Thesis authorised for defence

DOCTORAL DEGREE IN AGRI-FOOD TECHNOLOGY AND BIOTECHNOLOGY

• SOLER CAMPRECIÓS, JORDI: AVALUACIÓ DELS REQUERIMENTS REPRODUCTIUS I DEL CONTROL QUÍMIC DE L’AILANT (AILANTHUS ALTISSIMA), COM A ESPÈCIE INVASORA D’ESPAIS NATURALS
  
  Author: SOLER CAMPRECIÓS, JORDI
  Programme: DOCTORAL DEGREE IN AGRI-FOOD TECHNOLOGY AND BIOTECHNOLOGY
  Department: Department of Agri-Food Engineering and Biotechnology (DEAB)
  Mode: Normal
  Deposit date: 13/07/2026
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: IZQUIERDO FIGAROLA, JORDI
  Thesis abstract: Invasive plants, such as Ailanthus altissima, cause damage to biodiversity due to their high capacity for expansion and establishment. A thorough understanding of the reproductive traits of this species is essential to define eradication strategies based on effective control methods.During the literature review, insufficient information was found regarding chemical methods to break seed dormancy, resulting in low germination rates. Conversely, other studies have shown that alternating temperature regimes promote germination. However, this method involves temperature accumulation that is not compatible with base temperature experiments. The base temperature for seeds or roots has never been determined, and only a few studies have addressed the base water potential of seeds, all conducted outside our region. From the base temperature, predictive germination models can be developed—a task we included in this study to create tools that assist in planning future management actions for this invasive species.The results showed a low response in dormancy release across different treatments, with the best germination achieved through cold stratification at 10 °C for 21 days. The base temperature for seeds and roots was very similar, and under water stress conditions, both seed germination and root sprouting decreased.We focused on evaluating the effectiveness of commercially available herbicides at the time of this study. Different application periods, herbicides, and techniques were tested. Herbicide application provided better control compared to untreated trees. The most effective technique was cut-stump injection, and the most efficient herbicides were triclopyr combined with 2,4-D and/or aminopyralid. The effect of flazasulfuron on Ailanthus altissima was evaluated for the first time, showing satisfactory results.We also identified, for the first time in Catalonia, the eriophyid mite Aculus taihagensis, a species already reported in other countries as a potential biological control agent.In conclusion, Ailanthus altissima can be eradicated if the correct methods are used, while predictive models will assist managers in the management of eradication efforts.
  

DOCTORAL DEGREE IN APPLIED MATHEMATICS

• FACCIOTTI, BENEDETTA: Groupoids of local systems and decorated representations on marked bordered surfaces
  
  Author: FACCIOTTI, BENEDETTA
  Programme: DOCTORAL DEGREE IN APPLIED MATHEMATICS
  Department: School of Mathematics and Statistics (FME)
  Mode: Normal
  Deposit date: 13/07/2026
  Reading date: 20/10/2026
  Reading time: 18:00
  Reading place: Sala 327 SYMCREA, planta 3 de l'EPSEB, Campus Sud Join Zoom Meetinghttps://us06web.zoom.us/j/85064553889?pwd=hlFbcaUadWq4QQLS7FYGpUhbVNbUhH.1
  Thesis director: MAZZOCCO, MARTA | NIKOLAEV, NIKITA
  Thesis abstract: This thesis studies representations of fundamental groupoids of surfaces $\Sigma$ with boundaries, with values in $G:=\operatorname{GL}_n(\mathbb C)$, up to isomorphism. When no marked points are present on the boundary, the corresponding objects admit several equivalent descriptions: as linear local systems on $\Sigma$, as representations of the fundamental groupoid $\Pi_1 (\Sigma)$, as monodromy data, and as points of the associated character variety. The introduction of marked points on the boundary, motivated by the need to encode irregular singularities of meromorphic connections, has led to several generalizations of this Betti-type description in the literature. Although these approaches are generally understood to describe essentially the same mathematical objects, the precise relation between them has not yet been been formulated explicitly. Motivated by the broader programme of establishing a precise and conceptually coherent relationship between the existing approaches to the representation-theoretic description of irregular singularities of meromorphic connections, in this thesis we develop a categorical framework for the definition of decorated Betti objects associated with marked bordered surfaces encoding higher-order poles, in a form designed to specialize to the different points of view encountered in the literature.
  

DOCTORAL DEGREE IN BIOMEDICAL ENGINEERING

• RIVERA TORRES, PEDRO JUAN: Complex Engineering Systems: Expanding the Bioengineering Toolset with Biomimetic and Complexity Science-Based Solutions to Engineering Problems.
  
  Author: RIVERA TORRES, PEDRO JUAN
  Programme: DOCTORAL DEGREE IN BIOMEDICAL ENGINEERING
  Department: Department of Automatic Control (ESAII)
  Mode: Article-based thesis
  Deposit date: 13/07/2026
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: KANAAN IZQUIERDO, SAMIR
  Thesis abstract: This dissertation will seek to expand the toolset available for the solution of problems in engineering using probabilistic Boolean networks (PBN), a modeling methodology used mainly for analyzing Gene Regulatory Networks (GRN). Its purpose is validating their benefits as mechanisms of problem solving in engineering; general machine learning, reinforcement learning and fault detection and isolation in generation and transmission/distribution of electrical power and in manufacturing systems. The use of PBNs has been validated before as a mechanism of modeling of manufacturing processes and smart power. Modeling of systems using PBNs allows to construct models of multiple systems, know their respective failure modes, and incrementing their robustness using reinforcement learning to predictively react to faults and failures. We present the use of PBNs as a model constructing mechanism to determine the reliability of engineered systems and processes, and control of their evolution using machine learning. These models will enable us to study the mechanics of failure in engineered systems, making them more robust. We also present a Learning Probabilistic Boolean Network model of a manufacturing system and a Smart-grid system that can learn to preserve a healthy system state, in a way inspired by Artificial Neural Networks, but without the training that these systems require, and allowing the system to avoid faults and failures.
  

DOCTORAL DEGREE IN BUSINESS ADMINISTRATION AND MANAGEMENT

• GOYZUETA MEJÍA, ZARELA MÓNICA: L'orientació de client a partir de l'experiència educativa: la perspectiva d'estudiants de pregrau a les universitats privades del Perú
  
  Author: GOYZUETA MEJÍA, ZARELA MÓNICA
  Programme: DOCTORAL DEGREE IN BUSINESS ADMINISTRATION AND MANAGEMENT
  Department: Department of Management (OE)
  Mode: Normal
  Deposit date: 08/06/2026
  Reading date: 18/09/2026
  Reading time: 12:00
  Reading place: ETSETB- UPC, Aula B3 Teleensenyament Enllaç públic: meet.google.com/ipt-evpc-xzc
  Thesis director: CONSOLACION SEGURA, CAROLINA MARIA | BARREDO IBAÑEZ, DANIEL
  Thesis abstract: Neoliberalism, as a model of global governance, has promoted competition and market efficiency as pillars of economic and social progress. Its influence has permeated various sectors, and higher education has been no exception. In this sphere, this ideology has driven the emergence of marketization, a trend that conceives of the education system under a supply and demand model, where education is understood as a good or service that can be acquired, and whose value is measured primarily by the economic return it generates for the individual and its contribution to the economy as a whole.In this context, the metaphor of the student as customer arises, a concept of business origin that positions the student as the central consumer of an experiential educational service, aimed at providing them with a satisfactory academic foundation for their professional development.This phenomenon has generated extensive debate in literature, with arguments both for and against. However, existing research has not delved deeply into educational experience as a determining variable in shaping the profile of the student as client. Furthermore, most studies have focused on Europe and the United States, leaving Latin America—and particularly Peru—as a largely unexplored context.Within this framework, the purpose of this doctoral thesis is to analyze how client orientation is shaped in undergraduate students at private universities in Peru, considering the dimensions of their educational experience, the influence of demographic variables, and the perspective of academic experts. To this end, a mixed-methods approach was adopted.First, a systematic literature review on the student as customer metaphor (2000–2022) was conducted in the Scopus and Web of Science databases, identifying 83 studies that met the eligibility criteria. Second, the SCOQ (Student Customer Orientation Questionnaire) scale by Koris and Nokelainen (2015) was adapted to the Peruvian context, and 798 surveys were collected from three private universities. The data were analyzed using exploratory factor analysis, which identified the dimensions of the educational experience that define customer orientation in Peruvian students. Subsequently, a multiple regression model was applied to assess the influence of demographic variables. Finally, the results were triangulated with 12 in-depth interviews with academic experts to corroborate and enrich the findings.The research results reveal four main findings. First, the literature is structured around two predominant approaches: a critical perspective, focused on the risks of commodification and the weakening of academic rigor, and a relational perspective, which conceives of the student as a co-producer of the educational service. Second, adapting the SCOQ instrument to the Peruvian context allowed, through exploratory factor analysis, the identification of five factors of the educational experience. In four of these factors, students exhibit a client orientation. In contrast, positive self-demand is the only factor in which this orientation is not observed, highlighting the hybrid and multidimensional nature of the Peruvian student, who combines service demands with academic responsibility. Third, the multiple regression analysis, while having limited explanatory power, showed that some demographic variables have predictive value, with years of study standing out as the most influential factor. Finally, the triangulation with experts showed that teachers adopt a conditional acceptance stance, in which they recognize certain expectations inherent in a service logic on the part of students, but subordinate their validity to the preservation of academic rigor and teacher autonomy.
  

