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See detailLa sylviculture d'arbres "objectif" ou d'arbres de place (cahier technique n°27)
Baar, F.; Snoeck, B.; Balleux, P. et al

in Forêt Wallonne (2004), (68), 2-8

Ce cahier technique se présente en deux parties. La première est constituée du dossier remis à l’ensemble des agents de l’administration forestière lors des journées de formation. La seconde présente les ... [more ▼]

Ce cahier technique se présente en deux parties. La première est constituée du dossier remis à l’ensemble des agents de l’administration forestière lors des journées de formation. La seconde présente les exercices de la formation ainsi que les résultats obtenus. Complémentaires, ces deux parties cherchent à confronter la théorie et la pratique, l’exposé académique et les discussions à bâtons rompus. Cette formation a été délivrée, dans le contexte de l’accord cadre de recherche forestière liant l’Université Catholique de Louvain, la Faculté universitaire des Sciences agronomiques de Gembloux et l’asbl Forêt Wallonne, à l’ensemble des agents forestiers des cantonnements de la Région wallonne. [less ▲]

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See detailRiemannian geometry of Grassmann manifolds with a view on algorithmic computation
Absil, P.-A.; Mahony, R.; Sepulchre, Rodolphe ULg

in Acta Applicandae Mathematicae (2004), 80(2), 199-220

We give simple formulas for the canonical metric, gradient, Lie derivative, Riemannian connection, parallel translation, geodesics and distance on the Grassmann manifold of p-planes in R-n. In these ... [more ▼]

We give simple formulas for the canonical metric, gradient, Lie derivative, Riemannian connection, parallel translation, geodesics and distance on the Grassmann manifold of p-planes in R-n. In these formulas, p-planes are represented as the column space of n x p matrices. The Newton method on abstract Riemannian manifolds proposed by Smith is made explicit on the Grassmann manifold. Two applications - computing an invariant subspace of a matrix and the mean of subspaces - are worked out. [less ▲]

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See detailCharacteristics of peri-urban dairy herds of Bobo-Dioulasso (Burkina Faso)
Sidibe, M.; Boly, Hamidou ULg; Lakouetene, T. et al

in Tropical Animal Health and Production (2004), 36(1), 95-100

Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy ... [more ▼]

Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy objectives and were studied. Among these peri-urban dairy farmers, 60% were settled, 36% semi-settled, and 4% transhumant. In total, they held 4558 dairy cows, of which 32% lactated during the study. The prevalence of mastitis (55%) increased (p<0.05) with herd size. Advanced strategies for supplementary feeding and breeding were most frequent in small herds (< 30 cattle). None of the large herds ( > 60 cattle) had advanced breeding strategies. Bulls and cows were culled at younger ages in herds with better breeding strategy. Overall, this resulted in higher individual milk offtake in small herds (2.46 L/day) compared with large herds (1.25 L/day). Pure breeds were rarely used, and the presence of Bos taurus baoule naturally selected for trypanotolerance was low. The prevalence of trypanosomosis (40%) in herds dominated by Bos indicus zebu and Mere (Zebu x Baoule) is an argument for maintenance of biodiversity and selection of Baoule for milk production. [less ▲]

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See detailb - tau Yukawa nonunification in supersymmetric SU(5) with an Abelian flavor symmetry
Aristizabal Sierra, Diego ULg; Nardi, Enrico

in Physics Letters B (2004), 578

We present a supersymmetric SU(5) x U(1)H model, free from gauge anomalies, where the Abelian factor U(1)H, introduced to account for the hierarchy of fermion masses and mixings, is broken by the same ... [more ▼]

We present a supersymmetric SU(5) x U(1)H model, free from gauge anomalies, where the Abelian factor U(1)H, introduced to account for the hierarchy of fermion masses and mixings, is broken by the same adjoint representations of SU(5) that also break the GUT symmetry. The model predicts approximate, but never exact, bottom-τ Yukawa unification. The deviations are related to group theoretical coefficients and can naturally be at the level of 10%-20%. [less ▲]

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See detailLes troubles phonologiques : cadre théorique, diagnostic et traitement
Schelstraete, Marie -Anne; Maillart, Christelle ULg

in Schelstraete, Marie-Anne; Noel, Marie-Pascale (Eds.) Les troubles du langage et du calcul chez l’enfant. (2004)

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See detailL’évaluation des troubles phonologiques : illustration de la démarche linguistique par la présentation d’épreuves qualitatives.
Maillart, Christelle ULg; Schelstraete, Marie-Anne

in Schelstraete, Marie-Anne; Noël, Marie-Pascale (Eds.) Les troubles du langage et du calcul chez l’enfant. (2004)

