Search results for " costruzione."
showing 10 items of 477 documents
Modello numerico per la caratterizzazione elettromeccanica dei nanotubi di carbonio
2016
Nell’ultimo decennio i nanotubi di carbonio (Carbon nanotubes, CNTs) hanno suscitato un considerevole interesse nella comunità scientifica internazionale a causa delle loro proprietà meccaniche, bassa densità ed elevata conducibilità termica. I CNT possiedono inoltre peculiari proprietà elettroniche dipendenti da elicoicità e stato di deformazione, rendendoli potenziali elementi costruttivi di una nuova tecnologia nano-elettronica. Numerosissimi dispositivi elettronici basati sui CNTs (transistors, nano-switches, attuatori, ecc.) sono già stati realizzati. Un nuovo approccio è stato sviluppato per investigare la deformazione dei CNTs e si basa su modelli agli elementi finiti accuratamente s…
Çështja e gjuhës greke gjatë gjysmës së dytë të shekullit XVIII dhe kontributi i Tommaso Stanislao Velastit për lëvizjen e filohelenizmit napolitan
2022
Il saggio ricostruisce l'attività intellettuale di T. S. Velasti e illumina il suo contributo alla definizione della questione della lingua greca alla luce della documentazione inedita conservata presso l'Archivio del Seminario Greco Albanese di Palermo, dove trovò riparo dopo la soppressione della Compagnia di Gesù in Sicilia nel 1767. The essay reconstructs the intellectual activity of T. S. Velasti and illuminates his contribution to the definition of the question of the Greek language in the light of the unpublished documentation preserved in the Archives of the Greek Albanian Seminary in Palermo, where he found shelter after the suppression of the Society of Jesus in Sicily in 1767.
Indentation of rigidly supported sandwich beams with foam cores exhibiting non-linear compressive behaviour.
2011
A generalized analytical approach to investigate the indentation of sandwich beams under concentrated loads is presented, based on the Winkler foundation theory. A segment-wise model is implemented to the case of fully backed sandwich beams with polymeric foam cores exhibiting generic non-linear compressive behaviours. Closed-form analytical solutions of the indentation curve are obtained for simplified foam compression behaviours: elastic-perfectly-plastic, bilinear and bilinear-perfectly-plastic. Analytical predictions are compared with experimental data from sandwiches employing foam cores with peculiar non-linear behaviours. The proposed models are found to give a better match of the e…
Unconventional application of Image Correlation techniques on Biomaterials and cardiovascular applications
2022
Image Correlation techniques are increasing in popularity and are now suitable to investigate complex structural and fluid-dynamics of cardiovascular systems. These approaches operate through a digital correlation of a pair of images to determine physical quantities of complex systems. In this thesis, their application to the mechanical characterisation of complex biomaterials (Nitinol and soft materials), and the characterisation of complex biofluid-dynamics was investigated, with the aim to analyse their reliability and enhance their accuracy and field of application. Digital Image Correlation, supported by Infrared Thermography, was used to achieve a more in depth understanding of the me…
Thermomechanical Characterization of Polylactic Acid and Composites
2018
This paper presents the experimental tests for the thermomechanical characterization of biopolymer polylactic acid, and its composites with beech flour or with nanoreiforcement of modified montmorillonite, in order to evaluate any applicability in the automotive sector. Tests of torque and traction are executed for the mechanical characterization and the results comparison; dynamical tests are executed for the thermomechanical characterization, determining the elastic modulus and loss factor versus the actual temperature.
Caratterizzazione termomeccanica dell’acido polilattico e due suoi compositi
2018
Questa memoria presenta i test sperimentali per la caratterizzazione termomeccanica del biopolimero acido polilattico e dei suoi compositi con farina di faggio o con nanorinforzo di montmorillonite modifcata, per uno studio di applicabilità nel settore automobilistico. Per la caratterizzazione meccanica e il confronto dei risultati vengono eseguiti prove di coppia e di trazione; i test dinamici vengono eseguiti per la caratterizzazione termomeccanica, determinando il modulo elastico e il fattore di perdita rispetto alla temperatura effettiva. This paper presents the experimental tests for the thermomechanical characterization of biopolymer polylactic acid, and its composites with beech flour…
La fabbrica del cielo. Il soffitto della Cappella Palatina e il tetto della Cattedrale tra tecnica e arte
2020
Prodotto di successive demolizioni e ricostruzioni, la Cattedrale di Palermo, giunta a noi nell’attuale configurazione, ha subito numerose modificazioni la cui più nota è quella tardo settecentesca. Il Tempio primigenio risale al periodo successivo l'Editto di Costantino. Ricostruito al tempo di Gregorio Magno e convertito al culto islamico dopo la conquista araba sarà restaurato al culto cristiano sotto il regno normanno degli Altavilla e successivamente riedificato. La cattedrale normanna era coperta da un tetto ligneo composto da 19 incavallature riccamente decorate poggiate su mensole ed attraversato da una passerella centrale. Dalla configurazione normanna ad oggi la Cattedrale ha subi…
Measurement of edge residual stresses in glass by the phase-shifting method
2011
Abstract Control and measurement of residual stress in glass is of great importance in the industrial field. Since glass is a birefringent material, the residual stress analysis is based mainly on the photoelastic method. This paper considers two methods of automated analysis of membrane residual stress in glass sheets, based on the phase-shifting concept in monochromatic light. In particular these methods are the automated versions of goniometric compensation methods of Tardy and Senarmont. The proposed methods can effectively replace manual methods of compensation (goniometric compensation of Tardy and Senarmont, Babinet and Babinet–Soleil compensators) provided by current standards on th…
Review of RGB photoelasticity
2015
Abstract Automatic methods of photoelasticity have had a significant progress with the development of automatic acquisition and image processing methods. This article concerns RGB photoelasticity, which allows the determination of the photoelastic retardation using, usually, a single acquisition of the isochromatic fringes in white light by a colour camera. In particular, the article presents an overview of the main characteristics of RGB photoelasticity that is influence of the quarter-wave plate error, number of acquisitions, type of light source, determination of low and high fringe orders, methods for searching the retardation, scanning procedures, calibration on a material different fr…
Photoelastic Analysis of Edge Residual Stresses in Glass by Automated “Test Fringes” Methods
2011
Since the glass is a birefringent material, the analysis of residual stress in glass is usually carried out by means of photoelastic methods. This paper considers the automation of the “test fringes” method which is based on the use of a Babinet compensator or of a beam subjected to bending. In particular, two automated methods are proposed: the first one is based on the use of the centre fringe method in monochromatic light and the second one is based on the use of RGB photoelasticity in white light. The proposed methods have been applied to the analysis of membranal residual stresses in some tempered glasses, showing that they can effectively replace manual methods of photoelastic analysi…