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Repositório Digital da Universidade da Beira Interior
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E-Kerosene Potential for Commercial Aviation Decarbonization
Publication . Quaresma, Guilherme da Silva Nheu; Magalhães, Leandro; Ferreira, Ana Filipa; Silva, André Resende Rodrigues da
Reducing greenhouse gas emissions from aircraft transport is crucial to achieving climate goals. In this sense, the present study looks into the suitability of e-fuels such as e-kerosene in reducing CO2 emissions. The Fleet System Dynamic Model is employed to examine data and predict future trends in line with the Committee on Aviation Environmental Protection. While the findings suggest that achieving carbon-neutral growth is possible, it might take longer than current forecasts indicate. For instance, considering an e-fuel production rate of 15%, it is possible to cut emissions by half around 2060 concerning 2005 levels.
Modelling Asteroid Trajectory in Earth’s Atmosphere
Publication . Morais, Renato Henriques; Santos, Luis; Silva, André Resende Rodrigues da ; Melício, Rui
Earth’s atmosphere is humanity’s last defence against the potential threat of asteroid impacts. To assess the impact risk and devise effective mitigation strategies, it is essential to understand the interaction between asteroids and the atmosphere. This paper presents a comprehensive study that employs a system of differential-algebraic equations (DAEs) to model the trajectory and associated physical processes involved in an atmospheric entry and the consequent impact of an asteroid. The Apophis asteroid is utilized as a case study to compare and evaluate the performance of two numerical methods for solving these equations. The findings from this research contribute to advancing our understanding of asteroid entry dynamics and provide valuable insights for enhancing asteroid impact mitigation strategies. The Apophis asteroid, represented as a 340 m diameter sphere with a density of 3190 kg.m−3, enters the atmosphere at a velocity of 30759 m.s−1 and a 45-degree angle from an altitude of 81 km. The first method employed is the 4th-order Runge-Kutta method (RK4) with a constant time-step, commonly used for solving highly non-linear problems like this. The second method is based on the Dormand-Prince method, which utilizes a dynamic time step and provides a 4th-order solution with error estimation using a 5th-order solution. Computational efficiency and the resulting solutions are compared between the two methods. The study finds that the Dormand-Prince method offers a more accurate numerical solution with less computational effort. However, both approaches demonstrate a correspondence of at least three significant digits, confirming their validity. Overall, during its traversal through the atmosphere, the Apophis asteroid experiences a decrease in initial velocity by 0.83%, a loss of 22% of its initial mass, and a variation in its angle with the horizontal by 1.5%.
GeoBIM for Geothermal Energy Efficiency in Buildings and Smart Cities: A Review
Publication . Pinto, Hugo Alexandre Silva; Gomes, Luís Manuel Ferreira; Pais, Luís Andrade; Nepomuceno, Miguel Costa Santos; Bernardo, Luís; Gonçalves, Vanessa; Morais, Maria Vitoria; Perelló Marchiori, Leonardo
The global drive toward energy transition and carbon neutrality requires integrated and data-driven approaches for managing buildings and smart cities. Existing urban energy assessment frameworks remain fragmented and often lack multiscale interoperability between building-level models and territorial datasets. At the same time, shallow geothermal energy is emerging as an efficient and renewable solution for sustainable heating and cooling. To address these gaps, this study examines the potential of GeoBIM, the integration of Building Information Modeling (BIM) and Geographic Information Systems (GIS), as a unified framework for multiscale energy analysis and for supporting shallow geothermal applications. A systematic literature review was conducted based on the PRISMA framework, combining a systematic literature review using the Scopus database with the critical examination of representative case studies. The results show that GeoBIM-based modeling improves data quality, enhances thermal performance assessments, and supports the implementation of shallow geothermal systems, including energy piles and district-scale ground-coupled networks. Reported applications demonstrate energy consumption reductions exceeding 40% in certain urban contexts. Several research gaps and challenges were identified, particularly data interoperability issues, lack of standardization, computational complexity, and the need for specialized training. Overall, the review indicates that GeoBIM offers a promising pathway for optimizing resources, supporting informed decision-making, and advancing resilient and sustainable smart buildings and cities.
