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See detailPrésence de la publicité automobile dans la presse écrite belge : Analyse des quotidiens La Libre Belgique et Le Soir et des hebdomadaires Trends-Tendances et Le Vif-L’Express
Ozer, Pierre ULg

in Cybergeo : Revue Européenne de Géographie = Cybergeo - European Journal of Geography (2008)

Aspects relating to the environment, and more particularly climate change, are increasingly holding the stage when it comes to the way the media processes information. Of course, the link between climate ... [more ▼]

Aspects relating to the environment, and more particularly climate change, are increasingly holding the stage when it comes to the way the media processes information. Of course, the link between climate change and winters without snow, so-called exceptional flooding, devastating hurricanes or summer heatwaves is perfect material for the headlines of dailies and weeklies. But, what’s more, the concept of global warming is systematically in the headlines because it has become a major stake for society, the environment and the economy. Thus, the written press is calling upon its readers to be conscious of this problem but also to play an active role in this domain. Subsequently, the press tends to call upon us – to its credit – in relation to “good practices” to stop us from wasting energy, and proposes alternatives, which, in general, are not very restrictive. Often, the choice of a “clean” car appears to be an alternative. But compared with the car industry, is the written press coherent with what it puts on paper and the actions it promotes through the adverts it authorises for publication? Therefore, the objective of this paper is to provide an answer to the following three questions: 1] What is the position of car advertising in the written press? 2] What level of emissions are promoted in this advertising in relation to the objectives to be achieved? 3] What could be the solutions to this problem? A detailed analysis of car advertising was carried out in 2006 in four bodies of the Belgian French-speaking written press. The results of this study show that advertising boasts of cars which, in terms of CO2 emissions per kilometre, are from another age, and clearly contradict the values recommended in the in-depth articles written by the journalists of this type of media. [less ▲]

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See detailConceptualiser des actions professionnelles vécues, une compétence travaillée avec les futurs formateurs d’enseignants.
Beckers, Jacqueline ULg; Van der Linden, Sylvie ULg

Conference (2008, June 02)

Cette communication se focalisera sur la préparation au métier de formateur d’enseignants organisée notamment dans le cadre d’un module intitulé « Didactique Professionnelle et Formation Initiale des ... [more ▼]

Cette communication se focalisera sur la préparation au métier de formateur d’enseignants organisée notamment dans le cadre d’un module intitulé « Didactique Professionnelle et Formation Initiale des enseignants » du master en Sciences de l’Education de l’université de Liège (ULg – Belgique). La première partie de ce module privilégie le développement chez les futurs formateurs d’une compétence clé à nos yeux : « Accompagner chaque futur enseignant dans la conceptualisation et la régulation de son activité professionnelle ». Cette compétence est à la fois travaillée sur le terrain (cette année, en classes maternelles) et à l’ULg. Certaines séances de cours dispensées aux futurs formateurs les mettent face à des tâches complexes, proches de celles qu’ils auront à gérer pendant les accompagnements. Elles sont amorcées par des mises en situations ou par des récits exemplaires de pratiques récoltés auprès de formateurs d’enseignants chevronnés. D’autres séances de cours sont destinées à garantir des ressources conceptuelles (didactique professionnelle, utilisation délibérative et non applicationniste de la théorie, caractéristiques du métier enseignant, développement des compétences professionnelles, construction identitaire, …) et techniques (entretien d’explicitation, utilisation des ressources pédagogiques sur Internet, construction d’outils d’observation, utilisation de la caméra, …) à mobiliser dans les tâches complexes puis sur le terrain. Pendant l’accompagnement, l’exploitation par les futurs formateurs de traces (données d’observation, enregistrements vidéos et audios) soutient des entretiens de régulation individualisés et une séance d’analyse de pratiques en petits groupes. Quand un observable soutient la réflexion, on peut faire l’hypothèse qu’il favorise la conceptualisation voire même le changement du cadre interprétatif, particulièrement quand le groupe des pairs introduit des perceptions différentes, des significations autres et suggère des pistes d’actions alternatives. [less ▲]

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See detailAccompagner le développement du regard réflexif chez de futures institutrices préscolaires par la prise en compte de la diversité de leurs parcours, une compétence du formateur d’enseignants.
Van der Linden, Sylvie ULg

Conference (2008, June 02)

Pour instruire et éduquer leurs élèves, les enseignants mobilisent diverses compétences, résumées en « 13 compétences essentielles du métier » dans le décret réformant la Formation initiale des ... [more ▼]

