On the width of the last scattering surface

We discuss the physical effects of some accelerated world models on the width of the last scattering surface (LSS) of the cosmic microwave background radiation (CMBR). The models considered in our analysis are X-matter (XCDM) and a Chaplygin type gas. The redshift of the LSS does not depend on the kind of dark energy (if XCDM of Chaplygin). Further, for a Chaplygin gas, the width of the LSS is also only weakly dependent on the kind of scenario (if we have dark energy plus cold dark matter or the unified picture).Comment: 10 pages, 1 figure, 2 tables, accepted to IJMP

Utilização de clones de guaranazeiros em área de terra firme na região sudeste do Amapá.

A Empresa Brasileira de Pesquisa Agropecuária - EMBRAPA, através do Centro de Pesquisa Agroflorestal do Amapá - CPAF-Amapá, em meados da década de 80, iniciou estudos com culturas perenes, entre essas, o guaraná, por seu aparente potencial para as áreas de terra firme do estado, através de plantas obtidas por enraizamento de estacas, em busca de clones adaptados as condições locais.bitstream/item/64957/1/AP-1997-utilizacao-clones.pd

Multispecies effects in the equilibrium and out-of-equilibrium thermostatistics of overdamped motion

Progress has been recently made, both theoretical and experimental, regarding the thermostatistics of complex systems of interacting particles or agents (species) obeying a nonlinear Fokker-Planck dynamics. However, major advances along these lines have been restricted to systems consisting of only one type of species. The aim of the present contribution is to overcome that limitation, going beyond single-species scenarios. We investigate the dynamics of overdamped motion in interacting and confined many-body systems having two or more species that experience different intra- A nd interspecific forces in a regime where forces arising from standard thermal noise can be neglected. Even though these forces are neglected, the behavior of the system can be analyzed in terms of an appropriate thermostatistical formalism. By recourse to a mean-field treatment, we derive a set of coupled nonlinear Fokker-Planck equations governing the behavior of these systems. We obtain an H theorem for this Fokker-Planck dynamics and discuss in detail an example admitting an exact, analytical stationary solution.Fil: Plastino, Ángel Ricardo. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nobre, F. D.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Wedemann, R. S.. Universidade do Estado de Rio do Janeiro; Brasi

Enhancement of the ferromagnetic order of graphite after sulphuric acid treatment

We have studied the changes in the ferromagnetic behavior of graphite powder and graphite flakes after treatment with diluted sulphuric acid. We show that this kind of acid treatment enhances substantially the ferromagnetic magnetization of virgin graphite micrometer size powder as well as in graphite flakes. The anisotropic magnetoresistance (AMR) amplitude at 300 K measured in a micrometer size thin graphite flake after acid treatment reaches values comparable to polycrystalline cobalt.Comment: 3.2 pages, 4 figure

Resultados do controle de desenvolvimento ponderal: raça Nelore - 1975/1984.

A raça Nelore. Controle do desenvolvimento ponderal. Considerações sobre os resultados do controle de desenvolvimento ponderal da raça Nelore. Categorias dos animais inscritos. Sexo. Regime alimentar. Ano de nascimento. Mérito dos reprodutores.bitstream/item/104691/1/Resultados-do-controle-desev-podenral.pd

Destruction of first-order phase transition in a random-field Ising model

The phase transitions that occur in an infinite-range-interaction Ising ferromagnet in the presence of a double-Gaussian random magnetic field are analyzed. Such random fields are defined as a superposition of two Gaussian distributions, presenting the same width $\sigma$. Is is argued that this distribution is more appropriate for a theoretical description of real systems than its simpler particular cases, i.e., the bimodal ($\sigma=0$) and the single Gaussian distributions. It is shown that a low-temperature first-order phase transition may be destructed for increasing values of $\sigma$, similarly to what happens in the compound $Fe_{x}Mg_{1-x}Cl_{2}$, whose finite-temperature first-order phase transition is presumably destructed by an increase in the field randomness.Comment: 13 pages, 3 figure

Uso múltiplo da água e lâminas de irrigação da bananeira FHIA 18 nas condições de semiárida.

Este trabalho objetivou avaliar a contribuição nutricional do uso múltiplo da água da piscicultura na irrigação da bananeira cv. Fhia 18. O experimento foi desenvolvido no Projeto Piloto de Fruticultura Irrigada do Vale de Parnaíba, localizado no município de Santa Rosa do Piauí, região semi-árida do Piauí

Reações fisiológicas em diferentes grupos genéticos de bovinos de corte sob pastejo.

bitstream/item/137544/1/PESQ-EM-ANDAMENTO-22.pdfCNPGC

Resultados do controle de desenvolvimento ponderal - Raça Gir - 1976/1984.

A Raça Gir. Controle de desenvolvimento ponderal. Considerações sobre os resultados do controle de desenvolvimento ponderal das Raças Gir e Gir variedade Mocha. Controle ponderal das Raças Gir e Gir variedade mocha a nível nacional. Categorias de registro. Sexo. Regime alimentar. Ano de nascimento. Estação de nascimento. Mérito dos reprodutores. Controle ponderal da Raça Gir a nível de estado.bitstream/item/131353/1/resultados-do-controle-de-desenvolvimento-76-84.pd