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See detailFluid - structure interaction modeling with a coupled 1D - 2D free surface flow solver
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of Riverflow 2006 (2006)

Wolf software is a set of coupled numerical tools developed for almost ten years for simulating a wide range of free surface flows and transport phenomena. In the scope of new applications in hydraulic ... [more ▼]

Wolf software is a set of coupled numerical tools developed for almost ten years for simulating a wide range of free surface flows and transport phenomena. In the scope of new applications in hydraulic structure design and fluid-structure interaction, additional developments have been implemented in the finite volume 2D model to deal with boundaries not aligned along axis or with moving structures. The cut cell based approach, simpler than other classical methods, is based on the division with a sub-grid of the initial Cartesian meshes. While keeping the advantages of regular grids in terms of simplicity, accuracy and storage capacity, it enables to compute instantaneous effects of a structure movement on the fluid or to deal with complex boundaries inclined compared to mesh axis. Several test cases are presented, as well as an applica-tion of the enhanced model, coupled with a 1D one, to the computation of the hydrodynamic fields induced by a lock-door movement. [less ▲]

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See detail1D and 2D solvers coupling for free surface flow modelling
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of the 7th International Conference on Hydroinformatics (2006)

In the field of hydraulic engineering, the size of the simulations is one of the current challenges to model with precision the large areas involved by practical engineers applications. In this scope, the ... [more ▼]

In the field of hydraulic engineering, the size of the simulations is one of the current challenges to model with precision the large areas involved by practical engineers applications. In this scope, the linking in the same modelization of different solvers, each one used in the part of the simulation where its fundamental characteristics are most suitable, open the door to still unreached modelling possibilities. WOLF software includes a series of numerical tools for simulating a wide range of free surface flows and transport phenomena. This paper presents the coupling of the 1D and 2D multiblock finite volume models of WOLF to simulate in a unified way large river reaches (in 1D) with a very fine computation of local areas (in 2D). An application to the simulation of the propagation of the waves following the filling and emptying operations of a large locks system on a several kilometres long reach of the river Meuse (Belgium) is presented. [less ▲]

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See detailModelling flood events using high resolution digital elevation models and considering the sediment interaction with constructions in floodplains
Archambeau, Pierre ULg; Erpicum, Sébastien ULg; Dewals, Benjamin ULg et al

in Proceedings of the 7th International Conference on Hydroinformatics (2006)

The main objective of the present paper is a description of two effective numerical 2D models to be used as strategic tools in the process of flood risks assessment and mitigation. The first one is a ... [more ▼]

The main objective of the present paper is a description of two effective numerical 2D models to be used as strategic tools in the process of flood risks assessment and mitigation. The first one is a model for hydrodynamics simplified according to the diffusive assumption while the second one is a complete model based on the shallow water equations. Each of them is solved with an efficient numerical technique (including implicit time integration schemes and GMRES linear solvers) maximizing the convergence rate towards a steady state. A practical case study, for which a high resolution Digital Elevation Model exists, will be presented. The study shows the consequences on structures of a new construction in the floodplain in terms of inundation and erosion. [less ▲]

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See detailNumerical tools for dam break risk assessment: validation and application to a large complex of dams
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Hewlett, Henry (Ed.) Improvements in reservoir construction, operation and maintenance (2006)

The present paper first describes briefly the hydrodynamic model WOLF 2D. Secondly, the simulation of the Malpasset dam break enables to highlight the effectiveness of WOLF 2D. Lastly, the model is ... [more ▼]

The present paper first describes briefly the hydrodynamic model WOLF 2D. Secondly, the simulation of the Malpasset dam break enables to highlight the effectiveness of WOLF 2D. Lastly, the model is applied to simulate the flood generated by the hypothetic collapse of a large concrete dam, which would induce three dam breaks in cascade. [less ▲]

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See detailL'e-learning dans l'enseignement supérieur. Environnement International Francophone.
Balancier, Pascal; Georges, François ULg; Jacobs, Sarah et al

Report (2006)

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See detailMaturation de Form@sup : principes et instrument
Poumay, Marianne ULg

in Revue Internationale de Pédagogie Universitaire (2006), 3(2), 1-17

Without resuming its detailed description, the present article proposes a critical analysis of the options taken in Form@sup, a one-year postgraduate degree for higher education teachers who want to ... [more ▼]

