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2013
Bahubalindruni, P.G.a, Tavares Barquinha Duarte De Oliveira Martins Fortunato V. G. a P. "Transparent current mirrors with a-GIZO TFTs: Neural modeling, simulation and fabrication." IEEE/OSA Journal of Display Technology. 9 (2013): 1001-1006. AbstractWebsite

This paper characterizes transparent current mirrors with n-type amorphous gallium-indium-zinc-oxide (a-GIZO) thin-film transistors (TFTs). Two-TFT current mirrors with different mirroring ratios and a cascode topology are considered. A neural model is developed based on the measured data of the TFTs and is implemented in Verilog-A; then it is used to simulate the circuits with Cadence Virtuoso Spectre simulator. The simulation outcomes are validated with the fabricated circuit response. These results show that the neural network can model TFT accurately, as well as the current mirroring ability of the TFTs. © 2005-2012 IEEE.

Schulp, AS, M. J. Polcyn, O. Mateus, and LL Jacobs. "Two rare mosasaurs from the Maastrichtian of Angola and the Netherlands." Geologie en Mijnbouw/Netherlands Journal of Geosciences. 92 (2013): 3-10. Abstract
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Pinheiro, C., K. Sergeant, C. M. Machado, J. Renaut, and C. P. Ricardo. "Two Traditional Maize Inbred Lines of Contrasting Technological Abilities Are Discriminated by the Seed Flour Proteome." Journal of Proteome Research. 12 (2013): 3152-3165. AbstractWebsite
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Pinheiro, C., K. Sergeant, C. M. Machado, J. Renaut, and C. P. Ricardo. "Two Traditional Maize Inbred Lines of Contrasting Technological Abilities Are Discriminated by the Seed Flour Proteome." Journal of Proteome Research. 12 (2013): 3152-3165. AbstractWebsite
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2012
Delgado-Gomes, Vasco, Jose A. Oliveira-Lima, Joao F. Martins, Celson Lima, and Pedro Pereira. "Towards to a Web Service alert software system for standard electrical protective devices." Intelligent Engineering Systems (INES), 2012 IEEE 16th International Conference on. Lisbon, Portugal 2012. 197-201. Abstract

Electrical Protective Devices are key elements in the electrical network. Their purpose is to perform fault detection in electric power systems, by analysing power system voltages and currents. In order to achieve a more centralized control, protective devices can be connected using Web Services through a Service-Oriented Architecture (SOA) approach. This work targets planning and specification of a mapping between Abstract Communication Service Interface (ACSI) Reporting and Device Profile for Web Services (DPWS) Eventing to achieve a better protective electrical devices control, obtaining an event based alert software system, replacing conventional polling-based systems.

Pereira, Pedro, Amin Sallem, Mourad Fakhfakh, Maria H. Fino, and Fernando Coito. "A Technology-Aware Optimization of RF Integrated Inductors." Analog Circuits: Applications, Design and Performance. Ed. Esteban Tlelo-Cuautle. Nova Science Publishers, Inc., 2012. 213-234. Abstract

This Chapter presents the optimal design of radio-frequency integrated spiral inductors. The basic idea is to generate an analytical model to characterize integrated inductors based on the double {\ensuremathπ}-model, and offer to the designer an approach to determine the inductor layout parameters. Particle Swarm Optimization technique is used to generate optimal values of parameters of the developed models. Viability of the proposed models is highlighted via comparison with ASITIC simulation results.

Cismasiu, C., and Amarante F. P. dos Santos. "Towards a semi-active vibration control solution based on superelastic shape memory alloys." 15th WCEE. Lisbon, Portugal 2012. 2012_wcee_0379.pdf
Costa, Eunice, Margaret M. Lloyd, Caroline Chopko, Ana Aguiar-Ricardo, and Paula T. Hammond. "Tuning Smart Microgel Swelling and Responsive Behavior through Strong and Weak Polyelectrolyte Pair Assembly." LangmuirLangmuir. 28.26 (2012): 10082-10090. AbstractWebsite

