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See detailNon-linear magnetic model refinement via a finite element subproblem method
Dular, Patrick ULg; V Sabariego, Ruth ULg; Gyselinck, Johan et al

in Proceedings of the XXI Symposium on Electromagnetic Phenomena in Nonlinear Circuits (EPNC 2010) (2010, June)

Model refinements of non-linear magnetic circuits are performed via a finite element subproblem method. A complete problem is split into subproblems to allow a progression from 1- D to 3-D including ... [more ▼]

Model refinements of non-linear magnetic circuits are performed via a finite element subproblem method. A complete problem is split into subproblems to allow a progression from 1- D to 3-D including linear to non-linear model corrections. Its solution is then expressed as the sum of the subproblem solutions supported by different meshes. A convenient and robust correction procedure is proposed allowing independent overlapping meshes for both source and reaction fields. The procedure simplifies both meshing and solving processes, and quantifies the gain given by each model refinement on both local fields and global quantities. [less ▲]

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See detailNon-linear mechanical solvers for GMSH
Noels, Ludovic ULg; Becker; Nguyen, Van Dung ULg et al

Scientific conference (2012, March)

Detailed reference viewed: 33 (3 ULg)
See detailNon-linear neural networks forecasting of sea level anomaly in the Alboran Sea
Rixen, M.; Barth, Alexander ULg; Beckers, Jean-Marie ULg

Conference (2002)

Forecasts based on artificial intelligence (AI) concepts exploit past time series of satellite images to infer near future ocean conditions at the surface by feed-forward non-linear neural networks. The ... [more ▼]

Forecasts based on artificial intelligence (AI) concepts exploit past time series of satellite images to infer near future ocean conditions at the surface by feed-forward non-linear neural networks. The size of the AI problem is drastically reduced by splitting the spatio-temporal variability contained in the remote sensing data by using empirical orthogonal function (EOF) decomposition. The problem of forecasting the dynamics of a two-dimensional surface field can thus be reduced by selecting the most relevant empirical modes, and non-linear time series predictors are then applied on the time independent amplitudes only. In the present case study, we use altimetric maps of the Mediterranean Sea and the Alboran Sea, combining TOPEX-POSEIDON and ERS-1/2 data for the period October 1992 to March 2000. The learning procedure is applied to each mode individually. The final forecast is then reconstructed from the EOFs and the forecasted amplitudes, and compared to the real observed field, the persistence and linear forecasts for validation purposes. [less ▲]

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See detailNon-linear optical measurements and crystalline characterization of CdTe nanoparticles produces by thes electropulse technique
Loicq, Jerôme ULg; Renotte, Yvon ULg; Delplancke, Jean-Luc

in New Journal of Physics (2004), 6(32),

We propose to extend the ‘electropulse’ technique to synthesize CdTe nanoparticles for optical components. To do so, we create nuclei of the expected material on a titanium electrode immersed in an ... [more ▼]

We propose to extend the ‘electropulse’ technique to synthesize CdTe nanoparticles for optical components. To do so, we create nuclei of the expected material on a titanium electrode immersed in an electrolytic solution by using an electrochemical pulse. The nanoparticles are expelled from the titanium horn surface by cavitation bubbles, which are produced in the solution by a high intensity ultrasound pulse generated by a piezoelectric crystal. Optical absorption spectra and third-order non-linear optical properties of a colloidal solution of CdTe particles produced by this technique are presented. The non-linear refractive index was characterized using the single-beam z-scan technique, and measurements were carried out at several incidence intensities. Non-linear indices of refraction between −1.2×10−7 and −2×10−8 cm2W−1 were measured. [less ▲]

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See detailThe non-linear refractive index of colloidal PbSe nanocrystals:Spectroscopy and saturation behaviour
Moreels, Iwan; Kockaert, Pascal; Van Deun, Rick et al

in Journal of Luminescence (2006), 121

Detailed reference viewed: 23 (0 ULg)
See detailNon-linear structures
Newerla, A.; Kerschen, Gaëtan ULg

in Calvi, A.; Roy, N. (Eds.) Spacecraft Loads Analysis (2012)

Non-linearity is a frequent occurrence in engineering structures including spacecraft structures. It can take different forms, and it is at the origin of various dynamical phenomena with no linear ... [more ▼]

