Doctoral School

Reading date: 18/09/2025

• BAL, PRADEEP KUMAR: Mathematical and computational modeling of the active mechanics of multicellular systems: from cell-cell adhesion to epithelial reshaping
  
  Author: BAL, PRADEEP KUMAR
  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: 30/06/2025
  Reading date: 18/09/2025
  Reading time: 10:30
  Reading place: Sala Zienkiewich (CIMNE) Building C1, UPC - Campus North Gran Capitan S/N 08034 Barcelona
  Thesis director: ARROYO BALAGUER, MARINO
  Thesis abstract: This thesis develops theoretical and computational frameworks to model two fundamental mechanical functions of multicellular tissues: cell-cell adhesion and epithelial reshaping. These processes are controlled by sub-cellular dynamics, yet they manifest at mesoscopic scales, posing a challenge for existing models. The work is structured in two parts, each addressing a different aspect of tissue mechanics while sharing a common approach based on irreversible thermodynamics and active gel theory.In Part I, the focus is on modeling the dynamic formation and organization of cell-cell adhesions, particularly between pairs of cells. A mesoscale theoretical model is developed that couples the mechanics of the cellular surface, chemical kinetics of adhesion molecules, their lateral diffusion on the membrane, and feedback with the actomyosin cortex. The framework relies on Onsager's variational formalism to ensure thermodynamic consistency and is implemented computationally in both axisymmetric and 3D finite element formulations. Simulations reveal how mechano-chemical couplings (including the reduction of cortical contractility within adhesions, force-induced bond activation, and immobilization of activated bonds) drive the self-organization of mature adhesion patches. This work not only reproduces experimental observations of adhesion behavior but also sets the stage for future modeling of adhesion turnover, decohesion dynamics, and asymmetrical cell contacts.Part II focuses on epithelial reshaping, a key driver of morphogenesis. We propose a continuum shell theory for epithelial monolayers derived from sub-cellular descriptions of the actin cortex as an active gel. Two formulations are introduced: a Kirchhoff shell theory with perpendicular lateral junctions, and a more general Cosserat theory that allows for junctional tilt. These models are implemented numerically using finite element methods and validated against 3D vertex simulations. Applications include the study of apico-basal asymmetries, buckling, and wrinkling in epithelial tissues, particularly under rapid deflation as in recent experimental setups. The continuum model demonstrates how cortical viscoelasticity, viscous drag by the surrounding medium, and curvature anisotropy determine the morphology and patterning of wrinkles in epithelial shells. Future directions include accounting for evolving junctional networks and for biochemical signaling.Together, these contributions offer a mesoscale framework to bridge sub-cellular dynamics with tissue-scale mechanical behavior, providing mechanistic insight into processes central to tissue development, integrity, and morphogenesis
  

• ELNAGGAR, OMAR AHMED MAHMOUD: Framework for Optimizing the Construction Process in Saudi Arabia: The Integration of Lean Construction, Building Information Modeling (BIM), and Emerging Technologies
  