The layer-by-layer (LbL) assembly of polyelectrolyte pairs on temperature and pH-sensitive cross-linked poly(N-isopropylacrylamide)-co-(methacrylic acid), poly(NIPAAm-co-MAA), microgels enabled a fine-tuning of the gel swelling and responsive behavior according to the mobility of the assembled polyelectrolyte (PE) pair and the composition of the outermost layer. Microbeads with well-defined morphology were initially prepared by synthesis in supercritical carbon dioxide. Upon LbL assembly of polyelectrolytes, interactions between the multilayers and the soft porous microgel led to differences in swelling and thermoresponsive behavior. For the weak PE pairs, namely poly(l-lysine)/poly(l-glutamic acid) and poly(allylamine hydrochloride)/poly(acrylic acid), polycation-terminated microgels were less swollen and more thermoresponsive than native microgel, whereas polyanion-terminated microgels were more swollen and not significantly responsive to temperature, in a quasi-reversible process with consecutive PE assembly. For the strong PE pair, poly(diallyldimethylammonium chloride)/poly(sodium styrene sulfonate), the differences among polycation and polyanion-terminated microgels are not sustained after the first PE bilayer due to extensive ionic cross-linking between the polyelectrolytes. The tendencies across the explored systems became less noteworthy in solutions with larger ionic strength due to overall charge shielding of the polyelectrolytes and microgel. ATR FT-IR studies correlated the swelling and responsive behavior after LbL assembly on the microgels with the extent of H-bonding and alternating charge distribution within the gel. Thus, the proposed LbL strategy may be a simple and flexible way to engineer smart microgels in terms of size, surface chemistry, overall charge and permeability.The layer-by-layer (LbL) assembly of polyelectrolyte pairs on temperature and pH-sensitive cross-linked poly(N-isopropylacrylamide)-co-(methacrylic acid), poly(NIPAAm-co-MAA), microgels enabled a fine-tuning of the gel swelling and responsive behavior according to the mobility of the assembled polyelectrolyte (PE) pair and the composition of the outermost layer. Microbeads with well-defined morphology were initially prepared by synthesis in supercritical carbon dioxide. Upon LbL assembly of polyelectrolytes, interactions between the multilayers and the soft porous microgel led to differences in swelling and thermoresponsive behavior. For the weak PE pairs, namely poly(l-lysine)/poly(l-glutamic acid) and poly(allylamine hydrochloride)/poly(acrylic acid), polycation-terminated microgels were less swollen and more thermoresponsive than native microgel, whereas polyanion-terminated microgels were more swollen and not significantly responsive to temperature, in a quasi-reversible process with consecutive PE assembly. For the strong PE pair, poly(diallyldimethylammonium chloride)/poly(sodium styrene sulfonate), the differences among polycation and polyanion-terminated microgels are not sustained after the first PE bilayer due to extensive ionic cross-linking between the polyelectrolytes. The tendencies across the explored systems became less noteworthy in solutions with larger ionic strength due to overall charge shielding of the polyelectrolytes and microgel. ATR FT-IR studies correlated the swelling and responsive behavior after LbL assembly on the microgels with the extent of H-bonding and alternating charge distribution within the gel. Thus, the proposed LbL strategy may be a simple and flexible way to engineer smart microgels in terms of size, surface chemistry, overall charge and permeability.

Saramago, João, Diogo Mourão, and Hervé Paulino. "Towards an Adaptable Middleware for Parallel Computing in Heterogeneous Environments." 2012 IEEE International Conference on Cluster Computing Workshops, CLUSTER Workshops 2012, Beijing, China, September 24-28, 2012. IEEE, 2012. 143-151. Abstract
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Pinto, R. M., A. A. Dias, M. Coreano, M. de Simone, B. M. Giuliano, J. P. Santos, and M. L. Costa. "Tautomerism in 5-aminotetrazole investigated by core-level photoelectron spectroscopy and ΔSCF calculations." J. Electron. Spectrosc. Related Phenomena. 185 (2012): 13-17. AbstractWebsite

The C 1s and N 1s photoelectron spectra of gas-phase 5-aminotetrazole (5ATZ) were recorded using synchrotron radiation, with the aim of evaluating 1H/2H tautomer population ratios. The core-electron binding energies (CEBEs) were estimated from computational results, using the delta self-consistent-field (ΔSCF) approach. Simulated spectra were generated using these CEBEs and the results from Gaussian-n (Gn, n=1, 2 and 3) and Complete Basis Set (CBS-4M and CBS-Q) methods. Results reveal the almost exclusive predominance of the 2H-tautomer, with a 1H/2H ratio of ca. 0.12/0.88, taken from a gross analysis of the XPS C 1s spectrum, recorded at 365 K.

