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See detailThe challenge of understanding myopathies in horses using permeabilized muscle cells
Votion, Dominique ULg; Mouithys-Mickalad, Ange ULg; Ceusters, Justine ULg et al

in In proceedings 9th Conference on Mitochondrial Physiology (2013, September)

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See detailVibrations of cables with bending stiffness by an asymptotic approach
Canor, Thomas ULg; Denoël, Vincent ULg

in Zingoni, Alphose (Ed.) Fifth International Conference on Structural Engineering, Mechanics & Computation, Cape Town, 1-4 September 2013 (2013, September)

Vibrations of cables with a small bending stiffness concerns many engineering applications such as the fatigue assessment of stay cables. With the finite element (FE) method, the analysis can be performed ... [more ▼]

Vibrations of cables with a small bending stiffness concerns many engineering applications such as the fatigue assessment of stay cables. With the finite element (FE) method, the analysis can be performed with nonlinear truss elements, but bending effects are not taken into account. Otherwise, beam elements can be used, but the smallness of the bending stiffness may lead to numerical instability and mediocre results in boundary regions. In this context, the paper presents an alternative method to calculate the time evolution of the profile of bending moments in boundary layers of cables, avoiding heavy FE analysis. The developments combine the theory of vibrations of extensible rods with asymptotic methods. The equations are decoupled between the slow dynamics of the boundary regions and the fast dynamics of the span. Then, a composite solution is constructed by means of a matched asymptotic procedure. [less ▲]

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See detailEarly decision support for net zero energy buildings design using building performance simulation
Attia, Shady ULg; Gratia, Elisabeth; De Herde, Andre et al

in Clean Technology for Smart Cities and Buildings (2013, September)

This paper aims to investigate the use of building performance simulation tools as a method of informing the design decision of NZEBs. The aim of this study is to evaluate the effect of a simulation-based ... [more ▼]

This paper aims to investigate the use of building performance simulation tools as a method of informing the design decision of NZEBs. The aim of this study is to evaluate the effect of a simulation-based decision aid, ZEBO, on informed decision-making using sensitivity analysis. The objective is to assess the effect of ZEBO and other BPS tools on three specific outcomes: (i) knowledge and satisfaction when using simulation for NZEB design; (ii) users’ decision-making attitudes and patterns, and (iii) performance robustness based on an energy analysis. The paper utilizes three design case studies comprising a framework to test the use of BPS tools. Two types of data were collected, mainly preference and performance data. The preference data were used to collect information from participants using self-reported metrics. The performance data were used to collect information on the energy performance of the final design. The energy evaluations were compared with the results of a quantitative assessment of the overall design performance. Finally the results were compared and presented. The paper provides results that shed light on the effectiveness of sensitivity analysis as an approach for informing the design decisions of NZEBs. [less ▲]

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See detailAnalyse de l’interaction entraîneur-sportifs. Analyse qualitative exploratoire d’un modèle original
Remy, Elodie ULg; Manfredini, Tiber ULg; Cloes, Marc ULg

in Carnel, Béatrice; Moniotte, Julien (Eds.) Intervention, Recherche et Formation: Quels enjeux, quelles transformations? (2013, September)

Notre démarche, novatrice, s’inscrit dans une orientation sociale de la psychologie du sport. Selon Brown (2006), la psychologie sociale correspond à la compréhension d’un comportement individuel dans un ... [more ▼]

Notre démarche, novatrice, s’inscrit dans une orientation sociale de la psychologie du sport. Selon Brown (2006), la psychologie sociale correspond à la compréhension d’un comportement individuel dans un contexte social. La psychologie du sport, elle, se définit comme « l’étude de l’effet des facteurs psychologiques et émotionnels sur les performances et de l’influence de la pratique sportive sur ces mêmes facteurs » (Cox, 2005, p. 14). Notre objectif consistait à déterminer le lien entre, d’une part, ce que les coaches définissent comme leur(s) priorité(s) d’actions, ce qu’ils font concrètement et comment le vivent les sportifs et, d’autre part, ce qu’attendent ces derniers. Il s’agissait également de déterminer comment le lien entre ces quatre aspects influe sur la performance et comment la performance agit en retour sur ces aspects. Afin de développer une méthodologie rigoureuse, nous avons élaboré un modèle qui a servi de cadre de référence pour la collecte de données au sein de trois équipes de basket-ball de 1ère régionale féminine wallonne (deuxième niveau hiérarchique belge). Dans chaque site, nous avons sollicité à la fois les joueuses et les entraîneurs (interviews, focus group, observations et questionnaires). Dans la première équipe, un net décalage est mis en évidence entre le projet du coach, celui des joueuses et les moyens dont dispose le club. Il se manifeste par des comportements contradictoires et ambivalents entre joueuses et entraîneur, ce qui semble impacter considérablement la performance. La seconde équipe s’inscrit dans un cadre particulier (école de formation ne pouvant connaître ni promotion ni relégation). La jeunesse des joueuses et le style de coaching vécu comme oppressant par les plus jeunes débouche sur un climat susceptible de limiter la performance. Enfin, la troisième équipe se situe largement en-dessous du niveau attendu. Les joueuses composent avec un entraîneur démissionnaire et un préparateur physique porté aux nues dont le comportement est décrit comme affectif et protecteur. Ce constat fait obstacle à une vision objective des acteurs sur les résultats. Ces résultats plaident en faveur du modèle proposé et pour un approfondissement de l’étude des liens entre dimensions organisationnelle, groupale et individuelle dans l’étude de la performance sportive collective. [less ▲]

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See detailFrom zero-energy building to zero-energy neighbourhood : urban form and mobility matter
Marique, Anne-Françoise ULg; Penders, Marine ULg; Reiter, Sigrid ULg

in Proceedings PLEA 2013 (2013, September)

Zero-Energy” Building (ZEB) is arousing more and more interest internationally, both in policies aiming at a more sustainable built environment (such as the European Directive PEB that will require, for ... [more ▼]

Zero-Energy” Building (ZEB) is arousing more and more interest internationally, both in policies aiming at a more sustainable built environment (such as the European Directive PEB that will require, for example, all new buildings to be “nearly Zero-Energy” Buildings (nZEB) by 2020) and in the scientific literature. Although Zero-Energy can be considered at different scales, this approach only adopts the perspective of the individual building and neglects phenomena linked to larger scales. Therefore, this paper aims at investigating the “Zero-Energy Neighbourhood” concept. It proposes a calculation method that takes into account three main topics: the energy consumption of buildings, the impact of the location on the energy consumption for daily mobility and the use of renewable energies. An application of this calculation method to two representative case studies (one urban neighbourhood and one suburban neighbourhood) is proposed. Main parameters that act upon the energy balance are highlighted and combined to propose concrete results to improve our built environment and move towards more sustainability. Hourly and monthly balances, the potential of “energy mutualisation” and smart grids are keys challenges that are of crucial importance in the scope of a Zero-Energy objective at the neighbourhood scale. [less ▲]

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See detailBauschinger effect in thin metallic films by Fem simulations
marandi, kianoosh; vayrette, renaud; Pardoen, Thomas et al

in XII International Conference on Computational Plasticity. Fundamentals and Application COMPLAS XII , Barcelone 3-5 septembre 2013 (2013, September)

Unpassivated free-standing gold and aluminium thin films, subjected to tensile tests show Bauschinger effect (BE) during unloading [1,2]. The focus of this work is to investigate the effect of ... [more ▼]

Unpassivated free-standing gold and aluminium thin films, subjected to tensile tests show Bauschinger effect (BE) during unloading [1,2]. The focus of this work is to investigate the effect of microsstructural heterogeneity such as grain sizes on the BE and the macroscopic deformation behavior in thin metallic films. The finite element code LAGAMINE is used to model the response of films involving sets of grains with different strenghts. The numerical results are compared with experimental results from tensile tests on aluminium thin films from the work of Rajagolapan, et al. [2] [less ▲]

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See detailHedges and woody strips browsing by cattle on pasture in Wallonia, Belgium
Vandermeulen, Sophie ULg; Pascal, Mathilde; Marche, Christian et al

in Michalk, David L.; Millar, Geoffrey D.; Badgery, Warwick B. (Eds.) et al Revitalising Grasslands to Sustain our Communities: Proceedings 22nd International Grassland Congress, Sydney 15-19 september 2013 (2013, September)

Agri-environmental measures promote woody hedges along meadows in Wallonia, raising the interest in tree and shrub as forage in intensive mixed dairy temperate production systems. This study aimed at (1 ... [more ▼]

Agri-environmental measures promote woody hedges along meadows in Wallonia, raising the interest in tree and shrub as forage in intensive mixed dairy temperate production systems. This study aimed at (1) determining the influence of an access to hedges on the grazing behavior of young cattle and (2) assessing the fermentation characteristics of woody species promoted in Wallonia. Twelve heifers, divided in two groups, were set to graze a ryegrass and white clover-based pasture in May 2012. The first group had access to a hedge composed of 12 temperate tree and shrub species, and the second group grazed the pasture only. The grazing and browsing behavior of the animals was recorded for 4 weeks along with pasture biomass availability, using the hand-plucking method. Samples of the 12 tree species were fermented using rumen fluid in an automated gas pressure monitoring system and gas production kinetics compared to ryegrass and white clover. Results suggest that the feeding behavior was influenced by the hedge. Grazing time of the control group was higher than heifers that could browse woody foliage (P<0.05). Browsing was especially noticeable when grass availability on pasture was lowest. In vitro ruminal fermentation kinetics differed among species (P<0.01) with Populus nigra and Fraxinus excelsior showing a potential of fermentation similar to herbaceous forages. It can be concluded that due to the browsing by cattle some woody species could be interesting as complementary feeding. Besides their attributes regarding the agricultural landscape, their feeding qualities should be considered when planting the hedges. [less ▲]

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See detailProfils de discordance et comportement d’élèves dans un contexte d’éducation physique belge francophone
Martel, Denis; Cloes, Marc ULg; Colina-Valdor, Xavier et al

in Carnel, Béatrice; Moniotte, Julien (Eds.) Intervention, Recherche et Formation: Quels enjeux, quelles transformations? (2013, September)

Les profils de discordance sont déterminés à partir des écarts entre l’auto-évaluation des élèves (AÉ) et leur prédiction de l’évaluation de l’éducateur physique à leur égard (PrÉ) concernant leur niveau ... [more ▼]

Les profils de discordance sont déterminés à partir des écarts entre l’auto-évaluation des élèves (AÉ) et leur prédiction de l’évaluation de l’éducateur physique à leur égard (PrÉ) concernant leur niveau de performance, leur coopération et l’intensité de leurs efforts en classe d’éducation physique et sportive (ÉPS) (Martel et al., 2011). Une étude québécoise a permis d’établir que plus les élèves s’estiment sous-évalués par leur enseignant sur ces trois dimensions, moins ils tendent à rapporter l’adoption de comportements positifs durant les cours d’ÉPS. Pour la présente étude, réalisée dans un contexte belge francophone, les objectifs étaient : (1) de déterminer les profils de discordance d’élèves (PDi), et (2) d’analyser la relation entre ces PDi et les comportements que disent adopter les élèves en ÉPS. Un total de 1271 élèves (722 filles, 549 garçons) âgés entre 11 et 20 ans, provenant des niveaux secondaires inférieur (n=857) et supérieur (n=414) d’écoles (N=4) de l’agglomération de Liège, ont volontairement participé à l’étude. Un questionnaire validé, adapté d’une version québécoise, a été complété par les élèves vers la fin de l’année scolaire en l’absence de l'éducateur physique. Les résultats, inférieurs à ceux d’autres études, révèlent que 25% des élèves expriment un profil de concordance parfaite entre leur AÉ et leur PrÉ, c’est-à-dire s’estiment évalués à leur juste valeur à la fois pour leur niveau de performance, leur coopération et leurs efforts en ÉPS. Par ailleurs, 56% des élèves s’estiment sous-évalués (discordance négative) sur une seule dimension (27,7%), deux dimensions (19,4%) ou trois dimensions (9,5%) simultanément. Enfin, les résultats confirment ceux de Martel et al. (2011), à savoir que plus les élèves se sentent sous-évalués, particulièrement ceux qui se sentent sous-évalués sur au moins deux dimensions, moins ils rapportent de comportements positifs (p< .001) que ceux qui perçoivent être davantage en accord avec leur enseignant. [less ▲]

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See detailPapyrologie latine et bilinguisme gréco-latin : des perspectives nouvelles
Rochette, Bruno ULg

in Marganne, Marie-Hélène; Rochette, Bruno (Eds.) Bilinguisme et digraphisme dans le monde gréco-romain (2013, September)

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See detailReliability of ERT-derived Temperature - Insights from Laboratory Measurements
Robert, Tanguy ULg; Hermans, Thomas ULg; Dumont, Gaël ULg et al

in EarthDoc - Near Surface Geosciences 2013 - 19th European Meeting of Environmental and Engineering Geophysics (2013, September)

We performed laboratory measurements on fully saturated sand samples in the context of deriving reliable temperature from time-lapse electrical resistivity tomography (ERT). The experiment consisted in ... [more ▼]

We performed laboratory measurements on fully saturated sand samples in the context of deriving reliable temperature from time-lapse electrical resistivity tomography (ERT). The experiment consisted in monitoring an increase of temperature in sand samples with electrical resistivity measurements. We neglected the effect of surface conductivity since experiments showed two orders of magnitude between surface and fluid conductivities. We show that using simple linear relationship between fluid electrical conductivity and temperature alone does not allow reliable temperature estimates. Indeed, chemical analyses highlight the importance of accounting chemical reactions occurring when temperature changes, including dissolution/precipitation processes. We performed two experiments based on typical in-situ conditions. We first simulated the injection of a less conductive tap water and second, the injection of heated formation water. In the second case, minerals solubility decreases and precipitation occurs, leading to an increase of bulk resistivity. This mechanism competes with dissolution of minerals when tap water is injected, since tap water is not in equilibrium with the medium. In any case, further research is needed to fully understand the mechanisms and to develop a fully integrated law to derive better temperature estimates. [less ▲]

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See detailRelation between indoor thermal environment and renovation in Liege residential buildings
Singh, Manoj Kumar ULg; Mahapatra, Sadhan; Teller, Jacques ULg

in Matijašević, Sunčana; Ban, Marko (Eds.) Conference Digital proceedings (2013, September)

Indoor thermal environment monitoring has been done in 20 residential buildings of Liege city followed by questionnaire based comfort survey amongst the occupants of 85 houses in order to record their ... [more ▼]

Indoor thermal environment monitoring has been done in 20 residential buildings of Liege city followed by questionnaire based comfort survey amongst the occupants of 85 houses in order to record their preference and expectations about indoor thermal environment in winter and spring season. It is found from the analysis that change of glazing has a minimum or even sometimes an adverse effect on the existing indoor environment due to the absence of proper insulation of the rest of the building envelope. It is observed that in winter there is a sudden drop in indoor temperature and also overheating in summer. This is due to unplanned installation of glazing which actually increases the fenestration area ratio leading to higher indoor temperature fluctuation and causes discomfort. It is also important that the occupant’s preference and expectations as well as overall assessment of indoor environment needs to be consider towards energy efficiency improvement. [less ▲]

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See detailLa problématique des dispensés au cours d’éducation physique : analyse des représentations des enseignants en Belgique francophone
Van Hoye, Martin ULg; Cloes, Marc ULg

in Carnel, Béatrice; Moniotte, Julien (Eds.) Intervention, Recherche et Formation: Quels enjeux, quelles transformations? (2013, September)

Souvent, les enseignants en éducation physique se plaignent du nombre de dispensés et/ou d'absents constaté lors de leurs leçons et l'associent à un manque de motivation. Toutefois, ces plaintes sont ... [more ▼]

Souvent, les enseignants en éducation physique se plaignent du nombre de dispensés et/ou d'absents constaté lors de leurs leçons et l'associent à un manque de motivation. Toutefois, ces plaintes sont souvent assez abstraites. C'est pourquoi, dans cette étude, nous avons tenté de concrétiser le ressenti des enseignants en les interrogeant directement. Respectant les principes de l’approche écologique, cette recherche vise donc à enrichir les connaissances relatives à la problématique des dispensés en éducation physique en se basant sur l’analyse des perceptions des enseignants. Nous avons utilisé un questionnaire afin d’identifier l’importance de la non-participation lors des leçons d’éducation physique et les variables qui en seraient responsables. Dans le cadre d’un échantillonnage de convenance, les réponses ont été collectées lors de formations continues, dans des écoles et par l’intermédiaire d’une association professionnelle. Au total, 232 réponses (50% d’hommes et de femmes ayant en moyenne 18,6 années d’ancienneté dans l’enseignement) ont été encodées dans une base de données et traitées (Statistica, StatSoft, 2010). En moyenne, selon les estimations des enseignants, 82,4% des élèves seraient actifs lors des leçons d’éducation physique. Ce chiffre varie en fonction du réseau d’enseignement dans lequel on se trouve mais également de l’ancienneté de l’enseignant, confirmant les propos de Carlier et Brunelle (1998). Les enseignants mettent également en évidence que la non-participation est essentiellement liée à des problèmes médicaux rencontrés par les élèves. Ils considèrent d’ailleurs que les excuses médicales n’étant pas couvertes par un certificat seraient même presque aussi importantes quantitativement que celles qui le sont. Enfin, l’oubli de l’équipement représente la troisième raison de non-participation des élèves mentionnée par les enseignants. D’après ces derniers, l’âge des élèves aurait peu d’influence. Plusieurs implications pratiques sont formulées à partir des résultats. [less ▲]

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See detailFrom zero-energy building to zero-energy neighbourhood : urban form and mobility matter
Marique, Anne-Françoise ULg; Penders, Marine ULg; Reiter, Sigrid ULg

in Proceedings PLEA 2013 (2013, September)

Zero-Energy” Building (ZEB) is arousing more and more interest internationally, both in policies aiming at a more sustainable built environment (such as the European Directive PEB that will require, for ... [more ▼]

Zero-Energy” Building (ZEB) is arousing more and more interest internationally, both in policies aiming at a more sustainable built environment (such as the European Directive PEB that will require, for example, all new buildings to be “nearly Zero-Energy” Buildings (nZEB) by 2020) and in the scientific literature. Although Zero-Energy can be considered at different scales, this approach only adopts the perspective of the individual building and neglects phenomena linked to larger scales. Therefore, this paper aims at investigating the “Zero-Energy Neighbourhood” concept. It proposes a calculation method that takes into account three main topics: the energy consumption of buildings, the impact of the location on the energy consumption for daily mobility and the use of renewable energies. An application of this calculation method to two representative case studies (one urban neighbourhood and one suburban neighbourhood) is proposed. Main parameters that act upon the energy balance are highlighted and combined to propose concrete results to improve our built environment and move towards more sustainability. Hourly and monthly balances, the potential of “energy mutualisation” and smart grids are keys challenges that are of crucial importance in the scope of a Zero-Energy objective at the neighbourhood scale. [less ▲]

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See detailEVALUATION DES EMISSIONS DE METHANE IMPUTABLES AU SECTEUR AGRICOLE EN AFRIQUE DE L’OUEST (1961-2050)
Djaby, Bakary ULg; Ozer, Pierre ULg

in Boko, Michel; Vissin, Expédit W.; Afouda, Fulgence (Eds.) CLIMAT, AGRICULTURE & RESSOURCES EN EAU d'hier à demain (2013, September)

The objective of this study is to review the evolution of methane (CH4) emissions related to agriculture in West Africa over the last fifty years (1961-2010). The main agricultural sources of CH4 are ... [more ▼]

The objective of this study is to review the evolution of methane (CH4) emissions related to agriculture in West Africa over the last fifty years (1961-2010). The main agricultural sources of CH4 are ruminants (enteric fermentation) and rice production (anaerobic decomposition). To do this, we used the FAO statistics for both rice production and livestock. It appears that CH4 emissions are regionally rising although presenting large differences between the Sahelian countries and those of the Gulf of Guinea. Indeed, the countries bordering the Sahara seem to take profit of improving rainfall over the past two decades to increase livestock. On the contrary, wetter countries increase rice development. A close relationship is found between the human population and CH4 emissions from the agricultural sector. Yet, human population increase projected by 2050 is questionable, particularly in relation to the margin of CH4 emissions increase in West Africa. [less ▲]

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See detailDynamics of Elasto-Inertial Turbulence in Flows with Polymer Additives
Terrapon, Vincent ULg; Dubief, Yves; Soria, Julio

in Proceedings of the 8th International Symposium on Turbulence and Shear Flow Phenomena (TSFP-8) (2013, August 30)

The dynamics of elasto-inertial turbulence is investigated numerically from the perspective of the coupling between polymer dynamics and flow structures. In particular, direct numerical simulations of ... [more ▼]

The dynamics of elasto-inertial turbulence is investigated numerically from the perspective of the coupling between polymer dynamics and flow structures. In particular, direct numerical simulations of channel flow with Reynolds numbers ranging from 1000 to 6000 are used to study the formation and dynamics of elastic instabilities and their effects on the flow. Based on the splitting of the pressure into inertial and polymeric contributions, it is shown that the trains of cylindrical structures around sheets of high polymer extension that are characteristics to elasto-inertial turbulence are mostly driven by polymeric contributions. [less ▲]

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See detailEntreprises et développement durable: vers une nouvelle forme de responsabilité sociale?
Goemans, Adeline; Robert, Jocelyne ULg

in C. Dupont; R. Giuliano; J.M. Peretti (Eds.) "De l'audit social à l'audit de la responsabilité sociale: la RSE, renouveau pour la GRH" Proceeding colloque IAS (2013, August 30)

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See detailA mucin-enriched fermentation model to assess prebiotic potential of new indigestible carbohydrates
Boudry, Christelle ULg; Tran, Thi Hanh Tham ULg; Blaise, Yannick ULg et al

in 64th Annual Meeting of the European Federation of Animal Science (2013, August 29)

Screening the prebiotic potential of novel indigestible carbohydrates (ICH) is a challenge for feed and food industry and in vitro models are increasingly used for such purposes. Recently extracellular ... [more ▼]

Screening the prebiotic potential of novel indigestible carbohydrates (ICH) is a challenge for feed and food industry and in vitro models are increasingly used for such purposes. Recently extracellular binding proteins responsible for the adherence to intestinal mucus were described for several Lactobacillus species. As this genus is known for its beneficial effect on gut health, we enriched the in vitro gas fermentation model with mucin in order to evaluate the prebiotic potential of 5 ICH. Mucin-coated microcosms (MCM) were prepared as described by Van den Abbeele et al. (2012, Microbial Biotechnology, 5, 106-115) and introduced in the fermentation bottles with an inoculum prepared from fresh faeces of 3 sows mixed with a nutritive buffer solution. Fermentation was performed at 39°C, using 200 mg of substrate, 30 ml of inoculum and 6 MCM, yielding approx. 20 mg mucin each, in 140 ml glass bottles. A first study was performed with inulin and cellulose as substrates, with and without mucus in the bottles. A second study was performed with 5 substrates (inulin, IMO, beet pulp POS, cellobiose and gluconate) in presence of mucus. After 8 and 72h, SCFA and the microflora of fermentation broth was analysed as well as the microflora on the MCM. The comparison of the microflora evolution with and without mucus showed a better development of the Lactobacillus in the fermentation broth, mainly in presence of inulin. The development of the Lactobacillus genus allowed the classification of the 5 substrates tested in the second study (Inulin > IMO > Gluconate > Cellobiose > POS)(P < 0.05) which was not possible without mucus (P > 0.05). Inulin and IMO showed also the highest development of Bifidobacteria (P < 0.05) and the highest levels of butyrate production (P < 0.05) compared to the three other substrates, indicating a high prebiotic potential. [less ▲]

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See detailField Investigation of subacute ruminal acidosis in Walloon dairy herds
Lessire, Françoise ULg; Knapp, Emilie ULg; Theron, Léonard ULg et al

in Universität Bern (Ed.) Proceedings of 8th ECBHM (2013, August 28)

Subacute ruminal acidosis (SARA) has been considered as a major metabolic disease in high producing dairy herds for years. For instance, out of 737 cows from Wisconsin farms, 20% exhibited ruminal pH ... [more ▼]

Subacute ruminal acidosis (SARA) has been considered as a major metabolic disease in high producing dairy herds for years. For instance, out of 737 cows from Wisconsin farms, 20% exhibited ruminal pH values lower than 5.5, allowing diagnosis of SARA, while 23% of animals were considered at risk with ruminal pH values between 5.5 and 5.8. These findings were corroborated by further studies in Europe. However, different feeding practices and herd’s production levels are found in Wallonia, requiring evaluation of SARA prevalence in local herds. [less ▲]

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See detailIs the wheat distillers grains soluble ProtiWanze® a valuable alternative to soybean and canola meals in beef cattle?
Lessire, Françoise ULg; Rollin, Frédéric ULg

in Université de Berne (Ed.) Proceedings of 8th ECBHM (2013, August 28)

The objective of this study was to evaluate whether introducing the condensed distillers soluble (CDS) ProtiWanze® (PW) in beef cattle diets has an impact on feeding costs, health and production of the ... [more ▼]

The objective of this study was to evaluate whether introducing the condensed distillers soluble (CDS) ProtiWanze® (PW) in beef cattle diets has an impact on feeding costs, health and production of the animals. PW, a by-product derived from a Belgian bio-ethanol plant which utilizes only branless wheat, is an acid (pH=4) liquid feed rich in energy (VEM= 1130) and protein (TP= 282 mg/kg DM). PW supplementation from 9 to 13% on DM basis was tested in 4 suckler cattle farms for 4 months in 2011 and 2012: In 2011, 2 Belgian Blue (BB) (H1 and H3) and one Blonde d’Aquitaine (H2) herds were evaluated and in 2012, H2 was replaced by a third BB herd (H4). Every month, the animals’ health and production were checked by means of Body Condition Scoring (BCS), Ruminal Fill (RF), Fecal Consistency (FC), Undigested Fraction (UF) and Locomotion Scores (LS). Ruminal fluid was collected with a stomach tube (Ruminator®) on 5 cows for pH, redox potential (Methylene blue test) and protozoa assessment (optical microscopy). Reproduction performances during these 2 years were analyzed. The price of a diet containing the same amount of proteins brought by a mixture of 1/3 soybean and 2/3 canola meal was calculated to verify whether introducing PW reduced feeding costs. [less ▲]

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See detailDetection of antibodies against Schmallenberg virus in wild boars, Belgium, 2010-2012
Desmecht, Daniel ULg; Garigliany, Mutien-Marie ULg; Beer, Martin et al

in Lecoq, Yves (Ed.) 31th Congress of the International Union of Game Biologists (2013, August 27)

In the summer/fall of 2011, a nonspecific febrile syndrome characterized by hyperthermia and drop in milk production with occasional reports of watery diarrhea and abortion was reported among dairy cows ... [more ▼]

