Doctoral School

Reading date: 13/11/2026

• FOOLADIMAHANI, SAGHAR: Assessment of fracture and fatigue behavior of cemented carbides by using small-scale artificial flaws
  
  Author: FOOLADIMAHANI, SAGHAR
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: Department of Materials Science and Engineering (CEM)
  Mode: Article-based thesis
  Deposit date: 21/09/2026
  Reading date: 13/11/2026
  Reading time: 11:00
  Reading place: ESCOLA D'ENGINYERIA BARCELONA ESTC/Eduard Maristany, 16 (08019 Barcelona)EDIFICI A planta 0, SALA POLIVALENTmeet.google.com/swu-kiha-hwq
  Thesis director: LLANES PITARCH, LUIS MIGUEL
  Thesis abstract: This PhD thesis investigates the fracture and fatigue behavior of WC-Co cemented carbides through a deterministic damage-tolerance approach based on controlled artificial small-scale flaws. These materials, commonly referred to as hardmetals, are widely used in demanding engineering applications due to their combination of hardness, strength, and toughness. However, their structural reliability is strongly affected by microstructural heterogeneities and service-induced defects, which act as critical failure origins under monotonic and cyclic loading. Conventional assessment approaches rely mainly on stochastic natural flaws or long through-thickness cracks, thereby limiting reproducibility and predictive capability. This work addresses these challenges by developing and validating an experimental framework to systematically assess damage tolerance using well-defined artificial flaws.The research was conducted on four fine-grained WC-Co grades with different cobalt contents to isolate the influence of the metallic binder. Three complementary strategies were employed. Conical indentation reproduced blunt contact damage dominated by irreversible deformation and, at higher loads, radial cracking. Sharp Vickers indentation introduced surface fissures suitable for fatigue crack growth studies. Nanosecond laser ablation was optimized to generate reproducible microdimples and notch-like surface defects with controlled geometry. Their effects on residual strength, fatigue performance, crack growth behavior, and fracture toughness were assessed through mechanical testing, microscopy, fractography, crack-path inspection, and fracture-mechanics analysis.The results show that controlled artificial flaws provide a robust basis for evaluating damage tolerance in hardmetals. Under monotonic loading, residual strength is governed by flaw severity and intrinsic fracture toughness. For imprint-type or dimple-like defects without pre-existing cracks, strength reduction is mainly associated with geometric stress concentration. Once cracking occurs, fracture toughness becomes dominant, causing abrupt strength degradation in low-binder grades and more stable crack evolution in tougher materials. Under cyclic loading, the metallic binder plays a dual role. In crack-free damaged conditions, higher binder content increases fatigue sensitivity due to localized cyclic plasticity, whereas in pre-cracked conditions it improves resistance to subcritical crack propagation through crack-tip shielding and energy dissipation.A specific part of the thesis addresses laser ablation for fracture toughness determination. Laser-induced microdimples combined with quantitative fractography produced toughness values in close agreement with established fracture-mechanics methods. Laser-generated shallow notches also acted as controlled crack-initiation geometries for conventional toughness evaluation, providing a practical alternative to traditional pre-cracking procedures. These results demonstrate that laser-induced flaws are effective both for damage-tolerance studies and for reliable fracture-mechanics characterization.Overall, this thesis establishes a rigorous framework for investigating fracture and fatigue in WC-Co cemented carbides through controlled small-scale flaw engineering. The methodology distinguishes the effects of microstructure, damage condition, and flaw characteristics; clarifies the role of binder content under different loading conditions; and validates indentation- and laser-induced flaws for assessing strength, fatigue behavior, crack propagation, and fracture toughness. These findings provide a practical basis for reliability assessment and the design of hardmetals with improved resistance to service-like damage.
  

