17,011 research outputs found
Serendipity Face and Edge VEM Spaces
We extend the basic idea of Serendipity Virtual Elements from the previous
case (by the same authors) of nodal (-conforming) elements, to a more
general framework. Then we apply the general strategy to the case of
and conforming Virtual Element Methods, in two and three dimensions
Serendipity Nodal VEM spaces
We introduce a new variant of Nodal Virtual Element spaces that mimics the
"Serendipity Finite Element Methods" (whose most popular example is the 8-node
quadrilateral) and allows to reduce (often in a significant way) the number of
internal degrees of freedom. When applied to the faces of a three-dimensional
decomposition, this allows a reduction in the number of face degrees of
freedom: an improvement that cannot be achieved by a simple static
condensation. On triangular and tetrahedral decompositions the new elements
(contrary to the original VEMs) reduce exactly to the classical Lagrange FEM.
On quadrilaterals and hexahedra the new elements are quite similar (and have
the same amount of degrees of freedom) to the Serendipity Finite Elements, but
are much more robust with respect to element distortions. On more general
polytopes the Serendipity VEMs are the natural (and simple) generalization of
the simplicial case
Lowest order Virtual Element approximation of magnetostatic problems
We give here a simplified presentation of the lowest order Serendipity
Virtual Element method, and show its use for the numerical solution of linear
magneto-static problems in three dimensions. The method can be applied to very
general decompositions of the computational domain (as is natural for Virtual
Element Methods) and uses as unknowns the (constant) tangential component of
the magnetic field on each edge, and the vertex values of the
Lagrange multiplier (used to enforce the solenoidality of the magnetic
induction ). In this respect the method can be seen
as the natural generalization of the lowest order Edge Finite Element Method
(the so-called "first kind N\'ed\'elec" elements) to polyhedra of almost
arbitrary shape, and as we show on some numerical examples it exhibits very
good accuracy (for being a lowest order element) and excellent robustness with
respect to distortions
Drying kinetics and physico-chemical quality of mango slices
Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumer’s sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative process and extending the shelf-life. This study investigates the effect of dehydration at different temperatures (50, 60 and 70°C) on drying kinetics and volatile compounds of two cultivars (Keitt and Osteen) of mango fruits cultivated in Sicily. Significant losses of volatile constituents of fresh mango occurred at higher temperature, especially for the Osteen cultivar. A diffusion model including the effect of shrinkage is also proposed, which may be used to describe drying behaviour of fruits and to define the optimal drying conditions.. Experimental data of the moisture ratio during drying were well predicted by the model
Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors
Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy
physics (HEP) as high precision positioning and re-positioning sensors and as
low cost, easy to mount, radiation hard and low space- consuming temperature
and humidity devices. FBGs are also commonly used for very precise strain
measurements. In this work we present a novel use of FBGs as flatness and
mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM)
foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at
Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to
determine the optimal mechanical tension applied and to characterize the
mechanical stress applied to the foils. The preliminary results of the test
performed on a full size GE1/1 final prototype and possible future developments
will be discussed.Comment: Four pages, seven figures. Presented by Michele Caponero at IWASI
2015, Gallipoli (Italy
Eco-friendly gas mixtures for Resistive Plate Chambers based on Tetrafluoropropene and Helium
Due to the recent restrictions deriving from the application of the Kyoto
protocol, the main components of the gas mixtures presently used in the
Resistive Plate Chambers systems of the LHC experiments will be most probably
phased out of production in the coming years. Identifying possible replacements
with the adequate characteristics requires an intense R&D, which was recently
started, also in collaborations across the various experiments. Possible
candidates have been proposed and are thoroughly investigated. Some tests on
one of the most promising candidate - HFO-1234ze, an allotropic form of
tetrafluoropropane- have already been reported. Here an innovative approach,
based on the use of Helium, to solve the problems related to the too elevate
operating voltage of HFO-1234ze based gas mixtures, is discussed and the
relative first results are shown.Comment: 9 pages, 6 figures, 1 tabl
Can the plasma PD-1 levels predict the presence and efficiency of tumor-infiltrating lymphocytes in patients with metastatic melanoma?
Background: The immune response in melanoma patients is locally affected by presence of tumor-infiltrating lymphocytes (TILs), generally divided into brisk, nonbrisk, and absent. Several studies have shown that a greater presence of TILs, especially brisk, in primary melanoma is associated with a better prognosis and higher survival rate. Patients and Methods: We investigated by enzyme-linked immunosorbent assay (ELISA) the correlation between PD-1 levels in plasma and the presence/absence of TILs in 28 patients with metastatic melanoma. Results: Low plasma PD-1 levels were correlated with brisk TILs in primary melanoma, whereas intermediate values correlated with the nonbrisk TILs, and high PD-1 levels with absent TILs. Although the low number of samples did not allow us to obtain a statistically significant correlation between the plasma PD-1 levels and the patients' overall survival depending on the absence/presence of TILs, the median survival of patients having brisk type TILs was 5 months higher than that of patients with absent and nonbrisk TILs. Conclusions: This work highlights the ability of measuring the plasma PD-1 levels in order to predict the prognosis of patients with untreated metastatic melanoma without a BRAF mutation at the time of diagnosis
Do private health providers help achieve Universal Health Coverage? A scoping review of the evidence from low-income countries.
Universal Health Coverage (UHC) is the dominant paradigm in health systems research, positing that everyone should have access to a range of affordable health services. Although private providers are an integral part of world health systems, their contribution to achieving UHC is unclear, particularly in low-income countries (LICs). We scoped the literature to map out the evidence on private providers' contribution to UHC progress in LICs. Literature searches of PubMed, Scopus and Web of Science were conducted in 2022. A total of 1049 documents published between 2002 and 2022 were screened for eligibility using predefined inclusion criteria, focusing on formal as well as informal private health sectors in 27 LICs. Primary qualitative, quantitative and mixed-methods evidence was included, as well as original analysis of secondary data. The Joanna Briggs Institute's critical appraisal tool was used to assess the quality of the studies. Relevant evidence was extracted and analysed using an adapted UHC framework. We identified 34 papers documenting how most basic health care services are already provided through the private sector in countries such as Uganda, Afghanistan and Somalia. A substantial proportion of primary care, mother, child and malaria services are available through non-public providers across all 27 LICs. Evidence exists that while formal private providers mostly operate in well-served urban settings, informal and not-for-profit ones cater for underserved rural and urban areas. Nonetheless, there is evidence that the quality of the services by informal providers is suboptimal. A few studies suggested that the private sector fails to advance financial protection against ill-health, as costs are higher than in public facilities and services are paid out of pocket. We conclude that despite their shortcomings, working with informal private providers to increase quality and financing of their services may be key to realizing UHC in LICs
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