Nonlinear bi-stable vibration energy harvester at work

An extreme low power energy rectification, storage and management circuitry has been developed and used to power a small digital wireless sensor with a piezoelectric non-linear bi-stable vibration energy harvester for automotive application. All the system has been designed with off-the-shelf components and sends data in the 2.4 GHz band

Bistable electromagnetic generator based on buckled beams for vibration energy harvesting

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Multi Order Coverage data structure to plan multi-messenger observations

International audienceWe describe the use of Multi Order Coverage (MOC) maps as a practical way to manage complex regions of the sky for the planning of multi-messenger observations. MOC maps are a data structure that provides a multi-resolution representation of irregularly shaped and fragmentary regions over the sky based on the HEALPix (Hierarchical Equal Area isoLatitude Pixelization) tessellation. We present a new application of MOC, in combination with the astroplan observation planning package, to enable the efficient computation of sky regions and the visibility of these regions from a specific location on the Earth at a particular time. Using the example of the low-latency gravitational-wave alerts, and a simulated observational campaign with three observatories, we show that the use of MOC maps allows a high level of interoperability to support observing schedule plans. Gravitational-wave detections have an associated credible region localisation on the sky. We demonstrate that these localisations can be encoded as MOC maps, and how they can be used in visualisation tools, and processed (filtered, combined) and also their utility for access to Virtual Observatory services which can be queried ‘by MOC’ for data within the region of interest. The ease of generating the MOC maps and the fast access to data means that the whole system can be very efficient, so that any updates on the gravitational-wave sky localisation can be quickly taken into account and the corresponding adjustments to observing schedule plans can be rapidly implemented. We provide example Python code as a practical example of these methods. In addition, a video demonstration of the entire workflow is available

Capability for Encoding Gravitational-wave Sky Localizations with the Multi Order Coverage Data Structure: Present and Future Developments

International audienceThe IVOA standard Multi-Order Coverage map (MOC) is a data structure based on the HEALPix tessellation of the sky, and it can be used to encode the area within a given probability level contour of a gravitational-wave (credible region) sky localization. MOC encoded credible regions can be created, visualised and manipulated using Aladin Desktop. The Aladin Desktop enables the users to compare the MOC regions with existing electromagnetic surveys and to query the VizieR database. These tasks can also be performed via Python using the astropy affiliated package, mocpy, which are efficiently displayed in javascript applications with Aladin Lite, and integrated within Jupyter notebooks through the ipyaladin widgets. The paper also describes an enhanced MOC structure which allows us to include temporal information about gravitational-wave events. This data structure, the Space and Time MOC (ST–MOC), provides us with an effective way to develop new multi-messenger data analysis tools which will be necessary when the third-generation interferometric gravitational wave observatories, such as the Einstein Telescope (ET), will begin operation

Small scale Suspended Interferometer for Ponderomotive Squeezing (SIPS) as test bench of the EPR squeezer for Advanced Virgo

We are developing a small-scale interferometer with monolithic suspension of test masses (SIPS), that will be sensitive to the quantum radiation pressure noise in the audio frequency band of gravitational wave detectors. In the same time, a table-top experiment for the frequency dependent squeezing generation, through the Einstein Podolsky Rosen (EPR) principle, is under construction. SIPS interferometer, being designed to achieve the quantum radiation pressure noise limit exploiting high finesse optical cavities, turns out to be a suitable test bench for the EPR technique, before a possible integration in Virgo for broadband quantum noise reduction. In this work, we describe the concept of the SIPS experiment, the most important noises affecting this setup, and we briefly present the current status and the plan for the integration with the EPR squeezing experiment

Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

International audienceDuring their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100  M⊙, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93  Gpc−3 yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits