Author: REFACHINHO DE CAMPOS, PAULO ROBERTO
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: (DECA)
Mode: Change of supervisor
Deposit date: 22/07/2022
Reading date: 27/09/2022
Reading time: 14:00
Reading place: ETSECCPB- https://swanseauniversity.zoom.us/j/92197751813?pwd=enZ6Sk5xRk5OdXRkV0tqUndaWldZQT09
Thesis director: HUERTA CEREZUELA, ANTONIO | GIACOMINI, MATTEO | GIL RUIZ, ANTONIO JAVIER | LEE, CHUN HEAN
Committee:
     PRESIDENT: SEVILLA CÁRDENAS, RUBÉN
     SECRETARI: ROGERS, BENEDICT
     VOCAL NO PRESENCIAL: KHAYYER, ABBAS
Thesis abstract: This work presents a new updated reference Lagrangian Smooth Particle Hydrodynamics (SPH) algorithm for the analysis of large deformation by introducing a novel system of first order conservation laws. Both isothermal and thermally coupled scenarios are considered within the elasticity and elasto-plasticity domains. Taking as point of departure a total Lagrangian setting and considering as referential configuration an intermediate configuration of the deformation process, the equation of conservation of linear momentum and three geometric conservation laws (for the deformation gradient, its cofactor and its determinant) are rewritten leading to a very generic (incremental) system of first order conservation laws, which can be degenerated into a total Lagrangian system or into a purely updated Lagrangian system. The key feature of the formulation is a suitable multiplicative decomposition of the conservation variables, leading to a very simple final set of equations with striking similarities to the conventional total Lagrangian system albeit rewritten in terms of incremental updated conservation variables which are evolved in time. Taking advantage of this new incremental updated Lagrangian formalism, a second order (in space and time) entropy-stable SPH upwiding stabilisation method derived by means of the use of the Rankine Hugoniot jump conditions is introduced. No ad-hoc algorithmic regularisation procedures are needed. To demonstrate the robustness and applicability of the methodology, a wide spectrum of challenging problems are presented and compared, including benchmarks in hyperelasticity, elasto-plasticity and dynamic fracture problems. The work explores the use of a series of novel expressions for the evaluation of kernels and the gradients of kernels, all leading to equally convincingly robust results and circumventing the issues faced by classic isotropic (spherical) kernels in the presence of strong anisotropic changes in volume.

Author: MASÓ SOTOMAYOR, MIGUEL
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: (DECA)
Mode: Normal
Deposit date: 22/07/2022
Reading date: 29/09/2022
Reading time: 11:30
Reading place: Sala O.Zienkiewicz - Edifici C1, 2a planta, Campus Nord 08034 Barcelona
Thesis director: OÑATE IBAÑEZ DE NAVARRA, EUGENIO | DE POUPLANA SARDÀ, IGNASI
Committee:
     PRESIDENT: IDELSOHN BARG, SERGIO RODOLFO
     SECRETARI: BLADE CASTELLET, ERNEST
     VOCAL: ORTIZ ROSSINI, PABLO
Thesis abstract: This thesis investigates numerical methods for the simulation of surface water flows, focusing on the interaction between the large scale and the local scale and its application to natural hazards. Several families of numerical methods for the approximation of large scale phenomena and the coupling with the local scale have been analyzed.The general motion of a fluid mass is governed by the Navier-Stokes equations, which can accurately solve the local scale phenomena. However, the same level of accuracy is not required by the large scale solution of the water-related events. In this context, the shallow water equations are defined. In contrast to the extensive use of the Finite Element Method for solving the Navier-Stokes equations, the shallow-water equations are usually solved with the Finite Volume Method. Thus, an effort have been done to solve both equations in an unified framework.The first part of this thesis is devoted to study stabilized formulations of Finite Element Method for the different forms of the shallow water equations. Stabilized formulations arise from the need to mitigate the various instabilities inherent in numerical approximations. The first source of instability is the incompatibility of the equal interpolation of the variables. The second source of instability is the presence of shocks due to the change of regime or hydraulic jumps. Finally, Gibbs oscillations may appear on the moving shoreline and monotonic properties of the physical system are lost by the numerical approximation.The second part of the thesis is committed to the coupling strategies of the numerical methods for the Navier-Stokes and the shallow water equations. The case of a coupling from the local scale to the large scale is analyzed. This type of coupling corresponds to the generation of cascading natural hazard. The proposed strategy combines a Lagrangian Navier Stokes multi-fluid solver with an Eulerian method based on the Boussinesq equations, an extension of the shallow water equations.Finally, the proposed technique is applied to the numerical simulation of landslide-generated impulse waves. The Particle Finite Element Method has been used to model the landslide runout, its impact against the water body and the consequent wave generation. The results of this fully-resolved analysis are stored at selected interfaces and then used as input for the modelling of waves propagation on the far-field.This one-way coupling scheme drastically reduces the computational cost of the analyses while maintaining high accuracy in reproducing the key phenomena of cascading natural hazards.

