Aumento da nodulação da soja com suplementação de silício.

bitstream/item/67367/1/34259.pdfOrganizado por: Fábio Martins Mercante e Oscar Fontão de Lima Filho. RELARE

Analysing and controlling the tax evasion dynamics via majority-vote model

Within the context of agent-based Monte-Carlo simulations, we study the well-known majority-vote model (MVM) with noise applied to tax evasion on simple square lattices, Voronoi-Delaunay random lattices, Barabasi-Albert networks, and Erd\"os-R\'enyi random graphs. In the order to analyse and to control the fluctuations for tax evasion in the economics model proposed by Zaklan, MVM is applied in the neighborhod of the noise critical $q_{c}$. The Zaklan model had been studied recently using the equilibrium Ising model. Here we show that the Zaklan model is robust and can be reproduced also through the nonequilibrium MVM on various topologies.Comment: 18 pages, 7 figures, LAWNP'09, 200

Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites

With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3}, with Y concentrations x=0, 0.10, and 0.15. Yttrium doping yielded the appearance of a cluster-glass state, giving rise to unusual low-temperature behavior of the specific-heat. The main feature observed in the results is a strong enhancement of the specific-heat linear term, which is interpreted as a direct consequence of magnetic disorder. The analysis was further corroborated by resistivity measurements in the same compounds.Comment: 9 pages, 2 figure

Fertirrigação: injetores.

Bomba injetora; Venturi; Tubos de Pitot; Tanques de fertilizantes.bitstream/CNPAT-2010/11926/1/It-007.pd

Sociabilidade das especies florestais da caatinga em Santa Maria da Boa Vista,PE.

O trabalho foi executado na Fazenda Canaa, municipio de Santa Maria da Boa Vista, PE, com o objetivo de determinar o grau de afinidade entre as especies da caatinga e a importancia das mesmas, para fornecer subsidios tecnicos e eventuais programas de manejo, de formacao de povoamentos heterogeneos e de enriquecimento da comunidade vegetal com essencias de maior valor economico madeireiro. Avaliou-se a composicao floristica quanto a frequencia, densidade e dominancia. A similaridade entre as parcelas e a associacao de especies foram analisadas pelo Coeficiente de Jaccard. Os resultados obtidos permitiram concluir que a vegetacao e caracterizada pela presenca do angico (Anademanthera macrocarpa), jurema-preta (Mimosa hostilis), jurema-vermelha (Mimosa sp), manicoba-brava (Manihot sp) e pau-piranha (Pisonia sp), sendo essas especies mais frequents; o angico e a especie dominante, sendo a mais explorada. Rama-de-boi (Acacia piauhiensis) e espinheiro (Pithecellobium viridiflorium) apresentam alto indice de associacao, permitindo portanto aventar a possiblidade do seu uso em consorcio