Doctoral School

Reading date: 20/12/2024

• CARRASCO RIBELLES, LUCÍA AMALIA: Multimorbidity and frailty trajectories and explainable prediction models for health-related outcomes using longitudinal electronic health records of the ageing Catalan population
  
  Author: CARRASCO RIBELLES, LUCÍA AMALIA
  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: 07/11/2024
  Reading date: 20/12/2024
  Reading time: 10:30
  Reading place: Aula Teleensenyament, Edifici B3, ETSETB, Campus Nord, Barcelona
  Thesis director: CABRERA BEAN, MARGARITA ASUNCION | VIOLÁN FORS, CONCEPCIÓN
  Committee:
       PRESIDENT: GARCÍA GÓMEZ, JUAN MIGUEL
       SECRETARI: HERNANDO PERICAS, FRANCISCO JAVIER
       VOCAL: CATALÀ SABATÉ, MARTÍ
  Thesis abstract: As life expectancy rises, people over 65 years old become a larger proportion of the population. However, longer life expectancy does not imply healthy ageing. Older individuals are more likely to develop multiple chronic diseases and other disabling conditions such as frailty. These conditions not only reduce quality of life but also place significant demands on an already strained healthcare system. This thesis aimed to 1) enhance understanding of the relationship and progression of frailty and multimorbidity, 2) study how frailty modifies multimorbidity patterns and trajectories, and 3) develop explainable predictive models using longitudinal electronic health records (EHRs). All the studies focused on three outcomes: all-cause mortality, nursing home admission, and home care need. Utilising SIDIAP, the primary care EHR database in Catalonia, enabled the development of large, population-based longitudinal studies with greater generalisability and the application of more sophisticated analytical techniques. This thesis yielded several important findings and recommendations. Firstly, it was demonstrated how the characterisation of multimorbidity and frailty and their impact on health-related outcomes evolves with age. The accumulation of diseases increases the likelihood of death, but older individuals with fewer diseases and more frailty-related deficits are more likely to require specialised care. Therefore, treatment plans should be tailored based not only on age but also on the specific characterisation of the patient at any given time. Secondly, the study found that multimorbidity patterns and trajectories are modified when frailty is considered, improving their predictive power for some health-related outcomes. Thus, future research on multimorbidity in older populations should integrate frailty information. Thirdly, a predictive model that addressed the technical challenges of longitudinal EHRs and incorporated mechanisms to enhance transparency was developed and called ARIADNEhr. During ARIADNEhr's development, it was found that increased model complexity does not necessarily improve discriminability but does enhance the clinical plausibility of the resulting attention maps. This model generally outperformed others using cross-sectional data. Additionally, the model's performance was validated with an external population, specifically in the UK with the CPRD database. This thesis exemplifies the transfer of advanced analytical techniques, such as clustering and deep learning, to the health field, supported by rigorous validation to ensure reliability. It offers valuable insights for future studies on the ageing population, emphasising the need for having access to longitudinal, high-quality data such as that from primary care. The findings aim to improve treatment penalisation, enhance patients' quality of life, and reduce costs for the national healthcare system.
  

• GON MEDAILLE, AXEL: Advanced characterization and modelling of innovative low-dimensional materials for solar cells applications
  
