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See detailCoupling building energy simulation and computational fluid dynamics: Application to a two-storey house in a temperate climate
Barbason, Mathieu ULg; Reiter, Sigrid ULg

in Building & Environment (2014), 75

This article reports the coupling of a building energy simulation (BES) made with TRNSYS with a computational fluid dynamics (CFD) simulation made with ANSYS FLUENT and its application to a typical ... [more ▼]

This article reports the coupling of a building energy simulation (BES) made with TRNSYS with a computational fluid dynamics (CFD) simulation made with ANSYS FLUENT and its application to a typical Belgian two-storey house. The coupling scheme developed in this study aims to improve the overheating prediction for buildings. This phenomenon is becoming increasingly frequent in Northern Europe due to increased insulation and a lack of sun protection and natural cooling strategies. Complementary contributions of the two numerical approaches are underlined and used to obtain accurate results in an acceptable computing time, even in a thermally stratified room. The space and time coupling is discussed to obtain an optimised tool in which BES is in charge of the primary portion of the effort, while CFD intervenes punctually on one room of interest. The numerical results are compared both qualitatively and quantitatively to the experimental results, and the improved accuracy of the coupled tool compared with a standalone BES is underlined. [less ▲]

Detailed reference viewed: 63 (22 ULg)
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See detailCoupling cell cycle exit, neuronal differentiation and migration in cortical neurogenesis.
Nguyen, Laurent ULg; Besson, Arnaud; Roberts, James M et al

in Cell Cycle (Georgetown, Tex.) (2006), 5(20), 2314-8

The generation of new neurons in the cerebral cortex requires that progenitor cells leave the cell cycle and activate specific programs of differentiation and migration. Genetic studies have identified ... [more ▼]

The generation of new neurons in the cerebral cortex requires that progenitor cells leave the cell cycle and activate specific programs of differentiation and migration. Genetic studies have identified some of the molecules controlling these cellular events, but how the different aspects of neurogenesis are integrated into a coherent developmental program remains unclear. One possible mechanism implicates multifunctional proteins that regulate, both cell cycle exit and cell differentiation.(1) A prime example is the cyclin-dependent kinase inhibitor p27(Kip1), which has recently been shown to function beyond cell cycle regulation and promote both neuronal differentiation and migration of newborn cortical neurons, through distinct and separable mechanisms. p27(Kip1) is therefore part of a machinery that couples the multiple events of neurogenesis in the cerebral cortex. [less ▲]

Detailed reference viewed: 41 (1 ULg)
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See detailCoupling Cell Mechanics and Intracellular Signalling: Mechanotransduction through ERK
Kerkhofs, Johan ULg; Geris, Liesbet ULg; Bosmans, Bart et al

in Middleton, John (Ed.) The Proceedings of the 10th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering. Hotel Berlin, Berlin, Germany, April 7th – 11th, 2012 pages:0-0 (2012, April 12)

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See detailCoupling curvature-dependent and shear stress-stimulated neotissue growth in dynamic bioreactor cultures: a 3D computational model of a complete scaffold.
Guyot, Y.; Papantoniou, I.; Luyten, F. P. et al

in Biomechanics & Modeling in Mechanobiology (2016), 15(1), 169-80

The main challenge in tissue engineering consists in understanding and controlling the growth process of in vitro cultured neotissues toward obtaining functional tissues. Computational models can provide ... [more ▼]

The main challenge in tissue engineering consists in understanding and controlling the growth process of in vitro cultured neotissues toward obtaining functional tissues. Computational models can provide crucial information on appropriate bioreactor and scaffold design but also on the bioprocess environment and culture conditions. In this study, the development of a 3D model using the level set method to capture the growth of a microporous neotissue domain in a dynamic culture environment (perfusion bioreactor) was pursued. In our model, neotissue growth velocity was influenced by scaffold geometry as well as by flow- induced shear stresses. The neotissue was modeled as a homogenous porous medium with a given permeability, and the Brinkman equation was used to calculate the flow profile in both neotissue and void space. Neotissue growth was modeled until the scaffold void volume was filled, thus capturing already established experimental observations, in particular the differences between scaffold filling under different flow regimes. This tool is envisaged as a scaffold shape and bioprocess optimization tool with predictive capacities. It will allow controlling fluid flow during long-term culture, whereby neotissue growth alters flow patterns, in order to provide shear stress profiles and magnitudes across the whole scaffold volume influencing, in turn, the neotissue growth. [less ▲]

