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2016
Brás, C., G. Eichfelder, and J. Júdice. "Copositivity tests based on the Linear Complementarity Problem." Computational Optimization and Applications. 63.2 (2016): 461-493. AbstractWebsite

We present copositivity tests based on new necessary and sufficient conditions which require the solution of linear complementarity problems (LCP). We propose methodologies involving Lemke’s method, an enumerative algorithm and a linear mixed-integer programming formulation to solve the required LCPs. Moreover, we discuss a new necessary condition for (strict) copositivity based on solving a linear program, which can be used as a preprocessing step. The algorithms with these three different variants are thoroughly applied to test matrices from the literature and to max-clique instances with matrices of order up to 496×496. We compare our procedures with three other copositivity tests from the literature as well as with a general global optimization solver. The numerical results are very promising and equally good and in many cases better than the results reported elsewhere.

Hansen, Bitten Bolvig, Jesper Milàn, Lars B. Clemmensen, Jan Schulz Adolfssen, Eliza Jarl Estrup, Nicole Klein, Octávio Mateus, and Oliver Wings. "Coprolites from the Late Triassic Kap Stewart Formation, Jameson Land, East Greenland: morphology, classification and prey inclusions." Geological Society, London, Special Publications. 434.1 (2016): 49-69. Abstracthansen_et_al_2015_coprolites_from_the_late_triassic_kap_stewart_formation_jameson_land_east_greenland.pdfWebsite

A large collection of vertebrate coprolites from black lacustrine shales in the Late Triassic (Rhaetian–Sinemurian) Kap Stewart Formation, East Greenland is examined with regard to internal and external morphology, prey inclusions, and possible relationships to the contemporary vertebrate fauna. A number of the coprolites were mineralogically examined by X-ray diffraction (XRD), showing the primary mineral composition to be apatite, clay minerals, carbonates and, occasionally, quartz in the form of secondary mineral grains. The coprolite assemblage shows multiple sizes and morphotypes of coprolites, and different types of prey inclusions, demonstrating that the coprolite assemblage originates from a variety of different producers.Supplementary material: A description of the size, shape, structure, texture, contents and preservation of the 328 specimens is available at https://doi.org/10.6084/m9.figshare.c.2134335

Marques, Susana CS, Paula I. P. Soares, Coro Echeverria, Maria H. Godinho, and João P. Borges. "Confinement of thermoresponsive microgels into fibres via colloidal electrospinning: experimental and statistical analysis." RSC Advances. 6.80 (2016): 76370-76380. Abstract
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Marques, Susana CS, Paula I. P. Soares, Coro Echeverria, Maria H. Godinho, and João P. Borges. "Confinement of thermoresponsive microgels into fibres via colloidal electrospinning: experimental and statistical analysis." RSC Advances. 6.80 (2016): 76370-76380. Abstract
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Echeverria, Coro, Susete N. Fernandes, Pedro L. Almeida, and Maria H. Godinho. "Effect of cellulose nanocrystals in a cellulosic liquid crystal behaviour under low shear (regime I): Structure and molecular dynamics." European Polymer Journal. 84 (2016): 675-684. Abstract
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Ribeiro, IC, C. Pinheiro, C. M. Ribeiro, M. M. Veloso, M. C. Simoes-Costa, I. Evaristo, O. S. Paulo, and C. P. Ricardo. "Genetic Diversity and Physiological Performance of Portuguese Wild Beet (Beta vulgaris spp. maritima) from Three Contrasting Habitats." Frontiers in Plant Science. 7 (2016). AbstractWebsite
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Zarrouk, Olfa, Cecilia Brunetti, Ricardo Egipto, Carla Pinheiro, Tania Genebra, Antonella Gori, Carlos M. Lopes, Massimiliano Tattini, and M. Manuela Chaves. "Grape Ripening Is Regulated by Deficit Irrigation/Elevated Temperatures According to Cluster Position in the Canopy." Frontiers in Plant Science. 7 (2016). AbstractWebsite
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Mota, Pedro P., and Manuel L. Esquível. "Model selection for stock prices data." Journal of Applied Statistics. 43 (2016): 2977-2987. AbstractWebsite

