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2017
João, Carlos FC, Coro Echeverria, Alexandre Velhinho, Jorge C. Silva, Maria H. Godinho, and João P. Borges. "Bio-inspired production of chitosan/chitin films from liquid crystalline suspensions." Carbohydrate Polymers. 155 (2017): 372-381. Abstract
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João, Carlos FC, Coro Echeverria, Alexandre Velhinho, Jorge C. Silva, Maria H. Godinho, and João P. Borges. "Bio-inspired production of chitosan/chitin films from liquid crystalline suspensions." Carbohydrate Polymers. 155 (2017): 372-381. Abstract
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Yang, Yongming, Hugo Biscaia, Carlos Chastre, and Manuel A. G. Silva. "Bond characteristics of CFRP-to-steel joints." Journal of Constructional Steel Research. 138 (2017): 401-419. Abstract

Carbon Fiber Reinforced Polymer (CFRP) composites have a large potential for strengthening and retrofitting steel parts but due to their premature debonding from steel, further data and research are still required for wider application in such situations. In the present paper, the bond characteristics of CFRP-to-steel joints in pull-pull loaded conditions were studied. Monotonic loading of the double strap joints with different bond lengths was applied and the failure modes and interfacial bond-slip curves were obtained. A tri-linear bondslip model is proposed and it was derived from the experimental data. A closed-form solution approach is also proposed based on the tri-linear bond-slip model. The strength of the CFRP-to-steel interface, the distribution of the relative displacements between bonded materials, the strains developed in the CFRP laminate and the bond stresses along the interface are reported and the closed-form solution is compared with the experimental results. Two cases are selected for presentation: (i) one with the bond length greater than the effective bond length; and, inversely, (ii) one with bond length which is shorter than the effective bond length. The results predicted by the closed-form solutions are shown to be accurate enough when compared to the experiments.

Carlos, E., R. Branquinho, A. Kiazadeh, J. Martins, P. Barquinha, R. Martins, and E. Fortunato. "Boosting Electrical Performance of High-? Nanomultilayer Dielectrics and Electronic Devices by Combining Solution Combustion Synthesis and UV Irradiation." ACS Applied Materials and Interfaces. 9 (2017): 40428-40437. Abstract
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2016
Gomes, Ivette M., Frederico Caeiro, Lígia Henriques-Rodrigues, and B. g Manjunath. "Bootstrap Methods in Statistics of Extremes." Extreme Events in Finance. John Wiley & Sons, Inc., 2016. 117-138. Abstract
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da Mata, Pedro Paraíso, Paula F. da Silva, and Fernando F. S. Pinho. "BIM-GGIM: Conceitos e aplicações na Geotecnia." 15CNG/8CLBG – 15º Congresso Nacional de Geotecnia/8º Congresso Luso-Brasileiro de Geotecnia. FEUP, Porto 2016.
Moretto, Susana, Douglas Robinson, Jens Schippl, and António Brandão Moniz. "Beyond visions: survey to the high-speed train industry." Transportation Research Procedia. 2016.14 (2016): 1839-1846. AbstractWebsite

In Europe, the technology development of high-speed trains is increasingly exposed to societal needs, driven by ICT advancements, external to traditional design. Together with the liberalisation of the rail markets and increase pressures from other transport modes leads to an unprecedented situation where planers, operators and suppliers of high-speed have to take decision in this complex and competitive environment.
In such broadening of elements influencing design and, thus, product development process, from the survey here to be presented, it was not observed technology options assessment or strategic agenda setting from visions shifting in the same way.
For the high-speed train industry this new trend requires going beyond the visions of the past 15 to 20 years’ practices of “sector endogenous” and structurally closed strategic methods approaches to a broader interaction with the widening of societal actors now capable of being active contributors to innovation from digitalization.
This way to understand the European industry readiness for undertaking such supra systemic challenge, this paper presents the results from a survey conducted by the authors to 74 representatives of the high-speed train innovation chain regarding to which extent societal embedding is considered in the drafting of their visions and technology development projects.
This work becomes even more pertinent if considered that the debate is now open in the railway industry (not exclusive to high-speed trains) as they are launching the joint initiative SHIFT2RAIL, revise ERRAC (the European Rail Research Advisory Council) mandate and enter in a new research cycle with the European research framework Horizon 2020.

