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See detailModelling weathering processes at the catchment scale: The WITCH numerical model
Godderis, Y.; François, Louis ULg; Probst, A. et al

in Geochimica et Cosmochimica Acta (2006), 70(5), 1128-1147

A numerical model of chemical weathering in soil horizons and underlying bedrock (WITCH) has been coupled to a numerical model of water and carbon cycles in forest ecosystems (ASPECTS) to simulate the ... [more ▼]

A numerical model of chemical weathering in soil horizons and underlying bedrock (WITCH) has been coupled to a numerical model of water and carbon cycles in forest ecosystems (ASPECTS) to simulate the concentration of major species within the soil horizons and the stream of the Strengbach granitic watershed, located in the Vosges Mountains (France). For the first time, simulations of solute concentrations in soil layers and in the catchment river have been performed on a seasonal basis. The model is able to reproduce the concentrations of most major species within the soil horizons, as well as catching the first-order seasonal fluctuations of aqueous calcium, magnesium and silica concentrations. However, the WITCH model underestimates concentrations of Mg2+ and silica at the spring of the catchment stream, and significantly underestimates Ca2+ concentration. The deficit in calculated calcium can be compensated for by dissolution of trace apatite disseminated in the bedrock. However, the resulting increased Ca2+ release yields important smectite precipitation in the deepest model layer (in contact with the bedrock) and subsequent removal of large amount of silica and magnesium from solution. In contrast, the model accurately accounts for the concentrations of major species (Ca, Mg and silica) measured in the catchment stream when precipitation of clay minerals is not allowed. The model underestimation of Mg2+ and H4SiO4 concentrations when precipitation of well crystallized smectites is allowed strongly suggests that precipitation of well crystallized clay minerals is overestimated and that more soluble poorly crystallized and amorphous materials may be forming. In agreement with observations on other watersheds draining granitic rocks, this study indicates that highly soluble trace calcic phases control the aqueous calcium budget in the Strengbach watershed. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailModelling Young’s modulus on small clear specimens in relation to silvicultural treatment.
Jourez, Benoît ULg; Leclercq, André

Report (1994)

The aim of this research work performed in Task 11 "Modelling Young's modulus on small clear specimens in relation to silvicultural treatments" was the modelling of Young's modulus (MOE) on small clear ... [more ▼]

The aim of this research work performed in Task 11 "Modelling Young's modulus on small clear specimens in relation to silvicultural treatments" was the modelling of Young's modulus (MOE) on small clear specimens of 24 Belgian Norway spruces in relation with the silvicultural treatment. The aim of the research was also to compare Young's modulus on small clear specimens with Young's modulus on commercial size specimens with a view to defining the rate of prediction of wood quality of specimens including the natural timber defects. This work is corresponding to one task among the twelve of a large ECC Project entitled "SilvicuItural control and non destructive assessment of timber quality in plantation grown Spruces and Douglas fir" for which 210 trees have been sampled through 6 different European countries. The experimental raw material comes from the southern and eastern part<; of Belgium and concerns four different kinds of stands characterized by the site productivity class and the thinning intensity. Within each stand, the trees have been sampled in three different social positions classes. The small clear specimens have been marked off with reference to the radial and axial positions inside the 24 trees. On the whole 350 clear wood specimens have been selected and tested by two different laboratories in order to get young's modulus by a non destructive four points flexural method described by the French Standard NF B 51-016. Young's modulus appears to be positively related with specific gravity and negatively related with growth ring width. Stands growing on high productive sites or those submitted to low thinnings and also suppressed trees give rise to a stiffer wood. Among all these factors, only the social position of the tree within the stand influences significantly the Young's modulus values. Nevertheless, a slow growth producing a heavier timber is not always linked with a stiffer wood. Young's modulus differences between juvenile and adult wood vary in connection with the specific gravity class considered. In other words, juvenile wood is stiffer than adult wood when referring to low density classes, but adult wood becomes stiffer than juvenile wood when referring to high density classes. That means that the stiffness of adult wood is more sensitive to changes in specific gravity than the stiffness of juvenile wood. The distribution of Young's modulus in relation with specific gravity shows a higher variability when specific gravity increases. In searching the reasons for a higher Young's modulus variability when specific gravity increases by looking back to the population of clear specimens, we point out a very low slope of grain on some specimens and above all the presence of compression wood on other specimens. When rejecting these defects, then it appears that Young's modulus is more strongly related to specific gravity, thus giving rise to more accurate models. Among all these models, the best one is corresponding to a combination of variables such as specific gravity and growth ring width per sampling level within the tree. The variance analysis of residues of each model has revealed a tree effect always very highly significant. On the opposite, the other factors, as site productivity, thinning intensity and social position of the tree within the stand, have no significant effect on Young's modulus values. That means that inter trees variability is far higher than the other sources of variation (intra tree variability, site productivity variability, thinning intensity variability and social position variability). This also means that the general model established is valid whatever the silvicultural treatment could be. [less ▲]

