10,079 research outputs found
Avaliação de modelos para estabelecimento de figura de risco de ocorrência da Sigatoka-Negra em bananais.
bitstream/item/61174/1/DOC55-2011-1.pd
Cosmological scenarios from multiquintessence
In this work we derive and analyse cosmological scenarios coming from
multi-component scalar field models. We consider a direct sum of a sine-Gordon
with a Z2 model, and also a combination of those with a BNRT model. Moreover,
we work with a modified version of the BNRT model, which breaks the Z2 x Z2
symmetry of the original BNRT potential, coupled with the sine-Gordon and with
the standard Z2 models. We show that our approach can be straightforwardly
elevated to fields. All the computations are made analytically and some
parameters restriction is put forward in order to get in touch with complete
and realistic cosmological scenarios
Fungos associados a sementes de açaí: efeito da temperatura e do teor de água das sementes durante o armazenamento.
O trabalho teve como objetivo verificar os efeitos do teor de água e da temperatura do ambiente de armazenamento na incidência de fungos e na germinação de sementes de açaí (Euterpe oleracea Mart.). Foram utilizadas sementes da cultivar BRS Pará, com teores de água de 43%, 37%, 30%, 26%, 21% e 12%, que foram acondicionadas em sacos de polietileno, armazenadas sob temperaturas de 20 ºC, 15 ºC e 10 ºC, durante 360 dias e submetidas a avaliações bimensais do teor de água, da germinação e da incidência de Penicillium sp., Aspergillus sp., Fusarium solani e Fusarium verticillioides. Foi adotado o delineamento experimental inteiramente casualizado com quatro repetições para o teste de germinação e cinco repetições para os testes de sanidade. Foi observada maior ocorrência de Penicillium sp., e Aspergillus sp em sementes com teores de água abaixo de 30% e mantidas nas temperaturas de 15 ºC e 20 ºC. Enquanto, as maiores incidências de fungos do gênero Fusarium foram encontradas em sementes armazenadas com graus de umidade de 43% e 37% e mantidas em temperatura de 10 ºC
Electrostatic self-force in (2+1)-dimensional cosmological gravity
Point sources in (2+1)-dimensional gravity are conical singularities that
modify the global curvature of the space giving rise to self-interaction
effects on classical fields. In this work we study the electrostatic
self-interaction of a point charge in the presence of point masses in
(2+1)-dimensional gravity with a cosmological constant.Comment: 9 pages, Late
The pasta phase within density dependent hadronic models
In the present paper we investigate the onset of the pasta phase with
different parametrisations of the density dependent hadronic model and compare
the results with one of the usual parametrisation of the non-linear Walecka
model. The influence of the scalar-isovector virtual delta meson is shown. At
zero temperature two different methods are used, one based on coexistent phases
and the other on the Thomas-Fermi approximation. At finite temperature only the
coexistence phases method is used. npe matter with fixed proton fractions and
in beta-equilibrium are studied. We compare our results with restrictions
imposed on the the values of the density and pressure at the inner edge of the
crust, obtained from observations of the Vela pulsar and recent isospin
diffusion data from heavy-ion reactions, and with predictions from spinodal
calculations.Comment: 15 pages, 11 figures and 7 table
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