Runoff at the micro-plot and slope scale following wildfire, central Portugal

Through their effects on soil properties and vegetation/litter cover, wildfires can strongly enhance overland flow generation and accelerate soil erosion [1] and, thereby, negatively affect land-use sustainability as well as downstream aquatic and flood zones. Wildfires are a common phenomenon in present-day Portugal, devastating in an average year some 100.000 ha of forest and woodlands and in an exceptional year like 2003 over 400.000 ha. There therefore exists a clear need in Portugal for a tool that can provide guidance to post-fire land management by predicting soil erosion risk, on the one hand, and, on the other, the mitigation effectiveness of soil conservation measures. Such a tool has recently been developed for the Western U.S.A. [3: ERMiT] but its suitability for Portuguese forests will need to be corroborated by field observations. Testing the suitability of existing erosion models in recently burned forest areas in Portugal is, in a nutshell, the aim of the EROSFIRE projects. In the first EROSFIRE project the emphasis was on the prediction of erosion at the scale of individual hill slopes. In the ongoing EROSFIRE-II project the spatial scope is extended to include the catchment scale, so that also the connectivity between hill slopes as well as channel and road processes are being addressed. Besides ERMiT, the principal models under evaluation for slope-scale erosion prediction are: (i) the variant of USLE [4] applied by the Portuguese Water Institute after the wildfires of 2003; (ii) the Morgan–Morgan–Finney model (MMF) [5]; (iii) MEFIDIS [6]. From these models, MEFIDIS and perhaps MMF will, after successful calibration at the slope scale, also be applied for predicting catchment-scale sediment yields of extreme events

Diferenciação de isolados bacterianos com base no gene de Fe-hidrogenases

O processo fermentativo de producao de H2 por microrganismos depende fundamentalmente da presenca de metaloenzimas designadas por hidrogenases. As hidrogenases sao enzimas envolvidas no metabolismo do H2, capazes de produzir ou consumir hidrogenio molecular, em processos relacionados com a transferencia de electroes e obtencao de energia. Elas catalisam a reaccao reversivel: H2 . 2H++ 2e- [1]. As hidrogenases dividem-se em classes filogeneticamente distintas, caracterizadas pelas diferentes subunidades ou dominios que acomodam o centro catalitico: as metalo-hidrogenases e as hidrogenases nao metalicas. As metalo-hidrogenases em particular podem ser divididas em dois tipos diferentes, conforme o conteudo metalico do seu centro catalitico: as que contem apenas ferro ([FeFe]-H2ases) e as que contem niquel e ferro ([NiFe]-H2ases), e que por vezes contem tambem selenio no seu centro catalitico ([NiFe(Se)]-H2ases) [2]. As [FeFe]-H2ases, existentes apenas em bacterias anaerobias e num pequeno numero de algas verdes, e em particular o gene hydA de [FeFe]-H2ases, que e o principal gene envolvido na producao de H2, sao considerados um biomarcador util para examinar a diversidade e distribuicao de microrganismos produtores de hidrogenio.

Gestão do Estado Emocional da Criança (dos 6 aos 8 anos) através da Actividade de Brincar: Analisando o Cuidado de Enfermagem em Contexto de Internamento de Pediatria

O presente estudo, de abordagem qualitativa, visa compreender como o brincar integrado na prática de enfermagem pode ser usado na gestão do estado emocional da criança a viver uma experiência de hospitalização/cirurgia. Neste processo investigativo recorreu-se ao diário de campo para descrever e analisar a própria prática de enfermagem associada ao fenómeno em estudo. A recolha dos dados foi realizada num serviço de internamento de pediatria cirúrgica de um hospital pediátrico de Lisboa, no período de Abril a Junho de 2008, a partir de interacções de cuidados com 9 crianças de idades compreendidas entre os 6 e os 8 anos. Os dados foram analisados segundo a técnica de análise de conteúdo, os quais revelaram um processo de gestão do estado emocional da criança, através da actividade de brincar, que implica as seguintes acções/interacções: promover o confronto adaptativo, favorecer o relaxamento, incrementar o sentimento de controlo, promover o sentimento de segurança, facilitar a aproximação, promover a expressão emocional, minimizar o sentimento de solidão, promover a distracção e desmistificar os medos. Conclui-se que a actividade de brincar é um instrumento terapêutico primordial em enfermagem pediátrica, na medida em que se revela um meio para favorecer o bem-estar das crianças, e por isso é sugestivo de contribuir para resultados terapêuticos. De facto, usado de modo intencional e sistemático promove a adaptação e aprendizagem das crianças numa experiência positiva de hospitalização/cirurgia

