References of "Léonard, Angélique"
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See detailWEEE management using LCA methodology : the fridge case study
Belboom, Sandra ULg; Renzoni, Roberto ULg; Deleu, Xavier et al

Poster (2011, March 01)

This study is based on WEEE life cycle assessment and more particularly on treatment and valorization of fridges and freezers. Two scenarios were envisaged: situation before fridge collect and the Belgian ... [more ▼]

This study is based on WEEE life cycle assessment and more particularly on treatment and valorization of fridges and freezers. Two scenarios were envisaged: situation before fridge collect and the Belgian current situation where all national fridges are treated in Liège. Results of this study prove the importance of collecting and valorizing fridges especially for old fridges containing refrigerant banned by the Montreal Protocol. Recovery and incineration of the pollutants permit to reduce climate change and ozone depletion impacts. [less ▲]

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See detailWEEE management using LCA methodology : the fridge case study
Belboom, Sandra ULg; Renzoni, Roberto ULg; Deleu, Xavier et al

in SETAC Europe 17th LCA Case Studies Symposium : "Sustainable lifestyles", Budapest 28 February - 1 March 2011 (2011, March)

This study is based on WEEE life cycle assessment and more particularly on treatment and valorization of fridges and freezers. Two scenarios were envisaged: situation before fridge collect and the Belgian ... [more ▼]

This study is based on WEEE life cycle assessment and more particularly on treatment and valorization of fridges and freezers. Two scenarios were envisaged: situation before fridge collect and the Belgian current situation where all national fridges are treated in Liège. Results of this study prove the importance of collecting and valorizing fridges especially for old fridges containing refrigerant banned by the Montreal Protocol. Recovery and incineration of the pollutants permit to reduce climate change and ozone depletion impacts. [less ▲]

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See detailANALYSING THE SOIL STRUCTURE UNDER DIFFERENT TILLAGE SYSTEMS USING X-RAY MICROTOMOGRAPHY AND PF CURVES
Beekkerk van Ruth, Jöran ULg; Degre, Aurore ULg; Aubinet, Marc ULg et al

Poster (2011, February 23)

Assessing soil structure is primordial when comparing tillage systems. Whilst most conventional techniques characterize global parameters, X-ray microtomography allows a characterization of the poral ... [more ▼]

Assessing soil structure is primordial when comparing tillage systems. Whilst most conventional techniques characterize global parameters, X-ray microtomography allows a characterization of the poral space at a µm-scale. These results, combined with data from pF curves, can form a solid basis in order to quantify soil physical fertility. Soil samples were taken from the organic topsoil on two Belgian experimental sites implementing both conventional tillage (CT, ploughing) and simplified tillage (ST, superficial works), without straw restitution: Gentinnes, Brabant Wallon (March 2010), and Gembloux, Namur (November 2010). On the Gentinnes site (Aba(b)1), CT and ST have been implemented since October 2005, with a beet/winter wheat rotation. On the Gembloux site (Aba(b)), CT and ST have been implemented since September 2008, with a winter wheat cultivation since end 2009. Tomography (10 samples for Gentinnes, 8 for Gembloux) and pF curves (10 samples for Gentinnes, 14 for Gembloux) were used for analysis. Pressure pans were used in order to obtain the pF curves on 100 cm³ undisturbed samples. Soil cores (3 cm diameter, 5 cm height) were scanned using a Skyscan-1172 µ-CT device. The conical beam, operating at 100 kV, produced images having a 17µm pixel size, using a 16-bit 1048×2000 pixels camera equipped with an aluminium filter. The raw images were then treated under Matlab® for binarization, using a thresholding loop to fit the measured and the calculated porosity of each sample (Beckers et al, 2011). The 2D binary images were then analyzed under Matlab® and Skyscan™ CT-analyzer. On the site of Gentinnes, pF analysis showed a greater available water content (between pF 4.2 and 2.5) for ST, and a greater efficient porosity (between saturation and pF 2.5) for CT. The differences in available water content, although not significant, were confirmed by site observation. Tomography analysis yielded the following: under ST, the pores are smaller and the anisotropy less developed. As for the poral connectivity, it was found greater in CT. On the site of Gembloux, however, no significant differences were found between the tillage systems concerning the pF curves. Tomography analysis showed smaller pores for simplified tillage, but the differences deduced by the tomographic analysis of the Gentinnes samples concerning connectivity and anisotropy were not found in this case. To conclude, from the results, the soil structure is found to differ between CT and ST. The pores tend to be smaller and less oriented in ST, whilst in CT pores are more connected. Soils undergoing a CT show a greater efficient porosity, whilst soils under ST display a greater available water content. However, these differences were mostly spotted on the Gentinnes site: in Gembloux, the differences between the samples were less marked. This could be due to the fact that the soil did not have time to differentiate yet (less than 3 years of tillage differentiation). More sampling is needed in any case before inferring general conclusions from these observations. A further analysis of the soil images, especially concerning pore orientation, will be done in order to fully exploit the tomography results. [less ▲]

