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- Synthesis, characterisation, and thermal degradation kinetics of lignin-based polyurethane wood adhesivesPublication . Hernández-Ramos, Fabio; Esteves, Bruno; Carvalho, Luisa Hora de; Labidi, Jalel; Erdocia, XabierPolyurethane adhesives are widely employed in a range of industrial applications due to their exceptional bonding strength, flexibility, and chemical resistance. These materials play a crucial role in wood bonding technologies, where their versatility and durability make them ideal for creating strong, long-lasting joints. In this work, Four different polyurethane wood adhesives were synthesised using ligno-based bio-polyols obtained through microwave assisted liquefaction reaction of two wood species (hardwood and softwood) using polyethylene glycol and glycerol as solvents. The reaction conditions used for the synthesis of bio-polyols were optimised in a previous work. The synthesis of polyurethanes was carried out by one-shot method using Tetrahydrofuran (THF) as solvent and MDI as diisocyanate employing different NCO:OH ratios (2.0:1, 2.5:1, and 3.0:1). The chemical structure of polyurethanes was determined through ATR-FTIR and the shear strength was analysed using Automated Bonding Evaluation System (ABES) employing beech veneer strips. Through ABES it was concluded that an NCO:OH ratio of 2.5:1 was the formulation that showed the best shear strength for a pressing time of 120 s. Employing this ratio and the same synthesis procedure, two new polyurethanes were synthesised with the bio-polyols obtained using crude glycerol instead commercial glycerol. Finally, a study of thermal degradation kinetics employing the Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS) isoconversional methods of the polyurethanes synthesised with an NCO:OH ratio of 2.5:1 was carried out. On the one hand, the Ea of each system were estimated for the different α ratios, obtaining slightly higher values for the adhesives produced using commercial glycerol than crude glycerol. In addition, the pre-exponential factor was determined, enabling an estimation of the lifetime of the polymers. This study highlights demonstrated that crude glycerol could replace commercial glycerol without compromising adhesive properties. The findings revealed that the lignin source significantly influences the adhesive's characteristics and stability, while addressing challenges in achieving industrial viability remains essential for broader application.
- Healthy motivations for food consumption in 16 countriesPublication . Guiné, Raquel; Joana Gonçalves; Florença, Sofia de Guiné e; Ferreira, Manuela; Cardoso, Ana Paula; Elena Bartkiene; Djekić, Ilija; Tarcea,Monica; Rumbak, Ivana; Sarić, Marijana Matek; Černelič-Bizjak, Maša; Isoldi, Kathy; EL-Kenawy, Ayman; Ferreira, Vanessa; Klava, Dace; Korzeniowska, Małgorzata; Vittadini, Elena; Leal, Marcela; Papageorgiou, Maria; Anjos, OféliaThere are many factors that can influence people’s attitudes towards healthy eating, including personal nature, sociodemographic influences, and lifestyle. This work investigated to what extent the motivations for healthy food consumption are shaped in individuals from different countries. A questionnaire survey was carried out on a sample of 11,919 participants from 16 countries. The results indicated that the strongest motivations for healthy food consumption were related to the perception of consuming healthy food, eating foods rich in vitamins and minerals, allied to food safety and hygiene concerns. Significant differences were found in healthy motivations between countries. Additionally, the sociodemographic variables that had a higher influence on health motivation levels were country, age, and gender. Concerning the anthropometric and lifestyle variables influencing healthy motivation for food consumption, the discriminating variables were: believing in having a healthy diet, physical exercise, and chronic diseases. In conclusion, the work showed important differences in the motivations for a healthy diet in different countries, but other variables also play a role in the motivation for the consumption of foods for health and well-being.
- Phenolic content, volatile composition and sensory profile of red wines macerated with toasted woods from different South American botanical speciesPublication . Jordão, António; Correia, Ana Cristina; Vasconcelos Botelho, Renato; Ortega-Heras, Miriam; González-SanJosé, MariaThe use of wood species from South American origin was not previously considered for wine aging. Thus, this work focuses on the comparative analysis of phenolic content, volatile composition and sensory characteristics of a red wine macerated with woods, in form of toasted cubes, from jequitibá, jaqueira, ipê, amburana and lenga species. All wines macerated with these woods showed a tendency for an increase of the phenolic parameters evaluated. This tendency was more evident in wine chromatic characteristics, especially for the wine macerated with jequitibá wood, where significantly higher color intensity and total color difference values was detected. For volatile composition, the different wood species induced significant changes on wine volatile profile. Thus, 3-hydroxy-4-phenyl-2-butanone was only detected in wine macerated with jaqueira wood, while benzophenone, ethyl pentadecanoate, D-citronellol, linalool, geranic acid and isovainillic acid were only detected in wine macerated with amburana wood. For sensory profile, wine macerated with amburana wood showed significantly higher scores for “coconut”, “toasted” and “floral” aroma descriptors, while for taste and overall appreciation this wine also showed a tendency for a slightly higher score. The outcomes of this research improved the knowledge of the use of several South American wood species on red wine characteristics.
