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See detailLes perturbateurs endocriniens et le monde agricole
Charlier, Corinne ULg

Conference (2009)

Detailed reference viewed: 16 (5 ULg)
See detailPerturbateurs endocriniens reprotoxiques : ennemis de la fertilité chez l'Homme
Charlier, Corinne ULg

Conference (2010, March 16)

Detailed reference viewed: 26 (3 ULg)
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See detailLes perturbateurs endocriniens
Scippo, Marie-Louise ULg

Conference (2009, November 06)

Detailed reference viewed: 104 (43 ULg)
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See detailA perturbation approach for the modeling of eddy current nondestructive testing problems with differential probes
V Sabariego, Ruth ULg; Dular, Patrick ULg

in IEEE Transactions on Magnetics (2007), 43(4 Sp. Iss. SI), 1289-1292

A perturbation technique applied to the finite element modeling of eddy current nondestructive testing (ECNDT) problems is developed for taking into account differential probes. It concerns a h-conform ... [more ▼]

A perturbation technique applied to the finite element modeling of eddy current nondestructive testing (ECNDT) problems is developed for taking into account differential probes. It concerns a h-conform formulation. The source term of the formulation is directly determined by the projection of the unperturbed field in a relatively small region around the defect. The voltage change due to the presence of the flaw is calculated by performing an integral over the defect and a layer of elements in the exterior domain that touch its boundary. The considered test case involves a shielded differential probe scanning the surface of a metal specimen for the detection of flaws. [less ▲]

Detailed reference viewed: 27 (16 ULg)
See detailPerturbation de l’agentivité dans les symptômes obsessionnels-compulsifs
Belayachi, Sanaa ULg; Van der Linden, Martial ULg

in Brédart, Serge (Ed.) Psychologie et Neuroscience Cognitives de la Conscience de Soi (2012)

Il existe un nombre croissant de données suggérant que les symptômes obsessionnelscompulsifs sont associés à des dysfonctionnements affectant le traitement de l’action. Par ailleurs, la grande ... [more ▼]

Il existe un nombre croissant de données suggérant que les symptômes obsessionnelscompulsifs sont associés à des dysfonctionnements affectant le traitement de l’action. Par ailleurs, la grande hétérogénéité des symptômes obsessionnels-compulsifs semble indiquer l’existence d’atteintes à différents niveaux du traitement de l’action. Dans ce chapitre, nous aborderons tout particulièrement les symptômes de vérification et les caractéristiques phénoménologiques qui y sont associées (doute au sujet de la réalisation effective ou correcte de certaines actions routinières, sentiments d’incomplétude ou d’imperfection, diminution du sentiment de contrôle). Nous montrerons en quoi ces phénomènes peuvent être compris en termes d’une perturbation de l’agentivité, consécutive à des dysfonctionnements durant le traitement des informations liées à l’action. [less ▲]

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See detailPerturbation Finite Element Method for Magnetic Model Refinement of Air Gaps and Leakage Fluxes
Dular, Patrick ULg; V Sabariego, Ruth ULg; Ferreira da Luz, Mauricio V. et al

in IEEE Transactions on Magnetics (2009), 45(3), 1400-1403

Model refinements of magnetic circuits are performed via a subproblem finite element method based on a perturbation technique. An approximate problem considering ideal flux tubes and simplified air-gap ... [more ▼]

Model refinements of magnetic circuits are performed via a subproblem finite element method based on a perturbation technique. An approximate problem considering ideal flux tubes and simplified air-gap models is first solved. It gives the sources for a finite element perturbation problem considering the actual air gaps and flux tubes geometries with the exterior regions. The procedure simplifies both meshing and solving processes, and allows to quantify the gain given by each model refinement. [less ▲]

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See detailThe Perturbation Finite Element Method for Magnetic Modeling of a Loudspeaker
Ferreira da Luz, Mauricio V.; Dular, Patrick ULg; V Sabariego, Ruth ULg et al

in Proceedings of 6ème Conférence Européenne sur les Méthodes Numériques en Electromagnétisme (NUMELEC2008) (2008)

This paper shows that the application of a perturbation finite element method can provide a useful alternative to correct the equivalent magnetic circuits used to model loudspeakers. A ring magnet design ... [more ▼]

This paper shows that the application of a perturbation finite element method can provide a useful alternative to correct the equivalent magnetic circuits used to model loudspeakers. A ring magnet design of a loudspeaker is modeled by means of an axisymmetric magnetic vector potential formulation. The effects of geometry variations on its performances are analyzed. The perturbation solution allows further adapting and refining the equivalent magnetic circuit model of the loudspeaker to each possible variation. Results will be compared with the classical finite element solution. [less ▲]

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See detailPerturbation Finite Element Method for Magnetostatic and Magnetodynamic Problems
Dular, Patrick ULg; V Sabariego, Ruth ULg; Krähenbühl, Laurent

in Proceedings of MOMAG2008 (2008, September)

Magnetic flux distributions are calculated in magnetostatic and magnetodynamic problems via a subproblem finite element method based on a perturbation technique. An approximate finite element problem ... [more ▼]

