859 research outputs found
The TIER-2 site for the ARGO-YBJ experiment
No full textThe ARGO-YBJ experiment is taking data at the Yangbajing International Cosmic Ray Observatory located
at an altitude of about 4300 m a.s.l. (Tibet, P.R. China). The detector consists of an EAS array made of a full
coverage RPCs carpet. The experiment is taking data since 2007 in the final configuration, the trigger rate is about
3.5 kHz producing a throughput of data of about 2.5 MB/s. Taking into account the high duty cycle of the experiment,
the amount of raw data collected is about 200 TB/year and the amount of reconstructed data is about 60 TB/year. The
management of this volume of data and the production of a huge amount of Monte Carlo data samples require a suitable
computing power. A TIER-2 site is arranged to face out these tasks. In this paper the structure of the data transfer
method and data reconstruction/analysis based on the TIERs are presented. The hardware infrastructure and software
architecture of the Roma 3 TIER-2 site of the ARGO-YBJ experiment are also discussed
Fatigue strength of spot welded stainless steel components for railway carriages under operational loading conditions
No full text
Regression of cardiac abnormalities after replacement therapy in Addison's disease.
No full textOBJECTIVE: To evaluate by echocardiography the cardiac structure and function in patients with primary adrenocortical insufficiency.
DESIGN AND METHODS: Two-dimensionally guided M-mode echocardiograms and spectral Doppler studies were performed in seven consecutive patients with newly diagnosed autoimmune primary adrenal failure before and 4-8 months after an adequate regimen of steroid substitution. Echocardiographic parameters were also studied in ten healthy controls.
RESULTS: In the cases with untreated Addison's disease, both left ventricular end-systolic and end-diastolic dimensions were significantly reduced in comparison with those in controls (P<0.01). Four patients had echocardiographic signs of mitral valve prolapse (MVP) at the anterior leaflet, with no evidence of mitral regurgitation by Doppler echocardiography. Systolic clicks characteristic of MVP were present on auscultation in two of these cases. Left ventricular chamber size normalized, i.e. significantly increased (P<0.01), and both echocardiographic and physical signs of MVP resolved after steroid substitution in all patients. All other echocardiographic indices were normal before and after treatment.
CONCLUSIONS: Patients with untreated Addison's disease have cardiac abnormalities which regress after steroid substitution. A valvular-ventricular disproportion due to the hypovolemic state could explain these finding
Ground gamma-ray survey of the Solforata gas discharge area, Alban Hills-Italy: A comparison between field and laboratory measurements
No full text"Measurements of environmental radioactivity by HPGe gamma-spectrometry were carried out with the aim of investigating the distribution of natural radionuclides in a volcanic area and to compare two different methodologies an in situ gamma-survey of the area and high accuracy laboratory measurements of soil samples. Results demonstrate good performance of the in situ technique, also confirmed by a correlation analysis between the results obtained by the two methodologies. A volcanic gas discharge area was chosen as the test site for the presence of natural long-lived radionuclides such as K-40 and U-238, U-235 and Th-232, and their decay chain members. Clear evidence of Rn-222 degassing in the area was confirmed by Ra-226 values measured by the in situ technique. Higher K-40 values measured by the in situ technique may be attributed to the presence of vegetation in the study area. (C) 2012 Elsevier Ltd. All rights reserved.
Estimation of Radioactive Release from the Fukushima Dai-ichi Nuclear Power Plant Accident
No full textEstimation of the time-dependent radioactive source-term from the Fukushima nuclear power plant accident using atmospheric transport modelling
No full text""Caesium-137 and Iodine-131 radionuclides released after the Fukushima Dai-ichi nuclear power plant accident in March 2011 were detected at monitoring stations throughout the world. Using the CTBT radionuclide data and the assumption that the Fukushima accident was the only source of these radionuclides, it was possible to estimate their time-dependent source-term fourteen days following the accident by using atmospheric transport modelling. A reasonable agreement was obtained between the modelling results and the estimated radionuclide release rates from the Fukushima accident."
The Front-End electronics for the liquid Argon instrumentation of the LEGEND-200 experiment
No full textIn this paper we provide a detailed technical description of the Front-End
(FE) electronics for the liquid Argon instrumentation of the LEGEND-200
experiment, searching for the very rare, hypothetical neutrinoless double
decay process at the Italian Laboratori Nazionali del Gran Sasso. The
design stems from the need to read out the silicon photo-multiplier response to
the scintillation light in the liquid Argon with excellent single-photon
resolution. The FE electronics is required to be placed far from the detectors
to meet the experiment's radio-purity constraints. This constraint represents a
challenge for a high signal-to-noise ratio. We address how this could be
achieved in a stable way. The system was installed in July 2021 and has been
commissioned with the rest of LEGEND-200, proving we could attain a very low
overall level of electrical noise of 250 V peak-to-peak
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