Materiais para a Energia - ME
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Percorrer Materiais para a Energia - ME por Domínios Científicos e Tecnológicos (FOS) "Engenharia e Tecnologia::Outras Engenharias e Tecnologias"
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- Detection of corrosion on silvered glass reflectors via image processingPublication . Wiesinger, Florian; Baghouil, Sarah; Le Baron, Estelle; Collignon, Romain; Santos, Filipa; Cunha Diamantino, Teresa; Catarino, Isabel; Facão, Jorge; Ferreira, Cristina; Páscoa, Soraia; Sutter, Florian; Fernández-García, Aránzazu; Wette, JohannesABSTRACT: A novel characterization technique based on image analysis is presented, intended to complement state-of-the-art reflectometer measurements. The technique is developed by experts from different laboratories (OPAC, AGC, CEA and LNEG), which subsequently conduct two Round Robin experiments on corroded solar reflectors for validation. Regarding the inter-comparability, it is found that parameters like the corrosion spot density or the penetration maximum on coated edges exhibit an average coefficient of variation of 62.6 % and 54.9 %. Better agreement is found for parameters like the total corroded area and the maximum edge corrosion penetration, with coefficients of variation of 14.3 % and 13.4 %, respectively. The developed methodology is further applied during a 68-month lasting outdoor exposure campaign of two types of solar reflectors at two representative sites, one exhibiting corrosivity class C2 and the other C3. On the commercial coating RL1, a total corroded area of 59 mm2 and 426 mm2 is measured after the outdoor exposure on the C2 and the C3 site, respectively, while on the novel low-lead coated reflector RL3 corresponding values are 280 mm2 and 1308 mm2. This shows the superior quality of the coating RL1 in terms of corrosion resistance. Furthermore, the analysis highlights the importance of proper edge sealing for corrosion protection, since corrosion penetration is increased by a factor between 1.3 and 4.0 if the edges are unprotected. The reflectance decrease after the outdoor exposure is regarded as negligible (0.000 - 0.005), thus not permitting any of the conclusions that are made from the novel image analysis technique.
- Determination of reflectance of interest from limited state-of-the-art solar reflector field soiling measurementsPublication . Wette, Johannes; Sutter, Florian; Cunha Diamantino, Teresa; Montecchi, Marco; Bern, Gregor; Fernández-García, AránzazuABSTRACT: In concentrated solar thermal technologies, plant operators usually monitor the soiling of their solar field with handheld reflectometers. These measurements can be used for yield calculations and to adapt cleaning strategies: if the reflectometer reading falls below an empirically established threshold, the solar field should be cleaned. There are several commercial reflectometers available for this purpose, but all of them measure at different combinations of wavelength, acceptance angle or incidence angle. It is the purpose of this study to bring the readings from all main commercial reflectometers to the same representative value, enabling their comparison with one another and the translation of these readings into a meaningful reflectance parameter. Thus, different handheld reflectometers are correlated with a laboratory reflectometer, capable of measuring in the whole solar spectral region, covering a wide range of incidence and acceptance angles. The most significant parameter is the near-specular solar-weighted reflectance, measured at the typical incidence and acceptance angles for a given plant, as it is the most precise parameter to describe the reflected energy from the solar field. The correlations for all included reflectometers, show highly linear correlations over a wide range of soiling levels with low deviations. Consequently, the correlations presented herein enable the plant operators at the studied site to compute the near-specular solar-weighted reflectance from their reflectometer readings. and, with that, increase the significance of the measurements without collecting any additional data. The work also establishes a detailed procedure to derive this type of correlations at any site of interest.
