Browsing by resource type "working paper"
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- Algumas idades Rb-Sr e K-Ar de rochas granitóides da região de Vilarinho da Castanheira-Foz do Sabor (Carrazeda de Anciães-Nordeste de Portugal)Publication . Silva, Antero Ferreira da; Kawashita, KojiNeste trabalho apresentam-se algumas determinações isotópicas Rb/Sr e K/Ar de idades absolutas em rochas granitóides do antiforma de Alijó-Carviçais, correspondente à região es-sudeste de Carrazeda de Anciães (Vilarinho da Castanheira-Foz do Sabor). A rocha total de duas amostras dos granitos de Castedo-Cabanas de Cima e Zêdes-Cabeça Boa-Especiarias, indiferenciados localmente, proporcionaram as idades convencionais Rb/Sr de 361.1±23.8 e 404.7±22.3M.a., com razão inicial (87Sr/86Sr)i=0.705±0.002. As suas biotites forneceram as idades aparentes K/Ar de 284.5±9.3 e 313.9±8.3M.a. O granito de Vilarinho da Castanheira, muito cisalhado durante a fase de deformação D3 varisca, forneceu um diagrama isocrónico Rb/Sr verdadeiro, na rocha total de quatro amostras, computado em 326.3±59.2M.a., com razão inicial (87Sr/86Sr)i=0.7112±0.0059 (limite de confiança 95%) e MSWD=0.151158. As suas biotites forneceram a idade aparente K/Ar de 306.4±11.0M.a. Uma das idades aparentes K/Ar (284.5±9.3M.a.) reflecte o final do metamorfismo regional varisco, permitindo precisar o final da consolidação das rochas granitóides variscas e a influência dos cisalhamentos variscos tardios. Porém, as outras duas parecem confirmar a idade isocrónica Rb/Sr do granito de Vilarinho da Castanheira.
- Dynamics of knowledge production and technology diffusion: Insights from the emergence of wind energyPublication . Sousa, Cristina; Bento, Nuno; Fontes, MargaridaThe objective of this paper is to contribute to a better understanding of the relation between the dynamics of knowledge production and technology diffusion along the process of emergence of a new technology, as it unfolds in diverse spatial locations. For this purpose, the paper traces the process of knowledge production over time – expressed in the number of scientific publications - and assesses how its dynamics relate with those of technology up-scaling and diffusion, for the case of a new renewable energy technology: wind power. It also compares these processes in different spatial areas, looking at similarities and differences in the evolving patterns, in initial markets and follower regions. In order to trace the dynamics of knowledge production we conduct a bibliometric analysis, using data collected from the Thomson Reuters Web of Science database (for the period 1970-2012). In order to trace the diffusion dynamics we use data collected on both unit scale of turbines and installed capacity of wind power (starting in late 1970s), following the empirical scaling methodology. These analyses are conducted at global scale and, subsequently, at a regional scale, for a pioneer (Denmark) and a fast follower (Portugal). The comparison of the outcomes from the bibliometric and the technology growth analyses permits to understand the rhythm and order in which knowledge was created and applied in this particular innovation. It also provides a preliminary account of the interplay between pioneer and fast follower regions.
- Experimental calibration of the oxygen-isotope palaeotemperature proxy in the shells of the bivalves Mytilus edulis and Pecten maximusPublication . Freitas, Pedro Seabra; Clarke, Leon J.; Kennedy, H. A.; Richardson, Christopher A.
- A geologia da República de Angola desde o Paleoarcaico ao Paleozóico InferiorPublication . Silva, Antero Ferreira daNeste trabalho serão descritas sucintamente as formações rochosas da República de Angola, bem como tecidas considerações sobre a sua evolução geotectónica desde o Paleoarcaico (c.3.500-3.300M.a.) ao Paleozóico inferior (c.450M.a.). Suas litologias distribuem-se por rochas gnáissico-migmatíticas, metaultramáficas-máficas, metassedimentares, metavulcano-sedimentares, metavulcânicas, granitóides, sedimentares, ultrabásicas e básicas. De acordo com a época da sua cratonização fazem parte do Escudo Arcaico do Nordeste de Angola (Lunda)-Kasai e dos Cratões Proterozóico de Angola-Congo ou Centro-Africano e Fanerozóico do Kalahari, em função do soerguimento e da respectiva estabilização nos finais do Neoarcaico (c.2.500M.a.), do Paleoproterozóico (c.1.700M.a.) e do Paleozóico inferior (c.450M.a.), respectivamente.
