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See detailInfluence of the relative alveoli widths on Piano Key Weirs efficiency for varied weir heights
Machiels, Olivier ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Proceedings of Int. Symp. on Dams for a changing world (2012)

In the scope of dam rehabilitation to manage floods increase or to increase water storage, the Piano Key Weir is a good solution for concrete dams. Indeed, its labyrinth shape allows discharge capacities ... [more ▼]

In the scope of dam rehabilitation to manage floods increase or to increase water storage, the Piano Key Weir is a good solution for concrete dams. Indeed, its labyrinth shape allows discharge capacities until 4 times more important than traditional ogee-crested weirs and 10 percent more important than labyrinth weirs of same horizontal geometry. Furthermore, the use of up- and downstream overhangs reduces drastically its footprint and enables its use directly on dams crest. The efficiency of Piano Key Weirs is now well demonstrated through various experimental studies. Even if parametrical studies are currently undertaken, the definition of the optimal shape to give to the structure is still missing due to the lack of knowledge in the influence of the large set of geometrical parameters. This paper presents the results of a combine experimental and numerical study about the influence of the relative alveoli widths on the Piano Key Weir discharge capacity. 14 models have been tested providing results for a large range of the inlet to outlet widths ratio and considering variation of the weir height in accordance with former studies. The results of the experiments enable to define optimal values for a common variation of these two parameters. [less ▲]

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See detailInfluence of the resonator damping on its coupling with a slot-tone
Glesser, Martin; Billon, Alexis ULg; Valeau, Vincent et al

Conference (2005, July)

In ventilation systems, disturbing whistlings can occur at outlets. This whistling phenomenon belongs to the self-sustained tones class which can be produced when a low velocity flow impinges on a ... [more ▼]

In ventilation systems, disturbing whistlings can occur at outlets. This whistling phenomenon belongs to the self-sustained tones class which can be produced when a low velocity flow impinges on a downstream obstacle. The coupling of the tones with acoustic resonances (so-called indirect feedback path) can promote high-level harmonic noises. This experimental study deals with the coupling of a jet-slot oscillator, modelling a ventilation outlet, with the flow supply duct resonances. The flow supply duct is damped by using various amounts of acoustic damping foam, and the effect of this damping on the sound production is studied. It is shown that for a jet exit/obstacle distance higher than 2.5 jet height (L/H>2.5), the tone’s frequency matches satisfactorily with frequencies predicted by a model describing favourable phase relationships for the occurrence of tones along the feedback loop. When the flow supply duct is resonant, it is noticeable that the tone’s frequency occurs at a duct resonance frequency which is close to the frequency described by this model. For lower values of L/H (slot closer to the jet exit), a better knowledge of the convection velocity behaviour along the vortices path could improve the tone’s frequency prediction. The use of damping foam within the flow supply duct prevents the occurrence of the tones’ coupling with a duct resonance, especially with high amounts of damping material, and dramatically reduces the emitted acoustic levels. For moderate amounts of damping material, the suppression of coupling occurs only for higher flow speeds, as the tone’s frequencies are higher and the damping material is then more efficient. [less ▲]

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See detailInfluence of the reuse of OSB and marine plywood formworks on concrete surface aesthetics
Courard, Luc ULg; Martin, Marie; Goffinet, Cécile et al

in Materials and Structures (2012), 45(9), 1331-1343

Concrete surface quality becomes more and more important because aesthetics requirements tend to spread over a wide variety of construction works. Even if it is difficult to clearly define what is ... [more ▼]

Concrete surface quality becomes more and more important because aesthetics requirements tend to spread over a wide variety of construction works. Even if it is difficult to clearly define what is beautiful or not, existing techniques maybe used to quantify aesthetic properties of concrete. As they mainly depend on formwork, the research project focuses on the reuse of two types of panels – plywood and OSB – and two types of release agents – vegetal and mineral oils. Evolution of surface properties is measured through lightness and absorption. For plywood formworks, beyond 80 reuses, a modification of surface quality is noticed; this is only 50 for OSB panels. For both types of formworks, the release oil doesn’t seem to have a major influence on formwork absorption. It is also observed that alkalis cause early degradation of the panels: release agents are not always efficient to avoid this phenomenon. Finally, if reuse doesn’t have any influence on the absorption of the plywood formworks, it is not the case for OSB formworks. [less ▲]

