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- Reproduzir ou construir conhecimento? Funções da escrita no contexto escolar portuguêsPublication . Carvalho, José António Brandão; Barbeiro, LuísA escrita pode ser perspetivada como ferramenta de aprendizagem, desempenhando um papel relevante nos processos de aquisição, elaboração e expressão do conhecimento. O papel da escrita na construção do conhecimento pode ser compreendido focando as características linguísticas, os processos cognitivos implicados, ou a prática social e cultural em que se insere. Tendo por base o relevo que, no contexto da escola, a escrita pode assumir nesses processos, realizamos um estudo com o objetivo de verificar até que ponto essa dimensão é valorizada na escola portuguesa no ensino básico. Optamos por dois percursos metodológicos complementares: a análise de manuais escolares e um inquérito a professores por meio de questionário. Os dados recolhidos demonstram que, no contexto escolar, o uso da escrita acontece, sobretudo, no quadro de tarefas que visam à reprodução de informação e que, só muito raramente, ela é perspetivada como promotora da elaboração do conhecimento.
- Sustainable production of biologically active molecules of marine based originPublication . Murray, Patrick M.; Moane, Siobhan; Collins, Catherine; Beletskaya, Tanya; Thomas, Olivier P.; Duarte, Alysson W.F.; Nobre, Fernando S.; Owoyemi, Ifeloju O.; Pagnocca, Fernando C.; Sette, L.D.; McHugh, Edward; Causse, Eric; Pérez-López, Paula; Feijoo, Gumersindo; Moreira, Ma.T.; Rubiolo, Juan; Leirós, Marta; Botana, Luis M.; Pinteus, Susete; Alves, Celso; Horta, André; Pedrosa, Rui; Jeffryes, Clayton; Agathos, Spiros N.; Allewaert, Celine; Verween, Annick; Vyverman, Wim; Laptev, Ivan; Sineoky, Sergei; Bisio, Angela; Manconi, Renata; Ledda, Fabio; Marchi, Mario; Pronzato, Roberto; Walsh, Daniel J.The marine environment offers both economic and scientific potential which are relatively untapped from a biotechnological point of view. These environments whilst harsh are ironically fragile and dependent on a harmonious life form balance. Exploitation of natural resources by exhaustive wild harvesting has obvious negative environmental consequences. From a European industry perspective marine organisms are a largely underutilised resource. This is not due to lack of interest but due to a lack of choice the industry faces for cost competitive, sustainable and environmentally conscientious product alternatives. Knowledge of the biotechnological potential of marine organisms together with the development of sustainable systems for their cultivation, processing and utilisation are essential. In 2010, the European Commission recognised this need and funded a collaborative RTD/SME project under the Framework 7-Knowledge Based Bio-Economy (KBBE) Theme 2 Programme 'Sustainable culture of marine microorganisms, algae and/or invertebrates for high value added products'. The scope of that project entitled 'Sustainable Production of Biologically Active Molecules of Marine Based Origin' (BAMMBO) is outlined. Although the Union is a global leader in many technologies, it faces increasing competition from traditional rivals and emerging economies alike and must therefore improve its innovation performance. For this reason innovation is placed at the heart of a European Horizon 2020 Strategy wherein the challenge is to connect economic performance to eco performance. This article provides a synopsis of the research activities of the BAMMBO project as they fit within the wider scope of sustainable environmentally conscientious marine resource exploitation for high-value biomolecules.
- Additive manufacturing techniques for scaffold-based cartilage tissue engineeringPublication . Caseiro, Ana Rita; Almeida, Henrique A.; Bártolo, Paulo J.Articular cartilage damage is of great concern as it creates chronic pain and reduction of joint movement, leading to osteoarthritis. In current treatments, the resulting healing tissues lack structural organisation of cartilage and consequently have inferior mechanical properties when compared to native cartilage, therefore being prone to failure. Tissue engineering has long worked on cartilage regeneration and several requirements have been identified for the engineered structures to meet the desired function, by combining biodegradable and biocompatible materials, cells and growth factors, aiming at the production of biological structures closely resembling the native tissue.Within the scaffold based techniques for cartilage tissue production, conventional methods have shown limitations, especially regarding the control over the microstructure and repeatability of the produced constructs. Therefore, additive manufacturing techniques grew popular, allowing for a high level of control over the internal scaffold architecture and external shape of the construct, as well as guaranteeing its reproducibility.
- Synthesis, NMR and DFT conformational studies of homooxacalixarene (cyanopropyl)oxy derivatives, precursors to urea-terminated compoundsPublication . Marcos, Paula M.; Proença, Carla S.; Teixeira, Filipa A.; Ascenso, José R.; Bernardino, Raul; Cragg, Peter J.Direct O-alkylation of the parent compounds p-tert-butyldihomooxacalix[4]arene (1) and p-tertbutylhexahomotrioxacalix[3]arene (3) with 4-bromobutyronitrile and K2CO3 in acetonitrile afforded tetra- and tri-[(cyanopropyl)oxy] derivatives 2 and 4, respectively, as a mixture of conformers. These conformers were isolated and their conformational features studied by NMR spectroscopy (1H, 13C, COSY and NOESY) and DFT methods. Dihomooxacalix[4]arene tetra[(cyanobutyl)oxy] derivative 5 was also obtained and studied for comparison purposes. In general, good agreement was obtained between theoretical calculations and the NMR experimental data. For compounds 2 and 4 the partial cone conformation was the most stable, while the cone conformation was the most stable for derivative 5.
