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See detailAn Efficient Flamelet-based Combustion Model for Supersonic Flows
Saghafian, Amirreza; Terrapon, Vincent ULg; Ham, Frank et al

in 17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference 2011, Vol. 2; No AIAA 2011-2267 (2011, April)

A combustion model based on a Flamelet/Progress Variable approach for high-speed flows is introduced. In the proposed formulation, the temperature is computed from the transported total energy and ... [more ▼]

A combustion model based on a Flamelet/Progress Variable approach for high-speed flows is introduced. In the proposed formulation, the temperature is computed from the transported total energy and tabulated species mass fractions. The combustion is thus modeled by 3 additional scalar equations and a chemistry table that is computed in a pre-processing step. This approach is very efficient and allows the use of complex chemical mechanisms. An approximation is also introduced to eliminate costly iteration steps during the temperature calculation. To better account for compressibility e ects, the source term for the progress variable is rescaled with the pressure. The model is tested in both RANS and LES computations of a hydrogen jet in a supersonic transverse flow. Comparison with experimental measurements shows good agreement, particularly in the LES case. It is also found that the disagreement between RANS results and experimental data is mostly due to the mixing model de ciencies used in RANS. [less ▲]

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See detailAn efficient formulation for the simulation of elastic wave propagation in 1-dimensional collinding bodies
Depouhon, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the 11th International Conference on Vibration Problems (2013, September 09)

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See detailAn efficient global methodology for hazard analysis of dams complexes and cascades
Dewals, Benjamin ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Brebbia, C. A.; Popov, V.; Beriatos, E. (Eds.) Risk analysis Vol. 6 (2008)

Hazard analysis of dams arranged in complex or in cascade may involve the assessment of a large number of different scenarios of combined failures. However, a tremendous computation time would be needed ... [more ▼]

Hazard analysis of dams arranged in complex or in cascade may involve the assessment of a large number of different scenarios of combined failures. However, a tremendous computation time would be needed to perform a detailed modelling of the flows generated by all possible scenarios. Therefore, the present paper describes a methodology for analysing the flows induced by the most relevant incidents occurring on a complex or in a cascade of dams and reservoirs. The methodology combines several hydrodynamic models, including the two-dimensional flow solver WOLF 2D and a simplified lumped hydrodynamic model, to simulate the flows induced on the dams complex, the potential breaching in cascade of other dams, as well as the propagation of the flood wave in the whole downstream valley. The application of the methodology to a practical case study involving a complex of five dams is also described. [less ▲]

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See detailEfficient hydraulic numerical modeling with multiblock grids and linked models
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Houille Blanche (2011), 3

In the field of numerical hydraulic engineering, the size of the simulations is one of the current challenges to consider with sufficient precision the large areas involved by practical applications. In ... [more ▼]

In the field of numerical hydraulic engineering, the size of the simulations is one of the current challenges to consider with sufficient precision the large areas involved by practical applications. In this scope, the linking in the same computational domain of different solvers, each one used in the part of the simulation where its characteristics are most suitable, opens the door to huge modeling possibilities. Such optimized hydraulic numerical modeling is presented in this paper with a multiblock multimodel 2D solver and its linking to a 1D model. After a description of the solvers, with emphasis on the linking procedures, theoretical test cases and real applications are presented. [less ▲]

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See detailEfficient Immunoselection of Cytolytic Effectors with a Magnetic Cell Sorter
Jacobs, Nathalie ULg; Moutschen, Michel P; Boniver, Jacques ULg et al

in Research in Immunology (1993), 144(2), 141-50

This paper describes a rapid and efficient method for the sorting of in vitro activated cytolytic effectors cells. For cytotoxic assays, a large number of cells with conserved function must be rapidly ... [more ▼]

This paper describes a rapid and efficient method for the sorting of in vitro activated cytolytic effectors cells. For cytotoxic assays, a large number of cells with conserved function must be rapidly obtained. Immunomagnetic sorting was chosen because it is faster than flow cytometry sorting. The MACS system requires the use of paramagnetic beads of small diameter (100-150 nm), reputed to interfere minimally with cell function. In order to generate the cytolytic effectors, peripheral blood lymphocytes were cultivated in the presence of interleukin-2 (50 U/ml) and anti-CD3 monoclonal antibody (BMA030, 100 ng/ml) for 4 days. Cell separation was based on the membrane expression of the CD3 complex. The purity obtained for positive (CD3+) cell sorting with the MACS was higher than 95%. The purity of negative (CD3-) cell fraction was more variable, but further purification by flow cytometry rapidly yielded purity higher than 95%. Cytotoxic assays were performed against four target cell lines (K562, Daudi, HL60 and U937) and proliferation assays showed that both negatively and positively selected populations had conserved their function acquired during culture in the presence of anti-CD3 mAb and IL2. [less ▲]

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See detailAn efficient implicit approach for the thermomechanical behavior of materials submitted to high strain rates
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg

in Journal de Physique IV (2006), 134

In the present paper, three solutions are proposed to simulate fast phenomena with finite element method at best. At first, material constitutive laws of Johnson-Cook and Zerilli-Armstrong types are ... [more ▼]

