References of "Paper published in a book"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailIsolated response curves in a base-excited, two-degree-of-freedom, nonlinear system
Noël, Jean-Philippe ULg; Detroux, Thibaut ULg; Masset, Luc ULg et al

in Proceedings of the ASME 2015 International Design Engineering Technical Conferences (2015, August)

In the present paper, isolated response curves in a nonlinear system consisting of two masses sliding on a horizontal guide are examined. Transverse springs are attached to one mass to provide the ... [more ▼]

In the present paper, isolated response curves in a nonlinear system consisting of two masses sliding on a horizontal guide are examined. Transverse springs are attached to one mass to provide the nonlinear restoring force, and a harmonic motion of the complete system is imposed by prescribing the displacement of their supports. Numerical simulations are carried out to study the conditions of existence of isolated solutions, their bifurcations, their merging with the main response branch and their basins of attraction. This is achieved using tools including nonlinear normal modes, energy balance, harmonic balance-based continuation and bifurcation tracking, and global analysis. [less ▲]

Detailed reference viewed: 51 (9 ULg)
Full Text
See detailLes précédents. La bataille de Ravenna
Dumont, Jonathan ULg

in Viganò, Marino (Ed.) Marignano 1515 : la svolta. Atti del congresso internazionale, Milano, 13 settembre 2014 (2015, August)

Detailed reference viewed: 32 (2 ULg)
Peer Reviewed
See detailStroke Volume Estimation using Aortic Pressure Measurements and Aortic Cross Sectional Area: Proof of Concept
Kamoi, Shun; Pretty, Christopher G.; Chiew, Yeong Shiong et al

in Proceedings of the 37th International Conference of the IEEE Engineering in Medicine and Biology Society (2015, August)

Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of ... [more ▼]

Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of measurement devices. Current devices for indirect monitoring of SV are shown to be inaccurate during sudden hemodynamic changes. This paper presents a novel SV estimation using readily available aortic pressure measurements and aortic cross sectional area, using data from a porcine experiment where medical interventions such as fluid replacement, dobutamine infusions, and recruitment maneuvers induced SV changes in a pig with circulatory shock. Measurement of left ventricular volume, proximal aortic pressure, and descending aortic pressure waveforms were made simultaneously during the experiment. From measured data, proximal aortic pressure was separated into reservoir and excess pressures. Beat-to-beat aortic characteristic impedance values were calculated using both aortic pressure measurements and an estimate of the aortic cross sectional area. SV was estimated using the calculated aortic characteristic impedance and excess component of the proximal aorta. The median difference between directly measured SV and estimated SV was -1.4ml with 95% limit of agreement +/- 6.6ml. This method demonstrates that SV can be accurately captured beat-to-beat during sudden changes in hemodynamic state. This novel SV estimation could enable improved cardiac and circulatory treatment in the critical care environment by titrating treatment to the effect on SV. [less ▲]

Detailed reference viewed: 78 (5 ULg)
Full Text
See detailPotential of visible-near infrared spectroscopy for the characterization of butter properties
Troch, Thibault ULg; Baeten, Vincent; Dehareng, Frédéric et al

in Book of Abstracts of the 66th Annual Meeting of the European Federation of Animal Science (2015, August)

Detailed reference viewed: 20 (2 ULg)
Full Text
See detailOn the use of novel milk phenotypes as predictors of difficult-to-record traits in breeding programs
Bastin, Catherine ULg; Colinet, Frédéric ULg; Dehareng, Frédéric et al

in Book of Abstracts of the 66th Annual Meeting of the European Federation of Animal Science (2015, August)

Detailed reference viewed: 36 (9 ULg)
Full Text
Peer Reviewed
See detailAgriculture Seen Through the Prism of the French Media in Belgium
Dubois, Charline ULg

in Firmino, Ana (Ed.) Smart answers for a smiling future (2015, August)

Scholars agree on the importance of the farming activities to maintain the quality (aesthetic environment) of rural areas. The number of farmers in Belgium fall steadily in the recent decades (Van Hecke ... [more ▼]

Scholars agree on the importance of the farming activities to maintain the quality (aesthetic environment) of rural areas. The number of farmers in Belgium fall steadily in the recent decades (Van Hecke et al. 2010). In particular, the rural systems of Wallonia transformed, characterized by the increased presence of landscapes of consumption and the influx of urban migrants. Why do they live in the countryside? Do they know the farmers in the area? What are the rural idylls (Yarwood 2005)? The answers to these questions lead to the understanding of perceptions and recognitions of rural spaces among different stakeholders. On another scale, this leads to the need for the improvement of social and territorial cohesion to improve the quality of life and the integration of people into their new living environment. The topics about “to live and to build the countryside” are current (Cawley & Gillmor 2008, Frelat-Kahn & Lazzarotti 2012) and are also concerned with the future of the countryside, of farming, and of the vitality of rural systems that face challenges according to geographic situations. With increasing suburbanization and multifunctionality (Bills & Gross 2005), some inhabitants want to build an interdependent community with authentic values. But the inhabitants’ representations about rural way of life are inexistent (despite some local initiatives such as organic produces) or complex (Dubois & Schmitz 2011, Tencati & Zsolnai 2012). Each person can say that he/she lives in the countryside by considering different space realities, with the risk that farmers could become strangers (Simard & Guimond 2013)! “Each year we organised a party in our street with everybody from the surrounding areas. Some farmers come and it is amazing to socialize more than just pass each other by cars and tractors” (inhabitant in a rural town in Wallonia). This study presents a first step in exploring inhabitant’s representations of the countryside. We analyse here the organic image about agriculture developed by the media that partly influences the people's perception of agriculture. Other than the induced and experienced images, organic image or “those that arise from supposedly unbiased sources” such as books, school education, television, documentaries, newspapers, and word of mouth (Gunn 1972, O'Leary & Deegan 2005) is considered. “People are interested about agricultural features. We speak a lot about that in the media, so people would like to know more about us and our job! That is why they visit us and they are sometimes so disoriented!” (Farmer in Wallonia). The analysis focuses on 3 consecutive even-numbered years: 2010, 2012 and 2014, from January to December. The national online press platform was used to access the articles. This allows for an analytical look at how agriculture is represented in the newspapers: What themes were addressed? How often? And to know the level of importance, in which part of the newspapers did it appear? The study analysed articles from 2 Belgian French newspapers from different media groups (Le Soir, La Libre). Different regions were covered to take into account different agro-geographical landscapes, suburban and rural features of the countryside, and different social and economical realities of Wallonia. For each article, topic selection and content analysis (NVivo ) were undertaken. Bette (2012) made the first analysis of the topic in 2012 and put into evidence 13 different categories in which agriculture has been presented: organic, diversification, legislation, economy, crops, farming, food, biotechnology, energy, animal health, plant diseases, environment, other. However, for this research, we improved the typology and add other topics such as the tourism, the local produces, the (agro-) geographical regions. Qualitative analysis showed that economic difficulties, economic investment, local produces, slow food, European policies, environment are among the categories frequently explored. All the different categories were represented and were often sensationalised but the level of importance is not high as most news were often found inside the newspaper and not on the front page. These different elements influence the representations of the different readers and give an overview about the influence of images of agriculture on the inhabitants. Agriculture is related to multiple components but some of these aspects are not presented and remain unknown to the common public. A lot of other questions about agricultural and rural systems and agricultural regions are not covered because on-going social, economic environmental and cultural trends tend to influence the information that are found in the newspapers. Agriculture is often simplified in a positive (e.g. local products, organic farming) and in a negative way (e.g. pollutions, bankruptcies, suicides) which implied that it is difficult for laymen to have a valid representation based on newspapers. [less ▲]

Detailed reference viewed: 37 (2 ULg)
Full Text
Peer Reviewed
See detailBifurcation analysis of a spacecraft structure using the harmonic balance method
Detroux, Thibaut ULg; Renson, Ludovic ULg; Masset, Luc ULg et al

in Proceedings of the ASME 2015 International Design Engineering Technical Conferences (2015, August)

The harmonic balance (HB) method has been widely used in the past few years, as a numerical tool for the study of nonlinear models. However, in its classical formulation the HB method is limited to the ... [more ▼]

The harmonic balance (HB) method has been widely used in the past few years, as a numerical tool for the study of nonlinear models. However, in its classical formulation the HB method is limited to the approximation of periodic solutions. The present paper proposes to extend the method to the detection and tracking of bifurcations in the codimension-2 system parameters space. To validate the methodology, the forced response of a real spacecraft is examined. The paper first provides some numerical evidence of the presence of quasiperiodic oscillations and isolated solutions. It then demonstrates how the tracking of Neimark-Sacker and fold bifurcations can help get a deeper understanding of these attractors. [less ▲]

Detailed reference viewed: 37 (7 ULg)
Full Text
See detailTime-averaged phase-stepped ESPI with CO2 laser and shearography in the visible for identification of vibration mode shapes
Vandenrijt, Jean-François ULg; Thizy, Cédric ULg; Georges, Marc ULg

in Mendoza Santoyo, Fernando (Ed.) SPECKLE 2015: VI International Conference on Speckle Metrology (2015, August)

We present investigation of interferometric methods for vibration mode identification to be applied on shakers in industrial environment. We consider long wave infrared ESPI in time-averaged mode with the ... [more ▼]

We present investigation of interferometric methods for vibration mode identification to be applied on shakers in industrial environment. We consider long wave infrared ESPI in time-averaged mode with the use of phase-stepping which allows transforming Bessel fringes, typical to the time averaging, into phase values which provide a better way for identification of vibration mode shapes. The use of long laser wavelength allows measuring larger amplitudes of vibrations compared to what is achieved in visible light. Also longer wavelengths allow lower sensitivity to external perturbations. Time-averaged phase-stepped shearography in visible is also used as a compared alternative to LWIR ESPI for working in industrial environments. Although not demonstrated here, an interesting feature for the future investigations on LWIR ESPI is its potentiality of simultaneous temperature measurement during vibrations [less ▲]

Detailed reference viewed: 28 (4 ULg)
Full Text
Peer Reviewed
See detailPhysical modeling of lateral dike breaching due to overtopping
Rifai, Ismail ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in River, Coastal and Estuarine Morphodynamics, RCEM 2015 (2015, August)

Dikes are commonly used as defense structures for river flow channelization, protecting population and property from floods and against lateral riverbed migration. However, the aging of these structures ... [more ▼]

Dikes are commonly used as defense structures for river flow channelization, protecting population and property from floods and against lateral riverbed migration. However, the aging of these structures, combined with their increased vulnerability to extreme hydrological events may cause the dikes to breach, and subsequently to break. Furthermore, statistics show that flow overtopping is the main cause of dike failure, which emphasizes the need to understand thoroughly the process of breaching. Indeed, from a risk management perspective it is particularly important to have a detailed understanding of the mechanisms (e.g. internal erosion, overtopping erosion) underlying the formation of breaches due to overtopping and reliable information on flows passing through them. Conversely, the current knowledge of breaching mechanisms remains fragmented, especially because dike failure involves complex interactions between flows, materials of the structure, soil and foundations. The existing studies have addressed partially these interactions as the considered idealized dikes were generally homogenous, the piping erosion unaccounted for and the overtopping replicated in a dam-break like configuration. Yet, river embankments are subjected to high flow velocities parallel to the direction of the dike and to flow in the floodplain, which highly influence the shape of the breach and its evolution. The objective of the present work is to fill this gap. A laboratory experimental investigation is planned in the National Laboratory for Hydraulics and Environment (LNHE) of EDF R&D (France) and in the research group Hydraulics in Environmental and Civil Engineering (HECE) of the University of Liege (Belgium), reproducing realistic configurations of river dikes, accounting for the tangential flow in both main channel and floodplain. It enables thus the assessment of, on the one hand, the effect of the increase of the water level, and on the other hand, the influence of waves. The laboratory tests also consider the effect of a surface layer and composition of the dike core by testing different material mixtures. Geometry and composition of the idealized dikes are representative of typical field dikes, based on the similarity theory. [less ▲]

Detailed reference viewed: 170 (31 ULg)
Full Text
See detailComparison between thermographic and holographic techniques for nondestructive testing of composites: similarities, differences and potential cross-fertilization
Georges, Marc ULg

in Mendoza Santoyo, Fernando (Ed.) SPECKLE 2015: VI International Conference on Speckle Metrology (2015, August)

Thermography and different variants of holography (holographic interferometry, speckle interferometry, shearography) are full-field non-contact techniques which are used in nondestructive testing ... [more ▼]

Thermography and different variants of holography (holographic interferometry, speckle interferometry, shearography) are full-field non-contact techniques which are used in nondestructive testing applications. In particular they are attractive for damage detection in composite materials compared to other methods measuring in one point and which require scanning and contact with the samples, like ultrasounds. Currently thermography is a step forward compared to holographic techniques for this application. Indeed it is easier to interpret. Many thermography configurations and variants exist, from exciting sources to post-processing. Such a variety exists also among the holographic techniques but to a less extent. We will see how these techniques can share some aspects and what distinguish them. Also the complementarity of both will be addressed and how to combine them. At last we will discuss how processing developed for thermography can benefit to holography and vice-versa, specifically in the domain of composite materials. [less ▲]

Detailed reference viewed: 27 (6 ULg)
Peer Reviewed
See detailModelling of the Nonlinear End-Systolic Pressure-Volume Relation and Volume-at-Zero-Pressure in Porcine Experiments
Davidson, Shaun M.; Kannangara, D. Oliver; Pretty, Christopher G. et al

in Proceedings of the 37th International Conference of the IEEE Engineering in Medicine and Biology Society (2015, August)

The End-Systolic Pressure-Volume Relation (ESPVR) is generally modelled as a linear relationship between P and V as cardiac reflexes, such as the baroreflex, are typically suppressed in experiments ... [more ▼]

The End-Systolic Pressure-Volume Relation (ESPVR) is generally modelled as a linear relationship between P and V as cardiac reflexes, such as the baroreflex, are typically suppressed in experiments. However, ESPVR has been observed to behave in a curvilinear fashion when cardiac reflexes are not supressed, suggesting the curvilinear function may be more clinically appropriate. Data was gathered from 41 vena cava occlusion manoeuvres performed experimentally at a variety of PEEPs across 6 porcine specimens, and ESPVR determined for each pig. An exponential model of ESPVR was found to provide a higher correlation coefficient than a linear model in 6 out of 7 cases, and a lower Akaike Information Criterion (AIC) value in all cases. Further, the exponential ESPVR provided positive V0 values in a physiological range in6 out of 7 cases analysed, while the linear ESPVR produced positive V0 values in only 3 out of 7 cases, suggesting linear extrapolation of ESPVR to determine V0 may be flawed. [less ▲]

