Doctoral School

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.
  

Reading date: 08/01/2025

• GRATACÒS BATLLE, RICARD: La Carta de l'hàbitat. Aproximacions etnogràfiques i instruments d’estudi de l’espai habitat en el marc del novè CIAM d'Aix-en-Provence (1953)
  
  Author: GRATACÒS BATLLE, RICARD
  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: 21/11/2024
  Reading date: 08/01/2025
  Reading time: 11:00
  Reading place: Presencial (ETSAB. Sala de Graus)
  Thesis director: LLORENTE DIAZ, MARTA
  Committee:
       PRESIDENT: TORRES CUECO, JORGE
       SECRETARI: BITRIÁN VAREA, CARLOS
       VOCAL: ARDEVOL PIERA, ELISENDA
  Thesis abstract: The doctoral thesis revolves around the ninth CIAM (Congrès Internationaux d'Architecture Moderne) held in Aix-en-Provence in 1953. It focuses on the work presented by some European architects who were working in cultural contexts foreign to their own. Faced with the need to understand the “cultural other,” they incorporated into their work elements of ethnographic fieldwork. The main hypothesis of the research is that there is an ethnographic turn in the work of these modern architects, stemming from the necessity to approach the vital needs of a society different from their own.The CIAM IX took place in Provence to celebrate the opening of the Unité d'Habitation in Marseille the previous year, and on its rooftop, the 25-year history of CIAM was commemorated. The chosen debate topic was human habitat, with the primary goal of the gathering being the drafting of a Habitat Charter to complement the Athens Charter. The aim was to end the meeting with a solemn declaration proclaiming the right to housing for all human beings. The thesis explores the precise moment when the idea of working on a Habitat Charter was born. It reconstructs the “grids” presented by the CIAM groups from Algiers and Morocco, delving into the analytical study tools they used to understand the built realities of the Maghreb. In the context of profound transformations in international geopolitics following World War II, some architects and urban planners working in Morocco and Algeria were sensitive to the social and cultural realities with which they worked, developing studies, policies, and housing projects for Muslim populations. These architects adhered to the tenets of the functional city but adapted them to the specificities of the context in which they worked. They anticipated the industrialized future that Morocco and Algeria would achieve, participating in an economy of international exchange and acknowledging that they were working with a society in full transformation. For this reason, they aimed to develop a habitat capable of integrating into this changing society. We owe these architects the attention directed toward cities made of barrels and other industrial waste, as well as their insight that these constructed forms held lessons for modern architecture and the city.The doctoral thesis also addresses contributions presented at the congress focusing on the study of inhabited spaces in non-industrialized societies. The study and debate on the inhabited space of “primitive peoples” were represented by a group of young architecture students from the École des Beaux-Arts in Paris, who presented extensive documentation compiled after a long stay in Cameroon. In this context, some architects at the congress praised the lessons of architecture produced by “primitive societies,” which, without our industrialized technical skills, were able to shape their habitats through a singular worldview, a culture so balanced and just in meeting its needs that it appeared beautiful to the eyes of modern architects.The CIAM in Aix-en-Provence ended without successfully drafting the Habitat Charter. What remains from that time is a spirit and an energy from an era when architects and urban planners aspired to address the housing problem on a large scale. They were idealists who saw the need to collaborate with diverse disciplines, experimenting with ethnographic methods without formal training and approaching sociology to restore dignity to human habitats.
  

Reading date: 13/01/2025

• JIMENEZ ARGUIJO, ALEX: Advanced strategies for the defect management in high efficiency kesterite solar cells
  