DOCTORAL DEGREE IN CIVIL ENGINEERING

• GARCIA RIVERA, JUAN PABLO: ESTUDIO EXPERIMENTAL DE LA CONFLUENCIA DE LOS RÍOS TOLTÉN Y ALLIPÉN (CHILE): RESULTADOS HIDRODINÁMICOS
  
  Author: GARCIA RIVERA, JUAN PABLO
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Normal
  Deposit date: 20/05/2026
  Reading date: 28/07/2026
  Reading time: 10:30
  Reading place: UPC Campus Nord, ETSECCPB, C/ Jordi Girona 1-3, edificio C1, Sala 002, Barcelona
  Thesis director: MARTÍN VIDE, JUAN PEDRO | FERRER BOIX, CARLES
  Thesis abstract: This thesis was motivated by the need to understand the hydrodynamic behavior of the confluence of the Toltén and Allipén rivers (Chile), where a bedload measurement campaign was conducted over 90 days in 2013 using a Helley-Smith sampler. During this campaign, gravel and sand transport was recorded with a non-uniform transverse spatial distribution in the measurement section (transect), referred to in this thesis as section 9. However, the lack of simultaneous hydrodynamic measurements prevented the establishment of cause-and-effect relationships between flow and sediment transport distribution.During the field campaign, individual and total flow rates were also recorded, with values ​​between 180 and 900 m³/s. This information served as the basis for developing experimental scenarios in the physical model.The overall objective of this thesis was to understand the hydrodynamic behavior (three-dimensional velocity field) of this confluence in order to identify patterns that can be generalized to confluences with similar characteristics. The physical model was constructed in the Hydraulics Laboratory of the University of Piura (Peru), with a geometric scale of 1:57.9 defined, conditioned by spatial constraints of the model site. The range of flow rates tested in the model varied between 7.7 and 32.8 l/s.The experiments were designed considering different flow combinations, characterized by a Q_tributary/Q_main flow ratio, whose values ​​ranged between 0.33 and 3.97.The experimental campaign included the calibration of triangular weirs for flow control and the definition of boundary conditions through one-dimensional modeling, using information from the prototype.Sixteen cross-sections were measured, with special emphasis on sections 6, 8, 9, and 11, near the reference transect. A total of 1641 three-dimensional velocity measurements (u, v, w) were taken, recorded at 25 Hz for 120 seconds per point, generating more than 3000 data points per measurement.Data processing was performed in Matlab using proprietary algorithms that included correlation and noise filtering (AADV and CADV), application of the Space-Phase Thresholding method, and Wavelet decomposition. The latter allowed the signal to be separated into low-frequency components (pulsations) and high-frequency components (turbulent fluctuations), facilitating a more in-depth analysis of the flow's temporal structure.Additionally, low-frequency pulsations were identified in each measurement; over a 2-minute period, these pulsations were observed to repeat 6 times. The application of dyes visually confirmed these periodic mixing patterns.From the three-dimensional velocity field, different stress components were estimated: Reynolds stress, low-frequency stress, total stress, cross stresses, and near-bottom stresses. The stresses obtained were compared with the critical stress at the onset of movement for a dimensionless Shields parameter of 0.03 (sands and gravels), allowing the identification of potential bed mobilization zones.Finally, the main contribution of this thesis lies in the detailed experimental characterization of the three-dimensional hydrodynamic field at a confluence with morphological unconformity, through the direct measurement of the three instantaneous velocity components and the analysis of their fluctuations. The results obtained provide physical and methodological criteria transferable to the study of river confluences with similar geometric and hydraulic characteristics.
  
• KALLINGER, MAGNUS DANIEL: Layout Optimization in Floating Offshore Wind with Focus on Subsea Components
  
  Author: KALLINGER, MAGNUS DANIEL
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Normal
  Deposit date: 06/07/2026
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: DOMÍNGUEZ GARCÍA, JOSÉ LUIS | TRUBAT CASAL, PAU
  Thesis abstract: Floating offshore wind is regarded as a key technology for exploiting deep-water wind resources where bottom-fixed foundations become economically uncompetitive. Yet, large-scale floating wind deployments remain constrained by high cost, limited maturity, and strong multidisciplinary coupling among subsystems that jointly determine farm feasibility and performance. Subsea components are central to this coupling: station-keeping systems and dynamic/static power cables govern not only structural response and electrical performance, but also impose first-order constraints on wind-farm design (turbine placement, anchoring footprints, cable topology and routing corridors). In addition, the limited practicality of subsea instrumentation motivates monitoring strategies that can reduce O&M burden and support condition-based operation. In this context, this thesis addresses layout optimisation for floating wind with a focus on subsea components. The thesis is organised around three research lines, aligned with the subsequent contribution chapters. First, it develops an early-stage optimisation framework for station-keeping design that combines computationally efficient frequency-domain simulations with customised particle swarm optimisation to screen large design spaces (layouts, materials, and ancillary components). The framework is applied both to conventional floating wind platforms and to a single-point moored weathervaning concept. Second, it investigates virtual sensing for floating wind turbines to estimate critical mooring and structural loads from accessible measurements, motivated by the high installation and maintenance effort of subsea sensors and by the need for scalable monitoring. Third, it advances floating wind inter-array design through (i) farm-level topology optimisation that incorporates floating-specific cable length effects and techno-economic performance, and (ii) physically informed routing that explicitly accounts for floater offsets, mooring-cable interaction constraints, touchdown feasibility, and three-dimensional bathymetry. The results show, first, that early-stage station-keeping optimisation can be carried out efficiently while producing technically meaningful and cost-effective designs, and it highlights the importance of line-specific functionality, substructure type, and site-dependent choices. Second, the virtual sensing studies demonstrate that critical loads can be estimated with useful accuracy and improved robustness when physical structure is embedded into the learning process, enabling reduced reliance on subsea instrumentation. Third, in the electrical domain, the proposed topology and routing methods improve the physical consistency and feasibility of floating wind cable layouts and yield measurable reductions in cable length and investment cost, which propagate to lower levelized cost of energy. Relative improvements are modest, but the absolute savings become significant at farm scale.
  
• MONTERO VEGA, MARIANA: Joint Operations of Autonomous Delivery Robots and Mobile Micro Hubs: A Continuous-Approximation and Game-Theoretic Assessment for Urban E-Commerce Logistics
  
  Author: MONTERO VEGA, MARIANA
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Article-based thesis
  Deposit date: 03/07/2026
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: ESTRADA ROMEU, MIGUEL ANGEL
  Thesis abstract: Last-mile logistics is one of the most resource-intensive and externality-generating segments of urban freight systems, yet market forces consistently fail to align private incentives with social objectives. This thesis investigates the conditions under which Autonomous Delivery Robots can serve as a catalyst for a more sustainable and equitable urban logistics paradigm, examining the problem through the Desirability-Feasibility-Viability framework across four interconnected studies.On the desirability side, a global survey of 1,344 e-commerce users across Europe, Asia, and North America reveals that acceptance of ADRs is real but structurally uneven. Socio-demographic factors, particularly gender, age, and urbanity shapes delivery preferences in ways that have direct implications for infrastructure design and deployment strategy. Parcel lockers emerge as the most preferred delivery modality globally, a finding that motivates their inclusion as a full market participant in the subsequent viability analysis. A multi-regional acceptance study combining structural equation models with an ordered logit model identifies perceived competence as the central mediating variable driving behavioral intention across all regions, while revealing that risk sensitivity and price barriers are significant only in markets where ADRs have not yet achieved commercial deployment. On the feasibility side, the moving micro hub (MMH) concept, a two-echelon system combining Autonomous Hub Vehicles with ADRs is introduced and evaluated through a continuous approximation model across multiple urban demand scenarios. The system reduces delivery costs by 40–55% relative to business-as-usual (BaU) while significantly lowering global warming potential, with ADR body capacity emerging as the dominant cost lever and operational speed as essentially irrelevant. User-derived design constraints from the desirability studies including robot height preferences, multi-compartment design, and off-peak delivery windows are incorporated directly as operational parameters, establishing a quantitative link between stated user preferences and system cost structure.On the viability side, a two-stage game-theoretic model demonstrates that cooperation among business-as-usual, moving micro hub, and parcel locker operators never emerges endogenously under market conditions: the ε-core is strictly positive across all Monte Carlo simulations when there is little to no taxation , establishing that public subsidy is a structural necessity rather than a transitional feature. A Stackelberg regulatory layer shows that Pigovian and diversified tax schemes achieve near-subsidy-free coalition stability at substantially lower fiscal effort than flat entry tolls, while producing fairer profit distributions and maintaining the viability of all three operators. Critically, the minimum subsidy required is shown to be substantially smaller than the monetized externality savings generated by the demand shift toward cleaner technologies, reframing public investment in coalition support as a fiscally efficient instrument for urban sustainability rather than a transfer to private operators. Taken together, the findings establish that the future of last-mile logistics will not be decided by technology alone. ADRs are operationally viable and environmentally beneficial, but their transformative potential depends on the willingness of regulators to price externalities, of system designers to align operational parameters with real user needs, and of policymakers to accept that stable cooperation among heterogeneous operators is a governance achievement, not a market outcome.
  
• MOODE, SESHADRI NAIK: Platooning of Connected Autonomous Vehicles on Freeways: Microscopic Modelling and Management Strategies
  
  Author: MOODE, SESHADRI NAIK
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Normal
  Deposit date: 03/07/2026
  Reading date: 29/07/2026
  Reading time: 10:00
  Reading place: UPC Campus Nord, ETSECCPB, C/ Jordi Girona 1-3, edifici C1, Sala 002, Barcelona
  Thesis director: SORIGUERA MARTÍ, FRANCESC
  Thesis abstract: Platooning Connected and Autonomous Vehicles (CAVs) via V2X communications is a transformative freeway strategy. Coordinated road trains with short space-gaps increase capacity, harmonize traffic, and reduce emissions. Realizing these benefits in mixed traffic requires integrating microscopic platoon dynamics with macroscopic corridor management. This thesis develops novel vehicle-level models and freeway management strategies to address this.Microscopically, the thesis introduces Platoon Adaptive Cruise Control (PACC), a safe space-gap car-following framework. PACC optimizes efficiency, stability, and safety, maintaining asymptotic stability across diverse contexts. Under severe incidents, its emergency braking averts collisions for instantaneous decelerations up to 1g. In extreme scenarios, residual collisions are strictly localized to immediate followers, proving PACC substantially improves safety over human driving.Macroscopically, four lane-management policies for CAV platoons in mixed traffic (0–75% penetration) are evaluated: strict left-lane dedication (D1), left-lane shared (S1), hybrid dedicated-plus-shared (D1S1), and two-lane shared (S2). Using a hybrid PACC/CACC architecture, throughput benefits prove policy-dependent. Dedicated control (D1) achieves highest peak flows but induces cross-lane imbalance, bursty platoons, staggered breakdown, and turbulence. Shared policies (S1, S2) yield compact, predictable traffic. The hybrid policy (D1S1) balances capacity and stability at intermediate penetrations but exhibits erratic platooning at high penetrations, requiring stage-specific tuning.Environmental impacts are assessed using a physics-based tractive power and VT-Micro chain. Normalizing against 0% CAV baselines to isolate automation effects, the thesis proves environmental benefits depend on actual local platoon formation (r = -0.92 for energy versus platoon rate), not nominal corridor penetration. Broad two-lane sharing (S2) delivers robust reductions up to 14.6% in energy/CO2 and 68.3% in NOx. Conversely, strict dedication (D1) amplifies aggressive catch-up maneuvers; occupying 3–6% of distance, they contribute up to 43% of NOx emissions, yielding an 8.6% energy benefit and a 1.8% NOx increase.For dynamic CAV integration, a hierarchical optimal control framework for discretionary lane-changing in non-cooperative mixed traffic is proposed. The tactical layer uses a physics-informed Dynamic Programming (DP) planner, penalizing incipient shockwaves and speed mismatches. The operational layer employs a longitudinal Optimal Control Problem (OCP) with adaptive uncertainty buffers, alongside a continuous-time Control Barrier Function (CBF) safety filter. Operating without V2V negotiation, this DP+OCP+CBF architecture maximizes throughput and minimizes shockwaves. Though computationally viable online, metrics reveal an efficiency-comfort trade-off.Overall, the thesis demonstrates that systemic CAV platooning benefits depend fundamentally on the joint design of robust vehicle control, adaptive lane policies, and local CAV sorting, not just market penetration. These frameworks provide a blueprint for safe, sustainable CAV deployment.
  

