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See detailOn the transition between symmetric ans asymmetric flow in rectangular shallow reservoirs - a case of maximum energy dissipation?
Westhoff, M.C.; Erpicum, Sébastien ULiege; Archambeau, Pierre ULiege et al

Conference (2017, June)

Shallow reservoirs are often used in hydraulic engineering as sediment traps or storage basins. For short rectangular reservoirs, the main jet flows straight from the inlet to the outlet with on both sides ... [more ▼]

Shallow reservoirs are often used in hydraulic engineering as sediment traps or storage basins. For short rectangular reservoirs, the main jet flows straight from the inlet to the outlet with on both sides symmetric recirculation zones. In longer reservoirs, however, the main jet reattaches to the side of the reservoir leading to a small and a large recirculation zone. Previous studies have found an empirical geometric relation describing the switch between these two flow pattems. In this study, we demonstrate with a simple analytical model, that this switch in flow pattem coincides with a maximization of energy dissipation in the shear layer between the main jet and the recirculation zones. We show that for short reservoir lengths, energy dissipation is higher in the case of a symmetric fiow pattern, while for longer reservoir the energy dissipation is higher for asymmetric flow pattems. The simulated switch between the two flow patterns appears to be very close to the empirical relation. The strength of this approach lies in the fact that no detailed knowledge of small scale processes is needed, which may prove useful at an early stage of reservoir design. [less ▲]

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See detailFE modeling of the cooling and tempering steps of bimetallic rolling mill rolls
Neira Torres, Ingrid; Gilles, Gaëtan ULiege; Tchuindjang, Jérôme Tchoufack ULiege et al

in International Journal of Material Forming (2017), Volume 10,(Issue 3), 287305

Numerical simulations enable the analysis of the stress and strain histories of bimetallic rolling mill rolls. The history of rolling mill rolls is simulated by thermo-mechanical metallurgical finite ... [more ▼]

Numerical simulations enable the analysis of the stress and strain histories of bimetallic rolling mill rolls. The history of rolling mill rolls is simulated by thermo-mechanical metallurgical finite element code while considering two steps: post-casting cooling and subsequent tempering heat treatment. The model requires a notably large set of material parameters. For different phases and temperatures, Young modulus, yield limit and tangent plastic modulus are determined through compression tests. Rupture stresses and strains are obtained by tensile tests. Thermo-physical parameters are measured by such experimental methods as dilatometry, DSC (Differential Scanning Calorimetry) and Laser Flash methods. Such parameters as the transformation plasticity coefiicients for the ferrite, pearlite and martensite phases are identified through an inverse method. From the simulation results, the profile of the stresses evolution at different critical times is presented. An analysis of the potential damage is proposed by comparing the predicted axial stress \vith rupture stresses. The perspective of the Ghosh and McClintock damage criteria is also investigated. [less ▲]

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See detailMapping Soil Organic Carbon stocks and estimating uncertainties at the regional scale following a legacy sampling strategy (Southern Belgium, Wallonia)
Chartin, Caroline; Stevens, Antoine; Goidts, Esther et al

in Geoderma Regional (2017), 9

The quantification and the spatialisation of reliable SOC stocks (Mg C ha− 1) and total stock (Tg C) baselines and associated uncertainties are fundamental to detect the gains or losses in SOC, and to ... [more ▼]

