Geomorphological units of mainland Portugal

São representadas cartograficamente as unidades geomorfológicas identificadas para os 89015 km2 do território de Portugal Continental. A delimitação das unidades teve por base a análise dos padrões da textura fornecida por imagens SRTM, com revisão e adaptação posterior à altimetria e à geologia, para os quais foram usadas bases cartográficas digitais. Foram considerados três níveis taxionómicos que permitem descrever e caracterizar áreas homogéneas do ponto de vista geomorfológico. As três unidades de 1º nível baseiam-se nas unidades morfostruturais clássicas consideradas para a Península Ibérica. As dez unidades de 2º nível constituem, na sua maioria, divisões clássicas do relevo de Portugal Continental, agora agrupadas de acordo com a metodologia adoptada e designadas como unidades morfosculturais. As 56 unidades de 3º nível, ou subunidades morfosculturais, foram individualizadas com base nos padrões de relevo identifi cados nas imagens SRTM e na observação de campo e adquiriram uma designação baseada essencialmente nas geoformas que as individualizam e na toponímia local. As unidades geomorfológicas identificadas são descritas através de características do relevo, dissecação fluvial, estruturas, tipo de drenagem e base geológica, bem como de parâmetros numéricos gerados de forma automática, como classes de altitude e de declividade. Pretende-se que o mapa elaborado possa contribuir para a gestão territorial, em especial na tomada de decisões em conservação da natureza.Fundação para a Ciência e a Tecnologia (FCT); CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (Brasil

Quantification of a new water diversity index for large areas using GIS. Examples in Paraná State, Xingu river basin (Brazil) and Portugal

(Cuantificación de un nuevo index de diversidad hídrica para grandes áreas con SIG: ejemplos en lo estado del Paraná, en la cuenca del rio Xingú (Brasil) y en Portugal): Se presenta un método para la evaluación cuantitativa de la diversidad de recursos hídricos en grandes áreas, con los ejemplos del estado de Paraná (Brasil), de la Cuenca del rio Xingú (Brasil) y de Portugal continental. En la mayoría de las propuestas metodológicas para evaluación de la geodiversidad, la diversidad hidrológica respecta a las características de la hidrografía, en relación con la diversidad de geoformas fluviales. Este trabajo pretende contribuir al inclusión de recursos hídricos como un elemento significativo en metodologías de evaluación de la geodiversidad, incluyendo tanto las aguas superficiales y aguas subterráneas. El uso de procedimientos de SIG demuestra que estas técnicas pueden ser utilizados para acelerar el cálculo de los índices de diversidad y su representación cartográfica.The Portuguese authors express their gratitude for the financial support given by the FCT (Fundação para a Ciência e a Tecnologia) to the Institute of Earth Sciences (Pole of the University of Minho), which partially supports this research. The Brazilian authors express their gratitude for the financial support given by the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and CAPES (Cordenação de Aperfeiçoamento de Pessoal de Nível Superior).info:eu-repo/semantics/publishedVersio

Rational engineering of nanoporous anodic alumina optical bandpass filters

First published online 07 Jul 2016Herein, we present a rationally designed advanced nanofabrication approach aiming at producing a new type of optical bandpass filters based on nanoporous anodic alumina photonic crystals. The photonic stop band of nanoporous anodic alumina (NAA) is engineered in depth by means of a pseudo-stepwise pulse anodisation (PSPA) approach consisting of pseudo-stepwise asymmetric current density pulses. This nanofabrication method makes it possible to tune the transmission bands of NAA at specific wavelengths and bandwidths, which can be broadly modified across the UV-visible-NIR spectrum through the anodisation period (i.e. time between consecutive pulses). First, we establish the effect of the anodisation period as a means of tuning the position and width of the transmission bands of NAA across the UV-visible-NIR spectrum. To this end, a set of nanoporous anodic alumina bandpass filters (NAA-BPFs) are produced with different anodisation periods, ranging from 500 to 1200 s, and their optical properties (i.e. characteristic transmission bands and interferometric colours) are systematically assessed. Then, we demonstrate that the rational combination of stacked NAA-BPFs consisting of layers of NAA produced with different PSPA periods can be readily used to create a set of unique and highly selective optical bandpass filters with characteristic transmission bands, the position, width and number of which can be precisely engineered by this rational anodisation approach. Finally, as a proof-of-concept, we demonstrate that the superposition of stacked NAA-BPFs produced with slight modifications of the anodisation period enables the fabrication of NAA-BPFs with unprecedented broad transmission bands across the UV-visible-NIR spectrum. The results obtained from our study constitute the first comprehensive rationale towards advanced NAA-BPFs with fully controllable photonic properties. These photonic crystal structures could become a promising alternative to traditional optical bandpass filters based on glass and plastic.Abel Santos, Taj Pereira, Cheryl Suwen Law and Dusan Losi

Global Alfven Wave Heating of the Magnetosphere of Young Stars

Excitation of a Global Alfven wave (GAW) is proposed as a viable mechanism to explain plasma heating in the magnetosphere of young stars. The wave and basic plasma parameters are compatible with the requirement that the dissipation length of GAWs be comparable to the distance between the shocked region at the star's surface and the truncation region in the accretion disk. A two-fluid magnetohydrodynamic plasma model is used in the analysis. A current carrying filament along magnetic field lines acts as a waveguide for the GAW. The current in the filament is driven by plasma waves along the magnetic field lines and/or by plasma crossing magnetic field lines in the truncated region of the disk of the accreting plasma. The conversion of a small fraction of the kinetic energy into GAW energy is sufficient to heat the plasma filament to observed temperatures.Comment: Submitted to ApJ, aheatf.tex, 2 figure

Equivalence between the Lovelock-Cartan action and a constrained gauge theory

We show that the four-dimensional Lovelock-Cartan action can be derived from a massless gauge theory for the $SO(1,3)$ group with an additional BRST trivial part. The model is originally composed by a topological sector and a BRST exact piece and has no explicit dependence on the metric, the vierbein or a mass parameter. The vierbein is introduced together with a mass parameter through some BRST trivial constraints. The effect of the constraints is to identify the vierbein with some of the additional fields, transforming the original action into the Lovelock-Cartan one. In this scenario, the mass parameter is identified with Newton's constant while the gauge field is identified with the spin-connection. The symmetries of the model are also explored. Moreover, the extension of the model to a quantum version is qualitatively discussed.Comment: 17 pages. No figures. Final version accepted for publication at the EPJ

Happy 2 Smell (H2S)

A problem was initially identified: the emission of polluting gases into the atmosphere, namely hydrogen sulphide, H2S, by the tanneries close to our school district. After carrying out theoretical investigations in Biology and Chemistry, the students developed an idea for a project, which consisted of creating a biological filter, with a porous matrix that could be easily traversed by the H2S gas, using, for this purpose, the dry fruit of the plant Luffa aegyptiaca. This material possesses a high porosity and good physical and chemical resistance, serving as a support matrix for sulphur bacteria and, initially, also their culture medium. In collaboration with Alcanena's Wastwater Treatment Plant, sludge from different treatment stages containing sulphurous bacteria were collected. These bacteria manage to transform H2S into sulphur and water. Finally, in collaboration with CTIC (Technological Center for the Leather Industry), iodometric titrations were carried out, proving the effectiveness of the produced filter