  Author: ELNAGGAR, OMAR AHMED MAHMOUD
  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: Normal
  Deposit date: 25/07/2025
  Reading date: 18/09/2025
  Reading time: 16:00
  Reading place: C2-212
  Thesis director: TURMO CODERQUE, JOSE | ATENCIO CASTILLO, EDISON PATRICIO
  Thesis abstract: The construction industry in Saudi Arabia is experiencing rapid growth driven by the ambitious Vision 2030, but challenges related to inefficiencies, cost overruns, and delays persist. This research presents a comprehensive framework designed to optimize the construction process in Saudi Arabia by integrating Lean Construction, Building Information Modeling (BIM), and Emerging Technologies. Through an extensive review of 64 academic papers, this research identifies key tools and methodologies within Lean, BIM, and Emerging Technologies, that have been successfully applied in construction management. However, it also highlights the absence of a comprehensive framework that effectively integrates these domains in a structured manner.The research was developed through the Design Science Research Method (DSRM) and proposes a novel framework that categorizes these elements across the four phases of construction: Plan, Design, Construct, and Operate. This integration seeks to align functionality, optimize processes, and enhance lifecycle efficiency, while addressing the limitations of current approaches. The framework initially evaluated through expert consensus using the Delphi Method and subsequently tested in a real-world case study of a confidential mega-scale project in Saudi Arabia during the Design phase. Using pre-defined Key Performance Indicators (KPIs) such as cost efficiency, time efficiency, productivity, waste reduction, quality and safety, stakeholder satisfaction, and process automation, the study provides insights into the practical impact of the framework in improving project outcomes.The findings demonstrate the potential of the integrated framework to reduce waste, improve collaboration, and optimize overall project performance. This research contributes to the advancement of construction project management in Saudi Arabia by proposing a transformative approach that integrates Lean, BIM, and Emerging Technologies, offering practical recommendations for stakeholders seeking to enhance their construction processes. This framework aims to guide the Saudi construction industry in overcoming existing challenges and achieving more efficient, cost-effective, and high-quality project outcomes.Expert evaluations and practical applications validate the effectiveness and relevance of the framework, highlighting its potential to revolutionize construction management in Saudi Arabia and offering a robust model for other regions encountering similar challenges.
  

• FORNT MAS, JORDI: Designing Deep Learning Accelerators in the limits of Energy Efficiency
  
  Author: FORNT MAS, JORDI
  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: 25/07/2025
  Reading date: 18/09/2025
  Reading time: 11:00
  Reading place: Aula Multimedia, edifici B3 ETSETB, campus nord
  Thesis director: MOLL ECHETO, FRANCESC DE BORJA | ALTET SANAHUJES, JOSEP
  Thesis abstract: Deep Neural Network (DNN) models form the backbone of today’s Artificial Intelligence (AI) systems. Their large size and high computational cost have resulted in specialized hardware accelerators being essential for executing these models across many applications. However, the energy efficiency of state-of-the-art accelerator systems falls short of the demands of current AI, especially considering that, while DNN models keep getting larger and more complex, Moore’s Law is coming to a halt. This thesis aims at investigating new ways of optimizing the energy efficiency of AI accelerators by considering and leveraging different degrees of freedom involved in the computation of DNN workloads. Namely, several energy efficiency optimization techniques are explored involving accelerator dataflow, functional circuit approximations, low-bit quantization, mixed-precision, and undervolting; with the goal of pushing the limits of energy-efficient AI acceleration.
  

• FORTUNATO DOS SANTOS OLIVEIRA, DANIEL CAMILO: Synergy between ground-based remote-sensing instruments for retrieving microphysical-optical-radiative properties of atmospheric aerosols
  
  Author: FORTUNATO DOS SANTOS OLIVEIRA, DANIEL CAMILO
  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 SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 18/07/2025
  Reading date: 18/09/2025
  Reading time: 14:00
  Reading place: Sala de Juntes, edifici D4, Campus Nord, Barcelona
  Thesis director:
  Thesis abstract: The improvements in retrieving microphysical, optical, and radiative properties of aerosols can contribute to more detailed local observations and research, support local or global climate modeling and air quality forecasting, validate satellite products, and contribute to public policies. This PhD thesis aims at achieving such improvements through synergies between ground-based remote-sensing instruments. The objectives are to (1) evaluate the potential of an inversion algorithm, namely GRASP, for retrieving aerosol properties from the synergy between a polarized Sun-sky-lunar photometer and a state-of-the-art ACTRIS/EARLINET multi-wavelength lidar, and (2) estimate long-term aerosol radiative effects by combining net radiative fluxes from pyranometers and Aerosol Optical Depth (AOD) from photometers, and assessing GRASP’s ability to retrieve such effects on a case-by-case basis. To achieve Obj. 1, sensitive tests (noise-free and random noise retrievals) were performed with GRASP for several combinations of ground-based observations, including polarization information as GRASP inputs, for three aerosol scenarios in Barcelona, Spain. The sensitive tests showed that the addition of the Degree of Linear Polarization (DoLP) improved the noise-free and random-noise GRASP inversions, particularly under higher AOD. The gains were most notable for the coarse mode of the optical properties, and for the coarse mode of the Real Refractive Index. To achieve Obj. 2, a direct method was applied to estimate spectral Aerosol Forcing Efficiency (AFE) and Aerosol Radiative Forcing (ARF) for a 14-year database in Barcelona, Spain. The AFE-ARF estimations confirmed a dominant cooling forcing over Barcelona, with the strongest cooling effect caused by mineral dust, followed by urban/industrial-biomass burning and mixed aerosols. Furthermore, the GRASP inversions with DoLP were more accurate for the ARF, agreeing with the direct method in the high-AOD cases.
  