The quantification and the spatialisation of reliable SOC stocks (Mg C ha− 1) and total stock (Tg C) baselines and associated uncertainties are fundamental to detect the gains or losses in SOC, and to locate sensitive areas with low SOC levels. Here, we aim to both quantify and spatialize SOC stocks at regional scale (southern Belgium) based on data from one non-design-based or model-based sampling scheme. To this end, we developed a computation procedure based on Digital Soil Mapping techniques and stochastic simulations (Monte-Carlo) allowing the estimation of multiple (here, 10,000) independent spatialized datasets. The computation of the prediction uncertainty accounts for the errors associated to both the estimations of i) SOC stocks and ii) parameters of the spatial model. Based on these 10,000 individuals, median SOC stocks and 90% prediction intervals were computed for each pixel, as well as total SOC stocks and their 90% prediction intervals for selected sub-areas and for the entire study area. Hence, a Generalised Additive Model (GAM) explaining 69.3% of the SOC stock variance was calibrated and then validated (R2 = 0.64). The model overestimated low SOC stock (below 50 Mg C ha− 1) and underestimated high SOC stock (especially those above 100 Mg C kg− 1). A positive gradient of SOC stock occurred from the northwest to the center of Wallonia with a slight decrease on the southernmost part, correlating to the evolution of precipitation and temperature (along with elevation) and dominant land use. At the catchment scale higher SOC stocks were predicted on valley bottoms, especially for poorly drained soils under grassland. Mean predicted SOC stocks for cropland and grassland in Wallonia were of 26.58 Tg C (SD 1.52) and 43.30 Tg C (2.93), respectively. The procedure developed here allowed to predict realistic spatial patterns of SOC stocks all over agricultural lands of southern Belgium and to produce reliable statistics of total SOC stocks for each of the 20 combinations of land use/agricultural regions of Wallonia. This procedure appears useful to produce soil maps as policy tools in conducting sustainable management at regional and national scales, and to compute statistics which comply with specific requirements of reporting activities. [less ▲]

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See detailClap 48- Le 48è NO Jazz & Heritage Festival 2017 - Le festival de la démesure
Sacré, Robert ULiege

E-print/Working paper (2017)

Compte rendu du 48è Festival de la Nouvelle Orleans

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See detailSurface Modification of Powder Metallurgy Titanium by Colloidal Techniques and Diffusion Processes for Biomedical Applications
Ureña, Julia; Mendoza Gallego, Carlos ULiege; Ferrari, Begoña et al

in Advanced Engineering Materials (2017), 19(6),

This contribution focuses on modifying the composition and surface characteristics of powder metallurgy titanium substrates to improve their wear resistance and to reduce the surface Younǵs modulus, while ... [more ▼]

This contribution focuses on modifying the composition and surface characteristics of powder metallurgy titanium substrates to improve their wear resistance and to reduce the surface Younǵs modulus, while maintaining the corrosion resistance and biocompatibility. The modification consists of Mo and TiN coatings produced by colloidal techniques which are deposited by electrophoretic deposition (EPD) or spraying onto green or sintered titanium substrates. The final surface structures are formed during a heat treatment, during which diffusion and consolidation of the layers take place. The surfaces are characterised by XRD, SEM, and micro-indentation; showing diffusion areas of between 40 and 85 microns with clear microstructural changes as well as higher hardness values. [less ▲]

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See detailGelfand duality for compact pospaces
De Rudder, Laurent ULiege

Conference (2017, June)

It is well known that the category of compact Hausdorff spaces is dually equivalent to the category of commutative C^\star-algebras. More generally, this duality can be seen as a part of a square of ... [more ▼]

It is well known that the category of compact Hausdorff spaces is dually equivalent to the category of commutative C^\star-algebras. More generally, this duality can be seen as a part of a square of dualities between compact Hausdorff spaces, C^\star-algebras, compact regular frames and de Vries algebras. Three of these dualities have been extended to dualities between compact pospaces, stably compact frames and proximity frames, the fourth part of the square being lacking. We propose the category of bounded Archimedean l-semi-algebra to complete what will be the outside square of dualities and to extend to category of C^\star-algebras. [less ▲]

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See detailGuide de tutorat d’un TFE en médecine générale. Comment aider son assistant à réussir
Vanmeerbeek, Marc ULiege; Lafontaine, Jean-Baptiste; Felgueroso-Bueno, François et al

Learning material (2017)

Le travail de fin d’études en master de spécialisation en médecine générale s’ancre dans une pratique dont il contribue à améliorer la qualité et asseoir la pertinence. Parmi les personnes qui ... [more ▼]