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See detailCoupling EIA and SEA of large urban infrastructures: the Liege-Guillemins case study
Cremasco, Veronica; Ruelle, Christine ULg; Teller, Jacques ULg

in Proc. of COST C8 final conference, Sustainable Urban Infrastructure, approaches – solutions – networking (2003)

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See detailCoupling GIS with database for hydrogeological mapping.
Bouezmarni, Mohamed ULg

Conference (2003, May)

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See detailCoupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers
Wildemeersch, Samuel ULg; Jamin, Pierre ULg; Orban, Philippe ULg et al

in Journal of Contaminant Hydrology (2014), 169

Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore ... [more ▼]

Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ. However, there is a lack of in situ experiments and methodology for performing such a field characterization, especially for open systems. This study presents an in situ experiment designed for estimating heat transfer parameters in shallow alluvial aquifers with focus on the specific heat capacity. This experiment consists in simultaneously injecting hot water and a chemical tracer into the aquifer and monitoring the evolution of groundwater temperature and concentration in the recovery well (and possibly in other piezometers located down gradient). Temperature and concentrations are then used for estimating the specific heat capacity. The first method for estimating this parameter is based on a modeling in series of the chemical tracer and temperature breakthrough curves at the recovery well. The second method is based on an energy balance. The values of specific heat capacity estimated for both methods (2.30 and 2.54 MJ/m3/K) for the experimental site in the alluvial aquifer of the Meuse River (Belgium) are almost identical and consistent with values found in the literature. Temperature breakthrough curves in other piezometers are not required for estimating the specific heat capacity. However, they highlight that heat transfer in the alluvial aquifer of the Meuse River is complex and contrasted with different dominant process depending on the depth leading to significant vertical heat exchange between upper and lower part of the aquifer. Furthermore, these temperature breakthrough curves could be included in the calibration of a complex heat transfer model for estimating the entire set of heat transfer parameters and their spatial distribution by inverse modeling. [less ▲]

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See detailCoupling heat and salt tracer experiment for the estimation of heat transfer and solute transport parameters
Wildemeersch, Samuel ULg; Jamin, Pierre ULg; Orban, Philippe ULg et al

Conference (2013, April 22)

Geothermal energy is a promising source of energy in the context of sustainable development. Therefore, very low enthalpy geothermal systems (open or closed) are increasingly considered for heating or ... [more ▼]

Geothermal energy is a promising source of energy in the context of sustainable development. Therefore, very low enthalpy geothermal systems (open or closed) are increasingly considered for heating or cooling houses and offices using groundwater energy. However, prior to the development of such systems, a feasibility study and an impact study of the system on groundwater ressources are required. Thereliability of such studies is highly dependent on the quality of the estimation of heat transfer parameters. This highlights the necessity of estimating properly such parameters. The objective of this study is to combine the use of heat and salt tracers to estimate simultaneously heat transfer and solute transport parameters in an alluvial aquifer. Additionally, coupling heat and salt tracing experiments is particularly useful for comparing heat transfer and solute transport processes occurring in the subsurface. An experimental field site, located near Liege (Belgium), is equipped with 21 piezometers drilled in the alluvial deposits of the Meuse River. These alluvial deposits are composed of a loess layer (3 m) overlying a sand and gravel layer which constitutes the alluvial aquifer (7 m). The coupled tracing experiment consists in injecting simultaneously heated water and salt in a piezometer and monitoring the evolution of groundwater temperature and salt concentration in a series of control panels set perpendicularly to groundwater flow. This coupled tracing experiment is then simulated using a numerical model. The estimation of heat transfer and solute transport parameters is obtained by calibrating this numerical model using inversion tools. The present study proposes a methodology coupling heat and salt tracing experiment for estimating heat transfer parameters at the field scale. Furthermore, this coupled tracing experiment shows that the comportment of heat and solute in the subsurface presents key differences. [less ▲]

