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See detailNon-uniform adaptive vertical grids in one-dimensional numerical ocean models
Burchard, Hans; Beckers, Jean-Marie ULg

in Ocean Modelling (2004), 6(1), 51-81

It is demonstrated in this paper how the concept of general vertical coordinates can be exploited for constructing adaptive grids in primitive equation ocean models. The term adaptive is used here in the ... [more ▼]

It is demonstrated in this paper how the concept of general vertical coordinates can be exploited for constructing adaptive grids in primitive equation ocean models. The term adaptive is used here in the sense of coordinate iso-surfaces which follow certain internal structures of the flow in such a way that higher vertical resolution is obtained in locations where vertical gradients are large. The internal structures considered here are shear and stratification. In this paper, one-dimensional models are applied in order to demonstrate the ability of such grid adaptation methods to follow internal structures even in flow situations dominated by vertical mixing processes. Here, a variational approach is considered for the generation of grids which results in a diffusion equation for the vertical coordinate. The method is tested for five different idealised and realistic scenarios with the result that the discretisation error can be significantly reduced in comparison to equidistant Cartesian grids. Some recommendations for extending these methods for three-dimensional models are given at the end of this paper. (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailLe recyclage urbain en partenariat public-privé : le ''gap funding anglais'' et la ''revitalisation urbaine'' wallonne
Halleux, Jean-Marie ULg

in Bulletin de la Société Géographique de Liège (2004), 44

Urban recycling and public-private partnership : the English « gap funding » and the Walloon « revitalisation urbaine » The English « gap funding » and the Walloon « revitalisation urbaine » are both ... [more ▼]

Urban recycling and public-private partnership : the English « gap funding » and the Walloon « revitalisation urbaine » The English « gap funding » and the Walloon « revitalisation urbaine » are both, mechanisms of public-private partnership aiming at increasing the financial profitability of urban recycling property development. The objective of their analysis is to understand why, compared with the situation in Wallonia, where the urban regeneration policy has not yet been emblematically successful, the gap funding mechanism has actually led to the renewal of several traditional urban areas. From this comparative investigation, which perfectly illustrates how partnerships are dependent of both, cultural and political traditions, we state that the English success is related with : political choices in favour of the concentration of subsidies within areas where the potential demand is strong, with the transparency of the private financial statements of account and also with a tradition of flexible planning, which is particularly in favour of the setting-up of partnership networks. [less ▲]

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See detailAssimilation of sea surface temperature and sea surface height in a two-way nested primitive equation model of the Ligurian Sea
Barth, Alexander ULg

Doctoral thesis (2004)

A coarse grid primitive equation model of 1/4° resolution is implemented covering the whole Mediterranean Sea. Within this grid a 1/20° resolution model of the Liguro-Provençal basin and the northern part ... [more ▼]

A coarse grid primitive equation model of 1/4° resolution is implemented covering the whole Mediterranean Sea. Within this grid a 1/20° resolution model of the Liguro-Provençal basin and the northern part of the Tyrrhenian Sea is embedded. A third fine resolution model of 1/60° is nested in the latter one and simulates the dynamics of the Ligurian Sea. Comparisons between one-way and two-way nesting in representing the Northern Current (NC) are made. This system of nested models is coupled with a simplified Kalman-filter based assimilation method. The state vector for the data assimilation is composed by the temperature, salinity and elevation of the three models. The forecast error is estimated by an ensemble run by perturbing initial conditions and atmospheric forcings. The leading empirical orthogonal functions (EOF) of this ensemble are taken as the error covariance of the model forecast. This error covariance is assumed to be constant in time. Sea surface temperature (SST) and sea surface height (SSH) are assimilated in this system. Data assimilation is also used to couple the hydrodynamic model with a statistical predictor of SST in the Ligurian Sea. The forecast improvement of this hybrid modelling system is shown and applications to operational models are highlighted. [less ▲]

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See detailMonde sauvage et monde civilisé dans le mythe : le cas d'Orion
Renaud, Jean-Michel ULg

in Charpentier, Marie-Claude (Ed.) Les espaces du sauvage dans le monde antique. Approches et définitions (2004)

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See detailComputation of the Malpasset dam break with a 2D conservative flow solver on a multiblock structured grid
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of the 6th International Conference of Hydroinformatics (2004)

In the global framework of safety, the study of the hydraulic consequences of a dam breaking, sudden and instantaneous for concrete structures, gradual for earth ones, is of major interest in the scope of ... [more ▼]

