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See detailDetection of exozodiacal dust: a step toward Earth-like planet characterization with infrared interferometry
Defrere, Denis ULg

Doctoral thesis (2009)

The existence of other habitable worlds and the possible development of life elsewhere in the Universe have been among mankind's fundamental questions for thousands of years. These interrogations about ... [more ▼]

The existence of other habitable worlds and the possible development of life elsewhere in the Universe have been among mankind's fundamental questions for thousands of years. These interrogations about our origins and place in the Universe are today at the dawn of being answered in scientific terms. The key year was 1995 with the discovery of the first extrasolar planet orbiting around a solar-type star. About 400 extrasolar planets are known today and the possibility to identify habitable worlds and even life among them largely contributes to the growing interest about their nature and properties. However, characterizing planetary systems is a very difficult task due to both the huge contrast and the small angular separation between the host stars and their environment. New techniques have emerged during the past decades with the purpose of tackling these fantastic observational challenges. In that context, infrared interferometry is a very promising technique, since it provides the required angular resolution to separate the emission of the star from that of its environment. This dissertation is devoted to the characterization of extrasolar planetary systems using the high angular resolution and dynamic range capabilities of infrared interferometric techniques. The first part of the present work is devoted to the detection with current interferometric facilities of warm dust within the first few astronomical units of massive debris discs around nearby stars. In order to extend the imaging of planetary systems to fainter discs and to extrasolar planets, we investigate in a second step the performance of future space-based nulling interferometers and make a comparison with ground-based projects. Finally, the third part of this work is dedicated to the impact of exozodiacal discs on the performance of future life-searching space missions, the goal being to characterize extrasolar planets with sizes down to that of the Earth. [less ▲]

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See detailInfluence of Adhesive Rough Surface Contact on Micro-Switches
Wu, Ling ULg; Rochus, Véronique ULg; Noels, Ludovic ULg et al

in Journal of Applied Physics (2009), 106(11), 113502

Stiction is a major failure mode in micro electro-mechanical systems (MEMS). Undesirable stiction, which results from contact between surfaces, threatens the reliability of MEMS severely as it breaks the ... [more ▼]

Stiction is a major failure mode in micro electro-mechanical systems (MEMS). Undesirable stiction, which results from contact between surfaces, threatens the reliability of MEMS severely as it breaks the actuation function of MEMS switches for example. Although it may be possible to avoid stiction by increasing restoring forces using high spring constants, it follows that the actuation voltage has also to be increased significantly, which reduces the efficiency. In our research, an electrostatic-structural analysis is performed to estimate the proper design range of the equivalent spring constant which is the main factor of restoring force in MEMS switches. The upper limit of equivalent spring constant is evaluated based on the initial gap width, the dielectric thickness, and the expected actuation voltage. The lower limit is assessed on the value of adhesive forces between the two contacting rough surfaces. The MEMS devices studied here are assumed to work in a dry environment. In these operating conditions only the Van der Waals forces have to be considered for adhesion. A statistical model is used to simulate the rough surface, and the Maugis’s model is combined with Kim’s expansion to calculate adhesive forces. In the resulting model, the critical value of the spring stiffness depends on the material and surface properties, such as the elastic modulus, surface energy and surface roughness. The aim of this research is to propose simple rules for design purposes. [less ▲]

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See detailPhysical Properties of the 0.94-Day Period Transiting Planetary System WASP-18
Southworth, John; Hinse, T. C.; Dominik, M. et al

in Astrophysical Journal (2009), 707

We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we ... [more ▼]

We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M [SUB]b[/SUB] = 10.43 ± 0.30 ± 0.24 M [SUB]Jup[/SUB] and R [SUB]b[/SUB] = 1.165 ± 0.055 ± 0.014 R [SUB]Jup[/SUB] (statistical and systematic errors), respectively. The systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M [SUB]b[/SUB] > 3 M [SUB]Jup[/SUB]) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios. Based on data collected by MiNDSTEp with the Danish 1.54  m telescope at the ESO La Silla Observatory. [less ▲]

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See detailComparative Aspects Nationality Law - Selected Questions
Wautelet, Patrick ULg

Learning material (2009)

These slides were used as support for a course taught in English which provides an overview of the major questions arising in the field of nationality law. The course focuses on acquisition and loss of ... [more ▼]