Le travail de fin d’études en master de spécialisation en médecine générale s’ancre dans une pratique dont il contribue à améliorer la qualité et asseoir la pertinence. Parmi les personnes qui accompagnent le travail des assistant(e)s, deux sont plus précisément identifiées, qui se partagent à des degrés divers des rôles complémentaires : le promoteur, membre du département universitaire, qui assure principalement la validité du travail aux plans administratif et scientifique ; le tuteur, médecin généraliste en exercice et souvent maître de stage, qui est principalement le garant de la pertinence du TFE pour l’exercice de la profession. Le guide du tutorat est destiné aux accompagnateurs. Il contextualise leur démarche, et rassemble des conseils utiles à prodiguer aux assistant(e)s aux étapes clé de leur travail. Ce guide fait de nombreuses références au guide des assistant(e)s, accessibles par des hyperliens dans l’édition en ligne, de façon à mettre en résonance les conseils prodigués aux uns et aux autres (http://www.mgtfe.be/le-guide-de-tutorat-dun-tfe/). Ce guide fait partie d’un ensemble d’outils mis à disposition pour assurer également le dépôt en ligne, l’indexation et la diffusion des TFE (http://www.mgtfe.be/). [less ▲]

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See detailAccess to multilingual individual rubrics in URI format for ICPC-2 and the Q-Codes
Jamoulle, Marc ULiege; Grosjean, Julien; Darmoni, Stefan

Textual, factual or bibliographical database (2017)

ICPC-2 (v6), new ICPC-2 Process (v6) and Q-Codes are available on the University of Rouen's HeTOP server in URI format (Universal Resource Identifier) ICPC-2 is available in 19 languages. Q-Codes are ... [more ▼]

ICPC-2 (v6), new ICPC-2 Process (v6) and Q-Codes are available on the University of Rouen's HeTOP server in URI format (Universal Resource Identifier) ICPC-2 is available in 19 languages. Q-Codes are available in 8 languages ; change the two characters ‘en’ by the corresponding by the corresponding language Code ISO 3166-1 in lower case : es, pt, fr, nl, ko, tr, vi into the URI. Link to ICD-10 have been updtade in the HeTOP server. Automatic links to MeSH and Manually controlled links to Q-codes are also available for ICPC-2. Access is granted free of charge. ICPC-2 is copyrighted by Wonca. Q-Codes are under Creative common license share alike non commercial [less ▲]

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See detailUno scetticismo triste. Tozzi e la psicologia del primo Novecento
Boccaccini, Federico ULiege

in de Seta, Ilaria; Castellana, Riccardo (Eds.) Federigo Tozzi in Europa. Influssi culturali e convergenze artistiche (2017)

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See detailSafety update on dapagliflozin (DAPA) across the phase 2b/3 clinical trial program
Jabbour, Serge; Seufert, Jochen; SCHEEN, André ULiege et al

Poster (2017, June)

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See detailImpact of 3’-­‐sialyllactose and Bifidobacterium crudilactis on infant feces microbial composition and virulence modulation of Escherichia coli O157:H7, using the SHIME® gastrointes6nal model
Bondue, Pauline ULiege; Lebrun, Sarah ULiege; Crevecoeur, Sébastien ULiege et al

Poster (2017, June)

Bifidobacterium crudilactis, a bacterial species from bovine origin, growths on bovine milk oligosaccharides (BMO). Cell free spent media (CFSM) from B. crudilactis and 3’-sialyllactose (3’SL), a major ... [more ▼]

Bifidobacterium crudilactis, a bacterial species from bovine origin, growths on bovine milk oligosaccharides (BMO). Cell free spent media (CFSM) from B. crudilactis and 3’-sialyllactose (3’SL), a major BMO, modulated Escherichia coli O157:H7 virulence gene expressiona. In this study, the SHIME® gastrointestinal model was inoculated with 4 different treatments: 3’SL (ttm1), B. crudilactis (ttm2), 3’SL and B. crudilactis (ttm3) and CFSM from 3’SL and B. crudilactis culture (ttm4). In each section of the colon, samples were collected and analysed for short chain fatty acid (SCFA) concentration using HPLC, microbial populations using 16S rDNA metagenetic analysis and correlated with E. coli O157:H7 virulence gene expression. The results showed that SCFA levels were stable during the experiments. Metagenetic analysis showed a microbial diversity in transverse (TC) and descending colon (DC) close to feces, dominated by Bacteroides, Prevotella and Fusobacterium, while the ascending colon (AC) showed a different microbial diversity dominated by Veillonella. Ttm4 and ttm2 induced mainly a down-regulation of virulence genes: fliC in DC with ttm4, and luxS, stx1, qseA in AC, DC or TC with ttm2. Ttm1 also showed a down-regulation of fliC in DC, similar to the one observed with ttm4, but this was associated with an up-regulation of fliC and stx1 in AC or TC. Finally, ttm3 showed slight upregulation of ler, fliC and qseA in AC. These results show that ttm4 and ttm2 might have a positive effect against virulence expression of E. coli O157:H7. However, this trend has to be validated with the further replicates on the SHIME® system. [less ▲]

