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See detailAspects scientifiques du changement climatique: A quoi devons-nous nous attendre?
Ozer, Pierre ULg

Conference given outside the academic context (2016)

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See detailAnalytical Challenges in the Study of South-North Intra-EU Mobility
Lafleur, Jean-Michel ULg; Stanek, Mikolaj

Conference (2016, November 29)

This presentation discusses the challenges met in measuring the flows of Southern European EU migrants who moved to North Western Europe during the financial and economic crisis that started in 2008. The ... [more ▼]

This presentation discusses the challenges met in measuring the flows of Southern European EU migrants who moved to North Western Europe during the financial and economic crisis that started in 2008. The presentation shows that EU wide and national databases have strenghts and weaknesses and that further improvement in statistical data collection process could help the understanding of complex migratory patterns. More details is available on this research by downloading the free e-bbok at the following address: http://www.springer.com/gp/book/9783319397610 [less ▲]

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See detailImportance de l’océan pour la régulation du climat de nos régions
Gobert, Sylvie ULg

Scientific conference (2016, November 29)

Mise en évidence des rôles de l'océan dans notre climat et conséquences des changements actuels

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See detailThe influence of isoinertial-pneumatic ratio on force-velocity-power relationships
Jidovtseff, Boris ULg; Avrillon, Simon; Hug, François et al

Conference (2016, November 29)

Introduction: Isoinertial contractions are effective to generate maximal force during the initiation of the movement whereas they do not provide an appropriate training stimulus to generate force once ... [more ▼]

Introduction: Isoinertial contractions are effective to generate maximal force during the initiation of the movement whereas they do not provide an appropriate training stimulus to generate force once accelerative phase has been developed (1). Pneumatic resistance is one alternative that has been developed to overcome the aforementioned limitations associated with isoinertial contractions. This technique allow higher initial velocity and reduce the decrease of force towards the end of the concentric phase (1). There is some training interest by combining isoinertial and pneumatic loading. The aim of this study was to determine how different isoinertial-pneumatic ratio influence the force-velocity-power relationships during bench-press. Methods: Fifteen participants performed bench press at 30%, 45%, 60%, 75%, and 90% of their 1RM, with five isoinertial(I)-pneumatic(P) resistance ratio : 100%I/0%P, 75%I/25%P, 50%I/50%P, 25%I/75%P, and 0%I/100%P. Velocity, force and power were assessed using a linear transducer and mechanical parameters measured by the pneumatic ergometer. Force-, velocity- and power-time patterns were averaged over the push-off phase to build the corresponding force-velocity and power-velocity relationships for each resistance ratio. Results: The increase in pneumatic part in resistance ratio elicited higher movement velocity and lower force level from 0% to 80% of the concentric phase. The increase in isoinertial part in resistance balance resulted in higher velocity towards the end of the movement. As a consequence, the use of isoinertial resistance oriented the force-velocity relationship towards force, whereas pneumatic resistance elicited a more velocity-oriented profile. Conclusion: Pneumatic-oriented resistance could be used to develop initial velocity and force towards the end of the push-off. Isoinertial-oriented resistance should be used to develop maximal force and maximal power. Resistance modality could be modulated according to training objectives. Références : 1. Frost et al. A comparison of the kinematics, kinetics and muscle activity between pneumatic and free weight resistance. Eur J Appl Physiol. 2008;104:937-56. [less ▲]

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See detailActive Network Management for Electrical Distribution Systems
Gemine, Quentin ULg

Doctoral thesis (2016)

With the increasing share of renewable and distributed generation in electrical distribution systems, Active Network Management (ANM) has become a valuable option for a distribution system operator to ... [more ▼]

With the increasing share of renewable and distributed generation in electrical distribution systems, Active Network Management (ANM) has become a valuable option for a distribution system operator to operate his system in a secure and cost-effective way without relying solely on network reinforcement. ANM strategies are short-term policies that control the power injected by generators and/or taken off by loads in order to avoid congestion or voltage issues. While simple ANM strategies consist of curtailing temporary excess generation, more advanced strategies instead attempt to move the consumption of loads to anticipated periods of high renewable generation. Such advanced strategies mean that the system operator has to solve large-scale optimal sequential decision-making problems under uncertainty. The problems are sequential for several reasons. For example, decisions taken at a given moment constrain the future decisions that can be taken, and decisions should be communicated to the system’s actors sufficiently in advance to give them enough time for implementation. Uncertainty must be explicitly accounted for because neither demand nor generation can be accurately forecasted. This dissertation presents various research contributions about ANM for distribution systems. These contributions range from the motivation of using a framework of sequential decision-making under uncertainty to the study of computational methods that implement ANM strategies. A particular emphasis is placed on the formulation of the problem, which ultimately falls within the class of Markov decision processes. The modeling of stochasticity is explored and a novel approach that relies on a Gaussian Mixture Model is presented. Computational methods including several relaxations and approximations of multi-period and multi-scenario extensions of the optimal power flow problem with discrete decision variables were considered. [less ▲]