These slides were used as support for a course taught in English which provides an overview of the major questions arising in the field of nationality law. The course focuses on acquisition and loss of nationality and touches upon other issues such as multiple nationalities and the influence of the European construction on nationality law. All these questions are studied using comparative materials as basis. [less ▲]

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See detailActualités en droit de l'exécution forcée
Georges, Frédéric ULg

Book published by Anthemis (2009)

Cet ouvrage étudie les récents développements qu'a connus le droit de l'exécution en trois parties. La première examine les principes généraux et les différentes saisies consacrés par le Code judiciaire ... [more ▼]

Cet ouvrage étudie les récents développements qu'a connus le droit de l'exécution en trois parties. La première examine les principes généraux et les différentes saisies consacrés par le Code judiciaire. La deuxième est consacrée aux particularités du recouvrement en matière fiscale. La troisième est dédiée aux aspects du droit de l'exécution forcée propres au contentieux familial. [less ▲]

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See detailEuropean military higher education: War-Integrated Learning
Paile, Sylvain ULg

Conference (2009, December)

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See detailEstimation des effets du gène culard sur les caractères de production laitière au sein du rameau Blanc Bleu Belge de type mixte
Colinet, Frédéric ULg; Gengler, Nicolas ULg

in 16ièmes Rencontres Recherches Ruminants, Paris, les 2 et 3 Décembre 2009 (2009, December)

Le rameau Blanc Bleu Belge de type mixte (BBm) est apprécié pour sa rusticité, sa longévité, une bonne santé ainsi que pour ses bonnes performances de reproduction. Une délétion de 11 paires de base ... [more ▼]

Le rameau Blanc Bleu Belge de type mixte (BBm) est apprécié pour sa rusticité, sa longévité, une bonne santé ainsi que pour ses bonnes performances de reproduction. Une délétion de 11 paires de base (allèle mh) au sein du gène de la myostatine engendre le syndrome d’hypertrophie musculaire (plus connu sous le nom de type culard ; d’ailleurs, cet allèle mh est souvent appelé le gène culard). Bien que cet allèle mh soit très présent au sein du rameau Blanc Bleu Belge de type viandeux, seulement 41 et 39 % des animaux BBm sont respectivement mh/mh et mh/+. <br />Etant donné l’importance des effets du gène culard sur la conformation viandeuse des animaux et de son rôle potentiel indirect en production laitière, il nous a semblé intéressant de tenir compte de sa présence lors de l’évaluation génétique des animaux BBm. Néanmoins, il n’est pas envisageable et concevable de génotyper tous les individus de la population BBm. Dès lors, il a fallu modifier légèrement le modèle mixte utilisé pour pouvoir y incorporer ce génotype connu pour certains animaux. La méthodologie ici présentée permet l’estimation simultanée des effets polygéniques (plus connus sous le terme « valeur d’élevage », VE) et de l’effet du gène culard. [less ▲]

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See detailModèle d'équilibre des actifs financiers et autres facteurs de risque: le cas belge
Corhay, Albert ULg; El Khoury, Ghada ULg

in Corhay, Albert; Hübner, Georges; Muller, Aline (Eds.) Finance et valeur(s): Liber amicorum et discipulorum (2009)

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See detailC'est notre Terre !
Ozer, Pierre ULg; Blanchut, Fabienne; Locandro, Catherine et al

Diverse speeche and writing (2009)

Ces 12 petits films de 100 secondes présentent le point de vue des acteurs des négociations sur le climat. Ainsi, les revendications de l'UE, des USA, des pays en développement, de la Chine, mais aussi ... [more ▼]

Ces 12 petits films de 100 secondes présentent le point de vue des acteurs des négociations sur le climat. Ainsi, les revendications de l'UE, des USA, des pays en développement, de la Chine, mais aussi des producteurs d'énergie ou des ONG environnementales sont présentés. [less ▲]

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See detailLes tendinopathies et desmopathies de la région métacarpienne et –tarsienne: une revue des thérapies actuelles. Première partie : la structure, les lésions du tendon et le diagnostic.
Verwilghen, Denis ULg; Gabriel, Annick ULg; Busoni, Valeria ULg et al

in Annales de Médecine Vétérinaire (2009), 3(153), 145-155

Lesions to the horse’s tendon are very frequent and are a non negligible reason for early retirement of sport and leisure horses. For decades man has been searching for “the” treatment but unfortunately ... [more ▼]

