Cálculo dos níveis ótimos de rentabilidade para o desempenho energético de habitações residenciais unifamiliares objeto de reabilitação

Dissertação de mestrado em Construção e Reabilitação Sustentáveis

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.

Cost optimal strategies for the renovation of residential neighbourhoods towards energy and emissions neutrality – Rainha Dona Leonor case study

Buildings are one of the major consumers of energy in Europe. This makes them an important target when aiming to reduce the energy consumptions and carbon emissions. The majority of the European building stock has already some decades and so it needs renovation in order to keep its functionality. Taking advantage of these interventions, the energy performance of the buildings may also be improved. In Portugal the renovation techniques, both regarding energy efficiency measures as well as measures for the use of renewable energy sources, are normally planned at the building scale. It is important to explore the possibility of having large scale interventions, has it has been done in other countries, namely at neighbourhood scale with district energy system in order to optimize the results in terms of costs and environmental impact.