References of "Léonard, Angélique"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailThe use of tomography to determine the kinetics of water vapour adsorption
Lodewyckx, Peter; Léonard, Angélique ULg; Blacher, Silvia ULg

in Proceedings of Carbon 2005 – The International Carbon Conference (2005, July)

Detailed reference viewed: 7 (2 ULg)
Full Text
Peer Reviewed
See detailImage analysis of X-ray microtomograms of soft materials during convective drying: 3D measurements
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Journal of Microscopy-Oxford (2005), 218(Pt 3), 247-252

Drying dewatered sludge leads to a complex three-dimensional porous structure. Moreover, this operation is dependent on the way the material is processed. In this study, textural changes of sludge ... [more ▼]

Drying dewatered sludge leads to a complex three-dimensional porous structure. Moreover, this operation is dependent on the way the material is processed. In this study, textural changes of sludge extrudates submitted to convective drying are followed by a 3D image analysis of reconstructed X-ray microtomograms. To achieve this goal, two different wastewater sludges collected in wastewater treatment plant after the thickening step and dewatered in the laboratory are used. It is showed that the evolution of the 3D-crack ratio vs. the residual water content evolves following a hyperbolic law. The 3D opening crack size distribution reveals two different types of pore development, i.e. a continuous pore size evolution for one sludge and the sudden appearance of cracks for the other sludge. [less ▲]

Detailed reference viewed: 52 (6 ULg)
Full Text
See detailProduction of resorcinol formaldehyde xerogels by convective drying
Léonard, Angélique ULg; Jomaa, Wahbi; Crine, Michel ULg

in Proceedings of the joint conference of AFSIA (Association Française pour le Séchage dans l’Industrie et l’Agriculture) and Working group on Drying of EFCE at INA P-G, Paris, 12th and 13th May, 2005 (2005, May)

Detailed reference viewed: 17 (0 ULg)
Full Text
See detailEffect of back mixing during convective drying of wastewater sludges
Léonard, Angélique ULg; Meneses, Eustedio; Salmon, Thierry ULg et al

in Proceeedings of the joint of AFSIA (Association Française de Séchage dans l'Industrie et l'Agriculture) and Working group on Drying of EFCE at INA P-G, Paris, 12th and 13th May, 2005 (2005, May)

Detailed reference viewed: 12 (1 ULg)
Full Text
Peer Reviewed
See detailMoisture profiles determination during convective drying using x-ray microtomography
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Canadian Journal of Chemical Engineering (2005), 83(1), 127-131

The knowledge of internal moisture profiles which develop during drying is essential for model validation purposes, but they are difficult to determine experimentally. This paper shows that X-ray ... [more ▼]

The knowledge of internal moisture profiles which develop during drying is essential for model validation purposes, but they are difficult to determine experimentally. This paper shows that X-ray microtomography, together with image analysis, provides an accurate, non destructive and easy to use technique to determine moisture profiles. Results reported concern the drying of wastewater sludges whose management is becoming a real environmental challenge. An analysis of the development of moisture gradients at the sample external wall shows an influence of drying operating conditions. Finally, mass diffusion coefficients are estimated from the knowledge of both the moisture gradients and the drying flux. [less ▲]

Detailed reference viewed: 42 (13 ULg)
Peer Reviewed
See detailX-ray microtomography coupled with image analysis: a useful tool for 3D characterization of polymer foams
Blacher, Silvia ULg; Kerckhofs, Greet ULg; Caliberg, Cédric et al

in Proceedings of Imageries et polymères 2005 (2005)

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailConvective drying of wastewater sludges: Influence of air temperature, superficial velocity, and humidity on the kinetics
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Drying Technology (2005), 23(8), 1667-1679

The influence of air temperature, velocity, and humidity during convective drying of two different sludges (A and B) is investigated through a 3 3 factorial design. For sludge A, a constant drying flux ... [more ▼]

The influence of air temperature, velocity, and humidity during convective drying of two different sludges (A and B) is investigated through a 3 3 factorial design. For sludge A, a constant drying flux period is observed, while sludge B is characterized by a long decreasing drying flux phase. A sensitivity analysis shows that temperature is the main operating parameter affecting the drying kinetics. Mass and heat transfer coefficients as well as water evaporation capacities are calculated from drying curves. Transfer coefficients are related to operating conditions through dimensionless relations. For both sludges, a linear relation is found between water evaporation capacity and the maximal measured drying flux. [less ▲]

