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See detailValidation of x-ray microfocus computed tomography as an imaging tool for porous structures.
Kerckhofs, Greet ULiege; Schrooten, J.; Van Cleynenbreugel, T. et al

in The Review of scientific instruments (2008), 79(1), 013711

X-ray microfocus computed tomography (micro-CT) is recently put forward to qualitatively and quantitatively characterize the internal structure of porous materials. However, it is known that artifacts ... [more ▼]

X-ray microfocus computed tomography (micro-CT) is recently put forward to qualitatively and quantitatively characterize the internal structure of porous materials. However, it is known that artifacts such as the partial volume effect are inherently present in micro-CT images, thus resulting in a visualization error with respect to reality. This study proposes a validation protocol that in the future can be used to quantify this error for porous structures in general by matching micro-CT tomograms to microscopic sections. One of the innovations of the protocol is the opportunity to reconstruct an interpolated micro-CT image under the same angle as the physical cutting angle of the microscopic sections. Also, a novel thresholding method is developed based on matching micro-CT and microscopic images. In this study, titanium porous structures are assessed as proof of principle. It is concluded for these structures that micro-CT visualizes 89% of the total amount of voxels (solid and pore) correctly. However, 8% represents an overestimation of the real structure and 3% are real structural features not visualized by micro-CT. When exclusively focusing on the solid fraction in both the micro-CT and microscopic images, only an overestimation of about 5% is found. [less ▲]

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See detailVALIDATION OF “PROCULTURE” MODEL TO PREDICT SEPTORIA TRITICI DEVELOPMENT ON WINTER WHEAT IN THE GRAND-DUCHÉ OF LUXEMBOURG IN 2001.
El Jarroudi, Moussa ULiege; Tychon, Bernard ULiege; Maraite, Henri

in Villalobos, Francisco J.; Testi, Luca (Eds.) VII Congress of the European Society For Agronomy (2002, July)

Detailed reference viewed: 56 (8 ULiège)
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See detailValidation par biomarqueurs d’un FFQ permettant d’étudier le lien entre alimentation et risques cardiovasculaires
Sauvageot, Nicolas ULiege; Alkerwi, Alaa; Donneau, Anne-Françoise ULiege et al

Poster (2012, September)

Introduction La recherche sur l'alimentation et son lien avec les maladies nécessite une collecte rigoureuse des données nutritionnelles permettant d'estimer avec précision l'apport nutritionnel. Le « ... [more ▼]

Introduction La recherche sur l'alimentation et son lien avec les maladies nécessite une collecte rigoureuse des données nutritionnelles permettant d'estimer avec précision l'apport nutritionnel. Le « Food Frequency Questionnaire (FFQ) » a été choisie pour étudier le lien entre alimentation et risques cardiovasculaires dans un échantillon représentatif de la Grande région recruté pour l’étude NESCAV (Nutrition, environnement et santé cardio-vasculaire). Objectif Valider le FFQ utilisé à l’aide de biomarqueurs afin d’évaluer son habilité à estimer correctement les habitudes alimentaires. Méthodes Afin de prendre en compte les spécificités de la Grande région et le volet cardio-vasculaire, la liste d’items d’un FFQ existant a été modifiée et élargie. Tous les nutriments calculés à partir du FFQ ont été ajustés par rapport à l’énergie par la méthode des résidus. La comparaison des nutriments calculés par le FFQ et les bio-marqueurs correspondants a été faite par le calcul des coefficients de corrélation avec ajustement sur plusieurs facteurs confondants. L’accord entre les deux méthodes a été estimé par le calcul des pourcentages de concordance et du coefficient Kappa. Résultats La validation s’est effectuée sur un échantillon de 466 sujets (236 hommes et 241 femmes). Des corrélations significatives ont été observées pour les folates, le β-carotène dans les deux sexes et pour la vitamine B12 et l’iode chez les femmes. Discussion Ces résultats sont comparables à ceux d’études précédentes. Les corrélations sont souvent expliquées par le fait que les nutriments du FFQ représentent la quantité ingérée alors que les biomarqueurs représentent la quantité absorbée par le corps. [less ▲]

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See detailValidation Process for CFD Simulations of Wind Around Buildings
Reiter, Sigrid ULiege

in Proceedings of the European Built Environment CAE Conference (2008)

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See detailA validation process for CFD use in building physics – study of contaminant dispersion.
Barbason, Mathieu ULiege; Reiter, Sigrid ULiege

in Proceedings of the 5th international conference on advanced computational methods in engineering (2011, November)

Growing interests in environmental concerns oblige building engineers to develop new approaches and to get used to new skills. Among them, Computational Fluid Dynamics (CFD) holds more and more importance ... [more ▼]

