Reducing the seismic vulnerability of cultural heritage buildings

European-Indian Economic Cross Cultural Programme - contract n.º ALA-95-23-2003-077-122

Quark nuggets search using 2350 Kg gravitational waves aluminum bar detectors

The gravitational wave resonant detectors can be used as detectors of quark nuggets, like nuclearites (nuclear matter with a strange quark). This search has been carried out using data from two 2350 Kg, 2 K cooled, aluminum bar detectors: NAUTILUS, located in Frascati (Italy), and EXPLORER, that was located in CERN Geneva (CH). Both antennas are equipped with cosmic ray shower detectors: signals in the bar due to showers are continuously detected and used to characterize the antenna performances. The bar excitation mechanism is based on the so called thermo-acoustic effect, studied on dedicated experiments that use particle beams. This mechanism predicts that vibrations of bars are induced by the heat deposited in the bar from the particle. The geometrical acceptance of the bar detectors is 19.5 $\rm m^2$ sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. We will show the results of ten years of data from NAUTILUS (2003-2012) and 7 years from EXPLORER (2003-2009). The experimental limits we obtain are of interest because, for nuclearites of mass less than $10^{-4}$ grams, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates.Comment: presented to the 33rd International Cosmic Ray Conference Rio de Janeiro 201

Analysis of 3 years of data from the gravitational wave detectors EXPLORER and NAUTILUS

We performed a search for short gravitational wave bursts using about 3 years of data of the resonant bar detectors Nautilus and Explorer. Two types of analysis were performed: a search for coincidences with a low background of accidentals (0.1 over the entire period), and the calculation of upper limits on the rate of gravitational wave bursts. Here we give a detailed account of the methodology and we report the results: a null search for coincident events and an upper limit that improves over all previous limits from resonant antennas, and is competitive, in the range h_rss ~1E-19, with limits from interferometric detectors. Some new methodological features are introduced that have proven successful in the upper limits evaluation.Comment: 12 pages, 12 figure

Dark Matter searches using gravitational wave bar detectors: quark nuggets and newtorites

Many experiments have searched for supersymmetric WIMP dark matter, with null results. This may suggest to look for more exotic possibilities, for example compact ultra-dense quark nuggets, widely discussed in literature with several different names. Nuclearites are an example of candidate compact objects with atomic size cross section. After a short discussion on nuclearites, the result of a nuclearite search with the gravitational wave bar detectors Nautilus and Explorer is reported. The geometrical acceptance of the bar detectors is 19.5 $\rm m^2$ sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. The experimental limits we obtain are of interest because, for nuclearites of mass less than $10^{-5}$ g, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates. Particles with gravitational only interactions (newtorites) are another example. In this case the sensitivity is quite poor and a short discussion is reported on possible improvements.Comment: published on Astroparticle Physics Sept 25th 2016 replaced fig 1

Simplified indexes for the seismic assessment of masonry buildings : international database and validation

Heritage masonry buildings are particularly vulnerable to earthquakes because they are deteriorated and damaged, they were built with materials with low resistance, they are heavy and the connections between the various structural components are often insufficient. The present work details a simplified method of seismic assessment of large span masonry structures that was applied to a database of forty-four monuments in Italy, Portugal and Spain, providing lower bound formulas for different simplified geometrical indexes. Subsequently, the proposed thresholds are validated with data from the 2010-2011 Canterbury earthquakes, which includes forty-eight stone and clay brick masonry churches. Finally, fragility curves that can be used to estimate the damage as a function of the peak ground acceleration (PGA) are also provided

Effect of cosmic rays on the resonant gravitational wave detector NAUTILUS at temperature T=1.5 K

The interaction between cosmic rays and the gravitational wave bar detector NAUTILUS is experimentally studied with the aluminum bar at temperature of T=1.5 K. The results are compared with those obtained in the previous runs when the bar was at T=0.14 K. The results of the run at T = 1.5 K are in agreement with the thermo-acoustic model; no large signals at unexpected rate are noticed, unlike the data taken in the run at T = 0.14 K. The observations suggest a larger efficiency in the mechanism of conversion of the particle energy into vibrational mode energy when the aluminum bar is in the superconductive status.Comment: 7 pages, 3 figures, 2 tables. Accepted by Physics Letters

