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Characterization and electrochemical behaviour of nanostructured calcium samari...
Barrocas, B.; Sério, S.; Rovisco, A.; Nunes, Y.; Sá, A. I. Correia de; Pereira, M. I. da Silva; Jorge, M. E. MeloCa1-xSmxMnO3(0 . x . 0.4) films were successfully fabricated on Indium Tin Oxide (ITO) coated quartzglass substrates by radio frequency magnetron sputtering technique (RF- magnetron sputtering) fromcompacted nanosized powder targets, and subsequent annealing at 800.C in air, for 6 h. X-ray diffrac-tion shows a pure typical perovskite phase for x . 0.1. Scanning electron microscopy and atomic forcemicroscopy r...
Dielectric properties of Al-Nb amorphous mixed oxides
Di Franco, F.; Santamaria, M.; Di Quarto, F.; La Mantia, F.; Sá, A. I. Correia de; Rangel, C. M.An impedance study of amorphous thin oxide films grown on sputtered Al-Nb alloys is presented. The characterization of the electronic properties of mixed amorphous oxide on the basis of the theory of amorphous semiconductor Schottky barrier has been carried out for anodic film on Al-92at.%Nb in a very detailed manner. The semiconductor to insulator transition of formed oxides as a function of the alloy composit...
Electrocatalitic activity of platinum deposited on carbon functionalized with s...
Capelo, Anabela; Esteves, M. Alexandra; Sá, A. I. Correia de; Rangel, C. M.Results are presented for Pt deposited on 4-aminobenzenesulphonic acid-functionalized carbon, Pt/C_ABSA. Vulcan XC-72R was functionalized in order to influence catalyst dispersion and decrease the resistance of three phase boundary, by introducing sulphonic groups and lessening the amount of Nafion® added to the catalyst layers. Electrochemical characterization of the supported catalyst was done in a 0.5 M H2SO...
Gold deposition from 1-butyl-1-methyl-pyrrolidinium dicyanamide ionic liquid at...
Sá, A. I. Correia de; Eugénio, S.; Quaresma, S.; Rangel, C. M.; Vilar, R.In this work, the deposition of gold on copper substrates from solutions of HAuCl4.3H2O in 1-butyl-1-methylpyrrolidinium dicyanamide was studied. Deposition was carried out in open-circuit and under potentiostatic control at temperatures from 293 to 353 K, in normal atmosphere, with deposition conditions allowing water from atmospheric absorption up to 0.8 wt.%. Films of gold were obtained by both methods. Dep...
Electrochemical behaviour of ionic liquid functionalized carbon supported Pt-Ru...
Esteves, M. Alexandra; Sá, A. I. Correia de; Rangel, C. M.Ionic liquid (IL) functionalized carbon supported nanocatalysts, including platinum-ruthenium catalysts, have been under investigation to achieve better catalytic performance on polymer electrolyte membrane fuel cells. Ionic liquids have particular physical properties, which usually improve the stabillity and dispersion of metal nanosized particles, providing an increase of the electrochemical active surface ar...
Enhancing Pt electrocatalytic activity by surface functionalization of carbon s...
Capelo, Anabela; Esteves, M. Alexandra; Sá, A. I. Correia de; Rangel, C. M.Preliminary results are presented for Pt deposited on 4-aminobenzenesulphonic acid-functionalized carbon, Pt/C_ABSA. Vulcan XC-72R was functionalized with the objective of influencing the dispersion of catalyst nanoparticles and to decrease the resistance of three phase boundaries, by introducing sulphonic groups. Electrochemical characterization of the supported catalyst was done in a 0.5 M sulphuric acid solu...
Parotidite recorrente juvenil… nem sempre é o que parece
Sá, A.; Fraga, J.; Costa, A.M.; Dias, F.; Brito, I.RESUMO Introdução: A parotidite recorrente juvenil (PRJ) é uma inflamação recidivante idiopática da glândula parótida, geralmente associada a sialectasia não-obstrutiva. A síndrome de Sjögren (SS), rara em idade pediátrica, pode apresentar-se nesta faixa etária sob a forma de parotidites de repetição. Caso clínico: Menina, de 13 anos, que no quarto episódio de tumefação e dor parotídea, iniciou investigação eti...
Materiais e sistemas de construção sustentáveis
Paiva, A.; Pinto, J.; Boaventura-Cunha, J.; Lanzinha, J.; Pereira, S.; Briga-Sá, A.; Varum, H.Atualmente, tem-se verificado um interesse crescente em adotar comportamentos mais sustentáveis, nomeadamente relacionados com a redução dos consumos energéticos e das emissões de gases de efeito de estufa. A preocupação com o uso dos recursos ainda disponíveis no planeta tem sido um aspeto primordial contemplado nas agendas políticas da generalidade dos países. A indústria da construção civil está atenta a est...
Caso electroencefalográfico: epilepsia de ausências da infância
Sá, A.; Chorão, R.ABSTRACT Introduction: Typical absence seizures are quite common in chidhood, in most cases fitting the criteria for childhood absence epilepsy. Differential diagnosis is mainly with inattention and focal hypomotor seizures. Response to adequate antiepileptic drug therapy is usually very good. Case report: We report a classical case of a school-age girl with many episodes per day of staring and eye rolling with...
Miosite orbitária numa criança
Fraga, J.; Sá, A.; Cândido, C.; Pinto, J.; Dias, F.Introdução: A doença inflamatória orbitária caracteriza-se por um processo inflamatório, de etiologia desconhecida, que pode atingir qualquer estrutura da órbita. Apresentamos um caso clínico da forma que envolve os músculos extraoculares (miosite orbitária). Caso clínico: Criança do sexo masculino com nove anos de idade, sem antecedentes patológicos de relevo, que iniciou subitamente dor ocular à direita, acom...
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