Bahubalindruni, P.G.a, Tavares Barquinha Martins Fortunato V. c P. b. "Basic analog and digital circuits with a-IGZO TFTs." 2016 13th International Conference on Synthesis, Modeling, Analysis and Simulation Methods and Applications to Circuit Design, SMACD 2016. 2016. Abstract

This paper presents the characterization of fundamental analog and digital circuits with a-IGZO TFTs from measurements performed at normal ambient. The fundamental blocks considered in this work include digital logic gates, a low-power single stage high-gain amplifier with capcacitive bootstrapping and a level shifter/buffer. These circuits are important functional blocks in analog/Mixed signal IC design with oxide TFTs. Being fabricated at low temperature (< 200 °C), they can find potential applications in low-cost large-area flexible systems. © 2016 IEEE.

Cavalheiro, D., F. Moll, and S. Valtchev. "A battery-less, self-sustaining RF energy harvesting circuit with TFETs for ?w power applications." 14th IEEE International NEWCAS Conference, NEWCAS 2016 (2016). Abstract
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dos Santos, FA. "Buckling control using shape-memory alloy cables." Journal of Engineering Mechanics. 142 (2016). AbstractWebsite
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Loiola, Eliane Maria, Denis Silva da Silveira, João Araújo, and Ana Moreira. "Business Process Families: {A} Case Study in the Brazilian Public Sector." Proceedings of the CAiSE 2016 Industry Track co-located with 28th International Conference on Advanced Information Systems Engineering (CAiSE 2016), Ljubljana, Slovenia, June 13-17, 2016. 2016. Abstract
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2015
Monteiro-Henriques, T., M. J. Martins, J. O. Cerdeira, P. Silva, P. Arsénio, Á. Silva, A. Bellu, and J. C. Costa. "Bioclimatological mapping tackling uncertainty propagation: application to mainland Portugal." International Journal of Climatology. 36 (2015): 400-411. AbstractWebsite
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Caeiro, Frederico, and Ivette M. Gomes. "Bias reduction in the estimation of a shape second-order parameter of a heavy-tailed model." Journal Of Statistical Computation And SimulationJournal Of Statistical Computation And Simulation. 85.17 (2015): 3405-3419. AbstractWebsite

In extreme value theory, the shape second-order parameter is a quite relevant parameter related to the speed of convergence of maximum values, linearly normalized, towards its limit law. The adequate estimation of this parameter is vital for improving the estimation of the extreme value index, the primary parameter in statistics of extremes. In this article, we consider a recent class of semi-parametric estimators of the shape second-order parameter for heavy right-tailed models. These estimators, based on the largest order statistics, depend on a real tuning parameter, which makes them highly flexible and possibly unbiased for several underlying models. In this article, we are interested in the adaptive choice of such tuning parameter and the number of top order statistics used in the estimation procedure. The performance of the methodology for the adaptive choice of parameters is evaluated through a Monte Carlo simulation study.In extreme value theory, the shape second-order parameter is a quite relevant parameter related to the speed of convergence of maximum values, linearly normalized, towards its limit law. The adequate estimation of this parameter is vital for improving the estimation of the extreme value index, the primary parameter in statistics of extremes. In this article, we consider a recent class of semi-parametric estimators of the shape second-order parameter for heavy right-tailed models. These estimators, based on the largest order statistics, depend on a real tuning parameter, which makes them highly flexible and possibly unbiased for several underlying models. In this article, we are interested in the adaptive choice of such tuning parameter and the number of top order statistics used in the estimation procedure. The performance of the methodology for the adaptive choice of parameters is evaluated through a Monte Carlo simulation study.

