scholarly journals Filling rate dependence on theoretical Raman spectra of carbon C60 peapods

2016 ◽  
Vol vol1 (1) ◽  
Author(s):  
Hassane Chadli ◽  
A. Rahmani ◽  
A. Ait Abdelkader ◽  
F. Fergani ◽  
B. Fakrach
Keyword(s):  
Raman Spectra ◽  
Single Wall Carbon Nanotubes ◽  
Raman Intensity ◽  
Filling Rate ◽  
Spectral Moments ◽  
Moments Method ◽  
Polarization Theory ◽  
Intensity Ratios ◽  
Bond Polarization ◽  
Good Agreement

We use the spectral moments method in the framework of the bond-polarization theory to calculate nonresonant Raman spectra of C60 peapods as a function of the concentration of fullerenes inside the single wall carbon nanotubes. The evolution of the average Raman intensity ratios between Raman mode of C60 molecules and nanotube as a function of the concentration of fullerenes has been analyzed and a general good agreement is found between calculations and measurements. #CARBON_NANOTUBES #PEAPODS #RAMAN_SPECTROSCOPY #SIMULATION #SPECTRAL_MOMENT_METHOD

scholarly journals Raman active modes in defective peapods

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Fatima Fergani ◽  
S.M. Ait Abdelkader ◽  
H. Chadli ◽  
Ah Rahmani ◽  
A. Rahmani
Keyword(s):  
Spatial Arrangement ◽  
C60 Fullerene ◽  
Vibrational Properties ◽  
Single Walled Carbon Nanotube ◽  
Moments Method ◽  
Polarization Theory ◽  
The Subject ◽  
Resonant Raman ◽  
Bond Polarization ◽  
Theoretical Results

The vibrational properties of defective single-walled carbon nanotube filled with C60 fullerene is the subject of the current study. For this aim we use the spectral moments method in the framework of the bond-polarization theory to calculate the non-resonant Raman spectra of hexa-vacancy defective C60 peapods. Essentially, the vibrational properties are closely coupled with the atomic structure of the system. The evolution of the Raman spectrum as a function of the spatial arrangement of defects in carbon nanotubes is discussed. This work provides benchmark theoretical results to understand the experimental data of defective C60 peapods. #single_wall_carbon_nanotube #C60_peapods #hexa-vacancy_defect #Raman_spectroscopy #pectral_moment_method

Temperature dependence of the Raman spectra of single-wall carbon nanotubes

2000 ◽  
Vol 76 (15) ◽  
pp. 2053-2055 ◽  
Author(s):  
H. D. Li ◽  
K. T. Yue ◽  
Z. L. Lian ◽  
Y. Zhan ◽  
L. X. Zhou ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Dependence ◽  
Raman Spectra ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon

The infrared, Raman, and resonance Raman spectra and normal coordinate analysis of methyl and ethyl dithioacetate

1982 ◽  
Vol 60 (2) ◽  
pp. 174-189 ◽  
Author(s):  
J. J. C. Teixeira-Dias ◽  
V. M. Jardim-Barreto ◽  
Y. Ozaki ◽  
A. C. Storer ◽  
P. R. Carey
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Resonance Raman ◽  
Normal Coordinate Analysis ◽  
Raman Intensity ◽  
Normal Coordinate ◽  
Intensity Enhancement ◽  
Strong Intensity ◽  
Resonance Raman Spectra ◽  
Absorbance Peak

Infrared, Raman, and resonance Raman data are reported for ethyl and methyl dithioacetate together with data for their isotopically substituted analogs: CD3C(=S)SCH3, CH3C(=S)SCD3, 13CH3C(=S)SCH3, CH313C(=S)SCH3, CD3C(=S)SCH2CH3, CH3C(=S)SCD2CH3, and CH313C(=S)SCH2CH3. Based on these data and a normal coordinate analysis of methyl dithioacetate, assignments are proposed for the majority of bands appearing in the vibrational spectra. Using excitation wavelengths in the 324–356 nm region strong intensity enhancement is observed for Raman bands near 1195, 1100, 730, and 580 cm−1 which are assigned to stretching motions of the CCSSC skeleton. Raman excitation profiles are reported for the 1197 and 581 cm−1 bands of ethyl dithioacetate and the electronic absorbance peak near 305 nm is identified as the source of resonance Raman intensity enhancement.

Laser-induced effects in Raman spectra of single-wall carbon nanotubes

2003 ◽  
Vol 33 (7) ◽  
pp. 645-650 ◽  
Author(s):  
S N Bokova ◽  
Vitalii I Konov ◽  
Elena D Obraztsova ◽  
A V Osadchii ◽  
A S Pozharov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectra ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon

Liquid Core Optical Fibers in Raman Spectroscopy

1981 ◽  
Vol 35 (4) ◽  
pp. 439-442 ◽  
Author(s):  
Howard B. Ross ◽  
William M. McClain
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Optical Fibers ◽  
Liquid Core ◽  
Geometrical Optics ◽  
Laser Spectrometer ◽  
Trans Stilbene ◽  
Scan Speed ◽  
Good Agreement

Raman spectra of samples contained in hollow quartz fibers are compared quantitatively to conventional Raman spectra using identical laser, spectrometer, detector, and scan speed. We find the fiber signal to be enhanced by a factor of 250/m of fiber, in good agreement with calculations based on geometrical optics. A fiber spectrum of 2 mol% trans-stilbene in benzene is good enough to allow essentially perfect solvent subtraction.