Non-linearity is a frequent occurrence in engineering structures including spacecraft structures. It can take different forms, and it is at the origin of various dynamical phenomena with no linear counterpart. These phenomena include jumps, harmonics, bifurcation and non-unicity of the solutions. Even when they are local, non-linearities can affect the global dynamical behaviour of a structure and have a substantial impact on spacecraft loads. What makes non-linear dynamics challenging to analyse and model is the well-known result that the principle of linear superposition does not (generally) apply to non-linear systems. Even if linearisation may suffice in some cases, the rigorous analysis of non-linear structures requires adequate and dedicated numerical and experimental methodologies. The main objective of this chapter is to describe how to handle non-linearities for an accurate estimation of loads in spacecraft structures. Specifically, guidelines for both modeling and testing are provided. [less ▲]

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See detailNon-local damage-enhanced MFH for multiscale simulations of composites
Wu, Ling ULg; Noels, Ludovic ULg; Adam, Laurent et al

in Proceedings of the XII SEM International Conference & Exposition on Experimental and Applied Mechanics (2012)

In this work, a gradient-enhanced mean-field homogenization (MFH) procedure is proposed for fiber reinforced materials. In this approach, the fibers are assumed to remain linear elastic while the matrix ... [more ▼]

In this work, a gradient-enhanced mean-field homogenization (MFH) procedure is proposed for fiber reinforced materials. In this approach, the fibers are assumed to remain linear elastic while the matrix material obeys an elasto-plastic behavior enhanced by a damage model. As classical finite element simulations face the problems of losing uniqueness and strain localization when strain softening of materials is involved, we develop the mean-field homogenization in a non-local way. Toward this end we use the so-called non-local implicit approach, reformulated in an anisotropic way to describe the damage in the matrix. As a result we have a multi-scale model that can be used to study the damage process at the meso-scale, and in particular the damaging of plies in a composite stack, in an efficient computational way. As a demonstration a stack with a hole is studied and it is shown that the model predicts the damaging process in bands oriented with the fiber directions. [less ▲]

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See detailNon-local Damage-Enhanced MFH for Multiscale Simulations of Composites
Wu, Ling ULg; Noels, Ludovic ULg; Adam, Laurent et al

in Patterson, Eann; Backman, David; Cloud, Gary (Eds.) Composite Materials and Joining Technologies for Composites, Volume 7 (2013)

In this work, a gradient-enhanced mean-field homogenization (MFH) procedure is proposed for fiber reinforced materials. In this approach, the fibers are assumed to remain linear elastic while the matrix ... [more ▼]

In this work, a gradient-enhanced mean-field homogenization (MFH) procedure is proposed for fiber reinforced materials. In this approach, the fibers are assumed to remain linear elastic while the matrix material obeys an elasto-plastic behavior enhanced by a damage model. As classical finite element simulations face the problems of losing uniqueness and strain localization when strain softening of materials is involved, we develop the mean-field homogenization in a non-local way. Toward this end we use the so-called non-local implicit approach, reformulated in an anisotropic way to describe the damage in the matrix. As a result we have a multi-scale model that can be used to study the damage process at the meso-scale, and in particular the damaging of plies in a composite stack, in an efficient comput0ational way. As a demonstration a stack with a hole is studied and it is shown that the model predicts the damaging process in bands oriented with the fiber directions. [less ▲]

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See detailNon-Local Incremental-Secant Mean-Field-Homogenization of Damage-Enhanced Elasto-Plastic Composites
Wu, Ling ULg; Noels, Ludovic ULg; Adam, Laurent et al

Conference (2013, December)

An anisotropic gradient–enhanced continuum damage model is herein embedded in a mean–field homogenization (MFH) process for elasto-plastic composites. The homogenization procedure is based on the newly ... [more ▼]

An anisotropic gradient–enhanced continuum damage model is herein embedded in a mean–field homogenization (MFH) process for elasto-plastic composites. The homogenization procedure is based on the newly developed incremental secant mean-field homogenization formulation, for which the residual stress and strain states reached in the phases upon a fictitious elastic unloading are considered as starting point to apply the secant method. The mean stress fields in the phases are then computed using isotropic secant tensors, which are naturally used to define the Linear Comparison–Composite The resulting multi– scale model is then applied to study the damage process at the meso–scale of laminates, and in particular the damaging of plies in a composite stack. By using the gradient–enhanced continuum damage model, the problem of losing uniqueness upon strain softening is avoided. [less ▲]

