Symplectic Quantization of Open Strings and Noncommutativity in Branes

We show how to translate boundary conditions into constraints in the symplectic quantization method by an appropriate choice of generalized variables. This way the symplectic quantization of an open string attached to a brane in the presence of an antisymmetric background field reproduces the non commutativity of the brane coordinates.Comment: We included a comparison with previous results obtained from Dirac quantization, emphasizing the fact that in the symplectic case the boundary conditions, that lead to the non commutativity, show up from the direct application of the standard method. Version to appear in Phys. Rev.

A Discussion on Supersymmetric Cosmic Strings with Gauge-Field Mixing

In this paper, following a stream of investigation on supersymmetric gauge theories with cosmic string solutions, we contemplate the possibility of building up a D-and-F term cosmic string by means of a gauge-field mixing in connection with a U(1) x U(1)'-symmetry. The spontaneous break of both gauge symmetry and supersymmetry are thoroughly analysed and the fermion zero-modes are worked out. The role of the gauge-field mixing parameter is elucidated in connection with the string configuration that comes out. As an application of the model presented here, we propose the possibility that the supersimetric cosmic string yield production of fermionic charge carriers that may eject, at their late stages, particles that subsequently decay to produce cosmic rays of ultra-high energy. In our work, it turns out that massive supersymmetric fermionic partners may be produced for a susy breaking scale in the range 10^{11} to 10^{13} GeV, which is compatible with the phenomenology of a gravitino mass at the TeV scale. We also determine the range of the gauge-field mixing parameter, \alpha, in connection with the mass scales of the present model.Comment: 7 pages, no figures, ReVTex format, to appear in New Journal of Physic

Biochars from animal wastes as alternative materials to treat colored effluents containing Basic Red 9

Bovine bones (BB) and fish scales (FS) were used as alternative precursors to produce biochars, which in turn, were applied for the removal of Basic Red 9 (BR9) from aqueous solutions. BB and FS were pyrolyzed generating a solid (biochars), a liquid (pyrolytic oils) and a gas fraction. All fractions were characterized to evaluate the pyrolysis process. The biochars presented different functional groups and a mesoporous structure with surface areas around 90 m2 g–1. Both biochars demonstrated potential to adsorb BR9, with maximum adsorption capacities of 49.5 (BB–biochar) and 52.3 mg g–1 (FS–biochar). Pyrolytic oils were composed mainly by palmitic acid (BB) and imidazolidinedione (FS), which are compounds with biological and antioxidant activity. Pyrolysis of BB generated CO2 while pyrolysis of FS generated H2. In summary, bovine bones and fish scales are promising precursors to concomitantly produce biochars with great adsorbent potential and oils with interesting characteristics

Campanhas de produção de sementes de arroz e milho em comunidades rurais rondonienses.

Objetivou-se, especificamente, com estas duas campanhas anual e consecutivas, disponibilizar e transferir tecnologias de produção sementes (sem fins comerciais) de arroz e milho em 125 comunidades rurais rondonienses. Procurou-se também demonstrar que, com orientações técnicas adequadas, seria possível aos pequenos produtores rurais, produzirem sementes com qualidade genética e tecnológica para o seu uso e da comunidade rural, impactando positivamente na melhoria da produtividade e da qualidade do produto produzido.bitstream/item/24650/1/doc120-arroz.pd

Informes da avaliação de genótipos de girassol 2008/2009 e 2009.

bitstream/item/40374/1/Doc320VE.pd

Fractional Dirac Bracket and Quantization for Constrained Systems

So far, it is not well known how to deal with dissipative systems. There are many paths of investigation in the literature and none of them present a systematic and general procedure to tackle the problem. On the other hand, it is well known that the fractional formalism is a powerful alternative when treating dissipative problems. In this paper we propose a detailed way of attacking the issue using fractional calculus to construct an extension of the Dirac brackets in order to carry out the quantization of nonconservative theories through the standard canonical way. We believe that using the extended Dirac bracket definition it will be possible to analyze more deeply gauge theories starting with second-class systems.Comment: Revtex 4.1. 9 pages, two-column. Final version to appear in Physical Review

Informes da avaliação de genótipos de girassol 2008/2009 e 2009.

Esta publicação apresenta os resultados das avaliações da Rede de Ensaios de Avaliação de Genótipos de Girassol, realizadas em diferentes regiões edafoclimáticas do País.bitstream/CPAF-RO-2010/14590/1/Doc320VE.pd

Informes da avaliação de genótipos de girassol 2010/2011 e 2011.

Características gerais da Rede de Ensaios de Avaliação de Genótipos de Girassol. Resultados dos Ensaios Finais de Primeiro e de Segundo Ano -safra 2010/2011 e safrinha 2011. Lista dos genótipos de girassol avaliados e registrados no Ministério da Agricultura, Pecuária e Abastecimento - MAPA.bitstream/item/50315/1/informes.pd

Informes da avaliação de genótipos de girassol 2009/2010 e 2010.

Informes da avaliação de genótipos de girassol 2009/2010 e 2010. Características gerais da Rede de Ensaios de Avaliação de Genótipos de Girassol. Resultados dos ensaios finais de primeiro e de segundo ano - safra 2009/2010 e safrinha 2010. Lista dos genótipos de girassol avaliados e registrados no Ministério da Agricultura, Pecuária e Abastecimento (MAPA).bitstream/item/40064/1/Doc-326-VE.pd