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See detailModelling zooplankton impacts on sedimentation
Darchambeau, François ULg

Conference (2000, May 28)

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See detailModelling zooplankton impacts on sedimentation
Darchambeau, François ULg; Thys, Isabelle; Leporcq, Bruno et al

Poster (2000, June 05)

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See detailModelling, Design, and Optimisation of Net-Zero Energy Buildings
Attia, Shady ULg; Hamdy, Mohamed; Carlucci, Salvatore et al

in Athienitis, Andreas; O’Brien (Eds.) Building Performance Optimisation of Net Zero-Energy Buildings (2015)

Automated mathematical building performance optimisation (BPO) paired with building performance simulation (BPS) is a promising solution to use as a means to evaluating many different design options and ... [more ▼]

Automated mathematical building performance optimisation (BPO) paired with building performance simulation (BPS) is a promising solution to use as a means to evaluating many different design options and obtain the optimal or near optimal for a given objective or combination of objectives (e.g., lowest life-cycle cost, lowest capital cost, highest thermal comfort) while achieving fixed objectives (e.g., net zero-energy) (Wetter 2001; Charron and Athienitis 2006; Christensen and Anderson 2006; Brown, Glicksman et al. 2010; Bucking, Athienitis et al. 2010 ). Traditionally, buildings are designed based on heuristic rules separating the design process into early and late design stages with two different discipline specialisations mainly architecture and engineering. By employing optimisation techniques building designers can cross those barriers between disciplines and address the design process as one continuous stage. Optimisation can allow that by addressing all building design parameters, as shown in Figure 4.1, in a holistic approach allowing the optimisation of geometry, envelope, comfort, systems and renewable. The previously often ill defined design problem would under this perspective be defined as a problem with explicit multi-objective criteria. This will push fully integrated net zero-energy building (Net-ZEB) designs where the builder designers can act to influence the direction of the optimisation. Despite optimisation’s potential in Net-ZEB buildings, it remains largely a research tool and has yet to emerge in common industry practice. As this section reports, major obstacles to BPO in industry include lack of appropriate tools, lack of resources (time, expertise), and the requirement that the problem be very well defined (e.g., constraints, objective function, finite list of design options). The objective of this section is to document the current state-of-the-art and future research in terms of Net-ZEB optimisation tools in practice and its use for design and operation of buildings for energy, comfort and cost optimisation. [less ▲]

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See detailModelling, experimentation and simulation of a reversible HP/ORC unit to get a Positive Energy Building
Dumont, Olivier ULg; Carmo, carolina; Quoilin, Sylvain ULg et al

in ORC15 conference proceedings (2015)

Detailed reference viewed: 36 (8 ULg)
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See detailModelling, simulation and control of flexible multibody systems
Bruls, Olivier ULg; Cardona, Alberto; Géradin, Michel ULg

in Arnold, Martin; Schiehlen, Werner (Eds.) Simulation Techniques in Applied Dynamics (2008)

This chapter concerns the dynamic analysis of flexible multibody systems. After a brief review of the inertial frame, the corotational frame and the floating frame approaches, a general simulation ... [more ▼]

This chapter concerns the dynamic analysis of flexible multibody systems. After a brief review of the inertial frame, the corotational frame and the floating frame approaches, a general simulation framework is presented in detail. Based on the finite element concept, the proposed approach allows the coupled analysis of dynamic systems composed of rigid and flexible bodies, kinematic joints and control elements. The text is illustrated with some didactic examples and industrial applications. [less ▲]

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See detailModelling, Simulation and Optimization of a Shipbuilding Workshop
Bair, Frédéric ULg; Langer, Yves; Caprace, Jean-David ULg et al

in COMPIT'2005 -Conference on Computer Applications and Information Technology in the Maritime Industries, Hamburg (2005, May)

Detailed reference viewed: 165 (31 ULg)
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See detailModellnig of the Hydromechanical Coupling for Non Linear Problems: Fully Coupled and Staggered Approaches
Radu, Jean-Pol ULg; Charlier, Robert ULg

in Proc. of the 8th Int. Conf. of the Int. Ass. for Computer Methods and Advances in Geomechanics (1994, May)

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See detailUn modello di curva di ritenzione per terreni argillosi compattati
Della Vecchia, Gabriele; Jommi, Cristina; Dieudonné, Anne-Catherine ULg

Conference (2013)

Detailed reference viewed: 15 (1 ULg)
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See detailIl modello musical delle chiese nazionali a Rome in epoca barocca: panoramica e nuove prospettive di ricerca
Corswarem, Emilie ULg; Berti, Michela ULg

in Koller, Alexander; Kubersky-Piredda, Susanne (Eds.) Identità e rappresentazione. Le chiese nazionali a Roma, 1450-1650 (2016)

