O poder metropolitano da região de Lisboa

Este trabalho de investigação foi motivado pela preocupação em analisar a governação da área metropolitana de Lisboa como um fator determinante na resposta política aos problemas, desafios e oportunidades específicos deste território. O poder público existe para dar respostas assertivas e suficientes às exigências e necessidades da população que serve. O motivo essencial desta investigação é, desta forma, verificar se a solução governativa vigente na área metropolitana de Lisboa é capaz de responder com eficácia e eficiência às necessidades dos residentes e utilizadores deste extenso espaço urbano. As competências de âmbito metropolitano encontram-se distribuídas por vários organismos, entre os quais municípios, ministérios, comissão de coordenação e desenvolvimento regional, órgãos próprios da área metropolitana, empresas públicas e entidades privadas. Uma boa governação, ou governança, deste espaço exigiria uma eficaz coordenação entre estes diferentes atores, exigiria que não houvesse sobreposição de funções e, por fim, que cada uma das competências fosse desempenhada pelo ator territorial mais capaz de a desempenhar com elevado grau de eficiência. Concluiremos que esse nível de eficiência não está garantido na arquitetura institucional que gere a área metropolitana de Lisboa, e que as alterações feitas às leis fundamentais da distribuição de poderes não têm tido o efeito de alterar um paradigma que já se mostrou claramente inoperacional. As cidades ocupam, nos dias de hoje, uma posição central na organização do sistema global e das economias, tomando um lugar que foi, outrora, ocupado pelos impérios ou pelos Estados-nação. Trata-se essa mudança contemporânea de um efeito direto do complexo processo de globalização. Esse posicionamento estratégico das cidades gerou importantes mudanças na sua estrutura e no próprio conceito de cidade. Essas mudanças, porém, necessitavam ser acompanhadas de mudanças no modelo de governação das cidades, pois diferentes realidades necessitam de diferentes soluções de governo. O desenho de um modelo institucional eficaz para dar as respostas necessárias à área metropolitana de Lisboa exige um conhecimento profundo do território em estudo. Compreender as cidades contemporâneas e conhecer as propostas institucionais sugeridas por diferentes investigadores ao longo das últimas décadas é o primeiro passo desta investigação, depois do qual procuraremos analisar a metrópole de Lisboa, o modelo até então seguido, para sermos, por fim, capazes de o sujeitar a uma crítica construtiva que vise melhorá-lo para benefício da população e do próprio país.

Impactos territoriais de processos de cooperação transfronteiriça : caso de estudo : Elvas e Badajoz

A cooperação transfronteiriça é vista na União Europeia como um modelo de integração territorial e como uma alternativa para o desenvolvimento das regiões de fronteira, devido ao seu afastamento em relação aos grandes centros urbanos. No início da década de 90 foi lançado o programa do INTERREG tendo em vista a maior permeabilidade da fronteira e o desenvolvimento destes territórios, entre os quais o das regiões do Alto Alentejo e da Extremadura. A grande proximidade territorial entre Elvas e Badajoz permitiu desde sempre relações de cooperação mais ou menos intensas e consentidas, mesmo antes da abertura da fronteira, motivadas sobretudo pela diferença de valor entre as duas moedas. Contudo, com a entrada conjunta dos países ibéricos na CEE (1986), essas relações intensificaram-se ao nível do comércio, do emprego, do turismo, do lazer e da procura de serviços. Impactos territoriais como a procura e utilização conjunta de infraestruturas e de espaços públicos pelas populações das duas cidades, a promoção e realização de espetáculos culturais, a prática de cross-border shopping, a procura de uma segunda residência, em ambos os lados da fronteira, e a tendência para uma urbanização contínua no futuro, justificaram a criação da Eurocidade Elvas-Badajoz (2013). Esta iniciativa tem como principais objetivos promover a conceção, gestão e prestação conjunta de serviços, desenvolver projetos de cooperação em áreas de interesse comum, estimular a cooperação entre empresas e atrair investimentos geradores de novos postos de trabalho. No entanto os desafios para ambas as cidades prendem-se com a existência de um quadro jurídico e legal distinto que tem condicionado algumas das ações ou iniciativas e o desenvolvimento territorial conjunto ainda carece de uma proposta estratégica.

