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2017
Cain, A. J., G. Klein, Ł. Kubat, A. Malheiro, and J. Okniński A note on identities in plactic monoids and monoids of upper-triangular tropical matrices. ArXiv e-prints., 2017. Abstract

This paper uses the combinatorics of Young tableaux to prove the plactic monoid of infinite rank does not satisfy a non-trivial identity, by showing that the plactic monoid of rank n cannot satisfy a non-trivial identity of length less than or equal to n. A new identity is then proven to hold for the monoid of n×n upper-triangular tropical matrices. Finally, a straightforward embedding is exhibited of the plactic monoid of rank 3 into the direct product of two copies of the monoid of 3×3 upper-triangular tropical matrices, giving a new proof that the plactic monoid of rank 3 satisfies a non-trivial identity.

Lallensack, Jens N., Hendrik Klein, Jesper Milàn, Oliver Wings, Octávio Mateus, and Lars B. Clemmensen. "Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: Evidence for Late Triassic sauropods." Acta Palaeontologica Polonica. 62.4 (2017): 833-843. Abstractlallensack_et_al_2017_-_sauropodomorph_tracks_greenland.pdf

The Late Triassic (Norian–early Rhaetian) Fleming Fjord Formation of central East Greenland preserves a diverse fossil fauna, including both body and trace fossils. Trackways of large quadrupedal archosaurs, although already reported in 1994 and mentioned in subsequent publications, are here described and figured in detail for the first time, based on photogrammetric data collected during fieldwork in 2012. Two trackways can be referred to Eosauropus, while a third, bipedal trackway may be referred to Evazoum, both of which have been considered to represent sauropodomorph dinosaur tracks. Both the Evazoum and the Eosauropus trackways are distinctly larger than other trackways referred to the respective ichnogenera. The trackmaker of the best preserved Eosauropus trackway is constrained using a synapomorphy-based approach. The quadrupedal posture, the entaxonic pes structure, and five weight-bearing digits indicate a derived sauropodiform trackmaker. Other features exhibited by the tracks, including the semi-digitigrade pes and the laterally deflected unguals, are commonly considered synapomorphies of more exclusive clades within Sauropoda. The present trackway documents an early acquisition of a eusauropod-like pes anatomy while retaining a well-developed claw on pedal digit IV, which is reduced in eusauropods. Although unequivocal evidence for sauropod dinosaurs is no older than the Early Jurassic, the present trackway provides evidence for a possible Triassic origin of the group.

Karlovich, Alexei Yu. "Toeplitz operators on abstract Hardy spaces built upon Banach function spaces." Journal of Function Spaces. 2017 (2017): Article ID 9768210, 8 pages.Website
João, Carlos FC, Ana T. Kullberg, Jorge C. Silva, and João P. Borges. "Chitosan Inverted Colloidal Crystal scaffolds: Influence of molecular weight on structural stability." Materials Letters. 193 (2017): 50-53. Abstract
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Kullberg, A. T. G., A. A. S. Lopes, J. P. B. Veiga, and R. C. C. Monteiro. "Crystal growth in zinc borosilicate glasses." Journal of Crystal Growth. 457 (2017): 239-243. AbstractWebsite

Glass samples with a molar composition (64+x)ZnO–(16−x)B2O3–20SiO2, where x=0 or 1, were successfully synthesized using a melt-quenching technique. Based on differential thermal analysis data, the produced glass samples were submitted to controlled heat-treatments at selected temperatures (610, 615 and 620 °C) during various times ranging from 8 to 30 h. The crystallization of willemite (Zn2SiO4) within the glass matrix was confirmed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Under specific heat-treatment conditions, transparent nanocomposite glass-ceramics were obtained, as confirmed by UV–vis spectroscopy. The influence of temperature, holding time and glass composition on crystal growth was investigated. The mean crystallite size was determined by image analysis on SEM micrographs. The results indicated an increase on the crystallite size and density with time and temperature. The change of crystallite size with time for the heat-treatments at 615 and 620 °C depended on the glass composition. Under fixed heat-treatment conditions, the crystallite density was comparatively higher for the glass composition with higher ZnO content. © 2016 Elsevier B.V.

