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See detailPrediction of SOx and NOx Emissions from a Medium Size Biomass Boiler Biomass and Bioenergy
Sartor, Kevin ULg; Restivo, Yannick ULg; Ngendakumana, Philippe ULg et al

in Biomass and Bioenergy (2014), 65

While small and medium size biomass combined heat and power (CHP) plants (i.e., up to 5 MW of electrical rated power) represent an attractive option to exploit locally available biomass resources at low ... [more ▼]

While small and medium size biomass combined heat and power (CHP) plants (i.e., up to 5 MW of electrical rated power) represent an attractive option to exploit locally available biomass resources at low cost, the corresponding investment per unit of rated power significantly rises when the installed power decreases. In these cases, secondary pollutant emissions control measures are most of the time not economically viable and primary emissions control must be used alone to avoid the formation of undesired compounds such as $NO_x$ and $SO_x$. Primary control measures require the careful optimization of fuel quality and combustion process. For plant operators, being able to accommodate biomass quality changes in order to minimize the fuel cost can be of great importance in order to guarantee the profitability of the plant. This contribution is dedicated to the development of a zero-dimensional (input-output) combustion simulation model able to predict the pollutants emissions resulting from complete and incomplete combustion with respect to varying combustion operation (ambient temperature, humidity, fumes recirculation,..). This tool is intended to be integrated in a global simulation model of the CHP plant and the attached district heating network installed on the University campus in Liège. Doing so, the plant operation can be optimized with respect to economic as well as environmental and energetic aspects (3E approach) thus ensuring the sustainability of the approach. [less ▲]

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See detailProduction, Private Economy and State Entanglement in Early Northern Mesopotamia
Mas, Juliette ULg

Conference (2014, June)

Ancient economic systems from Southern and Central Mesopotamia are quite well known when Northern Mesopotamia ones remain less known from this point of view. If we already know that, during Bronze Age ... [more ▼]

Ancient economic systems from Southern and Central Mesopotamia are quite well known when Northern Mesopotamia ones remain less known from this point of view. If we already know that, during Bronze Age, households played a deciding role in several kinds of production, their degree of dependence or independence to the State still has to be cleared. The archaeological data clearly show that private workshops, set up in private houses, could be very efficient and specialized. Furthermore, these economic entities could be assimilated to private enterprises, which were able to handle their own administrative duties. On the other hand, we know from the texts that the Palace and the temples were also a main element of ancient economic systems. If public administrations should, in some cases, have supplied raw materials, hired workforce, and dealt with the distribution of produced goods, it seems that the production didn’t take place in the palace itself. Dealing both with archaeological and textual data, could help to better define the role and the importance of both public and private components in early Mesopotamian economic systems. [less ▲]

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See detailLa laïcité contre elle-même
Jacquemain, Marc ULg

in Collectif Tayush (Ed.) Les défis du pluriel. Egalité, diversité, laïcité (2014)

Résumé : la laïcité fait depuis une vingtaine d’année un retour remarqué dans le débat public, tant en France qu’au Québec ou en Belgique francophone. Un retour très ambigu cependant : la laïcité divise ... [more ▼]

Résumé : la laïcité fait depuis une vingtaine d’année un retour remarqué dans le débat public, tant en France qu’au Québec ou en Belgique francophone. Un retour très ambigu cependant : la laïcité divise aujourd’hui les mouvements qui s’en réclamaient depuis toujours (la gauche politique et syndicale, le féminisme, l’antiracisme …) et est au contraire revendiquée par ceux qui la rejetaient violemment (la droite populiste et l’extrême-droite). Cette logique « à front renversé » puise ses racines dans l’histoire de la dynamique laïque dans ces trois ensembles francophones, dynamique devenue majoritairement anti-religieuse, à force de s’affronter aux prétentions hégémoniques de l’Eglise catholique. Dans un contexte où le catholicisme a perdu beaucoup de sa vigueur, une partie (majoritaire) du mouvement laïque reproduit aujourd’hui cette logique anti-religieuse contre l’islam, religion minoritaire et stigmatisée. C’est le pire des choix : le discours laïque anti-religieux se fait le parfait symétrique du discours islamiste, puisqu’il répand l’idée qu’il est impossible d’être musulman et laïque. A l’inverse, une laïcité réanimant ses fondamentaux (séparation, neutralité, liberté de conscience et égalité) constituerait la meilleure garantie de la cohabitation pacifique des diverses convictions (religieuses ou non), en particulier dans un pays comme la Belgique où ces convictions ne constituent qu’une mosaïque de minorités. [less ▲]

