Analysis of Intermittent Distributed Connectivity in Urban Areas

Analysis of hypothetical connectivity of wirelessly interconnected networks and infrastructures deployed over a one-square kilometre of the Brussels Metropolitan area is presented. Upper and lower margins of wireless transceiver range are considered with a view to characterise representative interconnectivity profiles. Graph and percolation analyses of intermittent connectivity and its implications for resilience and vulnerability of the network are discussed. Based on these findings the report presents a proposal for the dimensioning of connectivity profiles for generic areas based on intrinsic algebraic network properties.JRC.E.4-Safety and Security of Building

Objective 2: Conduct Experimental Activities on Performance of Sensor‐Equipped Composite Elements

In this report we present the basic principles of our exploratory research for embedding sensors and energy-harvesting devices in sandwich composite structures. A range of piezopolymer sensors where used, varying in their dimensions, their capacitance and the electrode coating material. Sensors were tested in the surface-attached and embedded formats on composite sandwich laminates. Specimens were tested under three-point bending configuration to measure both the sensor voltages and the generated laminate strains. The electromechanical sensitivity performance with respect to frequency and strain amplitude were the key performance parameters investigated. Primary conclusions, of a practical nature, were extracted concerning the appropriate type of sensor for embedding applications as well as the parameters affecting the sensitivity and efficiency of the devices to perform as energy both strain gauges and energy-harvesting devices.JRC.G.5-European laboratory for structural assessmen

Evaluation of the physical and fatigue performance of embedded piezopolymer sensor systems in sandwich composite laminates

It has been claimed that embedding piezo-ceramic devices as structural diagnostic systems in advanced composite structures may introduce mechanical impedance miss-matches that favour the formation of intralaminar defects; this and other factors such as cost and their high strain sensitivity has motivated the use of thin-film piezo-polymer sensors. In this paper, we examine the performance of sandwich composite panels fitted with embedded piezopolymer sensors. Our experimental campaign examines both how such thin-film sensors perform within a structure and the converse effect; how the inclusion of sensor films affects structural performance. Strain-controlled tests on sandwich panels subjected to three-point bending under wide-ranging static and dynamic strains lead us to conclude that embedding thin piezopolymer films has no marked reduction on the tensile strength for a wide range of strain loading paths and magnitudes, and that the resilience of the embedded sensor is itself satisfactory, even up to the point of structural failure. Comparing base-line data obtained from standard surface-mounted sensors and foil gauges, we note that whereas it is possible to match experimental and theoretical strain sensitivities, key properties, especially the pronounced orthotropic electromechanical factor of such films must be duly considered before an effective calibration can take place.JRC.G.4-European laboratory for structural assessmen

Investigating efficiency of non-linear wave modulation spectroscopy for early detection of critical buckling damages in sandwich composite panels

This work presents experimental investigations into the potential of using, piezo-actuated, ultrasound waves for the detection of damage or incipient failure in fibre-reinforced sandwich panels under compressive axial load. Two methodologies are applied based on (i) frequency modulation spectroscopy and (ii) single-mode resonance shifting. Sensitivity of the techniques is studied during the loading till the failure of the specimens and also post failure. Representative measurements for both approaches are presented and discussed herein.JRC.G.4-European laboratory for structural assessmen

Evaluation of the sensitivity and fatigue performance of embedded piezopolymer sensor systems in sandwich composite laminates

It has been claimed that embedding piezo-ceramic devices as structural diagnostic systems in advanced composite structures may introduce mechanical impedance miss-matches that favour the formation of intralaminar defects; this and other factors such as cost and their high strain sensitivity has motivated the use of thin-film piezo-polymer sensors. In this paper, we examine the performance of sandwich composite panels fitted with embedded piezopolymer sensors. Our experimental campaign examines both how such thin-film sensors perform within a structure and the converse effect; how the inclusion of sensor films affects structural performance. Strain-controlled tests on sandwich panels subjected to three-point bending under wide-ranging static and dynamic strains lead us to conclude that embedding thin piezopolymer films has no marked reduction on the tensile strength for a wide range of strain loading paths and magnitudes, and that the resilience of the embedded sensor is itself satisfactory, even up to the point of structural failure. Comparing base-line data obtained from standard surface-mounted sensors and foil gauges, we note that whereas it is possible to match experimental and theoretical strain sensitivities, key properties, especially the pronounced orthotropic electromechanical factor of such films must be duly considered before an effective calibration can take place.JRC.G.4-European laboratory for structural assessmen

Collaboration and Semantic Networks of EU-funded Research in Quantum Technologies: 2007-2019.

A quantitative analysis is conducted of the distribution of budgets, participants and host countries from a compilation of EU-funded CORDIS projects with starting dates from Q2 2007 till Q3 2019. The projects are selected on the basis of containing the word 'quantum' in their objectives description texts. An accompanying semantic analysis of the concatenated texts is conducted by mapping the projects budget timeline to the word associations of the word quantum to its related technical fields.JRC.E.4-Safety and Security of Building

Evaluation of the Performance of an Energy Harvesting Chain Based on Piezopolymer Sensors

In this paper we measure the experimental performance of an energy-harvesting chain based on thin-film piezopolymers. We compare the optimal impedance-matched power output to the expected theoretical values and then measure the capacity of a commercial energy-harvesting electronic circuit (based on a rectifier and DC-DC buck converter) to optimize the energy-extraction from the sensor for a range of frequencies.JRC.G.4-European laboratory for structural assessmen