Theses authorised for defence

DOCTORAL DEGREE IN ARCHITECTURAL, BUILDING CONSTRUCTION AND URBANISM TECHNOLOGY

HUANG, DAWEI: Influence of interfacial bonding behavior on the compressive performance of sprayed mortar reinforced masonry walls
Author: HUANG, DAWEI
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 ARCHITECTURAL, BUILDING CONSTRUCTION AND URBANISM TECHNOLOGY
Department: Department of Architectural Technology (TA)
Mode: Article-based thesis
Deposit date: 18/07/2024
Reading date: 11/10/2024
Reading time: 11:30
Reading place: Presentially: Room Sala de Grados. ETSAB. Main floor) or Public link for the videoconference: meet.google.com/vzz-gkku-qyo
Thesis director: ALBAREDA VALLS, ALBERT | PONS VALLADARES, ORIOL
Committee:
     PRESIDENT: ÜSTÜNDAG, CENK
     SECRETARI: CORNADÓ BARDÓN, CÒSSIMA
     VOCAL NO PRESENCIAL: LIU, PENG
Thesis abstract: This thesis investigates the adhesion behavior between sprayed mortar and masonry substrates, focusing on the influence of compressive strength, mortar age, and surface roughness on adhesion strength. Through detailed experiments and comprehensive analysis, it seeks to better understand these factors and their impact on rehabilitation techniques for masonry structures. The results of this investigation not only expand theoretical knowledge about the adhesion behavior between mortar and masonry but also provide practical recommendations to improve the durability and effectiveness of retrofitting interventions.Experiments were conducted on samples with different compressive strengths (15 MPa, 30 MPa, and 45 MPa) to assess how these factors affect both tensile and shear adhesion strength. It was observed that the tensile adhesion strength decreases with increasing compressive strength of the masonry due to the brittle nature of high-strength materials. Specifically, masonry with a compressive strength of 15 MPa showed tensile adhesion strength ranging from 0.2 to 1 MPa, while masonry with a compressive strength of 40 MPa showed values concentrated between 0 and 0.1 MPa. This behavior is due to the fact that high-strength masonry tends to fail more abruptly, reducing its capacity to maintain adhesions under tension.On the other hand, the shear adhesion strength showed a positive correlation with compressive strength. Substrates with higher compressive strength provided greater shear capacity due to better mechanical interlocking facilitated by surface roughness. Experimental results demonstrated that the shear adhesion strength was almost double that of the tensile strength, highlighting the importance of surface texture in adhesion performance.The age of the mortar is also a crucial factor. Tests were conducted at 7 and 28 days to evaluate the development of adhesion strength over time. At 7 days, the adhesion strength was relatively low due to the ongoing hydration process and incomplete development of the mortar's mechanical properties. However, at 28 days, the adhesion strength increased significantly as the mortar achieved higher levels of hydration and improved mechanical properties. This underscores the importance of allowing adequate curing time in practical applications to ensure the longevity and effectiveness of reinforced structures.Surface roughness is a determining factor in adhesion strength. We measured roughness using the Joint Roughness Coefficient (JRC) and the arithmetic mean deviation (Ra) to quantify its impact. It was found that rougher surfaces facilitated better mechanical interlocking, improving adhesion strength. This finding highlights the importance of surface preparation in rehabilitation applications, where increasing the substrate's roughness can significantly enhance adhesion performance.The experiments revealed three typical modes of failure: adhesion disconnection, specimen fracture, and adhesion material fracture. Adhesion disconnection occurred when the adhesion strength was weaker than the individual strengths of the mortar and masonry, resulting in a clean separation at the interface without significant damage. Specimen fracture was mainly observed in samples with a fragile surface layer developed during mortar curing. Adhesion material fracture involved the rupture of the adhesion material itself, highlighting the impact of shear stress on adhesion integrity.

DOCTORAL DEGREE IN ARCHITECTURAL, CIVIL AND URBAN HERITAGE AND REFURBISHMENT OF EXISTING BUILDINGS

ROLANDO, LUDOVICA: Architecture by and for the community. The case of cohousing in Barcelona
Author: ROLANDO, LUDOVICA
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 ARCHITECTURAL, CIVIL AND URBAN HERITAGE AND REFURBISHMENT OF EXISTING BUILDINGS
Department: Departamento de Representación Arquitectónica (RA)
Mode: Change of supervisor
Deposit date: 18/09/2024
Reading date: 31/10/2024
Reading time: 15:00
Reading place: Face-to-face (Politecnico di Torino) and by videoconference: https://didattica.polito.it/pls/portal30/sviluppo.bbb_corsi.waitingRoom?id=289338&p_tipo=COMM_LAUREA_SCUDO
Thesis director: GILABERT SANZ, SALVADOR | ROBIGLIO, MATTEO
Committee:
     PRESIDENT: LARSEN, HENRIK GUTZON
     SECRETARI: LEDENT, GÉRALD LOUIS
     VOCAL: REDONDO DOMINGUEZ, ERNEST
Thesis abstract: Since the 2000s, collaborative housing has gained renewed interest in Europe as a solution to the growing demand for community-oriented living arrangements. This doctoral research focuses on cohousing, a collaborative housing form characterised by community living with self-contained private dwellings and shared spaces. These spaces are designed through a co-design process and self-managed by residents.This study examines the social, economic, and environmental dimensions of the cohousing phenomenon in relation to its architectural design. Cohousing is defined both as an event—a co-design process and a way of living—and as an object—a built artefact. The primary aim is to investigate the interdependence between these two spheres, i.e. spatial design and social dynamics. To achieve this aim, the research employs case study methodology with a mixed-methods approach is employed, combining quantitative data (such as mapping and listing cohousing initiatives and surveying space surfaces) with qualitative ethnographic methods (fieldwork, participant observation, and interviews).This dissertation analyses sixteen European cohousing projects built between 2000 and 2023. Almost half of these are in Southern Europe, addressing the knowledge gap in this region. The study maps the phenomenon in Southern European countries, analysing their main characteristics, evolution, and cross-country similarities and differences.The research focuses on the in-depth analysis of Barcelona's grant-of-use cohousing cooperatives, highlighting their transformation from a grassroots initiative to a systematic approach of implementation within a decade. Barcelona, with twenty projects built or under development, is the city with the most cohousing initiatives in Southern Europe. More importantly, it is the only city in the region to explicitly support cohousing in its municipal housing policies.The comparative analysis of the case studies demonstrates how community-driven design, promotion, and management generate procedural, normative, and architectural innovations. The co-design process involves intense negotiations between individual and collective interests, resulting in design solutions prioritising community values over individual convenience. These values often lead to innovations in design, urban planning, and housing regulations. At the same time, spatial characteristics are designed to encourage community life. This research applies Williams' Design for Social Contact Theory (2005) and Forty's concept of Flexibility (2004), demonstrating how design features can influence and enhance social dynamics and overall well-being within the cohousing community.Key design principles, such as shared facilities, gradual transitions between spaces, and strategically placed activity sites, significantly increase social interaction and community cohesion. The emphasis on flexibility, achieved through redundant space, technical means, or indeterminacy, allows spaces to adapt and respond to the evolving needs of cohousing residents. The findings of the post-occupancy analysis highlight the incremental inhabitation process, where spaces are progressively defined and transformed, and underscores the dynamic nature of cohousing environments.The work presented here provides the first systematic investigations of cohousing in Southern Europe. These quantitative and qualitative analyses can inform policies to support current and future initiatives. By identifying key elements, successful strategies, and challenges of the Barcelona model, this research offers valuable insights for replicating and scaling cohousing projects in Southern Europe. The cross-case spatial analysis gives designers guidance on effective design features. Additionally, the qualitative investigation into the project process sheds light on the critical challenges and innovative potential of need-based collaborative design.

DOCTORAL DEGREE IN ARCHITECTURE, ENERGY AND ENVIRONMENT

ROCA MUSACH, MARC: Automatismes, usuaris i arquitectura. Aplicació a la gestió energètica dels edificis
Author: ROCA MUSACH, MARC
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 ARCHITECTURE, ENERGY AND ENVIRONMENT
Department: Department of Architectural Technology (TA)
Mode: Normal
Deposit date: 19/09/2024
Reading date: 14/10/2024
Reading time: 11:00
Reading place: Room Sala de Grados. ETSAB. Main floor
Thesis director: CRESPO CABILLO, ISABEL | COCH ROURA, HELENA
Committee:
     PRESIDENT: LUNA NAVARRO, ALESSANDRA
     SECRETARI: LÓPEZ BESORA, JUDIT
     VOCAL: AGUACIL MORENO, SERGI
Thesis abstract: Digitalization and automation are being applied across various sectors of society, including buildings through Building Automation and Control Systems (BACS). These systems enable, for instance, the management of mobile exterior elements based on energy criteria that enhance the utilization of natural energy sources. However, they often completely replace the user’s role in managing the architecture, sometimes leading to uncomfortable and undesirable situations. The acceptance of BACS is well-studied in scientific literature, though this issues can arise only when people are present in the building. Some types of buildings, such as non-residential buildings with regular schedules (like offices, schools, universities, and administrative buildings), have a low annual occupancy rate, being occupied between one-sixth to one-third of the year. This means that they remain unoccupied most of the time. This thesis aims to quantify the impact of implementing control systems only when buildings are not in use (such as at night, during the weekends, and vacation periods), times when automation can operate freely without causing any disturbances to occupants. To achieve this, an energy simulation method is designed with three control scenarios: (i) entirely manual, (ii) fully automatic, and (iii) a combined system based on the occupancy, called hybrid, where the automation happens only when the building is not occupied, but allows manual control when people are present. This method is applied to nine case studies. The hybrid control system for solar protections reduces the energy demand by 5% to 15% compared to a manual control system, due to taking better advantage of solar radiation. The fully automatic system doubles the reduction of the energy demand of the hybrid system, but it does not take into consideration the user’s possible discomfort, such as glare. In conclusion, for buildings with regular occupancy patterns, hybrid systems are a good starting point for implementing BACS as they offer the advantages of automatic systems by efficiently utilizing natural environmental conditions, while still allowing for manual control by occupants, thus avoiding acceptance issues.

DOCTORAL DEGREE IN AUTOMATIC CONTROL, ROBOTICS AND VISION

FLORES VÁZQUEZ, CARLOS ALBERTO: CeCi: Design, Development and Validation of an Affordable Consumer Service Robot as a Social Robot
Author: FLORES VÁZQUEZ, CARLOS ALBERTO
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: Department of Automatic Control (ESAII)
Mode: Normal
Deposit date: 02/07/2024
Reading date: 14/10/2024
Reading time: 11:00
Reading place: Sala de Juntes de la Facultat de Matemàtiques i Estadística (FME), Campus Diagonal Sud, Edifici U. C. Pau Gargallo, 14 08028 Barcelona
Thesis director: ANGULO BAHON, CECILIO
Committee:
     PRESIDENT: VALLÈS PERIS, NÚRIA
     SECRETARI: REPISO POLO, ELY
     VOCAL: TREJO RAMÍREZ, KARLA ANDREA
Thesis abstract: This research discusses elements to be considered for designing, developing, and validating a service robot that performs its task in different social environments. Due to the social focus of the provided services, technical considerations are demanded toaccomplish the task, and the acceptability of use for the people interacting with the robot.The first stage of the research considers previous cases on the implementation of service mobile robots, their analysis, and the motivation of how to solve their acceptability and use by people. The developmental part presents the technical and social considerations for implementing the CeCi (Computer Electronic Communication Interface) social robot. Two main problems of social robots and service robots in social environments currently on the market are addressed, which are the main focus of this research: First, their costs are not affordable for many companies, universities, or individuals in developing countries. The second is that their design is exclusively oriented to the functional part with a viewpoint inherent to the engineers who create them without considering the end users’ views, preferences, or requirements, especially for their social interaction. This last reason ends up causing a certain aversion to the use of this type of robot.In response to the issues raised, an affordable, low-cost prototype is proposed, starting from a commercial platform for research development and using open-source code. The robot design presented here is centered on the criteria and preferences of the end user, prioritizing acceptability for social interaction. This document details the selection process and hardware capabilities of the robot. Moreover, a programming section is provided to introduce the different software packages used and adapted for social interaction, the main functions implemented, as well as the new and original part of the proposal. A list of applications currently developed with the robot and possible applications for future research are discussed.As a final step, the complete implementation of the social robot is explained based on two design elements. The first element is the use of the design thinking methodology for the development and implementation of the robot. The second element, of a technical nature, is a previous taxonomy generated for defining socially-aware robot assistants. Therefore, in the construction process, special emphasis is placed on the realization of prototypes and their adjustment to the users’ preferences. Interviewswith users who were unaware of the robot’s capabilities were used to improve and validate the prototype. These prototypes and their evolution will be presented based on the adjustments performed. Beyond the users’ feedback, previous experiences exposed to the state of the art were considered for the evolution of this robot. The entire methodological process is validated with surveys, and results are presented as a SWOT (strengths, weaknesses, opportunities, and threats) analysis for future improvements.

