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2011
Filanovsky, I. M., and L. B. Oliveira. "Regenerative current amplifier using van der Pol approximation." Circuits and Systems (MWSCAS), 2011 IEEE 54th International Midwest Symposium on. IEEE, 2011. 1-4. Abstract
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Santos, J., A. Costa, C. Madruga, F. Parente, and P. Indelicato. "Relativistic transition wavelenghts and probabilities for spectral lines of Ne II." The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics. 63 (2011): 89-96. AbstractWebsite

Transition wavelengths and probabilities for several 2 p 4 3 p -2 p 4 3 s and 2 p 4 3 d -2 p 4 3 p lines in fluorine-like neon ion (NeII) have been calculated within the multiconfiguration Dirac-Fock (MCDF) method with quantum electrodynamics (QED) corrections. The results are compared with all existing experimental and theoretical data.

Santos, J. P., A. Costa, C. Madruga, F. Parente, and P. Indelicato. "Relativistic transition wavelenghts and probabilities for spectral lines of Ne II." The European Physical Journal D. 63 (2011): 89-96. AbstractWebsite

Transition wavelengths and probabilities for several 2 p 4 3 p -2 p 4 3 s and 2 p 4 3 d -2 p 4 3 p lines in fluorine-like neon ion (NeII) have been calculated within the multiconfiguration Dirac-Fock (MCDF) method with quantum electrodynamics (QED) corrections. The results are compared with all existing experimental and theoretical data.

Cardoso, Alberto, M. & S. Vieira, P. Catré, and P. Gil. "Remote and Virtual Control Lab at DEI-FCTUC: Systems and Control Experiments for Engineering Courses." 1st World Engineering Flash Week. n/a 2011. Abstract
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Cardoso, Alberto, M. & S. Vieira, and P. Gil. "A Remote and Virtual Lab with Experiments for Secondary Education, Engineering and Lifelong Learning Courses." exp.at'11 - 1st Experiment@ International Conference. n/a 2011. Abstract
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Pereira, P., M. Helena Fino, F. Coito, and M. Ventim-Neves. "RF integrated inductor modeling and its application to optimization-based design." Analog Integrated Circuits and Signal Processing (2011): 1-9. Abstract
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c Chitanu, E.a, Barros Ionita Martins Fortunato R. b G. d. "RF magnetron sputtering deposition of AZO thin films." Metalurgia International. 16 (2011): 32-34. AbstractWebsite

Doped zinc oxide with aluminium are attractive alternative material as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO) for diffrent applications: solar cells, tft. Transparent aluminumdoped zinc oxide (AZO) thin films were deposited on glass substrates by RF magnetron sputtering at room temperature and 100W from ceramic target ZnO-Al2O3 (98:2 weight percent). The structural, electrical and optical properties of these films were characterized as a function of deposition pressure. AZO films with low resistivity 2.02×10-3 Ωcm and high transmittance (over 80% in vizible range) were thus prepared with a deposition pressure of 3 mTorr.

c Olziersky, A.a, Barquinha Vilà Magana Fortunato Morante Martins P. b A. a. "Role of Ga 2O 3-In 2O 3-ZnO channel composition on the electrical performance of thin-film transistors." Materials Chemistry and Physics. 131 (2011): 512-518. AbstractWebsite

In this work we present a study aiming to determine the role of Ga2O3-In2O3-ZnO (GIZO) channel layer composition on the electrical performance and stability exhibited by thin-film transistors (TFTs). The GIZO films were obtained by magnetron sputtering using ceramic targets of different compositions (Ga:In:Zn = 2:2:1, 2:2:2, 2:4:1 and 2:4:2 at.). Structural analysis corroborates the fully amorphous character of the GIZO deposited layers. For the target compositional range used we observe a Zn deficiency on the produced films, which affects the In/Ga atomic concentration ratios. Resistivity and mobility are found to show a general trend against the measured In/Ga ratio that reveals the role played by In and Ga cations on the transport mechanisms. Targets with increased In concentrations (2:4:1 and 2:4:2) allow to obtain the best TFT performances with field effect mobilities reaching values of 53.0 and 51.7cm2 V-1 s-1, respectively. In addition, the In-richer GIZO compositions result in considerably more stable TFTs, especially under positive gate bias stress conditions. Finally, it is verified that by using a target with a slightly lower In atomic composition (2:4:2 in comparison to 2:4:1), good stability and mobility can be achieved with potentially lower material costs.© 2011 Elsevier B.V. All rights reserved.