Avaliação experimental de compósitos de agregados leves impregnados com PCM, para aplicação em pavimentos rodoviários

Este trabalho visa, em primeiro lugar, a caracterização experimental do comportam ento de argamassas com materiais de mudança de fase (PCM) incorporados através de agregados leves, comparativamente com argamassas de referência sem incorporação de PCM. Verifica-se que a aplicação de argamassas com PCM em camadas de desgaste de pavimentos contribui para a minimização dos potenciais efeitos negativos de gelo e degelo. Os estudos experimentais permitem concluir que o método utilizado de impregnação de PCM em materiais porosos, para posterior incorporação em argamassa ou betão, é um método simples, mas muito eficaz. Os resultados indicam ainda que os materiais compósitos com PCM incorporado, podem melhorar a inércia térmica, bem como, atrasar o tempo de eventual ocorrência de congelamento sob a camada de desgaste de um pavimento

Recursos frutícolas na Várzea e na terra firme em onze comunidades rurais do alto Solimões, Amazonas, Brasil

A região do Alto Solimões é muito rica em recursos genéticos agrícolas, especialmente frutícolas, mas estes recursos contribuem principalmente para a subsistência em lugar de ter um papel mais amplo no desenvolvimento regional. Um levantamento qualitativo preliminar das espécies frutícolas nativas e exóticas foi executado em 11 comunidades rurais (8 caboclas, 3 Ticunas) nos ecossistemas principais (várzea, terra firme). Observou-se 37 fruteiras nativas em 20 famílias e 10 fruteiras exóticas em 9 famílias; das nativas, 9 foram raras (observadas em 1 ou 2 comunidades) e 3 foram comuns (observadas em 10 ou 11 comunidades); das exóticas, 2 foram raras e as bananas foram encontradas em todas as comunidades, sendo a fruteira mais importante na subsistência e na comercialização. As comunidades com mais acesso imediato à várzea e à terra firme tiveram mais espécies (22,5±6,6 nativas e 6,5±2,2 exóticas), que comunidades com acesso apenas à terra firme (19,0±2,2 nativas e 5,3±0,5 exóticas), que por sua vez tiveram mais espécies que comunidades com acesso apenas à várzea (5±2 nativas e 1,5±0,9 exóticas).

Cost-effective and lightweight mobile units for MixAR: A comparative trial among different setups

Cultural heritage has arousing the interest of the general public (e.g. tourists), resulting in the increasing number of visitations to archaeological sites. However, many buildings and monuments are severely damaged or completely destroyed, which doesn’t allow to get a full experience of “travelling in time”. Over the years, several Augmented Reality (AR) approaches were proposed to overcome these issues by providing three-dimensional visualization of reconstructed ancient structures in situ. However, most of these systems were made available through heavy and expensive technological bundles. Alternatively, MixAR intends to be a lightweight and cost-effective Mixed Reality system which aims to provide the visualization of virtual ancient buildings reconstructions in situ, properly superimposed and aligned with real-world ruins. This paper proposes and compares different AR mobile units setups to be used in the MixAR system, with low-cost and lightweight requirements in mind, providing different levels of immersion. It was propounded four different mobile units, based on: a laptop computer, a single-board computer (SBC), a tablet and a smartphone, which underwent a set of tests to evaluate their performances. The results show that mobile units based on laptop computer and SBC reached a good overall performance while mobile units based on tablet and smartphone did not meet such a satisfactory result even though they are acceptable for the intended use.

MixAR mobile prototype: visualizing virtually reconstructed ancient structures in situ

Archeology and related areas have a special interest on cultural heritage sites since they provide valuable information about past civilizations. However, the ancient buildings present in these sites are commonly found in an advanced state of degradation which difficult the professional/expert analysis. Virtual reconstructions of such buildings aim to provide a digital insight of how these historical places could have been in ancient times. Moreover, the visualization of such models has been explored by some Augmented Reality (AR) systems capable of providing support to experts. Their compelling and appealing environments have also been applied to promote the social and cultural participation of general public. The existing AR solutions regarding this thematic rarely explore the potential of realism, due to the following lacks: the exploration of mixed environments is usually only supported for indoors or outdoors, not both in the same system; the adaptation of the illumination conditions to the reconstructed structures is rarely addressed causing a decrease of credibility. MixAR [1] is a system concerned with those challenges, aiming to provide the visualization of virtual buildings augmented upon real ruins, allowing soft transitions among its interiors and exteriors and using relighting techniques for a faithful interior illumination, while the user freely moves in a given cultural heritage site, carrying a mobile unit. Regarding the focus of this paper, we intend to report the current state of MixAR mobile unit prototype, which allows visualizing virtual buildings – properly aligned with real-world structures – based on user's location, during outdoor navigation. In order to evaluate the prototype performance, a set of tests were made using virtual models with different complexities.

