Spatio-temporal conjecture for diffusion

We present here a conjecture about the equivalence between the noise density of states of a system governed by a generalized Langevin equation and the fluctuation in the energy density of states in a Hamiltonian system. We present evidence of this for a disordered Heisenberg system.Comment: 6 pages, 1 figure. Submitted to Physica

A method to search for topological signatures in the angular distribution of cosmic objects

We present a method to search for large angular-scale correlations, termed topological signatures, in the angular distribution of cosmic objects, which does not depend on cosmological models or parameters and is based only on the angular coordinates of the objects. In order to explore Cosmic Microwave Background temperature fluctuations data, we applied this method to simulated distributions of objects in thin spherical shells located in three different multiply-connected Euclidean 3-spaces ($T^3$, $T_{\pi}$, and $G_6$), and found that the topological signatures due to these topologies can be revealed even if their intensities are small. We show how to detect such signatures for the cases of full-sky and partial-sky distributions of objects. This method can also be applied to other ensembles of cosmic objects, like galaxies or quasars, in order to reveal possible angular-scale correlations in their distributions.Comment: 11 pages, 18 figures. To appear in A&

Constraints on the Polarization of the Anomalous Microwave Emission in the Perseus Molecular Complex from 7-year WMAP data

We have used the seven year Wilkinson Microwave Anisotropy Probe (WMAP) data in order to update the measurements of the intensity signal in the G159.6-18.5 region within the Perseus Molecular Complex, and to set constraints on the polarization level of the anomalous microwave emission in the frequency range where this emission is dominant. At 23, 33 and 41 GHz, we obtain upper limits on the fractional linear polarization of 1.0, 1.8 and 2.7% respectively (with a 95 per cent confidence level). These measurements rule out a significant number of models based on magnetic dipole emission of grains that consist of a simple domain (Draine & Lazarian 1999) as responsible of the anomalous emission. When combining our results with the measurement obtained with the COSMOSOMAS experiment at 11 GHz (Battistelli et al. 2006), we find consistency with the predictions of the electric dipole and resonance relaxation theory (Lazarian & Draine 2000) at this frequency range.Comment: 14 pages, 7 figures, ApJ submitte

Propriedades físicas de sementes de Baru em função da secagem.

O conhecimento das propriedades físicas das sementes são informações que auxiliam o dimensionamento de máquinas de pré-processamento, processamento e classificação das mesmas. O experimento teve o objetivo de efetuar a caracterização das propriedades físicas de sementes de Baru. Foram avaliados 4 tratamentos: T1 = sementes não secadas; T2 = sementes secadas em estufa de circulação forçada de ar por 48 horas à 40 Celsius; T3 = sementes secadas em estufa de circulação forçada de ar por 96 horas a 40 graus Celsius e T4 = sementes secadas em estufa de circulação forçada de ar por 24 horas a 105 graus Celsius, considerada desidratada. Foram avaliadas a massa específica aparente, esfericidade, circularidade, porosidade e massa específica real. Houve diferenças entre os tratamentos para a massa específica aparente e porosidade. A maior massa específica e a menor porosidade foram verificadas no tratamento T1. A massa específica aparente diminuiu com a secagem. Massa de sementes in natura apresentou menor porosidade.CONBEA 2013

Can the lack of symmetry in the COBE/DMR maps constrain the topology of the universe?

Although the cubic T^3 ``small universe" has been ruled out by COBE/DMR results as an interesting cosmological model, we still have the possibility of living in a universe with a more anisotropic topology such as a rectangular T^3 ``small universe" with one or two of its dimensions significantly smaller than the present horizon (which we refer to as T^1- and T^2-models, respectively). In order to rule out these anisotropic topologies as well, we apply a new data analysis method that searches for the specific kind of symmetries that these models should produce. We find that the 2 year COBE/DMR data set a lower limit on the smallest cell size for T^1- and T^2-models of 3000 h^{-1} Mpc, at 95% confidence, for a scale invariant power spectrum (n=1). These results imply that {\it all} toroidal universes (cubes and rectangles) are ruled out as interesting cosmological models

Some properties of two Nambu--Jona-Lasinio -type models with inputs from lattice QCD

We investigate the phase diagram of the so-called Polyakov--Nambu--Jona-Lasinio (PNJL) model at finite temperature and nonzero chemical potential. The calculations are performed in the light and strange quark sectors ($u$, $d$, $s$), which includes the 't Hooft instanton induced interaction term that breaks the axial symmetry, and the quarks are coupled to the (spatially constant) temporal background gauge field. On one hand, a special attention is payed to the critical end point (CEP). The strength of the flavor-mixing interaction alters the CEP location, since when it becomes weaker the CEP moves to low temperatures and can even disappear. On the other hand, we also explore the connection between QCD, a nonlocal Nambu--Jona-Lasinio type model and the Landau gauge gluon propagator. Possible links between the quenched gluon propagator and low energy hadronic phenomenology are investigated.Comment: Contribution to the International Meeting "Excited QCD", Peniche, Portugal, 06 - 12 May 201

Manejo da pastagem e rendimento potencial do azevém (lolium multiflorum lam.).

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