Detailed reference viewed: 15 (0 ULg)
See detail« Il modello musicale delle chiese nazionali a Roma in epoca barocca : panoramica e nuove prospettive di ricerca»
Berti, Michela ULg; Corswarem, Emilie ULg

in Koller, Alexander; Susanne, Kubersky-Piredda (Eds.) Identità e rappresentazione. Le chiese nazionali a Roma, 1450-1650 (in press)

Detailed reference viewed: 20 (1 ULg)
Peer Reviewed
See detailModellreduktion und Analyse des metabolen Netzwerks der Zuckeraufnahme in Escherichia coli
Conzelmann, H.; Sauter, T.; Bullinger, Eric ULg et al

Poster (2003)

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See detailModelo de componentes para análise de ligações de madeira com ligadores metálicos
Cachim, Paulo; Franssen, Jean-Marc ULg

Conference (2011, June 07)

Connections are key elements in any structure because the knowledge of their behaviour is fundamental to an appropriate structural modelling since this behaviour can influence the distribution of efforts ... [more ▼]

Connections are key elements in any structure because the knowledge of their behaviour is fundamental to an appropriate structural modelling since this behaviour can influence the distribution of efforts in different structural elements. In the particular case of wood structures, connections are usually considered as completely rigid or hinged, but their actual behaviour is intermediate between these two extreme limits, depending on the geometry of the connection and the type of connector used. For the design of these connections, the methodology proposed by Eurocode 5 is based on plastic limit analysis which allows the determination of load strength of the connection but not the determination of its stiffness. For the determination of stiffness, Eurocode 5 presents just a very simple expression that depends only on the density of the wood and the diameter of connector to characterize the force-displacement behaviour, disregarding for this purpose the geometry of the connection or the angle of force in relation to the grain. The objective of this paper is to present a component model that allows the characterization of the behaviour of dowel type connections. The results obtained with the model were calibrated with experimental results obtained in the litterature. [less ▲]

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See detailModels and Analysis Tools for the Columbus Contamination Environment
De Leuze, Anne; Barbier, Christian ULg

Conference (1991)

Detailed reference viewed: 4 (1 ULg)
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See detailModels and prospects for a sustainable suburban transition.
Marique, Anne-Françoise ULg; Reiter, Sigrid ULg

Conference (2013, July)

This paper addresses the challenges, transformations and conditions of a sustainable suburban transition. Two powerful levers are used: (1) urban form, which is considered in addition to the individual ... [more ▼]

This paper addresses the challenges, transformations and conditions of a sustainable suburban transition. Two powerful levers are used: (1) urban form, which is considered in addition to the individual building scale, and (2) mobility, because sprawl spatially separates activities, resulting in an increase in travel distances and energy used in transportation. Two main indicators (the heating needs of different types of suburban forms and a commute performance index) are developed and discussed. Three scenarios focused on the evolution of the existing building stock are modelled and assessed (the retrofitting of existing neighbourhoods, an increase in the built density and demolition / reconstruction) to answer two main questions: "how to intervene in suburban areas?" and" where to intervene? ". These main results focused on energy efficiency are then studied in a larger framework to highlight the opportunities, limitations, constraints and feasibility of each strategy. Concrete prospects and guidelines for policy makers are finally proposed to operationalize a "sustainable suburban renewal". These findings show that, beyond the traditional polarization of the debates on energy efficiency of our built environment between the “compact city” and the “sprawled city”, a new pragmatic paradigm, focused on the transition of suburban areas by densification, can make suburban areas evolve towards more sustainability. [less ▲]

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See detailModels describing the use of resources as basis for decision making
Kopriwa, Nicole; Pfennig, Andreas ULg

in Proceedings of Megacities - Interactions Between Land Use and Water Management (2010)

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See detailModels for assessing the cost-effectiveness of the treatment and prevention of osteoporosis
Zethraeus, N.; Ben Sedrine, Wafa ULg; Caulin, F. et al

in Osteoporosis International (2002), 13(11), 841-857

Detailed reference viewed: 85 (15 ULg)
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See detailModels for Decision Making: From Applications to Mathematics... and Back
Crama, Yves ULg

Conference (2010, March 15)

In this inaugural lecture, I describe some facets of the interplay between mathematics and management science, economics, or engineering, as they come together in operations research models. I intend to ... [more ▼]

In this inaugural lecture, I describe some facets of the interplay between mathematics and management science, economics, or engineering, as they come together in operations research models. I intend to illustrate, in particular, the complex and fruitful process through which fundamental combinatorial models find applications in management science, which in turn foster the development of new and challenging mathematical questions. [less ▲]

Detailed reference viewed: 21 (0 ULg)