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See detailInfluence of the section and of the insulation type of the equivalent time
Cadorin, Jean-François; Pérez Jiménez, C.; Franssen, Jean-Marc ULg

in Bradley, D. (Ed.) Proceedings of the 4th International Seminar Fire and Explosion Hazards (2004)

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See detailInfluence of the section and of the insulation type on the equivalent time
Cadorin, Jean-François; Perez, Christian; Franssen, Jean-Marc ULg

in Proceedings of the 4th International Seminar on Fire and Explosion Hazards (2003, September)

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See detailInfluence of the shaping effect on hardness homogeneity by Vickers indentation analysis
Guillaume, Bernard ULg; Boschini, Frédéric ULg; Rulmont, André ULg et al

in Journal of the European Ceramic Society (2006), 26(15), 3191-3196

In this study, indentation technique (Vickers indentation) has been unconventionally used to evaluate the homogeneity of barium zirconate ceramic samples which have been shaped through different routes ... [more ▼]

In this study, indentation technique (Vickers indentation) has been unconventionally used to evaluate the homogeneity of barium zirconate ceramic samples which have been shaped through different routes. Statistical tools have been used to estimate the con-elation which can be established between heterogeneities within the samples and their shaping ways. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailInfluence of the shielding currents lengthscale and anisotropy effects on the magnetic flux profiles of high-temperature superconductors
Vanderbemden, Philippe ULg; Lovchinov, Vassil

in Journal of Physics: Conference Series (2012), 398

The so-called "magnetic flux profile" AC inductive technique is a powerful method for determining the critical current density Jc of bulk superconductors. In this work we aim at reporting analytical ... [more ▼]

The so-called "magnetic flux profile" AC inductive technique is a powerful method for determining the critical current density Jc of bulk superconductors. In this work we aim at reporting analytical expressions for magnetic flux profiles of superconducting rectangular samples exhibiting a critical current density anisotropy. The results are used for examining the error resulting from approximating a rectangular cross-section by an "infinite cylinder" or "infinite slab" geometry. It is found that such approximations can lead to an artificial curvature of the flux profiles and errors of 10%–20% in the determination of Jc. Next, the effects of how planar defects (cracks, platelet boundaries,...) affect the magnetic flux profile signal are discussed. It is found that the magnetic flux profiles are much sensitive to the lengthscale of shielding currents, thereby providing means of investigation of the typical size of induced current loops in bulk superconductors. Finally some illustrative flux profile data measured on a bulk, large grain melt-processed YBCO single domain exhibiting Jc anisotropy are presented and discussed in relation with theoretical predictions. [less ▲]

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See detailInfluence of the surface morphology of smooth platinum electrodes for the sodium borohydride oxidation reaction
Olu, Pierre-Yves; Gilles, Bruno; Job, Nathalie ULg et al

in Electrochemistry Communications (2014), 43

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See detailInfluence of the temperature on the tensile behaviour of a modified 9Cr–1Mo T91 martensitic steel
Keller, Clément ULg; Margulies, Monique; Hadjem-Hamouche, Zehoua et al

in Material Science and Engineering A (2010), 527

The tensile behaviour of a modified 9Cr–1Mo T91 martensitic steel is investigated for temperatures between 300 and 700 K. Loading/unloading tensile tests are carried out to investigate the evolution of ... [more ▼]

The tensile behaviour of a modified 9Cr–1Mo T91 martensitic steel is investigated for temperatures between 300 and 700 K. Loading/unloading tensile tests are carried out to investigate the evolution of the tensile flow parameters and the different flow stress components with temperature. An increase in temperature reduces the ductility and the ultimate tensile stress. Three different deformation mechanisms are operative depending on the temperature. These mechanisms are discussed in terms of activation volume, dislocation motion and dynamic strain ageing. [less ▲]

