57 research outputs found

    Design of Wireless Sensor Nodes for Structural Health Monitoring applications

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    Enabling low-cost distributed monitoring, wireless sensor networks represents an interesting solution for the implementation of structural health monitoring systems. This work deals with the design of wireless sensor networks for health monitoring of civil structures, specifically focusing on node design in relation to the requirements of different structural monitoring application classes. Design problems are analysed with specific reference to a large-scale experimental setup (the long-term structural monitoring of the Basilica S. Maria di Collemaggio, L’Aquila, Italy). Main limitations emerged are highlighted, and adopted solution strategies are outlined, both in the case of commercial sensing platform and of full custom solutions

    Using a Recurrent Neural Network To Inform the Use of Prostate-specific Antigen (PSA) and PSA Density for Dynamic Monitoring of the Risk of Prostate Cancer Progression on Active Surveillance

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    The global uptake of prostate cancer (PCa) active surveillance (AS) is steadily increasing. While prostate-specific antigen density (PSAD) is an important baseline predictor of PCa progression on AS, there is a scarcity of recommendations on its use in follow-up. In particular, the best way of measuring PSAD is unclear. One approach would be to use the baseline gland volume (BGV) as a denominator in all calculations throughout AS (nonadaptive PSAD, PSADNA), while another would be to remeasure gland volume at each new magnetic resonance imaging scan (adaptive PSAD, PSADA). In addition, little is known about the predictive value of serial PSAD in comparison to PSA. We applied a long short-term memory recurrent neural network to an AS cohort of 332 patients and found that serial PSADNA significantly outperformed both PSADA and PSA for follow-up prediction of PCa progression because of its high sensitivity. Importantly, while PSADNA was superior in patients with smaller glands (BGV ≤55 ml), serial PSA was better in men with larger prostates of >55 ml. Patient summary: Repeat measurements of prostate-specific antigen (PSA) and PSA density (PSAD) are the mainstay of active surveillance in prostate cancer. Our study suggests that in patients with a prostate gland of 55 ml or smaller, PSAD measurements are a better predictor of tumour progression, whereas men with a larger gland may benefit more from PSA monitoring

    The catalytic role of uranyl in formation of polycatechol complexes

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    To better understand the association of contaminant uranium with natural organic matter (NOM) and the fate of uranium in ground water, spectroscopic studies of uranium complexation with catechol were conducted. Catechol provides a model for ubiquitous functional groups present in NOM. Liquid samples were analyzed using Raman, FTIR, and UV-Vis spectroscopy. Catechol was found to polymerize in presence of uranyl ions. Polymerization in presence of uranyl was compared to reactions in the presence of molybdate, another oxyion, and self polymerization of catechol at high pH. The effect of time and dissolved oxygen were also studied. It was found that oxygen was required for self-polymerization at elevated pH. The potential formation of phenoxy radicals as well as quinones was monitored. The benzene ring was found to be intact after polymerization. No evidence for formation of ether bonds was found, suggesting polymerization was due to formation of C-C bonds between catechol ligands. Uranyl was found to form outer sphere complexes with catechol at initial stages but over time (six months) polycatechol complexes were formed and precipitated from solution (forming humic-like material) while uranyl ions remained in solution. Our studies show that uranyl acts as a catalyst in catechol-polymerization

    Self-organised key management for the smart grid

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    As Smart Grid deployments emerge around the world, their protection against cyberattacks becomes more crucial. Before protective measures are put into place, one of the main factors to be considered is key management. Smart Grid poses special requirements compared to traditional networks; however, the review of previous work reveals that existing schemes are not complete. Here we propose a scalable and distributed key management scheme for the Smart Grid based on the Web-of-Trust concept. Our proposal is build on top of a Distributed Hash Table for efficient lookups of trust relationships. The target of this scheme is to create a key management system for the Smart Grid without the need of an always available Trusted Third Party. The underlying Distributed Hash Table can be further utilised as an infrastructure to build other Smart Grid services on top of it, like secure and/or anonymous aggregation, billing, etc. © Springer International Publishing Switzerland 2015

    Distributed structural Monitoring for a Smart City in a seismic area

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    The concept of Smart City (SC) has been introduced to categorize the vast area of activities to enhance the life quality of citizen, which are characterised by a pervasive use of Information and Communication Technologies (ICT), to help cities, with various urban domains, making better use of their resources. Monitoring the structural behaviour of strategic buildings and monuments may be desirable for citizens, which have recently experienced a destructive earthquake in their own town, such as the case of L'Aquila. The paper deals with the design of a distributed structural monitoring network for a selected set of strategic structures belonging to the city of L'Aquila. Preliminary design criteria are discussed on the basis of previous authors' experiences in this context. Specific attention has been dedicated to analyse the expected acceleration response measurements induced by small seismic excitations for the general purpose of monitoring
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