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See detailFirst steps in the development of a piston sensor for large aperture space telescopes
Guerri, Géraldine ULiege; Roose, Stéphane ULiege; Stockman, Yvan ULiege et al

in Oschmann, J.; Clampin, M.; MacEwen, H. (Eds.) Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave (2010, July 01)

Nowadays spaceborne missions for astronomy or Earth imaging need high resolution observation which implies the development of large aperture telescopes. This can be achieved by multi-aperture telescopes ... [more ▼]

Nowadays spaceborne missions for astronomy or Earth imaging need high resolution observation which implies the development of large aperture telescopes. This can be achieved by multi-aperture telescopes or large segmented telescopes. One of the major issues is the phasing of the sub-apertures or the segments of such telescopes. A cophasing sensor is therefore mandatory to achieve the ultimate resolution of these telescopes. In this framework, Liège Space Center (CSL) concern is the development of a compact cophasing sensor to phase new large lightweight segmented mirrors for future space telescopes. The sensor concept has its origins in new phase retrieval algorithms which have been recently developed. In this paper, we outline the concept and the experimental validation results of our piston sensor breadboard which is currently under development in our laboratory. Finally, future prospects and further developments of our experiment are presented. [less ▲]

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See detailImpact of mitral regurgitation and myocardial viability on left ventricular reverse remodeling after cardiac resynchronization therapy in patients with ischemic cardiomyopathy.
Senechal, Mario; Lancellotti, Patrizio ULiege; Magne, Julien ULiege et al

in American Journal of Cardiology (2010), 106(1), 31-7

This study investigated the impact of ischemic mitral regurgitation (MR) severity and viability on left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) in patients with ... [more ▼]

This study investigated the impact of ischemic mitral regurgitation (MR) severity and viability on left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) in patients with ischemic cardiomyopathy. Severe MR and ischemic cardiomyopathy have been associated with lack of LV reverse remodeling after CRT. Fifty-seven consecutive patients with ischemic MR, LV ejection fraction < or =35%, QRS duration > or =120 ms, and intraventricular dyssynchrony > or =50 ms were prospectively included. Stress echocardiography was performed before CRT implantation. Viability in the region of the LV pacing lead was defined as the presence of viability in 2 contiguous segments. Response to CRT at 6 months was defined by evidence of > or =15% LV decrease in end-systolic volume. Severe MR was defined by an effective regurgitant orifice (ERO) area > or =20 mm(2). Thirty-three patients (58%) were responders at follow-up. Baseline ERO area and prevalence of severe MR were not different between responders and nonresponders (19 +/- 11 vs 21 +/- 13 mm(2), p = 0.67; 52% vs 53%, p = 0.84). In responders, MR was decreased by 58% (ERO 19 +/- 12 to 8 +/- 6 mm(2)). In the presence of viability in the region of the pacing lead, 74% (n = 29 patients) were responders (sensitivity 88%, specificity 58%); in the subgroup of patients with viability in the region of the pacing lead and severe MR, 83% (n = 17 patients) were responders. In conclusion, LV remodeling is frequent and ischemic MR decrease important in patients with viability in the region of the pacing lead without regard to MR severity. [less ▲]

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See detailTechnofonctionalité des lipides alimentaires
Danthine, Sabine ULiege

Conference (2010, July 01)

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See detailOvershooting and semiconvection: structural changes and asteroseismic signatures
Noels-Grötsch, Arlette ULiege; Montalban Iglesias, Josefa ULiege; Miglio, Andrea ULiege et al

in Astrophysics & Space Science (2010), 328

Overshooting and semiconvection are two poorly known mechanisms which affect the extent and the efficiency of chemical mixing outside classical convection zones in stars. We discuss the uncertainties and ... [more ▼]

Overshooting and semiconvection are two poorly known mechanisms which affect the extent and the efficiency of chemical mixing outside classical convection zones in stars. We discuss the uncertainties and the inferences of those processes in main sequence stars burning hydrogen in a convective core. We then focus on the asteroseismic signatures of partially or fully mixed zones surrounding the convective core, through the detailed shape of the induced chemical composition profile. We emphasize the potential power of asteroseismology to determine the internal structure of stars and thus to help us understand the physical processes at work inside the stars. [less ▲]