The geometric Brownian motion (GBM) is very popular in modeling the dynamics of stock prices. However, the constant volatility assumption is questionable and many models with nonconstant volatility have been developed. In the papers [7,12] the authors introduce a regime switching process where in each regime the process is driven by GBM and the change in regime is defined by the crossing of a threshold. In this paper we used Akaike's and Bayesian information criteria to show that the GBM with regimes provides a better fit than the GBM. We also perform a forecasting comparison of the models for two selected companies.

Esquível, Manuel L., Pedro P. Mota, and João Tiago Mexia. "On some statistical models with a random number of observations." Journal of Statistical Theory and Practice. 10 (2016): 805-823. AbstractWebsite

We extend some classical statistical inference to the case of a random number of observations with a stabilized distribution: namely, in the normal model, inference for the mean with known and unknown variance and inference for the variance. We describe some useful models for the number of observations obtained by truncation or translation of usual models given by integer-valued random variables: Poisson, binomial, geometric, and negative binomial. We present an efficient random search algorithm for the computation of the quantiles of the relevant statistics, we describe an interval estimation procedure for the extended model, and we propose a parametric bootstrap simulation study to validate the proposed procedure.

Braslavsky, I. Y., V. P. Metelkov, S. Valtchev, D. V. Esaulkova, A. V. Kostylev, and A. V. Kirillov. "Some aspects of the reliability increasing of the transport electric drives." Proceedings - 2016 IEEE International Power Electronics and Motion Control Conference, PEMC 2016 (2016): 706-710. Abstract
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Santos-Silva, Teresa, Terao M, Romão MJ, Leimkühler S, Bolis M, Fratelli M, Coelho C, Santos-Silva T, and Garattini E. "Structure and function of mammalian aldehyde oxidases." (2016). AbstractWebsite
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Reifarth, R., et al. "{Nuclear astrophysics with radioactive ions at FAIR}." Vol. 665. Journal of Physics: Conference Series, 2016. 012044. Abstract
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2015
Machado, J., J. Adamczewski-Musch, A. Blanco, K. Boretzky, P. Cabanelas, L. Cartegni, Ferreira R. Marques, P. Fonte, J. Fruehauf, D. Galaviz, M. Heil, A. Henriques, G. Ickert, D. Körper, L. Lopes, M. Palka, A. Pereira, D. Rossi, H. Simon, P. Teubig, M. Traxler, P. Velho, S. Altstadt, L. Atar, T. Aumann, D. Bemmerer, C. Caesar, A. Charpy, Z. Elekes, E. Fiori, I. Gasparic, J. Gerbig, K. Göbel, T. Heftrich, M. Heine, A. Heinz, M. Holl, A. Ignatov, J. Isaak, H. Johansson, A. Kelic-Heil, C. Lederer, S. Lindberg, B. Löher, J. Marganiec, M. Martensson, T. Nilsson, V. Panin, S. Paschalis, M. Petri, R. Plag, M. Pohl, G. Rastrepina, R. Reifarth, T. P. Reinhardt, M. Röder, D. Savran, H. Scheit, P. Schrock, J. Silva, D. Stach, F. Strannerdahl, R. Thies, A. Wagner, F. Wamers, and M. Weigand. "{Performance of timing Resistive Plate Chambers with protons from 200 to 800 MeV}." Journal of Instrumentation. 10 (2015): C01043. AbstractWebsite
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Blanco, A., J. Adamczewski-Musch, K. Boretzky, P. Cabanelas, L. Cartegni, Ferreira R. Marques, P. Fonte, J. Fruehauf, D. Galaviz, M. Heil, A. Henriques, G. Ickert, D. Körper, L. Lopes, M. Palka, A. Pereira, D. Rossi, H. Simon, P. Teubig, M. Traxler, P. Velho, S. Altstadt, L. Atar, T. Aumann, D. Bemmerer, C. Caesar, A. Charpy, Z. Elekes, E. Fiori, I. Gasparic, J. Gerbig, K. Göbel, T. Heftrich, M. Heine, A. Heinz, M. Holl, A. Ignatov, J. Isaak, H. Johansson, A. Kelic-Heil, C. Lederer, S. Lindberg, B. Löher, J. Machado, J. Marganiec, M. Martensson, T. Nilsson, V. Panin, S. Paschalis, M. Petri, R. Plag, M. Pohl, G. Rastrepina, R. Reifarth, T. P. Reinhardt, M. Röder, D. Savran, H. Scheit, P. Schrock, J. Silva, D. Stach, F. Strannerdahl, R. Thies, A. Wagner, F. Wamers, and M. Weigand. "{Performance of timing resistive plate chambers with relativistic neutrons from 300 to 1500 MeV}." Journal of Instrumentation. 10 (2015): C02034. AbstractWebsite
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Guerra, M., S. C. Pé-Leve Santos, A. M. E. Barroso, C. P. S. Fonseca, M. Eloy Cruz, P. Amaro, J. L. Figueirinhas, M. L. Carvalho, and J. P. Santos. "Spatially resolved determination of toxic trace elements in plants of Panasqueira mining region using micro X-ray fluorescence." Microscopy and Microanalysis. 21 (2015): 54-55. AbstractWebsite
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Foth, Christian, Serjoscha W. Evers, Ben Pabst, Octávio Mateus, Alexander Flisch, Mike Patthey, and Oliver W. M. Rauhut. "New insights into the lifestyle of \\textitAllosaurus (Dinosauria: Theropoda) based on another specimen with multiple pathologies." PeerJ. 3 (2015): e940. AbstractWebsite