Detailed reference viewed: 22 (4 ULg)
Full Text
See detailGeophysical Investigation of the Pb-Zn deposit of Plombières, Belgium
Evrard, Maxime ULg; Pirard, Eric ULg; Nguyen, Frédéric ULg

in André-mayer, anne-Sylvie; Cathelineau, Michel; Muchez, Philippe (Eds.) et al Mineral resources in a sustainable worl, proceeding, volume 5 (2015, August)

Detailed reference viewed: 37 (5 ULg)
Peer Reviewed
See detailEthnic Differences in Travel Time Expenditure
Cools, Mario ULg; Eftekhar, Hamed ULg

in Proceeding of the 14th International Conference on Travel Behaviour Reresearch (IATBR 2015) (2015, July 23)

Detailed reference viewed: 34 (20 ULg)
Full Text
See detailA viscoelastic-viscoplastic-damage constitutive model based on a large strain hyperelastic formulation for amorphous glassy polymers
Nguyen, Van Dung ULg; Morelle, Xavier; Lani, Frédéric et al

in proceedings of the 20th International Conference on Composite Materials, Copenhagen, Denmark, 19-24th July 2015 (2015, July 20)

The aim of this work is to develop an efficient large-strain hyperelastic constitutive model for amorphous polymers in the glassy state. These materials exhibit a complex rate- and pressure-sensible ... [more ▼]

The aim of this work is to develop an efficient large-strain hyperelastic constitutive model for amorphous polymers in the glassy state. These materials exhibit a complex rate- and pressure-sensible behavior in both elastic and plastic regimes. After an initial linear elastic region, a nonlinear stage continues until reaching a peak stress, which is followed by a softening stage. At large strains, when the softening is saturated, a re-hardening stage is reached. The viscoelastic effect is captured using the generalized Maxwell model. The viscoplastic effect is considered using a Perzyna-type flow rule incorporating a pressure sensitive yield surface and a non-associated flow potential. This yield surface is extended from the Drucker-Prager one. The saturated softening phenomenon is modelled using an isotropic numerical damage variable progressed by a saturated softening law. With the introduction of the damage parameter, a non-local implicit gradient damage model is used to avoid the loss of the solution uniqueness. Through experimental comparisons, it is shown that the proposed model has the ability to model the complex mechanical responses of amorphous glassy polymers. [less ▲]

Detailed reference viewed: 82 (12 ULg)
Full Text
See detailExperimental study of Predictive Control strategies for optimal operation of Organic Rankine Cycle systems
Hernandez Naranjo, Jairo Andres ULg; Desideri, Adriano ULg; Ionescu, Clara et al

in Experimental study of Predictive Control strategies for optimal operation of Organic Rankine Cycle systems (2015, July 17)

In this paper the performance of Model Predictive Control (MPC) and PID based strategies to optimally recover waste heat using Organic Rankine Cycle (ORC) technology is investigated. First the ... [more ▼]

In this paper the performance of Model Predictive Control (MPC) and PID based strategies to optimally recover waste heat using Organic Rankine Cycle (ORC) technology is investigated. First the relationship between the evaporating temperature and the output power is experimentally evaluated, concluding that for some given heat source conditions there exists an optimal evaporating temperature which maximizes the energy production. Three different control strategies MPC and PID based are developed in order not only to maximize energy production but to ensure safety conditions in the machine. For the case of the MPC, the Extended Prediction Self-Adaptive Control (EPSAC) algorithm is considered in this study as it uses input/output models for prediction, avoiding the need of state estimators, making of it a suitable tool for industrial applications. The experimental results obtained on a 11kWe pilot plant show that the constrained EPSAC-MPC outperforms PID based strategies, as it allows to accurately regulate the evaporating temperature with a lower control effort while keeping the superheating in a safer operating range. [less ▲]

Detailed reference viewed: 28 (6 ULg)
Full Text
Peer Reviewed
See detailCrop supplemental irrigation experiences in Burkina Faso
Zongo, Bétéo ULg; Diarra, Abdoulaye; Barbier, Bruno et al

in Field, Christopher; Jouzel, Jean; Le Treut, Hervé (Eds.) Our ender common climate future change, Abstract Book (2015, July 10)

This study assesses the impact of supplemental irrigation from small man-made basins on cereal production in climate variability and change context marked by dry spells in the Sahelian zone of Burkina ... [more ▼]

This study assesses the impact of supplemental irrigation from small man-made basins on cereal production in climate variability and change context marked by dry spells in the Sahelian zone of Burkina Faso. After two years, the experiments showed that this innovation in family farms increases maize yield and allows growing a second crop with the surplus of water available in the basin. At the end of the 2012-2013 campaign, the average maize yield was estimated 2.5 t/ha on experimental plots (EP) and 1.7 t/ha on control plots (CP). The average yield of the 2013-2014 campaign was evaluated as 3.3 T/ha and 0.9 t/ha for EP and CP respectively. Increase in yield is 0.8 t/ha for the 2012-2013 campaign and 2.4 t/ha during 2013-2014. It appears as well as the yield obtained on EP in 2012-2013 and 2013-2014 for bridging cereal need of 2 and 6 additional persons respectively in agricultural households compared to the CP. The review of the Net present value, Internal rate of return and the Net benefits increase ratio show that the profitability to practice supplemental irrigation depends on the types of basins. [less ▲]

Detailed reference viewed: 30 (3 ULg)
Full Text
Peer Reviewed
See detailModelling Uncertainties in Long-Term Predictions of Urban Growth: A Coupled Cellular Automata and Agent-Based Approach
El Saeid Mustafa, Ahmed Mohamed ULg; Saadi, Ismaïl ULg; Cools, Mario ULg et al

in Ferreira, Joseph; Goodspeed, Robert (Eds.) Proceedings of CUPUM 2015 (2015, July 07)

Modelling the growth of urban settlements is of considerable interest for different applications, amongst which integrated flood management. This study aims at modelling urban growth for a long time ... [more ▼]

Modelling the growth of urban settlements is of considerable interest for different applications, amongst which integrated flood management. This study aims at modelling urban growth for a long time horizon up to 2100 and to integrate the model outcomes with a hydrological model for the same time horizon. Forecasting land-use change over such time frames entails very significant uncertainties. In this regard, the main focus of this paper is attributed to the handling of uncertainty in an urban growth model. To this end, we examine a Monte Carlo Simulation method, which is integrated in the proposed urban growth model. Transition probabilities for each non-urban cell are estimated by a coupled Cellular Automata-Agent-Based ap-proach. The results help to handle uncertainty over long time horizons and to assess the increment in degree of uncertainty at every time-step. [less ▲]

Detailed reference viewed: 160 (61 ULg)
Full Text
Peer Reviewed
See detailContribution du bilan de masse de surface antarctique à l’évolution du niveau des mers avec le modèle atmosphérique régional MAR
Agosta, Cécile ULg; Fettweis, Xavier ULg; Gallée, Hubert

in Actes du 28e colloque de l’Association Internationale de Climatologie (2015, July 02)

Detailed reference viewed: 13 (0 ULg)
Full Text
See detailSuppression of simulated self-excited oscillation using smart materials on flexible wing structure
Abdul Razak, N.; Nasip, N. S.; Hawari, A. F. et al

in Proceedings of the International Forum on Aeroelasticity and Structural Dynamics, IFASD 2015 (2015, July 01)

Suppression of simulated self-excited oscillation due to aeroelastic effects using piezoelectric patches is reported. The focus of the present work is suppressing simulated flutter oscillation using ... [more ▼]

Suppression of simulated self-excited oscillation due to aeroelastic effects using piezoelectric patches is reported. The focus of the present work is suppressing simulated flutter oscillation using piezoelectric patches bonded to the wing structure. First, a clean wing is exposed to airflow in the wind tunnel where it experienced limited amplitude oscillation. The responses were recorded. This is followed by bonding piezoelectric patches to the identical wing that was tested in the wind tunnel. Two of the patches were used as actuators to simulate self-excited oscillation in a control manner. The selected mode for excitation is 1st bending mode. The other two patches were used as suppressor for active control using negative velocity feedback Single-Input, Single-Output approach. The single input signal for negative feedback is also sensed using piezoelectric patches. The controller manages to suppress the simulated flutter response to a lower oscillation amplitude values. This works demonstrated the used of piezoelectric material as actuator to reproduce the oscillation amplitude during self-excited oscillation and suppress the oscillation at the same time. [less ▲]

Detailed reference viewed: 57 (3 ULg)
Full Text
Peer Reviewed
See detailGaz à effet de serre indirects et qualité de l'air aux latitudes moyennes de l'hémisphère nord : tendances à long terme et variabilité déduites de télémesures effectuées au Jungfraujoch (Alpes suisses, 3580 m)
Franco, Bruno ULg; Bader, Whitney ULg; Lejeune, Bernard ULg et al

in Erpicum, Michel (Ed.) Actes du XXVIIIe colloque annuel de l’Association Internationale de Climatologie : Modélisations et variabilités (2015, July 01)

Indirect greenhouse gases and air quality at Northern Hemisphere mid-latitudes: long-term trends and variability derived from ground-based remote sensing at Jungfraujoch (Swiss Alps, 3580 m a.s.l.). We ... [more ▼]

Indirect greenhouse gases and air quality at Northern Hemisphere mid-latitudes: long-term trends and variability derived from ground-based remote sensing at Jungfraujoch (Swiss Alps, 3580 m a.s.l.). We present an overview of recent investigations conducted by the Solar and Atmospheric Physics Infrared Group at the University of Liège and dedicated to the long-term monitoring of atmospheric gases with an indirect greenhouse effect and affecting air quality at Northern Hemisphere mid-latitudes. Gas concentrations are derived from high-resolution solar spectra recorded at the Jungfraujoch station (Swiss Alps, 46.5° N, 8.0° E, 3580 m a.s.l.), using Fourier transform infrared spectrometers. Time series obtained from these observations, along with satellite measurements and simulations from numerical models, allow for the study of both variability and recent evolution of these species and are critical for air quality monitoring and understanding climate changes. [less ▲]

Detailed reference viewed: 63 (10 ULg)
Full Text
See detailA new test of uniformity for object orientations in astronomy
Pelgrims, Vincent ULg

in Heavens, A. F.; Starck, J.-L.; Krone-Martins, A. (Eds.) Statistical Challenges in 21st Century Cosmology (2015, July 01)

We briefly present a new coordinate-invariant statistical test dedicated to the study of the orientations of transverse quantities of non-uniformly distributed sources on the celestial sphere. These ... [more ▼]

We briefly present a new coordinate-invariant statistical test dedicated to the study of the orientations of transverse quantities of non-uniformly distributed sources on the celestial sphere. These quantities can be projected spin-axes or polarization vectors of astronomical sources. [less ▲]

Detailed reference viewed: 19 (2 ULg)
Peer Reviewed
See detailMaking "Place" count in Risk perception studies
Ocampo, Lou Angeli ULg; Schmitz, Serge ULg

in Firmino, Ana (Ed.) Book of Abstracts and Programme: 23rd Annual Colloquium on Sustainable Rural Systems: Smart Answers for a smiling future (2015, July)

Detailed reference viewed: 28 (7 ULg)
Full Text
Peer Reviewed
See detailModel reduction for simulating the dynamic behavior of parabolic troughs and a thermocline energy storage in a micro-solar power unit
Dickes, Rémi ULg; Desideri, Adriano ULg; Lemort, Vincent ULg et al

in Proceedings of ECOS 2015 (2015, July)

Micro-scale concentrated solar power plants are characterized by strong transients and mostly operate in off-design working conditions. Both the sizing and the control of these systems are key challenges ... [more ▼]

Micro-scale concentrated solar power plants are characterized by strong transients and mostly operate in off-design working conditions. Both the sizing and the control of these systems are key challenges whose optimization requires powerful dynamic modeling tools. In this context, a system featuring a solar field of parabolic troughs, a thermocline thermal energy storage and a 5kWe organic Rankine cycle (ORC) power unit is modeled in the Modelica language. Model reduction methods applied to the solar field and the thermal storage are investigated and analyzed to improve the computational efficiency of the problem. Each model is described and integrated in the open-source ThermoCycle library. Results of simulation under identical operating conditions are compared and the benefits and limitations of model reduction are assessed. [less ▲]

Detailed reference viewed: 140 (18 ULg)
Full Text
Peer Reviewed
See detailHybrid processing of SCADA and synchronized phasor measurements for tracking network state
Alcaide-Moreno, Boris; Fuerte-Esquivel, Claudio; Glavic, Mevludin ULg et al

in Proc. IEEE PES General Meeting (2015, July)

This paper proposes a new tracking state estimator aimed at following some of the dynamics of the network state (bus voltage phasors) by a hybrid processing of SCADA and synchronized phasor measurements ... [more ▼]

This paper proposes a new tracking state estimator aimed at following some of the dynamics of the network state (bus voltage phasors) by a hybrid processing of SCADA and synchronized phasor measurements. The latter are assumed to be available in limited number. To avoid time skew effects, only the SCADA measurements received since the last execution of the estimator are processed. To ensure observability, estimated SCADA measurements are used as pseudo-measurements. The procedure includes a prediction, an innovation analysis and a correction step. The latter consists of solving a constrained least-squares optimization. The simulation results refer to a test system undergoing large disturbances, evolving to long-term voltage instability or stabilized by emergency control. The proposed method appears to satisfactorily track the overall network evolution, even during those severe conditions. [less ▲]

Detailed reference viewed: 87 (18 ULg)
Full Text
Peer Reviewed
See detailA Bayesian model for the Ebola epidemic in Sierra Leone
Frasso, Gianluca ULg; Lambert, Philippe ULg; Bonou, Wilfried ULg

in Friedl, Herwig; Wagner, Helga (Eds.) 30th International Workshop on Statistical Modelling, Linz, Austria, 2015, Proceedings (2015, July)

We propose a Bayesian model for the analysis of the 2014 ebola out- break in Sierra Leone. It is based on an extension of the popular compartmental SEIR model speci ed using a system of di erential ... [more ▼]

We propose a Bayesian model for the analysis of the 2014 ebola out- break in Sierra Leone. It is based on an extension of the popular compartmental SEIR model speci ed using a system of di erential equations. [less ▲]

