2,151 research outputs found
Numerical study of a banded precipitation event over Italy
Satellite images of 30 October 2008 show the development
over north-central Italy of rainbands and multiple
waves during a strong south-westerly wind episode
associated with a deepening synoptic trough and
cold front passage.
The event was studied by means of the ISAC model chain constituted
of the hydrostatic model BOLAM and the nested non-hydrostatic model
MOLOCH at 1.1 km resolution.
Diagnostics of model output was performed to reveal the
physical origin of the dynamical features and precipitation
field as simulated.
Based on our results we propose a theoretical framework in
which symmetric instability underlies some of the observed
precipitation patterns
Numerical study of a banded precipitation event over Italy
Satellite images of 30 October 2008 show the development
over north-central Italy of rainbands and multiple
waves during a strong south-westerly wind episode
associated with a deepening synoptic trough and
cold front passage.
The event was studied by means of the ISAC model chain constituted
of the hydrostatic model BOLAM and the nested non-hydrostatic model
MOLOCH at 1.1 km resolution.
Diagnostics of model output was performed to reveal the
physical origin of the dynamical features and precipitation
field as simulated.
Based on our results we propose a theoretical framework in
which symmetric instability underlies some of the observed
precipitation patterns
Case Report: Coexistence of SUNCT and Hypnic Headache in the Same Patient
Background: Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and hypnic headache (HH) are two exceedingly rare and distinctly classified primary headaches. The hypothalamus seems to be a crucial region involved in the pathophysiology of both conditions, but no cases of SUNCT and HH co-occurrence have been described so far. Case results: A 49-year-old woman who has been suffering from SUNCT for years, with alternation of symptomatic periods and remissions, developed a new headache with different clinical features, presenting exclusively during sleep and with a dramatic responsiveness to caffeine, that met the diagnostic criteria for HH. Conclusions: The available literature suggests that SUNCT and HH are different conditions but the association in the same patient that we describe supports the concept that they are not mutually exclusive. Further studies are needed to establish if they share a common pathophysiological mechanism
Raman excitation spectroscopy of carbon nanotubes: effects of pressure medium and pressure
Raman excitation and emission spectra for the radial breathing mode (RBM) are
reported, together with a preliminary analysis. From the position of the peaks
on the two-dimensional plot of excitation resonance energy against Raman shift,
the chiral indices (m, n) for each peak are identified. Peaks shift from their
positions in air when different pressure media are added - water, hexane,
sulphuric acid - and when the nanotubes are unbundled in water with surfactant
and sonication. The shift is about 2 - 3 cm-1 in RBM frequency, but
unexpectedly large in resonance energy, being spread over up to 100meV for a
given peak. This contrasts with the effect of pressure. The shift of the peaks
of semiconducting nanotubes in water under pressure is orthogonal to the shift
from air to water. This permits the separation of the effects of the pressure
medium and the pressure, and will enable the true pressure coefficients of the
RBM and the other Raman peaks for each (m, n) to be established unambiguously.Comment: 6 pages, 3 Figures, Proceedings of EHPRG 2011 (Paris
The CloudSME Simulation Platform and its Applications: A Generic Multi-cloud Platform for Developing and Executing Commercial Cloud-based Simulations
Simulation is used in industry to study a large variety of problems ranging from increasing the productivity of a manufacturing system to optimizing the design of a wind turbine. However, some simulation models can be computationally demanding and some simulation projects require time consuming experimentation. High performance computing infrastructures such as clusters can be used to speed up the execution of large models or multiple experiments but at a cost that is often too much for Small and Medium-sized Enterprises (SMEs). Cloud computing presents an attractive, lower cost alternative. However, developing a cloud-based simulation application can again be costly for an SME due to training and development needs, especially if software vendors need to use resources of different heterogeneous clouds to avoid being locked-in to one particular cloud provider. In an attempt to reduce the cost of development of commercial cloud-based simulations, the CloudSME Simulation Platform (CSSP) has been developed as a generic approach that combines an AppCenter with the workflow of the WS-PGRADE/gUSE science gateway framework and the multi-cloud-based capabilities of the CloudBroker Platform. The paper presents the CSSP and two representative case studies from distinctly different areas that illustrate how commercial multi-cloud-based simulations can be created
Secondary forest succession in the Mata Atlantica, Brazil: floristic and phytosociological trends.