Author: TROULLINOU, CHARIKLEIA
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: 18/07/2022
Reading date: 29/09/2022
Reading time: 10:00
Reading place: ICFO ¿ The Institute of Photonic Sciences - Campus Baix Llobregat - Av.Carl Friedrich Gauss, 3 08860 Castelldefels (Barcelona) - SPAIN
Thesis director: MITCHELL, MORGAN
Committee:
     PRESIDENT: SEWELL, ROBERT
     SECRETARI: NOVIKOVA, IRINA BORISOVNA
     VOCAL: VASILAKIS, GEORGIOS
Thesis abstract: This thesis describes experiments that employ squeezed light to improve the performance of a sensitive optically-pumped magnetometer (OPM). The squeezed light source employs parametric amplification of vacuum fluctuations to producesqueezed vacuum and polarization-squeezed light tunable around the Rb D1 line. The OPM employs Bell-Bloom optical pumping of a high density vapor (with atom number density 10^{13}) and paramagnetic Faraday rotation, also on the Rb D1line. The setup allows convenient switching from probing with laser light to probing with polarization-squeezed light, to study the use of the latter in atomic magnetometry.The magnetometer shows sub-pT/Hz^{1/2} sensitivity, limited by quantum noise; spin projection noise at low frequencies(<100Hz) and photon shot noise at high frequencies. Probing with polarization squeezed light suppresses the photon shot noise by 2dB, limited by the available squeezing and optical losses in passing through the vapor. This shot-noisesuppression improves the high-frequency sensitivity and increases the measurement bandwidth, with no observed loss ofsensitivity at any frequency. This result confirms experimentally the expected evasion of measurement back-action noise inthe Bell-Bloom magnetometer.The thesis also develops a physical model to explain the observed spin dynamics of the Bell-Bloom magnetometer. Themodel describes the combined spin and optical polarization dynamics using Bloch equations with stochastic drive and detection noise terms. A perturbative approach and Fourier methods are then used to obtain analytic expressions for themagnetometer's frequency response, spin projection noise and photon shot noise. The role of measurement back-action emerges from a study of this model. As polarization squeezing reduces optical noise in the detected Stokes parameter, theaccompanying ellipticity anti-squeezing is shunted into the unmeasured spin component.The thesis also reports a study of squeezed-light-enhanced magnetometry at a range of atomic densities, from 2.18 10^{12} atoms/cm3 to 1.13 10^{13} atoms/cm3 . Operating with fixed conditions of optical pumping, the signal amplitude, instrumentnoise spectrum and magnetic resonance width are measured as a function of atomic number density, for both laser- and squeezed-light probing. The equivalent magnetic noise spectra are then calculated. In the photon-shot-noise-limited portionof the spectrum, the squeezed light probing improves the magnetometer's sensitivity and measurement bandwidth for thefull range of atomic density values. In particular, the laser-probed magnetometer shows a sensitivity optimum at n ~ 6 10 ^{12} atoms/cm3, and the squeezed-light-probed magnetometer surpasses this sensitivity.The thesis concludes with a discussion of the potential of stronger optical squeezing to enhance the instrument's sensitivityin different portions of the spectrum. Using the theory model we estimate the enhancement of the equivalent magnetic noise spectrum for 2 dB , 5.6 dB and perfect squeezing (zero noise in the detected polarization component) at the input to theatomic medium.

