VIRTUAL REALITY FOR HISTORICAL ARCHITECTURE

Abstract. This article shows a first step in the development of an immersive virtual tour of the Cathedral of Palermo, entering the fields of Digital Cultural Heritage and Edutainment. Its purpose is to help people to gain knowledge about the site, highlighting the complex stratifications that have characterized its history.The development of the project has been possible thanks to different phases of work: surveys were initially carried out by laser scanning, then assembled and processed to obtain the 3D model of the current state; at the same time, the model of reconstruction was processed in several phases, based on historical, archival and iconographic sources; both models were, later, subject to post-processing, preparatory to the development of virtual navigation. The tour scenario includes options in order to make it attractive for the player, such as interactive elements, interfaces and animations.</p

Le geometrie del progetto: il disegno di Giovanni D'Avanzato e il rilievo della facciata di Santa Oliva

The text is focused on the surveying and geometric analysis of the north-eastern facade of the monument named "Quattro Canti" in Palerm

Optical properties of Ge-oxygen defect center embedded in silica films

The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation in the 10-300 K temperature range. This center exhibits two luminescence bands centered at 4.3eV and 3.2eV associated with its de-excitation from singlet (S1) and triplet (T1) states, respectively, that are linked by an intersystem crossing process. The comparison with results obtained from a bulk Ge-doped silica sample evidences that the efficiency of the intersystem crossing rate depends on the properties of the matrix embedding the Ge-oxygen defect centers, being more effective in the film than in the bulk counterpart.Comment: 10 pages, 3 figures, in press on J. Non cryst. solids (2007

La ricostruzione della citt\ue0 perduta: l'Esposizione Nazionale di palermo (1891-1892)

L'analisi e il ridisegno delle planimetrie di progetto e la restituzione prospettica di foto dell'epoca hanno condotto alla ricostruzione virtuale della volumetria e dei fronti esterni del Complesso dell'Esposizione Nazionale di Palermo del 1891. La ricostruzione \ue8 stata estesa al Padiglione delle Belle Arti, con l'inserimento di alcuni degli elementi esposti, rilevati con metodi laser scanning

The A(Kstop−,π±Σ∓)A′A(K^-_{stop},\pi^\pm\Sigma^\mp)A' reaction on p-shell nuclei

This letter is concerned with the study of the $K^-_{stop}A\rightarrow \pi^\pm\Sigma^\mp A'$ reaction in p-shell nuclei, i.e., $^{6,7}Li$, $^9Be$, $^{13}C$ and $^{16}O$. The $\pi^\pm\Sigma^\mp / K^-_{stop}$ emission rates are reported as a function of $A$. These rates are discussed in comparison with previous findings. The ratio $\pi^-\Sigma^+/\pi^+\Sigma^-$ in p-shell nuclei is found to depart largely from that on hydrogen, which provides support for large in-medium effects possibly generated by the sub-threshold $\Lambda(1405)$. The continuum momentum spectra of prompt pions and free sigmas are also discussed as well as the $\pi^\pm\Sigma^\mp$ missing mass behavior and the link with the reaction mechanism. The apparatus used for the investigation is the FINUDA spectrometer operating at the DA$\Phi$NE $\phi$-factory (LNF-INFN, Italy).Comment: 14 pages, 5 figures, accepted for publication in Phys. Lett.

29Si Hyperfine Structure of the E'_\alpha Center in Amorphous Silicon Dioxide

We report a study by electron paramagnetic resonance (EPR) on the E'_\alpha point defect in amorphous silicon dioxide (a-SiO2). Our experiments were performed on gamma-ray irradiated oxygen-deficient materials and pointed out that the 29Si hyperfine structure of the E'_alpha consists in a pair of lines split by 49 mT. On the basis of the experimental results a microscopic model is proposed for the E'_alpha center, consisting in a hole trapped in an oxygen vacancy with the unpaired electron sp3 orbital pointing away from the vacancy in a back-projected configuration and interacting with an extra oxygen atom of the a-SiO2 matrix.Comment: 4 page

H(II) centers in natural silica under repeated UV laser irradiations

We investigated the kinetics of H(II) centers (=Ge'-H) in natural silica under repeated 266nm UV irradiations performed by a Nd:YAG pulsed laser. UV photons temporarily destroy these paramagnetic defects, their reduction being complete within 250 pulses. After re-irradiation, H(II) centers grow again, and the observed recovery kinetics depends on the irradiation dose; multiple 2000 pulses re-irradiations induce the same post-irradiation kinetics of H(II) centers after each exposure cycle. The analysis of these effects allows us to achieve a deeper understanding of the dynamics of the centers during and after laser irradiation.Comment: Submitted to Journal of Non Crystalline Solid

Levantamiento del templo G. parque arqueologico de Selinunte, Trapani. Sicilia. Informe general

El trabajo de campo al que se refiere la presente comunicaci\uf3n, se puede considerar como la fase inicial del proyecto de levantamiento del templo G de Selinunte, ya que si bien se han podido tomar muchos datos del mismo durante la campa\uf1a de verano del 2005, quedan algunas zonas donde no ha sido posible acceder, por lo que ser\ue1 preciso completar la informaci\uf3n conforme se vaya avanzando en el modelo. La dificultad mayor vendr\ue1 con la definici\uf3n del propio modelo 3D, labor de investigaci\uf3n avanzada ya que actualmente no existen t\ue9cnicas ni metodolog\uedas de referencia a nivel mundial en el uso de escaners l\ue1ser 3d aplicados al campo de la arquitectura. Esta segunda tarea la estamos llevando a cabo, los equipos de las dos universidades, a lo largo de este a\uf1o 2006 poniendo a punto estrategias y centr\ue1ndonos en aquellos elementos singulares del conjunto arquitect\uf3nico que, a juicio de los arque\uf3logos, merezca la pena documentar con mucha precisi\uf3n. Del resto se obtendr\ue1 un modelo m\ue1s simple y menos preciso, tarea que a pesar de ello tambi\ue9n nos va a llevar mucho tiempo. Lo que hemos realizado en esta campa\uf1a ha sido una aproximaci\uf3n rigurosa al levantamiento del templo con la gu\ueda de diversos expertos en el tema, de manera que primero hemos ensayado nuevas t\ue9cnicas, como la del uso de una gr\ufaa y la gesti\uf3n del esc\ue1ner por control remoto, en segundo lugar hemos experimentado con su uso en posiciones elevadas con el operador a su lado llevando al l\uedmite los tensores para conseguir la m\ue1xima estabilidad. Posteriormente hemos probado la toma de datos desde diversos \ue1ngulos, su posterior interconexi\uf3n y su vinculaci\uf3n con redes topogr\ue1ficas as\ued como con la toma de datos tradicional y fotogram\ue9trica y para finalizar, ensayar las opciones de modelado y gesti\uf3n de los datos obtenidos