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See detailNeuropathies externes, canalaires et sportives
WANG, François-Charles ULg

Learning material (2016)

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See detailThe EU’s geo-blocking Regulation proposal and its impact on the coherence of EU e-commerce regulation
Van Cleynenbreugel, Pieter ULg

Scientific conference (2016, November 26)

This presentation analyses and contextualises the EU's proposed geo-blocking regulation and its relationship to EU e-commerce legislation. It is addressed to an audience of cyberspace and e-law lawyers ... [more ▼]

This presentation analyses and contextualises the EU's proposed geo-blocking regulation and its relationship to EU e-commerce legislation. It is addressed to an audience of cyberspace and e-law lawyers and takes place in an ecommerce panel. Questions to be discussed concern the approach taken by the EU in tackling the challenges of e-commerce. [less ▲]

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See detailL'activation comportementale est-elle pertinente pour tous les adultes dépressifs ? Une analyse en clusters
Wagener, Aurélie ULg; Baeyens, Céline; Van der Linden, Martial ULg et al

Poster (2016, November 26)

INTRODUCTION : L’hétérogénéité de la dépression est de plus en plus mise en évidence en termes de profils de symptômes, de réponse au traitement, etc. Les théories comportementales de la dépression ... [more ▼]

INTRODUCTION : L’hétérogénéité de la dépression est de plus en plus mise en évidence en termes de profils de symptômes, de réponse au traitement, etc. Les théories comportementales de la dépression soulignent l’importance de l’inactivité ainsi que des faibles niveaux de plaisir et de fréquence d’activités plaisantes dans le maintien de la dépression. Cette étude poursuit deux objectifs : (1) investiguer l’hétérogénéité de la depression via une analyse en clusters, (2) investiguer les valeurs prédictives de l’inactivité ainsi que des faibles niveaux de plaisir et de fréquence d’activités plaisantes sur la dépression en fonction du cluster d’appartenance. METHODE : Des adultes tout venant et/ou consultant des centres de santé mentale ont été recrutés (âge entre 18 et 60 ans). Ils ont complété l’Inventaire de Dépression de Beck – Seconde Edition, l’Echelle d’Activation Comportementale pour la Dépression – Version courte, et l’Inventaire des événements plaisants. RESULTATS : Une solution en six clusters a été mise en évidence : “gros dormeurs/heavy sleepers”, “dépressifs cognitifs/cognitive depressives”, “dépressifs affectifs-somatiques/affective-somatic depressives”, “dépressifs légers/mild depressives”, “dépressifs dormant peu/sleepless depressives”, “dépressifs typiques/typical depressives”. Des relations significatives entre inactivité, fréquence d’activités plaisantes et dépression ont seulement été observées chez les “dépressifs cognitifs/cognitive depressives”, les “dépressifs légers/mild depressives” et les “dépressifs typiques/typical depressives”. DISCUSSION : Les résultats confirment l’hétérogénéité de la dépression puisque six clusters ont été mis en évidence. Par ailleurs, l’activation comportementale ne semble pertinente que pour trois de ces clusters dans lesquels les postulats du modèle comportemental de la dépression sont confirmés (“dépressifs cognitifs/cognitive depressives”, “dépressifs légers/mild depressives”, “dépressifs typiques/typical depressives”). [less ▲]

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See detailEnhanced Biogas Production During Anaerobic Digestion of Steam-pretreated Lignocellulosic Biomass from Williams Cavendish Banana Plants
Kamdem, Irenée ULg

in Waste and Biomass Valorization (2016)

In the context of green energy valorisation, this study reports the chemical analysis and improvement of biogas production via anaerobic digestion of treated and untreated agricultural waste ... [more ▼]

In the context of green energy valorisation, this study reports the chemical analysis and improvement of biogas production via anaerobic digestion of treated and untreated agricultural waste lignocellulosic biomass from Williams Cavendish banana plants (WCLB). With a worldwide annual production of 26 million tons of dry matter (DM), large amounts of this waste are abandoned in plantations after fruit harvesting. Steam explosion (SE) and steam cracking (SC) pretreatments were investigated at severity factors of 3.16 and 4.29, respectively, to improve the biogas potential over 135 days under mesophilic conditions. The study revealed a carbon (C)/nitrogen (N) ratio of 27.3, indicating that WCLB has sufficient N content for successful fermentation. The proportions of liquid and solid fractions recovered after SC were 20% and 80%, respectively, whereas SE yielded 17% and 83% liquid and solids, respectively. The neutral sugar content of the studied fractions indicated that glucose and xylose constituted the highest hexose and pentose fractions, respectively, in WCLB. The highest and lowest total biogas potentials were obtained from LFSC (280 mL g-1 of DM) and untreated WCLB (240 mL g-1 of DM), respectively. The methane yield from untreated WCLB and combined solid and liquid fractions from SE and SC were 40, 42, and 51%, respectively, of the theoretical methane potential. The maximum biogas production rate (7.8 mL g-1 d-1) was obtained with SFSC. This study reveals that SC deconstructs WCLB efficiently and thereby greatly enhances methane production. [less ▲]