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See detailSuperconducting weak links created by electromigration
Silhanek, Alejandro ULiege

Conference (2017, June)

In this presentation, we explore in-situ controlled electromigration to fabricate superconducting weak links. We show evidence that in Al a transition from thermally assisted phase slips (TAPS) to quantum ... [more ▼]

In this presentation, we explore in-situ controlled electromigration to fabricate superconducting weak links. We show evidence that in Al a transition from thermally assisted phase slips (TAPS) to quantum phase slips may takes place when the effective cross section becomes smaller than ~150 nm2. In the regime dominated by quantum phase slips the nanowire loses completely its capacity to carry current without dissipation, even at the lowest possible temperature. We also discuss the origin of negative magnetoresistance at low magnetic fields in the bow-tie shaped constrictions. Strikingly, the detrimental effect caused by the repeated electromigration can be healed by simply inverting the current direction. These findings reveal perspectives of the proposed fabrication method for exploring various fascinating superconducting phenomena in atomic size constrictions. [less ▲]

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See detailThe Split-Band Interferometry Approach to Determine the Phase Unwrapping Offset
Libert, Ludivine ULiege; De Rauw, Dominique ULiege; d'Oreye, Nicolas et al

Poster (2017, June)

This poster presents an approach based on the Split-Band Interferometry to solve the ambiguities introduced during the phase unwrapping of separate regions.

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See detailDroplet microfluidics for single-cell manipulation
Van Loo, Stéphanie ULiege

Doctoral thesis (2017)

Detailed reference viewed: 39 (6 ULiège)
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See detailMicroplastics found in the stomach contents of Squalius cephalus from the Seine River
Collard, France ULiege; Gilbert, Bernard ULiege; Eppe, Gauthier ULiege et al

Poster (2017, June)

Microplastics (plastics < 5 mm) are emerging pollutants of growing concern. Since the 2000s their abundance, degradation and impacts on wildlife are more and more studied and understood. However, few data ... [more ▼]

Microplastics (plastics < 5 mm) are emerging pollutants of growing concern. Since the 2000s their abundance, degradation and impacts on wildlife are more and more studied and understood. However, few data are available particularly in freshwater ecosystems. Some fish species have plastic in their stomach contents such as: Gobio gobio, Alburnus alburnus, Leuciscus leuciscus while other species have not. In controlled conditions, microplastics were found to cause negative impacts in fish: leaching of micropollutants, endocrine disruption, hatching inhibition and decrease of growth rate of larvae. The first step in the understanding of these impacts is the quantification and the characterisation of ingested plastics by organisms in the field. Plastics and other anthropogenic particles (textile fibres) were isolated from 40 stomachs of Squalius cephalus (the European chub) collected in the Seine River (Paris) in August 2016. One station is upstream and the three others are downstream of the Paris Megacity conurbation. This megacity exerts a great pressure on the Seine River. Plastics were isolated thanks to a method using sodium hypochlorite and all particles were then analysed by Raman spectroscopy. The method consists in a degradation overnight of the organic matter in the stomach contents by sodium hypochlorite. This mixture is then filtrated and particles longer than 5 µm are resuspended into an ethanol (99%) solution for centrifugation. The precipitate, containing all particles denser than ethanol, is collected (1.3 ml) and spread on a mount for Raman spectroscopy. Several lasers were used, depending on the particle’s colour. Spectra were recorded with an accumulation ranging from 5 to 50s. Preliminary results showed that 7 individuals out of 25 already analysed (28%) had ingested at least one anthropogenic particle (AP). Eight APs were found and characterized, the majority of them (7) being dyed fibres. One of these fibres was made of a plastic polymer, the polyethylene terephthalate. The others were made of an undetermined material as Raman analyses gave only information on the dye. The eighth particle was a fragment of polypropylene. It is the first time that fish are studied as a part of plastic pollution in the Seine River. All isolated particles have been analysed leading to precise results. The percentage of occurrence is in the common range of other studies while much lower than the European flounder coming from the River Thames and higher than fish coming from Geneva Lake. It is not surprising that the majority of APs were fibres as another study in the river Seine found that the fibres concentration in water is far greater than the fragments concentration, as well as in urban runoff. It is also possible that the retention time of fibres in the gut is longer than fragments. Toxicological impacts of fibre ingestion is still unknown despite their ubiquity in many freshwater environments. [less ▲]

