Export 3109 results:
Sort by: Author Title Type [ Year  (Desc)]
2011
Palma, L. B., F. V. Coito, and P. S. Gil. "Real-time detection of oscillations in control loops." Power Engineering, Energy and Electrical Drives (POWERENG), 2011 International Conference on. IEEE, 2011. 1-6. Abstract
n/a
Palma, L., F. Coito, and P. Gil. "Real-Time Detection of Oscillations in Control Loops." IEEE International Conference on Power Engineering, Energy and Electrical Drives. n/a 2011. Abstract
n/a
Pereira, Vasco, Jorge Sá Silva, Alberto Cardoso, P. Gil, P. Furtado, R. M. Silva, J. Cecílio, A. Santos, A. Gomes, Edmundo Monteiro, J. d O, and R. Eiras. "Redes de Sensores sem Fios com Desempenho Controlado – Projecto FP7 GINSENG." Ingenium (Revista da Ordem dos Engenheiros) (2011): n/a. Abstract
n/a
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
n/a
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
n/a
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
n/a
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.

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
n/a
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
n/a
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
n/a
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
n/a
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.

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
n/a
Guimarães, D., M. L. Carvalho, V. Geraldes, I. Rocha, and J. P. Santos. "Study of lead accumulation in bones of Wistar rats by X-ray fluorescence analysis: aging effect." Metallomics. In Press (2011): DOI: 10.1039/c1mt00149c. AbstractWebsite

The accumulation of lead in several bones of Wistar rats with time was determined and comparedQ3 for the different types of bones. Two groups were studied: a control group (n = 20), not exposedto lead and a contaminated group (n = 30), exposed to lead from birth, first indirectly throughmother’s milk, and then directly through a diet containing lead acetate in drinking water (0.2%).Rats age ranged from 1 to 11 months, with approximately 1 month intervals and each of thecollections had 3 contaminated rats and 2 control rats. Iliac, femur, tibia–fibula and skull havebeen analysed by energy dispersive X-ray fluorescence technique (EDXRF). Samples offormaldehyde used to preserve the bone tissues were also analysed by Electrothermal AtomicAbsorption (ETAAS), showing that there was no significant loss of lead from the tissue to thepreservative. The bones mean lead concentration of exposed rats range from 100 to 300 mg g 1while control rats never exceeded 10 mg g 1. Mean bone lead concentrations were compared andthe concentrations were higher in iliac, femur and tibia–fibula and after that skull. However, ofall the concentrations in the different collections, only those in the skull were statisticallyQ4 significantly different (p o 0.05) from the other types of bones. Analysis of a radar chart alsoallowed us to say that these differences tend to diminish with age. The Spearman correlation testapplied to mean lead concentrations showed strong and very strong positive correlations betweenall different types of bones. This test also showed that mean lead concentrations in bones arenegatively correlated with the age of the animals. This correlation is strong in iliac and femur andvery strong in tibia–fibula and skull. It was also shown that the decrease of lead accumulationwith age is made by three plateaus of accumulation,

Costa, F., F. Coito, and L. Palma. "Switched Unfalsified Multicontroller." Technological Innovation for Sustainability (2011): 393-401. Abstract
n/a
Barbosa, Paulo E. S., João Paulo Barros, Franklin Ramalho, Lu{\'ı}s Gomes, Jorge Figueiredo, Filipe Moutinho, Anikó Costa, and André Aranha. "SysVeritas: {A} Framework for Verifying {IOPT} Nets and Execution Semantics within Embedded Systems Design." Technological Innovation for Sustainability - Second {IFIP} {WG} 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2011, Costa de Caparica, Portugal, February 21-23, 2011. Proceedings. 2011. 256-265. Abstract
n/a
Pinto, R. M., A. A. Dias, M. Coreno, M. de Simone, B. M. Giuliano, J. P. Santos, and M. L. Costa. "Tautomerism in 5-methyltetrazole investigated by core-level photoelectron spectroscopy and ΔSCF calculations." Chemical Physics Letters. 516 (2011): 149-153. AbstractWebsite

The relative populations of the 1H- and 2H-tautomer of gas-phase 5-methyltetrazole (5MTZ) have been assessed through core-level photoelectron spectroscopy, and compared with the results obtained from Gaussian-n (Gn, n = 1, 2 and 3) and Complete Basis Set methods (CBS-4M and CBS-Q). The C 1s and N 1s core‚Äìelectron binding energies (CEBEs) for each ionization site of both tautomers have been computed using the Œîself-consistent-field (ŒîSCF) approach. The C 1s and N 1s XPS spectra, obtained at 313 K, yield a 1H/2H tautomer ratio of ca. 0.16/0.84 and 0.21/0.79, respectively.

