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See detailNon Gaussian Response of Bridges Subjected to Turbulent Wind – Effect of the non Linearity of Aerodynamic Coefficients
Denoël, Vincent ULg; Degée, Hervé ULg

in Proceedings of the 3rd European Conference on Computational Solid and Structural Mechanics (2006)

In the context of a non linear quasi-steady wind loading, this paper shows the importance of the non linearity of the wind loading. More particularly, it focuses of the influence, on the structural ... [more ▼]

In the context of a non linear quasi-steady wind loading, this paper shows the importance of the non linearity of the wind loading. More particularly, it focuses of the influence, on the structural response, of the non linearity of the aerodynamic coefficients. It is shown that, in case of 2-D turbulent flow, the influence of this kind of non linearity may be significant. To do so, statistical characteristics of the loading as well as those of the response are computed in such a turbulent flow. [less ▲]

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See detailThe role of landscape design in improving the microclimate in traditional courtyard buildings in hot arid climates
Attia, Shady ULg

in Proceedings of 23rd International Conference on Passive and Low Energy Architecture - PLEA 2006 (2006)

Arab Islamic landscape design forms a unique source of inspiration for landscape architecture in barren open spaces of the Middle East. Arab Islamic gardens adopted a system marked by perfect ... [more ▼]

Arab Islamic landscape design forms a unique source of inspiration for landscape architecture in barren open spaces of the Middle East. Arab Islamic gardens adopted a system marked by perfect responsiveness to environment. The design of urban landscape and gardens in Arab Islamic culture was similarly guided by the dictation of aridity. The need to provide shade, to prevent dust and to conserve water meant that urban open spaces and gardens were sheltered and enclosed. Alhambra in Moorish Spain and the Al-Suhaymi House in Islamic Cairo are two useful historical references for vernacular Islamic landscape designs. This paper presents an overview of landscape design considerations for the composition of vegetation and water and initial observations of their influence in controlling and improving the microclimate in courtyards buildings as a way of passive cooling in the Middle East region. This paper is a part of a Master’s thesis in the field of passive landscape strategies at Wageningen University. The objective is to identify the comfort improvements potential of successfully-planned and integrated landscape design in traditional courtyard buildings. The layout and plant material of Alhambra, Generalife courts and Al-Suhaymi court in Islamic Cairo are examined and evaluated. This study demonstrates that in arid environments, the landscape planning, the composition of vegetation and water and choice of planting material all have important consequences in creating thermally-pleasant environments. [less ▲]

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See detailRépartition et écologie des reptiles sur le réseau ferroviaire en Wallonie
Graitson, Eric ULg

in Bulletin de la Société Herpétologique de France (2006), 120

In Wallonia, railways constitute valuable habitats for reptile conservation. All autochthonous species have colonized these man-made habitats, but their presence and abundance largely vary among the ... [more ▼]

In Wallonia, railways constitute valuable habitats for reptile conservation. All autochthonous species have colonized these man-made habitats, but their presence and abundance largely vary among the natural regions and the kinds of railways. Reptiles are more frequent along railways with remaining rails than along dismounted unused ways, which represents one half of the network. Although representing only a small part of the network, the unused railways not dismounted are particularly rich in reptiles. This is also the case of some active lines in sunny areas of large valleys and in some large switchyards. Anguis fragilis is the most widespread species on the Walloon railways, but P o d a rcis muralisis the most abundant. In Wallonia, railways seemed to have contributed to the local, more rarely regional, dispersion of at least five species of reptiles: Anguis fragilis, Lacerta agilis, Podarcis muralis, Zootoca viviparaa and Coronella austriaca. Some of these species – specifically Podarcis muralis– have most probably colonized new regions through unexpected transportation by merchandise cars. Finally, reptile populations inhabiting the Walloon railways face several threads. [less ▲]

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See detailTabac et poids corporel
PAQUOT, Nicolas ULg

in Patient Care (2006), (juin), 6-9

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See detailAn investigation on the sliding of pallets on storage racks subjected to earthquake
Degée, Hervé ULg; Denoël, Vincent ULg

in Proceedings of the 7th National Congres on Theoretical and Applied Mechanics (2006)

This article presents some basic aspects of a research about the evaluation of the effect of earthquakes on storage racking systems. In particular, it focuses on the possible sliding and friction of the ... [more ▼]

This article presents some basic aspects of a research about the evaluation of the effect of earthquakes on storage racking systems. In particular, it focuses on the possible sliding and friction of the stored good subjected to a horizontal inertial force. In the first part, a theoretical SDOF system is studied to derive general indications on the sliding behavior and to serve as a reference for the validation of a more advanced numerical model. The second part presents then an application of the numerical model to simple rack structures. [less ▲]

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See detailModave/Modave : étude de la séquence pléistocène-holocène du Trou Al'Wesse
Miller, Rebecca ULg; Otte, Marcel ULg; Zwyns, Nicolas

in Chronique de l'Archéologie Wallonne (2006), 13

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See detailEffect of excavation induced fractures on radionuclide migration through the Boom Clay (Belgium)
Huysmans, Marijke; Berckmans, Arne; Dassargues, Alain ULg

in Applied Clay Science (2006), 33(3-4), 207-218

In Belgium, the Boom Clay is being evaluated as a potential host formation for the disposal of high-level nuclear waste. In order to investigate this option, an underground research facility composed of ... [more ▼]

