University of Trento

About: University of Trento is a education organization based out in Trento, Italy. It is known for research contribution in the topics: Population & Context (language use). The organization has 10527 authors who have published 30978 publications receiving 896614 citations. The organization is also known as: Universitá degli Studi di Trento & Universita degli Studi di Trento.

Artificial gauge field for photons in coupled cavity arrays

Abstract: We propose and characterize solid-state photonic structures where light experiences an artificial gauge field. A nontrivial phase for photons tunneling between adjacent sites of a coupled cavity array can be obtained by inserting optically active materials in the structure or by inducing a suitable coupling of the propagation and polarization degrees of freedom. We also discuss the feasibility of observing strong gauge field effects in the optical spectra of realistic systems, including the Hofstadter butterfly spectrum.

New Insights on the Mechanism of Palladium-Catalyzed Hydrolysis of Sodium Borohydride from 11B NMR Measurements

Abstract: To gain insight on the mechanistic aspects of the palladium-catalyzed hydrolysis of NaBH4 in alkaline media, the kinetics of the reaction has been investigated by 11B NMR (nuclear magnetic resonance) measurements taken at different times during the reaction course. Working with BH4- concentration in the range 0.05−0.1 M and with a [substrate]/[catalyst] molar ratio of 0.03−0.11, hydrolysis has been found to follow a first-order kinetic dependence from concentration of both the substrate and the catalyst (Pd/C 10 wt %). We followed the reaction of NaBH4 and its perdeuterated analogue NaBD4 in H2O, in D2O and H2O/D2O mixtures. When the process was carried out in D2O, deuterium incorporation in BH4- afforded BH4-nDn- (n = 1, 2, 3, 4) species, and a competition between hydrolysis and hydrogen/deuterium exchange processes was observed. By fitting the kinetics NMR data by nonlinear least-squares regression techniques, the rate constants of the elementary steps involved in the palladium-catalyzed borohydride hyd...

Learning the Trade: A Culture of Safety in Practice:

Abstract: This paper presents an ethnographic study of how safety is mastered by novices on a building site, in order to highlight the social and cultural character of learning Adopting a situational focus, the paper explores how knowledge is acquired and transmitted, and how a culture of practice sediments and is perpetuated in the process The paper takes the community of practices as the privileged locus of learning and transmitting practical knowledge This study is therefore an attempt to understand in what forms and by means of what mechanisms building-site novices are socialized in the community of practices and how, within this process, the competence relative to safety and danger is learned

A Framework for Automatic and Unsupervised Detection of Multiple Changes in Multitemporal Images

Abstract: The detection of multiple changes (i.e., different kinds of change) in multitemporal remote sensing images is a complex problem. When multispectral images having B spectral bands are considered, an effective solution to this problem is to exploit all available spectral channels in the framework of supervised or partially supervised approaches. However, in many real applications, it is difficult/impossible to collect ground truth information for either multitemporal or single-date images. On the opposite, unsupervised methods available in the literature are not effective in handling the full information present in multispectral and multitemporal images. They usually consider a simplified subspace of the original feature space having small dimensionality and, thus, characterized by a possible loss of change information. In this paper, we present a framework for the detection of multiple changes in bitemporal and multispectral remote sensing images that allows one to overcome the limits of standard unsupervised methods. The framework is based on the following: 1) a compressed yet efficient 2-D representation of the change information and 2) a two-step automatic decision strategy. The effectiveness of the proposed approach has been tested on two bitemporal and multispectral data sets having different properties. Results obtained on both data sets confirm the effectiveness of the proposed approach.