Pinto, R. M., A. A. Dias, M. Coreno, M. de Simone, B. M. Giuliano, J. P. Santos, and M. L. Costa. "Tautomerism in 5-methyltetrazole investigated by core-level photoelectron spectroscopy and ΔSCF calculations." Chemical Physics Letters. 516 (2011): 149-153. AbstractWebsite

The relative populations of the 1H- and 2H-tautomer of gas-phase 5-methyltetrazole (5MTZ) have been assessed through core-level photoelectron spectroscopy, and compared with the results obtained from Gaussian-n (Gn, n = 1, 2 and 3) and Complete Basis Set methods (CBS-4M and CBS-Q). The C 1s and N 1s core‚Äìelectron binding energies (CEBEs) for each ionization site of both tautomers have been computed using the Œîself-consistent-field (ŒîSCF) approach. The C 1s and N 1s XPS spectra, obtained at 313 K, yield a 1H/2H tautomer ratio of ca. 0.16/0.84 and 0.21/0.79, respectively.

Palma, L. B., and F. V. Coito. "Tuning PCA controllers based on manual control data." Emerging Technologies & Factory Automation (ETFA), 2011 IEEE 16th Conference on. IEEE, 2011. 1-4. Abstract
n/a
Guimarães, D., J. P. Santos, M. L. Carvalho, G. Vale, H. M. Santos, V. Geraldes, I. Rocha, and J. L. Capelo. "Ultrasonic energy as a tool to overcome some drawbacks in the determination of lead in brain tissue and urine of rats." Talanta. 86 (2011): 442-446 . AbstractWebsite

An ultrasonic assisted solid‚Äìliquid extraction method was developed to determine the level of lead in the brain and urine of rats. Lead was determined by electrothermal atomic absorption spectrometry with longitudinal-Zeeman background correction. Several analytical drawbacks were addressed and overcome, namely small brain sample mass and the formation of precipitate in the urine samples. Utrasonication provided by an ultrasonic probe succeeded in extracting lead from brain samples. Furthermore, it was demonstrated that the formation of a precipitate lowered the lead content in the liquid phase of the urine. Lead was back extracted from the precipitate to the liquid phase with the aid of ultrasonic energy and acidifying the urine with 10% v/v nitric acid. A microwave-assisted acid digestion protocol was used to check the completeness of the lead extraction. The within bath and between bath precision was 5% (n = 9) and 7% (n = 3) respectively. The limit of quantification was 1.05 Œºg g‚àí1 for brain samples and 2.1 Œºg L‚àí1 for urine samples. A total of 6 samples of urine and 12 samples of brain from control rats and another 6 samples of urine and 12 samples of brain from rats fed with tap water rich in lead acetate were used in this research. Lead levels in brain and urine from exposed rats ranged from1.9 ¬± 0.2 Œºg g‚àí1 to 3.5 ¬± 0.2 Œºg g‚àí1 and from 752 ¬± 56 Œºg L‚àí1 to 60.9 ¬± 1.2 mg L‚àí1 respectively. Statistically significant differences of levels of lead in brain and urine were found between exposed and non exposed rats.

Guimarães, D., J. P. Santos, M. L. Carvalho, G. Vale, H. M. Santos, V. Geraldes, I. Rocha, and J. L. Capelo. "Ultrasonic energy as a tool to overcome some drawbacks in the determination of lead in brain tissue and urine of rats." Talanta. 86 (2011): 442-446. AbstractWebsite

An ultrasonic assisted solid‚Äìliquid extraction method was developed to determine the level of lead in the brain and urine of rats. Lead was determined by electrothermal atomic absorption spectrometry with longitudinal-Zeeman background correction. Several analytical drawbacks were addressed and overcome, namely small brain sample mass and the formation of precipitate in the urine samples. Utrasonication provided by an ultrasonic probe succeeded in extracting lead from brain samples. Furthermore, it was demonstrated that the formation of a precipitate lowered the lead content in the liquid phase of the urine. Lead was back extracted from the precipitate to the liquid phase with the aid of ultrasonic energy and acidifying the urine with 10% v/v nitric acid. A microwave-assisted acid digestion protocol was used to check the completeness of the lead extraction. The within bath and between bath precision was 5% (n = 9) and 7% (n = 3) respectively. The limit of quantification was 1.05 Œºg g‚àí1 for brain samples and 2.1 Œºg L‚àí1 for urine samples. A total of 6 samples of urine and 12 samples of brain from control rats and another 6 samples of urine and 12 samples of brain from rats fed with tap water rich in lead acetate were used in this research. Lead levels in brain and urine from exposed rats ranged from1.9 ¬± 0.2 Œºg g‚àí1 to 3.5 ¬± 0.2 Œºg g‚àí1 and from 752 ¬± 56 Œºg L‚àí1 to 60.9 ¬± 1.2 mg L‚àí1 respectively. Statistically significant differences of levels of lead in brain and urine were found between exposed and non exposed rats.

Carreira, R. J., M. S. Diniz, and J. L. Capelo. "Ultrasonic-based protein quantitation by18O-labeling: Optimization and comparison between different procedures." Rapid Communications in Mass Spectrometry. 25 (2011): 75-87. AbstractWebsite
n/a
Coito, F., and L. B. Palma. "Unfalsification based Fault Tolerant Controller." Emerging Technologies & Factory Automation (ETFA), 2011 IEEE 16th Conference on. IEEE, 2011. 1-4. Abstract
n/a