Reabilitação urbana : abordando práticas sustentáveis

O ambiente urbano construído carece atualmente de novas considerações e entendimentos sobre o seu potencial. Para isto é necessário compreender quais são as necessidades e prioridades no desenvolvimento das urbes de modo a traçar uma estratégia de intervenção coincidente com as necessidades das populações. De maneira a inverter a tendência dos centros urbanos cada vez mais amorfos, pensa-se que a reabilitação é hoje em dia encarada como uma espécie de possível solução capaz de contribuir para a redução do impacte ambiental e também como oportunidade de investimento financeiro. No desenvolvimento do presente artigo, procura-se entender através da abordagem a esta tendência - relacionada com os aspetos económicos, sociais e ambientais espelhados nos princípios sustentáveis - de que maneira podem a sustentabilidade e a reabilitação do espaço construído caminhar no mesmo sentido contribuindo para um crescimento social, económico e ambiental. É ainda abordado neste artigo como referência a uma digna prática sustentável, o recente caso de regeneração urbana do Parque Olímpico planeado e pensado para receber o evento Londres2012, devido às opções tomadas e à implementação de medidas na reabilitação, reconstrução e revitalização dos espaços construídos

Urban rehabilitation towards sustainability

The sustainable concern is nowadays reflected in construction, reconstruction and rehabilitation of the building and how it can contribute to a lower environmental impact. Is intended to understand how the culture expressions forms, by the (re)construction and, of architectural styles in their inherent periods, is able to transform implicitly with creativity in the evolution of cities and societies. To reverse the amorphous urban area situation, it is necessary to intervene with sustainable geniality based on particular policies and strategies to regenerate the built space contributing to a sustainable social, economical and environmental growth and development. Why rehabilitate? What is the weight of rehabilitation on sustainability? These are some questions seeking an answer approach on the development of this paper. It is further developed as a sustainable city reference, the city of Freiburg im Breisgau, Germany, due to the implementation of reconstruction and rehabilitation policies and measures environmentally viable

Identifying the centrality levels of futsal players : a network approach

The aim of this study it was verify the differences of prominence levels between tactical positions in futsal (indoor football). For that reason, it was performed an analysis of variance between competitive levels and tactical positions for the centrality metrics computed by using network analysis. Forty-six futsal players from different competitive levels (U12, U14, U16 and Amateurs) it were analysed during three official futsal matches. Results revealed no differences in centrality metrics between competitive levels (p = 1.00; = 0.001; very small effect size) had no significant statistical differences in the centrality metrics. Nevertheless, tactical position (p = 0.001; = 0.593; moderate effect size) had significant main effects on the centrality metrics. Centrality metrics revealed that defenders are the most prominent players in to receive the ball. By the other hand, defenders and wings are the positions with greater centralities in to pass the ball for the teammates.info:eu-repo/semantics/publishedVersio

Assessment of interactions at children playgrounds using network measures : an exploratory study based on graph theory

This study has used network measures to classify the children interactions in playground. The variance of network processes between genders was tested. Five girls and boys (n = 10; 4.6 0.6 years old) were observed. Statistical procedures has revealed significant differences between genders in IDC (p = 0.027; ES = 0.476; moderate effect) and BC (p = 0.011; ES = 0.576; moderate effect). Results revealed a greater cooperation process between boys.info:eu-repo/semantics/publishedVersio

Who is the prominent tactical position in rink-hockey? : a network approach based on centrality metrics

The aim of this study was to verify the prominence levels of rink-hockey players in different competitive levels. For that reason, it was analysed the variance of network centrality metrics between competitive levels and tactical positions. Fifty-four rink-hockey players from five different levels (U12, U14, U16, U18 and Elite) were analysed during three official matches. The results did not found statistical differences in centrality levels of players between competitive levels (p-value = 1.00; partial eta square = 0.001; very small effect size). Nevertheless, tactical position (p-value = 0.001; partial eta square = 0.534; moderate effect size) had significant main effects on the centrality metrics. In this study it was found that defender and forward are the positions that most receive balls from the teammates. In other hand, the forward is the position that most passes performed until the U16 and in older levels the defender assumes the centrality in passes performed.info:eu-repo/semantics/publishedVersio

Network measures and digraph theory applied to soccer analysis : midfielder is the key player in youth teams