This study aimed at understanding the dynamics of ecological processes and the use of secondary forests in Santa Catarina state (Brazil). The data base for these studies was formed through forest inventories carried out in the three forest types of the state. The results of this study demonstrate that the patterns of diversity are very similar among the three forest types; however, the species compositions among the types are quite different. A total of 343 woody species belonging to 73 families were found in the 24,000 m2 sampling area, revealing the potential role of secondary forest in the conservation of biodiversity at the landscape scale. As expected, a small set of pioneer species dominates young secondary forests with shade-tolerant species becoming structurally important after 30 years. The patterns of forest structure and species diversity observed in study largely conform to the postagricultural secondary succession observed for many tropical forests.Article ID 759893
Enabling Cloud-based Computational Fluid Dynamics with a Platform-as-a-Service Solution
Computational Fluid Dynamics (CFD) is widely used in manufacturing and engineering from product design to testing. CFD requires intensive computational power and typically needs high performance computing to reduce potentially long experimentation times. Dedicated high performance computing systems are often expensive for small-to-medium enterprises (SMEs). Cloud computing claims to enable low cost access to high performance computing without the need for capital investment. The CloudSME Simulation Platform aims to provide
a flexible and easy to use cloud-based Platform-as-a-Service
(PaaS) technology that can enable SMEs to realize the benefits of high performance computing. Our Platform incorporates workflow management and multi-cloud implementation across various cloud resources. Here we present the components of our technology and experiences in using it to create a cloud-based version of the TransAT CFD software. Three case studies favourably compare the performance of a local cluster and two different clouds and demonstrate the viability of our cloud-based approach
Eta photoproduction on the neutron at GRAAL: Measurement of the differential cross section
In this contribution, we will present our first preliminary measurement of
the differential cross section for the reaction gamma+n->eta+n. Comparison of
the reactions gamma+p->eta+p for free and bound proton (D2 target) will also be
discussed.Comment: 6 pages, 4 figures, Proceedings of the 10th International Symposium
on Meson-Nucleon Physics and the Structure of the Nucleon, August
29-September 4 2004, Beijing, Chin
Echocardiographic screening in pediatric asymptomatic or paucisymptomatic coronavirus disease 2019 outpatients: Is it a useful test or an excess of zeal?
IntroductionData regarding echocardiographic findings during follow-up of asymptomatic or pauci-symptomatic coronavirus disease 2019 (COVID-19) are scarce in pediatric patients. The aim of the present study is to assess post-COVID-19 sequelae through echocardiography in children who have experienced mild SARS-CoV-2.MethodsThis single-center, retrospective, observational study enrolled a cohort of 133 pediatric outpatients, born between 2005 and 2022, with a history of asymptomatic or paucisymptomatic SARS-CoV-2 infection, who underwent transthoracic echocardiographic (TTE) evaluation at an outpatient pediatric clinic in Northern Italy.ResultsThe percentage of the pediatric activity of the clinic which was focused on post-COVID evaluation was not negligible, representing almost 10% of the similar to 1500 pediatric patients examined from 1 January 2021 to 31 August 2022. According to ACEP classification, children enrolled in this study had previously experienced in 72.9% (97) asymptomatic COVID-19 and nearly 27% (36) a mild illness. Clinical and instrumental examinations did not show any relevant abnormality in the functional [left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PASP)] or structural [interventricular septum diameter (IVSd), left ventricular internal diameter (LViD, end-diastolic volume (EDV), left atrium volume (LAV)] parameters examined related to SARS-CoV-2 infection in the total of 133 children.ConclusionAccording to our results, children who experienced an asymptomatic or mild SARS-CoV-2 infection should not be systematically investigated with second-level techniques, such as TTE, in the absence of clinical suspicion or other risk conditions such as congenital heart diseases, comorbidities or risk factors
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