http://hdl.handle.net/10174/14410 2026-08-07T15:09:01Z 2026-08-07T15:09:01Z Luis, Lopes Moreira, Noel Vilarinho, Gil Martins, Rúben Carneiro, André Kezirian, Francis Silva, Marcelo Nogueira, Pedro http://hdl.handle.net/10174/42417 2026-07-28T11:04:04Z 2026-06-30T23:00:00Z

Title: Ancient Quarries on the Estremoz Anticline (Ossa Morena Zone, Portugal): Exploitation, Use and Dispersion of Estremoz Marbles during Roman times Authors: Luis, Lopes; Moreira, Noel; Vilarinho, Gil; Martins, Rúben; Carneiro, André; Kezirian, Francis; Silva, Marcelo; Nogueira, Pedro Abstract: The use of crystalline marbles from Estremoz Anticline, Alentejo (Southern Portugal), and their historical exploitation are documented since the Roman period. While most of the ancient quarries in the area were originally discovered due to the intense mining activity of the 20th century, the remains that still preserved in situ are very scarce, as this recent exploitation has often erased the existing evidence. However, in several of the cases here documented, recent quarrying operations have contrastingly provided and helped preserve these traces of earlier extractive activity. The analysis of aerial photographs, confirmed by a field visit to the area, identifies almost five hundred marble quarrying and exploration sites in the Estremoz Anticline, most of which were opened in the 70s and 90s of the 20th century, while official records show that in the late 80s there were 187 quarries operating simultaneously around the villages of Estremoz, Vila Viçosa and Borba. Today, for various reasons (including the globalisation of the economic market, the ageing of the population, recurring economic crises, the recent tightening of safety regulations, etc.), only around 40 quarries are still active, some of which are over 150 metres deep. Nevertheless, the analysis and conservation of the archaeological evidence of exploration remains a significant challenge. This paper presents a summary and characterisation of the identified ancient quarries and remains in terms of their location, geological setting and marble type, but also of the ancient exploitation methods observed. It also explains the current challenges for the conservation of the relevant geodiversity found and some resulting geoconservation measures, defined according to the site, which could be implemented on a larger scale to conserve and display the unique architectural and cultural heritage of these sites. This study assumes a particular relevance so that both landowners and industry continue to support and preserve this historical and cultural, tangible and intangible heritage of undeniable and differentiating value for this raw material.

2026-06-30T23:00:00Z Moreira, Noel Machado, Gil Piçarra d'Almeida, José Martins, Rúben Primo, Hugo Dimas, João Roseiro, José http://hdl.handle.net/10174/42290 2026-07-03T15:20:34Z 2026-01-01T00:00:00Z

Title: Sedimentação Carbonatada da Zona de Ossa-Morena: novos dados e desafios Authors: Moreira, Noel; Machado, Gil; Piçarra d'Almeida, José; Martins, Rúben; Primo, Hugo; Dimas, João; Roseiro, José Editors: Moreira, Noel Abstract: A sedimentação carbonatada evoluiu ao longo de cerca de 3,5 mil milhões de anos, desde precipitados inorgânicos/microbianos resultantes da precipitação de carbonatos diretamente da água do mar, para sistemas biogénicos maciços, mais ou menos complexos, ao longo do Fanerozoico. Esta evolução apresenta um salto qualitativo relacionado com o aparecimento de exoesqueletos carbonatados e dos primeiros organismos construtores de recifes no Fanerozoico: primeiramente com o aparecimento dos arqueociatídeos durante o Câmbrico, seguidos por esponjas e corais, bem como por outras faunas associadas a recifes portadoras de esqueletos carbonatados, como são exemplo os crinóides ou os briozoários. Nesse sentido, o Maciço Ibérico torna-se um sítio privilegiado para assistir a esta transição, possuindo sucessões de idades Ediacáricas e Paleozoicas que registam (ou poderiam registar) estas transformações. O Maciço Ibérico foi subdividido em várias zonas paleogeográficas com base no seu registo sedimentar e nas suas características tectono-metamórficas e magmáticas. Nas suas zonas paleogeográficas internas, nomeadamente na Zona de Ossa-Morena (ZOM), que é composta por uma sucessão meta-sedimentar de idade Ediacárica e Paleozoica, desenvolvem-se quatro episódios significativos de sedimentação carbonatada de natureza marinha: Câmbrico (Série 2), Ordovícico Superior, Silúrico superior e Devónico Inferior-Médio. Para além disso, ocasionalmente surgem rochas carbonatadas de natureza marinha nas bacias de idade mississíppica, sejam eles resultantes do desmantelamento de unidades mais antigas (olistólitos) ou resultantes da própria sedimentação marinha de unidades em níveis de natureza carbonatada. É sobre a idade das sucessões carbonatadas paleozoicas da ZOM que se debruça esta excursão realizada no âmbito do XII Congresso Nacional de Geologia. Embora várias unidades carbonatadas tenham sido reconhecidas, poucas são as sucessões meta-sedimentares onde o controlo estratigráfico esteja plenamente estabelecido, sendo alvo de debate há largas décadas. São exemplo disso as sucessões do sector Alter-do-Chão-Elvas, Estremoz, Ferrarias ou Ficalho, onde as sucessões apesar de apresentarem algum controlo bioestratigráfico, isotópico ou geocronológico, continuam sem dados significativos no que respeita à idade das sucessões carbonatadas, ou às sucessões de Viana do Alentejo e Trigaches, onde, face ao tectono--metamorfismo Varisco, apresentam incógnitas no que respeita à sua idade estratigráfica. Em ambos os casos, as idades atribuídas a estas sucessões decorrem das correlações litoestratigráficas com secções espanholas vizinhas, onde as idades das sucessões carbonatadas estão bem definidas, em muito devido às condições de preservação relacionadas com os processos pós-deposicionais (e.g. tectono-metamorfismo varisco e a dolomitização tardia). Ao longo dos últimos anos, os trabalhos realizados nestas sucessões têm aumentado o conhecimento e se há dúvidas e questões que foram estão comsensualmente esclarecidas, outras nem tanto. Nesta excursão pretende-se visitar alguns dos locais emblemáticos onde estas sucessões afloram (e em alguns casos onde são explorados) e discutir in situ a sua génese e significado estratigráfico e geodinâmico.