  Author: JIMENEZ ARGUIJO, ALEX
  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: Article-based thesis
  Deposit date: 24/10/2024
  Reading date: 13/01/2025
  Reading time: 10:00
  Reading place: Defensa pública a la Sala Polivalent del Campus EEBE (Besós)
  Thesis director: SAUCEDO SILVA, EDGARDO ADEMAR | GIRALDO MUÑOZ, SERGIO
  Committee:
       PRESIDENT: GROSSBERG-KUUSK, MAARJA
       SECRETARI: CAZORLA SILVA, CLAUDIO
       VOCAL: CALVO BARRIO, LORENZO
  Thesis abstract: Kesterite-based solar cells represent a promising avenue towards sustainable energy production due to their reliance on abundant, low-toxicity materials, aligning with global initiatives to minimize environmental impact and enhance energy security. This thesis contributes significantly to the field by advancing the understanding and efficiency of kesterite solar cells through innovative defect management strategies and the development of high-performance devices.The research initially focuses on developing a comprehensive and realistic model of kesterite solar cells, which is pivotal in bridging the theoretical predictions with experimental results, providing a robust framework for the analysis of the efficiency limitations and identifying avenues for enhancement. By incorporating a realistic depiction on the influence of defects on the device performance, this model sets a new benchmark for the assessment and optimization of thin-film solar cells. The innovative approaches for defect control within kesterite materials are central to the thesis. The research demonstrates that through precise defect control by an induced electric field or transient doping with small atoms, such as hydrogen and lithium, it is possible to significantly modulate the defect structure of kesterite absorbers. These modifications lead to the decoupling majority carrier density from minority carrier lifetime, effectively enhancing the performance and efficiency of the solar cells. These approaches not only improve the electrical properties of the material but also provides a method to systematically address the intrinsic limitations of kesterite semiconductors.Moreover, the thesis presents advancements in the synthesis and processing of kesterite solar cells, employing techniques such as solution processing, doping, and interface passivation. These methods have been shown to considerably improve the compositional uniformity and optoelectronic properties of the materials, driving the efficiencies closer to those required for commercial viability. Notably, the development of solution-processed kesterite solar cells emerge as a scalable and environmentally benign method, indicating a significant step towards the industrialization of this photovoltaic technology.The thesis concludes that the strategies and methodologies developed herein substantially enhance the understanding and performance of kesterite solar cells. The findings underscore the potential of these materials in the transition to renewable energy sources, highlighting their role in promoting a sustainable future. With further refinement and optimization, kesterite solar cells could play a critical role in the global energy landscape, offering a viable, cost-effective, and environmentally sustainable solution to meet the growing energy demands.In summary, the work presented in this thesis exemplifies a significant advance in the field of photovoltaics, offering practical solutions and novel insights that pave the way for further research and development towards achieving high-efficiency, sustainable solar energy techniques.
  

• PARRA MARTÍNEZ, ALBERT: Integrating AI with Multiphoton Autofluorescence-Based Hyperspectral Imaging for Enhanced Embryo and Oocyte Analysis
  
  Author: PARRA MARTÍNEZ, ALBERT
  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 OPTICAL ENGINEERING
  Department: Department of Optics and Optometry (OO)
  Mode: Normal
  Deposit date: 18/10/2024
  Reading date: 13/01/2025
  Reading time: 11:00
  Reading place: Defensa pública Auditori Joan Salvadó del Centre Universitari de la Visió
  Thesis director: OJOSNEGROS MARTOS, SAMUEL
  Committee:
       PRESIDENT: DUOCASTELLA SOLÀ, MARTÍ
       SECRETARI: TRULL SILVESTRE, JOSE FRANCISCO
       VOCAL: MARTIN BADOSA, ESTELA
  Thesis abstract: Infertility affects one in seven couples, according to the World Health Organization, and only around 30% of the embryos from in vitro fertilization treatments successfully implant in the uterus and develop to term. As a result, multiple transfer cycles are often required to achieve a successful pregnancy, which can lead to significant emotional, physical, and financial burden. To reduce time-to-pregnancy and stress for patients, there is a need for a diagnostic tool to better select embryos and oocytes based on their physiology.This thesis presents an innovative, non-invasive methodology to improve embryo and oocyte selection, moving beyond conventional brightfield imaging, which provides morphological information and therefore limited physiological insight. Using a combination of techniques including two-photon excitation, hyperspectral imaging, phasor analysis, and artificial intelligence, we have developed a novel imaging pipeline that enables the non-invasive study of metabolic profiles of embryos and oocytes through their intrinsic autofluorescence signals. This methodology not only offers a more comprehensive understanding of embryo viability, but also represents a significant advancement in the field of reproductive science, enabling non-invasive metabolic profiling in ways that were previously not possible.The proof-of-concept work conducted in this thesis led to the development of a prototype based on light-sheet microscopy for evaluating and classifying embryos. This technology was chosen because of its ability to provide faster, less invasive imaging, while avoiding photodamage, making it ideal for non-invasive analysis. This prototype represents the first step towards a clinical product to use in in vitro fertilization clinics. By offering a method to accurately assess embryo viability non-invasively, we aim to improve the effectiveness, and patient experience of infertility treatment.