In the summer/fall of 2011, a nonspecific febrile syndrome characterized by hyperthermia and drop in milk production with occasional reports of watery diarrhea and abortion was reported among dairy cows on farms in northwestern Europe. Further, in November 2011, an enzootic outbreak of malformed neonates emerged in several European countries, with stillbirth and birth at term of lambs, kids and calves with neurological signs or malformations of the head, spine, or limbs. Both syndromes were associated with the presence in the blood (adults) or in the central nervous system (newborns) of a new Shamonda/Sathuperi-like orthobunyavirus, provisionally named Schmallenberg virus (SBV) after the town in Germany where the first positive clinical samples were identified. Defining as precisely as possible the host range of the newcomer is a key point to predict the outcome of the emergence of SBV disease in Europe. In this respect, it must be pointed out that orthobunyaviruses infect more animal species than those in which the foetus is damaged. Recently, serological evidence for SBV infection in wild ruminant species (Cervus elaphus and Capreolus capreolus) was reported (Linden et al., 2012). In the present study, the objective was to seek after serological evidence of SBV infection among wild boars living in a geographical area where exposure to infected insect vectors was high in 2011, as judged from the very high seroprevalence reported among cattle in that region. About 700 animals were sampled during the 2010-2012 hunting seasons. All serum samples collected during the fall of 2010 were seronegative. On the contrary, apparent seroprevalence among wild boars in 2011 was ~27% and started to decline in 2012 (~11%). Acquired immunity against the new virus was thus already very high in the wild boar populations sampled in the fall 2011, suggesting that the new virus had quickly spread throughout the region since its emergence about 250 km northeast in the late summer 2011. The drop in seroprevalence recorded in 2012 suggests that the virus was no more circulating in the region. [less ▲]

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See detailSchmallenberg virus circulation among red and roe deer populations in Belgium
Garigliany, Mutien-Marie ULg; Volpe, Rosario ULg; Paternostre, Julien ULg et al

in 31th Congress of the International Union of Game Biologists, Abstract Book (2013, August 27)

Schmallenberg virus (SBV) is a recently discovered vector-borne Orthobunyavirus targeting ruminants. It is transmitted by Culicoides biting midges and caused a large outbreak in European sheep and cattle ... [more ▼]

Schmallenberg virus (SBV) is a recently discovered vector-borne Orthobunyavirus targeting ruminants. It is transmitted by Culicoides biting midges and caused a large outbreak in European sheep and cattle populations in 2011 and 2012. The infection of adults was associated with a drop in milk production, fever and diarrhea. But the virus was further shown to cross the placental barrier and to be responsible for a hydrocephaly/arthrogryposis syndrome in calves and lambs. After its occurrence in 2011 in Germany, SBV quickly spread across Europe and in spring 2012 more than 90% of Belgian domestic cattle had seroconverted. To assess the susceptibility of wild ruminants to the infection, a total number of 547 and 494 sera, from red (Cervus elaphus) and roe deer (Capreolus capreolus), respectively, were collected during the hunting seasons 2010 to 2012 and tested for the presence of anti-SBV antibodies. While no samples from 2010 revealed to be positive, about two-thirds of red deer and half of roe deer sampled in 2011 were seropositive. In 2012, the seroprevalence dropped to 33% in red deer and remained stable in roe deer. The high seroprevalence rates found in both species in Belgium shows that wild ruminants are susceptible to the infection by SBV. If the infection of deer was associated to a hydrocephaly/arthrogryposis syndrome similar to that observed in domestic ruminants is still unknown. There is currently no evidence of such a transplacental passage in red or roe deer. The decrease in the seroprevalence observed in red deer in 2012 might be the result of the turn-over in the red deer population and reflect an absence of virus circulation in 2012. Further investigations in the upcoming years will help to enlighten this point. [less ▲]

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See detailThe potential of MIR spectra to certify milk geographic origin
Dale, Laura-Monica ULg; Laine, Aurélie ULg; Goubau, Amaury et al

in 64rd Annual Meeting of the European Federation of Animal Science (2013, August 26)

Protecting and supporting local production systems, regional authorities, as well as producers, give a very important role to milk quality. Therefore, this study was aimed to investigate the potential of ... [more ▼]

Protecting and supporting local production systems, regional authorities, as well as producers, give a very important role to milk quality. Therefore, this study was aimed to investigate the potential of mid-infrared spectroscopy (MIR) for certifying the geographic origin of milk. Because milk MIR spectral databases and extra phenotypes (breed, testday, livestock herd and origin appellation of traditional products) were available in the Belgium Walloon Region via European project OptiMIR (INTERREG IVB North West Europe Program), discrimination studies were conducted to distinguish Ardennes region (which is linked to PDO “Beurre d’Ardennes”) from the rest of Wallonia. A total of 542,733 spectral records linked to their geographic origin coming from Wallonia milk recording were used (97,369 of MIR spectra -Ardennes region and 450,326 -rest of Wallonia). A mixed model (fixed: breed, year and month of record, random: herd x year) was applied to obtain predicted MIR spectral values for all testdays and prediction errors (residuals) representing the factors not present in the model. In order to test the MIR ability to milk authentication, chemometric tools, such as partial least squat regression and linear discriminant analysis were applied to residuals for three MIR spectral regions (e.g. 930-1600 cm-1, 1710-1810 cm-1 and 2560-2990 cm-1). The classifications on not-corrected MIR spectral data were 95% and the cross-validation were 95% for Ardennes region. Results showed after correction of MIR spectra, the discriminant function constructed on the residuals spectra allowed a good discrimination. The results show that MIR spectroscopy techniques may provide useful fingerprints to detect geographic origin and could be potentially used in routine management decision and quality assurance tools. [less ▲]

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See detailAssessment of the selenium status in cattle herds in Wallonia
Mehdi, Youcef ULg; Dotreppe, Olivier ULg; Robaye, Vincent ULg et al

in 64th Annual Meeting of the European Federation of Animal Science (2013, August 26)

The selenium content is low in the soil of Wallonia, the southern part of Belgium. It is therefore logical that the selenium content in feedstuffs grown in these fields-grass, conserved forages, cereals ... [more ▼]

The selenium content is low in the soil of Wallonia, the southern part of Belgium. It is therefore logical that the selenium content in feedstuffs grown in these fields-grass, conserved forages, cereals and by-products- is also low. A survey was carried on 166 farms in Wallonia. The farms were located in 4 specific agronomy areas- Pays de Herve with mainly pastures (4farms)- Ardennes (a sub-mountainous area and pastures, 24 farms), Hesbays with mainly arable lands (55 farms) and Condroz with both pastures and arable (83 farms) There were herds with dairy cow, herds with beef cow and herds with both types of animals. The average age was 44±15 months for the cows and 18±6 months for the heifers. The blood samples were taken on five healthy animals of each herd, on the end of the winter just before the animals went to pastures. The selenium status was assessed by the activity of the Glutathion peroydase. The selenium status was extremely variable for the different farms of the 4 areas with variation coefficient of 56%. It was in Pays de Herve and in Hesbaye that the average selenium status was the highest at 53 and 56 µg Se/l. By contrast, it was in Ardenne and in Condroz that the status was the lowest, at 39 and 43 µg Se/l. The selenium status was, on the whole, higher in the dairy herds than in the beef herds owing to the higher selenium provision by the mineral mixtures and the compound feedstuffs added to the diet. Assuming that the normal selenium concentration in plasma being 70µg/l, it appeared also that 81% of the individual animals tested were below the normal Se concentration. It can thus be concluded from the present survey that the cattle herds in Wallonia are deficient in selenium. [less ▲]

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See detailMacro-Kinematic Modelling of Continuous Deep Beams
Mihaylov, Boyan ULg

in Actes de la 14e édition des Journées Scientifiques, 22 et 23 août 2013, Université de Sherbrooke, Québec (2013, August 23)

Cet article présente une approche macro-cinématique permettant de décrire les schémas de déformation avec fissures diagonales des poutres-voile continues. On montre comment une poutre continue formée de ... [more ▼]

Cet article présente une approche macro-cinématique permettant de décrire les schémas de déformation avec fissures diagonales des poutres-voile continues. On montre comment une poutre continue formée de deux travées symétriques et supportant deux charges concentrées égales peut être modélisée à partir de seulement deux degrés de liberté. Ce modèle cinématique est combiné avec une théorie cinématique à trois paramètres (3PKT) qui permet de calculer la résistance au cisaillement de poutres-voile, les réactions d’appuis à la ruine et la capacité de déformation de poutres-voile continues. Cette approche a été appliquée à quatorze essais de cisaillement issus de la littérature avec différentes hauteurs de section, différents arrangement de l’armaturage longitudinal et différentes quantités d’armaturage de cisaillement. Les résultats montrent que cette approche macro-cinématique basée sur deux degrés de liberté reproduit correctement les tendances observées dans la capacité ultime au cisaillement des spécimens. [less ▲]

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See detailOn a modified bilinear law to model bit/rock interaction in percussive drilling
Depouhon, Alexandre ULg; Denoël, Vincent ULg; Detournay, Emmanuel

in Proceedings of the Nonlinear Dynamics in Engineering Conference (2013, August 21)

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See detailUncertainty quantification of the orbital lifetime of a LEO spacecraft
Dell'Elce, Lamberto ULg; Kerschen, Gaëtan ULg

in Proceedings of the Astrodynamics Specialist Conference (2013, August 12)

Orbital lifetime estimation is a problem of great timeliness and importance in astrodynamics. In view of the stochastic nature of the thermosphere and of the complexity of drag modeling, any deterministic ... [more ▼]

Orbital lifetime estimation is a problem of great timeliness and importance in astrodynamics. In view of the stochastic nature of the thermosphere and of the complexity of drag modeling, any deterministic assessment of orbital lifetime is likely to be bound to failure. This is why the present paper performs uncertainty quantification of satellite orbital lifetime estimation. Uncertainties in the initial state of the satellite and in the atmospheric drag force, as well as uncertainties introduced by modeling limitations associated with atmospheric density models, are considered. Mathematical statistics methods in conjunction with mechanical modeling considerations are used to infer the probabilistic characterization of these uncertainties from experimental data and atmospheric density models. Monte Carlo propagation is then exploited to achieve a probabilistic description of the orbital lifetime. [less ▲]

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See detailDeformations in deep continuous reinforced concrete transfer girders
Mihaylov, Boyan ULg; Hunt, Bradley; Bentz, Evan et al

in Concrete Structures in Urban Areas, CCC 2013, Wroclaw, Poland 4-6 September 2013 (2013, August 05)

This paper presents a three-parameter kinematic model for the deformation patterns of deep continuous transfer girders. The three degrees of freedom of the model are the average strains along the top and ... [more ▼]

This paper presents a three-parameter kinematic model for the deformation patterns of deep continuous transfer girders. The three degrees of freedom of the model are the average strains along the top and bottom longitudinal reinforcements within each shear span, as well as the transverse displacement in the critical loading zone. The model is validated with the help of a large test of a two-span continuous beam performed at the University of Toronto. It is shown that the apparently complex deformation patterns of the specimen are captured well by the kinematic model. [less ▲]

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See detailComparison between optical pulsed thermography and vibrothermography for the assessment of carbon fibers composite materials
Montrieux, Henri-Michel ULg; Demy, Philippe; Ibarra-Castanedo, Clemente et al

(2013, August 02)

Pulsed thermography and vibrothermography are two active thermography techniques characterized by different heating methods of the specimen. In pulsed phase thermography, a sample is heated by two flash ... [more ▼]

Pulsed thermography and vibrothermography are two active thermography techniques characterized by different heating methods of the specimen. In pulsed phase thermography, a sample is heated by two flash lamps for a short period to inject a Dirac impulse heat in the material. The cooling of the part is monitored with an infrared camera to detect thermal contrast in the image, characteristic of the presence of a defect. In vibrothermography, high frequency vibrations are injected into the sample causing an internal heating observed on surface right above the defect due to diverse phenomena as friction or viscoelastic hysteresis. If pulsed thermography is a well-known technique that has been integrated into the arsenal of industrial NDT methods, vibrothermography is a less common experimental method still subject to theoretical and practical investigations. This article aims to compare the effectiveness of the two methods in the case of different types of composites based on carbon fibers: carbon fiber reinforced plastic (CFRP) plates as well as a completely new material: carbon magnesium composite. [less ▲]

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See detailThe Airline Container Loading Problem with Pickup & Delivery and Multi Doors
Schyns, Michael ULg; Lurkin, Virginie ULg

in 53rd AGIFORS Annual Proceedings 2013: Annual Symposium and Study Group Meeting (2013, August)

We address the problem of allocating containers into predefined positions of a carrier, in this case aircraft, under several realistic structural and safety constraints, including the management of ... [more ▼]

We address the problem of allocating containers into predefined positions of a carrier, in this case aircraft, under several realistic structural and safety constraints, including the management of several doors. The originality of our approach is to allow multi-trips with pickup and delivery at some intermediate locations. The objective is to minimize the economic and environmental costs including the impact of the intermediate operations. We resort to an integer linear model. Numerical experiments have been performed using a standard B&C library. The cost impact is measured. The Airline Group of the International Federation of Operational Research Societies, composed of professionals and academics, has awarded us the price of the "Best technical presentation" for this work. [less ▲]

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See detailHerd-test-day variability of methane emissions predicted from milk MIR spectra in Holstein cows
Vanrobays, Marie-Laure ULg; Kandel, Purna Bhadra ULg; Soyeurt, Hélène ULg et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

The aim of this study was to estimate the herd-test-day (HTD) effect on milk yield, fat and protein content, and methane (CH4) emissions of Walloon Holstein first-parity cows. A total of 412,520 test-day ... [more ▼]

The aim of this study was to estimate the herd-test-day (HTD) effect on milk yield, fat and protein content, and methane (CH4) emissions of Walloon Holstein first-parity cows. A total of 412,520 test-day records and milk mid-infrared (MIR) spectra of 69,223 cows in 1,104 herds were included in the data set. The prediction equation developed by Vanlierde et al. (Abstract submitted to EAAP 2013; R² of cross-validation=0.70) was applied on the recorded spectral data to predict CH4 emissions (g/d). Daily CH4 emissions expressed in g/kg of milk were computed by dividing CH4 emissions (g/d) by daily milk yield of cows. Several bivariate (a CH4 trait with a production trait) random regression test-day models including HTD and classes of days in milk and age at calving as fixed effects and permanent environment and genetic as random effects were used. HTD solutions of studied traits obtained from these models were studied and presented large deviations (CV=17.54%, 8.93%, 4.68%, 15.51%, and 23.18% for milk yield, fat and protein content, MIR CH4 (g/d), and MIR CH4 (g/kg of milk), respectively) indicating differences among herds, especially for milk yield and CH4 traits. HTD means per month of milk yield and fat and protein contents presented similar patterns within year. The maximum of monthly HTD means corresponded to the spring (pastern release) for milk yield and to the winter for fat and protein contents. The minimum corresponded to the month of November for milk yield and to the summer for the other traits. For MIR CH4 (g/d), monthly HTD means showed similar patterns as fat and protein content within year. MIR CH4 (g/kg of milk) presented maximum values of monthly HTD means in November and minimum values in May. Finally, results of this study showed that HTD effects on milk production traits and on MIR CH4 emissions varied through herds and seasons. [less ▲]

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See detailUse of visible-near infrared spectroscopy to determine cheese properties
Troch, Thibault ULg; Vanden Bossche, Sandrine; De Bisschop, Céline et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailTracking network state from combined SCADA and synchronized phasor measurements
Glavic, Mevludin ULg; Van Cutsem, Thierry ULg

in Proceedings of the 2013 IREP Symposium-Bulk Power System Dynamics and Control -IX (2013, August)

Initiated by the authors’ previous work on state reconstruction from a limited number of synchrophasors [1], this paper goes one step further by exploring the possibility to track the network state using ... [more ▼]

Initiated by the authors’ previous work on state reconstruction from a limited number of synchrophasors [1], this paper goes one step further by exploring the possibility to track the network state using both SCADA and synchronized phasor measurements. When a SCADA measurement is received, it is used in the next state reconstruction; otherwise, it is replaced by a pseudo-measurement stemming from the previous state reconstruction. The approach resorts to a standard weighted least squares formulation and Hachtel’s augmented matrix method. State reconstruction is intended to be used at a much higher rate than classical state estimation, for instance every second. It has been validated using simulated measurements obtained from detailed time simulation. [less ▲]

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See detailMid-infrared prediction of cheese yield from milk and its genetic variability in first-parity cows
Colinet, Frédéric ULg; Troch, Thibault ULg; Vanden Bossche, Sandrine et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailPrevalence of Campylobacter spp infection in male mule ducks in Belgium
Flament, Aline; Soubbotina, Alexandra ULg; Mainil, Jacques ULg et al

in Abstracts of the XVIIIth World Veterinary Poultry Association Congress (2013, August)

Salmonella enterica and Campylobacter spp food poisoning are major public health burden. In Belgium, breeding of mule duck is well developed and “foie gras” consumption shows a yearly increase. Flament et ... [more ▼]

Salmonella enterica and Campylobacter spp food poisoning are major public health burden. In Belgium, breeding of mule duck is well developed and “foie gras” consumption shows a yearly increase. Flament et al. (2012) published a paper on the Belgian Salmonella spp infection in ducks but up to now there are no data about Campylobacter prevalence. The monitoring of Campylobacter spp infections was performed from March 2008 to April 2009 in 9 Belgian duck farms starting at the arrival of French ducklings up to the end of the force-feeding period. Cotton-tipped swabs of droppings were collected in duckling transportation boxes 24 to 48 h after the arrival of animals in the farm. Pools of bird droppings (10 to 50 g in 3 to 5 samples, representative of the housing area) were collected at 3, 6, 9 weeks of age and at time of introduction in the force-feeding rooms (at 11 or 12 weeks of age). A membrane filter method adapted from the original Steele and Mc Dermott (1984) method was used. After the filtering step, Campy blood free selective medium plates were incubated at 37°C, micro-aerobically ([O2] < à 10%) in anaerobic jars and colonies corresponding to putative Campylobacter spp were further identified with the API Campy® system. Campylobacter spp was isolated from all flocks, most of the time already at arrival of ducklings or at 3 weeks of age. Campylobacter jejuni subsp. jejuni (32/42) was the most frequent species isolated (Fig.1). Campylobacter coli (3/42), Campylobacter jejuni subsp. doylei (2/42) and Helicobacter fennelliae (3/42) were unfrequently isolated. Two isolates could not be identified to the species. Our results confirm those of Tsai et Hsiang (2005) who found a prevalence of 92% for Campylobacter in Taiwan. The isolations of Campylobacter jejuni subsp. doylei and Helicobacter fennelliae were unexpected. Indeed man is considered the reservoir of Campylobacter jejuni subsp. doyley and up to now the isolation of Helicobacter was never reported from ducks (Anas platyrhynchos) (Murphy et al., 2005). In conclusion the putative role of mule ducks in the transmission of Campylobacter food borne illness should not be underestimated [less ▲]

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See detailTourisme, privatisation des littoraux et érosion des côtes: cas de Phan Thiet, Vietnam
Ozer, Pierre ULg

in 8th International conference (IAG) on Geomorphology: « Geomorphology and sustainability », Paris, 27-31 August 2013 (2013, August)

Avec ses plus de 3200 km de côtes, le Vietnam fait partie des pays les plus exposés aux effets du réchauffement climatique : élévation du niveau des mers, augmentation de la fréquence des typhons et des ... [more ▼]

Avec ses plus de 3200 km de côtes, le Vietnam fait partie des pays les plus exposés aux effets du réchauffement climatique : élévation du niveau des mers, augmentation de la fréquence des typhons et des inondations. Début 2009, 27 maisons situées dans le village de pêcheurs de Phan Thiet se sont effondrées. Selon les médias internationaux et les autorités locales, une forte marée de tempête –conséquence du réchauffement climatique– était la cause de cette rapide érosion littorale. Cet article montre comment, en utilisant la fonction multi dates Google Earth, il est possible de nier cette argumentation et de mettre en évidence les vraies causes de ce rapide et inéluctable retrait des côtes au niveau de ce village de pêcheurs, à savoir la construction anarchique de la station balnéaire de Mui Ne, quelques kilomètres à l’est. La création de ce désormais haut lieu touristique est extrêmement récente, le premier établissement étant sorti de terre en 1994. Vu le succès croissant des plages de sable blanc, la côte a depuis été lotie sur près de 5 km. Mui Ne a modifié son espace pour accueillir les touristes occidentaux : les cocoteraies ont été abattues, les liserons des sables ont été arrachés, le sable a été égalisé et les infrastructures hôtelières ont recouvert les dunes pour être en contact direct avec la plage. Ainsi, le fragile équilibre littoral a été rompu et le bilan sédimentaire est devenu négatif. Entre 2006 et 2009, la plage de 30 m a totalement disparu. Or, la plage étant vitale pour ce lieu, les promoteurs ont eu recours à la construction d’épis qui interrompent le transit sédimentaire pour recréer les plages. La dérive littorale est ainsi stoppée ce qui engendre la disparition des plages suivantes et l’effondrement des maisons de pêcheurs. Cette analyse montre la rapide modification géomorphologique qui résulte d’une conversion économique locale non encadrée répondant aux processus de mondialisation sans tenir compte des externalités négatives. [less ▲]

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See detailControlled field study comparing organic and inorganic trace elements supplementation in hypermuscled Belgian Blue Breed: biochemical aspects
Guyot, Hugues ULg; Martin-Tereso, Javier; Litjens, Wilbert et al

in Proceedings of the Buiatrissima 8th ECBHM symposium (2013, August)

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See detailNon-industrial seeds as a civic entry point to sustainable food systems
Hecquet, Corentin ULg

in XXV Congres ESRS (2013, August)

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See detailContact model between superelements in dynamic multibody systems
Virlez, Geoffrey ULg; Bruls, Olivier ULg; Sonneville, Valentin ULg et al

in Proceedings of ASME2013 International Design Engineering Technical Conference & Computers and Information in Engineering Conference IDETC/CIE 2013 (2013, August)

In this paper, a new contact formulation defined between flexible bodies modeled as superelements is investigated. Unlike rigid contact models, this approach enables to study the deformation and vibration ... [more ▼]

In this paper, a new contact formulation defined between flexible bodies modeled as superelements is investigated. Unlike rigid contact models, this approach enables to study the deformation and vibration phenomena induced by hard contacts. Compared with full-scale finite element models of flexible bodies, the proposed method is computationally more efficient, especially in case of a large number of bodies and contact conditions. The compliance of each body is described using a reduced-order elastic model which is defined in a corotational frame that follows the gross motion of the body. The basis used to reduce the initial finite element model relies on the Craig-Bampton method which uses both static boundary modes and internal vibration modes. The formulation of the contact condition couples all degrees of freedom of the reduced model in a nonlinear way. The relevance of the approach is demonstrated by simulation results first on a simple example, and then on a gear pair model. [less ▲]

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See detailExperimental identification of the complex dynamics of a strongly nonlinear spacecraft structure
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Kerschen, Gaëtan ULg

in Proceedings of the ASME IDETC/CIE 2013 (2013, August)

The present paper addresses the identification of a real-life spacecraft structure possessing an impact-type nonlinear component. The complete identification procedure, i.e. from nonlinearity detection to ... [more ▼]

The present paper addresses the identification of a real-life spacecraft structure possessing an impact-type nonlinear component. The complete identification procedure, i.e. from nonlinearity detection to parameter estimation, is carried out using experimental data collected during a typical spacecraft qualification test campaign. The complementary use of several techniques reveals particularly interesting and complex phenomena such as nonlinear jumps, nonlinear modal interactions, internal force relaxation and chattering during impacts. [less ▲]

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See detailControlled field study comparing organic and inorganic trace elements supplementation in hypermuscled Belgian Blue Breed: clinical aspects
Rollin, Frédéric ULg; Martin-Tereso, Javier; Litjens, Wilbert et al

in Proceedings of the Buiatrissima 8th ECBHM symposium (2013, August)

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See detailLe contexte urbain et climatique des risques hydrologiques de la ville de Butembo (Nord Kivu/ RDC)
Sahani, Muhindo; Ozer, Pierre ULg; Moeyersons, Jan

in 8th International conference (IAG) on Geomorphology: « Geomorphology and sustainability », Paris, 27-31 August 2013 (2013, August)

Butembo constitue un cas typique de zone urbaine en région tropicale humide rencontrant une explosion démographique exceptionnelle. La concentration spontanée des populations, due à l’exode incontrôlé sur ... [more ▼]

Butembo constitue un cas typique de zone urbaine en région tropicale humide rencontrant une explosion démographique exceptionnelle. La concentration spontanée des populations, due à l’exode incontrôlé sur un territoire assez restreint, a conduit à une urbanisation sans cesse croissante. L’imperméabilisation des vastes étendues de terres consécutive à une expansion spatiale rapide de la ville a généré des problèmes environnementaux qui affectent la structure urbaine. La ville est actuellement confrontée à des risques hydrologiques diversifiés : ravinements progressif et régressif, inondations, et remobilisation d’anciens glissements de terrain. Après avoir réalisé la carte de la ville de Butembo, ce travail aboutit notamment à la production d’une carte des risques hydrologiques sur base d’approches combinant la télédétection et travaux de terrain. Les résultats révèlent une expansion urbaine exceptionnelle. L’emprise urbaine de la ville de Butembo est passée de 2,39 km² en 1957 à 85,83 km² en 2008. Son accroissement est consécutif à l’augmentation de la population qui est passée de 9 653 à 581 449 habitants entre 1957 et 2008. Cette urbanisation a abouti à une nouvelle affectation du sol avec des conséquences sur le paysage urbain. Depuis 1957, le ravinement de fond de vallée ainsi que celui sur les versants sont toujours restés confinés à l’intérieur des extensions urbaines respectives. L’urbanisation précède le développement des ravins et ceux-ci sont confinés dans les zones où le coefficient d’écoulement est accentué par elle. Les inondations pourraient s’étendre sur tous les fonds plats de vallées en cas d’inaction. Quant aux 16 glissements de terrain actifs, ils se trouvent dans la phase de creep et 11 sont partiellement co-engendrés par la sismicité. La pluie n’est pas à la base de l’accentuation des problèmes environnementaux qui perturbent la structure urbaine de Butembo. C’est bien l’urbanisation qui en est la principale cause. [less ▲]

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See detailCombination of genotype, pedigree, local and foreign information
Vandenplas, Jérémie ULg; Colinet, Frédéric ULg; Gengler, Nicolas ULg

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailDevelopment of a genomic evaluation for milk production for a local bovine breed
Colinet, Frédéric ULg; Vandenplas, Jérémie ULg; Faux, Pierre ULg et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailA FEW GOOD REASONS TO CONSIDER A BEAM FINITE ELEMENT FORMULATION ON THE LIE GROUP SE(3)
Sonneville, Valentin ULg; Bruls, Olivier ULg

in Proceedings of the ASME 2013 International Design Engineering Technical Conference & Computers and Information in Engineering Conference IDETC/CIE 2013 (2013, August)

Based on an original interpolation method we develop a beam finite element formulation on the Lie group SE(3) which relies on a mathematically rigorous framework and provides compact and generic notations ... [more ▼]

Based on an original interpolation method we develop a beam finite element formulation on the Lie group SE(3) which relies on a mathematically rigorous framework and provides compact and generic notations. We work out the beam kinematics in the SE(3) context, the beam deformation measure and obtain the expression of the internal forces using the virtual work principle. The proposed formulation exhibits important features from both the theoretical and numerical points of view. The approach leads to a natural coupling of position and rotation variables and thus differs from classical Timoshenko/Cosserat formulations. We highlight several important properties such as a constant deformation measure over the element, an invariant tangent stiffness matrix under of rigid motions or the absence of shear locking. [less ▲]

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See detailA Tool for Design Decision Making Zero Energy Residential Buildings in Hot Humid Climate
Attia, Shady ULg; Gratia, Elisabeth; De Herde, Andre et al

in Proceedings of the 13th Conference of International Building Performance Simulation Association (2013, August)

Informed decision-making is the basis for the design of Net Zero Energy Buildings (NZEBs). This paper investigates the use of building performance simulation tools as a method of informing the design ... [more ▼]

Informed decision-making is the basis for the design of Net Zero Energy Buildings (NZEBs). This paper investigates the use of building performance simulation tools as a method of informing the design decision of NZEBs. The aim of this study was to develop a design decision making tool, ZEBO, for zero energy residential buildings in hot climates and to evaluate the effect of a simulation-based decision aid, on informed decision-making using sensitivity analysis. An assessment of the role of the BPS tools used in informing the decision-making was ascertained through cases studies, usability testing and several self-reported metrics. The paper provides results that shed light on the effectiveness of sensitivity analysis as an approach for informing the design decisions of NZEBs [less ▲]

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See detailAccuracy of clinical examination and field tests for diagnosis of traumatic reticulo-peritonitis in cattle : a preliminary study
Gaillot, Claire ULg; Detilleux, Johann ULg; Touati, Kamal ULg et al

in Proceedings of the Buiatrissima 8th ECBHM Symposium (2013, August)

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See detailErosion littorale et migrations forcées de réfugiés environnementaux. L'exemple de Cotonou, Bénin
Ozer, Pierre ULg; Hountondji, Yvon-Carmen; De Longueville, Florence ULg

in 8th International conference (IAG) on Geomorphology: « Geomorphology and sustainability », Paris, 27-31 August 2013 (2013, August)

Situé dans le Golfe de Guinée, le littoral béninois est soumis –sur certains tronçons– à une érosion assez rapide ces dernières décennies. Cette érosion côtière est principalement due actuellement aux ... [more ▼]

Situé dans le Golfe de Guinée, le littoral béninois est soumis –sur certains tronçons– à une érosion assez rapide ces dernières décennies. Cette érosion côtière est principalement due actuellement aux activités humaines parmi lesquelles les perturbations sédimentaires occasionnées par la construction de divers barrages dont celui de Nangbéto sur le fleuve Mono ; le blocage du transit littoral par les ouvrages portuaires de Cotonou ; les carrières de sable exploitées à même la plage ; et la diminution d’apports sédimentaires provenant de l’ouest suite à divers travaux de protection des côtes. En utilisant la fonction multi dates disponible dans Google Earth, cet article estime la superficie érodée à Cotonou entre 2002 et 2011 à l’est de l’exutoire du Lac Nokoué. En outre, il évalue le nombre de maisons détruites ainsi que le nombre de personnes contraintes à une migration forcée. Les figures sont importantes puisque de l’ordre de cent mètres de zone côtière ont totalement disparu au cours des dix dernières années sur un tronçon de près de six kilomètres de long en pleine ville ou en proche périphérie. Cette analyse montre qu’actuellement les dommageables modifications géomorphologiques résultent essentiellement de l’addition non envisagée d’activités humaines couplée à l’absence de gouvernance. Par ailleurs, nous sommes en droit de nous interroger sur les risques d’érosion côtière dans les décennies à venir avec l’amplification annoncée de l’augmentation du niveau des océans due au réchauffement climatique. [less ▲]

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See detailGenetics of mastitis in the Walloon Region of Belgium
Bastin, Catherine ULg; Vandenplas, Jérémie ULg; Laine, Aurélie ULg et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailApplication of the Cradle to Cradle paradigm to a housing unit in Switzerland: Findings from a prototype design
Attia, Shady ULg; Beney, Jean François; Andersen, Marilyne

in PLEA 2013 Munich: Sustainable Architecture for a Renewable Future (2013, August)

The Cradle to Cradle (C2C) paradigm is emerging as an important regenerative design approach. C2C is aiming to create a positive footprint of the built environment, beyond carbon neutrality. The general ... [more ▼]

The Cradle to Cradle (C2C) paradigm is emerging as an important regenerative design approach. C2C is aiming to create a positive footprint of the built environment, beyond carbon neutrality. The general idea of the C2C approach is to design products, in this case buildings, in order to have a positive impact on the planet, instead of trying to go beyond the zero environmental impact concept. However, there are very few studies that address the application of the C2C concept in building design. More importantly, there is hardly any documentation processes on methods or tools currently being used to design and evaluate C2C buildings. Therefore, the purpose of this paper is to design, model and assess a C2C building prototype with a focus on energy and materials. The research methodology is based on literature review, case study design and performance (energy/materials) evaluation (DesignBuilder/SimaPro). The paper articulates the values, principles and goals of the C2C paradigm and translates them through the prototype design in the Swiss context. The results of the prototype design point to a 74% independence from non-renewable energy resources, compensating the operating and embodied energy during the building’s life. On the other hand only 8% of the building materials were totally recyclable according to the C2C principles. The design process delivers insights on the application of the C2C concept in the built environment reporting on the limitation and means of improvement. [less ▲]

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See detailComputational Optimisation for Zero Energy Buildings Design Interviews results with twenty eight International expert
Attia, Shady ULg; Hamdy, Mohamed; O’Brien, William et al

in Proceedings of the 13th Conference of International Building Performance Simulation Association (2013, August)

This paper summarizes a study that was undertaken to reveal potential challenges and opportunities for integrating optimisation tools in Net/Nearly Zero Energy Buildings (NZEB) Design. The paper reviews ... [more ▼]

This paper summarizes a study that was undertaken to reveal potential challenges and opportunities for integrating optimisation tools in Net/Nearly Zero Energy Buildings (NZEB) Design. The paper reviews current trends in simulation-based Building Performance Optimisation (BPO) and outlines major criteria for optimisation tools selection and evaluation. This is based on analyzing users’ needs for tools capabilities and requirement specifications. The review is carried out by means of interviews with 28 optimisation experts. The findings are based on an inter-group comparison between experts. The aim is to assess the gaps and needs for integrating BPO tools in NZEB Design. The findings indicate existing limitations including model uncertainty, computation time, difficulty of implementation and steep learning curve. Future directions anticipated or needed for improvement of current tools are presented. [less ▲]

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See detailGenetic effects of heat stress on milk yield and MIR predicted methane emissions of Holstein cows
Vanrobays, Marie-Laure ULg; Gengler, Nicolas ULg; Kandel, Purna Bhadra ULg et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

Dairy cows both contribute to and are affected by climate change. Breeding for heat tolerance and reduced methane (CH4) emissions is a key requirement to mitigate interactions between dairy cows and ... [more ▼]

Dairy cows both contribute to and are affected by climate change. Breeding for heat tolerance and reduced methane (CH4) emissions is a key requirement to mitigate interactions between dairy cows and climate change. This study was aimed to estimate genetic variation of milk yield and CH4 emissions over the whole trajectory of temperature humidity index (THI) using a reaction norm approach. A total of 257,635 milk test-day (TD) records and milk mid-infrared (MIR) spectra from 51,782 Holstein cows were used. Data were collected between January 2007 and December 2010 in 983 herds by the Walloon Breeding Association (Ciney, Belgium). The calibration equation developed by Vanlierde et al. (Abstract submitted to EAAP 2013; R² of cross-validation=0.70) was applied on the spectral data in order to predict CH4 emissions values (g CH4/d). These values were divided by fat and protein corrected milk yield (FPCM) defining a new CH4 trait (g CH4/kg of FPCM). Daily THI values were calculated using the mean of daily values of dry bulb temperature and relative humidity from meteorological data. Mean daily THI of the previous 3 days before each TD record was used as the THI of reference for that TD. Bivariate (milk yield and a CH4 trait) random regression TD mixed models with random linear regressions on THI values were used. Estimated average daily heritability for milk yield was 0.17 and decreased slightly at extreme THI values. However, heritabilities of MIR CH4 traits increased as THI values increase: from 0.10 (THI=28) to 0.14 (THI=75) for MIR CH4 (g/d) and from 0.14 (THI=28) to 0.21 (THI=75) for MIR CH4 (g/kg of FCPM). Genetic correlations between milk yield and MIR CH4 (g/d) ranged from -0.09 (THI=28) to -0.12 (THI=75) and those between milk yield and MIR CH4 (g/kg of FPCM) from -0.75 (THI=28) to -0.71 (THI=75). These results showed that milk production and CH4 emissions of dairy cows seemed to be influenced by THI. [less ▲]

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See detailNutritive value of four tropical forage legume hays fed to pigs in the Democratic Republic of Congo
Kambashi Mutiaka, Bienvenu ULg; Boudry, Christelle ULg; Picron, Pascale ULg et al

in 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailBenchmark Models for Air Conditioned Residential Buildings in Hot Humid Climate
Attia, Shady ULg; Evrard, Arnaud

in Proceedings of the 13th Conference of International Building Performance Simulation Association (2013, August)

This study reports the results of a recent field survey for residential apartment buildings in Egypt. The aim of the survey is to create representative building energy models. Two building performance ... [more ▼]

This study reports the results of a recent field survey for residential apartment buildings in Egypt. The aim of the survey is to create representative building energy models. Two building performance simulation models are created reflecting the average energy consumption characteristics of air-conditioned residential apartments in Alexandria, Cairo and Asyut. Aiming for future evaluation of the cost and energy affects of the new Egyptian energy standard this study established two detailed models describing the energy use profiles for air-conditioners, lighting, DHW and appliances in respect to buildings layout and construction. Using EnergyPlus simulation tool the collected surveyed data was used as input for two building simulation models. The simulation models were verified against the apartment characteristic found in the survey. This paper presents details of the building models including the energy use patterns and profiles created for this study. [less ▲]

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See detailHAEMATOLOGICAL PROFILES OF CALVES BELONGING TO HERDS WITH BOVINE NEONATAL PANCYTOPENIA HISTORY IN AND AROUND WALLONIA (BELGIUM).
Ronzoni, Anna ULg; Theron, Léonard ULg; Bayrou, Calixte ULg et al

in Buiatrissima, 8th ECBHM Symposium, 28-30 August 2013, Bern, Proceedings (2013, August)

The objective of the present study was to verify the hypothesis of subclinical BNP cases, by random sampling and haematological analysis in different herds with BNP history, in order to obtain a better ... [more ▼]

The objective of the present study was to verify the hypothesis of subclinical BNP cases, by random sampling and haematological analysis in different herds with BNP history, in order to obtain a better epidemiological picture of this disease. [less ▲]

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See detailStrategies for computation and inversion of the additive relationship matrix among genotyped animals
Faux, Pierre ULg; Gengler, Nicolas ULg

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

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See detailExperimental tests on the seismic behaviour of unreinforced load-bearing masonry structures
Mordant, Christophe ULg; Dietz, Matt; Degée, Hervé ULg

in Heuer, Rudolf; Adam, Christoph (Eds.) Proceedings of Vienna Congress on recent advances in earthquake engineering and structural dynamics (VEESD 2013) (2013, August)

The paper describes recent experimental shaking table tests carried out on load-bearing unreinforced masonry shear walls in earthquake conditions, within the European research project SERIES. The first ... [more ▼]

The paper describes recent experimental shaking table tests carried out on load-bearing unreinforced masonry shear walls in earthquake conditions, within the European research project SERIES. The first phase of the experimental activity investigates the response of four simple unreinforced masonry walls, two of them including rubber acoustic isolation devices. The second phase deals with the testing of specimens with T- and Lshaped walls (shear wall with flanges) coupled at their top by a concrete lintel and a prefabricated concrete slab. The paper summarizes interesting results obtained on the general behaviour of the walls, on the estimation of equivalent elastic and shear moduli, on the influence of the soundproofing devices and on the global frame behaviour of the system. [less ▲]

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See detailNumerical computation of nonlinear normal modes of nonconservative systems
Renson, Ludovic ULg; Kerschen, Gaëtan ULg

in Proceedings of the ASME IDETC/CIE 2013 (2013, August)

Since linear modal analysis fails in the presence of nonlinear dynamical phenomena, the concept of nonlinear normal modes (NNMs) was introduced with the aim of providing a rigorous generalization of ... [more ▼]

Since linear modal analysis fails in the presence of nonlinear dynamical phenomena, the concept of nonlinear normal modes (NNMs) was introduced with the aim of providing a rigorous generalization of linear normal modes to nonlinear systems. Initially defined as periodic solutions, numerical techniques such as the continuation of periodic solutions were used to compute NNMs. Because these methods are limited to conservative systems, the present study targets the computation of NNMs for nonconservative systems. Their definition as invariant manifolds in phase space is considered. Specifically, the partial differential equations governing the manifold geometry are considered as transport equations and an adequate finite element technique is proposed to solve them. The method is first demonstrated on a conservative nonlinear beam and the results are compared to standard continuation techniques. Then, linear damping is introduced in the system and the applicability of the method is demonstrated. [less ▲]

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See detailSemi-Continuous Fermentation for Gluconic acid Production at High Temperature
Zarmehrkhorshid, Raziyeh ULg; Shafiei, Rasoul ULg; Thonart, Philippe ULg

in World Acadamy of Science, Engineering and Technology (2013, July 31)

Gluconic acid (GA) is a multifunctional organic acid with versatile applications in food, beverage and pharmaceutical industries. Recently, owing to increasing demand for cheaper gluconic acid and its ... [more ▼]

Gluconic acid (GA) is a multifunctional organic acid with versatile applications in food, beverage and pharmaceutical industries. Recently, owing to increasing demand for cheaper gluconic acid and its salts; studies have mainly focused on more economical production process through using cheaper carbohydrate sources and isolation of appropriate microorganism. Despite progress towards its microbial production, fewer studies are available regarding its bacterial production at high temperature. It is believed that, withstanding high temperature during production of this acid can provide a new option for industrially cost effective production through reduction in cost of cooling. Results: A major challenge associated with semi-continuous process of gluconate production using A. senegalensis was inability in glucose consumption during the late stationary phase and next fermentation cycles. Inactivation of respiration system (total dehydrogenases activity) and entrance of cells into viable but nonculturable (VBNC) state during stationary phase were the main reasons of this inability. Conclusions: To improve gluconic acid fermentation at high temperature, it is necessary to induce the activity of total dehydrogenases as they carry the oxidation reaction of glucose. Supplementing the feed with ethanol, successfully conferred ability to cells for further glucose consumption. [less ▲]

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See detailEndokarsts and cryptokarsts in Cretaceous coarse and higly porous chalk at the Belgian-Dutch border
Willems, Luc ULg; Rodet, Joël

in Filippi, Michal; Bosák, Pavel (Eds.) Proceedings of the 16th International Congress of Speleology, July 21–28, Brno. Volume 3, p. 499. Czech Speleological Society. Praha. (2013, July 21)

Since 2003, the study of several quarries at the Belgian-Dutch border has made it possible to identify numerous karsts essentially developed in coarse chalk (calcarenites) of the Maastricht Formation ... [more ▼]

Since 2003, the study of several quarries at the Belgian-Dutch border has made it possible to identify numerous karsts essentially developed in coarse chalk (calcarenites) of the Maastricht Formation (Upper Cretaceous). This lithology is highly porous and is often considered unfavorable to karstification. However, caves, solution pipes, sponge networks, roof channel, pockets (alveoli) several meters in diameter developed inside without connection to fractures. These karsts belong to flooded karsts (caves and pockets) or to younger cryptokarsts (input karst type – thousands of solution pipes). When the endokarsts dewater, the high porosity of calcarenites inhibits closed caves from evolving. Tubular solution pipes are produced by the seepage water under fluvial terrace gravels and can exceed 30 m deep under the surface plateau. Sometimes, they encounter caves which are consequently filled and fossilized. By this process, they preserve caves from further collapsing inside a crumbly lithology. [less ▲]

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See detailIntervention ergonomique à visée cognitive pour le maintien au travail de patients atteints de sclérose en plaques : construction d’une méthodologie et validation d’un questionnaire
Blavier, Adelaïde ULg; Monisse, Aurélié; DELRUE, Gaël ULg et al

in Van de Leemput, Cécile (Ed.) Activités humaines, Technologies et Bien-être (2013, July 11)

The purpose of this paper is to present the construction of a questionnaire in order to evaluate the specific work difficulties and compensation mechanisms developed by multiple sclerosis patients (MS ... [more ▼]

The purpose of this paper is to present the construction of a questionnaire in order to evaluate the specific work difficulties and compensation mechanisms developed by multiple sclerosis patients (MS). At the moment, it does not exist any questionnaire that links the patients cognitive deficits with their professional situation. This lack of accurate assessment is detrimental to the patients job retention. Our questionnaire was constructed from review of literature and interviews of patients and experts. Three groups of patients answered the questionnaire: MS patients, diabetics patients and a control group. We controlled the effect of anxiety and depression and we conducted a factorial analysis that showed the existence of 3 factors: the ergonomics factor (that includes cognitive difficulties and resources and adaptation process), the description of work situation and the social support. The three groups of participants obtained similar results for the work description and the social support while the group of patients with MS obtained a higher score than the other 2 groups for the ergonomics factor. These results suggest that our questionnaire is specific to the MS patients population and to their difficulties they met in their work situations. These results offered also some ways to increase job retention in MS patients population. [less ▲]

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See detailVerification of a novel material model to predict damage in composite structures
Chiu, Louis N.S.; Falzon, Brian G.; Boman, Romain ULg et al

in International Conference on Structural Integrity and Fracture (2013, July 11)

An intralaminar damage model (IDM), based on continuum damage mechanics, was developed for the simulation of composite structures subjected to damaging loads. This model can capture the complex ... [more ▼]

An intralaminar damage model (IDM), based on continuum damage mechanics, was developed for the simulation of composite structures subjected to damaging loads. This model can capture the complex intralaminar damage mechanisms, accounting for mode interactions, and delaminations. Its development is driven by a requirement for reliable crush simulations to design composite structures with a high specific energy absorption. This IDM was implemented as a user subroutine within the commercial finite element package, Abaqus/Explicit[1]. In this paper, the validation of the IDM is presented using two test cases. Firstly, the IDM is benchmarked against published data for a blunt notched specimen under uniaxial tensile loading, comparing the failure strength as well as showing the damage. Secondly, the crush response of a set of tulip-triggered composite cylinders was obtained experimentally. The crush loading and the associated energy of the specimen is compared with the FE model prediction. These test cases show that the developed IDM is able to capture the structural response with satisfactory accuracy. [less ▲]

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See detailDry galloping on bridge cables: roughness and shape effects on an inclined circular cylinder
Benidir, Adel; Flamand, Olivier; Gaillet, Laurent et al

in Proceedings of the European-African Conference on Wind Engineering 2013 (2013, July 09)

Dry galloping of stays in cable-stayed bridges is a phenomenon that is still of interest to the scientific community. Over the course of the current three-year research project numerous experiments will ... [more ▼]

Dry galloping of stays in cable-stayed bridges is a phenomenon that is still of interest to the scientific community. Over the course of the current three-year research project numerous experiments will be carried out to investigate the effect of turbulence and inclination angle on dry galloping. The novel aspect of this study consists of an in-depth investigation into the effect of non uniformity of the pipe surrounding the stay cables on the dry galloping excitation mechanism. Previous studies reported that dry galloping is caused by the appearance of a negative pressure bubble on one side of the circular cylinder at the critical Reynolds number range, leading to a rapid drop in the drag coefficient and the appearance of a non negligible lift force. This paper presents results from initial experiments in the wind tunnel at CSTB – Nantes, France. [less ▲]

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See detailUncoupled spectral analysis with non-proportional damping
Canor, Thomas ULg; Blaise, Nicolas ULg; Denoël, Vincent ULg

in Proceedings of the European-African Conference on Wind Engineering (2013, July 07)

The use of normal modes of vibration in the analysis of structures with non-proportional damping reduces the number of governing equations, but does not decouple them. A common practice consists in ... [more ▼]

The use of normal modes of vibration in the analysis of structures with non-proportional damping reduces the number of governing equations, but does not decouple them. A common practice consists in decoupling the equations by disregarding the off-diagonal elements of the modal damping matrix. This paper proposes a method based on the asymptotic expansion of the modal transfer matrix to take into account the modal coupling in Gaussian spectral analysis. First, the mathematical background is introduced, then the relevance of the method is illustrated within the context of the analysis of a large and real structure submitted to wind loadings. [less ▲]

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See detailPrincipal static wind loads
Blaise, Nicolas ULg; Denoël, Vincent ULg

in 6th Proceedings of European-African Conference on Wind Engineering (2013, July 07)

The concept of static wind load is widely used in practice for structural wind design. In this context, this paper assesses the envelope reconstruction problem stated as follows: find the best set of ... [more ▼]

The concept of static wind load is widely used in practice for structural wind design. In this context, this paper assesses the envelope reconstruction problem stated as follows: find the best set of static loadings that is optimum to reproduce by static analyses, the envelope values of structural responses resulting from a formal buffeting dynamic analysis. A solution was recently derived by means of Principal Static Wind Loads which are well-suited for this problem. The concept is illustrated with a large stadium roof and the accuracy of the envelope reconstruction is analysed. [less ▲]

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See detail3D Modeling of Thin Resistive Sheets in the Discontinuous Galerkin Method for Transient Scattering Analysis
Boubekeur, Mohamed; Kameni, Abelin; Bernard, Laurent et al

in Proceedings of the 19th Conference on the Computation of Electromagnetic Fields (COMPUMAG 2013) (2013, July 03)

This papers presents a modeling of thin resistive sheets. An interface condition is used to avoid the fine mesh. The electromagnetic fields are computed with a time domain Discontinuous Galerkin method in ... [more ▼]

This papers presents a modeling of thin resistive sheets. An interface condition is used to avoid the fine mesh. The electromagnetic fields are computed with a time domain Discontinuous Galerkin method in order to evaluate the shielding effectiveness. A 3D cavity is treated to illustrate the efficiency of the condition. [less ▲]

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See detailUnraveling the mystery of exozodiacal dust
Ertel, Steve; Augereau, Jean-Charles; Thebault, Philippe et al

in Protostars and Planets VI (2013, July 01)

Exozodiacal dust clouds are thought to be the extrasolar analogs of the Solar System's zodiacal dust. Studying these systems provides insights in the architecture of the innermost regions of planetary ... [more ▼]

Exozodiacal dust clouds are thought to be the extrasolar analogs of the Solar System's zodiacal dust. Studying these systems provides insights in the architecture of the innermost regions of planetary systems, including the habitable zone. Furthermore, the mere presence of the dust may result in major obstacles for direct imaging of earth-like planets. Our EXOZODI project aims to detect and study exozodiacal dust and to explain its origin. We are carrying out the first large, near-infrared interferometric survey in the northern (CHARA/FLUOR) and southern (VLTI/PIONIER) hemisphere. Preliminary results suggest a detection rate of up to 30% around A to K type stars and interesting trends with spectral type and age. In addition to the statistical analysis of our survey results, detailed modeling studies of single systems, modeling of possible dust creation mechanisms and the development of next-generation modeling tools dedicated to address the mystery of exozodiacal dust are main tasks of our project. [less ▲]

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See detailDirect determination of physical parameters for main sequence stars
Rabus, Markus; Lachaume, Regis; Brahm, Rafael et al

in Protostars and Planets VI (2013, July 01)

The environment of planetary formation and evolution is mainly characterized by its host star's physical properties. Until recently most fundamental stellar parameters, like e. g. the star's radius and ... [more ▼]

The environment of planetary formation and evolution is mainly characterized by its host star's physical properties. Until recently most fundamental stellar parameters, like e. g. the star's radius and effective temperature, have only been estimated indirectly; but with advances in interferometric observing technique it is now possible to obtain a direct estimate of them. In this poster we present preliminary results from measured interferometric fringe visibilities of main-sequence stars. These visibilities were collected using the four-beam combiner VLTI/PIONIER instrument and the 1.8m Auxiliary Telescopes (ATs) in A1-G1-K0-J3 quadruplet configuration. We bracketed each science target with different calibrators to ensure reducing the systematic errors in our data. For each target star, the data reduction was performed several hundred times, each time randomizing the set of fringes by the bootstrap method and the calibrators' diameters. This allowed us to take into account error correlations across spectral channels, between consecutive observations, and overnight. Each result was least-squares fitted by a uniform disc, yielding a value for the target's diameter. From the distribution of diameters we assessed the statistical error in the respective measurement. Using the HIPPARCOS parallax we estimated the distance and obtained the star's linear radius. Combined with the bolometric flux we obtained a direct quantification of the effective temperature from the Stefan-Boltzmann equation. Finally, these direct determinations of stellar radii and effective temperatures enable us to better characterize planets around main-sequence stars. [less ▲]

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See detailThe VLTI/PIONIER survey of southern TTauri disks.
Anthonioz, Fabien; Ménard, Francois; Pinte, Christophe et al

in Protostars and Planets VI (2013, July 01)

Studying the inner regions of protoplanetary disks (1-10 AU) is of importance to understand the formation of planets and the accretion process feeding the forming central star. Herbig AeBe stars are ... [more ▼]

Studying the inner regions of protoplanetary disks (1-10 AU) is of importance to understand the formation of planets and the accretion process feeding the forming central star. Herbig AeBe stars are bright enough to be routinely observed by Near IR interferometers. The data for the fainter T Tauri stars is much more sparse. In this contribution we present the results of our ongoing survey at the VLTI. We used the PIONIER combiner that allows the simultaneous use of 4 telescopes, yielding 6 baselines and 3 independent closure phases at once. PIONIER's integrated optics technology makes it a sensitive instrument. We have observed 22 T Tauri stars so far, the largest survey for T Tauri stars to this date. Our results demonstrate the very significant contribution of an extended component to the interferometric signal. The extended component is different from source to source and the data, with several baselines, offer a way to improve our knowledge of the disk geometry and/or composition.These results validate an earlier study by Pinte et al. 2008 and show that the dust inner radii of T Tauri disks now appear to be in better agreement with the expected position of the dust sublimation radius, contrary to previous claims. [less ▲]

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See detailYield variability linked to climate uncertainty and nitrogen fertilisation
Dumont, Benjamin ULg; Basso, Bruno; Leemans, Vincent ULg et al

in Stafford, John V. (Ed.) Precision agriculture '13 (2013, July)

At the parcel scale, crop models such as STICS are powerful tools to study the effects of variable inputs such as management practices (e.g. nitrogen (N) fertilisation). In combination with a weather ... [more ▼]

At the parcel scale, crop models such as STICS are powerful tools to study the effects of variable inputs such as management practices (e.g. nitrogen (N) fertilisation). In combination with a weather generator, we built up a general methodology that allows studying the yield variability linked to climate uncertainty, in order to assess the best N practice. Our study highlighted that, applying the Belgian farmer current N practice (60 60 60 kgN.ha-1), the yield distribution was found to be very asymmetric with a skewness of -1.02 and a difference of 5% between the mean (10.5 t.ha-1) and the median (11.05 t.ha-1) of the distribution. Which implied that, under such practice, the probability for farmers to achieve decent yields, in comparison of the mean of the distribution, was the highest. [less ▲]

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See detailIdentification of mechanical systems with local nonlinearities through discrete-time Volterra series and Kautz functions
Shiki, Sidney Bruce; Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg et al

in Proceedings of the 11th International Conference on Recent Advances in Structural Dynamics (2013, July)

Mathematical modeling of mechanical structures is an important research area in structural dynamics. One of the goals of this area is to obtain a model that accurately predicts the dynamics of the system ... [more ▼]

Mathematical modeling of mechanical structures is an important research area in structural dynamics. One of the goals of this area is to obtain a model that accurately predicts the dynamics of the system. However, the nonlinear eff ects caused by large displacements and boundary conditions like gap, backlash or joint are not as well understood as the linear counterpart. This paper identifies a non-parametric discrete-time Volterra model of a benchmark nonlinear structure consisting of a cantilever beam connected to a thin beam at its free end. Time-domain data experimentally measured are used to identify the Volterra kernels, which are expanded with orthogonal Kautz functions to facilitate the identification process. The nonlinear parameters are then estimated through a model updating process involving optimization of the residue between the numerical and experimental kernels. The advantages and drawbacks of the Volterra series for modeling the behavior of nonlinear structures are finally indicated with suggestions to overcome the disadvantages found during the tests. [less ▲]

