Building analytical three-field cosmological models

A difficult task to deal with is the analytical treatment of models composed by three real scalar fields, once their equations of motion are in general coupled and hard to be integrated. In order to overcome this problem we introduce a methodology to construct three-field models based on the so-called "extension method". The fundamental idea of the procedure is to combine three one-field systems in a non-trivial way, to construct an effective three scalar field model. An interesting scenario where the method can be implemented is within inflationary models, where the Einstein-Hilbert Lagrangian is coupled with the scalar field Lagrangian. We exemplify how a new model constructed from our method can lead to non-trivial behaviors for cosmological parameters.Comment: 11 pages, and 3 figures, updated version published in EPJ

Avaliação de diferentes porta-enxertos de citrus cultivados em citropotes.

Este trabalho objetivou acompanhar o desenvolvimento de cinco porta-enxertos de citrus cultivados em citropotes com 7 litros de substrato

Composition of brazilian phosphate rocks used for cattle feed supplement.

Pbospbate rocks cünstitute lhe bulk of the raw materiaIs for the manufacture fertilizers and some phosphorus b-ased chemicals. !t is well known that natural pbosphate a great varíation of heavy melaIs, and some of lhem, depending of tlleir cOllcentratÍon, present nutritional lmd environmental problems [1]

Incidência de parasitismo em adultos de percevejos fitófagos em Goiás.

O objetivo deste trabalho foi determinar a incidência natural de parasitóides em ninfas e adultos de várias espécies de percevejos

Overcoming inertia : drivers of the outsourcing process

Almost all managers have directly or indirectly been involved in the practice of outsourcing in recent years. But as they know, outsourcing is not straightforward. Outsourcing inertia, when companies are slow to adapt to changing circumstances that accommodate higher outsourcing levels, may undermine a firm’s performance. This article investigates the presence of outsourcing inertia and the factors that help managers overcome it. Using statistical evidence, we show that positive performance effects related to outsourcing can accumulate when circumstances change. This is then followed by rapid increases in outsourcing levels (i.e. outsourcing processes). We investigate what gives rise to these outsourcing processes through follow-up interviews with sourcing executives, which suggest five drivers behind outsourcing processes: managerial initiative (using outside experience); hierarchy (foreign headquarters); imitation (of competitors and of similar firms); outsider advice (from external institutions); knowledge sources (using external information). These five drivers all offer scope for managerial action. We tie them to academic literatures and suggest ways of investigating their presence and impact on the outsourcing process. Overall, we conclude that while economizing factors play a key role in explaining how much firms outsource, it is socializing factors that tend to drive outsourcing processes