Huang, J., Vicente M. da Silva, and K. Krabbenhoft. "Three-dimensional granular contact dynamics with rolling resistance." Computers and Geotechnics (2012): In Press.
João, Costa, Ortigueira Manuel, Batista Arnaldo, and Paiva Teresa. "Threshold choice for automatic spindle detection." IWSSIP 2012: 19th International Conference on Systems, Signals and Image Processing. 2012.
Martins, R. M. S., R. Araújo, O. Mateus, R. Castanhinha, P. K. Pranzas, and F. Beckmann. "Tomography applied to the study of dinosaur fossils from the collection of the museum of Lourinhã (Portugal)." I Congresso Internacional GeoCiencias na CPL. Coimbra: Univ. Coimbra, 2012. martins_et_al_2012_abstract.pdf
Cunha, Jácome, João P. Fernandes, Hugo Ribeiro, and João Saraiva. "Towards a Catalog of Spreadsheet Smells." Proceedings of the 12th International Conference on Computational Science and Its Applications - Volume Part IV. ICCSA'12. Berlin, Heidelberg: Springer-Verlag, 2012. 202-216. Abstracticcsa-sq12.pdf

Spreadsheets are considered to be the most widely used programming language in the world, and reports have shown that 90% of real-world spreadsheets contain errors. In this work, we try to identify spreadsheet smells, a concept adapted from software, which consists of a surface indication that usually corresponds to a deeper problem. Our smells have been integrated in a tool, and were computed for a large spreadsheet repository. Finally, the analysis of the results we obtained led to the refinement of our initial catalog.

Cunha, Jácome, João Paulo Fernandes, Jorge Mendes, and João Saraiva. "Towards an Evaluation of Bidirectional Model-driven Spreadsheets." User evaluation for Software Engineering Researchers. USER' 12. ACM Digital Library, 2012. 25-28. Abstractuser12.pdf

Spreadsheets are widely recognized as popular programming systems with a huge number of spreadsheets being created every day. Also, spreadsheets are often used in the decision processes of profit-oriented companies. While this illustrates their practical importance, studies have shown that up to 90% of real-world spreadsheets contain errors. In order to improve the productivity of spreadsheet end-users, the software engineering community has proposed to employ model-driven approaches to spreadsheet development. In this paper we describe the evaluation of a bidirectional model-driven spreadsheet environment. In this environment, models and data instances are kept in conformity, even after an update on any of these artifacts. We describe the issues of an empirical study we plan to conduct, based on our previous experience with end-user studies. Our goal is to assess if this model-driven spreadsheet development framework does in fact contribute to improve the productivity of spreadsheet users.

Amado, M. P., and F. Poggi. "Towards Solar Urban Planning: a new step for better energy performance." Energy Procedia .30 (2012): 1261-1273.towards_solar_urban_planning.pdf
del Victoria, Mar Cólas M. ª, Arnaud Mazars, and Rui Micaelo TRACC Project: Road techniques adapted to climate change. 5th Congress Eurasphalt & Eurobitume 2012. Istanbul, Turkey, 2012.
Baquinha, Pedro, Rodrigo Martins, Luis Pereira, and Elvira Fortunato Transparent Oxide Electronics. Wiley, 2012.
Correia, Isabel, Teresa Melo, and Francisco Saldanha-da-Gama. "A two-echelon facility location problem with layout selection." Mathematics and Computers in Science and Engineering 3. 2012. Abstract

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Baptista, Susana, Maria Isabel Gomes, and Ana Paula Barbosa-povoa. "A Two-Stage Stochastic Model for the Design and Planning of a Multi-Product Closed Loop Supply Chains." 22nd European Symposium on Computer Aided Process Engineering. Eds. Ian David Lockhart Bogle, and Michael Fairweather. Vol. 30. Computer Aided Chemical Engineering, 30. London: Elsevier, 2012. 412-416. Abstractpreprint_baptistagomesbarbosa-povoa2012_escape22.pdf

In this paper we address the problem of uncertainty in the design and planning of a multi-period, multi-product closed loop supply chain, where the recovered products are end-of-life products that are disassembled and recycled. Uncertainty is explicitly modelled by considering customers’ demands and returns to be stochastic. A two–stage model is developed where first stage decisions concern the facility location while second stage decisions are the production planning of the supply chain. The integer L- shaped method was adopted as the solution tool and computational tests were performed on multi-period and multi-commodity networks randomly generated based on a reference case. A comparison between the proposed solution method and the straight use of the CPLEX is performed.

