Search results for "Beni culturali"
showing 10 items of 1017 documents
Cryogenic 35GHz pulse ENDOR probehead accommodating large sample sizes: Performance and applications.
2009
The construction and performance of a cryogenic 35GHz pulse electron nuclear double resonance (ENDOR) probehead for large samples is presented. The resonator is based on a rectangular TE(102) cavity in which the radio frequency (rf) B(2)-field is generated by a two turn saddle ENDOR coil crossing the resonator along the sample axis with minimal distance to the sample tube. An rf power efficiency factor is used to define the B(2)-field strength per square-root of the transmitted rf power over the frequency range 2-180MHz. The distributions of the microwave B(1)- and E(1)-field, and the rf B(2)-field are investigated by electromagnetic field calculations. All dielectrics, the sample tube, and…
Application of Electron Spin Resonance technique in neutron dosimetry
2012
Along with the Neutron Capture Therapy (NCT) development and with the use of thermal neutrons for radiotherapeutic purposes, many efforts have been devoted to the beam characterization in order to optimize the therapy procedures. Reliable dosimetric measurements should be able to determine the various components (neutronic and photonic) of the mixed beam usually employed for therapy [1]. We have studied the effect of the additive such as gadolinium and 10B-boric acid on the neutron sensitivity of alanine ESR dosimeters exposed to a gamma and mixed (n, gamma) field mainly composed by thermal neutrons. We have chosen both this additive nuclei because of their very high capture cross section t…
Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy
2011
Abstract The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.
Inquiry-Based Approach and Numerical Simulations: A Powerful Integration in Condensed Matter Physics Education
2020
In this chapter, we present and discuss two inquiry-based learning paths on condensed matter physics topics in which numerical simulations play a relevant role. The first one addresses the study of the electron transport dynamics via simulative explorations in 3D semiconductors. His emphasis is not on student modelling skills, but rather on a chain of reasoned investigations performed within a learning environment aimed at supporting a valuable understanding of the physics concepts underlying the complex world of semiconductor electronics. The second learning path is a 5E-cycle-based workshop of advanced physics targeted to strengthen student’s understanding of the various aspects of the Ha…
An approach based on wavelet analysis for feature extraction in the electroretinogram
2011
Most biomedical signals are non-stationary. The knowledge of their frequency content and temporal distribution is then useful in a clinical context. The wavelet analysis is appropriate to achieve this task. The present paper uses this method to reveal hidden characteristics and anomalies of the human a-wave, an important component of the electroretinogram since it is a measure of the functional integrity of the photoreceptors. We here analyse the time–frequency features of the a-wave both in normal subjects and in patients affected by Achromatopsia, a pathology disturbing the functionality of the cones. The results indicate the presence of two or three stable frequencies that, in the pathol…
Empirical mode decomposition and neural network for the classification of electroretinographic data
2013
The processing of biosignals is increasingly being utilized in ambulatory situations in order to extract significant signals' features that can help in clinical diagnosis. However, this task is hampered by the fact that biomedical signals exhibit a complex behaviour characterized by strong non-linear and non-stationary properties that cannot always be perceived by simple visual examination. New processing methods need be considered. In this context, we propose to apply a signal processing method, based on empirical mode decomposition and artificial neural networks, to analyse electroretinograms, i.e. the retinal response to a light flash, with the aim to detect and classify retinal diseases…
Modular, customisable, accomodation-friendly antenna system for satellite avionics: Development, prototyping and validation
2014
In the frame of ESA program AO/1- 6737/11/NL/MH, an innovative X-band antenna system for satellite avionics has been studied, demonstrated and validated at Proof of Concept Model level. The innovative contribution of such an antenna system relies on modularity, customizability and accommodation friendliness. The antenna concept is based on a Plug and Play architecture, where the basic module is a 2.7 cm-cube with a mass of 53 gr, which can be clustered in array configuration. A catalogue of predefined and ready-to-use clusters could be developed with the possibility of adapting the antenna systems to various platform types by tuning just a few control parameters. Different levels of customi…
Applying complexity science to air traffic management
2015
Versión aceptada obtenida del archivo digital en línea WestminsterResearch de la Universidad de Westminster. Complexity science is the multidisciplinary study of complex systems. Its marked network orientation lends itself well to transport contexts. Key features of complexity science are introduced and defined, with a specific focus on the application to air traffic management. An overview of complex network theory is presented, with examples of its corresponding metrics and multiple scales. Complexity science is starting to make important contributions to performance assessment and system design: selected, applied air traffic management case studies are explored. The important contexts of…
The "Livio Scarsi" X-Ray Facility at University of Palermo for Device Testing
2015
In this work, we report on the characteristics of the Livio Scarsi X-ray facility at University of Palermo. The facility is able to produce low energy X rays, within the energy range of 0.1-60 keV, with fluence rates ranging from 105-108 photons/mm2 s. The laboratory is equipped with an innovative digital detection system, based on semiconductor detectors (Si and CdTe detectors), able to provide accurate and precise estimation of the fluence rate, the energy and the exposure of X rays, even at high counting rate conditions. Instrumentation for electrical characterization (DC-AC) of semiconductor devices, for both off-line and on-line (i.e. during the irradiation) measurements, is also avail…
Digital techniques for high-rate high-resolution radiation measurements
2014
Digital pulse processing (DPP) techniques are increasingly used in the development of modern spectroscopic systems. DPP systems, based on direct digitizing and processing of detector signals (preamplifier output signals), ensure higher flexibility, stability, lower dead time, higher throughput and better energy resolution than traditional pulse processing systems. In this work, we present our progress in the development of DPP systems for high-rate high-resolution radiation measurements. An innovative digital system, able to perform multi-parameter analysis (input counting rate, pulse height, pulse shape, event arrival time, etc.) even at high photon counting rates is presented. Experimenta…