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See detailHow asteroseismology can constrain the global parameters of solar-like star models
Ozel, N.; Dupret, Marc-Antoine ULiege; Baglin, A.

in Astrophysics & Space Science (2010), 328

In the previous years, p-mode oscillations (pressure oscillations stochastically excited by convection) have been detected in several solar-like stars thanks to the ground-based spectroscopic and space ... [more ▼]

In the previous years, p-mode oscillations (pressure oscillations stochastically excited by convection) have been detected in several solar-like stars thanks to the ground-based spectroscopic and space spectroscopic and photometric observations. We study the importance of seismic constraints on stellar modeling and the impact of their accuracy on reducing the uncertainties of global stellar parameters (i.e. mass, age, etc.). We use the Singular Value Decomposition (SVD) method to analyze the sensitivity of stellar models to seismic constraints. In this context, we construct a grid of evolutionary sequences for solar-like stars with varying age and mass. Around each model of this grid, we evaluate the partial derivatives with respect to a large set of free parameters: mass â ³, age Ï , mixing-length parameter α, initial helium abundance Y [SUB]0[/SUB], and initial metallicity Z/ X [SUB]0[/SUB]. Masses between 0.9 and 1.55 M [SUB]ȯ[/SUB] and central hydrogen abundances from Xc=0.7 to 0.05 have been considered in this study. [less ▲]

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See detailDevelopment of a high-dynamic range imaging instrument for a single telescope by a pupil remapping system
Kotani, Takayuki; Lacour, Sylvestre; Choquet, Elodie et al

in Optical and Infrared Interferometry II (2010, July 01)

We present the laboratory demonstration of a very high-dynamic range imaging instrument FIRST (Fibered Imager foR Single Telescope). FIRST combines the techniques for aperture masking and a single-mode ... [more ▼]

We present the laboratory demonstration of a very high-dynamic range imaging instrument FIRST (Fibered Imager foR Single Telescope). FIRST combines the techniques for aperture masking and a single-mode fiber interferometer to correct wavefront errors, which leads to a very high-dynamic range up to 106 around very near the central object (~ λ/D) at visible to near-infrared wavelengths. Our laboratory experiments successfully demonstrated that the original image can be reconstructed through a pupil remapping system. A first on-sky test will be performed at the Lick Observatory 3- m Shane telescope for operational tests in the summer of 2010. [less ▲]

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See detailStochastic excitation of gravity modes in massive main-sequence stars
Samadi, R.; Belkacem, Kevin ULiege; Goupil, M. J. et al

in Astrophysics & Space Science (2010), 328

We investigate the possibility that gravity modes can be stochastically excited by turbulent convection in massive main-sequence (MS) stars. We build stellar models of MS stars with masses M=10 M [SUB]ȯ ... [more ▼]

We investigate the possibility that gravity modes can be stochastically excited by turbulent convection in massive main-sequence (MS) stars. We build stellar models of MS stars with masses M=10 M [SUB]ȯ[/SUB],15 M [SUB]ȯ[/SUB], and 20 M [SUB]ȯ[/SUB]. For each model, we then compute the power supplied to the modes by turbulent eddies in the convective core (CC) and the outer convective zones (OCZ). We found that, for asymptotic gravity modes, the major part of the driving occurs within the outer iron convective zone, while the excitation of low n order modes mainly occurs within the CC. We compute the mode lifetimes and deduce the expected mode amplitudes. We finally discuss the possibility of detecting such stochastically-excited gravity modes with the CoRoT space-based mission. [less ▲]

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See detailThe technical challenges of the Solar-Orbiter EUI instrument
Halain, Jean-Philippe ULiege; Rochus, Pierre ULiege; Appourchaux, Thierry et al

in Proceedings - Society of Photo-Optical Instrumentation Engineers (2010, July 01), 7732(26), 20

