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Sobre o conceito de incerteza em Física e na Metrologia
No full text3-13ppN.º 5CIC/NQMRevista Medições e Ensaio
Moving towards the sustainable city? The role of electric vehicles, renewable energy and energy efficiency
No full textIntegrated energy and urban mobility systems are key components for achieving cities’ sustainability. Several urban metabolism approaches are emerging as leading tools for quantifying energy consumption and use patterns of resources in urban environments. Examples are the mass balance accounting (or energy-materials flux approach) using several quantification methods such as material flow analysis and life cycle assessment and Odum’s emergy methods. In this research we adapt the extended metabolism model of a city developed by Newman (1999) and the material and energy flow accounting by Sheeri (2002) to assess the future role of electric vehicles, renewable energy use for mobility needs and energy efficiency increases for households living in the city of Aveiro, a medium-sized city of 78450 inhabitants in Portugal. The data used comprised an integrated set of energy, transport, socio-economic and solid waste production/treatment collected at the local and National level as part of the research project COST-TRENDS funded by the Portuguese Foundation for Science and Technology. The analysis of the potential energy mix (energy inputs from different sources) and households’ mobility needs refers to the horizon 2010-2020. Several energy sources were considered: hydric, wind, solar (thermic and photovoltaic) and solid waste (incineration and biogas). Potential accessibility indicators were developed to better convergence towards sustainable mobility objectives, measuring the potential for interaction and exchange of services and opportunities. Different household’s profiles were established to represent consumers’ behaviour. It was found that the above integrated energy system could provide a total of 2,61 MWh/household.year, which represents on average around 38,2% of the total energy needs for households’ daily mobility and 1,2 tonnes CO2/household.year avoided. On the other hand, the replacement of conventional internal combustion engine by battery electric vehicles could allow an energy reduction between 4,7 and 6,1 MWh/household.year until 2020 and a reduction of 1,6 tonnes CO2 /household.year.Fundação para a Ciência e Tecnologia, projeto COST-TRENDs3412Em 28 de fevereiro de 2013 foram cedidos os direitos de publicação/copyright à WIT Press,para efeitos da sua inserção na publicação no livro/Book da WIT Press - "Sustainable Development and Planning 2013".DT/NPTS201327 a 29 de mai
EIS study of amine cured epoxy-silica-zirconia sol-gel coatings for corrosion protection of the aluminium alloy EN AW 6063
No full textThe organic-inorganic hybrid sol-gel films have been reported as an environmentally
friendly anti-corrosion pre-treatment for several metals. These types of coatings present
combined mechanical and chemical properties typical of inorganic ceramics and of organic
polymers [1]. Among these, the epoxy-silane based hybrid sol-gel coatings are of particular
interest due to the increased properties of flexibility, density and functional compatibility
with organic coatings achieved as a result of the epoxide organic group present [1-3].
During the synthesis of these coatings occurs the simultaneous formation of an organic
network through epoxide rings opening and polymerization, and of an inorganic siloxane
network through the hydrolysis and subsequent condensation of the silicon alkoxide
groups. Uncatalysed organic polymerization usually requires elevated temperature.
However, by the addition of amine curing agents it is possible to promote the organic
network formation at low temperature [4], with inherent energy savings.
In this paper, epoxy-silica-zirconia hybrid sol-gel coatings were synthesized from
glycidoxypropyltrimethoxysilane (GPTMS) and zirconium n-propoxide (TPOZ) precursors,
applied to EN AW-6060 alloy by dip-coating and cured at room temperature using the
amine crosslinker diethylenetriamine (DETA), in different concentrations (GPTMS/amine-
Hreactive molar ratios: 1.5 and 1), and a tri-functional amino-silane in that molar ratio of 1.
