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2017
Maiti, B. K., L. B. Maia, S. R. Pauleta, I. Moura, and J. J. Moura. "Protein-Assisted Formation of Molybdenum Heterometallic Clusters: Evidence for the Formation of S2MoS2-M-S2MoS2 Clusters with M = Fe, Co, Ni, Cu, or Cd within the Orange Protein." Inorg Chem (2017). AbstractWebsite

The Orange Protein (ORP) is a small bacterial protein, of unknown function, that harbors a unique molybdenum/copper (Mo/Cu) heterometallic cluster, [S2MoVIS2CuIS2MoVIS2]3-, noncovalently bound. The apo-ORP is able to promote the formation and stabilization of this cluster, using CuII- and MoVIS42- salts as starting metallic reagents, to yield a Mo/Cu-ORP that is virtually identical to the native ORP. In this work, we explored the ORP capability of promoting protein-assisted synthesis to prepare novel protein derivatives harboring molybdenum heterometallic clusters containing iron, cobalt, nickel, or cadmium in place of the "central" copper (Mo/Fe-ORP, Mo/Co-ORP, Mo/Ni-ORP, or Mo/Cd-ORP). For that, the previously described protein-assisted synthesis protocol was extended to other metals and the Mo/M-ORP derivatives (M = Cu, Fe, Co, Ni, or Cd) were spectroscopically (UV-visible and electron paramagnetic resonance (EPR)) characterized. The Mo/Cu-ORP and Mo/Cd-ORP derivatives are stable under oxic conditions, while the Mo/Fe-ORP, Mo/Co-ORP, and Mo/Ni-ORP derivatives are dioxygen-sensitive and stable only under anoxic conditions. The metal and protein quantification shows the formation of 2Mo:1M:1ORP derivatives, and the visible spectra suggest that the expected {S2MoS2MS2MoS2} complexes are formed. The Mo/Cu-ORP, Mo/Co-ORP, and Mo/Cd-ORP are EPR-silent. The Mo/Fe-ORP derivative shows an EPR S = 3/2 signal (E/D approximately 0.27, g approximately 5.3, 2.5, and 1.7 for the lower M= +/-1/2 doublet, and g approximately 5.7 and 1.7 (1.3 predicted) for the upper M = +/-3/2 doublet), consistent with the presence of either one S = 5/2 FeIII antiferromagnetically coupled to two S = 1/2 MoV or one S = 3/2 FeI and two S = 0 MoVI ions, in both cases in a tetrahedral geometry. The Mo/Ni-ORP shows an EPR axial S = 1/2 signal consistent with either one S = 1/2 NiI and two S = 0 MoVI or one S = 1/2 NiIII antiferromagnetically coupled to two S = 1/2 MoV ions, in both cases in a square-planar geometry. The Mo/Cu-ORP and Mo/Cd-ORP are described as {MoVI-CuI-MoVI} and {MoVI-CdII-MoVI}, respectively, while the other derivatives are suggested to exist in at least two possible electronic structures, {MoVI-MI-MoVI} <--> {MoV-MIII-MoV}.

Pessanha, Sofia, Ana Samouco, Ricardo Adão, Maria Luisa Carvalho, Jose Paulo Santos, and Pedro Amaro. "Detection limits evaluation of a portable energy dispersive X-ray fluorescence setup using different filter combinations." X-Ray Spectrometry. 46 (2017): 102-106. AbstractWebsite

In this paper, we study the performance of a portable energy dispersive X‐ray fluorescence spectrometer by making use of different filter configurations at the X‐ray tube output. To fulfill this purpose,...

