Browsing by Subject "Física matemàtica"
Now showing items 1-20 of 72
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A one-phase Stefan problem with size-dependent thermal conductivity
(2018-07-02)
Article
Open AccessIn this paper a one-phase Stefan problem with size-dependent thermal conductivity is analysed. Approximate solutions to the problem are found via perturbation and numerical methods, and compared to the Neumann solution for ... -
A refined statistical cloud closure using double-Gaussian probability density functions
(2013-10-08)
Article
Open AccessWe introduce a probability density function (PDF)-based scheme to parameterize cloud fraction, average liquid water and liquid water flux in large-scale models, that is developed from and tested against large-eddy simulations ... -
A robust procedure for Damage detection from strain measurements based on Principal Component Analysis
(2013-04-17)
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 ... -
Application of an ALE formulation for density-dependent hyperelastic-plastic models to the simulation of powder compaction processes
(2001)
Conference report
Open AccessDifferent quasi-static cold compaction processes of powders have been simulated with a density-dependent plastic model. The model is formulated within the framework of isotropic finite strain multiplicative hyperelastoplasticity. ... -
Arbitrary lagrangian-eulerian finite element analysis of strain localization in transient problems
(John Wiley & Sons, 1995-10)
Article
Open AccessNon-local models guaranty that finite element computations on strain softening materials remain sound up to failure from a theoretical and computational viewpoint. The non-locality prevents strain localization with zero ... -
Arbitrary Lagrangian–Eulerian (ALE) formulation for hyperelastoplasticity
(John Wiley & Sons, 2002)
Article
Open AccessThe arbitrary Lagrangian–Eulerian (ALE) description in non-linear solid mechanics is nowadays stan- dard for hypoelastic–plastic models. An extension to hyperelastic–plastic models is presented here. A fractional-step ... -
Assessing the physics of models for transition in pipe flow
(Universitat Politècnica de Catalunya, 2022-07-06)
Bachelor thesis
Open Access
Covenantee: Universität Bremen / Zentrum für angewandte Raumfahrttechnologie und MikrogravitationTransition to turbulence in pipe flow is a long standing problem in the field of turbulence research. In the route to fully turbulent pipe flow, turbulence presents itself in a wide variety of forms. In recent years, a ... -
Controlling chaotic transport in two-dimensional periodic potentials
(2010-10-07)
Article
Open AccessWe uncover and characterize different chaotic transport scenarios in perfect two-dimensional periodic potentials by controlling the chaotic dynamics of particles subjected to periodic external forces in the absence of a ... -
Correlation studies for B-spline modeled F2 Chapman parameters obtained from FORMOSAT-3/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 4-D ionosphere modeling ... -
Direct Numerical Simulation of evaporative cooling at the lateral boundary of shallow cumulus clouds
(2013-07-23)
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 large-eddy simulations can ... -
Dynamical sectors for a spinning particle in AdS(3)
(American Physical Society, 2014-09-12)
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 Many-Body Quantum Systems
(Universitat Politècnica de Catalunya, 2015-07-03)
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 ... -
Eigenvalue curves for generalized MIT bag models
(Springer Nature, 2022-11-22)
Article
Restricted access - publisher's policyWe study spectral properties of Dirac operators on bounded domains O¿R3 with boundary conditions of electrostatic and Lorentz scalar type and which depend on a parameter t¿R; the case t=0 corresponds to the MIT bag model. ... -
Error estimates for a viscosity-splitting, finite element method for the incompressible Navier-Stokes 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 ... -
Exploration of the internal flux rope current density using a spacecraft constellation
(Universitat Politècnica de Catalunya, 2022-05)
Bachelor thesis
Open Access
Covenantee: Goddard Space Flight CenterDurant molts anys la comunitat científica ha estat treballant per entendre millor la topologia i les propietats físiques dels tubs de flux (flux ropes en anglès), car són una de les principals formes en les quals l’activitat ... -
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 pressure-Poisson equation using finite differences in colocated grids
(Wiley-VCH, 2012-02-29)
Article
Open AccessThe zero-divergence constraint on the velocity field in the numerical simulation of incompressible flows can be reduced, in certain cases, to a set of one-dimensional 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 Hamilton-Jacobi theory for higher-order autonomous systems
(2013-09-09)
Research report
Open AccessThe geometric framework for the Hamilton-Jacobi theory is used to study this theory in the ambient of higher-order mechanical systems, both in the Lagrangian and Hamiltonian formalisms. Thus, we state the corresponding ...