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See detailIs conspecific substrate marking a long-term external memory of previously colonized overwintering sites in Harmonia axyridis?
Durieux, Delphine ULg; Fassotte, Bérénice ULg; Vanderplanck, Maryse et al

in Journal of Applied Entomology (2014), 138(5), 338-345

The multicoloured Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during winters to survive the cold. This beetle uses chemical cues coming from congeners to select an ... [more ▼]

The multicoloured Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during winters to survive the cold. This beetle uses chemical cues coming from congeners to select an overwintering site. Recent research has shown that they preferentially gather at places where conspecifics previously laid a substrate marking made up of saturated and unsaturated hydrocarbons. Some authors have reported that H. axyridis colonizes the same overwintering sites from 1 year to another. Herein, the hypothesis that this substrate marking is used by H. axyridis to settle in the same aggregation sites from one winter to another was tested. To this aim, the temporal modification in the chemical profile of the hydrocarbon marking was studied by performing chromatographic analyses. After 1 year, the overall profile was modified qualitatively and quantitatively: the unsaturated hydrocarbons were no longer detected while some saturated hydrocarbons were still present in large quantities. In a behavioural assay conducted in the laboratory, the 12-month-old marking did not induce the aggregation of H. axyridis. This result indicates that the chemical markings left by conspecifics during a previous aggregation period in an overwintering site are not sufficient to induce the gathering of the newly arriving individuals. [less ▲]

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See detailSpatial augmented reality in collaborative design training : articulation between I-space, We-space and Space-between
Ben Rajeb, Samia ULg; Leclercq, Pierre ULg

in Lecture Notes in Computer Science (2014), LNCS 8526 / vol 2(part 2), 343-353

This paper analyses the use of augmented reality in advanced project-based training in design. Our study considers how augmented environments can contribute to this type of group training : what types of ... [more ▼]

This paper analyses the use of augmented reality in advanced project-based training in design. Our study considers how augmented environments can contribute to this type of group training : what types of interaction spaces constitute these new learning environments and how are these spaces constructed so as to promote collective reflection ? [less ▲]

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See detailCROSSROADS - magazine sonore des musiques noires US
Sacré, Robert ULg

in Sacré, Robert (Ed.) CROSSROADS le magazine sonore des musiques africaines américaines (2014)

émission radio hebdomadaire diffusée sur EQUINOXE FM 100.1 (on line via www.equinoxefm.be) : tous les mercredis de 18 à 20h : contenu : blues,R&B,Soul, gospel, Zydeco, jazz

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See detailComplex dynamics of a nonlinear aerospace structure: experimental identification and modal interactions
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Kerschen, Gaëtan ULg

in Journal of Sound & Vibration (2014), 333

Nonlinear system identification is a challenging task in view of the complexity and wide variety of nonlinear phenomena. The present paper addresses the identification of a real-life aerospace structure ... [more ▼]

Nonlinear system identification is a challenging task in view of the complexity and wide variety of nonlinear phenomena. The present paper addresses the identification of a real-life aerospace structure possessing a strongly nonlinear component with multiple mechanical stops. The complete identification procedure, from nonlinearity detection and characterization to parameter estimation, is carried out based upon experimental data. The combined use of various analysis techniques, such as the wavelet transform and the restoring force surface method, brings different perspectives to the dynamics. Specifically, the structure is shown to exhibit particularly interesting nonlinear behaviors, including jumps, modal interactions, force relaxation and chattering during impacts on the mechanical stops. [less ▲]

