Modeling separator membranes physical characteristics for optimized lithium ion battery performance

The effect of varying separator membrane physical parameters such as degree of porosity, tortuosity and thickness, on battery delivered capacity was studied in order to optimize performance of lithium-ion batteries. This was achieved by a theoretical mathematical model relating the Bruggeman coefficient with the degree of porosity and tortuosity. The inclusion of the separator membrane in the simulation model of the battery system does not affect the delivered capacity of the battery. The ionic conductivity of the separator and consequently the delivered capacity values obtained at different discharge rates depends on the value of the Bruggeman coefficient, which is related with the degree of porosity and tortuosity of the membrane. Independently of scan rate, the optimal value of the degree of porosity is above 50% and the separator thickness should range between 1 μm at 32 μm for improved battery performance.

Aplicação do Building Information Modeling na gestão de projetos de construção

Dissertação de mestrado em Construção e Reabilitação Sustentáveis

Modeling microbes: New methods for integrated metabolic and regulatory network reconstruction

PhD Thesis in Bioengineering

Avaliação de políticas públicas de desenvolvimento turístico das cidades de Gramado (Brasil) e Rovaniemi (Finlândia)

Tese de Doutoramento Geografia (Área de Especialização: Geografia e Planeamento Regional)

A relational algebra approach to ETL modeling

The MAP-i Doctoral Programme in Informatics, of the Universities of Minho, Aveiro and Porto

High strain rate constitutive modeling forhistorical structures subjected to blast loading

Doctoral Thesis Civil Engineering

Fused deposition modeling with polypropylene

This paper addresses the potential of polypropylene (PP) as a candidate for fused deposition modeling (FDM)-based 3D printing technique. The entire filament production chain is evaluated, starting with the PP pellets, filament production by extrusion and test samples printing. This strategy enables a true comparison between parts printed with parts manufactured by compression molding, using the same grade of raw material. Printed samples were mechanically characterized and the influence of filament orientation, layer thickness, infill degree and material was assessed. Regarding the latter, two grades of PP were evaluated: a glass-fiber reinforced and a neat, non-reinforced, one. The results showed the potential of the FDM to compete with conventional techniques, especially for the production of small series of parts/components; also, it was showed that this technique allows the production of parts with adequate mechanical performance and, therefore, does not need to be restricted to the production of mockups and prototypes.

[Editorial] Current challenges in modeling cellular metabolism

The authors would like to thank the financial support from the NovoNordiskFoundation.

Design and validation of a biomechanical bioreactor for cartilage tissue culture

Specific tissues, such as cartilage undergo mechanical solicitation under their normal performance in human body. In this sense, it seems necessary that proper tissue engineering strategies of these tissues should incorporate mechanical solicitations during cell culture, in order to properly evaluate the influence of the mechanical stimulus. This work reports on a user-friendly bioreactor suitable for applying controlled mechanical stimulation - amplitude and frequency - to three dimensional scaffolds. Its design and main components are described, as well as its operation characteristics. The modular design allows easy cleaning and operating under laminar hood. Different protocols for the sterilization of the hermetic enclosure are tested and ensure lack of observable contaminations, complying with the requirements to be used for cell culture. The cell viability study was performed with KUM5 cells.

Portuguese publication in the aim of regional science: a study of articles published in RPER from 2003 to 2015

This paper is a study of the full content of articles published by RPER, the Portuguese Review of Regional Studies, from the time it was launched in 2003 until the first quarter of 2015. RPER is a journal edited by the Portuguese section of the European Regional Science Association, which was established in the first half of the 1980s. The Association (APDR) and the journal are the result of contributions by researchers and technicians from different scientific fields, including mainly Economics, Geography, Sociology, Engineering and Architecture. The main focus of these contributions is the socio-economic life of concrete sites, and the way this life is conditioned by resources and capabilities, the historical and cultural heritage and institutions. Content analysis was undertaken to identify the main subjects chosen during the total period under analysis, the nature of the articles published (theoretical or empirical) and the main analytical framework used. The analysis also covers sub-periods to investigate major trends found in terms of subjects chosen and analytical methods, questioning the rationale behind them. The paper concludes with a few notes regarding the social echo the research received and an identification of the main limitations of the research. In the first part of the article, we conduct a summary review of the genesis and evolution of Regional Science at international level to serve as a basis for the empirical approach developed.

