The Universidade Federal de Itajubá , formerly known as the Escola Federal de Engenharia de Itajubá , is an important federal university located in the state of Minas Gerais, Brazil. It was founded on November 23, 1913, as the Instituto Eletrotécnico e Mecânico de Itajubá .On April 16, 1968, its name officially changed to Escola Federal de Engenharia de Itajubá .In 2002, it earned the title of University, and was renamed as Universidade Federal de Itajubá , by the Brazilian Law 10,435, approved by the former president, Fernando Henrique Cardoso. The university is considered to be one of the best universities of Brazil, according to the ranks published by the Ministério da Educação e Cultura - MEC .As been one of the first school of Electrical and Mechanical Engineering, it is publicly recognized for its great quality especially of these two courses. An example of this recognition is that Brazil's Government created the Electrical Engineering Day at November 23.It was elected in 2009 one of the top ten universities in Brazil by two different rankings, occupying the first position in one of them. In the IGC/2011 by MEC , the Itajubá Federal University obtained the grade 5, maximum, being among the best 27 higher-education colleges and among the top 10 universities of the country. In 2010 the University started three new courses: Atmospheric science , Electronic Engineering and Materials Engineering.The university owns and operates its own AM radio station, called Rádio Universitária 1570 kHz ZYL-242, operating in the 1570 kHz band since early 1961. Wikipedia.
Barreiroa L.A.,Claro |
Medina R.,Federal University of Itajuba
Journal of High Energy Physics | Year: 2012
The conventional S-matrix approach to the (tree level) open string low energy effective lagrangian assumes that, in order to obtain all its bosonic α' N order terms, it is necessary to know the open string (tree level) (N+2)-point amplitude of massless bosons, at least expanded at that order in α'. In this work we clarify that the previous claim is indeed valid for the bosonic open string, but for the supersymmetric one the situation is much more better than that: there are constraints in the kinematical bosonic terms of the amplitude (probably due to Spacetime Supersymmetry) such that a much lower open superstring n-point amplitude is needed to find all the α' N order terms. In this 'revisited' S-matrix approach we have checked that, at least up to α' 4 order, using these kinematical constraints and only the known open superstring 4-point amplitude, it is possible to determine all the bosonic terms of the low energy effective lagrangian. The sort of results that we obtain seem to agree completely with the ones achieved by the method of BPS configurations, proposed about ten years ago. By means of the KLT relations, our results can be mapped to the NS-NS sector of the low energy effective lagrangian of the type II string theories implying that there one can also find kinematical constraints in the N-point amplitudes and that important informations can be inferred, at least up to α' 4 order, by only using the (tree level) 4-point amplitude. © SISSA 2012.
Bernui A.,Federal University of Itajuba |
Reboucas M.J.,Brazilian Center for Research in Physics (CBPF)
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012
The detection of the type and level of primordial non-Gaussianity in the CMB data is essential to probe the physics of the early universe. Since one does not expect that a single statistical estimator can be sensitive to all possible forms of non-Gaussianity which may be present in the data, it is important to employ different statistical indicators to study non-Gaussianity of CMB. In recent works we have proposed two new large-angle non-Gaussianity indicators based on skewness and kurtosis of patches of CMB sky sphere, and used them to find significant deviations from Gaussianity in frequency bands and foreground-reduced CMB maps. Simulated CMB maps with assigned type and amplitude of primordial non-Gaussianity are important tools to determine the strength, sensitivity, and limitations of non-Gaussian estimators. Here we investigate whether and to what extent our non-Gaussian indicators have sensitivity to detect non-Gaussianity of local type, particularly with an amplitude within the 7 yr Wilkinson Microwave Anisotropy Probe (WMAP) bounds. We make a systematic study by employing our statistical tools to generate maps of skewness and kurtosis from several thousands of simulated maps equipped with non-Gaussianity of local type of various amplitudes. We show that our indicators can be used to detect large-angle local-type non-Gaussianity only for relatively large values of the nonlinear parameter fNLlocal. Thus, our indicators do not have enough sensitivity to detect deviation from Gaussianity with the nonlinear parameter within the 7 yr WMAP bounds. This result, along with the outcomes of frequency bands and foreground-reduced analyses, suggests that non-Gaussianity captured in the previous works by our indicators is not of primordial origin, although it might have a primordial component. We have also made a comparative study of non-Gaussianity of simulated maps and of the full-sky WMAP 7 yr foreground-reduced internal linear combination (ILC)-7 yr map. An outcome of this analysis is that the level of non-Gaussianity of the ILC-7 yr map is higher than that of the simulated maps for fNLlocal within WMAP bounds. This provides quantitative indications on the suitability of the ILC-7 yr map as Gaussian reconstruction of the full-sky CMB. © 2012 American Physical Society.