Without resuming its detailed description, the present article proposes a critical analysis of the options taken in Form@sup, a one-year postgraduate degree for higher education teachers who want to question their professional practice through the development of their online course. The article justifies the theoretical backgrounds of this training program and underlines the difficulties encountered in carrying out each of its basic principles. It then presents the decisions made for 2005-2006, insisting on the influence of the Scholarship of Teaching and Learning movement. Through its concrete examples, it also aims at fostering reflection and exchange of practice amongst the instructional developers teams. [less ▲]

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See detailGembloux : une bibliothèque universitaire au cœur du monde
Pochet, Bernard ULg

in Lectures : La Revue des Bibliothèques (2006), 146

Cet article est le premier d'une série d'articles, sur les bibliothèques universitaires de la Communauté française de Belgique, publiés dans la revue Lecture

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See detailNo efficiency of the lateral system on nocturnal feeding in the European sea bass (Dicentrarchus labrax L.)
Faucher, Karine ULg; Dutto, Gilbert; Covès, Denis et al

in Aquaculture (2006), 252(2-4), 462-475

In order to evaluate the effect and consequence of lateral system inactivation on fish nocturnal feeding, the differential growth of groups of European sea bass maintained in different rearing conditions ... [more ▼]

In order to evaluate the effect and consequence of lateral system inactivation on fish nocturnal feeding, the differential growth of groups of European sea bass maintained in different rearing conditions were compared. Whereas some fish with intact lateral system (placebo fish) were placed under a photoperiod of 12-L: 12-D, other placebo fish were kept in the dark. In the same way, fish deprived of lateral system by section of their lateral system nerves and antibiotic treatment were placed under a photoperiod of 12-L :12-D and the others in the dark. For each of these four rearing conditions, two sets of experiment were realized. Percent mortality, feed rhythm, averaged daily feed demand, specific growth rate and feed efficiency were compared among these four groups of fish. After four months of experiment, results revealed that, under a photoperiod of 12-L: 12-D, fish showed a diurnal feed rhythm whereas no rhythm appeared in fish kept in the dark. In addition, as reported by other authors, the average daily feed demand, the quantity of ingested food and specific growth rate were greater in fish maintained under a photoperiod of 12-L :12-D than those kept in the dark. The fish lateral system inactivation did not affect mortality, feed intake, specific growth rate or feed efficiency. These results demonstrated that lateral system is not the major sensory organ leading to European sea bass nocturnal feeding; chemoreception system undoubtedly taking over. If the olfactory system explains equal feed intake between placebo and treated fish, the greater specific growth rate in treated than in placebo fish indicates the action of another mechanism, such as a "booster effect" of antibiotics used for lateral system inactivation on fish. [less ▲]

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See detailL'accompagnement : une fonction multiforme, un contrat clair à établir d'emblée
Poumay, Marianne ULg

Learning material (2006)

La fonction d'accompagnateur est aujourd'hui répandue à travers de nombreux secteurs professionnels. Le présent document se propose de mobiliser deux auteures, Pierrette Massé et Maëlla Paul, pour dégager ... [more ▼]

La fonction d'accompagnateur est aujourd'hui répandue à travers de nombreux secteurs professionnels. Le présent document se propose de mobiliser deux auteures, Pierrette Massé et Maëlla Paul, pour dégager les caractéristiques essentielles de l'accompagnement et une taxonomie des postures d'accompagnement. Cette modélisation peut guider vers une classification empirique d'accompagnements réalisés dans le cadre de programmes tels "Formadis". [less ▲]

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See detailDu nouveau à l'interface materno-foetale: rôle du couple hCG/récepteur LH-hCG dans l'implantation embryonnaire
PERRIER d'HAUTERIVE, Sophie ULg; Charlet, Jeanne de Chantal ULg; Dubois, Michel ULg et al

in Revue Médicale de Liège (2006), 61(10), 705-12

Implantation of the embryo into the maternal endometrium represents a unique biological process, combining an immunological (tolerance of an allograft) and biological (adhesion of two epitheliums) paradox ... [more ▼]