Kowacz, Magdalena, Mateusz Marchel, Lina Juknaité, José M. S. S. Esperança, Maria João Romão, Ana Luísa Carvalho, and Luís Paulo N. Rebelo. "Infrared light-induced protein crystallization. Structuring of protein interfacial water and periodic self-assembly." Journal of Crystal Growth. 457 (2017): 362-368. AbstractWebsite

We show that a physical trigger, a non-ionizing infrared (IR) radiation at wavelengths strongly absorbed by liquid water, can be used to induce and kinetically control protein (periodic) self-assembly in solution. This phenomenon is explained by considering the effect of IR light on the structuring of protein interfacial water. Our results indicate that the IR radiation can promote enhanced mutual correlations of water molecules in the protein hydration shell. We report on the radiation-induced increase in both the strength and cooperativeness of H-bonds. The presence of a structured dipolar hydration layer can lead to attractive interactions between like-charged biomacromolecules in solution (and crystal nucleation events). Furthermore, our study suggests that enveloping the protein within a layer of structured solvent (an effect enhanced by IR light) can prevent the protein non-specific aggregation favoring periodic self-assembly. Recognizing the ability to affect protein-water interactions by means of IR radiation may have important implications for biological and bio-inspired systems.

Socratous, Josephine, Shun Watanabe, Kulbinder K. Banger, Christopher N. Warwick, Rita Branquinho, Pedro Barquinha, Rodrigo Martins, Elvira Fortunato, and Henning Sirringhaus. "{Energy-dependent relaxation time in quaternary amorphous oxide semiconductors probed by gated Hall effect measurements}." Physical Review B. 95 (2017): 045208. AbstractWebsite

Despite the success of exploiting the properties of amorphous oxide semiconductors for device applications, the charge transport in these materials is still not clearly understood. The observation of a definite Hall voltage suggests that electron transport in the conduction band is free-electron-like. However, the temperature dependence of the Hall and field-effect mobilities cannot be explained using a simple bandlike model. Here, we perform gated Hall effect measurements in field-effect transistors, which allow us to make two independent estimates of the charge carrier concentration and determine the Hall factor providing information on the energy dependence of the relaxation time. We demonstrate that the Hall factor in a range of sputtered and solution-processed quaternary amorphous oxides, such as a-InGaZnO, is close to two, while in ternary oxides, such as InZnO, it is near unity. This suggests that quaternary elements like Ga act as strong ionized impurity scattering centers in these materials.

Silva, A. L. M., S. Cirino, M. L. Carvalho, M. Manso, S. Pessanha, C. D. R. Azevedo, L. F. N. D. Carramate, J. P. Santos, M. Guerra, and J. F. C. A. Veloso. "Elemental mapping in a contemporary miniature by full-field X-ray fluorescence imaging with gaseous detector vs. scanning X-ray fluorescence imaging with polycapillary optics." (2017): 1-7. Abstract

Spectrochimica Acta Part B: Atomic Spectroscopy, 129 (2016) 1-7. doi:10.1016/j.sab.2016.12.006

Chiari, M., E. Alves, Bogdanović I. Radović, J. Cruz, L. Csedreki, M. Fonseca, D. Galaviz, A. Henriques, M. Jak{\v s}ić, A. P. Jesus, O. Kakuee, Á. Z. Kiss, A. Lagoyannis, F. Louren{\c c}o, H. Lu{\'ıs, J. Machado, B. Melon, C. K. Nuviadenu, L. Salvestrini, N. Sharifzadeh, Z. Siketić, G. Á. Sz{\'ıki, Z. Szikszai, P. Teubig, P. Velho, I. Zamboni, and M. Zarza. "{Measurement of proton induced $\gamma$-ray emission cross sections on Na from 1.0 to 4.1 MeV}." Nuclear Inst. and Methods in Physics Research, B (2017): 1-11. AbstractWebsite
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Vicente, António T., Andreia Araújo, Diana Gaspar, Lídia Santos, Ana C. Marques, Manuel J. Mendes, LuÍs Pereira, Elvira Fortunato, and Rodrigo Martins. "{Optoelectronics and Bio Devices on Paper Powered by Solar Cells}." Nanostructured Solar Cells. InTech, 2017. Abstract

The employment of printing techniques as cost-effective methods to fabricate low cost, flexible, disposable and sustainable solar cells is intimately dependent on the substrate properties and the adequate electronic devices to be powered by them. Among such devices, there is currently a growing interest in the development of user-oriented and multipurpose systems for intelligent packaging or on-site medical diagnostics, which would greatly benefit from printable solar cells as their energy source for autonomous operation. This chapter first describes and analyzes different types of cellulose-based substrates for flexible and cost effective optoelectronic and bio devices to be powered by printed solar cells. Cellulose is one of the most promising platforms for green recyclable electronics and it is fully compatible with large-scale printing techniques, although some critical requirements must be addressed. Paper substrates exist in many forms. From common office paper, to packaging cardboard used in the food industry, or nanoscale engineered cellulose (e.g. bacterial cellulose). However, it is the structure and content of paper that determines its end use. Secondly, proof-of-concept of optoelectronic and bio devices pro-duced by inkjet printing are described and show the usefulness of solar cells as a power source or as a chemical reaction initiator for sensors.

