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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2011), (mai-juin), 221-222

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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2009), (sept-Oct), 483-484

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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2006), (mars-avril), 132-133

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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2006), (mars-avril),

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Lecocq, Pascale ULg

in Revue de Jurisprudence de Liège, Mons et Bruxelles (2009)

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Lecocq, Pascale ULg

in Revue de Jurisprudence de Liège, Mons et Bruxelles (2009)

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Lecocq, Pascale ULg

in Revue de Jurisprudence de Liège, Mons et Bruxelles (2001), (15), 652-654

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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2000), 10-11

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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2013)

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Lecocq, Pascale ULg

in Journal des Juges de Paix = Tijdschrift van de Vrederecters (2013)

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See detailObservations and asteroseismic analysis of the rapidly pulsating hot B subdwarf PG 0911+456
Randall, Suzanna K.; Green, Elizabeth M.; Van Grootel, Valérie ULg et al

in Astronomy and Astrophysics (2007), 476

Aims:The principal aim of this project is to determine the structural parameters of the rapidly pulsating subdwarf B star PG 0911+456 from asteroseismology. Our work forms part of an ongoing programme to ... [more ▼]

Aims:The principal aim of this project is to determine the structural parameters of the rapidly pulsating subdwarf B star PG 0911+456 from asteroseismology. Our work forms part of an ongoing programme to constrain the internal characteristics of hot B subdwarfs with the long-term goal of differentiating between the various formation scenarios proposed for these objects. So far, a detailed asteroseismic interpretation has been carried out for 6 such pulsators, with apparent success. First comparisons with evolutionary theory look promising, however it is clear that more targets are needed for meaningful statistics to be derived. Methods: The observational pulsation periods of PG 0911+456 were extracted from rapid time-series photometry using standard Fourier analysis techniques. Supplemented by spectroscopic estimates of the star's mean atmospheric parameters, they were used as a basis for the “forward modelling” approach in asteroseismology. The latter culminates in the identification of one or more “optimal” models that can accurately reproduce the observed period spectrum. This naturally leads to an identification of the oscillations detected in terms of degree ℓ and radial order k, and infers the structural parameters of the target. Results: The high S/N low- and medium resolution spectroscopy obtained led to a refinement of the atmospheric parameters for PG 0911+456, the derived values being T_eff = 31 940 ± 220 K, log g = 5.767 ± 0.029, and log He/H = -2.548 ± 0.058. From the photometry it was possible to extract 7 independent pulsation periods in the 150-200 s range with amplitudes between 0.05 and 0.8% of the star's mean brightness. There was no indication of fine frequency splitting over the 68-day time baseline, suggesting a very slow rotation rate. An asteroseismic search of parameter space identified several models that matched the observed properties of PG 0911+456 well, one of which was isolated as the “optimal” model on the basis of spectroscopic and mode identification considerations. All the observed pulsations are identified with low-order acoustic modes with degree indices ℓ = 0,1,2 and 4, and match the computed periods with a dispersion of only 0.26%, typical of the asteroseismological studies carried out to date for this type of star. The inferred structural parameters of PG 0911+456 are T_eff = 31 940 ± 220 K (from spectroscopy), log {g} = 5.777 ± 0.002, Mast/Msun = 0.39 ± 0.01, log{M_env/Mast} = -4.69 ± 0.07, R/Rsun = 0.133 ± 0.001 and L/Lsun = 16.4 ± 0.8. We also derive the absolute magnitude MV = 4.82 ± 0.04 and a distance d = 930.3 ± 27.4 pc. [less ▲]

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See detailObservations and asteroseismological analysis of the rapid subdwarf B pulsator EC 09582-1137
Randall, Suzanna K.; Van Grootel, Valérie ULg; Fontaine, Gilles et al

in Astronomy and Astrophysics (2009), 507

We made photometric and spectroscopic observations of the rapidly pulsating subdwarf B star EC 09582-1137 with the aim of determining the target's fundamental structural parameters from asteroseismology ... [more ▼]

We made photometric and spectroscopic observations of the rapidly pulsating subdwarf B star EC 09582-1137 with the aim of determining the target's fundamental structural parameters from asteroseismology. This analysis forms part of a long-term programme geared towards distinguishing between different proposed formation scenarios for hot B subdwarfs on the basis of their internal characteristics. So far, secure asteroseismic solutions have been computed for 9 of these pulsators, and first comparisons with results from evolutionary calculations look promising. The new data comprise 30 h of fast time-series photometry obtained with SUSI2 at the NTT on La Silla, Chile, as well as 1 h of low-resolution spectroscopy gathered with EMMI, also mounted on the NTT. From the photometry we detected 5 independent harmonic oscillations in the 135-170 s period range with amplitudes up to 0.5% of the mean brightness of the star. In addition, we extracted two periodicities interpreted as components of a rotationally split multiplet that indicate a rotation period of the order of 2-5 days. We also recovered the first harmonic of the dominant pulsation, albeit at an amplitude below the imposed 4σ detection threshold. The spectroscopic observations led to the following estimates of the atmospheric parameters of EC 09582-1137: T_eff = 34 806±233 K, log{g} = 5.80±0.04, and log N(He)/N(H) = -1.68±0.06. Using the observed oscillations as input, we searched in model parameter space for unique solutions that present a good fit to the data. Under the assumption that the two dominant observed periodicities correspond to radial or dipole modes, we were able to isolate a well-constrained optimal model that agrees with the atmospheric parameters derived from spectroscopy. The observed oscillations are identified with low-order acoustic modes with degree indices ℓ = 0, 1, 2, and 4 and match the computed periods with a dispersion of 0.57%. Non-adiabatic calculations reveal all theoretical modes in the observed period range to be unstable, an important a posteriori consistency check for the validity of the optimal model. The inferred structural parameters of EC 09582-1137 are T_eff = 34 806 K (from spectroscopy), log{g} = 5.788±0.004, Mast = 0.485±0.011 Msun, log{(M_env/Mast)} = -4.39±0.10, R = 0.147±0.002 Rsun, and L = 28.6±1.7 Lsun. We additionally derive the absolute magnitude MV = 4.44±0.05 and the distance d = 1460±66 pc. [less ▲]

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See detailObservations and comments on the Walloon Competitive Clusters
Antoine, Mélanie ULg

Conference (2008, January)

In recent years, the promotion of R&D partnerships between universities, research labs and companies has become a key feature of innovation and development public policies. However, these collaborations ... [more ▼]

In recent years, the promotion of R&D partnerships between universities, research labs and companies has become a key feature of innovation and development public policies. However, these collaborations turn out to be fragile and their management very complex. In our literature review, the congruence between the nature of innovations (i.e. their radicalness) and the cooperation practices appears as a potentially powerful explanatory factor of interfirm innovation project’s outcome. Following this hypothesis, we explore, on two case studies of projects subsidized by the Walloon Competitive Clusters program, the way actors innovate and organize their actions. Though they face similar constraints, these projects illustrate diverse configurations, not only as to the nature of innovations but also as to cooperation practices. Besides, the analysis reveals that the criteria used to characterize the nature of innovations do not necessarily form a homogeneous set of factors. Considering these observations, we try to identify the main challenges faced by both projects’ partners. [less ▲]

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See detailObservations and physical properties of small solar system bodies
Gérard, Jean-Claude ULg; Brahic, André; Surdej, Jean ULg

Book published by Université de Liège (1992)

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See detailLes observations astronomiques au dehors de l’atmosphère terrestre
Swings, Polydore ULg

Book published by Centre National de Recherches de l’Espace. (1960)

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See detailObservations astronomiques et magnétiques exécutées sur le territoire de l'Etat Indépendant du Congo par A. Delporte et L. Gillis: rapport de F. Folie
Folie, François ULg

in Bulletins de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique (1893), 3e série, t. 25(6), 661-665

The author establishes a report on A. Delporte and L. Gillis’ work on the astronomical and magnetic observations executed on the Congo Free State territory.

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See detailObservations au large de Calvi en régime d'été
Djenidi, Salim ULg

in Bulletin de la Société Royale des Sciences de Liège (1985), 54(6), 287-300

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See detailObservations au microscope electronique a balayage de cellules nerveuses de moelle spinale d'embryons de poulet cultivees in vitro sur de la polylysine-L.
Noel-Courtey, B.; Heinen, Ernst ULg

in Comptes Rendus des Séances de l'Académie des Sciences. Série D : Sciences Naturelles (1977), 285(4), 385-7

Chick embryo nerve cells from the lumbo-sacral spinal cord have been isolated by trypsinisation and cultivated in Rose chambers on polylysine-L as a substrate. The cells are analysed by scanning electron ... [more ▼]

Chick embryo nerve cells from the lumbo-sacral spinal cord have been isolated by trypsinisation and cultivated in Rose chambers on polylysine-L as a substrate. The cells are analysed by scanning electron microscopy. The mode of adherence of these cells to the substrate and the modifications of the surface of the neuroblasts during their transformation into neurocytes are studied. [less ▲]

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See detailObservations coupled to the overpasses of the polar vortex over mid-latitude Europe in winter 1995-1996
Hennen, Olivier; De Mazière, Martine; Van Roozendael, Michel et al

in Harris, N. R. P.; Kilbane-Dawe, I.; Amanatidis, G.T. (Eds.) Polar stratospheric ozone 1997 (1998)

The spring 1996 polar vortex was very deep and cold, with temperatures down to the ice formation threshold, and persisted until March. The northern hemisphere ozone decrease in winter 1995-1996 was larger ... [more ▼]

The spring 1996 polar vortex was very deep and cold, with temperatures down to the ice formation threshold, and persisted until March. The northern hemisphere ozone decrease in winter 1995-1996 was larger than ever before in the nineties. Particularly at the European mid-latitudes, transport of air masses from the polar vortex towards mid-latitudes had a noticeable impact on the stratospheric temperatures and composition. Such was not observed that clearly in the latest winter 1996-1997. In this work, signatures of polar vortex overpasses in spring 1996 at several European mid-latitude stations are indicated. Most significant events have been observed at these stations with a delay of one to four days, on the following days: 18-22/1, 14-20/2, 1-6/3, 29/3, 15-17/4. The focus here will be on the two events in March. [less ▲]

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