Continuous Opinions and Discrete Actions in Opinion Dynamics Problems

A model where agents show discrete behavior regarding their actions, but have continuous opinions that are updated by interacting with other agents is presented. This new updating rule is applied to both the voter and Sznajd models for interaction between neighbors and its consequences are discussed. The appearance of extremists is naturally observed and it seems to be a characteristic of this model.Comment: 10 pages, 4 figures, minor changes for improved clarit

Note on improvement precision of recursive function simulation in floating point standard

An improvement on precision of recursive function simulation in IEEE floating point standard is presented. It is shown that the average of rounding towards negative infinite and rounding towards positive infinite yields a better result than the usual standard rounding to the nearest in the simulation of recursive functions. In general, the method improves one digit of precision and it has also been useful to avoid divergence from a correct stationary regime in the logistic map. Numerical studies are presented to illustrate the method.Comment: DINCON 2017 - Conferencia Brasileira de Dinamica, Controle e Aplicacoes - Sao Jose do Rio Preto - Brazil. 8 page

Finite temperature corrections and embedded strings in noncommutative geometry and the standard model with neutrino mixing

The recent extension of the standard model to include massive neutrinos in the framework of noncommutative geometry and the spectral action principle involves new scalar fields and their interactions with the usual complex scalar doublet. After ensuring that they bring no unphysical consequences, we address the question of how these fields affect the physics predicted in Weinberg-Salam theory, particularly in the context of the Electroweak phase transition. Applying the Dolan-Jackiw procedure, we calculate the finite temperature corrections, and find that the phase transition is first order. The new scalar interactions significantly improve the stability of the Electroweak Z string, through the ``bag'' phenomenon described by Watkins and Vachaspati. (Recently cosmic strings have climbed back into interest due to new evidence). Sourced by static embedded strings, an internal space analogy of Cartan's torsion is drawn, and a possible Higgs-force-like `gravitational' effect of this non-propagating torsion on the fermion masses is described. We also check that the field generating the Majorana mass for the $\nu_R$ is non-zero in the physical vacuum.Comment: 42 page

Structural studies of mesoporous ZrO2_{2}-CeO2_{2} and ZrO2_{2}-CeO2_{2}/SiO2_{2} mixed oxides for catalytical applications

In this work the synthesis of ZrO$_{2}$-CeO$_{2}$ and ZrO$_{2}$-CeO$_{2}$/SiO$_{2}$ were developed, based on the process to form ordered mesoporous materials such as SBA-15 silica. The triblock copolymer Pluronic P-123 was used as template, aiming to obtain crystalline single phase walls and larger specific surface area, for future applications in catalysis. SAXS and XRD results showed a relationship between ordered pores and the material crystallization. 90% of CeO$_{2}$ leaded to single phase homogeneous ceria-zirconia solid solution of cubic fluorite structure (Fm$\bar{3}$m). The SiO$_{2}$ addition improved structural and textural properties as well as the reduction behavior at lower temperatures, investigated by XANES measurements under H$_{2}$ atmosphere

Remarks on the neuropterofauna (Insecta, Neuroptera) from the Brazilian Cretaceous, with keys for the identification of the known taxa

This paper reviews all previous knowledge about neuropterans from the Santana Formation (Lower Cretaceous, northeastern Brazil) involving a decade of research in this group. The neuropterofauna from Santana Formation is one of the most complete and diverse known, formed by 50 species distributed in 28 genera, representing 11 families: Ascalaphidae, Myrmeleontidae, Psychopsidae, Chrysopidae, Berothidae, Sisyridae, Nemopteridae, Roeslerianidae, Babinskaiidae, Paleoleontidae and Makarkiniidae. All the know n material is from the laminated limestone, tip of the Crato Member, lowest unit of the Santana Formation, Lower Cretaceous, Ceará State, northeastern Brazil. This research have the objective to furnish the keys for the identification of all known Brazilian fossil neuropterans and 16 Figures containing the drafts of all Brazilian neuropterans holotypes