Author: BELTRÁN GONZÁLEZ, MARTÍ
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 Applied Physics (FA)
Mode: Normal
Deposit date: 16/11/2020
Reading date: 22/01/2021
Reading time: 11:00
Reading place: EEBE: Videoconferència per COVID-19 videoconferencia: meet.google.com/gsa-fvzy-hov
Thesis director: PRADELL CARA, TRINITAT
Committee:
     DIRECTOR: PRADELL CARA, TRINITAT
     PRESIDENT: GARCIA ARANDA, MIGUEL ANGEL
     SECRETARI: MOLERA I MARIMÓN, JUDIT
     VOCAL: VILARIGUES, MARCIA
Thesis abstract: Materials and methods used in the production of modernist (late 19th and early 20th century) stained glass from the city of Barcelona with special regards to the degradation mechanisms of enamels, grisailles and silver stains have been studied. Coloured enamels from the raw materials used in the Rigalt, Granell & cia modernist workshops from Barcelona were produced and compared to those found in the buildings and belonging to the private collection of J.M. Bonet workshop to explore the reason for the reduced stability of the blue and green enamels. The chemical composition has been determined (and pigments identified) by means of Laser Ablation Inductively-Coupled Plasma Mass Spectrometry (LA-ICP-MS), X-Ray Diffraction (XRD) and UV-Vis-NIR spectroscopy, and the thermal properties of the enamels measured by Differential Scanning Calorimetry (DSC) and Hot Stage Microscopy (HSM). The enamels are made of a lead-zinc borosilicate glass characterised by its low sintering temperatures and high stability against chemical corrosion, in particular to water corrosion. However, the relatively narrow range of firing temperatures necessary for correct adherence of the enamels to the contemporary glass base may have required the addition of a high lead borosilicate flux, which would have increased the lead content of the enamel, decreasing the firing temperature but also its stability. The historical enamels show a lead, boron and zinc depleted silica rich amorphous glass, with precipitated lead and calcium sulphates or carbonates, characteristic of extensive atmospheric corrosion. The blue and green enamels show a heterogeneous layered microstructure more prone to degradation which is augmented by a greater heating and thermal stress affectation produced by the enhanced Infrared absorbance of blue tetrahedral cobalt colour centres and copper ions dissolved in the glass and, in particular, of the cobalt spinel particles

Author: SANCHEZ ARTIGAS, 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 MATERIALS SCIENCE AND ENGINEERING
Department: (CEM)
Mode: Confidentiality
Deposit date: 15/12/2020
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: CABRERA MARRERO, JOSE MARIA | PICAS BARRACHINA, JOSEP ANTON
Committee:
     PRESIDENT: FERRARI FERNÁNDEZ, BEGOÑA
     SECRETARI: CALVO MUÑOZ, JESSICA
     VOCAL: BAILE PUIG, MARIA TERESA
     VOCAL: COLOMINAS GUARDIA, CARLES
     VOCAL: LLORCA ISERN, NURIA
Thesis abstract: This doctoral thesis has been carried out at the company VAC-TRON S.A., together with the Department of Materials Science and Engineering of Universitat Politècnica de Catalunya, in the Besós (EEBE) and Vilanova i la Geltrú (EPSEVG) campus, with the support of the Industrial Doctorate Plan of the Secretariat for Universities and Research of the Department of Business and Knowledge of the Generalitat de Catalunya. The scientific and technological interest that justifies this research line answers the concern to know, characterize and improve the products manufactured by glass to metal seal, achieving a knowledge scientifically based that allows optimizing the current way of working in the company.The technology of glass-metal sealing consists of the manufacture of hermetic components, composed of a metal base, a glass preform and metal pins, which are joined by heating the glass to practically a melting state, allowing it to join to metal parts. The bond generated must be hermetic and must guarantee the electrical resistivity of the glass.Glass is the most important part of the three latter components, being responsible to generate a hermetic seal. Its main properties have been analyzed, such as: characteristic temperatures, chemical composition, particle size and microstructure. The results obtained allowed to differentiate the two most commonly used glasses, borosilicate and sodalime, relating the difference in compositions with the sealing temperature of each glass, as well as the increase in this temperature as the heating rate increases.Once the properties of the analyzed glasses are known, the glass-metal seal has been studied according to the design of the piece and the materials used. Then the hermeticity and electrical resistance of the samples were verified and their behavior as a function of temperature and external mechanical stress were studied. The temperature cycles showed that there is no significant change in the properties of sodalime glasses, while in borosilicate glasses decreased their hermeticity