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See detailA life cycle assessment of injectable drug primary packaging: comparing the traditional process in glass vials with the closed vial technology (polymer vials)
Belboom, Sandra ULg; Renzoni, Roberto ULg; Verjans, Benoît et al

in International Journal of Life Cycle Assessment (2011), 16(2), 159-167

This study compares environmental impacts of two primary packaging alternatives used for injectable drugs: the traditional method based on glass vials and the method developed by Aseptic Technologies ... [more ▼]

This study compares environmental impacts of two primary packaging alternatives used for injectable drugs: the traditional method based on glass vials and the method developed by Aseptic Technologies based on polymer vials. A critical review by an external LCA expert was made. [less ▲]

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See detailA non-linear homogeneous model for bone-like materials under compressive load.
Mengoni, Marlène ULg; Voide, Romain; Toye, Dominique ULg et al

in Nithiarasu, P.; Löhner, R.; van Loon, R. (Eds.) et al Conference Proceedings - 2nd International Conference on Computational & Mathematical Biomedical Engineering (2011)

Using morphological data provided by computed tomography, finite element (FE) models can be used to compute the mechanical response of bone and bone-like materials without describing the complex local ... [more ▼]

Using morphological data provided by computed tomography, finite element (FE) models can be used to compute the mechanical response of bone and bone-like materials without describing the complex local microarchitecture. A constitutive law is here developed and proposed for this purpose. It captures the non-linear structural behavior of bone-like materials through the use of fabric tensors. It also allows for irreversible strains using a plastic material model, allowing hardening of the yield parameters. These characteristics are expressed in a constitutive law based on the anisotropic continuum damage theory coupled with isotropic elastoplasticity in a finite strains framework. This law is implemented into Metafor, a non-linear FE software. Simulations of cylindrical samples undergoing stepwise compression are presented. [less ▲]

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See detailBone regeneration using porous titanium particles vs. bovine hydroxyapatite: a sinus lift study in rabbits
LAMBERT, France ULg; LECLOUX, Geoffrey ULg; Léonard, Angélique ULg et al

Poster (2011)

Background: The use of porous titanium particles as space filling biomaterials for intraoral bone regeneration might be of interest because of both the mechanical stability and nonresorbable properties ... [more ▼]

Background: The use of porous titanium particles as space filling biomaterials for intraoral bone regeneration might be of interest because of both the mechanical stability and nonresorbable properties. Titanium particles were recently described for bone regeneration in sinus lifts and in the treatment of periimplantitis. Nevertheless, tissue integration and 3D bone regeneration with titanium particles were poorly explored in these previous reports. Aim: The first objective of this study was to qualitatively and quantitatively assess the bone formation process, particularly the long-term behavior and 3D volume stability of subsinusal bone regeneration, using titanium or bovine hydroxyapatite granules, in a rabbit model. The second objective was to evaluate the effect of the hydration of the BHA particles with a therapeutic concentration of doxycycline solution on the osteogenesis and biomaterial resorption. Methods: Rabbits underwent a double sinus lift procedure using one of three materials: grade 1 porous titanium particles (Ti), bovine hydroxyapatite (BHA) or chemically modified bovine hydroxyapatite (BHATTC). Animals were sacrificed after 1 week, 5 weeks or 6 months. Samples were analyzed using mCT and nondecalcified histology. Results: The materials used in each of the three groups allowed an optimal bone formation; bone quantities and densities were not statistically different between the three groups. At 6 months, more stable 3D volume stability was found with TI and BHATTC (P¼0.0033). At 5 weeks and 6 months, bone to material contact (BMC) corroborating osteoconduction was significantly higher with BHA and BHATTC than with Ti (P < 0.0001). Conclusions and clinical implications: Even though the studied biomaterials displayed different architectures, they are relevant candidates for sinus lift bone augmentation before dental implants because they allow adequate 3D stability and osteogenesis. However, to recommend the clinical use of Ti, both an observation on the drilling effects of Ti particles and clinical trials are needed. [less ▲]

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See detailEvolution of municipal waste management in Belgium (Liège) for the last thirty years
Belboom, Sandra ULg; Renzoni, Roberto ULg; Digneffe, Jean-Marc et al

in SETAC Europe 17th LCA Case Studies Symposium : "Sustainable lifestyles", Budapest 28 February - 1 March 2011 (2011)

Waste is considered as a major concern of our century. Management tools were provided to help municipalities to reduce their emissions and to find the best way to valorize their waste. Life cycle ... [more ▼]

Waste is considered as a major concern of our century. Management tools were provided to help municipalities to reduce their emissions and to find the best way to valorize their waste. Life cycle assessment methodology was used jointly by the University of Liège and by Intradel, inter-municipal of the region of Liège (Belgium) to evaluate the impact of their activities and their improvement through years. [less ▲]

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See detailSynthesis, characterization and photocatalytic properties of alkali metals doped tin dioxide
Benhebal, Hadj; Chaib, Messaoud; Léonard, Angélique ULg et al

in Journal of Molecular Structure (2011), 1004(1-3), 222-226

In order to improve the photocatalytic properties of tin dioxide, crystallized powders of SnO(2) photocatalysts doped by alkali metals (Li, Na and K) were synthesized by sol-gel process. The physical ... [more ▼]

In order to improve the photocatalytic properties of tin dioxide, crystallized powders of SnO(2) photocatalysts doped by alkali metals (Li, Na and K) were synthesized by sol-gel process. The physical properties of these materials were characterized by X-ray diffraction, nitrogen adsorption-desorption, Scanning electron microscopy and Ultraviolet-visible diffuse reflection spectroscopy. The photocatalytic tests under UV radiation conducted on four aromatic compounds (phenol, paranitrophenol, pentachlorophenol and benzoic acid) showed that tin dioxide modified by sodium possesses good photocatalytic activity; The Li-doped SnO(2) is moderately active, while modification by potassium does not improve this activity. (C) 2011 Elsevier B.V. All rights reserved. [less ▲]

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See detailÉvolution de l’impact environnemental lié à la gestion des déchets ménagers en Belgique (Liège) durant les trente dernières années
Belboom, Sandra ULg; Renzoni, Roberto ULg; Digneffe, Jean-Marc et al

in SFGP (Ed.) Récents Progrès en Génie des Procédés (2011)

The goal of this study was to evaluate the improvement of waste management through the last thirty years. Four steps of time and of technologies of waste treatment were evaluated. The first scenario is ... [more ▼]

The goal of this study was to evaluate the improvement of waste management through the last thirty years. Four steps of time and of technologies of waste treatment were evaluated. The first scenario is situated before 1970 with waste landfilling without recuperation and valorization of gas. The second one considers the situation between 1990 and 2009 with a unit comprising grinding and sorting of waste to obtain fluff which was burnt in an incinerator, remaining waste being sent to sanitary landfill with recuperation and valorization of gas. The third one is the current one, in operation since 2009, with incineration of the whole of the residual municipal waste. The last scenario is about future considering the current installation and adding a biomethanation of the biodegradable fraction of household waste. Main result of this study is the improvement through years starting from the important environmental impact of landfilling to a negative impact with the current installation coupled with biomethanation. Global warming impact from the eighties was reduced by 4 in the years 1990-2008, by 6 for the current scenario alone or coupled with a biomethanation plant. Valorization of electricity is helpful to reduce consumptions of fuels and associated impacts. This study confirms the improvement of technologies and emissions of waste management through years. [less ▲]

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See detailSustainable and Innovative Solutions for Sewage Sludge Management
Spinosa, Ludovico; Ayol, Azize; Baudez, Jean-Christophe et al

in Water (2011), 3(2), 702-717

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See detailThree-dimensional void space structure of activated carbon packed beds
Almazan Almazan, Maria Del Carmen; Léonard, Angélique ULg; Job, Nathalie ULg et al

in Journal of Porous Materials (2011), 18

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See detailInfluence of carbon xerogel textural properties on the dynamic adsorption of methyl iodide
Almazán-Almazán, M. C.; López-Domingo, F. J.; Domingo-García, M. et al

in Chemical Engineering Journal (2011), 173(1), 19-28

X-ray microtomography coupled to image analysis has been used to study the influence of the adsorbent pore texture and the experimental conditions on the dynamic adsorption of methyl iodide in packed ... [more ▼]

X-ray microtomography coupled to image analysis has been used to study the influence of the adsorbent pore texture and the experimental conditions on the dynamic adsorption of methyl iodide in packed filters. By applying this imaging technique the internal axial adsorption profiles for increasing exposure times to the gas stream are analysed. This experimental technique establishes a new technology to study in situ the dynamic adsorption of volatile compounds. Resorcinol-formaldehyde based carbon xerogels have been used as adsorbents, as their pore texture can be tuned by changing the synthesis conditions. The textural characteristics of the adsorbents (surface areas and pore volumes) have been assessed by using nitrogen and carbon dioxide adsorption as well as mercury porosimetry. The methyl iodide dynamic adsorption results show that, for the same gas flow rate and CH3I inlet concentration, the adsorbed amount is highly dependent on large pore volumes. Thus, samples with almost the same micropore volumes (adsorption volumes) have different methyl iodide adsorption capacities, which are related to, the above mentioned, large pores. The influence of both the gas carrier flow rate and the methyl iodide inlet concentration on the adsorption can be explained using the so-called linear driving force model. This approach takes into account the fact that internal transport limitations are directly related to the pore texture. Moreover, the simulation of the dynamic adsorption process has allowed relating the simulated axial concentration profiles to the experimental X-ray microtomography data. [less ▲]

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See detailEtude expérimentale et modélisation du séchage de boues générées par l’épuration des eaux usées
Bennamoun, Lyes; Léonard, Angélique ULg

in Revue des Energies Renouvelables (2011), 14(1), 1-12

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See detailImpact of Storage Duration on the Gaseous Emissions during Convective Drying of Urban Residual Sludges
Fraikin, Laurent ULg; Salmon, Thierry ULg; Herbreteau, B. et al

in Chemical Engineering and Technology (2011), 34(7), 1172--1176

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See detailUnderstanding and preventing structural changes during drying of gels
Metzger, T.; Léonard, Angélique ULg; Jomaa, W. et al

in Tsotsas, E.; Mujumdar, A. S. (Eds.) Modern Drying Technology, Vol 3. Product quality and formulation (2011)

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See detailManagement of Wastewater Sludge's: A Hot Topic at the European Level
Léonard, Angélique ULg

in Journal of Residuals Science and Technology [=JRST] (2011), 8(2), 38-38

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See detailLife cycle assessment as decision tool for sustainable choices in mineral materials field: environmental declarations of Belgian products and their foreign equivalents
Belboom, Sandra ULg; Renzoni, Roberto ULg; Léonard, Angélique ULg et al

in Martens, Per Nicolai (Ed.) Sustainable Development in the Minerals Industry : Institute of Mining Engineering I, RWTH Aachen University, 14-17 June 2011 (2011)

Construction is a field which is concerned by environment. Tools as environmental product declarations are increasingly often used to compare several products and to take account of the environmental ... [more ▼]

Construction is a field which is concerned by environment. Tools as environmental product declarations are increasingly often used to compare several products and to take account of the environmental sphere in the choice. Environmental declarations of Belgian bluestone and sandstone products were realized in accordance with the ISO standards and following the standard NF P 01-010. The main goals of these studies were to obtain Belgian environmental product declarations to strengthen existing databases and to provide defences against Asian competition. Indeed, competition with China for bluestone products and with India for sandstone pavement is very important due the fact of the very competitive prices for foreign products. The impacts on climate change, resources and acidification of the sole transport were taken into account for foreign products and they are at less as important as these obtained for the whole life cycle of Belgian products. [less ▲]

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See detailInfluence of space-filling materials in subantral bone augmentation: blood clot vs. autogenous bone chips vs. bovine hydroxyapatite
Lambert, France ULg; Léonard, Angélique ULg; Drion, Pierre ULg et al

in Clinical Oral Implants Research (2011), 22(5), 538-545

Aim: The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective ... [more ▼]

