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See detail"La réunion à la France": histoire et actualité
Lanneau, Catherine ULg

Conference given outside the academic context (2016)

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See detailFirst principles study of heavily doped full Heusler Fe2YZ for high thermoelectric power factor
Lemal, Sébastien ULg; Ghosez, Philippe ULg; Bilc, Daniel ULg

Poster (2016, May 02)

Using a combination of first-principles calculations based on density functional theory and Boltzmann semi-classical transport theory, we investigate the properties of heavily $n$-type doped full Heusler ... [more ▼]

Using a combination of first-principles calculations based on density functional theory and Boltzmann semi-classical transport theory, we investigate the properties of heavily $n$-type doped full Heusler Fe2YZ1-xAx compounds. Using a supercell approach and including explicitly the dopant impurities, we recover in some cases giant thermoelectric power factors as previously predicted under doping within the rigid band approximations [Phys. Rev. Lett. 114, 136601 (2015)]. In other cases, however, we highlight that the system evolves toward a ferromagnetic half-metallic ground state so that the power factor is strongly modified. We rationalize the appearance of this magnetic instability, showing that it consistent with the Stoner model. The uncovered properties of the heavily doped phases of the studied Fe2YZ1-xAx compounds appear promising for Seebeck and spin-Seebeck applications. [less ▲]

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See detailChangements climatiques : les impacts des ruminants et quels leviers d'action
Beckers, Yves ULg

Scientific conference (2016, May 02)

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See detailCrystallization behavior of neutralized and bleached shea butter under dynamic conditions
Gibon, V.; Dijckmans, P.; Blecker, Christophe ULg et al

Poster (2016, May 01)

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See detailChapter 2 - Fish Sound Production: Insights
Parmentier, Eric ULg; Fine, Michael

in Suthers, Roderick; Fitch, Temcuseh; Fay, Richard (Eds.) et al Vertebrate Sound Production and Acoustic Communication (2016)

In addition to briefly reviewing sound-producing mechanisms, this chapter focuses on an under-appreciated evolutionary process, exaptation, which could aid in understanding the independent origins and ... [more ▼]

In addition to briefly reviewing sound-producing mechanisms, this chapter focuses on an under-appreciated evolutionary process, exaptation, which could aid in understanding the independent origins and high diversity of sound-producing mechanisms in fishes. Existing anatomical structures first used in non-voluntary sound production provide advantages that result in further selection and refinement of sophisticated sonic organs. Moreover, comparisons of the relationships between fish size and spectral features in multiple not phylogenetically related species highlight two acoustic patterns. In species using superfast muscles, the slope of the relationship between fish size and sound frequency is weak (1°–5°) so that emitter size is unlikely inferred from call frequency. In other species that stridulate or use bones or tendons to stimulate the swimbladder, the high slopes (25°–80°) indicate major differences in the call frequencies within a species. These signals likely convey important information (size and potential fitness of the emitter) to conspecific receivers. [less ▲]

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See detailTemperate Earth-sized planets transiting a nearby ultracool dwarf star
Gillon, Michaël ULg; Jehin, Emmanuel ULg; Lederer, Susan M. et al

in Nature (2016), 533

Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as ‘ultracool dwarfs’. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs ... [more ▼]

Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as ‘ultracool dwarfs’. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15 per cent of the population of astronomical objects near the Sun. Core-accretion theory predicts that, given the small masses of these ultracool dwarfs, and the small sizes of their protoplanetary disks, there should be a large but hitherto undetected population of terrestrial planets orbiting them—ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets. Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Our data suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth. The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system. [less ▲]

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See detailThe X-ray light curve of the massive colliding wind Wolf-Rayet + O binary WR 21a
Gosset, Eric ULg; Nazé, Yaël ULg

in Astronomy and Astrophysics (2016), 590

Our dedicated XMM-Newton monitoring, as well as archival Chandra and Swift datasets, were used to examine the behaviour of the WN5h+O3V binary WR 21a at high energies. For most of the orbit, the X-ray ... [more ▼]