DOCTORAL DEGREE IN COMPUTATIONAL AND APPLIED PHYSICS

• GANCIO VAZQUEZ, JUAN: Characterizing and detecting changes in complex multidimensional data with permutation entropy
  
  Author: GANCIO VAZQUEZ, JUAN
  Programme: DOCTORAL DEGREE IN COMPUTATIONAL AND APPLIED PHYSICS
  Department: Department of Physics (FIS)
  Mode: Article-based thesis
  Deposit date: 25/06/2026
  Reading date: 30/07/2026
  Reading time: 11:00
  Reading place: Sala de conferencias, Edificio TR5, puerta 1.41, Campus Terrassa
  Thesis director:
  Thesis abstract: The analysis of signals obtained from complex dynamical systems is very important, not only from the point of view of many practical and interdisciplinary applications, but also, from the point of view of fundamental science, for elucidating the underlying mechanisms that generate complex behaviors. On one side, large amounts of data are currently used for purposes that have significant impact on society, for example, the detection and prediction of epidemic spreads, the analysis of trends in mobility and transportation networks, weather forecasting, to name a few. On the other side, many of the most challenging scientific endeavors intend to untangle many of these complex systems, such as the global climate and the human brain, and rely on the analysis of the signals that can be extracted from them. The analysis of these signals, even using modern approaches like machine learning and artificial intelligence, is based on the extraction of features that encode the relevant information that one needs for the specific end. One of the possible techniques used to extract features is ordinal analysis, which was proposed more than 20 years ago and looks at the relative ordering of data points to determine different aspects of the systems, like how predictable, complex, or efficient they are. Although it has been extensively applied to a wide variety of systems, and generalized to include additional aspects of the data, as well to extract temporal and spatial features, there are still aspects of its implementation to be addressed. The main goal of this thesis is to demonstrate new applications of ordinal pattern analysis for uncovering temporal and spatial structures in real world complex data. Specifically, I analyze experimental recordings obtained during the turn-on of a complex multimode laser; I analyze EEG signals recorded from healthy subjects in different conditions (eyes open or eyes open) and I analyze and compare sea surface temperature anomalies of two well-known climate datasets, in two important geography regions (El Niño and Gulf Stream). In the first chapter of the results section, I present the experimental analysis of a long cavity semiconductor laser in order to anticipate and identify the threshold bifurcation that occurs during its turn on. In the second chapter of the results section, I present the analysis of brain data obtained from electroencephalograms (EEG): recordings of the brains electrical activity obtained from the scalp in two conditions, the subjects having their eyes open (EO) or their eyes closed (EC). Here I show how the temporal and spatial features perform in the classification between the EO and EC states, and how, for the spatial features, evaluating the correlations with specific orientations can improve this performance. Finally, in the final chapter of the results section, I analyze two datasets of sea surface temperature anomaly, and I show how the spatial features allow the detection of transitions caused by changes in the acquisition and processing methodology of these datasets, showing also how their agreement improves with time. Taken together, the studies carried out in this thesis demonstrate that ordinal analysis offers great flexibility, allowing the selection of different time scales, different spatial scales, or different shapes and orientations of patterns, which allows to obtain relevant features that encapsulate complementary information to characterize complex spatio-temporal data.
  
• GARÍ GALÍNDEZ, JON: Developing Artificial Intelligence Strategies to Accelerate Scientific Research: Application to Thin-Film Photovoltaic Technologies
  
  Author: GARÍ GALÍNDEZ, JON
  Programme: DOCTORAL DEGREE IN COMPUTATIONAL AND APPLIED PHYSICS
  Department: Department of Physics (FIS)
  Mode: Article-based thesis
  Deposit date: 13/07/2026
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: IZQUIERDO ROCA, VICTOR | GUC, MAXIM
  Thesis abstract: The development cycle of new materials-based technologies typically spans 15-25 years due to the constantly increasing complexity of experimental research processes. Accelerating this process is essential to enable large-scale implementation of sustainable technologies that support the green energy transition and secure the electrification of society. Photovoltaics (PV) play a central role in this transition, particularly novel thin-film photovoltaic (TFPV) technologies, which promise to significantly broaden the application of solar modules in everyday life. Therefore, accelerating their development and transfer is key to achieving this goal. In this context, recent advances in artificial intelligence (AI), explainable artificial intelligence (XAI), robotics, and automation have enabled a new paradigm: the data-driven materials science, capable of accelerating materials discovery and optimization. However, despite the increasing use of machine learning (ML) in materials science, the application of XAI approaches to real experimental characterization datasets remains limited, and the translation of ML model outputs into physically meaningful insights is still a major challenge.The present work addresses this challenge by exploring and developing AI-driven strategies for the analysis and interpretation of experimental characterization data, following a proposed interpretability framework aimed at both accelerating research and enhancing explainability of ML models. The work begins by implementing and optimizing different training strategies for restricted Boltzmann machines (RBMs) using benchmark datasets. This study is aligned with the first level of the interpretability framework (Level 1: Using AI) and establishes the basis for the implementation of ML algorithms in experimental characterization datasets. Subsequently, an initial approach to XAI-driven strategies for extracting valuable information from experimental characterization data of kesterite-based TFPV devices is developed (Level 2: Using XAI), demonstrating the potential of interpretable ML models for identifying correlations between the physicochemical properties of materials and the PV performance of devices.Finally, building on this progression, an integrated XAI-driven methodology is implemented to analyze multimodal datasets obtained from holistic characterization of kesterite-based solar cells. It integrates the entire research cycle, from synthesis and characterization to data analysis, interpretation, and extraction of valuable feedback for further technology optimization. Particular emphasis is placed on interpretability, where the combination of intrinsic XAI models with post-hoc XAI techniques enables the identification of the physicochemical properties that govern device performance and reproducibility, linking the relevant spectral zones with the corresponding physical properties. This strategy reaches the third level of the interpretability framework (Level 3: Using XAI+) and provides meaningful feedback to guide subsequent research cycles. This feedback is validated through modified fabrication processes, resulting in improved device performance. Furthermore, it substantially reduces research cycle times, accelerating material optimization from timescales exceeding one year to less than a week. These results contribute to the development of self-driving laboratory (SDL) approaches and the advancement of data-driven materials research, ultimately supporting the green energy transition.
  

DOCTORAL DEGREE IN COMPUTER ARCHITECTURE

• ÁLVAREZ ROBERT, DAVID: On the co-design of runtimes, systems and programming interfaces for HPC
  
  Author: ÁLVAREZ ROBERT, DAVID
  Programme: DOCTORAL DEGREE IN COMPUTER ARCHITECTURE
  Department: Department of Computer Architecture (DAC)
  Mode: Normal
  Deposit date: 25/06/2026
  Reading date: 28/07/2026
  Reading time: 11:30
  Reading place: Sala d'Actes de la FIB, Edifici B6, planta 0, Campus Nord UPC
  Thesis director: BELTRAN QUEROL, VICENÇ
  Thesis abstract: High-performance computing (HPC) platforms are evolving towards increasingly complex architectures: many-core CPUs with multi-level NUMA hierarchies, heterogeneity with multiple classes of accelerators and higher-capacity interconnects. The increasing complexity and variety of resources in these machines make it harder for application programmers to use them efficiently and effectively. As a result, many resources in modern HPC clusters remain underutilized, limiting energy efficiency and the potential throughput of the machine.This thesis argues that addressing these challenges requires co-design across the software stack, from runtime mechanisms and programming interfaces to system-level policies. We first study task-based runtimes and identify opportunities to reduce overheads and improve scalability on many-core machines, introducing novel scheduling and dependency-management techniques that maintain throughput under extreme concurrency. We then tackle programmability and performance in heterogeneous systems, proposing runtime and interface support to better overlap data movement, accelerator offloading, and CPU computation.We also make a case for the effective co-design of applications and programming models through the study of an increasingly common application class: iterative data-flow computations, commonly used in simulations, iterative solvers, and AI. Through this study, we propose specific optimizations for this application class, showing how holistic co-design approaches can lead to significant speedups.Finally, we present the nOS-V library with the goal of improving system-wide utilization through application co-scheduling, and we later apply the same methodology to obtain truly interoperable programming models, enabling multiple runtimes and parallel libraries to coexist within a single application with reduced mutual interference.Overall, the contributions of this thesis provide a set of runtime techniques, programming abstractions, and system mechanisms that jointly improve throughput, efficiency, and composability on next-generation HPC systems.
  

