Vanishing Viscosity Limits and Boundary Layers for Circularly Symmetric 2D Flows

We continue the work of Lopes Filho, Mazzucato and Nussenzveig Lopes [LMN], on the vanishing viscosity limit of circularly symmetric viscous flow in a disk with rotating boundary, shown there to converge to the inviscid limit in $L^2$-norm as long as the prescribed angular velocity $\alpha(t)$ of the boundary has bounded total variation. Here we establish convergence in stronger $L^2$ and $L^p$-Sobolev spaces, allow for more singular angular velocities $\alpha$, and address the issue of analyzing the behavior of the boundary layer. This includes an analysis of concentration of vorticity in the vanishing viscosity limit. We also consider such flows on an annulus, whose two boundary components rotate independently. [LMN] Lopes Filho, M. C., Mazzucato, A. L. and Nussenzveig Lopes, H. J., Vanishing viscosity limit for incompressible flow inside a rotating circle, preprint 2006

Anisotropic Strange Stars in the Spotlight: Unveiling Constraints through Observational Data

Motivated by the recent suggestions that very massive and very light compact objects exist, in this letter we revisit the possibility of such objects being strange stars instead of the standard hadronic neutron stars. We study the possible presence of local anisotropy and how it affects the macroscopic properties of strange stars and compare our results with the recent constraints presented in the literature. We found that the presence of anisotropy increases the maximum mass, the radius of the canonical star, and its tidal deformability for positive values of $\lambda_{\rm BL}$, and the opposite for negative values. We also show that some observational constraints that are in conflict with the theory of standard hadronic neutron stars, can easily be taken into account considering strange stars.Comment: 5 pages, 2 figures, 1 table, comments are welcom

Portuguese term extraction methods: comparing linguistic and statistical approaches.

This paper discuss different extraction methods, linguistic informed and pure statistical, through a comparative analysis using usual metrics: Precision, Recall and F-measure. The experiments were made over a corpus from Pediatrics in portuguese, and the extracted terms were compared with a reference list.Propor 2010

Plant population and spatial arrangement studies in the intercropping of maize and beans in Northeast Brazil.

In Northeast Brazil the peasant farmer use to raise their cropa in mixture, and the intercropping of maise and beans is very frequent.Paper for International Intercropping Workshop at ICRISAT, Hydederabad, India, from jannuary 10 at 13, 1979

Non-parametric comparison of histogrammed two-dimensional data distributions using the Energy Test

When monitoring complex experiments, comparison is often made between regularly acquired histograms of data and reference histograms which represent the ideal state of the equipment. With the larger HEP experiments now ramping up, there is a need for automation of this task since the volume of comparisons could overwhelm human operators. However, the two-dimensional histogram comparison tools available in ROOT have been noted in the past to exhibit shortcomings. We discuss a newer comparison test for two-dimensional histograms, based on the Energy Test of Aslan and Zech, which provides more conclusive discrimination between histograms of data coming from different distributions than methods provided in a recent ROOT release.The Science and Technology Facilities Council, U

Tracking e-learning through published papers: a systematic review

Electronic learning (e-learning) is a broader approach to learning that brings new opportunities for learning and teaching in many fields of education far from the traditional classroom environment. Over the past decades, research in the field indicates a proliferation of e-learning contents and discrepancies that affect interoperability patterns in education for students and teachers; however, little has been done to assess the usability of e-learning systems. From a different perspective, this study aims to provide information on the numerous findings relating to the cumulative results of e-learning in education. This systematic review uses a full protocol with the aim of standardizing and specifying all the procedures adopted to collect and code 99 academic articles from 2010 to 2018 with keywords: education and e-learning. The text analysis as conducted using the qualitative software Leximancer to extract meaning from the large number of articles retrieved. The results highlight four dominant themes, namely education systems and learning issues that in turn promote student behaviours and the use of online learning tools. This research contributes towards providing research propositions that can be used in a cogent theoretical framework and, based on the analysis, we also propose a new definition of e-learning.info:eu-repo/semantics/acceptedVersio

Recent advances in the manipulation of circularly polarised light with cellulose nanocrystal films

This work is funded by FEDER funds through the COMPETE 2020 Program, National Funds through FCT - Portuguese Foundation for Science and Technology and POR Lisboa2020 , under the projects with references POCI- 01-0145-FEDER-007688 (Reference UID/CTM/50025), UID/BIA/00329/2013, PTDC/CTM-BIO/6178/2014, M-ERA-NET2/0007/2016 (CellColor) and PTDC/CTM-REF/30529/2017. S.N. Fernandes and L.F. Lopes acknowledge the Minister of Science, Technology and Higher Education for National Funds , European Social Funds and FCT for fellowships number SFRH/BDP/78430/2011 and SFRH/BPD/84478/2012 , respectively. This work was supported by the Histology and Comparative Pathology laboratory [Electron Microscopy service] of the Instituto de Medicina Molecular João Lobo Antunes, specifically Andreia Pinto for her kind support. We would like to thank Carlos Silva for providing the C. chrysina specimen. The C. aurata specimen observed was provided by the Insect Collection of the National Museum of Natural History and Science, University of LisboSignificant advances have been made to control the iridescence and the selective reflection of left circularly polarised (LCP) light, and transmission of right circularly polarised (RCP) light of solid films prepared from cellulose nanocrystals (CNCs). However the manipulation of the photonic properties of the CNCs films, which reflect both RCP and LCP light is less investigated. Solid films prepare from natural sources as CNCs have advantageous characteristics that are absent in other synthetic structures, such as wide availability and renewability. Here we review and compare recent research activity involving the production and characterization of photonic band gap structures resulting from an anisotropic layer inserted between two cholesteric layers with different helical pitches but the same handedness. We make connections between systems existing in Nature and synthetic ones with the hope of advancing in the production and manipulation of CNCs-based photonic structures.authorsversionpublishe