Reinforced brick-masonry light vaults : semi-prefabrication, construction, testing and numerical modeling

This work deals with short to mid span-length light vaults made of reinforced brick-masonry. The research is oriented at proposing semi-prefabrication and construction techniques. Numerical models for predicting the structural behavior of this type of structures are developed. Experimental research is performed with the following three main objectives: (i) validating the proposed construction techniques, (ii) investigating the structural performance, and (iii) calibrating the numerical models. The obtained results show that the proposed techniques are feasible, and that the structural behavior is adequate in terms of ductility and of strength. The structural system can be modeled with the developed numerical tools.This work has received financial support from the Catalonian Government (CIDEM, "CERARMAT" IT - Technological Innovation - project 605) the Spanish Government (Ministry of Industry and Energy, "PRECERAM" ATYCA project M172/1999) and the European Commission ("ISO-BRICK" CRAFT - Cooperative Research - Project G5ST-CT-2001-50095). All these supports are gratefully acknowledged

Study of the coincidences between the gravitational wave detectors EXPLORER and NAUTILUS in 2001

We report the result from a search for bursts of gravitational waves using data collected by the cryogenic resonant detectors EXPLORER and NAUTILUS during the year 2001, for a total measuring time of 90 days. With these data we repeated the coincidence search performed on the 1998 data (which showed a small coincidence excess) applying data analysis algorithms based on known physical characteristics of the detectors. With the 2001 data a new interesting coincidence excess is found when the detectors are favorably oriented with respect to the Galactic Disk

Search for Periodic Gravitational Wave Sources with the Explorer Detector

We have developped a procedure for the search of periodic signals in the data of gravitational wave detectors. We report here the analysis of one year of data from the resonant detector Explorer, searching for pulsars located in the Galactic Center (GC). No signals with amplitude greater than $\bar{h}= 2.9~10^{-24}$, in the range 921.32-921.38 Hz, were observed using data collected over a time period of 95.7 days, for a source located at $\alpha=17.70 \pm 0.01$ hours and $\delta=-29.00 \pm 0.05$ degrees. Our procedure can be extended for any assumed position in the sky and for a more general all-sky search, even with a frequency correction at the source due to the spin-down and Doppler effects.Comment: One zipped file (Latex+eps figures). 33 pages, 14 figures. This and related material also at http://grwav3.roma1.infn.it

Right versus left radial artery access for coronary procedures: an international collaborative systematic review and meta-analysis including 5 randomized trials and 3210 patients

BACKGROUND: Radial artery access is a mainstay in the diagnosis and treatment of coronary artery disease. However, there is uncertainty on the comparison of right versus left radial access for coronary procedures. We thus undertook a systematic review and meta-analysis comparing right versus left radial access for coronary diagnostic and interventional procedures. METHODS: Pertinent studies were searched in CENTRAL, Google Scholar, MEDLINE/PubMed, and Scopus, together with international conference proceedings. Randomized trials comparing right versus left radial (or ulnar) access for coronary diagnostic or interventional procedures were included. Risk ratios (RR) and weighted mean differences (WMD) were computed to generate point estimates (95% confidence intervals). RESULTS: A total of 5 trials (3210 patients) were included. No overall significant differences were found comparing right versus left radial access in terms of procedural time (WMD=0.99 [-0.53; 2.51]min, p=0.20), contrast use (WMD=1.71 [-1.32; 4.74]mL, p=0.27), fluoroscopy time (WMD=-35.79 [-3.54; 75.12]s, p=0.07) or any major complication (RR=2.00 [0.75; 5.31], p=0.49). However, right radial access was fraught with a significantly higher risk of failure leading to cross-over to femoral access (RR=1.65 [1.18; 2.30], p=0.003) in comparison to left radial access. CONCLUSIONS: Right and left radial accesses appear largely similar in their overall procedural and clinical performance during transradial diagnostic or interventional procedures. Nonetheless, left radial access can be recommended especially during the learning curve phase to reduce femoral cross-overs