ISEL - Física - Posters
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- Imaging the crustal structure of the Azores islandsPublication . Dias, Nuno; Veludo, IdalinaThe Azores archipelago (Portugal), in the Central Atlantic Ocean, is located in a tectonic triple junction, between the American, Eurasia and African plates, whose morphologic expression is the Azores Plateau. Geodetic measurements indicate spreading rates of 23 mm/year for the Mid-Atlantic Ridge (MAR) and 2.1 mm/year for the Azorean segment (Terceira Ridge). The Azores plateau is considered as the surface expression of the interaction between the Azores hotspot and the MAR, and presents significant tectonic and volcanic activity. The existence of an anomalously thick crust associated with excesso magmatism, related with the Hotspot, has long been established for the Plateau, however the detailed characterization on its crustal structure, and its variability within the plateau is not yet fully performed.
- The Arraiolos – Portugal – Moderate-Sized 2018 (M = 4.9) earthquake of January 15 and aftershocks: preliminary resultsPublication . Borges, José; Caldeira, Bento; Fontiela, João; Custódio, Susana; Dias, Nuno; Waschilala, Piedade; Oliveira, Rui; Vales, Dina; Bezzeghoud, Mourad; Araújo, Alexandre; Carrilho, Fernando; Corela, Carlos; Rio, Inês; Vaz, José; Matias, LuísOn 15 January 2018 at 11:51 UTC, an earthquake of 4.9 ML occurred in the Northeast of Arraiolos region near Aldeia da Serra village. The hypocentral location, determined by Instituto Português do Mar e da Atmosfera (IPMA), has coordinates 38.79 N, 7.93 W at 11 km depth. The focal mechanisms determined by P-wave first motion polarities and waveforms inversion indicate a dominance of strike-slip events with nodal plans near NS (left lateral) and EW (right lateral) directions. Due to the lower magnitude, the earthquake didn’t cause damage but was widely felt in the Centre and South of Portugal mainland. In the vicinity of the epicentre, at the Aldeia da Serra village, it reached a maximum intensity VI, having been felt with intensity IV/V in the city of Évora, about 20 km from the epicentre. The event was also felt with intensity III in Lisbon at more than 100 km from the epicentre. This event caused alarm in the population that haven’t felt an earthquake for several decades. It also raised the media attention with many reports and interviews on TV and newspapers. The main ear thquake was immediatel y followed by a sequence of aftershocks of which the largest one, with ML=3.1, occurred the 1st February, fifteen days after the main shock and was largely felt by the population in the region of Arraiolos.
- When is a surface foam-phobic?Publication . Teixeira, Miguel; Arscott, Steve; Cox, Simon; Teixeira, Paulo• In confined foams there exist wall Plateau borders (PBs), or menisci, where the films meet the confining substrates. • What is the shape of a PB of a given size on a surface of a given wettability (i.e., contact angle θc)? Can that surface support a foam? • This is important for firefighting foams, containers for foamy foodstuffs, etc • We solve the Young-Laplace equation with gravity for a planar film spanning a gap between two horizontal, flat substrates, to predict the shape of the PBs. • Validate results by comparing with Surface Evolver and experimental data
- Interplay between self-assembly and condensation in models with asymmetric patchesPublication . Tavares, Jose; Teixeira, Paulo
- From wrinkly elastomers to Janus particles to Janus fibresPublication . Trindade, A. C.; Canejo, J. P.; Patricio, Pedro; Brogueira, P.; Teixeira, Paulo; Godinho, Maria HelenaAim is to fabricate Janus objects possessing two distinct sides, through control and manipulation of uneable sub-micron scale long-lived textures in urethane/urea elastomer films, spheres and fibres. Textures are obtained by UV-irradiation of the elastomers followed by mechanical deformation or swelling in a solvent. Standard chemistry, no complex deposition techniques required. Resulting textures investigated using AFM, SEM, SALS and POM. Interpreted by assuming that each film, sphere or fibre consists of a thin, stiff surface layer (“skin”) lying atop a thicker, softer substrate (“bulk”).