In the global framework of safety, the study of the hydraulic consequences of a dam breaking, sudden and instantaneous for concrete structures, gradual for earth ones, is of major interest in the scope of prevention policies or protection plans for populations and goods. Suitable numerical models, coupled with contemporary computational possibilities, allow engineers to forecast these complex situations with a great reliability. In this field, WOLF 2D is an efficient analysis and optimisation tool, which has been completely developed by the Applied Hydrodynamics and Hydraulic Constructions team (HACH – http://www.ulg.ac.be/hach) of the University of Liege. It is part of WOLF free surface flows computation package, which includes in the same development environment the resolutions of the 1D Saint-Venant equations, the 2D shallow-water equations as well as a physically based hydrological model and powerful optimisation capabilities based on Genetic Algorithms. The interactive and unique user-interface, with high performance pre- and post-processing, allows monitoring 3-D large-scale runs graphically while they proceed, as well as generation of 3D videos. Each code handles general multiblock meshes, dealing with natural topography and mobile bed simultaneously, for any unsteady situation with mixed regimes and moving hydraulic jumps. By this way, WOLF deals with all free surface hydraulic phenomena, from hydrological runoff and river propagation to extreme erosive flows on realistic mobile topography, such as gradual dam breaching processes. It has moreover proved its efficiency and reliability for years by numerous real applications. The first part of this paper covers a brief description of the 2D multiblock flow solver WOLF 2D and the underlying mathematical model. The second part depicts the application of WOLF computation capabilities to the well-known Malpasset dam break (France, 1959), which induced a catastrophic almost instantaneous release of 48 millions m³ of water in the Reyran river valley down to the town of Frejus and the Mediterranean sea. Data available thanks to the CADAM EU-project are used to assess the results. [less ▲]

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See detailModelling of the wave propagation, the coastal currents and the induced topographic changes
Fraikin, Catherine; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Proceedings of the 9th International Symposium on River Sedimentation (2004)

This paper models the sea bottom evolution. This model is built up on three main parts. The first one describes the wave propagation, taking simultaneously into account the refraction, the diffraction and ... [more ▼]

This paper models the sea bottom evolution. This model is built up on three main parts. The first one describes the wave propagation, taking simultaneously into account the refraction, the diffraction and the reflection but also the energy dissipation caused by wave breaking. This model is solved by the numerical method of the finite volumes, using an iterative resolution (the GMRES method). Several validations of this model have been carried out on many examples such as harbors of various geometries and depths, beaches,… The wave induced currents are computed in the second part based on the concept of the radiation stresses describing the excess of the flux momentum caused by the waves. A model based on the complete Navier-Stokes equations integrated on the depth and associated with appropriated forcing and friction terms is used. This model is computed as an update of WOLF software (HACH, ULg) and is applied to some examples such as beaches with or without coastal structures. Finally, the third part is about the sediment transport. It exhibits the topographic modifications of the coastal sea bottom caused by the waves and their currents. A loop execution of these three models ends this work. It gives us an operational tool to describe the topographic evolution of the coastal areas caused by the incident waves, the induced currents and then the resulting sediment transport, fulfilling the objectives of this paper. [less ▲]

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See detailDéveloppement : la course à la compétitivité
Lebailly, Philippe ULg

Article for general public (2004)

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See detailDe l’“universel reportage” au poème univers : l’hybridation mallarméenne du livre et du journal
Durand, Pascal ULg

in Thérenty, M.-E.; Vaillant, A. (Eds.) Plumes et presse. Journalisme et littérature au XIXe siècle (2004)

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See detailEffects of a micro hydroelectric power plant upon population abundance, mobility and reproduction behaviour of European grayling T. thymallus and brown trout S. trutta in a salmonid river
Ovidio, Michaël ULg; Paquer, Frédéric ULg; Capra, Hervé et al

in Garcia de Jalon, Diego; Vizcaino Martinez, Pilar (Eds.) International Symposium on Ecohydraulics. Aquatic habitat: Analysis & Restoration (2004)

This study examines the potential effects of a new micro hydroelectric power plant (MHPP) on the behaviour (habitat use, movements) and population abundance of European grayling (T. thymallus) and brown ... [more ▼]

This study examines the potential effects of a new micro hydroelectric power plant (MHPP) on the behaviour (habitat use, movements) and population abundance of European grayling (T. thymallus) and brown trout (S. trutta) in the Lhomme (Belgian Ardennes). Thirteen grayling and five brown trout were captured before their spawning period and were manually radio-tracked up to 6 times a week. Population density and biomass were estimated into two different sampling sectors with electric fishing, before and after the MHPP started up. The mobility patterns of grayling and trout in the reach of the river Lhomme influenced by the MHPP strongly contrasted with results obtained in an undisturbed river of the same type in the Belgian Ardennes. Movements were mostly restricted and rarely increased during the spawning period. Spawning took place, but was disturbed by hydropeakings. The population biomass of grayling and trout decreased by 61 % and 23 % respectively, five months after the start-up of the MHPP exploitation. [less ▲]