• MARÍN RIVAS, ENRIQUE DAVID: Mechanochemical Preparation of Pd-Cu/CeO₂ Catalysts for Carbon Monoxide Oxidation
  
  Author: MARÍN RIVAS, ENRIQUE DAVID
  Programme: DOCTORAL DEGREE IN CHEMICAL PROCESS ENGINEERING
  Department: Department of Chemical Engineering (EQ)
  Mode: Normal
  Deposit date: 31/07/2026
  Reading date: 13/11/2026
  Reading time: 11:00
  Reading place: Sala Polivalent - Edifici IEEBEhttps://eebe.upc.edu/ca/lescola/com-arribar
  Thesis director: LLORCA PIQUE, JORDI | VENDRELL VILLAFRUELA, XAVIER
  Thesis abstract: Cerium oxide (CeO2)-based catalysts are widely studied for oxidation reactions due to their redox properties, oxygen storage capacity, and ability to stabilise metal-support interfacial sites. Among these systems, Pd/CeO2 and Cu/CeO2 catalysts are of particular interest for low-temperature CO oxidation. However, their catalytic behaviour depends on the synthesis method, metal dispersion, and defect structure. In this thesis, mechanochemical synthesis by planetary ball milling was investigated as a sustainable route for preparing CeO2-based catalysts, together with different treatments aimed at modifying their structural and catalytic properties.The first part of this work focused on Pd/CeO2 catalysts prepared by planetary ball milling under controlled atmospheres. The results demonstrated that mechanochemical synthesis promotes the formation of active Pd-Ce interfacial structures. Catalysts prepared at 250 rpm under air for 10 min exhibited the highest CO oxidation activity, outperforming those prepared by conventional impregnation. This behaviour was attributed to the formation of PdOx-Ce interfacial species and strong metal-support interactions. Electron microscopy revealed highly dispersed Pd nanoparticles and clusters on the ceria surface.The second part investigated Cu/CeO2 catalysts prepared by mechanochemical methods using different precursors, calcination temperatures, milling conditions, and reduction treatments. The results showed that mechanochemical synthesis can produce catalysts with superior performance compared with conventional methods. Catalysts prepared from copper nitrate and calcined at 300 °C showed the best activity. H2/N2 reduction further enhanced catalytic performance. Electron microscopy confirmed the absence of large CuOx aggregates and the presence of highly dispersed copper species. In addition, operando synchrotron experiments revealed dynamic Cu+/Cu2+ redox cycling under reaction conditions, contributing to catalyst stability and progressive activation.The third part addressed bimetallic Pd-Cu/CeO2 catalysts prepared by planetary ball milling. Different Cu/Pd ratios, metal loadings, and deposition sequences were evaluated. Under non-reduced conditions, Pd incorporation did not significantly improve activity compared with monometallic Cu/CeO2 catalysts. However, after H2 reduction, the bimetallic catalysts exhibited enhanced activity, highlighting the importance of pre-reduction in the formation of favourable Pd-Cu-Ce interfacial structures.Electron beam irradiation was also investigated as a post-synthesis treatment for Pd/CeO2 catalysts. Irradiation improved catalytic activity and reduced the apparent activation energy for CO oxidation. Raman and XPS analyses revealed an increase in structural defects, peroxide species, and additional PdOx-Ce interfacial sites.Finally, flash sintering was applied to ceria-based materials. Although the treatment induced significant microstructural and electrical modifications, the resulting materials exhibited lower catalytic activity than untreated CeO2, mainly due to the thermal effects associated with Joule heating.Overall, this thesis demonstrates that mechanochemical synthesis is an effective strategy for preparing highly active CeO2-based catalysts. The catalytic behaviour of Pd/CeO2, Cu/CeO2, and Pd-Cu/CeO2 systems is governed by metal-ceria interfacial structures, metal dispersion, and the redox properties of the support.
  

Reading date: 16/11/2026

• PLASCENCIA OROZCO, SUSANA: Quantum memories based on rare-earth doped solids: from spatial multiplexing to new materials
  