  Author: GON MEDAILLE, AXEL
  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: 05/11/2024
  Reading date: 20/12/2024
  Reading time: 11:00
  Reading place: Defensa pública en la Sala A2.14 del Edificio A del Campus Besós-EEBE
  Thesis director: SAUCEDO SILVA, EDGARDO ADEMAR | JEHL, ZACHARIE VICTOR SAMUEL NATHANAEL
  Committee:
       PRESIDENT: PÉREZ RODRÍGUEZ, ALEJANDRO
       SECRETARI: GARCÍA SÁNCHEZ SÁNCHEZ, MARIO FIDEL
       VOCAL: DIMITRIEVSKA, MIRJANA
  Thesis abstract: Energy transition keeps its course while new materials keep emerging promising better impact on environment. Among those materials, Q-1D chalco-halides materials using Bi and Sb, S, Se and I, Br, giving rise to wide combinations of materials. Most of them present the unique feature of a Pnma crystallographic structure allowing them to grow alongside one preferential direction, giving them optoelectronic properties highly seeked for PV applications, in particular for thin film solar cells. So far, Sb2Se3 has been the most investigated material within this class of material with an efficiency up until now of XX% in substrate configuration under AM1.5 spectrum illumination. Indeed, Sb2Se3 presenting the same crystallographic structure, is well-known within the PV community. However, despite having promising results over the past years, Sb2Se3-based solar cells reached a bottleneck in terms of efficiency. More generally, Q-1D chalco-halides materials either lack or do not have characterization data due to their recent emergence or re-emergence for some materials.This thesis will intend to address Sb2Se3 bottlenecks and present some solutions to allow Sb2Se3-based and other Q-1D chalco-halides solar cells to reach new heights through device modelling, present advanced characterization results from other Q-1D chalco-halides materials such as BiSeBr & SbSeI. Finally, the use of a novel material: Ti3C2Tx MXenes as selective contact suitable for those absorbers is also presented in this thesis. Firstly, a brief introduction of Sb2Se3 modelling parameters as well as BiSeBr & SbSeI results from by Raman spectroscopy and Time – Resolved Photoluminescence (TRPL) characterization are presented. A multi-wavelength investigation done by Raman spectroscopy coupled with novel Density Function Theory (DFT) are presented, giving information regarding the composition of the materials and the impact of the synthesis method for BiSeBr & SbSeI. Additionally, TRPL measurements highlighted the carriers’ dynamics and provide hints towards defects status of those materials. Altogether, this information helped to determine the potential of those new material as photo-absorber according to new figure of merit. Secondly, an emphasis is put on the device modelling using SCAPS-1D software and previous references to generate a qualitative model of Sb2Se3/CdS solar cells in substrate configuration to then design 2 numerical solutions to tackle the current bottlenecks experienced by the PV community. Those numerical solutions enable Sb2Se3 devices to reach 10.7% in efficiency by either implementing an ultrathin Al2O3 oxide intercalated between Sb2Se3 and CdS or operating a partial surface sulfurization on Sb2Se3 layer. Then, a simplified structure including only BiSeBr and 2 selective contacts was generated to pinpoint requirements from an electrical point of view. Although, due to software limitations, optical consideration is lacking to determine accurately suitable selective contacts, first approximations were determined through those simulations.Lastly, we develop the use of another novel material: MXenes Ti3C2Tx as a potential selective contact for Sb2Se3-based solar cells. Besides their wide range of deposition techniques and application, MXenes properties can be modulated alongside their synthesis. Initially, we perform materials characterization through Raman spectroscopy and X-Rays Diffraction (XRD) while changing intercalating agent and post deposition treatment (PDT) parameters to highlight this modulating feature. Then, we synthetized devices with Ti3C2Tx as hole transport layer (HTL) and Sb2Se3 as absorber. To improve carrier extraction, Se was incorporated on Ti3C2Tx layer under different PDT configurations. While PV performances were still poor compared to reference device without Ti3C2Tx some parameters presented some improvements upon Se incorporation onto Ti3C2Tx surface.
  