Implantation of the embryo into the maternal endometrium represents a unique biological process, combining an immunological (tolerance of an allograft) and biological (adhesion of two epitheliums) paradox. The success of implantation depends on a receptive endometrium, a functionally normal blastocyst and a synchronized cross-talk between embryonic and maternal tissues. Though sexual steroids control the process, a cascade of growth factors or cytokines are the prime paracrine mediators of the dialogue at the maternal-embryonic interface. HCG is one of the molecules most precociously produced by the embryo and is the most specific marker of its presence. HCG is a luteotropic factor which relays the inadequate support provided by the reduced rates of LH, but also influences the pregnancy on a paracrine mode by a local action on implantation process, probably by interacting with its receptor, the LH/hCG-R that we have evidenced on endometrial epithelium. We demonstrate that embryo actively participate into its implantation, tolerance and placentation. [less ▲]

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See detailPeut-on gérer la forme urbaine ? Les enjeux de la régulation morphologique (France, Angleterre, Etats-Unis)
Teller, Jacques ULg

in Descat, S.; Siret, D. (Eds.) La ville durable au risque de l’histoire (2006)

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See detailThe APPEAR Method for guiding the valorisation of urban archaeological sites
Teller, Jacques ULg; Warnotte, A.; Tinant, M. et al

Scientific conference (2006)

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See detailSingle-player games: introduction to a new solving method
Van Lishout, François ULg

Master of advanced studies dissertation (2006)

In many games, the machine has become stronger than the best human players. Machines have already beaten the human World Champion in famous games like Checkers, Chess, Scrabble and Othello. However ... [more ▼]

In many games, the machine has become stronger than the best human players. Machines have already beaten the human World Champion in famous games like Checkers, Chess, Scrabble and Othello. However, mankind has not been humbled by chips in all games. The best human players are still stronger than computers in games like Go, Poker, Chinese Chess and Hex. In this thesis, we will focus on a new way to model single-player games in order to improve the performances of the machine. We will demonstrate this technique on the game of Sokoban. [less ▲]

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See detailRelevance of soil mapping criteria to predict geochemical background of trace elements in soils from local to regional scales.
Colinet, Gilles ULg; Bogaert, Patrick; Bock, Laurent ULg

Poster (2006)

Among natural factors driving the soil content in metallic trace elements (MTE), the geochemical background is often deemed as a sound base for the detection of contaminations. Numerous studies have shown ... [more ▼]

Among natural factors driving the soil content in metallic trace elements (MTE), the geochemical background is often deemed as a sound base for the detection of contaminations. Numerous studies have shown the difficulties to take into account the multi-dimensionnality of the spatial variability of most soil properties. As far as a detailed soil map is available for Belgium, the relevance of its information was investigated at various spatial scales in the Walloon Region (Southern Belgium), from the plot to the entire region, to evaluate the feasibility of a multi-scale mapping of geochemical background. A database of soil profiles (gathering both agricultural and forest soils) was used to analyse the relationships between the MTE total content (measured after HF-HClO4-HCl dissolution) and other general characteristics such as pH, Total Organic Carbon content (TOC), Particle Size Distribution (PSD), and cationic exchange capacity (CEC). The factors of MTE spatial distribution inside and between solums were investigated through multivariate statistical analysis. The spatial dependence of these factors was then studied over plot, field, farm, county and region scales, and compared to the spatial structures of the soil map parameters. At the solum level, strong relationships between most of the studied MTE were found, as well as between stone charge and fine earth contents. The PSD is the main driving factor of MTE content in non-carbonated soils, whatever the land use. When considering soil associations, such as catenas, the slope redistribution processes must be taken into account. However, the PSD remains the main driving factors and, as the soil map contains information about that property (mainly the textural class and the profile development), a cartography of the geochemical background based on the use of the soil map and pedotransfer functions or regression models appears relevant. At the regional scale, some long-range spatial structures could be identified. These result mainly from the geological structure of the Walloon region, where the lithological zonation is rather clearly marked. The soil map (texture and nature of stone charge) appears relevant at that scale too but does need a generalization process and fails however to differenciate the intra-type soil spatial variability. Some basic processes of integration of point measurements and qualitative information have been explored. They should be further investigated in the future. [less ▲]