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See detailLes risques de la spécialisation sportive précoce
Jidovtseff, Boris ULg

Scientific conference (2016, November 26)

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See detailPoissons, tritons et pédomorphes
Denoël, Mathieu ULg

Scientific conference (2016, November 25)

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See detailMise en débat du marxisme et enjeux rhétoriques dans les textes de présentation des revues intellectuelles de l’immédiat après-guerre
Franck, Thomas ULg

Conference (2016, November 25)

À la suite d’une analyse de la mise en débat du marxisme au sein des revues intellectuelles de l’immédiat après-guerre et d’une étude de la trajectoire idéologique d’un intellectuel particulier, Gérard ... [more ▼]

À la suite d’une analyse de la mise en débat du marxisme au sein des revues intellectuelles de l’immédiat après-guerre et d’une étude de la trajectoire idéologique d’un intellectuel particulier, Gérard Genette, au sein de l’espace des revues militantes, cette communication analyse le cas particulier de la revue Socialisme ou barbarie dans une double perspective d’analyse du discours et de philosophie politique. Notre hypothèse serait la suivante : les revues favoriseraient, par leur matérialité discursive et éditoriale, l’émergence de débats idéologiques plus ou moins polémiques et oppositionnels autour du marxisme. En replaçant la création de ces revues dans leur contexte socio-discursif, nous entendons interroger la manière dont les textes de présentation singularisent, tout en les reproduisant, un interdiscours et une socialité bien précis. Si l’étude des articles parus dans Les Temps Modernes et Critique de mai à décembre 1946 a pu mettre en relation une obsession discursive quant aux marxismes orthodoxes et hétérodoxes et à la montée historique du P.C.F., le contexte de création de Socialisme ou barbarie (1949) nous obligera à tenir compte d’événements politiques et culturels divers (Guerre froide, constitution des deux Allemagnes, création de la revue La Table ronde, parution d’articles consacrés aux évolutions politiques et idéologiques dans Les Temps Modernes, Critique et Esprit, Traité de Londres, création de la République Populaire de Chine, centenaire du Manifeste du parti communiste, etc.). Notre communication se concentrera plus particulièrement sur le texte de présentation de la revue dans ce qu’il dit d’une historicité discursive et idéologique précise. Les textes de positionnement et de repositionnement des revues permettent en effet de dégager un ensemble d’enjeux et de tensions à l’oeuvre au sein de la communauté intellectuelle. Leur caractère plus ou moins affirmatif, parfois à la limite du pamphlétaire, entraîne une série de traits rhétoriques significatifs (attaques ad hominem, questions rhétoriques, allo-attributions, registre polémique, vocabulaire de l’attaque-défense, ironie, etc.), traduisant des positions idéologiques, qu’il sera nécessaire d’analyser dans le premier texte de la revue de Castoriadis et Lefort. L’attention portée aux thématiques marxistes se justifie par la véritable croissance des discours à ce propos dans l’immédiat après-guerre et par le besoin réel qu’éprouvent les intellectuels français de se positionner par rapport au P.C.F. et aux autres mouvances marxistes. Un rapport particulier se crée dès lors entre le savoir et une certaine temporalité que le genre de la revue met en oeuvre au travers de son éclatement et de sa périodicité. En effet, par la transmission d’un état des travaux non abouti et par l’urgence de sa situation sociale, il permet de saisir sur le vif un savoir en cours d’élaboration, constituant ainsi une forme de « mémoire immédiate » faisant état d’une histoire des idées collectives. Le rythme des publications, les stratégies de positionnement idéologique, la circulation des concepts et la nécessité de répondre aux besoins des lecteurs rendent ces savoirs intrinsèquement dynamiques et critiques, dans une constante interaction entre le monde social et les idées qui le façonnent. Comme le note Yves Peyré, dans Les Revues littéraires au XXe siècle, on trouve, d’une part, un « acte militant à la racine même de la revue » et, d’autre part, la réponse à un besoin de mettre en scène, par une polyphonie de voix, un dialogue agissant sur la réalité sociale et se construisant par le profit de débats, de dissonances et de dissensions internes et externes. [less ▲]