• HEINONEN, PIJATTA MAARIA: Beyond planning: Prefiguring horizontal practices of architecture in the context of autonomous geographies
  
  Author: HEINONEN, PIJATTA MAARIA
  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 THEORY AND HISTORY OF ARCHITECTURE
  Department: Department of History and Theory of Architecture and Communication Techniques (THATC)
  Mode: Normal
  Deposit date: 25/09/2024
  Reading date: 20/12/2024
  Reading time: 12:00
  Reading place: Face-to-face (Room Sala de Graus. ETSAB. Main floor)
  Thesis director: MONTANER MARTORELL, JOSE MARIA | HERNÁNDEZ FALAGÁN, DAVID
  Committee:
       PRESIDENT: OYON BAÑALES, JOSE LUIS
       SECRETARI: FERRERI, MARA
       VOCAL: GARCÍA VÁZQUEZ, CARLOS
  Thesis abstract: Hegemonic organization of space and architecture as its essential means respond to political and economic intentions whose determination is out of most people’s reach. Representations of dominant practices are embedded in the order and form of space, reaching the spaces and practices of everyday life. The reform of architecture alone has been understood as insufficient in addressing the imbalance of power, indicating the necessity of more fundamental changes in the societal context that architecture depends on. The possible politics of space that would be based on decentralization and inhabitants’ self-determination have been approached theoretically. However, investigations into architectural practices that are, in fact, taking place in counter-hegemonic contexts are few. This study investigated architecture that emerges within the prefiguration of social change, focusing on social movements whose autonomous politics are characterized by horizontal, egalitarian, and non-capitalist principles. The research questions were: What are the characteristics of architectural decision-making, and, what are the characteristics of the architecture carried out in occupied, largely self-built autonomous geographies? The research was based on grounded theory and was guided by simultaneous collection and analysis of data as well as theoretical sampling. Data was collected in three different autonomous geographies in Central Europe. The methods of data collection were participant observation, drawing, mapping, and interviews. The analysis was based on qualitative coding and followed the constant comparative method. The study found first that, in the examined geographies, the collective organization of space is carried out in a direct democratic, transparent manner. Collective decision-making highlights the direct participation of everyone in relevant decisions, from the founding principles of organization to the specific patterns and forms of space. Second, the collective organization of space is voluntary and partial. It is combined with decentralization of decision-making and individual autonomy of intervening in space. Autonomy facilitates a certain freedom to transform space and the social relations implied within, beyond their collective determination. In the examined geographies, spatial organization develops through simultaneous collective and autonomous interventions in a partially non-planned manner. Third, the inhabitants question the property of space and the permanence of architectural form. The open, common, and malleable nature of space enables its transformation according to horizontal lines, referring directly to the inhabitants present. The findings provide new insights into an architecture based on the politics of participation. While the study supports previous theorizations, one of its main contributions is the elaboration of architectural participation as it relates to the shifting negotiation between the individual and the collective. Furthermore, the principal theoretical implication of this study is the questioning and negation of overarching planning that the findings suggest. Instead of exhaustive instruments such as the urban plan, the findings indicate a less invasive idea of coordination-in-space that arises voluntarily from the bottom up. Finally, while questioning certain precepts of normative planning, the study also indicates directions to explore further the possibilities of an indeterminate, horizontal organization of space.
  

Reading date: 23/12/2024

• AGUDELO VALDERRAMA, VANESSA: Integración de la relación salud humana y cambio climático en el marco de la resiliencia urbana. Propuesta metodológica de evaluación y operacionalización en un contexto Latinoamericano
  
  Author: AGUDELO VALDERRAMA, VANESSA
  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: 22/11/2024
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: MORATO FARRERAS, JORDI
  Committee:
       PRESIDENT: CORREIA GUEDES, MANUEL
       SECRETARI: ALVAREZ DEL CASTILLO, JAVIER
       VOCAL: MENA NIETO, ÁNGEL ISIDRO
  Thesis abstract: This study addresses the relationship between climate change and human health in the framework of urban resilience in a Latin American context. It sought to strengthen the climate and health components through conceptual harmonization and integration, as well as the identification of indicators within urban resilience measurement models. Thus, the first proposal of a model for measuring the urban resilience index adapted to Latin American cities is presented, specifically addressing the relationship between climate change and health. This model was validated and operationalized through a case study in two vulnerable communities in urban-rural transition areas in Santiago de Cali, Colombia.The approach included estimating five indicators of health, natural disasters, climate variability, socio-economic, governance, and satisfaction, where resilience negatively correlates with vulnerability. Given the limited monitoring and systematization of information in Latin American cities, much of the data was collected through structured interviews. The results revealed patterns characteristic of highly vulnerable Latino communities, such as a high degree of self-management to solve problems and improve quality of life. These findings provide elements to infer and prioritize communities with a strong sense of ownership, enabling the effective implementation of climate change adaptation and mitigation measures, given the high likelihood of ownership and continuity.
  

