Resumo-Objetivou-se avaliar a resposta de Vigna unguiculata (L.) Walp. cv. "BR 17 Gurguéia" à inoculação com duas cepas isoladas de solos de mineração de bauxita em reabilitação: UFLA 3-164 e UFLA 3-155 e três cepas INPA 03 11B (BR 3301); UFLA 03 84 (BR 3302) e BR 3267 (SEMIA 6462), autorizadas pelo MAPA como inoculantes para a cultura do feijão-caupi. O experimento foi conduzido em campo na Universidade Federal do Piauí, Campus Professora Cinobelina Elvas, Bom Jesus, PI. Utilizou-se o delineamento experimental em blocos casualizados com sete tratamentos e com seis repetições, sendo cinco cepas citadas e dois controles não inoculados, um com N-mineral (70 kg ha-1 de N) e outra sem N mineral. Foram avaliados a nodulação (número e massa seca de nódulos), o crescimento (massa seca da parte aérea), o rendimento de grãos e o teor e acúmulo de nitrogênio na parte aérea e nos grãos, além da eficiência relativa. A inoculação das sementes com as cepas de bactérias diazotróficas simbióticas resultou em rendimentos de grãos equivalente à testemunha adubada com nitrogênio mineral. A cepa em fase de teste, UFLA 3-155 apresentou rendimento de grãos igual à cepa recomendada INPA 03 11B (BR 3301), podendo também ser testada em outras regiões brasileiras. Entre as cepas aprovadas pelo MAPA a INPA 03 11B (BR 3301) apresentou a maior produção de grãos. Palavras-chave-Bradyrhizobium. Fixação biológica de N 2. Leguminosas.

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In this work we disclose micro- and nanoscale origins of the unusually high dielectric constant characteristic of CaCu3Ti4O12 (CCTO) ceramic by using the Scanning Probe Microscopy (SPM) technique.

Articles you may be interested inRoom temperature magnetic and dielectric properties of cobalt doped CaCu3Ti4O12 ceramics CaCu 3 Ti 4 O 12 ceramic samples were prepared by solid state conventional route using stoichiometric amounts of CuO, TiO 2 , and CaCO 3 . Afterward the material was doped with GeO 2 with concentrations up to 6% by weight and sintered at 1050°C for 12 h. The influence of doping on the microstructure, vibrational modes, and dielectric properties of the material was investigated by x-ray diffraction, scanning electron microscopy coupled with an energy dispersive spectrometer, and infrared and dielectric measurements between 100 Hz and 30 MHz. The materials presented huge dielectric response, which increases with doping level relative to undoped CaCu 3 Ti 4 O 12 . The main effect of doping on the microstructure is the segregation of Cu-rich phase in the ceramic grain boundaries. Cole-Cole modeling correlates well the effects of this segregation with the relaxation parameters obtained. The intrinsic phonon contributions for the dielectric response were obtained and discussed together with the structural evolution of the system.

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The aim of this study was to evaluate the effect of sources and rates of organic waste and their interaction on the growth of Leucaena leucocephala (Lam.) de Wit, in the Southeast region of Piauí State. The treatments consisted of two sources (Copernicia prunifera (Mill.) H.E. palm residue and plant compound) and six organic waste rates. The study was conducted in the period of March-June 2011 and the following parameters were evaluated: stem diameter, height, number of leaves, shoot dry weight, root dry weight, total dry matter, root volume, shoot dry weight/root dry weight ratio, height/stem diameter ratio and the Dickson Quality Index. The Copernicia prunifera (Mill.) H.E. palm residue and plant compound showed a great potential to be used in the manufacture of substrates for the production of seedlings Leucaena leucocephala (Lam.) de Wit, since their initial development was influenced by the sources and proportions of these organic residues and by the interaction between these treatments. The substrate containing 50% of plant compound produced better quality of plants of Leucaena leucocephala (Lam.) de Wit in their initial development stage.