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See detailL’intégration architecturale et urbaine des vestiges archéologiques
Teller, Jacques ULg; Lefert, S.

in Actes du Colloque International APPEAR (2004)

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See detailLes carbonates de terres rares de Bertrix, Belgique.
Hatert, Frédéric ULg

in Bulletin de la Société Royale des Sciences de Liège (2004), 73(1), 27-34

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See detailCarminite et kintoreite de Hourt, Massif de Stavelot, Belgique.
Hatert, Frédéric ULg; Lefèvre, Pierre

in Bulletin de la Société Royale des Sciences de Liège (2004)

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See detailA study of the quantitative content of thiamine triphosphate in different biological objects by high-performance liquid chromatography
Makarchikov, Alexander F; Bettendorff, Lucien ULg

in News of Biomedical Sciences (2004), 2

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See detailPurification and characterization of glutathione S-transferases from two syrphid flies (Syrphus ribesii and Myathropa florae).
Vanhaelen, Nicolas; Francis, Frédéric ULg; Haubruge, Eric ULg

in Comparative Biochemistry & Physiology Part B (2004), 137(1), 95-100

Glutathione S-transferases (GST) play an important role in the detoxification of many substances including organic pollutants and plant secondary metabolites. We compared the GST of two syrphid species ... [more ▼]

Glutathione S-transferases (GST) play an important role in the detoxification of many substances including organic pollutants and plant secondary metabolites. We compared the GST of two syrphid species, the aphidophagous Syrphus ribesii and the saprophagous Myathropa florea to assess the relation between feeding type and GST patterns. Differences between the GST of the hoverfly species were observed after purification by affinity chromatography, SDS-PAGE and kinetic studies. While the specific activities of the purified enzymes were different, the purification yields were similar. The variation in specific activities was related to the presence of different isoenzymes in both syrphid species by SDS-PAGE. While two bands of 24 and 32 kDa were observed for M. florea, one more band of 26 kDa was present in S. ribesii. When a range of substrate and glutathione concentrations was tested, differences in Km and Vmax between the glutathione S-transferases from both hoverfly species were also observed. These results are discussed in terms of adaptations to the feeding habit and the habitat of the two syrphid species. [less ▲]

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See detailLarge-distance effects on spin observables at RHIC
Selyugin, Oleg V; Cudell, Jean-René ULg; Predazzi, E.

in Aulenbacher, K.; Bradamante, F.; Bressan, A. (Eds.) et al 16th International Spin Physics Symposium (SPIN 2004) (2004)

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See detailSaturation and non-linear effects in diffractive processes
Selyugin, Oleg V; Cudell, Jean-René ULg

in Burdik, C. (Ed.) 11th International Conference On Symmetry Methods In Physics (SYMPHYS-11) (2004)

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See detailA simple model for generalised parton distributions of the pion
Lansberg, Jean-Philippe ULg; Bissey, F.; Cudell, Jean-René ULg et al

in Bruncko, D.; Ferencei, J.; Strizenec, P. (Eds.) 12th International Workshop On Deep Inelastic Scattering (DIS 2004) (2004)

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See detailIntegral and derivative dispersion relations, analysis of the forward scattering data
Martynov, E.; Cudell, Jean-René ULg; Selyugin, Oleg V

in Eur. Phys. J. (2004), C33

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See detailFinite element computation of electromechanical micro-switches and micro-pump actuators
Lejeune, Jean-Michel; Rochus, Véronique ULg; Golinval, Jean-Claude ULg

Conference given outside the academic context (2004)

a new methodology to model the electromechanical behavior of microscale system components is presented. The original approach proposed in this paper is based on a unified FE formulation of the strong ... [more ▼]

a new methodology to model the electromechanical behavior of microscale system components is presented. The original approach proposed in this paper is based on a unified FE formulation of the strong electromechanical interaction problem, in which both the electric and the mechanical fields are considered simultaneously. To this aim, finite elements based on the Mindlin shell theory are implemented. In order to illustrate the proposed methodology, numerical results are presented on the modelling and simulation of microscale electromechanical switches and microscale pump actuators. [less ▲]

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See detailTransposition de la Directive Nitrate (CE) en Région wallonne : azote potentiellemnt lessivable de référence pour les sols cultivés en Région wallonne
Vandenberghe, Christophe ULg; Marcoen, Jean Marie ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2004), 8

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