Author: COELLO DE PORTUGAL - MARTINEZ VAZQUEZ, JAIME MARIA
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 NUCLEAR AND IONISING RADIATION ENGINEERING
Department: Institute of Energy Technologies (INTE)
Mode: Normal
Deposit date: 17/03/2021
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: TOMAS GARCÍA, ROGELIO | KOUBYCHINE MERKULOV, YOURI ALEXANDROVICH
Committee:
     PRESIDENT: PEREZ RODRIGUEZ, FRANCISCO JOSE
     SECRETARI: CORTES ROSSELL, GUILLEM PERE
     VOCAL: DALENA, BARBARA
Thesis abstract: In order to increase the performance of particle colliders, it is crucial to make the beam sizes at the collision points as small as possible. This causes an increase of the beam size in the region surrounding the collision points thus enhancing the effect of magnetic errors. These errors must therefore be kept under tight control to ensure the performance and safety of the accelerator.The present thesis studies effects of the expected magnetic errors in the regions around the collision points on the beam optics that determine the beam size in the future High-Luminosity upgrade of the Large Hadron Collider (HL-LHC), a 27 km particle accelerator situated on the French-Swiss border near Geneva, Switzerland. It has become clear in recent years that in correcting the magnetic errors in this region a crucial requirement is an accurate measurement of the beam optics at the collision point. This thesis demonstrates that the technique used traditionally in recent years, called ¿K-modulation¿, is not accurate enough to ensure the performance of the HL-LHC and therefore alternative methods of performing this measurement must be studied.To perform these studies a new automatic optics correction tool has been developed and is presented in this thesis. This new tool allows faster and more systematic calculation of corrections of the magnetic errors around the interaction regions and has been successfully tested during commissioning and experiments in the LHC.Two complementary techniques are proposed in order to improve the accuracy of the determination of the beam sizes at the collision points, namely determining the minimum beam size near the collision point using the ¿phase-advance¿ of the beam oscillations around the accelerator and locating the position of this minimum, the ¿beam waist¿, by displacing it and maximising the collision rate characterized by the collider luminosity. In the thesis these techniques are studied theoretically, and the first results of their experimental validation performed in the LHC are presented.This push for smaller beam sizes at the collision points not only increases the beam sizes in sections around this point but also, though to lesser degree, in the arcs of the accelerator. These regions also become susceptible to smaller magnetic errors. As some regions of the accelerator do not count with adequate corrector magnets alternative solutions are needed. Here we present the first experimental results of an optics correction performed by traversing sextupoles with off-central beam in the LHC as a solution proposal. Another consequence of the growth of the beam sizes in the regions around the collision points is the eventual necessity for larger beam pipes. This is the case for HL-LHC where the magnetic lenses around the collision points are going to be replaced by new ones with the beam pipe of larger diameter. In order to keep the same magnetic strength though a new superconducting technology is going to be used to build these magnets. A downside of this novelty is that it is susceptible to a type of magnetic instability called ¿flux-jumps¿. In the thesis the effect of the flux-jumps on the beam sizes is studied theoretically and concrete predictions using measurements of this effect on the prototypes of the new magnets of the HL-LHC are given. The study is also extrapolated to the Future hadron-hadron Circular Collider (FCC-hh), a proposed 100 km circular collider, in which superconducting magnets of this type are expected to be installed all around its circumference.Finally, the thesis presents a summary of software developments performed during the previously mentioned studies, including a user interface to facilitate the use of the automatic correction tool, a new harmonic analysis program that replaces legacy code and many refactors and rewrites that have significantly eased the development of the optics measurements and corrections programs.