The evolution of the curing process and the corrosion behaviour of the coated aluminium
alloy specimens were evaluated by Electrochemical Impedance Spectroscopy (EIS) in 0.5 M
NaCl. The morphology and surface chemistry of the hybrid coatings were also
characterized by Energy Dispersive Spectroscopy (EDS) coupled to Scanning Electron
Microscopy (SEM) and by Fourier Transform Infrared Spectroscopy (FTIR). The results
obtained revealed that the sol-gel coatings with less amine require longer times to finish
cure. Once cured, these coatings have shown the best anticorrosive performance with
time. It was found that increasing amine concentration led to a more cross linked organic
network, resulting in higher initial coatings resistance, however it has turned coatings
more hydrophilic, prone to rapid degradation in water.DM/NMM201322-24 Apri
Especificações de desempenho para camadas de agregados britados em fundações de infraestruturas de transporte
No full textQuando se avalia o desempenho de estruturas de pavimentos e de superestruturas ferroviárias, é reconhecida a importância determinante das condições de fundação nesse desempenho, em particular quando se avalia a fase de operação e manutenção (O&M). Com vista a garantir um adequado comportamento das referidas estruturas, é frequente empregar agregados britados nas camadas de fundação. Neste trabalho apresentam-se resultados de ensaios de caracterização mecânica de camadas compactadas de agregados britados, construídas num modelo físico e em obra; avalia-se a importância das condições de estado nas propriedades mecânicas das camadas e discutem-se aspetos relacionados com a utilização de especificações baseadas no desempenho no controlo da qualidade dessas camadas.10pDT/NIF201310 a 12 de Abri
Evolução da qualidade das águas subterrâneas na zona envolvente ao complexo químico de estarreja. Perspetivas futuras
No full textNo âmbito de um trabalho elaborado pelo Núcleo de Águas Subterrâneas do LNEC para a ARH Centro intitulado
"Modelação Qualitativa e Quantitativa em Aquíferos da Região Hidrográfica do Centro" foi caracterizada a qualidade da
massa de águas subterrâneas do Quaternário de Aveiro, em termos do seu estado químico global bem como uma
caracterização detalhada da evolução da qualidade das águas na área envolvente do Complexo Químico de Estarreja (CQE) e
perspetivas futuras. Neste artigo apresenta-se uma síntese dos resultados obtidos.
O objetivo subjacente a esta análise foi obter a informação necessária para compreender a evolução da qualidade das águas
subterrâneas nas últimas décadas junto ao CQE e, assim, dispor da informação de base para poder efetuar a modelação do
transporte de solutos com o modelo MODFLOW (apresentada em Martins et al., 2011). Esta ferramenta de gestão permitiu
não só compreender a evolução passada, mas também simular cenários de evolução futura que permitem melhor gerir o
sistema.FCT, AQUAGRI ACE,GRUNDFOS,GRANDEWATER,Nemus57-10DHA/NAS20137 e 8 de Març
Turbulent non-uniform flows in straight compound open-channels
No full textThe reported experimental study assesses the effects of flow non-uniformity on the momentum flux in straight compound channels. Two flumes were
used, featuring vertical and sloping banks. Starting with uniform flow condition, various imbalances in the upstream discharge distribution were
introduced. This resulted in a time-averaged lateral flow and advective transport of momentum, which interacted with the shear-layer turbulence
generated by the compound geometry. To investigate this interaction, the three contributions to transverse momentum flux (depth-averaged flow,
shear-layer turbulence and dispersive term of spanwise velocity) are assessed. The first two contributions were strengthened by the sloping banks,
while the third becomes important for the case of the vertical bank. With a lateral flow towards the main channel, the first contribution rises at the
expense of the second. With a lateral flow towards the floodplain, the first two contributions have the same order of magnitude, and the Boussinesq
approach is invalidated.12ppDOI: 10.1080/00221686.2013.818586DHA/NREJournal oh Hidraulic Researc
Numerical simulation of the behaviour of a moored ship inside an open coast harbour
No full textSea waves inside harbors can affect scheduled port operations. Hence it is
important to correctly predict and characterize the wave field inside ports and to describe the
movements of the ship and forces acting upon it. A classical approach is to assume that shipwave
interaction is linear, [1]. Then it is possible to decompose it in the so-called radiation
and diffraction problems. Numerical models that solve such problems have been developed
and used by the offshore industry for quite a while, [2], to study the interaction of sea-waves
with floating objects. However, these models cannot be used to solve the diffraction problem
of ships inside harbor basins where nearby reflecting boundaries and shallow depths create
very complex nonlinear wave fields.
A new set of procedures using coupled models is proposed in this work. First, a Boussinesqtype
finite element wave propagation model is used to determine the wave field in the
numerical domain containing the harbor. Then the velocity potentials are evaluated at the
ship’s hull and finally, the Haskind relations [3] are used to determine the wave forces on the
ship along the six modes of motion (heave, sway, surge, roll, pitch and yaw). This new
methodology for the evaluation of diffraction forces on a ship inside a harbor basin is
presented and tested in this paper. Movements of the moored ship and tensions on the
mooring system are obtained using a numerical solver for the motion equations of a moored
ship. An application to an open coast harbor is presented.6012pDHA/NPE201329 a 31 de Mai
Aplicação do sistema Delft3D na modelação de correntes longitudinais
No full text402pDHA/NPE20139 e 10 de Mai
O PRÉMIO INH/IHRU, UM PROCESSO DE REFERÊNCIA
No full text6020Infohabitar, Ano IX, n.º 423DED/NAURevista Infohabita