Elsa Pereira

A galvanic sensor for monitoring the corrosion condition of the concrete reinforcing steel: relationship between the galvanic and the corrosion currents.

This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, Igal, and the corrosion currents, Icorr, estimated from the polarization resistance, Rp. Sensors have been tested in saturated Ca(OH)2 aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O2. For all the conditions, the influence of temperature (20 to 55 °C) has also been considered. From this study, it could be concluded that the galvanic currents are sensitive to the various parameters following a trend similar to that of the Rp values. A relationship between the galvanic and the corrosion current densities was obtained and the limiting values of the Igal, indicative of the state condition of the reinforcing steel for the designed sensor, were established.

Hybrid Coatings Enriched with Tetraethoxysilane for Corrosion Mitigation of Hot-Dip Galvanized Steel in Chloride Contaminated Simulated Concrete Pore Solutions

Hybrid sol-gel coatings, named U(X):TEOS, based on ureasilicate matrices (U(X)) enriched with tetraethoxysilane (TEOS), were synthesized. The influence of TEOS addition was studied on both the structure of the hybrid sol-gel films as well as on the electrochemical properties. The effect of TEOS on the structure of the hybrid sol-gel films was investigated by solid state Nuclear Magnetic Resonance. The dielectric properties of the different materials were investigated by electrochemical impedance spectroscopy. The corrosion behavior of the hybrid coatings on HDGS was studied in chloride-contaminated simulated concrete pore solutions (SCPS) by polarization resistance measurements. The roughness of the HDGS coated with hybrids was also characterized by atomic force microscopy. The structural characterization of the hybrid materials proved the effective reaction between Jeffamine® and 3-isocyanate propyltriethoxysilane (ICPTES) and indicated that the addition of TEOS does not seem to affect the organic structure or to increase the degree of condensation of the hybrid materials. Despite the apparent lack of influence on the hybrids architecture, the polarization resistance measurements confirmed that TEOS addition improves the corrosion resistance of the hybrid coatings (U(X):TEOS) in chloride-contaminated SCPS when compared to samples prepared without any TEOS (U(X)). This behavior could be related to the decrease in roughness of the hybrid coatings (due TEOS addition) and to the different metal coating interaction resulting from the increase of the inorganic component in the hybrid matrix.

Autores brasileiros na página literária do Jornal da Manhã (1885-1892)

Considerado um dos melhores diarios aparecidos no Porto do ultimo quartel do seculo XIX, o Jornal da Manha foi o primeiro diario portugues a incluir uma pagina semanal inteiramente dedicada a literatura. Esta seccao literaria, que se publicou entre 1885 e 1892, inscreveu nas suas folhas um leque variado de autores brasileiros, testemunhando o interesse dos portuenses por tudo o que ia acontecendo no outro lado do Atlântico, inclusivamente em termos literarios. Pela sua relevância nas relacoes interculturais dos dois paises, o artigo apresenta um inventario geral das colaboracoes brasileiras que se publicaram na pagina literaria do jornal portugues. ***************************************************** Brazilian authors in the literary page of Jornal da Manha (1885-1892) Considered one of the best newspapers that appeared in Oporto at the end of the 19th century, Jornal da Manha was the first Portuguese daily paper to include a weekly page entirely dedicated to literature. This literary section, which was published between 1885 and 1892, included a wide range of Brazilian authors, testifying the interest that people from Oporto took on everything that was happening on the other side of the Atlantic. Given its interest for the intercultural relations between both countries, this article presents a list of the Brazilian collaborations that were published in the literary page of the Portuguese newspaper. Keywords: Brazilian; Writers; Portugal; Periodicals; 19th century

The Portuguese Cancioneiros of São João: Traditional Popular, Non-Traditional Popular, and Pseudo-Popular

The cancioneiro (song-collection) of São João (St John) is one of the richest manifestations of Portuguese popular culture. In this article, we review the principal bibliography—song collections and studies—devoted to the saint in popular (both traditional and non-traditional) or pseudo-popular song. We examine the symbolic and ethnographic importance of São João in the collective imagery, taking into account the relationship between literary representation and the anthropological and cultural aspects of this festivity.