Detailed reference viewed: 22 (4 ULg)
Full Text
Peer Reviewed
See detailEtude de l'évolution de l'enneigement dans les Hautes Fagnes (Belgique) au cours des cinquante dernières années à l'aide du modèle climatique régional MAR
Wyard, Coraline ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

in Erpicum, Michel (Ed.) Actes du XXVIIIe colloque annuel de l’Association Internationale de Climatologie : Modélisations et variabilités (2015, July)

The “Modèle Atmosphérique Régionale” MAR is a regional climate model originally developed to study the polar ice sheets. In this study, the MAR model has been adapted to Belgium in order to study the snow ... [more ▼]

The “Modèle Atmosphérique Régionale” MAR is a regional climate model originally developed to study the polar ice sheets. In this study, the MAR model has been adapted to Belgium in order to study the snow cover evolution of the High Fens (east of Belgium), a region covered by snow on average one to two months per year. As validation, we have sucessfully compared MAR based daily snow heights with snowcam-based and/or laser sensor-based observations over the period 2008-2013. Then, the model has been forced by ERA-Interim since 1958 to study the snow cover evolution during the last fifty years at the summit of Belgium. The results show no significant trend despite global warming. [less ▲]

Detailed reference viewed: 67 (14 ULg)
Full Text
Peer Reviewed
See detailMODIFYING PHYSICAL ENVIRONMENT TO BE APPROPRIATE FOR CHILDREN
Jidovtseff, Boris ULg; Delvaux, Anne ULg; Mornard, Manhattan ULg

in Book of abstracts AISEP 2015 (2015, July)

Our experience confirms that adapting physical environments is critical for providing appropriate physical activity for 3 to 8 years old children.. Moreover, the pedagogy has to favour success, discovery ... [more ▼]

Our experience confirms that adapting physical environments is critical for providing appropriate physical activity for 3 to 8 years old children.. Moreover, the pedagogy has to favour success, discovery and a fun environment. This work illustrates what can be achieved and provides clear guidance for developing centres to support the promotion of physical activity in early childhood. [less ▲]

Detailed reference viewed: 26 (5 ULg)
Peer Reviewed
See detailAre there different analysis paterns when people assess rural landscapes?
Vanderheyden, Vincent ULg; Schmitz, Serge ULg

in Firmino, Ana (Ed.) Book of Abstracts and Programme: 23rd Annual Colloquium on Sustainable Rural Systems: Smart Answers for a smiling future (2015, July)

Detailed reference viewed: 31 (7 ULg)
Full Text
Peer Reviewed
See detailWe forgot to pay attention to ordinary tourism! A call to revise the research agenda for rural tourism
Schmitz, Serge ULg; Crozat, Dominique

in Firmino, Ana (Ed.) Book of Abstracts and Programme: 23rd Annual Colloquium on Sustainable Rural Systems: Smart Answers for a smiling future (2015, July)

This paper aims to suggest a new research agenda for rural tourism, including for a smiling future for the countryside, in reversing the current trend to distinguish the destination, to aim at ... [more ▼]

This paper aims to suggest a new research agenda for rural tourism, including for a smiling future for the countryside, in reversing the current trend to distinguish the destination, to aim at supersegmentation of tourism and to target a cultural, elitist, tourism. Indeed most tourist activities can be done and are done in a relative vicinity, by ordinary tourists aiming to have a good time. Moreover, the countryside does not always offer extraordinary sights that attract people from the whole continent. We argue that there should be a place and more attention for ordinary tourism development. By ordinary tourism, we do not mean mass tourism but just the fact that some people spent a few days away from home. We do not want to reject the appealing concepts of cultural tourism, ecotourism, adventure tourism, ethnic tourism, gastronomic tourism, farm tourism and so on. We just want to be realistic and call to rethink the importance of ordinary tourism and its current challenges: facing new ways of traveling (e.g. Low cost), of buying vacation (e-commerce), of enjoying holidays (more frequently/with friends, alone or with the family/ being active or passive). [less ▲]

Detailed reference viewed: 54 (1 ULg)
Full Text
Peer Reviewed
See detailComparison of experimental results and numerical modelling of unreinforced load-bearing masonry structures subjected to earthquake loading
Mordant, Christophe ULg; Denoël, Vincent ULg; Degée, Hervé

in Proceedings of the SECED 2015 Conference: Earthquake Risk and Engineering towards a Resilient World (2015, July)

This paper presents a comparison of experimental tests results on unreinforced load-bearing masonry structures subjected to earthquake loading with numerical predictions. First, simple walls are submitted ... [more ▼]

This paper presents a comparison of experimental tests results on unreinforced load-bearing masonry structures subjected to earthquake loading with numerical predictions. First, simple walls are submitted to cyclic and shaking table tests. Some of them include soundproofing devices in order to investigate their influence on the general behaviour in static and dynamic conditions. Additional walls with an opening and T-shaped walls are then tested under cyclic loading. The study is focused on the frame effect, the contribution of the perpendicular wall to the global strength and the efficiency of the connection. These aspects are also studied through shaking table tests on two masonry frames with T- or L-shaped piers. The main information is expressed in terms of force-displacement curves, mechanical properties and energy dissipation for the cyclic tests. The shaking table tests provide results in terms of dynamic and mechanical properties. Comparison of the results with numerical predictions is finally performed thanks to the software TREMURI. [less ▲]

Detailed reference viewed: 34 (6 ULg)
Full Text
Peer Reviewed
See detailTentatives de prétraitement des granulats recyclés pour l’amélioration des bétons préfabriqués
Zhao, Zengfeng ULg; Courard, Luc ULg; Remond, Sébastien et al

in Ciments, bétons et fibres - Matériaux et structures (2015, July)

De très grandes quantités de déchets de construction et de démolition sont produites chaque année. Jusqu'à présent, seule une petite fraction de ces déchets de béton est réutilisée sous forme de granulats ... [more ▼]

De très grandes quantités de déchets de construction et de démolition sont produites chaque année. Jusqu'à présent, seule une petite fraction de ces déchets de béton est réutilisée sous forme de granulats pour la fabrication de béton. Afin de faire bon usage des granulats recyclés (GR) dans le béton, il est très important d’améliorer leurs propriétés. Dans cette étude, une méthode de traitement des GR au moyen d’une carbonatation accélérée en laboratoire et des méthodes de traitement par modification de l’état de surface des GR ont été étudiées. Les résultats montrent qu'après la carbonatation accélérée au laboratoire, la teneur en pâte de ciment durcie des GR mesurée par dissolution de l'acide salicylique diminue, que la densité et la surface spécifique des GR augmentent et que la porosité des GR diminue, ce qui conduit à la réduction de l'absorption d'eau des GR. Des agents hydrofuges à base de silane ont également été étudiés et semblent diminuer l’absorption d’eau par les GR. [less ▲]

Detailed reference viewed: 85 (27 ULg)
Full Text
Peer Reviewed
See detailSketch-based and parametric modeling: Association of two-externalization processes for early daylight optimization
Gallas, Mohamed Anis ULg; Delfosse, Vincent ULg

(2015, July)

This paper focuses on sketch-based and parametric modeling as two externalization devices used in architectural design practice. The first part of this paper addresses features and ability of these ... [more ▼]

This paper focuses on sketch-based and parametric modeling as two externalization devices used in architectural design practice. The first part of this paper addresses features and ability of these externalization tools to support design activities during the early design steps. The second part proposes an association process of a sketch-based modeling tool (SketSha-Archi®) and a parametric modeling tool (Grasshopper®) to create an advanced process for daylight optimization. The process aimed to associate the hand-sketching freedom with the precise exploration functions of digital tools (parametric modeling and evaluation tools). [less ▲]

Detailed reference viewed: 61 (1 ULg)
Full Text
Peer Reviewed
See detailiPot: Industrial Potato monitoring for the Belgian potato sector using remote sensing and crop growth modelling
Wellens, Joost ULg

in Qu, Dongyu (Ed.) Develop Together for a Better Future (2015 Beijing World Potato Congress) (2015, July)

The Belgian potato processing industry has known a spectacular growth during the last decades. The companies active in this sector (most of them family owned enterprises) have succeeded – together with ... [more ▼]

The Belgian potato processing industry has known a spectacular growth during the last decades. The companies active in this sector (most of them family owned enterprises) have succeeded – together with primary producers and traders – to grow from 500.000 tons of processed potatoes in 1990 till 3.650.000 tons of raw material in 2012. When considering the production (in tons) per habitant, Belgium is ranked on the 4th place with a production of 395 tons per 1.000 inhabitants. Nowhere in the world are higher yields obtained than in Belgium. To keep up its position on the forefront of innovation, the potato processing industries are continuously looking at promising novel technologies that could improve business processes at any stage of growth. The close follow up of parcels on the land as form above is becoming an important tool to improve the quantity and the quality of the potato crop, and reduce the risks in order to plan the storage, packaging or processing and as such to strengthen the competiveness of the Belgian potato in a global market. The iPot project, financed by the Belgian Science Policy Office (BELSPO), aims to provide the Belgian potato sector, represented by Belgapom, with near real time information on field condition (weather-soil) and crop development, and with early yield estimates, derived from a combination of satellite images and crop growth models. Satellite images are used since long for crop monitoring at regional level by the public sector. Traditionally, low to medium resolution images, with pixel sizes from 250m to 1km are used for providing information on crop growth and development, and on yield at regional scale. However, the recent launch of constellations of high resolution optical sensors (DMC, Sentinel-2) offering spatially detailed information (20m pixel size) at high frequency (every 2 to 3 days) and at low cost, is creating a (r)evolution in the world of crop monitoring. Automatic processing chains have been developed to derive vegetation indices (NDVI) and biophysical parameters (fAPAR, LAI, fCover). Maps are being derived on a regular basis with for each pixel the actual development stage of the potato crop. This on-line scanning of the growth (phenology) is expected to result in an increased performance of crop growth models and better yield predictions. Once the data for crop phenology are incorporated into the model (B-CGMS), the yield data collected at the parcel level will be assimilated into the model using optimization algorithms to minimize the discrepancies between observed and simulated yield time series in order to improve further yield estimations. The combination of these new earth observation and modelling techniques arose the interest of a new type of users, mainly from the private sector (agro-industry, agricultural insurers, etc.). The iPot project aims to bridge the gap between the latest research efforts regarding crop growth monitoring and the industry. An intuitive web based geo-information platform is being developed to allow both the Belgian potato industry and research centers to access, analyze and combine the data with their own field observations in closed collaboration with the farmers, for improved decision-making. [less ▲]

Detailed reference viewed: 64 (5 ULg)
Full Text
Peer Reviewed
See detailSemi-empirical correlation to model heat losses along solar parabolic trough collectors
Dickes, Rémi ULg; Lemort, Vincent ULg; Quoilin, Sylvain ULg

in Proceedings of ECOS 2015 (2015, July)

Solar thermal power plants convert sunshine energy into useful heat and electricity by means of solar collectors and a thermodynamic cycle. Among the different solar collector technologies, parabolic ... [more ▼]

Solar thermal power plants convert sunshine energy into useful heat and electricity by means of solar collectors and a thermodynamic cycle. Among the different solar collector technologies, parabolic troughs are nowadays the most widespread together with solar towers. In order to improve the computation speed required to simulate the temperature profile along solar parabolic trough collectors, a correlation estimating the effective heat losses of the receiver is an essential tool. However, the relations found in the literature lack accuracy and do not translate effectively the effects of the operating conditions in all cases. In this work, an alternative correlation is proposed and calibrated with the results of a deterministic model. Better fitting performance is demonstrated when compared to the prediction of the pre-existing correlations. The benefits and limitations of the new correlation are finally assessed. [less ▲]

Detailed reference viewed: 94 (14 ULg)
Full Text
Peer Reviewed
See detailComparative study of different output metrics for a three weakly coupled resonator sensor
Zhao, Chun; Wood, Graham; Xie, J.B. et al

in Proceedings of Solid-State Sensors, Actuators and Microsystems (Transducers 2015) (2015, July)

This work, for the first time, investigates the characteristics of different output metrics for a three degree-of-freedom (DoF) coupled resonator sensor. The main aspects examined are sensitivity and ... [more ▼]

This work, for the first time, investigates the characteristics of different output metrics for a three degree-of-freedom (DoF) coupled resonator sensor. The main aspects examined are sensitivity and linear range. It is shown from electrical measurements that using the vibration amplitude ratio as an output signal provides improved sensitivity and linearity range, compared to other methods such as shift in eigenstate, mode frequency or amplitude difference. [less ▲]

Detailed reference viewed: 37 (4 ULg)
Full Text
Peer Reviewed
See detailDynamic of agricultural innovations diffusion in Burkina Faso
Zongo, Bétéo ULg; Diarra, Abdoulaye; Barbier, Bruno et al

in Field, Christopher; Jouzel, Jean; Le Treut, Hervé (Eds.) Our ender common climate future change, Abstract Book (2015, July)

This study highlights the factors determining the spread of agricultural innovations for water harvesting since the drastic effects of drought 70s in Burkina Faso. These innovations include zaï, stone ... [more ▼]

This study highlights the factors determining the spread of agricultural innovations for water harvesting since the drastic effects of drought 70s in Burkina Faso. These innovations include zaï, stone bunds, bunds land, half-moons, mulching and grass strips. A survey of 629 farmers revealed that farmers fall into five categories which are the pioneer, early, latecomer, late and non-adopters. After four decades of diffusion (1974-2013) the rate is estimated at 69.3% for stone bunds, 49.1% for zaï, 26.2% for grass strips and less than 10% for half-moons, bunds land and mulching. The multinomial logit model showed that the climatic conditions in the Sahel zone, age and perception of increased dry spells of farm households promoted the spread of these innovations. However, the low level of organization and access to agricultural services were the major constraints to their adoption. [less ▲]

Detailed reference viewed: 41 (4 ULg)
Full Text
See detailMarcel-Henri Jaspar, "Le plus gaullien des Belges" ? Construction et déconstruction d'une réputation (1940-1966)
Genin, Vincent ULg

in Lanneau, Catherine; Depagie, Francis (Eds.) De Gaulle et la Belgique (2015, July)

Detailed reference viewed: 35 (5 ULg)
Peer Reviewed
See detailShaping Pulses to Control Bistable Biological Systems.
Sootla, Aivar ULg; Oyarzun, Diego; Angeli, David et al

in In Proceedings of the American Control Conference. (2015, July)

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailOn Monotonicity and Propagation of Order Properties
Sootla, Aivar ULg

in Proceedings of the American Control Conference (2015, July)

