Doctoral School

Reading date: 09/10/2025

• ROURA SALIETTI, MIREYA: Reuse of ICT devices as commons: A property rights governance model for collective access
  
  Author: ROURA SALIETTI, MIREYA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SUSTAINABILITY
  Department: University Research Institute for Sustainability Science and Technology (IS.UPC)
  Mode: Normal
  Deposit date: 15/07/2025
  Reading date: 09/10/2025
  Reading time: 11:00
  Reading place: Campus Nord, C6-E106
  Thesis director:
  Thesis abstract: Understanding the role of property rights in managing Information and Communication Technology devices, primarily computers, is fundamental to addressing resource waste and achieving digital inclusion and sustainability goals. Although ICT device acquisition, use, and disposal are predominantly governed by individual property, reuse ecosystems demonstrate significant benefits. In such ecosystems, diverse actors collaborate to recover discarded ICT devices, refurbish, maintain and deliver them at minimal environmental and economic cost to vulnerable populations. Based on Common-Pool Resources theory, this thesis introduces a model that applies a community property approach to govern the reuse of ICT devices, using the bundle of rights framework to organise and manage reuse ecosystems. Building on the eReuse initiative, developed through action-research by a multistakeholder community involved in computer refurbishment for social inclusion in Spain, it captures patterns of collective action, classifies participants by roles, and maps the property rights underpinning their interactions, ensuring fair relationships within the ecosystem. To assess the suitability and application in Ibero-American contexts, the model was evaluated in three reuse ecosystems in Argentina and Uruguay. Results indicate that, although local adaptation is often needed, the model works in practice and shows strong potential to inform the governance design in culturally aligned ICT reuse ecosystems. The model is operationalised through two digital tools, DeviceHub and Workbench, which facilitate the tracing of property changes in devices throughout their life cycle, while also collecting detailed usage and performance metrics. In eReuse, it was found that approximately 46% of discarded and donated devices could be reused, highlighting the premature recycling of functional equipment due to criteria such as accounting or software obsolescence. Data collected through these tools also enables more precise estimation of impacts and supports the creation of indicators for comparing digital inclusion strategies across various regions and scenarios. The results show that the CO2 equivalent efficiency of reusing devices ranges from 30% in areas with a higher proportion of renewable energy to 5% in regions dependent on fossil fuels, when compared to new devices. This underscores that reuse is not inherently efficient but is instead dependent on contextual factors. Furthermore, these findings emphasize the need for more granular data to refine these estimates and gain a better understanding of the full impact of ICT reuse in different contexts. Finally, this governance model was tested through practical case studies in real-world contexts. Our results demonstrate that the success or failure of reuse depends on the sociocultural context and barriers such as ensuring long-term maintenance and usability, which are more effectively mitigated in servitised reuse ecosystems, where maintainers and ICT agents ensure device performance in the face of rapid technological change. These insights contribute to bridging the gap between sustainability goals and ICT governance, highlighting the role of digitally enabled reuse ecosystems in fostering equitable, low-carbon digital transitions and generating local employment opportunities.
  