Araújo, João, Wolfram Bentz, and Janusz Konieczny. "Directed graphs of inner translations of semigroups." Semigroup Forum. 94 (2017): 650-673. AbstractWebsite
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Araújo, João, Michael Kinyon, Janusz Konieczny, and António Malheiro. "Four notions of conjugacy for abstract semigroups." Proc. Roy. Soc. Edinburgh Sect. A. 147 (2017): 1169-1214. AbstractWebsite
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Araújo, João, Michael Kinyon, Janusz Konieczny, and António Malheiro. "Four notions of conjugacy for abstract semigroups." Proc. Roy. Soc. Edinburgh Sect. A. 147 (2017): 1169-1214. AbstractWebsite
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Kuhn, P., G. Catalanotti, J. Xavier, P. P. Camanho, and H. Koerber. "Fracture toughness and crack resistance curves for fiber compressive failure mode in polymer composites under high rate loading." Composite Structures. 182 (2017): 164-175. AbstractWebsite

Abstract This work presents an experimental method to measure the compressive crack resistance curve of fiber-reinforced polymer composites when subjected to dynamic loading. The data reduction couples the concepts of energy release rate, size effect law and R-curve. Double-edge notched specimens of four different sizes are used. Both split-Hopkinson pressure bar and quasi-static reference tests are performed. The full crack resistance curves at both investigated strain rate regimes are obtained on the basis of quasi-static fracture analysis theory. The results show that the steady state fracture toughness of the fiber compressive failure mode of the unidirectional carbon-epoxy composite material IM7-8552 is 165.6kJ/m2 and 101.6kJ/m2 under dynamic and quasi-static loading, respectively. Therefore the intralaminar fracture toughness in compression is found to increase with increasing strain rate.

Pereira, B., O. Mateus, J. C. Kullberg, and R. Rocha. "The geotouristic potential of the Oeste Region of Portugal." 2017. Abstract
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Lallensack, Jens N., Hendrik Klein, Jesper Milàn, Oliver Wings, Octávio Mateus, and Lars B. Clemmensen. "Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods." Acta Palaeontologica Polonica. 62 (2017): 833-843. Abstract
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Lallensack,  Jens N.,  Hendrik Klein,  Jesper Milàn,  Oliver Wings,  Octávio Mateus, and  Lars B. Clemmensen. "Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods." (2017). AbstractWebsite
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Pohl, Randolf, Fran{\c c}ois Nez, Luis M. P. Fernandes, Marwan Abdou Ahmed, Fernando D. Amaro, Pedro Amaro, Fran{\c c}ois Biraben, João M. R. Cardoso, Daniel S. Covita, Andreas Dax, Satish Dhawan, Marc Diepold, Beatrice Franke, Sandrine Galtier, Adolf Giesen, Andrea L. Gouvea, Johannes Götzfried, Thomas Graf, Theodor W. Hänsch, Malte Hildebrandt, Paul Indelicato, Lucile Julien, Klaus Kirch, Andreas Knecht, Paul Knowles, Franz Kottmann, Julian J. Krauth, Eric-Olivier Le Bigot, Yi-Wei Liu, José A. M. Lopes, Livia Ludhova, Jorge Machado, Cristina M. B. Monteiro, Fran{\c c}oise Mulhauser, Tobias Nebel, Paul Rabinowitz, Joaquim M. F. dos Santos, José Paulo Santos, Lukas A. Schaller, Karsten Schuhmann, Catherine Schwob, Csilla I. Szabo, David Taqqu, João F. C. A. Veloso, Andreas Voss, Birgit Weichelt, and Aldo Antognini. "{Laser Spectroscopy of Muonic Atoms and Ions}." Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016). Journal of the Physical Society of Japan, 2017. Abstract
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Marouf, S., A. Beniaiche, K. Kardarian, MJ Mendes, O. Sanchez-Sobrado, H. Águas, E. Fortunato, and R. Martins. "{Low-temperature spray-coating of high-performing ZnO:Al films for transparent electronics}." Journal of Analytical and Applied Pyrolysis. 127 (2017). Abstract