Large-Scale Integration of Variable Renewable Energies in Electric Power Markets — Optimization Models, Options and Challenges
Publication . Bento, Pedro Miguel Rocha ; Mariano, Sílvio José Pinto Simões
Electrical Power Systems recognized as vast and complex entities, are the true ”engine” of contemporary societies. Currently, social and environmental concerns dominate the political agenda, notably highlighted by the Paris Agreement (2015), the EU’s Energy Roadmap 2050, and the UN’s 2030 Agenda for Sustainable Development. These initiatives stem from the detrimental impacts of persistent greenhouse gas emissions, requiring a significant contribution from these entities. This scenario foreshadows a substantial increase in renewable energy penetration, leading to increasingly decentralized and variable generation. Consequently, the Iberian Power Systems, as a leading adopter, faces additional and considerable transformations, requiring a reevaluation of otherwise outdated predicates and in more micro level, decisionmaking processes. Key areas demanding special attention include the future energy policy, which can only be effectively shaped after reviewing the evolution of the power generation structure within a market-integrated context, as well as the multitude of related options for providing system flexibility—a key enabler of this profound change. Moreover, a prevailing trend across nearly every field is the increasing reliance on data proliferation, machine learning models, and advanced optimization tools to address challenges that were once considered highly complex and less accessible. This is particularly evident in the context of electrical power systems design and operation, where such tools are now being applied to solve micro-level tasks with significant accuracy. As a result, to effectively integrate these tools, it is essential to first delve into the theoretical bedrock and practical intricacies — including the selection and tuning of hyperparameters, model architectures, and optimization strategies. This knowledge has become indispensable for modern power systems engineers, enabling them to better understand and tackle the micro-level challenges that often stem from broader energy policy decisions. In this context, the optimal power flow and short-term price forecasting problems — both of vital importance to electricity market participants — will serve as experimental test beds to rigorously evaluate and demonstrate the application of these data-driven methodologies.
Students’ Attitudes and Motivational Climate in Physical Education: Implications for Engagement in Community Youth Sport
Publication . Pereira, Paulo Alberto da Silva; Marinho, Daniel Almeida
The physical activity carried out by students in Physical Education classes is insufficient to meet the recommendations recommended by the World Health Organization. Therefore, it is essential that young people practice extracurricular physical activities in their free time and persist in this practice after compulsory schooling, (i.e., when they no longer have the Physical Education subject). Hence, one of the objectives of this discipline must be to promote the acquisition of active lifestyles. Students' attitudes towards Physical Education and the motivational climate in Physical Education classes seem to be key variables in the reasons for practicing sports. However, there are few studies that have analyzed the relationship between these variables. In this sense, the purpose of this thesis is to analyze the relationships between students' attitudes towards Physical Education, their perception of the motivational climate in the subject's classes and their reasons for practicing sporting activities in extracurricular contexts. Findings showcase the following: (i) for the most part, students have a moderately positive attitude towards Physical Education; (ii) students’ positive attitudes towards Physical Education differ depending on their school year and gender; (iii) a more positive attitude towards Physical Education facilitates a better grade in this discipline; (iv) students perceive Physical Education classes more as mastery-oriented than performance-oriented; (v) school year and socioeconomic status seem to influence perceptions towards the motivational climate in Physical Education; (vi) perceiving the climate in Physical Education as masteryoriented and a positive attitude towards Physical Education are positive predictors of engaging in community youth sport programming; (vii) a mastery-oriented climate in Physical Education influences grades in Physical Education; (viii) the Portuguese versions of the SAtPE, EPCM and SMS II have appropriate psychometric properties in terms of reliability and validity and can enable scholars to assess the variables at stake in secondary schools within the Portuguese context. Taken together, these findings can pave the way for quality Physical Education programming and for conducting additional research within this line of inquiry.