- Green energy harvesting: state of the artPublication . Neves, FilipeABSTRACT: Green energy harvesting aims to supply electricity to electric or electronic systems from an energy source present in the environment (e.g., thermal energy (thermoelectricity)) without grid connection or utilisation of batteries. Almost all manufacturing processes ranging from steel to food production generate heat (the so called “waste heat”), as do all machines from jet engines to microprocessors. The possibility of using a thermoelectric (TE) device to capture and to directly convert this waste heat into electric power is a very attractive and valuable approach to improve the overall energy efficiency and, thus, promotes a sustainable future.
- A litostratigrafia e estrutura do Supergrupo Dúrico-Beirão (Complexo Xisto-Grauváquico) em Portugal, e sua correlação com as correspondentes sucessões em EspanhaPublication . Silva, Antero Ferreira daNeste trabalho pretende-se caracterizar resumidamente a litostratigrafia de todas as sequências xisto-grauváquicas, actualmente identificadas em Portugal, constituindo o denominado Supergrupo Dúrico-Beirão (Complexo Xisto-Grauváquico). Serão tecidas considerações àcerca da sua sedimentação turbidítica, da sua paleogeografia e dos seus elementos cronoestratigráficos, bem como sobre a deformação e metamorfismo sofridos em tempos sardos e variscos. A finalizar procedeu-se a uma tentativa de correlação com as supostas correspondentes sucessões xisto-grauváquicas aflorantes em Espanha, neste mesmo Autóctone da Zona Centro-Ibérica. A sucessão do Supergrupo Dúrico-Beirão distribui-se pelos grupos das Beiras, do Douro e de Arda-Marofa. O primeiro é constituido pelas formações de Malpica do Tejo e de Rosmaninhal (fácies distal e proximal), de idade fundamentalmente do Ediacariano e, pontualmente, do Câmbrico inferior. O Grupo do Douro encontra-se sub-dividido pelas sucessões autóctone (formações de Bateiras e de Ervedosa do Douro) e alóctone (formações de Rio Pinhão ou Ponte da Chinchela e de Pinhão), com idade compreendida entre os finais do Ediacariano e o Câmbrico inferior a médio. Por fim, o Grupo de Arda-Marofa, que culminou a sedimentação da bacia xisto-grauváquica, distribui-se pelas formações de Póvoa, Real, Sátão, Excomungada-Ribeira do Colmeal, Queiriga, Desejosa, São Gabriel e São Domingos. A idade da sua sedimentação ter-se-ia processado desde o Ediacariano superior ao Câmbrico superior. As sucessões dos grupos das Beiras e do Douro são fundamentalmente constituidas por turbiditos distais e proximais clássicos, enquanto nas sequências do Grupo de Arda-Marofa se evidencia a presença de turbiditos de ondas modificadas, acompanhados de frequentes progradações a partir dos anteriores turbiditos, salvo nas formações de Desejosa e de São Gabriel, onde predominam os turbiditos distais e turbiditos vulcanoclásticos distais, respectivamente.
- Location of research-based spin-offs: how relevant are regional effects?Publication . Conceição, Oscarina; Faria, Ana Paula; Fontes, MargaridaUsing a unique self-collected dataset that comprehends the population of research-based spin-offs created in Portugal from 1995 until to 2007, we investigate the location choices of these firms. In order to do so we control for both university- and region-related mechanisms. Our results suggest that the latter play a lesser role than university-related mechanisms. Although the availability of qualified human capital and urbanization economies seem to exert some effect on the location choices of research-based spin-offs, our results suggest that the quality and prestige of the universities located in a region, as well as the presence of university-affiliated incubators and/or university research parks have a stronger impact on the intensity of RBSO location across regions.
