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  • Fortnightly switching of residual flow drivers produced by seawater intrusion in a long, non-rotating estuary
    Publication . Garel, Erwan; Khosravi, Maziar; Valle-Levinson, Arnoldo; Díez-Minguito, Manuel
    Towed and moored ADCP and salinity measurements were collected in Summer 2023 at two cross-channel transects of the 80-km-long Guadiana Estuary, at 4 km and 20 km from the mouth, during low (< 10 m(3)/s) river discharge conditions. The dataset indicates that the lateral structure of axial residual flows changed from vertically sheared to laterally sheared with tidal forcing. These structures resemble theoretical expectations for a density-driven or eddy viscosity-shear covariance (ESCO) circulation at neap tide and for a tidally driven circulation produced by longitudinal advection (tidal stress) at spring tide. The tidal variability of the residual flow magnitude and of the contributions of unidirectional or two-layer vertical profiles indicate that the primary driver of the residual circulation changes between neap tide and spring tide. Seawater (i.e. with salinity > 35 kg/g) intrusion was several kilometres, equivalent to similar to 1/8 of the estuary's length. As a result, the horizontal density gradient was weakest near the mouth where the residual circulation was barotropic, produced by tidal stress at spring tide and possibly by an ESCO mechanism at neap tide. At 20 km upstream, the dominant driver switched from tidal stress at spring tide to a baroclinic (and potentially ESCO) circulation at neap tide. At this location, scaling analyses of the tidally averaged momentum equation using the densimetric tidal Froude number supported the idea of dominance of tidal stress at spring tide.
    2025-09-20Journal article Open access Show more
  • Long-term performance of thermal insulating composite systems based on water resistance and surface multifunctionality
    Publication . Borsoi, Giovanni; Parracha, João L.; Bersch, Jéssica D.; Garcia, Ana; Dionísio, Amélia; Faria, Paulina; Veiga, Rosário; Flores-Colen, Inês
    External Thermal Insulation Composite Systems (ETICSs) are increasingly applied in both new construction and energy retrofitting, where long-term durability under environmental exposure is critical to preserving thermal efficiency. Moisture ingress represents a key degradation factor, reducing insulation performance and undermining energy savings promoted by the ETICS. The effectiveness of these systems is strongly influenced by surface protection, which also reflects aesthetic and biological resistance. This study investigates the influence of three commercial protective surface coatings, characterized by hydrophobicity, photocatalytic activity, and resistance to biological growth, on ETICS finishes based on acrylic, natural hydraulic lime (NHL), and silicate binders. An artificial aging protocol was employed to evaluate coating stability and compatibility with the finishing layers. Results show that acrylic-based finishes provided superior durability and protection, while coatings on NHL and silicate substrates exhibited lower performance. Notably, a TiO2 enriched photocatalytic coating, despite improved self-cleaning potential, demonstrated the least durability. The findings highlight that optimal ETICS protection requires coatings that combine low water absorption, effective drying, and biological resistance, thereby ensuring sustained thermal and energy performance over time.
    2025-09-20Journal article Open access Show more