Conferência de busca de futuro: relatório final.

Introdução; Metodologia; Focalizando o passado; Focalizando o presente; Focalizando o futuro; Pós-Conferência.bitstream/item/37176/1/Doc51.pd

Master Operators Govern Multifractality in Percolation

Using renormalization group methods we study multifractality in percolation at the instance of noisy random resistor networks. We introduce the concept of master operators. The multifractal moments of the current distribution (which are proportional to the noise cumulants $C_R^{(l)} (x, x^\prime)$ of the resistance between two sites x and $x^\prime$ located on the same cluster) are related to such master operators. The scaling behavior of the multifractal moments is governed exclusively by the master operators, even though a myriad of servant operators is involved in the renormalization procedure. We calculate the family of multifractal exponents ${\psi_l}$ for the scaling behavior of the noise cumulants, $C_R^{(l)} (x, x^\prime) \sim | x - x^\prime |^{\psi_l /\nu}$, where $\nu$ is the correlation length exponent for percolation, to two-loop order.Comment: 6 page

Percolation Threshold, Fisher Exponent, and Shortest Path Exponent for 4 and 5 Dimensions

We develop a method of constructing percolation clusters that allows us to build very large clusters using very little computer memory by limiting the maximum number of sites for which we maintain state information to a number of the order of the number of sites in the largest chemical shell of the cluster being created. The memory required to grow a cluster of mass s is of the order of $s^\theta$ bytes where $\theta$ ranges from 0.4 for 2-dimensional lattices to 0.5 for 6- (or higher)-dimensional lattices. We use this method to estimate $d_{\scriptsize min}$, the exponent relating the minimum path $\ell$ to the Euclidean distance r, for 4D and 5D hypercubic lattices. Analyzing both site and bond percolation, we find $d_{\scriptsize min}=1.607\pm 0.005$ (4D) and $d_{\scriptsize min}=1.812\pm 0.006$ (5D). In order to determine $d_{\scriptsize min}$ to high precision, and without bias, it was necessary to first find precise values for the percolation threshold, $p_c$: $p_c=0.196889\pm 0.000003$ (4D) and $p_c=0.14081\pm 0.00001$ (5D) for site and $p_c=0.160130\pm 0.000003$ (4D) and $p_c=0.118174\pm 0.000004$ (5D) for bond percolation. We also calculate the Fisher exponent, $\tau$, determined in the course of calculating the values of $p_c$: $\tau=2.313\pm 0.003$ (4D) and $\tau=2.412\pm 0.004$ (5D)

Effects of surfaces on resistor percolation

We study the effects of surfaces on resistor percolation at the instance of a semi-infinite geometry. Particularly we are interested in the average resistance between two connected ports located on the surface. Based on general grounds as symmetries and relevance we introduce a field theoretic Hamiltonian for semi-infinite random resistor networks. We show that the surface contributes to the average resistance only in terms of corrections to scaling. These corrections are governed by surface resistance exponents. We carry out renormalization group improved perturbation calculations for the special and the ordinary transition. We calculate the surface resistance exponents \phi_{\mathcal S \mathnormal} and \phi_{\mathcal S \mathnormal}^\infty for the special and the ordinary transition, respectively, to one-loop order.Comment: 19 pages, 3 figure

Logarithmic Corrections in Dynamic Isotropic Percolation

Based on the field theoretic formulation of the general epidemic process we study logarithmic corrections to scaling in dynamic isotropic percolation at the upper critical dimension d=6. Employing renormalization group methods we determine these corrections for some of the most interesting time dependent observables in dynamic percolation at the critical point up to and including the next to leading correction. For clusters emanating from a local seed at the origin we calculate the number of active sites, the survival probability as well as the radius of gyration.Comment: 9 pages, 3 figures, version to appear in Phys. Rev.

Agricultura apoiada pela comunidade: poderia a experiência dos agricultores americanos ser útil para os agricultores urbanos brasileiros?

O objetivo deste trabalho foi obter algumas informações sobre o projeto Agricultura Apoiada pela Comunidade (AAC) nos EUA e avaliar se consumidores e produtores urbanos pobres de uma cidade brasileira de baixa renda aceitariam se engaja neste tipo de projeto

Advances in technology transference: the experience of integrated crop-livestock-forestry (ICLF) adoption in Tocantins State.

In 2010 the Brazilian Government established a goal to reduce the emissions of greenhouse gases (GHG) by agriculture from 36.1 up to 38.9% in ten years (2010 -2020). To contribute for reaching part of this purpose in Tocantins State, Embrapa and other research and extension services partners have been conducting a project of technology transference on sustainable agricultural practices, including integrated crop-livestock-forestry (ICLF), since 2012

Relative water content in two grass cultivars in crop-livestock system in the State of Tocantins, Brazil.

In this presentation, we report the results of two grasses on Integrated Crop-Livestock System in the Tocantins Cerrado

Bovinocultura leiteira sustentável.

A bovinocultura leiteira e a cadeia do leite estão em desenvolvimento na região do MATOPIBA, que engloba parcelas dos Estados do Maranhão, Tocantins, Piauí e Bahia.bitstream/item/162178/1/CNPASA-2017-fd.pd

Economic results of the integrated crop-livestock systems implementation in degraded pastures in Pium, TO, Brazil.

In Pium, Tocantins state, Brazil, in 2012 Embrapa developed a technology transference project in partnership with the state?s rural extension service for the consolidation of low carbon emissions agriculture. The goal was to recover the degraded grasslands of the Trigueira farm (49°1'37.44"W and 10°24'58.84"S) with low cost using a crop-livestock system