Search results for "MISURE"
showing 10 items of 496 documents
A Hybrid Frequency-Space Approach for Shape Measurement by Shadow Moirè Technique with Carrier Fringe Pattern
2006
In this paper, a novel methodology to process fringe pattern is presented. The core of the signal processing technique is the use of the direction information, a modulo 2π quantity that locally informs about the direction along which fringes grow with maximum rate. By using this information, it was possible to perform adaptive, direction - and orientation-based operations on fringe images in order to remove unwanted effects, to enhance the contrast and to extract the phase information encoded. The method has been applied on shadow moiré interferograms with carrier fringes in order to measure the surface of small objects. The developed algorithm allows to process fringes whose phase informat…
Rilevamento Sperimentale delle Storie di Temperatura in Processi di Friction Stir Welding di Lamiere di Titanio
2010
Thermoelastic signal processing using an FFT lock-in based algorithm on extended sampled data
2009
A fast infrared scanner is used to acquire the thermoelastic effect induced temperature changes along a line on the surface of cyclically loaded tensile samples. The raster scanning movement of the single detector allows the sampling of temperature versus time. This data are then post-processed by means of a lock-in algorithm coupled with 1D and 2D FFT analyses in order to filter out the thermoelastic signal from the noisy measured signal. A data extension algorithm is proposed which uses the information from different acquired frames to extend the data sampling window. The whole signal processing setup is evaluated on experimental data with successful results, proposing a potential tool fo…
The Zero Power Nuclear Reactor AGN-201 “Costanza” as a tool for Higher Education and Research in Nuclear Engineering
2009
The “Zero Power” Nuclear Reactor AGN-201 “Costanza” available at Nuclear Engineering Department of Palermo University is a valuable tool for educational purpose and advanced research. Besides being a useful tool for training of operators, without the time period limits on start-up and shut-down of the larger reactors, it allows the study of all phenomena regarding Nuclear Reactor Physics, Applied Neutronics, Neutron Dosimetry, Nuclear measurements as well as testing of nuclear instrumentation and methods. The experience of work and the obtained results highlight the simplicity of AGN-201 reactor control, its intrinsic safety and its overall versatility in various fields of Nuclear Engineeri…
Fission Product Activity Measurements in Air Particulate Filters Collected after Fukushima Accident at Palermo, Italy
2012
In the framework of routine operation of AGN-201 COSTANZA Nuclear research reactor, measurements of radionuclide air concentration are periodically performed by filtering an high volume of air through paper filters and by using HPGe gamma-ray spectrometry. After Fukushima accident, a series of samplings was carried out with a daily frequency so to detect the possible arrival of air radioactive contamination and to follow its evolution. Particulate collection was performed by suction of atmospheric air through 45cm × 45cm Sofiltra-Poelman HYN-75 (Bleu type) cellulose filter paper using a high-volume air sampler located on the roof of our department 20 m above ground-level. The sampling time …
Neutron and gamma-ray radiation fields characterisation in an 241Am-Be irradiator in view of its use as reserach tool
2019
Introduction A neutron irradiation facility based on four 241Am–Be sources, activity of 1.11·1011 Bq each (yield ~7.0 ·106 n s-1), consisting in four source-channels and an irradiation channel placed in a tank filled with light water both as moderator and biological shielding, was realized at DEIM Department. The aim of this work is to evaluate neutron and gamma fluxes in several points inside the irradiation channel, in view of its use as a testing tool in various research activities. For this goal, an experimental measurement campaign was started also to validate Monte Carlo (MCNP5 code) simulation results. Methods Experimental measurements of neutron radiation fields (fast and thermal) w…
Testing and linearity calibration of films of phenol compounds exposed to thermal neutron field for EPR dosimetry
2015
This paper reports the preliminary results obtained by Electron Paramagnetic Resonance (EPR) measurements on films of IRGANOX® 1076 phenols with and without low content (5% by weight) of gadolinium oxide (Gd2O3) exposed in the thermal column of the Triga Mark II reactor of LENA (Laboratorio Energia Nucleare Applicata) of Pavia (Italy). Thanks to their size, the phenolic films here presented are good devices for the dosimetry of beams with high dose gradient and which require accurate knowledge of the precise dose delivered. The dependence of EPR signal as function of neutron dose was investigated in the fluence range between 10(11) cm(-2) and 10(14) cm(-2). Linearity of EPR response was fou…
Valutazione della dose neutronica ambientale a livello del suolo
2018
Lo studio e la conoscenza della variabilità della fluenza neutronica di origine cosmica a livello del suolo risulta importante per valutare le misurazioni di dose neutronica ambientale, effettuate sia nell’ambito di molte applicazioni mediche, essenziamente in terapia, sia nelle applicazioni industriali, come nello studio degli effetti delle radiazioni neutroniche sul funzionamento dei più comuni sistemi elettronici. Infatti la sorgente primaria dei neutroni è individuabile nell’interazione tra i raggi cosmici di origine solare ed i vari strati dell’atmosfera e pertanto il campo neutronico non è costante ma dipende fortemente dai cicli di attività solare. In questo lavoro sono presentati i …
Procedura di calibrazione di un set di Dosimetri TLD secondo la ISO/ASTM51956:2005(E) e la ASTM standard E-668
2016
La misura della dose assorbita da dosimetri passivi, a seguito della loro esposizione a radiazioni ionizzanti, è una procedura fondamentale per valutare gli effetti indotti da tali radiazioni nell’ambito della dosimetria ambientale. Per effettuare delle corrette valutazioni, è stato selezionato un set di dosimetri a termoluminescenza (TLD) scelti, tra un’ampia gamma di tipologie di dosimetri a nostra disposizione, come i più idonei a fornire misure di dose attendibili (nelle prescritte condizioni di funzionamento). Tali dosimetri sono stati sottoposti ad una specifica procedura di irraggiamento e successiva lettura, allo scopo di realizzare un’opportuna calibrazione nel rispetto di quanto p…