ORBi Open Repository and Bibliography
In may 2007, the ULg's Administrative Board (joined in June 2007 by the FUSAGx) decided to create an institutional repository and defined a strong institutional self-archiving policy to increase the visibility, accessibility and impact of the University's publications (Board's decision).
This decision led to the official launch, in November 2008, of the ORBi platform including both the Academic Bibliography and the Institutional Repository of the Wallonia-Europe University Academy.
A Riemannian approach to large-scale constrained least-squares with symmetries - Mishra, Bamdev
This thesis deals with least-squares optimization on a manifold of equivalence relations, e.g., in the presence of symmetries which arise frequently in many applications. While least-squares cost functions remain a popular way to model large-scale problems, the additional symmetry constraint should be interpreted as a way to make the modeling robust. Two fundamental examples are the matrix completion problem, a least-squares problem with rank constraints and the generalized eigenvalue problem, a least-squares problem with orthogonality constraints. The possible large-scale nature of these problems demands to exploit the problem structure as much as possible in order to design numerically efficient algorithms.
Roughness evolution of sol-gel optical coatings by ion beam sputtering - Gailly, Patrick; Dubreuil, Olivier; Fleury-Frenette, Karl
The surface roughness evolution of two silica-based sol-gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol-gel solutions had been applied on silicon substrates using the dip coating technique and then thermally cured to obtain solid thin films. Their thickness had then been controlled over the samples surface using spectroscopic ellipsometry. The surface roughness of the sol-gel films has been measured using both interferometric profilometry and atomic force microscopy at different sputtering depths. Roughness increases significantly faster with sputtering depth in sol-gel layers
than on bulk fused silica. Interestingly, the sputtering rates of the sol-gel layers...
Contexte hydrogéologique de la commune de Sprimont - Gesels, Julie; Gilson, Mylene; Brouyère, Serge; Ruthy, Ingrid
Cadre hydrogéologique de la commune de Sprimont : formations géologiques qui contiennent des ressources en eau intéressantes, variations de la profondeur d'eau dans les différentes nappes, volumes exploités et chimisme des eaux souterraines.
Towards enhanced estimates of future water demand in the Meuse basin: literature review - De Cuyper, Anaïs; Bruwier, Martin; Archambeau, Pierre; Erpicum, Sébastien; Pirotton, Michel; Dewals, Benjamin
With respect to water management in the Meuse basin, the hydrological consequences of climate change have been taken into account in several studies so far; but this is not the case of many other environmental and socio-economic changes, including trends in future water demand. The objective of this report is to serve as an onset for the development of a first approach to estimate at a relatively large-scale future water demand in the Meuse basin. Based on a review of recent literature, this report discusses the key drivers which influence water demand, with the aim of identifying the most suitable...
Wind Tunnel Experiments On Bridge Stays Cables Protection Tubes In Dry Galloping Conditions: Processing Method For Bi-Stable Phenomenon - Flamand, Olivier; Benidir, Adel; Gaillet, Laurent; Dimitriadis, Grigorios
Surface irregularity is one of the parameters that have not been deeply examined on stay cables of cable-stayed bridges. This paper focuses on wind tunnel tests on original High Density Polyethylene cable covers, in a range of Reynolds numbers from the sub-critical regime to the critical one, corresponding to values ranging from Re = 9.6x104 to Re = 3.3x105. The experiment consists in measurement of parietal pressures on cable covers in order to investigate the effect of surface irregularity on the mechanism of dry galloping excitation. Previous studies (,  and ) reported that dry galloping of cables with a...
Impact of Circularity Defect of Helical Fillets HDPE Bridge Stay Covers: Analysis of Bi-Stability at Critical Reynolds Number by Bifurcation Diagrams - Benidir, Adel; Flamand, Olivier; Gaillet, Laurent; Dimitriadis, Grigorios
Dry galloping of cables is still considered by the scientific community as an important phenomenon lacking investigation on cable stayed bridge. The helical fillet cylinders developed to overcome the Rain-Wind Induced Vibration (RWID) were reported to be affected by the appearance of vibration in dry conditions. This paper focuses on a method developed to process data issued from wind tunnel tests on original High Density Polyethylene (HDPE) cable covers with helical fillets, in a range of Reynolds numbers from the sub-critical regime to the critical regime. Corresponding values range from Re = 9.6x10^4 to Re = 3.6x10^5 for the present...