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See detailHow to check analytically the robustness of a building submitted to a column loss - A premiere
Huvelle, Clara ULg; Jaspart, Jean-Pierre ULg; Demonceau, Jean-François ULg

in Proceedings of Eurosteel 2014 conference (2014, September)

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under an exceptional event. According to Eurocodes and some ... [more ▼]

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under an exceptional event. According to Eurocodes and some other national design codes, the structural integrity of civil engineering structures should be guaranteed through appropriate measures and one way to guarantee it is to ensure an appropriate robustness of the structure, which may be defined as the ability of a structure to remain globally stable in case of exceptional event leading to local damages. However, although global design approaches are provided in modern codes and standards, no easy-to-apply practical guidelines are provided. The present paper reflects recent researches realised at the University of Liege with the scope of proposing such practical guidelines for the activation of alternative load path in the structure, design strategy generally leading to the most economical solutions. [less ▲]

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See detailControllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping
Peterchev, Angel; D'Ostilio, Kevin ULg; Rothwell, John et al

in Journal of Neural Engineering (2014), 11(5),

Abstract. Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We ... [more ▼]

Abstract. Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with lower voltage rating than prior cTMS devices. Main results. cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The nearzero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (< 10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in 10 healthy volunteers. Significance. The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool. [less ▲]

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See detailHammer head beam solution for beam-to-column joints in seismic resistant building frames
Hoang, Van Long ULg; Jaspart, Jean-Pierre ULg; Demonceau, Jean-François ULg

in Journal of Constructional Steel Research (2014)

This paper presents a research on an innovative stiffened extended end-plate joint, used to connect I-shaped beams to partially-encased composite wide flange columns. In the joint, T-shaped hammer heads ... [more ▼]

This paper presents a research on an innovative stiffened extended end-plate joint, used to connect I-shaped beams to partially-encased composite wide flange columns. In the joint, T-shaped hammer heads cut from the same I-profiles than the beams are used, instead of using traditional haunches. At the joint level, the column web is strengthened by two lateral plates welded to the column flanges; these plates also reinforce the column flanges. This type of joint is proposed to use in the seismic resistance building frames, as a full-strength and a fully-rigid joint solution. Firstly, a test program carried out within a RFCS European project titled HSS-SERF “High Strength Steel in Seismic Resistant Building Frames”, 2009–2013, will be presented. Then, analytical developments based on the component approach and aimed at predicting the joint response will be described; their validity will be demonstrated through comparisons with the tests. Moreover, a new design concept for full strength joint accounting for the actual position of the plastic hinge and the possible individual overstrength factors for each component is proposed, respecting the requirements of EN1998-1-1. [less ▲]

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See detailCIRCULAR TUBE COLUMNS IN HIGH STRENGTH STEEL: Economical solutions for building frames
Hoang, Van Long ULg; Jaspart, Jean-Pierre ULg; Demonceau, Jean-François ULg

in Landolfo, Raffaele; Mazzolani, Frederico (Eds.) Proceeding of the 7th European conference on steel and composite structures (Eurosteel 2014) (2014, September)

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See detailBOLTED END-PLATE BEAM-TO-COLUMN JOINTS USING HAMMERHEAD BEAMS: Experimental tests and proposal of design guidelines
Demonceau, Jean-François ULg; Hoang, Van Long ULg; Jaspart, Jean-Pierre ULg

in Landolfo, Raffaele; Mazzolani, Frederico (Eds.) Proceeding of the 7th European conference on steel and composite structures (Eurosteel 2014) (2014, September)

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See detailLa Meuse au fil des crues
Devuyst, Paul; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

Article for general public (2014)

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See detailImpact of Circularity Defect of Helical Fillets HDPE Bridge Stay Covers: Analysis of Bi-Stability at Critical Reynolds Number by Bifurcation Diagrams
Benidir, Adel; Flamand, Olivier; Gaillet, Laurent et al

in Proceedings of the Symposium on the Dynamics and Aerodynamics of Cables - SDAC 2014 (2014, September)

Dry galloping of cables is still considered by the scientific community as an important phenomenon lacking investigation on cable stayed bridge. The helical fillet cylinders developed to overcome the Rain ... [more ▼]

