Repositori Obert UdL
The institutional repository collects, manages, disseminates and preserves publications in open access derived from the academic and research activity of the University of Lleida.
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Open Access
Diseño de un modelo multidimensional de evaluación y seguimiento del futbolista en clubes de fútbol
(2026) Amador Martínez, Sergi
El presente Trabajo de Fin de Máster desarrolla un modelo multidimensional de evaluación y seguimiento del futbolista aplicable a clubes con diferentes niveles competitivos y estructuras organizativas. A partir de la revisión de la literatura y del diagnóstico de los procesos de evaluación y seguimiento, se propone una estructura integrada por seis dimensiones: técnico-táctica, físico-condicional, perceptivo-cognitiva, psicológica-psicosocial, biológica-individual y contextual-ambiental. El modelo combina información objetiva y cualitativa, incorpora una perspectiva longitudinal y mantiene el criterio profesional como elemento central de la interpretación. Su aplicación se articula mediante doce herramientas de recogida de información y un dashboard configurable que centraliza las evidencias, valoraciones, objetivos y evolución del jugador. El proyecto se completa con una propuesta organizativa, un estudio de viabilidad económica y una estrategia de comercialización. El resultado es una propuesta flexible y escalable, concebida para facilitar la integración de información y apoyar la toma de decisiones deportivas.
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Open Access
Adapting current protocols is necessary to eradicate the novel ASFV variant in the peri-urban wild boar population of Barcelona, Spain
(Elsevier, 2026-08-29) López-Olvera , Jorge Ramón; Relimpio Peral, David; Barasona, José Ángel; Kosowska, Aleksandra; Mentaberre García, Gregorio; López-Martín, Josep Maria; Gortázar, Christian
In November 2025, a new genotype II African swine fever virus (ASFV) variant emerged in wild boars (Sus scrofa) in Barcelona, Spain. The peri-urban setting favours a higher wild boar population density. Furthermore, the new variant seems associated to slower mortality, possibly resulting in longer-lasting transmission. Together, such particularities form a novel outbreak scenario that requires adapting the current ASF eradication strategies developed for highly pathogenic ASFV-strains in lower density wild boar populations. While the same main interventions (fencing; carcass search, removal and disposal; and wild boar depopulation) are to be applied, the intensity, relative importance, and spatiotemporal distribution of each intervention must be tailored. The main recommended adaption is increasing culling intensity to reach depopulation, compensating higher population density and slower disease-related mortality. This represents a challenging objective in the peri-urban MAB context and its multiple human, wildlife, and environment-related constraints.
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Open Access
Experimental investigation of inlet subcooling effects on flow boiling in an open microchannel under hydrostatic inlet-head control
(Elsevier, 2027) Camarasa Falip, Jaume; Vilarrubí, Montse; Rosell, Pol; Crespo, Alicia; Tadrist, Lounes; Barrau, Jérôme
Open microchannels are a promising configuration for flow boiling because the top gap facilitates vapor evacuation and liquid replenishment, thereby improving thermal performance and moderating flow instabilities. However, their behavior under different inlet subcooling conditions remains insufficiently understood under hydrostatically controlled inlet-head operation, particularly when water is used as the working fluid. Deionized water flow boiling was experimentally investigated in an open microchannel heatsink featuring a 100 μm top gap and microstructures with an aspect ratio of 15 and a length of 50 mm. Experiments were conducted at four prescribed hydrostatic heads (from 45 to 85 cm) at three different inlet temperatures: 60, 75 and 90 ºC. Quantitative thermohydraulic measurements were complemented by high-speed flow visualization. Raising inlet temperature from 60 to 90 ºC reduced the heat flux at the onset of nucleate boiling (ONB) by 73–79%, whereas the critical heat flux (CHF) decreased by only 19–34%. Consequently, the two-phase operating window widened and was largest at 90 ºC. The lowest subcooling condition yielded the highest heat transfer performance, with maximum heat transfer coefficients of 12,847–23,686 W/m2·K under surge-like vapor motion, but also the sharpest pre-CHF deterioration. This wider operating window incurred hydraulic and dynamic penalties: pressure drop increased by up to 335% from ONB to CHF and, at 102 W/cm2 under the highest hydrostatic-head condition, pressure drop oscillation severity increased by 169%. Increasing hydrostatic head from 45 to 85 cm more than doubled the ONB flow rate, whereas lower subcooling accelerated flow rate depletion and fluctuations toward CHF.