after temperature cycle, when the metal body had lower thickness. On the other hand, pressure tests have shown that the height of the glass was important, breaking at the bending limit of the glass. In addition, it has been found that the critical seal is the one formed with the base. As well, thesmaller the glass diameter, the more pressure the piece resists. These results were used to perform a series of numerical simulations to obtain the rupture pressures. Some results were coincident with the simulation but others no.Once the factors that influence the piece performance were known, new metallic materials for the bases have been studied, such as aluminum or titanium, which allow the company to enter new markets. With these new materials, it was necessary to determine the sealing curve and find the right glass to achieve the required tightness and electrical resistance. Solutions were found for both metals, although with certain limitations. In the case of titanium, the required electrical resistance was not attained by the glass, while in the aluminum case, the temperature cycles requirements were not achievedFinally, the evaluation of other alternative manufacturing methods for the metal bases was carried out. Metallic samples obtained by powder metallurgy and through the MIM and MEAM processes were studied. Because the samples manufactured by powder metallurgy and MIM were commercial ones, in which it was not possible to modify their manufacturing conditions, the results have been unfavorable, while with the samples manufactured by additive metal extrusion (MEAM), a proper seal was achieved.

Author: SHARAFELDEEN, MOHAMMED DIAB ELSAYED
Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
Programme: DOCTORAL DEGREE IN AUTOMATIC CONTROL, ROBOTICS AND VISION
Department: Institute of Industrial and Control Engineering (IOC)
Mode: Temporary seizure
Deposit date: 25/11/2020
Reading date: 22/01/2021
Reading time: 11:00
Reading place: ETSEIB: DEFENSA PER VIDEPCONFERÈNCIA PER COVID-19: Enllaç google meet: meet.google.com/wpx-caxo-yyo
Thesis director: ROSELL GRATACOS, JOAN
Committee:
     PRESIDENT: GONZÁLEZ JIMÉNEZ, JAVIER
     SECRETARI: SUAREZ FEIJOO, RAUL
     VOCAL: KUNZE, LARS
Thesis abstract: This thesis develops a series of modeling and reasoning tools for knowledge-oriented manipulation planning in semi/unstructured environments. The main idea is to use high-level knowledge-based reasoning to capture a rich semantic description of the scene, knowledge about the physical behavior of the objects, and inference mechanism to reason about the potential manipulation actions. Moreover, a multi-model sensory module is proposed to perceive the objects in the environment and build the ontological knowledge.The first part of the thesis is focused on the techniques to provide useful knowledge to guide and facilitate the planning process within a classical-based manipulation planning framework. This planning framework facilitates the combination of task and motion planning approaches which includes Fast Forward (FF), a classical symbolic planning approach to compute the sequence of actions to be done in a certain task, and physics-based motion planning which deals with motions and possible interactions with the objects. The tool proposed to provide useful knowledge to the planning process is called Perception and Manipulation Knowledge (PMK). It provides, on the one hand, a standardized formalization under several foundations, such as the Suggested Upper Merged Ontology (SUMO), and the Core Ontology for Robotics and Automation (CORA), in order to facilitate the shareability and reusability when the interaction between humans and/or robots is done. On the other hand, it provides the inference mechanism to reason about TAMP requirements, such as robot capabilities, action constraints, action feasibility, and manipulation behaviors. Moreover, PMK allows breaking the closed-world assumption of classical-based manipulation planning approaches. This proposal has been tested for a serving task in a table-top manipulation problem.The second part of the thesis is focused on providing FailRecOnt framework which provides a failure interpretation and recovery knowledge for any planner approaches. We are mainly interested in assembly manipulation tasks for bi-manual robots, which often encounter complexity or failures in the planning and execution phases and also takes into account the manipulation actions to couple/decouple or attach/detach the objects. Planning phase failures typically refer to failures of the planner itself, but we will use planning phase failures to also refer to situations where the planner reasons that some action would be infeasible, e.g. because objects block access to what the robot should reach. A correct selection of grasps and placements must be produced in such an eventuality. Depending on the type of problem, goal order must be carefully handled specially in the assembly domain; very large search