Detailed reference viewed: 7 (1 ULg)
Full Text
See detailAsymmetric limit cycle oscillations in systems with symmetric freeplay
Dimitriadis, Grigorios ULg

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

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

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

Detailed reference viewed: 39 (5 ULg)
Full Text
See detailUsing 2D-PIV measurements to compute unsteady aerodynamic loads on a flat plate at high angle of attack
Guissart, Amandine ULg; Bernal, Luis; Dimitriadis, Grigorios ULg et al

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

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

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

Detailed reference viewed: 69 (21 ULg)
Full Text
See detailUnsteady Viscous-Inviscid Coupling Simulations of Separated Laminar Flows Around 2D Airfoils
Rothkegel Ide, José Ignacio ULg; Dimitriadis, Grigorios ULg

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

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

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

Detailed reference viewed: 42 (10 ULg)
Full Text
See detailTheoretical and experimental investigation of a structurally and aerodynamically nonlinear pitch and flap wing
Verstraelen, Edouard ULg; Boutet, Johan ULg; Grappasonni, Chiara ULg et al

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

This paper presents and experimental and theoretical investigation of a novel nonlinear aeroelastic system. It consists of a wing with pitch and flap degrees of freedom, suspended from a leaf spring ... [more ▼]

This paper presents and experimental and theoretical investigation of a novel nonlinear aeroelastic system. It consists of a wing with pitch and flap degrees of freedom, suspended from a leaf spring secured in a nonlinear clamp. Both the structural and the aerodynamic forces acting on the wing can be nonlinear, depending on the amplitude of oscillations. Wind tunnel experiments show that the system undergoes a supercritical Hopf bifurcation that leads to small amplitude limit cycle oscillations. At a particular airspeed, the pitch amplitude jumps to a much higher value and dynamic stall starts to occur. Three mathematical models of the system are formulated, one based on linear aerodynamics and two based on the Leishman-Beddoes dynamic stall model. The objective of the modelling is to determine whether the jump in pitch oscillation amplitude is due to dynamic stall. The predictions for amplitude, frequency and mean angle of the limit cycle oscillations are compared to the experimental observations. All three models predict the small amplitude oscillations with satisfactory accuracy. The complete Leishman-Beddoes model predicts the occurrence of a jump in pitch amplitude but the magnitude of this jump is signi cantly overestimated. The other two models completely fail to model the jump. The failure of the Leishman-Beddoes model to predict the correct post-jump oscillation amplitude may be due to the values selected for the model parameters. [less ▲]

Detailed reference viewed: 86 (19 ULg)
Full Text
Peer Reviewed
See detailA comparative study for simulation of heat transport in large district heating network
Sartor, Kevin ULg; Thomas, David ULg; Dewallef, Pierre ULg

in Prooceedings of ECOS 2015 (2015, June 29)

Detailed reference viewed: 56 (23 ULg)
Peer Reviewed
See detailDéveloppement et analyse d’un modèle in vitro d’infection épidermique par dermatophytes anthropophiles
Faway, E; Cambier, Ludivine ULg; Lambert de Rouvroit, C et al

in Proceedings du 33e Congrès Annuel de Recherche Dermatologique (CARD) (2015, June 25)

Detailed reference viewed: 22 (0 ULg)
Full Text
Peer Reviewed
See detailOverview and recommendation on urban densification potential in Liège, Belgium
Attia, Shady ULg

in AEE INTEC (Ed.) High-quality retrofit and redensification with timber construction systems (2015, June 18)

Belgium, like many European Countries, has a serious challenge in the housing sector. The Federal planning bureau estimates the increase of population by one million inhabitants by 2030, which represent ... [more ▼]

Belgium, like many European Countries, has a serious challenge in the housing sector. The Federal planning bureau estimates the increase of population by one million inhabitants by 2030, which represent 600.000 additional family requiring accesses to new housing facilities. Population ageing (mainly due to increasing life expectancy) combined with a constant growing rate of individuals living in collective households, leads to a substantial increase of demand of collective households (Vandresse & Bureau, 2013). This highlights a substantial challenge underlined mainly in the need to live in cities, which as consequence will increase the demand for smaller housing with or without integrated services or equipment in common. Furthermore, the stringent European performance environmental regulations for the building sector require that by 2020, all new construction are zero or nearly zero energy, (equivalent to 15 kWh/m2/year), with 60% efficient on-site coverage by renewable energy. The shortage of vacant land and the increasing energy performance requirements is pushing the idea of urban densification and zero energy construction households. During the recent 6 years, there has been a trend to use timber frame constructions as a sustainable solution facing the economic and environmental crisis in Belgium. However, there is lack of knowledge on the design, construction and operation of zero energy lightweight constructions for urban densification. The goal of this research is to provide an overview and recommendation on urban densification potential in Liège Province. The focused aim is to demonstrate validated design prototypes and products of different zero energy, timber frame construction systems and composite components. Thus inform and support the decision making of policy makers, municipalities, developers, and architects and building engineers in Belgium. [less ▲]

Detailed reference viewed: 109 (31 ULg)
Full Text
Peer Reviewed
See detailScreening and analyzing retrofit systems for zero energy renovation and their potential application in Liège, Belgium
Attia, Shady ULg

in AEE INTEC (Ed.) High-quality retrofit and redensification with timber construction systems (2015, June 18)

Retrofit systems for Zero Energy Renovation comes energy as the most topical subject in the Belgian construction sector. Concepts and solutions for zero energy renovation are a new topic. Since 2006 ... [more ▼]

Retrofit systems for Zero Energy Renovation comes energy as the most topical subject in the Belgian construction sector. Concepts and solutions for zero energy renovation are a new topic. Since 2006, Belgium has been striving to achieve the European ambitions of fulfilling the Kyoto Protocol by insulating more effectively and reducing CO2 emissions associated with the use of fossil fuel for operational and embodied energy in buildings. In 2011, a Belgian decree mandated the construction of nearly zero and nets zero energy buildings by 2020. Following the German PassivHaus Standard performance requirements the Belgian residential sector is aiming to achieve an energy consumption to less than 15 kWh/m2/year and an onsite renewable energy production up to 60% for every newly construct household. In this, context the study will build on grounded knowledge developed and implemented by the IEA ECBCS Annex 50: Prefabricated Systems for Low Energy Renovation of Residential Buildings. The goal of this research is to screen and select a series of envelope retrofitting solutions. The focused aim is to demonstrate validated envelope prototypes and products of different zero energy, timber frame construction systems and composite components. This will include the comparison of timber retrofit systems with conventional systems. Thus inform and support the decision making of policy makers, municipalities, developers, and architects and building engineers in Belgium. [less ▲]

Detailed reference viewed: 138 (24 ULg)
Full Text
Peer Reviewed
See detailWood, the material of tomorrow's retrofits
Ruellan, Guirec ULg; Attia, Shady ULg

in High-quality retrofit and redensification with timber construction systems (2015, June 18)

The construction sector has focused for many years on performance improvement of new constructions. Today's largest problem is the energetic retrofitting of existing buildings. The building retrofit is an ... [more ▼]

The construction sector has focused for many years on performance improvement of new constructions. Today's largest problem is the energetic retrofitting of existing buildings. The building retrofit is an important strategy for energy savings. Building retrofit is addressed towards the real estate in Europe and allows for substantial gains, especially for heating houses and urban densification. However retrofit requires the use of special construction techniques. The problem is quite different from that of the new buildings: adaptation to existing building, heritage conservation, elimination of thermal bridges, etc. In this context, wood is experiencing strong growth in its use in new constructions, due to its qualities. And we think that some of those allow more appropriate responses to retrofit than other traditional materials. In this study, we will first present succinctly the problems related to the renovation, then we will dedicate ourselves to define the characteristics of the wood. The focus will be on some problems that commonly arise in wood constructions. We will then discuss a case, highlighting different characteristics of wood that are particularly important in this particular renovation. This allows us to observe on the ground the coherence of the choice of wood in the renovation. A discussion will close the study by summarizing the advantages and limitations of the use of wood in the renovation This is not to show that wood is one of the most environmentally friendly building materials, or demonstrate the sustainable character of retrofit. This is to see that the timber construction systems can provide an adequate response to many retrofit issues. [less ▲]

Detailed reference viewed: 49 (7 ULg)
Full Text
Peer Reviewed
See detailCompétition partisane, changement climatique et écologie politique : convergences et conflits sur les thématiques politiques
Piet, Grégory ULg

in Flipo, Fabrice (Ed.) Les actes du Colloque "Penser l'écologie politique" (2015, June 16)

Detailed reference viewed: 57 (3 ULg)
Full Text
See detailEVALUATION OF CONTINUOUS SUPRASCAPULAR NERVE BLOCKADE IN THE TREATMENT OF REFRACTORY ADHESIVE CAPSULITIS : A RETROSPECTIVE STUDY
MUTSERS, Pierre ULg; LECOQ, Jean-Pierre ULg; GOFFIN, Pierre ULg et al

in Abstract Book du Residence Meeting de la Société Belge d'Anesthésie (2015, June 15)

Detailed reference viewed: 40 (12 ULg)
Full Text
Peer Reviewed
See detailIs it possible for large herds to graze while keeping a high milk yield level? The experience of two Belgian dairy farms.
Lessire, Françoise ULg; Hornick, Jean-Luc ULg; Dufrasne, Isabelle ULg

in van den Pol-van Dasselaer, Agnes; Aarts, H.F.M; De Vliegher, Alex (Eds.) et al Grassland and forages in high output dairy farming systems (2015, June 15)

Grazing is more and more abandoned because of increasing size of herds and automation of herd management (e.g. automatic milking system – AMS). In this context, this study aims to evaluate milk production ... [more ▼]

Grazing is more and more abandoned because of increasing size of herds and automation of herd management (e.g. automatic milking system – AMS). In this context, this study aims to evaluate milk production and composition of 2 large Belgian dairy herds equipped with AMS during winter and summer. These herds were followed over 2 years. At grazing, 30% of the offered feed was grass. Milk production in both herds was similar in summer and winter (30.2 ± 7.14 vs 29.7 ± 7.8 ± in Herd 1 and 26.9 ± 0.8 vs 26.4 ± 0.8 in Herd 2) while their milk composition differed. In conclusion, it is possible for grazing to be preserved even in large herds without impacting noticeably on the herd performance. [less ▲]

Detailed reference viewed: 29 (5 ULg)
Full Text
See detailRegional crop and irrigation monitoring: some examples of (new) opportunities
Wellens, Joost ULg

in Begian workshop: Space4Food (2015, June 11)

Satellite images are used since long for agricultural monitoring at different spatial scales: from continental, national to regional and even field level. Combined with agro-meteorological data and ... [more ▼]

Satellite images are used since long for agricultural monitoring at different spatial scales: from continental, national to regional and even field level. Combined with agro-meteorological data and simulation models they constitute powerful decision support tools for agriculture throughout the world. Some examples at different scales and domains are presented. In Burkina Faso, free MODIS time series of coarse resolution vegetation indices (NDVI), phenological and meteorological data are combined in a multiple regression analysis for early yield warning in the cotton industry. Using a limited amount of data, it allows a decent yield forecasting more than a month before harvest. Time series of ERS radar images are analysed to monitor water intakes on the irrigated perimeter of Tadla (Morocco). The back-scatter intensity gives a clear indication of the top soil moisture state, permitting irrigation managers a regional monitoring of the irrigation water distribution and a guidance in the water allocation pricing. Actually in Belgium, and soon to be exported elsewhere, very-high resolution imagery (SPOT-5 Take5) are used to observe crop canopy development (fAPAR, fCover) on field level. Either by curve-fitting functions or assimilating these satellite derived data in existing crop growth models, improved and spatially more detailed forecasting systems are being developed. Although mostly still in the domain of applied research, the new availability of high spatial and temporal resolution imageries such those that will provide the Sentinel satellites paves the way to a growing number of operational end users. [less ▲]

Detailed reference viewed: 30 (4 ULg)
Full Text
See detailChronic Toxic Hepatitis in Beef Calves due to Mycotoxins in Mixed Feed
Theron, Léonard ULg; Callebaut, Alfons; Bayrou, Calixte ULg et al

in Zemljic, Borut; Podpecan, Ozbalt; Zmljic-Jokhadar, Spela (Eds.) Proceedings of the XV middle European Buiatric Congress (2015, June 10)

Mycotoxins intoxination is an emerging disorder in Belgium, due to evolution of cultural practices and harvesting weather conditions. These intoxinations are difficult to diagnose for the vet practioners ... [more ▼]

Mycotoxins intoxination is an emerging disorder in Belgium, due to evolution of cultural practices and harvesting weather conditions. These intoxinations are difficult to diagnose for the vet practioners, since unspecific clinical signs, and their impact on ruminant disorder remains controversial. Although legal concentrations have been established for mycotoxins in the EU, farm forages are most of the time not tested (EU 2006/576/EC). In January 2015, a 500 calvings cross-bred Belgian blue cattle herd (BVDV free) referred a second (the first was directly sent to the rendering-plant) unexplained fatal case of jaundice on a 2 months-old calf to the Clinic for Ruminants of the University of Liège for necropsy. In 2013, a case of jaundice due to a Salmonella dublin hepatocholecystitis had previously diagnosed in this farm (Ronzoni et al., 2014), but so far preventions measures were implemented. Necropsy revealed generalized icterus, mild bilirubinuria, splenomegaly, but no precise etiology. On February a second 2 month old calf with jaundice is referred, lethargic, normothermic with a mild diarrhea, Calf shown generalized jaundice, anemia, elevation of leukocytes (neutrophils, eosinophils and monocytes), TGO, bilirubinemia, total biliary acids and Globulins (alpha2). He had also diminished erythrocytes and albuminemia. Copraemia, leptospirosis serology, leademia, hemoculture and pancreatic enzymes were within normal ranges, ruling out classic causes of jaundice in calf. Abdomen ultrasonography revealed a mild hyperechogenicity of the liver but no gall bladder modifications. Symptomatic treatment was based on symptoms, with fluidotherapy and choleretics. A third calf was referred three days after in a worst clinical condition, with also a severely modified liver enzymes, but no anemia. Three days after, this calf died and a necropsy revealed petechiae and hemorrhages in the abomasum, congestive mucosae in the distal bowel, white depot in the kidney medulla, modified urine and splenomegaly. Bile bacteriology and leptospirosis PCR was negative and liver histopathology revealed a severe histopathological liver degeneration associated with a disruption of the parenchyma and marked hyperplasia of the bile ducts compatible with chronic metabolic disorder. Meanwhile, the anemic calf recovered from anemia without any treatment after 4 days and was discharged from the Clinic for Ruminants. Considering the weird clinical patterns of these jaundice cases, and the fact that only calves from 2 to 3 months were affected, a nutritional origin as etiology was suspected. To test it, eight clinically healthy two to three months-old calves, of two different pens were sampled. TGO, GLDH, GGT or biliary acids were either modified and the values tended to increase with the age of the calves. The water was analyzed for classic toxics, and cultured for total germ content and everything were within recommended values. The calves fed with a milk replacer (30 % milk powder), and a commercial calf starter until one month of age. Then, they were given a mixed feed (containing cereal mix, cocoa, beet pulp, soja, maize), made at the farm from primary product/byproducts bought from different sources. The mix was tested for mycotoxins presence and ranged from 0.8 to 1.5 ppm of Desoxynivalenone (DON), and 115-215 ppb of Zearalenone (ZEA). The principal source of DON was maize (3.1 to 6.2 ppm), as for ZEA (0.3-0.6 ppm), but several compounds contained small dose of DON (0.2-0.7 ppm) for Barley feed, Tanned soja. Cacao contained 2.7 to 5.9 ppb of Ochratoxine (OTA). Nutritionnal recommendations were immediately given with a change in the source of maize and an addition of clay and yeast at 40g/calf/day and hay. Since, any other hypothetic origin to this progressive hepatic intoxination was demostrated, and that the doses founded, even if barely legal in the mix, are not accounted for toxic in the EU regulation, we believe that the calves were chronically exposed to these toxins. However, some mycotoxins experts still claim that various clinical signs would be observed in ruminants, if the rumen is partially defaunated, like in our case with the lake of forage. We propose that monitoring of subclinical liver health could be a key to screen DON effects. [less ▲]

