392 research outputs found

    The GALATEA Test-Facility for High Purity Germanium Detectors

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    GALATEA is a test facility designed to investigate bulk and surface effects in high purity germanium detectors. A vacuum tank houses an infrared screened volume with a cooled detector inside. A system of three stages allows an almost complete scan of the detector. The main feature of GALATEA is that there is no material between source and detector. This allows the usage of alpha and beta sources as well as of a laser beam to study surface effects. A 19-fold segmented true-coaxial germanium detector was used for commissioning

    The EEE Project

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    The new experiment ``Extreme Energy Events'' (EEE) to detect extensive air showers through muon detection is starting in Italy. The use of particle detectors based on Multigap Resistive Plate Chambers (MRPC) will allow to determine with a very high accuracy the direction of the axis of cosmic ray showers initiated by primaries of ultra-high energy, together with a high temporal resolution. The installation of many of such 'telescopes' in numerous High Schools scattered all over the Italian territory will also allow to investigate coincidences between multiple primaries producing distant showers. Here we present the experimental apparatus and its tasks.Comment: 4 pages, 29th ICRC 2005, Pune, Indi

    Combined effects of compost and medicago sativa in recovery a PCB contaminated soil

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    The effectiveness of adding compost and the plant Medicago sativa in improving the quality of a soil historically contaminated by polychlorinated biphenyls (PCBs) was tested in greenhouse microcosms. Plant pots, containing soil samples from an area contaminated by PCBs, were treated with the compost and the plant, separately or together. Moreover, un-treated and un-planted microcosms were used as controls. At fixed times (1, 133 and 224 days), PCBs were analysed and the structure (cell abundance, phylogenetic characterization) and functioning (cell viability, dehydrogenase activity) of the natural microbial community were also measured. The results showed the effectiveness of the compost and plant in increasing the microbial activity, cell viability, and bacteria/fungi ratio, and in decreasing the amount of higher-chlorinated PCBs. Moreover, a higher number of ff-Proteobacteria, one of the main bacterial groups involved in the degradation of PCBs, was found in the compost and plant co-presence

    Prevalence and clinical significance of acquired left coronary artery fistulas after surgical myectomy in patients with hypertrophic cardiomyopathy

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    ObjectivesThe relevance of iatrogenic left coronary artery fistulas complicating surgical myectomy in patients with hypertrophic cardiomyopathy is not known. We prospectively defined the echocardiographic features, prevalence, and clinical significance of left coronary artery fistulas in 40 consecutive patients with hypertrophic cardiomyopathy undergoing extended septal myectomy.MethodsEchocardiographic analysis was performed preoperatively and 1 and 6 months after surgical intervention. Diagnosis of left coronary artery fistulas required evidence of diastolic flow draining from the left ventricular wall into the left ventricular cavity according to prespecified criteria.ResultsLeft coronary artery fistulas were detected in 9 (23%) of the 40 study patients as a single occurrence in all except 1 patient, who had multiple fistulas. At 6 months, left coronary artery fistulas could still be detected in only 2 of the 9 patients. Of these, 1 patient remained asymptomatic but continued to show left coronary artery fistula persistence at 37 months postoperatively. The other, a woman with prior alcohol septal ablation, had progressive severe symptoms that required percutaneous closure of the fistula with a covered stent after angiographic identification of a large first septal branch fistula associated with distal left anterior descending coronary artery steal.ConclusionsIn patients with hypertrophic cardiomyopathy, left coronary artery fistulas are common in the early period after surgical myectomy, although their echocardiographic prevalence is dependent on operator awareness. Most left coronary artery fistulas heal spontaneously. Occasionally, however, fistulas can persist and cause symptoms requiring therapeutic intervention

    Study of the effect of neutrino oscillation on the supernova neutrino signal with the LVD detector

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    We present an update of our previous study (astro-ph/0112312) on how ν\nu oscillations affect the signal from a supernova core collapse observed in the LVD detector at LNGS. In this paper we use a recent, more precise determination of the cross section (astro-ph/0302055) to calculate the expected number of inverse beta decay events, we introduce in the simulation also the ν\nu-{\rm Fe} interactions, we include the Earth matter effects and, finally, we study also the inverted mass hierarchy case.Comment: 4 pages, 4 figures, to appear in the Proceedings of ICRC 200
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