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See detailMétaphysique phénoménologique, suite
Seron, Denis ULg

in Bulletin d'Analyse Phénoménologique (2006), 2(2), 3-75

This paper, which is the sequel of a previous essay published in the same collection, provides an overview of some basic problems related to the notion of a phenomenological metaphysics. The key thesis in ... [more ▼]

This paper, which is the sequel of a previous essay published in the same collection, provides an overview of some basic problems related to the notion of a phenomenological metaphysics. The key thesis in the paper is that the very starting point of all "critical" metaphysics should first consist in an intensional interpretation of existential propositions. Starting from the idea (for him distinctive of the phenomenological approach in general) that intensionality with an 's' now needs to be described in terms of the intentionality with a 't', the author tries to outline some implications and consequences of applying the methods used in phenomenology to metaphysical problems. He then briefly surveys some of the possible applications of this view, especially as to the theory of truth. [less ▲]

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See detailComparison of different non-linear equations and corresponding unitarization schemes
Selyugin, O. V.; Cudell, Jean-René ULg

in Proceedings of science (2006)

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See detailUse of artificial diet system to assess the potential bio-insecticide effect of a fungal lectin from Xerocomus chrysenteron (XCL) on Myzus persicae.
Jaber, K.; Paquereau, L.; Fournier, D. et al

in Communications in Agricultural and Applied Biological Sciences (2006), 71(2 Pt B), 497-505

Lectins are carbohydrate binding proteins which are widely distributed in nature: they have been isolated from microorganisms, fungi, plants and animals. Many of these proteins were tested for their ... [more ▼]

Lectins are carbohydrate binding proteins which are widely distributed in nature: they have been isolated from microorganisms, fungi, plants and animals. Many of these proteins were tested for their potential biocide effect on lot of pests. Indeed, lectins can cause dramatic changes in the cellular morphology and metabolism, particularly on the digestive system of insect having ingested them, by lectin binding to membrane glycosyl groups of the digestive tract cells. A fungal lectin, namely Xerocomus Chrysenteron lectin (XCL) was previously purified and was shown to be toxic to several pests including aphids. At the cell level, an increase in the endocytosis, the induction of morphological changes such as the actin cytoskeleton shape was determined. In this work, the recombinant XCL was produced and was tested for its potential aphicide effect on Myzus persicae, a polyphagous aphid found on more than 400 host plant species and transmitting more than 100 viral diseases. We developed bioassays using different artificial diets incorporating a broad range of XCL concentrations (from 10 microgx ml(-1) to lmg.ml(-1)) to assess the potential negative effects of XCL on the development and reproduction of the M. persicae aphid. Significant mortality rates, changes of developmental durations and nymph production were observed depending on the XCL concentration in the artificial diet. Concanavalin A lectin was also used in a new range of experiments to compare the effects of the two lectins on the aphid biological parameters. According to the observed dose responses toward the XCL and Con-A lectins included in the artificial diet and the action mode of this kind of proteins, the perspectives of lectin use in pest control will be discussed. [less ▲]

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See detailCorrosion behaviour of different hot rolled steels
Perez, F. J.; Martinez, L.; Hierro, M. P. et al

in Corrosion Science (2006), 48(2), 472-480

The oxidation-corrosion behaviour of hot rolled alloys was examined by electrochemical impedance spectroscopy. The corrosion behaviour of the non-oxidised alloys was first determined in order to have a ... [more ▼]

The oxidation-corrosion behaviour of hot rolled alloys was examined by electrochemical impedance spectroscopy. The corrosion behaviour of the non-oxidised alloys was first determined in order to have a reference behaviour. Then, each alloy was oxidised for 1 and 3 days at 650 degrees C in air and its corrosion behaviour was also determined. For all the alloys, Fe2O3 was formed at the scale-gas interface. However, the Fe2O3 crystallographic structures varied as a function of the alloy composition. Differences in the corrosion behaviour are due to the thickness, the microstructure and the porosity of the scale. The new graphite chromium iron alloy (Hi-Cr + C) have an oxidation-corrosion behaviour close to the indefinite chill double paired (ICDP) one and is therefore thought to be a good candidate to replace the ICPD alloy. In the case of the high speed steel (HSS) alloy, the oxidation-corrosion kinetics are too slow to prevent sticking problems. The Co addition decreases the corrosion-oxidation rates for the non-oxidised and oxidised samples but this effect is limited in time. (C) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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