Export 4149 results:
Sort by: Author Title Type [ Year  (Desc)]
2016
Correia, Isabel, and Teresa Melo. "Multi-period capacitated facility location under delayed demand satisfaction." European Journal of Operational Research. 255 (2016): 729-746. AbstractWebsite
n/a
Almeida, R. M., S. Dell'acqua, L. Krippahl, J. J. Moura, and S. R. Pauleta. "Predicting Protein-Protein Interactions Using BiGGER: Case Studies." Molecules. 21 (2016). AbstractWebsite

The importance of understanding interactomes makes preeminent the study of protein interactions and protein complexes. Traditionally, protein interactions have been elucidated by experimental methods or, with lower impact, by simulation with protein docking algorithms. This article describes features and applications of the BiGGER docking algorithm, which stands at the interface of these two approaches. BiGGER is a user-friendly docking algorithm that was specifically designed to incorporate experimental data at different stages of the simulation, to either guide the search for correct structures or help evaluate the results, in order to combine the reliability of hard data with the convenience of simulations. Herein, the applications of BiGGER are described by illustrative applications divided in three Case Studies: (Case Study A) in which no specific contact data is available; (Case Study B) when different experimental data (e.g., site-directed mutagenesis, properties of the complex, NMR chemical shift perturbation mapping, electron tunneling) on one of the partners is available; and (Case Study C) when experimental data are available for both interacting surfaces, which are used during the search and/or evaluation stage of the docking. This algorithm has been extensively used, evidencing its usefulness in a wide range of different biological research fields.

Cabanelas, P., J. Cruz, M. Fonseca, A. Henriques, F. Louren{\c c}o, H. Lu{\'ıs, J. Machado, Pires J. Ribeiro, A. M. Sánchez-Ben{\'ıtez, P. Teubig, P. Velho, M. Zarza-Moreno, D. Galaviz, and A. P. Jesus. "{Cross sections for proton induced high energy $\gamma$-ray emission (PIGE) in reaction F(p,$\gamma$)O at incident proton energies between 1.5 and 4 MeV}." Nuclear Inst. and Methods in Physics Research, B. 381 (2016): 110-113. AbstractWebsite
n/a
Kiazadeh, Asal, Henrique L. Gomes, Pedro Barquinha, Jorge Martins, Ana Rovisco, Joana V. Pinto, Rodrigo Martins, and Elvira Fortunato. "{Improving positive and negative bias illumination stress stability in parylene passivated IGZO transistors}." Applied Physics Letters. 109 (2016): 051606. AbstractWebsite
n/a
Lopes, A., A. Gabriel, J. Machado, P. Ribeiro, R. Gomes, Jo M. P. o Coelho, C. O. Silva, C. P. Reis, J. P. Santos, and P. Vieira. "Multiple Source Phototherapy in Breast Cancer: A Viability Study." 9th International Conference on Biomedical Electronics and Devices. SCITEPRESS - Science and and Technology Publications, 2016. 247-250. Abstract
n/a
Kardarian, Kasra, Daniela Nunes, Paolo {Maria Sberna}, Adam Ginsburg, David A. Keller, Joana {Vaz Pinto}, Jonas Deuermeier, Assaf Y. Anderson, Arie Zaban, Rodrigo Martins, and Elvira Fortunato. "{Effect of Mg doping on Cu2O thin films and their behavior on the TiO2/Cu2O heterojunction solar cells}." Solar Energy Materials and Solar Cells. 147 (2016): 27-36. AbstractWebsite

Abstract The present work shows the effect of magnesium doping on structural, optoelectrical and electrical properties of Cu2O thin films prepared by spray pyrolysis. The variation in the concentration of Mg shows significant impact on the final thin film properties, whereas the film doped with 0.5 at{%} of Mg exhibited major property improvements in comparison with the undoped thin film and among the other concentrations tested. This condition was further applied for the deposition of an absorber layer in a heterojunction solar cell array with a gradient in thicknesses of active layers to investigate the impact of changing thicknesses on the PV parameters of the solar cell. TiO2 was used as a window layer and the 0.5 at{%} Cu2O doped film as an absorber layer. The produced heterojunction solar cell array was further exposed to a rapid thermal annealing treatment. The I–V measurements show an open circuit voltage of up to 365 mV and a short circuit current density, which is dependent on absorber layer thickness, and reaches to a maximum value of 0.9 mA/cm2.