• SANG, XIAOHAN: Real-time Data-driven Safety Assessment for Building Structures
  
  Author: SANG, XIAOHAN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN CONSTRUCTION ENGINEERING
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Change of supervisor + Article-based thesis
  Deposit date: 10/09/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: KONG, QINGZHAO | ROCA FABREGAT, PEDRO
  Committee:
       PRESIDENT: SHI -, ZHONGQI
       SECRETARI: ZHOU, ZHIGUANG
       VOCAL: ZHOU, HONGYUAN
  Thesis abstract: The evolution mechanism of structural performance remains a critical research topic in structural mechanics. Cracks, serving as indicators of performance deterioration, manifest physically at the meso-scale as processes of crack initiation and propagation, while at the macro-scale, they correspond to the global responses of structural stiffness degradation and load-bearing capacity attenuation. Traditional manual inspection methods are time-consuming and labor-intensive, and the acquired data are often unsuitable for direct application in structural evolution analysis. Consequently, this study focuses on developing performance evolution methodologies for crack-damaged buildings, aiming to enhance assessment efficiency and provide robust support for the lifecycle safety management of large-scale urban building structures.This research primarily addresses crack evolution prediction, crack-embedded finite element modeling techniques, rapid finite element modeling methods, and automated crack embedding approaches. Firstly, based on the curvature characteristics of reinforced concrete (RC) members, a method for predicting crack locations according to curvature variations is proposed and validated for accuracy through four-point bending tests. Secondly, to further improve prediction precision, an initial-condition-free crack prediction method is introduced. This approach, grounded in nonlinear bond-slip theory, is capable of describing extreme scenarios of reinforcement-concrete debonding, and its feasibility is experimentally verified.Regarding crack embedding within finite element models, this study presents a method for calculating the flexibility matrix of cracked elements based on strain energy release rate theory, along with modification techniques adaptable to diverse boundary conditions. Simultaneously, a novel simulation method utilizing nonlinear spring elements is proposed for unreinforced masonry structures, and its effectiveness is experimentally validated. Building upon this, a method for embedding cracks into masonry structures is further developed. This method simulates the alterations in tensile-compressive and shear behavior of post-cracking elements by adjusting the mechanical properties of planar elements and spring elements.Finally, a computer vision data-driven geometric adaptive modular finite element modeling method is proposed. This technique enables rapid acquisition of geometric information for frame structures, facilitating swift modeling and condition assessment. Additionally, to address the challenge of automated crack embedding in finite elements, a labeled crack embedding method is introduced. By assigning labels containing information on crack position, orientation, and boundary conditions, rapid integration of crack data is achieved.In summary, this study yields significant advancements in performance analysis methods for damaged buildings. It establishes theoretical formulations for crack location prediction and develops modeling approaches for damaged beams, columns, and walls, thereby laying a scientific foundation for constructing a structural performance evolution analysis framework.
  

Reading date: 10/10/2025

• ALARCÓN FERNÁNDEZ, DANIEL: A model for the aero‐hydro‐servo‐elastic analysis of floating offshore wind turbines based on a co‐rotational formulation
  
  Author: ALARCÓN FERNÁNDEZ, DANIEL
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Normal
  Deposit date: 12/09/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: MOLINS BORRELL, CLIMENT
  Thesis abstract: Nowadays, there is an increasing, despite reduced, number of models capable of performing fully coupled aerohydro‐servo‐elastic simulations in the time domain for the analysis of floating offshore wind turbines (FOWTs).Historically, in its beginnings, these models widely adopted rigid multibody systems (RMS) formulations todescribe the global dynamics response of the complete system. However, their incapability to determine theinternal stress‐strain state of hyperstatic components, in conjunction with the irruption of platform conceptswith higher structural complexity, promoted the development of a second generation of models adoptingflexible multibody systems (FMS) formulations. Whose main strategy, because they were fundamentally anevolution of the firsts, relied on describing the dynamic response of the flexible components by superimposinga first‐order deformational analysis over their spatial rigid‐body configuration. Nevertheless, because theindustry has quickly trended in the last decades toward bigger and more powerful wind turbines, somecomponents of the system have suffered from increasing slenderness and flexibility. As is the case of the rotorblades or the tower, which are starting to require the adoption of non‐linear analyses to assess their dynamicresponse and their internal stress state properly.In this context, there is an incipient but reduced number of models capable of performing fully coupled nonlineardynamic structural analyses of FOWTs. However, they are mostly strictly restricted to one‐dimensionalbeam type elements, forcing the adoption of approximated local load mapping procedures during the detailedengineering design phase. For that reason, a new advanced fully coupled model based on the Finite ElementsMethod (FEM) is proposed in the present thesis. Its main advantages lie in the ability to perform non‐lineardynamic analyses in time domain of complex structural models composed of multiple finite elements ofdifferent nature. This feature allows a more precise definition of the real structural behaviour and, therefore,leads to more detailed internal stress‐strain state analyses without the need of adopting additional techniques.The underlying balance equations of the model have been derived based on the Element Independent Corotational(EICR) method, whose foundations were laid in the work developed by C. C. Rankin and F. A. Broganin the 1980s and later readapted and improved by C.A. Felippa and B. Haugen in the 2000s. However, becauseit was initially mainly focused on non‐linear quasi‐static structural analysis, a detailed and consistent extensionto non‐linear dynamics based on continuum mechanics theory has been developed in the framework of thepresent thesis research.To evaluate the performance of the proposed structural model, it has been verified based on a set ofcomputational mechanics benchmarks available in the literature on non‐linear dynamics of flexible bodies.While the fully coupled aero‐hydro‐servo‐elastic model for the analysis of FOWTs has been validated based onthe experimental data provided in the framework of the Offshore Code Comparison, Collaboration, Continued,with Correlation and unCertainty (OC6) international project promoted by the International Energy Agency(IEA).
  