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See detailL'insertion internationale des petits pays. Le cas de l'Uruguay: de l'indépendance au nouveau régionalisme
Santander, Sébastian ULg; Bizzozero, Lincoln

in Santander, Sébastian (Ed.) Globalisation, gouvernance et logiques régionales dans les Amériques (2004)

L'article se penche sur les pays à faible poids économique et politique sur l'arène internationale. Il analyse la stratégie d'intégration régionale sud-américaine de l'Uruguay qui est entouré par deux ... [more ▼]

L'article se penche sur les pays à faible poids économique et politique sur l'arène internationale. Il analyse la stratégie d'intégration régionale sud-américaine de l'Uruguay qui est entouré par deux pays puissants que sont l'Argentine et le Brésil. [less ▲]

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See detailMarket dynamics driven by the decision-making power producers
Ernst, Damien ULg; Minoia, Anna; Marija, Ilic

in Proceedings of 2004 IREP Symposium - Bulk Power System Dynamics and Control - VI (2004)

In this paper we consider a tool for analyzing the market outcomes when competitive agents (power producers) interact through the market place. The market clearing mechanism is based on the locational ... [more ▼]

In this paper we consider a tool for analyzing the market outcomes when competitive agents (power producers) interact through the market place. The market clearing mechanism is based on the locational marginal price scheme. A model of the strategic behavior is formulated for the agents. Each agent chooses its bid in order to maximize its profit by assuming that the other agents will post the same bid as at the previous session of the market, and by knowing the network characteristics. The income of each agent over a certain temporal horizon for different power system configurations (the addition of new transmission capabilities, new power plants) is evaluated according to this market dynamics and by integrating this dynamics over the chosen temporal horizon. The mathematical formulation, for the sake of simplicity, is related to a two node power system. In the simulations, the influence of different conditions (line transfer capacity, the number and size of generators, the presence of portfolio) on market outcomes is analyzed, and interesting and sometimes counterintuitive results are found. [less ▲]

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See detailLa place de la recherche scientifique dans le tissu social
Laitat, E.; Marcoen, Jean Marie ULg

in Terre wallonne - Humains admis (2004), 8(2), 67-69

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See detailApplication of the CALUX bioassay for epidemiological study: analyses of Belgian human plasma
Van Wouwe, Nathalie; Debacker, Noemi; Sasse, André et al

in Organohalogen Compounds (2004)

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See detailTrajectoires professionnelles féminines : flexibilités et enjeux de genre
Gavray, Claire ULg

in Bulletin Sophia (2004), 37

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See detailDIOXIN BODY BURDEN AMONG BLOOD DONORS BEFORE AND AFTER THE BELGIAN DIOXIN/PCB INCIDENT
Debacker, Noemi; Sasse, André; Van Wouwe, Nathalie et al

in Organohalogen Compounds (2004)

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See detailLevels of contamination for various pollutants present in Belgian human plasma
Van Wouwe, Nathalie; Covaci, Adrian; Kannan, Kurunthachalam et al

in Organohalogen Compounds (2004)

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See detailQuestions d'actualité relatives aux débats succints
Boularbah, Hakim ULg

in Actualités et développements récents en droit judiciaire (2004)

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See detailPreparation of nanosized barium zirconate powder by precipitation in aqueous solution
Boschini, Frédéric ULg; Guillaume, Bernard ULg; Rulmont, André ULg et al

in Key Engineering Materials [=KEM] (2004), 264-268(Part 1-3), 2335-2338

Several ways were explored to synthesize barium zirconate by soft chemistry methods in aqueous solution. In the first method the synthesis of barium zirconate was initiated by urea decomposition, through ... [more ▼]

Several ways were explored to synthesize barium zirconate by soft chemistry methods in aqueous solution. In the first method the synthesis of barium zirconate was initiated by urea decomposition, through an homogeneous precipitation of barium and zirconium salts followed by a "low temperature" thermal treatment. The kinetic of the reaction and the optimum urea/cation ratio have been determined by means of X-ray diffraction and Inductive Coupled Plasma analyses. It has been demonstrated that an amorphous zirconium hydrated oxide starts to precipitate followed by the precipitation of barium carbonate[1]. A calcination at 1200degreesC during 2 hours gives rise to the formation of a pure barium zirconate phase. In the other methods, barium zirconate was synthesized, in one step without any thermal treatments, by precipitation in highly basic aqueous solutions containing barium and zirconium salts. The effect of the hydroxide concentration was discussed in relation to the barium zirconate phase formation, the particles size and the particles size distribution. For each powder, microstructural characterisations have been performed on sintered bodies in order to evaluate the influence of the thermal treatment on the final density. Dilatometric measurements have been also performed in order to quantify the densification process. Important informations were obtained by these techniques, as for example the existence of an internal porosity which severely limits the final density of the material, even if sintering was performed at high temperature. Thus a careful control of the heating profile seems to be necessary in order to produce dense materials. [less ▲]

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