DOCTORAL DEGREE IN BUSINESS ADMINISTRATION AND MANAGEMENT

BARRAJÓN RASTROLLO, JOSE LUIS: Navigating Organizational Change for Successful Implementation of HR Analytics
Author: BARRAJÓN RASTROLLO, JOSE LUIS
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 BUSINESS ADMINISTRATION AND MANAGEMENT
Department: Department of Management (OE)
Mode: Normal
Deposit date: 19/09/2024
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: FERNANDEZ ALARCON, VICENÇ | GALLARDO GALLARDO, EVA
Committee:
     PRESIDENT: MARIN GARCIA, JUAN A.
     SECRETARI: PONS PEREGORT, OLGA
     VOCAL: ORTIZ DE URBINA CRIADO, MARTA
Thesis abstract: Context: Numerous studies affirm the positive impact of Human Resources Analytics (HRA) on gaining a competitive edge and enhancing Human Resources (HR) strategic role therefore given the importance of knowing how to implement an HRA function in organizations successfully, this Ph.D. thesis brings relevant insights of the most critical variables, and the barriers to be faced during this process so that future researchers and practitioners have the enough knowledge and tools to address it with success.Purpose: The Ph.D. thesis is divided into two interrelated purposes: (1) identifying the most crucial factors through which organizations base their HRA implementation and (2) the learning barriers to face during the organizational change that suppose implementing those factors to become a data-driven decision-making organization.Method: For the culmination of both purposes, we have conducted an inductive/explorative study using semi-structured interviews as the qualitative data collection method. In this case, the sample consists of ten managers, seven HRA function leaders, and three from HR departments who had carried out analytics projects. Those ten leaders work for ten different organizations in distinct sectors and across varying levels of analytical maturity. We have based on a couple of frameworks, one of organizational learning and another of HRA to design and create our own to guide the research.Results: Through empirical qualitative research, we obtained the five key HRA factors highlighted in the literature: Data, Technology Support, Culture, People and Project Design. Additionally, we considered the analytical maturity level of our organization's sample and related to this, the results show that Data quality and accessibility are crucial in descriptive and predictive stages. On the contrary, prescriptive organizations seem to be more focused on Technology, to support advanced analytical models. As far as organizational change is concerned, our results show that the intensity of the learning barriers in HRA decreases as the organizations increase their analytical maturity level. Besides, communication problems seem to be in the descriptive organizations, especially with the Data and Technology departments and the management. On the other hand, in predictive organizations, HR and/or HRA departments seem to lack autonomy in accessing the Data, building their teams, and choosing the technology they need to mature the function. Finally, other factors, such as ethics, budget, and trust in the HR function, were shown in the results.Conclusions / Implications: This allows researchers and practitioners to design and implement an HRA function supported by a framework that guarantees success in the process.Originality: This Ph.D. thesis extends existing theory about HRA success factors (SSFF), as well as organizational learning, developing a new model including both disciplines for implementing HRA function in organizations successfully.
HURTADO ILLANES, MARISOL CAROL: Diseño de un Modelo Integrado para el Empoderamiento Individual y el Apoyo Social en la Gestión del Conocimiento de Enfermedades Crónicas
Author: HURTADO ILLANES, MARISOL CAROL
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 BUSINESS ADMINISTRATION AND MANAGEMENT
Department: Department of Management (OE)
Mode: Normal
Deposit date: 17/07/2024
Reading date: 14/10/2024
Reading time: 11:30
Reading place: Defensa pública al Seminari I - Dept. Organitació d'Empreses, planta 7 - ETSEIB- UPC - Avda. Diagonal, 647, Barcelona
Thesis director: VIEDMA MARTI, JOSE M. | COLL BERTRAN, JOSEP
Committee:
     PRESIDENT: CANALS PARERA, AGUSTI
     SECRETARI: BARTOLOME COMAS, ROSA MARIA
     VOCAL: SERRADELL LÓPEZ, ENRIC
Thesis abstract: This transdisciplinary research focuses on knowledge management and human capital development in the context of chronic diseases, investigating mechanisms of empowerment in virtual communities. Living with a chronic illness involves facing high uncertainty and stress, resulting in social limitations and challenges. However, health conditions do not alter the essence of the individual or their need to actively participate in society. Chronic diseases increase global morbidity and mortality, representing a significant economic burden for healthcare systems. In this context, individual and community empowerment is crucial to improving the well-being and quality of life of patients.The study develops an Integrated Model for Individual Empowerment and Social Support in the Knowledge Management of Chronic Diseases, aimed at improving quality of life and enhancing patient autonomy. Its objectives include analyzing the influence of individual empowerment on patient engagement, exploring the connection between individual empowerment and community development in virtual communities, and examining the impact of sustainable practices on long-term empowerment. Using a mixed methodology that combines Dubin's methodology for theoretical development, the TDR approach (Transdisciplinary Research), and qualitative methods, the model was validated in a virtual community of chronic patients.The model focuses on key aspects such as Individual Empowerment (IE), Active Participation (IEG), Community Development (CD), and Sustainable Practices (SP). Furthermore, it describes states ranging from initial levels of low empowerment to achieving complete autonomy and commitment, through the formulation of theoretical propositions and the identification of intermediate stages that connect these elements and describe their interrelationships.Self-efficacy was manifested in narratives and testimonies that revealed participants' confidence and control. Active participation was evidenced in contributions and community activities, demonstrating a commitment to self-care. Social support was detected in interactions, reflecting solidarity and collaboration. Collaboration was observed in teamwork and mutual aid. Community development became evident through practices aimed at collective well-being. Access to knowledge was manifested in participation and resource-seeking, while sustainable practices were identified in actions aimed at long-term positive change.The results revealed individual strengthening among members of the online support group, highlighting the sense of personal control and resilience fostered through emotional support and self-efficacy. Members of the virtual community showed adaptability in facing health challenges through innovative strategies and community support, resulting in significant improvements in lifestyle habits and well-being. These aspects underscore the crucial influence of online support in promoting self-care, resilience, and overall health.In conclusion, the research highlights that empowerment through virtual communities is fundamental for the effective management of chronic diseases, emphasizing the importance of a holistic approach that encompasses social, psychological, and health self-management support. These findings enrich existing knowledge and influence health decisions and policies, underscoring the need to integrate sustainable practices into health policies for general well-being. The unified model of individual and community empowerment shows potential for application in other aspects of personal development, focusing on human capital and knowledge management.

DOCTORAL DEGREE IN CHEMICAL PROCESS ENGINEERING

ARMENGOL PROFITÓS, MARINA: Cobalt-Ruthenium Bimetallic Catalysts for Dry Reforming of Methane
Author: ARMENGOL PROFITÓS, MARINA
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: 16/09/2024
Reading date: 03/12/2024
Reading time: 11:30
Reading place: EEBE - Sala Polivalent - Edifici A - Campus Diagonal-Besòs
Thesis director: LLORCA PIQUE, JORDI | JIMÉNEZ DIVINS, NÚRIA
Committee:
     PRESIDENT: MEDINA CABELLO, FRANCISCO
     SECRETARI: CABOT CODINA, ANDREU
     VOCAL: VELASCO VÉLEZ, JUAN JESÚS
Thesis abstract: The processes used nowadays for hydrogen and syngas production require more sustainable alternatives to advance in the necessary decarbonisation to fight against climate crisis. Currently, the main process is methane steam reforming (MSR) using natural gas. In this thesis, the use of dry reforming of methane (DRM) is proposed as a method of producing syngas. DRM is an attractive alternative since the two reactants, methane and carbon dioxide, are gases with a high global warming potential (GWP). Moreover, they are found together in the biogas resulting from the anaerobic digestion of organic matter. In the actual state-of-the-art, Ni catalysts supported on a wide range of metal oxides have been extensively studied. However, the main disadvantage is the accumulation of carbon that causes deactivation.In Chapter 4, the application of CoRu bimetallic catalysts supported on CeO2 has been studied. The catalysts have been prepared by conventional incipient wetness impregnation and by mechanochemical methods. A screening of catalytic activity has been conducted, and in-situ characterisation (NAP-XPS and XRD) has been used to get insight into the nature and behaviour of the catalytic active sites. It has been observed how the addition of ruthenium directly impacts the reducibility of cobalt species and results in smaller nanoparticles, as demonstrated by temperature-programmed reduction (H2-TPR) and XRD, respectively. The results of NAP-XPS show how ruthenium is able to modify the metal-support interaction, evidenced by a greater Ce3+/Ce ratio in the bimetallic samples. The synthesis method influences the dispersion of Co and Ru on the surface; NAP-XPS data suggested a higher Ru concentration on the surface of the bimetallic ball-milled samples, indicating the formation of small Ru clusters during milling, as confirmed by TEM analyses. Samples prepared by mechanochemistry, both mono- and bimetallic, have higher activity and stability than those synthesised by the conventional impregnation method, achieving higher CH4 and CO2 conversions. CoRu/CeO2-BM catalyst turns out as a stable catalyst for 24 hours at 700 C and with an average H2/CO ratio close to 1.In Chapter 5, the application of the same CoRu formulation supported on a Mg-Al-O mixed oxide has been studied. For these catalysts, the effect of Ru addition and the use of different precursors has also been studied, observing an effect on the catalytic activity and stability related to a synergy between Co and Ru. Through a "Design of Experiments" approach, the impact of various parameters of mechanochemical synthesis, such as milling frequency, milling time, and precursor addition order, has been studied. It should be highlighted that the samples synthesised by mechanochemistry show a lower amount of carbon deposits, which is ascribed to the particular architecture of the catalytic active sites.Finally, in Chapter 6, characterisation under operating conditions (X-ray absorption spectroscopy and X-ray diffraction) of the main samples synthesised in the previous chapter is performed. In addition to studying dry methane reforming, a small amount of water vapour is added to the reaction to study the combined reforming of methane (CRM), where steam reforming and dry reforming occur simultaneously. It is also observed that in CRM the carbon deposition in samples prepared by mechanochemical methods is substantially lower than those synthesised by conventional impregnation.
LUO, DA-SHUANG: Recovery of antimony and bismuth from copper metallurgical industry process streams
Author: LUO, DA-SHUANG
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: 16/09/2024
Reading date: 17/10/2024
Reading time: 11:00
Reading place: EEBE (Escola d'Enginyeria Barcelona), Sala Polivalent, Ed. A, Campus Diagonal - Besòs
Thesis director: CORTINA PALLAS, JOSE LUIS | LÓPEZ RODRÍGUEZ, JULIO
Committee:
     PRESIDENT: GIBERT AGULLO, ORIOL
     SECRETARI: CAMA I ROBERT, JORDI
     VOCAL: BRINGAS ELIZALDE, EUGENIO
Thesis abstract: The pyrometallurgical industry faces challenges in maintaining copper purity due to increasing impurities in the primary resources (Sb, Bi, and As) that can reach the electrorefining unit forming insoluble minerals, compromising copper purity. To address this, the copper industry is developing actions to reduce the presence of such impurities along different stages of the process flow sheet acting at: i) the final stages of the electrorefining process or ii) the mineral concentration stages (e.g. flotation). The main target objective of this PhD thesis has been centred in the evaluation of technological solutions to reduce such impurities (Sb, Bi and As) by introducing a sustainability concept, where elements considered as critics for the European Union (i.e. Sb and Bi) are recovered. In the case of acting in the final stage of electrorefining, ion-exchange (IX) technology is employed at industrial scale to continually treat the copper electrolyte of the electrorefining stage, removing Sb and Bi and ensuring a high copper purity. Upon IX resin saturation, regeneration with 6 M HCl produces a concentrated eluate containing Sb, Bi (7–14 g/L each), and As (1–4 g/L). Currently, lime treatment removes these impurities producing large volumes of waste containing As, Sb and Bi. Therefore, two valoriaztion routes of the eluate were evaluated based on solvent extraction (SX) and selective precipitation. SX route was based on the use of a solvated mixture of alkylphosphine oxides (commercialized as Cyanex 923) dissolved in kerosene and 1-decyl alcohol (10%) as a phase modifier. The separation factors of Sb, Biand As were evaluated and optimized as a function of extractant concentration and aqueous to organic (A/O) phase ratio. The results showed that 39% Bi and 78% Sb could be extracted with low co-extraction of As (<2.5%) working at the lowest Cyanex 923 concentration (0.15 mol/L) and A/O ratio of 1/3. Using 8M HNO3 as a stripping agent, both Sb and Bi were easily recovered (>90%). During the direct precipitation of eluate, As(V) forms an insoluble antimony arsenate (SbAsO4(s)). Therefore, it is necessary to pre-treat the eluent with SO2(g) or NaHSO3(s) to reduce As(V) to the (+III) state valence state. In this case, antimony oxychloride (Sb4O5Cl2, purity >93%) and bismuth oxychloride (BiOCl, purity >95%) can be obtained sequentially using NaOH, NaHCO3 and/or Na2CO3 under appropriate pH control. The recovered high purity Sb4O5Cl2(s) and BiOCl(s), still containing a low content of As, could be converted into oxides in alkaline media, improving the final purity making them suitable for commercial use. The techno-economic implications of Sb and Bi showed that the recovery of BiOCl(s)/Sb4O5Cl2(s) and BiOCl(s)/Sb2O3(s) is economically feasible in copper metallurgy facilities, especially when Sb and Bi prices are higher than 8.5 and 9.5 €/kg, respectively. Overall, the results highlighted the economic and technical potential of implementing Sb and Bi recovery routes in copper metallurgy plants, in line with the ambitious circular economy targets set by the European Union.In the case of approaching the reduction of the presence of impurities in the mineral copper concentrates, tetrahedrite (Cu12Sb4S13(s)) was selected as case study. Selective leaching of antimony using microwave-assisted technology in a laboratory scale was investigated at different concentrations of Na2S and NaOH, solid/liquid ratio, temperature, and microwave power. Results indicated that Sb dissolution is highly dependent on the concentrations of leaching reagents (Na2S/NaOH) and the temperature. The Sb content in the copper concentrate was successfully reduced from 1.1% to less than 0.2%, making it suitable for copper concentrate metallurgy processing. A proposal of potential integration of both alkaline leaching and selective precipitation of the Sb could provide a sustainable solution, promoting the recovery of a critical raw material for the European industry