DOCTORAL DEGREE IN CONSTRUCTION ENGINEERING

• KOMARIZADEH ASL, SEYED MAHYAD: Real-Time Temperature-Compensated Atmospheric Corrosion Monitoring at Low Cost: The CORTEX System and a Validated IoT Framework for Structural Health Monitoring
  
  Author: KOMARIZADEH ASL, SEYED MAHYAD
  Programme: DOCTORAL DEGREE IN CONSTRUCTION ENGINEERING
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 01/07/2026
  Reading date: 28/07/2026
  Reading time: 11:00
  Reading place: UPC Campus Nord, ETSECCPB, C/ Jordi Girona 1-3, edific C2, Sala 212 (Sala Conferències), Barcelona
  Thesis director: TOSIC, NIKOLA | TURMO CODERQUE, JOSE
  Thesis abstract: Civil infrastructure forms the physical substrate of contemporary economic activity, yet the metallic components of its load-bearing skeleton are continuously deteriorating under atmospheric attack at an annual cost approaching 3 to 4 percent of gross domestic product in every industrialized economy. Despite this scale, approximately 98 percent of the global bridge inventory is currently assessed exclusively through periodic visual inspection rather than continuous instrumented monitoring. Electrical resistance (ER) measurement has been the proven standard for service-condition corrosion monitoring in the petroleum industry for decades, but its adaptation to civil infrastructure has been obstructed by the cost of the dedicated commercial data-acquisition systems required to interrogate the probes, priced between 1,800 and 11,700 US dollars per channel.This dissertation develops and validates a low-cost open-source alternative. The Low-cost Electrical Resistance Ohm analYzer (LEROY), developed in the early phase of the doctoral program, achieved 7 to 30 microohm practical resolution on Arduino-class hardware and was validated against gravimetric mass loss within 3.31 percent over a 125-day accelerated test. The LEROY testing program also quantified why basic Arduino-class hardware cannot handle the temperature dependence of resistance under continuous field conditions and confined such hardware to static readings.Virtually every commercial ACM instrument addresses the temperature problem in hardware, by adding a coated reference probe. The strategy is structurally fragile because the reference probe's thermal mass and surface heat-transfer characteristics differ from those of the exposed active probe, producing phase-dependent compensation errors precisely when temperature is changing most rapidly. The central scientific decision was to address the temperature problem algorithmically: to eliminate the reference probe entirely and reformulate compensation as a real-time firmware operation grounded in the solid-state physics of metallic resistivity. This led to the CORrosion Temperature EXpert (CORTEX) system, the central technical contribution of the dissertation and the subject of European Patent Application EP25382628.CORTEX integrates an 18-bit delta-sigma ADC co-designed with a 156.23 mA precision current source so that one least significant bit corresponds to 0.1 milliohm, a four-wire Kelvin signal path, and an SHT35 digital temperature sensor co-located with the probe. A 12-stage autonomous firmware pipeline executes a real-time temperature compensation algorithm derived from first principles and validated across a 30-test program spanning laboratory, field, and isothermal regimes. The temperature coefficient was confirmed as a stable AISI 1010 material property (mean 0.448 plus or minus 0.007 percent per degree Celsius); the thermal lag was shown to be environment-dependent. Allan deviation analysis per IEEE Std 952-1997 established a field detection limit of 0.038 ± 0.009 μm (3σ). The platform completed 22.4 days of autonomous IoT-enabled field deployment in Barcelona with energy neutrality maintained by a 100 W solar panel.The dissertation closes with an accelerated wet-and-dry cycling campaign per ASTM G44 over 11 days, in which AISI 1010 probes were subjected to alternating immersion in 3.5 weight-percent NaCl electrolyte. The corrosion-progression measurement obtained from the temperature compensation algorithm, after correction for partial-immersion geometry and time-of-wetness scaling, reconciled with the independent ASTM G1 gravimetric mass-loss measurement to within 2.0 percent under ISO 9223 Category CX exposure. The work supports the central claim that a low-cost open-source framework can deliver commercial-grade quantitative atmospheric corrosion monitoring of metallic civil infrastructure.
  

DOCTORAL DEGREE IN ELECTRICAL ENGINEERING

• MONTALÀ PALAU, MONTSERRAT: Resilience in Power Systems: From Technology to System-Level Perspectives
  
  Author: MONTALÀ PALAU, MONTSERRAT
  Programme: DOCTORAL DEGREE IN ELECTRICAL ENGINEERING
  Department: Department of Electrical Engineering (DEE)
  Mode: Normal
  Deposit date: 17/06/2026
  Reading date: 28/07/2026
  Reading time: 10:00
  Reading place: Aula Capella - ETSEIB-UPC
  Thesis director: GOMIS BELLMUNT, ORIOL | CHEAH MAÑÉ, MARC
  Thesis abstract: This thesis is structured around a concept that has recently been linked to electrical systems: resilience. These systems have become fundamental for the functioning of modern societies, and, for this reason, it is necessary to continue transforming them while ensuring their proper operation. This thesis addresses the concept of resilience in electrical systems from two complementary perspectives. The first focuses on the development of a methodology, implemented in an open-source tool, that allows the assessment of the power system resilience and the analysis of how the deployment of different technologies can modify it. The second focuses on specific technologies and is articulated around the concept of ramp rate limit. Regarding the first part, the concept of resilience in electrical systems is relatively recent and has emerged to overcome the limitations of the traditional concept of reliability. Resilience aims to consider a wide range of events that may affect the electrical system, including those with low probability but high impact, and to quantify their consequences in energy, social, and economic terms. Although the concept of resilience has been incorporated into new policies, roadmaps, and technological developments, its measurement and quantification remain a challenge.In this context, the development of resilient electrical systems requires both the collection of data on current systems and the identification of possible future events that may affect them. This makes it necessary to have methodologies capable of integrating and evaluating this information in a coordinated manner. To address this challenge, the thesis proposes a methodology that combines traditional tools for the analysis of electrical systems, such as Optimal Power Flows (OPF), with Geographic Information Systems (GIS). In this approach, resilience is quantified in terms of the total energy at risk in a given power system when exposed to specific hazards. This methodology has been implemented in a tool whose objective is to facilitate its use with basic electrical knowledge, so that it can be used by a wide range of users. As for the second part, the ramp rate limit, adopted by several countries, is defined as a strategy to control the speed of variations in the rate of change of active power from generation plants, mainly wind and photovoltaic solar plants. In addition, since renewable plants may operate without dedicated voltage control and at constant power factor, limiting active power variations also slows down reactive power changes, giving the system additional time to activate alternative voltage control resources.Despite its relevance, the implementation of ramp rate limits continues to represent a challenge for the different agents of the electrical system. In this sense, the thesis proposes a methodology that allows system operators to determine the required ramp rate limit based on system parameters such as inertia, damping, and response time constants. Likewise, a methodology is presented for renewable energy plant developers to design installations that comply with these requirements. Since this often involves the incorporation of energy storage systems, the proposed methodology is flexible and allows the exploration of the use of different storage technologies.Each section includes case studies that have allowed for the validation of the robustness of the developed methodologies and tools, showing how different strategies and technologies affect the resilience and stability of the electrical system.Overall, this doctoral thesis makes a significant contribution to the development of resilient electrical systems, aiming to ensure their proper functioning and, in doing so, to support life and essential activities in contemporary societies.
  

DOCTORAL DEGREE IN ELECTRONIC ENGINEERING

• GARCÍA LIMÓN, JOSÉ ALBERTO: Diseño e implementación de un sistema de medida no invasiva de parámetros cardiovasculares en calzado
  
  Author: GARCÍA LIMÓN, JOSÉ ALBERTO
  Programme: DOCTORAL DEGREE IN ELECTRONIC ENGINEERING
  Department: Department of Electronic Engineering (EEL)
  Mode: Change of supervisor
  Deposit date: 29/06/2026
  Reading date: 03/09/2026
  Reading time: 11:00
  Reading place: Auditorio del departamento de Ingeniería Eléctrica del CINVESTAV, México
  Thesis director: CASANELLA ALONSO, RAMON | ALVARADO SERRANO, CARLOS
  Thesis abstract: Cardiovascular diseases remain the leading cause of mortality worldwide, driving the development of technologies for continuous monitoring. Among the most relevant biomarkers are heart rate (HR), heart rate variability (HRV), and pulse transit time (PTT), which is closely related to arterial stiffness and blood pressure. However, accurate estimation of PTT in wearable devices remains a challenge, mainly due to the difficulty of obtaining proximal references unaffected by the cardiac pre-ejection period (PEP).This thesis proposes a novel approach for cardiovascular monitoring based on plantar acquisition of physiological signals through sensors integrated into a shoe insole. A measurement system based on a piezoelectric sensor in the heel region was developed to capture the ballistocardiogram (BCG), a mechanical signal associated with blood ejection. Widely accepted physiological models relate its morphology to pressure gradients in the aorta, enabling the extraction of both proximal and distal information along the aortic segment. The proposed system was validated against the standard weighing scale BCG and employed to estimate several cardiovascular parameters.In addition, a continuous wavelet transform (CWT)-based algorithm was validated for robust J-wave detection in BCG signals. Evaluated using multiple datasets with different sensors, body positions, and mechanical interfaces, it yielded the following sensitivity (Se) and positive predictive value (P+): chair (99.87% and 98.48%), bed (99.64% and 97.60%), and weighing scale (99% and 88%) over a total of 9,266 heartbeats, demonstrating robust performance for HR estimation. This behavior was also observed using the proposed plantar BCG system, achieving P+ and Se values of (97.07% and 84.85%) and (98.20% and 93.42%) during standing and seated conditions, respectively, with coverage factors above 95%. Furthermore, robust estimation of temporal HRV parameters was achieved in the seated position, and a significant correlation (r = 0.8, p < 0.001) was observed between the plantar BCG I–J interval and carotid–femoral pulse transit time, suggesting its potential as an indirect marker of arterial stiffness.As a complementary approach, this work explored impedance plethysmography (IPG) for distal pulse arrival time (PAT) detection at the foot. Results showed that, although photoplethysmography generally provides higher signal quality, its performance is more sensitive to sensor contact pressure and peripheral vasoconstriction. In contrast, the IPG enabled robust pulse detection under realistic operating conditions, including the presence of textile layers, making it particularly suitable for footwear-based systems.Finally, combining BCG and IPG signals enabled the estimation of whole-body pulse transit time (wb-PTT), showing a significant correlation (r = 0.72, p = 0.001) with the reference system based on carotid tonometry and photoplethysmography. This approach overcomes the limitations of conventional wearable devices based on short arterial paths and enables continuous, non-invasive cardiovascular monitoring compatible with daily activities. Overall, the results demonstrate the feasibility of a new generation of smart insoles. Integrating BCG and IPG into a single platform enables a comprehensive characterization of cardiovascular status and opens new opportunities for applications in digital health, preventive medicine, and remote clinical monitoring.
  
