Doctoral School

Reading date: 19/05/2025

• BARBERO DEL RÍO, MANUEL: Estudio de los principales contaminantes en lavandería industrial y diseño de un sistema de reutilización de agua
  
  Author: BARBERO DEL RÍO, MANUEL
  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: 24/04/2025
  Reading date: 19/05/2025
  Reading time: pending
  Reading place: pending
  Thesis director: DE PABLO RIBAS, JOAN | CASAS GARRIGA, SANDRA
  Thesis abstract: This doctoral thesis has enabled the development of a technological solution for water reuse in the industrial laundry sector. In addition, the emission of microplastics and emerging pollutants associated with this activity has been studied, focusing on strategies that minimise the problems associated with them.The reuse system, whose main technology is ceramic ultrafiltration, and uses foam fractionation and chemical oxidation as post-treatment, achieves a water reuse rate of 86% in unitary washing processes without affecting their final quality. The design process has been carried out in different phases, including analysis of the feasibility of the technologies, laboratory testing and validation at pilot and real scale.Foam fractionation was tested using an aeration column, which achieved surfactant separation rates of up to 70% from water and, as a result, a surfactant-concentrated stream whose reintroduction in subsequent washing processes improved the removal of certain pattern stains by up to 20%.Preliminary ultrafiltration membrane tests allowed the generation of explanatory models of permeate quality and transmembrane flux from a matrix of working pressure iterations for molecular cut-off sizes from 1 to 1400 kDa.For the pilot-scale validation of ceramic membrane ultrafiltration technology, a direct treatment-reuse process was combined and only 23L of mains water was used in each wash. This was implemented in a 13 kg capacity washing machine over 10 processes and demonstrated the greater efficiency of the 15 kDa membranes over the 50 kDa ones for the separation of anionic surfactants (+9%) and COD (+13%). The analysis of the rinsing efficiency showed more stable results with the use of 15 kDa membranes, which is associated with the greater removal of surfactants throughout the reuse cycles, so this pore size was chosen for the final validation of the system.Finally, ultrafiltration was combined with foam fractionation and chemical oxidation using ozone. These last two techniques coexisted in a cylindrical reactor built for this purpose and placed after ultrafiltration, which increased the removal efficiency of anionic surfactants to 91% after 15 minutes of treatment. In addition, a complete elimination of the colour released by the garments was confirmed, thus avoiding the transfer of this colour to subsequent washing processes.The emission of microplastics during the washing of garments throughout their useful life was estimated at 7,957,942 microfibres per kg of clothing washed. 44% of these microparticles are emitted during the first 5 washes and their emission can be substantially reduced with washing programmes with low mechanical action.The study of emerging contaminants in industrial laundry has shown the presence of this type of compounds in the wastewater generated. These would migrate from the fabrics where they are deposited or impregnated, to the water used in the washing process and would then be discharged into the sewage system. In total, 27 compounds of different types have been detected, such as disinfectants, medicines, antibiotics, drugs of abuse, pesticides and insect repellents. Hospital laundry has been found to be the sub-sector in whose water the highest concentrations and a greater variety of micropollutants have been detected, followed by hotel laundry and work clothes laundry. The elimination of this type of contaminant has been validated with a treatment system, achieving yields of over 98% for most of the compounds studied.
  

• COLAUTTI, VIVIANA ELIZABETH: El orden desconcertado. Tensión entre soporte físico y cuadrícula. Lógicas de ocupación en la ciudad de Córdoba, Argentina.
  
  Author: COLAUTTI, VIVIANA ELIZABETH
  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 URBANISM
  Department: Department of Urbanism, Territory and Landscape (DUTP)
  Mode: Normal
  Deposit date: 10/04/2025
  Reading date: 19/05/2025
  Reading time: 18:30
  Reading place: ETSAB (Esc. Técnica Sup. Arquitectura de Bcn)-Planta Baja-Aula C-B4Av. Diagonal, 649-651-08028-Barcelona(Inicio conexión a las 18:00-hora Bcn)
  Thesis director: SABATE BEL, JOAQUIN | MOISSET DE ESPANES, INES
  Thesis abstract: This research was born with the firm conviction that the growth and transformation of the city of Córdoba (Argentina) result from a unique dialogue and a complementary relationship between the physical support (that includes topography, rivers, streams, railway lines linked to contour lines) and the geometric order of the grid. These tensions develop in a very particular Latin American historical context that has shaped the city.The transformations of urban growth mainly stem from industrial-productive use (railway) and are located on the edges of natural elements (such as the Suquía river, or the La Cañada stream), or between pericentral neighborhoods. In these neighborhoods, located around its central area, the city shows very diverse grids, marked by unique physical features.The complex order of the city arises from the meeting point of three distinct orders. The abstract order of the grid, the order of the physical support and the temporal historical component. This encounter produces a disconcerting order, characterized by accelerated changes, the coexistence of heterogeneous elements and the loss of memory in undefined and interstitial areas. These areas, located next to clearly ordered areas, are the remnants of the city and cause inequalities in the use of space and strong contrasts in the urban fabric.Our main objective is to detect the occupation logic during the urban transformation processes that result from the tension between the physical support and the grid.The processes of urban growth have determined both the productive destiny of the city of Córdoba and its identity. It is the merging between a geographical dimension and a geometric one, where the growth of the grid triggers the transformation processes. This urbanization process reveals an occupation strategy that involves the transformation of the natural environment into a built environment.The concept of order, understood as an instrument of organization and an articulator between various urban components, has faced tensions all throughout the history of our Latin American cities. Such tensions derive from pre-existing elements and practices, thus shedding light on a permanent counterpoint between order and disorder. The main contribution of this thesis is to reveal the transformation processes that influenced the changes in the city. We/I seek to detect the logic behind growth and the categorization at various scales of urban interstices of the pericentral neighborhoods of Córdoba.The main hypothesis is that the order of the grid, political in origin and related to the subdivision and distribution of the land, adapts to various situations and particular intersections, while simultaneously faces the definite and physical facts of the city; in contrast to the order of the physical support, that transformsg according to the technological advances of the city and that includes the geographical, topographical, geological and structural location of the city in itself. These orders are linked by temporal historical events, giving rise to unique urban forms that reflect local logics of occupation and production, consequently emphasizing the interaction of factors and the convergence of orders that shape urban growth.We propose three methodological stages: critique, inquiry and synthesis. In the critique stage, we characterize the study area, develop questions, and define the study components (physical support and grid). In the inquiry stage, our starting point is the bibliographic and cartographic analysis of the city of Córdoba and the reading and interpretation of drawings, maps, images and data of reality and we seek to perform a process of layered reading with a certain level of abstraction. We use a set of interpretive graphics to detect permanent and emerging elements in urban transformations. In the synthesis stage, we propose a series of possible interpretation instruments.
  

• GARCÍA HARO, ALAN: Isla de frío de los parques urbanos: Hacia la definición de parámetros de composición para la optimización del efecto de enfriamiento en distintos contextos climáticos mediante análisis remoto
  
  Author: GARCÍA HARO, ALAN
  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 URBAN AND ARCHITECTURAL MANAGEMENT AND VALUATION
  Department: Department of Architectural Technology (TA)
  Mode: Normal
  Deposit date: 02/04/2025
  Reading date: 19/05/2025
  Reading time: 17:30
  Reading place: ETSAB (Esc. Técnica Sup. Arquitectura de Bcn)-Planta Baja-Sala de GradosAv. Diagonal, 649-651-08028-Barcelona(Inicio conexión a les 17:00 h)
  Thesis director: ROCA CLADERA, JOSE NICASIO | ARELLANO RAMOS, BLANCA ESMARAGDA
  Thesis abstract: Due to their composition, generally characterized by the predominant presence of vegetation and permeable soils, urban parks exhibit lower temperatures compared to other areas of the city. In many cases, this thermal reduction extends to the surrounding areas, generating the phenomenon known as the "park’s cool island" (PCI). This effect makes parks essential elements for regulating and mitigating urban heat, a problem exacerbated by the urban heat island effect, the global increase in temperatures, and the growing frequency and intensity of extreme heat events associated with climate change. These situations pose significant threats to public health, disproportionately affecting vulnerable groups and increasing heat-related mortality rates. Moreover, the limited availability of updated and detailed climatic data hinders the planning and design of effective mitigation strategies at the local level.This research aims to establish design parameters that optimize the cool island effect of urban parks (PCI) in various climatic contexts, employing remote sensing techniques. To achieve this, a flexible methodology was developed based on satellite data analysis and statistical models, adaptable to both the availability of information and the specific characteristics of each case study. The methodology is structured into three main stages: 1) quantification of the intensity and spatial extent of the cool island effect generated by parks; 2) estimation of physical descriptors derived from remote sensing data; and 3) statistical analysis of the influence of the physical characteristics of parks and their surroundings on cool island effect indicators.This study focuses on the cases of Barcelona (Mediterranean climate) and Mexicali (hot arid climate), selected for their contrasting climatic conditions and differing levels of institutional data availability. Initial results reveal that in Barcelona, with 86 urban parks, the average daytime summer PCI intensity was 1.51°C with a spatial extent of 78.02 meters, whereas Mexicali, with 435 parks, recorded an intensity of 0.90°C and a spatial extent of 119.03 meters. A notable contrast emerges in these parameters, as two parks in Barcelona showed no cool island effect (2.3%), while in Mexicali, this number increased to 133 parks (30.6%). The results demonstrate that vegetation is the primary regulator of urban temperature in both cities. In Mexicali, explanatory models incorporating variables derived from NDVI and supervised land cover classification using Random Forest achieved R² values exceeding 90% in spring and summer. In Barcelona, although NDVI was also relevant, the analysis highlighted limitations related to proximity to the sea and forested areas.In conclusion, this research establishes a methodological framework to define design parameters for urban parks using remote sensing data, tailored to the functional and temporal needs of each context. This represents a significant step toward developing specific tools for urban planning decision-making, integrating key considerations for regulating and mitigating urban heat.
  

• PAVÓN RIVERA, JULIÁN: Turbo-boosting Vector Architectures For Applications With Irregular Memory Access Patterns
  
  Author: PAVÓN RIVERA, JULIÁN
  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 COMPUTER ARCHITECTURE
  Department: Department of Computer Architecture (DAC)
  Mode: Normal
  Deposit date: 24/04/2025
  Reading date: 19/05/2025
  Reading time: pending
  Reading place: pending
  Thesis director: CRISTAL KESTELMAN, ADRIAN
  Thesis abstract: Since we are reaching the boundaries of the trifecta of Von Neumann architectures, Moore’s Law and Dennard’s scaling, both software developers and hardware architects are forced to find better and novel approaches to exploit parallelism to improve the processing time of commodity and High Performance Computing (HPC) CPUs on the vast amount of data generated daily.As Von Neumann architectures, Moore’s Law, and Dennard’s scaling near their limits, new strategies are needed to improve the performance and efficiency of CPUs for data-intensive workloads. While ILP and TLP are widely explored, there is still untapped potential in Data-Level Parallelism (DLP), which vector architectures leverage via SIMD execution. These architectures perform well in workloads with regular memory access, such as dense linear algebra or image processing. However, many modern applications—including sparse linear algebra, databases, and genome analysis—exhibit irregular access patterns, leading to poor performance on commercial vector systems like AVX-512 and ARM SVE.Irregular workloads face three main challenges: (i) large memory footprints that cause frequent off-chip accesses and memory-bound behavior, (ii) underutilized memory bandwidth due to poor spatial locality, and (iii) low ILP and vector unit underutilization from fragmented access patterns. This thesis addresses these issues by introducing three vector acceleration frameworks tailored to these domains: VIA, VAQUERO, and QUETZAL.We begin with sparse linear algebra, where indirect accesses and sparsity hinder performance despite software optimizations like tiling. To address this, we propose VIA, a vector architecture with a tightly-coupled scratchpad memory that enhances locality and bandwidth utilization. VIA improves performance in key kernels (e.g., SpMV, SpMM) over leading libraries.Database workloads share irregularity but involve larger working sets and rely on different locality techniques. These patterns limit VIA’s effectiveness. We therefore propose VAQUERO, a vector accelerator with a scratchpad coherent with the CPU cache, enabling efficient processing of large-scale queries like joins and aggregations.In genome sequence analysis, long-read technologies demand high-throughput, low-latency processing. These workloads involve highly irregular and unaligned memory access, often with compacted data formats. To address this, we present QUETZAL, a vector architecture with hardware support for unaligned accesses and new vector instructions optimized for sequence alignment and edit distance computation.All three accelerators are implemented at RTL and synthesized for a 7nm node. VIA achieves a 5.5x speedup in sparse algebra, VAQUERO a 2.7x speedup in databases, and QUETZAL a 5.7x boost in genome analysis, all with only ~1% area overhead. Together, these designs show how targeted architectural innovation can close the performance gap for irregular workloads across key computational domains.
  

