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See detailCompact integrated surface plasmon resonance spectroscopic sensor platform with on-chip self-referencing
Hastanin, Juriy ULg; Fleury-Frenette, Karl ULg; Lenaerts, Cedric ULg et al

in Proceeding of the International Conference on Surface Plasmon Photonics (SPP6): Ottawa, Canada, May 2013 (2013, May)

We present the SPR_CD spectroscopic biosensor design experimentally investigated by our research group. The implemented sensor platform is dedicated to droplet biochemical analysis involving multichannel ... [more ▼]

We present the SPR_CD spectroscopic biosensor design experimentally investigated by our research group. The implemented sensor platform is dedicated to droplet biochemical analysis involving multichannel detection format. [less ▲]

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See detailCompact photorefractive holographic camera and its applications in interferometry
Georges, Marc ULg; Scauflaire, Véronique; Lemaire, Philippe ULg

in Nolte, D.; Salamo, G.; Siahmakoun, A. (Eds.) et al Photorefractive Effects, Materials, and Devices (2001, July)

A compact holographic interferometer that uses a photorefractive crystal of the sillenite family as holographic recording medium is presented. It was developed to provide high accuracy displacement ... [more ▼]

A compact holographic interferometer that uses a photorefractive crystal of the sillenite family as holographic recording medium is presented. It was developed to provide high accuracy displacement measurements of scattering objects, together with a high degree of flexibility, portability and versatility in function of the application. We briefly discuss the main technical aspects leading to a compact device. We present a couple of recent applications, among which the coefficient of thermal expansion of composite structures is measured, piezosheets calibration and fingerprint detection. [less ▲]

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See detailCompact quadratizations of nonlinear binary optimization problems
Crama, Yves ULg; Rodriguez Heck, Elisabeth ULg

Conference (2014, March 25)

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See detailCompact star clusters of the LMC H ii region N11 C
Heydari-Malayeri, Mohammad; Royer, Pierre; Rauw, Grégor ULg et al

in Astronomy and Astrophysics (2000), 361

Based on imaging and spectroscopy obtained at the ESO NTT telescope and using an efficient image analysis algorithm, we study the core of the LMC OB association LH 13, particularly the two compact stellar ... [more ▼]

Based on imaging and spectroscopy obtained at the ESO NTT telescope and using an efficient image analysis algorithm, we study the core of the LMC OB association LH 13, particularly the two compact stellar clusters Sk-66[SUP]deg[/SUP]41, and HNT in the H ii, region N 11C. We resolve Sk-66[SUP]deg[/SUP]41, into 15 components and for the first time the HNT cluster into 70 stars, and derive photometry for the members. Moreover, from medium resolution spectroscopy we determine the spectral types for sixteen stars in N 11C. We compare the color-magnitude diagrams of the clusters with that of the field stars and discuss the cluster ages. With an age of ~ ,100 Myr, the HNT cluster appears significantly older than the very young (<= 5 Myr) Sk-66[SUP]deg[/SUP]41, starburst. We suggest that most of the `field' O-stars in the core of N 11C have actually been ejected from Sk-66[SUP]deg[/SUP]41, through dynamical interactions in the compact cluster. The properties of the Sk-66[SUP]deg[/SUP]41, and HNT clusters suggest that we are viewing different star formation regions lying at different distances along the same line of sight. Based on observations obtained at the European Southern Observatory, La Silla, Chile [less ▲]

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See detailA compact system of small planets around a former red giant star
Charpinet, Stéphane; Fontaine, Gilles; Brassard, Pierre et al

in Nature (2011), 480

Planets that orbit their parent star at less than about one astronomical unit (1AU is the Earth-Sun distance) are expected to be engulfed when the star becomes a red giant. Previous observations have ... [more ▼]

Planets that orbit their parent star at less than about one astronomical unit (1AU is the Earth-Sun distance) are expected to be engulfed when the star becomes a red giant. Previous observations have revealed the existence of post-red-giant host stars with giant planets orbiting as close as 0.116AU or with brown dwarf companions in tight orbits, showing that these bodies can survive engulfment. What has remained unclear is whether planets can be dragged deeper into the red-giant envelope without being disrupted and whether the evolution of the parent star itself could be affected. Here we report the presence of two nearly Earth-sized bodies orbiting the post-red-giant, hot B subdwarf star KIC 05807616 at distances of 0.0060 and 0.0076AU, with orbital periods of 5.7625 and 8.2293 hours, respectively. These bodies probably survived deep immersion in the former red-giant envelope. They may be the dense cores of evaporated giant planets that were transported closer to the star during the engulfment and triggered the mass loss necessary for the formation of the hot B subdwarf, which might also explain how some stars of this type did not form in binary systems. [less ▲]

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See detailLa compaction des sols agricoles en Wallonie
Destain, Marie-France ULg

Book published by SPW (2014)

Dans nos pays industrialisés, l’agriculture fait appel à des machines de plus en plus lourdes. Lorsque des charges élevées sont appliquées sur des sols sensibles, une compaction du sol peut se produire ... [more ▼]

Dans nos pays industrialisés, l’agriculture fait appel à des machines de plus en plus lourdes. Lorsque des charges élevées sont appliquées sur des sols sensibles, une compaction du sol peut se produire conduisant à des diminutions de rendements suite aux difficultés que rencontrent les racines pour prélever l’eau et les nutriments et à la perturbation de l’activité de la pédofaune. Au niveau environnemental, du fait de la compaction, l’infiltration de l’eau dans le sol est réduite, principalement dans l’horizon superficiel. Une accumulation de l’eau à la surface du sol avec un accroissement des écoulements latéraux et du ruissellement peut apparaître. Il en résulte une augmentation des risques d’inondation et de pollution de surface provenant de l’application d’intrants. Le risque d’érosion sur des sols en pente, même faible, est également accru. En Europe, on estime que 32 % des couches profondes de sol sont largement dégradées. A l’inverse de l’érosion ou de la salinisation qui montrent des signes visibles de dégradation, les effets néfastes de la compaction ne sont pas immédiatement perceptibles. Du fait que la compaction des horizons profonds (au-delà de 30 cm) est un phénomène difficilement réversible par régénération naturelle et que les méthodes de restauration artificielles ne sont pas toujours couronnées de succès, l’Union Européenne considère la compaction comme l’un des facteurs majeurs de la dégradation physique des sols. Le projet de Directive européenne COM(2006)232 amendé par la note 16157/07 du 14 décembre 2007 établit un cadre général pour la protection des sols. Ce projet prévoit notamment que les Etats membres, dont fait partie la Belgique, identifient sur leur territoire les zones susceptibles de présenter des processus de dégradation du sol (érosion, perte de matière organique, compaction, salinisation, contamination et perte de biodiversité). Une fois les zones à risque identifiées, les Etats membres doivent proposer des objectifs de réduction des risques ainsi que des mesures concrètes permettant de les atteindre. Ils sont libres de fixer leurs propres objectifs et de décider comment et quand les atteindre. Le projet SoCo a établi une cartographie de la sensibilité des sols européens à la compaction. Cependant, étant donné sa faible résolution, cette carte ne permet pas de se faire une idée précise de la situation en Wallonie. La Direction générale opérationnelle Agriculture, Ressources naturelles et Environnement du SPW a donc décidé de mettre en œuvre une étude pour analyser de manière plus précise les risques de compaction des sols en Wallonie. [less ▲]

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See detailLa compaction des sols forestiers en Wallonie
Destain, Marie-France ULg

Book published by SPW (2014)

Dans nos pays industrialisés, l’exploitation forestière fait appel à des machines de plus en plus lourdes pour assurer la vidange des coupes et le débardage des grumes. Lorsque des charges élevées sont ... [more ▼]

Dans nos pays industrialisés, l’exploitation forestière fait appel à des machines de plus en plus lourdes pour assurer la vidange des coupes et le débardage des grumes. Lorsque des charges élevées sont appliquées sur des sols sensibles, une compaction du sol peut se produire entraînant une réduction de porosité, avec des conséquences néfastes sur la vitalité des peuplements. Au niveau environnemental, du fait de la compaction, l’infiltration de l’eau dans le sol est réduite, principalement dans l’horizon superficiel. Une accumulation de l’eau à la surface du sol avec un accroissement des écoulements latéraux et du ruissellement peut apparaître. Il en résulte une augmentation des risques d’inondation et de pollution de surface provenant de l’application d’intrants. Le risque d’érosion sur des sols en pente, même faible, est également accru. En Europe, on estime que 32 % des couches profondes de sol sont largement dégradées. A l’inverse de l’érosion ou de la salinisation qui montrent des signes visibles de dégradation, les effets néfastes de la compaction ne sont pas immédiatement perceptibles. Du fait que la compaction des horizons profonds (au-delà de 30 cm) est un phénomène difficilement réversible par régénération naturelle et que les méthodes de restauration artificielles ne sont pas toujours couronnées de succès, l’Union Européenne considère la compaction comme l’un des facteurs majeurs de la dégradation physique des sols. Le projet de Directive européenne COM(2006)232 amendé par la note 16157/07 du 14 décembre 2007 établit un cadre général pour la protection des sols. Ce projet prévoit notamment que les Etats membres, dont fait partie la Belgique, identifient sur leur territoire les zones susceptibles de présenter des processus de dégradation du sol (érosion, perte de matière organique, compaction, salinisation, contamination et perte de biodiversité). Une fois les zones à risque identifiées, les Etats membres doivent proposer des objectifs de réduction des risques ainsi que des mesures concrètes permettant de les atteindre. Ils sont libres de fixer leurs propres objectifs et de décider comment et quand les atteindre. Le projet SoCo a établi une cartographie de la sensibilité des sols européens à la compaction. Cependant, étant donné sa faible résolution, cette carte ne permet pas de se faire une idée précise de la situation en Wallonie. Par ailleurs, le Code Forestier Wallon entré en vigueur le 13 septembre 2008 prévoit explicitement l’interdiction d’occasionner des dégâts au sol qui pourraient avoir des conséquences à long terme sur la vitalité des peuplements. Dans ce cadre, la Direction générale opérationnelle Agriculture, Ressources naturelles et Environnement du SPW a décidé de mettre en œuvre une étude pour analyser de manière plus précise les risques de compaction des sols en Wallonie. [less ▲]

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See detailcompaction dynamics of magnetized powder
Lumay, Geoffroy ULg; Dorbolo, Stéphane ULg; Vandewalle, Nicolas ULg

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2009), 80

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See detailCompaction Dynamlics of Wet Granular Assemblies
Fiscina, J. E.; Lumay, Geoffroy ULg; Ludewig, François ULg et al

in Physical Review Letters (2010), 105

The extremely slow compaction dynamics of wet granular assemblies is studied experimentally. The cohesion, due to capillary bridges between neighboring grains, is tuned using different liquids having ... [more ▼]

The extremely slow compaction dynamics of wet granular assemblies is studied experimentally. The cohesion, due to capillary bridges between neighboring grains, is tuned using different liquids having specific surface tension values. The compaction dynamics of a cohesive packing obeys an inverse logarithmic law, like most dry random packings. However, the characteristic relaxation time 􏰌 grows strongly with cohesion. A model, based on free volume kinetic equations and the presence of a capillary energy barrier, is able to reproduce quantitatively the experimental curves. [less ▲]

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See detailCompaction of anisotropic granular materials: Experiments and simulations
Lumay, Geoffroy ULg; Vandewalle, Nicolas ULg

in Physical Review E (2004), 70(5, Pt 1), 51314

We present both experimental and numerical investigations of compaction in granular materials composed of rods. As a function of the particles size and with respect to the container diameter, we have ... [more ▼]

We present both experimental and numerical investigations of compaction in granular materials composed of rods. As a function of the particles size and with respect to the container diameter, we have observed large variations of the asymptotic packing volume fraction. The relevant parameter is the ratio between the rod length l and the tube diameter D. Even the compaction dynamics remains unchanged for various particle lengths, and a transition between 3d and 2d ordering for grain orientations is observed for l/D= 1. A toy model for the compaction of needles on a lattice is also proposed. This toy model gives a complementary view of our experimental results and leads to behaviors similar to experimental ones. [less ▲]

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See detailCompaction of granular materials: experiments and contact dynamics simulations
Lumay, Geoffroy ULg; Ludewig, François ULg; Vandewalle, Nicolas ULg

in Journal of Physics: Conference Series (2006), 40

We present an original experimental study of the slow compaction dynamics for two- dimensional isotropic granular systems. Compaction dynamics is measured at three different scales : the macroscopic scale ... [more ▼]

We present an original experimental study of the slow compaction dynamics for two- dimensional isotropic granular systems. Compaction dynamics is measured at three different scales : the macroscopic scale through the normalized packing fraction ˜ ρ, the mesoscopic scale through the normalized fraction ˜ φ of domains ideally ordered in the system, and the microscopic scale through the grain mobility μ. The domains ideally ordered are found to obey a growth process dominated by the displacement of domain boundaries. We present also preliminary results of three-dimensional simulations with a model of contact dynamics. These results allow to discuss the difference between the two-dimensional and the three-dimensional cases. [less ▲]

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See detailCompaction of granular mixtures
Ludewig, François ULg; Vandewalle, Nicolas ULg; Dorbolo, Stéphane ULg

in Granular Matter (2006), 8(2), 87-91

We propose a lattice model for studying the compaction of granular mixtures under taps. Two granular species are considered: small grains with low mobilities and T-shaped grains characterized by a larger ... [more ▼]

We propose a lattice model for studying the compaction of granular mixtures under taps. Two granular species are considered: small grains with low mobilities and T-shaped grains characterized by a larger ability to move. When those grains are mixed together, the compaction dynamics is mainly controlled by the volume fraction x of the small grains. Segregation have been found on the top layers of the pile. The grain mobilities have been studied for different values of the volume fraction x. An effective grain mobility has been defined for the mixture. This mobility is given by the linear combination of the mobility of both pure species minus a non-linear interaction term. Finally, the compaction speed depends on the fraction of the anisotropic grains. [less ▲]

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See detailCompactly supported wavelets in Sobolev spaces of integer order
Bastin, Françoise ULg; Laubin, P.

in Applied & Computational Harmonic Analysis (1997), 4(1), 51-57

We present a construction of regular compactly supported wavelets in any Sobolev space of integer order. It is based on the existence and suitable estimates of filters defined from polynomial equations ... [more ▼]

We present a construction of regular compactly supported wavelets in any Sobolev space of integer order. It is based on the existence and suitable estimates of filters defined from polynomial equations. We give an implicit study of these filters and use the results obtained to construct scaling functions leading to multiresolution analysis and wavelets. Their regularity increases linearly with the length of their supports as in the L(2) case. One technical problem is to prove that the intersection of the scaling spaces is reduced to 0. This is solved using sharp estimates of Littlewood-Paley type. (C) 1997 Academic Press, Inc. [less ▲]

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See detailLa Compagnie de Jésus à Liège. Aperçu historique
Delfosse, Annick ULg

in Revue Liégeoise de la Société de Musicologie (2008), 27

Historical presentation of the Jesuit schools story in the city of Liege and the Gallo-Belgian Province. Focus on the issues concerning the theatre and the solemn processions.

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See detailLa Compagnie de Jésus et Notre-Dame de Foy. Diffusion, appropriation, évangélisation
Delfosse, Annick ULg

in Dekoninck, Ralph; Delfosse, Annick; Pacco, Christian (Eds.) Foy Notre-Dame : Art, Politique et Religion. Actes du colloque de Dinant (16 mai 2009) (2009)

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See detailCompagnies d’aventure et armées françaises. Le cas des campagnes de Gênes et de Naples à l’époque du Grand Schisme d’Occident
Masson, Christophe ULg

in Pépin, Guilhem (Ed.) Actes du colloque Routiers et mercenaires d’Aquitaine, d’Angleterre et d’ailleurs (v. 1340-1453). Rôle militaire et impact sur les sociétés locales. Berbiguières, 13–14 septembre 2013 (in press)

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See detailCompanion search around β Pictoris with the newly commissioned L'-band vector vortex coronagraph on VLT/NACO
Mawet, D.; Absil, Olivier ULg; Milli, J. et al

in Booth, Mark; Matthews, Brenda; Graham, James (Eds.) Exploring the Formation and Evolution of Planetary Systems (2014, January 01)

Here we present the installation and successful commissioning of an L'-band Annular Groove Phase Mask (AGPM) coronagraph on VLT/NACO. The AGPM is a vector vortex coronagraph made from diamond ... [more ▼]

Here we present the installation and successful commissioning of an L'-band Annular Groove Phase Mask (AGPM) coronagraph on VLT/NACO. The AGPM is a vector vortex coronagraph made from diamond subwavelength gratings tuned to the L' band. The vector vortex coronagraph enables high contrast imaging at very small inner working angle (here 0''.09, the diffraction limit of the VLT at L'), potentially being the key to a new parameter space. During technical and science verification runs, we discovered a late-type companion at two beamwidths from an F0V star (Mawet et al. 2013), and imaged the inner regions of β Pictoris down to the previously unexplored projected radius of 1.75 AU. The circumstellar disk was also resolved from ~= 1'' to 5'' (see J. Milli et al., these proceedings). These results showcase the potential of the NACO L-band AGPM over a wide range of spatial scales. [less ▲]

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See detailComparaison avec les autres méthodes de mesure (au cabinet, MAPA)
Krzesinski, Jean-Marie ULg

Conference (2009, February 07)

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See detailComparaison between Numerical and Experimental Results in Study of Offshore Structure Movements
Marchal, Jean ULg; Lejeune, A.; Hoffay, T. et al

in Proceeding of the Int. Conf. Washington D.C. (1982)

Detailed reference viewed: 12 (1 ULg)