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Open Access
Más allá del acuerdo interjueces: protocolo y herramienta para la validación de contenido en investigación educativa
(Universitat de Barcelona, 2027) Calderón Garrido, Diego; Carrera, Xavier
INTRODUCCIÓN. La validez de contenido constituye una fuente de evidencia fundamental en la construcción de instrumentos de medición en ciencias sociales. El juicio de expertos es el procedimiento más extendido para obtenerla; sin embargo, su implementación adolece con frecuencia de falta de transparencia metodológica, criterios de decisión implícitos y ausencia de reglas de interpretación explícitas.MÉTODO.Este trabajo presenta un protocolo de validación interjueces orientado a sistematizar y objetivar ese proceso. El protocolo propone la valoración de cuatro indicadores por ítem —univocidad, pertinencia, relevancia y adecuación de la escala de respuesta— mediante una rúbrica de cuatro niveles.RESULTADOS.A partir de las puntuaciones otorgadas por los jueces, se calculan dos índices complementarios: el nivel de calidad del ítem y el grado de consenso interjueces estimado mediante la desviación estándar. La combinación de ambos índices permite adoptar decisiones fundamentadas de conservación, modificación o eliminación de cada ítem conforme a criterios replicables. El protocolo se acompaña de un ejemplo de implementación y de una herramienta en formato Excel que automatiza los cálculos. DISCUSIÓN.Se discuten los fundamentos metodológicos de la propuesta y sus limitaciones, situándola en el marco de los enfoques contemporáneos de validación basados en evidencia múltiple.
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Open Access
ImageGrains 2.0: Improved precision and generalization for grain segmentation
(Copernicus Publications, 2026-07-14) Mair, David; Witz, Guillaume; Do Prado, Ariel; Garefalakis, Philippos; Wild, Amanda; Ville, Fanny; Schuster, Bennet; Horn, Michael; Österle, Jürgen; Fabbri, Stefano Claudio; Litty, Camille; Achleitner, Stefan; Leistner, Sebastian; Hiller, Clemens; Schlunegger, Fritz
Recent advances in deep-learning-based image segmentation have enabled the development of automated approaches to detect individual grains and measure them for geoscientific applications. These methods facilitate the creation of much larger and more precise datasets than traditional manual grain measurements. However, they typically perform best as specialized models trained on homogeneous, task-specific datasets, and often show reduced accuracy when used on different data types.
Here, we present an updated framework, ImageGrains 2.0 that leverages Cellpose-SAM, a recently published next-generation deep-learning model originally developed for cell segmentation in biomedical research. It currently represents the state-of-the-art for dense segmentation in 2D and 3D biomedical datasets. It yields robust results and is capable to generalize across distinctly different image datasets. These properties allow us to re-train the model with geoscientific datasets comprising annotated images of fluvial gravel, coarse pro-glacial deposits, and X-ray computer tomography scans of glacial till and marine sand. We benchmark the segmentation performance of our method against ground-truth annotations, compare it to the performance of other segmentation methods, and we evaluate its measurement accuracy. Our results indicate that this approach outperforms existing methods and confirm that the outstanding performance of Cellpose-SAM is transferable to segment sediment grains. We analyze the size and shape of these segmented grains and find that an increase in grain segmentation accuracy leads to more precise and realistic morphometric results, e.g., more accurate grain size distributions. Additionally, we introduce an interactive graphical user interface for image annotation and correction of model predictions, facilitating the use of the framework for a broad range of image settings. Furthermore, this study underscores the importance of curating more publicly available datasets, which could pave the way towards the generation of a foundation model for segmenting granular particles in geoscientific imagery.