  Author: PLASCENCIA OROZCO, SUSANA
  Programme: DOCTORAL DEGREE IN PHOTONICS
  Department: Institute of Photonic Sciences (ICFO)
  Mode: Normal
  Deposit date: 12/10/2026
  Reading date: 16/11/2026
  Reading time: 10:00
  Reading place: ICFO Auditorium
  Thesis director: DE RIEDMATTEN, HUGUES
  Thesis abstract: Quantum repeaters play a fundamental role in the development of long-distance quantum network. In most architectures, their functional core is constituted by quantum memories. Although many systems have been investigated as potential quantum memory, no single platform yet satisfies all the requirements simultaneously. Solid-state systems, particularly cryogenically cooled rare-earth doped crystals represent one of the most promising routes toward efficient, long-lived and massively multiplexed quantum memories, with great prospects for integration. This thesis addresses two main objectives. The first is to extend the spatial multimode capacity of a rare-earth-doped quantum memory using a praseodymium-doped yttrium orthosilicate Pr^{3+}:Y_2SiO_5 to increase the entanglement generation rate required for realistic quantum repeater application. The second objective, carried out in collaboration with Corning, investigates the spectroscopic properties of erbium-doped-chalcogenides to assess their suitability as fiber-integrated quantum memory operating at the telecom wavelength. To achieve spatial multiplexing in the Pr^{3+}:Y$_2SiO_5 crystal, we implement a quantum memory array (QMA) using a pair of acousto-optic deflectors, creating ten individually controllable spin-wave memory cell featuring on-demand read-out. By combing the spatial multiplexing of the array with the intrinsic temporal multimodality of the atomic frequency comb (AFC) protocol, we store and retrieve on-demand up to 250 modes using weak coherent pulses at the single-photon level, both surpassing the current state-of-the-art for solid-state quantum memory. The high signal-to-noise ratio and low cross-talks enable the storage of heralded single-photons. To do so, we use a cavity enhanced spontaneous parametric down conversion source to generate a pair of photons, with the signal photon stored in the QMA and the idler at telecommunication wavelength. We demonstrate the violation of the Cauchy-Schwarz inequality by at least 4.8 standard deviations in all the memory cells, demonstrating light-matter quantum correlations between the QMA and the telecom photon. We further demonstrate the potential use of our system as a random access quantum memory (RAQM) by storing path and time-bin qubits encoded with weak coherent states in the quantum memory array, achieving average fidelities of 95 ± 2% and 91 ± 2%, respectively. We further load sequentially a time-bin qubit in two different memory cells, simultaneously store both qubits, and perform a collective read-out. The high fidelities together with independent control pair represent a significant step toward a solid-state RAQM for quantum repeaters and photonic quantum processors. For the fiber-compatible quantum memory, we study three Er-doped chalcogenide glasses with a different glass network rigidities quantified by the coordination mean number (MCN). We measure their optical coherence time (T_2) through two-pulse photon echo (TPE) technique and find that the sample with MCN < 2.4 exhibits the shortest T_2, while the most rigid sample (MNC = 2.9) suffers from internal stress that also limits the coherence time. The intermediate rigidity sample (MNC = 2.69) shows a T_2 close to 1 μs (corresponding to a homegeneous linewidth ≈ 370 kHz) at 2 K and 0.2 T, which is among the longest coherence times reported for Er-doped glasses under practical cryogenic conditions, reachable with a standard close-cycle cryostat. However, the spectral hole burning measurements reveal hole widths around 50 MHz for two best TPE performing samples, severely restricting the achievable comb finesse and therefore constraining the AFC efficiency in these materials.
  

Reading date: 17/11/2026

• CAPRARA, ADRIANO: Demand-Side Flexibility Algorithms for Industrial Loads and Data Centers
  