Lesions to the horse’s tendon are very frequent and are a non negligible reason for early retirement of sport and leisure horses. For decades man has been searching for “the” treatment but unfortunately most of the known treatments have empiric bases and very few have actually proven their real efficiency. Better knowledge of tendon anatomy and pathophysiology of tendonitis together with evolutions in diagnostic techniques like ultrasonography allows us to better evaluate the improvements made in tendonitis therapies today. The first part of this article gives a review on tendon structure, tendon healing and ultrasonographic evaluation of the tendon. In the second part an overview of therapeutic options for tendonitis will be discussed. [less ▲]

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See detailLes invasions biologiques ... quand Darwin s'en mêle
Vanderhoeven, Sonia ULg; Mahy, Grégory ULg; Vanparys, Valérie et al

in Parcs & Réserves (2009), 64(4), 7-9

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See detailFrom formalism to effects? The Commission's Communication on enforcement priorities in applying article 82 EC
Petit, Nicolas ULg

in World Competition : Law & Economics Review (2009), 32

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See detailQuelques réflexions sur les enjeux mémoriels autour de la répression du négationnisme en Belgique
Grandjean, Geoffrey ULg

in Revue de la Faculté de Droit de l'Université de Liège (2009), 4

Cet article propose de présenter quelques enjeux autour de la répression du négationnisme en Belgique. Il porte notamment sur la loi du 23 mars 1995 réprimant le négationnisme du génocide commis par le ... [more ▼]

Cet article propose de présenter quelques enjeux autour de la répression du négationnisme en Belgique. Il porte notamment sur la loi du 23 mars 1995 réprimant le négationnisme du génocide commis par le régime nationale socialiste allemand durant la Seconde Guerre mondiale et sur les débats qui eurent lieu suite à la volonté d'élargir le champ d'application de cette loi à d'autres génocides. L'article se base sur les documents parlementaires ainsi que sur une série d'entretiens semi-directifs. [less ▲]

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See detailMitral valve dynamics in a closed-loop model of the cardiovascular system
Paeme, Sabine ULg; Chase, J. Geoffrey; Hann, christopher et al

in Archives des Maladies du Coeur et des Vaisseaux. Pratique (2009, December), hors série 1

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics by means of Heaviside function to simulate “open on ... [more ▼]

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics by means of Heaviside function to simulate “open on pressure, close on flow” law. Thus, it does not consider the real time scale of the valve aperture and thus doesn’t fully capture valve dysfunction. This work describes a new coupled model of the cardiovascular system that accounts for progressive mitral valve aperture. Simulations show good correlation with physiologically expected results for healthy or diseased valves. The large number of valve model parameters indicates a need for emerging, lighter and minimal mitral valve models that are readily identifiable to achieve full benefit in real-time use. These results suggest a further use of this model to track, diagnose and control valves pathologies. [less ▲]

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See detailClostridial brain abscess after glioblastoma resection: case report and critical review of the literature
Duntze, J; Litré, Claude Fabien ULg; Bajolet, O et al

in Neuro-Chirurgie (2009), 55(6), 569-72

Clostridium perfringens is rare in neurosurgery. The source of clostridial brain abscess is usually a penetrating head injury. We report the case of a 57-year-old man who had parietal glioblastoma ... [more ▼]

Clostridium perfringens is rare in neurosurgery. The source of clostridial brain abscess is usually a penetrating head injury. We report the case of a 57-year-old man who had parietal glioblastoma resection with local carmustine chemotherapy and who presented a clostridial brain abscess three weeks later. Progression was especially brutal, leading to patient's death in few hours. We discuss the etiology and progression of this case compared to the data reported in the literature. [less ▲]

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See detailGMFS Final report Stage 1 and Stage 2
Gilliams, Sven; Bydekerke, Lieven; Delrue, Josefien et al

Report (2009)

Global Monitoring for Food Security (GMFS) is a Global Monitoring for Environment and Security (GMES) Service Element (GSE) project, part of the European Space Agency (ESA) contribution to the European ... [more ▼]