Detailed reference viewed: 84 (2 ULg)
Peer Reviewed
See detailQuelques écueils à éviter lors de la rédaction et la publication d'un règlement-taxe
Bortolotti, Aurélien ULg

in Le droit communal - Etat des lieux (2015, June 05)

La présente contribution a pour seule ambition d’énoncer et d’expliquer les écueils à éviter lors de la rédaction et de la publication d'un règlement-taxe. Il ne sera, par conséquent, pas question de ... [more ▼]

La présente contribution a pour seule ambition d’énoncer et d’expliquer les écueils à éviter lors de la rédaction et de la publication d'un règlement-taxe. Il ne sera, par conséquent, pas question de rappeler les principes généraux en la matière, mais au contraire d’envisager les problèmes récurrents soulevés devant les juridictions administratives et judiciaires. Nous analyserons successivement la motivation du règlement-taxe, sa rétroactivité, sa publication ainsi que le respect de la procédure de taxation d’office. Ensuite, nous examinerons la procédure de contestation de ces impôts. Nous rappellerons, à cette occasion, le délai pour introduire une réclamation administrative, mais également la représentation de l’autorité locale devant les instances judiciaires. Nous clôturerons notre analyse par la question de l’indemnité de procédure et plus particulièrement les questions préjudicielles récemment posées par le tribunal de première instance d’Arlon à la Cour constitutionnelle. Ce domaine n’échappant pas à la régionalisation des compétences, il convient préalablement d’envisager la manière dont les différents législateurs régionaux réglementent les principes applicables à ces perceptions tout en conservant à l’esprit que la loi du 24 décembre 1996 relative à l'établissement et au recouvrement des taxes provinciales et communales reste la colonne vertébrale de ces réformes. [less ▲]

Detailed reference viewed: 32 (6 ULg)
Full Text
See detailModélisation de la remontée des eaux dans les anciennes mines de charbon : un outil pour détecter les seuils de risques d’inondation en plaine alluviale de la Meuse près de Liège (Belgique)
Dassargues, Alain ULg; Wildemeersch, Samuel; Orban, Philippe ULg et al

in Des villes et des territoires sobres et sûrs, Synthèse des interventions (2015, June 03)

La plaine alluviale de la Meuse occupe la partie centrale du bassin charbonnier de Liège. Durant les exploitations minières, les niveaux d’eau des aquifères avaient été rabattus par des pompages d’exhaure ... [more ▼]

La plaine alluviale de la Meuse occupe la partie centrale du bassin charbonnier de Liège. Durant les exploitations minières, les niveaux d’eau des aquifères avaient été rabattus par des pompages d’exhaure. Des galeries d’exhaure creusées à partir des pieds de versant dans la vallée de la Meuse contribuaient également à dénoyer le gisement. La fermeture des dernières exploitations minières durant les années 70 et 80 a été le plus souvent assortie d’un arrêt des opérations de pompage qui y sont associées. Ceci a induit une remontée significative des eaux souterraines avec des conséquences indésirables possibles. Les modèles hydrogéologiques peuvent grandement aider à simuler les écoulements des eaux souterraines dans le contexte particulier des travaux miniers. Cependant, les techniques de modélisation classiques ne sont pas adaptées à ce contexte car le milieu est fortement perturbé par les anciens travaux et les réseaux de galeries. Par conséquent, des techniques de modélisation spécifiques ont été développées. Il s'agit d'une combinaison de modèles de boîte (ne nécessitant que quelques paramètres) pour calculer les niveaux d'eau moyens dans les zones exploitées, avec une modélisation physiquement basée et spatialement distribuée représentant explicitement les zones inexploitées et prenant en compte les interactions entre ces deux sous-domaines. Grâce à ce couplage, les échanges d'eau entre les zones exploitées et inexploitées sont explicitement pris en compte. La méthode permet de simuler la remontée des eaux souterraines après la fermeture des mines et des phénomènes associés tels que les 'coups d'eau' produits par les galeries drainantes. Les concepts et équations de la méthode sont présentés et illustrés sur des cas synthétiques, puis sur l'application de la zone de Cheratte-Blégny. [less ▲]

Detailed reference viewed: 42 (4 ULg)
Full Text
See detailImpact des changements climatiques sur la principale réserve en eau souterraine alimentant la ville de Liège (Belgique)
Goderniaux, Pascal; Orban, Philippe ULg; Compère, Jean-Michel et al

in Des villes et des territoires sobres et sûrs, Synthèse des interventions (2015, June 02)

Le changement climatique amène de nouvelles 'pressions' sur les ressources en eaux de surface et souterraines dans de nombreuses zones du monde. Des travaux scientifiques sont nécessaires pour aider les ... [more ▼]

Le changement climatique amène de nouvelles 'pressions' sur les ressources en eaux de surface et souterraines dans de nombreuses zones du monde. Des travaux scientifiques sont nécessaires pour aider les gestionnaires de l'eau à planifier les changements futurs. Un générateur de climats transitoire sophistiqué est utilisé en combinaison avec une modélisation intégrée hydrologique (HydroGeoSphere) pour évaluer les impacts sur les ressources en eaux souterraines de façon probabiliste. Cette nouvelle méthodologie est appliquée pour l'aquifère crayeux de Hesbaye (bassin Geer en Belgique) qui est le principal réservoir d'eau souterraine pour l'alimentation de la ville de Liège. Les sources d'incertitude étudiées sont les suivantes: (1) l'incertitude liée à la calibration du modèle hydrologique, en utilisant 'UCODE_2005'; (2) l'incertitude liée aux modèles climatiques mondiaux et régionaux (GCM et RCM); (3) l'incertitude liée à la variabilité naturelle du climat, en utilisant des scénarios stochastiques de changement climatique locaux. 100 changements climatiques équiprobables scénarios ont été générés sur 2010-2085 pour chacun des six RMC différents. Les résultats montrent que bien que les intervalles de confiance à 95% calculés autour des niveaux piézométriques calculés restent importants, l'effet du changement climatique devient clair et plus prononcé que la variabilité naturelle du climat d'ici 2085. Cette méthodologie constitue une réelle amélioration dans le domaine des prévisions de l'évolution des réserves en eau souterraine dans des conditions de changement climatique car il permet aux gestionnaires d'analyser les risques et prendre des décisions en toute connaissance du degré de confiance des résultats. [less ▲]

Detailed reference viewed: 80 (4 ULg)
Full Text
See detailNumerical study of intrinsic features of isolas in a 2-dof nonlinear system
Detroux, Thibaut ULg; Noël, Jean-Philippe ULg; Masset, Luc ULg et al

in Proceedings of the ICEDyn conference (2015, June)

In the present paper, isolated response curves in a nonlinear system consisting of two masses sliding on a horizontal guide are examined. Transverse springs are attached to one mass to provide the ... [more ▼]

In the present paper, isolated response curves in a nonlinear system consisting of two masses sliding on a horizontal guide are examined. Transverse springs are attached to one mass to provide the nonlinear restoring force, and a harmonic motion of the complete system is imposed by prescribing the displacement of their supports. Numerical simulations are carried out to study the conditions of existence of isolated solutions, their bifurcations, their merging with the main response branch and their basins of attraction. This is achieved using tools including nonlinear normal modes, energy balance, harmonic balance-based continuation and bifurcation tracking, and global analysis. [less ▲]

Detailed reference viewed: 59 (7 ULg)
Full Text
Peer Reviewed
See detailApplication of the morphological acceleration factor in fluvial hydraulics
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in E-proceedings of the 36th IAHR World Congress (2015, June)

The morphological acceleration factor (Morfac) has been widely used to speed-up morphodynamic simulations, mostly in coastal applications. The value of Morfac was generally set by trial and error and ... [more ▼]

The morphological acceleration factor (Morfac) has been widely used to speed-up morphodynamic simulations, mostly in coastal applications. The value of Morfac was generally set by trial and error and little theoretical background is available to identify an optimal value of Morfac for a given application and a target level of accuracy. In the present research, we generalize the few previous theoretical analyses regarding two main aspects. First, the range of the considered parameters (Froude number, relative roughness, transport rate …) has been considerably extended to cover typical values characterizing fluvial applications and not only coastal settings. Second, we show that the optimal value of Morfac depends greatly on the specific mathematical formulation of the flow model and on the flow regime. [less ▲]

Detailed reference viewed: 72 (4 ULg)
Full Text
Peer Reviewed
See detailRegression-based modelling of a fleet of gas turbine engines for performance trending
Borguet, Sébastien ULg; Léonard, Olivier ULg; Dewallef, Pierre ULg

in Proceedings of ASME Turbo Expo 2015 (2015, June)

Module performance analysis is a well-established framework to assess changes in the health condition of the components of the engine gas-path. The primary material of the technique is the so-called ... [more ▼]

Module performance analysis is a well-established framework to assess changes in the health condition of the components of the engine gas-path. The primary material of the technique is the so-called vector of residuals, which are built as the difference between actual measurement taken in the gas-path and values predicted by means of an engine model. Obviously, the quality of the assessment of the engine condition depends strongly on the accuracy of the engine model. The present paper proposes a new approach for data-driven modelling of a fleet of engines of a given type. Such black-box models can be designed by operators such as airlines and thirdparty companies. The fleet-wide modelling process is formulated as a regression problem that provides a dedicated model for each engine in the fleet, while recognising that all engines are of the same type. The methodology is applied to a virtual fleet of engines generated within the ProDiMES environment. The set of models is assessed quantitatively through the coefficient of determination and is further used to perform anomaly detection. [less ▲]

Detailed reference viewed: 55 (1 ULg)
Full Text
Peer Reviewed
See detailMéthodes de calcul des sources pour des bobines non-maillées avec la formulation éléments finis A − V
Ferrouillat, Pauline; Guérin, Christophe; Meunier, Gérard et al

in Proceedings of NUMELEC 2015 (2015, June)

Dans cet article, différents calculs du champ électromagnétique source sont décrits pour la formulation éléments finis A − V avec des bobines non-maillées. Ces différents calculs sont appliqués ... [more ▼]

Dans cet article, différents calculs du champ électromagnétique source sont décrits pour la formulation éléments finis A − V avec des bobines non-maillées. Ces différents calculs sont appliqués sur une machine asynchrone pour définir la meilleure approche. Cette source doit pouvoir ensuite être utilisée sur un domaine réduit fixe ou en mouvement. [less ▲]

Detailed reference viewed: 20 (1 ULg)
Full Text
Peer Reviewed
See detailDesign Sensitivity Analysis for Shape Optimization of Nonlinear Magnetostatic Systems
Kuci, Erin ULg; Duysinx, Pierre ULg; Dular, Patrick ULg et al

in Proceedings of COMPUMAG 2015 (2015, June)

In this paper, a direct and an adjoint analytic sensitivity analysis for a nonlinear magnetostatic system is obtained, in the context of shape optimization for any design function. The calculations are ... [more ▼]

In this paper, a direct and an adjoint analytic sensitivity analysis for a nonlinear magnetostatic system is obtained, in the context of shape optimization for any design function. The calculations are based on the material derivative concept of continuum mechanics. The resulting sensitivity formula can be expressed as either a volume integral or as a boundary integral along the interface where shape modification occurs. A method for the calculation of the design velocity field and mesh updating scheme is introduced as well. The accuracy of the methodology is analysed on an inductor system, suggesting that the volume integration technique should be preferred. All methods are freely available for further testing in the open source environment GetDP/Gmsh. [less ▲]

Detailed reference viewed: 31 (9 ULg)
Full Text
Peer Reviewed
See detailA process to address electricity distribution sector challenges: the GREDOR project approach
Cornélusse, Bertrand ULg; Vangulick, David; Glavic, Mevludin ULg et al

in Proceedings of the International Conference on Electricity Distribution, CIRED 2015 (2015, June)

This paper presents a general process set in the GREDOR (French acronym for “Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables”) project to address the challenges in distribution ... [more ▼]

This paper presents a general process set in the GREDOR (French acronym for “Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables”) project to address the challenges in distribution systems posed by the integration of renewable generation, changing load patterns, and the changes in the electricity market sector. A use case describing interactions among different players that fits the process is also presented. A pseudo-dynamic approach to Global Capacity Announcement as a way to increase penetration of Renewable Energy Sources in a distribution system is elaborated in more details. [less ▲]

Detailed reference viewed: 190 (14 ULg)
Full Text
See detailSpeckle interferometry in the long-wave infrared for combining holography and thermography in a single sensor. Applications to nondestructive testing: the FANTOM project
Georges, Marc ULg

in Lehmann, Peter; Osten, Wolfgang; Albertazzi, Armando (Eds.) Optical Measurement Systems for Industrial Inspection IX (2015, June)

Speckle interferometry in the thermal wavelengths range (long-wave infrared, 8-14 μm), combining a CO2 laser and recording with an uncooled microbolometer camera is presented. In this wavelength range ... [more ▼]