Reading date: 24/12/2024

• NIKSERESHT, SASAN: Self-Powered Integrated Circuits with Optical Communication
  
  Author: NIKSERESHT, SASAN
  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: 26/11/2024
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: COSP VILELLA, JORDI | FERNÁNDEZ MARTÍNEZ, DANIEL
  Committee:
       PRESIDENT: URANGA DEL MONTE, ARANTZAZU
       SECRETARI: MARTINEZ GARCIA, HERMINIO
       VOCAL: MICHALIK, PIOTR JOZEF
  Thesis abstract: The rapid development of Internet of Things (IoT) technologies is transforming data collection, analysis, and use across various industries, from industrial to biomedical applications. A specialized class of IoT, known as Smart Dust Motes (SDMs), has recently gained attention. These ultra-miniaturized, self-sustaining devices are capable of sensing, computation, and communication at a millimeter scale. However, despite their vast potential, SDM and IoT applications face significant challenges, particularly in power management, miniaturization, and communication efficiency.One of the primary challenges in distributing SDM technology is managing energy consumption. As the number of SDMs increases and they are deployed in remote environments, sustainable energy sources will be needed for autonomous operation over extended periods without maintenance. Traditional power solutions, such as batteries, are impractical for these systems due to size limitations and frequent maintenance requirements. Moreover, wireless communication, especially through Radio Frequency (RF), uses a significant amount of energy, which affects the requirements of these applications. As a result, current approaches, such as batteries and RF communication, often struggle to provide sustainable, long-term solutions for maintaining both power and communication efficiency.This dissertation proposes the design of a self-powered Application-Specific Integrated Circuit (ASIC) specifically developed for SDM and IoT applications, with the goal of addressing these challenges. The proposed system incorporates multiple key components, including a hybrid optical and RF transceiver and energy harvesting units. At the core of the system is the integration of negative photodiodes, which function both as light energy harvesters and optical data receivers, significantly minimizing the system's size and power consumption. The negative photodiodes provide higher efficiency than traditional positive photodiodes, improve energy conversion, and reduce both chip area and cost. The energy generated by the integrated photodiode is stored and regulated through an integrated voltage converter, which efficiently boosts the harvested energy to power the entire system. The hybrid communication system methods, offer flexibility for SDM applications where line-of-sight optical communication to be supplemented by RF transmission for enhanced range and reliability. A low-power reconfigurable RF transmitter, capable of operating in multiple modulation modes, enhance reliable communication even in non-line-of-sight conditions.To validate the proposed design, three prototype chips were fabricated using 0.18 µm CMOS technology and tested experimentally. The first prototype, featuring the hybrid optical/RF communication platform, achieved a data transmission rate of 20 kb/s with an optical receiver power consumption of 11 pJ/bit and RF transmission power of −18.65 dBm using light-harvested energy. The second optical receiver improved light data sensitivity using the DC-adapting comparison block technique. It consumed 60 nW of power and 1.5 pJ/bit at a transmission rate of 40 kb/s with a 0.5 V supply voltage. The energy-harvesting system demonstrated 57% efficiency and generated up to 8.7 µW of power from a negative photodiode area of 240 × 480 µm². These results demonstrate the system's capability to operate autonomously for extended periods, without the need for battery replacements or external power sources.