Search results for "sperimentale"
showing 10 items of 938 documents
The photophysics of distorted nanographenes: Ultra-slow relaxation dynamics, memory effects, and delayed fluorescence
2023
The controlled deformation and engineering of the sp2 carbon network in atomically-precise nanographenes, and their substantially larger size as compared to typical optical dyes, opens new opportunities for the modulation of optical and electronic properties, but the peculiar photophysics of these systems is still poorly understood. Here, through a detailed comparative study of two well-defined distorted nanographenes, we show that they can exhibit interesting photophysical features, such as triplet-triplet annihilation delayed fluorescence, ultra-slow excited state dynamics, and excitation-wavelength memory effects on the nanosecond and sub-nanosecond relaxation cascades. Some of these beh…
Differential branching fractions and isospin asymmetries of B -> K ((*)) μ(+) μ(-) decays
2014
The isospin asymmetries of $B \to K\mu^+\mu^-$ and $B \to K^{*}\mu^+\mu^-$ decays and the partial branching fractions of the $B^0 \to K^0\mu^+\mu^-$, $B^+ \to K^+\mu^+\mu^-$ and $B^+ \to K^{*+}\mu^+\mu^-$ decays are measured as functions of the dimuon mass squared, $q^2$. The data used correspond to an integrated luminosity of 3$~$fb$^{-1}$ from proton-proton collisions collected with the LHCb detector at centre-of-mass energies of 7$\,$TeV and 8$\,$TeV in 2011 and 2012, respectively. The isospin asymmetries are both consistent with the Standard Model expectations. The three measured branching fractions, while individually consistent, all favour lower values than their respective Standard M…
Observation of an Excited $B^{\pm}_c$ Meson State with the ATLAS Detector
2014
A search for excited states of the B±c meson is performed using 4.9 fb-1 of 7 TeV and 19.2 fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay B±c→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5 MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the B±c meson, B±c(2S).
Evaluating the effect of organization and context on technical efficiency: a second-stage DEA analysis of Italian hospitals
2022
Objective: the purpose of this study was to compare the technical efficiency of Italian hospitals at a regional level and to examine if differences could be explained by organisational and contextual factors. Technical efficiency was defined as the ability of the operating units evaluated to use optimal resource levels for their level of output.Methods: the effect of external factors was explored through a second stage Data Envelopment Analysis (DEA). Efficiency scores were calculated for each hospital using the DEA method (Stage I). Through Tobit regression analysis, the estimated efficiency scores were regressed against a set of organisational and contextual characteristics beyond manager…
Six Sigma in small- and medium-sized enterprises: a Black Belt project in the Swedish steel industry
2014
Many big companies around the world have solid Six Sigma infrastructures and it is easy to find in literature successful case studies. Conversely, small and medium-sized enterprises (SMEs) generally suffer lower attention in the literature. This happens because SMEs have only recently approached the methodology; they have weaker connection with the academia; or they do not rigorously pursue the frameworks. This paper is based on a Six Sigma project in a Swedish medium-sized company that produces steel tubes mainly for hydraulic applications. The project focused on the improvement of warehouse activities related to cutting processes. This Black Belt project was part of a Six Sigma education …
Multi-channel search for squarks and gluinos in root s=7 TeV pp collisions with the ATLAS detector at the LHC
2013
A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from b-quarks, in 4.7 fb[superscript −1] of √s = 7 TeV pp collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse and parallel to the beam line that are sensitive to several topologies expected in supersymmetry. Mutually exclusive final states are defined, allowing a combination of all channels to increase the search sensitivity. No deviation from the Standard Model expectation is observed. Upper limits at 95 % confidence level…
TRADITION AND MODERNITY OF CATALAN VAULTS: HISTORICAL AND STRUCTURAL ANALYSIS
2012
Il lavoro analizza da diversi punti di vista un particolare tipo di strutture voltate noto come volte catalane (bóveda tabicada) e la tecnica costruttiva correlata. Le volte catalane sono volte realizzate da strati alterni di mattoni e malta, caratterizzate da un esiguo spessore in relazione alle altre dimensioni. Il primo passo presentato nel lavoro è quello di investigare tutti gli aspetti storici al fine di inquadrare sia la tipologia che la tecnica costruttiva correlata all'interno della storia dell'architettura e di individuare le ragioni di un così grande successo lungo i secoli. Successivamente, è stata effettuata una campagna di indagini sperimentali, che completa una precedente, su…
DOSIMETRIA ESR CON ALANINA PER ADRONTERAPIA CON IONI CARBONIO
2015
La sicurezza del paziente sottoposto a trattamenti terapeutici con radiazioni ionizzanti e il buon esito degli ultimi sono strettamente legati all’ottimizzazione delle procedure di esposizione alle radiazioni ionizzanti. In particolare è fondamentale arrecare il danno minore possibile ai tessuti sani che circondano la neoplasia da trattare. Rispetto ai campi di radiazione convenzionali utilizzati in radioterapia (fotoni), le particelle cariche pesanti (protoni e ioni carbonio) offrono diversi vantaggi quali la bassa dispersione laterale, l’alta efficacia biologica (RBE) nella regione del picco di Bragg ed un profilo di dose caratteristico in profondità del tutto differente da quello dei fot…
Advances in High-Energy-Resolution CdZnTe Linear Array Pixel Detectors with Fast and Low Noise Readout Electronics
2023
Radiation detectors based on Cadmium Zinc Telluride (CZT) compounds are becoming popular solutions thanks to their high detection efficiency, room temperature operation, and to their reliability in compact detection systems for medical, astrophysical, or industrial applications. However, despite a huge effort to improve the technological process, CZT detectors’ full potential has not been completely exploited when both high spatial and energy resolution are required by the application, especially at low energies (<10 keV), limiting their application in energy-resolved photon counting (ERPC) systems. This gap can also be attributed to the lack of dedicated front-end electronics whic…
Highly Efficient Electron Transfer in a Carbon Dot–Polyoxometalate Nanohybrid
2020
Using solar radiation to fuel catalytic processes is often regarded as the solution to our energy needs. However, developing effective photocatalysts that are active under visible light has proven to be difficult, often due to the toxicity, instability, and high cost of suitable catalysts. We engineered a novel photoactive nanomaterial obtained by the spontaneous electrostatic coupling of carbon nanodots with [P2W18O62]6-, a molecular catalyst belonging to the class of polyoxometalates. While the former are used as photosensitizers, the latter was chosen for its ability to catalyze reductive reactions such as dye decomposition and water splitting. We find the electron transfer within the na…