• VILELLA VEGA, MANEL: Enhanced modulation strategies for a high-efficiency energy conversion system for electric vehicles
  
  Author: VILELLA VEGA, MANEL
  Programme: DOCTORAL DEGREE IN ELECTRONIC ENGINEERING
  Department: Department of Electronic Engineering (EEL)
  Mode: Normal
  Deposit date: 22/04/2026
  Reading date: 28/07/2026
  Reading time: 11:00
  Reading place: Sala de Conferències (TR1-085), campus de Terrassa
  Thesis director: ZARAGOZA BERTOMEU, JORDI | BERBEL ARTAL, NÉSTOR
  Thesis abstract: The global transition toward electric vehicles (EVs) has intensified the demand for high-efficiency power electronics. On-Board chargers (OBCs) and bidirectional energy conversion systems are essential to manage the flow between the grid and the vehicle battery. These systems must be compact, lightweight, and capable of high-power density to satisfy modern automotive requirements. In this context, isolated bidirectional DC-DC conversion, specifically the Dual Active Bridge (DAB) converter, has emerged as a key technology due to its inherent galvanic isolation and high performance. To achieve high power density and efficiency, this research utilizes WBG semiconductors, specifically GaN devices, which allow for higher switching frequencies compared to traditional silicon.The primary objective of this doctoral work is to optimise control and modulation techniques to exploit the full potential of GaN semiconductors while mitigating high-frequency operation challenges, such as parasitic effects, thermal management, and EMI. The research is structured around four main contributions.First, the thesis experimentally evaluates a GaN-based non-resonant DAB converter, analysing the trade-offs between switching frequency, efficiency, and EMI. It demonstrates that increasing the switching frequency up to 200 kHz maintains high efficiency while enabling a significant reduction in the size of passive components without compromising electromagnetic compatibility.Secondly, a mathematical quantification of the steady-state DC current in non-resonant DAB converters is introduced. The formulation, which accounts for semiconductor resistance variations and timing mismatches, is validated experimentally and coupled with a closed-loop voltage compensation control strategy to effectively mitigate these parasitic DC currents.Thirdly, a variable frequency modulation is developed to reduce transient surge currents during start-up and load variations. Finally, the thesis explores the modular series-parallel connection of converters to scale the system for different EV battery voltages.
  

DOCTORAL DEGREE IN MARINE SCIENCES

• ERBS, FLORENCE AMANDINE: AI-enhanced Passive Acoustic Monitoring of Tropical Freshwater Environments
  
  Author: ERBS, FLORENCE AMANDINE
  Programme: DOCTORAL DEGREE IN MARINE SCIENCES
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Article-based thesis
  Deposit date: 28/05/2026
  Reading date: 18/09/2026
  Reading time: 14:00
  Reading place: Place: ETSECCPBUPC, Campus NordBuilding C1. Classroom: 002C/Jordi Girona, 1-308034 Barcelona
  Thesis director: ANDRE SANCHEZ, MICHEL
  Thesis abstract: Tropical freshwater ecosystems, particularly in the Amazon basin, are among the world’s most vulnerable environments, facing escalating pressures from human activities such as overexploitation, pollution, and habitat degradation. Effective conservation efforts are constrained by the scarcity of long-term monitoring data, as traditional visual survey methods are often unsuitable for the high turbidity of Amazonian waters and the complex floodplain habitat mosaics where seasonally inundated lakes, channels, and forests make species detection challenging. This dissertation addresses these challenges by developing an innovative and scalable monitoring framework using Artificial Intelligence (AI)-enhanced Passive Acoustic Monitoring (PAM) focused on three ecological indicator species: the pink river dolphin (Inia geoffrensis), the tucuxi (Sotalia fluviatilis), and the Amazonian manatee (Trichechus inunguis).The research is presented as a compendium of two scientific publications that integrates longterm autonomous acoustic monitoring with Deep Learning techniques, specifically Convolutional Neural Networks (CNNs), to automate species detection in complex and noisy freshwater soundscapes. The first study focuses on Amazonian river dolphins, exploiting their near-continuous production of echolocation clicks for presence detection. The developed CNN classifier achieved a high average precision of 0.95 and successfully discriminated between dolphin clicks and impulsive interferences like rain and boat engine noise. This automation enabled the tracking of synchronized seasonal movements into floodplain bay and river channel habitats following the annual flood pulse. Furthermore, the study provided rare insights into the seasonal use of flooded forests revealing regular dolphin presence during high-water periods. Additionally, it quantified the spatio-temporal overlap between dolphins and boat traffic, establishing a baseline for assessing anthropogenic noise exposure in core habitats.The second study applied a similar AI-enhanced approach for detecting the Amazonian manatee, a cryptic species characterized by inconspicuous surfacing behavior and a previously poorly described vocal repertoire in the wild. By training a CNN model on wild vocalizations, the research provided the first detailed characterization of the wild Amazonian manatee’s vocal repertoire, identifying four distinct call types, and leading to new insights into the vocal behavior of the species in the floodplains. The analysis of vocal parameters, including repetition rates and frequency characteristics, revealed that Mamirau´a Lake, where the species was presumed absent, serves as a critical nursery habitat.This dissertation demonstrates that the integration of PAM and machine learning offers a noninvasive, cost-effective, and performant tool for monitoring biodiversity in remote tropical freshwater environments. The transition from manual acoustic analysis to automated processing allows for efficient conversion of high-volume acoustic datasets into ecological insights, facilitating the identification of critical habitats, supporting the understanding of floodplain ecological processes, and advancing the assessment of anthropogenic impacts and ecosystem health. These findings provide a robust foundation for a standardized Amazonian monitoring framework to support evidence-based conservation for these endangered species and their ecosystems.
  

DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING

• COLLADO CIPRÉS, VERÓNICA: Hot deformation behaviour of WC–Co cemented carbides
  
  Author: COLLADO CIPRÉS, VERÓNICA
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: Department of Materials Science and Engineering (CEM)
  Mode: Article-based thesis
  Deposit date: 03/06/2026
  Reading date: 10/09/2026
  Reading time: 11:30
  Reading place: ESCOLA D'ENGINYERIA BARCELONA ESTC/Eduard Maristany, 16 (08019 Barcelona)EDIFICI A planta 0, SALA D'ACTEShttps://meet.google.com/pcm-czdv-rxr
  Thesis director: LLANES PITARCH, LUIS MIGUEL | GARCÍA, JOSÉ LUIS
  Thesis abstract: This PhD thesis presents a systematic approach to describe, model, and understand the hot deformation behaviour of cemented carbides—composite materials based on tungsten carbide (WC) and cobalt (Co), commonly known as hardmetals—under service-like conditions. The work aims to bridge the gap between traditional room-temperature studies and the complex mechanical demands encountered at elevated temperatures.Hardmetals are used in applications requiring extreme mechanical performance, such as cutting tools, mining equipment, and forming dies. Historically, research has concentrated on their room-temperature properties, mainly hardness and fracture toughness. However, such studies do not capture the complex mechanical behaviour at elevated temperatures, where plastic deformation becomes a dominant wear mechanism.Previous investigations into high-temperature deformation have primarily relied on creep testing, which is conducted under very low strain rates and constant stress. While these studies have helped to identify deformation regimes and mechanisms such as grain boundary sliding and binder infiltration, they do not reflect the dynamic, high-strain-rate conditions experienced during actual service, such as in machining operations. Similarly, research on hot hardness has shown that fine-grained WC structures tend to retain higher hardness at lower temperatures but may soften more rapidly at elevated temperatures—highlighting the need for a deeper understanding of microstructural effects under thermal stress.This thesis addresses these critical knowledge gaps by systematically studying the hot deformation behaviour of WC–Co cemented carbides under service-like conditions, with strain rates ranging from 0.0005 to 0.1 s⁻¹ and temperatures from 700 °C up to 1000 °C. The research unfolds in three interconnected stages. The first study investigates sintered cobalt, the binder phase in WC–Co. Through hot compression testing, the deformation mechanisms were characterised, revealing a creep exponent of n = 5 and an activation energy consistent with self-diffusion in face-centered cubic Co. These findings indicate that deformation is governed by dislocation glide and climb.A physically based constitutive equation was developed to describe the peak stress in WC–Co as the sum of three components: stress carried by the binder, stress accommodated by the WC, and stress arising from the interaction between the two phases. The WC phase exhibited an activation energy of 585 kJ/mol, attributed to W pipe diffusion, and a high stress exponent (n = 19), indicating minimal sensitivity to temperature and strain rate—typical of ceramic materials. The interaction term was modelled using the binder mean free path and carbide skeleton stiffness, revealing its significant influence on overall mechanical resistance.The final study incorporated WC grain size into the constitutive model. Experimental results demonstrated that fine-grained WC structures exhibit higher resistance to plastic deformation at lower temperatures due to grain boundary strengthening. However, this advantage diminishes rapidly at elevated temperatures, where grain boundary sliding and binder infiltration become dominant deformation mechanisms. Coarser WC grains, while less resistant at room temperature, maintain structural integrity more effectively under thermal stress. Microstructural analysis via electron back-scattered diffraction confirmed these trends, highlighting the role of grain boundaries, phase transformations, and interface behaviour.These studies provide a framework for understanding and optimizing the high-temperature mechanical behaviour of WC–Co cemented carbides. By bridging the gap between microstructural characterisation and physical modelling, this thesis advances the field beyond traditional room-temperature and creep-based analyses, offering practical tools for designing hardmetals capable of withstanding extreme service conditions.
  

DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING

• HARBA, MOHANAD: Musculoskeletal simulations Integrating a smooth knee contact pressure model
  
  Author: HARBA, MOHANAD
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Mechanical Engineering (EM)
  Mode: Normal
  Deposit date: 07/07/2026
  Reading date: 31/07/2026
  Reading time: 10:00
  Reading place: Sala Polivalent de l'EEBE
  Thesis director: SERRANCOLÍ MASFERRER, GIL
  Thesis abstract: Knee osteoarthritis is one of the most common musculoskeletal conditions in the world, affecting hundreds of millions of people and causing chronic pain, reduced mobility, and disability. Understanding how mechanical forces are distributed across the knee joint during activities like walking is key for better diagnosis, treatment planning, and implant design. However, directly measuring these forces in a clinical setting is not possible, and existing computational models often cannot estimate the full spatial distribution of contact pressure across the joint surface, instead they estimate the resultant forces and moment at the knee joint.This thesis addresses these limitations through three studies. The first study developed a method to reduce the complexity of muscle-tendon length and moment arm parameterizations in musculoskeletal simulations. By applying an error-threshold approach to remove redundant polynomial coefficients, the method reduced the number of required parameters by approximately 50 % for muscles spanning the knee and ankle, while preserving accuracy in joint kinematics and knee contact force tracking. This led to a 15.6 % reduction in average computation time.The second study developed and validated a smooth, mesh-based knee contact pressure model included in a full body movement simulation. The model computes contact pressure at each triangular face of the tibial surface at every time step of the simulation, using smoothed penetration detection and a linear elastic foundation relationship. A sensitivity analysis was carried out to evaluate the influence of key model parameters on computation time, convergence, and tracking accuracy. The model was validated on eight gait trials from the Grand Challenge to predict in ivo knee loads dataset, and was also used in a predictive simulation, demonstrating its ability to generate new movement patterns while accounting for joint contact mechanics.The third study investigated the spatial relationship between tibiofemoral contact pressure and tibial cartilage composition, assessed using quantitative MRI T₂ relaxation time mapping, in a group of 23 subjects including 5 healthy individuals and 18 patients with early osteoarthritis. In healthy subjects, no consistent relationship was found between contact pressure and T₂ values. In the early osteoarthritis group, however, the most heavily loaded cartilage regions tended to show above-average T₂ values, suggesting that early compositional changes in cartilage are spatially linked to mechanical loading. This finding was consistent across all pressure thresholds tested. Together, this work shows that it is possible to estimate how contact pressure is distributed across the knee during walking within a computationally efficient simulation framework. The smooth contact model developed here removes a key barrier that has long prevented pressure estimation from being integrated into full-body movement simulations. These findings bring us one step closer to bridging the gap between computational biomechanics and clinical practice, where understanding the link between joint loading and cartilage health could ultimately inform more targeted strategies for osteoarthritis prevention and management.
  

DOCTORAL DEGREE IN NATURAL RESOURCES AND THE ENVIRONMENT

• MULERO JIMÉNEZ, LORENA: Bosc i Sostenibilitat: proposta educativa a l’entorn dels serveis ecosistèmics del bosc i els ODS amb pedagogia de ciència oberta a secundària
  
  Author: MULERO JIMÉNEZ, LORENA
  Programme: DOCTORAL DEGREE IN NATURAL RESOURCES AND THE ENVIRONMENT
  Department: Department of Mining, Industrial and ICT Engineering (EMIT)
  Mode: Normal
  Deposit date: 18/06/2026
  Reading date: 03/09/2026
  Reading time: 12:00
  Reading place: Sala de Juntes de l'EPSEM
  Thesis director:
  Thesis abstract: We live in a society that normalizes crises. These crises affect the very pillars of civilization, and education is the engine that moves the world. Furthermore, what would become of society and the education of new generations without caring for the environment and nature?This thesis develops a series of actions related to forests and their contribution to sustainability through their connection with the Sustainable Development Goals (SDGs). This is a process of raising awareness among secondary school students regarding their essential role in the journey toward a sustainable and respectful society. Likewise, it analyzes the impact of implementing the "Forest and Sustainability Project," applying the innovative teaching methodology known as Open Science Schooling. The study focuses on how this approach fosters students' awareness of their role as key agents in changing society and steering it toward sustainability.A case study is conducted using teaching materials created and developed within this thesis. The activities are implemented in secondary schools across Catalonia. Additionally, activities are carried out within the framework of the Exploratori dels Recursos de la Natura that aims to promote science and technology among youth and conducts activities addressed to both secondary school teachers and students.
  

DOCTORAL DEGREE IN NUCLEAR AND IONISING RADIATION ENGINEERING

• TOBAJAS ASENSIO, LUIS MIGUEL: ANÁLISIS DE LA INFORMACIÓN INSTITUCIONAL Y EL TRATAMIENTO DE LA PRENSA DE LOS INCIDENTES NUCLEARES ESPAÑOLES (1989-2009)
  
  Author: TOBAJAS ASENSIO, LUIS MIGUEL
  Programme: DOCTORAL DEGREE IN NUCLEAR AND IONISING RADIATION ENGINEERING
  Department: Department of Physics (FIS)
  Mode: Normal
  Deposit date: 17/06/2026
  Reading date: 18/09/2026
  Reading time: 11:30
  Reading place: Aula I 28.8 de l'Escola Tècnica Superior d'Enginyeria Industrial de Barcelona, ETSEIB
  Thesis director: REVENTOS PUIGJANER, FRANCESC-JOSEP | PONT SORRIBES, CARLES
  Thesis abstract: The general objective of this research is to analyze the safety of the nuclear power plants in Spain during the period between 1989 and 2009, through a comprehensive analysis of institutional information and press coverage of nuclear incidents.The methodology employed includes a mixed qualitative and quantitative model. Scientific production on nuclear incidents has been analysed through technical information databases, academic databases (Wos and Scopus), and newspaper archives.The newspapers ABC, La Vanguardia, and El País were selected based on the criterion of being among the most widely followed newspapers in Spain during the period studied, considering the press as the best means of monitoring incidents at the end of the 1980s.In 1990, following the Chernobyl accident, the INES Scale was introduced, created by the International Atomic Energy Agency (IAEA) and the Nuclear Energy Agency, with the aim of facilitating international communication to the public and the media. This study analyses incidents classified as level two or higher according to IAEA criteria. The results of this work consider the use of the INES Scale in institutional information and in the media.The conclusions allow for a deeper understanding of the treatment of information provided to the public and the media coverage of nuclear incidents. The analysis of lessons learned from the four incidents studied and their follow-up makes it possible to conclude that there have been advances in nuclear safety and in institutional and public information, with the consolidation of the INES Scale in nuclear communication in Spain. However, it is determined that the completion of corrective actions does not reach public opinion despite its relevance.The research provides proposals for improvement with the aim of promoting better communication in the future, including the participation of experts. Communication is one of the most relevant issues in nuclear crises and must be clear, timely, accurate, transparent, and proactive.
  

DOCTORAL DEGREE IN OPTICAL ENGINEERING

• EL GHARBI EL AOUFI, MARIAM: Análisis de los parámetros biométricos oculares en escolares de 8 a 11 años: Influencia de los factores refractivos, sociodemográficos antropométricos y perinatales. Proyecto CISViT
  
  Author: EL GHARBI EL AOUFI, MARIAM
  Programme: DOCTORAL DEGREE IN OPTICAL ENGINEERING
  Department: Department of Optics and Optometry (OO)
  Mode: Normal
  Deposit date: 06/07/2026
  Reading date: 29/07/2026
  Reading time: 11:00
  Reading place: Auditorio del Centro Universitario de la Visión (Paseo 22 de Julio, 660. 08222 TerrassaMeet: meet.google.com/oje-tiad-dmj
  Thesis director: VILA VIDAL, NÚRIA | GUISASOLA VALENCIA, LAURA
  Thesis abstract: Myopia is one of the most prevalent visual disorders worldwide and an emerging public health issue, particularly in the pediatric population, where its early onset is associated with faster progression and a higher risk of complications in adulthood. In this context, it is crucial to have tools that enable the anticipation of myopia development prior to its clinical manifestation.This thesis addresses this issue through the analysis of ocular biometrics in a cohort of schoolchildren aged 8 to 11 from Southern Europe (CISViT project), evaluating the evolution of axial length (AL), corneal radius (CR), and the AL/CR ratio, as well as their association with refractive, sociodemographic, anthropometric, and perinatal factors.Through a longitudinal follow-up, specific ocular growth patterns and risk profiles have been identified within this population. The findings demonstrate that changes in ocular biometrics are detectable before the clinical onset of myopia. In particular, the AL/CR ratio emerges as a robust and consistent indicator, capable of integrating biometric data and identifying subgroups with greater vulnerability. Furthermore, it was found that while axial length and corneal radius are influenced by sociodemographic, anthropometric, and perinatal factors, the AL/CR ratio remains unaffected by these individual variables, thereby emerging as a universal predictive parameter.
  

DOCTORAL DEGREE IN PHOTONICS

• PINILLA SANCHEZ, ADRIAN: Advanced Catalytic Interface Analysis Through In Situ Studies and Automated Experimental Platforms
  
