Search results for "sperimentale"

Diffusive equilibrium properties of O2 in amorphous SiO2 nanoparticles probed via dependence of concentration on size and pressure

2014

An experimental study on the diffusive equilibrium value of interstitial O2 in silica nanoparticles was carried out on samples with average particles diameter 40, 14, and 7 nm. The investigation was performed by measuring the concentration of interstitial O2 by Raman and photoluminescence techniques. The dependence of diffusive equilibrium concentration on pressure and temperature was investigated in the pressure range from 0.2 to 76 bar and in the temperature range from 98 to 244 °C. The equilibrium concentration of interstitial O2 follows Henry’s law at pressures below 13 bar whereas a departure from this model is observed at higher pressures. In particular, O2 concentration saturates abo…

Study of scintillation light collection, production and propagation in a 4 tonne dual-phase LArTPC

2020

The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electroluminescence light created by passing particles has been studied in various detector conditions. In particular, the scintillation light production and propagation processes have been analyzed and compared to simulations, improving the understanding of some liquid argon properties.

Didattica e sviluppo delle competenze del Maestro. Docenti e studenti protagonisti in un percorso di ricerca

2010

Il volume affronta il tema dell’integrazione delle lezioni, dei laboratori e del tirocinio nella formazione dei futuri maestri, presentando concrete modalità di interazione tra le esperienze maturate dagli studenti del Corso di Laurea in Scienze della Formazione Primaria durante il percorso universitario. Nel libro sono descritte le modalità con cui durante le ore di lezione, di laboratorio e di tirocinio si è cercato di stimolare la riflessione degli studenti e di aumentare la loro consapevolezza circa i processi attivati nell’apprendimento, le motivazioni sottostanti, le situazioni contingenti e gli aspetti più favorevoli allo sviluppo della competenza professionale del maestro. La ricerc…

Performance of jet substructure techniques for large-$R$ jets in proton-proton collisions at $\sqrt{s}$ = 7 TeV using the ATLAS detector

2013

This paper presents the application of a variety of techniques to study jet substructure. The performance of various modified jet algorithms, or jet grooming techniques, for several jet types and event topologies is investigated for jets with transverse momentum larger than 300 GeV. Properties of jets subjected to the mass-drop filtering, trimming, and pruning algorithms are found to have a reduced sensitivity to multiple proton-proton interactions, are more stable at high luminosity and improve the physics potential of searches for heavy boosted objects. Studies of the expected discrimination power of jet mass and jet substructure observables in searches for new physics are also presented.…

Updated measurement of the τ lepton lifetime

1997

A new measurement of the mean lifetime of the tau lepton is presented. Three different analysis methods are applied to a sample of 90000 tau pairs, collected in 1993 and 1994 with the ALEPH detector at LEP. The average of this measurement and those previously published by ALEPH is tau_tau = 290.1 +- 1.5 +- 1.1 fs.

Digital performance improvements of a CdTe pixel detector for high flux energy-resolved X-ray imaging

2015

Abstract Photon counting detectors with energy resolving capabilities are desired for high flux X-ray imaging. In this work, we present the performance of a pixelated Schottky Al/p-CdTe/Pt detector (4×4) coupled to a custom-designed digital readout electronics for high flux measurements. The detector (4×4×2 mm 3 ) has an anode layout based on an array of 16 pixels with a geometric pitch of 1 mm (pixel size of 0.6 mm). The 4-channel readout electronics is able to continuously digitize and process the signals from each pixel, performing multi-parameter analysis (event arrival time, pulse shape, pulse height, pulse time width, etc.) even at high fluxes and at different throughput and energy re…

Nanoseconds Timing System Based on IEEE 1588 FPGA Implementation

2019

Clock synchronization procedures are mandatory in most physical experiments where event fragments are readout by spatially dislocated sensors and must be glued together to reconstruct key parameters (e.g. energy, interaction vertex etc.) of the process under investigation. These distributed data readout topologies rely on an accurate time information available at the frontend, where raw data are acquired and tagged with a precise timestamp prior to data buffering and central data collecting. This makes the network complexity and latency, between frontend and backend electronics, negligible within upper bounds imposed by the frontend data buffer capability. The proposed research work describ…

Structural Modification Processes in Bulk and Nano-sized Amorphous SiO2 Systems.

2011

Stochastic modeling and prediction of catalytic converters degradation

2009

This paper proposes a stochastic model for describing the degradation process of catalytic converters over time, where the degradation is indirectly measured through the emission of complex hydrocarbons (HC) in legislated driving cycles. The proposed model is the superposition of two processes, the former being a dependent increments process which describes the actual degradation process, and the latter a white noise process which models the experimental errors. In particular, the proposed model assumes that the degradation growth in a small usage interval depends on the degradation level at the beginning of the interval, rather than on the age of the converter. The model has been applied t…

IRIDE: Interdisciplinary research infrastructure based on dual electron linacs and lasers

2014

This paper describes the scientific aims and potentials as well as the preliminary technical design of RUDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity "particles factory", based on a combination of high duty cycle radio-frequency superconducting electron linacs and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of sci…