Strategic analysis on urban mobility

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and EconomicsAfrican urban cities are growing very rapidly. By 2050, 1.2 billion people, or 60 percent of all Africans, will live in urban areas.1 We are witnessing an unprecedented pace of urbanization in Africa and we have seen similar movements in other continents before. This report presents a strategic and broad analysis on the problem of urban mobility in Luanda, capital of Angola. An integrated urban planning solution will be presented as one of the best alternatives in order to solve the problem. Throughout the analysis, the political importance will always be taken into consideration as a key success factor for the successful implementation of an integrated urban plan

Desenvolvimento de sistema de tracção baseado em pilha de combustível

Mestrado em Engenharia Electrónica e TelecomunicaçõesO presente trabalho visa a implementação de um sistema de tracção baseado em pilha de combustível. Apresenta como objectivo principal a sua inclusão num veículo automóvel, cuja eficiência deverá ser o ponto fulcral. De facto, na origem da concepção deste veículo está a participação na prova de eficiência “Shell Eco Marathon”. Nesse sentido, foi necessário elaborar um estudo do estado de arte relativo às pilhas de combustível, de modo a definir uma tecnologia cujos requisitos se encontrem enquadrados com o sistema a desenvolver. Posteriormente, efectuou-se um estudo relativo aos motores eléctricos de acordo com as especificações. Desenhou-se um controlador electrónico capaz de efectuar o controlo do motor. Este proporciona o controlo da velocidade e rotação do mesmo. A gama de velocidade implementada varia desde os 250 rpm e os 3400 rpm. Ao longo desta dissertação são apresentados os conteúdos descritos anteriormente, bem como os principais resultados e conclusões retiradas da realização do trabalho. ABSTRACT: This work aims the implementation of a traction system based on fuel cells. Displays primary purpose for inclusion in a car, whose efficiency should be the focal point. Indeed, behind the design of this vehicle is the participation in the efficiency challenge called "Shell Eco Marathon”. Accordingly, it was necessary to prepare a study on the fuel cells state of the art in order to define a technology whose requirements are framed with the system to develop. Subsequently, a study of the electric motors in accordance with the specifications. Drew is an electronic controller able to check the engine. This provides the control of rotation speed and the direction of the motor. The range of speed implemented varies from 250 rpm and 3400 rpm. Throughout this dissertation are the contents described above, and the main results and conclusions drawn from the completion of work

Biomarkers in Overactive Bladder: A New Objective and Noninvasive Tool?

Overactive bladder syndrome (OAB) is a highly prevalent urinary dysfunction, with considerable economic and human costs. Clinical diagnosis of OAB is still based on subjective symptoms. A new accurate, objective and noninvasive test to diagnose OAB and assess therapeutic outcome is lacking. Recent studies in lower urinary tract (LUT) dysfunctions, particularly in OAB patients, indicate that urinary proteins (neurotrophins, prostaglandins, and cytokines), serum C reactive protein, and detrusor wall thickness are altered, and such changes could be used as biomarkers of the disease. Nowadays, increasing emphasis has been given to the role of urinary neurotrophins, namely nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF), as key players in some urinary dysfunctions. Although recently considered to be a bladder dysfunction biomarker, urinary NGF presents low sensitivity and specificity. Preliminary results suggest that BDNF may serve as a more efficient biomarker. Even though we have to wait for future studies to confirm the potential role of NGF and BDNF as OAB biomarkers, it is already clear that neurotrophins will contribute to elucidate the physiopathological basis of OAB. Herein are reviewed the latest advances in this new and exciting field, the detection and clinical application of emerging OAB biomarkers

Unified power converter based on a dual-stator permanent magnet synchronous machine for motor drive and battery charging of electric vehicles

An electric vehicle (EV) usually has two main power converters, namely one for the motor drive system and another for the battery-charging system. Considering the similarities between both converters, a new unified power converter for motor drive and battery charging of EVs is propounded in this paper. By using a single unified power converter, the cost, volume, and weight of the power electronics are reduced, thus also making possible a reduction in the final price of the EV. Moreover, the proposed unified power converter has the capability of bidirectional power flow. During operation in traction mode, the unified power converter controls motor driving and regenerative braking. Additionally, during operation in battery-charging mode, with the EV plugged into the electrical power grid, the unified power converter controls the power flow for slow or fast battery charging (grid-to-vehicle (G2V) mode), or for discharging of the batteries (vehicle-to-grid (V2G) mode). Specifically, this paper presents computer simulations and experimental validations for operation in both motor-driving and slow battery-charging mode (in G2V and V2G modes). It is demonstrated that the field-oriented control used in the traction system presents good performance for different values of mechanical load and that the battery-charging system operates with high levels of power quality, both in G2V and in V2G mode.This work was supported by the Portuguese Foundation of Science and Technology (FCT) (in Portuguese, Fundação para a Ciência e Tecnologia) within the R&D Units Project Scope: UIDB/00319/2020. This work was also supported by the FCT Project DAIPESEV PTDC/EEIEEE/30382/2017 and by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017. T.J.C.S. is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the FCT

Collagen from Atlantic cod (Gadus morhua) skins extracted using CO2 acidified water with potential application in healthcare

