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Magnetic Field-Based Strategy for Damage Detection and Stratigraphy Assessment for Structural Health Monitoring Applications
No full textStrong efforts are being carrying out to implement efficient and accurate structural health monitoring (SHM) strategies for large surfaces. The criticality of high demanding structures, such as vessels, pipelines, or aircrafts, requires costly integrity inspections to ensure their performance and security. This study presents a novel SHM approach using magnetic particles for precise damage detection and coating stratigraphy assessment. The methodology is demonstrated on an industrially produced sheet molding compound (SMC) laminate composite, incorporating an epoxy coating layer doped with 20 wt% NdFeB particles. The coating achieves a coercive field (Hc) of 7000 Oe and a saturation magnetization (Ms) of 136.8 emu g−1. Uniform dispersion of magnetic particles is confirmed, while surface characterization indicates minimal impact on roughness and wettability. Mechanical testing shows a negligible effect on flexural modulus but a reduction in bending strength due to constrained molecular mobility. Magnetic flux mapping enables fast and accurate damage detection and coating depth assessment. Perpendicular magnetization enhances damage detection and sensitivity, while longer acquisition times (3 s) and higher magnetization fields (1.1 T) improve resolution and facilitate thickness evaluation. These findings highlight the potential of these coatings for SHM, offering precise damage detection and insights into coating uniformity, ultimately supporting advanced monitoring solutions for critical structures.This project was supported by the BASQUE GOVERNMENT INDUSTRIAL DEPARTMENT, grant number KK-2021/00124 under the FRONTIERS 2021 project (Elkartek program). This study forms part of the Advanced Materials programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) as well as by IKUR Strategy under the collaboration agreement between Ikerbasque Foundation and Fundacion BCMaterials on behalf of the Department of Education of the Basque Government. The authors thank the FCT—Fundação para a Ciência e Tecnologia—for financial support in the framework of the Strategic Funding UID/FIS/04650/2021 and under project 2022.05540.PTDC
SiO2 gels as anode precursors for lithium-ion batteries
No full text[EN] This work aims to prepare different SiO2 gels and to prove their viability as anode materials for Li-ion batteries.[ES] Este trabajo tiene como objetivo la preparación de geles de sílice para estudiar su viablidad como materiales anódicos en baterías de ion-Li
Evolutionary implications of a deep-time perspective on insect pollination
No full textPlant pollination by insects represents one of the most transformative and iconic ecological relationships in the natural world. Despite tens of thousands of papers, as well as numerous books, on pollination biology published over the past 200 years, most studies focused on the fossil record of pollinating insects have only been published in the last few decades, and this field is still undergoing major developments. Current palaeontological evidence indicates that pollinating insects were diverse and participated in the reproduction of different gymnosperm lineages long before their association with flowering plants (angiosperms). However, since much of this literature remains unfamiliar to many scientists working on extant plant–pollinator interactions, as well as the wider public, the notion that insect pollination began with the origin of angiosperms is still widespread. Herein we highlight how all the known insect orders with extant and/or extinct pollinator representatives radiated long before the evolution of flowering plants. We also illustrate the changing composition of the insect pollinator fauna through time, reflecting the different nature of these communities compared to those existing today. Addressing plant pollination by insects from a perspective skewed towards present-day biological groups, patterns, and processes risks missing an important deep-time evolutionary component. Our conclusions show that the fossil record is fundamental to elucidating the origin and evolution of insect pollination, as well as informing on present-day plant–pollinator interactions.We thank two anonymous reviewers for their valuable comments on earlier drafts, as well as Alison Cooper for careful edits on the manuscript. We also thank the programme RYC2022-037026-I, funded by AEI/10.13039/501100011033 and the FSE+, and the projects “CREI” (PID2022-137316NB) and “FLOW” (PID2023-151735NA-I00) funded by the Ministry of Science, Innovation and Universities of Spain MICIU/AEI/FEDER. Thanks also to the Secretary of Universities and Research (Government of Catalonia) for the project “Sedimentary Geology” (2021SGR-349). J. O. is funded by a Yunnan Government (China) High-end Foreign Expert Project of the Yunnan Revitalization Talent Support Program. C. P.-K. is funded by the National Agency for Research and Development (ANID) Scholarship Program, Doctorado en el Extranjero, BECAS CHILE 2020-Folio 72210321. F. L. C. is supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (project GAIA, agreement no. 851188). The authors declare that they have no competing interests
¿Influyen la motivación, la autoeficacia creativa y la satisfacción vital en la competencia digital de estudiantes del Grado de Educación Social?