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See detailThe X-ray emission of the massive stars population in Cyg OB2
Rauw, Grégor ULg; Nazé, Yaël ULg; Wright, Nick et al

Poster (2014, June)

Cygnus OB2 contains a wealth of massive stars of spectral types O, B and Wolf-Rayet. In the framework of a Chandra legacy program to study the X-ray emission from this important association, we have ... [more ▼]

Cygnus OB2 contains a wealth of massive stars of spectral types O, B and Wolf-Rayet. In the framework of a Chandra legacy program to study the X-ray emission from this important association, we have studied the X-ray properties of its massive stars population. We show that the O-stars in Cyg OB2 follow a well-defined scaling relation between their X-ray and bolometric luminosities: log(Lx/Lbol) = −7.2 ± 0.2. Except for the brightest O-star binaries, there is no general X-ray overluminosity due to colliding winds in O-star binaries. Roughly half of the known B-stars in the surveyed field are detected, but they fail to display a clear relationship between Lx and Lbol. Out of the three WR stars in Cyg OB2, probably only WR144 is itself responsible for the observed level of X-ray emission, at a very low log(Lx/Lbol) = −8.8±0.2. The X-ray emission of the other two WR-stars (WR145 and 146) is most probably due to their O-type companion along with a moderate contribution from a wind-wind interaction zone. [less ▲]

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See detailX-raying the winds of the evolved massive binary HDE228766
Rauw, Grégor ULg; Mahy, Laurent; Nazé, Yaël ULg

Poster (2014, June)

HDE228766 is an evolved massive binary hosting a rare Of-WN8ha transition object on a circular orbit about a normal O7 star. We have obtained XMM-Newton EPIC spectra of this system at three key orbital ... [more ▼]

HDE228766 is an evolved massive binary hosting a rare Of-WN8ha transition object on a circular orbit about a normal O7 star. We have obtained XMM-Newton EPIC spectra of this system at three key orbital phases (two conjunctions and quadrature phase) that allow us to probe the absorbing column towards the wind interaction zone as seen through the wind of the O7 star and the Of-WN8ha star. We combine these observations with a simple model of the wind-wind collision to infer the properties of the wind interaction zone (opening angle of the shock cone) and constrain the properties of the stellar winds in this system. [less ▲]

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See detailThe X-ray properties of lambda Cep, a true twin of zeta Pup?
Rauw, Grégor ULg; Nazé, Yaël ULg; Gonzalez-Perez, Nicolas et al

Conference (2014, June)

Oef stars are O-stars that display a double-peaked He II λ 4686 line in their optical spectra, suggesting that the inner part of the stellar wind is co-rotating with the star. This hypothesis is also ... [more ▼]

Oef stars are O-stars that display a double-peaked He II λ 4686 line in their optical spectra, suggesting that the inner part of the stellar wind is co-rotating with the star. This hypothesis is also often used to explain their ubiquitous spectral variability in the optical domain. In this context, the fact that the high-resolution X-ray spectra of ζ Pup (O4Ief) meet the expectations of the wind-embedded shock model, assuming a spherically symmetric wind came as a surprise. To understand what is going on, we have obtained a 300 ksec observation of λ Cephei, the second brightest Oef star. This observation not only allows to collect the RGS high-resolution spectrum of the star, but further enables us to search for X-ray variability. To correlate the potential X-ray variability with that of the optical spectrum of λ Cep, we monitored the optical spectrum simultaneously with the TIGRE telescope. We present here the first results of this campaign, both in terms of the line profiles in the RGS spectrum and the search for X-ray variability in correlation with the optical variations. [less ▲]

