https://hdl.handle.net/20.500.12008/26173 Incluye artículos, objetos de conferencias, seminarios y jornadas, reportes técnicos, comunicaciones y otros 2026-06-17T16:45:59Z https://hdl.handle.net/20.500.12008/55554 Título: Rate –limiting steps of the oxygen reduction reaction in REBa2Cu3O6+ẟ (RE = La, Nd, Sm, Gd and Y) layered perovskites as IT-SOFC cathodes Autor: Grassi, J.; Montenegro-Hernandez, A.; Serquis, A.C.; Basbus, J.F.; Suescun, L Resumen: The classical high-temperature superconductor YBa2Cu3O6+δ (YBCO) with an oxygen-vacant triple perovskite structure has been proposed as a potential cathode for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs), and REBa2Cu3O6+ẟ (RE = La, Nd, Sm, Gd and Y) triple perovskites synthesized by a self-combustion method were evaluated. The total substitution of Y by lanthanide ions (RE3+) proved to modify relevant bulk and surface properties, thus changing performance under operating conditions, i.e., the incorporation–diffusion mechanism by oxygen vacancies and oxide anion transport. Electrochemical Impedance Spectroscopy (EIS) under different oxygen partial pressure (pO2) and temperature (T) conditions allowed elucidating a co-limited oxygen incorporation/diffusion mechanism as Oxygen-Reduction Reaction (ORR) limiting steps. Ionic radii (ri) variation from Y3+ to La3+ impacts the kinetics of the two steps, thereby modifying the overall cathode performance. The results provide evidence of the complex relationship between crystallography, point defect concentration, chemical composition and electrochemical properties in REBCO cathodes. Data suggest that the Cu–O bond distance in cuprates may be critical for shifting the rate-limiting step and improving ORR activity. Overall, this research advances the comprehension of ORR kinetics in cobalt-free materials with layered diffusion. 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/55535 Título: Sustainable food posts on social media : an exploratory study on X using hashtags Autor: García-León, Ruth Areli; Ares, Gastón Resumen: Social media is considered a powerful tool to spread information about sustainable food, with both positive and negative impacts on sustainable food behavior. Thus, this exploratory study aimed to investigate the topics related to the hashtag #sustainablefood and their sources on “X.” Posts in English containing the hashtag #sustainablefood, between June 1st, 2021 and May 30th, 2022, were retrieved using a combination of the Twitter API and the social networking scraper SNS in Python. Characteristics of users generating the posts were retrieved from their profiles and analyzed using content analysis. Results indicated that companies and media organizations led the communications related to #sustainablefood, whereas regular consumers were a minority of the users posting content on the topic. In addition, associations between hashtags were analyzed with network analysis and using hierarchical cluster analysis, nine main topics were identified: agriculture, climateaction, climatechange, environmental, farm, plantbased, vegan, innovation, and foodtech. Hashtags on each topic varied by source, producing different messages. Plantbased and climatechange were identified as key bridging hashtags via betweenness centrality. This study contributes to understanding how sources use hashtags differently regarding sustainable food on social media and highlights the importance of analyzing post sources to avoid misattributing content to regular users. 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/55531 Título: Fruit and vegetables loss and waste in Uruguay, a high-income Latin American country : causes and reduction strategies from a multi-stakeholder perspective Autor: Giménez, Ana; Ares, Gastón Resumen: Fruits and vegetables are a cornerstone of healthy and sustainable diets. Paradoxically, despite global consumption levels falling below recommendations worldwide, they are among the most lost and wasted food groups along the agri-food supply chain. The aim of this study was to qualitively explore the loss and waste of fruits and vegetables in Uruguay, a high-income Latin American country, from the perspective of diverse stakeholders. Semi-structured interviews were conducted with 20 key informants. Results suggest that most fruit and vegetable losses and waste occur at the production stage. Key causes identified include the commercial quality standards based on aesthetic criteria, overproduction resulting from uncoordinated planning, technological limitations in post-harvest handling, and the limited capacity of the national industry to absorb surpluses and suboptimal products. These structural factors are compounded by cultural dimensions, such as reluctance to consume imperfect-looking products or non-traditional edible parts. Interviewees proposed multiple strategies to reduce losses and waste, including awareness campaigns to revalue aesthetically imperfect products; strengthening coordination and planning within the production sector; investment in infrastructure and technology for appropriate product handling; implementation of recovery and redistribution processes; and the valorization of surplus and off-grade products through industrial processing. The central role of consumers was emphasized in reshaping demand patterns to foster more inclusive quality standards. These findings highlight the need for a systemic and cross-sectoral approach to reduce fruit and vegetable loss and waste in the country and to advance towards more sustainable, equitable, and resilient food systems. 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/55398 Título: Catalytic hydrophosphorylation of propiolates and three-component phosphorylation of aldehydes Autor: Delgado-Hernández, Samuel; Peixoto de Abreu Lima, Alejandro; Martín-Díaz, Eva M.; Scoccia, Jimena; Carrillo, Romen; Tejedor, David Resumen: A practical and efficient regio- and stereoselective hydrophosphorylation of propiolates, as well as a multicomponent reaction incorporating an aldehyde component, is reported. Both processes proceed with atom economy in very straightforward experimental procedures. The reactions are catalyzed by DABCO (1,4- diazabicyclo[2.2.2]octane) and use readily available H-phosphonates as the phosphorylating agent. 2026-01-01T00:00:00Z