Bombard A.J.F.,Federal University of Itajuba |
De Vicente J.,University of Granada
Tribology Letters | Year: 2012
This article is concerned with an investigation of the tribological performance of magnetorheological (MR) fluids in pure sliding soft-elastohydrodynamic lubrication (EHL) steel/polytetrafluoroethylene (PTFE) point contacts. The lubricating properties of MR fluids were measured in thin film, lubricated conditions using a ball-on-three-plates tribometer and compared to base fluids in the form of Stribeck curves. A range of techniques was employed to interpret the possible mechanisms of friction and wear of dispersed iron microparticles. The friction surfaces were investigated using optical microscopy, environmental scanning electron microscopy (ESEM), X-ray photoelectron spectroscopy, and energy-dispersive spectroscopy (EDS). In all cases investigated, the friction coefficient is found to strongly depend on the viscosity of the lubricant oil. In the case of low-viscosity liquids, iron microparticles are entrapped in the contact and plow the PTFE surfaces resulting in a sensibly constant friction coefficient. For intermediate viscosities, friction decreases at low speeds because of the so-called "ball- bearing" effect, and later, friction increases as particles become embedded in the PTFE matrix. Finally, for high-viscosity fluids, iron particles either accumulate around the rubbing zone as a barrier that reduces the supply of oil available to the contact for boundary lubrication or the particles indent PTFE surfaces. © 2012 Springer Science+Business Media, LLC.
Romao E.C.,Federal University of Itajuba |
Mendes De Moura L.F.,University of Campinas
Numerical Heat Transfer; Part A: Applications | Year: 2012
This study addresses how to implement the Galerkin finite element and least square finite element methods using auxiliary equations to solve the partial differential equation numerically, which models the convection-diffusion- reaction, set on a steady 3D domain. In the spatial discretization, hexahedral elements with eight (linear element) and 27 (quadratic element) nodes were used, in which Lagrange interpolation functions were adopted in local coordinates. Turning all the formulation of the problem of global coordinates into local coordinates, the Gauss-Legendre quadrature method was used to integrate coefficients of the element matrices numerically. In addition to the formulation by the two methods, a computer code was implemented to simulate the phenomenon proposed. By using analytical solutions, sundry numerical error analysis was performed from L2 norm (domain-average error) and L∞ norm (domain-top error), thus validating the numerical results. A real case is proposed and assessed. © 2012 Copyright Taylor and Francis Group, LLC.
Leal M.R.L.V.,CTBE - Brazilian Bioethanol Science and Technology Laboratory |
Horta Nogueira L.A.,Federal University of Itajuba |
Cortez L.A.B.,University of Campinas
Applied Energy | Year: 2013
Several key indicators of the sustainability of biofuels are related to the land used to produce the feedstock. Most of the agronomic costs and energy use (fertilizers, herbicides, soil preparation, and harvesting) are more related to the cropped area than to the feedstock quantity produced; this is also the case of soil greenhouse gas (GHG) emissions (CO2 and N2O) and land use change (LUC) impacts, both direct (dLUC) and indirect (iLUC), socio-economic impacts (land tenure, land prices and traditional crop displacement), impacts on biodiversity and on the environment (soil, water and air). Today, biofuels use only a little more than 2% of the world arable land but if their use to displace fossil fuels increases, as indicated by some low carbon scenarios, the land demand for the production of feedstocks could become a constraint to the expansion. It is quite apparent that the biofuel yields, present and future, should be one of the main characteristics to be evaluated in the initial screening process. This work uses the cases of corn and sugarcane ethanol to draw some comparisons on the use of these biofuels to meet the targets of some of the International Energy Agency (IEA) biofuel use scenarios in terms of land demand and also will use some of the most important study results concerning the GHG emission reduction potential, including LUC and iLUC impacts, when meeting the Renewable Energy Directive (RED) of the European Union (EU) and the Renewable Fuel Standard (RFS2) of the USA. Some technology improvements will be considered including the integration of first and second generation technologies in the same site processing corn or sugarcane for ethanol. The results of the simulations indicated that the land demands for the 2030 projected ethanol production in the two alternatives seems not to give reasons for concern on a global scale, but are large enough to produce significant local impacts. The GHG abatement potential is strongly dependent on the biofuel alternative considered. © 2012 Elsevier Ltd.