254 research outputs found
Stabilized least squares finite element method for 2D and 3D convection-diffusion
In this study, a computational code has been developed based into Finite Elements Method in the version of LSFEM (Least Squares Finite Element Method). The numeric development of this method has as a main advantage, the obtaining of an always symmetrical and defined positive algebraic system, independently of the considered partial-differential equation system. The computational code was applied in the solution of two-dimensional and three-dimensional convection-diffusion problems, through domain discretization of structured meshes of quadratic elements. Obtained numerical results showed a good concordance with available results, showing the developed model validity9455
NUMERICAL SIMULATION OF INCOMPRESSIBLE FLOWS BY THE STABILIZED FINITE ELEMENT METHOD
The fast progress has been observed in the development of numerical and analytical techniques for solving convection-diffusion and fluid mechanics problems. Here, a numerical approach, based in Galerkin Finite Element Method with Finite Difference Method is presented for the solution of a class of non-linear transient convection-diffusion problems. Using the analytical solutions and the L2 and L∞ error norms, some applications is carried and valuated with the literature
Proposta de um modelo de maturidade para Gestão do Conhecimento: KM3
A implementação da Gestão do Conhecimento (GC) ocorre em estágios, ou seja, é um processo que demanda mudanças na organização. O objetivo principal desta pesquisa é desenvolver um modelo de maturidade de gestão do conhecimento. Esta pesquisa adotou os princípios da Teoria do Ciclo de Vida. A pesquisa é qualitativa de caráter exploratório. Inicialmente, a partir da análise dos modelos de GC existentes foi desenvolvida uma proposta de Modelo de Maturidade para Gestão do Conhecimento, denominado KM3. Na sequência, esta proposta foi analisada por profissionais. Estes confirmaram os estágios do modelo de maturidade de GC e contribuíram para o refinamento dos fatores alocados em cada estágio. O KM3 é formado por cinco estágios: Falta de Consciência (2 fatores), Planejamento (15 fatores), Iniciação (20 fatores), Desenvolvimento (24 fatores) e Integração (24 fatores)
Neutrino Masses and Mixings from Supersymmetry with Bilinear R--Parity Violation: A Theory for Solar and Atmospheric Neutrino Oscillations
The simplest unified extension of the MSSM with bi-linear R--Parity violation
naturally predicts a hierarchical neutrino mass spectrum, in which one neutrino
acquires mass by mixing with neutralinos, while the other two get mass
radiatively. We have performed a full one-loop calculation of the
neutralino-neutrino mass matrix in the bi-linear \rp MSSM, taking special care
to achieve a manifestly gauge invariant calculation. Moreover we have performed
the renormalization of the heaviest neutrino, needed in order to get meaningful
results. The atmospheric mass scale and maximal mixing angle arise from
tree-level physics, while solar neutrino scale and oscillations follow from
calculable one-loop corrections. If universal supergravity assumptions are made
on the soft-supersymmetry breaking terms then the atmospheric scale is
calculable as a function of a single \rp violating parameter by the
renormalization group evolution due to the non-zero bottom quark Yukawa
coupling. The solar neutrino problem must be accounted for by the small mixing
angle (SMA) MSW solution. If these assumptions are relaxed then one can
implement large mixing angle solutions, either MSW or just-so. The theory
predicts the lightest supersymmetic particle (LSP) decay to be observable at
high-energy colliders, despite the smallness of neutrino masses indicated by
experiment. This provides an independent way to test this solution of the
atmospheric and solar neutrino anomalies.Comment: 46 pages, references added + several misprints correcte
The amino acids motif-32GSSYN36-in the catalytic domain of E. coli flavorubredoxin NO reductase is essential for its activity
Funding Information: Funding: This study was financially supported by the Portuguese Fundação para a Ciência e Tec-nologia (FCT), grants PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020, and Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020. This project has also received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement 810856. MCM is the recipient of FCT grant SFRH/BD/143651/2019. BAS is the recipient of FCT grant DFA/BD/8066/2020. Funding Information: This study was financially supported by the Portuguese Funda??o para a Ci?ncia e Tecnologia (FCT), grants PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020, and Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020. This project has also received funding from the European Union?s Horizon 2020 research and innovation program under grant agreement 810856. MCM is the recipient of FCT grant SFRH/BD/143651/2019. BAS is the recipient of FCT grant DFA/BD/8066/2020. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Flavodiiron proteins (FDPs) are a family of modular and soluble enzymes endowed with nitric oxide and/or oxygen reductase activities, producing N2O or H2O, respectively. The FDP from Escherichia coli, which, apart from the two core domains, possesses a rubredoxin-like domain at the C-terminus (therefore named flavorubredoxin (FlRd)), is a bona fide NO reductase, exhibiting O2 reducing activity that is approximately ten times lower than that for NO. Among the flavorubredoxins, there is a strictly conserved amino acids motif,-G[S,T]SYN-, close to the catalytic diiron center. To assess its role in FlRd’s activity, we designed several site-directed mutants, replacing the conserved residues with hydrophobic or anionic ones. The mutants, which maintained the general characteristics of the wild type enzyme, including cofactor content and integrity of the diiron center, revealed a decrease of their oxygen reductase activity, while the NO reductase activity—specifically, its physiological function—was almost completely abolished in some of the mutants. Molecular modeling of the mutant proteins pointed to subtle changes in the predicted structures that resulted in the reduction of the hydration of the regions around the conserved residues, as well as in the elimination of hydrogen bonds, which may affect proton transfer and/or product release.publishe
A Supersymmetric Solution to the Solar and Atmospheric Neutrino Problems
The simplest unified extension of the Minimal Supersymmetric Standard Model
with bi-linear R--Parity violation provides a predictive scheme for neutrino
masses which can account for the observed atmospheric and solar neutrino
anomalies in terms of bi-maximal neutrino mixing. The maximality of the
atmospheric mixing angle arises dynamically, by minimizing the scalar
potential, while the solar neutrino problem can be accounted for either by
large or by small mixing oscillations. One neutrino picks up mass by mixing
with neutralinos, while the degeneracy and masslessness of the other two is
lifted only by loop corrections. Despite the smallness of neutrino masses
R-parity violation is observable at present and future high-energy colliders,
providing an unambiguous cross-check of the model.Comment: 5 pages, final version published in Phys. Rev. D61, 2000, 071703(R
Spontaneous R-Parity violation bounds
We investigate bounds from tree-level and one-loop processes in generic
supersymmetric models with spontaneous R-parity breaking in the superpotential.
We analyse the bounds from a general point of view. The bounds are applicable
both for all models with spontaneous R-parity violation and for explicit
bilinear R-parity violation based on general lepton-chargino and
neutrino-neutralino mixings. We find constraints from semileptonic B, D and K
decays, leptonic decays of the mu and tau, electric dipole moments, as well as
bounds for the anomalous magnetic moment of the muon.Comment: 22 page
Prediction of total acid number in distillation cuts of crude oil by ESI(-) FT-ICR MS coupled with chemometric tools
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCompetitive adaptive reweighted sampling-partial least squares (CARS-PLS) and negative-ion mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI(-) FT-ICR MS) data were adopted to assess the total acid number (TAN)28918221829FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESSEM INFORMAÇÃOSEM INFORMAÇÃOSEM INFORMAÇÃOThis research was generously funded by PETROBRAS/CENPES, FAPESP, CNPq, CAPES, and FINE
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