Search results for " Infrared"
showing 10 items of 945 documents
Design of a Multichannel Continuous Wave fNIRS System implemented with SiPM
2013
Development of a CW-fNIRS System for brain monitoring
2014
Progettazione e realizzazione di un sistema Continuous Wave fNIRS basato su tecnologia SiPM
2014
Progettazione e realizzazione di un sistema Continuous Wave fNIRS basato su tecnologia SiPM
Optical techniques represent a suitable tool for in vivo and non-invasive diagnosis of human brain and tissues. Functional Near InfraRed Spectroscopy (fNIRS) is revealing as an emerging neuroimaging technology, since it is safe, relatively inexpensive and little cumbersome. fNIRS relies on the measurement of the oxygen concentration in the blood by means of light beams impinging on the tissues under test. Haemoglobin concentration variations (oxygenated/deoxygenated) can provide very important information on brain activity and allow to discriminate the main brain area involved during tests. Herein, we present the design and development of an innovative solution for a portable continuous wav…
Localization and interactions of melatonin in dry cholesterol/lecithin mixed reversed micelles used as cell membrane models
2005
The state of melatonin confined in dry cholesterol/lecithin mixed reversed micelles dispersed in CCl4 was investigated using 1H-NMR and FT-IR spectroscopies as a function of the melatonin to lecithin molar ratio (R(MLT)) and of the cholesterol to lecithin molar ratio (R(CHL)). An analysis of experimental results leads to the hypothesis that, independent of R(MLT) and as a consequence of anisotropic melatonin/lecithin, melatonin/cholesterol and cholesterol/lecithin interactions, melatonin is totally solubilized in reversed micelles. Melatonin is mainly located in and oriented in the nanodomain constituted by the hydrophilic groups of cholesterol and lecithin. A competition of melatonin and c…
Effect of lithium ions on the catalytic efficiency of calcium oxide as a nanocatalyst for the transesterification of lard oil
2019
The present work encompasses the effect of Li+ ions on CaO nanoparticles for the transesterification of lard oil. The modification of CaO nanoparticles was achieved by the impregnation of different molar ratios of lithium hydroxide. Later, each catalyst was screened for the catalytic conversion of lard oil to a fatty acid methyl ester (FAME). The nanocatalyst CaO–0.5LiOH (1 : 0.5 molar ratio) showed the best conversion rate for FAME. The synthesized nanocatalyst was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, and Hammett indicato…
Brain Monitoring Via an Innovative CW-FNIRS System
2015
Functional Near InfraRed Spectroscopy (fNIRS) is an imaging technique mainly devoted to human brain monitoring. It is used as a non-invasive technique, in medical field, in order to measure the oxygen concentration of blood. This because the relatively good transparency of biological materials in the near infrared allows sufficient photon transmission through tissues. Within the so-called fNIRS range (650-900 nm), the main absorbers are blood chromophores, in particular the oxygenated and deoxygenated haemoglobin (HbO2 and Hb, respectively). When two or more wavelengths are used, changes of such chromophores can be computed by employing the modified Beer-Lambert law, thus providing importan…
Design and realization of a portable continuous wave fNIRS
2015
A design and implementation of a portable functional Near InfraRed Spectroscopy embedded system prototype is described. In this theoretical and experimental work, we present an embedded system hosting 64 LED sources and 128 Silicon PhotoMultiplier detectors (SiPM). The elementary part of the structure is a flexible probe “leaf” consisting of 16 SiPMs, 4 couples of LEDs, each operating at two wavelengths, and a temperature sensor. The hardware system is based on an ARM main microcontroller that allows to perform both the switching time of LEDs and the acquisition of the SiPM outputs. The performed preliminary experimental tests achieved very promising results, thus demonstrating the effectiv…
Continuous Wave fNIRS with Silicon Photomultiplier
2015
This work is focused on the development of a Continuous Wave (CW) NIRS integrated system with multi-wavelength LED sources between 700 and 950 nm and a Silicon Photomultiplier detector (SiPM) developed by STMicroelectronics. The Signal Noise Rate (SNR), measured placing the LEDs and an SiPM in a direct contact with the surface of a plastic phantom mimicking a real human head, results higher than the calculated minimum, required to detect small variation in the HbO2 and HHb concentration, till a source detector separation (SDS) of 6 cm.
Authentication of extra virgin olive oils by Fourier-transform infrared spectroscopy
2010
Fourier-transform infrared spectroscopy (FTIR), followed by multivariate treatment of the spectral data, was used to classify vegetable oils according to their botanical origin, and also to establish the composition of binary mixtures of extra virgin olive oil (EVOO) with other low cost edible oils. Oil samples corresponding to five different botanical origins (EVOO, sunflower, corn, soybean and hazelnut) were used. The wavelength scale of the FTIR spectra of the oils was divided in 26 regions. The normalized absorbance peak areas within these regions were used as predictors. Classification of the oil samples according to their botanical origin was achieved by linear discriminant analysis (…