Impactos socioeconômicos de cultivares de feijão caupi na Região Meio-Norte do Brasil.

Caracterizacão das cultivares geradas; BR 17-Gurgueia; BR 14-Mulato; Cultivar Monteiro; Impactos socioeconômicos; Desafios.bitstream/item/36496/1/Doc52.pd

Long-range Kondo signature of a single magnetic impurity

The Kondo effect, one of the oldest correlation phenomena known in condensed matter physics, has regained attention due to scanning tunneling spectroscopy (STS) experiments performed on single magnetic impurities. Despite the sub-nanometer resolution capability of local probe techniques one of the fundamental aspects of Kondo physics, its spatial extension, is still subject to discussion. Up to now all STS studies on single adsorbed atoms have shown that observable Kondo features rapidly vanish with increasing distance from the impurity. Here we report on a hitherto unobserved long range Kondo signature for single magnetic atoms of Fe and Co buried under a Cu(100) surface. We present a theoretical interpretation of the measured signatures using a combined approach of band structure and many-body numerical renormalization group (NRG) calculations. These are in excellent agreement with the rich spatially and spectroscopically resolved experimental data.Comment: 7 pages, 3 figures + 8 pages supplementary material; Nature Physics (Jan 2011 - advanced online publication

Populacao de plantas no consorcio milho x feijao macassar sob regimes de sequeiro e irrigado.

Foi avaliado o comportamento produtivo do milho (Zea mays L.) associado ao feijao macassar (Vigna unguiculata (L.) Walp.), em condicoes de sequeiro, em solo Podzolico Vermelho-Amarelo, no municipio de Elizeu Martins, PI, e em condicoes de irrigacao por aspersao, em solo Aluviao Eutrofico, no municipio de Teresina, Pi, no ano de l988. Foram usadas tres populacoes de plantas de milho/ha (20, 40 e 80 mil) e quatro populacoes de feijao/ha (30, 60, 90 e 120 mil), arranjadas em esquema fatorial 3 x 4, em delineamento experimental de blocos casualizados com cinco repeticoes. O arranjo espacial de plantas foi milho (cv. BR 5006 Fidalgo) e feijao (cv. BR l2-Caninde) na mesma fileira. As produtividades medias de graos de milho sob regime de sequeiro e irrigado foram, respectivamente, de 2,877, 4.066 e 4.131 kg/ha e 3.875, 5.314 e 5.890kg/ha, nas populacoes 20, 40 e 80 mil plantas/ha, nao sendo afetadas pelo incremento da populacao de feijao. Seja no regime de sequeiro como no regime irrigado, o aumento da populacao de milho reduziu ( 0,01) a produtividade media de graos de feijao para 475, 304 234 kg/ha (regime de sequeiro) e 1.008, 804 e 604 kg/ha (regime irrigado), respectivamentoe, nas populacoes de 20, 40 e 80 mil plantas/ha, sendo a causa principal a producao de graos/planta. As produtividades medias de graos de ambas as culturas foram maiores quando desenvolvidas sob irrigacao,que produziram, respectivamente, 36% e 138% a mais de milho e feijao, em relacao ao regime de sequeiro.bitstream/item/98442/1/BOL140001.pd

Pion-Muon Asymmetry Revisited

Long ago an unexpected and unexplainable phenomena was observed. The distribution of muons from positive pion decay at rest was anisotropic with an excess in the backward direction relative to the direction of the proton beam from which the pions were created. Although this effect was observed by several different groups with pions produced by different means, the result was not accepted by the physics community, because it is in direct conflict with a large set of other experiments indicating that the pion is a pseudoscalar particle. It is possible to satisfy both sets of experiments if helicity-zero vector particles exist and the pion is such a particle. Helicity-zero vector particles have direction but no net spin. For the neutral pion to be a vector particle requires an additional modification to conventional theory as discussed herein. An experiment is proposed which can prove that the asymmetry in the distribution of muons from pion decay is a genuine physical effect because the asymmetry can be modified in a controllable manner. A positive result will also prove that the pion is NOT a pseudoscalar particle.Comment: 9 pages, 3 figure

Unveiling oxygen vacancy impact on lizardite thermo and mechanical properties

Here, we performed a systematic DFT study assisted by the workflow framework SimStack for the mechanical and thermodynamic properties of the clay mineral lizardite in pristine and six different types of O vacancies configurations. In most cases, the defect caused a structural phase transition in the lizardite from the trigonal (pristine) to the triclinic phase. The results show that oxygen vacancies in lizardite significantly reduce the lattice thermal conductivity, accompanied by an elastic moduli reduction and an anisotropy index increase. Through the P–V relation, an increase in compressibility was evidenced for vacancy configurations. Except for the vacancy with the same crystalline structure as pristine lizardite, the sound velocities of the other vacancy configurations produce a decrease in these velocities, and it is essential to highlight high values for the Grüneisen parameter. We emphasize the great relevance of the punctual-defects introduction, such as O vacancies, in lizardite, since this microstructural design is responsible for the decrease of the lattice thermal conductivity in comparison with the pristine system by decreasing the heat transfer ability, turning lizardite into a promising candidate for thermoelectric materials