spaces are possible, requiring objects to be moved more than once for achieving the goals. Execution phase failures refer to hardware failures related to the system devices, e.g. robot or camera needs to be re-calibrated, or software failures related to the capabilities offered by specific software components, or failures in action performance such as an unexpected occluding object, or slippage. Description of how to use the failure ontology in a task and motion planning process, such as the knowledge-enabled approaches or the heuristic search classical approaches is proposed. The third part of the thesis is focused on the use of knowledge-based experience, called experiential knowledge, in every-day manipulation problems, such as, in service robotics applications, serve a cup in a cluttered environment, where some repeatable skills are usually used like pick-up, place-down or navigate. To efficiently handle these tasks, a planning and execution framework, called SkillMaN, for robotic manipulation tasks is proposed, which is equipped with a module withexperiential knowledge (learned from its experience or given by the user) on how to execute a set of skills, like pick-up, put-down or open a drawer.

Author: ÁVILA GARCÍA, DANIELA
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: Temporary seizure
Deposit date: 26/11/2020
Reading date: 22/01/2021
Reading time: 16:00
Reading place: AULA 001 edifici B1 ETSECCPB - UPC CAMPUS NORD - C/ Jordi Girona, 08034 Barcelona - videoconferència:https://meet.google.com/mmb-ytny-fxm
Thesis director: MORATO FARRERAS, JORDI | COMÍN SEBASTIÁN, FRANCISCO
Committee:
     PRESIDENT: MUÑOZ SEVILLA, NORMA PATRICIA
     SECRETARI: ALCARAZ SENDRA, OLGA
     VOCAL NO PRESENCIAL: CASTRO MARTÍNEZ, ANTONIO JESÚS
Thesis abstract: Water ecosystem services (ESw) are related to aquatic ecosystems and to the interaction with water and land in different ecosystems such as forests, agricultural lands, riparian areas, wetlands and water bodies. ESw play a central role in human well-being and water management at different scales. Some of these services include the provision of drinking water, irrigation water, fishing, recreation and flood mitigation. However, different drivers of change, such as land-cover degradation and climate change, affect the ability of forests to provide ESw, resulting in water insecurity. This Ph.D. thesis explores the forest-water nexus and provides an overview of the water management related to potential hydrological impacts of land-use and land-cover changes and climate change in two neotropical mountain watersheds in Latin America: Río Grande de Comitán-Lagos de Montebello (RGC-LM) watershed, Chiapas, México, and Las Piedras river (LPR) watershed, Cauca, Colombia. Although ESw related to cloud forest and páramos are of vital importance for their socio-ecological functioning, both study areas face water-related challenges because of different pressures, such as climate change, land-use and land cover (LULC) change, deforestation, and accelerated urban, agricultural, grazing and touristic growth. Therefore, a combination of methods recommended by the Toolkit for Ecosystem Service Site-based Assessment (TESSA), as well as scenario modelling based on an ecological index of riparian quality, were used to assess how alternative scenarios of reforestation or deforestation and climate change scenarios can affect water provision and water quality at different scales. Considering the socio-ecological context, a total four scenarios were modelled on each study area: two of the modelling scenarios included the implementation of land-use policies that aimed at mitigating the likely consequences of land conversion to cropland or cattle grazing. In contrast, the two opposite scenarios represented increased deforestation, forest fragmentation and degradation of riparian vegetation. Hydrological modelling and the impacts of change were assessed annually using WaterWorld modelling tool. In the case of the RGC-LM watershed, the results were statistically compared at watershed and subwatershed scale, whereas in LPR watershed, climate change scenarios were included, and three zones were delimited according to altitude differences.The results in both watersheds indicate that water quality is positively related to forest cover. The effects of terrain, climate and forest-cover conditions on fog inputs and actual evapotranspiration were relevant to increase or decrease water yield under all scenarios. However, deteriorated water quality and decreased water quantity are not only related to climate change, degradation and reduction of forest and riparian vegetation, but also to inadequate water management in the study areas. Therefore, an effective improvement of ESw in the long-term would require management policies that consider forest-based solutions at different scales, sustainable productive practices, equitable local agreements and efficient distribution networks for water resources.