Adult large-bodied theropods are often found with numerous pathologies. A large, almost complete, probably adult \\textitAllosaurus specimen from the Howe Stephens Quarry, Morrison Formation (Late Kimmeridgian–Early Tithonian), Wyoming, exhibits multiple pathologies. Pathologic bones include the left dentary, two cervical vertebrae, one cervical and several dorsal ribs, the left scapula, the left humerus, the right ischium, and two left pedal phalanges. These pathologies can be classified as follows: the fifth cervical vertebra, the scapula, several ribs and the ischium are probably traumatic, and a callus on the shaft of the left pedal phalanx II-2 is probably traumatic-infectious. Traumatically fractured elements exposed to frequent movement (e.g., the scapula and the ribs) show a tendency to develop pseudarthroses instead of a callus. The pathologies in the lower jaw and a reduced extensor tubercle of the left pedal phalanx II-2 are most likely traumatic or developmental in origin. The pathologies on the fourth cervical are most likely developmental in origin or idiopathic, that on the left humerus could be traumatic, developmental, infectious or idiopathic, whereas the left pedal phalanx IV-1 is classified as idiopathic. With exception of the ischium, all as traumatic/traumatic-infectious classified pathologic elements show unambiguous evidences of healing, indicating that the respective pathologies did not cause the death of this individual. Alignment of the scapula and rib pathologies from the left side suggests that all may have been caused by a single traumatic event. The ischial fracture may have been fatal. The occurrence of multiple lesions interpreted as traumatic pathologies again underlines that large-bodied theropods experienced frequent injuries during life, indicating an active predatory lifestyle, and their survival perhaps supports a gregarious behavior for \\textitAllosaurus. Alternatively, the frequent survival of traumatic events could be also related to the presence of non-endothermic metabolic rates that allow survival based on sporadic food consumption or scavenging behavior. Signs of pathologies consistent with infections are scarce and locally restricted, indicating a successful prevention of the spread of pathogens, as it is the case in extant reptiles (including birds).