Detailed reference viewed: 83 (10 ULg)
Full Text
Peer Reviewed
See detailWastewater sludge convective drying: Influence of sludge origin
Léonard, Angélique ULg; Vandevenne, P.; Salmon, Thierry ULg et al

in Environmental Technology (2004), 25(9), 1051-1057

This paper deals with thermal drying of wastewater sludges, whose management will become crucial in the forthcoming years. Sludges collected after mechanical dewatering in 5 different WWTPs are submitted ... [more ▼]

This paper deals with thermal drying of wastewater sludges, whose management will become crucial in the forthcoming years. Sludges collected after mechanical dewatering in 5 different WWTPs are submitted to the same convective drying treatment in order to try finding some relations between the drying behaviours, the type of effluent and wastewater treatments. Results show clearly sludge drying remains a particularly complex operation because sludges may exhibit very different behaviours, both from kinetic and texture points of view. Initial moisture content and global composition are not sufficient to explain the different observed behaviours. It is too early to claim one or another type of water treatment has an influence on the drying behaviour. However, the drying rates can be classified in the inverse order of the organic content. Moreover for sludges at the same siccities, the harder the material (rheological properties), the higher the drying rate. Final textural properties can be related to the rheological properties and the internal diffusion limitations lowering the drying intensity. [less ▲]

Detailed reference viewed: 78 (12 ULg)
See detailImage reconstruction in X-ray tomography
Toye, Dominique ULg; Fransolet, Emmanuelle; Léonard, Angélique ULg et al

Scientific conference (2004, August)

Detailed reference viewed: 16 (7 ULg)
See detailComputed Tomography at the University of Liège – Chemical Engineering Laboratory
Toye, Dominique ULg; Fransolet, Emmanuelle; Léonard, Angélique ULg et al

Scientific conference (2004, August)

Detailed reference viewed: 12 (3 ULg)
See detailComputed X-ray tomography investigations in packed beds
Toye, Dominique ULg; Fransolet, Emmanuelle; Léonard, Angélique ULg et al

Scientific conference (2004, August)

Detailed reference viewed: 15 (5 ULg)
See detailElectrical tomography investigation in bubble columns
Toye, Dominique ULg; Fransolet, Emmanuelle; Léonard, Angélique ULg et al

Scientific conference (2004, August)

Detailed reference viewed: 10 (2 ULg)
Full Text
Peer Reviewed
See detailImage analysis of X-ray microtomograms of Pd-Ag/SiO2 xerogel catalysts supported on Al2O3 foams
Blacher, Silvia ULg; Léonard, Angélique ULg; Heinrichs, Benoît ULg et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2004), 241(1-mars Sp. Iss. SI), 201-206

In order to preshape and mechanically strengthen, Pd-Ag/SiO2 xerogel catalysts were carried out in Al2O3 foams (pore-sizes similar to40 mum). The final material consists of a Pd-Ag/SiO2 xerogel ... [more ▼]

In order to preshape and mechanically strengthen, Pd-Ag/SiO2 xerogel catalysts were carried out in Al2O3 foams (pore-sizes similar to40 mum). The final material consists of a Pd-Ag/SiO2 xerogel immobilized in the open cells of the alumina foam. The localization of the xerogel catalyst in alumina foams of various pore structure was studied by X-ray microtomography. The three-dimensional (3D) porous structure was reconstructed from the consecutive cross-sections obtained by this technique. Total porosity, porous density distribution, and pore-size distribution were determined by image analysis on the free and impregnated supports. Our results show that the success of the used impregnation technique depends on the pore structure of the support. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 49 (10 ULg)
Full Text
Peer Reviewed
See detailMeasurement of shrinkage and cracks associated to convective drying of soft materials by X-ray microtomography
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Drying Technology (2004), 22(7), 1695-1708

Traditionally, the measurement of shrinkage occurring during drying is performed by destructive or poorly accurate techniques such as volume displacement methods. Cracks detection and quantification are ... [more ▼]

Traditionally, the measurement of shrinkage occurring during drying is performed by destructive or poorly accurate techniques such as volume displacement methods. Cracks detection and quantification are realised either by destructive techniques or sophisticated but expensive nondestructive ones (NMR imaging). X-ray microtomography in combination with image analysis provides an accurate, nondestructive and easy to use technique to determine simultaneously shrinkage and crack extent. Results reported in this article concern drying of wastewater sludges whose management will become a real challenge in the years to come. These results show a clear relation between drying kinetics and crack development. This could be related to the development of internal diffusional limitations inducing moisture gradients and mechanical stresses leading to cracks formation. [less ▲]

Detailed reference viewed: 54 (12 ULg)