Istituto Universitario Di Studi Superiori Di Pavia

About: Istituto Universitario Di Studi Superiori Di Pavia is a education organization based out in Pavia, Italy. It is known for research contribution in the topics: Pulsar & Neutron star. The organization has 162 authors who have published 566 publications receiving 22605 citations.

Spin-down rate and inferred dipole magnetic field of the soft gamma-ray repeater SGR 1627-41

Abstract: Using Chandra data taken on 2008 June, we detected pulsations at 2.594 39(4) s in the soft gamma-ray repeater SGR 1627‐41. This is the second measurement of the source spin period and allows us to derive for the first time a long-term spin-dow n rate of (1.9 ± 0.4) × 10 11 s s 1 . From this value we infer for SGR 1627‐41 a characteristic age of �2.2 kyr, a spin-down luminosity of �4 × 10 34 erg s 1 (one of the highest among sources of the same class), and a surface dipole magnetic field strength of �2× 10 14 G. These properties confirm the magnetar nature of SGR 1627‐41; however, they should be considered with caution since they were derived on the basis of a period derivative measurement made using two epochs only and magnetar spin-down rates are generally highly variable. The pulse profile, double-peaked and with a pulsed fraction of (13 ± 2)% in the 2‐10 keV range, closely resembles that observed by XMM-Newtonin 2008 September. Having for the first time a timing model for this SGR, we also searched for a pulsed signal in archival radio data collected with the Parkes radio telescope nine months after the previous X-ray outburst. No evidence for radio pulsations was found, down to a luminosity level �10‐20 times fainter (for a 10% duty cycle and a distance of 11 kpc) than the peak luminosity shown by the known radio magnetars.

SMA Biomedical Applications

Abstract: Shape memory alloys (SMAs) are a group of metallic materials that exhibit unique properties and, accordingly, draw the interest of scientific communities and industries. The most used SMA in the biomedical field is Nitinol (NiTi). Nowadays, a large majority of SMA medical devices are produced using NiTi alloys, thanks to the material's good workability during the martensite phase, good resistance to corrosion and fatigue, U.S. Food and Drug Administration approval, and good compatibility with magnetic resonance imaging and computer tomography scanning.

Ground-motion models for average spectral acceleration in a period range: direct and indirect methods

Abstract: Average spectral acceleration, AvgSA, is defined as the geometric mean of spectral acceleration values over a range of periods and it is a ground motion intensity measure used for structural response prediction. One of its advantages stands on the assumption that its distribution is computable from the available GMPEs for spectral acceleration, GMPE-SA, (called here indirect method) without the need for deriving new specific GMPEs for AvgSA, GMPE-AvgSA, (called here direct method). To what extent this assumption is valid, however, has never been verified. As such, we derived an empirical GMPE-AvgSA based on RESORCE ground motion dataset and we compared its predicted values with those from a GMPE-SA via the indirect approach. As expected, the results show that the indirect approach yields median AvgSA estimates that are identical to those of the direct approach. However, the estimates of AvgSA variance of the two methods are identical only if both the GMPE-SA and their empirical correlation coefficients among different SA ordinates are derived from the same record dataset.

Quiescent state and outburst evolution of SGR 0501+4516

Abstract: This work was supported by the grants AYA2012-39303, SGR2009-811, and iLINK2011-0303. AP is supported by a Juan de la Cierva Fellowship in IEEC. NR is supported by a Ramon y Cajal fellowship and by an NWO Vidi Award. DV was supported by the grants AYA2010-21097-C03-02, ACOMP/2012/135, AYA 2012-39303 and SGR 2009-811.