97828 research outputs found
Sort by
Experimental investigation of a R290 domestic heat pump equipped with a thermoelectric-aided sub-cooler
No full textThe energy efficiency of heat pumps is an important factor for the sustainability and electrification of domestic heating, especially for the most common air-to-water heat pumps, which are a competitive solution to conventional heating methods. However, novel solutions for cold and moderate climate zones must be developed considering environmentally friendly natural refrigerants such as hydrocarbons. One idea is to introduce a thermoelectric-aided sub-cooler into an air-to-water heat pump to improve the coefficient of performance. Therefore, this work aims to experimentally investigate a novel propane heat pump system with a prototype thermoelectric-aided sub-cooler for domestic heating. Energy analysis was performed to evaluate the energy impact of the sub-cooler in terms of ambient conditions from -10.0 ∘C to 5.0 ∘C, different water temperatures for heating applications in existing buildings from 45.0 ∘C to 55.0 ∘C and varying operating conditions of thermoelectric modules in the sub-cooler. The performance of the sub-cooler was evaluated. The results confirm that introducing a thermoelectric-aided sub-cooler can improve the heat pump performance by up to 6.0% and the heating capacity improvement by up to 17.0% for the low ambient temperature of -10.0 ∘C. Furthermore, an optimal direct current voltage below 3.0 V was found for every investigated operating condition to ensure the best system coefficient of performance
DLIJ, gènere i revisionisme curricular
No full textDins de la didàctica de la Literatura infantil i juvenil (DLIJ) cal reflexionar sobre la influència de la realitat en els canvis curriculars vinculats a la lectura. La polèmica al voltant de la cultura de la cancel·lació i la llibertat de pensament acadèmic en nombrosos casos està unida a la censura. Compartim el nostre treball en la formació inicial de mestres, articulat des del gènere, vinculant les obres de no-ficció i les de ficció, de diversos autors i autores que compten amb obres adreçades a la infància i l'adolescència, també còmics o novel·les gràfiques que poden llegir els futurs i les futures mestres, incidint en la necessitat d'aquesta revisió en l'aproximació a la seua obra, considerant la polèmica social que han provocat i els beneficis de la reflexió sobre la violència simbòlica i/o real en el seu context, implícita a la seua trajectòria
Datafeudalism and Democracy: The Domination of Big Tech Corporations in the Age of Generative AI
No full textCompendi d'articles, Doctorat internacionalThis doctoral thesis examines the adverse effects stemming from the transformation of digital giants’ socio-economic model —from surveillance capitalism to datafeudalism— and from the rapid emergence and popularisation of generative AI (GenAI) tools on European Union (EU) democratic systems. The research pursues three interrelated objectives. Firstly, it applies a hermeneutic-critical methodological framework to analyse the global system of social, economic, and political domination established by big tech corporations and its detrimental consequences for the proper functioning of EU democracies. Secondly, it examines the dangers posed by the emergence and strategic use of GenAI to the existence of an autonomous and authentic public sphere and to the formation of a critical and mature public opinion. Thirdly, it proposes a set of guidelines aimed at mitigating these threats and enhancing the performance of EU democratic systems in a fair, transparent, responsible, and explainable manner.Programa de Doctorat en Ètica i Democràci
Biomaterials based on LMWG-polymer multicomponent supramolecular hydrogels
No full textDoctorat internacionalSupramolecular hydrogels are formed through the self-assembly of low-molecular-weight gelators (LMWGs) in water, creating three-dimensional fiber networks via non-covalent interactions. The primary drawback of supramolecular hydrogels is their generally low mechanical strength. Therefore, the fabrication of hybrid LMWG-biopolymer materials is a useful strategy to enhance the final properties of the material. In this context, the synthesis of novel supramolecular hybrid hydrogels combining LMWGs with biopolymers for use as multicomponent biomaterials is notably relevant. On one hand, LMWG-polymer conjugates are prepared by synthesizing two low-molecular-weight peptide fragments that are covalently linked to the polymer, L-polyglutamic acid (PGA). On the other hand, multicomponent supramolecular hydrogels are developed. These hydrogels are formulated using biocompatible polymers such as hyaluronic acid (HA), L-polyglutamic acid (PGA), or different gelatins, which are combined with a supramolecular gelator based on dipeptides.Programa de Doctorat en Cièncie
Autopercepción de competencias y entorno de prácticas en estudiantes de enfermería en el este de Inglaterra
