• Title, Summary, Keyword: IR spectroscopy

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Classification of gallstones using Fourier-transform infrared spectroscopy and photography

  • Ha, Byeong Jo;Park, Sangsoo
    • Biomaterials Research
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    • v.22 no.3
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    • pp.202-209
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    • 2018
  • Background: Gallstones have conventionally been classified by gross inspection into 4 categories: cholesterol gallstones, black pigment (calcium bilirubinate) gallstones, brown gallstones, and mixed gallstones that contain both cholesterol and calcium bilirubinate. Classification using Fourier-transform infrared (FT-IR) spectroscopy supplements gross inspection; however, the issue of ambiguity in gallstone classification has not been fully addressed to date. Methods: Twenty-six gallstones obtained after surgical gallbladder removal were examined using FT-IR spectroscopy and digital photography, and classified into 6 gallstone groups according to characteristic FT-IR absorption bands. Results: FT-IR spectra of nine gallstones matched well with that of pure cholesterol, and the gallstones were thus classified as cholesterol stones. Twelve gallstones were classified as calcium bilirubinate stones as they showed characteristic absorption bands of calcium bilirubinate. However, the FT-IR spectra of these gallstones always showed a broad absorption band of bound water at $3600-2400\;cm^{-1}$. The other five gallstones were classified as mixed stones with combinations of cholesterol, calcium bilirubinate, and calcium carbonate. Conclusion: FT-IR spectroscopy is a powerful and convenient method for gallstone classification. Nevertheless, one should take serious note of the superposition of FT-IR absorption bands of different chemical components of gallstones including that of bound water.

Extracting Frequency-Frequency Correlation Function from Two-Dimensional Infrared Spectroscopy: Peak Shift Measurement

  • Kwak, Kyung-Won
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3391-3396
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    • 2012
  • Two-dimensional infrared (2D-IR) spectroscopy can probe the fast structural evolution of molecules under thermal equilibrium. Vibrational frequency fluctuation caused by structural evolution produced the time-dependent line shape change in 2D-IR spectrum. A variety of methods has been used to connect the evolution of 2D-IR spectrum with Frequency-Frequency Correlation Function (FFCF), which connects the experimental observables to a molecular level description. Here, a new method to extract FFCF from 2D-IR spectra is described. The experimental observable is the time-dependent frequency shift of maximum peak position in the slice spectrum of 2D-IR, which is taken along the excitation frequency axis. The direct relation between the 2D-IR peak shift and FFCF is proved analytically. Observing the 2D-IR peak shift does not need the full 2D-IR spectrum which covers 0-1 and 1-2 bands. Thus data collection time to determine FFCF can be reduced significantly, which helps the detection of transient species.

Study of the hydrogen concentration of SiNx film by Fourier transform infrared spectroscopy (Fourier transform infrared spectroscopy를 이용한 SiNx박막의 수소농도 연구)

  • Lee, Seok-Ryoul;Choi, Jae-Ha;Jhe, Ji-Hong;Lee, Lim-Soo;Ahn, Byung-Chul
    • Journal of the Korean Vacuum Society
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    • v.17 no.3
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    • pp.215-219
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    • 2008
  • The bonding structure and composition of silicon nitride (SiNx) films were investigated by using Fourier transform infrared spectroscopy (FT-IR). SiNx films were deposited on Si substrate at $340^{\circ}C$ using a conventional PECVD system. The compositions of Si and N in SiNx films were confirmed by using Rutherford backscattering spectroscopy (RBS) and photoluminescence (PL) analysis. The surface morphology of SiNx films was also analyzed by using atomic force microscopy (AFM). It was found that the contents of NH(at. %) is the reverse related with those of SiH corresponding to the result of FT-IR. we conclude that a quantitative analysis on SiNx films can be possible through a precise detection of the contents of H in SiNx films with a FT-IR analysis only.