Author: ARELLANO RAMOS, BLANCA ESMARAGDA
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 URBAN AND ARCHITECTURAL MANAGEMENT AND VALUATION
Department: Department of Architectural Technology (TA)
Mode: Article-based thesis
Deposit date: 25/07/2022
Reading date: 30/09/2022
Reading time: 01:00
Reading place: ETSAB- UPC CAMPUS NORD - videoconferència: https://meet.google.com/cia-wngh-ppj
Thesis director: ROCA CLADERA, JOSE NICASIO
Committee:
     PRESIDENT: MARMOLEJO DUARTE, CARLOS RAMIRO
     SECRETARI: FLORES LUCERO, MARIA DE LOURDES
     VOCAL NO PRESENCIAL: CERASOLI, MARIO
Thesis abstract: The present thesis consists in a PhD thesis by compendium of publications. The general objective of the thesis is the analysis of the phenomenon of the Urban Sprawl, on a planetary scale, starting from the hypothesis that it is an unsustainable process. For the development, specific objectives were set that include the evolution of the research through a selection of 20 papers. The objectives are:a) Analyzing the Urban Sprawl urbanization model, by reviewing the specialized literature;b) Studying the genesis and evolution c) Quantify the Urban Sprawl from databases of local, regional and global, raising the question: is the Sprawl a phenomenon of planetary scope?d) Verify the hypothesis that in Europe, despite having a relatively dense metropolitan structure, there is a pronounced process of Urban Sprawl in the peripheries of large citiese) Define the ¿city¿ in the Sprawl era, defining urban and metropolitan systems based on morphological, economic and functional criteriaf) Develop a methodology for the analysis of the internal structure of metropolises, capable of contrasting the degree of monocentrism and polycentrism of urban and metropolitan systems and verify the hypothesis that a higher degree of polycentrism reduces the degree of Sprawl (+ Polycentrism =-Sprawl)g) Apply this methodology to the analysis of specific cases, such as the Spanish urban systemh) Apply the above methodology to analyze the efficiency in land consumption of the metropolitan systems of Madrid and Barcelona, Los Angeles and Chicagoi) Analyze the process of urbanization through the land impacted by urbanization on a global scale, through images of night lights, delimiting metropolitan and megalopolitan areas and defining the different landscapes of human settlementsj) Assess suitability of nighttime images to identify urban areas (in relation to rural settlements), and especially the Urban Sprawl, as well as, quantify the retrospective (and prospective) dynamics of the urbanization process (with special attention to China)k) Evaluate the climatic behavior of dispersed and low-density fabrics in comparison to the rest of urban and rural fabrics and uses;l) Study the daytime and nighttime Urban Heat Island (UHI), its spatial distribution and climatic performance of the different types of land covers;m) Study the urban factors that increase the adaptation of cities to global warming, specifically, urban parks as islands of cold in the context of the UHIn) Analyze the effects of heat waves on health, as well as the effect of urban greenery.The thesis, on the one hand, confirms the hypothesis of the unsustainability of the Urban Sprawl, since it implies a high consumption of land, in addition to generating unsustainable mobility. In the same way, it implies a fragmented and dispersed urbanization model, higher energy consumption and promotes social segregation. On the other hand, from the perspective of adaptation to climate change, the Urban Sprawl undoubtedly has a better performance, mainly due to the quality and quantity of green areas present in this type of urban fabric (absent in the central and dense city) and its proximity to those rural or forest areas, which are spaces that produce fresh air.The great challenge of spatial and urban planning is to stop this process of urban expansion without compromising the quality of life, comfort and human health. In this sense, it is necessary to proceed with a radical regeneration of the inherited urban fabrics. The compact city model cannot simply be considered the paradigm of sustainability. It must learn from the green spaces per inhabitant present in the Sprawl. Therefore, it can be concluded that green compactness is the new paradigm of 21st century cities.