- Optimized Production of Fungal Polygalacturonase Using Cupuaçu (Theobroma grandiflorum) Peel as Substrate and Its Effect on Clarification of Cupuaçu JuicePublication . Falcão, Lucas; Monteiro, Trisha; Azevedo, Sthéfanny; Batista, Bárbara; Jordão, António; Albuquerque, PatríciaPectinolytic enzymes play a key role in many beverages manufacturing processes, improving their clarification and filtration steps. Fungal pectinases are considered promising green catalysts for industrial applications, and they can be produced using fruit-processing residues as substrate. In this study, we investigated the optimal conditions to produce polygalacturonase from Aspergillus brasiliensis in a solid-phase bioprocess, using cupuaçu (Theobroma grandiflorum) peel as substrate. Then, the pectinolytic extract was applied in the clarification of cupuaçu juice. A central composite design was used to determine the optimal fungal cultivation conditions. Thus, the optimal fungal cultivation (maximum production of 11.81 U/g of polygalacturonase) was obtained using cupuaçu peel with 80% moisture, at 34 ◦C, for 7 days in a medium containing 4.2% phosphorus and 2.6% nitrogen. The enzymatic extract showed greater activity at 60 ◦C and stability at a pH range between 5.0 and 7.0. The pectinolytic extract was able to clarify the cupuaçu juice, causing a 53.95% reduction in its turbidity and maintaining its antioxidant activity. Our results demonstrate that the cupuaçu peel can be used as a substrate to produce polygalacturonase, and the enzymatic extract produced can be applied in the cupuaçu juice processing, contributing to the circular economy.
- Machine Learning Approaches for Predicting Maize Biomass Yield: Leveraging Feature Engineering and Comprehensive Data IntegrationPublication . Abbasi, Maryam; Vaz, Paulo; Silva, José; Martins, Pedro; Silva, José; ANTUNES VAZ, PAULO JOAQUIMThe efficient prediction of corn biomass yield is critical for optimizing crop production and addressing global challenges in sustainable agriculture and renewable energy. This study employs advanced machine learning techniques, including Gradient Boosting Machines (GBMs), Random Forests (RFs), Support Vector Machines (SVMs), and Artificial Neural Networks (ANNs), integrated with comprehensive environmental, soil, and crop management data from key agricultural regions in the United States. A novel framework combines feature engineering, such as the creation of a Soil Fertility Index (SFI) and Growing Degree Days (GDDs), and the incorporation of interaction terms to address complex non-linear relationships between input variables and biomass yield. We conduct extensive sensitivity analysis and employ SHAP (SHapley Additive exPlanations) values to enhance model interpretability, identifying SFI, GDDs, and cumulative rainfall as the most influential features driving yield outcomes. Our findings highlight significant synergies among these variables, emphasizing their critical role in rural environmental governance and precision agriculture. Furthermore, an ensemble approach combining GBMs, RFs, and ANNs outperformed individual models, achieving an RMSE of 0.80 t/ha and R2 of 0.89. These results underscore the potential of hybrid modeling for real-world applications in sustainable farming practices. Addressing the concerns of passive farmer participation, we propose targeted incentives, education, and institutional support mechanisms to enhance stakeholder collaboration in rural environmental governance. While the models assume rational decision-making, the inclusion of cultural and political factors warrants further investigation to improve the robustness of the framework. Additionally, a map of the study region and improved visualizations of feature importance enhance the clarity and relevance of our findings. This research contributes to the growing body of knowledge on predictive modeling in agriculture, combining theoretical rigor with practical insights to support policymakers and stakeholders in optimizing resource use and addressing environ mental challenges. By improving the interpretability and applicability of machine learning models, this study provides actionable strategies for enhancing crop yield predictions and advancing rural environmental governance.