Growing interests in environmental concerns oblige building engineers to develop new approaches and to get used to new skills. Among them, Computational Fluid Dynamics (CFD) holds more and more importance. This technique can help to improve the comfort of the occupants but also to predict very early building energy performance. Moreover, it is possible to study the quality of the air. This last point will greatly help building engineers to improve sanitary conditions in various cases such as hospitals, clean rooms or even in classical buildings. However, this approach is still new and need to be validated. Indeed, CFD is still new in the frame of building physics. This paper aims to prove the ability of CFD to predict accurately contaminant dispersion and to demonstrate the breakthroughs that CFD can bring in the near future. [less ▲]

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See detailA validation process for CFD use in building physics – Study of the different length scales
Barbason, Mathieu ULiege; Reiter, Sigrid ULiege

in Proceedings of ROOMVENT 2011 (2011, June)

Due to growing environmental concerns, Computational Fluid Dynamics (CFD) is more and more used in building physics. Until today, the research community has validated separately several cases but there is ... [more ▼]

Due to growing environmental concerns, Computational Fluid Dynamics (CFD) is more and more used in building physics. Until today, the research community has validated separately several cases but there is no global validation process for this method. The aim of this paper is to provide a way for new users to develop and improve their CFD skills. This paper deals with the different geometry scales involved in building physics. Experimental results are available and will assess the ability of CFD to predict accurately the thermal behaviour of buildings. Thanks to this validation process, building engineers and architects can improve their simulations results and their understanding of the physical phenomena in building physics. [less ▲]

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See detailA validation process for CFD use in building physics.
Barbason, Mathieu ULiege; van Moeseke, Geoffrey; Reiter, Sigrid ULiege

in Proceedings of the 7th conference on Indoor Air Quality, Ventilation and Energy Conservation in buildings (2010)

Due to growing interests in environmental and building energy performance concerns, building physics simulations - and especially Computational Fluid Dynamics (CFD) – are more and more used. Unfortunately ... [more ▼]

Due to growing interests in environmental and building energy performance concerns, building physics simulations - and especially Computational Fluid Dynamics (CFD) – are more and more used. Unfortunately, until now, there is no clearly defined method to validate the use of these models by building engineers. This paper describes a validation process of CFD tools dealing with physical phenomena occurring in building physics. The comparison between experimental data and numerical results proves the validity of CFD use and its specific contribution to building physics modelling in comparison with thermal multizonal models. Thanks to this validation process, building engineers can improve their CFD simulations performance and their comprehension of building physics. [less ▲]

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See detailVALIDATION RELEVANCE OF ANALYTICAL METHODS IN BIOTECHNOLOGY
Marini Djang'Eing'A, Roland ULiege; Hubert, Philippe ULiege

Conference (2015, September 24)

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See detailValidation sur base des navires 032 et H32 -Report R&D6
Rigo, Philippe ULiege

Report (2004)

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See detailValidation tests of the Bosfort system (plateforme Offshore)
Rigo, Philippe ULiege; Sahloul, M.; Hage, André ULiege et al

Report (1995)

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See detailValidation tests of the full-discontinuous Galerkin / extrinsic cohesive law framework of Kirchhoff-Love shells
Becker, Gauthier ULiege; Noels, Ludovic ULiege

in International Journal of Fracture (2012), 178(1), 299-322

Due to its ability to account for discontinuities, the discontinuous Galerkin (DG) method presents two main advantages for modeling crack initiations and propagation. On the one hand, it provides an easy ... [more ▼]

Due to its ability to account for discontinuities, the discontinuous Galerkin (DG) method presents two main advantages for modeling crack initiations and propagation. On the one hand, it provides an easy way to insert the cohesive elements during the simulation and therefore avoids the drawbacks inherent to the use of an extrinsic cohesive law. On the other hand, the capture of complex crack path requires very thin meshes and the recourse to a parallel implementation of DG formulations exhibits a high scalability of the resolution scheme. Recently, the authors developed such a DG-fracture framework for Kirchhoff-Love shells in the linear and non-linear ranges. They proved that this framework dissipates, during the fracture process, an amount of energy equal to the fracture energy of the material and that the model is able to propagate the crack with the right speed. In this paper, novel numerical benchmarks are presented to validate the method in various fracture conditions. The two first ones include an initial notch and study the fracture propagation under two different dynamic loadings (impact and blast). The two other ones focus on the fragmentation of initially unbroken specimens due to uniform expansion in order to demonstrate the ability of the new framework to model crack initiations. Results are in all cases in agreement with the ones reported in the literature. [less ▲]

Detailed reference viewed: 82 (35 ULiège)