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Papers
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Aspetos gerais da aplicação em Portugal do Eurocódigo 8 Parte 3 Anexo C (Informativo) Edifícios de alvenaria
Procuram-se sintetizar neste artigo os principais aspetos relacionados com a avaliação e a reabilitação sísmica de edifícios existentes de alvenaria, compatibilizando a NP EN 1998-3:2017 com os respetivos Anexo C, específico para edifícios de alvenaria, e Anexo Nacional, específico para Portugal. A avaliação sísmica é um procedimento quantitativo através do qual se verifica se um edifício existente, danificado ou não, satisfaz os requisitos de desempenho, definidos por uma combinação de um estado limite com um nível de ação sísmica, através de critérios de conformidade. Neste procedimento estão envolvidos a definição da ação sísmica, a modelação da estrutura, os métodos de análise para determinação dos efeitos das ações e as verificações de segurança. São abordados os métodos de análise, dois lineares e dois não lineares, aplicáveis a edifícios existentes de alvenaria, bem como as recomendações específicas do Anexo C e as informações complementares do Anexo Nacional.
Year: 2020
Number Pages:
99-120pp.
Author(s): Candeias, P.; Correia, A.A.; Campos Costa, A.; Catarino, J. M.; Pipa, M.; Cruz, H.; Cansado Carvalho, E.; Costa, A.
: Revista Portuguesa de Engenharia de Estruturas (rpee)
Editor: LNEC
Volume:
Série III, N.º 12.
Keywords: Eurocódigo 8; Avaliação sísmica; Edifícios de alvenaria existentes
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Assessing the applicability of a new carob waste-derived powdered activated carbon to control pharmaceutical compounds in wastewater treatment.
This paper assesses the applicability of a new carob waste-derived powdered activated carbon (PAC) obtained by steam activation for pharmaceutical compounds (PhCs) removal in urban wastewater treatment plants (WWTPs) with activated sludge (AS) secondary treatment. The new carob-derived PAC presents chemical and textural properties similar to a high-performing commercial PAC produced from vegetable source by physical activation. The adsorption isotherms of three target PhCs, carbamazepine, diclofenac and sulfamethoxazole, spiked (at around 100 ?g/L) in mixed liquor (ML) and in clarified-ML from the AS-bioreactor of a WWTP show: (i) minor reduction of PAC capacity with real MLs compared to clarified MLs; (ii) the higher the PhC hydrophobicity, the higher the PAC adsorption capacity in both water matrices; (iii) hydrophobic interactions probably overweight electrostatic interactions between the PhCs and the slightly positively charged PAC in these real water matrices with background organics and inorganics. The PhC adsorption results with ML and clarified-ML are used to calibrate the IAST-based tracer model (TRM) and predict the new PAC performance when added to AS-bioreactor vs. in post-secondary treatment, at the PhC naturally-occurring trace concentrations. The modelling projections show (i) one needs higher PAC doses than those reported in the literature, particularly in post-treatment, and (ii) the benefits of PAC dosing to the bioreactor, with only a slightly higher PAC dose being needed when compared to its post-secondary dosing and minimising the capital investment.
Year: 2020
Number Pages:
10 pp..
Author(s): Viegas, R.M. C.; Mestre, A.S.; Mesquita, E.; Campinas, M.; Andrade, M. A.; Carvalho, A. P.; Rosa, M. J.
: Science of The Total Environment
Editor: Elsevier
Volume:
Volume 743.
Keywords: Modelling; Pharmaceutical compounds; Adsorption; Steam activation; Waste-derived activated carbons
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Assessing urban resilience in complex and dynamic systems: the RESCCUE project approach in Lisbon research site
Urban environments are challenged with unprecedented anthropogenic and natural pressures, the latter being accelerated by the growing awareness of the consequences of climate change. The concept of urban resilience has been growing in response, since it allows us to understand city behaviour as a system of systems, improving its response to extreme climate-related events. This paper presents the EU H2020 Resilience to Cope with Climate Change in Urban Areas (RESCCUE) project approach in Lisbons research site, regarding the Hazur® resilience assessment methodology.
Year: 2020
Number Pages:
15 pp..
Author(s): Barreiro, J.; Lopes, R.; Ferreira, F.; Brito, R.; Telhado, M.; Matos, J. S.; Matos, R. S.
: Sustainability
Editor: MDPI
Volume:
Volume 12, Issue 21.