Gonçalves, G.a, Grasso Barquinha Pereira Elamurugu Brignone Martins Lambertini Fortunato V. b P. a. "Role of room temperature sputtered high conductive and high transparent indium zinc oxide film contacts on the performance of orange, green, and blue organic light emitting diodes." Plasma Processes and Polymers. 8 (2011): 340-345. AbstractWebsite

The core of this paper concerns the use of an amorphous transparent conductive oxide (a-TCO), whose performance is on par with the classical indium tin oxide (ITO) films as a transparent contact in organic light emitting diodes (OLEDs). The main advantage of indium zinc oxide (IZO) films relies on their amorphous structure and high mobility that turns them likely to be used with high conductivity and high transmittance even at the infrared region. The mobility of IZO films (47.8 cm2 · V-1 · s-1) surpasses the one exhibited by ITO films (26.4 cm2 · V-1 · s-1), which along with its smoother surface and better current distribution plays an important role on OLEDs performance. Besides their similar turn-on voltage, the devices using IZO anodes exhibit higher power efficiency than the ITO ones, which is 66, 18, and 62% for orange, green, and blue OLEDs, respectively. These results suggest that IZO can potentially be applied as an anode in full color displays based on OLEDs. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lai, Livia, Janene Bumstead, Yan Liu, James Garnett, Maria A. Campanero-Rhodes, Damer P. Blake, Angelina S. Palma, Wengang Chai, David J. P. Ferguson, Peter Simpson, Ten Feizi, Fiona M. Tomley, and Stephen Matthews. "The Role of Sialyl Glycan Recognition in Host Tissue Tropism of the Avian Parasite Eimeria tenella." Plos Pathogens. 7 (2011). Abstract
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Orestes Cerdeira, J., R. M. V. Figueiredo, A. Pereira, and C. Requejo. "Scheduling with sequence-dependent batch setup times: Planning tests for a pharmaceutic industry." International Journal of Mathematical Modelling and Numerical Optimisation. 2 (2011): 273-287. Abstract
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Silva, A., D. Cavalheiro, S. Abdollahvand, L. B. Oliveira, M. Figueiredo, and J. Goes. "A self-biased ring oscillator with quadrature outputs operating at 600 MHz in a 130 nm CMOS technology." Mixed Design of Integrated Circuits and Systems (MIXDES), 2011 Proceedings of the 18th International Conference. IEEE, 2011. 221-224. Abstract
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Queirós, Alexandra, Pedro Conde, Vera Cunha, Paula Ambrósio, Filipe J. Marques, and Fátima Serrano. "Sexuality in the third trimester of pregnancy." Revista Portuguesa de Cl{\'ınica Geral. 27 (2011): 434-443. Abstract
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Águas, Hugo, Sanjay K. Ram, Andreia Araújo, Diana Gaspar, António Vicente, Sergej A. Filonovich, Elvira Fortunato, Rodrigo Martins, and Isabel Ferreira. "Silicon thin film solar cells on commercial tiles." Energy & Environmental Science. 4.11 (2011): 4620-4632. Abstract
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Águas, H., Ram Araújo Gaspar Vicente Filonovich Fortunato Martins Ferreira S. K. A. "Silicon thin film solar cells on commercial tiles." Energy and Environmental Science. 4 (2011): 4620-4632. AbstractWebsite

Nanostructured silicon single junction thin film solar cells were deposited on commercial red clay roof tiles with engobe surfaces and earthenware wall tiles with glazed surfaces, with a test area of 24 mm 2. We studied the influence of the type of substrate tile, back contact, buffer layer and SiO x passivation layer on the optoelectronic performance of the solar cells. Despite the fact that typical micrometre-sized defects on the surfaces of the tiles and the porous nature of the ceramic substrates make deposition of homogeneous thin films on them quite challenging, we have been able to achieve a cell efficiency of 5% and a quantum efficiency of 80% on non-fully optimized cells on commercial tiles. The method is industrially employable utilizing pre-existing plasma-enhanced chemical vapour deposition technologies. The cost-effectiveness and industrial feasibility of the technique are discussed. Our study shows that photovoltaic tiles can combine energy generation with architectural aesthetics leading to significant implications for advancement in building integrated photovoltaics. © 2011 The Royal Society of Chemistry.

Águas, Hugo, Sanjay K. Ram, Andreia Araújo, Diana Gaspar, António Vicente, Sergej A. Filonovich, Elvira Fortunato, Rodrigo Martins, and Isabel Ferreira. "Silicon thin film solar cells on commercial tiles." Energy & Environmental Science. 4 (2011): 4620-4632. Abstract
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Ortigueira, E., I. Bastos, L. Oliveira, J. Oliveira, and J. Goes. "A Simplified Design Methodology for MOSFET-Only Wideband Mixer." (2011). Abstract
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Ortigueira, E., I. Bastos, L. B. Oliveira, JP Oliveira, and J. Goes. "A simplified design of a MOSFET-only wideband Gilbert Cell." Mixed Design of Integrated Circuits and Systems (MIXDES), 2011 Proceedings of the 18th International Conference. IEEE, 2011. 225-230. Abstract
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Ferreira, Isabel, Bruno Brás, José Inácio Martins, Nuno Correia, Pedro Barquinha, Elvira Fortunato, and Rodrigo Martins. "Solid-state paper batteries for controlling paper transistors." Electrochimica Acta. 56.3 (2011): 1099-1105. Abstract
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Ferreira, I.a, Brás Martins Correia Barquinha Fortunato Martins B. a J. I. "Solid-state paper batteries for controlling paper transistors." Electrochimica Acta. 56 (2011): 1099-1105. AbstractWebsite