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See detailA non-local MLT treatment fitting 3D simulations
Dupret, Marc-Antoine ULg; Goupil, M*-J; Samadi, R. et al

in Proceedings of SOHO 18/GONG 2006/HELAS I, Beyond the spherical Sun (2006, October 01)

Not Available

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See detailNon-local multiscale analyzes of composite laminates based on a damage-enhanced mean–field homogenization formulation
Wu, Ling ULg; Noels, Ludovic ULg; Adam, Laurent et al

Conference (2013, June)

Properties of carbon fiber reinforced epoxy laminates are studied using an anisotropic gradient–enhanced continuum damage model embedded in a mean–field homogenization (MFH) procedure. The fibers are ... [more ▼]

Properties of carbon fiber reinforced epoxy laminates are studied using an anisotropic gradient–enhanced continuum damage model embedded in a mean–field homogenization (MFH) procedure. The fibers are assumed to remain elastic, and the matrix material obeys an elasto–plastic behavior enhanced by the proposed damage model. The resulting multi– scale model is then applied to study the damage process at the meso–scale of laminates, and in particular the damaging of plies in a composite stack. By using the gradient–enhanced continuum damage model, the problem of losing uniqueness and strain localization, which happens in classical finite element simulations when strain softening of materials is involved, is avoided. As a demonstration a stack with a hole is studied and it is shown that the model predicts the damaging process in bands oriented with the fiber directions, accordingly to the conducted experimental results. [less ▲]

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See detailNon-local time-dependent treatments of convection in A-G type stars
Dupret, Marc-Antoine ULg; Samadi, R.; Grigahcene, A. et al

in Communications in Asteroseismology (2006), 147

Time-Dependent Convection (TDC) models obtained by combining the local treatment of Gabriel (1996) and Grigahcene et al. (2005) and the non-local prescriptions of Spiegel (1963) are presented. We show ... [more ▼]

Time-Dependent Convection (TDC) models obtained by combining the local treatment of Gabriel (1996) and Grigahcene et al. (2005) and the non-local prescriptions of Spiegel (1963) are presented. We show that in the stationary unperturbed case, these non-local treatments can be constrained by the results of 3D hydrodynamic simulations (Stein & Nordlund 1998). We consider here the case of solar-type stars with a large convective envelope and A-F type stars with two very thin surface convection zones. [less ▲]

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See detailNon-Lte Effects and Abundance Analyses of Halo Stars
Magain, Pierre ULg

in Cayrel de Strobel, G.; Spite, M. (Eds.) The Impact of Very High S/N Spectroscopy on Stellar Physics (1988)

The possible existence of departures from LTE affecting the abundance analyses of halo dwarfs and subgiants is analysed from the observational point of view, and illustrated by the case of the ... [more ▼]

The possible existence of departures from LTE affecting the abundance analyses of halo dwarfs and subgiants is analysed from the observational point of view, and illustrated by the case of the intermediate halo subgiant HD 76932. [less ▲]

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See detailNon-LTE effects on H-3(+) emission in the jovian upper atmosphere
Melin, Henrik; Miller, Steve; Stallard, Tom et al

in Icarus: International Journal of Solar System Studies (2005), 178(1), 97-103

Calculations of column intensities are performed for a number of infrared transitions of the H-3(+) molecular ion, using a model atmosphere recently produced by Grodent et al. [2001. A self-consistent ... [more ▼]

Calculations of column intensities are performed for a number of infrared transitions of the H-3(+) molecular ion, using a model atmosphere recently produced by Grodent et al. [2001. A self-consistent model of the jovian auroral thermal structure. J. Geophys. Res. 106, 12933-12952]. The line intensities integrated along the line of sight through the model atmosphere are first computed assuming that all of the emitting energy levels are in local thermodynamic equilibrium (LTE). These results are compared with those derived from a detailed balance calculation using a method recently proposed by Oka and Epp [2004. Non-thermal rotational distribution of H-3(+). Astrophys. J. In press]. It is shown that the population of excited vibrational levels starts to depart from that derived from LTE at attitudes higher than 500 km (above the jovian cloud tops). This effect has been noted previously by Kim et it. [1992. Densities and vibrational distribution of H-3(+) in the jovian auroral atmosphere. J. Geophys. Res. 97, 6093-6101]. By 2000 km, all of the excited vibrational levels are Populated at less than 10% of the expected LTE value. This has important implications for the jovian upper atmosphere. In particular, the H-3(+) cooling effect will be greatly reduced high in the atmosphere. Modelled LTE line emission is greater than that derived from non-LTE modelling. Comparison of the non-LTE modelling with recent spectral measurements of the jovian auroral/polar regions in the L- and K-infrared windows shows that the Grodent et al. [2001. A self-consistent model of the jovian auroral thermal structure. J. Geophys. Res. 106, 12933-12952] profile overestimates the measured line intensity by similar to 3. Allowing for this, the non-LTE modelling shows that the column densities derived from (quasi-)LTE treatment of the measured line intensities may underestimate the real H-3(+) abundance by a factor of between 6 and 200. This means that attempts to derive important ionospheric properties, such as conductivity and related energy inputs due to magnetosphere-ionosphere coupling, front observed spectra will need to take this into account, if they are not to be seriously in error. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailLe non-marchand, frein ou moteur pour la croissance ?
Defourny, Jacques ULg; Mertens de Wilmars, Sybille ULg; Salamé, Marc