- Development of lightweight Sandwich Composites with improved Reaction to Fire and UV resistance for Double Curvature Façade Panels [Poster]Publication . Rocha, Helena; Vasconcelos, Miguel; Malheiro, Joana; Nascimento, António; Paula, Delves; Simões, Nuno; Barreiros, Maria Alexandra; Cunha Diamantino, Teresa; Ferreira, Cristina; Gonçalves, Diana; Antunes, PauloABSTRACT: Buildings with double curvature façades can be aesthetically pleasing, being capable of enchanting both architects and the general public Though, manufacturing of such façades can be a challenge in both technologic and economic terms Traditional molding technologies demand a unique mold for each panel geometry resulting in substantial costs related to raw materials and storage space, and long lead times for designing and manufacturing. A reconfigurable multipoint mold has been identified to solve this issue, where an array of moving pins can have their height quickly adjusted to form the required shape and molding surface. Another present technological challenge is the highly demanding fire resistance requirements Certain European countries require that public and civil buildings comply with the highest grades of EN 13501 standard, A 2 s 1 d 0 and B, s 1 d 0. That is a serious constraint when developing lightweight sandwich fiber reinforced polymer FRP composites, as polymeric materials do not naturally present good reaction to fire behavior Furthermore, the polymeric raw materials should present suitable processability with the reconfigurable multipoint mold and supporting processing equipment and allow the manufacturing of sandwich structures Sandwich composites structures are lightweight solutions with high stiffness, consisting of two composite laminate faces, separated by a lightweight core material, commonly made of foam or honeycomb.
- Dielectric UV filters for protection of fire-resistant glass based on intumescent layersPublication . Silva, Ricardo Magno Lopes; Hashim, Hurraira; Roy, Deepto; Oliveira Fernandes, Carolina; Oliveira, Kevin; Leitão Pinheiro, Xavier Alexandre; Esteves, M. Alexandra; Capelo, Anabela; Donato, Mariana; Oliveira, Fernando; Ferreira, Cristina; Alves, Isabel N.; Cunha Diamantino, Teresa; Barreiros, Maria Alexandra; Rocha, Jorge; Passos Teixeira, Jennifer; Salomé, PedroABSTRACT: Structures such as OLEDs, perovskite solar cells, intumescent glasses, and other components in modern devices and buildings contain materials suscep-tible to degradation when exposed to UV radiation, requiring protection to with-stand outdoor environmental conditions. In this work, multilayer coating config-ured as a Bragg Reflector on glass is employed as spectral filtering to protect the intumescent component of fire-resistant glass from degradation due to prolonged UV solar radiation exposure. By alternating low-n (SiO2)/high-n (TiO2) dielectric layers through spin-coating, precise control over film thickness could be achieved, allowing the fabrication of thin (<700 nm) UV filters with high trans-mission of visible sunlight – 88% of the 780 to 380 nm wavelength range – while reflecting almost all the incident UV – 90% of the wavelength below 380nm. Using relatively simple techniques, high precision coating was successfully achieved, resulting in an effective UV radiation protective barrier applied to en-hance the durability of the components in fire-resistant glass.
- Dielectric UV filters for protection of fire-resistant glass based on intumescent layers [Comunicação oral]Publication . Silva, Ricardo Magno Lopes; Hashim, Hurraira; Roy, Deepto; Oliveira Fernandes, Carolina; Oliveira, Kevin; Leitão Pinheiro, Xavier Alexandre; Esteves, M. Alexandra; Capelo, Anabela; Donato, Mariana; Oliveira, Fernando; Ferreira, Cristina; Alves, Isabel N.; Cunha Diamantino, Teresa; Barreiros, Maria Alexandra; Rocha, Jorge; Passos Teixeira, Jennifer; Salomé, Pedro
- Enhancing modular facade systems with natural materials: Durability and sustainability of wood-based solutions [Poster]Publication . Morgado, Vanessa; Ferreira, Cristina; Vieira, Ana; Alves, Isabel N.; Donato, Mariana; Costa, Luís; Rocha, Jorge; Barreiros, Maria Alexandra; Cunha Diamantino, Teresa