DOCTORAL DEGREE IN CIVIL ENGINEERING

SILVA CANCINO, NATHALIA: Evaluation of potential hazard due to off-stream reservoir failure using Machine Learning techniques
Author: SILVA CANCINO, NATHALIA
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: Article-based thesis
Deposit date: 22/07/2024
Reading date: 11/10/2024
Reading time: 11:30
Reading place: Defensa pública a la sala C1-002 (C/Jordi Girona 1-3, mòdul C1, Campus Nord, Barcelona).ETSECCPB
Thesis director: BLADE CASTELLET, ERNEST | SALAZAR GONZÁLEZ, FERNANDO
Committee:
     PRESIDENT: BALAIRON PÉREZ, LUIS
     SECRETARI: SANCHEZ JUNY, MARTI
     VOCAL: BERMÚDEZ PITA, MARÍA
Thesis abstract: Hazard classification for dams and off-stream reservoirs, which entails identifying potential damages in the event of structural failure, is a crucial tool for implementing local-level risk reduction plans. Consequently, national administrations have developed guidelines including suggested methodologies and tools.The modification of the Spanish Regulation of the Public Hydraulic Domain (Royal Decree 849/1986, of April 11), carried out through Royal Decree 9/2008, of January 11, obliges owners of off-stream reservoirs with a height of 5 meters or a capacity higher than 100,000 m3, whether public or private, to develop a classification study based on the potential risk of their failure (Articles 356 and 367). This represented a significant paradigm shift, under the former regulation, such a study was only required for dams exceeding 15 m in height or those with a height between 10 and 15 m and a capacity exceeding 100,000 m3.The procedure for this classification is time and resource-consuming, and in the specific case of owners of off-stream reservoirs, they may not have these assets. Therefore, this research proposes a simplified methodology to classify off-stream reservoirs, utilizing a surrogate Machine Learning (ML) model that is simpler and has a lower computational cost than conventional approaches. Additionally, the influence of two sources of uncertainties on hazard classification is analysed. This research is based on the generation of synthetic data. A specialized tool in Iber was developed to generate massive 2D hydraulic models of synthetic off-stream reservoir failures, which make all the processes of construction, calculation and extraction of results automatic.The first analysis was focused on the effect of selecting a breach parametric model on the hydraulic variables, the potential damages, and the hazard classification of the structures. Three common parametric models were compared, using a set of synthetic cases and a real off-stream reservoir. The results highlighted that the choice of the model has significant effects. Notably, the erodibility of the material exerts a high influence, surpassing that of the failure mode. The use of an inappropriate model or a lack of information regarding dike material can lead to overly conservative or underestimated results, consequently affecting hazard classification.The ML model constructed for the simplified methodology was a Random Forest classifier capable of identifying potential damages at any point in the vicinity of an off-stream reservoir. This ML model was trained using synthetic data, offering an estimation of potential damages by considering the physical characteristics of the structure, the surrounding terrain, and vulnerable areas. During a real case application, the simplified methodology achieved an accuracy rate of 91%. The simplified methodology allows owners and administration to obtain a pre-classification without the need to make a 2D hydraulic model, which saves time and money.Furthermore, an interface called ACROPOLIS was developed, integrating the ML model. Users can apply the simplified methodology through ACROPOLIS, which guides them step by step, providing the overall classification of the off-stream reservoir based on Spanish regulations.Finally, the analysis of uncertainties related to breach formation and the location of the breaking points in reservoirs was integrated. This involved comparing the current deterministic approach for hazard classification and a newly proposed fourth-step probabilistic approach that accounts for uncertainties in constructing hazard maps. The study revealed variations in classifications between scenarios, as different breaking points and breach formations generate diverse classifications that can affect emergency plans. Additionally, the proposed visualization can be used for various purposes, including tracking the evolution of categorization over time due to land use changes.

DOCTORAL DEGREE IN COMPUTATIONAL AND APPLIED PHYSICS

NABAHAT, MEHRAN: Dynamic Heterogeneity in Metallic Glasses: Study of Structural Relaxation, Aging, and Mechanical Properties of Vit4 alloy
Author: NABAHAT, MEHRAN
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 COMPUTATIONAL AND APPLIED PHYSICS
Department: Department of Physics (FIS)
Mode: Normal
Deposit date: 12/09/2024
Reading date: 10/10/2024
Reading time: 14:00
Reading place: Defensa pública a la Sala Polivalent - Edifici I - Campus Diagonal Besos / https://meet.google.com/kcv-bnqh-qya
Thesis director: PINEDA SOLER, ELOY
Committee:
     PRESIDENT: SUÑOL MARTÍNEZ, JUAN JOSÉ
     SECRETARI: BRUNA ESCUER, PERE
     VOCAL NO PRESENCIAL: LYU, GUOJIAN
Thesis abstract: Metallic glasses (MGs), distinguished by their unique microstructural features and exceptional mechanical properties, offer compelling materials for exploring relaxation dynamics and related phenomena within glass science. This doctoral thesis provides an in-depth examination of the dynamic and structural heterogeneity of Zr46.8Ti8.2Cu7.5Ni10Be27.5 (Vit4) glass-forming alloy, investigating the intricate relationships between its structural dynamics, thermal behavior and mechanical properties. The overarching objective is to advance in theoretical knowledge while also exploring innovative techniques for material manipulation and optimization of MGs.Firstly, a thorough examination of the viscoelastic and anelastic behavior of MGs is conducted, focusing on the spectrum of structural dynamic processes and characteristic times under small stress in the linear regime. This analysis highlights the reversible nature of most processes, where thermally activated anelastic particle rearrangements can be frozen by quenching after creep experiments, revealing new configurations of the potential energy landscape. This comprehensive approach significantly deepens our understanding of the viscoelastic properties of MGs.Secondly, the study critically evaluates the limitations of existing microscopic models, such as shear transformation zones, in explaining the anelastic recoverable strain of MGs. By analyzing experimental data, particularly recovery curves, the research isolates the pure anelastic response, minimizing the influence of the viscous component. This method uncovers the dependence of anelastic relaxation timescales on prior loading duration, providing crucial insights for interpreting mechanical probe results and refining assessments of MG properties.Lastly, the investigation delves into the dynamic heterogeneity and aging effects in MGs. In the supercooled liquid state, time-temperature superposition of α-relaxation and coherence between experimental and mechanical observations indicate a stable dynamic heterogeneity. However, transitioning to the glass state reveals an intensifying dynamic heterogeneity with aging, leading to inconsistencies between microscopic and mechanical studies. At the micrometer scale, significant changes in local hardness due to aging are observed, emphasizing the intricate nature of relaxation processes and their impact on the mechanical properties of Vit4. This detailed study advances our comprehension of the aging and dynamic behaviors in MGs.

DOCTORAL DEGREE IN COMPUTER ARCHITECTURE

EXENBERGER BECKER, PEDRO HENRIQUE: Improving autonomous driving systems with CPU extensions for point cloud processing
Author: EXENBERGER BECKER, PEDRO HENRIQUE
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: 29/07/2024
Reading date: 21/10/2024
Reading time: 11:00
Reading place: Sala E106 - Edifici C6 (FIB) - Campus Nord - Barcelona
Thesis director: ARNAU MONTAÑES, JOSÉ MARÍA | GONZÁLEZ COLÁS, ANTONIO MARIA
Committee:
     PRESIDENT: ACACIO SÁNCHEZ, MANUEL EUGENIO
     SECRETARI: MORETÓ PLANAS, MIQUEL
     VOCAL NO PRESENCIAL: JONES, TIMOTHY
Thesis abstract: Autonomous Driving Systems (ADS) are at the cusp of large-scale adoption, promising accident reduction and market potential. However, the complex software and sensor data pressure for better hardware support in this safety-critical scenario, where high performance is mandatory to meet latency deadlines. Additionally, energy efficiency, cost, and volume must also be first-class for market feasibility, calling computer architects into action.To enrich hardware support for ADS, we carry out a performance and power characterization of Autoware.ai, a state-of-the-art ADS software stack. We find significant time spent processing Light Imaging Detection and Ranging (LiDAR) sensor data, which are widely used by ADS. LiDAR captures 3D point clouds for tasks such as segmentation, localization, and object detection.Despite its importance, hardware support for LiDAR has only recently gained traction. Further, while most point cloud processing algorithms run on CPUs, recent works propose costly hardware accelerators. Instead, we aim to use existing general-purpose hardware and software for point cloud processing with minor CPU augmentations. For that, we introduce a small set of CPU instructions targeting point cloud neighbor search based on k-d trees, a key operation used in various algorithms.The first technique we propose is K-D Bonsai, which reduces data movement during the neighbor search by compressing k-d tree leaves in execution time, exploiting value similarity. K-D Bonsai further compresses the data using a reduced floating-point representation, exploiting the physically limited range of point cloud values collected with LiDAR. We implement K-D Bonsai through a small set of new CPU instructions to compress, decompress, and operate on points. To maintain baseline accuracy,we carefully craft the instructions to detect precision loss due to compression, allowing re-computation in full precision to take place if necessary. Therefore, K-D Bonsai reduces data movement, improving performance and energy efficiency while guaranteeing baseline accuracy and programmability. K-D Bonsai improves the end-to-end latency of the segmentation task of Autoware.ai by 9.26% on average, 12.19% in tail latency, and reduces energy consumption by 10.84%. Unlike the expensive accelerators proposed in related work, K-D Bonsai improves neighbor search with minimal area increase (0.36%).In the second technique, we found that consecutive neighbor search queries are often similar, visiting k-d tree nodes with considerable resemblance. We leverage this observation to cheaply speed up neighbor search with the available CPU Vector Processing Unit (VPU). We propose a hardware/software co-design called Caravan. At the software level, Caravan- SW exploits search similarity, gathering consecutive queries to search for their neighbors in parallel with SIMD instructions. Yet, when the navigation of queries diverges, particularly in the deeper levels of the k-d tree, Caravan-SW faces sparsity and the VPU lanes are underutilized. We tackle this with Caravan-HW, adding two new instructions that re-index valid vector elements and allow fast operand shuffling and dense SIMD operations to take place, suppressing the hard-to-predict runtime sparsity of Caravan-SW.With AVX512, Caravan-SW speeds up neighbor search by 4.05× (1.85× end-to-end) in Autoware.ai point cloud segmentation.With the additional Caravan-HW support, the leaf processing part of neighbor search can be further optimized, boosting gains to 5.19× (1.97× end-to-end), with minimal area costs. Our programmable and minimally intrusive solution has end-to-end benefits comparable to accelerators.

DOCTORAL DEGREE IN ELECTRICAL ENGINEERING

HEIN, THIEMO HARALD: Active Online Characterization of Lithium-Ion Batteries
Author: HEIN, THIEMO HARALD
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 ELECTRICAL ENGINEERING
Department: Department of Electrical Engineering (DEE)
Mode: Normal
Deposit date: 16/09/2024
Reading date: 23/10/2024
Reading time: 10:00
Reading place: Aula Capella - ETSEIB- UPC - Avda. Diagonal, 647, Barcelona
Thesis director: MONTESINOS MIRACLE, DANIEL | ACKVA, ANSGAR
Committee:
     PRESIDENT: ARNDT, BERNHARD
     SECRETARI: DÍAZ GONZÁLEZ, FRANCISCO
     VOCAL: BOHN, GUNTHER
Thesis abstract: Lithium-ion cells are commonly used in a variety of applications today. Depending on the power and energy requirements of the application, several cells are interconnected. Due to intrinsic and extrinsic factors, the parameters of each cell differ. Characterizing and monitoring individual cell parameters during operation and aging is a critical challenge to optimize battery utilization. The main objective of this thesis is to develop and evaluate an accurate and robust characterization methodology that determines the capacity and associated state of health of each series-connected cell in a battery during operation. The proposed method, called Iterative Learning State of Health Estimation Method (ILEM-SOH), extends the conventional use of an active balancing system to obtain additional information about the capacity differences between individual cells, thus providing a new approach to characterize individual series-connected cells. In order to evaluate the proposed method, several cells are systematically aged in various tests.Consequently, a second important aspect of this work is the investigation of the aging behavior and the resulting cell-to-cell variation. First, the capacity and internal resistance of 200 new cells from the same production batch are investigated and the initial cell-to-cell variation of key parameters are calculated. From this pool of cells, 8 cells are used to initially study the aging behavior and the associated development of cell-to-cell parameter variation of series-connected cells. The test setup is designed to minimize extrinsic battery design influences on cell aging, which can usually not be excluded when using completely assembled batteries.The main contribution of this thesis is the development of a novel iterative learning state of health estimation method. This method is described in detail, including the topology and algorithm of the applied active balancing system. The proposed methodology aims to provide a reliable state of health estimation while reducing the reliance on individual cell modeling and thus reducing the potential for errors due to inaccurate models, which is a critical limitation of most conventional methods. A first evaluation under steady state conditions is performed using the 8 aged cells from the aging study.To evaluate the novel ILEM-SOH in depth, two long-term aging tests are performed, each with a 12s1p battery, under varying conditions. The performance as well as the limitations of the method and the balancing hardware that may arise due to changing aging mechanisms over the lifetime of the batteries are investigated. Additionally, the tests are used to investigate the effects of active balancing on the aging behavior of the connected cells.The proposed ILEM-SOH provides good accuracy for almost the entire duration of the two long-term tests, despite the significant differences in the state of health values between the cells. A comparison with a benchmark state of health estimation method also shows that using the balancing charges of an active balancing system provides a more robust estimation than relying solely on measurable cell voltages.The thesis concludes with a summary of all results and suggestions for further optimization and investigation.

