Optical demultiplexer based on an a-SiC:H voltage controlled device

In this paper we present results on the use of a semiconductor heterostructure based on a-SiC:H as a wavelength-division demultiplexer for the visible light spectrum. The proposed device is composed of two stacked p-i-n photodiodes with intrinsic absorber regions adjusted to short and long wavelength absorption and carrier collection. An optoelectronic characterisation of the device was performed in the visible spectrum. Demonstration of the device functionality for WDM applications was done with three different input channels covering the long, the medium and the short wavelengths in the visible range. The recovery of the input channels is explained using the photocurrent spectral dependence on the applied voltage. An electrical model of the WDM device is proposed and supported by the solution of the respective circuit equations. Short range optical communications constitute the major application field however other applications are foreseen. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

NEE: inclusão e relação escola-família

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção do grau de Mestre em Educação Especial - Especialidade Problemas de Cognição e Multideficiência

Notes on the feeding habits of Gaidropsarus guttatus (Collett, 1890) from Faial Island, Azores, NE Atlantic, PT

Copyright © 2014 Société Française d’Ichtyologie.

Selecção do melhor descolorante para a eliminação da cor residual num efluente têxtil

Mestrado em Engenharia Química

Influence of ventilation type in volatile organic compounds exposure: poultry case

Agricultural workers especially poultry farmers are at increased risk of occupational respiratory diseases. Epidemiological studies showed increased prevalence of respiratory symptoms and adverse changes in pulmonary function parameters in poultry workers. In poultry production volatile organic compounds (VOCs) presence can be due to some compounds produced by molds that are volatile and are released directly into the air. These are known as microbial volatile organic compounds (MVOCs). Because these compounds often have strong and/or unpleasant odors, they can be the source of odors associated with molds. MVOC's are products of the microorganisms primary and secondary metabolism and are composed of low molecular weight alcohols, aldehydes, amines, ketones, terpenes, aromatic and chlorinated hydrocarbons, and sulfur-based compounds, all of which are variations of carbon-based molecules.

Occupational exposure to toxigenic fungi from Aspergillus flavus complex

Bioaerosols are mainly composed of fungal particles, bacteria and plant spores, being fungi responsible for the release of VOCs and micotoxins into indoor environments. Aspergillus flavus is a common opportunistic pathogen causing human infections and is involved in the production of aflatoxin and other secondary metabolites associated with toxic and allergic reactions. Poultry workers are exposed to high concentrations of fungi and are therefore more prone to develop associated pathologies. To evaluate occupational exposure of the workers to Aspergillus flavus and aflatoxins, six animal production facilities were selected, including 10 buildings, from which indoor air samples and outdoor reference samples were obtained. Twenty-five duplicate samples were collected by two methodologies: impactation onto malt extract agar of 25L air samples using a Millipore Air Tester were used to evaluate quantitative (CFU/m3) and qualitative (species identification, whenever possible) sample composition; 300 L air samples collected with the Coriolis Air Sampler into phosphate–saline buffer were used to isolate DNA, following molecular identification of Aspergillus section flavi using nor-1 specific primers by real-time PCR.

The Month-of-the Year Effect nos mercados europeu, americano, australiano e asiático

Dissertação de Mestrado em Gestão/MBA

CCTα and CCTδ chaperonin subunits are essential and required for cilia assembly and maintenance in Tetrahymena

Background - The eukaryotic cytosolic chaperonin CCT is a hetero-oligomeric complex formed by two rings connected back-to-back, each composed of eight distinct subunits (CCTalpha to CCTzeta). CCT complex mediates the folding, of a wide range of newly synthesised proteins including tubulin (alpha, beta and gamma) and actin, as quantitatively major substrates. Methodology/Principal findings - We disrupted the genes encoding CCTalpha and CCTdelta subunits in the ciliate Tetrahymena. Cells lacking the zygotic expression of either CCTalpha or CCTdelta showed a loss of cell body microtubules, failed to assemble new cilia and died within 2 cell cycles. We also show that loss of CCT subunit activity leads to axoneme shortening and splaying of tips of axonemal microtubules. An epitope-tagged CCTalpha rescued the gene knockout phenotype and localized primarily to the tips of cilia. A mutation in CCTalpha, G346E, at a residue also present in the related protein implicated in the Bardet Biedel Syndrome, BBS6, also caused defects in cilia and impaired CCTalpha localization in cilia. Conclusions/Significance - Our results demonstrate that the CCT subunits are essential and required for ciliary assembly and maintenance of axoneme structure, especially at the tips of cilia.

Estudo de rendimentos queijeiros em leites das raças Holstein e Jersey numa exploração da ilha Terceira

Dissertação de Mestrado em Engenharia Zootécnica

Adesão terapêutica do idoso hospitalizado com doença crónica

Dissertação de Mestrado em Gerontologia Social

Envelhecimento bem sucedido : que percepções?

Dissertação de Mestrado em Gerontologia Social

Efeitos de um programa prolongado de exercício na tolerância ao esforço de indivíduos com antecedentes de síndrome coronário agudo

Objectivos: Este estudo teve por objectivo verificar a influência de um programa prolongado de exercício físico em parâmetros de aptidão física e cardiovasculares avaliados em prova de esforço máximo, em sujeitos com diagnóstico recente de síndrome coronário agudo. Métodos: A amostra, constituída por 50 sujeitos, foi distribuída por um grupo experimental (n=25) e por um grupo controlo (n=25), tendo o grupo experimental ficado sujeito a um programa de exercício físico regular durante 52 semanas. Todos os indivíduos realizaram duas provas de esforço máximas (PEM) em tapete rolante, uma no início e a outra no final do protocolo experimental, tendo a primeira prova sido realizada 2-3 meses após o evento cardíaco. Nas PEM foram registados parâmetros de aptidão física (velocidade máxima, inclinação máxima do tapete e tempo de prova), dos indicadores metabólicos (METs máximo) e parâmetros cardiovasculares (frequência cardíaca repouso e máxima durante a prova, tensão arterial de repouso e máxima durante a prova e o duplo produto máximo e em repouso). Resultados: Comparativamente à primeira prova, na segunda PEM verificou-se no grupo experimental um aumento significativo (p<0,05) dos valores absolutos dos indicadores de aptidão física, com uma percentagem de variação destes parâmetros significativamente superior à do grupo controlo. No entanto, apesar do melhor desempenho físico evidenciado pelo grupo experimental, não se verificaram diferenças significativas entre os dois grupos no que respeita aos parâmetros cardiovasculares. Conclusão: Os resultados permitem concluir que o programa de exercícios se revelou vantajoso para os indivíduos do grupo experimental, tendo-lhes aumentado a tolerância ao esforço físico máximo sem uma aparente sobrecarga cardiovascular adicional.

Avaliação preliminar do potencial eólico com recurso a um modelo de Mesoescala

Mestrado em Engenharia Química. Ramo optimização energética na indústria química.

Do man-made habitats affect spatial patterns of mollusk abundance?

XVIII Simposio Ibérico de Estudios de Biología Marina (SIEBM), Gijón (Asturias), 2 al 5 de septiembre de 2014.

Cobble beaches in oceanic islands : how they react to hydrodynamics and location in the island?

1st Mares Conference on Marine Ecosystems Health and Conservation. Olhão, Portugal 17-21 November 2014.