This work has received funding from European Union, under the scope of European Regional Development Fund (ERDF) through the Structured Project NORTE-01-0145-FEDER-000021 (Norte2020) and under the scope of the European Union Seventh Framework Programme (FP7/2007-2013) through grant agreement ERC-2012-ADG 20120216-321266 (ERC Advanced Grant ComplexiTE). PhD grant of C. O. (Norte-08-5369-000037) with financial support by Norte 2020. The authors would like to acknowledge Frigoríficos da Ermida, Lda. (Gafanha da Nazaré, Portugal) for the kind offer of Atlantic cod skins and to Dr. Manuela Pintado, Dr. Raquel Madureira and Joana Costa (Universidade Católica Portuguesa, Porto) for the use of microDSC and assistance during measurements. The authors also thank to Dr. Catarina Marques and Dr. Sandra Pina (3B’s Research Group) for assistance on XRD measurements, to Dr. Rita Lopez-Cebral (3B’s Research Group) for assistance on SEC measurements and to Dr. Alexandre Barros for discussions.The extraction of collagen from fish skins is being proposed as strategy for valorization of marine origin by-products, being a sustainable alternative to mammal collagen. The method commonly uses solutions of organic acids, but new methodologies are arising, aiming to improve process yields and/or the properties of the resulting products. In this work, skins removed from salt brine Atlantic cod (Gadus morhua) were used to extract collagen, using water acidified with CO2, obtaining an extraction yield of 13.8% (w/w). Acidified water extracted collagen (AWC) presented a total content of proline-like amino acids of 151/1000 residues, with a degree of hydroxylation of 38%, and its SDS-PAGE profile is compatible with type I collagen. Moreover, FTIR, CD and XRD results suggest the presence of preserved triple helix, having a denaturation temperature of 32.3 °C as determined by micro-DSC. AWC exhibited a typical shear thinning behavior, interesting regarding their further processing, namely in jelly-like formulations. Additionally, the presence of AWC in MRC-5 human fibroblasts culture did not affect cell viability, demonstrating the non-cytotoxic behavior. Overall, the results support the efficiency of the proposed approach for collagen extraction and further enable the design of methodologies to address AWC use in biomedical or cosmetic context.authorsversionpublishe

Comparative analysis of Vehicle-to-Vehicle (V2V) power transfer configurations without additional power converters

This paper presents a comparative analysis of power transfer configurations towards vehicle-to-vehicle (V2V) battery charging operation without using additional power converters, i.e., using just the on-board battery chargers of two electric vehicles (EVs). Three access interfaces were considered, namely the ac power grid interface, the dc-link interface and the dc battery interface, which allow the establishment of eight V2V configurations. The defined configurations are described and verified through computational simulations. A comparison is performed based on quantitative data, i.e., power transfer efficiency for a given output power range, and qualitative data, i.e., flexibility and safety. According to the obtained results, it can be concluded that each V2V configuration has its pros and cons regarding efficiency, number of possible quadrant operation and need for additional equipment.This work has been supported by FCT –Fundação para a Ciência e Tecnologiawith-in the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by FCTProject new-ERA4GRIDs PTDC/EEI-EEE/30283/2017. Mr. Tiago J. C. Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency

Battery charging station for electric vehicles based on bipolar dc power grid with grid-to-vehicle, vehicle-to-grid and vehicle-to-vehicle operation modes

This paper proposes an electric vehicle (EV) battery charging station (EV-BCS) based on a bipolar dc power grid with the capabilities of returning energy back to the power grid (vehicle-to-grid – V2G mode), as well as to perform power transfer between different EVs connected to the EV-BCS without drawing power from the power grid (vehicle-to-vehicle – V2V mode), besides the traditional battery charging operation (grid-to-vehicle – G2V mode). The proposed EV-BCS is modular, using three-level bidirectional dc-dc converters. In this paper, for simplicity reasons, only two converters, and hence two EVs, are considered in order to validate the previously referred operation modes. Furthermore, unbalanced operation from the EVs side is also considered for all the operation modes, aiming to consider a real scenario of operation. Simulation results verify the correct operation of the EV-BCS in all cases, with balanced and unbalanced current consumption from the EVs resulting always in balanced currents from the bipolar dc power grid side

Power quality phenomena in electrified railways: Conventional and new trends in power quality improvement toward public power systems

Nowadays, railway electrification is the most efficient way to power the trains. However, power quality (PQ) phenomena toward public power systems (PPSs) have always a main concern to the railway operators, especially when the single phase traction power system is interconnected to the three phase PPS. The last decades have witnessed an on going evolution of PQ improvement and traction power supply systems, contributing to diminish the negative impacts of AC railway networks on PQ of the three phase PPS. In this context, this paper presents a global overview of the PQ phenomena in AC railway electrification, as well as the impacts of the potential hazards on the safe operation of electrified railways. The paper also reviews PQ improvement methods from the early use of AC railway electrification until the emergence of the new power electronics devices in railways industry.Mohamed Tanta was supported by FCT (Fundação para a Ciência e Tecnologia) PhD grant with a reference PD/BD/127815/2016. This work has been supported by COMPETE: POCI-01-0145–FEDER–007043 and FCT within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio