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See detailSpectroscopic survey of Kepler stars. I. HERMES/Mercator observations of A- and F-type stars
Niemczura, E.; Murphy, S. J.; Smalley, B. et al

in Monthly Notices of the Royal Astronomical Society (2015), 450

The Kepler space mission provided near-continuous and high-precision photometry of about 207,000 stars, which can be used for asteroseismology. However, for successful seismic modelling it is equally ... [more ▼]

The Kepler space mission provided near-continuous and high-precision photometry of about 207,000 stars, which can be used for asteroseismology. However, for successful seismic modelling it is equally important to have accurate stellar physical parameters. Therefore, supplementary ground-based data are needed. We report the results of the analysis of high-resolution spectroscopic data of A- and F-type stars from the Kepler field, which were obtained with the HERMES spectrograph on the Mercator telescope. We determined spectral types, atmospheric parameters and chemical abundances for a sample of 117 stars. Hydrogen Balmer, Fe I, and Fe II lines were used to derive effective temperatures, surface gravities, and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. The atmospheric parameters obtained were compared with those from the Kepler Input Catalogue (KIC), confirming that the KIC effective temperatures are underestimated for A stars. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined from the spectral line analysis. The analysed sample comprises stars with approximately solar chemical abundances, as well as chemically peculiar stars of the Am, Ap, and Lambda Boo types. The distribution of the projected rotational velocity, Vsini, is typical for A and F stars and ranges from 8 to about 280 km/s, with a mean of 134 km/s. [less ▲]

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See detailComparison of fracture prediction models on sheet metal blanking simulations
Canales Cardenas, Cristian ULg; Boman, Romain ULg; Bussetta et al

Conference (2015, July)

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See detailReinforcement Learning of Heuristic EV Fleet Charging in a Day-Ahead Electricity Market
Vandael, Stijn; Claessens, Bert; Ernst, Damien ULg et al

in IEEE Transactions on Smart Grid (2015), 6(4), 1795-1805

This paper addresses the problem of defining a day-ahead consumption plan for charging a fleet of electric vehicles (EVs), and following this plan during operation. A challenge herein is the beforehand ... [more ▼]

This paper addresses the problem of defining a day-ahead consumption plan for charging a fleet of electric vehicles (EVs), and following this plan during operation. A challenge herein is the beforehand unknown charging flexibility of EVs, which depends on numerous details about each EV (e.g., plug-in times, power limitations, battery size, power curve, etc.). To cope with this challenge, EV charging is controlled during opertion by a heuristic scheme, and the resulting charging behavior of the EV fleet is learned by using batch mode reinforcement learning. Based on this learned behavior, a cost-effective day-ahead consumption plan can be defined. In simulation experiments, our approach is benchmarked against a multistage stochastic programming solution, which uses an exact model of each EVs charging flexibility. Results show that our approach is able to find a day-ahead consumption plan with comparable quality to the benchmark solution, without requiring an exact day-ahead model of each EVs charging flexibility. [less ▲]

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See detailLate Holocene history of the Fuji Five Lakes (Japan)
Lamair, Laura ULg; Hubert, Aurelia ULg; Boes, Evelien et al

Conference (2015, July)

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See detailDevelopping competencies of public managers: a hybrid system analysis in a critical management education perspective
Göransson, Marie; Rondeaux, Giseline ULg

Conference (2015, July)

The role and competencies of public managers are a central topic of public administration reforms implemented these last 30 years in OECD countries. In fact, as New Public Management (NPM) doctrines ... [more ▼]

The role and competencies of public managers are a central topic of public administration reforms implemented these last 30 years in OECD countries. In fact, as New Public Management (NPM) doctrines suggest, public administration managers have to be professionalized and free to manage (Minogue, Hulme & Polidano, 1998). This professionalization and managerial freedom imply the development of new competencies borrowed from the private sector. This leads public managers to be focused on the search for performance and to consider citizens as clients. Without losing its dominance, the NPM conception has evolved with the development of new theoretical paradigms such as Neo-Weberian State (Pollitt & Bouckaert, 2004 ; Peters, 2001 ; Drechsler, 2005) and Public Value Management (Stoker, 2006 ; Moore, 1995). In these models, the manager is still driven by performance targets to provide citizen-customers professional and quality service. However, these paradigms reassert the centrality of the State and the specificity of the public sector by comparison with the private sector. In addition, the public manager must play a role in the co-construction of public value for citizens and political actor in both the short and long term (Greve, 2010). These evolutions have led to a need for hiring public managers with new profiles, and this has been reflected in new practices for recruiting and training future top civil servants. In Belgium, at some levels of government, these practices include for instance mandatory training prior to the appointment of public managers. This training aims at developing the managerial skills of the Walloon and French-speaking public services leaders. Doing so, the purpose is to guarantee the objectification of public managers’ nomination. But so far, do these trainings develop the skills highlighted by the theoretical models above? Are they in line with the ambitions of public management reforms of the last thirty years? From these first questions, we analyse on the one hand the training system genesis and the interactions between the original actors, and on the other hand, the effects of the training, in a critical perspective. Our study of the training effects is critical for two reasons. First, it questions the role of training in the transmission of the dominant principles conveyed by the NPM and its successors. Second, it considers the role of this training in the reproduction of power games between actors. In other words, we analyse how the compulsory training actually reflects a new conception of public managers and their competencies. Moreover, we consider the impact of this training on the political-administrative system and the power relations included. To this end, we articulate two distinctive approaches: one inspired by the strategic analysis (Crozier & Friedberg, 1977) to understand the interactions between actors at the genesis of the dispositive; and the other one inspired by Critical Management Education (CME), emphasizing the role of management training in the transmission of dominant ideology (Caproni & Arias, 1997). [less ▲]

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See detailVitesse ou précipitation ? La question du temps dans le traitement des affaires pénales en France et en Belgique
Bastard, Benoit; Delvaux, David ULg; Mouhanna, Christian et al

in Droit et Société (2015), 90

Le temps a changé de valeur dans le fonctionnement des institutions pénales. La réponse instantanée à toute sollicitation est devenue l’objectif prioritaire dans le travail des parquets. L’efficacité de ... [more ▼]

Le temps a changé de valeur dans le fonctionnement des institutions pénales. La réponse instantanée à toute sollicitation est devenue l’objectif prioritaire dans le travail des parquets. L’efficacité de la réponse pénale impose de rapprocher autant que possible le temps de la sanction de celui de l’infraction. Les normes de bonne gestion publique passent par la quantification des affaires et la réduction des délais de traitement. Cette tendance générale est observée ici dans une perspective comparative : France et Belgique. Alors que, dans les deux pays, les discours tenus mettent uniformément l’accent sur l’efficacité accrue des services, les comparaisons effectuées font ressortir des décalages importants dans les modalités du traitement rapide. Une réflexion générale peut alors être engagée sur les régimes de changement qui prévalent au sein de l’institution judiciaire dans les deux pays. [less ▲]

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See detailWorld Finance Conference
Platania, Federico ULg; Lambert, Marie ULg; Moreno, Manuel

Scientific conference (2015, July)

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See detailXXIII Foro de Finanzas, Meeting of the Spanish Finance Association
Platania, Federico ULg; Lambert, Marie ULg; Moreno, Manuel

Scientific conference (2015, July)

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See detailModifications acoustiques de la voix d’enseignantes au cours de la journée et de l’année scolaire
Remacle, Angélique ULg; David, Claire; Petillon, Caroline et al

Conference (2015, June 30)

Introduction Les enseignants font partie des professionnels de la voix, définis comme des travailleurs qui ne peuvent se passer de leur voix dans l’exercice de leur profession, et qui à ce titre ... [more ▼]

Introduction Les enseignants font partie des professionnels de la voix, définis comme des travailleurs qui ne peuvent se passer de leur voix dans l’exercice de leur profession, et qui à ce titre nécessitent une qualité de vocale constante (1). Cette population est particulièrement à risque et constitue le groupe de travailleurs le plus nombreux à consulter les ORL pour cause de dysphonie (2). Dans ce contexte, la recherche tente d’identifier les indices acoustiques de la fatigue vocale dans le but d’améliorer le dépistage précoce des problèmes de voix, leur traitement et leur prévention. Cette étude menée in situ a pour objectif de mettre en évidence des modifications acoustiques et prosodiques consécutives à 1) une journée de travail et 2) cinq mois de travail en milieu scolaire. Méthode La population est constituée de 22 enseignantes du primaire ayant moins de 5 années d’expérience. Pour chaque participante, cinq /a/ tenus ainsi que la lecture d’un texte ont été enregistrés 1) à deux moments de la journée de travail, soit au matin et au soir, et 2) à trois temps de l’année, soit en octobre (T0), en décembre (T1) et en février (T2). Sur les voyelles tenues, nous avons mesuré le temps maximum phonatoire (TMP), la fréquence moyenne, le jitter, le shimmer, et le rapport harmoniques/bruit (HNR). Sur les textes, nous avons mesuré la fréquence moyenne, la variation de fréquence et d’intensité (écart-type), ainsi que des paramètres relatifs au débit de parole (nombre de syllabes par seconde, nombre de pauses et durée moyenne des pauses). Pour chaque paramètre, une ANOVA en mesure répétées (2 moments * 3 temps) a été réalisée. Résultats L’effet principal du moment montre une augmentation de la fréquence moyenne mesurée sur les voyelles et sur le texte suite à une journée de travail (p<.01). Parallèlement, le TMP et le HNR augmentent (p<.01), tandis que le jitter et le shimmer diminuent en fin de journée (p<.05). Les mesures de débit montrent que les enseignantes tendent à faire moins de pauses lors de la lecture de texte en fin de journée, et que ces pauses sont de plus courte durée (p<.05). L’effet principal du temps montre une augmentation de la fréquence moyenne des voyelles et du texte au cours de l’année (p<.01), avec des valeurs plus élevées observées en décembre (T1). Les mesures relatives au débit montrent également une augmentation du nombre de syllabes par seconde (p<.01) et une tendance des locutrices à faire moins de pauses. Conclusion L’évolution des paramètres observés suggère une augmentation de la fatigue vocale et un comportement phonatoire davantage hyperfonctionnel au cours de la journée et au cours de l’année. Les résultats montrent une dégradation vocale majorée au mois de décembre, en comparaison avec les autres moments de l’année. Bibliographie 1.Titze IR, Lemke J, Montequin D. Populations in the U.S. workforce who rely on voice as a primary tool of trade: A preliminary report. Journal of Voice. 1997;11(3):254-259. 2. Remacle, A., Petitfils, C., Lejeune, L., Finck, C., & Morsomme, D. Quel est le profil professionnel des patients consultant en phoniatrie ? 70e Congrès de la Société Française de Phoniatrie, Paris, France. (13 octobre 2014). [less ▲]

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See detailAsymmetric limit cycle oscillations in systems with symmetric freeplay
Dimitriadis, Grigorios ULg

in Proceedings of the International Forum on Aeroelasticity and Structural Dynamics, IFASD 2015 (2015, June 30)

In this paper, a simple 2D aeroelastic system with degrees of freedom in pitch, plunge and control surface deflection is investigated with freeplay in the pitch degree of freedom. It is shown that this ... [more ▼]

In this paper, a simple 2D aeroelastic system with degrees of freedom in pitch, plunge and control surface deflection is investigated with freeplay in the pitch degree of freedom. It is shown that this system features a fixed point at the origin as well as two anti-symmetric fixed points. Asymmetric limit cycles that span only two of the three piecewise linear subdomains of the phase plane can orbit these anti-symmetric fixed points. A single three-domain symmetric cycle and two two-domain cycles appear as a result of a grazing bifurcation occurring at the flutter speed of the underlying linear system. The two-domain cycles can undergo further fold, period doubling and torus bifurcations. They can cause both periodic and aperiodic oscillations, including highly chaotic responses at parameter values where they interact strongly. [less ▲]

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See detailCould alternative solanaceous hosts act as refuges for the tomato leafminer, Tuta absoluta?
Bawin, Thomas ULg; Dujeu, David ULg; De Backer, Lara ULg et al

in Arthropod-Plant Interactions (2015), 9(4), 425-435

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous plants. The characterization of its effective ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous plants. The characterization of its effective host range could help to understand and prevent the dispersion behavior of the insect in the environment. In this study, the ability of T. absoluta to locate and develop on wild (Solanum nigrum, Atropa belladonna, Datura stramonium) and cultivated (Solanum tuberosum) solanaceous plant species under laboratory conditions was assessed. Dual-choice behavioral assays performed in flying tunnels (S. tuberosum versus another plant) revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to the other tested plants. The volatile molecules released by each tested plant species provide some explanations in the observed behavioral discrimination: S. nigrum and S. tuberosum volatile profiles were similar, and were presenting quantitative and qualitative differences with the other tested Solanaceous plants. To determine whether the host plant choice was adaptive or not, we have finally conducted fitness assays, by rearing T. absoluta larvae on each plant species and have shown that Solanum species allowed higher larval survivability and lower development time (from egg to adult emergency) compared to the other plants. We conclude that Solanum species are suitable host plants for T. absoluta, but other Solanaceous plant species could be opportunistically colonized with fewer incidences. [less ▲]

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See detailLe lecteur de Barthes : jouisseur du judas ?
Lorent, Fanny ULg

Conference (2015, June 30)

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See detailExploiting Interspecific Genetic Variability for Improving Common bean for higher productivity on soils presenting biotic and abiotic stresses
Butare, Louis ULg

Doctoral thesis (2015)

Biotic and abiotic stresses often occur in the same field of rural poor farmer households in tropical countries resulting in heavy losses of common bean yields. To improve resistance of common beans ... [more ▼]

Biotic and abiotic stresses often occur in the same field of rural poor farmer households in tropical countries resulting in heavy losses of common bean yields. To improve resistance of common beans, sensitive Phaseolus vulgaris (SER16) was crossed to resistant P. coccineus (G35346-3Q) to create 94 F5:6 recombinant inbred lines (RILs) of the pedigree SER16♀ x (SER16♀ x G35346-3Q♂). The objectives of this study were to (i) identify potential parents for resistance to Al, drought and Fusarium root rot among 11 bean genotypes, (ii) to evaluate 94 F5:6 Recombinant Inbred Lines (RILs) of the cross SER 16♀ x (SER 16♀ x G35346-3Q♂) both for their resistance to Al and /or drought, (iii) to evaluate RILs for resistance to Fusarium root rot, and (iv) to identify QTL for resistance to these stresses. RILs were characterized in greenhouse for resistance to Al using a hydroponic screening employing a nutrient solution with or without 20 μM Al , to Al-toxic acid soil with high Al (HAl) and low Al (LAl) saturation, to terminal drought simulation with and without progressive soil drying, to combined stresses of Al and terminal drought in 80 cm long soil cylinder system, and to Fusarium root rot using inoculated perlite soil and sand (2:1). Two field studies were also carried on in Colombia under rainfed and irrigated conditions in Palmira, and high Al saturated acid soil in Santander of Quilichao. Our studies confirmed the superiority in Al response of Andean common beans in greenhouse trials compared to Middle American type for several root traits. Each screening method of our Al greenhouse experiments permitted an evaluation of different aspects of root traits. The two parents were virtually equal for tap root elongation rate at 24 h in the 20 μM Al treatment at about 1.4 mm h-1 while progenies ranged from less than 1-1.75 mm h-1. The correlation between leaf area and total root length was highly significant under high Al saturation (r = 0.70***) for HAl-acid soil. Two genotypes (ALB88 and ALB 91) emerged as strong multiple trait lines for the two abiotic stresses. Fusarium root rot induced root growth inhibition as high as 80.8% for the susceptible ALB 5, while resistant RILs (ALB45, ALB41, ALB126, ALB84, ALB49, ALB34, ALB88 and ALB85) didn`t show any inhibition . Seed yield under drought stress conditions was positively associated to 100-seed weight both under irrigated field (r = 0.28**) and rainfed field (r = 0.36***), and negatively associated to days to maturity (DTM) (r = - 0.36***) in field evaluation in Al-toxic acid soil in Quilichao (Colombia). QTLs for important traits including root characteristics under high Al , grain yield and yield components for drought and high Al saturation soil were identified. The use of both soil and hydroponic system, and field could contribute to evaluation of breeding materials to identify genotypes that combine Al resistance with acid soil tolerance, drought and root rot tolerance. [less ▲]

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See detailERT to monitor the bioremediation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale
Masy, Thibaut ULg; Caterina, David; Tromme, Olivier et al

Conference (2015, June 30)

Petroleum hydrocarbons (HC) represent the most widespread contaminants in the world and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the ... [more ▼]

Petroleum hydrocarbons (HC) represent the most widespread contaminants in the world and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on numerous environmental characteristics (heterogeneities of the subsurface structure, soil moisture, oxygen and pollutants bioavailability, microbial niches…) and is still difficult to predict a priori. In order to lower these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was thus to isolate with ERT an electrical signature corresponding to an enhanced biodegrading activity, in an aged HC-contaminated clay loam soil. To achieve it, a pilot tank with metric dimensions (3.6 × 0.9 × 0.6 m) and a recirculating system (which is quite unique for this type of purpose) was built to mimic field conditions and to control the evolution of the bio-physico-chemical parameters (microbial concentration in soil and groundwater, temperature, pH, pO2, redox potential, bulk and fluid conductivities, water flow, hydrocarbon content) through time and space. Five panels of electrodes were placed at different locations in the tank to detect lithological heterogeneities and to monitor the bulk resistivity variations with time-lapse ERT. Compared to a first insufficient biostimulation phase with H2O2 and KNO3, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600 ppm) in 3 months in the center of the contaminated clay, where pollutants were less bioavailable. Furthermore, lithological heterogeneities (clay, sand, gravels) and microbial activities (growth, degradation and biosurfactant production) were successfully discriminated by ERT images obtained during both remediation phases. In the future, this cost-effective technique should be transferred to the field in order to either (i) detect and forecast biodegradation processes before choosing an appropriate remediation technique, or (ii) monitor the efficiency of this biodegradation during an in-situ bioremediation. [less ▲]

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See detailMetal bioavailability and bioaccumulation in the polychaete Nereis virens (Sars): the effects of site-specific sediment characteristics
Pini, Jennifer; Richir, Jonathan ULg; Watson, Gordon

in Marine Pollution Bulletin (2015), 95(2), 565575

The present study investigates the relationships between copper (Cu) and zinc (Zn) concentrations in sediment, pore water and their bioaccumulation in the polychaete Nereis (Alitta) virens, as well as the ... [more ▼]

The present study investigates the relationships between copper (Cu) and zinc (Zn) concentrations in sediment, pore water and their bioaccumulation in the polychaete Nereis (Alitta) virens, as well as the importance of site-specific sediment characteristics in that process. Sediment, pore water and N. virens were sampled from seven sites with different pollution histories along the English Channel coast. Results showed that site-specific metal levels and sediment characteristics were important in determining the bioavailability of metals to worms. Significant correlations were found between Cu in the sediment and in the pore water and between Zn in the pore water and in N. virens. Zn from the pore water was thus more readily available from a dissolved source to N. virens than Cu. Data also showed that metal concentrations in N. virens were lower than those found in other closely related polychaetes, indicating that it may regulate tissue concentrations of Cu and Zn. [less ▲]

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See detailUsing 2D-PIV measurements to compute unsteady aerodynamic loads on a flat plate at high angle of attack
Guissart, Amandine ULg; Bernal, Luis; Dimitriadis, Grigorios ULg et al

in Proceedings of the 16th International Forum on Aeroelasticity and Structural Dynamics, IFASD 2015 (2015, June 30)

This work exposes and discusses results obtained for aerodynamic forces using an indirect calculation based on Particle Image Velocimetry (PIV) measurements. The methodology used is based on the integral ... [more ▼]

This work exposes and discusses results obtained for aerodynamic forces using an indirect calculation based on Particle Image Velocimetry (PIV) measurements. The methodology used is based on the integral formulation of the Navier-Stokes equations and is applied to spatio-temporal data for different flows around a plate with a 16:1 chord-to-thickness ratio at high angle of attack. Experimental data are obtained in a water channel for both a static and a pitching plate. In addition to PIV data, direct measurements of aerodynamic loads are carried out to assess the quality of the indirect calculation. It is demonstrated that this indirect method is able to compute the mean and the temporal evolution of the lift and drag coefficients with a reasonable accuracy. It is also shown that the noise sensitivity of the method can be partly alleviated through the use of Dynamic Mode Decomposition (DMD) as a pre-processing step to smooth the spatio-temporal data. [less ▲]

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See detailA comparative study for simulation of heat transport in large district heating network
Sartor, Kevin ULg; Thomas, David ULg; Dewallef, Pierre ULg

in Prooceedings of ECOS 2015 (2015, June 29)

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See detailUnsteady Viscous-Inviscid Coupling Simulations of Separated Laminar Flows Around 2D Airfoils
Rothkegel Ide, José Ignacio ULg; Dimitriadis, Grigorios ULg

in Proceedings of the International Forum on Aeroelasticity and Structural Dynamics, IFASD 2015 (2015, June 29)

An interactive boundary layer model has been developed in 2D in order to solve the unsteady flow around an airfoil. The inviscid problem is solved using a panel method, by the discretization of the ... [more ▼]

An interactive boundary layer model has been developed in 2D in order to solve the unsteady flow around an airfoil. The inviscid problem is solved using a panel method, by the discretization of the airfoil into linear-varying vortex panels. The solution of the boundary layer equations is carried out using a finite volume scheme. Viscous-inviscid coupling is preformed by imposing a permeation velocity on the skin panels of the airfoil and the addition of a free wake at each separation point. [less ▲]

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