Author: AMBROSO, STEFANO
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: (DECA)
Mode: Normal
Deposit date: 27/11/2020
Reading date: 25/01/2021
Reading time: 16:00
Reading place: ETSECCPB_ Videoconferència per COVID-19: https://meet.google.com/awx-qksq-smt
Thesis director: GILI SARDÁ, JOSEP MARIA | TEIXIDÓ ULLOD, NÚRIA
Committee:
     PRESIDENT: RODRIGUEZ DIAZ, ESTEFANIA
     SECRETARI: GRINYÓ ANDREU, JORDI
     VOCAL NO PRESENCIAL: PINEDA METZ, SANTIAGO ESTEBAN AGUSTIN
Thesis abstract: Knowledge of the abundance, distribution patterns, and population ecology of antarctic benthic biodiversity have increased considerably during the last decades. Antarctic marine benthic biodiversity has been sampled primarily in areas close to research stations and mainly at shallow depths since more than 100 years using a range of sampling methods, including benthic sleds or trawls and grabs each of which targets a particular community or habitat. Recent technological advances and increased availability of remotely operated vehicles (ROVs), manned submersibles, and video equipped towed gears have significantly increased accessibility to mid and outer continental shelves, continental slopes, submarine canyons and seamounts, thus allowing the direct observation and quantitative study of megabenthic assemblages wthout any impact on the benthic community.Due to the high cost and logistics of these benthic sampling, particularly in Antarctica, studies are often limited to only one biological sampling method. Results of biodiversity studies are used for a range of purposes, including taxonomy, trophic ecology, growth rates, reproductive ecology, environmental impact assessments, and predictive modelling, all of which underpin appropriate marine resource management. However, the generality of marine biodiversity patterns identified among different sampling methods is unknown.This is one of the resons why more comparative studies are necessary to better understand the ecosystem patterns and processes in antactic regions in a context of climate change scenario. Major regions of the Antarctic shelf appear to be undergoing rapid climate change, such as warming on the Antarctic Peninsula in the past few decades. Such climate change will affect benthic ecosystems through changes in benthic-pelagic coupling. For these porpouse this tesis pretend to generally understand the distribution and the eocological paper that benthic organisms have on the benthic ecosystem of the antarctic continental shelf. This thesis includes for chaptersIn the first chapter we investigate ophiuroid assemblages in terms of the distribution and diversity patterns at three different environmental regimes and depths in the Antarctic Peninsula. In the second chapter we assessed the health status of Antarctic gorgonian assemblages in a pristine and remote area in the southernmost part of the Weddell Sea continental shelf. In the third chapter we compared the performance of two sampling gears by assessing quantitative data on the continental shelf of three oceanographically very distinct regions in Antarctic Peninsula. Finally in the fourth chapter we tried to understand the way in which a gorgonian population affects the diversity of the surrounding megafaunal species, by characterizing gorgonian assemblages dwelling on two very contrasting continental shelves.