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See detailCoupling long term database with SWAT and STICS models for testing modles and simulating nitrogen management scenarios
Deneufbourg, Mathieu ULg; Pugeaux, Nicolas; Huguet, Jean et al

Poster (2012, June 26)

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See detailCoupling of cell migration with neurogenesis by proneural bHLH factors.
Ge, Weihong; He, Fei; Kim, Kevin J. et al

in Proceedings of the National Academy of Sciences of the United States of America (2006), 103(5), 1319-24

After cell birth, almost all neurons in the mammalian central nervous system migrate. It is unclear whether and how cell migration is coupled with neurogenesis. Here we report that proneural basic helix ... [more ▼]

After cell birth, almost all neurons in the mammalian central nervous system migrate. It is unclear whether and how cell migration is coupled with neurogenesis. Here we report that proneural basic helix-loop-helix (bHLH) transcription factors not only initiate neuronal differentiation but also potentiate cell migration. Mechanistically, proneural bHLH factors regulate the expression of genes critically involved in migration, including down-regulation of RhoA small GTPase and up-regulation of doublecortin and p35, which, in turn, modulate the actin and microtubule cytoskeleton assembly and enable newly generated neurons to migrate. In addition, we report that several DNA-binding-deficient proneural genes that fail to initiate neuronal differentiation still activate migration, whereas a different mutation of a proneural gene that causes a failure in initiating cell migration still leads to robust neuronal differentiation. Collectively, these data suggest that transcription programs for neurogenesis and migration are regulated by bHLH factors through partially distinct mechanisms. [less ▲]

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See detailCoupling of hydrogeological models with hydrogeophysical data to characterize seawater intrusion and shallow geothermal systems
Beaujean, Jean ULg; Kemna, Andreas; Engesgaard, Peter et al

Conference (2013, December 12)

While coastal aquifers are being stressed due to climate changes and excessive groundwater withdrawals require characterizing efficiently seawater intrusion (SWI) dynamics, production of geothermal energy ... [more ▼]

While coastal aquifers are being stressed due to climate changes and excessive groundwater withdrawals require characterizing efficiently seawater intrusion (SWI) dynamics, production of geothermal energy is increasingly being used to hinder global warming. To study these issues, we need both robust measuring technologies and reliable predictions based on numerical models. SWI models are currently calibrated using borehole observations. Similarly, geothermal models depend mainly on the temperature field at few locations. Electrical resistivity tomography (ERT) can be used to improve these models given its high sensitivity to TDS and temperature and its relatively high lateral resolution. Inherent geophysical limitations, such as the resolution loss, can affect the overall quality of the ERT images and also prevent the correct recovery of the desired hydrochemical property. We present an uncoupled and coupled hydrogeophysical inversion to calibrate SWI and thermohydrogeologic models using ERT. In the SWI models, we demonstrate with two synthetic benchmarks (homogeneous and heterogeneous coastal aquifers) the ability of cumulative sensitivity-filtered ERT images using surface-only data to recover the hydraulic conductivity. Filtering of ERT-derived data at depth, where resolution is poorer, and the model errors make the dispersivity more difficult to estimate. In the coupled approach, we showed that parameter estimation is significantly improved because regularization bias is replaced by forward modeling only. Our efforts are currently focusing on applying the uncoupled/coupled approaches on a real life case study using field data from the site of Almeria, SE Spain. In the thermohydrogeologic models, the most sensitive hydrologic parameters responsible for heat transport are estimated from surface ERT-derived temperatures and ERT resistance data. A real life geothermal experiment that took place on the Campus De Sterre of Ghent University, Belgium and a synthetic case are tested. They consist in a thermal injection and storage of water in a shallow sandy aquifer. The use of a physically-based constraint accounting for the difference in conductivity between the formation and the tap injected water and based on the hydrogeological model calibrated first on temperatures is necessary to improve the parameter estimation. Results suggest that time-lapse ERT data may be limited but useful information for estimating groundwater flow and transport parameters for both the convection and conduction phases. [less ▲]