Pour instruire et éduquer leurs élèves, les enseignants mobilisent diverses compétences, résumées en « 13 compétences essentielles du métier » dans le décret réformant la Formation initiale des enseignants préscolaires, primaires et du début du secondaire en Communauté Française de Belgique (décembre 2000). Les compétences que les formateurs des futurs enseignants cités mobilisent pour les accompagner dans le développement des compétences professionnelles et la construction identitaire, sont quant à elles résumées en « 14 compétences essentielles de ce deuxième métier » au sein du décret définissant le certificat d'aptitude pédagogique approprié à l'enseignement supérieur (juillet 2002). Cette communication se focaliserait sur le développement de la compétence porter un regard réflexif sur sa pratique pour développer chez des futurs enseignants préscolaires de première année de formation la capacité de réguler leur propre action et de se projeter dans le métier. En parallèle, le développement de la compétence promouvoir la réussite des étudiants notamment par la prise en compte de la diversité des parcours auprès de leur professeur de pédagogie sera décrit et analysé. [less ▲]

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See detailSupercritical carbon dioxide, a tool for the dispersion ROP of lactone and PCL foaming: Part A
Grignard, Bruno ULg; Urbanczyk, Laetitia ULg; Stassin, Fabrice et al

Poster (2008, June 02)

Aliphatic polyesters, namely polylactide (PLA) and poly-ε-caprolactone (PCL) are biodegradable and biocompatible materials that find applications as resorbable suture (PLA) and drugs delivery vectors (PCL ... [more ▼]

Aliphatic polyesters, namely polylactide (PLA) and poly-ε-caprolactone (PCL) are biodegradable and biocompatible materials that find applications as resorbable suture (PLA) and drugs delivery vectors (PCL). Nevertheless, these polymers were mainly prepared by ring opening polymerization using aluminum alkoxide or tin alkoxide initiators in organic media. Recently, the use of supercritical carbon dioxide as polymerization medium was proposed as a potential alternative to the use toxic organic solvents. Nevertheless, due to the non-solubility of PCL in this medium, the growing chains rapidly precipitate during their synthesis leading to the formation of a bulky material that is typical of a precipitation polymerization. This work aims at investigating the dispersion ring-opening polymerization (ROP) of ε-caprolactone in the presence of fluoropolymer-based stabilizers, that were prepared by combining the ring opening polymerization of ε-caprolactone and atom transfer radical polymerization of heptadecafluorodecylacrylate (AC8) and so, stabilizing PCL micrometric particles in supercritical carbon dioxide. In practice, the ROP of CL was initiated by dibutyltin dimethoxide in the presence of PCL-b-PAC8 diblock stabilizers of differents molecular weight and composition. After 24h at 40°C, PCL was collected as a powder that consists of small-sized microspheres. Finally, post-polymerization purification of PCL (removal of tin catalyst that may lead to toxicological problems) was demonstrated to be quite feasible by supercritical fluid extraction (SFE) leading to the preparation of PCL with low catalytic residues. The second goal of this work aims at reporting on the use of sc CO2 for the preparation of foams of poly(epsilon-caprolactone) (PCL), that could be useful in the packaging sector and/or the biomedical sector as potential scaffolds for tissue engineering but also as substitutes for polystyrene thermoformed trays. The method that consists of saturating a polymer with a compressed or supercritical fluid, such as carbon dioxide followed by depressurization and polymer expansion was investigated. Indeed, no residual product is left in the foam, no toxic gas is produced and no resort to hydrocarbon solvents is required. Moreover, CO2 is cheap, non-toxic, recyclable, non-flammable and the technology of CO2-assisted foaming can be used in either a batch mode or in a continuous mode within a high-pressure extruder. [less ▲]

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See detailThe stellar population of the Rosat North Ecliptic Pole survey. II. Spectral analysis
Affer, L.; Micela, G.; Morel, Thierry ULg

in Astronomy and Astrophysics (2008), 483

Context: X-ray surveys allow to identify young, main-sequence stars in the solar neighborhood. Young, stellar samples, selected according to their activity, can be used to determine the stellar birthrate ... [more ▼]

