RUN
Repositório Institucional da Universidade NOVA de Lisboa
Entradas recentes
Electron Scattering from NO2
Publication . Lozano, Ana I.; García-Abenza, Adrián; Rosado, Jaime; Blanco, Francisco; Oller, Juan C.; Limão-Vieira, Paulo; García, Gustavo; DF – Departamento de Física; CeFITec – Centro de Física e Investigação Tecnológica; MDPI - Multidisciplinary Digital Publishing Institute
Total electron scattering cross sections (TCSs) for NO2 molecules have been measured with a magnetically confined electron beam transmission apparatus for impact energies ranging from 1 to 200 eV. The estimated total uncertainty limits are within ±5%. Moreover, integral elastic, ionization, electronic and rotational excitation cross sections in the (20–1000 eV) energy range have been calculated with our independent atom model-based screening corrected additivity rule including interference effects (IAM-SCAR+I) method. The cross-section data set derived from this study is critically compared with the recommended values available in the literature.
Literacias críticas dos adolescentes no encontro com as notícias nas redes sociais
Publication . Moreira, Mariana da Fonseca Garrido Baldaia; Brites, Maria José; Silva, Marisa Rodrigues Pinto Torres da
As redes sociais assumem, atualmente, um lugar privilegiado no encontro dos jovens com as notícias no quotidiano. Neste fluxo híbrido de conteúdos, o encontro com a informação é sobretudo acidental, o que, a par das mecânicas das plataformas, transformam a avaliação crítica das notícias num processo mais complexo. Deste modo, adquirir conhecimentos e competências de literacia para as notícias e literacia crítica dos media torna-se fundamental para navegar conscientemente o universo informacional deste ecossistema. No entanto, a investigação sobre envolvimento crítico com as notícias segue maioritariamente abordagens que podem limitar a compreensão deste fenómeno, além de os estudos se centrarem sobretudo em jovens adultos, pelo que certas faixas etárias – como os adolescentes – permanecem sub-representadas.
Neste panorama, a presente dissertação procura compreender a literacia crítica das notícias dos adolescentes, partindo das suas experiências informacionais quotidianas nas redes sociais. Tendo como abordagem teórica a viragem “radical” para a audiência nos estudos do jornalismo, o estudo iniciou nos entendimentos dos adolescentes para perceber que critérios e táticas mobilizam na avaliação da qualidade das notícias. Deste modo, o estudo empírico procurou responder a duas perguntas de investigação: 1) Em que consiste, para os adolescentes, uma notícia de qualidade na esfera das redes sociais?; e 2) Através de que modos os adolescentes avaliam a qualidade das notícias nas redes sociais? Ao analisar estas práticas, procurou-se compreender em que medida as avaliações de qualidade das notícias expressam literacias críticas, contribuindo para aprofundar conhecimento sobre o envolvimento crítico dos adolescentes com a informação nas redes sociais. Para tal, desenvolveu-se uma metodologia qualitativa centrada no utilizador, articulando diários mediáticos com grupos de foco participativos junto de adolescentes a partir dos 15 anos, provenientes do ensino secundário profissional.
Os resultados indicam que os adolescentes articulam dimensões institucionalizadas, pessoais e sociotécnicas de plataforma na definição da qualidade das notícias, abrangendo aspetos de conteúdo e formato. No entanto, a predominância destas dimensões varia entre indivíduos, em função dos seus conhecimentos sobre os media, hábitos e preferências informacionais. No que concerne aos modos de avaliação da qualidade, destacaram-se a análise da apresentação do conteúdo e a verificação da veracidade da informação, que acompanham a mobilização de diversas táticas individuais e intuitivas. As variações observadas na aplicação destas práticas relacionam-se com diferentes entendimentos de qualidade das notícias, conhecimentos sobre os media e motivação intrínseca dos participantes, refletindo diferentes expressões de literacia crítica das notícias. O estudo evidenciou a literacia para as notícias enquanto situada, no sentido em que as avaliações críticas dos adolescentes surgem interligadas às suas aprendizagens e experiências informativas nas redes sociais. Os resultados salientam a importância de desenvolver iniciativas de literacia para as notícias ajustadas às experiências e dificuldades dos adolescentes, incluindo, por exemplo, atividades participativas e conhecimentos sobre as dinâmicas entre media e audiências.
