Search results for " Infrared Spectroscopy"
showing 10 items of 438 documents
Comparative study of historical woods from XIX century by thermogravimetry coupled with FTIR spectroscopy
2019
Thermal and structural properties of historical woods from apparatuses of the Historical Collection of the Physics Instruments of the University of Palermo have been investigated by FTIR spectroscopy coupled with thermogravimetric analysis. Specifically, the wooden portions of apparatuses from XIX century have been studied. The investigated woods belong to different taxa (Swietenia mahagoni, Picea abies and Juglans regia). The thermal behavior of the wooden materials has been successfully interpreted on the basis of specific indexes determined by the quantitative analysis of the FTIR spectra. The kinetics of the wood pyrolysis have been investigated by using a non-isothermal approach based …
Structural, mechanical and thermal behavior assessments of PCL/PHB blends reactively compatibilized with organic peroxides
2018
Abstract The efficiency of two commercially available organic peroxides, dicumyl peroxide (DCP) and di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB), during reactive processing of poly(e-caprolactone)/poly(3-hydroxybutyrate) (PCL/PHB) blends was investigated. The changes in chemical structure of PCL/PHB blends, as a function of organic peroxide type (DCP/BIB) and content (in range: 0–1.0 parts by weight - pbw), were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis combined with infrared spectroscopy, and headspace analysis combined with gas chromatography with flame ionization detector. Performance properties of PCL/PHB blends were evaluated based on diffe…
Hierarchical structure and cytocompatibility of fish scales from Carassius auratus
2014
Abstract To study the structure and the cytocompatibility of fish scales from Carassius auratus , scanning electron microscopy (SEM) was used to observe the morphology of fish scales treated with different processing methods. Based on varying morphologies and components, the fish scales can be divided into three regions on the surface and three layers in vertical. The functions of these three individual layers were analyzed. SEM results show that the primary inorganic components are spherical or cubic hydroxyapatite (HA) nanoparticles. The fish scales have an ~ 60° overlapped plywood structure of lamellas in the fibrillary plate. The plywood structure consists of co-aligned type I collagen …
Gravimetric and FTIR study of the interaction of tetramethylethylene on a MFI zeolite
2005
The adsorption of tetramethylethylene on a high siliceous ZSM-5 zeolite was performed by thermogravimetry, in situ FTIR spectroscopy and molecular dynamics simulation. Sorption and spectroscopic data were analysed as a function of loading and compared with molecular dynamics simulated results to characterize the adsorption process. The isotherm at 298 K does not show any deviation from the type I behaviour. The presence of admolecules in micropores does not or weakly affect zeolite framework vibration bands but induces an additional band at around 1715 cm−1 mainly due to a contribution of the microporous surface of the adsorbent. A confinement effect of the adsorbate is characterized during…
Classification of Pecorino cheeses produced in Italy according to their ripening time and manufacturing technique using Fourier transform infrared sp…
2010
Fourier-transform infrared spectroscopy, followed by linear discriminant analysis of the spectral data, was used to classify Italian Pecorino cheeses according to their ripening time and manufacturing technique. The Fourier transform infrared spectra of the cheeses were divided into 18 regions and the normalized absorbance peak areas within these regions were used as predictors. Linear discriminant analysis models were constructed to classify Pecorino cheeses according to different ripening stages (hard and semi-hard) or according to their manufacturing technique (fossa and nonfossa cheeses). An excellent resolution was achieved according to both ripening time and manufacturing technique. A…
Comparison of transflection and transmission FTIR imaging measurements performed on differentially fixed tissue sections
2015
The widespread and cost-effective use of transflection substrates in Fourier transform infrared (FTIR) imaging of clinical samples is affected by the presence of artefacts including the electric field standing wave (EFSW) and contributions from light dispersion. For IR-based diagnostics, the manifestation of undesirable artifacts can distort the spectra and lead to erroneous diagnosis. Nevertheless, there is no clear consensus in the literature about the degree of influence of these effects. The aim of this work is to contribute to this discussion by comparing transflection and transmission images of the same tissue. For this purpose two adjacent sections of the same tissue (lymphoma sample…
Lipid phase transition in saccharide-coated cholate-containing liposomes: coupling to the surrounding matrix.
2005
We performed FTIR measurements on cholate-containing liposomes (CCL) embedded in saccharide (trehalose or sucrose) matrixes with different contents of residual water. We obtained information on the CCL phase transition following the thermal evolution (310-70 K) of the IR spectrum of the carbonyl moieties of phospholipids in the frequency range 4225-4550 cm(-1). Furthermore, we simultaneously followed the thermal evolution of the water association band, which gave information on the behavior of the surrounding water-saccharide matrix. The analysis revealed a small sub-band of the water association band present in CCL but not in cholate-free liposomes, the thermal evolution of which is tightl…
Near infrared spectroscopic study on the adsorption of methanol on silica gel
2013
Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.150 The silanol groups on Silica gel surface are sites for adsorption of polar molecules. Alcohols and other polar molecules are easily adsorbed by forming hydrogen bondings with OH groups on silica gel surface. A study on the adsorption of methanol on silica gel was carried out by using NIR spectroscopy in combination with ssecond derivative techniques. Four of the well characterised silica gel samples were used in this study. Each of the silica gel (0.25g) samples with different surface areas and silanol number was pressed i…
Density Functional Theory Calculated Raman Spectra of Ergocalciferol (Vitamin D2) and Cholecalciferol (D3)
2021
Density functional theory (DFT)-calculated Infrared and Raman spectra of Vitamin D2 and D3 are presented. The calculated results are compared with each other and with available experimental data. Applicability of Raman spectra for non-invasive optical Vitamin D sensors is discussed.
Isotopically (δ13C and δ18O) heavy volcanic plumes from Central Andean volcanoes: a field study
2017
International audience; Stable isotopes of carbon and oxygen in volcanic gases are key tracers of volatile transfer between Earth's interior and atmosphere. Although important, these data are available for few volcanoes because they have traditionally been difficult to obtain and are usually measured on gas samples collected from fumaroles. We present new field measurements of bulk plume composition and stable isotopes (δ13CCO2 and δ18OH2O+CO2) carried out at three northern Chilean volcanoes using MultiGAS and isotope ratio infrared spectroscopy. Carbon and oxygen in magmatic gas plumes of Lastarria and Isluga volcanoes have δ13C in CO2 of +0.76‰ to +0.77‰ (VPDB), similar to slab carbonate;…