Soft supersymmetry breaking in the nonlinear sigma model

In this work we discuss the dynamical generation of mass in a deformed ${\cal N}=1$ supersymmetric nonlinear sigma model in a two-dimensional ($D=1+1$) space-time. We introduce the deformation by imposing a constraint that softly breaks supersymmetry. Through the tadpole method, we compute the effective potential at leading order in $1/N$ expansion showing that the model exhibit a dynamical generation of mass to the matter fields. Supersymmetry is recovered in the limit of the deformation parameter going to zero.Comment: 9 pages, 2 figures. Revised version. arXiv admin note: text overlap with arXiv:1308.471

Lorentz-violating effects in the Bose-Einstein condensation of an ideal bosonic gas

We have studied the effects of Lorentz-violation in the Bose-Einstein condensation (BEC) of an ideal boson gas, by assessing both the nonrelativistic and ultrarelativistic limits. Our model describes a massive complex scalar field coupled to a CPT-even and Lorentz-violating background. We irst analyze the nonrelativistic case, at this level by using experimental data, we obtain upper-bounds for some LIV parameters. In the sequel, we have constructed the partition function for the relativistic ideal boson gas which to be able of a consistent description requires the imposition of severe restrictions on some LIV coefficients. In both cases, we have demonstrated that the LIV contributions are contained in an overall factor, which multiplies almost all thermodynamical properties. An exception is the fraction of the condensed particles.Comment: 7 pages Latex2e. To be published in Modern Physics Letters

An investigation relating to the design parameters of diaphragm mandrels

The aim of the present investigation was to establish the equations relating the deformations and the gripping pressure of diaphragm mandrels, as well as to simplify them, enabling their utilization by a designer. Diaphragm mandrels, to be used in lathe or finishing machining work, can be seen as revolution pieces constituted of an assemblage of elastic elements disposed around their revolution axis. The centering and gripping operations rely only on the elastic forces generated when those elements are elasticly deformed. The non-existence of metalic sliding parts distinguishes this type of mandrels from the usual types and assures an high degree of repeatability and accuracy during the machining operations. Four fundamental stages constitute the present work. Firstly, the preliminary design of the geometrical shape for the diaphragm mandrels has been developed in chapter 2. The second and third fundamental stages have been undertaken simultaneously. They are constituted of an theoretical and experimental analysis in view to obtain the equations earlier refered. This analysis has been undertaken firstly on two different types of Specimen, simulating the constituting elements of a diaphragm mandrel and finally on a third Specimen simulating an actual section of the mandrel. The first Specimen simulated the tapered parts of the mandrel, and the second type simulated the assemblage of those tapered parts and the holding part in between them. On pages 42, 71 and 126 are represented the first, the second and the third type of those Specimen, respectively. In chapter 3 is elaborated the theoretical analysis of the first type, in chapter 7 the second type and in chapter 11 the third type. Their experimental analysis is presented on chapter 4, 5 and 6 for the first type, on chapters 8, 9 and 10 for the second one and on the chapter 12, 13 and 14 for the third type. The theoretical analysis, based upon the energy method enabled the calculations of deformations, load forces and gripping pressure relationships, and from the experimental work the experimental values have been obtained and used to verify the accuracy of the theoretical analysis. Mechanical and electronic techniques have been used during the experiments and close correlation between the predicted results and the experimental ones have been obtained, this being stated in chapter 6, chapter 10 and chapter 14. Finally the third stage of this investigation has been related with the simplification of the theoretical expressions and their presentation in a tabled way providing their use by a designer to characterize the behaviour of a mandrel as well as to define its geometrical dimensions under a specific work situation, chapter 17 and 18

Caracterização agronômica de novos genótipos de mamoeiro na Chapada do Apodi.

O mamoeiro (Carica papaya L.) possui expressiva importância econômica para o Brasil, destacando-se como segundo maior produtor mundial. Em 2012 o país produziu 1.517.696 toneladas de mamão (FAO, 2012). No Brasil o mamoeiro é cultivado na quase totalidade do seu território, merecendo destaque os estados da Bahia, Espirito Santo, Ceará e Rio Grande do Norte, que são responsáveis por 87,35% da produção nacional (IBGE, 2013)

Sistema de Monitoramento de Indicadores para a Produção Agrícola Sustentável.

bitstream/CPACT-2010/12913/1/documento-272.pd