- Enhanced Properties of Cryptomeria japonica (Thunb ex L.f.) D.Don from the Azores Through Heat-TreatmentPublication . Esteves, Bruno; Nunes, Lina; A. Lopes, Rogério; Gonçalves Oliveira Valente da Cruz-Lopes, Luísa PaulaThis study evaluates the chemical, physical, mechanical, and biological properties of untreated and heat-treated Cryptomeria japonica (Thunb ex L.f.) D.Don wood from the Azores, Portugal. Heat treatment was performed at 212 ◦C for 2 h following the Thermo-D class protocol. Chemical analysis revealed an increase in ethanol soluble extractives and lignin content after heat treatment, attributed to hemicellulose degradation and condensation reactions. Dimensional stability improved significantly, as indicated by reduced swelling coefficients and higher anti-swelling efficiency (ASE), particularly in the tangential direction. Heat-treated wood demonstrated reduced water absorption and swelling, enhancing its suitability for applications requiring dimensional stability. Mechanical tests showed a decrease in bending strength by 19.6% but an increase in the modulus of elasticity (MOE) by 49%, reflecting changes in the wood’s structural integrity. Surface analysis revealed significant color changes, with darkening, reddening, and yellowing, aligning with trends observed in other heat-treated woods. Biological durability tests indicated that both untreated and treated samples were susceptible to subterranean termite attack, although heat-treated wood exhibited a higher termite mortality rate, suggesting potential long-term advantages. This study highlights the impact of heat treatment on Cryptomeria japonica wood, emphasizing its potential for enhanced stability and durability in various applications.
- O impacto da inteligência Artificial na esfera do TurismoPublication . Caldeira, Bruna Vanessa Teixeira; Antunes, Joaquim Gonçalves; Malva, Maria Madalena de FreitasAtualmente deparamo-nos com transformações de paradigmas que impulsionam constantes mudanças na nossa sociedade, no setor industrial e nas estratégias de marketing. Esta tecnologia tem um impacto significativo no comportamento dos consumidores alinhando as suas preferências e necessidades de uma maneira mais rápida. Na indústria no turismo, a implementação da IA representa tanto uma vantagem competitiva, como de igual forma conduz a uma redefinição das estratégias de marketing dentro das empresas, permitindo uma comunicação mais clara e eficiente junto dos consumidores. O principal objetivo desta dissertação foi desenvolver conhecimento empírico sobre as opiniões de profissionais e não profissionais do setor turístico relativamente à utilização da inteligência artificial, com um foco particular nos seus impactos positivos e negativos no setor turístico e no ambiente de trabalho das empresas. A metodologia adotada consistiu numa abordagem quantitativa materializada num inquérito online, que constou com uma amostra de 162 indivíduos. Os resultados foram submetidos a testes estatísticos para validar as conclusões de investigação. Os resultados revelaram que, apesar de alguns receios relacionados com a substituição de postos de trabalho, a maioria dos participantes reconheceu que a implementação desta tecnologia oferece benefícios para os setores económicos. Destaca-se no conjunto dos impactos positivos, a melhoria de personalização das ofertas turísticas e o aumento da eficiência nas campanhas de marketing. A inteligência artificial também é reconhecida como uma ferramenta para aprimorar a acessibilidade no planeamento territorial dos destinos turísticos, tornando-os os espaços mais acessíveis para responder de forma mais eficaz a necessidade de grupos específicos de visitantes, como pessoas com mobilidade reduzida ou turistas com necessidades especiais. Este estudo pretende enfatiza o impacto da inteligência artificial no setor turístico e no ambiente laboral, evidenciando os desafios e oportunidades da sua implementação. Além de aumentar a competitividade das empresas, a IA tem como objetivo criar experiencias mais personalizadas e eficientes aos consumidores.
