5,103 research outputs found
Esperienze di didattica della fisica in diversi livelli del sistema educativo
The growing interest of people in science events, the projects supported by
the Italian Ministry of Education, University and Research to foster STEM
teaching in different levels of the education system and the introduction of
modern physics in some Italian high schools, contributed to the strengthening
of interaction between schools, universities and research centers. This
interaction realized in dedicated activities characterized by innovative
communication and education strategies.This paper presents the events of
science dissemination organized in the last years by the University of Ferrara
and the National Institute for Nuclear Physics taking into account some case
study differentiated by contents, recipients and education strategies.Comment: The article is written in Italia
Impacto Econômico da Neosporose no Sistema Produtivo de Gado de Corte no Estado de Mato Grosso do Sul.
bitstream/item/109939/1/DOC201.pd
Erosion waves: transverse instabilities and fingering
Two laboratory scale experiments of dry and under-water avalanches of
non-cohesive granular materials are investigated. We trigger solitary waves and
study the conditions under which the front is transversally stable. We show the
existence of a linear instability followed by a coarsening dynamics and finally
the onset of a fingering pattern. Due to the different operating conditions,
both experiments strongly differ by the spatial and time scales involved.
Nevertheless, the quantitative agreement between the stability diagram, the
wavelengths selected and the avalanche morphology reveals a common scenario for
an erosion/deposition process.Comment: 4 pages, 6 figures, submitted to PR
Data from a multidisciplinary poll of 178 expert physicians on the usage of non-vitamin K Oral Anticoagulants in patients with atrial fibrillation and venous thromboembolism
This data article contains data from a multidisciplinary questionnaires filled in by 178 expert physicians on the usage of non-vitamin K Oral Anticoagulants in patients with atrial fibrillation (AF) and for the treatment of patients with venous thromboembolism (VTE). The questionnaire consists of 9 statements of clinical complex AF and VTE cases and informative campaign on antithrombotic therapy for stroke prevention in AF. The data are potentially valuable for the scientific community, showing the doubts of different specialists (Internists, Pneumologists, Geriatricians, Cardiologists and Neurologists) with a large experience in prescribing oral anticoagulation in difficult AF and VTE cases (see full list of participants provided). The data obtained in some particular clinical cases such as CHA2DS2-VASc=1, comorbid coronary artery disease, frailty, advanced age, risk of falling and prior haemorrhagic stroke, can be compared with indications from published guidelines and recommendations for future insight and to be considered as a benchmark for future trials in the area or oral anticoagulation for AF and VTE.The data concerning informative campaign on antithrombotic therapy for stroke prevention showed the expert panel agreement on the inclusion of self monitoring of heart rhythm by pulse taking in subjects older than 64 years of age (81% agreement, item 3); knowledge that the risk of stroke associated with AF is almost twice the risk associated with hypertension (95% agreement, item 4); knowledge that the CHA2DS2-VASc score exerts a higher influence on stroke risk compared to AF duration (92% agreement, item 5); knowledge that stroke prevention in AF with a NOAC is more effective, does not cause any higher bleeding risk, and is equally simple compared to aspirin treatment (91% agreement, item 6).Data on strategies to optimise appropriate prescription of antithrombotic therapy showed agreement on the utility of short television advertisements about the risks of stroke associated with AF (79% agreement, item 8), on a campaign encouraging regular control of cardiac rhythm by pulse taking (77% agreement, item 1), on a campaign reporting the advantages of anticoagulation over no antithrombotic therapy (98% agreement, item 2) or of NOACs over aspirin (96% agreement, item 3) or on the practical use of NOAC (93% agreement, item 6) or on stroke and bleeding risk scores (87% agreement, item 7). See Colonna et al. (2017) [1] for further interpretation and discussion
A collimation system for ELI-NP Gamma Beam System - design and simulation of performance
