756 research outputs found
La ricerca delle onde gravitazionali
We summarize the features of the gravitational waves in the
framework of the General Relativity theory and report the principles of operation and the present status of resonant g.w. antennas. We describe the instrumentation and a typical performance of one of the two Rome group cryogenic detectors
CLIC Muon Sweeper Design
There are several background sources which may affect the analysis of data
and detector performans at the CLIC project. One of the important background
source is halo muons, which are generated along the beam delivery system (BDS),
for the detector performance. In order to reduce muon background, magnetized
muon sweepers have been used as a shielding material that is already described
in a previous study for CLIC [1]. The realistic muon sweeper has been designed
with OPERA. The design parameters of muon sweeper have also been used to
estimate muon background reduction with BDSIM Monte Carlo simulation code [2,
3].Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS15), Whistler, Canada, 2-6 November 2015, 7 pages, 6 figure
Studying the coincidence excess between EXPLORER and NAUTILUS during 1998
The coincidences between EXPLORER and NAUTILUS during 1998 (Astone et al.
2001) are more deeply studied. It is found that the coincidence excess is
greater in the ten-day period 7-17 September 1998 and it occurs at the sidereal
hour 4, when the detectors axes are perpendicular to the Galactic Disk. The
purpose of this paper is to bring our results with the GW detectors to the
attention of scientists working in the astrophysical field, and ask them
whether are they aware of any special phenomenon occurring when EXPLORER and
NAUTILUS showed a coincidence excess.Comment: 5 pages, 7 figures, submitted to A &
Use of CR100 scale for session-RPE in soccer and interchangeability with CR10
©2016 Human Kinetics,Inc. Purpose: To examine the construct validity of the session rating perceived exertion (s-RPE) assessed with the Borg CR100® scale to measure training loads in elite soccer and to examine if the CR100® is interchangeable and can provide more accurate ratings compared to the CR10® scale. Methods: Two studies were conducted. The validity of the CR100® was determined in 19-elite soccer players (age 28 ± 6 y, height 180 ± 7 cm, body mass 77 ± 6 kg) during training sessions through correlations with Edwards heart rate method (study one). The interchangeability with CR10® was assessed in 78 soccer players (age 19.3 ± 4.1 y, height 178 ± 5.9 cm, body mass 71.4 ± 6.1 kg) through Bland?Altman method and correlations between change scores in different sessions. To examine whether the CR100® is more fine graded than the CR10®, the proportion of responses corresponding to the verbal expressions were calculated (study two). Results: Individual correlations between Edwards' and s-RPE were large to very large (0.52 to 0.85). The mean difference between the two scales was -0.3 ± 0.33 AU (90% CI -0.41 to -0.29 AU) with 95% limits of agreements 0.31 to -0.96 AU. Correlations between scales and between changes scores were nearly perfect (0.95 and 0.91 to 0.98). Ratings corresponding to the verbal anchors were 49% in CR10® and 26% in CR100®. Conclusions: The CR100® is valid for assessing the training load in elite soccer players. It can be used interchangeably with the CR10® and may provide more precise measures of exercise intensity
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
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 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
Integração de dados em SIG - geológicos e sensoriamento remoto na caracterização da IG Farroupilha para vinhos de qualidade, RS, Brasil.
Este trabalho visou elaborar uma base geológica da IG Farroupilha, a fim de contribuir com a delimitação da mesma, integrando e processando os dados num sistema de informações geográficas
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 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 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
Remote ischaemic preconditioning in coronary artery bypass surgery: a meta-analysis
Aim Randomised trials exploring remote ischaemic preconditioning (RIPC) in patients undergoing coronary artery bypass graft (CABG) surgery have yielded conflicting data regarding potential cardiovascular and renal protection, and are individually flawed by small sample size.
Methods Three investigators independently searched the MEDLINE, EMBASE and Cochrane databases to identify randomised trials testing RIPC in patients undergoing CABG.
Results Nine studies with 704 patients were included. Standardised mean difference of troponin I and T release showed a significant decrease ( 120.36 (95% CI 120.62 to 120.09)). This difference held true after excluding the trials with cross-clamp fibrillation, the study with off-pump CABG and studies using a flurane as anaesthetic agent ( 120.41 (95% CI 120.69 to 120.12), 120.38 (95% CI 120.70 to 120.07) and 120.37 (95% CI 120.63 to 120.12), respectively). A similar trend was also obtained for patients with multivessel disease ( 120.41 (95% CI 120.73 to 120.08)). The trials evaluating postoperative creatinine reported a non-significant reduction (0.02 (95% CI 120.09 to 0.13)). Moreover, the length of in-hospital stay was not influenced by the kind of treatment (weighted mean difference 0.27 (95% CI 120.24 to 0.79)).
Conclusion RIPC reduced the release of troponin in patients undergoing CABG. Larger randomised trials are needed to clarify the presence of a causal relationship between RIPC-induced troponin release and clinical adverse events
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