No full textLa experiencia práctico-clínica tiene un papel esencial en la formación universitaria de las enfermeras. La percepción de los estudiantes de su entorno de prácticas y la autopercepción de su preparación para desenvolverse en dicho entorno aparecen destacados en la literatura. Se llevó a cabo un estudio descriptivo y transversal de tipo correlacional en estudiantes del Grado de Enfermería en una universidad del este de Inglaterra para analizar la relación entre el entorno en las prácticas clínicas y el nivel de competencia percibido por los participantes. Se encontró una asociación positiva entre el entorno y el nivel de competencia y diferencias significativas de competencia autopercibida entre los grupos. Los estudiantes del grado de Enfermería valoran de forma favorable su entorno de prácticas, lo cual influye en una autopercepción general positiva de su nivel de competencia. Sería recomendable explorar en mayor profundidad a los diferentes grupos de estudiantes.Practice experience plays an essential role in the undergraduate education of nurses. Students' perceptions of their practice environment and the self-perception of their preparedness to work in that environment are highlighted in the literature as relevant factors. A descriptive, cross-sectional, correlational study of undergraduate nursing students at a university in the East of England was conducted to examine participants' perceived level of competence and its relationship to the clinical practice environment. A positive association was found between environment and level of competence. There were significant differences in self-perceived competence between the groups. Nursing students rate their practice environment favourably, and this influences their overall positive perception of their level of competence. Further exploration of these findings in different groups of students would be advisable.Programa de Doctorat en Ciències de la Infermeri
We know who wins: graph-oriented approaches of passing networks for predictive football match outcomes
No full textFootball is one of the most popular sports worldwide. Football fans, in their pursuit of maximizing enjoyment from supporting their favorite teams, are eager to know the outcome of ongoing matches. However, related studies to predict football match outcomes have focused on predicting them before the match starts, using measures from previous match data. Therefore, we propose a method to predict the outcome of an ongoing match at any time during the game as one of three classes: home win, away win, or draw. We focus on the event of passes, the most fundamental unit of movement in football, and have been shown in many studies to influence match outcomes. Unlike previous studies that used generalized aggregated variables such as total pass counts for pass information, we propose a graph-based classification model that directly utilizes the dynamically changing passing network as a graph. Our proposed graph-based model effectively leverages information about the location of each pass and the players attempting these passes from the passing network. As a result, in experiments predicting the final outcome at the 45, 60, 75, and 90-minute marks, our model outperformed baseline models that used general pass measures.
Furthermore, by additionally incorporating non-pass event information, our model achieved a performance improvement of 5 to 20% across various classes compared to using only the passing network. This study holds substantial implications for integrating graph theory and graph modeling into the domain of football, highlighting the impact of passing information on outcome prediction
Las competencias docentes del profesorado universitario en un mundo digital: políticas y estrategias para el proceso de inducción a la docencia
No full textCompendi d'articles, Doctorat internacionalLa presente tesis doctoral analiza las políticas y estrategias del proceso de inducción a la profesión docente universitaria a nivel nacional, dentro del contexto tecnológico actual. Mediante un enfoque cualitativo, se realiza un análisis documental y de contenido de: los marcos de competencias docentes, la formación docente del profesorado novel en las universidades españolas y cinco grupos de discusión con diferentes agentes (administradores, noveles y formadores). Los resultados, presentados en siete artículos, destacan la necesidad de un enfoque integral y contextualizado para la formación docente novel. Se recomienda combinar la mentorización, la innovación, la reflexión y una evaluación de impacto del programa. También es relevante ofrecer un mayor apoyo y reconocimiento institucional, así como un tratamiento integral y pedagógico de las tecnologías digitales en el desarrollo profesional docente. A su vez, la conexión entre teoría y práctica, así como la personalización de las formaciones en un entorno colegiado, resulta