Silva, Teresa, Francisco Costa, Judite Fernandes, Rogério Calvo, and Octávio Mateus The use of a portable X-ray fluorescence analyzer in the reconstitution of dinosaur fossils. European Conference on X-Ray Spectrometry (EXRS), 2016. Abstract

Portable X-ray fluorescence spectrometers (p-XRF) have been used in many fields of application/studies like art, archaeology, heavy metals in soil, rocks and ores characterization, and have been a powerful tool for a rapid non-destructive in-situ analysis, without any sample preparation required. This approach was applied in the present case, to distinguish the origin of the fossil bones of two dinosaur specimens from different localities that were accidentally put together in the museum a few years ago. Fossil bones with sedimentary matrix associated were stored together until today in the collection of Geological Museum (Lisbon) and regarded as one single specimen. One set of bones is part of the holotype MG 5787 of the ankylosaur Dracopelta zbyszweskii, which was discovered at Praia do Sul, and described in 1980, while the other, is an undescribed half skeleton of dacentrurine stegosaur, unearthed in the 1960’s at Atouguia da Baleia, near Peniche (both in the coast of central Portugal, distanced about 100 km from each other). Since both specimens are highly valuable for paleontology, a study was developed with the aim of separating and reconstituting the two specimens. The handheld p-XRF (Genius 9000+7000 from Skyray Instrument) was directly used in the sedimentary matrix when it was separated from the bone, and the measure of the chemical content was performed in the intermediate layer between the surface and the bone, to avoid contaminations. Although the light elements could not be attained, because the analyzer is not equipped with the option of gas charging system, the spectra obtained showed differences mainly in the ratio K/Ca, allowing distinguishing the provenance of the bones (Atouguia or Praia do Sul). These results were compared with chemical analysis obtained with XRF laboratorial equipment and complemented by the mineralogical study through X-ray diffraction (XRD) of the sediments where the bones fossilized. The difference observed in the mineralogical constitution of the sedimentary matrix from the two localities (mainly quartz, calcite, feldspars and micas with variable content) explains the variation in the values found for the ratio K/Ca (<0.5 for Atouguia and >>1 for Praia do Sul). The data obtained will be presented and discussed focusing on the importance of using a portable X-ray fluorescence analyzer applied to the reconstitution of dinosaur fossils that proved to be very useful in the present case.

Bombonatti, Denise, Catarina Gralha, Ana Moreira, João Araújo, and Miguel Goulão. "Usability of Requirements Techniques: A Systematic Literature Review." The 31st ACM/SIGAPP Symposium on Applied Computing. Pisa, Italy: ACM/SIGAPP, 2016. Abstract

The usability of requirements engineering (RE) techniques has been recognised as a key factor for their successful adoption by industry. RE techniques must be accessible to stakeholders with different backgrounds, so they can be empowered to effectively and efficiently contribute to building successful systems. When selecting an appropriate requirements engineering technique for a given context, one should consider the usability supported by each of the candidate techniques. The first step towards achieving this goal is to gather the best evidence available on the usability of RE approaches by performing a systematic literature review, to answer one research question: How is the usability of requirements engineering techniques and tools addressed? We systematically review articles published in the Requirements Engineering Journal, one of the main sources for mature work in RE, to motivate a research roadmap to make RE approaches more accessible to stakeholders with different backgrounds.

Chastre, Carlos, Hugo Biscaia, António Monteiro, and Noel Franco. "Análise experimental de vigas de betão armado reforçadas à flexão com compósitos de FRP." TEST&E 2016 - 1º Congresso de Ensaios e Experimentação em Engenharia Civil. IST, Lisbon, Portugal 2016. 8. Abstractteste2016_-_01066_-_chastre.pdf

O reforço das estruturas de betão armado com compósitos de FRP tem tido um incremento considerável nos últimos anos devido às características de durabilidade e das elevadas relações resistência-peso e rigidez-peso dos compósitos de FRP comparativamente com outros materiais de reforço. A fim de analisar o comportamento de diferentes soluções de reforço estrutural de vigas de betão armado (BA) com compósitos de FRP foi realizado um programa experimental que incluiu o ensaio de vigas de BA reforçadas com as seguintes técnicas de reforço: EBR (Externally-Bonded Reinforcement), NSM (Near Surface Mounted) e pela técnica CREatE (continuous reinforcement embedded at ends). As vigas de BA ensaiadas tinham seção em T, com um vão de 3,0 m e uma altura de 0,3 m e foram solicitadas em flexão em 4 pontos e testadas até a rotura. A técnica CREatE provou ser a mais eficaz das três alternativas testadas mobilizando a totalidade do CFRP e apresentando a maior capacidade resistente e a ductilidade mais elevada.