The purpose of this study was to evaluate the performance and refine the design of the collimation system for the gamma radiation source (GBS) currently being realised at ELI-NP facility. The gamma beam, produced by inverse Compton scattering, will provide a tunable average energy in the range between 0.2 and 20 MeV, an energy bandwidth 0.5% and a flux of about 108 photons/s. As a result of the inverse Compton interaction, the energy of the emitted radiation is related to the emission angle, it is maximum in the backscattering direction and decreases as the angle increase [1,2]. Therefore, the required energy bandwidth can be obtained only by developing a specific collimation system of the gamma beam, i.e. filtering out the radiation emitted at larger angles. The angular acceptance of the collimation for ELI-NP-GBS must be continuously adjustable in a range from about 700 to 60 μrad, to obtain the required parameters in the entire energy range. The solution identified is a stack of adjustable slits, arranged with a relative rotation around the beam axis to obtain an hole with an approximately circular shape. In this contribution, the final collimation design and its performance evaluated by carrying out a series of detailed Geant4 simulations both of the high-energy and the low-energy beamline are presented
Field evidence for the upwind velocity shift at the crest of low dunes
Wind topographically forced by hills and sand dunes accelerates on the upwind
(stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind
regime, however, possesses a subtle effect, reported here for the first time
from field measurements of near-surface wind velocity over a low dune: the wind
velocity close to the surface reaches its maximum upwind of the crest. Our
field-measured data show that this upwind phase shift of velocity with respect
to topography is found to be in quantitative agreement with the prediction of
hydrodynamical linear analysis for turbulent flows with first order closures.
This effect, together with sand transport spatial relaxation, is at the origin
of the mechanisms of dune initiation, instability and growth.Comment: 13 pages, 6 figures. Version accepted for publication in
Boundary-Layer Meteorolog
Invasive and non-invasive analyses for knowledge and conservation of Roman wall paintings of the Villa of the Papyri in Herculaneum
none7noThe Villa of the Papyri is one of the most imposing architectural examples of Herculaneum dated before the eruption occurred on 79 A.D. During the earliest years of the excavation of the site (18th century), the Villa has been explored through a thick network of tunnels dug into the hard bank of tuff rock. Recent excavations went on discontinuously between 1990s and 2008, until the discovery of a room located in the lower floor of the build- ing, showing serious phenomena of colour change of some areas of the painted walls. Some dark green parts of mural paintings after volcanic mud removal became white and powdered, detaching from the plaster.
During the last restoration works a scientific approach became necessary in order to acquire detailed information about the wall painting technique and the degradation phenomena occurring in some decorative elements in the vault of the Basis Villa (a room in the lower floor of the building); it was established to perform a scientific recognition.
Integrated investigations – carried out by optical microscopy, scanning electron microscopy with X-ray microanalysis (EDS), X-ray diffractometry (XRD), ion chromatography (IC), FT-IR spectroscopy, gas chromatog- raphy mass spectrometry (GC-MS) – had primarily the goal to characterize the materials used for the realization of the these impressive wall paintings, as well as to assess their state of conservation.
A second aim of the research was to test the reliability of non-invasive analyses that are sometimes performed in situ to study mural paintings, like reflectance spectrometry in the visible range (vis-RS), X-ray fluorescence (ED-XRF) and micro-Raman spectroscopy, as well as imaging analyses like false colour IR (IRC) and visible induced IR luminescence (VIL).
The whole set of analyses allowed to identify a typical Vitruvian plaster with the following pigments: Egyptian blue, red and yellow ochre, goethite and hematite particles, green earth and carbon black particles.
The high content of soluble salts, which is related to the sulphur-rich water in the site located few metres above water level in the walls and floors, caused a worsening in the state of conservation of mural paintings.openM. L. Amadori; P. Baraldi; S. Barcelli; G. Poldi; F. Ferrucci; A. Andreotti; M.P. ColombiniAmadori, MARIA LETIZIA; P., Baraldi; S., Barcelli; G., Poldi; Ferrucci, Fabiano; A., Andreotti; M. P., Colombin
Quantification of HIV-RNA from dried blood spots using the Siemens VERSANT(R) HIV-1 RNA (kPCR) assay
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