Salgueiro, Daniela, Asal Kiazadeh, Rita Branquinho, Lídia Santos, Pedro Barquinha, Rodrigo Martins, and Elvira Fortunato. "{Solution based zinc tin oxide TFTs: the dual role of the organic solvent}." Journal of Physics D: Applied Physics. 50 (2017): 065106. AbstractWebsite

Chemical solution deposition is a low cost, scalable and high performance technique to obtain metal oxide thin films. Recently, solution combustion synthesis has been introduced as a chemical route to reduce the processing temperature. This synthesis method takes advantage of the chemistry of the precursors as a source of energy for localized heating. According to the combustion chemistry some organic solvents can have a dual role in the reaction, acting both as solvent and fuel. In this work, we studied the role of 2-methoxyethanol in solution based synthesis of ZTO thin films and its influence on the performance of ZTO TFTs. The thermal behaviour of ZTO precursor solutions confirmed that 2-methoxyethanol acts simultaneously as a solvent and fuel, replacing the fuel function of urea. The electrical characterization of the solution based ZTO TFTs showed a slightly better performance and lower variability under positive gate bias stress when urea was not used as fuel, confirming that the excess fuel contributes negatively to the device operation and stability. Solution based ZTO TFTs demonstrated a low hysteresis ($Δ$V = −0.3 V) and a saturation mobility of 4–5 cm2 V−1 s−1.

Sallem, A., P. Pereira, and M. Fakhfakh. "Automatic sensitivity analysis tool for analog active filter." 2017 24th IEEE International Conference on Electronics, Circuits and Systems (ICECS). 2017. 124-127. Abstract

In this paper we deal with analog active filter design using discrete components taking into consideration tolerance effects. Sensitivity analysis is performed to determine the most influential components in the considered circuit, thus relative higher precision is offered to those parameters. Further, an in-loop optimization technique is considered, thus actual IC models are handled. An application example is presented. HSpice simulation results, supported by Monte Carlo analysis, are given to highlight efficiency of the proposed selection technique.

Antunes, V., A. C. Freire, L. Quaresma, and R. Micaelo. "Evaluation of waste materials as alternative sources of filler in asphalt mixtures." Materials and Structures. 50 (2017): 254. AbstractWebsite

There are many different ways to reduce the construction industry's impact on environment. The incorporation of waste in the fabrication of construction materials may be beneficial for both the waste management sector and the construction industry. The aim of this research was to investigate the use of three different waste materials (construction and demolition waste, brick powder and fly ash) as filler in asphalt mixtures. Limestone filler was used as reference material. The materials were characterized in terms of their geometrical, physical and chemical properties, and the interaction with bitumen was assessed with two mastic test methods using four different bitumens. The specific surface of waste materials shows a wide-ranging variation due to material specific shape and texture of particles. However, the Rigden voids and bitumen number tests adequately measure the stiffening effect of these materials. The delta ring and ball test results showed there is a good relation with the filler content when the results are affected by the bitumen type. The f/b ratio for a specific bitumen–filler combination can be determined from the maximum filler-to-bitumen ratio and the recommended stiffening increase. The mastics with these waste materials showed strong resistance to water damage.

