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See detailNumerical modeling of hydro-mechanical fracture behavior
Guiducci, Chiara; Pellegrino, Antonio; Radu, Jean-Pol ULg et al

in Pande, G. N.; Pietruszczak, S. (Eds.) Numerical models in Geomechanics (2002)

A numerical approach for modeling coupled hydro-mechanical fracture behavior is proposed. The movement of fluids through rock fractures is important in many engineering areas of practical interest such as ... [more ▼]

A numerical approach for modeling coupled hydro-mechanical fracture behavior is proposed. The movement of fluids through rock fractures is important in many engineering areas of practical interest such as those ones of petroleum and mining engineering. In that context, one of the most investigated and complex subjects is the effect on well productivity due to changes in hydraulic conductivity both on the matrix rock and on its main fractures. It is well known, that these flow characteristics are strongly controlled by fracture apertures. Recent investigations on the distribution of the apertures in natural fractures suggest that the cubic law can, better than the Darcy law, predict the fluid flux through rough walled fractures as long as the appropriate average fracture aperture is used. A finite element code is developed to predict the influence that the stresses variation in the soil has on the distributed hydraulic conductivity field. The proposed model combines the stochastic cubic law with a non-linear deformation function (hyperbolic) that is suggested to describe the stress-closure/opening curves of the joints and that allows to couple together the hydraulic and the mechanic fracture behavior. The relationships used and the validity of the present model are tested through comparison between experimental data and numerical predictions (Bart 2000) in various boundary and loading conditions. Comparison between the Darcy model governing fluid flow equation and linear stress-closure/opening relation has also been performed showing the differences and the better de-scription given by the proposed new model. [less ▲]

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See detailL'exclusion de la réassurance des règles européennes de conflits de juridictions en matière de contrats d'assurance
Boularbah, Hakim ULg

in Bulletin des Assurances = Tijdschrift voor Verzekeringen (2002)

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See detailA transformed fish cell line expressing a green fluorescent protein-luciferase fusion gene responding to cellular stress
Molina, A.; Carpeaux, Rudy ULg; Martial, Joseph ULg et al

in Toxicology in Vitro (2002), 16(2), 201-7

We obtained a stable transformed fish (EPC) cell line containing a reporter gene under the control of the tilapia HSP70 promoter. Expression of the reporter gene, coding for a green fluorescent protein ... [more ▼]

We obtained a stable transformed fish (EPC) cell line containing a reporter gene under the control of the tilapia HSP70 promoter. Expression of the reporter gene, coding for a green fluorescent protein (GFP)-luciferase fusion protein, was assessed by measuring the luciferase enzymatic activity by luminometry and the GFP expression by fluorescence microscopy and flow cytometry. The clone was characterized for its capacity to respond to heat shock treatment. The results show high induction after 1 h at 37 degrees C of treatment, up to 500-fold. In addition, its convenience to detect a large range of cellular stressors was evaluated. We observed high induction when Cd2+, Zn2+, Hg2+ or Cu2+ was added, but not Pb2+. In addition, activation of the reporter gene was observed in the presence of other compounds such as acetyl chloride, tetrachlorophenol, chloroacetamide and sodium arsenite. In conclusion, this cell line can be used as a rapid, cheap and easy biological test to determine cellular stress induced by environmental pollutants, alone or in conjunction with other, more specific assays. [less ▲]

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See detailAtteintes neuromusculaires aiguës de réanimation (ANMAR) : étude électrophysiologique prospective de 56 cas
BARTSCH, Valérie ULg; TOMASELLA, Marco ULg; Zeevaert, Bernard et al

in Neurophysiologie Clinique = Clinical Neurophysiology (2002)

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See detailÉcriture et système de prescription. L’exemple du “Lecteur du Petit Journal” (Zola, 1865)
Durand, Pascal ULg

in Jurt, J.; Einfalt, M. (Eds.) Le texte et le contexte. Analyses du champ littéraire français (XIXe et XXe siècle) (2002)

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See detailExpression of the zinc finger Egr1 gene during zebrafish embryonic development
Close, Renaud; Toro, Sabrina; Martial, Joseph ULg et al

in Mechanisms of Development (2002), 118(1-2), 269-72

Egr1 is a highly conserved zinc finger protein which plays important roles in many aspects of vertebrate development and in the adult. The cDNA coding for zebrafish Egr1 was obtained and its expression ... [more ▼]

Egr1 is a highly conserved zinc finger protein which plays important roles in many aspects of vertebrate development and in the adult. The cDNA coding for zebrafish Egr1 was obtained and its expression pattern was examined during zebrafish embryogenesis using whole-mount in situ hybridization. Egr1 mRNA is first detected in adaxial cells in the presomitic mesoderm between 11 and 20 h post-fertilization (hpf), spanning the 4-24 somite stages. Later, Egr1 expression is observed only in specific brain areas, starting at 21 hpf and subsequently increasing in distinct domains of the central nervous system, e.g. in the telencephalon, diencephalon and hypothalamus. Between 24 and 48 hpf, Egr1 is expressed in specific domains of the hypothalamus, mesencephalon, tegmentum, pharynx, retina, otic vesicle and heart. [less ▲]

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See detailLésion du nerf interosseux postérieur liée à une randonnée prolongée en vélo-tout-terrain (VTT)
Zeevaert, Bernard; CRIELAARD, Jean-Michel ULg; WANG, François-Charles ULg

in Neurophysiologie Clinique = Clinical Neurophysiology (2002)

