Search results for "MISURE"
showing 10 items of 496 documents
ESR response of watch glasses to neutron irradiation
2012
Abstract In this paper we report the results of the electron spin resonance (ESR) study of the radiation-induced signal of watch glasses exposed to neutrons. This work extends the series of analyses of the response of watch glasses to various radiation beams which our research group is carrying out for possible applications in retrospective dosimetry. We have considered fluences up to about 3 × 1011 cm−2. We evaluated the signal fading and we found that in the first hours after exposure the signal rapidly decreases. After about 1000 h, it decreases much more slowly. The signal was reduced by about 25% in about 5 months. The radiation induced signal is found to be linearly dependent on neutr…
Correlation between ferrous ammonium sulfate concentration, sensitivity and stability of Fricke gel dosimeters exposed to clinical X-ray beams
2014
Abstract This work describes the characterization of various Fricke-Agarose-Xylenol gels (FXG) dosimeters using NMR relaxometry and MRI analysis. Using X-rays from a clinical linear accelerator (LINAC), the gels were irradiated in the dose range from 0 Gy to 20 Gy. The photon sensitivity of the FXGs was measured in terms of NMR relaxation rates; its dependence on radiation dose was determined as a function of ferrous ammonium sulfate contents (from 0.5 mM to 5 mM). Furthermore, the stability of the NMR signal was monitored over several days after irradiation. These measurements were aided by Magnetic Resonance Imaging (MRI) scans which allowed three-dimensional (3D) dose mapping. In order t…
Fuzzy modelling of HEART methodology: application in safety analyses of accidental exposure in irradiation plants
2009
The present paper refers to the obtained results by using Fuzzy Fault Tree analyses of accidental scenarios which entail the potential exposure of operators working in irradiation industrial plants. For these analyses the HEART methodology, a first generation of the Human Reliability Analysis method, has been employed to evaluate the probability of human erroneous actions. This technique has been modified by us on the basis of fuzzy set concept to more directly take into account the uncertainties of the so called error-promoting factors, on which the method is grounded. The results allow also to provide some recommendations on procedures and safety equipments to reduce the radiological expo…
Analysis of spatial diffusion of ferric ions in PVA-GTA gel dosimeters through magnetic resonance imaging
2017
Abstract This work focused on the analysis of the temporal diffusion of ferric ions through PVA-GTA gel dosimeters. PVA-GTA gel samples, partly exposed with 6 MV X-rays in order to create an initial steep gradient, were mapped using magnetic resonance imaging on a 7T MRI scanner for small animals. Multiple images of the gels were acquired over several hours after irradiation and were analyzed to quantitatively extract the signal profile. The spatial resolution achieved is 200 μm and this makes this technique particularly suitable for the analysis of steep gradients of ferric ion concentration. The results obtained with PVA-GTA gels were compared with those achieved with agarose gels, which …
Analysis of the response of PVA-GTA Fricke-gel dosimeters with clinical magnetic resonance imaging
2018
Abstract Fricke gel dosimeters produced with a matrix of Poly-vinyl alcohol (PVA) cross-linked with glutaraldehyde (GTA) were analyzed with magnetic resonance imaging (MRI). Previous studies based on spectrophotometry showed valuable dosimetric features of these gels in terms of X-ray sensitivity and diffusion of the ferric ions produced after irradiation. In this study, MRI was performed on the gels at 1.5 T with a clinical scanner in order to optimize the acquisition parameters and obtain high contrast between irradiated and non-irradiated samples. The PVA gels were found to offer good linearity in the range of 0–10 Gy and a stable signal for several hours after irradiation. The sensitivi…
Coincidence-summing correction equations in gamma-ray spectrometry with p-type HPGe detectors
2011
Abstract Equations to compute γ−γ and γ−X K coincidence-summing corrections in gamma-ray spectrometry with p-type HPGe detectors are reported. For point sources only full-energy-peak and total efficiencies are needed.
Characterization of multifunction meters based on integrated devices in the presence of harmonic distortion
2008
This paper is focused on the problem of the metrological characterization of multifunction static meters based on integrated devices, in both reference and actual operating conditions. The influence of the measurement transducers on the performance of such meters is also discussed. The analysis is supported by some experimental tests, which were carried out on a meter based on a commercial integrated device, both in the absence and in the presence of the measurement transducers.
A Monitoring and Management System for Energy Storage Integration in Smart Grids
2019
The integration of distributed storage systems (DSSs) at users and prosumers level can significantly contribute to energy efficiency and increase profits from renewable energy exploitation, thanks to suitable scheduling of charging and discharging periods. On the other hand, to preserve network stability and secure operation, Distribution Systems Operators (DSOs) are interested in DSSs control and cooperation with the grid. In this framework this work proposes a simple monitoring and management system for DSSs scheduling and its integration in a distributed measurement and control system architecture for smart grids. In the paper the proposed algorithm is tested on a simple case study at ho…
Radiation protection evaluations about a radiopharmaceutical production center based on a cyclotron
2012
Positron Emission Tomography (PET) has became a worldwide used functional and molecular imaging technique. Most of PET (or PET/CT- Computed Tomography) diagnostic facilities are installed within large population cities as well as dimensions of modern medical cyclotrons allow to install them inside hospitals or other health centers. Therefore, special radiation protection evaluations to assure safety operational conditions to operators and population are required. This work is focused on training activities oriented to evaluate PET/Cyclotron radiation protection procedures or to study special safety systems. The students are particularly oriented to determine shielding thickness according to…
Uncertainty management in the measurements for the electric power quality analysis
2014
The paper deals with the uncertainty estimation in the measurements performed to assess the electric power quality. In a first steps, all the error sources, which give a significant contribution to the combined uncertainty associated to the measurement results, are identified. Successively, in order to analyze how the errors combine and propagate through the measurement chain, four approaches are proposed and validated. These approaches entail a greater and greater uncertainty overestimation, but, at the same time, require less and less time and resources. Therefore, the four methodologies are perfectly adequate for the implementation of the PUMA (Procedure for Uncertainty Management) metho…