Reading date: 13/10/2025

• GARCÍA DE ALBÉNIZ LÓPEZ DE ABERÁSTURI, NEREA: Engineering zirconia surfaces with cell instructive and antibacterial properties
  
  Author: GARCÍA DE ALBÉNIZ LÓPEZ DE ABERÁSTURI, NEREA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: Department of Materials Science and Engineering (CEM)
  Mode: Article-based thesis
  Deposit date: 29/07/2025
  Reading date: 13/10/2025
  Reading time: 10:30
  Reading place: ESCOLA D'ENGINYERIA BARCELONA ESTC/Eduard Maristany, 16 (08019 Barcelona)934137400Planta 2 Aula A A2.13https://meet.google.com/ztp-qftd-pqu
  Thesis director: JIMENEZ PIQUÉ, EMILIO | MAS MORUNO, CARLOS
  Thesis abstract: Tetragonal zirconia polycrystals stabilized with 3 mol% yttria (3Y-TZP) has gained growing interest as an alternative to titanium for dental implants, owing to its excellent biocompatibility, high mechanical strength and corrosion resistance and superior aesthetics. Despite these advantages, the clinical performance of zirconia implants still depends on their ability to promote osseointegration while simultaneously minimizing the risk of bacterial colonization, a competitive process known as "race for the surface". Surface properties of dental implants, such as topography, chemistry, and wettability, critically influence the biological response at the tissue-implant interface. In particular, micro- and nanotopographies directly impact cell-material interaction and can modulate several cellular functions including adhesion, migration, proliferation, and differentiation. Similarly, these topographical features affect bacterial response, either promoting bacterial adhesion or, conversely, reducing colonization through antifouling or bactericidal effects. For this reason, surface modifications have become a widely explored strategy to enhance the biological performance of implants. Nevertheless, the major challenge lies in designing surfaces that simultaneously support osseointegration while also preventing bacterial adhesion.This PhD Thesis addressed this challenge by investigating different surface modification approaches to improve the biological performance of zirconia. The aim was to create topographies that simultaneously improve cell behavior while exhibiting antibacterial properties. In concrete, we developed and characterized a series of micro and nanostructured zirconia surfaces and evaluated their biological performance both in terms of human mesenchymal stem cell (hMSC) response and bacterial adhesion of different strains. Prior to experimental work, a comprehensive bibliographic review on topographical modification strategies for 3Y-TZP was conducted (Chapter I), highlighting existing knowledge gaps and guiding the selection of surface treatments. Following this, different surface modification techniques were employed, including hydrofluoric acid (HF) etching for generating nanotopography (Chapter II) and laser patterning via nanosecond (ns-) and femtosecond (fs-) laser to create defined microstructures (Chapter III). These techniques were also combined to evaluate a potential synergistic effect of hierarchically rough micro- and nanotopographies on the biological response (Annex I). Our findings demonstrate both chemical etching and laser patterning techniques successfully enhanced the biological performance of zirconia by improving the hMSCS behavior and reducing bacterial adhesion. However, their combination did not result in a synergistic improvement. Among all the surfaces, the 3 μm linear pattern (L3) created through fs-laser patterning offered the best balance by simultaneously enhancing hMSC adhesion, migration, and osteogenic differentiation, while significantly reducing the adhesion of Staphylococcus aureus and Pseudomonas aeruginosa bacteria. It also led to the most favorable biological outcome under competitive co-culture conditions. Furthermore, biofunctionalization of this topography using a multifunctional peptide containing both antimicrobial and cell-adhesive sequences showed promising synergistic biological effects (Annex II). Importantly, these improvements were achieved without compromising the mechanical integrity of the L3-patterned surface (Annex III). In conclusion, this PhD Thesis demonstrated that topographical modification of zirconia offers promising strategies for developing zirconia implant with improved biological performance, enhancing both osseointegration and antibacterial properties. Future directions should focus on integrating biochemical cues, in vivo validations, and complete assessment of the mechanical integrity.
  