Nonsolvent induced phase separation preparation of poly(vinylidene fluoride-co-chlorotrifluoroethylene) membranes with tailored morphology, piezoelectric phase content and mechanical properties

Poly(vinylidene fluoride-co-chlorotrifluoroethylene) – P(VDF-CTFE) membranes are increasingly interesting for a wide range of applications, including battery separators, filtration membranes and biomedical applications. This work reports on the morphology, hydrophobicity, thermal and mechanical properties variation of P(VDF-CTFE) membranes processed by nonsolvent induced phase separation technique (NIPS) as a function of the main processing parameters. All membranes show a porous structure composed of large spherulites, (interconnected) micropores and/or microvoids depending on the processing conditions used that in turn affect their hydrophobicity and mechanical properties. The degree of crystallinity of the membranes remains approximately constant with a value of about 15 %, except for the membranes immediately immersed in ethanol, which is of about 23 %. In turn, the crystalline phases present in the copolymer is mainly affected by the temperature and nonsolvent characteristics of the coagulation bath, the β-phase content ranging from 33 to 100 %, depending on those processing parameters. It was show that the temperature of water-based coagulation bath plays an important role in order to produce structurally uniform and homogeneous porous membranes, which is particularly important from the point of view of technological applications.

Novel hybrid multifunctional magnetoelectric porous composite films

Novel multifunctional porous films have been developed by the integration of magnetic CoFe2O4 (CFO) nanoparticles into poly(vinylidene fluoride)-Trifuoroethylene (P(VDF-TrFE)), taking advantage of the synergies of the magnetostrictive filler and the piezoelectric polymer. The porous films show a piezoelectric response with an effective d33 coefficient of -22 pC/N-1, a maximum magnetization of 12 emu.g-1 and a maximum magnetoelectric coefficient of 9 mV.cm-1.Oe-1. In this way, a multifunctional membrane has been developed suitable for advanced applications ranging from biomedical to water treatment.

State of the art and open questions on cathode preparation based on carbon coated lithium iron phosphate

One important component with particular relevance in battery performance is the cathode, being one of the main responsible elements for cell capacity and cycle life. Carbon coated lithium iron phosphate, C-LiFePO4, active material is one of the most promising cathode materials for the next generation of large scale lithium ion battery applications and strong research efforts are being devoted to it, due to its excellent characteristics, including high capacity, ~170 mAh/g, and safety. This review summarizes the main developments on C-LiFePO4 based cathode film preparation and performance. The effect of the binder, conductive additive, relationship between active material-binder-conductive additive and drying step, in the electrode film fabrication and performance is presented and discussed. Finally, after the presentation of the cell types fabricated with C-LiFePO4 active material and their performance, some conclusions and guidelines for further investigations are outlined.

Piezoelectric polymers as biomaterials for tissue engineering applications

Tissue engineering often rely on scaffolds for supporting cell differentiation and growth. Novel paradigms for tissue engineering include the need of active or smart scaffolds in order to properly regenerate specific tissues. In particular, as electrical and electromechanical clues are among the most relevant ones in determining tissue functionality in tissues such as muscle and bone, among others, electroactive materials and, in particular, piezoelectric ones, show strong potential for novel tissue engineering strategies, in particular taking also into account the existence of these phenomena within some specific tissues, indicating their requirement also during tissue regeneration. This referee reports on piezoelectric materials used for tissue engineering applications. The most used materials for tissue engineering strategies are reported together with the main achievements, challenges and future needs for research and actual therapies. This review provides thus a compilation of the most relevant results and strategies and a start point for novel research pathways in the most relevant and challenging open questions.

Tailored magnetic and magnetoelectric responses of polymer-based composites

The manipulation of electric ordering with applied magnetic fields has been realized on magnetoelectric (ME) materials, however, their ME switching is often accompanied by significant hysteresis and coercivity that represents, for some applications, a severe weakness. To overcome this obstacle, this work focus on the development of a new type of ME polymer nanocomposites that exhibits tailored ME response at room temperature. The multiferroic nanocomposites are based on three different ferrite nanoparticles, Zn0.2Mn0.8Fe2O4 (ZMFO), CoFe2O4 (CFO) and Fe3O4 (FO), dispersed in a piezoelectric co-polymer poly(vinylindene fluoride-trifluoroethylene), P(VDF-TrFE), matrix. No substantial differences were detected on the time-stable piezoelectric response of the composites (≈ -28 pC.N−1) with distinct ferrite fillers and for the same ferrite content of 10wt.%. Magnetic hysteresis loops from pure ferrite nanopowders showed different magnetic responses. ME results of the nanocomposite films with 10wt.% ferrite content revealed that the ME induced voltage increases with increasing DC magnetic field until a maximum of 6.5 mV∙cm−1∙Oe−1, at an optimum magnetic field of 0.26 T, and 0.8 mV∙cm−1∙Oe−1, at an optimum magnetic field of 0.15T, for the CFO/P(VDF-TrFE) and FO/P(VDF-TrFE) composites, respectively. On the contrary, the ME response of the ZMFO/P(VDF-TrFE) exposed no hysteresis and high dependence on the ZMFO filler content. Possible innovative applications such as memories and information storage, signal processing, ME sensors and oscillators have been addressed for such ferrite/PVDF nanocomposites.