in Defourny, Jacques; Jacquemin, J.-Ch. (Eds.) Avec quelle croissance devons-nous apprendre à vivre ? (1996)

Detailed reference viewed: 95 (7 ULg)
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See detailNon-myeloablative allogeneic hematopoietic cell transplantation following fludarabine plus 2 Gy TBI or ATG plus 8 Gy TLI: a phase II randomized study from the Belgian Hematological Society
Baron, Frédéric ULg; Zachée, Pierre; Maertens, Johan et al

in Journal of Hematology & Oncology (2015), 8(4), 10118613045-014-0098-9

Background: Few studies thus far have compared head-to-head different non-myelooablative conditioning regimens for allogeneic hematopoietic cell transplantation (allo-HCT). Methods: Here, we report the ... [more ▼]

Background: Few studies thus far have compared head-to-head different non-myelooablative conditioning regimens for allogeneic hematopoietic cell transplantation (allo-HCT). Methods: Here, we report the results of a phase II multicenter randomized study comparing non-myeloablative allo-HCT from HLA-identical siblings (n = 54) or from 10/10 HLA-matched unrelated donors (n = 40) with either fludarabine plus 2 Gy total body irradiation (Flu-TBI arm; n = 49) or 8 Gy TLI + anti-thymocyte globulin (TLI-ATG arm; n = 45) conditioning. Results: The 180-day cumulative incidences of grade II-IV acute GVHD (primary endpoint) were 12.2% versus 8.9% in Flu-TBI and TLI-ATG patients, respectively (P = 0.5). Two-year cumulative incidences of moderate/severe chronic GVHD were 40.8% versus 17.8% in Flu-TBI and TLI-ATG patients, respectively (P = 0.017). Five Flu-TBI patients and 10 TLI-ATG patients received pre-emptive DLI for low donor chimerism levels, while 1 Flu-TBI patient and 5 TLI-ATG patients (including 2 patients given prior pre-emptive DLIs) received a second HCT for poor graft function, graft rejection, or disease progression. Four-year cumulative incidences of relapse/progression were 22% and 50% in Flu-TBI and TLI-ATG patients, respectively (P = 0.017). Four-year cumulative incidences of nonrelapse mortality were 24% and 13% in Flu-TBI and TLI-ATG patients, respectively (P = 0.5). Finally, 4-year overall (OS) and progression-free survivals (PFS) were 53% and 54%, respectively, in the Flu-TBI arm, versus 54% (P = 0.9) and 37% (P = 0.12), respectively, in the TLI-ATG arm. Conclusions: In comparison to patients included in the Flu-TBI arm, patients included in the TLI-ATG arm had lower incidence of chronic GVHD, higher incidence of relapse and similar OS. [less ▲]

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See detailNon-myeloablative transplantation with CD8-depleted or unmanipulated peripheral blood stem cells: a phase II randomized trial.
Willems, Evelyne ULg; Baron, Frédéric ULg; Baudoux, Etienne ULg et al

in Leukemia : Official Journal of the Leukemia Society of America, Leukemia Research Fund, U.K (2009), 23(3), 608-10

Detailed reference viewed: 81 (39 ULg)
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See detailNon-native prosody: production and perception of accent
Rasier, Laurent ULg; Caspers, Johanneke; Van Heuven, Vincent

Conference (2008)

Detailed reference viewed: 15 (1 ULg)