Electrostatic self-force in (2+1)-dimensional cosmological gravity

Point sources in (2+1)-dimensional gravity are conical singularities that modify the global curvature of the space giving rise to self-interaction effects on classical fields. In this work we study the electrostatic self-interaction of a point charge in the presence of point masses in (2+1)-dimensional gravity with a cosmological constant.Comment: 9 pages, Late

Dilute-phase pneumatic conveying of polystyrene particles: pressure drop curve and particle distribution over the pipe cross-section

During the pneumatic conveying of plastic pellets, it has been observed that materials with similar physical characteristics may develop a substantial difference in pressure drop. In this work, the pressure drop in a particle-laden 2.7 meter long horizontal channel with circular cross-section is presented from an experimental perspective. Experiments are carried out for cylindrical polystyrene beads with an average diameter of 3.2 mm and mass loadings of 0.06 to 0.11 (kg particles/kg gas). The air mass flow rate was studied in the range from 0.085 kg/s to 0.170 kg/s. The pressure drop curve is shown as a function of air velocity and particle load. Response surface methodology showed high statistical significance for air velocity, particle load and their cross-relation.8188Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

The self-energy of a charged particle in the presence of a topological defect distribution

In this work we study a charged particle in the presence of both a continuous distribution of disclinations and a continuous distribution of edge dislocations in the framework of the geometrical theory of defects. We obtain the self-energy for a single charge both in the internal and external regions of either distribution. For both distributions the result outside the defect distribution is the self-energy that a single charge experiments in the presence of a single defect.Comment: 12 pages, Revtex4, two figures,to appear in Int. Joun. Mod. Phys.

Resíduo micropulverizado da moagem a seco de milho não afeta biodisponibilidade de zinco em ratos.

Trabalho apresentado no XV Congresso Latinoamericano de Nutricion e XVI Jornadas de la Sociedad Chilena de Nutrición, 2009, Santiago do Chile

Nematic liquid crystal dynamics under applied electric fields

In this paper we investigate the dynamics of liquid crystal textures in a two-dimensional nematic under applied electric fields, using numerical simulations performed using a publicly available LIquid CRystal Algorithm (LICRA) developed by the authors. We consider both positive and negative dielectric anisotropies and two different possibilities for the orientation of the electric field (parallel and perpendicular to the two-dimensional lattice). We determine the effect of an applied electric field pulse on the evolution of the characteristic length scale and other properties of the liquid crystal texture network. In particular, we show that different types of defects are produced after the electric field is switched on, depending on the orientation of the electric field and the sign of the dielectric anisotropy.Comment: 7 pages, 12 figure

Teor de nitrogênio em sementes de Araucaria angustifolia.

Edição dos resumos do 18º Congresso Brasileiro de Sementes, 2013, Florianópolis