PV system modeling by five parameters and in situ test

This paper focuses on a novel formalization for assessing the five parameter modeling of a photovoltaic cell. An optimization procedure is used as a feasibility problem to find the parameters tuned at the open circuit, maximum power, and short circuit points in order to assess the data needed for plotting the I-V curve. A comparison with experimental results is presented for two monocrystalline PV modules.

Impacto da síncope na qualidade de vida: validação duma escala de avaliação em doentes submetidos a teste de inclinação em mesa basculante

Introdução e objetivos: A síncope recorrente tem um impacto significativo na qualidade de vida. O desenvolvimento de escalas de medida de fácil aplicabilidade clínica para avaliar este impacto é fundamental. O objetivo do presente estudo é a validação preliminar da escala Impact of Syncope on Quality of Life, para a população portuguesa. Métodos: O instrumento foi submetido a um processo de tradução, validação, adequação cultural e cognitive debriefing. Participaram 39 doentes com história de síncopes recorrentes (>1 ano de evolução), submetidos a teste de inclinação em mesa basculante (teste de tilt), que constitui uma amostra de conveniência, com idade de 52,1±16,4 anos (21-83; 43,5% do sexo masculino), a maioria com uma situação profissional ativa (n=18) ou reformados (n=13). A versão portuguesa resultou numa versão semelhante unidimensional à original com 12 itens agregados num único somatório, tendo passado por validação estatística, com avaliação da fidelidade, validade e estabilidade no tempo. Resultados: Em relação à fidelidade, a consistência interna da escala é de 0,9. Avaliámos a validade convergente, tendo obtido resultados estatisticamente significativos (p<0,01). Avaliámos a validade divergente tendo obtido resultados estatisticamente significativos. Relativamente à estabilidade no tempo foi efetuado um teste-reteste do instrumento aos seis meses após o teste de inclinação com 22 doentes desta amostra não submetidos a intervenção clínica, que não mostrou alterações estatisticamente significativas da qualidade de vida. Conclusões: Os resultados obtidos indicam a pertinência da utilização deste instrumento em contexto português na avaliação da qualidade de vida de doentes com síncope recorrente.

Importance of program physical activity in quality of life in multiple sclerosis patients, six months after the intervention

Background: Multiple Sclerosis (MS) is a chronic disease of the central nervous system that affects more often young adults in the prime of his career and personal development, with no cure and unknown causes. The most common signs and symptoms are fatigue, muscle weakness, changes in sensation, ataxia, changes in balance, gait difficulties, memory difficulties, cognitive impairment and difficulties in problem solving MS is a relatively common neurological disorder in which various impairments and disabilities impact strongly on function and daily life activities. Purpose: The aim of this study is to examine the implications of an Intervention Program of Physical Activity (IPPA) in quality of life in MS patients, six months after the intervention.

Unstabilized rammed Earth: characterization of material collected from old constructions in South Portugal and comparison to normative requirements

Unstabilized rammed earth is a recyclable, economical, and eco-friendly building material, used in the past and still applied today. Traditionally, its use was based on a long empirical knowledge of the local materials. Because this knowledge was mostly lost or is no longer sufficient, in many countries normative documents have been produced to allow the assessment of rammed earth soils. With the aim of contributing for a refining of these normative requirements, this article presents a research work that included: (i) collection of Unstabilized rammed earth samples from six constructions in Portugal; (ii) a literature survey of normative and complementary documents to identify the most mentioned key-properties, the test procedures and the corresponding threshold limits; and (iii) a discussion of the test procedures and of the thresholds limits in the light of the experimental results. The analyzed properties are the particle size distribution, maximum particle size, plasticity, compaction, linear shrinkage, organic content, and salt content. The work highlights the advantages of taking into account the characteristics of existing constructions as a basis for the establishment and further refining of consistent threshold values. In particular, it shows that it is essential to adjust the requirements to the specificities of local materials.

PV system modeling by five parameters and in Situ test

This paper focuses on a novel formalization for assessing the five parameter modeling of a photovoltaic cell. An optimization procedure is used as a feasibility problem to find the parameters tuned at the open circuit, maximum power, and short circuit points in order to assess the data needed for plotting the I-V curve. A comparison with experimental results is presented for two monocrystalline PV modules.

Caracterização do desempenho das redes rodoviárias com base em modelos de afetação de tráfego: aplicação à Rede Rodoviária Nacional

Relatório de estágio para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Vias de Comunicação e Transportes

Choosing amine-based absorbents for CO2 capture

CO2 capture from gaseous effluents is one of the great challenges faced by chemical and environmental engineers, as the increase in CO2 levels in the Earth atmosphere might be responsible for dramatic climate changes. From the existing capture technologies, the only proven and mature technology is chemical absorption using aqueous amine solutions. However, bearing in mind that this process is somewhat expensive, it is important to choose the most efficient and, at the same time, the least expensive solvents. For this purpose, a pilot test facility was assembled and includes an absorption column, as well as a stripping column, a heat exchanger between the two columns, a reboiler for the stripping column, pumping systems, surge tanks and all necessary instrumentation and control systems. Some different aquous amine solutions were tested on this facility and it was found that, from a set of six tested amines, diethanol amine is the one that turned out to be the most economical choice, as it showed a higher CO2 loading capacity (0.982 mol of CO2 per mol of amine) and the lowest price per litre (25.70 ¤/L), even when compared with monoethanolamine, the benchmark solvent, exhibiting a price per litre of 30.50 ¤/L.

Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2. © Author(s) 2015.