Our dedicated XMM-Newton monitoring, as well as archival Chandra and Swift datasets, were used to examine the behaviour of the WN5h+O3V binary WR 21a at high energies. For most of the orbit, the X-ray emission exhibits few variations. However, an increase in strength of the emission is seen before periastron, following a 1 /D relative trend, where D is the separation between both components. This increase is rapidly followed by a decline due to strong absorption as the Wolf-Rayet (WR) comes in front. The fitted local absorption value appears to be coherent with a mass-loss rate of about 1 × 10[SUP]-5[/SUP] M[SUB]⊙[/SUB] yr[SUP]-1[/SUP] for the WR component. However, absorption is not the only parameter affecting the X-ray emission at periastron as even the hard X-ray emission decreases, suggesting a possible collapse of the colliding wind region near to or onto the photosphere of the companion just before or at periastron. An eclipse may appear as another potential scenario, but it would be in apparent contradiction with several lines of evidence, notably the width of the dip in the X-ray light curve and the absence of variations in the UV light curve. Afterwards, the emission slowly recovers, with a strong hysteresis effect. The observed behaviour is compatible with predictions from general wind-wind collision models although the absorption increase is too shallow. Based on observations collected at ESO as well as with Swift, Chandra, and the ESA science mission XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). [less ▲]

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See detailPulsating hot O subdwarfs in ω Centauri: mapping a unique instability strip on the extreme horizontal branch
Randall, S. K.; Calamida, A.; Fontaine, G. et al

in Astronomy and Astrophysics (2016), 589

We present the results of an extensive survey for rapid pulsators among Extreme Horizontal Branch (EHB) stars in ω Cen. The observations performed consist of nearly 100 h of time-series photometry for ... [more ▼]

We present the results of an extensive survey for rapid pulsators among Extreme Horizontal Branch (EHB) stars in ω Cen. The observations performed consist of nearly 100 h of time-series photometry for several off-centre fields of the cluster, as well as low-resolution spectroscopy for a partially overlapping sample. We obtained photometry for some 300 EHB stars, for around half of which we are able to recover light curves of sufficient quality to either detect or place meaningful non-detection limits for rapid pulsations. Based on the spectroscopy, we derive reliable values of log g, T[SUB]eff[/SUB] and log N(He) /N(H) for 38 targets, as well as good estimates of the effective temperature for another nine targets, whose spectra are slightly polluted by a close neighbour in the image. The survey uncovered a total of five rapid variables with multi-periodic oscillations between 85 and 125 s. Spectroscopically, they form a homogeneous group of hydrogen-rich subdwarf O stars clustered between 48 000 and 54 000 K. For each of the variables we are able to measure between two and three significant pulsations believed to constitute independent harmonic oscillations. However, the interpretation of the Fourier spectra is not straightforward due to significant fine structure attributed to strong amplitude variations. In addition to the rapid variables, we found an EHB star with an apparently periodic luminosity variation of ~2700 s, which we tentatively suggest may be caused by ellipsoidal variations in a close binary. Using the overlapping photometry and spectroscopy sample we are able to map an empirical ω Cen instability strip in log g - T[SUB]eff[/SUB] space. This can be directly compared to the pulsation driving predicted from the Montréal "second-generation" models regularly used to interpret the pulsations in hot B subdwarfs. Extending the parameter range of these models to higher temperatures, we find that the region where p-mode excitation occurs is in fact bifurcated, and the well-known instability strip between 29 000-36 000 K where the rapid subdwarf B pulsators are found is complemented by a second one above 50 000 K in the models. While significant challenges remain at the quantitative level, we believe that the same κ-mechanism that drives the pulsations in hot B subdwarfs is also responsible for the excitation of the rapid oscillations observed in the ω Cen variables. Intriguingly, the ω Cen variables appear to form a unique class. No direct counterparts have so far been found either in the Galactic field, nor in other globular clusters, despite dedicated searches. Conversely, our survey revealed no ω Cen representatives of the rapidly pulsating hot B subdwarfs found among the field population, though their presence cannot be excluded from the limited sample. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (proposal IDs 083.D-0833, 386.D-0669, 087.D-0216 and 091.D-0791).The reduced spectra are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/589/A1">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/589/A1</A> [less ▲]

