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Brandao R.R.,Instituto Nacional da Propriedade Industrial | Moriconi L.,Federal University of Rio de Janeiro
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2015

We study the electron/hole transport in puddle-disordered and rough graphene samples which are subject to in-plane magnetic fields. Previous treatments, mostly devoted to regimes where the electron/hole scattering wavelengths are larger than the surface height correlation length, are based on the use of transport equations with appropriate forms for the collision term. We point out in this work, as a counterpoint, that classical Lorentz force effects, which are expected to hold when the Fermi level is far enough away from the charge neutral point, can be heuristically assessed through disordered Boltzmann equations that contain magnetic-field dependent material derivatives, and keep the zero magnetic-field structure of the collision term. It turns out that the electric conductivity tensor gets a peculiar nondiagonal component, induced by the in-plane magnetic field that crosses the rough topography of the graphene sheet, even if the projected random transverse magnetic field vanishes in the mean. Numerical estimates of the transverse conductivities suggest that they are suitable of observation under conditions which are within the reach of up-to-date experimental methods. © 2015 Elsevier B.V. All rights reserved.

Garcia R.I.,Instituto Nacional da Propriedade Industrial | Moura F.J.,Pontifical Catholic University of Rio de Janeiro | Bertolino L.C.,Brazilian National Council for Scientific and Technological Development | De Albuquerque Brocchi E.,Pontifical Catholic University of Rio de Janeiro
Environmental Progress and Sustainable Energy | Year: 2014

There is growing concern regarding the inappropriate disposal of industrial wastes. The impossibility of adequately treating certain wastes and the desire to eliminate any environmental risk has led the industry to apply different techniques to meet these challenges. The use of waste coprocessing in cement furnaces as a substitute for a portion of the fuel can provide energy gains without changing the gas emissions and the quality of the produced clinker. This study aims to describe the effects of a mixture of wastes coprocessed in an industrial rotary kiln on cement properties. The leaching and solubilization tests proved that the analyzed elements presented in the cement are not transferred to the environment. The cement compressive strength tests conducted showed that coprocessed cement achieved the minimum values specified by the Brazilian Standard Association. © 2013 American Institute of Chemical Engineers.

Coelho M.L.V.,Federal University of Rio de Janeiro | Coelho M.L.V.,Instituto Nacional da Propriedade Industrial | Coutinho B.G.,Federal University of Rio de Janeiro | Cabral da Silva Santos O.,Federal University of Rio de Janeiro | And 2 more authors.
Research in Microbiology | Year: 2014

Aureocin A70, which is produced by Staphylococcus aureus A70, is the only four-component bacteriocin described thus far. The genetic determinants responsible for its production are arranged as three transcriptional units encoded by the 7.9-kb plasmid pRJ6. While the transcriptional unit formed by the genes aurABCD encodes the bacteriocin structural peptides, a second divergent gene, aurT, codes for an ABC transporter involved in bacteriocin externalization. The third transcriptional unit is composed of two genes, orfAB, whose functions were hitherto unknown. RT-PCR analysis of orfAB expression revealed that they are arranged as an operon. When orfAB, either with or without the transcriptional terminator found downstream of orfB, was expressed in two different S. aureus strains sensitive to aureocin A70, all strains became immune to this bacteriocin. Cloning of orfB alone, with or without the transcriptional terminator, confirmed orfB participation in immunity, although full immunity was not observed. An increase in immunity was achieved when two copies of orfB were cloned oriented with the exogenous Plac promoter present in the expression vector pT181mcs. orfB (here referred to as aurI) was shown to be responsible for aureocin A70 immunity, but the full immunity phenotype seems to depend on translational coupling involving orfA, which encodes a putative transcriptional regulator, and aurI. © 2013 Institut Pasteur.

Codognoto L.,University Camilo Castelo Branco | Winter E.,Instituto Nacional da Propriedade Industrial | Doretto K.M.,University of Campinas | Monteiro G.B.,University of Campinas | Rath S.,University of Campinas
Microchimica Acta | Year: 2010

Monolayers of 2-mercapto-5-methylbenzimidazole (MMB) were prepared on a polycrystalline gold electrode via a self-assembly process to produce a self-assembled monolayer. The resulting electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy, and applied to the determination of chloramphenicol (CAP) in a pharmaceutical formulation using flow injection analysis along with amperometric detection. The amperometric cell was operated at -0.75 V (vs Ag/AgCl) at a flow rate of 3 mL min -1. The method was applied to the determination of CAP in ophthalmic solutions, and its performance was compared to a previously validated HPLC method. The response to CAP is linear in the range from 0.050 to 1.000 μmol L -1 (r = 0.9990), and the limit of detection is 44 μmol L -1. © Springer-Verlag 2010.

Da Silva G.,Instituto Nacional da Propriedade Industrial | Iha K.,Brazilian Technological Institute of Aeronautics
Journal of Aerospace Technology and Management | Year: 2012

Hypergolic reactions may be useful in civil and military applications. In the area of rocket propulsion, they constitute a potential field due to the reduced weight and complexity of fuel injection systems, allowing yet controlled use of the propulsors. This manuscript aimed at presenting different hypergolic systems and their particularities, comparing them with chemical propulsion systems, which are most commonly employed in rocket motors, for example.

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