- EditorialPublication . Bártolo, Paulo; Chua, C.K.Additive manufacturing (AM) technologies play a key role in the advancement of biomedical applications. In this issue, we share with the readers the roles of AM technologies in two applications for biomedical engineering, namely scaffolds for tissue engineering and a composite model for club foot.
- Fatigue behaviour of nanoclay reinforced epoxy resin compositesPublication . Ferreira, J.A.M.; Borrego, L.P.; Costa, J.D.M.; Capela, C.Nanoparticle filling is a feasible way to increase the mechanical properties of polymer matrices. Abundant research work has been published in the last number of years concerning the enhancement of the mechanical properties of nanoparticle filled polymers, but only a reduced number of studies have been done focusing on the fatigue behaviour. This work analyses the influence of nanoclay reinforcement and water presence on the fatigue behaviour of epoxy matrices. The nanoparticles were dispersed into the epoxy resin using a direct mixing method. The dispersion and exfoliation of nanoparticles was characterised by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fatigue strength decreased with the nanoclay incorporation into the matrix. Fatigue life of nanoclay filled composites was significantly reduced by the notch effect and by the immersion in water.
- Depth map concealment using interview warping vectors from geometric transformsPublication . Marcelino, S.; Assunção, P.; Faria, S.M.M.; Soares, S.This paper deals with reconstruction of corrupted depth maps received by multivew video-plus-depth (MVD) decoders from error prone channels. An interview-based method is proposed using warping vectors obtained through a block matching approach with geometric transforms (BMGT) between two colour views. It is shown that BMGT is able to find efficient warping vectors for reconstruction of lost regions in the depth maps associated with the colour views. The proposed concealment method uses an additional contour reconstruction technique, applied to arbitrary shapes within the lost regions, which is used for weighted interpolation. In comparison to a reference method based on simple weighted interpolation, the proposed method is able to achieve PSNR gains in synthesised views up to 5.61dB, at data loss ratios up to 40%.
- Predictive depth map coding for efficient virtual view synthesisPublication . Lucas, Luis F R.; Rodrigues, Nuno M. M.; Pagliari, Carla L.; Silva, Eduardo A. B. da; Faria, Sérgio M. M. deThis paper presents a novel approach to compress depth maps envisioned for virtual view synthesis. This proposal uses a sophisticated prediction model, combining the HEVC intra prediction modes with a flexible partitioning scheme. It exhaustively evaluates the prediction modes for a large amount of block sizes, in order to find the minimum coding cost for each depth map block. Unlike HEVC, no transform is used, the residue being trivially encoded through the transmission of just its mean value. The experimental results show that, when the encoding evaluation metric is the quality of the view synthesized using the encoded depth map against the map encoding rate, the proposed algorithm generates reconstructed depth maps that provide, for most bitrates, some of the best performances among state-of-the-art depth maps encoders. In addition, it runs approximately as fast as the HEVC HM.
- District Metered Areas Design Under Different Decision Makers’ Options: Cost AnalysisPublication . Gomes, Ricardo; Marques, Alfeu S. A.; Sousa, JoaquimWater loss is a big challenge for water supply companies worldwide, and the Water Network Partitioning (WNP) is an excellent tool for water loss management–particularly in the current difficult economic and financial conditions. WNP is a recent research line and consists in dividing the water distribution network into smaller zones called District Metered Areas (DMAs) with one (or more, in exceptional cases) supply point, to reduce the network complexity and/or allow pressure management. Since there are several possible future scenarios, such as the water demand and/or the infrastructure degradation forecasts, which may have different impacts on the hydraulic behaviour, in this paper a computational application, based on an optimization model, is proposed to achieve a compromise between robustness required for the DMAs design (using a baseline scenario) and different decision makers’ options (using other scenarios with a lower “probability” of occurrence), to reduce the total cost. The objective function reflects the minimization of the squared deviations between the total cost of the DMAs design and the minimum cost for each scenario forecasted for the project plan, multiplied by the weight or “probability” of occurrence for each of the scenarios. The performance of the computational application is illustrated with a case study, and the results are encouraging.
- Influence of the Washcoat Structure in the Performance of Automotive Three Way CatalystsPublication . Santos, Helder; Pires, João; Costa, MárioTransport limitations inside the porous washcoat layer have an important influence in the light-off and overall conversions even in the case of relatively thin layers used in automotive three way catalysts (TWC). The porous structure of the washcoat layer is controlled at two levels: i) at the level of mesoporous structure, which can be determined by the use of specific synthesis techniques (e.g., sol-gel or pore-templating method), and ii) at the level of macroporous structure, which is influenced by the particle size distribution of mesoporous in a slurry that has undergone a specific thermal treatment. This paper investigates the influence of the washcoat structure in the performance of automotive TWC. Furthermore, the article presents a method that allows to quantify the magnitude of the reaction resistance (chemical kinetics), internal mass transfer resistance (washcoat diffusion), and external mass transfer resistance on the TWC conversions. From experimental data gathered at different operating temperatures (from light-off to 1100 K) and applying the developed methodology for resistances quantification, it was found that the internal mass transfer limitations play a major role in the TWC conversions. The main conclusions from this study are: i) the effective diffusivity strongly depends on the washcoat layer structure, which in turn depends on its preparation process; ii) the resistance quantification analysis reveals that the lower effective diffusivity interval is more adequate for the TWC used in the present investigation, which also indicates that the TWC washcoat has a low percentage of macropores; and iii) to decrease the relevance of the internal mass transfer limitation requires an increase in the effective diffusivity and/or a thinner washcoat layer.