Nonlinear oscillators for vibration energy harvesting

Vibration to electricity energy conversion strategies are discussed by using nonlinear stochastic dynamics. General principles for the exploitation of nonlinear oscillators in energy harvesting that provide useful leads for the realization of micropower generators of practical interest are presented

Thermal noise limit in the Virgo mirror suspension

Abstract The expected current limit to the Virgo sensitivity is presented. New materials to realize a low thermal noise suspension for the Virgo optics are investigated. A promising fused silica suspension for the Virgo mirrors is presented

A parallel Beowulf-based system for the detection of gravitational waves in interferometric detectors

The detection, in a modern interferometric detector like Virgo, of a gravitational wave signal from a coalescing binary stellar system is an intensive computational task both for the on-line and off-line computer systems. A parallel computing scheme using the Message Passing Interface (MPI) is described. Performance results on a small scale cluster are reported

Low-frequency internal friction in silica glass

Precise low-frequency internal friction measurements on vitreous silica, taken over a wide temperature (4 K160 K the loss angle develops a distinct step-like structure followed by a plateau, both independent of ν, thus signalling the onset of a competing relaxation mechanism with much higher an activation energy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58117/2/epl_80_5_50008.pd

LISA test mass charging process due to cosmic ray nuclei and electrons

none10noolar energetic particles and galactic cosmic rays with energies larger than 100 MeV cause progressive charging of the LISA experiment test masses. Consequently, Coulomb forces occur between the test masses and the surrounding conducting surfaces generating spurious signals that might be mistaken for gravitational wave signals. We have parametrized the energy spectra of galactic cosmic-ray nuclei and electrons near the LISA orbit in order to evaluate their role in the test-mass charging relative to the most abundant proton component. This work has been carried out using the FLUKA Monte Carlo program.openC. GRIMANI; H. VOCCA; G. BAGNI; L. MARCONI; R. STANGA; F. VETRANO; A. VICERÉ; P. AMICO; L. GAMMAITONI; F. MARCHESONIGrimani, Catia; H., Vocca; G., Bagni; L., Marconi; R., Stanga; Vetrano, Flavio; Vicere', Andrea; P., Amico; L., Gammaitoni; F., Marcheson

Thermal noise reduction for present and future gravitational wave detectors

Thermal noise in mirror suspension is and will be the most severe fundamental limit to the low-frequency sensitivity of interferometric gravitational wave detectors currently under construction. The technical solutions, adopted in the Virgo detector, optimize the current suspension scheme, but new materials and new designs are needed to further reduce the suspension thermal noise. Silicon fibers are promising candidates both for room temperature advanced detectors and for future cryogenic interferometric detectors

A computational test facility for distributed analysis of gravitational wave signals

In the gravitational wave detector Virgo, the in-time detection of a gravitational wave signal from a coalescing binary stellar system is an intensive computational task. A parallel computing scheme using the message passing interface (MPI) is described. Performance results on a small-scale cluster are reported