Chastre, Carlos, António Monteiro, Hugo Biscaia, and Noel Franco. "Novo sistema de reforço estrutural de vigas de betão armado com compósitos de FRP ancorados internamente por aderência." II Encontro Luso-Brasileiro de Degradação de Estruturas de Betão. LNEC, Lisbon, Portugal 2016. 12p. Abstractdegrada_2016_-_carlos_chastre_-_ext-abstract.pdf

A reabilitação de estruturas de betão armado com compósitos de FRP tem tido uma grande aceitação em especial devido às excelentes características de durabilidade dos materiais compósitos, ao seu baixo peso e às suas elevadas prestações mecânicas. Contudo, o comportamento elástico-linear dos compósitos de FRP e a sua forma de aplicação pode originar roturas prematuras, quer na técnica de reforço EBR (Externally Bonded Reinforcement), em que o compósito é colado externamente, quer na técnica NSM (Near Surface Mounted) em que o compósito é inserido na zona do recobrimento. No sentido de minimizar o risco de roturas prematuras e ao mesmo tempo aumentar a ductilidade dos elementos reforçados, desenvolveu-se um novo sistema de reforço estrutural em que as armaduras são ancoradas internamente por aderência. A fim de validar o novo sistema de reforço estrutural com compósitos de FRP foi realizado um programa experimental que incluiu o ensaio de vigas de betão armado (BA) reforçadas com as seguintes técnicas de reforço: EBR, NSM e pela nova técnica CREatE (continuous reinforcement embedded at ends). Neste artigo descrevem-se os ensaios experimentais realizados e analisam-se os resultados obtidos. As vigas de BA ensaiadas tinham seção em T, com um vão de 3,0 m e uma altura de 0,3 m e foram solicitadas em flexão em 4 pontos e testadas até a rotura. A técnica CREatE provou ser a mais eficaz das três alternativas testadas mobilizando a totalidade do CFRP e apresentando a maior capacidade resistente e a ductilidade mais elevada.

Almeida, Graça, Fernando Melício, Hugo Biscaia, Carlos Chastre, and José Manuel Fonseca. "In-Plane Displacement and Strain Image Analysis." Computer-Aided Civil and Infrastructure Engineering. 31 (2016): 292-304. AbstractWebsite

Measurements in civil engineering load tests usually require considerable time and complex procedures. Therefore, measurements are usually constrained by the number of sensors resulting in a restricted monitored area. Image processing analysis is an alternative way that enables the measurement of the complete area of interest with a simple and effective setup. In this article photo sequences taken during load displacement tests were captured by a digital camera and processed with image correlation algorithms. Three different image processing algorithms were used with real images taken from tests using specimens of PVC and Plexiglas. The data obtained from the image processing algorithms were also compared with the data from physical sensors. A complete displacement and strain map were obtained. Results show that the accuracy of the measurements obtained by photogrammetry is equivalent to that from the physical sensors but with much less equipment and fewer setup requirements.

da Mata, Pedro Paraíso, Ana Paula F. da Silva, and Fernando F. S. Pinho. "Risk management procedure in the construction of deep foundations." The 3rd International Conference on “Geotechnics for Sustainable Infrastructure Development. Phung (edt). ISBN 978-604-82-0013-8. Hanoi, Vietnam 2016.
Souza, Sueli, Válter Lúcio, Carlos Chastre, Luiz Souza, and David Martins. "Experimental Analysis of Column To Column Connections for Precast Concrete Truss." fib Symposium 2016. Performance-based approaches for concrete structures. Cape Town, South Africa 2016. 10p. Abstract