DOCTORAL DEGREE IN ELECTRONIC ENGINEERING

MARTINEZ SUAREZ, FRANK: Sistema de electrocardiografía ambulatoria para el análisis de la variabilidad de los intervalos de repolarización ventricular del ECG en la progresión de la enfermedad renal crónica en pacientes diabéticos e hipertensos
Author: MARTINEZ SUAREZ, FRANK
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: Change of supervisor
Deposit date: 29/07/2024
Reading date: 14/10/2024
Reading time: 11:00
Reading place: Auditorio del Departamento de Ingeniería Eléctrica del Cinvestav Unidad Zacatenco.
Thesis director: CASAS PIEDRAFITA, JAIME OSCAR | ALVARADO SERRANO, CARLOS
Committee:
     PRESIDENT: LEIJA SALAS, LORENZO
     SECRETARI: ALVARADO SERRANO, CARLOS
     VOCAL: GUTIERREZ SALGADO, JUAN MANUEL
Thesis abstract: Chronic kidney disease is considered a risk factor for the development of cardiovascular disease because it is one of the main complications of diabetes mellitus and arterial hypertension, which are themselves considered cardiovascular risk factors. Therefore, it is important to periodically evaluate renal function in at-risk groups, such as diabetic and hypertensive patients or those with cardiovascular disease. In this doctoral thesis, six parameters of ECG ventricular activity are proposed to assess the progression of renal damage in diabetic subjects, with and without hypertension and hemodialysis treatment.To obtain ECG recordings from subjects and patients, a low-power, long-duration ambulatory monitor was developed for the simultaneous acquisition of three ECG leads. This monitor incorporates an algorithm that uses the continuous wavelet transform (CWT) to measure heart rate beat-by-beat in real-time. It has a CMRR greater than 80 dB at 60 Hz, a bandwidth of 0 to 150 Hz, a sampling rate of 1 kHz, and a current consumption of 50 mA, resulting in an average battery life of 84 hours. The monitor also detects false electrode contacts, stores data on a microSD memory card, and includes a user interface that facilitates interaction with the device.Specific PC software was developed for reading, storing, visualizing, and analyzing ECG records, as well as managing the patient's personal information. A SQL Server database was implemented to manage the records, corresponding analysis results, and patient data. The software uses Microsoft Excel files for the exchange of input and output information, with formats that are easy to create and interpret in other software development applications. The software algorithms employ CWT and are robust against the presence of noise, artifacts, and baseline drifts in the recording. These algorithms include detection and classification of T waves and QRS complexes, adaptation to changes in heart rate, and interval calculation. The algorithms work with CWT using B-spline basis functions, allowing them to handle any integer scale and ensuring that the analysis is not restricted to scales that are powers of two. The software enables the analysis of ECG recordings with different sampling rates by automatically selecting the CWT scale.The QRS complex detector, evaluated with the MIT-BIH, ST-T, and QT databases, achieved excellent performance with a sensitivity and positive predictivity of 99% from a total of 986,467 QRS complexes analyzed. For the QRS complex and T-wave characteristic point delineator, evaluated with the CSE, PTB, and QT databases, the errors at the Qi, J, and Te points were within the tolerance limits for deviations with respect to the manual measurements by CSE experts. For the Tp point, compared to another similar algorithm, the deviation was 1 sample (4 ms). According to these results, the developed algorithms allow reliable measurement of ECG ventricular activity intervals.For the analysis of the progression of renal damage in diabetic patients with and without hypertension and hemodialysis treatment, ECG records from the following databases of diabetic patients were used: GE-71, GE-75, and HR-48H. To analyze the five stages of diabetic nephropathy, three groups of diabetic patient records were created from the above databases: 39 patients without hypertension and without hemodialysis (DSH_SH), 22 patients with hypertension and without hemodialysis (DH_SH), and 20 patients with hypertension and hemodialysis (DH_CH). The proposed parameters representing ECG ventricular activity and heart rate are: the intervals (QpTe)c, (RTp)c, and (SpTp)c, and the ratios TpQp/RR, TpSp/RR, and RTe/TeR, which relate to two consecutive beats of the cardiac cycle. These parameters cover the five stages of diabetic nephropathy and enable the evaluation of the progression of renal damage in diabetic patients with and without hypertension and hemodialysis.

DOCTORAL DEGREE IN GEOTECHNICAL ENGINEERING

BARANDIARÁN VILLEGAS, LUCÍA BELÉN: THM numerical modeling of multiphase flow in fractured rock masses using zero-thickness interface elements
Author: BARANDIARÁN VILLEGAS, LUCÍA BELÉN
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 GEOTECHNICAL ENGINEERING
Department: Department of Civil and Environmental Engineering (DECA)
Mode: Normal
Deposit date: 18/07/2024
Reading date: 11/10/2024
Reading time: 12:30
Reading place: Defensa pública presencial-ETSECCPB. UPC, Campus Nord-Edifici D2. Aula: 216 C/Jordi Girona, 1-3 08034 Barcelona
Thesis director: CAROL VILARASAU, IGNACIO | LOPEZ GARELLO, CARLOS MARIA
Committee:
     PRESIDENT: PRAT CATALAN, PERE
     SECRETARI: SEGURA SERRA, JOSE MARIA
     VOCAL: XOTTA, GIOVANNA
Thesis abstract: To address the impacts of climate change, several measures have been suggested among which utilizing renewable energy sources such as geothermal energy and implementing technologies such as hydrogen storage or CCUS. Some of these solutions imply the injection of fluids into fractured rock masses (e.g. depleted O&G reservoirs) with the subsequent change in local stress conditions. This alteration may lead to the initiation of micro-seismic events by reactivating existing faults or the generation of new fractures, with the risk of ultimately establishing pathways for fluid leakage. Additionally, depleted reservoirs contain multiphase and multicomponent fluids that could react chemically with the new injection fluids. Therefore, the accurate prediction of operation conditions demands advanced geomechanical software capable of evaluating the viability and safety of potential extraction or storage locations. In this context, the main objective of this thesis is to develop a thermo-hydro-mechanical multiphase model in fractured porous medium with the Finite Element Method using zero-thickness interface elements to model discrete discontinuities. The main assumptions of the model are: the small strain theory, the system composition with two fluid phases (liquid and gas), two species (water and dry gas) and one solid phase. The gas phase follows the ideal gas law and the liquid phase evaporation is considered. The main variables are: displacements, phase pressures and temperature. The formulation takes into account: the equilibrium equation, the mass balance equation of the water species, the mass balance equation of the gas species and the balance of energy. The formulation of the discontinuities considers similar assumptions as the porous medium and takes into account a reduction factor of the water retention curve parameters based on the mechanical opening of the fracture. The model has been implemented and validated with academic verification examples in a FE code.However, some limitations were observed related to the time integration scheme, the treatment of storage terms of the governing equations and the mass flow. This issues have motivated the following new developments: new mass-conservative approach for diffusion equations using FE formulations, a new physically-based exponential model which considers the pore size or aperture distribution in case of the porous medium or discontinuities, respectively, and a new damage-frictional law which properly models discontinuity closure.
LEI, JIANGTAO: A micromechanical investigation of pile set-up effect in sands
Author: LEI, JIANGTAO
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 GEOTECHNICAL ENGINEERING
Department: Department of Civil and Environmental Engineering (DECA)
Mode: Normal
Deposit date: 18/09/2024
Reading date: 17/10/2024
Reading time: 11:00
Reading place: ETSECCPB. UPC, Campus Nord Building D2. Classroom: 216 C/Jordi Girona, 1-3 08034 Barcelona
Thesis director: ARROYO ALVAREZ DE TOLEDO, MARCOS | CIANTIA, MATTEO
Committee:
     PRESIDENT: BROWN, MICHAEL JOHN
     SECRETARI: ALONSO PEREZ DE AGREDA, EDUARDO
     VOCAL: GONZALEZ TEJADA, IGNACIO
Thesis abstract: Driven piles in granular soils gain shaft capacity after installation in a phenomenon known as “pile set-up”. Set-up effects in sand have not been incorporated into design procedures largely because the underlying mechanisms are not well understood. This thesis reports a micromechanical investigation of pile set-up effect in sand using a newly developed fracture-based DEM model for simulating time-dependent behaviour in sand. Creep and stress relaxation around the pile have been widely discussed as possible underlying mechanism for pile set-up effect. Following the idea that creep and stress relaxation in sands are frequently accompanied by grain breakage, a new model based on the discrete-element method (DEM) to simulate creep/stress relaxation in sands was proposed. The model aims for conceptual simplicity, computational efficiency and ease of calibration. To this end a new form of normalized Charles power law is incorporated into a DEM model for rough crushable sands based on the particle splitting technique. The creep/stress relaxation time is advanced using an off-DEM ageing strategy. The model is validated by simulating creep/stress relaxation in quartz sands in oedometric and triaxial conditions. Model predictions are shown to compare favourably with experimental creep results in terms of creep strain, creep strain rates and particle breakage/GSD evolution, and with experimental stress relaxation results in terms of relaxed stress, stress relaxation rate, and GSD evolution.The fracture-based DEM model was then implemented to a centrifuge DEM chamber to simulated pile creep and pile set-up. Simulated pile creep settlements agree with observations in terms of pile creep parameter m and pile creep rate. Simulated pile set-up falls into the range of field observations for jacked piles. The results obtained indicate that particle breakage may play a significant role in set-up and represent the first validated modelling attempt of this complex phenomenon. To gain familiarity with DEM modelling of penetration problems, a DEM based CPT and SPT simulation on a volcanic sand was also conducted, using a virtual calibration chamber (VCC). The simulated CPT results are shown to capture well experiments from the literature over a range of density and confining stress. A good correlation between the energy-based equivalent SPT tip resistance with the CPT tip resistance can be observed if shaft resistance effects are discounted. SPT driven scheme may be used for simulating pile driven in the future study once proper driven parameters are determined.

DOCTORAL DEGREE IN MARINE SCIENCES

SAMPER GARCIA, YAIZA JULIA: RENEWAL TIME AS A TOOL FOR WATER QUALITY CONTROL IN PORTS ENVIRONMENTS.
Author: SAMPER GARCIA, YAIZA JULIA
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 MARINE SCIENCES
Department: Department of Civil and Environmental Engineering (DECA)
Mode: Article-based thesis
Deposit date: 12/07/2024
Reading date: 25/11/2024
Reading time: 11:00
Reading place: Defensa pública a l'Aula C2-212 de l'ETSECCPB
Thesis director: SANCHEZ-ARCILLA CONEJO, AGUSTIN | ESPINO INFANTES, MANUEL
Committee:
     PRESIDENT: GARCÍA SOTILLO, MARCOS
     SECRETARI: GRIFOLL COLLS, MANUEL
     VOCAL: LORENTE JIMENEZ, PABLO
Thesis abstract: Currently, maritime transport plays a fundamental role in the global distribution of goods. In addition to their commercial function, ports are becoming of increasing importance in the recreational and tourism sectors. As a result, ports and the surrounding areas are subjected to strong environmental pressures, especially in the aquatic environment. This research analyses in six Spanish harbours the meteo-oceanographic variables that influence water inflows and outflows and, consequently, the renewal time of the harbours. This parameter can serve as an indicator of water quality in a semi-confined domain, as it is influenced by a wide range of factors, including environmental conditions, hydrodynamic characteristics and the harbour shape itself. The main objective of this doctoral thesis is to calculate and propose the use of the renewal time as a tool to control and improve water quality in port environments.The first part of this work is based only on observational data from measurement campaigns carried out in the ports of Barcelona, Tarragona and Castellón. This section analyses the meteorological and hydrodynamic conditions during the campaigns and investigates the occurrence of downwelling events under N/NE wind conditions, as well as upwelling events during S/W wind episodes. In addition, these events are related to variations in harbour renewal time and it is suggested that, under strong anticyclone conditions, the renewal time increases.The second study combines observations and numerical simulations to investigate the days with renewal times above the period mean in the ports of Huelva, Gijón and Cartagena. Using the results of the SAMOA system, it analyses the influence of atmospheric forcings such as wind and atmospheric pressure on the water exchanges between the port and the exterior. The results show that the majority of the days with a high renewal time can be attributed to wind events that favour the inflow of water into each port. Also, variations in atmospheric pressure lead to differences in water level between the inside and outside of the harbour, causing inflows or outflows of water that significantly affect the renewal time. In the third part of the thesis, the renewal time in the ports of Barcelona, Tarragona and Gijón is recalculated the LOCATE model, which integrates Eulerian hydrodynamic information from SAMOA and PARCELS, a Lagrangian particle solver. In this case, particle launches are simulated inside the harbours to study circulation and renewal trends both at the surface and at the bottom. The results show spatial variations both horizontally and vertically in all ports. Moreover, in the Mediterranean harbours (microtidal), the renewal time obtained at the bottom is higher than at the surface, however, in the Gijón harbour (mesotidal) the inverse is observed, it is higher at the surface.Throughout the three articles that compose it, the hydrodynamics of six Spanish ports have been characterized, combining the use of observational data with numerical simulations. This characterization allows for the study of water exchanges between the port and the exterior, as well as to calculate the renewal time, which is fundamental to guarantee the quality of the water in these semi-confined domains. The results have shown significant differences in the renewal time of the different harbours depending on the size and shape of the harbour, the environmental conditions and forcings, and the location and tidal regime. Therefore, it is essential to develop adapted management strategies based on the needs of each harbour to ensure adequate water quality.
STEENBEEK, JEROEN: Ecosystem modelling for the Ocean Decade - facing the challenges.
Author: STEENBEEK, JEROEN
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 MARINE SCIENCES
Department: Department of Civil and Environmental Engineering (DECA)
Mode: Article-based thesis
Deposit date: 18/09/2024
Reading date: 22/10/2024
Reading time: 11:00
Reading place: Sala d'Actes de l'Escola de Camins, Mòdul C2, planta baixa, Campus Nord - UPC Enllaç públic: https://meet.google.com/vpe-fkxx-phv
Thesis director: CHRISTENSEN, VILLY | FULTON, ELIZABETH
Committee:
     PRESIDENT: UUSITALO, LARUA ANITA
     SECRETARI: GRIFOLL COLLS, MANUEL
     VOCAL: RENAUD, PAUL ERIC
Thesis abstract: The worlds’marine ecosystems are degrading under wide ranges of ever intensifying, diversifying and co-occurring human pressures. Ecosystem-based management (EBM) approaches have emerged as an alternative to ineffective single species and single sector management, veering away from siloed top-down approaches towards science-based, participatory processes that recognise connections across the system and seek to balance economic benefits with sustainably harvested and healthy ecosystems. To galvanize a global push towards EBM, the United Nations declaration of the Decade of Ocean Science for Sustainable Development (Ocean Decade) has given the oceanographic community a unique imperative to transform marine sciences into holistic, participatory, transparent and inclusive forms that involve and serve society.Transforming actual ocean sciences is easier said than done. Marine Ecosystem Models or MEMs are powerful mathematical tools for understanding past marine ecosystem and their dynamics under cumulative pressures, and have utility for predicting how ecosystems may continue to develop under scenarios of change. MEMs are widely used in science, and have significant utility to advice decision making and policy. However, despite decades of scientific progress, and despite an abundance of scientific recipes in the literature that can be deployed towards the aims of the Ocean Decade, the actual uptake of MEMs in management remains low.This dissertation explores why this is, and argues that the actual uptake of MEMs in policy and society is in part hampered by a factor largely ignored by the marine sciences: technical issues, institutionalized by the current competitive andachievement-driven academic funding model. The dissertation is based on four manuscripts, which explore the specific challenges raised by the Ocean Decade, and define and implement working prototypes to demonstrate that the gap between theory and practice can be bridged.The first challenge, enabling decision processes to use MEMs, is addressed in manuscript 1 where a MEM is integrated into a decision support tool for marine spatial planning, beyond the operational control of marine scientists. The second challenge, related to meaningfully communicating MEM output to outside audiences, is addressed in manuscript 2 where a MEM is interconnected with a 3D gaming engine to empathically visualize environmental change. The last challenge, making sure that MEM output is robust, is discussed in manuscripts 3 and 4. Of these, the first manuscript explores the reasons behind lack of systematic MEM assessments and puts forth a potential framework to overcome this 30-year old limitation. Manuscript 4 introduces a working and open-source prototype of that framework.Overall, these studies show that relatively simple software engineering can empower the use of MEMs towards the aims of the Ocean Decade, EBM, and beyond. This dissertation underscores that scientific and technical developments must go hand in hand, but also suggests that the status quo may not change unless long-term tool development and support become academic funding priorities. Last, although the prototypes developed in this dissertation should be taken as ideas that need further maturing in future research, the ideas throughout irrevocably demonstrate that the field of marine ecosystem modelling with relatively simple means can be made operational for the Ocean Decade. If anything, this dissertation is a rallying cry to the global marine ecosystem modelling community to rethink and reshape how we build, validate, calibrate and deploy our tools, with the aim to reach and involve the audiences that need marine science advice but do not have the means to generate it.

DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING

ABDELLATIF, AHMED MOHAMMED ABDELFATTAH: Heat Transfer in Supercritical Fluids: Computational Approaches & Studies
Author: ABDELLATIF, AHMED MOHAMMED ABDELFATTAH
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 MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
Department: Department of Fluid Mechanics (MF)
Mode: Article-based thesis
Deposit date: 20/09/2024
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: JOFRE CRUANYES, LLUÍS | TORRES CAMARA, RICARDO
Committee:
     PRESIDENT: HUETE RUIZ DE LIRA, CESAR
     SECRETARI: FONT MARTÍNEZ, FRANCESC
     VOCAL: FONT GARCÍA, BERNAT
Thesis abstract: This thesis delves into investigating the complexities of heat transfer in supercritical fluids through the application of advanced theoretical and computational methodologies. The research primarily focuses on conducting large-scale direct numerical simulations (DNSs) to capture the intricate thermal behaviors of these fluids. Following the simulations, a comprehensive analysis is performed, leading to the generation of empirical heat transfer correlations tailored for high-pressure transcritical fluids. This work aims to bridge the gap between theoretical predictions and practical applications, offering valuable insights into the thermal dynamics of supercritical systems. In detail, the work introduces methods for compressible turbulence simulations on GPU-accelerated nodes, achieving significant speedups. Next, artificial compressibility method for high-pressure transcritical fluids is extended to enhance computational efficiency. Following, a comprehensive dataset for high-pressure fluid channel flows is presented, facilitating detailed analysis and modeling. Finally, novel heat transfer correlations for transcritical fluids are developed, offering improved accuracy for engineering applications.The work is organized into six chapters. The first chapter introduces the type of flows considered and the methodology used to study them. The next four chapters form the core of the dissertation, containing content published in peer-reviewed journals, thus being largely self-contained with minor changes from the original papers. Consequently, some theoretical and numerical content is repeated. The final chapter provides concluding remarks and suggestions for future work. Two appendices include supplementary material useful for understanding parts of the thesis without disrupting its main flow. Specifically, the second chapter introduces a computational approach for large-scale compressible turbulence simulations on heterogeneous nodes with GPUs. It uses MPI for node distribution and OpenACC for GPU acceleration, discussing GPU porting, data management, solver performance, and scalability. Two OpenACC methods --- automated (managed) and manual (non-managed) --- are compared, with the non-managed strategy outperforming the managed one, achieving up to 6x speedup overall and up to 26x for specific kernels. The approach is validated with high-fidelity simulations of turbulent flow, proving its efficiency for modern GPU-accelerated architectures. The third chapter extends the artificial compressibility method for high-pressure transcritical fluids by decoupling thermodynamic and hydrodynamic pressure fields, allowing the modification of acoustic time scales without affecting flow physics. The method is computationally efficient and includes an automatic speedup factor selection. Numerical tests show it can achieve speedups over 10x while maintaining accuracy in simulating high-pressure transcritical flows. The fourth chapter introduces the first comprehensive, open-source dataset for studying high-pressure transcritical fluid channel flows in microconfined environments. It includes 18 direct numerical simulations of carbon dioxide at various pressures and velocities between differentially-heated walls, covering laminar, transitional, and turbulent regimes. The dataset captures the fluid's transcritical trajectory through the pseudo-boiling region and offers detailed physical quantities for comprehensive parametric analysis, aiming to enhance the study and modeling of high-pressure transcritical fluid dynamics in microfluidics. Finally, the fifth chapter focuses on empirical heat transfer correlations, crucial for optimizing thermal performance in engineering applications like energy conversion and propulsion. This study aims to develop new correlations for high-pressure transcritical fluids at low Reynolds numbers, using data from 18 direct numerical simulations between differentially heated walls.
BETRIU ROURE, PAULA: Optimization Techniques in Science Planning for Planetary Exploration missions
Author: BETRIU ROURE, PAULA
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 MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
Department: Department of Physics (FIS)
Mode: Normal
Deposit date: 06/09/2024
Reading date: 23/10/2024
Reading time: 11:30
Reading place: Defensa pública a la Sala de Juntes del TR5 de l'ESEIAAT
Thesis director: SORIA GUERRERO, MANUEL | GUTIERREZ CABELLO, JORGE LUIS
Committee:
     PRESIDENT: HUESO ALONSO, RICARDO
     SECRETARI: ROVIRA GARCIA, ADRIÀ
     VOCAL: CARDESIN MOINELO, ALEJANDRO
Thesis abstract: Solar System robotic missions explore objects in space to elicit key information that contributes to our understanding of the origins and evolution of the Solar System as well as of life. Noticeably, such an ambitious purpose demands an equally challenging endeavor from the scientific and engineering perspectives—an effort that compels to procure high scientific revenues. In this context, science planning plays a key part to guarantee that the mission obtains as large an information harvest as possible to ultimately fulfill a set of scientific objectives. This list of mission objectives can be very extensive and diverse; from the search for life to the identification of planetary resources or the geomorphological analysis, many disciplines come together in this quest. To meet these objectives, spacecraft are equipped with a varied suite of instruments capable of conducting a wide range of experiments. Thorough planning is required to conciliate the instruments' operations while concurrently guaranteeing the spacecraft performance and safety, ensuring a good management of the available resources, as well as the feasibility to forward this information to Earth. These requirements and constraints often result in trade-offs among spacecraft subsystems, including the payload. All in all, the activity plan of a mission constitutes a complex problem that needs to account for a wide spectrum of agents in order to draw a suitable mission program that effectively fulfills the scientific objectives. Within this context, observation and mission planning software tools have played an important role in space missions—and their relevance is only expected to grow in the near future. From designing the instrumental observational activities to overall management of spacecraft resources and activity scheduling, various software tools have greatly assisted in the planning process of missions like Cassini, Dawn or Rosetta. Drawing upon these, this work presents the development and validation of a software prototype designed to streamline science planning processes for planetary exploration missions. Our study focuses on devising an optimized activity plan for a camera instrument, aiming to maximize its scientific return while ensuring efficient mission operations. This software prototype tool, named Observation Planning Tool for Instrument and Mission Analysis (OPTIMA), consists of two consecutive stages. The first one utilizes spacecraft trajectory and, possibly, attitude data to identify feasible observational opportunities based on geometric constraints derived from instrument measurement requirements. These opportunities, defined as science opportunity windows, are used to constrain the exploration space in the subsequent stage. The second phase applies optimization heuristics to develop potential activity plans that maximize scientific returns while adhering to both geometric and operational constraints. The tool's modularity allows for the application of various optimization heuristics tailored to the specific problem. Additionally, OPTIMA includes a component for simulating the camera's observation through mosaic heuristics that aim to achieve maximum coverage of Regions of Interest (ROIs) with minimal make-span. Finally, the methodology's efficacy is demonstrated through hypothetical case studies set in realistic mission scenarios, including a validation case study on Galileo's flybys over Europa and two others during different phases of the JUICE mission. These cases focus on optimizing coverage and/or resolution across various ROIs, considering additional adjustments such as downlink windows allocation and data compression. The algorithm successfully identifies nearly-optimal activity plans that comply with the specified constraints in all cases, showcasing the tool's efficiency and adaptability across different mission scenarios. This makes OPTIMA a valuable asset for multi-mission science planning in planetary exploration.
GUANCHEZ REYES, EDINSON ASDRUBAL: ESTUDIO DE LA INFLUENCIA DE LOS FENÓMENOS DE INTERACCIÓN SUELO-ESTRUCTURA EN LA RESPUESTA SÍSMICA DE ESTRUCTURAS TÍPICAS DE ACERO CON ARRIOSTRAMIENTOS CONCÉNTRICOS
Author: GUANCHEZ REYES, EDINSON ASDRUBAL
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 MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
Department: Department of Strength of Materials and Structural Engineering (RMEE)
Mode: Normal
Deposit date: 10/09/2024
Reading date: 15/10/2024
Reading time: 12:00
Reading place: Defensa pública a la Sala Àgora del Campus Nord de la Universitat Politècnica de Catalunya
Thesis director: SANCHEZ ROMERO, MONTSERRAT | WEYLER PEREZ, RAFAEL
Committee:
     PRESIDENT: DEL COZ DÍAZ, JUAN JOSÉ
     SECRETARI: VELAZQUEZ AMEIJIDE, JUAN
     VOCAL: CITO, SALVATORE
Thesis abstract: Steel concentrically braced frames (CBF) are considered efficient in resisting lateral forces because they provide high lateral strength and stiffness, which is particularly beneficial in seismic zones. However, this type of structure has a significant overstrength that is not considered during foundation design, which can lead to uplift of the footings under the braced members and to rocking mechanisms. On the other hand, soil-structure interaction (SSI) phenomena and foundation flexibility are generally not considered in performance-based analyses of new or existing structures.In this research, the influence of SSI phenomena on the seismic response of CBF is evaluated by considering the nonlinear response of embedded footings using the BNWF (Beam on Nonlinear Winkler Foundation) approach. To model the vertical stress-displacement behaviour of the footings, it is possible to define a backbone curve by combining the response of the compression zone in series with that of the tension zone.When uplift of the footing is allowed, it is shown that it is necessary to consider the horizontal stresses of the native soil in situ and the degree of compaction of the soil above the footing to avoid significant deviations between the analysis results and the real response. The tension zone in the response curves has been calibrated to take these parameters into account and, given the difficulty associated with their calibration, an estimate is reported which could also be used for practical applications.The implementation has been validated by various pushover analyses on a steel CBF archetype originally tested in the fixed base condition, and predictions for the flexible base condition have been made considering different soil types and footing embedment depths (Df). The results show a direct relationship between the nonlinear response of steel CBF and the uplift mechanism of embedded footings, with the embedment depth (Df) and the shape of the tension-displacement curve being the most important variables that influence the response.The model has been incorporated in various nonlinear time-history analyses considering a set of seismic records on a well-known steel CBF archetype. The results obtained suggest that, when analysing the response of steel CBF on a nonlinear flexible base condition, it is possible to report variations in the yielding sequence of the superstructure with respect to the fixed base condition. It is reported that the embedment depth (Df) of the footing, and hence its uplift stiffness, is able to modify the overall response of the superstructure. On the other hand, the cyclic response of the foundation determines a process of energy dissipation which is reflected in a reduction of the seismic force on the bracing system of the structure. The energy dissipation mechanism due to vertical response is more efficient for the supports located under the braced frames compared to those footings located under unbraced columns, and the effect is much more pronounced in soft or loose soils. The proposed model can be implemented as part of both static and dynamic analyses to have a more realistic prediction of the seismic response during performance-based designs of structures supported on embedded footings, particularly for the case of steel CBF.