© 2017 Elsevier B.V. Ultrasonic spray pyrolysis deposition of ZnO-based materials offers an attractive high-throughput low-cost route towards industrial production of high-quality transparent conductive oxide (TCO) thin-films. In this work, undoped and aluminium-doped ZnO films have been grown employing ultrasonic spray pyrolysis at relatively low-temperate (300 °C), followed by a post-annealing treatment. The role of Al concentration in the starting solution, as well as the rapid thermal annealing (RTA) atmosphere, were investigated and correlated to the morphological, structural, electrical and optical properties of the films. The remarkable enhancement of electrical conductivity attained here is mainly ascribed to the combined effects of: (1) homogenous incorporation of Al3+into the ZnO matrix, which enhances crystal quality providing higher electronic mobility; and (2) the RTA which releases the localized electrons caused by oxygen absorption and thereby increases the free carrier density. Under optimum deposition conditions, a low resistivity and a high optical transmittance around 4 × 10−3$Ømega$ cm and 87{%}, respectively, were obtained. The application of the RTA post-process after low temperature growth has several advantages relative to the direct growth at high temperature (usually 400–575 °C), such as shorter growth time and lower cost associated to the spray pyrolysis equipment requirements and usage. The results suggest that the electrical and optical properties of the ZnO:Al films can be further improved for solar cell applications by controlling the temperature of the post-deposition annealing in reducing atmosphere.

Goswami, S., S. Nandy, A. N. Banerjee, A. Kiazadeh, G. R. Dillip, JV Pinto, S. W. Joo, R. Martins, and E. Fortunato. "{“Electro-Typing” on a Carbon-Nanoparticles-Filled Polymeric Film using Conducting Atomic Force Microscopy}." Advanced Materials. 29 (2017). Abstract

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Next-generation electrical nanoimprinting of a polymeric data sheet based on charge trapping phenomena is reported here. Carbon nanoparticles (CNPs) (waste carbon product) are deployed into a polymeric matrix (polyaniline) (PANI) as a charge trapping layer. The data are recorded on the CNPs-filled polyaniline device layer by “electro-typing” under a voltage pulse (VET, from ±1 to ±7 V), which is applied to the device layer through a localized charge-injection method. The core idea of this device is to make an electrical image through the charge trapping mechanism, which can be “read” further by the subsequent electrical mapping. The density of stored charges at the carbon–polyaniline layer, near the metal/polymer interface, is found to depend on the voltage amplitude, i.e., the number of injected charge carriers. The relaxation of the stored charges is studied by different probe voltages and for different devices, depending on the percolation of the CNPs into the PANI. The polymeric data sheet retains the recorded data for more than 6 h, which can be refreshed or erased at will. Also, a write–read–erase–read cycle is performed for the smallest “bit” of stored information through a single contact between the probe and the device layer.

2016
Branquinho, Rita, Ana Santa, Emanuel Carlos, Daniela Salgueiro, Pedro Barquinha, Rodrigo Martins, and Elvira Fortunato. "{Solution Combustion Synthesis: Applications in Oxide Electronics}." Developments in Combustion Technology. Eds. Kyprianidis G. Konstantinos, and Jan Skvaril. InTech, 2016. 397-417. Abstract

Oxide-based electronics have been well established as an alternative to silicon technology; however, typical processing requires complex, high-vacuum equipment, which is a major drawback, particularly when targeting low-cost applications. The possibility to deposit the materials by low-cost techniques such as inkjet printing has drawn tremendous interest in solution processible materials for electronic applications; however, high processing temperatures still required. To overcome this issue, solution combustion synthesis has been recently pursued. Taking advantage of the exothermic nature of the reaction as a source of energy for localized heating, the precursor solutions can be converted into oxides at lower process temperatures. Theoretically, this can be applied to any metal ions to produce the desired oxide, opening unlimited possibilities to materials' composition and combinations. Solution combustion synthesis has been applied for the production of semiconductor thin films based on ZnO, In2O3, SnO2 and combinations of these oxides, and also for high $ąppa$ dielectrics (Al2O3). All of which are required for numerous electronic devices and applications such as fully oxide-based thin-film transistors (TFTs). The properties of produced thin films are highly dependent on the precursor solution characteristics; hence, the influence of several processing parameters; organic fuel, solvent and annealing temperature was studied. Although precursor solution degradation/oxide formation mechanisms are not yet fully understood, particularly for thin films, we demonstrate that high-performance devices are obtained with combustion solution-based metal oxide thin films. The results clearly show that solution combustion synthesis is becoming one of the most promising methods for low-temperature flexible electronics.

