Browsing by Author "Santos, Tiago"
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- Assessment of an Innovative Way to Store Hydrogen in VehiclesPublication . Baptista, Andresa; Pinho, Carlos; Pinto, Gustavo Filipe; Ribeiro, Leonardo; Monteiro, Joaquim; Santos, TiagoThe use of hydrogen as an alternative to fossil fuels for vehicle propulsion is already a reality. However, due to its physical characteristics, storage is still a challenge. There is an innovative way, presented in this study, to store hydrogen in conventional vehicles propelled by spark-ignition reciprocating engines and fuel cells, using hydrogen as fuel; the storage of hydrogen will be at high pressure within small spheres randomly packed in a tank, like the conventional tank of fuel used nowadays in current vehicles. Therefore, the main purpose of the present study is to assess the performance of this storage system and compare it to others already applied by car manufacturers in their cars. In order to evaluate the performance of this storage system, some parameters were taken into account: The energy stored by volume and stored by weight, hydrogen leakage, and compliance with current standards. This system is safer than conventional storage systems since hydrogen is stored inside small spheres containing small amounts of hydrogen. Besides, its gravimetric energy density (GED) is threefold and the volumetric energy density (VED) is about half when compared with homologous values for conventional systems, and both exceed the targets set by the U.S. Department of Energy. Regarding the leakage of hydrogen, it complies with the European Standards, provided a suitable choice of materials and dimensions is made.
- Compliance study of hazard analysis and critical control point systemPublication . Pinto, Tatiana Sousa; Faria, Brígida Mónica; Reis, Luis Paulo; Cardoso, Henrique Lopes; Santos, TiagoHazard Analysis and Critical Control Point (HACCP) system is based on a preventive methodology to avoid potential hazards that can cause harm and to ensure that unsafe food is not made available to consumers. This system is recognized by the Economic and Food Safety Authority, a criminal police responsible for food safety and economic inspection in Portugal. Every day, Economic and Food Safety Authority generates a large and complex volume of data from inspections and complaints, also in its classification, registration and in monitoring until the end of the process analysis. This study focuses on the reported entities that are related to non-compliance with HACCP, and tries to understand the most common infractions. Results show values between 30% and 37% related to non-compliance to HACCP. As main conclusions, from 2014 to 2018, the number of these infractions maintained the same level and it will be important to understand if the relationship between these problems are related to legislation understanding or application.
- Efeitos do ruído na audiçãoPublication . Lopes, Paula; Santos, Tiago; Neto, Catarina; Castro, Fátima; Caeiro, Alberto; Tomé, DavidCom a evolução da tecnologia, os jovens utilizam cada vez mais dispositivos portáteis para entretenimento, aprendizagem e como forma de comunicação. A maioria da utilização destes dispositivos envolve uma exposição excessiva e desnecessária ao ruído e/ou a sons de elevada intensidade, que podem provocar perda auditiva. O setor educacional, pela sua abrangência, é um parceiro importante para a concretização de sensibilizações e ações promotoras da saúde individual e de grupo tendo como objetivo o bem-estar de toda a comunidade escolar. Assim, as escolas serão o local de eleição na preservação auditiva e na sua promoção.
- Evaluation of activated carbons produced from Maize Cob Waste for adsorption-based CO2 separation and biogas upgradingPublication . Surra, Elena; Ribeiro, Rui P.P.L.; Santos, Tiago; Bernardo, Maria; Mota, José P.B.; Lapa, Nuno; Esteves, Isabel A.A.C.Two activated carbons (AC) resulting from CO2 activation of Maize Cob Waste (MCW) were investigated as adsorbent materials for biogas upgrading to bio-methane applying a biorefinery concept. The porous carbons were originated from different times of activation and the one resulting from 3 h with CO2 (MCW(PA)3 h) showed better textural properties, higher working capacity, and selectivity towards CO2 than the carbon resulting from 2 h of activation (MCW(PA)2 h), making it the best candidate for biogas purification. The adsorption equilibrium measurements of CO2 and CH4 on MCW(PA)3 h carbon showed that the Sips isotherm model, as well as the Adsorption Potential Theory (APT), can be confidently employed to accurately correlate the adsorption equilibrium data of the adsorbates employed. In the range of the partial pressures typical for biogas upgrading units, MCW(PA)3 h showed higher CO2 uptakes than the ones reported for coal-based commercial ACs and similar uptakes to the ones reported for bio-based ACs. Moreover, the axial dispersed plug-flow and Linear Driving Force (LDF) approximation for lumped solid-diffusion mass transfer model used for the prediction of the dynamic behaviour of the adsorbate-adsorbent system, provided a good agreement with the experimental results, demonstrating its applicability to the studied system. This work represents the basis of future modelling works of a Pressure Swing Adsorption (PSA) cycle based on the use of MCW(PA)3 h as adsorbent material and demonstrates the high potential of this novel material to be applied in biogas upgrading processes
- Primary hearing health: action to raise awareness on secondary educationPublication . Tomé, David; Neto, Catarina; Santos, Tiago; Lopes, PaulaWith the evolution of technology, young people increasingly use portable devices for entertainment, learning and as a means of communication. Most of the use of these devices involves excessive and unnecessary exposure to noise and/or high intensity sounds, which can cause hearing loss. The aim of this work was to know the receptiveness on lecturing sessions to raise awareness of hearing health and risk behaviors in the eighth year of secondary education and what are the activities/exercises more appropriate for knowledge consolidation.
- Saúde auditiva: ação de sensibilização para jovens do 3º cicloPublication . Tomé, David; Neto, Catarina; Santos, Tiago; Lopes, PaulaAtualmente, com a evolução da tecnologia, os jovens utilizam cada vez mais dispositivos portáteis para entretenimento, aprendizagem e como forma de comunicação. A maioria da utilização destes dispositivos envolve uma exposição excessiva e desnecessária ao ruído e/ou a sons de elevada intensidade, que podem provocar perda auditiva. Para além disto, verifica-se ainda um aumento da poluição sonora nas cidades ou mesmo perto dos locais que estes jovens costumam frequentar, o que poderá contribuir ainda mais para o risco de perda auditiva e/ou sintomas otológicos, para além de outros. A exposição contínua ao ruído e a sons de elevada intensidade, pode resultar na morte ou lesão irreversível das células ciliadas do ouvido interno (cóclea). Poderá também trazer aos jovens outros sintomas auditivos como por exemplo zumbidos.