Graph and digraph theories have been used to test the relationships between teammates and the network properties of team sports. Nevertheless, no studies in young soccer teams have been found, as far we know. Therefore, the objective of the study was to apply network measures to identify centrality levels of young soccer players during official matches and analyse the variance between tactical positions and tactical line-ups. Seventy young soccer players from under-10 competitive level were observed during 10 matches. Significant statistical differences were found between players’ positions in IDC (p = 0.001; ES = 0.090; minimum effect); ODC (p = 0.001; ES = 0.156; minimum effect); and BC (p = 0.001; ES = 0.110; minimum effect) variables. No significant statistical differences were found between 1-3-2-1 and 1-2-3-1 line-ups for %IDC (p = 0.113; ES = 0.056; minimum effect), %ODC (p = 0.126; ES = 0.048; minimum effect) and %BC (p = 0.204; ES = 0.035; minimum effect). This study found that midfielder is the key position on the field, being a linkage player to attacking building.info:eu-repo/semantics/publishedVersio

A bidirectional multilevel DC-DC converter applied to a bipolar DC grid: analysis of operation under fault conditions

Recently, DC grids have been an important subject of research due to their attractive features comparing with AC grids. The characteristic advantages of DC grids are not only related with the integration of native DC technologies, as renewable energy sources (RES) and energy storage systems (ESS), but also with the reduced number of power converters. Relatively to the configurations of DC grids, in this paper, it is presented a bipolar DC grid, where an innovative bidirectional multilevel DC-DC converter is considered under a fault-tolerance analysis. This converter can be used to interface with several technologies, but, in the scope of this paper, it is considered the application of an electric vehicle (EV) battery charger. Taking into account that some failures can occur, namely in the DC-DC converter and in the bipolar DC grid, the operation of the DC-DC converter within the bipolar DC grid can be harmful. Therefore, this paper also presents a fault-tolerance analysis of the DC-DC converter when facing the occurrence of failures in itself and in the bipolar DC grid, namely for different scenarios of failure in the DC-link wires. Besides, the control strategy for the DC-DC converter is described in detail for distinct scenarios of operation, both in steady-state and transient-state.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017 and the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017

Fault analysis of a non-isolated three-level DC-DC converter integrated in a bipolar DC power grid

DC power grids present significant advantages over AC power grids, namely higher stability and controllability, and the absence of harmonic currents and reactive power. Moreover, DC grids facilitate the interface with renewable energy sources (RES) and energy storage systems (ESS). DC grids can be either unipolar or bipolar, where the latter consists of three wires and provides higher flexibility, reliability and transmission capacity. However, failures in bipolar DC grids (especially in the power semiconductors) can occur. The consequences of these failures can result in increased costs, depending on the damage, e.g., if it occurs a wire of the DC grid or in the connected power converter. Thus, in this paper is presented a fault analysis of a non-isolated three-level DC-DC converter used to interface solar photovoltaic (PV) panels into a bipolar DC power grid. The fault analysis is conceived through computational simulations, where can be observed the performance of the presented DC-DC converter under fault conditions in each wire of the bipolar DC grid. The simulation results demonstrate the DC-DC converter operating in two different situations: steady-state and transient-state. The control strategy applied in normal and fault conditions, as well as the different operation modes, are explained in detail.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017

Experimental validation of a bidirectional multilevel dc–dc power converter for electric vehicle battery charging operating under normal and fault conditions

This paper presents a bidirectional multilevel dc–dc power converter for electric vehicle (EV) battery charging. The operating principle of the power converter was presented, analyzed, and experimentally validated under normal and fault conditions. The topology under study was integrated into a bipolar dc grid through the split dc-link of the bidirectional multilevel dc–dc power converter. Considering the failures that can occur in the bipolar dc grid, i.e., in each wire of the bipolar dc grid (positive, negative, and neutral), it was experimentally verified that the dc–dc power converter ensures that the EV battery-charging process continues, regardless of the occurrence or absence of open-circuit failures. In light of this fact, the proposed control algorithms and the presented topology were validated through a set of considerable simulation and experimental results, analyzing the distinct states of the power semiconductors, which compose the bidirectional multilevel dc–dc power converter, for distinct conditions of operation. The developed laboratory prototype of the bidirectional multilevel dc–dc power converter for EV battery charging, which was implemented to obtain the experimental results, is described in detail in this paper. The experimental validation was carried out for the main different fault conditions in the bipolar dc grid in terms of open-circuit failures and, moreover, considering the steady-state and transient-state operations of the dc–dc power converter. The experimental analysis demonstrated that even in the presence of failures in the positive, negative, or neutral wires of the bipolar dc grid, the bidirectional multilevel dc–dc power converter guarantees the correct EV battery-charging operation.This work has been supported by FCT–Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the MEGASOLAR Project POCI-01-0247-FEDER-047220