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See detailLe patient, le médecin de famille et la SNOMEDISATION de l’information de santé
Jamoulle, Marc ULg

Conference (2016, May 19)

Some thoughs of a practicing family doctor on the recent evolution of terminological field in health care and the marketing of medicine

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See detailA Reversal of Long-term Global Trends in Atmospheric Ethane and Propane from North American Oil and Natural Gas Emissions
Helmig, D.; Rossabi, S.; Hueber, J. et al

Conference (2016, May 18)

Ethane, the longest-lived and most abundant non-methane hydrocarbon (NMHC) peaked in the background atmosphere around 1970. This was followed by a ~20% reduction of the atmospheric burden and a resulting ... [more ▼]

Ethane, the longest-lived and most abundant non-methane hydrocarbon (NMHC) peaked in the background atmosphere around 1970. This was followed by a ~20% reduction of the atmospheric burden and a resulting atmospheric downward trend for the next four decades, mostly due to reduced emissions from oil and gas industries and stricter air quality controls. Here, we show that the near 40-year trend of declining global ethane halted between 2005-2010 in most of the Northern Hemisphere (NH), and that since it has reversed. The largest increases in ethane and of the shorter-lived propane are seen in the central and eastern U.S. and immediately downwind, identifying this region as the primary source of increased NMHC emissions. The spatial distribution of observed concentration increases for ethane and propane provides convincing evidence that renewed emissions are primarily associated with the growth of oil and natural gas development in North America. Using source region relationships, emission estimates for increases of co-emitted NMHCs and methane, as well as impacts on tropospheric ozone production have been developed. [less ▲]

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See detailAharonov-Bohm oscillations of bosonic matter-wave beams in the presence of disorder and interaction
Chrétien, Renaud ULg; Dujardin, Julien; Petitjean, Cyril ULg et al

Poster (2016, May 18)

We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein condensed atoms through Aharonov-Bohm (AB) rings. Our system consists of a Bose-Einstein condensate (BEC) that ... [more ▼]

We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein condensed atoms through Aharonov-Bohm (AB) rings. Our system consists of a Bose-Einstein condensate (BEC) that is outcoupled from a magnetic trap into a 1D waveguide which is made of two semi-infinite leads that join a ring geometry exposed to a synthetic magnetic flux φ. We specifically investigate the effects both of a disorder potential and of a small atom-atom contact interaction strength on the AB oscillations. The main numerical tools that we use for this purpose are a mean-field Gross-Pitaevskii (GP) description and the truncated Wigner (tW) method. We find that a correlated disorder suppress the AB oscillations leaving thereby place to weaker amplitude, half period oscillations on transmission, namely the Aronov-Al’tshuler-Spivak (AAS) oscillations. The competition between disorder and interaction leads to a flip of the transmission at the AB flux φ = π. This flip could be a possible preliminary signature of an inversion of the coherent backscattering (CBS) peak. Our study paves the way to an analytical description of the inversion of that peak. [less ▲]

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See detailEthane rise associated with North American oil and gas exploitation
Franco, Bruno ULg; Mahieu, Emmanuel ULg; Emmons, Louisa et al

Conference (2016, May 18)

Ethane (C2H6) is mainly emitted in the atmosphere from leakage during production and transport of natural gas, biofuel consumption and biomass burning. As it shares concurrent anthropogenic emission ... [more ▼]

Ethane (C2H6) is mainly emitted in the atmosphere from leakage during production and transport of natural gas, biofuel consumption and biomass burning. As it shares concurrent anthropogenic emission sources with methane (CH4), a better understanding of the atmospheric distribution of C2H6 and any trends in its abundance can be used to better constrain the sources of CH4 from oil and gas activities. Until very recently, the C2H6 abundance in the atmosphere has been declining due to the reduction of fugitive emissions as a result of air pollution abatement measures. However, a renewal of the atmospheric C2H6 burden has been detected over North America and Europe from 2009 onwards. It is attributed to the unprecedented growth in the exploitation of shale gas and tight oil reservoirs in North America. Using time series of C2H6 abundance derived from ground-based high-resolution infrared solar absorption spectra recorded at complementary NDACC FTIR sites, we present here sharp C2H6 rises in the Northern Hemisphere, of up to 5 %/yr since 2009. Using model simulations, we show that the HTAP2 bottom-up inventories for anthropogenic emissions greatly underestimate the observed pre-increase C2H6 abundances and that they are too low by a factor two. We also evaluate new top-down emissions of C2H6 from the North American oil and gas activities, biofuel consumption and biomass burning, derived from space-borne observations of CH4 from GOSAT. We find a good agreement with the observations at the North American mid-latitudinal sites, close to regions with high drilling productivity, but an overestimation at remote sites. We also estimate that the North American C2H6 emissions have increased by 75% over the past six years (2009-2014), annihilating the benefits of more than two decades of successful anthropogenic emission reduction, and that the associated annual CH4 emissions from the North American oil and gas sector grew from 20 to 35 Tg/yr over the same period. [less ▲]