Magnetic flux distributions are calculated in magnetostatic and magnetodynamic problems via a subproblem finite element method based on a perturbation technique. An approximate finite element problem considering ideal flux tubes or ideal materials is first solved. It gives the source for finite element perturbation problems considering the flux tubes with their exterior regions, accounting thus for leakage fluxes, as well as for changes of material properties and shapes. The proposed technique aims to accurately quantify the gain given by each model refinement on both local fields and global quantities and to justify the usefulness of this refinement. It is also well adapted to parameterized analyses on geometrical and material data. [less ▲]

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See detailA Perturbation Finite Element Method for Modeling Electrostatic MEMS without Remeshing
Boutaayamou, Mohamed ULg; V Sabariego, Ruth ULg; Dular, Patrick ULg

in Proceedings of the 9th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems (EuroSimE2008) (2008)

This paper deals with the coupled electrostatic- mechanical analysis of electrostatically actuated MEMS. An iterative perturbation procedure in conjunction with the finite element method is used to solve ... [more ▼]

This paper deals with the coupled electrostatic- mechanical analysis of electrostatically actuated MEMS. An iterative perturbation procedure in conjunction with the finite element method is used to solve the coupled problem without the need of remeshing the whole electric domain. The method offers the advantage of overcoming degenerated finite elements in the mesh of some electric regions where the deflection of the MEMS moving parts is critical. The actuation of such systems is achieved by applying either an electric voltage or a global charge. [less ▲]

Detailed reference viewed: 48 (25 ULg)
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See detailA perturbation finite element method for modeling moving conductive and magnetic regions without remeshing
Dular, Patrick ULg; V Sabariego, Ruth ULg

in COMPEL (2007), 26(3), 700-711

Purpose - To develop a sub-domain perturbation technique for efficiently modeling moving systems in magnetodynamics with a magnetic field h-conform finite element (FE) formulation. Design/methodology ... [more ▼]

Purpose - To develop a sub-domain perturbation technique for efficiently modeling moving systems in magnetodynamics with a magnetic field h-conform finite element (FE) formulation. Design/methodology/approach - A reference problem is first solved in a global mesh excluding some moving regions and thus avoiding the inclusion of their meshes. Its solution gives the sources for a sequence of perturbation problems with the supplementary moving magnetic and conductive regions. Each of these sub-problems requires an appropriate proper volume mesh of the associated moving region and its surrounding region, with no need of interconnection. The solutions are transferred from one problem to the other through projections of source fields between meshes. Findings - The consideration of sub-problems and associated sources, in a sequence of perturbation problems, leads to a significant speed-up of the repetitive solutions in analyses of moving systems. A free movement in any direction can be considered with no need of remeshing. Originality/value - When working with the perturbation fields, the volume sources can be limited to the moving regions, what allows for homogeneous perturbation boundary conditions and reduces the computational efforts for projecting and evaluating the sources. The curl-conformity of the unknown magnetic field is preserved during the whole process thanks to the use of edge FEs for both the magnetic field and the intermediate source quantities. The sub-problem approach also gives an easy way to directly express the time derivatives in moving frames. [less ▲]

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See detailPerturbation Finite Element Method for Refining Magnetic Circuit Models
Dular, Patrick ULg; V Sabariego, Ruth ULg; Ferreira da Luz, Mauricio Valencia et al

in Proceedings of the XX Symposium Electromagnetic Phenomena in Nonlinear Circuits (EPNC2008) (2008)

Model refinements of magnetic circuits are performed via a subproblem finite element method based on a perturbation technique. An approximate problem considering ideal flux tubes is first solved. It gives ... [more ▼]

Model refinements of magnetic circuits are performed via a subproblem finite element method based on a perturbation technique. An approximate problem considering ideal flux tubes is first solved. It gives the sources for finite element perturbation problems considering all the details of the exterior regions, thus accounting for leakage fluxes. The procedure simplifies both meshing and solving processes. It quantifies the gain given by each model refinement on both local and global quantities. [less ▲]

Detailed reference viewed: 19 (1 ULg)
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See detailPerturbation finite element method for the analysis of earthing systems with vertical and horizontal rods
V Sabariego, Ruth ULg; Ferreira da Luz, Mauricio V.; Nzuru Nsekere, Jean-Pierre et al

in Proceedings of the 6ème Conférence Européenne sur les Méthodes Numériques en Electromagnétisme (NUMELEC2008) (2008, December)

This paper deals with the electrokinetic modeling of earthing systems by means of a sub-domain perturbation finite element technique. An axisymmetric problem is solved for each single grounding rod or ... [more ▼]

This paper deals with the electrokinetic modeling of earthing systems by means of a sub-domain perturbation finite element technique. An axisymmetric problem is solved for each single grounding rod or cable. Its solution must then be corrected by taking into account the influence of the other rods and cables. The electric scalar potential is transferred from one problem to the other through projections between meshes. An inherently 3D problem can thus be solved as a succession of 2D sub-problems, which significantly speeds up the solution and enables to tackle complicated grounding systems. [less ▲]