  Author: PINILLA SANCHEZ, ADRIAN
  Programme: DOCTORAL DEGREE IN PHOTONICS
  Department: Institute of Photonic Sciences (ICFO)
  Mode: Normal
  Deposit date: 08/07/2026
  Reading date: 07/09/2026
  Reading time: 15:00
  Reading place: ICFO Auditorium i https://teams.microsoft.com/meet/393968795433086?p=iOTHwY4gw6m1ZfoLbp
  Thesis director: GARCÍA DE ARQUER, FRANCISCO PELAYO
  Thesis abstract: Electrochemical technologies offer a route to decarbonize key industries, such as energy, chemical and fertilizer manufacturing, by converting abundant chemicals like carbon dioxide (CO₂) and nitrate into fuels and feedstocks using renewable electricity. Realizing this potential requires electrocatalytic systems that achieve technoeconomic viability, which is linked to performance metrics such as activity, selectivity, and stability. Their deployment is constrained by two coupled challenges: incomplete mechanistic understanding of dynamic electrochemical interfaces and slow manual workflows that cannot efficiently explore the high-dimensional design spaces of catalysts, electrolytes, and operating parameters. In electrochemical reactions, performance across its many dimensions emerges from the evolving interplay of catalyst structure and local reaction environment at polarized interfaces. Advancing electrocatalytic performance therefore requires tools that can both reveal and enable control over the evolving catalyst-electrolyte interface during operation. This thesis addresses these challenges by combining operando surface-enhanced Raman spectroscopy (SERS), automated data-analysis frameworks, and self-driving laboratory approaches to accelerate electrocatalyst development under technologically relevant conditions for CO₂ and nitrate electroreduction reactions.Operando SERS probes acidic CO₂ electroreduction on copper-based gas diffusion electrodes up to 0.2 A cm⁻², showing how interfacial species like sulfate, hydroxide, carbon monoxide (CO), and carbon-containing intermediates evolve with potential and pH. Our findings suggest that strongly adsorbed sulfate blocks active sites and delays CO₂E onset at low overpotentials, while co-adsorbed hydroxide and carbon on reconstructed copper surfaces stabilize *CO coverages that favor C-C coupling and multicarbon product formation. These results identify electrolyte anions and local alkalization as key levers for tuning the onset potential, intermediate stabilization, and selectivity in acidic CO₂ electroreduction, opening new strategies for rational system-level design of catalysts and electrolytes.To handle the complexity of operando experiments, the thesis introduces SERSFlow, a modular framework for structured operando SERS data and reusable analysis pipelines. Implemented as a local-first Python service with a web interface, it combines preprocessing, feature extraction, and multivariate analysis in deterministic workflows that reproduce expert trends while reducing analysis time from hours to minutes. Benchmarking shows that baseline subtraction alone can shift fitted peak areas by 40–100% for weak or overlapping bands, and spatiotemporal mapping reveals micron-scale heterogeneity in adsorbate populations and double-layer structure.Finally, the Autoammonia platform—a distributed self-driving laboratory for nitrate-to-ammonia reduction—is developed with two active nodes in different institutions. It integrates in situ catalyst electrodeposition, flow-cell nitrate electroreduction, and automated ammonia quantification within a closed-loop workflow managed by orchestration, planning, and safety software. Autonomous campaigns with copper-based catalysts show that self-driving experimentation is feasible in realistic flow-cell architectures and complex electrolytes using accessible hardware and open-source software.Collectively, the thesis shows that mechanistic operando characterization, reproducible data workflows, and autonomous experimentation are mutually reinforcing components of a coherent strategy for advancing electrocatalysis. The concepts and tools developed here provide a foundation for more systematic, data-rich, and scalable approaches to the design and optimization of electrocatalysts and electrochemical interfaces for sustainable, electrified chemical production.
  
• PRELAT OLIVARES, LEILA ROCIO: Free-electron interaction with nanophotonic excitations
  
  Author: PRELAT OLIVARES, LEILA ROCIO
  Programme: DOCTORAL DEGREE IN PHOTONICS
  Department: Institute of Photonic Sciences (ICFO)
  Mode: Normal
  Deposit date: 07/07/2026
  Reading date: 10/09/2026
  Reading time: 10:00
  Reading place: ICFO Auditorium i https://teams.microsoft.com/meet/322181711925000?p=OtJ34OjGTLMTdTXLs6
  Thesis director: GARCÍA DE ABAJO, JAVIER
  Thesis abstract: Free electrons provide a powerful platform to control optical excitations at the nanoscale because they carry electromagnetic fields that are tightly localized and contain large evanescent wave-vector components inaccessible to propagating light. Although this property makes electron beams uniquely suited to address confined optical modes, their full potential for technological applications is still being actively developed. This Thesis aims to contribute to this effort by exploring novel phenomena that arise when electron beams are incorporated into different optical systems.As an introduction to the main concepts underlying this Thesis, Chapter 1 summarizes the theoretical frameworks used to describe electromagnetic excitations, with emphasis on linear and nonlinear optical phenomena, surface waves such as polaritons and waveguide modes, and electron beams.Chapter 2 explores electron-driven excitation of surface polaritons through resonant scatterers placed near polariton-supporting materials. The passing electron polarizes a small resonant particle, which then launches surface modes with a spectrum determined by the particle’s response. Our semi-analytical model reveals an optimum scatterer-surface separation that maximizes polariton emission. This approach is extended to periodic arrays of scatterers, leading to a polaritonic analog of the Smith-Purcell effect, in which surface polaritons are emitted directionally into diffraction orders controlled by the array period, electron velocity, and polariton dispersion relation. Hexagonal boron nitride nanodisks coupled to graphene plasmons are identified as a realistic mid-infrared implementation for small resonant scatterers, with efficiency comparable to resonant lossless particles.In Chapter 3, we introduce wave-mixing cathodoluminescence as a nonlinear spectromicroscopy technique for detecting low-frequency excitations through visible-range optical readout. In this mechanism, the evanescent field of a swift electron mixes with an external optical pump through the second-order nonlinear response of a specimen, generating sum- and difference-frequency photons. The method up-converts far-infrared spectral fingerprints into the visible range, avoiding the need for low-frequency light sources or detectors. Calculations for retinal-coated silver nanorods show that molecular vibrational signatures can be accessed with nanometer-scale spatial resolution under external illumination and visible-range detection.Chapter 4 explores electrostatic control of electron trajectories as a means of tuning coupling to guided modes in silicon waveguides. By deflecting electrons into grazing trajectories using a static electron-repulsive field, the minimum electron-waveguide separation becomes a controllable parameter that governs both coupling strength and modal selectivity. In particular, we consider three doped silicon waveguides placed on a sapphire substrate, with the two side elements acting as lateral gating structures. Including image-force effects and collision thresholds, the analysis predicts voltage-tunable photon yields reaching several photons per electron in realistic integrated photonic geometries.In Chapter 5 cylindrical waveguides are studied as mediators between free electrons and nanoscale absorbers. A gate-controlled grazing electron launches a guided wave packet that subsequently drives a nearby resonant particle. This waveguide-mediated channel concentrates the broadband electron field spectrally and spatially, producing strong absorption enhancements relative to direct bare-electron excitation.In summary, this Thesis establishes free-electron-nanophotonic interactions as a versatile platform for nanoscale excitation, spectroscopy, and control of optical, polaritonic, and guided modes, with potential applications in integrated photonics, molecular sensing, and quantum nanophotonics.
  
• RUÍZ GONZÁLEZ, JOSÉ JAVIER: Development of computational tools and pipelines for enhanced interpretation of Raman spectroscopy in biomedical applications
  
  Author: RUÍZ GONZÁLEZ, JOSÉ JAVIER
  Programme: DOCTORAL DEGREE IN PHOTONICS
  Department: Institute of Photonic Sciences (ICFO)
  Mode: Normal
  Deposit date: 07/07/2026
  Reading date: 14/10/2026
  Reading time: 10:00
  Reading place: ICFO Auditorium
  Thesis director: LOZA ALVAREZ, PABLO
  Thesis abstract: Raman spectroscopy has gained increasing attention over the last few decades due to its ability to non-destructively extract chemical information from samples. However, despite advances in instrumentation, it has not yet become standard practice in the biomedical field. One of the main reasons is the difficulty in interpreting and extracting the chemical information encoded in Raman signal, so as to validate the technique using complementary, well established techniques.Considering this, the aim of this Thesis is to develop tools and analytical pipelines that enhance the biochemical interpretation of Raman spectra, and to demonstrate its usefulness in two relevant biomedical research lines: breast cancer resistance to neoadjuvant treatments and the diagnosis of choroidal melanoma.Firstly, we developed and validated RamanBiolib, an open-source Raman spectral library accompanied by search algorithms, aimed at providing rapid and objective identification of biomolecules. Secondly, we used RamanBiolib after spectral unmixing to identify and quantify cytochrome c molecule in breast cancer cells resistant to neoadjuvant treatments. This revealed a shift towards its reduced state to avoid apoptosis and acquire drug resistance. Then we also characterized lipid droplets in triple-negative breast cancer cells, highlighting the relevance of variable importance analysis in classification models. This approach allows for the biochemical interpretation of their classification performance and assessing possible background contributions to their accuracy. By doing so, significant changes in lipid unsaturation were detected. Furthermore, we developed RamanTF, a transformer-based algorithm that automatically quantifies key biomolecules from raw spectra.Finally, to study melanin-rich samples, we defined a pre-processing and analysis workflow to correct instrumental interferences that were observed in previous studies, but not corrected yet. With this established workflow, key melanin properties were identified, such as melanin structural disorder or defects abundance, which can be used as biomarkers to diagnose choroidal melanomas. Overall, the tools, discussions, and results presented in this Thesis advance Raman spectroscopy towards clinical application and provide a basis for its widespread adoption as a routine technique in biomedical and diagnostic research.
  

DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS

• CARRINO, CASIMIRO PIO: Multilingual and Cross-Lingual Machine Reading Comprehension in Few-Resource Settings: Synthetic Data, Cross-Lingual Transfer, and Domain-Specific Evaluation
  
  Author: CARRINO, CASIMIRO PIO
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 06/07/2026
  Reading date: 04/09/2026
  Reading time: 12:00
  Reading place: Aula MERIT D5010, Campus Nord, Barcelona
  Thesis director: RODRIGUEZ FONOLLOSA, JOSE ADRIAN
  Thesis abstract: Machine Reading Comprehension (MRC) is a fundamental benchmark for evaluating natural language understanding systems, requiring models to generate answers grounded in context. Despite advances with transformer-based architectures and large language models (LLMs), challenges persist in multilingual and cross-lingual scenarios, especially under few-resource and domain-specific constraints. This thesis addresses these challenges through three principal contributions, spanning the progression from encoder-based extractive to generative MRC, and covering data regimes from large-scale in-language supervision to zero-shot cross-lingual transfer in domain-specific settings.The first contribution introduces the Translate-Align-Retrieve (TAR) methodology, which preserves answer span alignment during translation of extractive QA datasets. By integrating neural machine translation, unsupervised word alignment, and alignment-based answer retrieval, TAR enables systematic construction of high-quality multilingual training data for low-resource languages. This approach produced SQuAD-es v1.1, the first large-scale Spanish extractive QA dataset (87,599 question-answer pairs). Models trained on this resource achieve or surpass established baselines on Spanish QA benchmarks, demonstrating that alignment-based translation is effective for mitigating data scarcity.The second contribution develops a self-knowledge distillation framework with cross-lingual sampling to enhance transfer in few-resource settings with limited parallel data. This work addresses Cross-Lingual Transfer (XLT) and Generalised Cross-Lingual Transfer (G-XLT), where question and context are in different languages. The method integrates cross-lingual sampling as data augmentation with self-knowledge distillation as regularisation, introducing a mean Average Precision at k (mAP@k) coefficient to modulate distillation loss by teacher model quality. Evaluations on MLQA, XQuAD, and TyDiQA-GoldP demonstrate consistent improvements over standard fine-tuning, providing a robust alternative to machine translation-based augmentation when only limited parallel resources exist.The third contribution presents a semi-automatic methodology for constructing privacy-preserving multilingual QA benchmarks in sensitive, data-scarce domains, exemplified by the Human Resources (HR) domain with JobResQA. This combines data de-identification, LLM-based synthesis, and human-in-the-loop translation with MQM error annotations and post-editing. JobResQA comprises 105 synthetic résumé–job description pairs and 581 QA items across five languages and four question types. Baseline evaluation using the G-Eval LLM-as-judge metric across nine open-weight models reveals persistent cross-lingual challenges, with only the largest models attaining high accuracy across all languages. The methodology also enables bias and fairness investigations in high-stakes HR applications.Collectively, these contributions show that data scarcity, cross-lingual transfer, and domain specificity persist as central challenges across architectural paradigms, particularly in few-resource settings. All resources, including datasets, models, and code, are released as open-source. The TAR methodology has seen widespread adoption with over 100 citations, producing datasets for diverse languages and scripts. While performance has improved with LLMs, the core challenges addressed in this thesis remain central to advancing multilingual and cross-lingual MRC.
  