  Author: CAPRARA, ADRIANO
  Programme: DOCTORAL DEGREE IN ELECTRICAL ENGINEERING
  Department: Department of Electrical Engineering (DEE)
  Mode: Normal
  Deposit date: 30/09/2026
  Reading date: 17/11/2026
  Reading time: 10:00
  Reading place: Aula LS9 - Edifici L - ETSEIB-UPC
  Thesis director: ARAGÜÉS PEÑALBA, MÒNICA | BULLICH MASSAGUÉ, EDUARD
  Thesis abstract: The decarbonisation of electricity systems, the disruption of fossil-fuel supply chains, and the rapid growth of new digital loads such as artificial-intelligence data centres are together making generation-led flexibility insufficient. Meeting the energy transition is increasingly an operational problem: the power system needs resources that can adjust their consumption in response to market and system signals. This thesis studies demandside flexibility from two families of large consumers —energy-intensive industrial loads and data centres— and argues that their latent flexibility becomes useful only when it is converted, through the explicit modelling of operational and market constraints, into actions that can be scheduled, activated, and valued. The thesis develops this conversion idea through a set of algorithms. For industrial loads, it introduces a day-ahead flexibility service in which a balance responsible party combines electricity-price forecasting with the optimal activation of alternative, production-preserving consumption schedules, lowering procurement costs without curtailing output. This approach is then extended to a cooperative cluster of industrial sites that share on-site renewable generation and storage, coordinating their schedules, fairly distributing the resulting benefit, and assessing how much of their residual flexibility is genuinely admissible in balancing markets. For data centres, it uses the observed latency of computational tasks to identify deferrable workloads and to activate them under realistic market conditions while preserving quality of service. Across all cases, deliverable flexibility proves smaller than its theoretical potential, aggregation is essential to reach market thresholds, and value concentrates in the moments of greatest system stress. The thesis thus provides methods and evidence for turning the demand-side flexibility we already have into a dependable contribution to the energy transition.
  

• CLARAMUNT MOLET, MIREIA: Development of a novel clinical gait assessment tool for monitoring and stratifying neuromuscular diseases
  
  Author: CLARAMUNT MOLET, MIREIA
  Programme: DOCTORAL DEGREE IN BIOMEDICAL ENGINEERING
  Department: Department of Mechanical Engineering (EM)
  Mode: Normal
  Deposit date: 24/07/2026
  Reading date: 17/11/2026
  Reading time: 10:30
  Reading place: Aula 28.8. Planta 1, Escola Tècnica Superior d'Enginyeria Industrial de Barcelona (ETSEIB), Av. Diagonal, 647, 08028 Barcelona
  Thesis director: FONT LLAGUNES, JOSEP MARIA | IDELSOHN ZIELONKA, SEBASTIAN
  Thesis abstract: Neuromuscular diseases are chronic and degenerative conditions of the skeletal musculature that progressively impair gait, one of the primary determinants of functional independence. Their monitoring, both in clinical practice and clinical trials, relies on clinical scales and functional tests that are subject to observational bias, ceiling effects, and insufficient sensitivity to detect subtle changes. At a time when novel disease-modifying therapies are emerging, the availability of an objective, portable tool integrable into routine clinical practice for biomechanical mobility assessment represents an unmet clinical need.To address this need, the present thesis develops the biomechanical algorithms to derive spatiotemporal parameters, sagittal joint kinematics, muscle activation, plantar pressure distribution, and heart rate from raw wearable sensor data. Data capture relies on the Ephion Mobility system, which integrates and synchronises inertial sensors, surface electromyography, plantar pressure insoles, and a cardiac sensor within a single mobile application. Using this system, data were collected from 176 volunteers, 90 patients and 86 controls, across two countries and standard hospital settings.The first study, conducted in collaboration with Hospital Sant Joan de Déu, serves as the proof of concept. It validates a multidimensional gait score for Duchenne muscular dystrophy, derived from multisensor data through unsupervised learning, which demonstrates good agreement with current clinical metrics and promising capacity for disease monitoring.With the validity of the approach established, the second study, carried out at the Copenhagen Neuromuscular Center, explores its applicability in two conditions with markedly different distributions of muscle weakness: Becker muscular dystrophy and myotonic dystrophy type 1. Biomechanical gait assessment is shown to discriminate disease-specific patterns and severity gradients that functional tests do not capture. Finally, the third study, conducted in collaboration with the Spanish Pompe Patient Association, addresses the most demanding question: whether the tool can detect longitudinal progression in a slowly evolving disease. The Pompe-MDPI achieves statistical significance over one year of follow-up in a context where current metrics fail to detect change over the same interval.Taken together, the results provide preliminary evidence that portable multidimensional biomechanical assessment is clinically feasible, sensitive to functional severity, and capable of detecting longitudinal disease progression where conventional measures fall short. The derived scores represent promising candidates as digital biomarkers for natural history studies and clinical trials of disease-modifying therapies.