Percorrer por autor "Alves, Raquel"
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- Ecogeodidactic resource - A circular path for natural stone wastes: Didactic interest, economic potential and safety assessment proposalPublication . Torres, Maria Madalena; Alves, Raquel; Carvalho, Cristina Isabel Paulo; Figueiredo, Bruno; Vilaça, Maria TeresaABSTRACT: This research project integrates Sustainable Development Goals (SDGs), specifically Quality Education (SDG4) and Responsible Consumption and Production (SDG12), and involves Education Sciences, Geosciences, and (Eco)Design. The project aims to create an ecogeodidactic resource that includes both physical and theoretical components, pedagogical strategies, and teacher training, while incorporating inputs from children and the educational community. The methodologies of action-research and cocreation have been adopted, focusing specifically on Environmental Education for Sustainability within the Geosciences (mineral resources and geological heritage). The project seeks to revalue stone waste from slab processing, by developing a high-value by-product. During the pilot phase, stone pieces (“geoelements”) were selected for interaction with preschool children, and a prototype was created to be installed in a kindergarten to monitor its impact. This resulted in a validation framework, that allowed for the discussion of the geodidactic interest, and the economic potential of this Project, as well as the definition of the initial guidelines for assessing their safety.
- EN 12440: A necessary review of the denomination criteria standard to elevate EU natural stone in a digital and sustainable marketPublication . Alves, Raquel; Carvalho, Cristina Isabel Paulo; Carvalho, Jorge; Silva, António José Ferreira da; Magalhães, Anabela; Rebola, Paula; Matias, Gina; Vinagre, Ana; Galego Lopes, Joaquim LuísABSTRACT: The European standard EN 12440, which regulates the denomination of natural stones, is a vital strategic asset for the industry's competitiveness. However, its effectiveness has long been compromised by ambiguous criteria and a slow revision process. As the new Construction Products Regulation (CPR) and the introduction of Digital Product Passports (DPPs) make traceability and transparency mandatory, the shortcomings of the standard have become a critical liability. This paper presents a detailed analysis of EN 12440's deficiencies and, drawing on the work of a multidisciplinary technical group, outlines concrete proposals for its modernisation. The aim is to transform the standard into a robust and dynamic tool, enabling the natural stone sector to meet future regulatory, digital, and sustainability requirements.
- Natural Stone Image Classification Using Online Databases and Convolutional Neural NetworksPublication . Brito, J. H.; Morim, D. M.; Carvalho, Cristina Isabel Paulo; Alves, RaquelABSTRACT: In this paper, we discuss the relevance of two distinct types of online natural stone databases (technical-institutional repositories and logistics-commercial e-platforms) for extracting (training and testing) input images and creating an automatic visual inspection system for natural stone classification. Using convolutional neural networks (CNNs) and images from a selected online data repository, a Deep Learning (DL) system was developed to estimate the class of the natural stone in a given image. The DL models were developed through transfer learning from existing image classifiers, as pre-trained classifiers were retrained on our dataset. Our best model achieved an Accuracy of 70.3% and an F-score of 0.67 for 70 classes.
- Natural Stones from EU - Denomination Criteria Standard: A ReviewPublication . Alves, Raquel; Carvalho, Cristina Isabel Paulo; Carvalho, Jorge; Silva, António José Ferreira da; Magalhães, Anabela; Rebola, Paula; Matias, Gina; Vinagre, Ana; Galego Lopes, Joaquim LuísABSTRACT: Harmonization is vital in the European Union. It is mainly applied to materials, processes, products and services. However, it is also crucial for other domains. An example of this is the denomination of natural stones. It is important that denomination meets strict criteria to promote natural stone Market, as well as their products in the imperative new “Construction Products Regulation (CPR)”. This was the purpose behind the development and recent revision of EN 12440. However, the important role that was intended for this standard in the natural stone sector was never fully achieved, due to the vague and unobjective way in which the denomination criteria were laid down. This review aims to analyse the standard, pointing out what needs to be harmonized, and to present concrete proposals for its improvement, so that the standard can fully perform its purpose.