Dry galloping of cables is still considered by the scientific community as an important phenomenon lacking investigation on cable stayed bridge. The helical fillet cylinders developed to overcome the Rain-Wind Induced Vibration (RWID) were reported to be affected by the appearance of vibration in dry conditions. This paper focuses on a method developed to process data issued from wind tunnel tests on original High Density Polyethylene (HDPE) cable covers with helical fillets, in a range of Reynolds numbers from the sub-critical regime to the critical regime. Corresponding values range from Re = 9.6x10^4 to Re = 3.6x10^5 for the present work. The experiment consists of investigating the effect of the helical fillets with natural or controlled deformation of his circularity defect. Previous studies ([1], [3] and [4]) reported that dry galloping is caused by the appearance of a negative pressure bubble on one side of a 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. Because the flow oscillates between two states, say TrBL0 and TrBL1, giving way to a fluctuating lift force supposed to cause the vibration of cables. However, [1] reports that the TrBL1 regime disappears in the presence of helical fillets. The aim of the current study was to investigate a possible appearance of the TrBL1 regime when the circularity defect threshold exceeds the filet thickness. In this case, the second purpose was to characterize the bi-stability of this phenomenon and provide new tools for wind engineering processing. [less ▲]

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See detailWind Tunnel Experiments On Bridge Stays Cables Protection Tubes In Dry Galloping Conditions: Processing Method For Bi-Stable Phenomenon
Flamand, Olivier; Benidir, Adel; Gaillet, Laurent et al

in Proceedings of the Symposium on the Dynamics and Aerodynamics of Cables - SDAC 2014 (2014, September)

Surface irregularity is one of the parameters that have not been deeply examined on stay cables of cable-stayed bridges. This paper focuses on wind tunnel tests on original High Density Polyethylene cable ... [more ▼]

Surface irregularity is one of the parameters that have not been deeply examined on stay cables of cable-stayed bridges. This paper focuses on wind tunnel tests on original High Density Polyethylene cable covers, in a range of Reynolds numbers from the sub-critical regime to the critical one, corresponding to values ranging from Re = 9.6x104 to Re = 3.3x105. The experiment consists in measurement of parietal pressures on cable covers in order to investigate the effect of surface irregularity on the mechanism of dry galloping excitation. Previous studies ([1], [3] and [4]) reported that dry galloping of cables with a circular cross section is linked to the appearance of a negative pressure bubble, on one side of the circular cylinder at the critical Reynolds number range, leading locally to a rapid drop in the drag coefficient and the appearance of a no negligible lift force. But such a steady change in local lift force does not generate an alternate excitation on a whole cable. The question of the spatial correlation of this “one bubble “ regime along a cable in real conditions and the capability of this lift force to be varied with time are still not resolved. The present paper aims at showing one first exploration of the spatial and temporal correlation of the pressure pattern along the HDPE tube with respect to the natural circularity defect. The Proper Orthogonal Decomposition (POD) was used to characterize the bi-stability phenomenon occurring at critical Reynolds number regime. [less ▲]

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See detailBIODIVERSITY AND REDOX CONDITIONS THROUGH THE PROTEROZOIC TAOUDENI BASIN OF MAURITANIA
Beghin, Jérémie ULg; Poulton, Simon; Gueneli, Nur et al

Conference (2014, September)

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See detailNon-isothermal moisture balance equation in porous media: a review of mathematical formulations in Building Physics
Dubois, Samuel ULg; Lebeau, Frédéric ULg; Evrard, Arnaud ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(3),

Understanding heat and mass transfers in porous materials is crucial in many areas of scientific research. Mathematical models have constantly evolved, their differences lying mainly in the choice of the ... [more ▼]

Understanding heat and mass transfers in porous materials is crucial in many areas of scientific research. Mathematical models have constantly evolved, their differences lying mainly in the choice of the driving potentials used to describe moisture flows, as well as in the complexity of characterizing the physical phenomena involved. Models developed in the field of Building Physics (HAM models) are used to describe the behavior of envelope parts and assess their impact on user comfort and energy performance. The water balance equation can be described in many ways; it is a function of the boundary conditions considered and the fact they induce high or low water content in the porous materials used. This paper gives an overview of various formulations for this equation that are found in the Building Physics literature. It focuses first on the physically based formulation of moisture balance, drawing on the Representative Elementary Volume (REV) concept, coupled with thermodynamic flow rates description. This is then reformulated in line with various main moisture state variables offering a wide variety of expressions that are compared with available models. This approach provides access to all secondary transport coefficients associated with the process of mathematical transformation. Particular emphasis is placed on the moisture storage function choice and its impact on the final mathematical formulations. [less ▲]

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See detailJugement dernier (Anonyme, Rouergue, XVe s).
Henrard, Nadine ULg

in Smith, Darwin; Parussa, Gabriella; Halévy, Olivier (Eds.) Le théâtre français du Moyen Âge et de la Renaissance. Histoire, textes choisis, mise en scène (2014)

Présentation du Mystère du Jugement dernier qui appartient au cycle des Mystères rouergats écrit en langue d'oc au XVe s. Traduction et commentaire d'un extrait (d'après l'éd. Lazar) illustrant le ... [more ▼]

Présentation du Mystère du Jugement dernier qui appartient au cycle des Mystères rouergats écrit en langue d'oc au XVe s. Traduction et commentaire d'un extrait (d'après l'éd. Lazar) illustrant le chapitre consacré aux rapports entre théâtre et religion. [less ▲]

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See detailJeu de sainte Agnès (Anonyme)
Henrard, Nadine ULg

in Smith, Darwin; Parussa, Gabriella; Halévy, Olivier (Eds.) Le théâtre français du Moyen Âge et de la Renaissance. Histoire, textes choisis, mise en scène (2014)

Présentation du Jeu de sainte Agnès, traduction et commentaire d'un extrait du texte (dans l'éd. Jeanroy) visant à illustrer le chapitre consacré aux manifestations de la merveille et du merveilleux dans ... [more ▼]

Présentation du Jeu de sainte Agnès, traduction et commentaire d'un extrait du texte (dans l'éd. Jeanroy) visant à illustrer le chapitre consacré aux manifestations de la merveille et du merveilleux dans le théâtre médiéval. [less ▲]

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See detailFlow and turbulence characterization as an onset for assessing the stability of gravel beds
Duma, Diana ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in 7th International Conference on Fluvial Hydraulics (2014, September)

The flow characteristics, such as velocity profiles and turbulence intensities, are of high practical relevance in the assessment of riverbed stability. So far, the Shields diagram remains the most widely ... [more ▼]

The flow characteristics, such as velocity profiles and turbulence intensities, are of high practical relevance in the assessment of riverbed stability. So far, the Shields diagram remains the most widely accepted approach for defining the initiation of sediment motion. However, it faces a number of shortcomings. In principle, it is only valid for uniform flow conditions and, under non-uniform flow conditions, it fails to account properly for the influence of turbulence in sediment entrainment. In this paper, we focus on a more detailed description of quasi-uniform and non-uniform flow characteristics in the vicinity of the critical flow conditions for inception of motion of gravel beds. Laboratory experiments were designed, involving two configurations. First, the entire bottom of the flume was paved with stones of uniform diameter (8 or 15 mm), leading to quasi-uniform flow conditions. Second, the flume bottom was smooth upstream of the zone of measurement while the downstream part was covered with gravels, leading to a sudden smooth-to-rough transition. The flow velocity was obtained by acoustic measurements and the turbulence intensity was calculated for both configurations. By fitting the velocity profile to a modified logarithmic law, the shear velocity was estimated. Standard approaches for predicting the threshold of motion, initially developed for uniform flows, were compared to other methods, based on depth-averaged turbulence kinetic energy, recently proposed in literature for non-uniform flow conditions. [less ▲]

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See detailGlucose use and lactate production by equine fresh semen in human and equine extender
Ponthier, Jérôme ULg; De Tullio, Pascal ULg; Parrilla-Hernandez, Sonia et al

in Reproduction in Domestic Animals (2014, September), 49(suppl 3), 13

This study shows that this human semen extender doesn’t support equine semen preservation. Sperm cells’ glucose consumption and lactate production seem to be negligible, as these parameters were not ... [more ▼]

This study shows that this human semen extender doesn’t support equine semen preservation. Sperm cells’ glucose consumption and lactate production seem to be negligible, as these parameters were not affected by sperm concentrations in our study. Our results suggest that spermatozoa are able to cleave complex carbohydrates as glucose concentration in INRA96 increased over time. [less ▲]

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See detailOù il est question de se faire une idée juste de la réalité... (partie 1)
Bruyère, Olivier ULg

in Medi-Sphere (2014), 454

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