O PNEF: instrumento facilitador ou inibidor da rotura no processo pedagógico?

info:eu-repo/semantics/publishedVersio

Avaliação sumativa: o erro do avaliador

info:eu-repo/semantics/publishedVersio

Gestão integrada de um túnel em meio urbano (TÚNEL)

Quando falamos de trânsito numa cidade, normalmente não nos referimos a um bom fluxo de circulação mas sim aos problemas causados por acidentes e congestionamento das vias, ou seja, falamos de uma mobilidade deficiente. Dada a necessidade de imprimir um novo ritmo ao tráfego rodoviário na cidade, há que tentar eliminar as dificuldades causadas pelo cruzamento de vias, onde os conflitos de interesses dos vários utentes reduzem a fluidez de circulação. Também terá que ser retirado das vias do centro da cidade, aquele tráfego que a ele não se destina, que por ali só passa por não haver alternativa e que agrava o estado das coisas, principalmente nas horas de ponta. È aqui que a necessidade de construir túneis se coloca. Os túneis rodoviários urbanos são, nos dias de hoje, estruturas fundamentais na gestão do tráfego. Neste trabalho pretende-se mostrar como a gestão integrada pode ser atingida, implementando regras e procedimentos de segurança que, de uma maneira racional, nos conduzam à melhor regulação possível do tráfego, em cada momento

Inspection of the thickness of resin cements for ceramic veneers

O objetivo principal deste estudo foi realizar uma revisão da literatura sobre a espessura do cimento resinoso após cimentação de facetas cerâmicas. Para a seleção de artigos publicados até fevereiro de 2019, uma pesquisa bibliográfica foi realizada no PUBMED usando os seguintes termos de pesquisa: “veneer” AND resin cement AND thickness” OR “layer”. Os resultados mostram que a espessura do cimento resinoso se mostra mais pronunciada na zona occlusal do dente, com valores que podem variar entre os 50 e 110 µm. Também na mesma zona é onde se pode encontrar a maior concentração das tensões. O aumento da espessura do cimento tem pouco efeito na variação das tensões provocadas nas facetas cerâmicas. Contudo, o tipo de cimento, a preparação das margens do dente, o tipo e espessura de facetas que vão condicionar o comportamento do cimento, e as forças mastigatórias vão afetar a vida útil da faceta

Development of new oil/water partitioning tracers for the determination of residual oil saturation in the inter-well region of water-flooded reservoirs