No full textEn una sociedad digitalizada, desarrollar habilidades digitales se ha convertido en un objetivo prioritario en la formación de futuros educadores sociales. Este estudio persigue analizar el nivel de competencia digital (CD) de estudiantes del grado de Educación Social e identificar factores predictores entre distintas variables académicas y psico-emocionales. Se ha utilizado una muestra intencional compuesta por 151 estudiantes de cuatro cursos. Los resultados indican que el alumnado presenta un nivel medio-bajo en las áreas y los indicadores de la CD. Tiene un dominio mayor en tareas básicas, especialmente asociadas al área de alfabetización tecnológica, aunque muestra dificultades en las dimensiones y los indicadores que abarcan actividades complejas como la aplicación de pensamiento crítico para tomar decisiones informadas. También, revelan que existen diferencias en base al curso académico, siendo el alumnado de tercero el que mejores destrezas digitales presenta. Asimismo, se aprecia que la satisfacción vital, la autoeficacia creativa y la orientación a metas intrínsecas son factores predictores de la CD. Ante estos hallazgos, es preciso repensar los planes de estudios para ofrecer una formación actualizada y adaptada a las necesidades digitales particulares de cada estudiante, considerando también otros factores académicos y psico-emocionales que interfieren en su desarrollo
Modelos epidemiológicos: análisis, control y aplicación al COVID-19
No full text[ES] En este trabajo se da una introducción a los modelos epidemiológicos, describiendo varios modelos y analizando sus puntos de equilibrio y estabilidad. A continuación, se estudian dos estrategias de control sobre el modelo, basadas en la cuarentena y la vacunación. Finalmente, se comprueba la utilidad real del modelo sobre datos reales del COVID-19, logrando utilizar el modelo para realizar pequeñas prediccionesa corto plazo
Global synthesis and regional insights for mainstreaming urban nature-based solutions
No full textNature-based solutions (NbS) have emerged as a key strategy for sustainably addressing multiple urban challenges, with rapidly increasing knowledge production requiring synthesis to better understand whether and how NbS work in different social, ecological, economic, or governance contexts. Insights in this Perspective are drawn from a thematic review of 61 NbS review articles supported by an expert assessment of NbS knowledge in seven global regions to examine key challenges, fill gaps in Global South assessment, and provide insights for scaling up NbS for impact in cities. Eight NbS challenges emerged from our review of NbS reviews including conceptual, thematic, geographic, ecological, inclusivity, health, governance, and systems challenges. An additional expert assessment reviewing literature and cases in seven global regions further revealed the following: 1) Local context-based ecological knowledge is essential for NbS success; 2) Improved technical knowledge is required for planning and designing NbS; 3) NbS need to be included in all levels of planning and governance; 4) Putting justice and equity at the center of urban NbS approaches is critical, and 5) Inclusive and participatory governance processes will be key to long-term success of NbS. We synthesized findings from the NbS review results and regional expert assessments to offer four critical pathways for scaling up NbS: 1) foster new NbS research, technological innovation, and learning, 2) build a global NbS alliance for sharing knowledge, 3) ensure a systems approach to NbS planning and implementation, and 4) increase financing and political will for diverse NbS implementation.We thank the US NSF (grants #1927468, #1927167, #1444755, and #1934933), the NSF of China (grant #42225104), the GreenCityLabHue Project (FKZ 01LE1910A), the CLEARING HOUSE, Horizon 2020 projects (#821242), CONNECTING Nature (#730222), CARDIMED (#101112731) as well the “Urban and Peri-Urban Agriculture as Green Infrastructure” project funded by the British Academy’s “Urban Infrastructures of Well-Being” programme
Effect of Bio-Based Flame Retardants in Sustainable Epoxy Systems for the Development of Composite Materials
No full textThe composite materials industry is increasingly seeking sustainable alternatives to mitigate the environmental impact of end-of-life materials. As a result, many sectors are transitioning toward bio-based or partially bio-based matrices (e.g., epoxy resins) to preserve material properties while improving sustainability. The transportation sector, in particular, demands materials that meet stringent mechanical and fire resistance standards. In this study, various epoxy systems with bio-based and/or recyclable content were investigated, along with renewable additives designed to enhance fire resistance through their functional groups and chemical structure. The research focused on developing formulations compatible with Sheet Moulding Compound (SMC) technology, which is widely used in transportation applications. Through extensive testing, materials with high bio-based content were successfully developed, exhibiting competitive mechanical properties and compliance with key fire safety requirements of the railway sector, as per the EN 45545-2 standard.This research was funded by CDTI (Centro para el Desarrollo Tecnológico Industrial), within the framework of grants for Technological Centers of Excellence “Cervera” (MARFIL Project, CER-20231001). This research is included in “Plan Nacional de Recuperación, Transformación y Resiliencia”, which receives funding from the “Next Generation EU” funds. Furthermore, it was funded by the Provincial Council of Bizkaia under its Technology Transfer Program 2021 (BIOKONP Project, 6/12/TT/2021, and by the Department of Economic Development and Infrastructures of the Basque Government under its ELKARTEK 2022 Program (FRONTIERS Project, KK-2022/00109)