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See detailThe influence of the token frequency on the generalization of construction schemas in French-speaking children with SLI
Leroy, Sandrine ULg; Parisse, Christophe; Moulin, Mélissa et al

Poster (2012, June)

Constructivist approach (Goldberg, 1995 ; Tomasello, 2003) postulates that children build their linguistic system from their own linguistic experience. To be productive with their language, children have ... [more ▼]

Constructivist approach (Goldberg, 1995 ; Tomasello, 2003) postulates that children build their linguistic system from their own linguistic experience. To be productive with their language, children have to generalize construction schemas to never heard items. Because children with SLI seem to show limited morphosyntactic creativity and variability, we hypothesize that they would have difficulties to generalize their construction schemas what would hinder their access to the most abstract level of their linguistic competence. Given this lack of productivity of construction schemas in children with SLI, they would produce more lexicalized forms than abstract form what would lead to a limitation of the linguistic competence. The aim of our study was to test if children with SLI had more difficulties than children with typical language development (TLD) to generalize a schema to new items. Given the role of the token frequency in the abstraction of construction schemas (cf. Bybee, 1995), we decided to create a task in which we manipulated this variable. [less ▲]

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See detailInfluence of the Transfer Climate and Job Attitudes on the Transfer Process: Modelling the Direct and Indirect Effects
Peters, Stéphanie ULg; Cossette, Michel; Bates, Reid et al

in Journal of Personnel Psychology (in press)

This study investigates the impact job satisfaction, job involvement, organizational commitment and transfer climate on the training transfer process. Training transfer refers to the application of the ... [more ▼]

This study investigates the impact job satisfaction, job involvement, organizational commitment and transfer climate on the training transfer process. Training transfer refers to the application of the new learning and to performance at work. A two-time data collection was implemented among employees of a public health insurance company who attended professional training programs (N=118). Data analysis revealed that (1) job involvement negatively influenced transfer; (2) peer support positively influenced transfer; (3) openness to change had a negative relationship with transfer; and (4) these three predictors have an indirect effect on performance at work. [less ▲]

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See detailInfluence of the tyrosine environment on the second harmonic generation of iturinic antimicrobial lipopeptides at the air–water interface
Nasir, Mehmet Nail ULg; Benichou, Emmanuel; Loison, Claire et al

in Physical Chemistry Chemical Physics [=PCCP] (2013), 15

The second harmonic generation (SHG) response at the air–water interface from the tyrosine-containing natural iturinic cyclo-lipopeptides mycosubtilin, iturin A and bacillomycin D is reported. It is shown ... [more ▼]

The second harmonic generation (SHG) response at the air–water interface from the tyrosine-containing natural iturinic cyclo-lipopeptides mycosubtilin, iturin A and bacillomycin D is reported. It is shown that this response is dominated by the single tyrosine residue present in these molecules owing to the large first hyperpolarizability arising from the non-centrosymmetric aromatic ring structure of this amino acid. The SHG response of these iturinic antibiotics is also compared to the response of surfactin, a cyclo-lipopeptide with a similar L,D-amino acid sequence but lacking a tyrosine residue, and PalmATA, a synthetic linear lipopeptide possessing a single tyrosine residue but lacking the amino acid sequence structuring the cycle of the iturinic antibiotics. From the light polarization analysis of the SHG response, it is shown that the tyrosine local environment is critical in defining the SHG response of these peptides at the air–water interface. Our results demonstrate that tyrosine, similar to tryptophan, can be used as an endogenous molecular probe of peptides and proteins for SHG at the air–water interface, paving the way for SHG studies of other tyrosine-containing bioactive molecules. [less ▲]

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See detailInfluence of the viscosity on liquid hold-up in modular catalytic packings
Aferka, Saïd ULg; Viva, Aurora ULg; Brunazzi, Elisabetta et al

