Point-Coupling Models from Mesonic Hypermassive Limit and Mean-Field Approaches

In this work we show how nonlinear point-coupling models, described by a Lagrangian density that presents only terms up to fourth order in the fermion condensate $(\bar{\psi}\psi)$, are derived from a modified meson-exchange nonlinear Walecka model. The derivation can be done through two distinct methods, namely, the hypermassive meson limit within a functional integral approach, and the mean-field approximation in which equations of state at zero temperature of the nonlinear point-coupling models are directly obtained.Comment: 18 pages. Accepted for publication in Braz. J. Phy

Yield and Quality of Annual Ryegrass Grown in Pure Stand and in Mixtures with Squarrosum Clover

The objective of this study was to evaluate the importance of growing annual ryegrass in mixtures instead of ryegrass alone in order to reduce nitrogen application and thereby lowering production costs, and environmental pollution

The Effect of Plant Population on the Yield and Quality of Annual Rye-Grass

The primary objectives of this study were to evaluate the effect of three plant population levels (350, 750 and 1150 plants m-2) on dry matter yield and forage quality (crude protein and dry matter digestibility) of four rye-grass genotypes (Barspectra, Billion, Clipper and Pollanum) used in two harvests (March and May). The results for dry matter yield means by year, genotype, and harvest were always higher in the second harvest than in the first, and the highest total mean value was reached in the first year (5853 Kg ha-1). The genotype Billion was the most stable over years. Concerning to plant population there was a trend for the highest level to conduct to the best results only in the first year, for most of the genotypes. Protein concentration was greater in the first harvest (206 g kg-1) than in the second (124 g kg-1). It was also found that the best value was reached at the lowest plant population level and that Billion genotype showed the lowest content, 161 g kg-1, but not very much different from the others. For dry matter digestibility the highest values were found in the second year (740 g kg- 1) and in the first harvest (854 g kg-1). The genotype Clipper presented the greatest value (740 g kg-1) and so did the intermediate level of plant population. As a general conclusion it can be stated that, for practical purposes, the intermediate population level (750 pl m-2), especially in dry years, and the genotype Billion should be recommended

Alvenaria armada : soluções inovadoras em Portugal

Neste trabalho pretende-se abordar aspectos relacionados com as tipologias de paredes de alvenaria estrutural e com a concepção de edifícios em alvenaria. Além disso, são apresentadas duas principais soluções em alvenaria armada que têm vindo a ser objecto de estudo na Universidade do Minho. Discutem-se aspectos de concepção e tipologias e complementarmente os resultados experimentais obtidos na validação experimental de ambas as soluções

Relativistic Mean-Field Hadronic Models under Nuclear Matter Constraints

Relativistic mean-field (RMF) models have been widely used in the study of many hadronic frameworks because of several important aspects not always present in nonrelativistic models, such as intrinsic Lorentz covariance, automatic inclusion of spin, appropriate saturation mechanism for nuclear matter, causality and, therefore, no problems related to superluminal speed of sound. With the aim of identifying the models which best satisfy well known properties of nuclear matter, we have analyzed $263$ parameterizations of seven different types of RMF models under three different sets of constraints related to symmetric nuclear matter, pure neutron matter, symmetry energy, and its derivatives. One of these (SET1) is formed of the same constraints used in a recent work [M. Dutra et al., Phys. Rev. C 85, 035201 (2012)] in which we analyzed $240$ Skyrme parameterizations. The results pointed to $2$ models consistent with all constraints. By using another set of constraints, namely, SET2a, formed by the updated versions of the previous one, we found $4$ models approved simultaneously. Finally, in the third set, named SET2b, in which the values of the constraints are more restrictive, we found $3$ consistent models. Another interesting feature of our analysis is that the results change dramatically if we do not consider the constraint regarding the volume part of the isospin incompressibility ($K_{\tau,\rm v}$). In this case, we have $35$ approved models in SET2a and $30$ in SET2b.Comment: 63 pages, 3 figures and 9 tables. Version accepted for publication in PR

Relativistic Mean-Field Models and Nuclear Matter Constraints

This work presents a preliminary study of 147 relativistic mean-field (RMF) hadronic models used in the literature, regarding their behavior in the nuclear matter regime. We analyze here different kinds of such models, namely: (i) linear models, (ii) nonlinear \sigma^3+\sigma^4 models, (iii) \sigma^3+\sigma^4+\omega^4 models, (iv) models containing mixing terms in the fields \sigma and \omega, (v) density dependent models, and (vi) point-coupling ones. In the finite range models, the attractive (repulsive) interaction is described in the Lagrangian density by the \sigma (\omega) field. The isospin dependence of the interaction is modeled by the \rho meson field. We submit these sets of RMF models to eleven macroscopic (experimental and empirical) constraints, used in a recent study in which 240 Skyrme parametrizations were analyzed. Such constraints cover a wide range of properties related to symmetric nuclear matter (SNM), pure neutron matter (PNM), and both SNM and PNM.Comment: 3 Pages, submitted for proceedings of XXXV Reuni\~ao de Trabalho sobre F\'isica Nuclear no Brasil 201

An experience in building a parallel and distributed problem-solving environment

We describe our experimentation with the design and implementation of specific environments, consisting of heterogeneous computational, visualization, and control components. We illustrate the approach with the design of a problem-solving environment supporting the execution of genetic algorithms. We describe a prototype steering parallel execution, visualization, and steering. A life cycle for the development of applications based an genetic algorithms is proposed.publishersversionpublishe

Validation of masonry systems for in-plane lateral loading using truss reinforcement

The paper presents and describes the main issues related to two building systems for modern masonry structures using truss reinforcement, currently under development at University of Minho, one based on lightweight concrete blocks and another based on reinforced concrete block masonry. Details of the experimental and numerical work carried out are addressed, together with conclusions on the performance of the system for in-plane lateral loading