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See detail188Re and 68Ga radiolabeled Starch-Based Microparticles as potential theranostic radiopharmaceutical for Hepatocellular Carcinoma
Verger, Elise ULg; Drion, Pierre ULg; MEFFRE, Geneviève ULg et al

in Journal of Nuclear Medicine (The) (2016, May 01), 57(suppl. 2),

The SBMP as a unique vector is a promising theranostic agent for the SIRT of HCC.

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See detailShakespeare and Belgium
Hamélius, Paul ULg

in Gollancz, Israel; McMullan, Gordon (Eds.) A Book of Homage to Shakespeare (2016)

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See detailModelling and Emulation of an Unbalanced LV Feeder with Photovoltaic Inverters
López-Erauskin, Ramón; Gyselinck, Johan; Olivier, Frédéric ULg et al

in Proc. of 8th IEEE Benelux Young researchers symposium in Electrical Power Engineering (2016, May)

In this paper, the penetration of grid-connected pho- tovoltaic systems is studied, experimentally tested and compared to simulation results. In particular, how the inverse current flow and unbalance ... [more ▼]

In this paper, the penetration of grid-connected pho- tovoltaic systems is studied, experimentally tested and compared to simulation results. In particular, how the inverse current flow and unbalance situations affect the voltage in the low-voltage grid. Thus, a test platform has been developed for obtaining experimental results with grid-tied commercial inverters. Photo- voltaic arrays are emulated and subjected to different irradiance profiles and the inverters are controlled to produce at different power conditions. A model has been developed in order to repro- duce the same operating conditions and working environment. Simulations are performed with the software PowerFactory and the results compared to the experimental ones. [less ▲]

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See detailA Comparison of 3D Methods for Identifying the Stance Phase in Treadmill Running for Both Rearfoot and Forefoot Runners
Deflandre, Dorian ULg; Schwartz, Cédric ULg; Weertz et al

in Journal of sports Science (2016), 4

We compared six 3D methods, OptoGait, and Myotest Run for the determination of contact time for runners with different foot strike patterns. Twenty male participants were divided into two groups: the heel ... [more ▼]

We compared six 3D methods, OptoGait, and Myotest Run for the determination of contact time for runners with different foot strike patterns. Twenty male participants were divided into two groups: the heel group, who attack the ground with the heel (n = 12), and the toe group, who attack the ground with the middle/front of the foot (n = 8). They performed trials at speeds of 8 km/h then 16 km/h. To detect foot strike, the use of peak velocity of 3D markers located on the heel, the fifth metatarsal, and the great toe provided the best results for both groups. To detect the toe off, the minimum vertical position of a 3D marker placed in line with the great toe gave the most satisfactory results for both groups. In this way, the values of contact time measured with the 3D methods are consistent. Values measured with OptoGait appear consistent too, while those of the Myotest Run underestimate the contact time for both speeds. 3D analysis provides interesting opportunities for calculation of contact time for both rearfoot and forefoot runners, using specific peak velocities to determine foot strike and marker displacement to determine toe off. [less ▲]

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See detailDeep Background Subtraction with Scene-Specific Convolutional Neural Networks
Braham, Marc ULg; Van Droogenbroeck, Marc ULg

in International Conference on Systems, Signals and Image Processing, Bratislava 23-25 May 2016 (2016, May)

Background subtraction is usually based on low-level or hand-crafted features such as raw color components, gradients, or local binary patterns. As an improvement, we present a background subtraction ... [more ▼]