DOCTORAL DEGREE IN NATURAL RESOURCES AND THE ENVIRONMENT

MASSAGUÉ OBRADORS, JORDI: Tendencias y dinámica de los episodios de contaminación por ozono troposférico en España.
Author: MASSAGUÉ OBRADORS, 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 NATURAL RESOURCES AND THE ENVIRONMENT
Department: Department of Mining, Industrial and ICT Engineering (EMIT)
Mode: Article-based thesis
Deposit date: 12/09/2024
Reading date: 29/10/2024
Reading time: 11:00
Reading place: Defensa pública a la Sala Tesines C1-002 ETSECCPB
Thesis director: QUEROL CARCELLER, XAVIER | ESCUDERO TELLECHEA, MIGUEL
Committee:
     PRESIDENT: DOS ANJOS ALVES, CÉLIA
     SECRETARI: GAMISANS NOGUERA, XAVIER
     VOCAL: MUÑOZ CINTAS, AMALIA
Thesis abstract: Tropospheric ozone (O3) is a secondary gaseous photochemical pollutant with adverse effects on health, ecosystems, and materials, and it contributes to the greenhouse effect. 94% of the urban population in Europe is exposed to harmful levels of O3, especially in the south and Mediterranean countries like Spain, where regulatory values are systematically exceeded. The abatement of O3 concentrations is complex due to the nonlinear reactions between its key precursors - nitrogen oxides (NOx) and volatile organic compounds (VOCs)- , and the influence of meteorology and atmospheric transport processes at various scales. The aim of this thesis is to enhance the understanding of O3 dynamics in Spain and contribute to the future National Ozone Plan aimed at reducing its levels. This research is based on the analysis of experimental air quality and meteorological data. A regionalization of the territory has been proposed according to the severity of O3 pollution. Critical zones (hotspots) are those with the highest O3 levels and should therefore be prioritized in implementing reduction policies. These include: the Madrid basin, the north of Barcelona (NoB), the closed basin of Puertollano, the interior of the Valencian Community, and the Guadalquivir basin (GB). In these hotspots, external contributions of O3 to Spain and Europe add to the considerable O3 production generated from intense local/regional precursor emissions, causing exceedances of regulatory values. Proper management of these emissions could significantly reduce O3 levels during episodes.Two hotspots have been studied in depth: (i) the GB, where some O3 contributions have been estimated. Controlling local/regional emissions could reduce O3 levels by up to ~50% during acute episodes. (ii) Barcelona - NoB axis, where three exceptional O3 episodes in the city have been analyzed, identifying their causes (mostly common): prior accumulation of O3, weekend effect, specific meteorological conditions, with Tramontana at altitude and very high temperatures, and multiregional convergence of air masses. The evolution of O3 levels has been analyzed in three phases: before (2008- 2019), during (2020- 2021), and after (2022- 2023) the COVID-19 pandemic, due to its impact on precursor emissions. Between 2008-2019, O3 levels in the hotspots showed divergent trends. In the Madrid basin, they increased generally due to meteorology, reduced NOx emissions from road traffic, and a slight increase in VOCs, in a VOC-limited O3 formation regime. In contrast, Seville recorded decreases in O3, attributed to an atypical urban O3 formation regime (more limited by NOx). Other hotspots showed no clear trends, due to slight variations in precursor emissions and the absence of meteorological variations. During the pandemic, O3 levels decreased widely across the country, especially on the Mediterranean littoral, where for the first time regulatory values were not exceeded, due to the unprecedented reduction in precursor emissions at various scales (local, regional, European, and hemispheric), and unfavorable meteorological conditions for O3 production/accumulation. During the post-pandemic period, O3 levels increased compared to the pandemic, although they generally did not reach pre-pandemic levels, despite multiple and intense heat waves conducive to O3. In all three periods, O3 levels increased in urban areas affected by traffic emissions, indicating various causes. The results suggest a long-term convergence between O3 levels in rural and urban environments. Additionally, they highlight the importance of analyzing O3 dynamics at the local/regional scale and applying differentiated management for the various hotspots.

DOCTORAL DEGREE IN OPTICAL ENGINEERING

FRESNO CAÑADA, CARLOS: Estudio de la función visual en pacientes afectos de NF1 con y sin glioma de la vía óptica
Author: FRESNO CAÑADA, CARLOS
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: 16/09/2024
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: PRAT BARTOMEU, JOAN
Committee:
     PRESIDENT: VIÑUELA NAVARRO, VALLDEFLORS
     SECRETARI: CATALA MORA, JAUME
     VOCAL: GARZÓN PARRA, SANDRA JOHANNA
Thesis abstract: Neurofibromatoses (NF) are a group of three related but genetically distinct disorders of the nervous system that cause tumors to grow around nerves. The tumors originate in the cells that make up the myelin sheath, a thin membrane that surrounds and protects nerve fibers, and often spread to adjacent areas. The type of tumor that develops depends on its location in the body and the type of cells involved. The most common tumors are neurofibromas, which develop in the tissue surrounding peripheral nerves. Most tumors are non-cancerous, although they can occasionally become cancerous over time.The exact cause of these tumors is not fully understood, but it appears to be primarily related to mutations in genes that play key roles in suppressing tumor growth in the nervous system. These mutations lead to the NF1 and NF2 genes no longer producing specific proteins that control cell production. Without these proteins, cells multiply uncontrollably and form tumors.There are three types of neurofibromatosis: NF1, NF2, and Schwannomatosis. NF1 is a rare disease with an incidence of 2500-3000 live newborns. This type of disease produces alterations in the whole body, being at ophthalmologic level, Lisch nodules, optic pathway glioma, orbital neurofibroma and alterations in the choroid as the most frequent. Optic pathway glioma can produce a decrease in visual acuity and/or visual field, so early detection is important to apply the recommended treatment and thus avoid vision loss.In this study, we specifically investigated the visual pathway in pediatric patients with NF1 aged 0 to 18 years. We included patients who were seen at the ophthalmology department of the Hospital Sant Joan de Déu in Barcelona.To assess the quality of life of these patients, we used two different life questionnaires based on age. For patients aged 6 months to 7 years, we used the CVFQ test, with a specific version for patients aged 6 months to 3 years and another version for those aged 4 to 7 years. For the age group of patients aged 8 to 18 years, we used the IVI-C test. Before using it in our sample, we first conducted validation and cultural adaptation of the test.In addition to assessing the quality of life in patients with NF1, the feasibility of including choroidal nodule detection using the Triton OCT DRI SS-OCT instrument (Topcon Corporation, Tokyo, Japan) as a clinical criterion for diagnosis and disease monitoring has been studied. It has been concluded that this equipment lacks sufficient sensitivity to detect these nodules. If choroidal nodules were to be included in the clinical diagnostic criteria for the condition, an infrared technology-equipped device would be needed for precise detection.In this sample, the visual pathway function has been studied by measuring visual acuity using age recommended tests and examining retinal layers through Triton OCT DRI SS-OCT optical coherence tomography. The data have been processed using machine learning to predict the possibility of irreversible visual loss. Necessary cutoff points have been identified to raise suspicion of visual deterioration in clinical practice. The most sensitive layer has been found to be the ganglion cell layer, which can be examined both in the macular region and the optic nerve zone.These findings impact the therapeutic monitoring of these patients. Currently, treatment is initiated once visual deterioration is diagnosed based on visual acuity, visual field, or the appearance/growth of optic pathway tumors using magnetic resonance imaging. This study suggests considering treatment when patients are in the suspected visual deterioration zone based on OCT findings, before actual visual acuity decline occurs, thus improving prognosis.

DOCTORAL DEGREE IN PHOTONICS

ANGULO CAPEL, JESSICA: Imaging and Analytical Tools to Study the Spatiotemporal Dynamics of Protein Export
Author: ANGULO CAPEL, JESSICA
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 PHOTONICS
Department: Institute of Photonic Sciences (ICFO)
Mode: Normal
Deposit date: 18/09/2024
Reading date: 18/10/2024
Reading time: 15:00
Reading place: ICFO, Mediterranean Technology Park, Avinguda Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona
Thesis director: GARCÍA PARAJO, MARÍA | CAMPELO AUBARELL, FELIX
Committee:
     PRESIDENT: AVEZOV, EDWARD
     SECRETARI: KRIEG, MICHAEL
     VOCAL: GERSHLICK, DAVID
Thesis abstract: Intracellular trafficking, particularly protein secretion, faces numerous unresolved challenges. This thesis aims to provide and evaluate tools for quantitative investigation of these processes using fluorescent microscopy. Quantitative analysis offers two main benefits: detailed characterization of molecular dynamics for mechanistic understanding and objective measurements for accurate comparisons across experiments. In Chapter 1, we introduce the secretory pathway, a cellular pathway responsible for the synthesis, processing, sorting and delivery of secretory proteins to the extracellular environment. In Chapter 2, we provide a thorough description of the methodologies used in this thesis. They include various fluorescence microscopy techniques, automated image analysis, and biological methods tailored to the secretory pathway. The tools were selected to achieve high spatial and temporal resolution, enable quantitative analysis, and allow live-cell characterization. In Chapter 3, we used fluorescence imaging to objectively evaluate results in four projects addressing protein secretion and intracellular trafficking. These included quantifying colocalization and proximity of structures, measuring fluorescent intensity differences, and characterizing dynamics of particles like ERGIC-derived nanotubules. Consistent sample preparation and image acquisition, coupled with computational analysis, are crucial for accurate, unbiased results.Chapter 4 focuses on single-particle tracking (SPT) in the secretory pathway, proposing control experiments and parameter descriptors to maximize data quality. We emphasized labeling strategies, imaging, and data analysis considerations for reliable results.Chapter 5 applied these methodologies to study protein sorting at the TGN, examining the role of ER-Golgi membrane contact sites (MCS) in TGN-derived carrier biogenesis. Using super-resolution fluorescence microscopy, we identified cargo accumulation regions and conducted SPT experiments, revealing confined, slow motion of cargo proteins near MCS. This effect was inhibited by the lipid transfer blocker 25-HC, indicating upstream regulation of cargo localization preferences by MCS.
LAU, LUKAS DOMINIK: Integrin dynamics and mechanobiology in leukocytes – A multiscale tracking study
Author: LAU, LUKAS DOMINIK
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 PHOTONICS
Department: Institute of Photonic Sciences (ICFO)
Mode: Normal
Deposit date: 20/09/2024
Reading date: 22/10/2024
Reading time: 11:00
Reading place: ICFO, Mediterranean Technology Park, Avinguda Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona
Thesis director: GARCÍA PARAJO, MARÍA
Committee:
     PRESIDENT: MELLADO GARCÍA, JOSÉ MARIO
     SECRETARI: KRIEG, MICHAEL
     VOCAL: CAMBI, ALESSANDRA
Thesis abstract: This thesis explores the molecular mechanisms underpinning leukocyte adhesion and migration, with a primary focus on the mechanobiology of integrin Lymphocyte function-associated antigen 1 (LFA-1). Integrins are key mediators of cell adhesion, which are pivotal in immune response and facilitate leukocyte adhesion, migration, and extravasation at infection sites. This thesis begins by summarizing the structural characteristics of integrins, their mechanobiology and the physiological processes involved in LFA-1 activation, emphasizing the roles of chemokines, adaptor proteins, and tensile forces in modulating integrin function.The experimental research employs advanced single-particle tracking (SPT) using a home-built live-cell microscope with single molecule sensitivity. This multiline-illumination dual-view microscope, combined with a custom-built flow system, enables the investigation of LFA-1 activation at the level of individual molecules under shear flow. We use specific surface functionalization to provide the appropriate stimuli and interaction partners for leukocyte adhesion and migration.The study highlights the characteristics of LFA-1 mobility and engagement, showing how it is regulated by various stimuli, including physiological chemokines like CXCL12 and divalent cations such as Mn2+. The critical role of adaptor proteins, particularly talin, in mediating the integrin-actin cytoskeleton linkage essential for leukocyte motility, is also examined. The findings underscore the importance of integrin ligation and cytoskeletal association in integrin activation for effective leukocyte migration, highlighting the need for precise spatiotemporal control of integrin engagement for leukocyte motility.We further dissect the impact of external tensile forces, such as shear flow, on integrin activation. We demonstrate that these forces significantly increase integrin activation, consequently reinforcing cell adhesion and migration under varying flow conditions. The study also reveals the complex interplay between biochemical stimuli and mechanical forces in modulating integrin activation and consequently leukocyte behavior. In this context, we additionally we bring attention to the relevance of adaptor proteins like talin.Finally, we shift focus to the spatiotemporal relationship between the C-X-C chemokine receptor type 4 (CXCR4) and LFA-1. The focus lies on the functionally relevant CXCR4 nanoclustering and its vicinity to LFA-1 activation. We uncover unexpected behaviors in functional CXCR4 nanoclustering and investigate its spatial relation to integrin activation. The study extends to both healthy CXCR4 and a pathologically altered form, a R334X mutation found in patients with Warts, Hypogammaglobulinemia, Infections, and Myelokathexis (WHIM) syndrome.The thesis concludes by synthesizing these findings, emphasizing the critical role of mechanobiology in leukocyte migration and the complex regulatory mechanisms governing integrin activation. By providing a detailed framework for understanding integrin dynamics, the research points towards its potential implications for pathophysiological alterations of the blood flow and the potential for further studies using advanced biophysical techniques to unravel the intricate molecular interplays at work. Future perspectives include investigating the interplay of the regulatory network for integrin activation, the impact of integrin ligand organization, and the effect of mechanical forces on the relevant players. The insights gained from this work could pave the way for novel therapeutic strategies that target the mechanobiological aspects of immune cell motility, offering new avenues for the treatment of inflammatory diseases and immune-related disorders where aberrant cell adhesion and migration plays a critical role.

DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS

BALLESTAR DE LAS HERAS, RICARDO LUIS: Manufacturing and recycling of polyolefins and biopolymers in a circular economy model. Mechanical, thermal and morphological characterization of polymers and high-performance films.
Author: BALLESTAR DE LAS HERAS, RICARDO LUIS
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 POLYMERS AND BIOPOLYMERS
Department: Department of Chemical Engineering (EQ)
Mode: Article-based thesis
Deposit date: 26/07/2024
Reading date: 22/11/2024
Reading time: 16:00
Reading place: Defensa pública a ESEIAAT (Escola Superior d'Enginyeries Industrial, Aeroespacial i Audiovisual de Terrassa) Edifici TR1. C. Colom, 1 08222 Terrassa
Thesis director: COLOM FAJULA, XAVIER | CAÑAVATE AVILA, FRANCISCO JAVIER
Committee:
     PRESIDENT: SAURINA CANALS, JOAN
     SECRETARI: GARRIGA SOLE, PERE
     VOCAL: MARÍN GENESCÀ, MARC
Thesis abstract: On April 29th, 2015, the EU enacted Directive 2015/720, aimed at reducing plastic consumption, promoting the use of reusable bags and encouraging the replacement of single-use plastic bags with biodegradable alternatives. This European legislation was transposed into Spanish law by Royal Decree 293/2018, dated May 18th.This legislation and its accompanying regulations have significantly impacted the transformation sector, forcing it to reinvent itself to continue its activities. This work aims to provide answers to the challenges faced by manufacturers due to this new context, as well as address the needs resulting from it. Distinctive features of this project are its practical nature and industrial scale.A primary objective is to establish the processability and quality windows for recycled post-industrial and post-consumer materials, ensuring the production of a final product with predefined quality standards. The study examines three types of polyethylene: virgin, post-industrial, and post-consumer. Each type undergoes a combined cycle simulating an industrial recycling process, with post-industrial material being processed up to twelve times and post-consumer material up to four times. This methodology of cyclic processing supports the principle of circularity in sample characterization.For each cycle, involving extrusion and recycling, the study examines micro and macroscopic changes, analyzing morphological and structural changes (using DSC, TGA, GPC, and FTIR techniques) and the evolution of mechanical properties (tensile strength, elongation at break, tear resistance, impact resistance (dart test), and colorimetric changes).At the microstructural level, two types of crystalline structures are observed, and they evolve differently through the processing cycles due to the thermo-oxidative degradation phenomena that occur along the process. The changes include a reduction in crystallinity due to the breakdown of more linear and less branched chains, and an increase in cross-linking among more branched structures. These microstructural changes affect post-industrial and post-consumer recycled polyethylene differently.Macroscopically, tear resistance is the most critical property affected during the recycling cycles, decreasing by up to 40% from the initial value and potentially becoming the main limitation for the successive reuse of these polymers.In line with the previously mentioned regulations, biodegradable polymers are another focus of interest. The study examines biodegradable compostable polymers used to manufacture single-use bags. A secondary objective is to determine how long these biodegradable polymers retain their usability properties under standard storage conditions, analyzing the samples over twelve consecutive months.Macroscopically, a progressive loss in tensile, elongation, and impact properties is the most significant phenomenon. Microscopically, two degradation mechanisms—hydrolysis and thermo-oxidation—are observed, both occurring in the amorphous phase of the material.The study concludes that the tested bags have a shelf life of over twelve months under standard storage conditions.
FONTANA ESCARTIN, ADRIÁN: Autonomous Diagnostic Systems: Design of Sensors Capable of Recognizing and Releasing Biomolecules
Author: FONTANA ESCARTIN, ADRIÁN
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 POLYMERS AND BIOPOLYMERS
Department: Department of Chemical Engineering (EQ)
Mode: Normal
Deposit date: 26/07/2024
Reading date: 21/10/2024
Reading time: 11:00
Reading place: Defensa pública a l'EEBE (Escola d'Enginyeria Barcelona Est), Aula A1.12, Campus Diagonal-Besòs
Thesis director: ALEMAN LLANSO, CARLOS ENRIQUE | BERTRAN CÀNOVAS, ÒSCAR
Committee:
     PRESIDENT: SANTAMARÍA RAMIRO, JESÚS MARCOS
     SECRETARI: GARCÍA TORRES, JOSÉ MANUEL
     VOCAL: FERREIRA MORGADO, JORGE MANUEL
     VOCAL: GENTA, IDA
     VOCAL: ALVES FERREIRA, FREDERICO CASTELO
Thesis abstract: This Ph.D. thesis delves into the realm of electrochemical biosensors, pivotal devices enabling the sensitive and timely detection of diverse biomolecules. Specifically, it explores the critical role of biosensors in biomedical applications, where the swift identification of biomarkers like Glucose (G), Dopamine (DA), Serotonin (SE), and Nicotinamide Adenine Dinucleotide (NADH) is imperative for diagnosing conditions such as diabetes, Parkinson's disease, Alzheimer's disease, and emerging infections, among other diseases.The thesis offers an in-depth examination of various biosensors engineered to target specific biomolecules, elucidating the methodologies and recent advancements pivotal in shaping device development. Noteworthy is the investigation into the influence of different materials, including conducting polymers (CPs), ceramic materials, carbon-based materials among others, on biosensor performance. Special attention is devoted to the design of intricate nanocomposites aimed at achieving heightened selectivity and sensitivity.Incorporating conducting polymers (CPs) like PEDOT into biosensors has proven successful, especially in detecting Nicotinamide Adenine Dinucleotide (NADH) from various bacteria. This enhances sensor conductivity and sensitivity, crucial for identifying bacterial activity. Notably, this thesis implements this approach in biomedical devices such as sutures and meshes, expanding biosensor applications to infection detection.On another front, the thesis highlights the success of engineering biosensors from 3D printed insulating thermoplastics for the detection of Dopamine (DA) among other biomolecules. Leveraging innovative strategies, these biosensors demonstrate remarkable selectivity and sensitivity in detecting DA, paving the way for enhanced diagnosis and monitoring of neurological disorders and other related conditions.Furthermore, the thesis explores the engineering of conductive devices based on biological materials such as Alginate hydrogels and peptides. These bio-inspired materials offer unique properties conducive to biosensor development, including biocompatibility and tunable conductivity. By harnessing the inherent characteristics of biological materials, novel biosensors with enhanced performance and functionality can be realized, opening new avenues for biomedical diagnostics and therapeutic interventions.Through this comprehensive exploration of diverse biosensor technologies and strategies, the thesis aims to contribute significantly to the ongoing evolution of electrochemical biosensors. By shedding light on the successful incorporation of advanced materials and innovative engineering approaches, it offers valuable insights into the potential of biosensors for transformative applications in various biomedical fields, ultimately advancing the frontiers of medical diagnosis and treatment.
QIZILBASH, MASOOMA: Computational Fluid Dynamic (CFD) Study of Polymer Microencapsulation Processes
Author: QIZILBASH, MASOOMA
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 POLYMERS AND BIOPOLYMERS
Department: Department of Chemical Engineering (EQ)
Mode: Normal
Deposit date: 26/07/2024
Reading date: 11/11/2024
Reading time: 10:00
Reading place: EEBE - Sala Polivalent - Edifici A - Campus Diagonal-Besòs (Hora: 10h (hora local) / 12h. (a Jeddah))
Thesis director: GUARDO ZABALETA, ALFREDO DE JESUS | DEL VALLE MENDOZA, LUIS JAVIER
Committee:
     PRESIDENT: RAMIREZ RANGEL, ELIANA
     SECRETARI: MARTÍNEZ GOMARIZ, EDUARDO
     VOCAL: NASIR, RIZWAN
Thesis abstract: Microencapsulation process of polymers and biopolymer is the most important technique in a polymer industry to make it unique and applicable in various fields of daily life. When it comes to the accuracy of the method only Computational Fluid Dynamic (CFD) simulations or numerical solution provides the authenticity of the method. CFD analysis gives a more schematic approach instead of any other Simulation method.In this thesis detailed use of governing equations of CFD is used to predict the accuracy of the microencapsulation method. The experimentation was done in the laboratory of the department of polymers and biopolymers under the supervision of Prof Luis J. Dell Valle. By using CFD the results are more precise, clear and accurate along with the zero minimum percentage of human error. After representing a literature review for the modeling of microencapsulation process in the first chapter, the methodology about how the process began and what parameters we followed to fulfill the requirement of the project. The effect of impeller speed 5000 rpm, 7500 rpm, 1000 rpm, 12000 rpm and 15000 rpm were determined on the number density functions and particle size reduction in the microencapsulation domain.Ansys. Fluent R2 2020 was used to model the experimental data. For the purpose of modeling the particle size distribution discrete method of population balance model is used. A total of five bins were selected to perform the size distribution analyze. The reason for selecting this small diameter range is the focus and accuracy of the solver. The bins should be more than enough to cover the distribution range and small enough to save computational time. Realizable k-e, Eulerian framework and appropriate bins initial values are used to predict the multiphase behavior. Under these conditions simulation converges very well and gives good agreement with the validation and experimental data.

DOCTORAL DEGREE IN STRUCTURAL ANALYSIS

WIERNA QUIROGA, PABLO NICOLÁS: A Novel Computational Homogenization Theory for Multilayered Plates: The Multiscale 2D+ Approach.
Author: WIERNA QUIROGA, PABLO NICOLÁS
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 STRUCTURAL ANALYSIS
Department: Department of Civil and Environmental Engineering (DECA)
Mode: Normal
Deposit date: 06/09/2024
Reading date: 17/10/2024
Reading time: 17:00
Reading place: Defensa pública a la Sala O.C. Zienkievicz, Centre Internacional de Mètodes Numèrics a l'Enginyeria (CIMNE) C. Gran Capità, s/n, Mòdul C1, 2a planta, 08034 Barcelona
Thesis director: OLIVER OLIVELLA, FRANCISCO JAVIER | LLOBERAS VALLS, ORIOL
Committee:
     PRESIDENT: ARTEIRO, ALBERTINO
     SECRETARI: CANTE TERAN, JUAN CARLOS
     VOCAL NO PRESENCIAL: SANCHEZ, PABLO JAVIER
Thesis abstract: This doctoral thesis presents a novel multiscale theory for the analysis of multilayered plate structures, termed the "Multiscale 2D+ approach" or, simply, "2D+". Based on the formalism of computational homogenization theory, this approach is specifically tailored to account for the mechanical behaviour of multilayered materials, which contain a heterogeneous distribution of thin layers across the thickness and often exhibit substantial non-linear material behavior. After identifying the macroscopic scale as the (2D) reference plane of the plate, the strategy models the through-the-thickness heterogeneity by means of a (1D) meso-scale filament, orthogonal to such plane and spanning the plate depth. At the macro-scale level, classical First Order Shear Deformation Theory (FSDT) kinematics is adopted. At the fine-scale level, the Representative Volume Element (RVE) kinematics is initially derived through the linearization of the macro-scale displacement field along the thickness, in accordance with the first-order computational homogenization theory. The RVE is then endowed with a fluctuating displacement field, which aims to capture the well-known (higher-order) zig-zag displacements observed across the thickness of composite laminates. The Hill-Mandel principle is used to establish the mechanical energy balance across both scales, resulting in a one-dimensional Boundary Value Problem (BVP) to be solved at the meso-scale level in terms of the fluctuating displacement field. Furthermore, the variational RVE-problem allows for the enforcement of an additional condition: the fulfillment of the linear momentum balance (equilibrium) equations at every point across the thickness. This yields a physically meaningful computational setting, in which both scales are represented through simple (degenerated) kinematic descriptions, accounting for the essential mechanical behavior observed at each level yet remaining computationally inexpensive. The Multiscale 2D+ approach can therefore be seen as a modern plate theory, where the through-the-thickness mechanical behavior of the plate is obtained upon the solution of the equilibrium problem of a meso-scale filament. Particularly well-suited for bending-dominated scenarios, it provides accurate stress distributions at the ply-level in non-linear simulations, close to those of full-3D models, at a computational cost similar to that of 2D models. The thesis comprises the development of both the formulation and the corresponding numerical multiscale model within the context of the finite element method. Through a series of representative simulations−including assessments of accuracy, computational performance, and non-linear material modeling− the merits of the 2D+ approach in successfully accounting for the mechanical behavior of multilayered plates are clearly evidenced in this contribution.

