Browsing by Subject "Física matemàtica"
Now showing items 120 of 57

A onephase Stefan problem with sizedependent thermal conductivity
(20180702)
Article
Open AccessIn this paper a onephase Stefan problem with sizedependent thermal conductivity is analysed. Approximate solutions to the problem are found via perturbation and numerical methods, and compared to the Neumann solution for ... 
Application of an ALE formulation for densitydependent hyperelasticplastic models to the simulation of powder compaction processes
(2001)
Conference report
Open AccessDifferent quasistatic cold compaction processes of powders have been simulated with a densitydependent plastic model. The model is formulated within the framework of isotropic finite strain multiplicative hyperelastoplasticity. ... 
Arbitrary Lagrangian–Eulerian (ALE) formulation for hyperelastoplasticity
(John Wiley & Sons, 2002)
Article
Open AccessThe arbitrary Lagrangian–Eulerian (ALE) description in nonlinear solid mechanics is nowadays stan dard for hypoelastic–plastic models. An extension to hyperelastic–plastic models is presented here. A fractionalstep ... 
Arbitrary lagrangianeulerian finite element analysis of strain localization in transient problems
(John Wiley & Sons, 199510)
Article
Open AccessNonlocal models guaranty that finite element computations on strain softening materials remain sound up to failure from a theoretical and computational viewpoint. The nonlocality prevents strain localization with zero ... 
A refined statistical cloud closure using doubleGaussian probability density functions
(20131008)
Article
Open AccessWe introduce a probability density function (PDF)based scheme to parameterize cloud fraction, average liquid water and liquid water flux in largescale models, that is developed from and tested against largeeddy simulations ... 
A robust procedure for Damage detection from strain measurements based on Principal Component Analysis
(20130417)
Article
Restricted access  publisher's policyFBGs are excellent strain sensors, because of its low size and multiplexing capability. Tens to hundred of sensors may be embedded into a s tructure, as it has already been demonstrated. Nevertheless, they only afford ... 
Controlling chaotic transport in twodimensional periodic potentials
(20101007)
Article
Open AccessWe uncover and characterize different chaotic transport scenarios in perfect twodimensional periodic potentials by controlling the chaotic dynamics of particles subjected to periodic external forces in the absence of a ... 
Correlation studies for Bspline modeled F2 Chapman parameters obtained from FORMOSAT3/COSMIC data
(2014)
Article
Open AccessThe determination of ionospheric key quantities such as the maximum electron density of the F2 layer NmF2, the corresponding F2 peak height hmF2 and the F2 scale height HF2 are of high relevance in 4D ionosphere modeling ... 
Direct Numerical Simulation of evaporative cooling at the lateral boundary of shallow cumulus clouds
(20130723)
Article
Open AccessThis study investigates the dynamics of the subsiding shell at the lateral boundary of cumulus clouds, focusing on the role of evaporative cooling. Since the size of this shell is well below what largeeddy simulations can ... 
Dynamical sectors for a spinning particle in AdS(3)
(American Physical Society, 20140912)
Article
Open AccessWe consider the dynamics of a particle of mass M and spin J in AdS(3). The study reveals the presence of different dynamical sectors depending on the relative values of M, J and the AdS(3) radius R. For the subcritical ... 
Dynamics of ManyBody Quantum Systems
(Universitat Politècnica de Catalunya, 20150703)
Bachelor thesis
Open AccessWe study the ground state and the excitations of quantum bose systems. The hypernetted chain equations (HNC) are introduced and we show that the methods based on them produce acceptable approximations of the static structure ... 
Error estimates for a viscositysplitting, finite element method for the incompressible NavierStokes equations
(2000)
Article
Open Access 
Experimental and numerical characterization of metallic studs
(European Acoustics Association, 2006)
Conference report
Open AccessIn this paper, the characterization of metallic studs used to mount lightweight double wall systems is studied both experimentally and numerically. The metallic studs are usually considered by introducing translational and ... 
Exponential stability in thermoelasticity with microtemperatures
(2003)
Article
Open AccessThis article is concerned with a linear theory for elastic materials with inner structure, whose particles in addition to the classical displacement, possess microtemperatures. In the main part of the paper we restrict ... 
Factorization of the Fourier transform of the pressurePoisson equation using finite differences in colocated grids
(WileyVCH, 20120229)
Article
Open AccessThe zerodivergence constraint on the velocity field in the numerical simulation of incompressible flows can be reduced, in certain cases, to a set of onedimensional linear difference equations for the pressure. These ... 
Flow computations on imprecise terrains
(Springer Verlag, 2011)
Conference report
Restricted access  confidentiality agreementWe study water flow computation on imprecise terrains. We consider two approaches to modeling flow on a terrain: one where water flows across the surface of a polyhedral terrain in the direction of steepest descent, and ... 
Geometric HamiltonJacobi theory for higherorder autonomous systems
(20130909)
External research report
Open AccessThe geometric framework for the HamiltonJacobi theory is used to study this theory in the ambient of higherorder mechanical systems, both in the Lagrangian and Hamiltonian formalisms. Thus, we state the corresponding ... 
Geometric Quantization of real polarizations via sheaves
(201301)
External research report
Open AccessIn this article we develop tools to compute the Geometric Quantization of a symplectic manifold with respect to a regular Lagrangian foliation via sheaf cohomology. The starting point is the definition of representation ... 
Gravitational Particle Production in Massive Chaotic Inflation and the Moduli Problem
(201202)
Article
Restricted access  publisher's policyParticle production from vacuum fluctuations during inflation is briefly revisited. The moduli problem occurring with light particles produced at the end of inflation is addressed, namely the fact that some results are in ... 
Groupoids and Faà di Bruno Formulae for green functions in bialgebras of trees
(201207)
External research report
Open AccessWe prove a Faa di Bruno formula for the Green function in the bialgebra of Ptrees, for any polynomial endofunctor P. The formula appears as relative homotopy cardinality of an equivalence of groupoids. For suitable choices ...