Unravelling the hidden complexity of Arcobacter butzleri biofilms: Functional characterisation of biofilm associated genes and matrix components using both classical methods and genetic analysis of mutants
No full text526 p.The ability to form biofilms represents a major virulence factor of the foodborne pathogen Arcobacter butzleri, facilitating its persistence, survival, and dissemination along the food production chain. This capacity poses a significant public health concern, as it enhances the potential for infection and the development of gastrointestinal illness in humans and animals. Moreover, it may explain the widespread occurrence of this microorganism across diverse ecological niches, including foodstuffs, water sources, clinical samples, food processing environments, and domestic animals. Despite increasing scientific attention towards A. butzleri and its biofilm-forming capabilities, critical knowledge gaps remain. In particular, the molecular mechanisms governing biofilm formation and the detailed composition of the extracellular matrix are not yet fully characterised. This PhD thesis addresses these gaps by integrating microbiological and molecular methodologies to investigate A. butzleri biofilms from multiple analytical perspectives. Using both directed and random mutagenesis approaches, six genes (flaA, flaB, fliS, luxS, pta, and spoT) were identified as functionally implicated in biofilm formation. In addition, random transposon mutagenesis revealed 29 further candidate genes potentially involved not only in biofilm development but also in other physiological processes, including motility, methionine auxotrophy, L-lactate metabolism, antimicrobial resistance, and cold adaptation. A notable outcome of this work is the successful design, construction, characterisation, and validation of the first shuttle vector capable of replicating and expressing genes in both Escherichia coli and A. butzleri. This vector constitutes a valuable genetic tool that will facilitate gene manipulation and functional complementation studies in A. butzleri, thereby advancing genetic and functional analyses in this species. The composition of the A. butzleri biofilm matrix was also examined in detail. The matrix was found to be primarily composed of proteins and extracellular DNA, followed by carbohydrates and lipids. The carbohydrate component appears to exhibit a cellulose like structure consisting of N-substituted monomers linked by ß-1,4-O-glycosidic bonds. This hypothesis is supported by multiple complementary techniques, including Congo red and Calcofluor white staining, Fourier-transform infrared spectroscopy, gas chromatography¿mass spectrometry, and high-performance liquid chromatography¿ mass spectrometry. Overall, the findings of this study contribute to a deeper understanding of A. butzleri biofilm biology and highlight the complexity of its extracellular matrix. Further research is warranted to fully elucidate the biochemical composition of the biofilm and to define the specific roles of the genes identified through transposon mutagenesis. Such knowledge is crucial for the development of targeted and effective strategies aimed at the prevention, control, and eradication of A. butzleri biofilms, particularly within food safety, clinical, and veterinary context
Producción sostenible de alcohol furfurílico mediante catálisis en fase acuosa: hidrogenación in-situ de la molécula furfural mediante catalizador basado en cobre
No full text[ES] Hidrogenación in-situ del furfural para generar alcohol furfurílico utilizando catalizador de cobre. Pruebas de formaldehído, metanol y ácido fórmico como donantes de hidrógeno Sintetización y caracterización de catalizador de aluminato de cobre. Estudio del APR de los donantes de hidrógeno y de la hidrogenación in-situ del furfural mediante estos donantes. Efectos e temperatura y tiempo en la hidrogenación mediante el donante seleccionado como óptimo, el formaldehído
Entanglement and nonlocality in multiparticle systems
No full text[EN] In this Bachelor Thesis, I present some of the fundaments of entanglement detection. I introduce basic entanglement criteria namely the PPT and CCNR criteria. Entanglement witnesses are defined and used in illustrative examples. I also explain Bell inequalities and their relation with other entanglement witnesses. Lastly, in the last section of the theoretical background I introduce some collective observables and show how we can use them to detect entanglement in our experiments.
Once the basics have been explained, I present a new criterion that gives us a lower bound in the amount of entanglement particles of a system. This caracterizes the quantum system from a new perspective and can be of great interest in modern multipartite entanglement experiments. Some results will be used to validate our approach, demostrating that it complements previous methods