- Evolution of atomically dispersed co-catalysts during solar or UV photocatalysis for efficient and sustained H2 productionPublication . Capelo, Anabela; Fattoruso, Domenico; Valencia-Valero, Laura; Esteves, M. Alexandra; Rangel, Carmen M.; Puga, AlbertoABSTRACT: The evolution of metal/titania photocatalysts during photocatalytic H-2 evolution is herein studied. Samples containing atomically dispersed Pt co-catalysts (single atoms, clusters and sub-nanoparticles) formed after calcination were compared to pre-reduced analogues mostly having metallic nanoparticles (diameters >1 nm) during ethanol photoreforming under either UV-rich irradiation or natural sunlight. Aggregation of ultra-dispersed oxidised platinum entities (Pt delta+) with concomitant reduction into Pt-0 nanoparticles (1-2 nm) was observed after UV irradiation by transmission electron microscopy (TEM), and diffuse reflectance UV-visible (DRUV-vis) and X-ray photoelectron (XPS) spectroscopies. A parallel, albeit slower, evolution trend was evidenced during solar photocatalysis. Conversely, atomically dispersed Cu co-catalyst species did not grow and became in-situ reduced into sub-nanometric Cu-0 under irradiation. Hydrogen production rates were remarkably high during initial stages of UV irradiation, and then declined to a sustained regime (approximate to 50 and 8 mmol g(-1) h(-1) for Pt/TiO2 or Cu/TiO2, respectively, for up to 24 h of irradiation). Steadier solar photoreforming was observed in experiments performed in a compound parabolic collector tubular reactor (approximate to 7.6 and 1.7 mmol g(-1) h(-1) for Pt/TiO2 or Cu/TiO2, respectively). Despite the non-negligible effect of co-catalyst rearrangement on activity rationalised herein, attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy measurements pre- and post-photocatalysis suggest that accumulation of strongly adsorbed degradation intermediates, chiefly acetate, is a major cause for rate decreases. Notwithstanding, this phenomenon did not result in total deactivation, so that sustained hydrogen production upon long-term irradiation was not compromised.
- Exploring Marine Biomineralization on the Al-Mg Alloy as a Natural Process for In Situ LDH Growth to Improve Corrosion ResistancePublication . Marques, Maria João; Mercier, Dimitri; Seyeux, Antoine; Zanna, Sandrine; Tenailleau, Christophe; Duployer, Benjamin; Jeannin, Marc; Marcus, Philippe; Basséguy; BASSEGUY, RegineABSTRACT: This study provides a detailed characterization of the AA5083 aluminum alloy, surface, and interface over 6 months of immersion in seawater, employing techniques such as SEM/EDX, GIXRD, mu-Raman and XPS. The purpose was to evaluate the evolution of the biomineralization process that occurs on the Al-Mg alloy. By investigating the specific conditions that favor the in situ growth of layered double hydroxide (LDH) during seawater immersion as a result of biomineralization, this research provides insights into marine biomineralization, highlighting its potential as an innovative and sustainable strategy for corrosion protection.
- Exploring photozincographic metal plates collections: Manufacturing techniques and zinc corrosionPublication . Ioaneș, Alexandra; Roldão, Élia; Cunha Diamantino, Teresa; Tissot, IsabelABSTRACT: This study explores the materials, manufacturing processes, and corrosion behavior of photozincographic plates from the Lactário Museum in Lisbon, Portugal. Analysis of thirty-three historical plates (1927–1971) and three non-historical plates using stereomicroscopy, micro-X-ray fluorescence, X-ray diffraction, and accelerated aging tests revealed that the plates are primarily composed of zinc with trace elements (lead, iron, and calcium) and produced by distinct manufacturing techniques. Corrosion products containing sulfur-based compounds indicate the influence of an outdoor environment. Accelerated aging demonstrates significant image degradation from corrosion, highlighting the need for tailored preservation strategies for these unique composite objects.
- Fire-resistant materials: characterization and thermal behavior of intumescent gels for fire resistant glass [Poster]Publication . Donato, Mariana; Esteves, M. Alexandra; Capelo, Anabela; Oliveira, Fernando; Ferreira, Cristina; Alves, Isabel N.; Morgado, Vanessa; Correia, Jose B.; Teixeira, Jennifer P.; Oliveira Fernandes, Carolina; Silva, Ricardo Magno Lopes; Rocha, Jorge; Salomé, Pedro; Cunha Diamantino, Teresa; Barreiros, Maria Alexandra
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