Now showing items 61-80 of 97

    Mathematical modelling of diffusion processes at the nanoscale 

    Ribera Ponsa, Helena (Date of defense: 2018-03-16)

    In this thesis we study diffusion processes of nanoparticle evolution and develop appropriate models with the aim of being able to optimise their functions according to the needs of industry. Two distinct diffusion processes ...

    Modeling and numeriacal study of nonsmooth dynamical systems. Applications to Mechanical and Power Electronics Systems. 

    Merillas Santos, Iván (Date of defense: 2007-02-22)

    This thesis is concerned with the modeling and numerical study of nonsmooth dynamical systems (NSDS). The first part of the thesis deals with the modeling of some DC-DC power converters using the complementarity formalism. ...

    Modelització de corbes i superfícies amb aplicacions al disseny geomètric assistit per ordinador i a l'arquitectura 

    Monreal, Amadeo (Date of defense: 2001-12-17)

    En primer lloc, s'evidencia que el disseny que involucra grafisme es pot analitzar com articulat en dos nivells o etapes, un de concepció, intel·lectual, i un altre d'execució, manual o físic, ambdós sempre en interrelació ...

    Monotonicity preserving shock capturing techniques for finite elements 

    Hierro Fabregat, Alba (Date of defense: 2016-11-28)

    The main object of study of this thesis is the development of artificial diffusion shock capturing techniques for continuous and discontinuous Galerkin (cG and dG) approximations of the convection-diffusion problem. Special ...

    Multimodal ventricular tachycardia analysis : towards the accurate parametrization of predictive HPC electrophysiological computational models 

    López-Yunta, Mariña (Date of defense: 2018-07-30)

    After a myocardial infarction, the affected areas of the cardiac tissue suffer changes in their electrical and mechanical properties. This post-infarction scar tissue has been related with a particular type of arrhythmia: ...

    Multiscale clutch models for cell mechanics 

    Venturini, Chiara (Date of defense: 2022-07-22)

    Integrin-based cell adhesion is a key mechanism in fundamental biological processes such as cell migration and wound healing, and in diseases like osteoporosis and cancer. For example, during migration, cells form adhesion ...

    A multisymplectic approach to gravitational theories 

    Gaset Rifà, Jordi (Date of defense: 2018-07-25)

    The theories of gravity are one of the most important topics in theoretical physics and mathematical physics nowadays. The classical formulation of gravity uses the Hilbert-Einstein Lagrangian, which is a singular ...

    New geometrical and dynamical techniques for problems in celestial mechanics 

    Braddell, Róisín (Date of defense: 2021-02-17)

    In this thesis, we study the application of symplectic geometry, regular and singular, to symplectic dynamical systems.We start with a motivating case: the relation between symplectic foliations and global transverse ...

    Non-classical thermal transport and phase change at the nanoscale 

    Calvo Schwarzwälder, Marc (Date of defense: 2019-07-12)

    For 200 years, Fourier’s law has been used to describe heat transfer with excellent results. However, as technology advances, more and more situations arise where heat conduction is not well described by the classical ...

    Normal forms around lower dimensional tori of hamiltonian systems 

    Villanueva Castelltort, Jordi (Date of defense: 1997-03-10)

    L'objectiu bàsic d'aquesta tesi és l'estudi de la dinàmica a l'entorn de tors de dimensió baixa de sistemes hamiltonians analítics. Per aquest estudi l'eina fonamental és l'ús de formes normals al voltant d'aquests ...

    Novel consensus strategies applied to spacecraft formation flight 

    Paita, Fabrizio (Date of defense: 2017-09-04)

    In this thesis we consider the problem of developing distributed control strategies for spacecraft formation flying. In light of possible interferometric applications, the study is conducted in two different contexts: ...

    Noves técniques en l'análisi del senyal electrocardiogràfic. Aplicació a l'ECA d'alta revolució 

    Jané Campos, Raimon (Date of defense: 1989-07-10)

    L'estudi del senyal electrocardiogràfic (ECG) obtingut mitjançant elèctrodes de superfície és una prova mèdica freqüent que té una gran significació en el diagnòstic de l'activitat cardíaca. <br/>Des de la incorporació ...

    Numerical study of hopf bifurcations in the two-dimensional plane poiseuille flow 

    Sánchez Casas, José Pablo (Date of defense: 2002-11-28)

    In this work we try to analyse the dynamics of the Navier-Stokes equations in a problem without domain complexities as is the case of the plane Poiseuille flow. The Poiseuille problem is described as the flow of a viscous ...

    NURBS-Enhanced Finite Element Method (NEFEM) 

    Sevilla Cárdenas, Rubén (Date of defense: 2009-07-24)

    Aquesta tesi proposa una millora del clàssic mètode dels elements finits (finite element method, FEM) per a un tractament eficient de dominis amb contorns corbs: el denominat NURBS-enhanced finite element method (NEFEM). ...

    On Normal Forms and Splitting of Separatrices in Reversible Systems 

    Lázaro Ochoa, José Tomás (Date of defense: 2003-10-23)

    És difícil dibuixar una frontera, dins la Teoria de Sistemas Dinàmics, entre lleis de conservació i simetries doncs, sovint, les seves característiques es confonen. Un clar exemple d'aquest fenómen el constitueixen els ...

    On some spectral and combinatorial properties of distance-regular graphs and their generalizations 

    Diego, Víctor (Date of defense: 2017-11-24)

    In this work we present the study we did in Graph Theory. In the firsts chapteres of the tesis we study the pieces of information that can be obtained from a graph: the spectrum of the adjacency matrix, the preintersection ...

    On the quasiperiodic hamiltonian andronov-hopf bifurcation 

    Pacha Andújar, Juan Ramón (Date of defense: 2002-10-21)

    Aquest treball es situa dintre del marc dels sistemes dinàmics hamiltonians de tres graus de llibertat. Allà considerem famílies d'òrbites periòdiques amb una transició estable-complex inestable: sigui L el paràmetre que ...

    On the role of oscillatory dynamics in neural communication 

    Pérez Cervera, Alberto (Date of defense: 2019-04-04)

    In this Thesis we consider problems concerning brain oscillations generated across the interaction between excitatory (E) and inhibitory (I) cells. We explore how two neuronal groups with underlying oscillatory activity ...

    p-adic L-functions, p-adic Gross-Zagier formulas and plectic points 

    Hernández Barrios, Víctor (Date of defense: 2022-04-19)

    In this work we generalize the construction of p-adic anticyclotomic L-functions associated to an elliptic curve E/F and a quadratic extension K/F, by defining a measure µ_f^p attached to K/F and an automorphic form. In ...

    Parallel Lagrangian particle transport : application to respiratory system airways 

    Olivares Mañas, Edgar (Date of defense: 2018-11-09)

    This thesis is focused on particle transport in the context of high computing performance (HPC) in its widest range, from the numerical modeling to the physics involved, including its parallelization and post-process. The ...