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See detailOrbital, spin state and thermophysical characterization of near-Earth asteroid (3200) Phaethon
Hanus, Josef; Delbo, Marco; Vokrouhlický, D. et al

in Astronomy and Astrophysics (2016)

The near-Earth asteroid (3200) Phaethon is an intriguing object: its perihelion is only at 0.14 au and is associated with the Geminid meteor stream. We aim to use all available disk-integrated optical ... [more ▼]

The near-Earth asteroid (3200) Phaethon is an intriguing object: its perihelion is only at 0.14 au and is associated with the Geminid meteor stream. We aim to use all available disk-integrated optical data to derive reliable convex shape model of Phaethon. By interpreting the available space- and ground-based thermal infrared data and Spitzer spectra using a thermophysical model, we also aim to further constrain its size, thermal inertia, and visible geometric albedo. We apply the convex inversion method to the new optical data obtained by six instruments together with the already existing observations. The convex shape model is then used as an input for the thermophysical modeling. We also study the long-term stability of Phaethon’s orbit and spin axis by a numerical orbital and rotation-state integrator We present a new convex shape model and rotational state of Phaethon – sidereal rotation period of 3.603958(2) h and ecliptic coordinates of the preferred pole orientation of (319◦ , −39◦) with a 5◦ uncertainty. Moreover, we derive its size (D=5.1±0.2 km), thermal inertia (Γ=600±200 J m-2s -1/2K -1), geometric visible albedo (pV=0.122±0.008), and estimate the macroscopic surface roughness. We also find that the Sun illumination at the perihelion passage during past thousands of years is not connected to a specific area on the surface implying non-preferential heating. [less ▲]

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See detailÉtude de cas : le site Gamekult (période « post-premium »)
Krywicki, Boris ULg

Scientific conference (2016, May 18)

Ce pure player dédié à l’actualité généraliste du jeu vidéo reflète un positionnement assez hybride au sein du champ de la presse vidéoludique numérique. Tout en restant chevillé au traitement classique « ... [more ▼]

Ce pure player dédié à l’actualité généraliste du jeu vidéo reflète un positionnement assez hybride au sein du champ de la presse vidéoludique numérique. Tout en restant chevillé au traitement classique « news – previews – tests » de ce type de médias, il cherche à se montrer plus intransigeant que ses concurrents. Le lancement de son modèle économique « premium », qui fait basculer une partie des articles proposés par le portail en accès payant, s’accompagne d’une série de discours réflexifs sur le métier de journaliste de jeu vidéo et ses pratiques endogamiques, que l’équipe ne manque pas de montrer du doigt. Ainsi, les contenus éditoriaux de Gamekult s’inscrivent dans le suivi de l’actualité « chaude » du jeu vidéo, mais cherchent à paraître plus pertinents ou plus avertis que les propositions des autres sites par toute une série de stratégies rédactionnelles et oratoires. Le choix, loin de s’avérer anodin, de mettre en scène l’équipe de la rédaction au sein d’un documentaire, à l’occasion des 15 ans du site, lui confère un espace pour illustrer ce qu’elle présente à plusieurs reprises comme un « combat ambitieux ». De la même manière, nous pourrons observer comment, par une kyrielle d’adresses à sa destination plus ou moins subtiles, Gamekult performe son lectorat, lui bâtit un ouitllage clé-en-main pour se définir en tant que lecteur-partisan des valeurs proposées par le portail et, par effet communautaire, opposé à la concurrence. L’information que construit Gamekult s’appuie énormément sur une vision du jeu vidéo et de son industire qui, à plusieurs égards, vient justifier et légitimer le parti-pris du portail en termes de modèle économique. Ce cas particulier permettra de résumer les enjeux des adresses aux lecteurs de la critique culturelle et, par extension, d’interroger les limites de l’instrumentalisation des récepteurs en tant que porte-étendards d’une communauté de valeurs définies par l’orientation politico-économique d’un média. Il illustrera comment l’accumulation de petits clins d’œil, parfois triviaux d’apparence, permettent de convaincre, sur le long terme, de la bonne foi des acteurs d’un milieu, par opposition aux déviances d’autres, et de la glorification d’un ethos à l’aune de l’éthique, pourtant relative. [less ▲]

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See detailDébats autour du concept de type en typologie des langues
Lttr13; Badir, Sémir ULg; Polis, Stéphane ULg et al

Conference (2016, May 18)

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See detailChaotic Bohmian trajectories for stationary states
Cesa, Alexandre ULg; Martin, John ULg; Struyve, Ward

Poster (2016, May 18)

We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical ... [more ▼]