Author: LI, JUN
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 ENVIRONMENTAL ENGINEERING
Department: (DECA)
Mode: Change of supervisor
Deposit date: 18/03/2021
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: FERRER MARTI, IVET | DU LAING, GIJS
Committee:
     PRESIDENT: DE SMET, STEFAAN
     SECRETARI: ROUSSEAU, DIEDERIK
     VOCAL NO PRESENCIAL: LIANG, DONGLI
Thesis abstract: This thesis aimed to explore the potential of Se/Zn-enriched bioproducts produced from wastewater treatment processes by eco-technologies (phytoextraction, bioreduction and microalgae-based systems) as Se/Zn feed supplements and biofertilizers.In the first part, two aquatic plants (Lemna and Azolla) with substantial protein content were applied to evaluate the possibility of Se and Zn bioaccumulation/removal from wastewater while producing micronutrient-enriched dietary proteins (for feed/food supplements) and biofertilizers. High transformation to organic Se forms and accumulation in plants after taking up Se(IV), together with the high protein content and fast growth rate, makes Lemna (also named duckweed later on) and Azolla good candidates for the production of Se- and Zn-enriched biomass, which can be used as crop fertilizers or protein-rich food/feed supplements or ingredients. The second and third parts, respectively, evaluated the valorization potential of the produced micronutrient-enriched duckweed as well as sludge generated in wastewater treatment processes containing single Se or Se combined with Zn as micronutrient biofertilizers. Micronutrient-enriched sludge dominated by the presence of Se in zero oxidation state (Se(0)) was found to be the preferred slow-release Se biofertilizer and an effective Se source to produce Se-enriched beans for Se-deficient populations, as compared to micronutrient-enriched duckweed. On the contrary, the Zn content in the seeds of beans was not successfully improved through the application of micronutrient-enriched biofertilizers in comparison with the control. This could be attributed to the lower Zn amount applied into soils as Se/Zn-enriched biomaterials. The following experiment explored the potential of Se removal in high rate algae ponds (HRAPs) treating domestic wastewater, while producing high-value Se-enriched biomass. Results indicated that the wastewater treatment performance of the HRAPs was effective. The produced Se-enriched microalgae in HRAPs fed with domestic wastewater contained a high content of crude protein (48% of volatile suspended solids), the selenoamino acid selenomethionine (SeMet) (91% of total Se), and the essential amino acid. The production of Se-enriched microalgae in HRAPs may offer a promising alternative for upgrading low-value recovered resources into high-value feed supplements. The last experiment aimed to evaluate the Se-enriched microalgae generated in the previous experiment as a potential biostimulant to enhance plant growth and as a Se biofertilizer to improve the Se content of plants. This study demonstrated that the application of raw Se-enriched microalgae biomass to soil (1-10%, soil application) and its extracts to leaves (1%, foliar spray) enhanced plant growth, which confirmed that Se-enriched microalgae acts as a biostimulant. Besides, a higher Se content in the plant was achieved after the application of Se-enriched microalgae or extracts thereof. This indicated that Se-enriched microalgae can be valorized as a biostimulant and biofertilizer to improve both the seed yields and Se content of beans, leading to a higher market value of the beans.This thesis contributes to offering an environmentally friendly and sustainable way for micronutrient biofortification/ supplementation in Se/Zn-deficient areas, while recovering nutrients from wastewater.

