Electrical resistivity change in amorphous Ta42Si13N45 films by stress relaxation

In a first experiment, a reactively sputtered amorphous Ta₄₂Si₁₃N₄₅ film about 260 nm thick deposited on a flat and smooth alumina substrate was thermally annealed in air for 30 min and let cooled again repeatedly at successively higher temperatures from 200 to 500 °C. This treatment successively and irreversibly increases the room temperature resistivity of the film monotonically from its initial value of 670 μΩ cm to a maximum of 705 μΩ cm (+5.2 %). Subsequent heat treatments at temperatures below 500 °C and up to 6 h have no further effect on the room temperature resistivity. The new value remains unchanged after 3.8 years of storage at room temperature. In a second experiment, the evolution of the initially compressive stress of a film similarly deposited by reactive sputtering on a 2-inch silicon wafer was measured by tracking the wafer curvature during similar thermal annealing cycles. A similar pattern of irreversible and reversible changes of stress was observed as for the film resistivity. Transmission electron micrographs and secondary ion mass profiles of the film taken before and after thermal annealing in air establish that both the structure and the composition of the film scarcely change during the annealing cycles. We reason that the film stress is implicated in the resistivity change. In particular, to interpret the observations, a model is proposed where the interface between the film and the substrate is mechanically unyielding

Applying Extensions of Evidence Theory to Detect Frauds in Financial Infrastructures

The Dempster-Shafer (DS) theory of evidence has significant weaknesses when dealing with conflicting information sources, as demonstrated by preeminent mathematicians. This problem may invalidate its effectiveness when it is used to implement decision-making tools that monitor a great number of parameters and metrics. Indeed, in this case, very different estimations are likely to happen and can produce unfair and biased results. In order to solve these flaws, a number of amendments and extensions of the initial DS model have been proposed in literature. In this work, we present a Fraud Detection System that classifies transactions in a Mobile Money Transfer infrastructure by using the data fusion algorithms derived from these new models. We tested it in a simulated environment that closely mimics a real Mobile Money Transfer infrastructure and its actors. Results show substantial improvements of the performance in terms of true positive and false positive rates with respect to the classical DS theory

Innovative techniques integrating advanced and biocomposite materials for energy and seismic retrofitting of built heritage

Cultural heritage is recognized as a driver of the sustainable development. The UNESCO’s 1972 World Heritage Convention has addressed key topics that link heritage practices to sustainability objectives. Historic buildings make up a considerable part of EU building stock, and their renovation and safeguarding require retrofit solutions that balance safety, energy efficiency, human comfort, heritage value preservation and environmental sustainability. This article tries to throw light on innovative techniques for heritage restoration based on sustainability, reuse, and recycle principles through non-invasive interventions. The work outlines the progress in the field of advanced materials obtained through the reuse of recycled materials, showing outcomes from MIRACLE research carried out by University of Florence on the development of an innovative fiber-reinforced bio-composite matrix to be applied for energy plus seismic retrofitting of existing masonry buildings built before 1945

Acceptability of the transitional wearable companion “+me” in typical children: a pilot study

This work presents the results of the first experimentation of +me-the first prototype of Transitional Wearable Companion–run on 15 typically developed (TD) children with ages between 8 and 34 months. +me is an interactive device that looks like a teddy bear that can be worn around the neck, has touch sensors, can emit appealing lights and sounds, and has input-output contingencies that can be regulated with a tablet via Bluetooth. The participants were engaged in social play activities involving both the device and an adult experimenter. +me was designed with the objective of exploiting its intrinsic allure as an attractive toy to stimulate social interactions (e.g., eye contact, turn taking, imitation, social smiles), an aspect potentially helpful in the therapy of Autism Spectrum Disorders (ASD) and other Pervasive Developmental Disorders (PDD). The main purpose of this preliminary study is to evaluate the general acceptability of the toy by TD children, observing the elicited behaviors in preparation for future experiments involving children with ASD and other PDD. First observations, based on video recording and scoring, show that +me stimulates good social engagement in TD children, especially when their age is higher than 24 months