Runoff and erosion at the micro-plot and slope scale in a small burnt catchment, central Portugal

Wildfires can have important impacts on hydrological processes and soil erosion in forest catchments, due to the destruction of vegetation cover and changes to soil properties. However, the processes involved are non-linear and not fully understood. This has severely limited the understanding on the impacts of wildfires, especially in the up-scaling from hillslopes to catchments; in consequence, current models are poorly adapted for burnt forest conditions. The objective of this presentation is to give an overview of the hydrological response and sediment yield from the micro-plot to slope scale, in the first year following a wildfire (2008/2009) that burnt an entire catchment nearby the Colmeal village, central Portugal. The overview will focus on three slopes inside the catchment, with samples including: • Runoff at micro-plot scale (12 bounded plots) and slope scale (12 open plots); • Sediments and Organic Matter loss at micro-plot scale (12 bounded plots) and slope scale (12 open plots plus 3 Sediment fences); • Rainfall and Soil moisture data; • Soil Water Repellency and Ground Cover data. The analysis of the first year following the wildfire clearly shows the complexity of runoff generation and the associated sediment transport in recently burnt areas, with pronounced differences between hillslopes and across spatial scales as well as with marked variations through time. This work was performed in the framework of the EROSFIRE-II project (PTDC/AGR-CFL/70968/2006) which has as overall aim to predict soil erosion risk in recently burnt forest areas, including common post-fire forest management practices; the project focuses on the simultaneous measurement of runoff and soil erosion at multiple spatial scales.The results to be presented in this session are expected to show how sediment is generated, transported and exported in the Colmeal watershed; and contribute to understand and simulate erosion processes in burnt catchments, including for model development and evaluation

Polyvinylidene fluoride based nanocomposites for the development of energy systems