• TIAN, YI: Bio-inspired Event-driven Intelligence for Motion Estimation
  
  Author: TIAN, YI
  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 AUTOMATIC CONTROL, ROBOTICS AND VISION
  Department: Institute of Robotics and Industrial Informatics (IRI)
  Mode: Normal
  Deposit date: 18/03/2025
  Reading date: 19/05/2025
  Reading time: 11:00
  Reading place: Sala d'Actes de la Facultat de Matemàtiques i Estadística (FME), Campus Diagonal Sud, Carrer de Pau Gargallo, 14, 08028 Barcelona
  Thesis director: ANDRADE CETTO, JUAN
  Thesis abstract: Motion estimation problems can range from low degrees of freedom (DOF) ego-motion estimation to complex, high-DOF motion, which includes dense pixel displacement or optical flow. This information is essential for enabling robots to perceive and navigate their environments. However, existing vision systems for motion estimation are less robust and efficient than biological systems, largely due to limitations in sensor technology and processing methods. This thesis builds on the bio-inspired sensor -event camera-, and the brain-inspired computing approach -Spiking Neural Networks (SNNs)-, presenting a promising solution that bridges these gaps. Event-based cameras have high temporal resolution, low latency, reduced data redundancy, and are power efficient. These unique capabilities make them particularly well-suited for environments and tasks where traditional frame-based cameras struggle. They show great potential for the solution of motion estimation problems across a wide range of applications, such as providing accurate and low-latency motion estimation for autonomous vehicles or aerial robots. SNNs are inspired by how neurons in the human brain communicate through synapses using spikes, which are brief and discrete electrical signals that allow highly efficient and robust information processing. The thesis begins with estimating 3-DOF ego-motion, progresses to sparse optical flow, and ultimately tackles dense optical flow. In the first step, the thesis addresses event-based ego-motion estimation by integrating SNN approaches with traditional optimization-based techniques. It explores the ego-motion estimation problem from inference optical flow obtained by an SNN and proposes a pooling method to address the aperture problem encountered in the sparse and noisy normal flow output of the SNN. In the next step, modern artificial neural network (ANN) architectures are leveraged to improve event-based optical flow estimation. This step proposes a U-Net transformer-based architecture with a recurrent neural network as the backbone. In the final phase of this research, the visual transformer architecture is further extended to flow encoders, incorporating spatiotemporal attention to enhance the extraction of temporal information. This led to the development of a swin transformer-based ANN model and its spiking counterpart. Notably, this work marks the first use of spikeformers in event-based optical flow estimation, demonstrating the potential of combining transformer architectures with SNNs for regression tasks. Overall, this thesis advances the understanding of motion estimation using event cameras. It sets the stage for their application in real-world scenarios such as high-speed object tracking and simultaneous localization and mapping (SLAM). The biologically inspired methods developed in this thesis offer promising avenues for balancing the performance and efficiency of computer vision and robotics systems, paving the way for future innovations in this field.