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- Chemical and morpho-structural characterization of atmospheric aerosol (PM10 and PM2.5) in a city of São Paulo state, BrazilPublication . Trevizan Franzin, Bruno; Guizellini, Filipe; HOJO, OSSAMU; Pastre, Iêda Aparecida; Marchi, Mary Rosa Rodrigues de; Silva, Hugo; Luis Fertonani, Fernando; Oliveira, CristinaTo access the sources of air pollutants is crucial to control atmospheric pollution in urban areas, minimizing human exposure. Particulate matter is a pollutant of great concern making its chemical and morpho-structural characterization of enormous importance. The present work aims at the characterization of atmospheric PM10 and PM2.5. Data of the aerosol mass concentration was correlated bymultivariate analysis with water-soluble ion fraction composition accessed by ion chromatography (IC), as well as with meteorological information and air mass backward trajectories. The gravimetric analysis presented average values 3 to 4 times higher than the guide values recommended by the World Health Organization (WHO). A morpho-structural analysis by SEM/FEG coupled to EDS was also carried out identifying the coarse fraction elements from minerals and from soil resuspension organic spherical particles that originated from combustion processes as well as Ti, associated with long-distance transportation. In the fine fraction, Zn with origin probably in tires and vehicle brakes was found. These origins were confirmed by the air masses’ backward trajectories obtained by the HYSPLIT model (NOAA). This study contributes to a better understanding of the complex composition of the particulate material in the atmosphere of Araraquara City, resulting from the combination of local and long-distance sources, and serves as a basis for the comparison with future studies related to the air quality at this and other regions in Brazil and in the world.
- Road tunnel, roadside, and urban background measurements of aliphatic compounds in size-segregated particulate matterPublication . Oliveira, Cesar; Martins, Natercia; Mirante, Fátima; Caseiro, Alexandre; Pio, Casimiro; Matos, Manuel; Silva, Hugo; Oliveira, Cristina; Camões, FilomenaParticulate matter samples were collected in a road tunnel in Lisbon (PM0.5, PM0.5-1, PM1-2.5, and PM2.5-10) and at two urban locations representing roadside and background stations (PM2.5 and PM2.5-10). Samples were analysed for organic and elemental carbon (OC and EC), n-alkanes, n-alkenes, hopanes, some isoprenoid compounds, and steranes. Particulate matter concentrations in the tunnel were 17-31 times higher than at roadside in the vicinity, evidencing an aerosol origin almost exclusively in fresh vehicle emissions. PM0.5 in the tunnel comprised more than 60% and 80% of the total OC and EC mass in PM10, respectively. Concentrations of the different aliphatic groups of compounds in the tunnel were up to 89 times higher than at roadside and 143 times higher than at urban background. Based on the application of hopane-to-OC or hopanes-to-EC ratios obtained in the tunnel, it was found that vehicle emissions are the dominant contributor to carbonaceous particles in the city but do not represent the only source of these triterpenic compounds. Contrary to what has been observed in other studies, the Sigma hopane-to-EC ratios were higher in summer than in winter, suggesting that other factors (e.g. biomass burning, dust resuspension, and different fuels/engine technologies) prevail in relation to the photochemical decay of triterpenoid hydrocarbons from vehicle exhaust
- O projeto MySafeWater no ISELPublication . Barreiros, Ana Maria; Silva, Hugo; Matos, Manuel; Gonçalves Cavaco Mendes, Mário José; Monge, Nuno; Sousa, Ana Catarina; Costa, AlexandraO projeto MySafeWater pretendeu promover os objetivos nacionais e europeus, em matéria de Ambiente, no que se refere essencialmente à promoção do “consumo da água da torneira como forma ambientalmente sustentável de consumo, prevenindo a produção de resíduos e diminuindo a pegada ecológica”, através da informação e da conscientização do papel dos cidadãos na promoção do desenvolvimento sustentável em aspetos como a qualidade da água para consumo humano, abrangendo a participação ativa do público e pela sensibilização ambiental e a participação passiva do público.
- Heavy metals contamination of urban soils—a decade study in the city of Lisbon, PortugalPublication . Silva, Hugo; Silva, Nelson A. F.; Oliveira, Cristina; Matos, ManuelThere is an intense and continuous growth of the world population living in cities. This increase in population means an increase in car traffic, an increase in new constructions and an increase in the production of waste that translates into an intensive use of land, particularly in terms of soil contaminants. Among other environmental contaminants, toxic metals, such as lead (Pb), cadmium (Cd), nickel (Ni) and chromium (Cr) represent a public health problem. In this study the content of toxic metals in Lisbon’s (Portugal) soils was determined. The study was conducted over approximately a decade in six city locations, with a total of about 700 samples. Each site has different urban characteristics: traffic zone, residential area, urban park and mixed areas. The study allowed to verify the heterogeneity of metal content values in the city soils and their dependence on local traffic. Metal contents were determined by graphite furnace atomic absorption spectroscopy (GFAAS). For each site the geo-accumulation index, pollution factor, degree of contamination, pollution load índex and ecological risk factor were calculated. The mean concentrations of Cd, Cr, Ni and Pb in soils were 0.463, 44.0, 46.6 and 5.73 mg/kg of dry soil, respectively. In the last year of the study the values were 0.417, 51.5, 62.4 and 8.49 mg/kg of dry soil, respectively. Cd and Ni exceeded the typical content values of these metals in the earth’s crust, indicating their anthropogenic origin. The correlation analysis revealed a significant correlation between Cr and Ni, Cd and Ni and Cd and Pb contents in the city soils. Regarding the results obtained in this long monitoring campaign, Lisbon’s soils can be considered as having low levels of pollution by these metals.