Biscaia, Hugo C., Carlos Chastre, and Manuel A. G. Silva. "Bond-slip model for FRP-to-concrete bonded joints under external compression." Composites Part B: Engineering. 80 (2015): 246-259. AbstractWebsite

The influence of compressive stresses exerted on FRP-concrete joints created by external strengthening of structural members on the performance of the system requires better understanding especially when mechanical devices are used to anchor the externally bonded reinforcement (EBR). The numerical modelling of those systems is a tool that permits insight into the performance of the corresponding interfaces and was used in the present study, essentially directed to analyse the effectiveness of EBR systems under compressive stresses normal to the composite surface applied to GFRP-to-concrete interfaces. The compressive stresses imposed on the GFRP-to-concrete interface model the effect produced by a mechanical anchorage system applied to the EBR system. An experimental program is described on which double-lap shear tests were performed that created normal stresses externally applied on the GFRP plates. A corresponding bond-slip model is proposed and the results of its introduction in the numerical analysis based in an available 3D finite element code are displayed, showing satisfactory agreement with the experimental data. The results also showed that lateral compressive stresses tend to increase the maximum bond stress of the interface and also originate a residual bond stress which has significant influence on the interface strength. Also, the strength of the interface increases with the increase of the bonded length which have consequences on the definition of the effective bond length.

Karlovich, Alexei Yu. "Banach algebra of the Fourier multipliers on weighted Banach function spaces." Concrete Operators. 2.1 (2015): 27-36. AbstractWebsite

Let \(\mathcal{M}_{X,w}(\mathbb{R})\) denote the algebra of the Fourier multipliers on a separable weighted Banach function space \(X(\mathbb{R},w)\). We prove that if the Cauchy singular integral operator \(S\) is bounded on \(X(\mathbb{R},w)\), then \(\mathcal{M}_{X,w}(\mathbb{R})\) is continuously embedded into \(L^\infty(\mathbb{R})\). An important consequence of the continuous embedding \(\mathcal{M}_{X,w}(\mathbb{R})\subset L^\infty(\mathbb{R})\) is that \(\mathcal{M}_{X,w}(\mathbb{R})\) is a Banach algebra.

Silva, João, João M. Lourenço, and Hervé Paulino. "Boosting Locality in Multi-version Partial Data Replication." Proceedings of the 30th ACM/SIGAPP Symposium On Applied Computing (SAC'15). 2015. Abstractsac15_cache.pdf

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Franco, J., B. Galinhas, Borges P. de Sousa, D. Martins, I. Catarino, and G. Bonfait. "Building a Thinner Gap in a Gas-Gap Heat Switch." Physics Procedia. 67 (2015): 1117-1122. Abstract

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Mendes, Manuel J., Seweryn Morawiec, Tiago Mateus, Andriy Lyubchyk, Hugo Águas, Isabel Ferreira, Elvira Fortunato, Rodrigo Martins, Francesco Priolo, and Isodiana Crupi. "Broadband light trapping in thin film solar cells with self-organized plasmonic nano-colloids." Nanotechnology. 26 (2015): 135202. Abstract
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c c d Mendes, M.J.a b, Morawiec Mateus Lyubchyk Águas Ferreira Fortunato Martins Priolo Crupi S. b T. a. "Broadband light trapping in thin film solar cells with self-organized plasmonic nanocolloids." Nanotechnology. 26 (2015). AbstractWebsite