Speckle interferometry in the thermal wavelengths range (long-wave infrared, 8-14 μm), combining a CO2 laser and recording with an uncooled microbolometer camera is presented. In this wavelength range specklegrams are affected by the thermal radiation emitted by objects at room temperature. This allows simultaneously capturing temperature and surface shape information about objects. The FANTOM project is based on this concept and an instrument was developed to take advantage of this natural data fusion. It has been used in a variety of nondestructive testing applications where both information are useful, specifically in aeronautical composite structures. [less ▲]

Detailed reference viewed: 33 (2 ULg)
Full Text
Peer Reviewed
See detailTime-domain finite-element homogenisation of laminated iron cores with net circulating currents
Gyselinck, Johan; Dular, Patrick ULg; Krähenbühl, Laurent et al

in Proceedings of COMPUMAG 2015 (2015, June)

This paper deals with the time-domain homogenization of laminated cores in 2D or 3D finite element (FE) models of electromagnetic devices, in particular allowing for net circulating current in the ... [more ▼]

This paper deals with the time-domain homogenization of laminated cores in 2D or 3D finite element (FE) models of electromagnetic devices, in particular allowing for net circulating current in the laminations (which may result from imperfect or damaged insulation). The homogenization is based on the decomposition of the variation of the induction in the lamination thickness by means of a orthogonal set of polynomial basis functions, in conjunction with the magnetic vector potential (MVP) formulation. The conventional even skin-effect basis functions are linked to net flux, whereas the odd ones are now added so as to allow for net current. The approach is validated through a simple linear 2D test case, although the extension to 3D nonlinear problems is straightforward. [less ▲]

Detailed reference viewed: 23 (0 ULg)
Full Text
Peer Reviewed
See detailFinite element models for studying the capacitive behaviour of wound components
De Grève, Zacharie; Dular, Patrick ULg; Sabariego, Ruth V. et al

in Proceedings of COMPUMAG 2015 (2015, June)

Finite element models of increasing accuracy are proposed for the study of the capacitive behaviour of wound magnetic components. Simple models, which are based on the classical assumption of a decoupling ... [more ▼]

Finite element models of increasing accuracy are proposed for the study of the capacitive behaviour of wound magnetic components. Simple models, which are based on the classical assumption of a decoupling between electric and magnetic fields, are first described. Formulations which enable such a coupling are then presented. The models are tested on various coreless inductors, made of round conductors or copper sheets. The results are discussed and compared with experimental data measured with an impedance analyzer. [less ▲]

Detailed reference viewed: 22 (1 ULg)
Peer Reviewed
See detailHydrodynamics, mixing and mass transfer in baffled stirred tanks
de Lamotte, Anne ULg; Delafosse, Angélique ULg; Calvo, Sébastien ULg et al

in Proceedings of the 15th European Conference on Mixing (2015, June)

The present work presents CFD simulations of hydrodynamics, mixing and mass transfer in a surface-aerated baffled stirred tank. The modelling of the multiphase flow is realized via an Euler-Euler approach ... [more ▼]

The present work presents CFD simulations of hydrodynamics, mixing and mass transfer in a surface-aerated baffled stirred tank. The modelling of the multiphase flow is realized via an Euler-Euler approach. Three closure models are tested for the resolution of the RANS equations. When fully-developed flow field is reached, gas-liquid transfer is implemented with a local mass transfer coefficient estimated by the eddy cell model, and the temporal evolution of dissolved gas concentration is predicted.Hydrodynamic and mixing quantities as well as mass transfer parameters for the different turbulence models are compared with experimental data available for the same geometrical and operating features. A critical analysis of the prediction results allow to assess the models capabilities and to highlight the possible critical issues of the simulations. [less ▲]

Detailed reference viewed: 90 (23 ULg)
Full Text
Peer Reviewed
See detailWide range progressive inductor models in magnetic vector potential finite element formulations
Dular, Patrick ULg; Kuo-Peng, Patrick; Ferreira da Luz, Mauricio et al

in Proceedings of NUMELEC 2015 (2015, June)

Wide range progressive refinements of the inductors in magnetic vector potential finite element formulations are done with a subproblem method. Their current sources are first considered via magnetomotive ... [more ▼]

Wide range progressive refinements of the inductors in magnetic vector potential finite element formulations are done with a subproblem method. Their current sources are first considered via magnetomotive force or Biot-Savart models up to their volume finite element models, from statics to dynamics. A novel way to define the associated source fields is proposed to lighten the computational efforts, via the conversion of the common volume sources to surface sources, with no need of any pre-resolution. Accuracy improvements are then efficiently obtained for local currents and fields, and global quantities, i.e. inductances, resistances, Joule losses and forces. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailEfficient Delta-Parametrization of 2D Surface-Impedance Solutions
Krähenbühl, Laurent; Dular, Patrick ULg; Péron, Victor et al

in Proceedings of COMPUMAG 2015 (2015, June)

Impedance boundary condition methods (IBCs) are among the most efficient methods for solving time-harmonic eddy-current problems with a small skin depth (delta). However for a wide range of frequencies ... [more ▼]

Impedance boundary condition methods (IBCs) are among the most efficient methods for solving time-harmonic eddy-current problems with a small skin depth (delta). However for a wide range of frequencies (or material conductivities) the standard approach is no more efficient, since it requires for each frequency (or conductivity) the computation of a finite element (FE) complex-valued problem. Moreover, the accuracy of IBC decreases dramatically for large delta. As an extension of our previous work, we propose here a more detailed method of parametrization in delta of the 2D small-delta eddy-currents problem. This numerically efficient method gives a very good precision for all the frequencies difficult to address, i.e. from the frequency corresponding to the last good solution obtainable by meshing the conductor up to infinity (perfect conductor solution). [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailModular modelling of combined AC and DC systems in dynamic simulations
Aristidou, Petros ULg; Papangelis, Lampros ULg; Guillaud, Xavier et al

in Proc. of IEEE PES 2015 PowerTech conference (2015, June)

A formulation is proposed in which an AC-DC system is modeled as a combination of AC grids, DC grids, injectors, AC two-ports and AC/DC converters, respectively. This modular modelling facilitates the ... [more ▼]

A formulation is proposed in which an AC-DC system is modeled as a combination of AC grids, DC grids, injectors, AC two-ports and AC/DC converters, respectively. This modular modelling facilitates the dynamic simulation of future complex AC/DC systems. Furthermore, it can be exploited by the solver, which performs less operations on components with lower dynamic activity, and offers parallel processing of the time simulation. This approach is illustrated on a test system in which a multi-terminal DC grid connects two asynchronous AC systems, allows frequency support between them, and acts as emergency control against AC voltage instability. [less ▲]

Detailed reference viewed: 96 (22 ULg)
See detailNonlinear ground vibration identification of an F-16 aircraft - Part 1: Fast nonparametric analysis of distortions in FRF measurements
Vaes, Mark; Schoukens, Johan; Peeters, Bart et al

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

Although they are generally modelled as linear systems, aircraft structures are known to be prone to nonlinear phenomena. A specific challenge encountered with fighter aircraft, besides aeroelastic ... [more ▼]

Although they are generally modelled as linear systems, aircraft structures are known to be prone to nonlinear phenomena. A specific challenge encountered with fighter aircraft, besides aeroelastic nonlinearity, is the modelling of the wing-to-payload mounting interfaces. For large amplitudes of vibration, friction and gaps may be triggered in these connections and markedly impact the dynamic behaviour of the complete structure. In this series of two papers, the nonlinear dynamics of an F-16 aircraft is investigated using rigorous methods applied to real data collected during a ground vibration test campaign. The present work focuses on the detection, qualification and quantification of nonlinear distortions affecting frequency response function (FRF) measurements. The key idea of the approach is to excite the structure using a random signal with a user-defined amplitude spectrum, where only a set of well-selected frequencies is different from zero in the band of interest. It is demonstrated that this careful choice of the input frequencies allows, without any further user interaction, to quantify the importance of odd and even nonlinear distortions in the output spectra with respect to the noise level. At high excitation amplitude, the F-16 dynamics is found to exhibit substantial odd nonlinearities and less significant, yet not negligible, even nonlinearities. [less ▲]

Detailed reference viewed: 120 (10 ULg)
Full Text
Peer Reviewed
See detailA new formulation of state estimation in distribution systems including demand and generation states
Rousseaux, Patricia ULg; Toubeau, Jean-François; De Grève, Zacharie et al

in proceeedings of the 2015 Power Tech conference (2015, June)

Distribution system state estimation faces a major difficulty: the lack of real-time measurements. This imposes to add information, usually pseudo-measurements from historical data. This paper proposes a ... [more ▼]

Distribution system state estimation faces a major difficulty: the lack of real-time measurements. This imposes to add information, usually pseudo-measurements from historical data. This paper proposes a different, novel formulation of state estimation relying on the classification of loads into components (e.g. residential, commercial, etc.) and accounting for dispersed generation. The approach “by-passes” the use of pseudo-measurements by expressing the medium-voltage bus injections as functions of a small number of active power components at low-voltage level, treated as additional state variables. The injections at medium-voltage buses become equality constraints. A procedure to identify the above functions is detailed, which takes advantage of data collected by smart meters. [less ▲]

Detailed reference viewed: 92 (11 ULg)
Full Text
Peer Reviewed
See detailComparison of Nonlinear Domain Decomposition Schemes for Coupled Electromechanical Problems
Halbach, Alexandre ULg; Dular, Patrick ULg; Geuzaine, Christophe ULg

in Proceedings of COMPUMAG 2015 (2015, June)

The aim of this paper is to compare several domain decomposition schemes for nonlinear, coupled electromechanical problems. Both staggered and monolithic electrostatic/elastic formulations are combined ... [more ▼]

The aim of this paper is to compare several domain decomposition schemes for nonlinear, coupled electromechanical problems. Both staggered and monolithic electrostatic/elastic formulations are combined with an overlapping domain decomposition method applied either to the uncoupled, linear staggered resolutions or to the monolithic nonlinear system. The influence of the elastic waves frequency, of the electrostatic potential and of the mesh on the convergence rate is investigated on a simple 2D model of a vibrating micromembrane array. [less ▲]

Detailed reference viewed: 30 (5 ULg)
Full Text
Peer Reviewed
See detailMutation de l'image, mutation de l'intention ? L'impact des représentations numériques en composition architecturale
Cunin, Maxime; Yang, Maria C.; Elsen, Catherine ULg

in de Boissieu, Aurélie; Deshayes, Catherine; Tufano, Antonella (Eds.) Mutations du Projet - Milieux et Cultures Numériques (2015, June)

Les architectes ont toujours eu recours à de multiples représentations pour générer, faire évoluer puis communiquer leurs concepts architecturaux (tant aux pairs qu’aux usagers, ou encore aux décideurs ... [more ▼]

Les architectes ont toujours eu recours à de multiples représentations pour générer, faire évoluer puis communiquer leurs concepts architecturaux (tant aux pairs qu’aux usagers, ou encore aux décideurs). Cet article envisage comment la représentation externe impacte la perception « naïve » d’une intention architecturale, les « non experts » assumant des rôles de plus fondamentaux au sein de certains mécanismes décisionnels. Comment l’image, en pleine mutation depuis l’ère du numérique, façonne-t-elle la perception des facteurs clés (ou « attributs ») d’une intention architecturale ? L’article résume les principaux résultats d’une enquête menée en ligne via l’interface « Amazon Mechanical Turk » et générant 790 échelles d’évaluation de 6 avant-projets architecturaux. Les résultats abordent l’analyse des données en regard des différentes attributs; en regard des trois types de représentation choisies et en regard enfin des inconsistances dont font preuve les architectes eux-mêmes, étant donné l’évaluation de leurs propres projets et représentations. Ils révèlent que les attributs ne sont pas équitablement propices à un transfert d’intention exclusivement graphique et que les formes plus abstraites de représentations constituent, dans certains contextes, le moyen le plus efficace pour le transfert fidèle d’une intention architecturale. [less ▲]

Detailed reference viewed: 57 (10 ULg)
Full Text
Peer Reviewed
See detailNo interest for a second closely-timed infiltration of platelet-rich plasma (PRP) to treat jumper’s knees
Kaux, Jean-François ULg; CROISIER, Jean-Louis ULg; Forthomme, Bénédicte ULg et al

in Radmann, A; Hedenborg, S; Tsolakidis, E (Eds.) 20th annual Congress of the EUROPEAN COLLEGE OF SPORT SCIENCE - BOOK OF ABSTRACTS (2015, June)

Introduction: Some clinical series have evaluated the effect of platelet-rich plasma (PRP) in the treatment of jumper’s knee. Although it is possible that a single infiltrative administration may prove to ... [more ▼]

Introduction: Some clinical series have evaluated the effect of platelet-rich plasma (PRP) in the treatment of jumper’s knee. Although it is possible that a single infiltrative administration may prove to be an effective treatment for this indication, most of the existing studies evaluated the effects of 2 or 3 successive infiltrations. The aim of this study was to evaluate whether 2 infiltrations of PRP proves moreeffective than a single treatment. Methods: Twenty patients suffering from chronic jumper’s knee were enrolled into our prospective, randomized and comparative study of level 2, and split into two randomized groups (1 or 2 infiltrations of PRP, respectively). The 3-month follow-up evaluation consisted of VAS, IKDC and VISA-P scores, along with algometer, isokinetic and ultrasounds evaluations. After 1 year, subjects were contacted to define their functional evolution. Results: The concentration of the PRP used for each infiltration was similar in both groups, and contained no red or white cells. Results revealed no difference in treatment efficacy between the groups.Discussion: The comparison between 1 or 2 infiltrations of PRP did not reveal any difference between the 2 groups at short to mid term. A second closely-timed infiltration of PRP to treat jumper’s knees is not necessary to improve the efficacy of this treatment in the short term. References: Kaux JF, Croisier JL, Bruyere O, Rodriguez de la Cruz C, Forthomme B, Brabant G et al. One injection of platelet-rich plasma associated to a submaximal eccentric protocol to treat chronic jumper’s knee. J Sports Med Phys Fitness. 2014 Jun 19. [Epub ahead of print]. Kaux JF, Croisier JL, Forthomme B, Le Goff C, Buhler F, Savanier C et al. Using platelet-rich plasma to treat jumper’s knees: exploring the effect of a second closely-timed infiltration. J Sci Med Sport. Submitted. Kaux JF, Bruyère O, Croisier JL, Forthomme N, Le Goff C, Rohr N et al. One-year follow-up of platelet-rich plasma infiltration to treat chronic upper patellar tendinopathies. Acta Orthop Belg. In press. [less ▲]