Tese de doutoramento em Física (especialidade em Ciências)The economic and environmental costs of current energy resources created the need to develop new methods to generate and store energy. In this sense, the development of polymer materials led to the emergence of a new generation of porous polymers for energy applications, which are typically described as “energy polymers”. The specific properties of poly(vinylidene fluoride) (PVDF) and its copolymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)), such as high dielectric permittivity, high polarity, softness and flexibility, among others, make them excellent choices for energy applications. The incorporation of fillers into these polymeric matrices can also be highly advantageous, since it allows tuning certain properties of the matrices optimizing their characteristics for specific applications. According this, P(VDF-TrFE) based composite membranes with zeolites (Y zeolite, NaY), clays (montmorillonite, MMT), multiwalled-carbon nanotubes (MWCNT) and barium titanate (BaTiO3) fillers were prepared by thermally induced phase separation (TIPS) for batteries separator applications. PVDF and P(VDF-TrFE) polymers and composites with BaTiO3 were also prepared by electrospinning for energy harvesting systems. P(VDF-TrFE) composite membranes showed suitable morphological, thermal, mechanical and electrochemical properties for the development of lithium ion separator membranes for battery applications. The developed membranes showed high degrees of porosity, ranging from 70 % for the pristine polymer to a maximum of 83 % for MMT filled membrane, excepting NaY membrane which showed the lowest value of 36 %. The porosity increase is reflected in electrolyte solution uptake, which increases markedly for membranes with higher porosity reaching values above 300 % for BaTiO3 and MMT filled membranes, whereas for the pristine polymer is ~225 %. The room temperature ionic conductivity showed a strong increase for all composites, from 5.24×10-7 S/cm for the pristine polymer to a maximum of 9.22×10-6 S/cm for the BaTiO3/P(VDF-TrFE) membrane. The ionic conductivity variation with temperature is diminished with the inclusion of fillers, in particular for the MMT and MWCNT filled membranes. The stable operation window is at least 6.0 V for all membranes. Pristine polymer electrospun fibers of PVDF showed the best energy harvesting performance with generated output powers of 0.02 W and 25 W, under low and high mechanical deformation conditions, respectively. Pristine P(VDF-TrFE) and BaTiO3/P(VDF-TrFE) composites fibers showed lower output powers. The objectives of the study were successfully achieved, and the overall results are an effective contribute for the development of novel polymer based materials for energy systems applicationsOs custos económicos e ambientais das fontes de energia mais usadas na atualidade criaram a necessidade de procurar novos métodos de armazenar e gerar energia. Neste sentido, a disponibilidade de materiais poliméricos possibilitou o aparecimento de uma nova geração de polímeros porosos para aplicações energéticas designados por “polímeros energéticos”. As propriedades específicas do poli(fluoreto de vinilideno) (PVDF) e do seu copolímero poli(fluoreto de vinilideno-co-trifluoretileno) (P(VDF-TrFE)), tais como elevada constante dielétrica, alta polaridade e flexibilidade, entre outras, fazem deles excelentes escolhas para este tipo de aplicações. Desta forma prepararam-se membranas poliméricas compósitas baseadas em P(VDF-TrFE) com zeólitos (zeólito Y, NaY), argilas (montmorillonite, MMT), nanotubos de carbono (MWCNT) e titanato de bário (BaTiO3), pelo método de separação de fase termicamente induzida (TIPS), para aplicações em separadores de baterias, bem como fibras de PVDF, P(VDF-TrFE) e BaTiO3/P(VDF-TrFE) por electrospinning para sistemas de energy harvesting. As membranas compósitas de P(VDF-TrFE) revelaram propriedades morfológicas, térmicas, mecânicas e eletroquímicas adequadas para aplicações em separadores de baterias de lítio. A maior parte das membranas compósitas apresentaram elevados valores de porosidade, desde 70 % para o polímero simples até 83 % para a membrana com MMT, com a exceção da membrana com zeólitos que apresentou o valor mais baixo de 36 %. Os aumentos da porosidade refletiram-se na absorção de líquido eletrólito, que aumentou de forma mais acentuada nas membranas com maior porosidade atingindo valores superiores a 300 % para as membranas com BaTiO3 e MMT, quando comparado com os 200 % do polímero puro. A condutividade iónica à temperatura ambiente apresentou fortes aumentos em todos os compósitos, desde o valor de 5.24×10-7 S/cm para o polímero puro até ao máximo de 9.22×10-6 S/cm para a membrana de BaTiO3/P(VDF-TrFE). As variações da condutividade em função da temperatura foram diminuídas nos compósitos, principalmente para as membranas com MMT e MWCNT. A janela estável de operação foi no mínimo de 6.0 V para todas as membranas. As fibras poliméricas de P(VDF-TrFE) produzidas por electrospinning apresentaram o melhor resultado em termos de geração de energia, gerando potências saída de 0.02 W e 25 W, em condições de baixa a alta deformação mecânica, respetivamente. O polímero P(VDF-TrFE) e o compósito BaTiO3/P(VDF-TrFE) apresentaram potências mais baixas. Os objetivos deste estudo foram alcançados com sucesso e os resultados globais são um contributo efetivo para o desenvolvimento de novos materiais poliméricos para aplicações em sistemas de energia