Reading date: 14/10/2025

• CAMÓS VIDAL, ROBERT: Design and characterization of an unobtrusive ECG monitoring system for wheelchairs
  
  Author: CAMÓS VIDAL, ROBERT
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ELECTRONIC ENGINEERING
  Department: Department of Electronic Engineering (EEL)
  Mode: Normal
  Deposit date: 16/09/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: ROSELL FERRER, FRANCISCO JAVIER | SUDRIA ANDREU, ANTONI
  Thesis abstract: This work was carried out within the framework of the “Doctorats Industrials” program, in collaboration with Regner Engineering S.L., a company specialized in the manufacturing of wheelchair solutions, and the Universitat Politècnica de Catalunya.As cardiovascular diseases (CVDs) remain the leading cause of death globally, and people with disabilities are at increased risk, the need for continuous, non-obtrusive heart monitoring becomes urgent. Three high-growth markets relevant to Electrocardiography (ECG) monitoring in wheelchairs were analyzed. First, the global wheelchair market is growing steadily, with powered models showing strong demand. Next, wearable and medical wearable markets are expanding rapidly, driven by advances in sensor integration and healthcare needs. Finally, the mHealth and IoHT sectors are experiencing major growth due to digital health trends and remote monitoring. Together, these markets highlight strong commercial potential for the proposed system.This PhD thesis presents the design and validation of a novel unobtrusive ECG monitoring system fully embedded into a wheelchair, tailored to the daily needs of individuals with mobility impairments.The developed solution integrates single-lead ECG sensors into the wheelchair’s armrests, using active electrodes powered by a bootstrapped supply to ensure ultra-high input impedance and high Common Mode Rejection Ratio (CMRR) in front of electrode impedance mismatch. This design allows the system to operate under both direct conductive contact (similar to dry electrodes) and indirect capacitive coupling (through clothing), without requiring hardware changes.Furthermore, the ECG sensor includes a protection circuit against electrostatic discharges (ESD), compliant with IEC 61000-4-2, which has been accurate designed and simulated in order not to degrade the high input impedance. The system also features Bluetooth connectivity and a modular backend, aiming for future scalability and industrial application.Sensor characterization was performed using an original experimental setup with an AC coupling inside a Faraday cage, allowing the measurement of very high input impedance values at low frequencies, i.e.191 fF at 50 Hz and common-mode rejection ratios (CMRR) up to 76.1 dB. Real-ECG recording tests with a volunteer wearing a cotton shirt confirmed accurate signal acquisition, with 117 µV RMS amplitude for the ECG and 31 dB of Signal to Noise Ratio (SNR).The research successfully achieved its goals by designing and validating a reliable unobtrusive ECG system for wheelchairs, meeting both clinical and industry standards. It lays a strong foundation for future developments in health monitoring. The proposed solution lays the foundation for future integration into chairs, beds, vehicle seats or even wearable technologies. It marks an important advance toward reliable, non-intrusive ECG monitoring for people with limited mobility, with both clinical and commercial potential.