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See detailMultiple Viewpoints on Landscape Quality Assessment: some evidence from a survey in Wallonia and Romania
Schmitz, Serge ULg; Vanderheyden, Vincent ULg; Teleuca, Alexandra et al

in Morimoto, Takehiro; Ichikawa, Yasuo; Kim, Doo-Chul (Eds.) Globalization and New Challenges of Agricultural and Rural Systems (2013, July)

Actually assessing landscapes out of a specific framework is not an easy task due to the multiple functions that landscapes perform.The paper presents the result of a survey among landscape experts in ... [more ▼]

Actually assessing landscapes out of a specific framework is not an easy task due to the multiple functions that landscapes perform.The paper presents the result of a survey among landscape experts in Romania and Wallonia. Expert had to specify their level of agreement on 52 Likert items regarding landscape quality indicators [less ▲]

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See detailPoroelastic Center of Dilation Revisited
Huynen, Alexandre ULg; Detournay, Emmanuel

in Hellmich, Christian; Pichler, Bernhard; Dietmar, Adam (Eds.) Poromechanics V: Proceedings of the Fifth Biot Conference on Poromechanics (2013, July)

A comparison of the original elastic solution for the center of dilation with the classic Lame ́ solution reveals an unexpected dependence of the center of dilation solu- tion on Poisson’s ratio. This ... [more ▼]

A comparison of the original elastic solution for the center of dilation with the classic Lame ́ solution reveals an unexpected dependence of the center of dilation solu- tion on Poisson’s ratio. This inconsistency is investigated by means of two alternative representations of the singularity which lead to the identification of a compressed zone inside the singularity. The poroelastic equivalent to this nucleus of strain is shown to be the superposition of the elastic one with drained material parameters and an instan- taneous point fluid source associated with a finite volume of fluid that is expelled from the compressed region inside the singularity and is injected in the porous medium. [less ▲]

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See detailA multirate approach to combine electromagnetic transients and fundamental-frequency simulations
Plumier, Frédéric ULg; Geuzaine, Christophe ULg; Van Cutsem, Thierry ULg

in Proc. 10th International Conference on Power System Transients (2013, July)

Abstract--- A new multi-rate technique is proposed to combine fundamental-frequency simulation (typical of stability studies) with electromagnetic transients simulation. The objective of this hybrid ... [more ▼]

Abstract--- A new multi-rate technique is proposed to combine fundamental-frequency simulation (typical of stability studies) with electromagnetic transients simulation. The objective of this hybrid approach is to obtain more accurate simulations than with the fundamental-frequency approximation, while saving computing time by applying the detailed model to a subsystem only, in some neighbourhood of the disturbance. It also allows to remove some limitations of fundamental-frequency simulation, such as the difficulty of simulating unbalanced faults. A relaxation technique is used to iterate between both models with simple interfacing. Preliminary results obtained with a 74-bus test system are presented, together with a comparison with full electromagnetic transients simulation. [less ▲]

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See detailInfluence des communications sur la construction du common ground. Proposition d'une méthodologie d'analyse de la dynamique temporelle des échanges multimodaux.
Defays, Aurore ULg; Leclercq, Pierre ULg; Nyssen, Anne-Sophie ULg

in van de Leemput, Cécile; Chauvin, Christine; Hellemans, Catherine (Eds.) Activités humaines, Technologies et Bien-être (EPIQUE 2013) (2013, July)

L’objectif de cette étude est de présenter une méthodologie d’analyse des communications multimodales dans les situations de conception collective. Cette méthodologie permet de décrire quelles sont les ... [more ▼]

L’objectif de cette étude est de présenter une méthodologie d’analyse des communications multimodales dans les situations de conception collective. Cette méthodologie permet de décrire quelles sont les modalités de communication qui supportent particulièrement l’élaboration du common ground, zone de partage indispensable pour l’efficacité de la communication, et donc pour la performance collaborative. La méthode présentée vise également à pouvoir identifier les articulations pertinentes entre modalités de communication, dans le sens où elles favorisent l’élaboration de ce processus. Dans une première phase de notre recherche, nous avons observé et analysé les échanges multimodaux tels qu’ils prennent place en situation « naturelle » (ou non-médiatisée) dans le but de prétester notre méthode, mais également de pouvoir comparer cette situation avec les situations de collaboration distantes et outillées par des nouvelles technologies que nous envisagerons par la suite. [less ▲]

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See detailContributions to the process modelling of resin infusion under flexible tooling (RIFT) manufacturing for composite aerostructures
Pierce, R.S.; Falzon, B.G.; Thompson, M.C. et al

in Proceedings of ICCM19 (2013, July)

The cost of manufacturing textile-reinforced composite aerostructures using Resin Infusion under Flexible Tooling (RIFT) can be reduced by computational modelling. This paper outlines the current progress ... [more ▼]

The cost of manufacturing textile-reinforced composite aerostructures using Resin Infusion under Flexible Tooling (RIFT) can be reduced by computational modelling. This paper outlines the current progress and contributions made towards this goal. A continuum-based material model was incorporated into a finite element package to simulate the draping of a dry carbon fibre fabric. It accurately tracks the changes in the warp and weft fibre orientations and has been experimentally validated. Material characterisation was performed to determine the tensile and shear properties of a plain weave fabric reinforcement material. In support of bias extension shear testing, an accessible Digital Image Correlation (DIC) approach was developed for accurate optical strain measurement. A relationship between permeability and shear angle was also experimentally determined using a novel permeability measurement technique. Future work is planned to combine all these aspects in an infusion model and demonstrate the complete process model. [less ▲]

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See detailNonlinear Computational Homogenization Method for the Evaluation of Eddy Currents in Soft Magnetic Composites
Niyonzima, Innocent ULg; Sabariego, Ruth Vazquez; Dular, Patrick ULg et al

in Proceedings of the 19th Conference on the Computation of Electromagnetic Fields (COMPUMAG2013) (2013, July)

In this paper, a heterogeneous multiscale method (HMM) technique is applied to model the behaviour of electromagnetic fields in soft magnetic composites (SMC). Two problems are derived from the two-scale ... [more ▼]

In this paper, a heterogeneous multiscale method (HMM) technique is applied to model the behaviour of electromagnetic fields in soft magnetic composites (SMC). Two problems are derived from the two-scale homogenization theory: a macroscale problem that captures the slow variations of the overall solution, and many mesoscale problems that allow determining the constitutive laws at the macroscale. As application, an SMC core is considered. [less ▲]

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See detailPrediction of non-linear time-variant dynamic crop model using bayesian methods
Mansouri, Majdi ULg; Dumont, Benjamin ULg; Destain, Marie-France ULg

in John Stafford (Ed.) Precision agriculture '13 (2013, July)

This work addresses the problem of predicting a non-linear time-variant leaf area index and soil moisture model (LSM) using state estimation. These techniques include the extended Kalman filter (EKF ... [more ▼]

This work addresses the problem of predicting a non-linear time-variant leaf area index and soil moisture model (LSM) using state estimation. These techniques include the extended Kalman filter (EKF), particle filter (PF) and the more recently developed technique, variational filter (VF). In the comparative study, the state variables (the leaf-area index LAI, the volumetric water content of the layer 1, HUR1 and the volumetric water content of the layer 2, HUR2) are estimated from noisy measurements of these variables, and the various estimation techniques are compared by computing the estimation root mean square error with respect to the noise-free data. The results show that VF provides a significant improvement over EKF and PF. [less ▲]

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See detailNumerical and Experimental Investigation of Slot-Blowing Air Over a Cylinder
Runge, William; Buysschaert, Frank; Hayez, Jules et al

in Proceedings of the 5th European Conference for Aeronautics and Space Sciences (2013, July)

Tangential slot blowing around a cylinder in the Coanda effect has been proposed as a mechanism for yaw control in a novel coaxial helicopter. The proposed design has been investigated computationally ... [more ▼]

Tangential slot blowing around a cylinder in the Coanda effect has been proposed as a mechanism for yaw control in a novel coaxial helicopter. The proposed design has been investigated computationally, using the unsteady k-ω SST solver in NUMECA, as well as experimentally in the wind tunnel at the Université de Liège. While the concept in general is promising, it has been shown that there are some potential problems, including pitch-yaw coupling and some unsteady flow conditions. These problems exist under varied circumstances, and, exist at least in part due to the complicated flow-field in this problem, even in 2-dimensions. [less ▲]

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See detailEquivalent static wind loads for structures with non-proportional damping
Blaise, Nicolas ULg; Canor, Thomas ULg; Denoël, Vincent ULg

in Proceedings of the 11th International Conference on Recent Advances in Structural dynamics (2013, July)

In current practice, wind structural design is often carried out using the concept of equivalent static wind loads. The main characteristic of such loadings is to reproduce, with static analyses, the same ... [more ▼]

In current practice, wind structural design is often carried out using the concept of equivalent static wind loads. The main characteristic of such loadings is to reproduce, with static analyses, the same extreme structural responses as those resulting from a formal buffeting analysis. This paper proposes a method for the computation of equivalent static wind loads for structures with slight non-proportional damping in a modal framework. Because of the smallness of the out-of diagonal terms, this method is based on recent developments related to asymptotic expansion of the modal transfer matrix of such structures. As a main benefit, the static loading is described as a perturbation of the equivalent loading that would be obtained for the uncoupled system. The main contribution of this paper is to formalize the expression of the correction terms resulting from the non-proportionality of damping. The method is presented with a detailed illustrative example. [less ▲]

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See detailUsing Proper Orthogonal Decomposition and Dynamic Mode Decomposition Methods for Comparing CFD Results Experimental Measurements
Guissart, Amandine ULg; Andrianne, Thomas ULg; Dimitriadis, Grigorios ULg et al

in Proceedings of the 16th International Forum on Aeroelasticity and Structural Dynamics, IFASD 2013 (2013, June 26)

A method for the quantitative comparison of numerical and/or experimental data of unsteady aerodynamics around static and oscillating bodies is introduced. It is based on Proper Orthogonal Decomposition ... [more ▼]

A method for the quantitative comparison of numerical and/or experimental data of unsteady aerodynamics around static and oscillating bodies is introduced. It is based on Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) to extract the dominant structures of the unsteady flow. The proposed method is applied to spatio-temporal data for the flow around a 4:1 rectangular cylinder. Exper- imental data are obtained from wind tunnel testing and two dimensional Time-resolved Particle Image Velocimetry (Tr-PIV) measurements, while unsteady Reynolds Averaged Navier-Stokes (uRANS) are used to compute numerical results. It is demonstrated that the two approaches are complementary and represent a powerful tool that enables the analysis and the quantitative comparison of the main spatial (POD) and temporal (DMD) characteristics of unsteady aerodynamic data. [less ▲]

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See detailAeroelastic response of a 2-DOF wing with structural and aerodynamic nonlinearity
Norizham, Abdul Razak ULg; Dimitriadis, Grigorios ULg

in Proceedings of the International Forum on Aeroelasticity and Structural Dynamics, IFASD 2013 (2013, June 25)

The aeroelastic behaviour of a wing oscillating in the heave and pitch degrees of freedom with continuos nonlinear stiffness is examined by means of wind tunnel experiments. The phenomena of interest are ... [more ▼]

The aeroelastic behaviour of a wing oscillating in the heave and pitch degrees of freedom with continuos nonlinear stiffness is examined by means of wind tunnel experiments. The phenomena of interest are classical flutter and limit cycle oscillation. The focus of the present work is the transformation of classical flutter into LCOs by varying the stiffness from linear to nonlinear stiffness. The interaction of flow separation-related nonlinearity with structural nonlinearities is also of interest. The measured aeroelastic responses are analyzed and the bifurcation behavior of the dynamic system is characterized. The analysis shows that the bifurcation behaviour is dictated neither by the structural nor from the aerodynamic nonlinearity but by a combination of the two. [less ▲]

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See detailSimulation of bird wing flapping using the unsteady vortex lattice method
Gardiner, James; Norizham, Abdul Razak ULg; Dimitriadis, Grigorios ULg et al

in Proceedings of the International Forum on Aeroelasticity and Structural Dynamics, IFASD 2013 (2013, June 24)

The flight of barnacle geese at airspeeds representing high-speed migrating flight is investigated using experiments and simulations. The experimental part of the work involved the filming of three ... [more ▼]

The flight of barnacle geese at airspeeds representing high-speed migrating flight is investigated using experiments and simulations. The experimental part of the work involved the filming of three barnacle geese flying at different airspeeds in a wind tunnel. The video footage was analysed in order to extract the wing kinematics. Additional information, such as wing geometry and camber was obtained from a 3D scan of a dried wing. An unsteady vortex lattice method was used to simulate the aerodynamics of the measured flapping motion. It was found that the simulation correctly predicted the shape of the wake and the fact that the wing is aerodynamically inactive during the upstroke. The predicted aerodynamic lift and thrust forces were very sensitive to the wing's camber. Future work will attempt to identify the sensitivity to all the wing shape and kinematic parameters. Additional phenomena will also be modelled, including passive twisting of the wingtip, body lift and leading edge suction. [less ▲]

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See detailIs the wheat distillers grains soluble ProtiWanze a valuable alternative to soybean and canola meals in beef cattle diet?
Lessire, Françoise ULg; Rollin, Frédéric ULg

in ICPD (Ed.) Book of Abstracts (2013, June 24)

The objective of this study was to evaluate whether introducing the condensed wheat distillers soluble ProtiWanze® (PW) in diets of beef cattle has an impact on feeding costs, health and production of the ... [more ▼]

The objective of this study was to evaluate whether introducing the condensed wheat distillers soluble ProtiWanze® (PW) in diets of beef cattle has an impact on feeding costs, health and production of the animals. PW by-product from a Belgian bio-ethanol plant which utilized only wheat without bran, is an acid (pH=4) liquid feed rich in energy (VEM= 1130) and protein (TP= 282 mg/kg DM). PW supplementation from 9 to 13% on DM basis has been tested in 4 suckler cows’ farms for 4 months in 2011 and 2012. In 2011, 2 BB (H1 and H3) and 1 Blonde d’Aquitaine (H2: 23 cows) herds were evaluated and in 2012, the Blonde d’Aquitaine herd was replaced by a third BBB herd (H4: 42 cows). Every month, animals’ health and production were checked by the mean of Body Condition Score, Ruminal Fill, Fecal Consistency, Undigested Fraction and Locomotion Scores determination, as described by Zaaier et al.(2001) and Sprecher et al.(1997). Ruminal fluid was sampled by a stomach tube (Ruminator®) on 5 cows for pH, redox potential (Methylene blue test) and protozoa assessment (optical microscopy). Reproduction performances of this 2 year’s-period were analyzed. Price of a diet containing the same amount of proteins brought by a mixture of 1/3 soybean and 2/3 canola meal was calculated to verify whether introducing PW reduced feeding costs. Whatever the concentration of PW used, no adverse effect has been observed concerning reproduction, production performance, ruminal pH. Feeding costs were reduced by 0.08 €/cow/day in 2011 and by 0.02 €/cow/day in 2012. This lower spared amount in 2012 is the consequence of the reduction in PW protein concentration while its price increased. Anyway, comparison has to take into account the energy brought by this CDS as it has been suggested by Petersen’s equation, which compares CDS price with soybean meal but also with maize price. Further argument to be considered, especially in BB, is the high PW palatability, its low ruminal filling value and better roughage digestion. [less ▲]

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See detailHemoreactivity of polymeric carriers designed for drug delivery systems
Grandfils, Christian ULg; Sevrin, Chantal ULg

in Proceeding Biomedica 2013 (2013, June 19)

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See detailIMPLEMENTATION OF A WEAK COUPLING APPROACH BETWEEN A CFD AND AN FE SOFTWARE FOR FIRES IN COMPARTMENT
Tondini, Nicola; Franssen, Jean-Marc ULg

in Idelsohn, S; Papadrakakis, M; Schrefler, B (Eds.) V International Conference on Computational Methods for Coupled Problems in Science and Engineering (2013, June 17)

The paper presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a ... [more ▼]

The paper presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a Finite Element (FE) software applied to structural systems subjected to fire. In particular, a weak coupling approach used to simulate a fire exposed structure by modelling the fire development in the compartment, the heat penetration in the structure and the mechanical response is described. The advantages and the disadvantages of such a technique are highlighted compared to a full coupling that conversely takes into account all mutual interactions. The favourable aspect of computing the thermal response of the structure in the FE model in order to avoid modelling the structure in the CFD model is underlined, namely a sensitive reduction of computational demand. Finally, the study is enriched by an application of this methodology that concerns the simulation of a pool fire in an open compartment the results of which are compared with those obtained by employing the simplified Hasemi model included in the Eurocodes. [less ▲]

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See detailChemically resistant encapsulant to enable a novel MEMS fabrication process
Stoukatch, Serguei ULg; Walewyns, Thomas; Tooten, Ester et al

in Conf. Proceedings (2013, June 13)

We have proposed and demonstrated a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”, whereas a ... [more ▼]

We have proposed and demonstrated a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”, whereas a standard process starts form MEMS release and ends up with packaging. The process is explored on a 3D capacitive MEMS sensor (3 x 3 mm²). Unreleased wafer is singulated by sawing on individual dies, then the individual sensor is mounted to the package, wire bonded and encapsulated. Because the sensors are still unreleased there is no damage occurred during the assembly. However the choice for the encapsulant material is not evident. The encapsulant must survive the chemical attack during the MEMS release process (mixture of 73%HF and IPA (isopropanol)), followed by a triple rinse in IPA. We pre-selected 6 different encapsulants: a silicone-, an epoxy- and an urethane-based. At least one encapsulant passed the acceptance criteria: there is no delamination, there is no texture change and the encapsulant maintains a sufficient mechanical adhesion. Additionally to that we measured micro-hardness of the encapsulant before and after the HF release test. We also performed an electrical characterization of the flow meter sensor before and after the HF release and we detected no changes in the sensor’s performance caused by HF exposure. We have proposed and demonstrated a novel sequence for MEMS fabrication. We packaged the sensor first, and performed the release after that. The key enabler for the novel process is the encapsulant which can withstand exposure to the release solution (73%HF:IPA). [less ▲]

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See detailDYNAMIC LINE RATING AND AMPACITY FORECASTING AS THE KEYS TO OPTIMISE POWER LINE ASSETS WITH THE INTEGRATION OF RES. THE EUROPEAN PROJECT TWENTIES DEMONSTRATION INSIDE CENTRAL WESTERN EUROPE
Nguyen, Huu-Minh ULg; Schell, Peter; Lilien, Jean-Louis ULg

in Proceedings of Congrès International des Réseaux Electriques de Distribution (2013, June 12)

The general increase of Distributed & intermittent renewable Generation is pushing TSOs and DSOs to find innovative solutions to increase the capacity of their networks. Dynamic Line Rating (DLR) has ... [more ▼]

The general increase of Distributed & intermittent renewable Generation is pushing TSOs and DSOs to find innovative solutions to increase the capacity of their networks. Dynamic Line Rating (DLR) has proven to be a very promising solution to cope with this issue. However, few experiments so far have addressed ampacity forecasting, which is critical to allow the integration of DLR in the electricity market processes. To tackle this gap, we developed an algorithm based on real-time DLR measurements and weather forecasts, which provides ampacity forecasts up to two days ahead. This paper describes the results of the EU-funded TWENTIES Demo led in Belgium on two 150kV lines. Currently, the DLR system used provides a two-day ahead ampacity forecast with more than 10% average gain over static rating (dynamic gain forecast varying roughly between 0% and 30%) with 98% confidence. Operational gains allowed by this increase of flexibility are still being assessed. [less ▲]

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See detailGradient urbain-rural de la ville de Lubumbashi: dynamique entre 2002 et 2009
Andre, Marie ULg; Bogaert, Jan ULg; Mahy, Grégory ULg et al

in Ernoult, Aude (Ed.) Dynamiques écologiques des paysages: de l'agricole à l'urbain (2013, June 12)

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See detailExperimental analysis of the stability of coarse sediments
Duma, Diana ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Symposium on Two-phase Modelling for Sediment Dynamics in Geophysical Flows (2013, June 12)

To predict the inception of sediment motion, Shields diagram remains the most widely used criterion in engineering practice so far. However, this approach faces several limitations and a number of gaps in ... [more ▼]

To predict the inception of sediment motion, Shields diagram remains the most widely used criterion in engineering practice so far. However, this approach faces several limitations and a number of gaps in knowledge still remain. The present research aims to provide new knowledge about the inception of motion in rivers with coarse sediments. A series of experiments was conducted in a flume horizontal 6 m long and 15 cm wide. The bottom was paved, either entirely or partly, with gravels of approximately 12 mm in diameter. Ultrasonic sensors were used to measure the water depth, a flowmeter for the discharge, an ultrasonic velocity profiler (UVP) transducer for the flow velocity. Three different thresholds were defined to distinguish between the following states: no motion, vibration of stones, local motion, and large scale motion. The overwhelming influence of turbulence was emphasized by the conducted tests. This paper details the results of these experiments and demonstrates the need for further research in order to better quantify these effects. [less ▲]

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See detailA Simplified Procedure to Assess the Strength of a Ship Impacting a Lock Miter Gate
Buldgen, Loïc ULg; Le Sourne, Hervé; Rigo, Philippe ULg

in Proceedings of the ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering (2013, June 09)

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See detailPrédiction des performances sportives et détection précoce des myopathies par respirométrie à haute résolution
Votion, Dominique ULg; Serteyn, Didier ULg

in cheval athlète, stress oxydant & inflammation (2013, June 07)

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See detailA PML for convex truncated domains in time-dependent acoustics with a DG-FE discretization
Modave, Axel ULg; Lambrechts, Jonathan; Delhez, Eric ULg et al

in Proceedings of the 11th International Conference on Mathematical and Numerical Aspects of Waves (WAVES 2013) (2013, June 03)

A new perfectly matched layer (PML) is proposed for convex truncated domains in the context of time-dependent acoustics. With this formulation, the size of the computational domain can be reduced when ... [more ▼]

A new perfectly matched layer (PML) is proposed for convex truncated domains in the context of time-dependent acoustics. With this formulation, the size of the computational domain can be reduced when classical shapes of truncated domains are less appropriate. A numerical discretization based on the discontinuous Galerkin method is then described and validated. An example of realistic three-dimensional application is finally proposed. [less ▲]

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See detailShip Manoeuvring Behaviour in Crossing Current Near-by a Lock
HASEGAWA, K; OH, K G; Ahmed, Y A et al

in VanTorre, Marc (Ed.) Third International Conference on Ship Manoeuvring in Shallow and Confined Water (2013, June 03)

Ship behaviour in current is one of the classical problems in ship manoeuvrability. However, it is not yet fully investigated. The study is motivated by an assessment study on the ship navigation near by ... [more ▼]

Ship behaviour in current is one of the classical problems in ship manoeuvrability. However, it is not yet fully investigated. The study is motivated by an assessment study on the ship navigation near by a river lock where relatively strong current exists. It is demonstrated how a ship behaves in the current and relatively large drift angle may happen, if the current is comparative to ship speed. In this situation, the hydrodynamic forces and moment acting on a ship is not any more at the range of lift force/moment, and therefore normal mathematical model cannot be applied. Similar situation may occur in case of rapid river stream condition, when a ship losts its power in current. At East Japan Great Earthquake happened in 2011, many ships without their power were drifting in tsunami. It is urgent matter to investigate on the ship behaviour in such situation. [less ▲]

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See detailOptimization of the operating conditions of an existing biomass CHP plant with respect to pollutants levels
Sartor, Kevin ULg; Restivo, Yannick ULg; Ngendakumana, Philippe ULg et al

in Proceedings of 21st Biomass Conference and Exhibition (2013, June 03)

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

While small and medium size biomass combined heat and power 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 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 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 detailAn Observational Study of Mixing in Fast-Rotating Massive Stars: Description of the Method and Very First Results
Morel, Thierry ULg; Palate, Matthieu ULg; Rauw, Grégor ULg

in Massive Stars: From alpha to Omega (2013, June 01)

Collecting He and CNO abundances for a large sample of fast-rotating massive stars is crucial for addressing the efficiency of rotational mixing in these objects. This is becoming a pressing issue ... [more ▼]

Collecting He and CNO abundances for a large sample of fast-rotating massive stars is crucial for addressing the efficiency of rotational mixing in these objects. This is becoming a pressing issue following the recent recognition based on observations by the VLT-FLAMES Survey of massive stars that fast rotators can show no signs of deep mixing contrary to the predictions of models. We have embarked in a project aiming at determining the abundances of the key elements indicators of mixing in a sample of bright, Galactic OB dwarfs. We present here the method and the very first results for two of the fastest OB stars known vsin i = 400 km/s : HD 93521 and zeta Oph. [less ▲]

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See detailThe Nebula around the Luminous Blue Variable WRAY 15-751 as seen by Herschel
Vamvatira-Nakou, Chloi ULg; Hutsemekers, Damien ULg; Royer, P. et al

in Massive Stars: From alpha to Omega (2013, June 01)

To understand the evolution of massive stars it is crucial to study the nebulae associated to Luminous Blue Variables which can reveal the star mass-loss history. We obtained far-infrared Herschel PACS ... [more ▼]

To understand the evolution of massive stars it is crucial to study the nebulae associated to Luminous Blue Variables which can reveal the star mass-loss history. We obtained far-infrared Herschel PACS imaging and spectroscopic observations of the nebula associated with the Luminous Blue Variable star WRAY 15-751. These images revealed a second nebula, bigger and cooler, lying in an empty cavity that probably delineates the remnant of the O-star bubble formed when the star was on the Main Sequence. The dust mass and temperature were derived from the modeling of the far-infrared SED. The analysis of the emission line spectrum revealed that the main nebula consists of a region of photoionised gas surrounded by a thin photodissociation region. Both regions are mixed with dust. The calculated C, N, O abundances, together with the estimated mass-loss rate, show that the nebula was ejected from the star during a Red Supergiant phase. This is compatible with the latest evolutionary tracks for a ~40 Mo star with little rotation. [less ▲]

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See detailSimultaneous X-ray and Optical Variability Study of the O-star Binary delta Orionis with Chandra and MOST
Nichols, Joy; Moffat, Anthony F. J.; Ignace, Richard et al

in Massive Stars: From alpha to Omega (2013, June 01)

We report preliminary results from variability analysis of delta Ori in Chandra high-resolution X-ray spectroscopy and concurrent MOST high-precision optical photometry. With nearly complete phase ... [more ▼]

We report preliminary results from variability analysis of delta Ori in Chandra high-resolution X-ray spectroscopy and concurrent MOST high-precision optical photometry. With nearly complete phase coverage of the 5-day eclipsing binary orbit, it is possible to measure directly radial velocity and flux variations as a function of phase, leading to a mapping of the stellar wind distribution for the massive primary star. The phase dependence of the X-ray overall intensity and the comparative behavior of the emission lines are also presented. [less ▲]

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See detailRecent results on the hierarchical triple system HD 150136
Gosset, Eric ULg; Berger, J. P.; Absil, Olivier ULg et al

in Bonanos, Alceste (Ed.) Massive Stars: From alpha to Omega (2013, June 01)

HD 150136 is a hierarchical triple system, non-thermal radio emitter, made of three O stars totalling some 130 solar masses. The 2.67-day inner orbit is rather well-known. Recent works derived a good ... [more ▼]

HD 150136 is a hierarchical triple system, non-thermal radio emitter, made of three O stars totalling some 130 solar masses. The 2.67-day inner orbit is rather well-known. Recent works derived a good approximation for the outer orbit with a period of 3000 days. We report here on interferometric observations that allow us to angularly resolve the outer orbit. First evidences for an astrometric displacement are given. The determination of the outer system orbit gives access to the inclinations of the systems and to the masses, including the one of the O3-O3.5 primary star. [less ▲]

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