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- Evaluation of the speed control cameras in the city of LisbonPublication . dos Santos, José Nuno Dias Crespo Martins; Carvalheira, Carmen; Picado Santos, Luis; Magusic, RadmilaIn Portugal, urban areas still have a high number of fatalities as a result of road crashes. In 2016, 78% of road crashes with victims, 62% with serious injuries and 54% with fatalities occurred in urban areas. Knowing where crashes occur and what circumstances contributed to these occurrences is the key to finding solutions that minimize injuries and deaths. At the end of 2016, as a safety measure, speed control cameras from SINCRO (Sistema Nacional de Controlo de Velocidade, the national speed control system), began to be installed in different parts of the country. The first application was in 2006 at several spots in the urban area of Lisbon. Cameras were installed in 20 of these locations. This study, using the location of the speed control cameras (which were only effective in 19 spots) and the 2004-2011 crash databases, sought to assess the effectiveness of the measure. The results showed that there was a positive effect on crash rates soon after implementation, but it was also perceived that this effect was attenuated in subsequent years. It is assumed that the reasons for this are due to the familiarization with the system, together with inefficient sanctioning of the violators, and additionally due to malfunctioning equipment not being repaired in a timely manner, which was evident to the users.
- 3D nickel foams with controlled morphologies for hydrogen evolution reaction in highly alkaline mediaPublication . Siwek, K. I.; Eugénio, S.; Santos, Diogo; Moura E Silva, Teresa; MONTEMOR, FATIMAWater electrolysis is the cleanest method for hydrogen production, and can be 100% green when renewable energy is used as electricity source. When the hydrogen evolution reaction (HER) is carried out in alkaline media, nickel (Ni) is a low cost catalyst and an interesting alternative to platinum. Still, its performance has to be enhanced to meet the high efficiency of the nobler metals, an objective that requires further tailoring of the surface area and morphology of Ni-based electrode materials. Unlike commercially available porous Ni, these features can be easily controlled via electrodeposition, a one-step process, taking advantage of the dynamic hydrogen bubble template (DHBT). Generally, changes in surface porosity and morphology have been mainly achieved by altering the main parameters, such as the current density or the deposition time. However, very scarce work has been done on the role of supporting electrolyte (i.e., its concentration and composition) in tailoring the foam features and consequently their catalytic activity. Hence, this approach paves the way to optimum design of metallic foam structures that can be obtained only with modifications in the electrolytic bath. In this work, 3D Ni foams are obtained from different composition baths by galvanostatic electrodeposition in the hydrogen evolution regime on stainless steel current collectors. Their porosity and morphology are analysed by optical microscopy and SEM. The electrochemical performance is evaluated by cyclic voltammetry, while catalytic activity towards HER and materials' stability in 8 M KOH are tested using polarisation curves and chronoamperometry measurements, respectively. The recorded high currents and extended stability of the Ni foams with dendritic morphology demonstrate its outstanding performance, making it an attractive cathode material for HER in highly alkaline media. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.