DOCTORAL DEGREE IN SUSTAINABILITY

HIDROBO MORALES, JACQUELINE TATIANA: Metodología para el mapeo de conductores de innovación en empresas, con base en mapas de innovación
Author: HIDROBO MORALES, JACQUELINE TATIANA
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: 22/07/2024
Reading date: 28/10/2024
Reading time: 15:30
Reading place: Defensa pública a l'aula C1-002 de l'ETSECCPB (a les 15:30 hores Espanya i 09:30 a Colòmbia)
Thesis director: GARCIA CARRILLO, AGUEDA
Committee:
     PRESIDENT: ROSAS PAREDES, KARINA
     SECRETARI: MORENO ROJAS, SIDIA
     VOCAL: MONTES HINCAPIÉ, JUAN MANUEL
Thesis abstract: Globally, the generation of innovation enables better economic, social, and environmental development for countries. Innovation mapping is a tool for visualizing internal and external innovation perspectives in the business environment. Although scientific works on innovation mapping mainly focus on developed economies such as the United States and Western Europe, innovation maps also play a significant role in fostering entrepreneurship and innovation in developing economies. There are no published scientific studies that comprehensively analyze the different existing tools and methods for innovation mapping or provide a structured methodology. The aim of this doctoral thesis is to provide companies with a method for innovation mapping based on the internal and external analysis of their innovation drivers. This method is also useful for mapping the most relevant drivers at the organizational and national levels.To achieve a comprehensive understanding of the evolution of scientific studies published on innovation mapping, a bibliometric analysis is conducted to extract and identify tools, methods, and drivers related to innovation and innovation mapping. The importance of innovation drivers in Ecuador during the years of significant entrepreneurship and innovation boost is identified and analyzed. This analysis is conducted through an exploratory systematic review. Statistical methods are used to perform an empirical analysis based on the Ecuadorian survey of Science, Technology, and Innovation Activities. The results expand the number of drivers from the bibliometric analysis and provide a better understanding of them in developing countries.Based on the results, a methodology for mapping innovation drivers in companies is developed, validated with experts, pilot tested with a Panamanian company, and the final proposal is made. The proposed methodology, MACI, uses a dimensionality reduction approach called Multiple Correspondence Analysis that allows mapping the innovation factors in a two-dimensional Euclidean space.The proposed MACI methodology is applied to four Panamanian companies from the perspective of relevant variables, human resources, innovation, financial aspect, and sustainability. The result is the innovation map of the studied companies and the identification of the most important variables for these companies to improve their innovation drivers.MACI provides a basis for a better understanding of the analyzed factors, not only at the company level but also at the organizational, regional, or national level. The findings of this doctoral thesis can help companies, business clusters, governments, and researchers to better understand the innovation drivers, promoting the formulation of strategies to foster R&D&I.

DOCTORAL DEGREE IN TEXTILE AND PAPER ENGINEERING

ALIEI, HESAM: Influence of household washing on the variation of the properties of intrinsic natural color organic cotton fabrics
Author: ALIEI, HESAM
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 TEXTILE AND PAPER ENGINEERING
Department: Terrassa Institute of Textile Research and Industrial Cooperation (INTEXTER)
Mode: Normal
Deposit date: 22/07/2024
Reading date: 06/11/2024
Reading time: 11:00
Reading place: Sala d'Actes de l'INTEXTER (Institut d'Investigació Tèxtil i de Cooperació Industrial de Terrassa), C/ Colom 15, 08222 Terrassa.
Thesis director: CARRERA GALLISSÀ, ENRIQUE | CAYUELA MARIN, DIANA
Committee:
     PRESIDENT: BONET ARACIL, MARÍA ÁNGELES
     SECRETARI: LIS ARIAS, MANUEL JOSÉ
     VOCAL: MANICH BOU, ALBERT M.
Thesis abstract: Natural colored organic cotton fabrics gained considerable attention in recent years owing to due to their environmental friendliness and sustainability production. This imparts unique colors and patterns to the textiles. The colorimetric characteristics of these fabrics, including lightness and saturation, can be influenced by various factors being household washing one of them. To assess this effects, the colorimetric properties of knitted and woven fabrics were measured before and after 30 washing cycles with a skincare detergent with tap water at 40 ºC. The most significant difference in colorimetric properties was observed after the initial wash, highlighting the reduction in both parameters, lightness and saturation, after the first wash. Also, there was a notable colorimetric difference between the second wash and the fifth washout from the fifth wash onward, the changes were minimal. Additionally, the FTIR-ATR analysis of the extracts in petroleum ether and subsequently in ethanol of the NaCOC fabrics, before and after home washing, in conjunction with a comparison with shrinkage, demonstrated that the latter process is accountable for the darkening of the sample.Furthermore, the impact of various washing conditions on the fabric’s color change was investigated. Specifically, three detergents (Fox Fiber® Colorganic®, Klar, and Pure Nature), two types of water (tap and distilled), and three different temperatures (20, 40, and 60°C) were considered as variables. In this study, the effect of washing variables on the color and integrity of fabrics using colorimetric measurements was evaluated. The findings demonstrated that water hardness was the most influential variable in terms of color changes in fabrics.Overall, these findings highlight that household washing significantly affected the colorimetric properties of NaCOC fabrics, with the initial wash having the most substantial impact. The hardness of the water used in washing has been identified as a crucial factor in color changes, providing insights into the quality and color of natural-colored organic cotton textiles.Keywords: natural color, organic cotton, household washing, color change, colorimetric.
FERNÁNDEZ SANTOS, JULIA: DESARROLLO DE NUEVAS ESTRUCTURAS LAMINARES DE NANOCELULOSA CON PROPIEDADES AVANZADAS PARA EL PACKAGING
Author: FERNÁNDEZ SANTOS, JULIA
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 TEXTILE AND PAPER ENGINEERING
Department: Department of Engineering Graphics and Design (DEGD)
Mode: Normal
Deposit date: 03/07/2024
Reading date: 31/10/2024
Reading time: 11:00
Reading place: Defensa pública a la Sala de juntes del TR5, ESEIAAT (TERRASSA).
Thesis director: RONCERO VIVERO, MARIA BLANCA | VALLS VIDAL, CRISTINA
Committee:
     PRESIDENT: GRIFOLL RUIZ, MAGDALENA
     SECRETARI: VIDAL LLUCIA, TERESA
     VOCAL NO PRESENCIAL: VALENZUELA, SUSANA
Thesis abstract: Changes in the use of raw materials and major lifestyle changes in first world societies have driven the massive use of petroleum-based materials in a wide range of applications. Plastic waste has become pervasive in our surroundings, creating serious problems concerning both the environment (affecting biodiversity) and human health. For this reason, it is essential to develop alternatives to these materials, which are finite, polluting and non-biodegradable. It is upon this context that the present doctoral thesis is framed, wherein from one of the most abundant natural biopolymers on the planet (cellulose), new laminar and transparent biomaterials with barrier and biodegradable properties were created, suitable for use in food packaging. Specifically, nanocellulose was used, combined with natural additives or, chemically or enzymatically functionalised to obtain the required properties: transparency, physico-mechanical properties, acting as a barrier to water and water vapour, grease and oxygen. In order to achieve the objective of this thesis, three work lines have been followed.In the first line of work, films were prepared using crystalline nanocellulose (CNC) and the effects of different natural additives such as sorbitol, glycerol, maltitol, xylitol, mannitol, gellan gum, and ethylene glycol on the CNC matrix at different doses were evaluated. Transparent films with UV protective properties were obtained. Most of the additives showed good results at low doses, both in terms of elongation and tensile strength, as well as to homogeneity, smoothness, and oxygen and water barrier properties (including at high relative humidity conditions). At all the doses tested, biodegradability of films was improved. With the two additives that provided the best properties (maltitol and xylitol), the possibility of a synergistic effect between them was evaluated an improvement in transparency, tensile strength, elongation, as well as an improvement in water vapour and oxygen barrier properties were observed. The second line of work was also based on CNC, but this time it was mixed with fibrillar nanocellulose (CNF) and/or carboxymethylcellulose (CMC) in varying percentages. The obtained films also demonstrated good barrier and mechanical properties. Both the CNF and the CMC increased tensile strength and elasticity (elongation) in the CNC films, as well as providing increased resistance to airflow and UV light. Moreover, both increased hydrophobic, and barrier properties to water vapour as well as oxygen. These effects were confirmed by a food packaging simulation test, in which the CMC films provided the best food preservation. Finally, it was demonstrated that the created films were biodegradable, and this property was enhanced in the presence of either CMC or CNF.Finally, the final line of work began with CNF films and investigated the effects of selective oxidation with sodium periodate upon the creation of aldehyde groups. These groups formed hemiacetal and hemialdal bonds and consequently the resulting films were highly transparent, elastic, and resistant, even under conditions of humidity saturation. In fact, the oxidation treatment with periodate reduced the polarity of the films, thereby significantly improving their water barrier properties. The presence of aldehyde groups allowed the immobilisation of the enzyme laccase, which efficiently captures oxygen and therefore prevents food decomposition. The laccase-containing films oxidised 80% of the methylene blue dye and maintained their enzymatic activity after a month of storage and twelve cycles of reuse, which opens the door to the possible creation of a reusable packaging that could substitute single-use packaging.
KOETZSCH, ANJA: Integrating Machine Learning Models to Optimize Nozzle Design and Enhance Airflow Dynamics in Airjet Spinning
Author: KOETZSCH, ANJA
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 TEXTILE AND PAPER ENGINEERING
Department: Terrassa School of Industrial and Aeronautical Engineering (ETSEIAT)
Mode: Normal
Deposit date: 23/07/2024
Reading date: 18/10/2024
Reading time: 10:00
Reading place: Defensa pública a la Sala d'actes de l'Intexter, ESEIAAT.
Thesis director: TORNERO GARCÍA, JOSÉ ANTONIO | WEIDE, THOMAS
Committee:
     PRESIDENT: WEBER, MARCUS OLIVER
     SECRETARI: MANICH BOU, ALBERT M.
     VOCAL NO PRESENCIAL: KADOGLU, HUSEYIN
Thesis abstract: This research delves into using Machine Learning techniques to enhance production efficiency in Airjet spinning. It focuses on understanding the factors that affect airflow by examining the components of a spinning nozzle, including the fiber inlet element, injector nozzle and spinning spindle. A prototype Airjet spinning nozzle was developed to evaluate the Intake Airflow and Airflow Rate, the basis for a simulation model. Five hundred-one data points were empirically gathered and analyzed to develop a computational model driven by Machine Learning algorithms.The investigation targets understanding the dynamics of airflows within the spinning nozzle, which plays a pivotal role in determining the properties and quality of the spun yarn. The cornerstone of this research lies in elucidating these complex interactions within the spinning nozzle, which, in turn, have far-reaching implications for the effectiveness and efficiency of the Airjet spinning process.The developed Machine Learning models, particularly CatBoost, effectively detected patterns within the data. These patterns revealed critical insights into how various factors impact yarn quality, including delivery speed, fiber material, and nozzle design. The study identified significant relationships between these factors and yarn properties, such as fiber loss, yarn evenness, breaking tenacity and elongation. However, neural network models, including Feedforward Neural Networks and autoencoders, faced challenges due to dataset variability, highlighting the need for more refined data.Findings highlight the significant impact of nozzle design and operational parameters on airflow dynamics and yarn quality. For instance, a smaller cross-sectional area of the fiber inlet improves yarn evenness and tenacity. At the same time, steeper angles and moderate diameters of the injector nozzle orifices enhance yarn evenness and strength. Additionally, shorter spindle tips and smaller inner diameters of the spinning spindle are associated with reduced fiber loss and improved yarn evenness.The thesis concludes by offering recommendations for optimizing Airjet spinning nozzle design based on the insights gleaned from the ML models.

DOCTORAL DEGREE IN THEORY AND HISTORY OF ARCHITECTURE

RIMBAUD BLENGINI, TATIANA: Poetas de la arquitectura en Uruguay. Construcciones para la nueva nación, 1894-1914
Author: RIMBAUD BLENGINI, TATIANA
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: 29/07/2024
Reading date: 08/11/2024
Reading time: 10:00
Reading place: Presencial (ETSAB. Sala de Graus)
Thesis director: ROSSELLO NICOLAU, MARÍA ISABEL
Committee:
     PRESIDENT: SALA GARCIA, TERESA MONTSERRAT
     SECRETARI: NAVAS FERRER, MARIA TERESA
     VOCAL: ALEMÁN KSIAZENICKI, LAURA
Thesis abstract: The present work addresses the brief and complex moment of the turn from the 19th to the 20th century from the perspective of the history of architecture. The objective is to explore the architecture of the end of the century in Uruguay and its relationship with the country's modernization and consolidation processes. To do this, it proposes from a necessarily disciplinary perspective the scope of the proposals that collectively shaped the Uruguayan nation and capital during a short period of explosive growth.The proposed time cut takes as its beginning the year 1894, when the first architect graduated from the Faculty of Mathematics -the first architectural training institution in the country- and 1914, the last year of existence of that institution that later gave rise to the Faculty of Architecture (1915). Furthermore, 1914 was the year of the creation of the Society of Architects of Uruguay and the beginning of the First World War, among other important events that marked a general change in the situation.The architects working during that period emerged from a predominantly polytechnic professional training in the country, which became a field of opportunity for design and formal exploration. The qualities recognized in their works appeal to the professional responsibility of the collective construction of the necessary structures for the functioning of the State. Therefore, the starting point hypothesis of this is that at the beginning of the 20th century, the architects of the first generations of technicians trained in Uruguay assumed the responsibility of creating the architectures of the new nation.The work is structured into five chapters that address different aspects within the broad scope of the study. On the one hand, the people involved with the urban and architectural projects to assemble the nation are identified. The areas of professional training are investigated in terms of their composition and transformation throughout the period. The labor, professional, and corporate organizations are observed, as well as the debates and public demonstrations the architects carried out collectively.On the other hand, the works and projects of architecture are taken as manifestations of the modernization strategies deployed, both from the national scope of the entire territory and in the exponents of the city's urban life, particularly in the capital of the Republic. Thus, the structures associated with consolidating the state institution, those related to the healthcare project, and those of public education at all levels are included. In the same sense, the capital city is analyzed as an urban project of the nation. The actions of the technical body linked to the municipality are reviewed. The city project is addressed in two large areas: public life, through leisure structures, and private life, in housing.Finally, the idea of the constructions for the new nation is taken up and the country's first professionals' role in them is analyzed. A reflection is presented on the possible reasons for the analyzed phenomena ephemerality and repercussions. It has, to this day, incorporated a look at the historiographic and heritage assessment of the legacy of these architectures.This text aims to collaborate in generating architectural history knowledge that makes it possible to make visible and value the architectural and urban dimension carried out in Uruguay between 1894 and 1914, both in the disciplinary and cultural context, at the national level, and in possible international links. It is expected that this sharing will invite discussions and new inquiries into the various architectures carried out in Uruguay throughout its history.

Last update: 10/10/2024 04:45:27.