Author: GARNICA GONZALEZ-BARCENA, JULIO FIDEL
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: (THATC)
Mode: Normal
Deposit date: 02/09/2022
Reading date: 03/10/2022
Reading time: 11:00
Reading place: ETSAB- Sala de Graus ETSAB
Thesis director: GARCIA ESTEVEZ, CAROLINA BEATRIZ | ROVIRA GIMENO, JOSE MARIA
Committee:
     PRESIDENT: SANCHEZ LAMPREAVE, RICARDO
     SECRETARI: GRANELL TRIAS, ENRIQUE
     VOCAL: GUERRERO LOPEZ, SALVADOR
Thesis abstract: At the end of 1949, the American architect Peter G. Harnden (1913-1971), then in charge of the Marshall Plan's exhibition center in Europe, and the young Italian architect Lanfranco Bombelli (1921-2008), trained in Switzerland in the practice of Concrete Art, met in Paris. A fruitful professional and personal relationship began between the two -truncated in 1971 with Harnden's premature death- which trajectory, as surprising as it is unclassifiable, is centered on architecture, exhibition techniques and visual advertising. The aim of this paper is to describe, analyze and interpret - as an unicum - an architectural path as unexpected as it is still little known. Along this path, Harnden and Bombelli cross modernity thanks to an unprecedented compromise between the conditions imposed by their own present, characterized by the events of the so-called Cold War, and the yearning to achieve a particular interpretation of the most timeless Mediterranean tradition.During the first years of the 1950s, Harnden and Bombelli developed from various agencies of the American administration installed in Paris (ECA, MSA, USIA) an intense program for the design and organization of the exhibitions that toured Europe proclaiming the advantages of the Marshall Plan, the history of the birth of NATO, or the advantages of productivity. Under the American's baton, Harnden's big band architecture, an international team of professionals who always work as a team, is in charge of the various traveling exhibitions that tour the old continent: Europe builds, Caravan of peace, Train of Europe, Productivity or Barges. The strategy also includes the mounting of several fixed exhibitions such as Wir bauen ein besseres leben or the organization of a series of exhibitions aimed at disseminating the benefits of atomic energy. From 1955 onwards, Americanization takes command and, commissioned by the Department of Commerce, they were responsible for designing the pavilions with which the USA participated in European trade fairs. In 1956 they founded in Orgeval PGHA Peter Graham Harnden Associates, an "international office of architects and technicians specialized in visual advertising and industrial aesthetics", where they dedicated, as independent professionals, to the design of all types of exhibitions for various American organizations. Their work included the pavilions designed for the Valencia (1955), Barcelona (1955, 1956, 1957) and Madrid (1959) Fairs, a series of imported rationalisms that made an impact on the general public, but also on local professionals, who took note of the advantages of dry construction, the efficiency of assembly and the visual possibilities of advertising.In 1959, upon the recommendation of architect J.A. Coderch, Harnden and Bombelli visited the Spanish town of Cadaqués, "the only beautiful village left in Spain". Fascinated by the landscape, the geography and the effervescent cultural and social atmosphere of this authentic Mediterranean island, they decided to buy and renovate Villa Gloria, and shortly afterwards, in 1962, they settled in Barcelona and founded the firm Harnden&Bombelli. From then on, they combined commissions for exhibition installations with new projects, among which the houses built in Spain stand out. In barely a decade, their brief but intense work, both in Cadaqués and in other Mediterranean areas, establishes an unprecedented and enriching dialogue between modernity and Mediterranean tradition. A sort of Westinghouse regionalism that oscillates between a passionate respect for the landscape and traditional construction, and the uninhibited display of a particular sense of comfort. Artificially popular and with no other pretension than to go unnoticed, these houses are like exhibitions, organized in genuinely democratic living rooms arranged around the atavistic fire of the fireplaces.