Background subtraction is usually based on low-level or hand-crafted features such as raw color components, gradients, or local binary patterns. As an improvement, we present a background subtraction algorithm based on spatial features learned with convolutional neural networks (ConvNets). Our algorithm uses a background model reduced to a single background image and a scene-specific training dataset to feed ConvNets that prove able to learn how to subtract the background from an input image patch. Experiments led on 2014 ChangeDetection.net dataset show that our ConvNet based algorithm at least reproduces the performance of state-of-the-art methods, and that it even outperforms them significantly when scene-specific knowledge is considered. [less ▲]

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See detailHow Service Managers Can Shape Frontline Employees' Organizational Values to Reduce Person-Role Conflicts
Selzer, Veronika Luisa; Schumann, Jan Hendrik; Büttgen, Marion et al

Conference (2016, May)

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See detailRoof Frames in the Buit Heritage of Brussels (Belgium): The contribution of dendrochronology and written sources
Weitz, Armelle ULg; Charruadas, Paulo; Fraiture, Pascale et al

in Tree Rings in Archaeology, Climatology and Ecology (2016, May), 14

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See detailInflammation et alimentation: des pistes intéressantes
Knapp, Emilie ULg; Guyot, Hugues ULg

in SNGTV (Ed.) Journées Nationales des GTV: Nutrition et pratique vétérinaire, du b.a.-ba à l'innonvation (2016, May)

Les processus inflammatoires sont déclenchés lors d'une agression et font partie intégrante du système immunitaire. La problématique réside lorsque ces processus inflammatoires ne sont plus contrôlés et ... [more ▼]

Les processus inflammatoires sont déclenchés lors d'une agression et font partie intégrante du système immunitaire. La problématique réside lorsque ces processus inflammatoires ne sont plus contrôlés et provoquent plus de lésions que l'agression elle-même. Cette inadéquation des réactions inflammatoires aggravent souvent des pathologies comme les mammites, les métrites ou les pathologies métaboliques. La quantité et la qualité de l'alimentation, ainsi que le statut métabolique sont des points majeurs de régulation du système inflammatoire. En effet, de nombreuses molécules intervenant dans l'inflammation sont des protéines synthétisées par le foie ou sont dérivés des acides gras alimentaires. En début de lactation, la mobilisation graisseuse et les corps cétoniques ont une action directe sur l'activité inflammatoire ce qui expliquent l'état de stress oxydatif, la chute d'immunité ainsi que l'état pro-inflammatoire des vaches en post-partum. La digestion ruminale et intestinale des hydrates de carbone et des protéines peuvent également provoquer et réguler l'état inflammatoire systémique du ruminant. L'acidose chronique en est un exemple, cependant, l'alcalose et la mal-digestion des fibres peuvent également provoquer de l'inflammation. En pratique, il existe des paramètres qui permettent d'évaluer l'inflammation d'un animal et d'un troupeau. A l'aide d'une prise de sang et de dosage des protéines totales plasmatiques et sériques on pourra facilement et à des coûts limités, mesurer la présence d'inflammation aiguë ou chronique. La présence d'inflammation chronique est un facteur de risque sous-jacent important dans nos troupeaux de vaches laitières puisqu'il concerne environ 25% des troupeaux qui ont présenté des problèmes de défaut d’efficience alimentaire. Dans les troupeaux avec des signes cliniques de type amaigrissement, sous-production, mal-digestion des fibres et inflammation chronique, l'acidose chronique n'a été diagnostiquée que sur 5% des vaches alors que l'inactivité ruminale a été montrée sur 40% des animaux. Cette inactivité est souvent liée à un déficit en matière organique fermentescible couplée avec un excès de protéines fermentescible ce qui entraine des pH élevés et diminue la multiplication de la flore du rumen. L'analyse du jus de rumen, couplée avec celle des protéines totales permet dans la plupart des cas de poser un diagnostic et de discriminer les cas de SARA des cas de maldigestion et adapter correctement la ration. [less ▲]

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