Pinto, R. M., A. A. Dias, M. Coreno, M. de Simone, B. M. Giuliano, J. P. Santos, and M. L. Costa. "Tautomerism in 5-aminotetrazole investigated by core-level photoelectron spectroscopy and ΔSCF calculations." Journal of Electron Spectroscopy and Related Phenomena. 185 (2012): 13-17. AbstractWebsite

The C 1s and N 1s photoelectron spectra of gas-phase 5-aminotetrazole (5ATZ) were recorded using synchrotron radiation, with the aim of evaluating 1H/2H tautomer population ratios. The core-electron binding energies (CEBEs) were estimated from computational results, using the delta self-consistent-field (ΔSCF) approach. Simulated spectra were generated using these CEBEs and the results from Gaussian-n (Gn, n=1, 2 and 3) and Complete Basis Set (CBS-4M and CBS-Q) methods. Results reveal the almost exclusive predominance of the 2H-tautomer, with a 1H/2H ratio of ca. 0.12/0.88, taken from a gross analysis of the XPS C 1s spectrum, recorded at 365 K.

Cardoso, Alberto, and P. Gil. "Teaching and Online Learning Activities in Engineering Courses using Wireless Sensor and Actuator Networks." ICL/IGIP2012 - International Conference on Engineering Pedagogy. n/a 2012. Abstract
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Pereira, P., A. Sallem, M. Fakhfakh, M. H. Fino, and F. Coito. "A Technology-Aware Optimization of RF Integrated Inductors." (2012). Abstract
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de Calheiros Velozo, A., G. Lavareda, C. Nunes de Carvalho, and A. Amaral. "Thermal dehydrogenation of amorphous silicon deposited on c-Si: Effect of the substrate temperature during deposition." PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 9, NO 10-11. Eds. S. Pizzini, G. Kissinger, H. YamadaKaneta, and J. Kang. Vol. 9. Physica Status Solidi C-Current Topics in Solid State Physics, 9. European Mat Res Soc (E-MRS), 2012. 2198-2202. Abstract

Samples of doped and undoped a-Si: H were deposited at temperatures ranging from 100 degrees C to 350 degrees C and then submitted to different dehydrogenation temperatures (from 350 degrees C to 550 degrees C) and times (from 1 h to 4 h). a-Si: H films were characterised after deposition through the measurements of specific material parameters such as: the optical gap, the conductivity at 25 degrees C, the thermal activation energy of conductivity and its hydrogen content. Hydrogen content was measured after each thermal treatment. Substrate dopant contamination from phosphorus-doped a-Si thin films was evaluated by SIMS after complete dehydrogenation and a junction depth of 0.1 mu m was obtained. Dehydrogenation results show a strong dependence of the hydrogen content of the as-deposited film on the deposition temperature. Nevertheless, the dehydrogenation temperature seems to determine the final H content in a way almost independent from the initial content in the sample. H richer films dehydrogenate faster than films with lower hydrogen concentration. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

de Calheiros Velozo, A., G. Lavareda, C. Nunes de Carvalho, and A. Amaral. "Thermal dehydrogenation of amorphous silicon deposited on c-Si: Effect of the substrate temperature during deposition." PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 9, NO 10-11. Eds. S. Pizzini, G. Kissinger, H. YamadaKaneta, and J. Kang. Vol. 9. Physica Status Solidi C-Current Topics in Solid State Physics, 9. European Mat Res Soc (E-MRS), 2012. 2198-2202. Abstract

Samples of doped and undoped a-Si: H were deposited at temperatures ranging from 100 degrees C to 350 degrees C and then submitted to different dehydrogenation temperatures (from 350 degrees C to 550 degrees C) and times (from 1 h to 4 h). a-Si: H films were characterised after deposition through the measurements of specific material parameters such as: the optical gap, the conductivity at 25 degrees C, the thermal activation energy of conductivity and its hydrogen content. Hydrogen content was measured after each thermal treatment. Substrate dopant contamination from phosphorus-doped a-Si thin films was evaluated by SIMS after complete dehydrogenation and a junction depth of 0.1 mu m was obtained. Dehydrogenation results show a strong dependence of the hydrogen content of the as-deposited film on the deposition temperature. Nevertheless, the dehydrogenation temperature seems to determine the final H content in a way almost independent from the initial content in the sample. H richer films dehydrogenate faster than films with lower hydrogen concentration. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim