References of "Plougonven, Erwan"
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See detailCan the pore scale geometry explain soil sample scale hydrodynamic properties?
Smet, Sarah ULiege; Beckers, Eléonore ULiege; Plougonven, Erwan ULiege et al

in Frontiers in Environmental Science (2018), 6(20),

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See detailStructures macroscopique et microscopique et formation des aegagropiles de Posidonia oceanica (L.) Delile (1813)
Lefebvre, Laurence ULiege; Gobert, Sylvie ULiege; Compère, Philippe ULiege et al

Poster (2018, April 11)

Il est courant de retrouver le long de plages de Méditerranée des agglomérations de débris végétaux originaire de l’herbier à Posidonies. Ces agglomérats portent le nom d’aegagropiles de P. oceanica ... [more ▼]

Il est courant de retrouver le long de plages de Méditerranée des agglomérations de débris végétaux originaire de l’herbier à Posidonies. Ces agglomérats portent le nom d’aegagropiles de P. oceanica , ceux-ci arborent des formes sphériques et ellipsoïdes. Les objectifs principaux de ce travail étaient d’identifier les différents composants des aegagropiles de P. oceanica et de déterminer la formation de ceux-ci. Pour ce faire, différentes analyses microscopiques (MET, MEB et MO) ont été effectuées ainsi que l’usage d’un mécanisme simulant la houle. Les observations en microscopie électronique à balayage ont été réalisées à l’aide de différents détecteurs (SSD et ETD) de SE et BSE, ce qui additionnés à diverses techniques de colorations et de contrastants ont permis de répondre à de nombreux objectifs. Les aegagropiles se forment par l’hydrodynamisme qu’engendre la houle et se composent d’un assemblage de débris végétaux provenant de P. oceanica ainsi que de grains de sable. Au fil des différentes étapes du cycle de la plante et de l’hydrodynamisme, les organes de la plante se rompent, s’accumulent au sein de la litière et subissent une combinaison de dégradations biotique et abiotique. Ces organes sont majoritairement des feuilles et des morceaux de rhizomes. La dégradation biotique est notamment engendrée par des champignons noirs septés nommés « Dark Septate Endophyte - DSE » qui, en s’attaquant spécifiquement à la lamelle mitoyenne des cellules permet des scissions longitudinales. La dégradation abiotique est quant à elle engendrée par les forces hydrodynamiques. Cette combinaison entraîne dès lors un lessivage important des différents organes végétaux qui se scindent et se courbent formant finalement de fines « fibres » qui s’accumuleront et s’entremêleront ensemble des ripples-marks afin d’élaborer des aegagropiles de P. oceanica. Les aegagropiles de P. oceanica se formeront initialement avec des débris intacts de rhizomes ou bien avec des faisceaux de fibres lignifiés ronds provenant également de ces rhizomes où de nombreux grains de nature minérale s’enchevêtreront à ces débris végétaux afin de constituer une structure initiale consolidée et résistante. Ensuite, d’autres débris végétaux, majoritairement de formes plates et provenant des feuilles et de gaines foliaires de P. oceanica , s’entremêleront à cette structure afin d’obtenir une agrégation allongée. Enfin, via une fragmentation aléatoire et des mouvements suivant préférentiellement une direction, des aegagropiles de P. oceanica de formes majoritairement ellipsoïdales s’échoueront le long des plages. [less ▲]

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See detailComprehensive study of the drying behavior of Boom clay:Experimental investigation and numerical modeling
Hubert, Julien ULiege; Plougonven, Erwan ULiege; Prime, Noémie et al

in International Journal for Numerical and Analytical Methods in Geomechanics (2018)

This paper presents a thermo-hydro-mechanical framework to model the dryingbehavior of Boom clay. First, the experimental campaign conducted Noémie Primeis briefly presented because it is used to validate ... [more ▼]

This paper presents a thermo-hydro-mechanical framework to model the dryingbehavior of Boom clay. First, the experimental campaign conducted Noémie Primeis briefly presented because it is used to validate the model. The data acquisitionand processing is emphasized because of the use of X-ray microtomography to beable to more accurately compare experimental and numerical strain fields. The dif-ferent submodels are introduced. Numerical simulations are performed to illustratethe capability of the proposed model to reproduce the observed behavior. Finally,a comprehensive sensitivity study on several key model parameters associated withthe water retention curve, and the permeability of the medium, is performed to get abetter understanding of the physics behind the coupled model. [less ▲]

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See detailConvective drying : experimental campaign and numerical modelling
Hubert, Julien ULiege; Plougonven, Erwan ULiege; Léonard, Angélique ULiege et al

Conference (2017, June 19)

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See detailDynamic of soil drying close to saturation: What can we learn from a comparison between X-ray computed microtomography and the evaporation method?
Parvin, Nargish ULiege; Beckers, Eléonore ULiege; Plougonven, Erwan ULiege et al

in Geoderma (2017), 302

The soil water retention curve (SWRC) is a unique relationship between water content and soil water potential. SWRC in near saturation gives the dimension of soil macroporosity which plays an important ... [more ▼]

The soil water retention curve (SWRC) is a unique relationship between water content and soil water potential. SWRC in near saturation gives the dimension of soil macroporosity which plays an important role in water translocation into soil. Thus, the accurate measurement of SWRC is crucial. The aim of this study is to compare SWRC obtained through two different methods: X-ray computed microtomography (X-ray CT) and evaporation method by HYPROP device. Three different depths (0–10, 25–30 and 45–60 cm) are considered for soil sampling. The results showed significant differences in SWRC between the techniques. The SWRC from X-ray CT showed more volumetric water content at 25–30 cm (0.044) and 45–60 cm (0.024) than evaporation at saturation (0 kPa) in cases where the macroporosity was higher. Macropores may have connections with neighbouring pores of smaller sizes. Hence we assume that these pores can be observed through X-ray CT but cannot be evaluated by evaporation. As macropores with narrow opening do not evaporate at very low tension. These pores therefore got empty at relatively higher tension. Consequently, SWRC near saturation appeared rather flatter with the evaporation method where the X-ray CT presented deviation. Accordingly, interpretation of macro pores from SWRC through evaporation method would give comparatively smaller volume of macropores than they really are. Pore morphology and other hydraulic functions of soil, for example, mean connection surface of pores, hydraulic conductivity, and the efficiency of water conducting macropores also support the X-ray CT findings. [less ▲]

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See detailInfluence of sawdust addition on drying of wastewater sludges: Comparison of structural characteristics
Li, Jie; Plougonven, Erwan ULiege; Fraikin, Laurent ULiege et al

in Drying Technology (2017), 35(8), 925-932

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See detailAccurate measurement of radius evolution as a function of direction in 3D images
Plougonven, Erwan ULiege; Hubert, Julien ULiege; Collin, Frédéric ULiege et al

Poster (2016, May 11)

Very often the reason for using of X-Ray tomography in a research project is to measure the evolution of some geometrical characteristic. The sought characteristic may be explained in simple words like ... [more ▼]

Very often the reason for using of X-Ray tomography in a research project is to measure the evolution of some geometrical characteristic. The sought characteristic may be explained in simple words like size, shape, or distance, but in practice measures based on these notions can have a complex implementation. We present a simple problem, measuring the evolution of radius in a cylindrical sample (a common shape for sample preparation for tomography) and how this value differs according the direction in which we look, when such evolution is known to be anisotropic. The solution is not unique, but we show that a naïve manual approach are not accurate enough, and how even a simple geometric notion such as radius needs a thorough definition in relation to its applicability to 3D image analysis. We extend the argument to how a good understanding of the notions and algorithms used in the quantification of geometrical characteristics can directly affect the pertinence and representativity of the results. [less ▲]

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See detailBoom clay drying behavior: experimental and numerical study
Hubert, Julien ULiege; Plougonven, Erwan ULiege; Léonard, Angélique ULiege et al

Conference (2016, May)

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See detailDesiccation cracks formation in clay-barrier for nuclear waste disposal
Hubert, Julien ULiege; Prime, Noémie; Plougonven, Erwan ULiege et al

Conference (2016, February 16)

In geotechnical engineering, the desiccation cracking of soil is commonly observed. This phenomenon is detrimental to the behavior of earth material and earth structure. Desiccation cracks can lead to the ... [more ▼]

In geotechnical engineering, the desiccation cracking of soil is commonly observed. This phenomenon is detrimental to the behavior of earth material and earth structure. Desiccation cracks can lead to the overall failure of many geotechnical structures: • They can affect the slope stability of earth dams or embankments; • They can initiate internal erosion of embankments due to water flow through the cracks; • They can compromise the efficiency of soil barriers such as landfill liners and top covers. Nowadays, the storage of nuclear waste in deep impermeable geological layers is considered. These storages are based on the multi-barrier principle, the last of which being the host rock, typically a clayey material. In this context, maintaining the very low hydraulic conductivity of the host rock is crucial. Unfortunately, the ventilation of excavated galleries causes convective drying of the host material and can lead to crack formation. This work aims to understand in which conditions exactly, during convective drying, does cracking occur in clayey materials. An experimental campaign has been carried out to characterize the drying behavior of Boom clay which is the host rock at the underground research facility in Mol (Belgium). X-Ray micro-tomography has been used to analyze crack development as well as shrinkage. The experiments are used to calibrate the transfer parameters of a convective drying law based on the limit layer model. This calibration is based on agreement of the drying kinetics. A numerical study is then performed and aims at reproducing the behavior observed during the experiments. A thermo-hydro-mechanical coupled model is used to determine the stress distribution during the drying and a tensile failure criterion is suggested to predict crack genesis. Simulations are performed using the in-house built FEM code LAGAMINE. [less ▲]

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See detailConvective drying of cherry tomato: Study of skin effect
Khama, Reda; Aissani, F.; Alkama, R. et al

in Journal of Engineering Science and Technology (2016), 11(3), 443-457

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See detailPositive Operations on Wastewater Sludge Drying: Comparison of Back-Mixing and Sawdust Addition
Li, Jie; Plougonven, Erwan ULiege; Fraikin, Laurent ULiege et al

in Energy & Fuels (2016), 30(4), 3014-3019

Detailed reference viewed: 25 (4 ULiège)
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See detailConvective drying behavior of sawdust-sludge mixtures in a fixed bed
Li, Jie; Fraikin, Laurent ULiege; Salmon, Thierry ULiege et al

in Drying Technology (2016), 34(4), 395-402

Detailed reference viewed: 35 (10 ULiège)