Global Monitoring for Food Security (GMFS) is a Global Monitoring for Environment and Security (GMES) Service Element (GSE) project, part of the European Space Agency (ESA) contribution to the European Union (EU) /ESA GMES Programme. GMFS aims to establish an operational service for crop monitoring in support of Food Security Monitoring to serve policy makers and operational users. The GMFS project started in March 2003 as part of Stage 1 of the ESA Earthwatch GMES services Element “Service Consolidation Actions”, and was continued in October 2005 as part of the Stage 2 of the ESA Earth watch GMES services Element – “Scaling Up Consolidated GMES Services”. In this document an overview is given of the work done throughout the previous six years. GMFS aimed at monitoring crop state /vegetation condition at continental and national scale. Low resolution Earth Observation (EO) data was used for monitoring purposes at continental scale, while at national scale products were based upon medium and high resolution data, field work and agro-meteorological models. The project was guided by a project strategy group with members from the United States Agency for International Development - Famine Early Warning System Network (USAID-FEWSNET), Directorate General for Development (DG-DEV), Consultative Group on International Agricultural Research - International Wheat Improvement Center (CGIAR-CIMMYT), European Commission Joint Research Center (EC-JRC), United Nations World Food Programme (WFP) and United Nations Food and Agricultural Organisation (FAO). The goal of the project in Stage 1 (March 2003 –November 2004) was to consolidate an early warning system for food security. This started off by an intensive literature review and setting up an initial service for the Centre de Suivi Ecologique (CSE) in Dakar Senegal. In the second Phase of Stage 1 activities focussed more on the actual service delivery and setting up activities with users. Those activities included the monitoring agricultural production for Senegal, monitoring agriculture in Malawi and giving support to the Crop and Food Supply Assessment Mission (CFSAM) of FAO /WFP. Additionally, services were set up for the centre Agro-Hydro-Météorologique (AGRHYMET) as a result of a meeting between AGHRYMET and Vlaamse Instelling voor Technologisch Onderzoek (VITO). During 2005 the early warning service was continued to support GMFS users although there was at that time no formal contract to do so. At the start of the Second Stage, in October 2005, a GMFS user executive board, consisting of one representative from: EC-JRC, FAO, WFP, Southern Africa Development Community Regional Remote Sensing Unit (SADC-RRSU), Regional Centre for Mapping of Resources for Development (RCMRD) and AGRHYMET, was set up to support the consortium in defining the correct services and to review the work. Since the focus for the Second Stage was on up scaling the consolidated services, it was decided that the early warning service and support to the CFSAM were to be continued, the agricultural mapping service was to be expanded to more countries - namely, Senegal, Sudan, Ethiopia, Malawi and Zimbabwe - and extra services on yield modeling using remote sensing and agro-meteorological models were to be provided. During the second year of this stage, the services were even more extended with, support to the Ministry of Agriculture and Meteorological Department in Mozambique, extra activities in Ethiopia and Sudan and support to the regional centers on operational use of the ESA Data Dissemination System (DDS). [less ▲]

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See detailThe benefit and cost of winner-picking: Redistribution vs. Incentives
Gautier, Axel ULg; Heider, Florian

in Journal of Institutional and Theoretical Economics = Zeitschrift für die Gesamte Staatswissenschaft (2009), 165(4), 622-649

This paper examines the agency cost of winner-picking in multidivision firms and uses explicit incentive contracts to analyze the interaction between corporate headquarters' investment and incentive ... [more ▼]

This paper examines the agency cost of winner-picking in multidivision firms and uses explicit incentive contracts to analyze the interaction between corporate headquarters' investment and incentive policies. Winner-picking, i.e. the efficient reallocation of scarce resources in an internal capital market, adds an extra layer of noise to the moral hazard problem of incentivizing division managers to produce the resources that can then be redistributed. In particular, division managers with strong future investment opportunities anticipate that headquarters will bail them out should they fail to produce enough resources themselves. This reduces incentives to create the resources in the first place with possible consequences for the optimal investment policy. [less ▲]

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See detailFaut-il continuer à prendre en charge les accidents hémorragiques des AVK en neurochirurgie ?
Théret, E; Litré, Claude Fabien ULg; Noudel, R et al

in Neuro-Chirurgie (2009), 55(6 - supp 1), 3-10

Les complications hémorragiques des AVK sont en augmentation, surtout chez les personnes âgées. Nous cherchons à évaluer l’intérêt d’un traitement neurochirurgical versus traitement médical bien conduit ... [more ▼]

Les complications hémorragiques des AVK sont en augmentation, surtout chez les personnes âgées. Nous cherchons à évaluer l’intérêt d’un traitement neurochirurgical versus traitement médical bien conduit, en fonction des différents types de localisation. [less ▲]

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See detailSleep vs Coma
Noirhomme, Quentin ULg; Laureys, Steven ULg; Boly, Mélanie ULg

in Frontiers in Neuroscience (2009), 3(3), 406-407

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