Detailed reference viewed: 52 (8 ULg)
Full Text
Peer Reviewed
See detailProgressive Current Source Models in Magnetic Vector Potential Finite Element Formulations
Dular, Patrick ULg; Kuo-Peng, Patrick; Ferreira da Luz, Mauricio et al

in Proceedings of COMPUMAG 2015 (2015, June)

Progressive refinements of the current sources in magnetic vector potential finite element formulations are done with a subproblem method. The sources are first considered via magnetomotive force or Biot ... [more ▼]

Progressive refinements of the current sources in magnetic vector potential finite element formulations are done with a subproblem method. The sources are first considered via magnetomotive force or Biot-Savart models up to their volume finite element models, from statics to dynamics. A novel way to define the source fields is proposed to lighten the computational efforts, via the conversion of the common volume sources to surface sources, with no need of any pre-resolution. Accuracy improvements are then efficiently ob-tained for local currents and fields, and global quantities, i.e. inductances, resistances, Joule losses and forces. [less ▲]

Detailed reference viewed: 34 (5 ULg)
Full Text
Peer Reviewed
See detailSubproblem Methodology for Progressive Finite Element Modeling of Transformers
Dular, Patrick ULg

in Proceedings of COMPUMAG 2015 (2015, June)

Model refinements of transformers are performed via a subproblem finite element method. A complete problem is split into subproblems with overlapping meshes, to allow a progressive modeling from ideal to ... [more ▼]

Model refinements of transformers are performed via a subproblem finite element method. A complete problem is split into subproblems with overlapping meshes, to allow a progressive modeling from ideal to real flux tubes, 1-D to 2-D to 3-D models, linear to nonlinear materials, perfect to real materials, wired to volume inductors, and homogenized to fine models of cores and coils, with any coupling of these changes. Its solution is the sum of the subproblem solutions. The procedure simplifies both meshing and solving processes, and quantifies the gain given by each refinement on both local fields and global quantities. Efficient ways to chain the refinements are proposed and tested. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailDynamic modeling of thermal systems using a semi-empirical approach and the ThermoCycle Modelica Library
Altés Buch, Queralt ULg; Dickes, Rémi ULg; Desideri, Adriano ULg et al

in Proceedings of the 28th International Conference on Efficiency, Costs, Optimization and Simulation of Energy Systems (2015, June)

This paper proposes an innovative approach for the dynamic modeling of heat exchangers without phase transitions. The proposed thermo-flow model is an alternative to the traditional 1D finite-volumes ... [more ▼]

This paper proposes an innovative approach for the dynamic modeling of heat exchangers without phase transitions. The proposed thermo-flow model is an alternative to the traditional 1D finite-volumes approach and relies on a lumped thermal mass approach to model transient responses. The heat transfer is modeled by the well-known Logarithmic Mean Temperature Difference approach, which is modified to ensure robustness during all possible transient conditions. The lumped parameter models are validated with references models and tested within a Concentrating Solar Power plant model. Results indicate that the developed lumped models are robust and computationally efficient, ensuring the convergence of the Newton Solver. They are significantly faster (~10-fold) than the traditional finite volume models, although a more extensive comparisons would be needed to confirm this figure. They are well suited to be integrated in larger system models, but are not appropriate for the simulation of detailed thermo-flow phenomena. [less ▲]

Detailed reference viewed: 161 (17 ULg)
Full Text
Peer Reviewed
See detailComputation of Source for Non-Meshed Coils in a Reduced Domain with A–V Formulation
Ferrouillat, Pauline; Guérin, Christophe; Meunier, Gérard et al

in Proceedings of COMPUMAG 2015 (2015, June)

The discretized source magnetic vector potential Aj, interpolated from source field Hs with H(curl,Ω) semi-norm, is studied for non-meshed coils with magnetic vector potential A and electric scalar ... [more ▼]

The discretized source magnetic vector potential Aj, interpolated from source field Hs with H(curl,Ω) semi-norm, is studied for non-meshed coils with magnetic vector potential A and electric scalar potential V formulation. As a novelty, source potential Aj is computed in a reduced domain Ωred instead of the complete domain Ω. For domains with fixed and moving parts, potential Aj can be computed on each part, for each of the related current sources, with no need to ensure its continuity between these parts. [less ▲]

Detailed reference viewed: 15 (0 ULg)
Full Text
See detailMeasurement of 3D Room Impulse Responses with a Spherical Microphone Array
Embrechts, Jean-Jacques ULg

in Proceedings of the Euronoise 2015 Congress (2015, June)

Directional room impulse responses (DRIRs) are composed of the sound contributions reaching a given location in the room from a well-defined direction in space. DRIRs can be useful in many applications ... [more ▼]

Directional room impulse responses (DRIRs) are composed of the sound contributions reaching a given location in the room from a well-defined direction in space. DRIRs can be useful in many applications, such as the evaluation of spatial room acoustics parameters, the detection of unwanted specular reflections or the 3D auralization of acoustic spaces. A spherical array containing 16 microphones has been realized to measure DRIRs. The logarithmic sinesweep technique is first applied to measure 16 impulse responses, one for each microphone. A spherical harmonics (SH) decomposition of the sound field is then obtained. Spatial aliasing, placement errors and the ‘white noise gain’ (WNG) have been analysed to define the useful bandwith of this measure, i.e. [250Hz – 4kHz]. The coefficients of the SH decomposition are then processed by some beamforming methods, in order to compute the DRIR in any direction around the spherical array. Time and 3D space representations can be generated. The results obtained in some rooms are illustrated in this paper: it is shown that the combination of the ‘delay-and-sum’ and ‘minimum-variance distorsionless response’ beamforming methods is particularly well suited for the analysis of DRIRs. [less ▲]

Detailed reference viewed: 114 (1 ULg)
Full Text
See detailDo T2-hypointense GH-secreting pituitary adenomas behave differently under somatostatin analogues as primary therapy in acromegaly ?
Potorac, Iulia ULg; PETROSSIANS, Patrick ULg; Daly, Adrian ULg et al

in The International Journal of The Romania Society of Endocrinology - Abstract book (2015, June)

Detailed reference viewed: 27 (3 ULg)
Full Text
See detailDescription of the research project CIMEDE for the industrial construction of evolutionary, sustainable and economic houses
Duthoit, Fabienne ULg; Embrechts, Jean-Jacques ULg

in Proceedings of the Euronoise 2015 Congress (2015, June)

CIMEDE is a research project supported by the Region of Wallonia (Belgium). It stands for CIMEDE “Construction Industrielle de Maisons Evolutives, Durables et Economiques – industrial construction of ... [more ▼]

CIMEDE is a research project supported by the Region of Wallonia (Belgium). It stands for CIMEDE “Construction Industrielle de Maisons Evolutives, Durables et Economiques – industrial construction of evolutionary, sustainable and economic houses”. Since the materials envisaged for this project are timber and gypsum fibre board, it was necessary to design a constructive principle of lightweight timber frame constructions which meets the industrial, sustainable, evolutionary and economic requirements and also the requirements of the Belgian acoustic standard NBN S01-400-1. First of all, an inventory of constructive elements that are currently used in this type of construction (floors, walls and facades) is presented with their acoustic performances. Then, the laboratory measurements of some samples of floors, facades, interior walls and partition walls are described and discussed. On the basis of the measurement results, several solutions that best meet all criteria were retained and a mock-up was built with these constructive elements. Measurement results on this mock-up are also presented. The final solution for the floor, the partition wall, the interior wall and the facade which meets the acoustic requirements is finally described [less ▲]

Detailed reference viewed: 49 (3 ULg)
Full Text
Peer Reviewed
See detailMacroscopic analysis of interaction models for the provision of flexibility in distribution systems
Mathieu, Sébastien ULg; Ernst, Damien ULg; Cornélusse, Bertrand ULg

in Proceedings of the International Conference on Electricity Distribution, CIRED 2015 (2015, June)

To ease the transition towards the future of distribution grid management, regulators must revise the current interaction model, that is, the set of rules guiding the interactions between all the parties ... [more ▼]

To ease the transition towards the future of distribution grid management, regulators must revise the current interaction model, that is, the set of rules guiding the interactions between all the parties of the system. Five interaction models are proposed, three of them considering active network management. This paper evaluates the economic efficiency of each model using macroscopic representation of the system, by opposition to more techniques requiring a complete picture of the system. The interaction models are simulated on the horizon 2015-2030. Results show that for the first five years all the models provide similar economic efficiency. For the remaining ten years, interaction models implementing active network management provide up to a 10% higher economic efficiency. [less ▲]

Detailed reference viewed: 166 (23 ULg)
Full Text
See detailNonlinear ground vibration identification of an F-16 aircraft - Part 2: Understanding Nonlinear Behaviour in Aerospace Structures Using Sine-sweep Testing
Dossogne, Tilàn ULg; Noël, Jean-Philippe ULg; Grappasonni, Chiara ULg et al

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

Although they are generally modelled as linear systems, aircraft structures are known to be prone to nonlinear phenomena. A specific challenge encountered with fighter aircraft, besides aeroelastic ... [more ▼]

Although they are generally modelled as linear systems, aircraft structures are known to be prone to nonlinear phenomena. A specific challenge encountered with fighter aircraft, besides aeroelastic nonlinearity, is the modelling of the wing-to-payload mounting interfaces. For large amplitudes of vibration, friction and gaps may be triggered in these connections and markedly impact the dynamic behaviour of the complete structure. In this series of two papers, the nonlinear dynamics of an F-16 aircraft is investigated using rigorous methods applied to real data collected during a ground vibration test campaign. The present work focuses on the analysis of sine-sweep measurements in order to get an insightful understanding about the nonlinear behaviour of the aircraft. To this extent, restoring force surface and wavelet transform methods are applied both on the collected GVT data and simulation results performed on a simple numerical model of the F-16 wing and its payload. [less ▲]

Detailed reference viewed: 120 (19 ULg)
Full Text
Peer Reviewed
See detailLanduse change and future flood risk: an integrated and multi-scale approach
Dewals, Benjamin ULg; Bruwier, Martin ULg; Mohamed El Saeid Mustafa, Ahmed ULg et al

in E-proceedings of the 36th IAHR World Congress (2015, June)

The goal of this research is a better understanding of the complex interactions between landuse change and future flood risk. Landuse change is mainly driven by population growth and socio-economic ... [more ▼]

The goal of this research is a better understanding of the complex interactions between landuse change and future flood risk. Landuse change is mainly driven by population growth and socio-economic factors. It affects future flood risk by altering catchment hydrology and vulnerability in the floodplains, as well as through the feedback effect that changes in flood hazard may have on landuse evolution. The research is based on a chain of modelling tools, including: stochastic landuse change modelling, traffic modelling as well as Land-Use and Transport Interactions models, continuous hydrological modelling and efficient hydraulic modelling of floodplains inundation. The coupling of these modelling tools will allow assessing direct and indirect impacts of land use change on future flood risk, while considering the uncertainties related to each of these processes and their combinations at a 2100 time horizon. [less ▲]

Detailed reference viewed: 117 (50 ULg)
Full Text
Peer Reviewed
See detailAtmospheric pressure mode localization coupled resonators stiffness sensor
Montaseri, Mohammad; Xie, J.B.; Chang, Homglong et al

in Proceedings of Solid-State Sensors, Actuators and Microsystems (Transducers 2015) (2015, June)

This paper reports on a 3-DoF mode localization resonant sensor experimentally evaluated under atmospheric conditions. It was demonstrated that using amplitude ratio as an output signal, even when the ... [more ▼]

This paper reports on a 3-DoF mode localization resonant sensor experimentally evaluated under atmospheric conditions. It was demonstrated that using amplitude ratio as an output signal, even when the device is operated in air, yields a higher sensitivity compared to the frequency variation sensitivity when assuming vacuum conditions. [less ▲]

Detailed reference viewed: 62 (6 ULg)
Full Text
Peer Reviewed
See detailImpédances de surface en 2D : comparaison de méthodes de paramétrisation en δ
Krähenbühl, Laurent; Dular, Patrick ULg; Péron, Victor et al

in Proceedings of NUMELEC 2015 (2015, June)

Les méthodes d’impédance de surface sont parmi les plus efficaces pour résoudre les problèmes de courants de Foucault à faible profondeur de pénétration (δ) en régime harmonique linéaire ... [more ▼]

Les méthodes d’impédance de surface sont parmi les plus efficaces pour résoudre les problèmes de courants de Foucault à faible profondeur de pénétration (δ) en régime harmonique linéaire. Cependant l’effort de calcul devient considérable lorsqu’on s’intéresse à une large gamme de fréquences (ou de conductivités), car chacun des résultats correspond à la résolution d’un problème d’éléments finis en valeurs complexes ; de plus, l’erreur est en δ2 et augmente donc très vite avec δ. Nous avions précédemment montré qu’un développement limité permet des paramétrisations en δ des solutions, très précises pour toutes les valeurs de δ comprises entre la limite conducteur parfait (δ→0) et les premiers résultats accessibles par maillage de l’effet de peau (δ=δFE), avec un coût numérique équivalent à celui de 2 résolutions. Nous comparons ici la précision de deux des méthodes possibles pour construire un tel développement limité. [less ▲]

Detailed reference viewed: 15 (1 ULg)
Peer Reviewed
See detailDe novo sequencing using MELD proteolysis coupled to a "sequence assembly" algorithm
Mazzucchelli, Gabriel ULg; Zimmerman, Tyler; Smargiasso, Nicolas ULg et al

in 63rd ASMS Conference Proceedings, May 30 - June 4 2015, St. Louis, MO (2015, June)

Introduction Protein de novo sequencing requires a method that combines extensive MSMS fragmentation and an appropriate data processing. This can be applied either on intact protein or on its proteolytic ... [more ▼]

