3,476 research outputs found
First in-beam studies of a Resistive-Plate WELL gaseous multiplier
We present the results of the first in-beam studies of a medium size
(1010 cm) Resistive-Plate WELL (RPWELL): a single-sided THGEM
coupled to a pad anode through a resistive layer of high bulk resistivity
(10cm). The 6.2~mm thick (excluding readout electronics)
single-stage detector was studied with 150~GeV muons and pions. Signals were
recorded from 11 cm square copper pads with APV25-SRS readout
electronics. The single-element detector was operated in Ne\(5%
) at a gas gain of a few times 10, reaching 99
detection efficiency at average pad multiplicity of 1.2. Operation at
particle fluxes up to 10 Hz/cm resulted in 23 gain drop
leading to 5 efficiency loss. The striking feature was the
discharge-free operation, also in intense pion beams. These results pave the
way towards robust, efficient large-scale detectors for applications requiring
economic solutions at moderate spatial and energy resolutions.Comment: Accepted by JINS
What Has Changed During the COVID-19 Pandemic? - The Effect on an Academic Breast Department in Portugal
Introduction: One year ago, Portugal entered its first lockdown because of the coronavirus disease-2019 (COVID-19) pandemic. The impact of this on delays in cancer diagnosis and treatment is a major concern, which may negatively affect the outcomes of these patients.
Materials and methods: This retrospective, single-center analysis compared the clinical and pathological characteristics of breast cancer (BC) patients referred to a medical oncology first appointment between March 2020 and 2021, with the same period in the previous year.
Results: Strikingly, there was a 40% reduction in the number of BC patients during lockdown. However, there was a statistically significant increase in the proportion of metastatic BC patients admitted for the first time for systemic therapy (13.6% vs. 28.9%, p = 0.003). Additionally, a statistically significant increase in the number of patients with bilateral early BC at diagnosis after March 2020 was found (7.2% vs. 1.9%, p = 0.043).
Conclusion: These findings support international recommendations for an accelerated restoration of BC screening, to reduce incidence of advanced breast cancer at diagnosis and mitigate the expected impact of the COVID-19 pandemic on patients with cancer. Further work is needed to examine in detail the impact of measures to manage the COVID-19 pandemic on breast cancer outcomes.info:eu-repo/semantics/publishedVersio
Linearization of Cohomology-free Vector Fields
We study the cohomological equation for a smooth vector field on a compact
manifold. We show that if the vector field is cohomology free, then it can be
embedded continuously in a linear flow on an Abelian group
OPTIMIZATION TO INCREASE ENERGY EFFICIENCY OF A SIROCCO CENTRIFUGAL FAN USING COMPUTATIONAL FLUID DYNAMICS (CFD)
This paper presents a numerical and experimental study on the aerodynamic performance of Sirocco centrifugal fans seeking an increase in energy efficiency. Numerical simulations are performed by the Finite-Volume Method commercial code ANSYS Fluent. Characteristics such as flow rate at the outlet, consumed power and sound pressure levels emitted by centrifugal fans with the original model of 16 blades and the optimized models of 16 and 14 blades are compared. Numerical calculations are performed by the continuity equation, the Reynolds Averaged Navier- Stokes (RANS) equations and the k-ω SST turbulence model. The quality of the mesh is evaluated for three different mesh densities. Results demonstrate that it was possible to obtain an increase of flow rate up to 22.7%, and reductions in the noise levels without increasing the consumption of the electric motor
Green function approach for scattering quantum walks
In this work a Green function approach for scattering quantum walks is
developed. The exact formula has the form of a sum over paths and always can be
cast into a closed analytic expression for arbitrary topologies and position
dependent quantum amplitudes. By introducing the step and path operators, it is
shown how to extract any information about the system from the Green function.
The method relevant features are demonstrated by discussing in details an
example, a general diamond-shaped graph.Comment: 13 pages, 6 figures, this article was selected by APS for Virtual
Journal of Quantum Information, Vol 11, Iss 11 (2011
Eletroejaculação e caracterÃsticas seminais em caititus (Tayassu tajacu) - resultados parciais.
Resumo 31.006. DisponÃvel também on-line
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