The wind energy production is a growing industry and the energy produced is renewable and environmentally cleaner than most of the other systems. The towers to support the wind energy generators may be built with precast concrete elements that are competitive in comparison to other structural systems. The evolution of the technology for wind energy production shows a clear need for larger wind turbines and longer blades and, consequently, taller towers, where precast concrete solutions are competitive. Truss precast concrete towers is a solution that complies with the demands of the present and future wind energy production. The research on the execution and structural behaviour of the connections between the tower elements is an important issue. This communication presents the experimental analysis of column to column connections for precast concrete towers. The tests included connections with commercial threaded bars welded to the rebars and connections with grouted corrugated steel sleeves. Thick joints (50 mm) filled with fibre reinforced grout and thin joints (3 mm) filled with epoxy resin were tested and analysed.

Caeiro, Frederico, Filipe J. Marques, Ayana Mateus, and Serra Atal. "A note on the Jackson exponentiality test." International Conference of Computational Methods in Sciences and Engineering 2016, ICCMSE 2016. Vol. 1790. American Institute of Physics Inc., 2016. Abstract

In this paper we revisit the Jackson exponentiality test. We study and provide functions in R language to compute theoretical moments, the distribution function and quantiles of the statistic test. Approximations to the exact distribution function and quantiles are also provided and their precision discussed. In addition, we provide an application of the Jackson test to real data.In this paper we revisit the Jackson exponentiality test. We study and provide functions in R language to compute theoretical moments, the distribution function and quantiles of the statistic test. Approximations to the exact distribution function and quantiles are also provided and their precision discussed. In addition, we provide an application of the Jackson test to real data.

Mateus, Ayana, Frederico Caeiro, Dora Prata Gomes, and Inês J. Sequeira. "Statistical analysis of extreme river flows." International Conference of Computational Methods in Sciences and Engineering 2016, ICCMSE 2016. Vol. 1790. AIP Conference Proceedings, 1790. American Institute of Physics Inc., 2016. Abstract

Floods are recurrent events that can have a catastrophic impact. In this work we are interested in the analysis of a data set of gauged daily flows from the Whiteadder Water river, Scotland. Using statistic techniques based on extreme value theory, we estimate several extreme value parameters, including extreme quantiles and return periods of high levels.Floods are recurrent events that can have a catastrophic impact. In this work we are interested in the analysis of a data set of gauged daily flows from the Whiteadder Water river, Scotland. Using statistic techniques based on extreme value theory, we estimate several extreme value parameters, including extreme quantiles and return periods of high levels.

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
n/a
Micaelo, R., T. Al-Mansoori, and A. Garcia. "Study of the mechanical properties and self-healing ability of asphalt mixture containing calcium-alginate capsules." Construction and Building Materials. 123 (2016): 734-744. AbstractWebsite

n/a

Noack, F., P. Katranuschkov, R. Scherer, V. Dimitriou, SK Firth, TM Hassan, N. Ramos, P. Pereira, P. Maló, and T. Fernando Technical challenges and approaches to transfer building information models to building energy. Eds. Symeon E. Christodoulou, and Raimar Scherer. Proceedings of ECPPM 2016. CRC Press, 2016. Abstract

The complex data exchange between architectural design and building energy simulation constitutes the main challenge in the use of energy performance analyses in the early design stage. The enhancement of BIM model data with additional specific energy-related information and the subsequent mapping to the input of an energy analysis or simulation tool is yet an open issue. This paper examines three approaches for the data transfer from 3D CAD applications to building performance simulations using BIM as central data repository and points out their current and envisaged use in practice. The first approach addresses design scenarios. It focuses on the supporting tools needed to achieve interoperability given a 74 wide-spread commercial BIM model (Autodesk Revit) and a dedicated pre-processing tool (DesignBuilder) for EnergyPlus. The second approach is similar but addresses retrofitting scenarios. In both workflows gbXML is used as the transformation format. In the third approach a standard BIM model, IFC is used as basis for the transfer process for any relevant lifecycle phase.