In Belgium, the Boom Clay is being evaluated as a potential host formation for the disposal of high-level nuclear waste. In order to investigate this option, an underground research facility composed of two access shafts and 200m of galleries was excavated. Excavation induced fractures were observed in a zone of approximately 1 m around the galleries. In this study, the potential effect of these fractures on radionuclide migration in the Boom Clay is investigated. Therefore, a hydrogeological model of the clay is built with a radionuclide source in the middle of the clay layer surrounded by different fracture configurations. Two types of fracture configurations are inserted in the model. The first type of fracture properties is drawn stochastically from the probability distributions of the properties of the fractures observed around previously excavated galleries. These fracture patterns are considered to be realistic although in this study it is conservatively assumed that no self-sealing occurs. The model is run for a large number of stochastically drawn fracture configurations and the results are compared to a model without fractures. These calculations show that the radionuclide fluxes through the clay are not significantly influenced by these fractures. For the second type of fracture configurations, the fracture properties are varied over a much larger range. Hypothetical fractures with much higher values of fracture extent, aperture, dip and frequency than observed are modeled, With these hypothetical fracture configurations, the critical values of the fracture parameters are determined that must be exceeded to have a significant effect on the radionuclide fluxes through the clay. These calculations show that the extent of the fractured zone has the largest effect on radionuclide migration. The other fracture parameters (aperture, spacing and dip) have a limited effect on the radionuclide fluxes. To obtain a total radionuclide flux through the lower clay boundary that is respectively 10%, 50% and 100% larger than without a fractured zone, the extent of the hypothetical fractured zone should be respectively 27.97 m, 43.86 m and 46.92 m. Such fractures are not expected to be generated by mechanical excavation in the Boom Clay. The obtained critical extent values of the hypothetical fractures are a factor 30 to 40 higher than the measured values of the extent of the excavation disturbed zone. These calculations thus indicate that it is very unlikely that the extent of the fractured zone around the galleries will be large enough to have a significant effect on the radionuclide fluxes through the Boom Clay. This conclusion is further supported by the conservative assumption that no self-sealing occurs. These calculations can function as a preliminary robustness test in ongoing safety analysis studies. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailNumerical study of the fatigue crack in welded beam-to-column connection using cohesive zone model
Lequesne, Cédric ULg; Plumier, André ULg; Degée, Hervé ULg et al

in Proceedings of the International Conference on Fracture and Damage Mechanics V (2006)

The fatigue behaviour of the welded beam-to-column connections of steel moment resisting frame in seismic area must be evaluated. The cohesive zone model is an efficient solution to study such connections ... [more ▼]

The fatigue behaviour of the welded beam-to-column connections of steel moment resisting frame in seismic area must be evaluated. The cohesive zone model is an efficient solution to study such connections by finite elements. It respects the energetic conservation and avoids numerical issues. A three-dimensional cohesive zone model element has been implemented in the home made finite element code Lagamine [1]. It is coupled with the fatigue continuum damage model of Lemaître and Chaboche [2]. The cohesive parameters are identified by the inverse method applied on a three points bending test modelling. [less ▲]

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See detailNumber-Set Representations for Infinite-State Verification
Boigelot, Bernard ULg

in Proceedings of VISSAS 2005 (2006)

In order to compute the reachability set of infinite-state models, one needs a technique for exploring infinite sequences of transitions in finite time, as well as a symbolic representation for the finite ... [more ▼]

In order to compute the reachability set of infinite-state models, one needs a technique for exploring infinite sequences of transitions in finite time, as well as a symbolic representation for the finite and infinite sets of configurations that are to be handled. The representation problem can be solved by automata-based methods, which consist in representing a set by a finite-state machine recognizing its elements, suitably encoded as words over a finite alphabet. Automata-based set representations have many advantages: They are expressive, easy to manipulate, and admit a canonical form. In this survey, we describe two automata-based structures that have been developed for representing sets of numbers (or, more generally, of vectors): The Number Decision Diagram (NDD) for integer values, and the Real Vector Automaton (RVA) for real numbers. We discuss the expressiveness of these structures, present some construction algorithms, and give a brief introduction to some related acceleration techniques. [less ▲]

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See detailLes couples de personnes de même sexe en droit belge, sous l'angle particulier du droit international privé
Wautelet, Patrick ULg

in Leleu, Yves-Henri (Ed.) Rapports belges au Congrès de l'Académie internationale de droit comparé à Utrecht (2006)

In this report written for the Utrecht Congress of the International Academy of International Law, I review the position of same sex couples, be they married or bound by a partnership, under Belgian law ... [more ▼]

In this report written for the Utrecht Congress of the International Academy of International Law, I review the position of same sex couples, be they married or bound by a partnership, under Belgian law. Specific attention is devoted to the treatment under Belgian law of cross-border couples (couples with other nationalities than Belgian nationality, or whose habitual residence is or was established outside Belgium). Among the questions studied two stand out : first the question of who can validly conclude a same sex marriage or enter into a partnership in Belgium and second the issue of the recognition in Belgium of same sex marriages or partnerships concluded abroad. [less ▲]