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See detailHistoire du thymus : d'un organe vestigial à la programmation de la tolérance immunitaire
Geenen, Vincent ULiege

in Medecine Sciences : M/S (2017), 33(6-7), 634-644

This synthesis presents the most important disruptions of conceptions about the thymus since its discovery in Antique Greece. For centuries, the thymus has been considered as a vestigial organ, and its ... [more ▼]

This synthesis presents the most important disruptions of conceptions about the thymus since its discovery in Antique Greece. For centuries, the thymus has been considered as a vestigial organ, and its role in T-lymphocyte differentiation has been proposed only in the 1960’s. Most recent studies attribute to the thymus an essential and unique role in the programming of central immunological self-tolerance. The basal mechanism implicated in this function is the transcription in thymic epithelium of genes encoding precursors of self-antigens. Processing of these latters leads to presentation of self-antigens by the major histocompatibility complex (MHC) machinery expressed by thymic epithelial and dendritic cells. During fetal life, this presentation drives negative selection of T-cell clones harboring receptors with high affinity for these complexes MHC/self-antigen. After birth, this presentation promotes the generation of regulatory T cells specific for these complexes. A number of studies, as well as the identification of Aire and Fezf2 genes, have shown that a thymus dysfunction plays a crucial role in the development of organ-specific autoimmunity. [less ▲]

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See detailEditorial
Dewals, Benjamin ULiege

in Proceedings of ICE : Water Management (2017), 170(WM3), 109-110

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See detailValidation of a new elastoplastic constitutive model dedicated to the cyclic behaviour of brittle rock materials
Cerfontaine, Benjamin ULiege; Charlier, Robert ULiege; Collin, Frédéric ULiege et al

in Rock Mechanics & Rock Engineering (2017)

Old mines or caverns may be used as reservoirs for fuel/gas storage or in the context of large-scale energy storage. In the first case, oil or gas is stored on annual basis. In the second case pressure ... [more ▼]

Old mines or caverns may be used as reservoirs for fuel/gas storage or in the context of large-scale energy storage. In the first case, oil or gas is stored on annual basis. In the second case pressure due to water or compressed air varies on a daily basis or even faster. In both cases a cyclic loading on the cavern’s/mine’s walls must be considered for the design. The complexity of rockwork geometries or coupling with water flow requires finite element modelling and then a suitable constitutive law for the rock behaviour modelling. This paper presents and validates the formulation of a new constitutive law able to represent the inherently cyclic behaviour of rocks at low confinement. The main features of the behaviour evidenced by experiments in the literature depict a progressive degradation and strain of the material with the number of cycles. A constitutive law based on a boundary surface concept is developed. It represents the brittle failure of the material as well as its progressive degradation. Kinematic hardening of the yield surface allows the modelling of cycles. Isotropic softening on the cohesion variable leads to the progressive degradation of the rock strength. A limit surface is introduced and has a lower opening than the bounding surface. This surface describes the peak strength of the material andallows the modelling of a brittle behaviour. In addition a fatigue limit is introduced such that no cohesion degradation occurs if the stress state lies inside this surface. The model is validated against three different rock materials and types of experiments. Parameters of the constitutive laws are calibrated against uniaxial tests on Lorano marble, triaxial test on a sandstone and damage-controlled test on Lac du Bonnet granite. The model is shown to reproduce correctly experimental results, especially the evolution of strain with number of cycles. [less ▲]

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