• TSIAMAS, IOANNIS: Robust and Data-Efficient End-to-End Speech Translation: Segmentation, Cross-Modal Alignment, and Prosody-Aware Evaluation
  
  Author: TSIAMAS, IOANNIS
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 15/05/2026
  Reading date: 18/09/2026
  Reading time: 15:00
  Reading place: Aula MERIT D5010, Campus Nord UPC, Barcelona
  Thesis director: RODRIGUEZ FONOLLOSA, JOSE ADRIAN | RUIZ COSTA-JUSSA, MARTA
  Thesis abstract: End-to-end (E2E) Speech Translation (ST) offers a streamlined alternative to traditional cascaded systems, promising lower latency and reduced error propagation. However, its adoption in real-world scenarios is currently hindered by three critical bottlenecks: input processing challenges (mismatch between static data and continuous audio), training data scarcity, and evaluation limitations regarding paralinguistic information.This dissertation addresses these limitations through a cohesive set of methodological and architectural innovations. First, we tackle the segmentation and input processing challenge. We introduce Supervised Hybrid Audio Segmentation (SHAS), a method that effectively bridges the gap between manual training segmentation and automatic inference segmentation, allowing E2E models to process continuous audio streams with minimal performance loss. Building on this, we propose SEGAUGMENT, a data augmentation strategy that utilizes training data re-segmentation to maximize the utility of existing datasets, significantly improving performance in low-resource settings.Second, we tackle data scarcity by developing methods for zero-shot speech translation through cross-modal alignment. We introduce ZEROSWOT, which leverages Optimal Transport to align speech encoders with massively multilingual machine translation models at the subword level, enabling translation without paired ST data. We further refine this approach with CHARSONAR, demonstrating that character-level modeling significantly improves cross-lingual and cross-modal transfer, achieving state-of-the-art results, despite being a zero-shot method.Finally, we investigate the semantic richness of E2E translations. We present a focused evaluation on prosody, revealing that while current E2E architectures possess the internal capacity to represent paralinguistic features like intonation and stress, they often fail to manifest these in the final translation.Collectively, these contributions advance the state of the art by creating E2E ST systems that are more robust to unsegmented inputs and more data-efficient, while also providing insights into the limitations of current E2E systems in preserving the nuances of spoken communication.
  

DOCTORAL DEGREE IN STRUCTURAL ANALYSIS

• GONÇALVES JUNIOR, LUIS ANTONIO: Modeling the influence of manufacturing processes on the fatigue behavior of metallic materials through a continuum damage-based constitutive framework
  
  Author: GONÇALVES JUNIOR, LUIS ANTONIO
  Programme: DOCTORAL DEGREE IN STRUCTURAL ANALYSIS
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 29/06/2026
  Reading date: 07/09/2026
  Reading time: 14:00
  Reading place: Sala Zienkiewich (CIMNE) Building C1, UPC - Campus North Gran Capitan S/N 08034 Barcelona
  Thesis director: BARBU, LUCIA GRATIELA | OLLER MARTINEZ, SERGIO HORACIO
  Thesis abstract: Since the mid-19th century, the study of fatigue in metals has become a major field of interest for materials scientists and structural engineers because fatigue represents one of the principal failure mechanisms in metallic engineering structures. Initially based on empirical approaches such as the stress amplitude–life (S–N) curves derived from Wöhler’s pioneering studies, fatigue prediction capabilities have evolved significantly, leading to sophisticated numerical models capable of predicting not only fatigue life but also the progressive degradation of material properties associated with the fatigue phenomenon, including crack initiation and propagation up to the complete failure of the component.Despite these advances, the systematic incorporation of manufacturing process effects —such as machining, forming, trimming, and punching— into fatigue formulations remains limited. Most existing approaches still rely on simple modifications of S–N curves through reduction factors, restricting their applicability mainly to coupon-level specimens and preventing the accurate prediction of crack initiation and propagation patterns.In this context, the present thesis proposes a constitutive framework to incorporate manufacturing-induced effects into the fatigue response of metals in the high-cycle regime. The model is formulated in a general manner, allowing different manufacturing processes to be considered through suitable specializations based on relevant process-related data, such as residual stresses, surface roughness, porosity, and defect volume fraction.To develop this framework, several fatigue modeling approaches are reviewed, with particular emphasis on fracture mechanics, continuum damage mechanics, and phase-field formulations, commonly implemented using numerical methods such as the finite element method and the extended finite element method. Among them, a continuum damage mechanics-based high-cycle fatigue model is selected as the baseline framework due to its high computational efficiency and its ability to model complex stress–strain states throughout the material degradation process, from the intact condition to complete failure.The constitutive framework is first enhanced through the introduction of a novel hardening–softening stress–strain curve for damage. In addition, a methodology to convert average-based S–N data obtained from standardized fatigue tests into local material-point information is proposed to ensure a consistent calibration of the fatigue parameters with the local nature of the formulation. The enhanced model is validated against experimental data from stiffness-based rapid fatigue tests and durability tests performed on real automotive components, demonstrating strong predictive capabilities at both coupon and component levels while maintaining high computational efficiency.Finally, the framework is extended to explicitly account for manufacturing-induced effects. A residual stress relaxation model and a formulation to account for notch effects associated with manufacturing operations are introduced. The resulting model is specialized for shear-cutting operations, such as trimming and punching, using residual stresses obtained from process simulations and measured surface roughness as process-related inputs. The formulation is validated against uniaxial fatigue tests performed on trimmed and punched complex-phase steel specimens, demonstrating its ability to accurately predict fatigue life and crack initiation locations.
  
• GUO, ZHIMING: Study on HTPB propellant passivation, mixing, casting and curing processes by experiment and simulation
  
  Author: GUO, ZHIMING
  Programme: DOCTORAL DEGREE IN STRUCTURAL ANALYSIS
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Article-based thesis
  Deposit date: 11/05/2026
  Reading date: 04/09/2026
  Reading time: 12:00
  Reading place: UPC Campus Nord, ETSECCPB, C/ Jordi Girona 1-3, edificio C1, Sala 002, Barcelona
  Thesis director: ROSSI BERNECOLI, RICCARDO | FU, XIAOLONG
  Thesis abstract: This study investigates the key physical issues involved in the four propellant production steps (passivation, kneading, casting, and curing) through a combination of experimental and numerical simulations.In this experimental study using HTPB propellant ingredients as raw materials, we first investigate the passivation and dehydration (similar to reduced pressure micro-boiling) of this raw material (N-butylnitroxyethylnitramine (BuNENA)). Next, we add other materials (including liquids and granules) to the passivated raw material and mix them in a vertical kneader. The resulting propellant slurry is then cast into a specific mold. Finally, we investigated the solidification of the propellant samples formed in the mold.In this numerical simulation study, First, the passivation process (bubble generation and movement) of the BuNENA material was studied through numerical simulation. Next, the mixing process of the propellant in a vertical kneader was investigated. The uniformity and flow characteristics of the HTPB propellant material were studied under stirring conditions.Finally, the slurry casting process was simulated, and finally, the curing of the cast propellant model was simulated.This paper contains the following research contents:(1) A passivation experimental device was established and experiments were carried out using a principle similar to reduced pressure micro-boiling; in the fluid dynamics simulation model, the Lagrangian framework was applied to track the formation and movement of bubbles, and the bubbles themselves were modeled as rigid spheres subjected to buoyancy and viscous forces. The Euler framework based on variational multiscale (VMS) was used to simulate the fluid around the bubbles. The bubble movement was analyzed. By combining experimental and simulation methods, the passivation process of BuNENA was analyzed in detail, which is of substantial significance in the field of passivation of composite solid propellants.(2) A computational fluid dynamics (CFD) method was used to establish a digital simulation model of the mixing process of the vertical kneader. Changes in various flow field related characteristics of the vertical kneader were analyzed. The mixing performance of the propellant slurry in the kneader was studied by establishing a mixing uniformity index analysis method. The accuracy of the simulation results was verified by real kneading experiments, SEM-EDS and density experiments. (3) The vacuum casting process was optimized by combining experiments and numerical simulations. First, the shear thinning behavior was revealed through rheological tests, and the Herschel-Bulkley model parameters confirmed non-Newtonian fluid characteristics. The variational multi-scale finite element method was used to simulate and analyze the vacuum casting process of HTPB propellant slurry. Second, the flow rate and impact force of droplets under different vacuum pressures were studied by combining real-time image recognition with machine vision and Kalman filtering. (4) Finally, the curing reaction kinetic model of HTPB propellant was studied by the non-isothermal DSC method. The distribution and evolution of the internal temperature and temperature degree of the propellant during the molding process were analyzed using a thermochemical model. The temperature gradient and curing time variation of the propellant curing process were explored by the thermocouple-integrated method.