Efeito piezoresistivo em polímeros condutores em substrato flexível

Dissertação de mestrado em Física (área de especialização em Ensino)Os materiais poliméricos têm vindo a substituir outros materiais nas mais variadas aplicações, desde estruturais até electrónicas. Em particular, desde a descoberta dos polímeros condutores por Hideki Shirakawa na década de 1970, e desde o início do fabrico de compósitos condutores com fibras de carbono e carbon black (CB), tem-se assistido a uma crescente utilização destes materiais na fabricação de componentes electrónicos, visores tácteis, telas de televisão, sensores, baterias recarregáveis, geradores de fotocorrente, músculos artificiais, entre outras aplicações. Um tipo de sensores, com grande potencial de aplicação, por exemplo, em monitorização estrutural ou aplicações biomédicas, é os piezoresistivos. Com esta dissertação pretende-se estudar o efeito piezoresistivo de polímeros condutores e compósitos baseados em fibras de carbono. Para tal, foram preparados filmes do polímero condutor polianilina (PANI) por spin coating, compósitos de polipropileno (PP) Pro-fax 6301 com as nano fibras de carbono (NFC’s) Pyrograf®-III por extrusão e prensagem e compósitos do composto comercial PRE-ELEC® PP 1384 por prensagem. Seguidamente, foi analisada a dependência da sua resposta eléctrica com as condições de preparação e mediu-se a resposta eléctrica a solicitações mecânicas. Os resultados obtidos permitiram caracterizar a resposta piezoresistiva presente nos diferentes tipos de amostras, assim como a sua dependência com as condições de preparação. Os valores de gauge factor (GF) obtidos para os diferentes materiais, da ordem de 1,7 - 2,7 para o polímero condutor e 0,8 - 2,4 para os compósitos de carbono, permitem afirmar a viabilidade destes materiais como sensores piezoresistivos em diferentes aplicações.The polymeric materials have been replacing other materials in various applications, from structural to electronic. In particular, since the discovery of conducting polymers by Hideki Shirakawa in the 1970s and the beginning of the manufacture of conducting composites with carbon fibers and carbon black (CB), has been a growing use of these materials in the manufacture of electronic components, tactile displays, television screens, sensors, batteries, generators photocurrent, artificial muscles, among other applications. A type of sensors with great potential for application, for example, in structural monitoring or biomedical applications, are piezoresistive. The aim of this dissertation is to study the piezoresistive effect of conductive polymers and composites based on carbon fibers. With this purpose, the films were prepared conducting polymer polyaniline (PANI) by spin coating, composites of polypropylene (PP) Pro-fax 6301 with the nanocarbonfibers (NCF's) Pyrograf®-III by extrusion and pressing of composites and composite commercial PRE -ELEC® PP 1384 by pressing. Next, I examined the dependence of their electrical response to the conditions of preparation and measured the electrical response to mechanical stress. The results allowed the characterization of piezoresistive response present in different types of samples, as well as its dependence on the preparation conditions. The gauge factor (GF) values obtained for the different materials, in order from 1,7 to 2,7 for the conducting polymer and 0,8 to 2,4 for carbon composites, enable to affirm the viability of these materials as piezoresistive sensors for different applications

Hydrological and erosion response at micro-plot to -catchment scale following forest wildfire, north-central Portugal

Wildfires can have important impacts on hydrological and soil erosion processes, due to the destruction of vegetation cover and changes to soil properties. According to Shakesby and Doerr (2006), these wildfire effects are: i) much better known at small spatial scales (especially erosion plots) than at the scale of catchments; ii) much better studied with respect to overland flow and streamflow (and, then, especially peak discharges) than to soil erosion. Following up on a precursor project studying runoff generation and the associated soil losses from micro-plot to slope-scale in Portuguese eucalypt forests, the EROSFIRE-II project addresses the connectivity of these processes across hillslopes as well as within the channel network. This is done in the Colmeal study area in central Portugal, where the outlet of an entirely burnt catchment of roughly 10 ha was instrumented with a gauging station continuously recording water level and tubidity, and five slopes were each equipped with 4 runoff plots of < 0,5 m2 (“micro-plot”) and 4 slope-scale plots as well as 1 slope-scale sediment fence. Starting one month after the August 2008 wildfire, the plots were monitored at 1- to 2-weekly intervals, depending on the occurrence of rainfall. The gauging station became operational at the end of November 2008, since the in-situ construction of an H-flume required several weeks. A preliminary analysis of the data collected till the end of 2008, focusing on two slopes with contrasting slope lengths as well as the gauging station: revealed clear differences in runoff and erosion between: (i) the micro-plot and slope-scale plots on the same hillslope; (ii) the two slopes; (iii) an initial dry period and a subsequent much wetter period; (iv) the slopes and the catchment-scale, also depending on the sampling period. These results suggest that the different processes govern the hydrological and erosion response at different spatial scales as well as for different periods, with soil water repellency playing a role during the initial post-fire period. The current presentation will review these preliminary results based on the data collected during the first year after the wildfire

Incidence and impact of hospital-acquired pneumonia: a Portuguese nationwide four-year study

This article presents the incidence of hospital-acquired pneumonia (HAP) in Portugal during a four-year period (2014-2017). Data were retrieved from the 100 Portuguese hospital diagnosis discharge database for adult patients and included gender, age, chronic comorbidities, mortality and hospital length of stay. There were 28,632 episodes of HAP, an incidence of 0.95 per 100 admissions. HAP patients had both a prolonged hospital length of stay (mean 26.4 days) and high mortality (33.6%). Most episodes occurred in patients aged ≥65 years and in males (76.1% and 61.7%, respectively). Invasive ventilation was required in 18.8%.info:eu-repo/semantics/publishedVersio