Ternary W-Si-N thin films have been reactively sputter-deposited from a W5Si3 target at different... more Ternary W-Si-N thin films have been reactively sputter-deposited from a W5Si3 target at different nitrogen partial pressures. The composition has been determined by 2.2 MeV 4 He + beam, the structure by x-ray diffraction and transmission electron microscope, the chemical bonds by Fourier transform - infrared spectroscopy and the surface morphology by scanning electron microscopy. Electrical resistivity was measured by four point probe technique on the as grown films. The film as-deposited is amorphous with the Si/W ratio increasing from about 0.1 up to 0.55 with the nitrogen content going from 0 to 60 at%. The heat treatments up to 980 °C induce a loss of nitrogen in the nitrogen rich samples. Segregation of metallic tungsten occurs in the sample with low nitrogen content (W 58 Si 21 N 21 ). Samples with high nitrogen content preserve the amorphous structure, despite of the precipitation of a more ordered phase inferred by FT-IR absorbance spectrum of the layer treated at highest te...
Silk fibroin is a well-known biopolymer used in several applications in which the interaction wit... more Silk fibroin is a well-known biopolymer used in several applications in which the interaction with biological tissue is required. In fact, fibroin is extremely versatile and can be shaped to form several constructs useful in tissue engineering applications. Confocal imaging is usually per-formed to test the cells behaviour on the construct and in this context the fibroin autofluorescence is regarded as a problem. In addition, the autofluorescence is not intense enough to provide useful morphological images. In fact, to control study the constructs morphology other techniques are used (i.e. SEM, Micro-CT). In this work we propose a method based on the fluorescence energy transfer (FRET) to suppress the fibroin autofluorescence moving it to higher wavelength accessible to the confocal microscopy for a direct imaging.
We report on a scintillator-based online detection system for the spectral characterization of po... more We report on a scintillator-based online detection system for the spectral characterization of polychromatic proton bunches. Using up to nine stacked layers of radiation hard polysiloxane scintillators, coupled to and readout edge-on by a large area pixelated CMOS detector, impinging polychromatic proton bunches were characterized. The energy spectra were reconstructed using calibration data and simulated using Monte-Carlo simulations. Despite the scintillator stack showed some problems like thickness inhomogeneities and unequal layer coupling, the prototype allows to obtain a first estimate of the energy spectrum of proton beams.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2017
In this work we present for the first time an application of PARAllel FACtor (PARAFAC) analysis t... more In this work we present for the first time an application of PARAllel FACtor (PARAFAC) analysis to the investigation of Ion Beam Induced Luminescence (IBIL) spectra of Ag+↔Na+ ion exchanged silicate glasses, in order to check the possibility to obtain additional information on the formation of silver aggregates under ion irradiation by a proper statistical rearrangement of experimental spectra. We decomposed the data by PARAFAC taking into account both IBIL emission features and their evolution as a function of the time. Shape and trend under irradiation of the extracted components were correlated to silver concentration and aggregates in the investigated systems. Strength and weakness of this statistical approach applied to IBIL spectra recorded as a function of time were evidenced and discussed.
The aim of this research is to establish reliable criteria to distinguish mobile sediments collec... more The aim of this research is to establish reliable criteria to distinguish mobile sediments collected from Veneto rivers that are expected to be of very similar composition since they share nearby hydrographic basins. In particular sediments from the riverbeds of Adige, Brenta, and Bacchiglione were collected and investigated by IBIL and DRIFT spectroscopy. Since it was recognized that likely sources for Roman building materials were rivers flowing close to the corresponding locations, results from the present study are expected to be useful in identifying the origin of sands obtained from mortars belonging to some I-century-AC Roman villas located in the X Regio [1]. In this work FT-IR and Ion Beam Induced Luminescence (IBIL) spectroscopies have been used for the first time for analyzing mobile sediments. In particular, the main spectral features, suitable for the identification of the provenance of the different samples, are examined.
