71 research outputs found
Measurement of the atmospheric muon flux with the NEMO Phase-1 detector
The NEMO Collaboration installed and operated an underwater detector
including prototypes of the critical elements of a possible underwater km3
neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box.
The detector was developed to test some of the main systems of the km3
detector, including the data transmission, the power distribution, the timing
calibration and the acoustic positioning systems as well as to verify the
capabilities of a single tridimensional detection structure to reconstruct muon
tracks. We present results of the analysis of the data collected with the NEMO
Mini-Tower. The position of photomultiplier tubes (PMTs) is determined through
the acoustic position system. Signals detected with PMTs are used to
reconstruct the tracks of atmospheric muons. The angular distribution of
atmospheric muons was measured and results compared with Monte Carlo
simulations.Comment: Astrop. Phys., accepte
Use of electronic devices by people attending vision rehabilitation services in Italy: A study based on the device and aids registry (D.A.Re)
Purpose
To investigate the characteristics of electronic device users, specifically smartphones and tablets, in the Device & Aids Register (D.A.Re), from several low-vision rehabilitation services in Italy.
Methods
We collected general and clinical information about ocular and systemic diseases, visual function, reading speed and Instrumental Activities of Daily Living (IADL) questionnaire score. Technological details of each optical and electronic device, (including screen size, touch-screen and OCR functions, text-to-speech function) were also collected.
Results
1218 patients (752 females and 466 males) were included in our analysis, mean age 71.5 (±18.8) years. Users of electronic aids (n.237) were slightly younger (67 vs 72 years, p < 0.001) than non-users (n.981), had a worse reading speed (38 vs 65 words/minute), critical print size (43 vs 28 print size, p < 0.001), poorer visual acuity (VA)(1.0 logMAR or less: 30% non-users vs 73% users, p < 0.001) and more commonly visual field restriction within 10° (23% vs 14%, p = 0.001). A similar proportion of users and non-users were retired (about 70%) and about 16–17% were employed. The use of portable electronic devices (5″or less, p < 0.001; 6″ to 18″ screen size, p = 0.017) was associated with better IADL scores, and the use of stand devices with worse IADL score (p < 0.001); Furthermore, using smartphones and tablets (193 subjects) was strongly associated with better IADL scores.
Conclusion
We found that using electronic devices, and especially smartphone and tablets, were associated with better vision-related quality of life in low-vision people attending rehabilitation services. While this association does not mean causality, these findings seemed robust to confounder adjustment
Performance of the First ANTARES Detector Line
In this paper we report on the data recorded with the first Antares detector
line. The line was deployed on the 14th of February 2006 and was connected to
the readout two weeks later. Environmental data for one and a half years of
running are shown. Measurements of atmospheric muons from data taken from
selected runs during the first six months of operation are presented.
Performance figures in terms of time residuals and angular resolution are
given. Finally the angular distribution of atmospheric muons is presented and
from this the depth profile of the muon intensity is derived.Comment: 14 pages, 9 figure
Status of NEMO
The activities towards the realization of a km3 Cherenkov neutrino detector carried out by the NEMO Collaboration are described. Long-term exploration of a 3500 m deep-sea site close to the Sicilian coast has shown that it is optimal for the installation of the detector. The realization of a Phase-1 project, which is under way, will validate the proposed technologies for the realization of the km3 detector on a Test Site at 2000 m depth. The realization of a new infrastructure on the candidate site (Phase-2 project) will provide the possibility to test detector components at 3500 m depth
Sensitivity of an underwater Cerenkov km3 telescope to TeV neutrinos from Galactic Microquasars
In this paper are presented the results of Monte Carlo simulations on the
capability of the proposed NEMO-km telescope to detect TeV muon neutrinos
from Galactic microquasars. For each known microquasar we compute the number of
detectable events, together with the atmospheric neutrino and muon background
events. We also discuss the detector sensitivity to neutrino fluxes expected
from known microquasars, optimizing the event selection also to reject the
background; the number of events surviving the event selection are given. The
best candidates are the steady microquasars SS433 and GX339-4 for which we
estimate a sensitivity of about erg/cm s; the predicted
fluxes are expected to be well above this sensitivity. For bursting
microquasars the most interesting candidates are Cygnus X-3, GRO J1655-40 and
XTE J1118+480: their analyses are more complicated because of the stochastic
nature of the bursts.Comment: 20 pages, 3 figures, accepted by Astroparticle Physic
First results of the Instrumentation Line for the deep-sea ANTARES neutrino telescope
In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system. as well as the calibration devices of the detector. The in situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. These results demonstrate that with the full ANTARES neutrino telescope the design angular resolution of better than 0.3 degrees can be realistically achieved
Performance of the front-end electronics of the ANTARES neutrino telescope
ANTARES is a high-energy neutrino telescope installed in the Mediterranean
Sea at a depth of 2475 m. It consists of a three-dimensional array of optical
modules, each containing a large photomultiplier tube. A total of 2700
front-end ASICs named Analogue Ring Samplers (ARS) process the phototube
signals, measure their arrival time, amplitude and shape as well as perform
monitoring and calibration tasks. The ARS chip processes the analogue signals
from the optical modules and converts information into digital data. All the
information is transmitted to shore through further multiplexing electronics
and an optical link. This paper describes the performance of the ARS chip;
results from the functionality and characterization tests in the laboratory are
summarized and the long-term performance in the apparatus is illustrated.Comment: 20 pages, 22 figures, published in Nuclear Instruments and Methods
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