Numerical modeling and assessment of the thermal environment in an industrial premise of automotive components

Dissertação de mestrado em Engenharia Industrial

Método de desagregação temporal para a previsão da taxa de desemprego em Portugal

Dissertação de mestrado em Estatística

As imigrantes brasileiras no jornalismo impresso regional

O estudo sobre a representação das brasileiras nos media é revisto sob vários aspectos e nos diversos meios de comunicação. Alguns estudos aprofundam a imagem das imigrantes, enquanto outros se concentram nos meios (rádio, televisão e imprensa). Existe ainda uma linha de investigação que se centra nos estudos da recepção. Todavia, verificámos a escassez de um estudo específico sobre a representação deste grupo no jornalismo de proximidade. Esta comunicação tem por objectivo apresentar parte dos resultados sobre a representação dos imigrantes brasileiros nas notícias publicadas durante o ano de 2007 em dois jornais regionais (um português – Diário do Minho – e um italiano – L'Adige). A escolha de um jornal externo ao contexto português foi extremamente enriquecedora para identificar possíveis convergências no tratamento dos imigrantes brasileiros (homens e mulheres) em diferentes contextos sócioculturais. Além disso, tanto Portugal como Itália foram países de forte emigração, influenciando os processos migratórios de ambos. A investigação inicial mostrou uma acentuada assimetria de género, o que nos levou a aprofundar a análise sob este aspecto. Observámos que os jornais analisados, em relação ao tratamento informativo da imigrante brasileira, trabalham na mesma linha dos jornais de âmbito nacional e, mesmo que em escala inferior, continuam a representar estas mulheres com um baixo estatuto, associadas a temas e comportamentos socialmente conotados com a marginalidade. De salientar que as imigrantes brasileiras que têm visibilidade nas peças noticiosas dos dois jornais são geralmente conotadas com a prostituição, clandestinidade, crime e exploração.

Influence of the hip joint modeling approaches on the kinematics of human gait

The influence of the hip joint formulation on the kinematic response of the model of human gait is investigated throughout this work. To accomplish this goal, the fundamental issues of the modeling process of a planar hip joint under the framework of multibody systems are revisited. In particular, the formulations for the ideal, dry, and lubricated revolute joints are described and utilized for the interaction of femur head inside acetabulum or the hip bone. In this process, the main kinematic and dynamic aspects of hip joints are analyzed. In a simple manner, the forces that are generated during human gait, for both dry and lubricated hip joint models, are computed in terms of the system’s state variables and subsequently introduced into the dynamics equations of motion of the multibody system as external generalized forces. Moreover, a human multibody model is considered, which incorporates the different approaches for the hip articulation, namely ideal joint, dry, and lubricated models. Finally, several computational simulations based on different approaches are performed, and the main results presented and compared to identify differences among the methodologies and procedures adopted in this work. The input conditions to the models correspond to the experimental data capture from an adult male during normal gait. In general, the obtained results in terms of positions do not differ significantly when the different hip joint models are considered. In sharp contrast, the velocity and acceleration plotted vary significantly. The effect of the hip joint modeling approach is clearly measurable and visible in terms of peaks and oscillations of the velocities and accelerations. In general, with the dry hip model, intra-joint force peaks can be observed, which can be associated with the multiple impacts between the femur head and the cup. In turn, when the lubricant is present, the system’s response tends to be smoother due to the damping effects of the synovial fluid.

A integração de técnicas BIM (Building Information Modeling) no projeto e na construção de estruturas de madeira

Dissertação de mestrado integrado em Engenharia Civil