Keywords: Urban services; Urban resilience; Urban flooding; Climate change; Cascading effects
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Assessment of CFD Solvers and Turbulent Models for Water Free Jets in Spillways
The capability of two different OpenFOAM® solvers, namely interFoam and twoPhaseEulerFoam, in reproducing the behavior of a free water jet was investigated. Numerical simulations were performed in order to obtain the velocity and air concentration profiles along the jet. The turbulence intensity was also analyzed. The obtained results were compared with published experimental data and, in general, similar velocity and air concentration profiles were found. InterFoam solver is able to reproduce the velocity field of the free jet but has limitations in the simulation of the air concentration. TwoPhaseEulerFoam performs better in reproducing the air concentration along the jet, the results being in agreement with the experimental data, although the computational runs are less stable and more time consuming. The sensitivity analysis of the inlet turbulent intensity showed that it has no influence in the characteristics of the jet core. With this research it is possible to conclude that: interFoam with k-Epsilon (k-?) turbulence model is the best choice if the goal of the numerical simulations is the simulation of the velocity field of the jet. Meanwhile, twoPhaseEulerFoam with mixturek-Epsilon (mk-?) shall be considered if the objective is the simulation of the velocity field and the air concentration.
Year: 2020
Number Pages:
17pp.
Author(s): Muralha, A.; Melo, J.; Ramos, H.
: Fluids
Editor: MDPI
Volume:
V5, 104.
Keywords: Spillways; Turbulence models; Waterair flow; CFD solvers; Free water jet
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Atenolol removal by nanofiltration: a case-specific mass transfer correlation
Concentration polarization is a phenomenon inherent to membrane separation operations and as a precursor of membrane fouling is frequently related to the decrease in the performance of these operations. In the present work, a case-specific mass transfer correlation was developed to assess the concentration polarization when nanofiltration, in different operating conditions, was applied to treat a pharmaceutical wastewater containing atenolol. NF runs with two membranes, two atenolol concentrations and three feed circulating velocities were conducted, and the corresponding experimental mass transfer coefficients were determined using film theory to describe the concentration polarization phenomenon. Higher velocities led to higher mass transfer coefficients and, consequently, lower concentration polarization. These mass transfer coefficients were correlated with the circulating velocity (Re), the solute diffusivity (Sc) and the membrane permeability (LPþ) (the membrane is a permeable interface with effect on the concentration profiles developed from the interface towards the bulk feed), yielding the following correlation Sh ¼ 1.98 × 104Re0.5Sc0.33LP þ0.32. The good agreement between the calculated and the experimental results makes this correlation a valuable tool for water practitioners to predict and control the concentration polarization during atenolol-rich wastewater treatment by nanofiltration, thereby increasing its productivity and selectivity.
Year: 2020
Number Pages:
7 pp..
Author(s): Giacobbo, A.; Fernandes, E.; Bernardes, A.M.; Rosa, M. J.; Pinho, M.N.
: Water Science & Technology
Editor: IWA Publishing
Volume:
Vol. 81.2.
Keywords: Nanofiltration; Mass transfer; Concentration polarization; Atenolol
Info
Atenolol removal by nanofiltration: a case-specific mass transfer correlation.
Concentration polarization is a phenomenon inherent to membrane separation operations and as a precursor of membrane fouling is frequently related to the decrease in the performance of these operations. In the present work, a case-specific mass transfer correlation was developed to assess the concentration polarization when nanofiltration, in different operating conditions, was applied to treat a pharmaceutical wastewater containing atenolol. NF runs with two membranes, two atenolol concentrations and three feed circulating velocities were conducted, and the corresponding experimental mass transfer coefficients were determined using film theory to describe the concentration polarization phenomenon. Higher velocities led to higher mass transfer coefficients and, consequently, lower concentration polarization. These mass transfer coefficients were correlated with the circulating velocity (Re), the solute diffusivity (Sc) and the membrane permeability (LP+) (the membrane is a permeable interface with effect on the concentration profiles developed from the interface towards the bulk feed), yielding the following correlation Sh = 1.98 × 104Re0.5Sc0.33LP+0.32. The good agreement between the calculated and the experimental results makes this correlation a valuable tool for water practitioners to predict and control the concentration polarization during atenolol-rich wastewater treatment by nanofiltration, thereby increasing its productivity and selectivity.
Year: 2020
Number Pages:
7 pp..
Author(s): Giacobbo, A.; Bernardes, A.M.; Rosa, M. J.; Pinho, M.N.
: WATER SCIENCE & TECHNOLOGY
Editor: IWA Publishing
Volume:
Volume 81, Issue 2.
Keywords: Nanofiltration; Mass transfer; Concentration polarization; Atenolol
Info
Avaliação da resiliência dos serviços urbanos de águas face às alterações climáticas.
As áreas urbanas constituem sistemas dinâmicos, complexos e vulneráveis envolvendo múltiplos serviços urbanos estratégicos, como os serviços de águas e resíduos. As pressões e impactos causados por eventos climáticos, como chuvas fortes, efeitos de maré ou secas, podem ter impactos significativos nestes serviços causando efeitos em cascata, com graves consequências para pessoas, ambiente natural e economia.