We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical computations, for one particle moving in 3 spatial dimensions and for two and three entangled particles in 2 dimensions. What is important for the amount of chaos is the overall complexity of the wave function. Some simple measures that partly capture the complexity of the wave function are considered: the participation ratio and different measures of entanglement. We find that these measures often tend to correlate to the amount of chaos. However, the correlation is not perfect, because the measures do not depend on the intrinsic complexity of the states of a given basis. [less ▲]

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See detailDevelopment of a hydrogen maser in the TE111 mode
Van Der Beken, Emeline ULg; Léonard, Daniel; Counet, Arnaud et al

Poster (2016, May 18)

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design ... [more ▼]

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design hydrogen masers with significant reduced dimensions which represents a huge benefit for space applications and in particular for the global positioning system. We present in details the different parts of our model : cavity with a thin Teflon sheet, magnetic shielding, temperature control of the maser... [less ▲]

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See detailA New Approach for the Characterization of Organic Residues from Stone Tools Using GC×GC-TOFMS
Perrault, Katelynn ULg; Stefanuto, Pierre-Hugues ULg; Dubois, Lena ULg et al

in Separations (2016), 3(2), 16

Headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) have traditionally been used, in combination with other analyses, for the chemical characterization of ... [more ▼]

Headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) have traditionally been used, in combination with other analyses, for the chemical characterization of organic residues recovered from archaeological specimens. Recently in many life science fields, comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) has provided numerous benefits over GC-MS. This study represents the first use of HS-SPME-GC×GC-TOFMS to characterize specimens from an experimental modern reference collection. Solvent extractions and direct analyses were performed on materials such as ivory, bone, antlers, animal tissue, human tissue, sediment, and resin. Thicker film column sets were preferred due to reduced column overloading. The samples analyzed by HS-SPME directly on a specimen appeared to give unique signatures and generally produced a higher response than for the solvent-extracted residues. A non-destructive screening approach of specimens may, therefore, be possible. Resin and beeswax mixtures prepared by heating for different lengths of time appeared to provide distinctly different volatile signatures, suggesting that GC×GC-TOFMS may be capable of differentiating alterations to resin in future studies. Further development of GC×GC-TOFMS methods for archaeological applications will provide a valuable tool to uncover significant information on prehistoric technological changes and cultural behavior. [less ▲]

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See detailAnticoherence of spin states with point-group symmetries
Baguette, Dorian ULg; Damanet, François ULg; Giraud, Olivier et al

Poster (2016, May 18)

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See detailSuper- and subradiance from indistinguishable atoms with quantized motion
Damanet, François ULg; Braun, Daniel; Martin, John ULg

Poster (2016, May 18)

Detailed reference viewed: 18 (2 ULg)
See detailAvatar et jeu vidéo. Réflexions sur le rapport au corps virtuel
Delbouille, Julie ULg

Scientific conference (2016, May 17)

Cette intervention se penche sur les différentes modalités relationnelles qui s’instaurent entre le corps physique du joueur et son répondant virtuel. La question du rapport au corps est centrale dans la ... [more ▼]

Cette intervention se penche sur les différentes modalités relationnelles qui s’instaurent entre le corps physique du joueur et son répondant virtuel. La question du rapport au corps est centrale dans la relation avatariale : touchant à la tension entre l’ « ici » — la physicalité du joueur faisant face à l’écran — et le « là » — la présence de l’avatar au sein de l’univers de jeu —, elle met en relief le paradoxe caractérisant le rôle actif du joueur, dont l’action s’étend à la fois au sein et aux marges du jeu. Cette problématique du rapport au corps, entendu comme « moyen général d’avoir un monde », apporte un regard neuf sur l’histoire du jeu vidéo depuis ses origines. [less ▲]

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See detailInfluence of the balls kinematics and ball/race contact models on quasi-static approaches for ball bearing
Servais, Christophe ULg; Bozet, Jean-Luc ULg

Conference (2016, May 17)

The frictional power dissipated within dry lubricated ball bearings is a prime concern, especially for high speed applications. Nevertheless, the exact balls behavior is still a source of interrogations ... [more ▼]

The frictional power dissipated within dry lubricated ball bearings is a prime concern, especially for high speed applications. Nevertheless, the exact balls behavior is still a source of interrogations. Firstly, a comparison of several ball/race contact models has been performed by prescribing the kinematical variables. This has been done by using an existing quasi-static approach to reach the ball bearing equilibrium. Secondly, a parametric study has been carried out on the ball kinematics. This time the contact model remained fixed. The results demonstrate the predominance of the kinematics on the ball bearing behavior with an emphasis on the dissipated power within ball/race contacts. This shows that the kinematics must be rightly computed. On the other hand, the ball/race contact model doesn’t necessitate a high refinement in order to evaluate the ball bearing equilibrium. Conversely, this refinement is essential for a precise evaluation of the power losses. [less ▲]

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