The intense light scattered from metal nanoparticles sustaining surface plasmons makes them attractive for light trapping in photovoltaic applications. However, a strong resonant response from nanoparticle ensembles can only be obtained if the particles have monodisperse physical properties. Presently, the chemical synthesis of colloidal nanoparticles is the method that produces the highest monodispersion in geometry and material quality, with the added benefits of being low-temperature, low-cost, easily scalable and of allowing control of the surface coverage of the deposited particles. In this paper, novel plasmonic back-reflector structures were developed using spherical gold colloids with appropriate dimensions for pronounced far-field scattering. The plasmonic back reflectors are incorporated in the rear contact of thin film n-i-p nanocrystalline silicon solar cells to boost their photocurrent generation via optical path length enhancement inside the silicon layer. The quantum efficiency spectra of the devices revealed a remarkable broadband enhancement, resulting from both light scattering from the metal nanoparticles and improved light incoupling caused by the hemispherical corrugations at the cells' front surface formed from the deposition of material over the spherically shaped colloids. © 2015 IOP Publishing Ltd.

2014
Espadinha-Cruz, Pedro, António Gonçalves-Coelho, António Mourão, and António Grilo. "Business Interoperability: Dyadic supply chain process decomposition using Axiomatic Design." 2014. 93-100. Abstract
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Otelo-Cardoso, AR, V. Schwuchow, D. Rodrigues, E. J. Cabrita, S. Leimkühler, MJ Romão, and T. Santos-Silva. "Biochemical, Stabilization and Crystallization Studies on a Molecular Chaperone (PaoD) Involved in the Maturation of Molybdoenzymes." PLoS One. 9 (2014): e87295 . AbstractWebsite

Molybdenum and tungsten enzymes require specific chaperones for folding and cofactor insertion. PaoD is the chaperone of the periplasmic aldehyde oxidoreductase PaoABC. It is the last gene in the paoABCD operon in Escherichia coli and its presence is crucial for obtaining mature enzyme. PaoD is an unstable, 35 kDa, protein. Our biochemical studies showed that it is a dimer in solution with a tendency to form large aggregates, especially after freezing/thawing cycles. In order to improve stability, PaoD was thawed in the presence of two ionic liquids [C4mim]Cl and [C2OHmim]PF6 and no protein precipitation was observed. This allowed protein concentration and crystallization using polyethylene glycol or ammonium sulfate as precipitating agents. Saturation transfer difference – nuclear magnetic resonance (STD-NMR) experiments have also been performed in order to investigate the effect of the ionic liquids in the stabilization process, showing a clear interaction between the acidic ring protons of the cation and, most likely, negatively charged residues at the protein surface. DLS assays also show a reduction of the overall size of the protein aggregates in presence of ionic liquids. Furthermore, cofactor binding studies on PaoD showed that the protein is able to discriminate between molybdenum and tungsten bound to the molybdenum cofactor, since only a Mo-MPT form of the cofactor remained bound to PaoD.

Coelho, T., De Oliveira, R., Cardoso, T., Rosas, J., and Rybarczyk Y. "Body ownership of virtual avatars: an affordance approach of telepresence." Innovative and Creative Developments in Multimodal Interaction Systems. Eds. Y. Rybarczyk, T. Cardoso, J. Rosas, and L. Camarinha-Matos. Heidelberg: Springer, 2014. 3-19.
Rybarczyk, Yves, Tiago Cardoso, Tiago Coelho, Rita Oliveira, and João Rosas. "Body Ownership of Virtual Avatars: An affordance Approach of Telepresence." Enterface 2013 Proceedings. Springer, 2014. Abstract

Virtual environments are an increasing trend in today’s society. In this scope, the avatar is the representation of the user in the virtual world. However, that relationship lacks empirical studies regarding the nature of the interaction between avatars and human beings. For that purpose it was studied how the avatar’s modeled morphology and dynamics affect its control by the user. An experiment was conducted to measure telepresence and ownership on participants who used a Kinect Natural User Interface (NUI). The body ownership of different avatars was assessed through a behavioral parameter, based on the concept of affordances, and a questionnaire of presence. The results show that the feelings of telepresence and ownership seem to be greater when the kinematics and the avatar’s proportions are closer to those of the user.