1,661 research outputs found
Meridional rank of whitehead doubles
We prove that the meridional rank and the bridge number of the Whitehead
double of a prime algebraically tame knot coincide. Algebraically tame knots
are a broad generalization of torus knots and iterated cable knots.Comment: 29 pages, 28 figure
Estabelecimento de sementes de Eucalyptus benthamii e Eucalyptus badjensis em meio de cultura MS.
EVINCI. Resumo 007
Desinfestação de segmentos nodais de Eucalyptus dunnii visando estabelecimento in vitro.
A espécie Eucalyptus dunnii apresenta potencial econômico e técnico de exploração na metade sul do Rio Grande do Sul. Esta espécie tem como característica produzir poucas sementes, o que dificulta sua propagação. A cultura de tecidos oferece grande potencial para a propagação in vitro de espécies lenhosas. A micropropagação só pode ocorrer se o processo de desinfestação obtiver sucesso. O objetivo deste trabalho foi avaliar e adequar o processo de desinfestação de segmentos nodais pertencentes à espécie Eucalyptus dunnii. Foram realizados tratamentos com hipoclorito de sódio (NaClO) á 0%; 0,5%; 1,0%; 1,5% e 2,0% de cloro ativo. As avaliações nos tratamentos foram em relação as contaminações fúngicas e bacterianas; oxidações; sobrevivência e o estabelecimento dos explantes. Observou-se que não houve diferença significativa entre os tratamentos, porém, os níveis de contaminações diminuíram quando submetidos nas diferentes variações de concentração de (NaClO) em relação ao tratamento testemunha. Pode-se verificar que os explantes submetidos nas concentrações de 1,5% e 2,0% de (NaClO), obtiveram melhores resultados quando comparados aos demais tratamentos
Concentrações de sacarose na sobrevivência de plântulas de Eucalyptus benthamii Maid e Camb. durante o enraizamento ex vitro.
Resumo
Two field BPS solutions for generalized Lorentz breaking models
In this work we present nonlinear models in two-dimensional space-time of two
interacting scalar fields in the Lorentz and CPT violating scenarios. We
discuss the soliton solutions for these models as well as the question of
stability for them. This is done by generalizing a model recently published by
Barreto and collaborators and also by getting new solutions for the model
introduced by them.Comment: 12 pages, 2 figure
Aplicações de biossensores na análise da qualidade de alimentos.
Biossensores; Classificação de biossensores; Desenvolvimento de biossensores; Aplicaçõs de biossensores; Aplicações de biossensores na indústria de alimentos.bitstream/item/33970/1/Dc-117.pd
Effect of non-Newtonian fluid rheology on an arterial bypass graft: A numerical investigation guided by constructal design
In post-operative scenarios of arterial graft surgeries to bypass coronary artery stenosis, fluid dynamics plays a crucial role. Problems such as intimal hyperplasia have been related to fluid dynamics and wall shear stresses near the graft junction. This study focused on the question of the use of Newtonian and non-Newtonian models to represent blood in this type of problem in order to capture important flow features, as well as an analysis of the performance of geometry from the view of Constructive Theory. The objective of this study was to investigate the effects rheology on the steady-state flow and on the performance of a system consisting of an idealized version of a partially obstructed coronary artery and bypass graft. The Constructal Design Method was employed with two degrees of freedom: the ratio be- tween bypass and artery diameters and the junction angle at the bypass inlet. The flow problem was solved numerically using the Finite Volume Method with blood modeled employing the Carreau equation for viscosity. The Computational Fluid Dynamics model associated with the Sparse Grid method generated eighteen response surfaces, each representing a severe stenosis degree of 75% for specific combinations of rheological parameters, dimensionless viscosity ratio, Carreau number and flow index at two distinct Reynolds numbers of 150 and 250. There was a considerable dependence of the pressure drop on rhe- ological parameters. For the two Reynolds numbers studied, the Newtonian case presented the lowest value of the dimensionless pressure drop, suggesting that the choice of applying Newtonian blood may underestimate the value of pressure drop in the system by about 12.4% ( Re = 150) and 7.8% ( Re = 250). Even so, results demonstrated that non-Newtonian rheological parameters did not influence either the shape of the response surfaces or the optimum bypass geometry, which consisted of a diameter ratio of 1 and junction angle of 30 °. However, the viscosity ratio and the flow index had the greatest im- pact on pressure drop, recirculation zones and wall shear stress. Rheological parameters also affected the recirculation zones downstream of stenosis, where intimal hyperplasia is more prevalent. Newto- nian and most non-Newtonian results had similar wall shear stresses, except for the non-Newtonian case with high viscosity ratio. In the view of Constructal Design, the geometry of best performance was in- dependent of the rheological model. However, rheology played an important role on pressure drop and flow dynamics, allowing the prediction of recirculation zones that were not captured by a Newtonian model
Identificação de enzimas expressas em clones metagenômicos por espectrometria de massa.
Dissertação (Mestrado) - Universidade Católica de Brasília, Brasília, DF. Orientadora: Beatriz Simas Magalhães. Coorientadora CNPAE: Betania Ferraz Quirino
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