http://hdl.handle.net/10174/1027 Tue, 07 Jul 2026 17:49:43 GMT 2026-07-07T17:49:43Z http://hdl.handle.net/10174/42293 Title: GCxGC-TOFMS with flow modulation for fingerprinting volatile compounds in Portuguese grape varieties Authors: Fonseca, Daniela; Martins, Nuno; Garcia, Raquel; Cabrita, Maria João Abstract: Comprehensive two-dimensional gas chromatography offers a powerful analytical tool for profiling volatile compounds in complex matrices. The characterization of grapevine varieties that are resilient to water stress, such as autochthonous varieties, while safeguarding quality characteristics, is fundamental to viticulture. For this reason, the objective of this study was to characterize the volatile composition of four white varieties from the Alentejo region (Portugal), subjected to three different irrigation regimes: water comfort, moderate water deficit, and rainfed. The first step was to optimize the modulation conditions, and it was found that the most effective modulation period was 5 s, with a flush time of 0.20 s. After optimizing these conditions, the grapes of the Diagalves, Manteúdo, Perrum and Rabo de Ovelha varieties were analyzed by HS-SPME-GCxGC-TOFMS. A total of seventy-six volatile compounds, of which fifty-one were varietal volatiles, were identified and semi-quantified in these varieties. The results reveal that the irrigation regime influences the volatile profile with varying responses across the varieties. While Diagalves exhibited no significant differences between irrigation regimes, Manteúdo and Perrum demonstrated higher levels of varietal volatile compounds, particularly terpenes and C13 norisoprenoids, under rainfed conditions. According to PCA, irrigation regimes affect each variety differently. In conclusion, Manteúdo and Perrum emerge as the most statistically promising varieties in terms of adaptability to water scarcity. These findings highlight the significance of selecting resilient autochthonous grape varieties as an effective strategy to mitigate the impacts of climate change while maintaining the wine's distinctive aromatic character. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10174/42293 2026-01-01T00:00:00Z http://hdl.handle.net/10174/42202 Title: Towards an ecological metaphor for regenerative circular economies Authors: Zisopoulos, Filippos; D. Fath, Brian; Meirelles de Oliveira, Bruno; Toboso-Chavero, Susana; D'Assenza-David, Hugo; Miranda de Souza, Vitor; Huang, Hao; Scrieciu, Serban; Clark, O. Grant; Noll, Dominik; Singh, Simron; Stefanakis, Alexandros; Boyd, Graham; Schraven, Daan; de Jong, Martin Abstract: An ecological metaphor can enable transitions towards regenerative circular economies. Yet, this potential remains latent because its conceptual development, which is a prerequisite for its practical operationalization, is in its incipient phase and largely vague. To strengthen its epistemological underpinning, we propose a forward-looking interdisciplinary research agenda which brings together theories, ontological positions, analytical approaches, and strategies of action from ecological economics, panarchy theory, socio-metabolic research, process ecology, environ network theory, the constructal law, nature-based solutions, complexity economics, doughnut economics, regenerative economics, and ergodicity economics. The agenda facilitates the concentration, consolidation, and acceleration of theoretical and methodological innovation for the generation and accumulation of a diverse yet coherent body of knowledge on the interpretation of the process of regeneration and for illuminating the ways in which regenerative circular economies may function. Wed, 30 Apr 2025 23:00:00 GMT http://hdl.handle.net/10174/42202 2025-04-30T23:00:00Z http://hdl.handle.net/10174/42192 Title: Inequities blocking the path to circular economies: A bio-inspired network-based approach for assessing the sustainability of the global trade of waste metals Authors: Zisopoulos, Filippos; D. Fath, Brian; Toboso-Chavero, Susana; Huang, Hao; Schraven, Daan; Steuer, Benjamin; Stefanakis, Alexandros; Clark, O. Grant; Scrieciu, Serban; Singh, Simron; Noll, Dominik; de Jong, Martin Abstract: Considering the importance of waste metals for the transition to circular economies, this study follows a bio-inspired approach to evaluate their material and monetary global trade patterns for sustainability and equity. Between 2000 and 2022, the global trade grew by 5 % in trading countries, by 37 % in trade links, by 71 % in material flows, and by 569 % in economic flows. Driven by indirect effects, the average circulation of material and monetary flows ranged between 21.8–34.9 % depending on the demand or supply perspective but showed a declining trend. Due to homogenization, high network redundancy, and low network efficiency the trade remained robust yet outside the "window of vitality" characterizing natural ecosystems. A few, mostly high-income countries dominated the market, consolidating imports of high-value metal waste mostly from low- and middle-income exporters. Policies should address circularity and trade inequities, accounting for environmental and social ramifications throughout the lifecycle of products and materials. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/42192 2025-01-01T00:00:00Z http://hdl.handle.net/10174/42171 Title: Recycling Composite Food Packaging: Recovering and Valorization of Individual Components Authors: Mourão, Paulo; Coelho, David; Marques, Carolina; Assis, Carolina; Panizio, Roberta; Nobre, Catarina; Brito, Paulo Editors: Sérgio Brito, Paulo; Sanches Galvão, João; Almeida, Henrique; Rosa Ferreira, Liliana; Flores de Oliveira Gala, Pedro Abstract: Paper composite packaging, increasingly used in various sectors including food, offers benefits like enhanced product preservation. However, its recycling poses challenges due to the difficulty in separating its components, leading to waste accumulation in landfills or incineration. This work aims to develop a sustainable recycling strategy to address this environmental issue. The methodology was designed to investigate and assess the materials present in composite packaging, their compatibility with various solvents, and the feasibility of recovering packaging components such as paper, synthetic polymers, metals, and others. Additionally, the study aimed to recover solvents used in the process and determine the calorific value of the recycled samples. Using Hansen Solubility Parameters, we identified the most effective solvents for dissolving the composite food packages under analysis. Following solubilization, two samples (SL1’ and SH1’) were selected for further investigation, both dissolved using p-Cymene. These samples underwent FTIR-ATR and NMR analysis, that enabled the identification of specific polymers, including PE (Polyethylene), LDPE (Low-density polyethylene), HDPE (High-density polyethylene), PP (Polypropylene), and PC (Polycarbonate), present on those composite packaging. Furthermore, both samples were incinerated, and their calorific values were measured, ranging from 18.19 to 18.76 MJkg−1, demonstrating that they have potential for being valorized via energy recovery. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/42171 2025-01-01T00:00:00Z