Repositório do LNEG

National Laboratory of Energy and Geology Scientific Repository

Welcome to LNEG’s Scientific Repository

The LNEG’s Scientific Repository intends to preserve, disseminate and give access to LNEG's scientific production in digital format.

The objectives of the Repository are: to increase the visibility and impact of the research carried out at LNEG, to improve internal and external communication and to preserve the institution's intellectual memory.

Email repositorio@lneg.pt

Recent Submissions

Is the Rosario Antiform, Iberian Pyrite Belt, a Variscan tectonic window?: a tectono-stratigraphic interpretation based on the geology of the Neves-Corvo mine region

Publication . Oliveira, José Tomas

ABSTRACT: This work suggests a new structural interpretation for the Rosario Antiform, Portuguese Pyrite Belt. This is based on the following successive developments: 1 - Deposition of an upper Visean flysch succession, designated by CMt2, which conformably overlaid the autochthon represented in ascending order by the clastic succession of the Phyllite-Quartzite Formation (PQ) followed by the lower Volcano-Sedimentary Complex (VSC, CVS in the geological map annex) dominated by felsic volcanism and black shale sediments, all of late Devonian age, and the upper VSC composed by shales, volcanoclastic sediments, including cherts and jaspers, and mafic volcanic and igneous rocks of late Tournaisian – late Visean ages; 2 - the reinterpretation of fifteen selected drill hole logs previously carried out by Somincor and LNEG geologists and recovered from the region west of the Neves-Corvo mine proved that below the CMt2 flysch succession the upper VSC is absent in many places and the unit is in direct fault contact with the lower VSC, in a position similar to that recognized in the mine. This abnormal contact is inferred to represent the trace of an extensional fault that locally erased the upper VSC lithologies. A sub-autochthon block composed of remnants of the lower VSC and the overlying CMt2 sediments was then formed above the extensional fault, as discussed below; 3 - a SW directed tangential transport, well documented in the Neves-Corvo mine region, placed a distinct flysch succession (CMt1) and the underlying clastic dominated upper VSC units, all of late Visean age, both forming the allochthon, upon the CMt2 succession. The allochthon is organized as a thinskinned package moving southwestward upon the subautochthon developing a large overthrust. All the package units were folded by a second episode of pervasive regional tectonic compression. 4 – a second tectonic reverse fault at the west limb of the antiform caused the uplifting of the autochthon and the subautochthon which after the regional erosion became a true tectonic window according to this interpretation.

2025-02Journal article

Open access

Empowering Citizen Science Through Stakeholder Engagement

Publication . Correia, Vítor; Romão, José; Tyrologou, Pavlos; Gomes, Rui Carrilho; Correia, Vítor; Bodó, Balazs

ABSTRACT: The chapter examines how citizen science projects, particularly in geohazard monitoring, can be strengthened through systematic stakeholder engagement. Using the AGEO project as a case study, with five established Citizen Observatories across Europe, it details how stakeholders were identified, classified, and engaged across political, economic, knowledge and socio-cultural systems. The paper identifies five crucial factors for successful engagement: relevance, accessibility, trust, recognition/incentives, and sustainability. It concludes that citizen science, supported by technological advances and proper stakeholder engagement, can make significant contributions to disaster preparedness and risk reduction, particularly in the context of climate change, by fostering collaboration between experts and communities.

2025-02Book part

Open access

Sustainability assessment of collagen extraction from fish skins: A comparative life cycle assessment of conventional and NADES-enhanced processes

Publication . Miguel P. Batista; Fernández, Naiara; Gaspar, Frédéric B.; Bronze, MR; Duarte, Ana Rita C.; Ortigueira, Joana; Lopes, Tiago

ABSTRACT: Collagen from blue shark skins offers a promising solution to utilize fishery by-products, reducing waste and improving resource efficiency. This study develops green chemistry-based extraction processes to minimize reliance on traditional chemical methods and lower environmental impacts, prioritizing sustainability and circularity. Two methods for collagen extraction are compared: a conventional alkaline-acid process and an innovative approach using natural deep eutectic solvents (NADES). Process simulations were conducted using SuperPro Designer software for the annual production of 500 kg of pure extracted collagen, followed by life cycle assessment (LCA) using SimaPro software and the Ecoinvent database, applying the Environmental Footprint (EF) method. For 1 kg of pure marine collagen from fish skin residues, defined as the Functional Unit, the conventional approach yielded a single-score impact of 48.1 mPt, while the NADES method achieved 41.5 mPt. Subsystem analysis reveals that, in the conventional method, the extraction and purification stages account for most of the environmental impact (43 % and 45 %, respectively). In contrast, the NADES method attributed 94 % of its total environmental impact to extraction stage, primarily due to NADES component production (citric acid, xylitol). Uncertainty analysis suggests that conclusions regarding impact reduction should be drawn with caution due to the environmental impact variability of considered inputs. Nevertheless, the mathematical model underscores the potential of the NADES method to reduce the environmental impact and promote more sustainable bioprocessing. This work offers valuable insights into the life cycle assessment of large-scale bioprocesses using green chemistry, providing a tool for optimization and environmental impact screening.

2025-02Journal article

Open access

Detection of corrosion on silvered glass reflectors via image processing

Publication . 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, Johannes

ABSTRACT: 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.

2025-03Journal article

Open access

Mapping less sensitive areas with a view to the potential installation of solar and wind electricity generation units [Comunicação oral]

Publication . Simoes, Sofia; Barbosa, Juliana Pacheco; Oliveira, Paula; Simões, Teresa; Quental, Lídia; Costa, Paula; Picado, Ana; Catarino, Justina; Patinha, Pedro

2024-10Conference object

Open access