Search results for "Icon"
showing 10 items of 3539 documents
MICROSCOPIC TECHNIQUES AND A MULTI-ANALYTICAL APPROACH TO CHARACTERIZE THE MATERIALS OF TWO RUSSIAN ICONS
2018
Two 19th century Russian icons, from the Museo Diocesano of Palermo, were analysed by UV photography, X-ray fluorescence, energy-dispersive X-ray fluorescence (ED-XRF), optical microscopy, micro-Raman spectroscopy and Scanning Electron Microscopy, combined with energy dispersive x-ray analysis, (SEM/EDS). The multi-analytical study of the icons “Protezione della Madre di Dio” (Pokrov’s Icon, Protection of Holy Mother of God) and ‘’Madre di Dio Gioia di Tutti gli Afflitti’’, (Holy Mother of God, Joy of all the afflicted), have been performed to reveal materials and technological features of the original painting of the 19th century as well as the materials used during past restoration works.…
Comparison between catalytic and photocatalytic activity in gas-solid regime of semiconductor oxides and carbon nanotubes supported Keggin heteropoly…
2015
Catalytic and photocatalytic 2-propanol dehydration was carried out by using a supported Keggin heteropolyacid H3PW12O40 (PW12). Binary materials were prepared by impregnation and/or solvothermal treatment by using commercial supports: SiO2 (Mallinckrodt), TiO2 (Evonik P25) and multiwall carbon nanotubes (Sunnano) or home solvothermically prepared SiO2 and TiO2. All the materials have been characterized by X-ray diffraction (XRD), scanning electron microscopy observations (SEM) coupled with EDX microanalysis, specific surface area measurements, diffuse reflectance spectroscopy (DRS), FTIR and Raman spectroscopy. (Photo)catalytic 2-propanol dehydration was studied in gas-solid regime by usin…
Vacuum-ultraviolet absorption of amorphous SiO2: intrinsic disorder and role of silanol groups
2008
We present a study on the vacuum-ultraviolet VUV absorption properties of amorphous SiO2 a-SiO2 with high concentrations of silanol groups Si-OH . We found that the absorption spectra are made up of a couple of exponential profiles. The first, in the range from 7.5 to 8.1 eV, was attributed to Si-OH group absorption, while the second, in the range from 8.1 to 8.25 eV, was ascribed to the intrinsic absorption. The VUV absorption cross section of Si-OH groups in a-SiO2 was determined as well. The intrinsic absorption was found to be affected by the Si-OH concentration: high silanol group contents allow lower values of the Urbach energy. This result is interpreted in terms of a reduction in th…
Sturctural disorder and silanol groups content in amorphous SiO2
2009
We present a study on the features of the Urbach edge in amorphous silicon dioxide a-SiO2 . The effects of temperature on the absorption edge in the range from 4 to 300 K were studied in both materials having negligible dry, 1017 cm−3 and significant wet, 1019 cm−3 silanol groups contents. Remarkable differences in the values and in the temperature dependence of the Urbach energy in the dry and wet samples were observed. These differences are interpreted as a consequence of a drastic reduction in the degree of disorder in wet materials, which turn out to be characterized by an electronic structure more similar to that of crystalline quartz. Furthermore, our results indicate that silanol gro…
The Large Area Detector onboard the eXTP mission
2022
The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a flagship mission of the Chinese Academy of Sciences and the China National Space Administration, with a large European participation coordinated by Italy and Spain. The eXTP mission is currently performing its phase B study, with a target launch at the end-2027. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. The LAD instrument is based on the design originally proposed for the LOFT mission. It envisages a deployed 3.2 m2 effective area in the 2-30 keV energy range, a…
Ottimizzazione delle prestazioni di una rete stradale tramite l’unificazione del sistema della segnaletica
2010
L’argomento principale di questa tesi si manifesta nella soddisfazione della necessità di armonizzare la segnaletica stradale verticale europea, definendo una strategia di minimizzazione dei costi di sostituzione complessivi della cartellonistica non uniforme, per contribuire a migliorare i livelli di sicurezza e di soddisfacimento dell’utenza dell’infrastruttura stradale. Una maggiore uniformità della segnaletica stradale permetterebbe ai conducenti impegnati nei traffici transfrontalieri su gomma di dover recepire un minor carico di informazioni visive, facendo riferimento ad un numero minore di segnali stradali, in quanto armonizzati con quelli dei loro paesi di provenienza. Altro scopo …
Sul PAESAGGIO - Milano, costruzione di nuove icone
2009
lezione/conferenza tenuta ad allievi e docenti presso la facoltà di Architettura POLIMI BOVISA in occasione del workshop finale, organizzato per i progetti redatti su commessa del Comune di Milano dalla facoltà di Architettura
The Urban Landscape in the Graphic Representation of the Cathedral of Palermo
2018
This study proposes some reflections on the relationship between the Cathedral of Palermo and the urban portion where it is placed, in relation to the indissoluble connection with the landscape that in the history offered a variety of perceptive suggestions marked by the passage and the coexistence of different cultural and social domination. To this end, the multiscale historical-urban planning analysis puts in place the role that territorial and urban morphology has had over time in relation to the Cathedral of Palermo. In this sense, the relationship between the architectural artefacts, such as the Royal Palace and the Town Hall, and the urban context is studied according to its access r…
La Piazza del Garraffello a Palermo tra iconografia storica e attualità
2018
The proposed contribution is focused on the graphic analysis of an eighteenth-century perspective view portraying one of the most ancient squares of the City of Palermo (piazza Garraffello). It is an engraving print made by F. Cichè in 1711 on commission of the Guild of Silversmiths: the square is completely described with the fountain (still existing) in the foreground, and with the corporate lodges of foreign nations in the background (these two buildings nowadays have disappeared). In the picture is also visible a temporary triumphal arch with canopy erected by the same guild who had commissioned the view: this is the object of main perspectival interest. The study of the perspective use…
ViC-CH: un modello di sintesi tra tecnologie digitali image-based ed educazione
2018
L'articolo raccoglie i risultati del lavoro condotto nell’ambito del workshop intensivo ViC-CH Visual Culture and Cultural Heritage svolto dalla Libera Università di Bolzano (Scienze della Formazione-Bressanone) e dall'Università di Trento (Ingegneria Edile Architettura). Il paragrafo dal titolo “Un percorso iconografico tra le rappresentazioni storiche del Seminario Maggiore di Bressanone” (S. Vattano) ha riguardato una fase di studio preliminare sull’evoluzione storico urbanistica di Bressanone attraverso il reperimento iconografico delle cartografie storiche della città. I dati raccolti hanno riguardato le vedute realizzate già a partire dalla seconda metà del XVI secolo attraverso le qu…