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See detailPerturbation finite element method for the analysis of earthing systems with vertical rods
V Sabariego, Ruth ULg; Ferreira da Luz, Mauricio V.; Nsekere, Jean-Pierre et al

in Proceedings of MOMAG2008 (2008, September)

This paper deals with the electrokinetic modeling of earthing systems by means of a sub-domain perturbation finite element technique. An axisymmetric problem is solved for each single grounding rod. Its ... [more ▼]

This paper deals with the electrokinetic modeling of earthing systems by means of a sub-domain perturbation finite element technique. An axisymmetric problem is solved for each single grounding rod. Its solution must then be corrected by taking into account the influence of the other rods. The electric scalar potential is transferred from one problem to the other through projections between meshes. An inherently 3D problem can thus be solved as a succession of 2D sub-problems, what significantly speeds up the solution and enables to tackle complicated grounding systems. The method is validated by means of both analytical formulas and 3D computations. [less ▲]

Detailed reference viewed: 91 (19 ULg)
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See detailPerturbation finite-element method for magnetic circuits
Dular, Patrick ULg; V Sabariego, Ruth ULg; Ferreira da Luz, Mauricio et al

in IET Science, Measurement & Technology (2008), 2(6), 440-446

Accurate magnetic flux distributions are calculated in magnetic circuits via a subproblem finite-element (FE) method based on a perturbation technique. An approximate FE problem considering ideal flux ... [more ▼]

Accurate magnetic flux distributions are calculated in magnetic circuits via a subproblem finite-element (FE) method based on a perturbation technique. An approximate FE problem considering ideal flux tubes is first solved. It gives the source for FE perturbation problems considering the flux tubes with their exterior regions, accounting thus for leakage fluxes, as well as for changes of material properties and shapes. The proposed technique aims to accurately quantify the gain given by each model refinement on both local fields and global quantities and to justify the usefulness of this refinement. It is also well adapted to parameterised analyses on geometrical and material data. [less ▲]

Detailed reference viewed: 16 (1 ULg)
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See detailA perturbation method for computing field distortions due to conductive regions with h-conform magnetodynamic finite element formulations
Dular, Patrick ULg; V Sabariego, Ruth ULg

in IEEE Transactions on Magnetics (2007), 43(4), 1293-1296

A method for solving eddy current problems in two separate steps is developed for global-local analyses with h-conform finite element formulations. An unperturbed problem is first solved in a global mesh ... [more ▼]

A method for solving eddy current problems in two separate steps is developed for global-local analyses with h-conform finite element formulations. An unperturbed problem is first solved in a global mesh excluding additional conductive regions. Its solution gives the sources for a sequence of other problems, perturbed by adding conductive regions. Each problem only requires a new adapted mesh of a local region. The way the local problems and their sources are defined leads to a significant speedup of parameterized analyses, e.g., in optimization and sensitivity analyses. [less ▲]

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See detailA perturbation method for the 3D finite element modeling of electrostatically driven MEMS
Boutaayamou, Mohamed ULg; V Sabariego, Ruth ULg; Dular, Patrick ULg

in Sensors (2008), 8(2), 994-1003

In this paper, a finite element (FE) procedure for modeling electrostatically actuated MEMS is presented. It concerns a perturbation method for computing electrostatic field distortions due to moving ... [more ▼]

In this paper, a finite element (FE) procedure for modeling electrostatically actuated MEMS is presented. It concerns a perturbation method for computing electrostatic field distortions due to moving conductors. The computation is split in two steps. First, an unperturbed problem (in the absence of certain conductors) is solved with the conventional FE method in the complete domain. Second, a perturbation problem is solved in a reduced region with an additional conductor using the solution of the unperturbed problem as a source. When the perturbing region is close to the original source field, an iterative computation may be required. The developed procedure offers the advantage of solving sub-problems in reduced domains and consequently of benefiting from different problem-adapted meshes. This approach allows for computational efficiency by decreasing the size of the problem. [less ▲]

Detailed reference viewed: 81 (29 ULg)
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See detailA Perturbation Method for the 3D Finite Element Modeling of Electrostaticaly Driven MEMS
Boutaayamou, Mohamed ULg; V Sabariego, Ruth ULg; Dular, Patrick ULg

in Proceedings of the 8th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems (2007, April)

In this paper, a finite element (FE) procedure for modeling electrostatically actuated MEMS is presented. It concerns a perturbation method for computing electrostatic field distortions due to moving ... [more ▼]

In this paper, a finite element (FE) procedure for modeling electrostatically actuated MEMS is presented. It concerns a perturbation method for computing electrostatic field distortions due to moving conductors. The computation is split in two steps. First, an unperturbed problem (in the absence of certain conductors) is solved with the conventional FE method in the complete domain. Second, a perturbation problem is solved in a reduced region with an additional conductor using the solution of the unperturbed problem as a source. When the perturbing regions are close to the original source field, an iterative computation may be required. The developed procedure offers the advantage of solving sub-problems in reduced domains and consequently of benefiting from different problem-adapted meshes. This approach allows for computational efficiency by decreasing the size of the problem. [less ▲]

Detailed reference viewed: 33 (9 ULg)