Reading date: 19/09/2025

• LU, XUAN: Metal-Decorated Ceria-Based Reducible Oxide Catalysts for CO2 Transformation
  
  Author: LU, XUAN
  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 CHEMICAL PROCESS ENGINEERING
  Department: Department of Chemical Engineering (EQ)
  Mode: Normal
  Deposit date: 16/07/2025
  Reading date: 19/09/2025
  Reading time: 11:00
  Reading place: EEBE Sala Polivalent, Edif. ICampus Diagonal Besòs, Av. Eduard Maristany, 16 08019 Barcelonahttps://eebe.upc.edu/ca/lescola/com-arribar
  Thesis director: LLORCA PIQUE, JORDI | CABOT CODINA, ANDREU
  Thesis abstract: Noble metal clusters and single atoms have been considered as effective co-catalysts for the enhancement of carbon dioxide hydrogenation due to their singular geometric structures, electronic properties and unique reactivity. Nevertheless, the design of a low-cost and easy synthesis procedure for ultrasmall metal species is an urgent yet challenging task. In this thesis, we have synthesized CeO2-based catalysts decorated with non-noble metals (Cu and Ni) and bimetallic clusters (Cu-Ga) through hydrothermal and mechanochemical processes for CO2 transformation. In Chapter 3, bimetallic clusters (Cu-Ga) loaded on Ce0.9Zr0.1O2 are synthesized and characterized, and their catalytic performance for methanol production was investigated. By maintaining a constant total amount of Cu and Ga while varying the Cu/Ga ratio, we demonstrate that modifying the support surface with an optimal Cu/Ga ratio enhances CO2 adsorption and activation. This improvement stems from the compensatory generation of H2 dissociation at Ga sites, which directly interact with oxygen vacancies-a critical factor in the catalytic process.In Chapter 4, CeO2 exposing preferentially {001}, {110} and {111} facets are prepared and loaded with Ni monometallic clusters to investigate their unique catalytic properties for CO2 methanation. Experimental characterization reveals that Ni supported on CeO2 nanorods exposing {110} and {111} facets exhibited the highest activity.In Chapter 5, I analyze the effect of different highly-dispersed copper on CeO2 for the reverse water-gas shift reaction (RWGS). I systematically examine both the copper loading amount and the preparation method (ball milling versus conventional incipient wetness impregnation), observing significant differences in catalytic activity. To elucidate the enhanced Cu-CeO2 interaction induced by ball milling, I conduct comprehensive characterization (XRD, XPS, N2O Titration and in situ DRIFT et. al) studies to determine copper speciation at varying dispersion levels and to clarify the reaction mechanism. In Chapter 6, the effect of the introduction of Ga to Cu/CeO2 for thermostability during the RWGS reaction is studied. To improve the stability of Cu/CeO2 catalysts, a strategy through Ga incorporation is developed, achieving an optimal balance between activity and stability for the RWGS reaction. It is also observed that Ga doping in the CeO2 support effectively suppresses Cu aggregation during reduction treatments by modulating both CeO2 reducibility and electron transfer from CeO2 to Cu.