In the present paper, three solutions are proposed to simulate fast phenomena with finite element method at best. At first, material constitutive laws of Johnson-Cook and Zerilli-Armstrong types are implemented. These well-known laws are efficient for the description of material behavior at high velocities, especially for material used in automotive or aeronautics industry. The second contribution of this paper is the coupling of an implicit Chung-Hulbert algorithm taking into account the inertial effects with a staggered scheme for solving the thermal problem. The last input of this paper is the use of EAS (Enhanced Assumed Strain) finite elements to better capture complex strain modes, especially bending that is not accurately evaluated with classical finite elements. These EAS finite elements are used in the scope of thermomechanical dynamic phenomena implemented in a modular C++ environment at the University of Liege in the home made software METAFOR. [less ▲]

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See detailAn Efficient Implicit Scheme for the Treatment of Contact Between Deformable Bodies
Ponthot, Jean-Philippe ULg; GRAILLET

in Idelsohn, S.; Onate; Dvorkin (Eds.) Proceedings of "World Congress on Computational Mechanics IV (1998)

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See detailAn Efficient Implicit Scheme for the Treatment of Contact between Deformable Bodies
GRAILLET, D.; Ponthot, Jean-Philippe ULg

in . Proceedings of "NUMIFORM'98, Simulation of Materials Processing: Theory, Methods and Applications (1998, June)

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See detailAn Efficient Implicit Scheme for the Treatment of Frictional Contact between Deformable Bodies
GRAILLET, D.; Ponthot, Jean-Philippe ULg

in Proceedings of "First ESAFORM Conference on Material Forming" (1998)

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See detailEfficient Implicit Schemes for Finite Element Impact Simulation
Ponthot, Jean-Philippe ULg; Graillet, D.

in International Journal of Crashworthiness (1999), 4(3), 273-285

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See detailEfficient Implicit Schemes for High-Speed Dynamics and Crash Simulation. Application to shock-absorber devices
Hogge, Michel ULg; GRAILLET, D.; Ponthot, Jean-Philippe ULg

in Proceedings of «ACOMEN’98», Advanced Computational Methods in Engineering: Invited Papers (1998, September)

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See detailEfficient implicit schemes for the treatment of the contact between deformable bodies. Application to shock absorber devices
GRAILLET, D.; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg

in Proceedings of the Fifth National Belgian Congress on Theoretical and Applied Mechanics (2000)

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See detailEfficient Implicit Schemes for Transient Problems in Metal Forming Simulation
Hogge, Michel ULg; Ponthot, Jean-Philippe ULg

in Proc. of NUPHYMAT'96, Numerical and Physical Study of Material Forming Processe (1996)

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See detailAn efficient interpolation algorithm for Fourier and diffractive optics
Roose, Stéphane ULg; Brichau, Bart; Stijns, Erik

in Optics Communications (1993), 97(5-6), 312-318

An alternative algorithm for the computation of diffraction (Fourier) integrals is described. Its computation time is comparable with the computation time of an FFT-algorithm combined with zero-framing ... [more ▼]

An alternative algorithm for the computation of diffraction (Fourier) integrals is described. Its computation time is comparable with the computation time of an FFT-algorithm combined with zero-framing. On the other hand it allows a free choice of resolution, as in numerical integration. The features of this algorithm are illustrated on the calculation of a PSF of an aberrated lens. [less ▲]

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See detailEfficient lipofection of human trophoblast cells in primary cultures
Jacquemin, P.; Alsat, E.; Oury, Cécile ULg et al

in Biochemical and Biophysical Research Communications (1993), 196(1), 376-81

Human choriosomatomammotropic hormone, also known as placental lactogen, is expressed in syncytiotrophoblast cells of the placenta. Studying transcriptional regulation of the genes coding for this hormone ... [more ▼]

Human choriosomatomammotropic hormone, also known as placental lactogen, is expressed in syncytiotrophoblast cells of the placenta. Studying transcriptional regulation of the genes coding for this hormone, we became interested in transfecting primary cultures of these trophoblast cells. In this study, we show that it is possible to transfect, by the lipofection method, these giant cells in an efficient and reproducible manner. We show the presence of an enhancer region downstream from the hCS-B gene, functionally active in these cells; furthermore, we demonstrate the placenta-specific characteristic of this enhancer, previously identified in a human choriocarcinoma cell line. [less ▲]

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See detailEfficient mesh management in Eulerian-Lagrangian formulation
Ponthot, Jean-Philippe ULg

in Proceedings of NUMIFORM'89, Numerical Methods in Industrial Forming Processes (1989)

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See detailEfficient method for a controlled deposition of Pd nanoparticles on a glassy carbon electrode
Olu, Pierre-Yves; Chatenet, Marian; Job, Nathalie ULg

Poster (2014)

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See detailAn efficient method for the regeneration of wheat (Triticum aestivum) from anther cultures.
Zhang, Lihong ULg; Anceau, Christine ULg; Lepoivre, Philippe ULg et al

in Bulletin des Recherches Agronomiques de Gembloux (1987), 22(4),

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See detailAn efficient method to generate data and compute exact P-values in goodness-of-fit testing
Magis, David ULg

in Communications in Statistics : Simulation & Computation (2008), 37

In this article, we use a characterization of the set of sample counts that do not match with the null hypothesis of the test of goodness of fit. Two direct applications arise: first, to instantaneously ... [more ▼]

In this article, we use a characterization of the set of sample counts that do not match with the null hypothesis of the test of goodness of fit. Two direct applications arise: first, to instantaneously generate data sets whose corresponding asymptotic P-values belong to a certain pre-defined range; and second, to compute exact P-values for this test in an efficient way. We present both issues before illustrating them by analyzing a couple of data sets. Method’s efficiency is also assessed by means of simulations. We focus on Pearson’s X2 statistic but the case of likelihood-ratio statistic is also discussed. [less ▲]

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