Desenvolvimento do método de Índice de Qualidade ("QIM-Quality Index Method") para as lapas (Patella candei e Patella aspera) e estudo das suas condições de transporte

Dissertação de Mestrado, Estudos Integrados dos Oceanos, 15 de Março de 2016, Universidade dos Açores.

Evaluación de los recursos marisqueros (lapas y cangrejos) del archipiélago canario

Máster en Medio Ambiente Litoral y Marino

Paleoceanographic record since 13kyr BP of sediment core LaPAS-KF02

In this paper we present a paleoceanographic reconstruction of the southwestern South Atlantic for the past 13 kyr based on faunal and isotopic analysis of planktonic foraminifera from a high-resolution core retrieved at the South Brazil Bight continental slope. Our record indicates that oceanographic changes in the southwestern South Atlantic during the onset of the Holocene were comparable in strength to those that occurred during the Younger Dryas. Full interglacial conditions started abruptly after 8.2 kyr BP with a sharp change in faunal composition and surface hydrography (SST and SSS). Part of the observed events may be explained in terms of changes in thermohaline circulation while the other part suggests a dominant role of winds. Our data indicate that during the Early Holocene upwelling was significantly strengthened in the South Brazil Bight promoting high productivity and preventing the establishment of the typically interglacial menardiiform species. In general terms, oceanographic changes recorded by core KF02 occurred in synchrony with Antarctica's climate.

Efficient route update and maintenance processes for multipath routing in large-scale industrial wireless sensor networks

Reliable communications is one of the major concerns in wireless sensor networks (WSNs). Multipath routing is an effective way to improve communication reliability in WSNs. However, most of existing multipath routing protocols for sensor networks are reactive and require dynamic route discovery. If there are many sensor nodes from a source to a destination, the route discovery process will create a long end-to-end transmission delay, which causes difficulties in some time-critical applications. To overcome this difficulty, the efficient route update and maintenance processes are proposed in this paper. It aims to limit the amount of routing overhead with two-tier routing architecture and introduce the combination of piggyback and trigger update to replace the periodic update process, which is the main source of unnecessary routing overhead. Simulations are carried out to demonstrate the effectiveness of the proposed processes in improvement of total amount of routing overhead over existing popular routing protocols.

An efficient proactive route maintenance process for reliable data transmissions in sensor networks

For industrial wireless sensor networks, maintaining the routing path for a high packet delivery ratio is one of the key objectives in network operations. It is important to both provide the high data delivery rate at the sink node and guarantee a timely delivery of the data packet at the sink node. Most proactive routing protocols for sensor networks are based on simple periodic updates to distribute the routing information. A faulty link causes packet loss and retransmission at the source until periodic route update packets are issued and the link has been identified as broken. We propose a new proactive route maintenance process where periodic update is backed-up with a secondary layer of local updates repeating with shorter periods for timely discovery of broken links. Proposed route maintenance scheme improves reliability of the network by decreasing the packet loss due to delayed identification of broken links. We show by simulation that proposed mechanism behaves better than the existing popular routing protocols (AODV, AOMDV and DSDV) in terms of end-to-end delay, routing overhead, packet reception ratio.

Effective routing with utilisation of cross-layer information for industrial wireless sensor networks

This thesis focuses on providing reliable data transmissions in large-scale industrial wireless sensor networks through improving network layer protocols. It addresses three major problems: scalability, dynamic industrial environments and coexistence of multiple types of data traffic in a network. Theoretical developments are conducted, followed by simulation studies for verification of theoretic results. The approach proposed in this thesis has been shown to be effective for large-scale network implementation and to provide improved data transmission reliability for both periodic and sporadic traffic.

Limites de distribuição vertical da espécie Patella depressa: padrões e processos

Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Análise de risco e inspeções de segurança em elevadores, escadas mecânicas e tapetes rolantes

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Apoios educativos a alunos com dificuldades na aprendizagem: o que acontece quando não são abrangidos pelo Ensino Especial?

O presente trabalho tem como o objetivo analisar quais tipos de apoio têm sido oferecidos aos alunos que apresentam dificuldade de aprendizagem mas que não foram diagnosticados como alunos com necessidades educativas especiais dentro de uma escola regular, ou seja, alunos que não podem estar abrangidos ou integrados nas medidas do ensino especial. Neste trabalho será feita uma reflexão sobre recursos e políticas educativas, em especial nos primeiros anos da Educação Básica, uma das fases mais importantes para o desenvolvimento e a aprendizagem dos alunos. Trata-se de um estudo descritivo, com base num questionário respondido por uma amostra de 20 professores a exercer na zona de Lisboa. O questionário continha um conjunto de perguntas fechadas e 4 questões abertas, e os dados foram analisados quantitativamente e as perguntas abertas alvo de análise qualitativa. Em complemento realizou-se uma entrevista de aprofundamento e clarificação das respostas. Os resultados sugerem que apesar de ser um número pequeno de participantes ainda sim foi possível identificar uma variedade muito grande de dificuldades encontradas nos seus alunos. Os professores especificaram algumas dessas dificuldades encontradas, juntamente com alguns fatores que contribuem para o agravamento das mesmas. Os resultados apontam ainda para algumas medidas de apoio usadas por esses professores e as medidas de apoio oferecidas pelo sistema educativo para amenizar essas dificuldades. Através deste estudo foi possível pensar sobre as dificuldades encontradas nos nossos alunos, e verificar que a muito por ser feito apesar do esforço de muitos professores, ainda sim e preciso repensar as práticas pedagógicas, os apoios oferecido, e se essas estratégias realmente surte efeito para esses alunos.

Heat transfer between nanoparticles: Thermal conductance for near-field interactions

We analyze the heat transfer between two nanoparticles separated by a distance lying in the near-field domain in which energy interchange is due to the Coulomb interactions. The thermal conductance is computed by assuming that the particles have charge distributions characterized by fluctuating multipole moments in equilibrium with heat baths at two different temperatures. This quantity follows from the fluctuation-dissipation theorem for the fluctuations of the multipolar moments. We compare the behavior of the conductance as a function of the distance between the particles with the result obtained by means of molecular dynamics simulations. The formalism proposed enables us to provide a comprehensive explanation of the marked growth of the conductance when decreasing the distance between the nanoparticles.