Image Diagnostics of Contemporary Art: some instances and perspectives

The research of new ways of expression of contemporary artists, the employment of new materials, often in different and astonishing assemblies, pose newer and newer problems in the conservation and documentation practice. As a consequence, new issues are required also in diagnostics protocols.In this frame, emerging digital techniques – like 3D-scanning and Image Spectroscopy, for instance – may find extensive and useful applications. A large space for dedicated, innovative analyses is still unexplored but even well-known techniques, like grazing light photography, may find a new placement

Misura della frazione di decadimento dei mesoni K carichi: K+ -> pi+ nu antinu

La collaborazione internazionale P326 si propone l' obiettivo di preparare l'apparato sperimentale necessario per misurare circa 100 eventi K+ -> pi+ nu antinu utilizzando un fascio di kaoni carichi di impulso 75 GeV/c prodotto presso l'acceleratore di protoni SPS del CERN. Tale obiettivo e' molto ambizioso dal punto di vista sperimentale e richiede uno sviluppo di rivelatori innovativi di altissima efficienza ed eccellente risoluzione temporale, allo scopo di identificare i mesoni K carichi nel fascio con grande precisione e di rigettare ad altissimo livello gli eventi provenienti dai principali modi di decadimento K+->muone neutrino e K+->pi+pi0. La frazione di decadimento K+ -> pi+ nu antinu, se misurata con una precisione del 10% puo' essere confrontata con accurate predizioni teoriche per fornire una misura del parametro Vtd della matrice CKM di mescolamento dei sapori e confermare o escludere alcune delle più interessanti estensioni supersimmetriche del Modello Standar

Le Pleiadi

Questa Collana e' dedicata agli studenti dei Corsi di Laurea in Scienze e in Tecnologie per i Beni Culturali e a chi si interessi delle applicazioni scientifiche in questo campo. Con uno stile semplice ed un approccio non specialistico si propone di illustrare vari aspetti dello studio dei beni culturali con metodi scientifici, iniziando con argomenti di prima grandezza per soddisfare via via esigenze piu' raffinate

Bioerodible hydrogels based on 2-hydroxyethyl methacrylate: synthesis and characterization

Biocompatible polymers with specific shape and tailored hydrogel properties were obtained by polymerization of mixtures of 2-hydroxyethyl methacrylate (HEMA) with 1-8 wt %, ethylene glycol dimethacrylate (EGDMA) or tetra(ethylene glycol) diacrylate (TEGDA) as crosslinking agents, by using a redox initiator. Introduction of charged positive and negative groups was easily achieved by direct polymerization of appropriate monomer mixtures and by chemical transformation of preformed hydrogels. Investigation of the swelling behavior of the prepared hydrogels evidenced an appreciable dependence on both solvent type and polymer chemical structure. Additionally, the solvation process resulted in being controlled by solvent diffusion, according to a Fickian II mechanism. The presence of several types of water with different melting behavior was observed in fully swollen hydrogel

Un anno di monitoraggio microclimatico in una sala della Pinacoteca Nazionale di Ferrara: problematiche di gestione ambientale e conclusioni

The article deals with the microclimate monitoring of a room in the national picture gallery of Ferrara, started in May 2006 for a term of twelve months. This work was aimed to draw a general and complete picture of the microclimate conditions in which paintings are subjected. Two paintings on wooden tables, representing “Coronation of the Virgin” and “St. John the Evangelist”, dated XV century, have been subjected to several investigations like the study of EMC (equilibrium moisture content) and its variations during all months of the year, and illuminance levels on pictorial surfaces to evaluate the suitability of lighting system of the museum. Solutions are suggested to create a suitable environment for the good conservation of works of art

The Gigatracker: An ultra-fast and low-mass silicon pixel detector for the NA62 experiment

The Gigatracker is a hybrid silicon pixel detector developed to track the highly intense NA62 hadron beam with a time resolution of 150ps(rms). The beam spectrometer of the experiment is composed of three Gigatracker stations installed in vacuum in order to precisely measure momentum, time and direction of every traversing particle. Precise tracking demands a very low mass of the detector assembly (< 0.5% X0 per station) in order to limit multiple scattering and beam hadronic interactions. The high rate and especially the high timing precision requirements are very demanding: two R&D options are ongoing and the corresponding prototype read-out chips have been recently designed and produced in 0.13 mm CMOS technology. One solution makes use of a constant fraction discriminator and on-pixel analogue-based time-to-digital-converter (TDC); the other comprises a delay-locked loop based TDC placed at the end of each pixel column and a time-over-threshold discriminator with time-walk correction technique. The current status of the R&D program is overviewed and results from the prototype read-out chips test are presented

The Fenice Detector At the E+e- Collider Adone

The FENICE detector, installed at the Frascati e+e- storage ring ADONE, for measuring the neutron e.m. form factors in the timelike region, is described. FENICE is a nonmagnetic detector and consists of a complex array of scintillators, limited streamer tubes and iron converters for detecting mainly the process e+e- --> nnBAR. Antineutrons are identified by the charged prongs produced in their annihilation and the antineutron velocity is measured by the retrieved annihilation time with respect to the beam crossing time. Neutrons are detected in plastic scintillator layers. To reduce the cosmic rays background a concrete shield, covered by an active veto system, is added