A Study on Quantitative Measurement of Combustion Gases of Textiles Using a FTIR Spectroscopy(I) -Characteristic Spectral Range of Combustion Gases in the IR Region- (FT-IR을 이용한 섬유 연소가스 정량분석에 대한 연구(I) -각 연소가스의 특성피크영역 -)

  • 이근완;유종춘;정용식;우제완;김재필
    • Textile Science and Engineering
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    • v.40 no.3
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    • pp.257-263
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    • 2003
  • In order to determine the applicability of FT-IR spectroscopy for quantitative measurement of 7 individual combustion gases of textiles, NH$_3$, CO, $CO_2$, HCl, HCN, NO, NO$_2$, the combustion gas analysis system was equipped with FT-IR spectrophotometer. It is found that each standard gas shows a group of spectral absorption bands consisting of a large number of small peaks in the IR region. Through the comparision between the spectrum of standard gas and that of combustion gas, it was found that each component of combustion gas, except for NO$_2$, has a characteristic spectral range which does not overlap with that of other components.

Characterization and Synthesis of Titanium (IV) Isopropoxide Derivatives (Titanium(IV) isoproxide 유도체의 합성 및 특성연구)

  • Jung, Mie-Won
    • Analytical Science and Technology
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    • v.12 no.6
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    • pp.509-514
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    • 1999
  • The systematic modification of titanium(IV) isopropoxide with acetic acid as a organic additive was done and identifided by FT-IR, $^1H$, $^{13}C$ NMR and UV-Vis spectroscopy. The structure was cbanged after hydrolysis-condensation reaction and drying process. The hydrolysis-condensation rates of modified Ti alkoxide with acetic acid were investigated by $^1H$ NMR spectroscopy. This modified Ti(IV) alkoxide was less reactive toward hydrolysis-condensation reaction than $Ti(OPr^i)_4$, which can be attributed to the stable ligand structure between Ti alkoxide and ligand. The structural change on obtained from gel powders with heat treatment was also observed by FT-IR spectroscopy.

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Growing High-Quality Ir-Sb Nanostructures by Controlled Electrochemical Deposition

  • Nisanci, Fatma Bayrakceken
    • Journal of Electrochemical Science and Technology
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    • v.11 no.2
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    • pp.165-171
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    • 2020
  • The electrochemical preparation and spectroscopic characterisation of iridium-antimony (Ir-Sb) species is important owing to their potential applications as nanostructure materials. Nanostructures, i.e. nanoflower and nanodisk, of Ir-Sb were electrodeposited on conductive substrates using a practical electrochemical method based on the simultaneous underpotential deposition (UPD) of Ir and Sb from the IrCl3 and Sb2O3 at a constant potential. Electrochemical UPD mechanism of Ir-Sb was studied using cyclic voltammetry and potential-controlled electrochemical deposition techniques. Herein, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron and Raman spectroscopy were used to determine the morphological and structural properties of the electrochemically-synthesised Ir-Sb nanostructures.

The Chemical Constituents from Unidentified Sponge (해면의 화학적 성분 연구)

  • Park, Seon Gu;Paul J. Scheuer
    • Journal of the Korean Chemical Society
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    • v.38 no.2
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    • pp.169-173
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    • 1994
  • The previously reported cytotoxic metabolites, against the KB cell line, xestoquinone, halenaquinol sulfate and $halenaquinol^{5,6}$ were isolated from the unidentified sponge collected in October 1992, Manado Bay, Sulawesi in Indonesia. Their structure were elucidated by $^1H-,\;^{13}C$-NMR, $^1H-,\;^{13}C$(1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy$(HMQC)^1$, $^1H-,\;^{13}C$C(2 and 3 bond) Heteronuclear multiple Bond Correlation Spectroscopy$(HMBC)^2$, Electron Impact Mass Spectroscopy(EI ms), Ultraviolet Spectroscopy(UV), and Infrared Spectroscopy(IR)

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The Chemical Constituents from the Sponge Spongia sp. (해면 Spongia sp.의 화학적 성분 연구)

  • Park, Sun-Ku;Oh, Chang-Sok;Scheuer, Paul-J.
    • Journal of the Korean Chemical Society
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    • v.39 no.4
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    • pp.301-305
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    • 1995
  • The cytotoxic metabolites, against the KB cell line, halenaquinone, epispongiatriol and aldisin were isolated from the sponge Spongia sp. collected in September 1992, Manado Bay, Sulawesi in Indonesia. Their structures were elucidated by 1H, 13C NMR, 1H 13C(1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy (HMQC), 1H 13C(2 and 3 bond) Heteronuclear Multiple Bond Correlation Spectroscopy (HMBC), Electron Impact Mass Spectroscopy (EI ms) and Infrared Spectroscopy (IR).

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