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See detailClimate Change: Opportunity or …?
Ozer, Pierre ULg

Scientific conference (2016, November 25)

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See detailDevelopment of a new design method to define the rotation capacity of steel hollow sections
Saloumi, Elsy ULg

Doctoral thesis (2016)

The present PhD thesis is dedicated to the characterisation of hollow section shapes’ rotational capacity. More precisely, the effort was made towards suggesting new ways to resort to plastic analysis, by ... [more ▼]

The present PhD thesis is dedicated to the characterisation of hollow section shapes’ rotational capacity. More precisely, the effort was made towards suggesting new ways to resort to plastic analysis, by defining a new and accurate proposition to characterise the rotation capacity Rcap of sections, which could be associated with the rotation demand of a structure Rdem. Therefore, the purpose of this thesis is to establish a direct dependence of the rotation capacity Rcap with a newly defined cross-section slenderness CS. Hence, current design standards disregard the rotation demand of the structure and allow plastic analysis based on a plate slenderness limit. To achieve this purpose, an experimental campaign was performed consisting in 23 bending tests on square and rectangular hollow sections tested in bending, in addition to 8 stub columns. Then, a numerical model based on the finite element software FINELg was calibrated to well represent these experimental tests, as well as cold-formed bending tests from literature. Based on these results, a good agreement between experimental and numerical results was shown and the numerical software was therefore validated. Accordingly, since the numerical software was proved to well represent the bending behaviour of hollow beams, around 8000 finite element simulations were performed while varying sections dimensions, material properties and loading configuration. These results reported that actual standards limitations were inappropriate, and stricter values were proposed. Moreover, based on the numerical computations, a continuous curve capable of describing the rotation capacity of sections as a function of the cross-section slenderness was proposed. The production route, loading application and yield strength were identified as key parameters having a major impact on the rotation capacity of sections. Consequently, different curves were proposed for each parameter; based on these curves, the rotation capacity of the section could be compared to the rotation demand of a structure in order to obtain a practical, safe, and reliable design calculation. [less ▲]

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See detailUncertainties in determination of fire resistance by experimental testing and by calculation
Dumont, Fabien ULg; Gernay, Thomas ULg; Franssen, Jean-Marc ULg

Conference (2016, November 24)

In Europe, certification of the fire resistance of building construction elements can be assessed by experimental testing or by calculation. To date, both communities (testing and calculation) express the ... [more ▼]

In Europe, certification of the fire resistance of building construction elements can be assessed by experimental testing or by calculation. To date, both communities (testing and calculation) express the fire resistance results in a deterministic way, i.e. each fire resistance result consists in a single number as if there was no uncertainty. However, when asking different partners within a community to assess the fire resistance of a given element of building construction subjected to a given fire scenario (a so-called “round robin” exercise), the reported results exhibit a very significant variability. Recent efforts have been undertaken to evaluate the extent of the scatter for fire resistance results, i.e. a process of "uncertainty evaluation". This process recognizes the fact that, for a given element of building construction and a given fire scenario, only a probability distribution (as opposite to a deterministic value) can be attributed to the fire resistance result. This approach opens the door to probabilistic reporting as an alternative to deterministic one. [less ▲]

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See detailEvaluation du cursus  Sciences industrielles et de l’ingénieur industriel
Courard, Luc ULg

Conference given outside the academic context (2016)

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See detailLaser Additive Manufacturing of Metal Matrix Composites
Mertens, Anne ULg

Learning material (2016)

Current trends in the mechanics and energy industries impose increasing demands on metallic materials, combining elevated service temperatures and severe mechanical solicitations. Metal matrix composite ... [more ▼]

Current trends in the mechanics and energy industries impose increasing demands on metallic materials, combining elevated service temperatures and severe mechanical solicitations. Metal matrix composite coatings with ceramic reinforcements are good candidates in view of fulfilling the requirements for an improved mechanical durability, and for other complex functions (e.g. self-lubrication, biocompatibility...). First of all, this paper provides an introduction to metal matrix composites with a particular attention for the process known as laser cladding that appears as a promising technology for making composite coatings. In this process, a (mixture of) metallic powder(s) is projected onto a substrate through a nozzle and simultaneously melted by a laser beam. Laser cladding is characterised by ultra-fast solidification and cooling rates, thus giving rise to ultra-fine microstructures and potentially enhanced mechanical properties. The paper thus focuses on the relationships between the thermal history during the production of a composite coating, and the resulting microstructure and properties, with special attention to the dissolution of ceramic particles (e.g. carbides) and to interfacial reactions taking place between the particles and the metallic matrix. [less ▲]

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