The Extreme Ultraviolet Imager (EUI) onboard Solar Orbiter consists of a suite of two high-resolution imagers (HRI) and one dual-band full Sun imager (FSI) that will provide EUV and Lyman-α images of the ... [more ▼]

The Extreme Ultraviolet Imager (EUI) onboard Solar Orbiter consists of a suite of two high-resolution imagers (HRI) and one dual-band full Sun imager (FSI) that will provide EUV and Lyman-α images of the solar atmospheric layers above the photosphere. The EUI instrument is based on a set of challenging new technologies allowing to reach the scientific objectives and to cope with the hard space environment of the Solar Orbiter mission. The mechanical concept of the EUI instrument is based on a common structure supporting the HRI and FSI channels, and a separated electronic box. A heat rejection baffle system is used to reduce the Sun heat load and provide a first protection level against the solar disk straylight. The spectral bands are selected by thin filters and multilayer mirror coatings. The detectors are 10μm pitch back illuminated CMOS Active Pixel Sensors (APS), best suited for the EUI science requirements and radiation hardness. This paper presents the EUI instrument concept and its major sub-systems. The current developments of the instrument technologies are also summarized. [less ▲]

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See detailEffect of stellar rotation on oscillation frequencies
Ouazzani, R. M.; Goupil, M. J.; Dupret, Marc-Antoine ULiege et al

in Astrophysics & Space Science (2010), 328

We investigate whether the rotational splittings of β Cephei stars can give some clue about the existence of a differential rotation in latitude, and if they are contaminated by the cubic order effects ... [more ▼]

We investigate whether the rotational splittings of β Cephei stars can give some clue about the existence of a differential rotation in latitude, and if they are contaminated by the cubic order effects of rotation on oscillation frequencies. We also study some properties of splitting asymmetries and axisymmetric mode frequencies which provide seismic constrains on the distortion of the star. We find that only non-perturbative methods are able to reproduce those two seismic characteristics within 0.01% error bars for stars when they rotate faster than 3.3% Ω [SUB] k [/SUB]. If error bars of 1% are acceptable, the threshold of validity of perturbative methods is extended to 10% Ω [SUB] k [/SUB]. [less ▲]

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See detailOnderzoek Verplaatsingsgedrag Vlaanderen 4.1 (2008-2009): Verkeerskundige interpretatie van de belangrijkste gegevens
Miermans, Willy; Janssens, Davy; Cools, Mario ULiege et al

Report (2010)

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See detailFish farm impacts on meiofauna and the microbenthic loop in Posidonia oceanica meadows
Pete, Dorothée ULiege; Mannard, Jennifer ULiege; Velimirov, Branko et al

in Hendrik, Gheerardyn; Nara Bezerra, Tania; Cnudde, Clio (Eds.) et al Fourteenth International Meiofauna Conference, Aula Academia, Ghent, 11-16 July 2010. (2010, July)

For about ten years, fish farming has been expanding all over the world. Even if this way of producing fishes is presented as a solution against overfishing, its impact on the surrounding environment can ... [more ▼]

For about ten years, fish farming has been expanding all over the world. Even if this way of producing fishes is presented as a solution against overfishing, its impact on the surrounding environment can be important. For example, meadows of Posidonia oceanica, the endemic seagrass of the Mediterranean coastal zone, are fading close to those aquaculture, showing negative impacts on this hot spot of biodiversity. This seagrass is used as an indicator of perturbations, although it does not react quickly, mainly because of its low turnover rate (1,5 y-1). So, it is proposed here to use meiofauna and the microbenthic loop (organic matter, bacteria, microphytobenthos and meiofauna) of this ecosystem to detect earlier perturbations due to fish farms. Moreover, the exergy index, measuring the distance between an ecosystem and its optimum state (climax), is also calculated on the microbenthic loop in order to show its interrest in ecological studies. Study sites are both situated in the Gulf of Calvi (Corsica, France), in P. oceanica meadows, at a depth of 22 m. The studied fish farm is small (10 cages), situated offshore in front of Calvi and produces 40 tons of seabass (Dicentrarchus labrax) per year. The reference site is located in front of the research station STARESO (STation de REcherches Sous-marine et Oceanographiques). Sediment cores (diameter: 4,7 cm) were taken in November 2008 at both sites and sliced in four layers (0-1 cm, 1-2 cm, 2-5 cm and 5-10 cm), according to the expected abundance of meiofauna organisms. Biomass and abundance of every parts of the microbenthic loop were thus analysed. Results concerning abundance, biomass and diversity of meiofauna organisms are presented here and compared with the rest of the microbenthic loop. Values of biomasses are also integrated in the calculation of the exergy index. Finally, this study evaluate the interest of meiofauna and the microbenthic loop to detect perturbations due to an aquaculture. [less ▲]