clave.This thesis analyses the policies and strategies of the induction process to the university teaching profession at a national level, in the current digital context. Using a qualitative approach, a documentary and content analysis is carried out of teaching competency frameworks, of teacher training for new teachers in Spanish universities and of five focus groups with key agents (administrators, novices and teacher educators). The results, presented in seven articles, indicate the need for a holistic and contextualised approach to new teacher education. A combination of mentoring, research-based innovation, reflection and evaluation of the impact of these programmes is recommended. To this end, the university must offer greater institutional recognition and it is essential to adopt a holistic and pedagogical approach on digital teaching competence. Finally, personalisation of training and the connection between theory and practice in a collegial environment are essential.Programa de Doctorat en Educaci
Comparative life cycle assessment of lead-free halide perovskite composites/polymer for piezoelectric energy harvesting
No full textLead zirconate titanate (PZT) is one of the most widely used piezoelectric materials due to its excellent performance. However, its lead content raises serious environmental and health concerns, prompting the search for more sustainable alternatives. In this work, we explore whether a lead-free composite based on the halide perovskite FASnI3 embedded in a polyvinylidene fluoride (PVDF) matrix could serve as a viable substitute for PZT in piezoelectric energy harvesting applications. To assess this potential, we conduct a comparative life cycle assessment (LCA) of both materials in thin-film device configurations, following a cradle-to-grave approach. The analysis includes the environmental impacts of raw material extraction, manufacturing, potential energy recovery during use, end-of-life treatments, and accidental release scenarios. The results show that PZT-based devices have consistently higher environmental impacts across all life cycle stages, mainly due to the high energy requirements for their synthesis and thin-film deposition, as well as the use of lead. In contrast, the FASnI3–PVDF composite benefits from low-temperature processing and the absence of lead, resulting in significantly lower impacts during manufacturing and the use phase. This study offers a first comparative insight into the environmental trade-offs of substituting PZT with halide perovskite-based composites, contributing to the identification of more sustainable piezoelectric solutions
What Shapes Quality of Life in Youth? A Multidimensional Approach from Lifestyle to Residential Context—Cor-School Study
No full textBackground: Health-related quality of life is a key indicator of well-being that
integrates physical, emotional, and social dimensions. Identifying its determinants during childhood and adolescence is essential to guide effective health promotion strategies.
Objective: To analyze the association between health-related quality of life and demographic, anthropometric, biochemical, lifestyle, and environmental variables in school-aged
children and adolescents. Methods: A cross-sectional study was conducted during the
2023–2024 academic year in northeastern Spain. A total of 571 children and adolescents
participated in the study (mean age = 11.64 ± 1.64 years), of whom 254 were girls (44.48%).
Health-related quality of life was assessed using the Revised Children’s Quality of Life
Questionnaire (KINDL-R), a validated instrument for assessing perceived well-being in
pediatric populations. Independent variables included waist-to-height ratio, high-density
lipoprotein cholesterol, low-density lipoprotein cholesterol, adherence to the Mediterranean
diet, weekly physical activity, sleep quality, and residential context (i.e., large urban areas,
small urban areas, and municipalities). Multiple linear regression analysis was performed
to explore the associations. Results: Older age was associated with lower health-related
quality of life (β = −1.07; 95% CI: −1.61 to −0.53; p < 0.001). In contrast, better adherence
to the Mediterranean diet (β = 0.72; 95% CI: 0.09 to 1.37; p = 0.023), better sleep quality
(b = −2.48; p < 0.001), and participants living in cities and large urban areas reported
compared to those in municipalities were associated with higher HRQoL (p < 0.05), with
moderate effect sizes. No significant associations were found for sex, waist-to-height ratio,
cholesterol levels, or physical activity. Conclusions: This study highlights the importance
of adopting a multidimensional approach to promote health-related quality of life in young
populations, addressing dietary habits, sleep quality, and environmental factors within
health promotion strategies
When the Mediterranean boils
No full textTreball Final de Grau en Periodisme. Codi: PE0932. Curs: 2024/202