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See detailIn situ study of cotton dyed fibres by Raman spectroscopy
Lepot, Laurent ULg

Conference (2006)

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See detailBitterkomix: de kunstvorm anders bekeken
Meesters, Gert ULg

in Kannemeyer, Anton; Botes, Conrad (Eds.) The Big Bad Bitterkomix Handbook (2006)

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See detailQuelques réflexions sur l'activité du juge constitutionnel comme législateur-cadre
Behrendt, Christian ULg

in Cahiers du Conseil constitutionnel (2006), n° 20

The article summarizes a PhD research in comparative constitutional law, dealing with the influence of the constitutional courts of France, Germany and Belgium on their respective legislative norm-making ... [more ▼]

The article summarizes a PhD research in comparative constitutional law, dealing with the influence of the constitutional courts of France, Germany and Belgium on their respective legislative norm-making bodies. [less ▲]

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See detailStrategic assessment of urban cultural heritage : the case of Old Town Square in Prague
Teller, Jacques ULg; Drdacky, T.

in European research on cultural heritage : state of the art studies - Vol. 4 (2006)

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See detailInbreeding depression for global and partial economic indexes, production, type, and functional traits
Croquet, Coraline; Mayeres, Patrick; Gillon, Alain ULg et al

in Journal of Dairy Science (2006), 89(6), 2257-2267

The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and ... [more ▼]

The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and its components were studied by using data from the genetic evaluations of February 2004 for production, somatic cell score (SCS), computed from somatic cell counts and type. Inbreeding coefficients for 956,516 animals were computed using a method that allows assigning an inbreeding coefficient to individuals without known parents. These coefficients were equal to the mean inbreeding coefficient of contemporary individuals with known parents. The significance of inbreeding effects on the different evaluated traits and on the different indexes were tested using a t-test comparing estimated standard errors and effects. The inbreeding effect was significantly different from zero for the vast majority of evaluated traits and for all of the indexes. Inbreeding had the greatest deleterious effects on production traits. Inbreeding decreased yield of milk, fat, and protein during a lactation by 19.68, 0.96, and 0.69 kg, respectively, per each 1% increase in inbreeding. The regression coefficient of SCS per 1% increase in inbreeding was +0.005 SCS units. The inbreeding depression was thus relatively low for SCS, but inbred animals had higher SCS than non-inbred animals, indicating that inbred animals would be slightly more sensitive to mastitis than non-inbred animals. Estimates of inbreeding effects on evaluated type traits per 1% increase were small. The most strongly affected type traits were chest width, rear leg, and overall development on a standardized scale. For several type traits, particularly traits linked to the udder, the estimates suggested a favorable effect of inbreeding. The global economic index was depressed by around 6.13 Euro of lifetime profit per 1% increase in inbreeding for the Holstein animals in the Walloon region of Belgium. [less ▲]

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See detailEvaluation of hoverfly Episyrphus balteatus De Geer (Diptera: Syrphidae) oviposition behaviour toward aphid-infested plants using a leaf disc system.
Almohamad, Raki; Verheggen, François ULg; Francis, Frédéric ULg et al

in Communications in Agricultural and Applied Biological Sciences (2006), 71(2 Pt B), 403-12

Several aphidophagous beneficials such as parasitoids and predators are known to respond positively to aphid infested plants. Semiochemicals from the latter association play an important role in the ... [more ▼]

Several aphidophagous beneficials such as parasitoids and predators are known to respond positively to aphid infested plants. Semiochemicals from the latter association play an important role in the foraging of predators in a tritrophic approach. In this work, three host plants infested with green peach aphid, Myzus persicae Sulzer were used to study the effect of prey density and aphid colony location on plant toward Episyrphus balteatus female. Their reproductive behaviour and efficiency (in terms of fecundity) were observed in net cages. Three kinds of experiments were performed using a disc leaf on agar diet in small Petri dishes under different conditions: 1) leaf disc of broad bean (Vicia faba) were infested with different aphid prey densities, 2) three host plants (Vicia faba, Solanum tuberosum, Solanum nigrum) infested with 3 different aphid prey densities and 3) three different heights of aphid colony location on V. faba plant infested with constant aphid density were also tested using leaf disc system. Aphid-free leaf discs were also used as control for predator behaviour observations. Oviposition rates of hoverfly on leaf disc system vary significantly with prey aphid densities. The means of eggs per laying were 0.9, 5.3, and 31.2 for 0, 10 and 100 aphid densities respectively. E. balteatus females were also able to evaluate and adjust oviposition rates according to different aphid prey densities/host plant. The 5 and 20 cm stakes were the most attractive heights of aphid colony location for the hoverfly oviposition. The means of eggs per laying were 16.7, 18.5 and 5.8 for 5, 20 and 40cm heights respectively. Our leaf disc system was found to be a practical and efficient way to assess chemical cues from aphids according to different conditions on the hoverfly reproductive behaviour. [less ▲]

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