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See detailValeurs de références de l’analyse en mode multi-MUP du multifidus dorso-lombaire
TOMASELLA, Marco ULg; CRIELAARD, Jean-Michel ULg; WANG, François-Charles ULg

in Neurophysiologie Clinique = Clinical Neurophysiology (2002)

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See detailDistribution et comportement biogéochimique des métaux en trace dans les sédiments estuariens de l'Escaut.
Bouezmarni, Mohamed ULg

Doctoral thesis (2002)

L’objectif de cette étude est la détermination de la distribution et des propriétés des métaux traces dans les sédiments de l’estuaire de l’Escaut, en vue d’améliorer la compréhension de leur comportement ... [more ▼]

L’objectif de cette étude est la détermination de la distribution et des propriétés des métaux traces dans les sédiments de l’estuaire de l’Escaut, en vue d’améliorer la compréhension de leur comportement biogéochimique. Dans ce but, les distributions des éléments majeurs (Si, Al, Fe, Ca, Mg, Na, K, P, matières organiques et pertes au feu) et mineurs (Cd, Pb, Cu, Zn, Cr, Ni, Co, Mn et Li) ont été examinées dans 59 échantillons de sédiments de surface. L’analyse factorielle des résultats de la composition des dépôts montre que le processus de piégeage dans la zone de turbidité maximale constitue le facteur le plus important qui explique les teneurs des métaux traces dans les sédiments. De plus, la distribution de ces éléments a été étudiée dans différentes fractions granulométriques démontrant l’accumulation des métaux toxiques dans les fractions les plus fines. Elle permis de discuter de manière critique les méthodes de normalisation les plus utilisées dans la littérature et d’adopter la normalisation par le Li comme la méthode la plus adéquate dans le cas de l’Escaut, l’Al reste un bon élément de normalisation sauf pour les sables. La normalisation des concentrations métalliques des sédiments par le Li, montre une accumulation importantes du Cd, du Zn, du Cu, du Pb et du Mn limitée à la zone amont et un comportement conservatif pour le Cr, le Ni et le Co. Une étude de spéciation géochimique des solides a été réalisée par une nouvelle approche basée sur la titration acide des sédiments mis en suspension. Cette méthode permet, contrairement à la méthode de digestion sélective, de préciser la spéciation, la mobilité et la réactivité des métaux traces dans les sédiments. Les fractions les plus réactives des métaux étudiés sont notées dans le cas du Cd (80%), du Pb (70%), du Cu (70%), du Zn (80%) et du Mn (80%), notamment dans les vases anaérobiques de la zone amont. Le piégeage de ces métaux d’origine anthropogénique s’explique par la précipitation du Cd et du Zn sous forme de sulfures, la précipitation du Mn avec les carbonates et le recyclage du Pb avec les oxyhydroxydes de Fer à l’interface eau/sédiment. [less ▲]

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See detailLes acteurs et les enjeux au coeur de l'évaluation
Vandoorne, Chantal ULg

in Education santé (2002), 173(173), 9-11

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See detailHydro-mechanical behavior of fractures: 2D, F.E.M. modeling
Guiducci, Chiara; Pellegrino, Antonio; Radu, Jean-Pol ULg et al

in Auriault, J. L.; Geindreau, C.; Royer, P. (Eds.) Poromechanics II (2002)

A numerical approach for modeling the coupled hydro-mechanical fracture behavior is proposed. The movement of fluids through rock fractures and consequently the evolution of their hydraulic conductivity ... [more ▼]

A numerical approach for modeling the coupled hydro-mechanical fracture behavior is proposed. The movement of fluids through rock fractures and consequently the evolution of their hydraulic conductivity is an important subject in many petroleum related activities, mainly concerning the change of well productivity during the reservoir life. It is well known that the flow in the fractures is strongly controlled by the fracture apertures. Recent investigations on the distribution of the apertures in natural fractures suggest that the cubic law can, better than the Darcy law, predict the fluid flux through rough walled fractures as long as the appropriate average fracture aperture is used. A finite element code is developed to predict the influence that the stresses variation in the fracture has on the distributed hydraulic conductivity field. The proposed model combines the stochastic cubic law with a non-linear deformation function (hyperbolic) that is suggested to describe the stress-closure/opening curves of the joints and that allows to couple together the hydraulic and the mechanic fracture behavior. The relationships used and the validity of the present model are tested by means of the comparison between experimental data and numerical predictions (Bart 2000) in various bound-ary and loading conditions. Comparisons between the proposed new model and a no coupled one have also been performed. They show that the proposed coupled model allows for a more realistic description of the fracture behavior. [less ▲]

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See detailWilliam S. Burroughs: Du cut-up au simulacre
Claisse, Frédéric ULg

in Réseaux : Revue Interdisciplinaire de Philosophie Morale et Politique (2002), (94-95-96), 151-174

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See detailL'image du mois. Malacoplasie pulmonaire a Rhodococcus equi chez un patient atteint du SIDA.
Delbecque, Katty ULg; Radermecker, Maurice ULg; Leonard, Philippe ULg et al

in Revue Médicale de Liège (2002), 57(11), 685-7

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See detailConfirmation des effets délétères rénaux des AINS anti COX2 illustrée par trois cas cliniques
Piront, P.; Krzesinski, Jean-Marie ULg

in Acta Clinica Belgica (2002), 57(1), 35

Detailed reference viewed: 5 (0 ULg)