Material Reuse in the European Union Construction Sector
Publication . Silva, Inês; Martinho, Graça; Ramos, Mário; DCEA - Departamento de Ciências e Engenharia do Ambiente; MARE - Centro de Ciências do Mar e do Ambiente; MDPI - Multidisciplinary Digital Publishing Institute
The progression towards a circular economy in the construction sector has gained attention as a response to rising resource consumption and construction and demolition waste generation, with material reuse playing a central role. In this context, this study analyses the literature on reuse in the construction sector, examining its investigation over time and its relation to European regulatory frameworks and policy strategies. A systematic literature review was conducted using a structured search across the B-on, Scopus, and Web of Science databases. The search targeted peer-reviewed journal articles in English, published between 2008 and 2023, focusing on titles, abstracts, and keywords with predefined terms. A total of 78 articles met the inclusion criteria and were analysed. Research activity has increased in recent years, reflecting growing European policy attention, particularly the Waste Framework Directive, its 2018 amendment, and the Circular Economy Action Plan. Most studies address strategies to promote the circular economy, waste management practices, life cycle assessments, and the identification of barriers and opportunities to reuse. Despite the expanding literature, reuse remains insufficiently addressed. These findings underline the need for more targeted research and stronger integration between policy and practice to support effective reuse in the construction sector.
Life Cycle Assessment of Anaerobic Co-Digestion of Mixed Sewage Sludge with Fruit and Vegetable Waste in a Wastewater Treatment Plant
Publication . Azevedo, André; Moldão-Martins, Margarida; Duarte, Elizabeth; Lapa, Nuno; DQ - Departamento de Química; LAQV@REQUIMTE; Mary Ann Leibert
In municipal wastewater treatment plants (WWTPs), anaerobic digestion of municipal mixed sludge (MMS) often yields low energy recovery and operational instability due to imbalances between primary and secondary sludges. Anaerobic co-digestion (AcoD) with readily biodegradable wastes, such as fruit and vegetable waste (FVW), can enhance process stability and biogas production. Life cycle assessment (LCA) methodology is used in this study to evaluate the environmental performance of implementing AcoD of MMS and FVW in a municipal WWTP, compared with a business-as-usual scenario combining mono-digestion of MMS and incineration of FVW. The LCA was modelled in openLCA 2.5 using the ecoinvent 3.9.1 database (cut-off allocation approach), and impacts were assessed with the ReCiPe 2016 Midpoint (H) method, focusing on climate change, terrestrial acidification, fossil fuel depletion, and marine eutrophication. Results indicate that AcoD reduces impacts across all environmental categories, mainly due to higher biogas yields that increase on-site electricity generation and decrease reliance on grid electricity. Improved total solids removal also lowers digestate production and composting-related burdens. Electricity consumption remains the main hotspot in both scenarios, highlighting the importance of energy efficiency and electricity mix. Sensitivity analysis on methane content (61–65% v/v) confirms the robustness of AcoD’s environmental benefits.
How nutrients, pH and element concentration shape the biosorption of classical and emerging contaminants by living Gracilaria gracilis
Publication . Jacinto, Jéssica; Tavares, Daniela; Ferreira, Nicole; Viana, Thainara; Pinto, João; Lapa, Nuno; Pereira, Eduarda; Henriques, Bruno; DQ - Departamento de Química; LAQV@REQUIMTE; Elsevier Science B.V., Inc
Marine and freshwater ecosystems are not only exposed to metals but to increasing macronutrient enrichment, causing environmental and health consequences. Macroalgae can bind contaminants and use nutrients in their growth. The influence of nutrients in the biosorption of Rare Earth Elements (REEs) and Classical contaminants, in complex mixtures, has not been fully covered. Response Surface Methodology (RSM) with Box-Behnken Design was applied to study the influence of biosorbent mass, element concentration and nutrient concentration on the removal response. Batch sorption experiments were performed for 48 h at salinity (10) and pH (6 and 8). Living biomass exhibited high removal rates ('80%) for REEs, Hg, and Pb, while As and Cd showed less affinity. Biosorbent dosage showed to be an influential parameter, while nutrients were not significant. Quadratic models exhibited the best fit after 48 h of exposure for all elements, except Hg. Despite the negligible effect of nutrients, in different optimisation scenarios, it was possible to improve the removal response in their presence. To better understand the environmental impact of adding nutrients or the need for high doses of biosorbent, LCA methodology would give further insights into the cost and environmental impacts of a macroalgae cultivation step.