Author: CALDERON VEGA, FELICITAS
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: Article-based thesis
Deposit date: 16/03/2021
Reading date: 20/04/2021
Reading time: 17:00
Reading place: Escola de Camins - UPC Campus Nord - enllaç públic: https://meet.google.com/yzf-nrnb-qco
Thesis director: GARCÍA SOTO, ADRIAN DAVID | MÖSSO ARANDA, OCTAVIO CESAR
Committee:
     PRESIDENT: OCAMPO TORRES, FRANCISCO JAVIER
     SECRETARI: SANCHEZ-ARCILLA CONEJO, AGUSTIN
     VOCAL NO PRESENCIAL: FERRER RODRÍGUEZ, LUIS
Thesis abstract: This thesis encompasses a set of different subjects related to metocean variables but studied from different perspectives. The metocean variables are mainly significant wave heights and wind velocities and, to a lesser extent, wave periods. The extreme value theory is used to probabilistically characterized the metocean variables by means of the generalized extreme value distribution (GEV). The effect of seasonality is included by considering monthly maxima and using harmonic and subharmonic functions (i.e., time dependency in the GEV model is incorporated). Although Mexican information was not available to this study, the studies are considered applicable to Mexican coasts in the Gulf of Mexico and the Pacific, since available public information from U.S. buoys located in the Atlantic and Pacific oceans relatively close to the Mexican coasts is employed. For the Pacific region, the GEV model accounting for seasonality is applied to data from a buoy (this is reported in an article in the appendix and summarized as a book chapter in the compendium of publications) and comparisons are carried out versus analogous results for buoys in the Gulf of Mexico obtained in a previous study (included also in the appendix). In other part of the thesis (another book chapter in the compendium), but also for the buoy in the Pacific Ocean, a study is carried out to assess the impact of including or excluding an atypical wave height in the seasonality and in future projections (i.e., wave heights associated with given return periods), since an atypically large significant wave heigh was observed for the considered buoy. One more study (an article in the compendium) introduces the wind velocity as a Metocean variable to be characterized with the time-dependent GEV model from data of a buoy in the Gulf of Mexico. This wind velocity is not for monthly maxima, but for the recorded wind velocity which simultaneously occurred with the maximum significant wave heights. This allowed to propose a simplified approach to determined concurrent significant wave heights and associated wind velocities for given return periods, while accounting for seasonality and quantitatively establishing the uncertainty in the correlated metocean variables in question. This proposal can be potentially used for design and engineering purposes, if the metocean are considered as hazards which imposed demands on coastal (and structural) engineering systems. Additionally, the effect of varying the considered time window for the extreme projections is explored. In a final study (also an article in the compendium), an introduction to the reliability of coastal (and also structural) engineering systems is presented; a breakwater is used as case-study. The coastal structure is subjected to the action of wave heights with different wave periods, for which the joint Longuet-Higgins distribution is used, and the overtopping probability of failure is computed by using classical and revisited reliability approaches. Future studies could combine the characterization of metocean variables as time-dependent GEV models and the used reliability approaches to further investigate the reliability of coastal and offshore systems.

Author: SILVA LAYA, SILVIA JOSEFINA
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: (DECA)
Mode: Article-based thesis
Deposit date: 27/11/2020
Reading date: 21/04/2021
Reading time: 17:00
Reading place: ETSECCPB - CAMPUS NORD - C/ Jordi Girona, 1, 08034 Barcelona - videoconferència: https://meet.google.com/qrf-iida-kvy
Thesis director: ALVAREZ DEL CASTILLO, JAVIER | PÉREZ MARTÍNEZ, SIMÓN
Committee:
     PRESIDENT: GONZALEZ DE MOLINA, MANUEL
     SECRETARI: HAURIE IBARRA, LAIA
     VOCAL NO PRESENCIAL: PENGUE, WALTER
Thesis abstract: The Jarillo, Venezuelan Mirandina parish, has had an intense agricultural development since the end of the 19th century, the peach occupies one of its main crops since the middle of the last century. They are currently the second production community of this fruit at the national level. Producing families have indiscriminately employed the use of agrochemicals to increase and maintain their productivity, with negative effects on the environment and on human health. There is an appreciation that the economic success produced by producers is unquestionable. A series of problems (ecological, economic and socio-cultural)related to the agricultural development model that is explained from a multidimensional perspective and studied from the perspective of complex systems are combined. An unidisciplinary look used in other works in El Jarillo does not help tounderstand the complexity of the relationships that are woven around the use of agrochemicals to increase agricultural productivity as an essential attribute of the jarrilla