- Wind-CSP short-term coordination by Milp approachPublication . Pousinho, Hugo Miguel Inácio; Silva, Hugo; Mendes, Victor; Collares-Pereira, Manuel; Cabrita, C. PereiraThis paper is on the maximization of total profit in a day-ahead market for a price-taker producer needing a short-term scheduling for wind power plants coordination with concentrated solar power plants, having thermal energy storage systems. The optimization approach proposed for the maximization of profit is a mixed-integer linear programming problem. The approach considers not only transmission grid constraints, but also technical operating constraints on both wind and concentrated solar power plants. Then, an improved short-term scheduling coordination is provided due to the more accurate modelling presented in this paper. Computer simulation results based on data for the Iberian wind and concentrated solar power plants illustrate the coordination benefits and show the effectiveness of the approach.
- ECG-based biometrics: A real time classification approachPublication . Lourenço, André Ribeiro; Silva, Hugo; Fred, AnaBehavioral biometrics is one of the areas with growing interest within the biosignal research community. A recent trend in the field is ECG-based biometrics, where electrocardiographic (ECG) signals are used as input to the biometric system. Previous work has shown this to be a promising trait, with the potential to serve as a good complement to other existing, and already more established modalities, due to its intrinsic characteristics. In this paper, we propose a system for ECG biometrics centered on signals acquired at the subject's hand. Our work is based on a previously developed custom, non-intrusive sensing apparatus for data acquisition at the hands, and involved the pre-processing of the ECG signals, and evaluation of two classification approaches targeted at real-time or near real-time applications. Preliminary results show that this system leads to competitive results both for authentication and identification, and further validate the potential of ECG signals as a complementary modality in the toolbox of the biometric system designer.
- Experimental apparatus for finger ECG biometricsPublication . Lourenço, Renato; Leite, Paulo; Lourenço, André Ribeiro; Silva, Hugo; Fred, Ana; Coutinho, DavidCurrent Electrocardiographic (ECG) signal acquisition methods are generally highly intrusive, as they involve the use of pre-gelled electrodes and cabled sensors placed directly on the person, at the chest or limbs level. Moreover, systems that make use of alternative conductive materials to overcome this issue, only provide heart rate information and not the detailed signal itself. We present a comparison and evaluation of two types of dry electrodes as interface with the skin, targeting wearable and low intrusiveness applications, which enable ECG measurement without the need for any apparatus permanently fitted to the individual. In particular, our approach is targeted at ECG biometrics using signals collected at the hand or finger level. A custom differential circuit with virtual ground was also developed for enhanced usability. Our work builds upon the current stateof-the-art in sensoring devices and processing tools, and enables novel data acquisition settings through the use of dry electrodes. Experimental evaluation was performed for Ag/AgCl and Electrolycra materials, and results show that both materials exhibit adequate performance for the intended application.
- Estimação de tráfego misto para UMTSPublication . Silva, Hugo; Serrador, AntónioEsta comunicação aborda um simulador que estima tráfego misto em sistemas de terceira geração. Para tal foram usados modelos de fonte de tráfego numa região urbano denso. Para se estimar o tráfego gerado numa grande cidade são considerados os seguintes parâmetros: densidade populacional ao nível das freguesias, 12 serviços e 3 perfis de utilizador (Business, SOHO, Mass Market). Foi ainda estudado o impacto dos serviços mais relevantes na rede, assim como, a sensibilidade da rede ao aumento do tráfego dos utilizadores. O volume do tráfego estimado no total, é muito útil para determinar a melhor localização das estações base. Tendo Lisboa como cenário, foram estimadas para Lisboa 325 estações base UMTS para o ano 2006.
- MySafeFiller adaptador para o enchimento de garrafas de água impresso em 3DPublication . Monge, Nuno; Matos, M.; Sousa, Ana Catarina; Barreiros, Ana Maria; Gonçalves Cavaco Mendes, Mário José; Costa, Alexandra; Silva, HugoO MySafeFiller facilita o enchimento de todo o tipo garrafas de água reutilizáveis, com diferentes diâmetros de bocais e diferentes tamanhos, em qualquer torneira de abastecimento de água potável, bebedouro público ou dispensador de água, permite encher a garrafa inclinada sem esta encostar à torneira e sem verter água. Além disso, evita a contaminação do local de abastecimento pelo contacto com o bocal de uma garrafa, e do bocal da garrafa pelo contacto com o local de abastecimento, torneira de abastecimento de água potável, bebedouro público ou dispensador de água.
- Size-segregated chemical composition of aerosol emissions in an urban road tunnel in PortugalPublication . Pio, Casimiro; Mirante, Fátima; Oliveira, Cesar; Matos, Manuel; Caseiro, Alexandre; Oliveira, Cristina; Querol, Xavier; Alves, Célia; Martins, Natércia; Cerqueira, Mário; Camões, Filomena; Silva, Hugo; Plana, FelicianoAn atmospheric aerosol study was performed in 2008 inside an urban road tunnel, in Lisbon, Portugal. Using a high volume impactor, the aerosol was collected into four size fractions (PM0.5, PM0.5-1, PM1-2.5 and PM2.5-10) and analysed for particle mass (PM), organic and elemental carbon (OC and EC), polycyclic aromatic hydrocarbons (PAH), soluble inorganic ions and elemental composition. Three main groups of compounds were discriminated in the tunnel aerosol: carbonaceous, soil component and vehicle mechanical wear. Measurements indicate that Cu can be a good tracer for wear emissions of road traffic. Cu levels correlate strongly with Fe, Mn, Sn and Cr, showing a highly linear constant ratio in all size ranges, suggesting a unique origin through sizes. Ratios of Cu with other elements can be used to source apportion the trace elements present in urban atmospheres, mainly on what concerns coarse aerosol particles. (C) 2013 Elsevier Ltd. All rights reserved.