Search results for " fisica"

ThT influences Abeta(1-40) aggregation process

2013

Tirocinio Formativo Attivo, I Ciclo. Classe A049, Matematica e Fisica: estratti delle relazioni finali

2013

Il volume contiene gli estratti delle relazioni finali di alcuni degli abilitati del Primo Ciclo del Tirocinio Formativo Attivo per la classe A049 - Matematica e Fisica, presso l'Università degli Studi di Palermo.

Effects of high pressure thermal treatments in oxygen and helium atmospheres on amorphous silicon dioxide and its radiation hardness

2009

The effects of thermal treatments at similar to 400 degrees C in oxygen or helium atmospheres at similar to 180 baron the radiation hardness of amorphous SiO(2) are studied. The generation efficiency of several point defects under gamma irradiation is compared to that of the untreated material. All the effects on point defects generation here observed can be explained in terms of changes in the precursor sites. In particular it has been observed that the thermal treatments can change the precursors sites of point defects both through temperature and pressure related processes, not depending on the atmosphere, and through oxygen related processes creating oxygen excess sites. The presence of…

OH-related Infrared Absorption Bands in Oxide Glasses

2005

We report the infrared activity, in the spectral region of the OH stretching modes, of different composite silicate glasses whose chemical composition is established by X-ray fluorescence measurements. The analysis of the absorption line profiles is made in terms of different spectral contributions, Gaussian in shape. The comparison with analogous spectra obtained in vitreous silica samples with impurity concentrations < 100 part per million moles is evidence of the effects of the different oxides on the vibrational properties of the OH groups. In particular, for oxide glasses a red shift of the composite band at about 3670 cm(-1), assigned to the OH stretching modes of free Si-OH groups an…

In-situ observation of beta-ray induced UV optical absorption in a-SiO2: radiation darkening and room temperature recovery

2006

International audience; We studied the optical absorption in the 3.0-6.2 eV range induced in bulk amorphous SiO2 by beta-ray irradiation up to similar to 1 MGy at room temperature. The induced absorption was measured in situ both during irradiation and in the post irradiation time. Our data evidence E', center as the main defect induced by irradiation and the partial decay of their absorption band at about 5.8 eV after irradiation. A quantitative analysis of the time evolution of the induced absorption shows that the transmission recovery observed after irradiation is compatible with the reaction of radiation-induced defects with H-related (H-2, H2O) species diffusing in the amorphous matrix

Evaluating the Effectiveness of Modelling-Oriented Workshops for Engineering Undergraduates in the Field of Thermally Activated Phenomena

2017

Two 20-h modelling-based workshops focused on the explanation of ther- mally activated phenomena were held at the University of Palermo, Italy, during the Academic Year 2014–2015. One of them was conducted by applying an inquiry-based approach, while the other, still based on laboratory and modelling activities, was not focused on inquiry. Seventy-two students belonging to the Undergraduate Program for Chemical Engineering attended the two workshops. The related content was focused on an à la Feynman unifying approach to thermally activated phenomena. Question- naires were administered to the students of both groups, before and post instruction. Responses were analysed using k-means cluster…

A comparison among different techniques for human ERG signals processing and classification

2014

A comparison among different techniques for human ERG signals processing and classification ( Articles not published yet, but available online Article in press About articles in press (opens in a new window) ) Barraco, R.a, Persano Adorno, D.a , Brai, M.a, Tranchina, L.b a Dipartimento di Fisica e Chimica, Università di Palermo and CNISM, Viale delle Scienze, Ed. 18, I-90128 Palermo, Italy b Laboratorio di Fisica e Tecnologie Relative - UniNetLab, Università di Palermo, Viale delle Scienze, Ed. 18, I-90128 Palermo, Italy Abstract Feature detection in biomedical signals is crucial for deepening our knowledge about the involved physiological processes. To achieve this aim, many analytic appro…

Acoustic characterization of the ancient theatre at Syracuse

2008

The ancient theatre at Syracuse, the largest open air theatre in Sicily, experienced many structural changes along its history. Today its very renowned drama festival attracts visitors from all the world that fill the entire cavea: customized seats accomodation and a prominent stage play an important role in the theatre acoustics. Because no data were available in literature on its acoustical perfomance a measurement session was carried out by our team in the framework of a wide research project on ancient theatres acoustics in the modern use. From data recorded "room criteria" parameters have been evaluated together with spectral analysis in order to gain a deeper information on the acoust…

Perfil de la educación física y sus profesores desde el punto de vista de los alumnos.

2007

El objetivo de este trabajo ha sido conocer el pensamiento de los alumnos sobre la Educación Física y sus profesores. Para ello, 788 estudiantes de Educación Secundaria Obligatoria (337 alumnos y 451 alumnas) han respondido a un cuestionario abierto en el que se les preguntaba qué es lo que más y lo que menos les gusta de EF, cómo se imaginan a su profesor/a ideal de EF, y las tres características más importantes que debería tener su profesor o profesora de EF. Tras un análisis de contenido de las respuestas de los alumnos se concluye que las cosas que más les gustan de EF son las prácticas de deportes de equipo y los juegos y actividades variadas; las cosas que menos les gustan son los eje…

Automatic Segmentation of HEp-2 Cells Based on Active Contours Model

2018

In the past years, a great deal of effort was put into research regarding Indirect Immunofluorescence techniques with the aim of development of CAD systems. In this work a method for segmenting HEp-2 cells in IIF images is presented. Such task is one of the most challenging of automated IIF analysis, because the segmentation algorithm has to cope with a large heterogeneity of shapes and textures. In order to address this problem, numerous techniques and their combinations were evaluated, in a process aimed at maximizing the figure of merit. The proposed method, for a greater definition of cellular contours, uses the active contours in the last phase of the process. The initial conditions, c…