1,721,117 research outputs found
Dispositivo di illuminazione a LED, particolarmente per illuminazione stradale e metodo per la progettazione dello stesso
No full textDispositivo di illuminazione a LED, particolarmente per illuminazione stradale e metodo per la progettazione dello stess
Fluorescence lifetime imaging and spectroscopy: a new analytical technique for non destructive analysis of art surfaces
No full textUna nuova tecnica di indagine per i beni culturali: la fluorescenza per immagini risolta in tempo
No full textTotal Synchronous Fluorescence Spectroscopy Combined with Multivariate Analysis: Method for the Classification of Selected Resins, Oils, and Protein-Based Media Used in Paintings
No full textRecent interest in the fluorescence of binding media and varnishes (proteins, oils, and resins) commonly used in paintings is based on the potential for discriminating these organic materials. A useful way of studying the presence of the broad-band fluorescence emissions found in these complex organic materials is fluorescence excitation emission spectroscopy. However, due to the presence of Raman and Rayleigh scattering which may necessitate correction or preprocessing for statistical analysis and visualization, an alternative approach has been adopted for the analysis of different samples of artist materials based on total synchronous fluorescence spectroscopy. Films of selected drying oils, glue, egg, and casein and the resins mastic, dammar, copal, and shellac were analyzed using total synchronous fluorescence spectroscopy, and an interpretation of the differences between spectra is given. A data reduction method based on the transformation of fluorescence contours extracted from total synchronous fluorescence from Cartesian to polar coordinates is presented and is followed by the comparison of data using multivariate analysis and hierarchical cluster analysis. Results suggest that the new method can be used to classify samples on the basis of their fluorescence spectra, clearly differentiating oils, resins, and protein-based media into groups
PL micro-imaging supported by FTIR mapping for the study of historical musical instruments
No full textCoatings in historical bowed string instruments made in Cremona (Italy) during 17th and 18th C. are often multi-layered systems, where organic binders are variously mixed with inorganic materials to enhance the sound and the aesthetic features of the objects. These materials were applied in superimposed coats in order to seal the wood porosity and prepare the surface to the application of the external varnish.
In this work, we propose to employ photoluminescence (PL) micro-imaging, with hyperspectral resolution, and FTIR mapping to fully characterize the different layers of the multi-layered system, with a specific focus on the interface between the ground coat and the wood
Fluorescence lifetime imaging and spectroscopy for the investigation of works of art
No full textcontribution n.5
Analisi di opera d’arte mediante l’utilizzo della spettroscopia di fluorescenza per immagini
No full textClinical system for skin tumour detection by fluorescence lifetime imaging
No full textA portable system based on Fluorescence Lifetime Imaging has been developed and tested for the detection of skin tumors in humans. The Heme precursor δ-aminolevulinic acid, which promotes the preferential accumulation of the endogenous Protoporphyrin IX in proliferative tissues, is used as an exogenous marker to target the tumor. Then, using a gated intensified camera, two or more images of the sample are acquired after different delays with respect to the excitation pulses. The images are processed in order to calculate the spatial map of the fluorescence decay time of the sample. The localization of the tumor is based on the longer decay time detected in neoplastic tissues with respect to healthy ones
Fluorescence Lifetime Imaging and Fourier Transform Infrared Spectroscopy of Michelangelo's David
No full textWe developed a combined procedure for the analysis of works of art based on a portable system for fluorescence imaging integrated with analytical measurements on microsamples. The method allows us to localize and identify organic and inorganic compounds present on the surface of artworks. The fluorescence apparatus measures the temporal and spectral features of the fluorescence emission, excited by ultraviolet (UV) laser pulses. The kinetic of the emission is studied through a fluorescence lifetime imaging system, while an optical multichannel analyzer measures the fluorescence spectra of selected points. The chemical characterization of the compounds present on the artistic surfaces is then performed by means of analytical measurements on microsamples collected with the assistance of the fluorescence maps. The previous concepts have been successfully applied to study the contaminants on the surface of Michelangelo's David. The fluorescence analysis combined with Fourier transform infrared (FT-IR) measurements revealed the presence of beeswax, which permeates most of the statue surface, and calcium oxalate deposits mainly arranged in vertical patterns and related to rain washing
Post-capture data analysis as an aid to the interpretation of ultraviolet-induced fluorescence images
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