family farming system. The objective of this work was to integrate the ecological and social dimensions in a study of the socio-ecological dynamics that are defined between the different elements of the familyfarming system and their levels of analysis, with the purpose of understanding the adaptation and transformation processes that it undergoes The system in relation to the use of agrochemicals. A study of complex systems was designed in which a theoretical model was constructed in a participatory manner where the central process is used in agrochemicals to increase agriculturalproductivity in the family farming system of El Jarillo, Venezuela. Three levels of analysis were defined: local, at farm level (first),regional (second) and national (third). The time scale that was considered for the agro-productive subsystem was influenced by two events that marked the history of El Jarillo as an agricultural producing agricultural zone: a) the incorporation of peaches as the main production item (in the 30s, last century) and b) the adoption of green revolution techniques as the main form ofmanagement in agricultural production (from the 60s, also from the last century). To conceive the model, we first structured an epistemological framework with theoretical bases from a documentary review and then, with a systematic review to define the concept of socio-ecological systems of peri-urban family farming. Then we proposed a methodology of diagnosis, characterization and typification of these systems; as well as energy efficiency compared to monetary efficiency. With the information we model the system and validate it in the community with the families. The system presented a complex structureand dynamic relationships involved in the phenomenon of production. A scenario of technical / Figura 1. Estructura metodológica propuesta para comprender las dinámicas socioecológicas de la producción de durazno bajo el sistema de agricultura familiar periurbana en el Jarillo, Venezuela productive difficulties in ecological management was identified, clearly determined by the use of agrochemicals to increase productivity, control pests and diseases and fertilize the soil (local level). At the national level, thelack of support was identified by the State to promote a transition towards systems that are less harmful to human and environmental health.

Author: ANITORI, GIORGIO
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 CONSTRUCTION ENGINEERING
Department: (DECA)
Mode: Normal
Deposit date: 25/02/2021
Reading date: 23/04/2021
Reading time: 12:00
Reading place: AULA 002 Edifici C1 Escola de Camins - UPC CAMPUS NORD - C/ Jordi Girona, 1, 3, 08034
Thesis director: CASAS RIUS, JUAN RAMON
Committee:
     PRESIDENT: RAMOS SCHNEIDER, GONZALO
     SECRETARI: SILVA CARVALHO CAMPOS MATOS, JOSE ANTONIO
     VOCAL: TANNER, PETER
Thesis abstract: Infrastructure maintenance programs establish schedules for routine inspections of highway bridges with little consideration of their current conditions. The time interval between two inspections is traditionally set based on experience and on engineering judgment. For example, in the US considerable expenditures are incurred to meet the required biennial routine inspection of all bridges many of which may be in good condition. It is therefore of great interest for the engineering community to develop an approach to control inspection schedules of individual bridges and minimize their associated costs using rational criteria that account for the lower risk of postponing the inspection of bridges that are subject to reduced deterioration mechanisms and low traffic loadings. The implementation of such a risk-based approach would go a long way in helping optimize the limited resources available for maintaining the vast highway infrastructure system. The object of this Ph.D. dissertation is to develop a rational approach for determining a risk-based optimum time interval between bridge inspections. The proposed theoretical approach subsequently serves for proposing a simple procedure that is implementable in routine practice by bridge engineers using easily available bridge-specific data.To illustrate the proposed procedure using actual bridge data, the work uses highway data from the state of New York (NYS) in the United States of America (USA) in the form of Weigh-in-Motion (WIM) truck traffic data and bridge records provided through the National Bridge Inventory (NBI) database. These data are used to develop a theoretical framework able to define the capacity of bridges probabilistically and the risk of bridge failure if a bridge¿s inspection is deferred for a limited period of time.The calculations performed in this dissertation based on data collected in the state of New York are limited to simple span composite steel-concrete superstructures that constitute a large proportion of short to medium span bridges in North America. However, the same concepts can be extended to other types of superstructures and other regions of the world as appropriate data become available.The conclusions of this study include the demonstration of the inadequacy of utilizing a standard two-year inspection interval for all bridges. To overcome this problem a simplified procedure is proposed for an easy practical engineers¿ application.