Foth, Christian, Serjoscha Evers, Ben Pabst, Octávio Mateus, Alexander Flisch, Mike Patthey, and Oliver W. M. Rauhut. "New insights into the lifestyle of Allosaurus (Dinosauria: Theropoda) based on another specimen with multiple pathologies." PeerJ PrePrints. 3 (2015): e824v1. Abstractfoth_et_al_2015_peerj-preprints-824.pdfWebsite

Adult large-bodied theropods are often found with numerous pathologies. A large, almost complete, probably adult Allosaurus specimen from the Howe Stephens Quarry, Morrison Formation (Late Kimmeridgian–Early Tithonian), Wyoming, shows multiple pathologies. Pathologic bones include the left dentary, two cervical vertebrae, one cervical and several dorsal ribs, the left scapula, the left humerus, right ischium, and two left pedal phalanges. These pathologies can be classified as follows: the fifth cervical vertebra, the scapula, several ribs and the ischium are traumatic, and a callus on the shaft of the left pedal phalanx II-2 is traumatic-infectious. Traumatically fractured elements exposed to frequent movement (e.g. the scapula and the ribs) show a tendency to develop pseudarthroses instead of callus healing. The pathologies in the lower jaw and a reduced flexor tubercle of the left pedal phalanx II-2 are most likely traumatic or developmental in origin. The pathologies on the fourth cervical are most likely developmental in origin or idiopathic, that on the left humerus is infectious or idiopathic, whereas left pedal phalanx IV-1 is classified as idiopathic. With exception of the ischium, all traumatic / traumatic-infectious pathologic elements show unambiguous evidences of healing, indicating that the respective pathologies did not cause the death of this individual. Alignment of the scapula and rib pathologies from the left side suggests that all may have been caused by a single traumatic event. The ischial fracture may have been fatal. The occurrence of multiple traumatic pathologies again underlines that large-bodied theropods experienced frequent injuries during life, indicating an active predatory lifestyle, and their survival perhaps supports a gregarious behavior for Allosaurus. Signs of infections are scarce and locally restricted, indicating a successful prevention of the spread of pathogens, as it is the case in extant reptiles (including birds).

Santos, Lídia, Pawel Wojcik, Joana V. Pinto, Elamurugu Elangovan, Jaime Viegas, LuÍs Pereira, Rodrigo Martins, and Elvira Fortunato. "Structure and Morphologic Influence of WO3 Nanoparticles on the Electrochromic Performance of Dual-Phase a-WO3/WO3 Inkjet Printed Films." Advanced Electronic Materials (2015): n/a-n/a. AbstractWebsite

The optimization of tungsten trioxide (WO3) nanoparticles produced via hydrothermal synthesis for application in electrochromic (EC) devices is reported. The structure and morphology of the nanoparticles are controlled by changing the acidity of the aqueous solvent added to the sol-gel precursor (peroxopolytungstic acid) during synthesis. Orthorhombic hydrated WO3 nanorods or monoclinic WO3 nanoslabs are obtained when HCl is added, while synthesis only in aqueous medium results in a mixture of both types of polymorphs. Dual-phase thin films are processed by inkjet printing deposition of the nanoparticles in flexible polyethylene terephthalate substrate with indium tin oxide coating (ITO PET) followed by the deposition of the precursor solution. When compared with purely amorphous tungsten oxide films, the dual phase ones present higher optical densities and improved capacity, and cyclability stability. The best results, obtained for orthorhombic hydrated nanoparticles (ortho-WO3·0.33H2O), are due to its high surface area and improved conductivity. Additionally, the ex situ X-ray diffraction (XRD) lithiation studies show evidence of a higher distortion of the monoclinic when compared with the orthorhombic crystallographic structure, which contribute to the inferior EC performance. These results validate the use of inkjet printing deposition with low processing temperatures for EC dual-phase thin films containing optimized nanoparticles which are compatible with low-cost substrates.