Aim: The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective was to assess qualitatively and quantitatively the early bone formation process and long-term behavior of the regenerated bone. Materials and methods: Fifteen rabbits underwent a double sinus lift procedure using: blood clot (Clot), autogenous bone chips (Auto) and bovine hydroxyapatite (BHA). Animals were euthanized at 1 week, 5 weeks and 6 months. Samples were subjected to X-ray microtomography and histology. Variations in the volume of bone augmentations were calculated at different time points. Qualitative analysis was performed using 7 μm sections and quantitative histomorphometric analyses were carried out using scanning electron microscopy. Results: From baseline (100%) to 5 weeks, the augmented volumes declined to 17.3% (Clot), 57.6% (Auto) and 90.6% (BHA). After 6 months, only 19.4% (Clot) and 31.4% (Auto) of initial volumes were found, while it remained more stable in the BHA group (84%). At 1 week, an initial osteogenesis process could be observed in the three groups along the bone walls. At 5 weeks, despite a significant decline in the volume, newly formed bone density was higher with Clot and Auto than with BHA. At 6 months, bone densities were statistically similar in the three groups. However, after 6 months, the surface invaded by newly formed bone (regenerated area) was significantly higher when BHA was used as space filler. In the BHA group, the biomaterial area slightly decreased from 42.7% (1 week) to 40% (5 weeks) and 34.9% (6 months) and the density of the composite regenerated tissue (bone+BHA) reached >50% at 6 months. Conclusions and clinical implications: The three space fillers allowed bone formation to occur. Nevertheless, augmented volumes declined in the Clot and Auto groups, while they remained stable with BHA. A slowly resorbable biomaterial might be suitable in sub-sinusal bone augmentation for preventing the re-expansion process and for augmenting the density of the regenerated tissues. [less ▲]

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See detailVecteurs énergétiques et énergies renouvelables
Léonard, Angélique ULg

Learning material (2011)

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See detailImpact of thresholding techniques on X-ray soil microtomogram analyses
Beckers, Eléonore ULg; Léonard, Angélique ULg; Beekkerk van Ruth, Jöran ULg et al

in Geophysical Research Abstracts (2011), 13

Using X-ray microtomography, 3D soil structure can be visualised and analysed through useful factors like pore size distribution, shape, connectivity, orientation, etc. X-ray scans yield grey-level 2D ... [more ▼]

Using X-ray microtomography, 3D soil structure can be visualised and analysed through useful factors like pore size distribution, shape, connectivity, orientation, etc. X-ray scans yield grey-level 2D images, which can be recombined to form 3D structures. Treatments of the grey-level images can consist of either a binarization -distinguishing soil and pores- or a permeability level attribution directly linked to the grey-level values. The latter leads to problems in order to assign a permeability for each point (in soil a same grey level value can be assigned to points with a different permeability), as well as to analyse the 3D structure. On the other hand, treatment of black and white 3D structures is well-handled. However, the impact of the choice of one thresholding technique on the resulting images has already been demonstrated. Moreover, thresholding methods are various and numerous. Many of them are based on the image histogram analysis. But because of the soil complexity, the relevance of these techniques becomes debatable, with a risk of producing non reliable images. We propose to palliate this with a simple new algorithm based on physical measurements: it uses a loop fixing the threshold value in order to match the measured porosity for each sample. In this communication, our point is to highlight the impact of different thresholding techniques on the analysis and interpretation of our soil microtomograms. The underlying questions could be: Does the thresholding method influence our conclusions? Are the results depending on the sample itself or on the methodology? In order to answer these questions we tested the Otsu technique and our physically based algorithm. Soils samples were removed from the upper layer (Ap horizon) of a silty soil (Gentinnes, Brabant Walloon, Belgium) in plots with different management practices. In fact, since 2004, the field has been cultivated in conventional tillage (CT) or reduced tillage (RT). In order to empty the meso- and macroporosity, samples were placed under a 1.5 MPa pressure (Richards apparatus). Samples were then scanned by X-ray microtomography using a Skyscan-1172 high-resolution desktop micro-CT system (Skyscan, Kontich, Belgium). The cone beam source operated at 100 kV, using an aluminium filter. The detector configuration, i.e. 1048x2000 pixels with a 16-bit X-ray camera, and the distance source-object-camera were adjusted to produce images with a pixel size of 17 µm. Porosity was measured for each scanned sample. Then the threshold methods -the Otsu technique on one hand and our developed algorithm on the other - were applied, and morphological factors were calculated for both methods. A comparison of the first results shows a threshold influence on average porosity and number of pores, but also on connectivity factors and size distribution. The apparent porosity of the images, as well as connectivity, is underestimated with the Otsu technique. Despite the fact that the changes induced by thresholding are more important for RT than CT, global conclusions about the comparison of these agricultural practices are approximately the same in this case. However, differences between tillage systems are less important with the Otsu method, confirming the impact of choosing the adapted threshold method. [less ▲]

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