Most of the hydrocarbon-rich large unexplored basins are located in remote and/or highly environmentally sensitive regions. As more and more oilfields reach maturity at the end of the secondary stage of recovery, while on average more than 50% of the original reserves of hydrocarbons are left in place, the future of oil production on the Norwegian Continental shelf (NCS) will increasingly rely on IOR projects to face the demand. A partitioning inter-well tracer test (PITT) is a type of tracer test that measures the water contactable saturation of immobile oil (SOR) in the inter-well region of water flooded reservoirs. Knowledge about SOR in the swept volumes between injector/producer pairs is a key parameter for the design and evaluation of IOR projects. The PITT explores the lag in production experienced by an oil/water partitioning tracer relatively to a passive water tracer which directly correlates to SOR. This principle was introduced to the industry in 1971 and relied on the use of molecules successfully applied in hydrology and/or labelled with radioactive nuclides for easier detection. The conditions encountered in oil reservoirs, particularly in deep oil formations, are significantly harsher than in the near surface subsoil. Thus, several unsuccessful inter-well tracer tests resulted from a poor selection of the tracer compounds used at that time because of insufficient knowledge about their behaviour under typical reservoir conditions. Much work has been done to improve the original concept of the PITT regard its deployment and interpretation. However, little effort has been put in place to establish a systematic procedure for selecting, testing and describing the dynamic behaviour of the substances used as oil/water partitioning tracers. Thus, this thesis aims to present a methodology for selection and testing of new PITT tracer candidates, with the results and findings of its application to a selected group of molecules. The methodology presented here starts by describing the base requirements for selection of new oil/water partitioning tracer candidates. Additionally, guidelines for testing and qualification are presented. There are several steps in the qualification procedure. These can be divided into static stability experiments, development of analytical methods for laboratory samples, development of analytical methods for identification and quantification of the stable molecules in real produced waters, characterisation of the oil/water partition coefficient (K) of the molecules, and dynamic flooding experiments using cores of consolidated sedimentary rock. Following this method, step by step, 16 molecules from 4 different chemical “families” were selected and tested for qualification as new oil/water partitioning tracers. The static stability experiments evaluated the thermal stability of the PITT tracer candidates, in the absence and presence of typical reservoir rock materials, different pH conditions, and elevated salinity up to 150 0C for 12 weeks contact time. Ultra-performance liquid chromatography (UPLC) coupled with ultra-violet detection (UV) and high-resolution mass spectrometry (HRMS), and gas chromatography (GC) coupled with flame ionisation detection (FID) were the techniques used to follow the concentration of the PITT tracer candidates along the 12 weeks of experiment. UPLC-HRMS was used to try to obtain relevant information to describe the observed phenomena. The static stability experiments proved that only 5 of the 16 tested compounds were stable for 12 weeks up to 150 ℃. Two additional compounds were stable for the same period up to 125 ℃. This is sufficient to allow for their use in most oilfields, and they were thus included as possible inter-well PITT tracers. These experiments also revealed dramatic interactions between some of the studied molecules and clay minerals of undefined nature, as well as thermally driven degradation of the candidates that is well described by a pseudo-first order kinetic model. The latter two findings open the possibility of using tracers to retrieve information about temperature and geochemistry/mineralogy in the inter-well region, though the latter requires further development. A method based on sequential direct immersion (DI) headspace (HS) solid-phase microextraction (SPME) proved effective as analytical sample pre-treatment followed by GC-MS/MS for analysis of the PITT tracer candidate concentrations in real production waters. The DI-HS-SPME-GC-MS/MS method allows for quantification of the stable molecules investigated in low ng/L concentrations and introduces significant improvements in comparison to the commonly used methodologies for analysis of tracers in produced waters: it requires just 5 mL of sample and eliminates the need for use of organic solvents in the laboratory. Furthermore, sample processing times are significantly reduced as the cleaning/concentration step becomes much faster. This is of utmost importance for a PITT, as several hundreds of samples are analysed in these examinations. The characterisation of the K-values of the stable PITT tracer candidates revealed that they will likely vary along the volume swept between injector/producer pairs. K is influenced primarily by the ionic strength of the aqueous phase and composition of the hydrocarbon phase, and to a smaller extent by temperature T. The influence of temperature can, however, be very relevant: The K-value is used in the calculation of SOR together with the times of arrival of the different tracers using the same landmark of their respective production curves (i.e., the theoretically most correct is the first moments of the curves). It is likely that the temperature varies between injector and producer well-pairs. The variation of the K-value as function of T needs to be accounted for to determine accurate SOR values. Variations of the ionic strength will lead to even bigger variations of the K-value independently of the valency of the ions present in the aqueous phase. The experiments performed also confirmed the constant and reversible equilibrium distribution of the oil/water tracer candidates between hydrocarbon and aqueous phases, as well as their suitability for use on most oilfields of the NCS. The flooding experiments were performed on sandstone and chalk cores prepared both to pure water saturation and to residual oil saturation, SOR. Residence time distribution analysis (RTD) was used to interpret the production curves. These experiments proved that the PITT tracer candidates behave as water tracers in the absence of hydrocarbons, with no significant difference encountered between their production curves and the ones obtained from the reference water tracer (tritiated water). SOR was determined for two different mass recovery landmarks in each of the experiments for all partitioning tracers using the K-values previously determined in the experiments for characterisation of the K-values. Good agreement between all SOR values measured by the tracer candidates and the values determined by a balance to the oil used to prepare the cores was encountered. This is also valid when SOR measured by the tracers is compared to the value obtained by the differences in water flooded pore volumes measured by tritiated water. The methodology presented and applied in this thesis produced 7 new oil/water partitioning tracers ready to be used in oil fields with low probability of failure. The findings and observations presented here can be incorporated into reservoir models to obtain more accurate data from PITTs, and consequently better reservoir description. Furthermore, the reinjection of produced waters will lead to contaminations of the inter-well region with tracers used there. Thus, the present study offers guidelines and methods for the development of new tracers. The oil industry, service companies, and other researchers working with tracer technology will be the primary beneficiaries of this study, that will hopefully contribute to disseminate the use of PITTs by the industry. This technology has a large potential to contribute to a future efficient and profitable oil production

Avaliar em educação física: a necessidade de um quadro conceptual

A avaliação é considerada parte integrante do processo educativo, imprescindível em qualquer proposta de educação. Esta encontra-se ligada ao processo ensino e aprendizagem, contudo sabemos que na prática pedagógica esta fica muitas vezes desvinculada neste processo. Muitas vezes a avaliação é apenas vista como uma mera atribuição de notas, dando aos alunos um ”rótulo” e não como um meio de o mesmo orientar a sua prática indo deste modo ao encontro das reais necessidades dos seus alunos. Consideramos que este tema é bastante complexo, contudo pretendemos compreender como a mesma pode ser um instrumento facilitador e de reflexão das práticas, buscando assim progredir na construção do conhecimento. A avaliação feita nos moldes tradicionais e sem qualquer objetivo parece-nos estar descontextualizada, estamos em crer que a mesma deve ser inovadora que leve o aluno a assimilar informações e utilizá-las em contextos adequados, de modo a que possa tomar decisões autónomas e criativas. O importante é a aprendizagem efetiva que existe. Mas se pensarmos na origem deste tema podemos compreender este pensamento, contudo está desatualizado e descontextualizado na nossa realidade. O mais importante é saber o que avaliar? Quem? Como? Porquê? E com que resultados. Neste sentido com esta comunicação procuramos mostrar a necessidade de um quadro conceptual, de modo a que todos possam saber qual o caminho a seguir e que opções tomar.N/

Pedradas no charco: contributos para a rotura do processo pedagógico

info:eu-repo/semantics/publishedVersio

Pedradas no pântano: contributos para a rotura do processo

info:eu-repo/semantics/publishedVersio

Towards an interdisciplinary framework for automated negotiation

Negotiation is an important and pervasive form of social interaction. The design of autonomous negotiating agents involves the consideration of insights from multiple relevant research areas to integrate different perspectives on negotiation. As a starting point for an interdisciplinary research effort, this paper presents a model that handles bilateral multi-issue negotiation, employs game-theoretic techniques to define equilibrium strategies for the bargaining game of alternating offers, and formalizes a set of negotiation strategies and tactics studied in the social sciences. Autonomous agents equipped with the model are currently being developed using the Jade framework. The agents are able to negotiate under both complete and incomplete information, thereby making the model in particular and the agents in general very compelling for automated negotiatio