- A desinformação nos meios de comunicação social portugueses, o papel do jornalismo e do factchecking: o caso da guerra na UcrâniaPublication . Santos, Tifany Isabel Valente dos; Midões, Miguel; Martins , JoanaA dissertação de mestrado apresentada tem como objetivo analisar, compreender e estudar a desinformação mediática em Portugal, com foco no caso da guerra da Ucrânia, procurando responder à questão: existe desinformação nos media portugueses relativamente ao caso da guerra na Ucrânia? Desta forma, foi realizado um enquadramento teórico de modo a entender melhor esta temática, quais os procedimentos que estão a ser tomados para combater os problemas que surgem através da desinformação e verificar de que forma as informações falsas se tornaram uma propaganda para qualquer tópico apresentado ao público, uma vez que, com o surgimento da internet e das redes sociais, este problema foi amplamente difundido. A dissertação tem como objetivo abordar o conflito bélico entre Ucrânia e Rússia, procurando explorar a relação entre ambos os países ainda antes da guerra, bem como perceber o seu passado e os motivos que possam ter levado ao conflito. Relativamente ao estudo de caso, foi realizada uma análise noticiosa, que envolve o jornal Público e o telejornal do canal de televisão TVI, de modo a perceber se existe desinformação nos media em Portugal. E, ainda por forma a perceber como lidam os jornalistas com esta realidade, também foram realizadas entrevistas a jornalistas de diferentes meios de comunicação social (imprensa, rádio e televisão), de modo a entender o lado dos profissionais nesta temática. Em relação às conclusões retiradas do estudo de caso, tanto a análise noticiosa como as entrevistas revelam que a desinformação nos media portugueses, relativamente à guerra na Ucrânia, é que de facto existe, porém poucas vezes os media portugueses difundem informação falsa sobre o assunto, e quando o fazem, tendem a corrigir essa informação. A análise noticiosa mostrou que, embora existam esforços para combater a desinformação, há certos casos de informação falsa que chega ao público. Já os jornalistas de meios de comunicação portugueses evidenciaram as dificuldades que os profissionais enfrentam em relação ao fact-checking, especialmente devido à velocidade com que a desinformação chega ao público geral.
- Consumer Motivations Towards Second-hand Clothing: a Case Study in PortugalPublication . Simões, Cláudia Pereira; Amaro, Suzanne Fonseca; Reis, Manuel António Lourenço dosThis research aims to explore the current dynamics of second-hand clothing (SHC) consumption among Portuguese consumers, focusing on the motivations behind it, the barriers to its adoption, and other behavioural and attitudinal dimensions to gain a deeper understanding of consumer engagement in this market. A comprehensive literature review was conducted, examining key topics such as consumerism, sustainability, fast fashion, consumer motivations, and the circular economy. This review provided a solid theoretical foundation and underscored the importance of addressing second-hand clothing consumption as a sustainable alternative in the context of contemporary environmental and social challenges. To gather data, an online survey was conducted in Portugal during November 2024. A total of 230 respondents participated, and the survey categorized them as SHC consumers or non-consumers. The questionnaire aimed to capture motivational and attitudinal factors, as well as behavioural patterns, providing a multidimensional perspective on SHC consumption. Factor analysis revealed four motivational factors for SHC consumption: sustainable, economic, hedonic, and ethical motivations, with sustainable and economic motivations being the most significant. Gender differences were observed, with females scoring higher on sustainability and economic motivations. For non-consumers, three barrier factors were identified: contaminated interaction, social perception, and availability of local second-hand stores, with the latter being the most substantial. By identifying these motivations, barriers, and behavioral patterns, this study contributes to a better understanding of how to design effective communication strategies aimed at promoting sustainable consumption practices. Encouraging the reuse of clothing is not only a step toward fostering a circular economy but also a means to combat consumerism and ensure a more sustainable future for society as a whole.
- Comprehensive Evaluation of Deepfake Detection Models: Accuracy, Generalization, and Resilience to Adversarial AttacksPublication . Abbasi, Maryam; ANTUNES VAZ, PAULO JOAQUIM; Silva, José; Martins, PedroThe rise of deepfakes—synthetic media generated using artificial intelli gence—threatens digital content authenticity, facilitating misinformation and manipu lation. However, deepfakes can also depict real or entirely fictitious individuals, leveraging state-of-the-art techniques such as generative adversarial networks (GANs) and emerging diffusion-based models. Existing detection methods face challenges with generalization across datasets and vulnerability to adversarial attacks. This study focuses on subsets of frames extracted from the DeepFake Detection Challenge (DFDC) and FaceForensics++ videos to evaluate three convolutional neural network architectures—XCeption, ResNet, and VGG16—for deepfake detection. Performance metrics include accuracy, precision, F1-score, AUC-ROC, and Matthews Correlation Coefficient (MCC), combined with an assessment of resilience to adversarial perturbations via the Fast Gradient Sign Method (FGSM). Among the tested models, XCeption achieves the highest accuracy (89.2% on DFDC), strong generalization, and real-time suitability, while VGG16 excels in precision and ResNet provides faster inference. However, all models exhibit reduced performance under adversarial conditions, underscoring the need for enhanced resilience. These find ings indicate that robust detection systems must consider advanced generative approaches, adversarial defenses, and cross-dataset adaptation to effectively counter evolving deep fake threats