Ânforas da Villa Romana de Vilares de Alfundão (Ferreira do Alentejo)

Os autores estudam um conjunto anfórico recolhido nos restos conservados à superfície de uma villa romana, Vilares de Alfundão (Ferreira do Alentejo). Da análise tipológica e do estudo das pastas cerâmicas, conclui-se que a maioria terá sido fabricada nos fornos do Baixo Sado, predominando largamente as formas Dressel 14b e Almagro 51c. Tais resultados são comparados e discutidos, especialmente com os obtidos do estudo das ânforas de S. Cucufate (Vidigueira). Em dois fundos de ânforas DresseI 14 aparece o mesmo grafito e um dos exemplares da forma Almagro 50 ostenta na asa a marca [ . .. ] CVRVCVNIN

Parainfectious Optic Neuritis Followed by Microcystic Macular Oedema

Parainfectious optic neuritis is a very rare cause of acute vision loss. We present a case of a 51-year-old man with a recent upper respiratory tract infection, presumably of viral aetiology, who showed up with complains of painless right eye vision loss, followed by the same symptoms on the left eye 3 weeks later. Ophthalmological examination revealed optic disc swelling (sequential in severity) which was confirmed by optic disc imaging. The remaining evaluations (lumbar puncture, MRI, laboratory and genetic testing) were completely normal. Considering a postviral aetiology, 5-day intravenous methylprednisolone treatment was performed. Follow-up examinations revealed slight visual acuity and visual fields recovery, with subsequent optic disc atrophy and microcystic macular oedema, bilaterally. This case illustrates how important a correct clinical history is to guide a correct diagnosis and posterior management.info:eu-repo/semantics/publishedVersio

Changes in lignin content of Hypericum perforatum cells after Colletotrichum gloeosporioides elicitation

Fundação para a Ciência e a Tecnologia (FCT) - POCTI/AGR/40283/200

Sensitivity Analysis on PM Traffic Emission Modeling Parameters

Trabalho apresentado em 15th International Conference on Harmonisation Within Atmospheric Dispersion Modelling for Regulatory Purposes, 6-9 May 2013, Madrid, Spain.info:eu-repo/semantics/publishedVersio

Maquinagem não convencional sobre placas compósitas

A utilização de materiais compósitos tem crescido nas últimas décadas em virtude do seu baixo peso, elevada resistência e rigidez. A furação de placas compósitas é um desafio que se coloca às indústrias que trabalham com este tipo de materiais, sendo frequente o recurso a ferramentas convencionais, normalmente utilizadas na construção mecânica, com adaptações. Neste trabalho, apresenta-se uma técnica não convencional baseada na furação por jacto de areia sendo avaliadas as descontinuidades causadas em placas compósitas. Durante este processo de furação, as camadas da placa não resistem o tempo necessário para concluir a perfuração, aquecendo e fragmentando- se, e a areia, com o impacto, perde rapidamente o poder abrasivo. Além disso, o tempo necessário para completar com sucesso a operação seria superior a 5 horas, uma vez que a primeira etapa de jateamento durou aproximadamente uma hora, sendo necessário no fim da mesma repor um novo isolamento devido desgaste sofrido. Nesse momento da operação o progresso obtido era imperceptível. O trabalho experimental realizado permite concluir que a furação por jacto de areia, utilizando um compressor com um caudal de 1700 l/min e jateadora de sucção, não se mostra uma ferramenta promissora para executar operações de furação em placas compósitas

Induction of phenolic compounds in Hypericum perforatum L. cells by colletotrichum gloeosporioides elicitation

Changes in phenolic metabolism after elicitation with Colletotrichum gloeosporioides (CG) has been studied in Hypericum perforatum L. (HP) cell suspension cultures. Soluble phenolics were analysed by HPLC–DAD and HPLC–DAD–MS/MS. HP cultures elicited with the CG elicitor showed a significant increase in xanthone accumulation. Xanthone accumulation increased twelve fold when the cells were primed with methyl-jasmonate (MeJ) or salicylic acid (SA), before elicitation. HP cultures exposed only to MeJ produced a set of flavonoids, the flavones which represent a substantial part (approx. 40%) of the total flavonoids accumulated in these cells. The possible importance of xanthones as a component of defence mechanism of HP against biotic stress is discussed.Fundação para a Ciência e a Tecnologia (FCT

Damage assessment of drilled hybrid composite laminates

Hole drilling operations are common in fibre reinforced plastics - FRP’s - to facilitate fastener assembly to other parts in more complex structures. As these materials are non-homogeneous, drilling causes some damages, like delamination, for example. Delamination can be reduced by a careful selection of drilling parameters, drill material and drill bit geometry. In this work two types of laminates are drilled using different machining parameters and comparing drill geometries. Results show the importance of a cautious selection of these variables when composites’ drilling is involved

Evaluation of delamination damages on composite plates using techniques of image processing and analysis and a backpropagation artificial neural network

Nowadays, drilling of carbon/epoxy laminates is extremely frequent in manufacturing and assembling processes and is normally carried through using standard drills, like twist or Brad drills. However, it is always necessary to have in mind the need to adapt properly the drilling operations and/or the drilling tools used as the risk of delamination occurrence in the laminates involved, or other kind of damages, is very high. Moreover, delamination can be critical because the mechanical properties of the produced parts can be severely affected. Thus, the production of higher quality holes, with damage minimization, is a key challenge to everyone related with composites industry to develop adequate methodologies to delamination characterization and assessment. In this paper, the delamination caused on laminates by drilling machining operations is analytically evaluated by processing and analyzing enhanced conventional radiography images of the laminates involved. In resume, in order to evaluate the delamination damage in laminates plates caused by drilling operations, the radiography images acquired are processed using a computational methodology that uses techniques of image processing and analysis and a backpropagation artificial neural network. Experimental results show that the proposed methodology can be successfully used to measure and characterize the delaminated area. Hence, using our methodology, the damage evaluation on laminates can become more accurate, efficient and simple

Estudo da influência da pré-furação no dano em laminados carbono/epóxido

Na furação de placas em materiais compósitos é corrente o uso de técnicas tradicionais de furação adaptadas. O defeito mais grave é a delaminação, que nem sempre é visível à superfície e pode causar o colapso prematuro das estruturas. Para a avaliação dos danos provocados nas peças utilizam-se meios de controlo não-destrutivo. Neste artigo são analisados os resultados obtidos através do recurso à pré-furação em placas carbono/epóxido e de duas técnicas de controlo. Os resultados obtidos permitem estabelecer a influência da pré-furação na delaminação Neste trabalho, utilizam-se técnicas de Visão Computacional no processamento e análise das imagens obtidas nos ensaios experimentais

How does dilution affect the conductivity, the propensity to aggregate and the biological activity of enzymes?

The current theories do not provide a convincing explanation for many of the protein' manifestations in solution. Therefore, to shed some light on this critical question, the present work analyzed the effect of dilution on the ability of proteins to catalyze chemical reactions, the so-called biological activity. As models enzymes, laccase from Trametes versicolor and chicken egg white lysozyme were used. The results show that the enzymes' specific biological activity increases on dilution. Three explanations for the intriguing observation were advanced and submitted to experimental scrutiny. Amongst the three hypotheses, only one was corroborated by experiments. According to this explanation, when dissolved in water, proteins reveal two populations: one biologically active whose relative occurrence increases on dilution and another which is not active and whose molecular proportion varies in the opposite direction. Therefore, the reported experimental facts strongly support the chemical behaviour of the proteins in the solution. According to the herein-advocated concepts, they could undergo a dissociation process similar to that found in electrolyte chemistry.publishe