Introduction Protein de novo sequencing requires a method that combines extensive MSMS fragmentation and an appropriate data processing. This can be applied either on intact protein or on its proteolytic peptides. Peptide analysis has the advantage to be compatible with well-known workflows. Nevertheless the connectivity between peptides is lost. Taking these considerations into account, a specific digestion method and a sequence assembly software were developed. The MELD method relies on a combination of MultiEnzymatic AND Limited proteolytic Digestions. The MELD generates in a single experiment numerous different peptides with miss-cleavages that overlap when aligned on the matching protein sequence. The two major benefices are an increased probability to obtain the entire protein sequence and a redundancy in the protein sequence matches. Methods The MELD consists in two parallel 2h digestions both using an optimized protease mixture. The mixtures are composed of the same proteases but in different relative quantities. Analyses were performed by UPLC-Orbitrap (IClass, Waters, QExactive, Thermo). Data were processed with PEAKS (BSI) to generate de novo sequence candidates. After data importation into our software, a seed sequence is set or can be found automatically. The software extends the seed sequence in both directions with moving windows of three amino acids, plus a fourth one to be added. The added amino acid is validated in several ways, including by the total frequency of occurrence, by larger windows of aa, by the local spectrum-derived confidence, and by combinations of these factors. Preliminary Data The MELD protocol was first validated by applying a traditional database search workflow on several commercial proteins with an inter-day and inter-individual procedure. These experiments showed 100% sequence coverage for each protein analyzed, involving information on peptide identity and modifications localization. Strong confident identification was obtained due to multiple overlapping peptides matches with the given sequence and with a high number of overlapping peptides assignments. The analysis of the four proteins provided the following results: HSA, Myoglobin and Lysozyme were identified with 100% sequence coverage with respectively 890, 300 and 120 unique peptides (CV<10%, peptide FDR<0.1%). The variable region of each heavy and light chains of Adalimumab antibody were identified with 100% sequence coverage. With the MELD, an average of 10 different peptides covering each sequence stretch of the protein could be obtained. The combinatory effect of the multiple enzymes used and the limited digestions leads to an increased robustness, very high confidence identifications and allows clear localization of PTMs. The MELD protocol as presented here and tested on several pure proteins digested in solution, certainly improves the general "bottom-up" strategy applied for highly confident protein identification and would allow better protein characterization, even for those having PTMs. In addition, in our analysis, each fragment position of the entire protein sequence was evidenced either by a "y" or a "b" fragment ion. This high and confident amount of information enables extensive de novo sequencing using PEAKS software, followed by application of our “sequence assembly” algorithm. The first version of our assembling tool on MELD experimental data generated long sequence tags, up to 90 amino acids long. [less ▲]

Detailed reference viewed: 157 (13 ULg)
Full Text
See detailExtension patterns in pituitary macroadenomas and relation to T2-weighted signal on diagnostic MRI examinations
Potorac, Iulia ULg; Cattin, F; KREUTZ, Julie ULg et al

in The International Journal of The Romania Society of Endocrinology - Abstract book (2015, June)

Detailed reference viewed: 27 (2 ULg)
Full Text
Peer Reviewed
See detailUsing a vector Jiles-Atherton hysteresis model for isotropic magnetic materials with the FEM, Newton-Raphson method and relaxation procedure
Guérin, Christophe; Jacques, Kevin; Sabariego, Ruth V. et al

in Proceedings of NUMELEC 2015 (2015, June)

This paper deals with the use of a vector Jiles- Atherton hysteresis model included in 2D finite element modelling. The Newton-Raphson algorithm is used with a relaxtion procedure, which ensures the ... [more ▼]

This paper deals with the use of a vector Jiles- Atherton hysteresis model included in 2D finite element modelling. The Newton-Raphson algorithm is used with a relaxtion procedure, which ensures the convergence in most of the cases. We have simulated a T-shaped magnetic circuit with rotating fields and then a three-phase transformer model. [less ▲]

Detailed reference viewed: 51 (2 ULg)
Full Text
Peer Reviewed
See detailA novel resonant accelerometer based on model localization of weakly coupled resonators.
Zhang, Hemin; Yuan, W.Z.; Li, B.Y. et al

in Proceedings of Solid-State Sensors, Actuators and Microsystems (Transducers 2015) (2015, June)

This paper describes a novel MEMS resonant accelerometer based on two weakly coupled resonators (WCRs) using the phenomenon of mode localization. It is the first time that this principle is demonstrated ... [more ▼]

This paper describes a novel MEMS resonant accelerometer based on two weakly coupled resonators (WCRs) using the phenomenon of mode localization. It is the first time that this principle is demonstrated experimentally for an accelerometer. The measured relative shift in amplitude ratio (~312162 ppm/g) is 302 times higher than the shift in resonance frequency (~1035 ppm/g). [less ▲]

Detailed reference viewed: 68 (2 ULg)
Full Text
Peer Reviewed
See detailGalectin-3 and Suppression of Tumorigenicity 2 measurement in participants at the “Tor des Géants”
LE GOFF, Caroline ULg; Kaux, Jean-François ULg; Gergelé, Laurent et al

in Radmann, A; Hedenborg, S; Tsolakidis, E (Eds.) 20th annual Congress of the EUROPEAN COLLEGE OF SPORT SCIENCE - BOOK OF ABSTRACTS0th annual Congress of the EUROPEAN COLLEGE OF SPORT SCIENCE - BOOK OF ABSTRACTS (2015, June)

Introduction: Gal-3 is a carbohydrate binding lectin produced by macrophages, upregulated in hypertrophied heart, emerging as a mediator for fibrosis development and cardiac remodeling. ST2 is a family ... [more ▼]

Introduction: Gal-3 is a carbohydrate binding lectin produced by macrophages, upregulated in hypertrophied heart, emerging as a mediator for fibrosis development and cardiac remodeling. ST2 is a family member of IL-1 receptors initially known for its role in immunological processes. It has a potential role in the cardiac pathogenesis. These receptors are led in cardiomyocytes and fibroblasts due to a mechanical stress. We aimed to examine the evolution of Gal-3 and ST2 in trailers who ran one of the most challenging ultra-marathon in the world: the Tor des Géants (330 km, altitude range: 24000m). Methods: Levels of plasma Gal-3 and ST2 were determined at 4 times: before the start, after 158km, at the end and 3 days after the end of the race in 33 trailers. Samples were directly centrifuged and frozen at -80°C. Gal-3 measurement was performed on the VIDAS (Biomerieux) and ST2 was analyzed with the Presage ST2 Assay (Critical Diagnostic). The reference values are <17.8ng/mL for Gal-3 and <35ng/mL for ST2. Statistica was used for the statistical analysis (ANOVA). We calculated the difference between the different time and expressed in delta: Δ1=(T2-T1)/T1*100, Δ2=(T3-T2)/T2*100, Δ3=(T4-T3)/T3*100, Δ4=(T3-T1)/T1*100, Δ5=(T4-T1)/T1*100. After that, we tried to correlate the delta between them (results= R(p-value)). Results were considered as significant with p<0.05. Results: Plasmatic levels of Gal-3 did never exceed the cut-off of 17.8ng/mL, except for 1 trailer in T2. A slight increase of levels of Gal-3 was observed at T2 (min-max:7.5-17.6ng/mL). These ones did not vary a lot at T3 (min-max:7.0- 18.8ng/mL) but return to normality at T4 (min-max:6.0-12.8ng/mL). For ST2, at T1, 12 subjects had plasmatic levels above the reference value of 35ng/ml. At T2, only 2 trailers blood samples were still in the reference interval. Indeed, a great increase of ST2 plasmatic levels observed (min-max:18.8-158.8ng/mL). A slight decrease of ST2 levels was observed at T3, but only one subject had a value below 30ng/ml (min-max:20.1-182.7ng/mL). However, a subject had still plasmatic levels above T2 values. A return to normality was observed at T4 with 16 trailers blood levels in the reference interval (min-max:12.0-56.4ng/mL). We observed an increase for Gal-3 and ST2, above the reference values only for ST2. We noted for both a decrease up to the normal values 3 days after the trail. For the correlation between deltas, we observed that Gal-3 and ST2 are correlated for each delta. Discussion: A logical correlation is observed between Gal-3 andST2 as they are involved in cardiac fibrosis and inflammation. But we do not known why it is not in the same proportion. We know that some trailers take NSAIDs and painkillers during the race. The results of this study demonstrate that this exercise was associated with biochemical abnormalities that may reflect adverse consequences on cardiac structure as fibrosis. However, ST2 values were higher, perhaps due to a mechanical stress more than a cardiac stress. Gal-3 is perhaps then more cardiospecific than ST2. [less ▲]

Detailed reference viewed: 68 (1 ULg)
Full Text
Peer Reviewed
See detailDamage process sensitivity analysis using an XFEM-Level Set framework
Noël, Lise ULg; Duysinx, Pierre ULg; Maute, Kurt

in Proceedings of the 11th World Congress on Structural and Multidisciplinary Optimization (WCSMO-11) (2015, June)

Designing efficient and lightweight structures is a key objective for many industrial applications such as in aerospace or the automotive industry. To this end, composite materials are appealing as they ... [more ▼]

Designing efficient and lightweight structures is a key objective for many industrial applications such as in aerospace or the automotive industry. To this end, composite materials are appealing as they combine high stiffness and light weight. The main challenge slowing down the integration of such materials in real structures is their damage be- havior. The latter should be considered in the design process of the structures. This work focuses on developing a systematic approach to designing structures that can sustain an acceptable amount of degradation or exhibit a low sensitivity to damage. An optimization approach is chosen to achieve this goal. To deal with complex geometries and to allow for large shape modifications in the optimization process, the extended finite element method (XFEM) is advantageously combined with a level set description of geometry. The degradation of materials is modeled by using a non-local damage model, motivated by the work of James and Waisman on a density approach to topol- ogy optimization. To solve design problems with damage constraints by gradient-based optimization method, a sensitivity analysis of the damage process is developed. Damage propagation and growth is an irreversible pro- cess. Therefore, the path dependence of the structural response needs to be accounted for in the sensitivity analysis. In this paper, we present an analytical approach for efficiently and accurately evaluating the design sensitivities, considering both direct and adjoint formulations. Finally, the sensitivity analysis approach is studied with simple benchmark problems and compared with the results obtained by finite differences. [less ▲]

Detailed reference viewed: 67 (14 ULg)
Full Text
Peer Reviewed
See detailLes leviers de l'inovation pédagogique: contraintes externes vs régulations internes
Scheffers, Patricia ULg

in Scheffers, Patricia (Ed.) Actes du colloque (2015, June)

Depuis les années 60, la fréquence de mutations organisationnelles de l'enseignement supérieur et universitaire en Belgique s'amplifie et adopte même un rythme frénétique ces dix dernières années. Les ... [more ▼]

Depuis les années 60, la fréquence de mutations organisationnelles de l'enseignement supérieur et universitaire en Belgique s'amplifie et adopte même un rythme frénétique ces dix dernières années. Les causes sont tour à tour l'évolution des professions et la volonté politique et/ou économique de restructuration. Deux niveaux de régulations pédagogiques sont amenés à s'articuler. D'une part, celui de l'enseignant acteur-réflexif de son enseignement et d'autre part, des injonctions externes qui réorganise le cadre général. Retour d'expérience sur les innovations en Faculté d'Architecture à Liège. [less ▲]

Detailed reference viewed: 56 (15 ULg)
Full Text
Peer Reviewed
See detailA dynamic simulation approach to identify additional reactive reserves against long-term voltage instability
Papangelis, Lampros ULg; Panciatici, Patrick; Debry, Marie-Sophie et al

in Proc. of IEEE PES 2015 PowerTech conference (2015, June)

A simple method is proposed to identify additional reactive reserves enabling to counteract long-term voltage instability after a large disturbance. In contrast to the many references based on power flow ... [more ▼]

A simple method is proposed to identify additional reactive reserves enabling to counteract long-term voltage instability after a large disturbance. In contrast to the many references based on power flow calculations, the method resorts to dynamic simulation. The post-disturbance system evolution is simulated in the presence of time-varying shunt susceptances with specified rate of change. This allows to deal with dynamic issues such as the required speed of the additional reactive power sources, or the onset of unstable electromechanical oscillations. Furthermore, a compromise is sought between the speed of action and the volume of additional compensation. The method is demonstrated on a detailed model of the Nordic test system. [less ▲]

Detailed reference viewed: 108 (25 ULg)
Full Text
Peer Reviewed
See detailL'enseignement du latin à Constantinople : une mise au point
Rochette, Bruno ULg

in Haverling, Gerd V.M. (Ed.) Latin Linguistics in the Early 21st Century. Acts of the 16th International Colloquium on Latin Linguistics, Uppsala, June 6th-11th, 2011 (2015, June)

Nous savons que Constantinople a possédé une chaire stable de latin vers 360. Plusieurs grammairiens latins qui ont travaillé à Constantinople ou dans d’autres villes du monde grec ont mis au point des ... [more ▼]

Nous savons que Constantinople a possédé une chaire stable de latin vers 360. Plusieurs grammairiens latins qui ont travaillé à Constantinople ou dans d’autres villes du monde grec ont mis au point des artes destinées à un public hellénophone. Les analogies entre le grec et le latin dans la grammaire et le lexique n’ont pas échappé à l’attention à ces grammairiens. Aboutissement d’une tradition qui remonte à Claudius Didymus, Macrobe donne une σύγκρισις du système verbal grec et latin dans son traité De uerborum Graeci et Latini differentiis uel societatibus. Il offre un exemple unique pour l’antiquité de linguistique comparative, mais son but n’est pas pédagogique. Il décrit, mais n’explique pas les ressemblances et les différences entre le système verbal grec et latin. C’est toutefois la même méthode qui est mise en œuvre dans l’enseignement du latin comme L², à savoir l’approche comparative. Le latin s’enseigne aux hellénophone par analogie ou en contraste avec le grec. [less ▲]

Detailed reference viewed: 45 (0 ULg)
Full Text
Peer Reviewed
See detailA shallow-water model with depth-dependent porosity for urban flood modeling
Bruwier, Martin ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in E-proceedings of the 36th IAHR World Congress (2015, June)

The availability of high-resolution topographic data enables the modeling of urban floods with a high level of accuracy. However, such a modelling has a poor computational efficiency. Subgrid models ... [more ▼]

The availability of high-resolution topographic data enables the modeling of urban floods with a high level of accuracy. However, such a modelling has a poor computational efficiency. Subgrid models enable to decrease the computational time by using coarse cells while preserving information from the detailed topographic data to some degree. In particular, shallow-water models with porosity constitute a subgrid model well-adapted for urban flood modeling. In this article, a new set of fully dynamic shallow-water equations with depth-dependent porosities is presented. Then, the implementation of the model is detailed and preliminary results obtained for a theoretical two-dimensional urban area are analyzed. Unlike recent works, the new model solves the fully dynamic shallow-water equations with depth-dependent and anisotropic porosities, a divergent formulation of the bed slope term, a non-staggered grid with quadrilateral cells and an efficient use of look-up tables to store the porosity relations. [less ▲]

Detailed reference viewed: 53 (15 ULg)