- Oceans of energy? The non-linear trajectory of the emerging wave energy technologyPublication . Fontes, Margarida; Sousa, Cristina; Ferreira, J.This paper addresses the construction and structuring of a technological niche – i.e. a protected space where promising but still underperforming technologies are stabilized and articulated with societal needs – and discusses the processes that influence niche development and may enable niche breakout. In theoretical terms the paper is grounded on the multi-level approach to sustainability transitions, and particularly on the niche literature. But it also attempts to address the limitations of this literature in what concerns the spatial dimension of niche development. It is argued that technological niches can transcend the narrow territorial boundaries to which they are often confined, and encompass communities and actions that span several spatial levels, without losing some territorial embeddedness. It is further proposed that these features shape the niche trajectory and, therefore, need to be explicitly considered by the niche theoretical framework. To address this problem the paper builds on and extends the socio-cognitive perspective to technology development, introducing a further dimension – space – which broadens the concept of technological niche and permits to better capture the complexity of niche behaviour. This extended framework is applied to the case of an emerging renewable energy technology – wave energy - which exhibits a particularly slow and non-linear development trajectory. The empirical analysis starts by examining how an “overall niche space” in wave energy was spatially constructed over time. Then it investigates in greater detail the niche development processes that took place in Portugal, a country that was among the pioneers in the field, and whose actors have been, from very early stages, engaged in the activities conducted at various spatial levels. Through this combined analysis, the paper seeks to understand whether and how niche development is shaped by processes taking place at different spatial levels. More specifically it investigates the interplay between territorial and relational elements in niche development, and how these different dynamics influence the performance of the niche processes and impact on the overall niche trajectory. The results confirm the niche multi-spatial dynamics, showing that it is shaped by the interplay between a niche relational space constructed by actors’ actions and interactions on/across levels, and the territorial effects introduced by these actors’ embeddedness in particular geographical and institutional settings. They contribute to a more precise understanding of the processes that can accelerate or slow down the trajectory of a technological niche. In addition, the results shed some light into the niche activities conducted in/originating from a specific territorial setting - Portugal - offering some insights into the behaviour of key actors and its implications for the positioning of the country in the emerging field, which can be relevant for the formulation of strategies and policies for this area.
- Potencial biomássico para a energiaPublication . Eusebio, AnaRESUMO: O projeto CONVERTE pretende identificar de uma forma objetiva e quantitativa as diferentes tipologias de biomassas endógenas que possam ser aplicadas no curto-médio prazo em soluções tecnológicas viáveis para a produção de eletricidade, calor, vetores energéticos e biocombustíveis avançados, que cumpram todos os critérios de sustentabilidade definidos pelas Diretivas Europeias, em particular na Diretiva (UE) 1513/2015 (ILUC).
- Research-based spin-offs as agents of knowledge dissemination: evidence from the analysis of innovation networksPublication . Conceição, Oscarina; Sousa, Cristina; Fontes, MargaridaThe paper addresses the role played by research-based spin-offs (RBSOs) as knowledge dissemination mechanisms, through their position in knowledge networks. For this purpose the paper analyses the formal networks established by Portuguese RBSOs, in the context of publicly funded research, technology and pre-commercial product development projects, and investigates their configuration across two levels. At organisational level, in order to understand whether RBSOs extend their reach beyond the academic sphere; and if they do, whether they connect to organisations located downstream in the knowledge value chain, and which is their position in networks involving both research organisations and other firms. At spatial level, in order to understand whether RBSOs extend their reach beyond the region where they are created, thus potentially acting as connectors between diverse regions. The analysis starts from the population of RBSOs created in Portugal until 2007 (327 firms) and identifies those that have established formal technological relationships, as part of projects funded by all the relevant programmes launched in the period 1993-2012. As a result, the analysis encompasses 192 collaborative projects and involves 82 spin-offs and 281 partners, of which only 20% are research organisations, the remaining being other firms and a variety of other downstream organisations. The results, although still preliminary, provide some insights into the knowledge networking behaviour of the RBSOs. As expected, research organisations are a central actor in spin-offs’ networks, being the sole partner for some of them. But half of the RBSOs have moved beyond the academic sphere, being frequently a central element in tripartite technological relationships between research and other organisations, and occupying an intermediation position in the network, thus potentially acting as facilitators in knowledge circulation and transformation. Also as expected, RBSOs are predominantly located in the main metropolitan areas and tend to relate with organisations similarly located. But while geographical proximity emerges as important in the choice of partners, in about half of the cases, RBSOs knowledge networks have extended beyond regional boundaries. Given their central position in the network, this suggests a role as connectors across regions that will be explored in subsequent research.