Baptista, Susana, Maria Isabel Gomes, Laureano Escudero, Pedro Medeiros, and Filipe Cabrita. "A Fix-and-Relax Algorithm for Solving Parallel and Sequential Versions of a Multi-period Multi-product Closed Loop Supply Chain Design and Operation Planning Model." Operations Research and Big Data: IO2015-XVII Congress of Portuguese Association of Operational Research (APDIO). Eds. Barbosa Ana Paula Ferreira Dias Póvoa, and Luis Joao de Miranda. Springer International Publishing, 2015. 9-14. Abstract2015_baptistagomesescuderomedeiroscabrita_io2015.pdf

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Koerber, H., J. Xavier, P. P. Camanho, Y. E. Essa, and Martín F. de la Escalera. "High strain rate behaviour of 5-harness-satin weave fabric carbon-epoxy composite under compression and combined compression-shear loading." International Journal of Solids and Structures. 54 (2015): 172-182. AbstractWebsite

Abstract The strain rate dependent mechanical behaviour was studied for the common out-of-autoclave aerospace textile composite 5-harness-satin carbon�epoxy. End-loaded 15 � , 30 � and 45 � off-axis and 90 � compression tests were carried out at three different strain rate levels ( 4 � 10 - 4 s - 1 , 200 s - 1 and 1000 s - 1 ) to determine the effect of strain rate for transverse compression and combined transverse compression/in-plane shear loading. The dynamic tests were carried out on a split-Hopkinson pressure bar, where high speed photography and digital image correlation allowed a detailed study of the specimen deformation and failure process. Quasi-static reference tests were carried out on an electro-mechanical test machine using the same specimen type and a static \{DIC\} system. Pronounced strain rate effects on the axial stress�strain response were observed for all specimen types. Failure envelopes for the combined s 22 c - t 12 stress state were derived from the experimental data and compared with the maximum stress criterion, which appears well suited to approximate the experimental failure envelope at all strain rate levels. It was observed that the failure envelope was simply scaled up with increasing strain rate, while the overall shape was found to be strain rate independent.

Baptista, Susana, Ana Paula Barbosa-povoa, Laureano Escudero, Maria Isabel Gomes, and Celeste Pizarro. "A Metaheuristic for Solving Large-Scale Two-Stage Stochastic Mixed 0-1 Programs with the Time Stochas- tic Dominance Risk Averse Strategy." 12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering. Copenhagen, Denmark : Elsevier, 2015. 857-862. Abstractescape25.pdf

Supply Chain Design problems often result into multiperiod stochastic mixed integer problems that are hard to solve. In this paper we propose a metaheuristic algorithm as a specialization for two- stage problems of the so-named Fix-and-Relax Algorithm presented previously for solving large- scale multiperiod stochastic mixed 0-1 optimization problems under a time stochastic dominance risk averse strategy, so-named TSD. Some computational experience is presented.

Corvo, Marta C., João Sardinha, Teresa Casimiro, Graciane Marin, Marcus Seferin, Sandra Einloft, Sonia C. Menezes, Jairton Dupont, and Eurico J. Cabrita. "A rational approach to sustainable CO2-capture by imidazolium ionic liquids: tuning CO2 solubility by cation alkyl branching." Chem. Sus. Chem.. 8 (2015): 1935-1946.
Aquino, Aline S., FL Bernard, JV Borges, Luis Mafra, Felipe Dalla Vecchia, MO Vieira, R. Ligabue, VV Chaban, E. J. Cabrita, and S. Einloft. "Rationalizing the role of the anion in CO2 capture and conversion using imidazolium-based ionic liquid modified mesoporous sílica." RSC Advances. 5 (2015): 64220-64227.
Rodríguez-Martínez, E. V., R. M. R. Cardoso, and A. D. Egídio dos Reis. "Some advances on the Erlang(n) dual risk model." ASTIN Bulletin. 45.1 (2015): 127-150.