Tool geometry evaluation for carbon reinforced composite laminates

The use of composite laminates in complex structures has increased significantly. However, there are still some issues when considering their use, mainly related with machining, leading to some difficulties and lack of acceptance. In this work, a methodology to evaluate drill geometry and feed rate based on thrust force and delamination extension is presented.

Evaluation of tools and cutting conditions on carbon fibre reinforced laminates

The distinctive characteristics of carbon fibre reinforced plastics, like low weight or high specific strength, had broadened their use to new fields. Due to the need of assembly to structures, machining operations like drilling are frequent. In result of composites inhomogeneity, this operation can lead to different damages that reduce mechanical strength of the parts in the connection area. From these damages, delamination is the most severe. A proper choice of tool and cutting parameters can reduce delamination substantially. In this work the results obtained with five different tool geometries are compared. Conclusions show that the choice of an adequate drill can reduce thrust forces, thus delamination damage.

Phytoplankton analysis of portuguese reservoirs: a cluster analysis with R

In this work, cluster analysis is applied to a real dataset of biological features of several Portuguese reservoirs. All the statistical analysis is done using R statistical software. Several metrics and methods were explored, as well as the combination of Euclidean metric and the hierarchical Ward method. Although it did not present the best combination in terms of internal and stability validation, it was still a good solution and presented good results in terms of interpretation of the problem at hand.

Atividade tradutológica: a (r)evolução dos últimos 20 anos

Trabalho de natureza profissional para a atribuição do Título de Especialista do Instituto Politécnico do Porto, na área de Línguas e Cuturas - Línguas e Literaturas Estrangeiras, defendido a 11-11-2015.

Stochasticity favoring the effects of the R&D strategies of the firms

We present stochastic dynamics on the production costs of Cournot competitions, based on perfect Nash equilibria of nonlinear R&D investment strategies to reduce the production costs of the firms at every period of the game. We analyse the effects that the R&D investment strategies can have in the profits of the firms along the time. We observe that, in certain cases, the uncertainty can improve the effects of the R&D strategies in the profits of the firms due to the non-linearity of the profit functions and also of the R&D parameters.

Cournot duopoly with competition in the R&D expenditures

We present a new R&D investment in a Cournot Duopoly model and we analyze the different possible types of Nash R&D investments. We observe that the new production costs region can be decomposed in three economical regions, depending on the Nash R&D investment, showing the relevance of the use of patents in new technologies.