Amaro, Pedro, Jose Paulo Santos, Ana Samouco, Ricardo Adão, Luís Souto Martins, Sebastian Weber, Stanislav Tashenov, Maria Luisa Carvalho, and Sofia Pessanha. "Validation of the Geant4 Monte Carlo package for X-ray fluorescence spectroscopy in triaxial geometry." Spectrochimica Acta Part B: Atomic Spectroscopy. 130 (2017): 60-66. AbstractWebsite

Spectrochimica Acta Part B: Atomic Spectroscopy, 130 (2017) 60-66. doi:10.1016/j.sab.2017.02.012

Mateus, Octávio, Marco Marzola, Anne S. Schulp, Louis L. Jacobs, Michael J. Polcyn, Vladimir Pervov, António Ol{\'ı}mpio Gonçalves, and Maria Luisa Morais. "Angolan ichnosite in a diamond mine shows the presence of a large terrestrial mammaliamorph, a crocodylomorph, and sauropod dinosaurs in the Early Cretaceous of Africa." Palaeogeography, Palaeoclimatology, Palaeoecology. 471 (2017): 220-232. AbstractWebsite
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Garde, Francois, Daniel Aelenei, Laura Aelenei, Alessandra Scognamiglio, and Josef Ayoub Solution Sets for Net-Zero Energy Buildings. Wiley-{VCH} Verlag {GmbH} {&} Co. {KGaA}, 2017. AbstractWebsite
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Rebelo, Hugo Bento, and Corneliu Cismasiu. "A Comparison between Three Air Blast Simulation Techniques in LS-DYNA." 11th European LS-DYNA Conference 2017. Salzburg, Austria: DYNAMORE, 2017.
Mudrov, Mikhail, Anatoliy Zyuzev, Konstantin Nesterov, and Stanimir Valtchev. "FPGA-based Hardware-in-the-Loop system bits capacity evaluation based on induction motor model." Conference Proceedings - 2017 17th IEEE International Conference on Environment and Electrical Engineering and 2017 1st IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2017. United States: Institute of Electrical and Electronics Engineers Inc., 2017. Abstract

The Hardware-in-the-Loop (HiL) systems become nowadays popular. In the same time, the Field Programmable Gate Arrays (FPGAs) allow for creating the HiL with time step 1 μs or less. The FPGA usually executes the numerical operations on Fixed Point variables. That is why during the FPGA-based HiL creation process it is important to select a proper number of bits for the modeled variables. A mathematical model based on the induction motor is selected as a basis for comparative tests between the floating point model and the fixed point model. In consequence, recommendations for the Bit Capacity (the length of the digital word) selection are given, based on the obtained results.

Mudrov, Mikhail, Anatoliy Zyuzev, Nesterov Konstantin, Stanimir Valtchev, and Svilen Valtchev. "Hardware-in-The-loop system numerical methods evaluation based on brush DC-motor model." Proceedings - 2017 International Conference on Optimization of Electrical and Electronic Equipment, OPTIM 2017 and 2017 Intl Aegean Conference on Electrical Machines and Power Electronics, ACEMP 2017. United States: Institute of Electrical and Electronics Engineers Inc., 2017. 428-433. Abstract

Hardware-in-The-loop (HiL) systems nowadays become popular. During the HiL creation process it is important to select a proper numerical method because the accuracy of the process simulation, in case of the HiL, depends on the correct numerical approach selection. That is why it is important to evaluate the most popular numerical approaches. The {"}Sequential{"} Euler (solves equations step-by-step), the Forward Euler (the most popular method for HiL creators), and the Second-order Adams-Bashforth approach are under consideration. A mathematical model based on the DC-motor with independent excitation is selected as a basis for the experimental numerical calculation. In consequence, recommendations for the numerical method selection are given, based on the obtained results.

Ferreira, Sofia, Stanimir Valtchev, Fernando Coito, and Mikhail Mudrov. "Mechanical vibration using piezoelectric material." Proceedings - 2017 International Conference on Optimization of Electrical and Electronic Equipment, OPTIM 2017 and 2017 Intl Aegean Conference on Electrical Machines and Power Electronics, ACEMP 2017. United States: Institute of Electrical and Electronics Engineers Inc., 2017. 681-686. Abstract

Piezoelectric energy harvesting has received great attention over the last 20 years. The main goal of this work is to discuss the potential advantages of introducing non-linearities in the dynamics of a beam type piezoelectric vibration energy harvester. The described device is essentially a cantilever beam partially covered by piezoelectric material with a force electromagnetically applied to the beam. Through experimental tests it has been confirmed the benefits of introducing non-linearities in these types of systems.

