Specific heat amplitude ratios for anisotropic Lifshitz critical behaviors

We determine the specific heat amplitude ratio near a $m$-axial Lifshitz point and show its universal character. Using a recent renormalization group picture along with new field-theoretical $\epsilon_{L}$-expansion techniques, we established this amplitude ratio at one-loop order. We estimate the numerical value of this amplitude ratio for $m=1$ and $d=3$. The result is in very good agreement with its experimental measurement on the magnetic material $MnP$. It is shown that in the limit $m \to 0$ it trivially reduces to the Ising-like amplitude ratio.Comment: 8 pages, RevTex, accepted as a Brief Report in Physical Review

Anisotropic Lifshitz Point at O(ϵL2)O(\epsilon_L^2)

We present the critical exponents $\nu_{L2}$, $\eta_{L2}$ and $\gamma_{L}$ for an $m$-axial Lifshitz point at second order in an $\epsilon_{L}$ expansion. We introduced a constraint involving the loop momenta along the $m$-dimensional subspace in order to perform two- and three-loop integrals. The results are valid in the range $0 \leq m < d$. The case $m=0$ corresponds to the usual Ising-like critical behavior.Comment: 10 pages, Revte

Qualidade da água para consumo humano.

Água em quantidade e qualidade e de forma permanente; Doenças relacionadas à água; Valores de referência de qualidade da água; Formas de tratamento da água para consumo humano; Transporte e armazenamento da água no meio rural.bitstream/CPATSA/35649/1/SDC196.pd

Aplicação de sistema WebGIS para análise geoespacial da agricultura na região de MATOPIBA.

Este trabalho analisou a produção agrícola das culturas de soja, milho e algodão entre 2000 e 2010 na região denominada de Matopiba, que abrange parte dos estados do Maranhão, Tocantins, Piauí e Bahia. As mesorregiões analisadas fazem parte principalmente do Bioma Cerrado e têm condições edafoclimáticas apropriadas para esses cultivos, desde que acompanhadas por tecnologias adequadas. Os dados foram obtidos por meio do Sistema de Observação e Monitoramento da Agricultura no Brasil (SOMABRASIL) e apoiaram a análise da expansão e intensificação agrícola. As variáveis analisadas foram área plantada, quantidade produzida e produtividade. Barreiras, BA, foi a microrregião que mais se destacou com base nos valores observados

Charge and spin distributions in GaMnAs/GaAs Ferromagnetic Multilayers

A self-consistent electronic structure calculation based on the Luttinger-Kohn model is performed on GaMnAs/GaAs multilayers. The Diluted Magnetic Semiconductor layers are assumed to be metallic and ferromagnetic. The high Mn concentration (considered as 5% in our calculation) makes it possible to assume the density of magnetic moments as a continuous distribution, when treating the magnetic interaction between holes and the localized moment on the Mn(++) sites. Our calculation shows the distribution of heavy holes and light holes in the structure. A strong spin-polarization is observed, and the charge is concentrated mostly on the GaMnAs layers, due to heavy and light holes with their total angular momentum aligned anti-parallel to the average magnetization. The charge and spin distributions are analyzed in terms of their dependence on the number of multilayers, the widths of the GaMnAs and GaAs layers, and the width of lateral GaAs layers at the borders of the structure.Comment: 12 pages,7 figure