Ternary W-Si-N thin films have been reactively sputter-deposited from a W5Si3 target at different... more Ternary W-Si-N thin films have been reactively sputter-deposited from a W5Si3 target at different nitrogen partial pressures. The composition has been determined by 2.2 MeV 4 He + beam, the structure by x-ray diffraction and transmission electron microscope, the chemical bonds by Fourier transform - infrared spectroscopy and the surface morphology by scanning electron microscopy. Electrical resistivity was measured by four point probe technique on the as grown films. The film as-deposited is amorphous with the Si/W ratio increasing from about 0.1 up to 0.55 with the nitrogen content going from 0 to 60 at%. The heat treatments up to 980 °C induce a loss of nitrogen in the nitrogen rich samples. Segregation of metallic tungsten occurs in the sample with low nitrogen content (W 58 Si 21 N 21 ). Samples with high nitrogen content preserve the amorphous structure, despite of the precipitation of a more ordered phase inferred by FT-IR absorbance spectrum of the layer treated at highest te...
Silk fibroin is a well-known biopolymer used in several applications in which the interaction wit... more Silk fibroin is a well-known biopolymer used in several applications in which the interaction with biological tissue is required. In fact, fibroin is extremely versatile and can be shaped to form several constructs useful in tissue engineering applications. Confocal imaging is usually per-formed to test the cells behaviour on the construct and in this context the fibroin autofluorescence is regarded as a problem. In addition, the autofluorescence is not intense enough to provide useful morphological images. In fact, to control study the constructs morphology other techniques are used (i.e. SEM, Micro-CT). In this work we propose a method based on the fluorescence energy transfer (FRET) to suppress the fibroin autofluorescence moving it to higher wavelength accessible to the confocal microscopy for a direct imaging.
We report on a scintillator-based online detection system for the spectral characterization of po... more We report on a scintillator-based online detection system for the spectral characterization of polychromatic proton bunches. Using up to nine stacked layers of radiation hard polysiloxane scintillators, coupled to and readout edge-on by a large area pixelated CMOS detector, impinging polychromatic proton bunches were characterized. The energy spectra were reconstructed using calibration data and simulated using Monte-Carlo simulations. Despite the scintillator stack showed some problems like thickness inhomogeneities and unequal layer coupling, the prototype allows to obtain a first estimate of the energy spectrum of proton beams.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2017
In this work we present for the first time an application of PARAllel FACtor (PARAFAC) analysis t... more In this work we present for the first time an application of PARAllel FACtor (PARAFAC) analysis to the investigation of Ion Beam Induced Luminescence (IBIL) spectra of Ag+↔Na+ ion exchanged silicate glasses, in order to check the possibility to obtain additional information on the formation of silver aggregates under ion irradiation by a proper statistical rearrangement of experimental spectra. We decomposed the data by PARAFAC taking into account both IBIL emission features and their evolution as a function of the time. Shape and trend under irradiation of the extracted components were correlated to silver concentration and aggregates in the investigated systems. Strength and weakness of this statistical approach applied to IBIL spectra recorded as a function of time were evidenced and discussed.
The aim of this research is to establish reliable criteria to distinguish mobile sediments collec... more The aim of this research is to establish reliable criteria to distinguish mobile sediments collected from Veneto rivers that are expected to be of very similar composition since they share nearby hydrographic basins. In particular sediments from the riverbeds of Adige, Brenta, and Bacchiglione were collected and investigated by IBIL and DRIFT spectroscopy. Since it was recognized that likely sources for Roman building materials were rivers flowing close to the corresponding locations, results from the present study are expected to be useful in identifying the origin of sands obtained from mortars belonging to some I-century-AC Roman villas located in the X Regio [1]. In this work FT-IR and Ion Beam Induced Luminescence (IBIL) spectroscopies have been used for the first time for analyzing mobile sediments. In particular, the main spectral features, suitable for the identification of the provenance of the different samples, are examined.
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