Tschopp, {Emanuel David}, {Friedrich A. } Tschopp, and Octávio Mateus. "Overlap Indices: Tools to quantify the amount of anatomical overlap among groups of incomplete terminal taxa in phylogenetic analyses." Acta Zoologica. 99 (2017): 169-176. Abstract

Phylogenetic analyses of morphological data are often characterized by missing data due to incomplete operational taxonomic units, as in fossils. This incomplete knowledge derives from various reasons, including—in the case of fossils—the numerous filters an organism has to pass through during taphonomy, fossilization, weathering and collecting. Whereas several methods have been proposed to address issues raised by the inclusion of incomplete terminal taxa, until recently no tool existed to easily quantify the amount of anatomical overlap within a particular clade. The Overlap Indices provide such values and might prove useful for comparative cladistics. We herein describe these new indices and their applications in detail and provide an example file for their calculation. A case study of diplodocid sauropod dinosaurs shows how the Overlap Indices will help to explore and quantify, which one of a number of conflicting tree topologies is supported by more anatomical traits, which skeletal regions are underrepresented in a particular phylogenetic matrix, and which taxon would improve character state score completeness.

Ramos, N. R., P. Pereira, and J. F. Martins. "Smart-meter in power quality." 2017 International Young Engineers Forum (YEF-ECE). 2017. 42-46. Abstract

In this paper, an innovative approach for monitoring home electric power quality indicators is presented. Using an electric power analysis device (for this work purpose it will be a smart-meter) and a personal computer it is proved that it is possible to monitor and register electric power quality anomalies, such as long interruptions, voltage dips/swells and frequency oscillations. Through an application developed in Java, a user can view real-time electric parameters, check for electric power quality anomalies and assess load diagram of previous days. Experimental results regarding the application performance are also presented with the respective conclusions.

Henriques, Dulce, Fernando F. S. Pinho, Jorge de Brito, Maria João Falcão, Rita Moura, and Vasco Peixoto de Freitas. "Reabilitação urbana em Portugal. Especificidades e fundamentos para um plano estratégico." 4.º CIHEL2017 - 4.º Congresso Internacional da Habitação no Espaço Lusófono. ISBN 978-989-654-363-1. Universidade da Beira Interior, Covilhã 2017.
Joaquim, Ana, Corneliu Cismasiu, Filipe Santos, and Elsa Caetano. "Estimation of the tensile force in the stay-cables of Salgueiro Maia Bridge using ambient vibration tests." ISDAC2017 - International Symposium on the Dynamics and Aerodynamics of Cables. Porto: FEUP, 2017. artigo_isdac_v5_ec.pdf
Campian, C., M. Pop, C. Cismasiu, T. Josza, and A. Popa. "Seismic retrofitting of an existing steel structure." 17th International Multidisciplinary Scientific GeoConference SGEM 2017. Albena; Bulgaria 2017.
Pereira, Rui, Marco Couto, Francisco Ribeiro, Rui Rua, Jácome Cunha, João P. Fernandes, and João Saraiva. "Energy Efficiency across Programming Languages: How Do Energy, Time, and Memory Relate?" 10th ACM SIGPLAN International Conference on Software Language Engineering (SLE’17). Vancouver, Canada: ACM, 2017. paper.pdf
Pacheco, J., J. de Brito, C. Chastre, and L. Evangelista. "Model uncertainty of recycled aggregate concrete beams subjected to bending." HISER International Conference on Advances in Recycling and Management of Construction and Demolition Waste. Delft, The Netherlands 2017. Abstract

This paper investigates whether the model uncertainty of reinforced recycled aggregate concrete (RAC) beams subjected to bending differs from that of reinforced natural aggregate concrete (NAC) beams. An introductory remark concerning the importance of the codification of RAC structural design is made and notions concerning model uncertainties and their role on structural codification are given. Afterwards, the criteria used in the construction of a database of RAC and NAC beams are referred before presenting the key findings of an analysis on the model uncertainty of the cracking, yielding and ultimate moments of beams subjected to four-point bending tests. The analytical moments were calculated following Eurocode 2 provisions. Probabilistic models for model uncertainties are proposed. Negligible differences in the model uncertainty of NAC and RAC beams are reported.