Combined Vibrational Spectroscopic and Elemental Studies of 18th Century Transylvanian Stove Tiles

2020 ◽  
Author(s):  
Ioan Bratu ◽  
Constantin Marutoiu ◽  
Antonio Hernanz ◽  
Olivia Florena Nemes ◽  
M Tiplic ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Spectral Region ◽  
18Th Century ◽  
Raman Microscopy ◽  
Ftir Spectra ◽  
The Other ◽  
Processing Temperature ◽  
Railway Station ◽  
Good Agreement

Abstract Three Transylvanian fragments of some 18th century Saxon tiles obtained from excavations in the Central Railway Station Square in Sibiu (Romania) have been studied by Raman microscopy, FTIR, SEM-EDX and XRF techniques. A lead-rich aluminosilicate was found to have been used as enamel/glaze for the tile fragments. An analysis of the band components of the Raman spectra of the enamel of one fragment in the 400–1200 cm− 1 spectral region indicates that their processing temperature was in the 600–800 °C range, in good agreement with the temperature obtained from FTIR spectra of the other two tile fragments.

scholarly journals Chemometrics-Enabled Raman Spectrometric Qualitative Determination and Assessment of Biochemical Alterations during Early Prostate Cancer Proliferation in Model Tissue

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
John I. Githaiga ◽  
Hudson K. Angeyo ◽  
Kenneth A. Kaduki ◽  
Wallace D. Bulimo
Keyword(s):  
Prostate Cancer ◽  
Nucleic Acids ◽  
Raman Spectra ◽  
Cell Lines ◽  
Difference Spectra ◽  
Cancer Proliferation ◽  
Biochemical Alterations ◽  
Pc3 Cells ◽  
Intensity Ratios ◽  
Spectral Intensities

The use of Raman spectroscopy combined with multivariate chemometrics for disease diagnosis has attracted great attention from researchers in recent years. This is because it is a noninvasive and nondestructive detection approach with enhanced sensitivity. However, a major challenge when analyzing spectra from biological samples has been the detection of subtle biochemical alterations buried in background and fluorescence noise. This work reports a qualitative chemometrics-assisted investigation of subtle biochemical alterations associated with prostate malignancy in model biological tissue (metastatic androgen insensitive (PC3) and immortalized normal (PNT1a) prostate cell lines). Raman spectra were acquired from PC3 and PNT1a cells at various stages of growth, and their biochemical alterations were determined from difference spectra between the two cell lines (for prominent alterations) and principal component analysis (PCA) (for subtle alterations). The Raman difference spectra were computed by subtracting the normalized mean spectral intensities of PNT1a cells from the normalized mean spectral intensities of PC3 cells. These difference spectra revealed prominent biochemical alterations associated with the malignant PC3 cells at 566 ± 0.70 cm−1, 630 cm−1, 1370 ± 0.86 cm−1, and 1618 ± 1.73 cm−1 bands. The band intensity ratios at 566 ± 0.70 cm−1 and 630 cm−1 suggested that prostate malignancy can be associated with an increase in relative amounts of nucleic acids and lipids, respectively, whereas those at 1370 ± 0.86 cm−1 and 1618 ± 1.73 cm−1 suggested that prostate malignancy can be associated with a decrease in relative amounts of saccharides and tryptophan, respectively. In the analysis using PCA, intermediate-order and high-order principal components (PCs) were used to extract the subtle biochemical fingerprints associated with the cell lines. This revealed subtle biochemical differences at 1076 cm−1, (1232, 1234 cm−1), (1276, 1278 cm−1), (1330, 1333 cm−1), (1434, 1442 cm−1), and (1471, 1479 cm−1). The band intensity ratios at 1076 cm−1 and 1232 cm−1 suggested that prostate malignancy can be associated with an increase in subtle amounts of nucleic acids and amide III components, respectively. The method reported here has demonstrated that subtle biochemical alterations can be extracted from Raman spectra of normal and malignant cell lines. The identified subtle bands could play an important role in quantitative monitoring of early biomarker alterations associated with prostate cancer proliferation.

Dispersive Raman spectra observed in graphite and single wall carbon nanotubes

2002 ◽  
Vol 323 (1-4) ◽  
pp. 100-106 ◽  
Author(s):  
R. Saito ◽  
A. Jorio ◽  
A.G. Souza Filho ◽  
A. Grueneis ◽  
M.A. Pimenta ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectra ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon

scholarly journals Temperature-Dependent Raman Spectroscopic Study of the Double Molybdate KBi(MoO4)2

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5453
Author(s):  
Min Wang ◽  
Changhao Wang ◽  
Jian Wang ◽  
Liming Lu ◽  
Xiaoye Gong ◽  
...  
Keyword(s):  
High Temperature ◽  
Raman Spectra ◽  
Monoclinic Phase ◽  
Raman Band ◽  
Vibrational Modes ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Thermal Stability Of ◽  
Good Agreement

In situ high-temperature Raman spectra of polycrystalline KBi(MoO4)2 were recorded from room temperature to 1073 K. Thermal stability of the monoclinic KBi(MoO4)2 was examined by temperature-dependent XRD. The monoclinic phase transformed into the scheelite tetragonal structure at 833 K, and then to the monoclinic phase at 773 K. Quantum chemistry ab initio calculation was performed to simulate the Raman spectra of the structure of KBi(MoO4)2 high-temperature melt. The experimental Raman band at 1023 K was deconvoluted into seven Gaussian peaks, and the calculated results were in good agreement with the experimental data. Therefore, the vibrational modes of Raman peaks of molten KBi(MoO4)2 were assigned. It was confirmed that the isolated structure of [Bi(MoO4)2]− monomer, consisting of Mo6+ centers and Bi3+ sub-centers connected by edge-sharing, mainly exists in the melt of KBi(MoO4)2.

Sign in / Sign up

Export Citation Format

Share Document