Novel anisotropic magnetoelectric effect on δ-FeO(OH)/P(VDF-TrFE) multiferroic composites

The last decade has witnessed an increased research effort on multi-phase magnetoelectric (ME) composites. In this scope, this paper presents the application of novel materials for the development of anisotropic magnetoelectric (ME) sensors based on δ-FeO(OH)/P(VDF-TrFE) composites. The composite is able to precisely determine the amplitude and direction of the magnetic field. A new ME effect is reported in this study, as it emerges from the magnetic rotation of the δ-FeO(OH) nanosheets inside the piezoelectric P(VDF-TrFE) polymer matrix. δ-FeO(OH)/P(VDF-TrFE) composites with 1, 5, 10 and 20 δ-FeO(OH) filler weigh percentage in three δ-FeO(OH) alignment states (random, transversal and longitudinal) have been developed. Results shown that the modulus of the piezoelectric response (10-24 pC.N-1) is stable at least up to three months, the shape and magnetization maximum value (3 emu.g-1) is dependent on δ-FeO(OH) content and the obtained ME voltage coefficient, with a maximum of ≈0.4 mV.cm-1.Oe-1, is dependent on the incident magnetic field direction and intensity. In this way, the produced materials are suitable for innovative anisotropic sensor and actuator applications.

Gd2O3: Eu Nanoparticle-Based Poly(vinylidene fluoride) Composites for Indirect X-ray Detection

Polymer based scintillator composites have been fabricated by combining poly(vinylidene fluoride) (PVDF) and Gd2O3:Eu nanoparticles (50nm). PVDF has been used since it is a flexible and stable binder matrix and highly resistance to thermal and light deterioration. Gd2O3:Eu has been selected as scintillator material due to its wide band gap, high density and suitable visible light yield. The structural, mechanical, thermal and electrical characteristics of the composites were studied as a function of filler content, together with their performance as scintillator material. The introduction of Gd2O3:Eu nanoparticles into the PVDF matrix does not influence the morphology of the polymer or the degree of crystallinity. On the other hand, an increase of the Young´s modulus with respect to PVDF matrix is observed for filler contents of 0.1-0.75 wt.%. The introduction of Gd2O3:Eu into the PVDF matrix increases dielectric constant and DC electrical conductivity as well as the visible light yield in the nanocomposite, being this increase dependent upon Gd2O3:Eu content and X-ray input power. In this way, Gd2O3:Eu/PVDF composites shows suitable characteristics to be used as X-ray radiation transducers, in particular for large area applications.

Advances and future challenges in printed batteries

There is an increasing interest in thin and flexible energy storage devices to meet modern society needs for applications such as, radio frequency sensing, interactive packaging and other consumer products. Printed batteries comply these requirements and are an excellent alternative to conventional batteries for many applications. Flexible and micro-batteries are also included in the area of printed batteries whenever fabricated by printing technologies. The main characteristics, advantages, disadvantages, developments, and printing techniques of printed batteries are presented and discussed in this review. The state-of-art takes into account both the research and industrial levels. In the academic one, the research progress of printed batteries is summarized divided in lithium-ion battery (Li-ion), zinc-manganese dioxide (Zn-MnO2), and other battery types with emphasis on the different materials for anode, cathode and separator as well as in the battery design. With respect to the industrial state-of-art, materials, device formulations and manufacturing techniques are presented. Finally, the prospects and challenges of printed batteries are discussed.

Determination of the magnetostrictive response of nanoparticles via magnetoelectric measurements

It is successfully demonstrated that nanoparticle’s magnetostriction can be accurately determined based on the magnetoelectric effect measured on polymeric-composite materials. This represents a novel, simple and versatile method for the determination of particle’s magnetostriction at their nano-sized and dispersed state, which is, up to date, a difficult and imprecise task.