Lorenz, M., et al. "{The 2016 oxide electronic materials and oxide interfaces roadmap}." Journal of Physics D: Applied Physics. 49 (2016): 433001. AbstractWebsite

Oxide electronic materials provide a plethora of possible applications and offer ample opportunity for scientists to probe into some of the exciting and intriguing phenomena exhibited by oxide systems and oxide interfaces. In addition to the already diverse spectrum of properties, the nanoscale form of oxides provides a new dimension of hitherto unknown phenomena due to the increased surface-to-volume ratio. Oxide electronic materials are becoming increasingly important in a wide range of applications including transparent electronics, optoelectronics, magnetoelectronics, photonics, spintronics, thermoelectrics, piezoelectrics, power harvesting, hydrogen storage and environmental waste management. Synthesis and fabrication of these materials, as well as processing into particular device structures to suit a specific application is still a challenge. Further, characterization of these materials to understand the tunability of their properties and the novel properties that evolve due to their nanostructured nature is another facet of the challenge. The research related to the oxide electronic field is at an impressionable stage, and this has motivated us to contribute with a roadmap on 'oxide electronic materials and oxide interfaces'. This roadmap envisages the potential applications of oxide materials in cutting edge technologies and focuses on the necessary advances required to implement these materials, including both conventional and novel techniques for the synthesis, characterization, processing and fabrication of nanostructured oxides and oxide-based devices. The contents of this roadmap will highlight the functional and correlated properties of oxides in bulk, nano, thin film, multilayer and heterostructure forms, as well as the theoretical considerations behind both present and future applications in many technologically important areas as pointed out by Venkatesan. The contributions in this roadmap span several thematic groups which are represented by the following authors: novel field effect transistors and bipolar devices by Fortunato, Grundmann, Boschker, Rao, and Rogers; energy conversion and saving by Zaban, Weidenkaff, and Murakami; new opportunities of photonics by Fompeyrine, and Zuniga-Perez; multiferroic materials including novel phenomena by Ramesh, Spaldin, Mertig, Lorenz, Srinivasan, and Prellier; and concepts for topological oxide electronics by Kawasaki, Pentcheva, and Gegenwart. Finally, Miletto Granozio presents the European action 'towards oxide-based electronics' which develops an oxide electronics roadmap with emphasis on future nonvolatile memories and the required technologies. In summary, we do hope that this oxide roadmap appears as an interesting up-to-date snapshot on one of the most exciting and active areas of solid state physics, materials science, and chemistry, which even after many years of very successful development shows in short intervals novel insights and achievements.

Carlos, Emanuel, Rita Branquinho, Asal Kiazadeh, Pedro Barquinha, Rodrigo Martins, and Elvira Fortunato. "{UV-Mediated Photochemical Treatment for Low-Temperature Oxide-Based Thin-Film Transistors}." ACS Applied Materials {&} Interfaces. 8 (2016): 31100-31108. AbstractWebsite

Solution processing of amorphous metal oxides has lately been used as an option to implement in flexible electronics, allowing a reduction of the associated costs and high performance. However, the research has focused more on the semiconductor layer rather than on the insulator layer, which is related to the stability and performance of the devices. This work aims to evaluate amorphous aluminum oxide thin films produced by combustion synthesis and the influence of far-ultraviolet (FUV) irradiation on the properties of the insulator on thin-film transistors (TFTs) using different semiconductors, in order to have compatibility with flexible substrates. An optimized dielectric layer was obtained for an annealing of 30 min assisted by FUV exposure. These thin films were applied in gallium–indium–zinc oxide TFTs as dielectrics showing the best results for TFTs annealed at 180 °C with FUV irradiation: good reproducibility with a subthreshold slope of 0.11 ± 0.01 V dec –1 and a turn-on voltage of −0.12 ± 0.05 V...

Röder, Marko, et al. "{Coulomb dissociation of $^{20,21}$N}." Physical Review C. 93 (2016): 065807. AbstractWebsite
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Bahubalindruni, Pydi Ganga, Asal Kiazadeh, Allegra Sacchetti, Jorge Martins, Ana Rovisco, Vitor Grade Tavares, Rodrigo Martins, Elvira Fortunato, and Pedro Barquinha. "{Influence of Channel Length Scaling on InGaZnO TFTs Characteristics: Unity Current-Gain Cutoff Frequency, Intrinsic Voltage-Gain, and On-Resistance}." Journal of Display Technology. 12 (2016): 515-518. AbstractWebsite
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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.

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
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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.

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.