Imagem de tensor de difusão em alzheimer

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Engenharia Biomédica

On the choice of posittioning and cluster size for fixed relay stations in a LTE network

The long term evolution (LTE) is one of the latest standards in the mobile communications market. To achieve its performance, LTE networks use several techniques, such as multi-carrier technique, multiple-input-multiple-output and cooperative communications. Inside cooperative communications, this paper focuses on the fixed relaying technique, presenting a way for determining the best position to deploy the relay station (RS), from a set of empirical good solutions, and also to quantify the associated performance gain using different cluster size configurations. The best RS position was obtained through realistic simulations, which set it as the middle of the cell's circumference arc. Additionally, it also confirmed that network's performance is improved when the number of RSs is increased. It was possible to conclude that, for each deployed RS, the percentage of area served by an RS increases about 10 %. Furthermore, the mean data rate in the cell has been increased by approximately 60 % through the use of RSs. Finally, a given scenario with a larger number of RSs, can experience the same performance as an equivalent scenario without RSs, but with higher reuse distance. This conduces to a compromise solution between RS installation and cluster size, in order to maximize capacity, as well as performance.

Matching CO2 large point sources and potential geological storage sites in mainland Portugal

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, Perfil Gestão e Sistemas Ambientais

Dinossauros e Portugal: dois casos menos conhecidos

After some remarks on the protection of sites recognized as most interesting, two less known items about dinosaurs and Portugal are dealt with. The first of theme concerns the first published account on dinosaur tracks. Jacinto Pedro Gomes, then (1884) preparing a report on the Cabo Mondego coal mines, was told of the occurrence of large footprint casts that subsequently were sent to the Museum of the Escola Politécnica in Lisbon. Gomes has shown drawings of them to B. Geinitz (Dresden), who ascribed the casts to dinosaurs. Karl Zittel (München), corroborated this viewpoint, and Louis Dollo (Brussels) reported them to Ornithopods. A posthumous note by GOMES (1915-1916) is the first scientific paper on dinosaur tracks in Portugal. However, it is not the first published report. João Bonança, a reporter, presented in his large book "HISTORIA / DA / LUZITANIA E DA IBERIA ..." (1891), a new (both irrealistic and useless) stratigraphic classification. He also replaced Zoological and Botanic Nomenclature by another one devised by him. Having seen the footprint casts at the Museum of the Escola Politécnica, he referred bird or dinosaur footprints in Cabo Mondego's Upper Jurassic, this being the first published report on such fossils as far as Portugal is concerned. The second theme is about Late Cretaceous dinosaurs from Viso, Aveiro and Taveiro. Faunas are marked by generalized nannism, and seem impoverished by previous extinctions of larger forms; their probable insular character has been acknowledged. Extinctions may well be explained by non-catastrophic causes. The general fall of temperatures may have been far more important.