Context: X-ray surveys allow to identify young, main-sequence stars in the solar neighborhood. Young, stellar samples, selected according to their activity, can be used to determine the stellar birthrate in the last billion years. The ROSAT North Ecliptic Pole survey (NEP), with its moderately deep sensitivity (fluxes â 10[SUP]-14[/SUP] erg cm[SUP]-2[/SUP] s[SUP]-1[/SUP]), is the best survey, to date, able to sample the intermediate-age (10^8{-}10[SUP]9[/SUP] years) nearby population. The identification process of NEP X-ray sources resulted in 144 X-ray sources having a normal stellar counterpart, with an excess of yellow stars with respect to model predictions. <BR />Aims: We want to determine if these X-ray active stars are young or intermediate-age stars, or active binaries. <BR />Methods: We acquired high-resolution, high signal-to-noise ratio optical spectra, to determine the age and physical properties of the NEP X-ray-detected stellar sources. We measure the (i) lithium abundance using the Li I 6707.8 à line, which is an excellent, youth indicator for our age range of interest; (ii) rotational and radial velocities (through cross-correlation methods); and (iii) chromospheric emission (from Hα and Na I D{_1} and D{_2} lines). <BR />Results: The radial velocities distribution is consistent with that of a young field star population of age 4à 10{^9} yrs, or younger. Rotational velocity measurements imply that our sample is dominated by relatively young or intermediate-age stars, as confirmed by our lithium measurements. <BR />Conclusions: Most of the detected stars probably belong to a young or intermediate-age population. Our measurements suggest that a burst in the stellar birthrate of a factor of four occurred in the last 10[SUP]8[/SUP] years. We cannot, however, exclude the possibility that a small fraction of sources, amongst the fastest of the K-rotators, are old binary systems with tidally-locked rotation. [less ▲]

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See detailFirst detection of hydroxyl in the atmosphere of Venus
Piccioni, G.; Drossart, P.; Zasova, L. et al

in Astronomy and Astrophysics (2008), 483

Context: Airglow emissions, such as previously observed from NO and O2(a-X) (0-0) on Venus, provide insight into the chemical and dynamical processes that control the composition and energy balance in the ... [more ▼]

Context: Airglow emissions, such as previously observed from NO and O2(a-X) (0-0) on Venus, provide insight into the chemical and dynamical processes that control the composition and energy balance in the upper atmospheres of planets. The OH airglow emission has been observed previously only in the Earth's atmosphere where it has been used to infer atomic oxygen abundances. The O2(a-X) (0-1) airglow emission also has only been observed in the Earth's atmosphere, and neither laboratory nor theoretical studies have reached a consensus on its transition probability. Aims: We report measurements of night-side airglow emission in the atmosphere of Venus in the OH (2-0), OH (1-0), O2(a-X) (0-1), and O2(a-X) (0-0) bands. This is the first detection of the first three of these airglow emissions on another planet. These observations provide the most direct observational constraints to date on H, OH, and O3, key species in the chemistry of Venus' upper atmosphere. Methods: Airglow emission detected at wavelengths of 1.40-1.49 and 2.6-3.14 mum in limb observations by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the Venus Express spacecraft is attributed to the OH (2-0) and (1-0) transitions, respectively, and compared to calculations from a photochemical model. Simultaneous limb observations of airglow emission in the O2(a-X) (0-0) and (0-1) bands at 1.27 and 1.58 mum, respectively, were used to derive the ratio of the transition probabilities for these bands. Results: The integrated emission rates for the OH (2-0) and (1-0) bands were measured to be 100 ± 40 and 880±90 kR respectively, both peaking at an altitude of 96 ± 2 km near midnight local time for the considered orbit. The measured ratio of the O2(a-X) (0-0) and (0-1) bands is 78 ± 8. Conclusions: Photochemical model calculations suggest the observed OH emission is produced primarily via the Bates-Nicolet mechanism, as on the Earth. The observed ratio of the intensities of the O2(a-X) (0-0) and (0-1) bands implies the ratio of their transition probabilities is 63±6. [less ▲]

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See detailL'astronomie dans le monde
Manfroid, Jean ULg

in Ciel (Le) (2008), 70

Les Antennes se rapprochent; Matière manquante; Galaxies trapues; Fusion de trous noirs; Thermomètre moléculaire; Supernova récente dans la Voie Lactée; Naine blanche particulière; L'étoile à neutrons 4U ... [more ▼]

Les Antennes se rapprochent; Matière manquante; Galaxies trapues; Fusion de trous noirs; Thermomètre moléculaire; Supernova récente dans la Voie Lactée; Naine blanche particulière; L'étoile à neutrons 4U 1636-53; Pulsar étrange; Hubble; Fin du monde; Lunes; Extinction KT; L'axe changeant d'Europe; Ondes dans la haute atmosphère de Saturne; Anneau de Mars; Mars plus froid; [less ▲]

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See detailPushing the precision limit of ground-based eclipse photometry
Gillon, Michaël ULg; Anderson, D. R.; Demory, B *-O et al

Report (2008)

Until recently, it was considered by many that ground-based photometry could not reach the high cadence sub-mmag regime because of the presence of the atmosphere. Indeed, high frequency atmospheric noises ... [more ▼]

Until recently, it was considered by many that ground-based photometry could not reach the high cadence sub-mmag regime because of the presence of the atmosphere. Indeed, high frequency atmospheric noises (mainly scintillation) limit the precision that high SNR photometry can reach within small time bins. If one is ready to damage the sampling of his photometric time-series, binning the data (or using longer exposures) allows to get better errors, but the obtained precision will be finally limited by low frequency noises. To observe several times the same planetary eclipse and to fold the photometry with the orbital period is thus generally considered as the only option to get very well sampled and precise eclipse light curve from the ground. Nevertheless, we show here that reaching the sub-mmag sub-min regime for one eclipse is possible with a ground-based instrument. This has important implications for transiting planets characterization, secondary eclipses measurement and small planets detection from the ground. [less ▲]

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See detailOptical evolution of Nova Ophiuchi 2007 = V2615 Oph
Munari, U.; Henden, A.; Valentini, Marica ULg et al

in Monthly Notices of the Royal Astronomical Society (2008), 387

The moderately fast Nova Oph 2007 reached maximum brightness on 2007 March 28 at V = 8.52, B - V = +1.12, V - R[SUB]C[/SUB] = +0.76, V - I[SUB]C[/SUB] = +1.59 and R[SUB]C[/SUB] - I[SUB]C[/SUB] = +0.83 ... [more ▼]

The moderately fast Nova Oph 2007 reached maximum brightness on 2007 March 28 at V = 8.52, B - V = +1.12, V - R[SUB]C[/SUB] = +0.76, V - I[SUB]C[/SUB] = +1.59 and R[SUB]C[/SUB] - I[SUB]C[/SUB] = +0.83, after fast initial rise and a pre-maximum halt lasting a week. Decline times were t[SUP]V[/SUP][SUB]2[/SUB] = 26.5, t[SUP]B[/SUP][SUB]2[/SUB] = 30, t[SUP]V[/SUP][SUB]3[/SUB] = 48.5 and t[SUP]B[/SUP][SUB]3[/SUB] = 56.5 d. The distance to the nova is d = 3.7 +/- 0.2 kpc, the height above the Galactic plane is z = 215 pc, the reddening is E(B - V) = 0.90 and the absolute magnitude at maximum is M[SUP]max[/SUP][SUB]V[/SUB] = -7.2 and M[SUP]max[/SUP][SUB]B[/SUB] = -7.0. The spectrum four days before maximum resembled a F6 supergiant, in an agreement with broad-band colours. It later developed into that of a standard `FeII'-class nova. Nine days past maximum, the expansion velocity estimated from the width of Hα emission component was ~730 km s[SUP]-1[/SUP], and the displacement from it of the principal and diffuse-enhanced absorption systems was ~650 and 1380 km s[SUP]-1[/SUP], respectively. Dust probably formed and disappeared during the period from 82 to 100 d past maximum, causing (at peak dust concentration) an extinction of ΔB = 1.8 mag and an extra ΔE(B - V) = 0.44 reddening. [less ▲]

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See detailInternal dynamics from asteroseismology for two sdB pulsators residing in close binary systems
Van Grootel, Valérie ULg; Charpinet, Stéphane; Fontaine, Gilles et al

Conference (2008, June)

Since their discovery eleven years ago, short-period pulsating sdB stars have proved their potential for quantitative asteroseismological studies. We have recently updated our asteroseismic diagnostic ... [more ▼]

Since their discovery eleven years ago, short-period pulsating sdB stars have proved their potential for quantitative asteroseismological studies. We have recently updated our asteroseismic diagnostic tools in order to incorporate the effects of stellar rotation on pulsations, assuming various internal rotation laws. It was possible, with these new tools, to determine the internal rotation profile of two short-period pulsating sdB stars residing in close binary systems, namely Feige 48 and PG 1336−018. They exhibit orbital periods of, respectively, 9.024 h and 2.424 h measured from spectroscopy. For the two stars, we show that spin-orbit synchronism is reached from the surface down to ∼ 0.22 R∗ and 0.55 R∗, respectively. The rotation of deeper layers cannot be inferred with the type of modes observed in short-period pulsating sdB stars. These results could also provide new elements to test tidal friction theories, particularly the angular momentum transport, in close binary systems. [less ▲]

