Search results for " SCIENZA"
showing 10 items of 1301 documents
Effect of the Si doping on the properties of AZO/SiC/Si heterojunctions grown by low temperature pulsed laser deposition
2020
Abstract The structural and photoelectrical properties of Al-doped ZnO (AZO)/SiC/p-Si and AZO/SiC/n-Si heterojunctions, fabricated at low temperature by pulsed laser deposition, were investigated by means of a number of techniques. Raman analysis indicates that SiC layers have the cubic 3C-SiC phase, whilst X-ray diffraction measurements show that AZO films exhibit a hexagonal wurtzite structure, highly textured along the c-axis, with average crystallites size of 35.1 nm and lattice parameter c of 0.518 nm. The homogeneous and dense surface morphology observed by scanning electron microscopy was confirmed by atomic force microscopy images. Moreover, UV–Vis-NIR spectra indicated a high trans…
Influence of Calcium Carbonate Nanoparticles on the Soil Burial Degradation of Polybutyleneadipate-Co-Butylenetherephthalate Films.
2022
A polybutyleneadipate-co-butylenetherephthalate (PBAT) sample, commercially known as Ecoflex®, was processed via melt extrusion with CaCO3 nanoparticles coated with a hydrophobic coating. Blown films of PBAT and two composites with nanofiller (2% and 5%wt) were prepared and degradation tests in soil at 30 °C up to 180 days were carried out with weight loss measurements. Furthermore, biodegradation test according to ISO 14851 was carried out at 30 °C. The effect of CaCO3 on soil burial degradation was assessed by surface wettability and SEM. ATR-FTIR and XPS analyses highlighted chemical modifications induced by soil degradation. CaCO3 nanoparticles decreased surface wettability …
Specific Mechanical Properties of Glass/Carbon Epoxy Composites for Marine Applications
2009
Natural stabilization for bio-polymeric systems
2014
Italy in Uncertain Times: Europeanizing Foreign Policy in the Declining Proces of the American Hegemony
2019
Il libro analizza l'influenza dei cambiamenti nell'ordine internazionale egemonico a guida americana sulle variazioni nei pilastri tradizionali della politica estera italiana (USA, UE e multilateralismo) ed il ruolo che l'Italia gioca all'interno di quell'ordine. Per esplorare queste variazioni, il libro propone un'analisi del comportamento di voto e di sponsorizzazione dell'Italia alle Nazioni Unite nel periodo 2000-2017, guardando sia all'Assemblea Generale sia al Consiglio di Sicurezza, ed enfatizza l'importanza di quest'ultima sede per individuare i riflessi dei cambiamenti nel sistema internazionale sul comportamento italiano. Concentrandosi sul comportamento coalizionale, il libro esp…
A specific operative protocol set up during the restoration of San Michele Arcangelo’s marble statue
2009
Questo lavoro descrive le diverse fasi dell’intervento di conservazione di una statua di marmo del XVI secolo, raffigurante San Michele Arcangelo, custodita presso la Galleria Regionale di Palazzo Abatellis di Palermo. Inizialmente è stata effettuata un’indagine di archivio per inquadrare l’opera dal punto di vista storico artistico ed iconografico. Quindi sono stati effettuati: un rilievo grafico e digitale 3D, una mappatura di tutte le forme di degrado rilevate e dei segni di interventi precedenti, le analisi dei materiali costitutivi e dello stato di conservazione, mediante tecniche non distruttive o microdistruttive. Infine è stato progettato ed eseguito l’intervento di conservazione, a…
A specific operative protocol set up during the restoration of the Grammichele slate slab
2009
This work deals with the conservation of a slate slab, representing the map of Grammichele, a small town in the hinterland of South Eastern Sicily. The slab was engraved and painted in 1693, just after the tremendous earthquake that distroyed most of the towns in that area. The conservation process is illustrated through three steps: i) archive research; ii) physical chemical analysis of constitutive materials and degradation products; iii) planning and carrying out of the restoration and conservation operations.
Review of M. Beretta - F. Citti (ed.), 'Lucrezio, la natura e la scienza', Biblioteca di Nuncius / Istituto e Museo di storia della scienza, Firenze;…
2009
Si fornisce una recensione analitica dei diversi contributi che compongono il volume in oggetto, nonché della silloge nel suo insieme. Attraverso tale esame sono messi in luce e discussi alcuni nodi tematici essenziali della contemporanea critica lucreziana, con opportuni riferimenti al più vasto ambito di studi a cui il volume afferisce, ossia le indagini relative alla storia della scienza antica.
On the structural optimization in presence of base isolating devices
2012
The minimum volume design of plane frames constituted by elastic perfectly plastic material and subjected to appropriate combinations of fixed, cyclic and dynamic loads is studied. The influence on the design, in terms of cost (volume) and behavioural features, of seismic protecting devices is particularly focused. The considered protecting device is a lead rubber bearing base isolation system. Two optimal design problem formulations are proposed for the structure with or without the protecting device, both based on the so-called statical approach. The minimum volume frame is reached accounting for three different resistance limits: the purely elastic limit, the (elastic) shakedown limit an…
Il degrado degli stucchi serpottiano a Palermo in relazione alle condizioni ambientali di conservazione
2009
This work is part of a demanding project, called “Progetto Serpotta”, performed since 2000 in cooperation with Soprintendenza Beni Culturali of Palermo. Aim of the project is the restoration of the unique stucco's artworks moulded by Giacomo Serpotta and his co-workers end of 17th -beginning of 18th century. This paper is focused on the problem of salt efflorescences, that are widely present in all of the churches and oratories restored in the framework of “Progetto Serpotta”. Particular attention is given to the relationship between the constitutive matter of the stuccoes, as analysed by means of both X ray diffractometry and optical microscopy, and the salts composition, as analysed by me…