Pereira, André, Rui Micaelo, Luís Quaresma, and Maria Teresa Cidade. "Evaluation of Different Methods for the Estimation of the Bitumen Fatigue Life with DSR Testing." Springer Netherlands, 2016. 1017-1028. Abstract
n/a
Tsoukantas, Spyros, Giandomenico Toniolo, Stefano Pampanin, S. K. Ghosh, Larbi Sennour, Thomas D’Arcy, Saha Sthaladipti, Marco Menegotto, Şevket Özden, Válter Lúcio, Carlos Chastre, Stefanos Dritsos, Ioannis Psycharis, Tryfon Topintzis, Georgia Kremmyda, David Fernández-Ordóñez, André de Chefdebien, Simon Hughes, and Lasse Rajala fib Bulletin 78. Precast-concrete buildings in seismic areas. fib bulletin. Lausanne: International Federation for Structural Concrete (fib), 2016. Abstractfib_bulletin78.jpgWebsite

This document has a broad scope and is not focussed on design issues. Precast construction under seismic conditions is treated as a whole. The main principles of seismic design of different structural systems, their behavior and their construction techniques are presented through rules, construction steps and sequences, procedures, and details that should lead to precast structures built in seismic areas complying with the fundamental performance requirements of collapse prevention and life safety in major earthquakes and limited damage in more frequent earthquakes.The content of this document is largely limited to conventional precast construction and, although some information is provided on the well-known “PRESSS technology” (jointed ductile dry connections), this latter solution is not treated in detail in this document.The general overview, contained in this document, of alternative structural systems and connection solutions available to achieve desired performance levels, intends to provide engineers, architects, clients, and end-users (in general) with a better appreciation of the wide range of applications that modern precast concrete technology can have in various types of construction from industrial to commercial as well as residential. Lastly, the emphasis on practical aspects, from conceptual design to connection detailing, aims to help engineers to move away from the habit of blindly following prescriptive codes in their design, but instead go back to basic principles, in order to achieve a more robust understanding, and thus control, of the seismic behaviour of the structural system as a whole, as well as of its components and individual connections.

Carvalho, R. N. L., R. M. Almeida, JJG Moura, N. T. Lourenço, L. J. P. Fonseca, and C. M. Cordas. "Sandwich-Type Enzymatic Fuel Cell Based on a New Electro-Conductive Material - Ion Jelly." ChemistrySelect. 1.20 (2016): 6546-6552. AbstractWebsite
n/a
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.
Silva, Lyrene, Ana Moreira, João Araújo, Catarina Gralha, Miguel Goulão, and Vasco Amaral. "Exploring Views for Goal-Oriented Requirements Models." 35th International Conference on Conceptual Modeling, ER2016. Gifu, Japan 2016. Abstractsilva2016er.pdf

Requirements documents and models need to be used by many stakeholders with di erent technological pro ciency, during software development. Each stakeholder may need to understand the entire (or simply part of the) requirements artifacts. To empower those stakeholders, views of the requirements should be con gurable to their particular needs. Information visualization techniques may help in this process. In this paper, we propose di erent views aimed at highlighting information that is relevant for a particular stakeholder, helping him to query requirements artifacts. We o er three kinds of visualization capturing language and domain elements, while providing a gradual model overview: the big picture view, the syntax-based view, and the concern-based view. We instantiate these views with i* models and introduce an implementation prototype in the iStarLab tool.

Chastre, Carlos, Hugo Biscaia, Noel Franco, and António Monteiro. "Experimental Analysis of Reinforced Concrete Beams Strengthened with Innovative Techniques." 41th IAHS Word Congress of Housing. Sustainability and Innovation for the Future. Albufeira, Portugal 2016. 10. Abstract41_iahs_2016_-_carlos_chastre-ext-abstract.pdf

The strengthening of reinforced concrete structures with FRP materials has received a considerable increment in recent years due to their durability characteristics, high strength-weight and stiffness-weight ratios of FRP compared to other materials.An experimental program was conducted in order to analyse the behaviour of different structural solutions to strengthen reinforced concrete beams with carbon FRP composites: EBR (Externally-Bonded Reinforcement), NSM (Near Surface Mounted) reinforcement and an innovative technique externally-bonded using continuous reinforcement embedded at ends (CREatE). The RC beams had a 3m span by 0.3m height and were tested until rupture in a 4-point bending test system.The CREatE technique has proved to be the most effective of the three alternatives tested, with the full utilisation of the CFRP and the highest strength, combined with the highest ductility.