Conference (2010)

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See detailInfluence of the water content in the synthesis of fructose laurate by immobilized lipase B of Candida antarctica (Novozym 435)
Olive, Gilles ULg; Pompeu Torezan, Gabriela A.; Blecker, Christophe ULg

in Bulletin de la Société Royale des Sciences de Liège (2012), 81(2012), 82-89

New synthesis conditions for a direct esterification of fructose by lauric acid with Novozym 435 as a catalyst are reported in this paper. With these new conditions, a conversion rate of 72% was achieved ... [more ▼]

New synthesis conditions for a direct esterification of fructose by lauric acid with Novozym 435 as a catalyst are reported in this paper. With these new conditions, a conversion rate of 72% was achieved, which is almost the same value as in the case of transesterification where no water as by-product is produced (74.6 %). The conversion rate of these reactions can be modeled as a function of the initial water content by a three-parameter power law for the esterification and by an exponential law for the transesterification. The influence of the water content on the mono over di-ester ratio will also be discussed to a lesser extent. [less ▲]

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See detailInfluence of thermal acclimation on the survival of Sitophilus granarius (L) and Oryzaephilus surinamensis (L) at low temperatures
Mignon, Jacques ULg; Haubruge, Eric ULg; Gaspar, Charles ULg

in Netherlands Journal of Zoology (1996), 46(3-4), 317-325

Low temperatures have been used for many years to control populations of stored-product insects. The aim of aeration was primarily to cool down the grain and then to prevent its deterioration by reducing ... [more ▼]

Low temperatures have been used for many years to control populations of stored-product insects. The aim of aeration was primarily to cool down the grain and then to prevent its deterioration by reducing the number of insects. In Belgium, the mild winters enable insects to survive to the next season. In autumn, the progressive lowering of temperature has an acclimation effect on stored-product insects. The present study was undertaken to determine the survival at low temperatures of non cold-acclimated and laboratory- and field-cold-acclimated insects. We have chosen to work with the granary weevil Sitophilus granarius (L.) and the saw-toothed grain beetle Oryzaephilus surinamensis (L.). They are the most frequent stored-grain pests in Belgium. To compare the cold-hardiness of different laboratory cold-acclimated insects, S. granarius and O. surinamensis were placed at nine different cold-acclimation temperature regimes. Insects were kept at 5 degrees C for 2, 4 and 6 weeks or at -5 degrees C for 4, 7 and 14 days. To assess the field-cold-acclimation in autumn and in winter, insects were monthly taken from a bin and transferred to 5 degrees C for 6 weeks. S. granarius adults were more cold-hardy than O. surinamensis, but O. surinamensis adults compensated their cold-sensibility by a great ability to acclimate. S. granarius is able to survive the winter in Belgium because of its cold-hardiness while O. surinamensis survives because of its ability to acclimate to low temperatures. [less ▲]

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See detailInfluence of thermal treatment on YBa2Cu3O7-x thick films prepared by electrophoretic deposition on Ni and Ag substrates
Dusoulier, Laurent; Denis, Samuel; Dirickx, Michel et al

in Materials Research Society Symposium Proceedings (2007), 1001E

We have studied the sintering parameters of YBa2Cu3O7-x (YBCO) coatings produced by electrophoretic deposition (EPD) on Ag and Ni substrates. The maximal sintering temperature is ~ 930°C due to partial ... [more ▼]

We have studied the sintering parameters of YBa2Cu3O7-x (YBCO) coatings produced by electrophoretic deposition (EPD) on Ag and Ni substrates. The maximal sintering temperature is ~ 930°C due to partial melting and chemical contamination for Ag and Ni substrates respectively. Increasing the sintering duration does not improve significantly the densification. When Ar sintering atmosphere is used, the coating density is strongly increased on Ag substrates while adhesion is poor on Ni substrates. The Ar-sintered YBCO coating deposited on planar Ag substrate displays a significant magnetic shielding effect for low frequency applied magnetic induction. [less ▲]

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