2026-01-01T00:00:00Z Machado, K.V. Pepe, V.R. Miguel, A.F. Rocha, L.A.O. Haeberle, F. http://hdl.handle.net/10174/42143 2026-06-08T11:44:09Z 2026-01-01T00:00:00Z

Title: Numerical investigation of a concentration divider for ultrasound calibration using constructal design. Authors: Machado, K.V.; Pepe, V.R.; Miguel, A.F.; Rocha, L.A.O.; Haeberle, F. Abstract: This study applies the Constructal Design method to the geometric optimization of a branched symmetric concentration divider for calibrating ultrasound devices used to monitor tumor response with dynamic contrast. Accurate calibration ensures image quality and diagnostic reliability. The geometry consists of a three-dimensional, tree-shaped flow network with two inlets and three outlets, where inlet 1 carries water containing contrast particles, while inlet 2 carries only water. Laminar flow simulations are performed using Computational Fluid Dynamics (CFD) with Ansys Fluent, assuming no-slip wall conditions and zero-pressure outlets. The analysis investigates the effects of the inlet velocity ratio, the diameter ratio, and the vertical positions of the central outlet and inlet tubes, while keeping the total volume and inlet diameter constant. Additionally, velocity, pressure, particle distributions, flow partition ratio, and hydraulic resistance are evaluated. Results show nearly linear concentration responses among the outlets (100%, 50%, and 0%) when the device approaches geometric symmetry with equal inlet velocities, demonstrating efficient control of flow splitting. Although the diameter ratio imposes a trade-off with hydraulic resistance, geometric symmetry combined with Constructal Design promotes improved flow uniformity and enhanced performance, with potential applications in microfluidic mixers that require precise intermediate concentrations.

2026-01-01T00:00:00Z Miguel, Antonio http://hdl.handle.net/10174/42119 2026-06-05T10:21:57Z 2026-01-01T00:00:00Z

Title: Non-equilibrium transport dynamics and macroscopic thermodynamic efficiency of binary Knudsen flow in tapered semipermeable channels Authors: Miguel, Antonio Abstract: This study investigates the non-equilibrium transport dynamics and macroscopic thermodynamic efficiency of a binary gas mixture traversing a tapering, selectively permeable cascade operating strictly within the Knudsen regime. By employing a Lagrangian test particle Monte Carlo framework alongside a Fokker-Planck formalism, discrete stochastic trajectories driven by particle-boundary interactions are coupled with ensemble macroscopic concentration profiles. The separation process is thermodynamically evaluated by balancing the separation work gain against two primary costs: the microscopic entropic penalty of momentum erasure via diffuse wall colli­sions, and the macroscopic transport penalty induced by geometric backscattering. To formalize this, the specific separation thermodynamic efficiency is introduced, a metric that normalizes overall performance against the intrinsic material transmission probability. The results reveal a critical morphological transition in optimal cascade architecture. It is demonstrated that low-affinity membranes fundamentally require moderate geometric constriction to mechanically force boundary collisions and maximize the integrated probability of permeation, optimally balancing permeation against induced backscattering. On the other hand, in high-affinity systems, the active species is rapidly extracted near the inlet, localizing maximum thermodynamic dissipation and rendering severe tapering physically detrimental. Consequently, highly selective membranes strictly favor uniform channel geometries to mitigate irreversible transport losses. Finally, this framework establishes that optimal geometric design is not static but must be dynamically tailored to the intrinsic surface affinity to maximize macroscopic thermodynamic efficiency.

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