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See detailThermal performance of condensing boilers
Makaire, Danielle ULiege; Ngendakumana, Philippe ULiege

Scientific conference (2010, July)

Nowadays, condensing technology is widely used in space heating. This paper presents a model that predicts thermal performance of condensing boilers. The structure of the model is similar to the one of a ... [more ▼]

Nowadays, condensing technology is widely used in space heating. This paper presents a model that predicts thermal performance of condensing boilers. The structure of the model is similar to the one of a conventional boiler model with a dry heat exchanger at which a wet heat exchanger is added to simulate the heat recovered by condensation. Tests have been performed on two household 24 kW condensing boilers (gas- and oil-fired boilers). The experimental results are compared to the simulated values. According to the results, the model correctly predicts the thermal efficiency of the boiler. Indeed, predicted values are in good agreement with measured values (if one takes into account the measurements uncertainties). [less ▲]

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See detailCAPACITY BUILDING OF ACP EXPERTS AND MIDDLE MANAGERS
Schiffers, Bruno ULiege

in EDULEARN10 Conference (2010, July)

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See detailL'abreuvement des porcs : une eau en quantité et de qualité !
Boudry, Christelle ULiege

Article for general public (2010)

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See detailCongostrip, La Bande Dessinée Congolaise
Dony, Christophe ULiege; Bragard, Véronique

in Revue Nouvelle (2010)

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See detailShort range of motion isokinetic testing of wrist flexors and extensors strength in normal subjects and patients with carpal tunnel syndrome
Reichard, L. Bezalel; Katz-Leurer, Michal; Rubinstein, Meron et al

in Journal of Strength & Conditioning Research (2010), 24(7), 1866-1873

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See detailFormation and evolution of planetary systems: the impact of high-angular resolution optical techniques
Absil, Olivier ULiege; Mawet, Dimitri

in Astronomy and Astrophysics Review (2010), 18(3), 317-382

The direct images of giant extrasolar planets recently obtained around several main sequence stars represent a major step in the study of planetary systems. These high-dynamic range images are among the ... [more ▼]

The direct images of giant extrasolar planets recently obtained around several main sequence stars represent a major step in the study of planetary systems. These high-dynamic range images are among the most striking results obtained by the current generation of high-angular resolution instruments which will be superseded by a new generation of instruments in the coming years. It is, therefore, an appropriate time to review the contributions of high-angular resolution visible/infrared techniques to the rapidly growing field of extrasolar planetary science. During the last 20 years, the advent of the Hubble Space Telescope, of adaptive optics on 4- to 10-m class ground-based telescopes, and of long-baseline infrared stellar interferometry, has opened a new viewpoint on the formation and evolution of planetary systems. By spatially resolving the optically thick circumstellar discs of gas and dust where planets are forming, these instruments have considerably improved our models of early circumstellar environments and have thereby provided new constraints on planet formation theories. High-angular resolution techniques are also directly tracing the mechanisms governing the early evolution of planetary embryos and the dispersal of optically thick material around young stars. Finally, mature planetary systems are being studied with an unprecedented accuracy thanks to single-pupil imaging and interferometry, precisely locating dust populations and putting into light a whole new family of long-period giant extrasolar planets. [less ▲]

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See detailÉditer autrement. Faire comme tout le monde comme personne
Habrand, Tanguy ULiege

Article for general public (2010)

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See detailPublie.net : La littérature est-elle soluble dans le numérique ?
Habrand, Tanguy ULiege

Article for general public (2010)

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