A commercial sheet of paper based on natural cellulose fibers acting as permeable membrane with thin film metal cathode (Cu) and anode (Al) layers in each face was used to produce paper batteries that could be interconnected in series and rechargeable using water as electrolyte. Their electrical characteristics and the set of electrochemical reactions that support the experimental behavior observed are described in this paper. A series of integrated batteries able to supply a voltage of about 3 V and a current ranging from 0.7 μA to 25 μA in cells with sizes of 1.2 cm × 3.0 cm for a relative humidity in the range of 50-65% were produced in a single sheet of paper, and successfully applied to control the ON/OFF gate state of paper transistors. © 2010 Elsevier Ltd. All rights reserved.

Hollander, Yoav, Alan Hu, João Louren{\c c}o, and Ronny Morad. "Special Session on Debugging." Hardware and Software: Verification and Testing. Eds. Sharon Barner, Ian Harris, Daniel Kroening, and Orna Raz. Vol. 6504. Lecture Notes in Computer Science, 6504. Springer Berlin / Heidelberg, 2011. 24-28. Abstract
In software, hardware, and embedded system domains, debugging is the process of locating and correcting faults in a system. Depending on the context, the various characteristics of debugging induce different challenges and solutions. Post-silicon hardware debugging, for example, needs to address issues such as limited visibility and controllability, while debugging software entails other issues, such as the handling of distributed or non-deterministic computation. The challenges that accompany such issues are the focus of many current research efforts. Solutions for debugging range from interactive tools to highly analytic techniques. We have seen great advances in debugging technologies in recent years, but bugs continue to occur, and debugging still encompasses significant portions of the life-cycles of many systems. The session covered state-of-the-art approaches as well as promising new research directions in both the hardware and software domains.
Carvalho, Carlos, Jose Lameiro, Nuno Paulino, and Guilherme Lavareda. "A Step-up mu-Power Converter for Solar Energy Harvesting Applications, using Hill Climbing Maximum Power Point Tracking." 2011 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS). IEEE International Symposium on Circuits and Systems. IEEE, 2011. 1924-1927. Abstract

This paper presents a step-up micro-power converter for solar energy harvesting applications. The circuit uses a SC voltage tripler architecture, controlled by an MPPT circuit based on the Hill Climbing algorithm. This circuit was designed in a 0.13 mu m CMOS technology in order to work with an a-Si PV cell. The circuit has a local power supply voltage, created using a scaled down SC voltage tripler, controlled by the same MPPT circuit, to make the circuit robust to load and illumination variations. The SC circuits use a combination of PMOS and NMOS transistors to reduce the occupied area. A charge re-use scheme is used to compensate the large parasitic capacitors associated to the MOS transistors. The simulation results show that the circuit can deliver a power of 1266 mu W to the load using 1712 mu W of power from the PV cell, corresponding to an efficiency as high as 73.91%. The simulations also show that the circuit is capable of starting up with only 19% of the maximum illumination level.

Watson, A. A., A. A. Lebedev, B. A. Hall, A. E. Fenton-May, A. A. Vagin, W. Dejnirattisai, J. Felce, J. Mongkolsapaya, A. S. Palma, Y. Liu, T. Feizi, G. R. Screaton, G. N. Murshudov, and C. A. O'Callaghan. "Structural flexibility and ligand-binding characteristics of the macrophage dengue virus receptor CLEC5A." Immunology. 135 (2011): 101. Abstract
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Watson, Aleksandra A., Andrey A. Lebedev, Benjamin A. Hall, Angharad E. Fenton-May, Alexei A. Vagin, Wanwisa Dejnirattisai, James Felce, Juthathip Mongkolsapaya, Angelina S. Palma, Yan Liu, Ten Feizi, Gavin R. Screaton, Garib N. Murshudov, and Christopher A. O'Callaghan. "Structural Flexibility of the Macrophage Dengue Virus Receptor CLEC5A IMPLICATIONS FOR LIGAND BINDING AND SIGNALING." Journal of Biological Chemistry. 286 (2011): 24208-24218. Abstract
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Bras, Joana L. A., Alan Cartmell, Ana Lusia M. Carvalho, Genny Verze, Edward A. Bayer, Yael Vazana, Marcia A. S. Correia, Jose A. M. Prates, Supriya Ratnaparkhe, Alisdair B. Boraston, Maria J. Romao, Carlos M. G. A. Fontes, and Harry J. Gilbert. "Structural insights into a unique cellulase fold and mechanism of cellulose hydrolysis (vol 108, pg 5237, 2011)." Proceedings of the National Academy of Sciences of the United States of America. 108 (2011): 8525. Abstract
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