Year: 2020
Number Pages:
63-67 pp..
Author(s): Cardoso, M. A.; Brito, R.; Pereira, C.; David, L. M.
: Revista Águas & Resíduos
Editor: APESB
Volume:
série IV n.º 6.
Keywords: Alterações climáticas.; Resiliência; Serviços urbanos de água
Info
Benefícios e desafios na cocriação de espaço público aberto com apoio das ferramentas digitais. As experiências dos Projetos CyberParks e C3Places
As tecnologias de informação e comunicação (TIC) podem ser ferramentas inovadoras para a interação com e entre os utilizadores do espaço público. Por um lado, as ferramentas digitais (smartphones, relógios inteligentes, tablets, portáteis, etc.) colaboram para intermediar a criação de contextos socio-espaciais interativos; por outro, as TIC podem ser consideradas como recurso instigador de processos de planeamento mais colaborativos e participativos. O artigo discute alguns benefícios e desafios que as TIC apresentam no âmbito do aperfeiçoar o conhecimento sobre a relação entre espaço público aberto, pessoas e práticas sociais; e no que respeita à mediação e ao fomento de processos participativos na produção do espaço através do recurso às dinâmicas de cocriação. Para o desenvolvimento desta reflexão, realiza-se uma abordagem teórica e enquadradora a partir de perspetivas etnográficas e de planeamento e recorre-se ao conhecimento adquirido e experiências protagonizadas nos projetos CyberParks e C3Places.
Year: 2020
Number Pages:
27-36.
Author(s): Menezes, M.; Costa, C.
: Geotema - Rivista dell'Associazione Geografi Italian
Editor: AGEI
Volume:
62.
Keywords: perspetivas etnográficas e de planeamento urbano; co-criação na produção do espaço público; Espaço público aumentado/híbrido
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Blue gum: assessment of its potential for glued laminated timber beams
Portuguese forests are mainly composed of hardwoods, which represent 69% of the forest area in 2010, being Blue gum (Eucalyptus globulus Labill.) the most abundant species (26%). The suitability of Blue gum for structural applications was demonstrated in previous studies. However, the most common uses are still related to the pulp and paper industry as well as energy production, mainly due to sawing and drying issues. The present paper describes a preliminary study on the potential application of non-destructive tests and analytical methods to predict the most important mechanical properties of glued laminated timber (glulam) beams made of Blue gum. The potential of mixed beams made of Blue gum and poplar was also analysed. The longitudinal vibration method and the transformed section method were considered. A total of 11 non-finger jointed full-scale glulam beams (7 of Blue gum and 4 mixed) were manufactured in the laboratory and tested for modulus of elasticity and bending strength assessment. After the bending tests, the density and moisture content of the beams were determined, and the bonding performance was checked by delamination and shear strength tests. Correlation coefficients were established between the predicted values and the experimentally assessed mechanical properties, indicating a huge potential of the predictive methods used. The mechanical properties of non-finger jointed beams tested were above the typical values found in the literature for the most common hardwoods available in European forest.
Year: 2020
Number Pages:
9p.
Author(s): Martins, C.; Dias, A.; Cruz, H.
: European Journal of Wood and Wood Products
Editor: Springer-Verlag GmbH
Volume:
Volume 78, nº 4.
Keywords: Beams; Glued laminated timber; Production; Blue gum
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Bond behaviour between steel / stainless-steel reinforcing bars and low binder concrete (LBC)
Reducing the cement content of concrete is of paramount importance towards sustainability, since its production process is highly energy-consuming and delivers massive CO2 emissions to the atmosphere. In this paper, the bond behaviour between steel and stainless-steel reinforcing bars and Low Binder Concrete (LBC), produced with approximately one half and almost one fourth of the minimum cement content prescribed in the standards, is experimentally investigated. Results show the compactness of the mixture to be the main parameter controlling bond development, more than the mixture compressive strength as suggested in published results and standards. A more compact and denser mixture increases the contact surface between the reinforcing bars and concrete, improving friction between both. LBC mixtures with lowered cement content, up to almost one fourth of the minimum recommended, can be used without jeopardizing the bond strength of reinforcing bars. LBC mixtures promise to be a fitting approach towards greater sustainability in the concrete production sector.
Year: 2020
Number Pages:
11p.
Author(s): Freitas, E.; Louro, A. S.; Costa, H.; Júlio, E.; Pipa, M.; Cavaco, E.
: Engineering Structures
Editor: Elsevier Ltd.
Volume:
Volume 221, nº 111072.
Keywords: Sustainability; Low binder concrete; Steel / stainless steel rebars; Bond behaviour
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