal by less than $3.5^{\circ}$, but in opposite directions. Arachidic acid monolayers were concluded to have same structure as stearic acid monolayers.

A Study on the MDTF for Uncooled Infrared Ray Thermal Image Sensors with High Thermal Coefficient of Resistance (높은 열저항 계수를 가지는 비냉각형 적외선 열영상 이미지 센서용 MDTF(Metal-dielectric Thin Film)에 관한 연구)

  • Jung, Eun-Sik;Jeong, Se-Jin;Kang, Ey-Goo;Sung, Man-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.5
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    • pp.366-371
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    • 2012
  • In this paper, fabricated by MEMS uncooled micro-bolometer detector for the study in the infrared sensitivity enhancement. Absorption layer SiOx-Metal series MDTF (metal-dielectric thin film) by high absorption rate and has a high thermal coefficient of resistance, low noise characteristics were implemented. Then MDTF were made in a vacuum deposition method. And MDTF for the analysis of the physical properties of silicon wafers were fabricated, TCR (temperature coefficient of resistance) value was made in order to measure the glass wafer and FT-IR (Fourier Transform Infrared spectroscopy) values were made in order to measure the germanium window. The analyzed results of MDTF -3 [%/K] has more characteristics of the TCR. And 8~12 um wavelength region close to 70% in the absorption characteristic.