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See detailCoupling of Liquid Chromatography/Tandem Mass Spectrometry and Liquid Chromatography/Solid-Phase Extraction/NMR Techniques for the Structural Identification of Metabolites following In Vitro Biotransformation of SUR1-Selective ATP-Sensitive Potassium Channel Openers
Gillotin, F.; Chiap, Patrice ULg; Frederich, Michel ULg et al

in Drug Metabolism and Disposition : The Biological Fate of Chemicals (2010), 38(2), 232-240

SUR1-selective ATP-sensitive potassium channel openers (PCOs) have been shown to be of clinical value for the treatment of several metabolic disorders, including type I and type II diabetes, obesity and ... [more ▼]

SUR1-selective ATP-sensitive potassium channel openers (PCOs) have been shown to be of clinical value for the treatment of several metabolic disorders, including type I and type II diabetes, obesity and hyperinsulinemia. Taking into account these promising therapeutic benefits, different series of 3-alkylamino-4H-1,2,4-benzothiadiazine 1,1-dioxides structurally related to diazoxide were developed. In view of the lead optimisation process of the series, knowledge of ADMET parameters, and more particularly the metabolic fate of these compounds, is a fundamental requirement. For such a purpose, two selected promising compounds (BPDZ 73 and BPDZ 157) were incubated in the presence of phenobarbital-induced rat liver microsomes to produce expected mammal in vivo phase I metabolites. The resulting major metabolites were then analysed by both MS and NMR in order to completely elucidate their chemical structures. The two compounds were also further incubated in the presence of non-treated rats and human microsomes in order to compare the metabolic profiles. In the present study, the combined use of an exact mass LC-MS/MS platform and a LC-SPE-NMR system allowed the clarification of some unresolved structural assessments in the accurate chemical structure elucidation process of the selected PCOs drugs. These results greatly help the optimization of the lead compounds. [less ▲]

Detailed reference viewed: 159 (42 ULg)
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See detailCoupling of Local and Global Quantities in Various Finite Element Formulations and its Application to Electrostatics, Magnetostatics and Magnetodynamics
Dular, Patrick ULg; Legros, Willy ULg; Nicolet, André

in IEEE Transactions on Magnetics (1998), 34(5), 3078-3081

A method for defining global quantities related to fluxes and circulations is proposed in the frame of the finite element method. The definition is in perfect accordance with the discretized weak ... [more ▼]

A method for defining global quantities related to fluxes and circulations is proposed in the frame of the finite element method. The definition is in perfect accordance with the discretized weak formulations of the problems. It therefore enables a natural coupling between local and global quantities in various formulations, while keeping a symmetrical matrix for the system, and then is open to the coupling of physical problems. Applications are given for electrostatics, magnetostatics and magnetodynamics [less ▲]

Detailed reference viewed: 13 (4 ULg)
See detailCoupling of N Qubits to Any Dicke State via Projective Measurements
Thiel, C.; Maser, A.; Bastin, Thierry ULg et al

Conference (2008)

Detailed reference viewed: 8 (0 ULg)
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See detailCoupling of parallel river and groundwater models to simulate dynamic groundwater boundary conditions
Carabin, Guy; Dassargues, Alain ULg

in Bentley, L. R.; Sykes, J. F.; Brebbia, C. A. (Eds.) et al Proc. of Computational Methods in Water Resources 2000 (2000)

Detailed reference viewed: 24 (2 ULg)
Peer Reviewed
See detailThe coupling of quark and gluon condensates in hot and dense systems
Jaminon, Martine ULg; Van den Bossche, Bruno

in Nuclear Physics A (1994), 567

Detailed reference viewed: 10 (1 ULg)