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See detailMicro-plasto-hydrodynamic lubrication: a fundamental mechanism in cold rolling
Laugier, Maxime; Boman, Romain ULg; Legrand, Nicolas et al

in Advanced Materials Research (2014), 966-967

Micro Plasto-Hydrodynamic (MPH) lubrication is a general mechanism in metal forming that consists in a re-lubrication of tool-piece solid contacts by an outflow of lubricant from pressurized “pockets” ... [more ▼]

Micro Plasto-Hydrodynamic (MPH) lubrication is a general mechanism in metal forming that consists in a re-lubrication of tool-piece solid contacts by an outflow of lubricant from pressurized “pockets” promoted by the plastic deformation. MPH lubrication is one of the main sources of friction variation (e.g. uncontrolled friction) in metal forming processes like strip drawing or cold rolling. This paper presents experimental results giving evidence of the MPH lubrication mechanism in cold rolling and a new lubrication model that predicts for strip drawing conditions MPH lubrication initiation and lubricant extension along the solid contacts initially in boundary condition. This MPH model could be implemented in a cold rolling model soon to help in high strength steels developments on cold rolling mills. [less ▲]

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See detailIntegrating axle weight restrictions in a two-dimensional vehicle routing problem with sequence based loading
Pollaris, Hanne; Braekers, Kris; Caris, An et al

Scientific conference (2014, June)

A mixed integer linear programming model for a two-dimensional capacitated vehicle routing problem (2L-CVRP) with sequence based loading and axle weight restrictions is provided. To the authors’ knowledge ... [more ▼]

A mixed integer linear programming model for a two-dimensional capacitated vehicle routing problem (2L-CVRP) with sequence based loading and axle weight restrictions is provided. To the authors’ knowledge, it is the first time that axle weight restrictions are incorporated in a VRP. Axle weight limits impose a great challenge for transportation companies. Trucks with overloaded axles represent a significant threat for traffic safety and may cause serious damage to the road surface. Transporters face high fines when violating these limits. The problem is based on a real-world problem from a Belgian logistics service provider. The demand of the customers consists of europallets. Pallets can be placed in two horizontal rows inside the vehicle. No vertical stacking is allowed. The center of gravity of the pallets inside the vehicle is calculated to determine the axle weights. Results of the model are compared to results of a 2L-CVRP with sequence based loading without axle weight restrictions. Numerical experiments demonstrate that the model performs adequately and that the integration of axle weight constraints in vehicle routing models is necessary for a feasible route planning. [less ▲]

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See detailCrise ou catharsis ?
Vanmeerbeek, Marc ULg

in Exercer (2014), 113(Editorial), 99

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See detailBayes Adaptive Reinforcement Learning versus Off-line Prior-based Policy Search: an Empirical Comparison
Castronovo, Michaël ULg; Ernst, Damien ULg; Fonteneau, Raphaël ULg

in Proceedings of the 23rd annual machine learning conference of Belgium and the Netherlands (BENELEARN 2014) (2014, June)

This paper addresses the problem of decision making in unknown finite Markov decision processes (MDPs). The uncertainty about the MDPs is modeled using a prior distribution over a set of candidate MDPs ... [more ▼]

This paper addresses the problem of decision making in unknown finite Markov decision processes (MDPs). The uncertainty about the MDPs is modeled using a prior distribution over a set of candidate MDPs. The performance criterion is the expected sum of discounted rewards collected over an infinite length trajectory. Time constraints are defined as follows: (i) an off-line phase with a given time budget can be used to exploit the prior distribution and (ii) at every time step of the on-line phase, decisions have to be computed within a given time budget. In this setting, we compare two decision-making strategies: OPPS, a recently proposed meta-learning scheme which mainly exploits the off-line phase to perform policy search and BAMCP, a state-of-the-art model-based Bayesian reinforcement learning algorithm, which mainly exploits the on-line time budget. We empirically compare these approaches in a real Bayesian setting by computing their performances over a large set of problems. To the best of our knowledge, it is the first time that this is done in the reinforcement learning literature. Several settings are considered by varying the prior distribution and the distribution from which test problems are drawn. The main finding of these experiments is that there may be a significant benefit of having an off-line prior-based optimization phase in the case of informative and accurate priors, especially when on-line time constraints are tight. [less ▲]

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See detailL’Anonyme de Londres (P. Lit. Lond. 165, Brit. Libr. inv. 137). Édition et traduction d’un papyrus médical grec du Ier siècle
Ricciardetto, Antonio ULg

Book published by PULg (2014)

Acquis en 1889 par le British Museum, l’Anonyme de Londres est, à ce jour, le plus long papyrus médical grec conservé. Daté du Ier siècle de notre ère et provenant peut-être d’Hermopolis, en Moyenne ... [more ▼]

Acquis en 1889 par le British Museum, l’Anonyme de Londres est, à ce jour, le plus long papyrus médical grec conservé. Daté du Ier siècle de notre ère et provenant peut-être d’Hermopolis, en Moyenne Égypte, il contient un texte autographe où sont exposées et discutées de nombreuses théories nosologiques, étiologiques et physiologiques, qui ont pour auteurs au moins vingt-cinq médecins et philosophes, dont peu sont postérieurs au IVe siècle avant notre ère et dont plusieurs sont inconnus par ailleurs. Après une introduction générale sur l’Anonyme de Londres, où sont notamment étudiés les circonstances relatives à la découverte et à l’étude du papyrus, ainsi que ses caractéristiques matérielles et son contenu, le livre présente l’édition critique, accompagnée de la première traduction française, des textes grecs du recto et du verso de ce témoin exceptionnel pour notre connaissance de la médecine et de la librairie antiques. Il est complété par deux bibliographies, l’une, relative aux textes du papyrus, l’autre, générale, par des index, en français et en grec, et par un fascicule de planches. [less ▲]

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See detailDéfaire le discours d'autorité. Les 'Physiologies' à la limite de l'essai
Stienon, Valérie ULg

in Glaudes, Pierre; Lyon-Caen, Boris (Eds.) Essai et essayisme en France au XIXe siècle (2014)

Les Physiologies déferlent sous la Monarchie de juillet, alimentant les dépôts de pittoresques et prolongeant les caricatures en vitrine des passages parisiens. Si, presqu’un siècle plus tard, l’emprunt ... [more ▼]

Les Physiologies déferlent sous la Monarchie de juillet, alimentant les dépôts de pittoresques et prolongeant les caricatures en vitrine des passages parisiens. Si, presqu’un siècle plus tard, l’emprunt littéraire à la «physiologie» compose encore un effet de titre pour un essai théorique tel que la Physiologie de la critique d’Albert Thibaudet (1920), le petit genre du même nom, qui présente d’autres caractéristiques formelles et thématiques, n’est pas nettement défini par rapport à une conception et une pratique de l’essai. Au mieux peut-on lui trouver certaines parentés avec la chronique sous la forme de la notation des faits-Paris et avec une fiction d’actualité féconde en savoirs culturels et sociaux. Cette indétermination générique est particulièrement intéressante en raison de la diversité des paramètres poétiques et contextuels sur lesquels elle repose. Ce sont ces aspects qui font l’objet du présent parcours synthétique dans un corpus foisonnant, en préalable à une étude plus spécifiquement dédiée aux infinies nuances qui caractérisent ces textes. [less ▲]

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See detailMallarmé dans la prison des signes
Durand, Pascal ULg

in Cahiers du CérédI (2014, June), 10

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See detailPhysician Induced Demand for C-Sections: Does the Convenience Incentive Matter?
Lefevre, Mélanie ULg

Scientific conference (2014, June)

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See detailModeling of the Iturinic Antimicrobial Lipopeptide Mycosubtilin at Interfaces
Loison, Claire; Nasir, Mehmet Nail ULg; Benichou, Emmanuel et al

Conference (2014, June)

Detailed reference viewed: 12 (2 ULg)