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See detailDuctility requirements for the design of bolted shear connections
Henriques, José; Jaspart, Jean-Pierre ULg; Piraprez, E.

in Proceedings of the Sixth International Workshop on Connections (2008, June)

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See detailA hybrid optimization technique coupling evolutionary and local search algorithms
Kelner, Vincent ULg; Capitanescu, Florin ULg; Léonard, Olivier ULg et al

in Journal of Computational & Applied Mathematics (2008), 215(2), 448-456

Evolutionary Algorithms are robust and powerful global optimization techniques for solving large scale problems that have many local optima. However, they require high CPU times, and they are very poor in ... [more ▼]

Evolutionary Algorithms are robust and powerful global optimization techniques for solving large scale problems that have many local optima. However, they require high CPU times, and they are very poor in terms of convergence performance. On the other hand, local search algorithms can converge in a few iterations but lack a global perspective. The combination of global and local search procedures should offer the advantages of both optimization methods while offsetting their disadvantages. This paper proposes a new hybrid optimization technique that merges a Genetic Algorithm with a local search strategy based on the Interior Point method. The efficiency of this hybrid approach is demonstrated by solving a constrained multi-objective mathematical test-case. [less ▲]

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See detailComparison of bovine and human O26 EHEC strains by the Whole Genome PCR Scanning
Bardiau, Marjorie ULg; Ogura, Y.; Hayashi, T. et al

Conference (2008, June)

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See detailComparison of bovine and human O26 EHEC strains by the Whole Genome PCR Scanning
Bardiau, Marjorie ULg; Ogura, Y.; Hayashi, Tetsuya et al

Conference (2008, June)

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See detailImpact of pre-treatment processing on cereal by-products valorisation through enzymatic extraction of ferulic acid.
Barberousse, Hélène; Roiseux, Olivier; Deroanne, Claude et al

Poster (2008, June)

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See detailEfficiency of sieving or classification for dry fractionation of aot mills and beta-glucans enrichment.
Roiseux, Olivier; Vanderbeke, E.; Blecker, Christophe ULg et al

Poster (2008, June)

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See detailPlastic capacity of semi-compact steel sections
Lechner, A.; Kettler, M.; Greiner, R. et al

in Proceedings of the CIMS2008 - Coupled Instabilities in Metal Structures (2008, June)

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See detailGénération de maillages surfaciques pour la création de modèles biomécaniques du cerveau
D'Otreppe, Vinciane ULg

Master's dissertation (2008)

Le planning préopératoire en neurochirurgie est réalisé à partir d'images structurelles et fonctionnelles du patient. Cependant l'intervention chirurgicale réalisée à partir de ce planning se fonde sur l ... [more ▼]

Le planning préopératoire en neurochirurgie est réalisé à partir d'images structurelles et fonctionnelles du patient. Cependant l'intervention chirurgicale réalisée à partir de ce planning se fonde sur l'hypothèse que les structures anatomiques ne bougent pas pendant l'opération. En réalité, pendant l'opération, le cerveau se déforme de sorte que les images préopératoires, sur lesquelles se base le neurochirurgien, ne correspondent plus à la réalité anatomique du patient. Un approche envisagée pour résoudre ce problème est de modéliser, par la méthode des éléments finis, le comportement mécanique du cerveau pendant l'opération. Ceci permettrait de fournir au chirurgien, tout au long de l'intervention, des images mises à jour de la même qualité que les images préopératoires. La création du maillage du modèle biomécanique du cerveau à partir d'images IRM préopératoires fait l'objet de ce travail. La première et majeure partie du travail est consacrée à l'élaboration d'un mailleur surfacique. L'extraction de la surface, définie soit à l'aide d'une fonction implicite, soit à l'aide d'une image tridimensionnelle, se fait au moyen de la méthode Marching Tetrahedra. Le maillage ainsi obtenu étant inadapté au calcul éléments finis, il est ensuite simplifié et amélioré de manière à obtenir un maillage de bonne qualité. Afin de découpler la taille des mailles générées de la distance inter-slices, une méthode d'interpolation entre images a également été implémentée. La seconde partie est l'intégration du mailleur surfacique créé dans l'embryon du système de neuronavigation en cours de développement à l'ULg. Par simplicité, le cerveau est considéré comme un milieu homogène et seul le phénomène du brain shift est modélisé. De plus, les images IRM sont supposées avoir été préalablement corrigées, segmentées et recalées. Les résultats obtenus après calcul éléments finis similaires à ceux trouvés dans la littérature. [less ▲]

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