Titanium dioxide was synthesized on glass substrates from titanium (IV)isopropoxide and hydrochloride acid aqueous solutions through microwave irradiation using as seed layer either fluorine-doped crystalline tin oxide (SnO2:F) or amorphous tin oxide (a-SnOx). Three routes have been followed with distinct outcome: (i) equimolar hydrochloride acid/water proportions (1HCl:1water) resulted in nanorod arrays for both seed layers; (ii) higher water proportion (1HCl:3water) originated denser films with growth yield dependent on the seed layer employed; while (iii) higher acid proportion (3HCl:1water) hindered the formation of TiO2. X-ray diffraction (XRD) showed that the materials crystallized with the rutile structure, possibly with minute fractions of brookite and/or anatase. XRD peak inversions observed for the materials synthesized on crystalline seeds pointed to preferred crystallographic orientation. Electron diffraction showed that the especially strong XRD peak inversions observed for TiO2 grown from the 1HCl:3water solution on SnO2:F originated from a [001] fiber texture. Transmittance spectrophotometry showed that the materials with finer structure exhibited significantly higher optical band gaps. Photocatalytic activity was assessed from methylene blue degradation, with the 1HCl:3water SnO2:F material showing remarkable degradability performance, attributed to a higher exposure of (001) facets, together with stability and reusability. © 2015 Elsevier B.V.

Robótica virtual ou robótica tangível, qual a ferramenta mais apelativa para os professores e alunos? Fomos à procura da resposta junto de cinco alunos que participaram em atividades com estas duas ferramentas. As atividades foram desenvolvidas no

Large-area electronics for applications in environments with radioactive contamination or medical X-ray detectors require materials and devices resistant to continuous ionizing radiation exposure. Here the superior X-ray radiation hardness of oxide thin film transistors (TFTs) based on gallium-indium-zinc oxide is demonstrated, when compared to organic ones. In the experiments both TFTs are subjected to X-ray radiation and their performances are monitored as a function of total ionizing dose. Flexible oxide TFTs maintain a constant mobility of 10 cm2 V−1 s−1 even after exposure to doses of 410 krad(SiO2), whereas organic TFTs lose 55% of their transport performance. The exceptional resistance of oxide semiconductors ionization damage is attributed to their intrinsic properties such as independence of transport on long-range order and large heat of formation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Presentamos en este trabajo un estudio realizado en dos escuelas públicas, una en Brasil y otra en Portugal, sobre el potencial integrador de la robótica virtual y tangible. El enfoque metodológico se mezcló y se basó en dos talleres de capacitación de profesores sobre el potencial integrador de estas dos herramientas. Los participantes fueron cuatro profesores y cuatro estudiantes con necesidades educativas especiales. Se aplicó un cuestionario a los estudiantes y profesores que participaron en los talleres de formación y se procedió a la descripción de las actividades. Los resultados indicaron que las dos herramientas obtuvieron evaluaciones similares, que tienen potencial educativo e integrador, ya que permiten suavizar las diferencias y promover la cooperación y el aprendizaje de modo activo y significativo, a través de actividades lúdicas y divertidas para los estudiantes.