Análise da acurácia das simulações do modelo BRAMS na Amazônia Ocidental.

O objetivo deste estudo é avaliar o modelo de previsão numérica do tempo BRAMS (Brazilian Regional Atmospheric Modelling System), a partir da comparação entre os valores preditos e os observados (dados do NCEP (National Center Environmental Prediction). Foram realizadas comparações entre os valores preditos e os observados através da raiz do erro quadrático médio (RMSE) para os prognósticos de precipitação de 24, 48, 72 e 96 hs, no período de novembro de 2008 a março de 2009. Os resultados mostraram que o modelo BRAMS teve uma performance melhor quando assimilado com dados do modelo global do NCEP

Phase transitions in simplified models with long-range interactions

We study the origin of phase transitions in some simplified models with long range interactions. For the ring model, we show that a possible new phase transition predicted in a recent paper by Nardini and Casetti from an energy landscape analysis does not occur. Instead of such phase transitions we observe a sharp, although without any non-analiticity, change from a core-halo to an only core configuration in the spatial distribution functions for low energies. By introducing a new class of solvable simplified models without any critical points in the potential energy, we show that a similar behaviour to the ring model is obtained, with a first order phase transition from an almost homogeneous high energy phase to a clustered phase, and the same core-halo to core configuration transition at lower energies. We discuss the origin of these features of the simplified models, and show that the first order phase transition comes from the maximization of the entropy of the system as a function of energy an an order parameter, as previously discussed by Kastner, which seems to be the main mechanism causing phase transitions in long-range interacting systems

Divergência genético-morfológica entre acessos de feijão caupi de porte semi-ereto e ereto.

O estudo da divergência é essencial para o melhoramento vegetal, pois possibilita a quantificação da variabilidade genética..

In vitro degradation and gas production of brachiaria grass with levels of biodiesel byproducts.

ABSTRACT This study aimed to evaluate the in vitro degradability and gas production in diets containing byproducts from the national biodiesel industry (castor bean, canola, forage radish and black sunflower) replacing Brachiaria grass in four levels (0, 30, 50 and 70%). The inoculum for in vitro incubation was obtained from three fistulated Holstein cows. The experimental design was 4 x 4 factorial completely randomized experimental design consisting of four byproducts and four levels. All byproducts studied had a significant effect (p < 0.05) on in vitro digestibility. The castor bean byproducts promoted the lowest cumulative gas production at the end of 48 hours incubation. Regarding digestibility, the byproducts of canola and radish at 70% level did not affect the degradability of dry matter

Statistical Mechanics of Unbound Two Dimensional Self-Gravitating Systems

We study, using both theory and molecular dynamics simulations, the relaxation dynamics of a microcanonical two dimensional self-gravitating system. After a sufficiently large time, a gravitational cluster of N particles relaxes to the Maxwell-Boltzmann distribution. The time to reach the thermodynamic equilibrium, however, scales with the number of particles. In the thermodynamic limit, $N\to\infty$ at fixed total mass, equilibrium state is never reached and the system becomes trapped in a non-ergodic stationary state. An analytical theory is presented which allows us to quantitatively described this final stationary state, without any adjustable parameters

GEOMETRIC EVALUATION OF FOUR STAGGERED CYLINDERS ARRAY SUBJECTED TO FORCED CONVECTIVE FLOWS BY MEANS OF CONSTRUCTAL DESIGN

This work presents a numerical study on the geometric evaluation of forced convective flows over four staggered arrangement of four cylinders. The forced convective flow is considered incompressible, two-dimensional, laminar and unsteady. Geometry varies according to Constructal Design method. The objectives are the maximization of Nusselt number (NuD) and minimization of drag coefficient (CD) between the cylinders and the surrounding flow. Simulations were performed considering Reynolds numbers of ReD = 10, 40 and 150 and air as working fluid, i.e., Prandtl number is assumed Pr = 0.71. The problem presents three degrees of freedom: ST/D (ratio between transversal pitch of the intermediate cylinders and the cylinders diameter), SL1/D (ratio between the frontal and intermediate cylinders longitudinal pitch and the cylinders diameter) and SL2/D (ratio between the intermediate and posterior cylinders longitudinal pitch and the cylinders diameter). However, SL1/D and SL2/D measures were kept fixed at 1.5 and ST/D varies in the range 1.5 ≤ ST/D ≤ 5.0. The conservation equations of mass, momentum and energy conservation are solved with the Finite Volume Method (FVM). Optimal results for fluid-dynamic study in all ReD cases occurred for the lowest values of ST/D, i.e., (ST/D)o,f = 1.5. For thermal analysis, NuD behavior was assessed, where optimal results for ReD = 10 and 40 occurred for the highest values of ST/D, whilst, for ReD = 150, the optimal value was achieved for the intermediate ratio of ST/D = 4.0

Estimativas de parâmetros genéticos em linhagens de feijão-caupi de porte prostrado avaliadas em Aquidauana, MS.

Foram avaliados 20 genótipos de feijão-caupi, provenientes da Embrapa Meio-Norte, em relação a seis características morfo-agronômicas. O experimento foi conduzido na Universidade Estadual de Mato Grosso do Sul, Unidade de Aquidauana, no delineamento de blocos casualizados, com quatro repetições. As estimativas de parâmetros genéticos demonstraram situação favorável ao melhoramento por seleção da característica peso de cem grãos, que apresentou elevado valor de herdabilidade e valor de índice de variação superior à unidade

Adaptabilidade e estabilidade de linhagens de feijão-caupi de porte ereto em Mato Grosso do Sul.

Este trabalho teve como objetivo estudar a adaptabilidade e estabilidade de 20 genótipos de feijão-caupi provenientes da Embrapa Meio-Norte, em três municípios de Mato Grosso do Sul (Chapadão do Sul, Dourados e Aquidauana), com relação à produção de grãos (kg ha-1). Os experimentos foram conduzidos no delineamento de blocos ao acaso, com quatro repetições. Para identificação de genótipos com boa adaptabilidade e estabilidade em relação aos locais estudados, aplicou-se a metodologia de Eberhart & Russell (1966). A linhagem MNC00-553D-8-1-2-3 foi a mais promissora, podendo vir a ser recomendada para cultivo em Chapadão do Sul, Dourados e Aquidauana, com grande chance de sucesso na produção de grãos de feijão-caupi