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See detailIntegrated control and structural analysis of DFIG wind turbines using a monolithic approach
Chen, Qiongzhong ULg; D'Ambrosio, Flavio; Defourny, Michel et al

in Proceedings of the European Wind Energy Conference and Exhibition 2012 (EWEA 2012) (2012, April)

Design of wind turbines requires the coupled analysis among the mechanical, control and aerodynamic subsystems. Different from previous research, which either uses a complicated mechanical model with a ... [more ▼]

Design of wind turbines requires the coupled analysis among the mechanical, control and aerodynamic subsystems. Different from previous research, which either uses a complicated mechanical model with a simple control system model, or vice versa, this paper studies the coupling of subsystems’ dynamics using a high-fidelity aeroelastic model of wind turbine and a detailed analytical model of control generating systems. A monolithic time integration approach is applied so that better numerical accuracy and stability are achieved. Control strategies on power optimization are discussed taking into account the influence of structural flexibility. Simulation examples are given on both stable and turbulent wind situation. [less ▲]

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See detailIntegrated control of crown rot of banana with Candida oleophila strain O, calcium chloride and modified atmosphere packaging
Bastiaanse, H.; de Lapeyre de Bellaire, Luc; Lassois, Ludivine ULg et al

in Biological Control (2010), 53

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See detailIntegrated detection and correction of outliers in a random regression test-day model
Mayeres, Patrick; Gillon, Alain ULg; Gengler, Nicolas ULg

in INTERBULL Bulletin (2003), 31

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See detailIntegrated dynamical models of down-the-hole percussive drilling
Depouhon, Alexandre ULg

Doctoral thesis (2014)

Due to the overall process complexity, studies about percussive drilling usually focus on a limited set of the subprocesses underlying it, e.g., the hammer thermodynamics or the interaction between the ... [more ▼]

Due to the overall process complexity, studies about percussive drilling usually focus on a limited set of the subprocesses underlying it, e.g., the hammer thermodynamics or the interaction between the bit and the rock. Following this paradigm, the assessment of the process performance is typically performed by considering a single percussive activation and a single interaction cycle between the bit and the rock, from arbitrary initial conditions. The need for an integrated approach to evaluate drilling performance, based on the dynamical interaction of the subprocesses underlying drilling, is evident. Such an approach requires simplified models, however, as the computational cost associated with full scale models is simply unbearable. In this thesis, three dynamical integrated models are proposed and a preliminary analysis is conducted for a reference configuration and around it. The models couple three modules that represent: (i) the dynamics of the mechanical system, (ii) the interaction between the bit and the rock, and (iii) the activation of the mechanical system. For each module, simple representations are considered; of particular importance is the bit/rock interaction model which is a generalization to repeated interactions of experimental evidence observed for a single interaction. In the first model, the dynamics of a rigid bit is cast into a drifting oscillator and the activation modeled as a periodic impulsive force. The second and third models account for the dynamics of the piston and the activation results from the impact of the piston on the bit. They are respectively based on elastic and rigid representations of the two bodies. In the rigid model, analytical results of wave propagation in thin rods are used to represent the contact interaction between the piston and the bit. In the elastic model, wave propagation is resolved. Their preliminary analysis has revealed the occurrence of complex dynamical responses in the space of parameters. Expected trends are recovered around a reference configuration corresponding to a low-size hammer, with an increase of the rate of penetration with the feed force and the percussive frequency. The latter is seen to have a strong influence on the rate of penetration. Interestingly, our analyses show that when the activation period has the same order of magnitude as the timescale associated with the bit/rock interaction, a lower power consumption is observed, indicating a possible resonance phenomenon in the drilling system. Also, the predictions of the rigid model are shown to be in good agreement with the ones of the elastic model, in the explored range of parameters. Given the piecewise linear nature of the proposed models, dedicated numerical tools have been developed to conduct their analysis. As such, the thesis proposes a high-order time integration scheme for structural dynamics as well as a novel framework to evaluate the accuracy of such schemes, and a root-solving module to perform event-detection for coupling with event-driven integration strategies. Specific to the framework is the account for both structural damping and external forcing in the evaluation of the scheme order of accuracy. Specific to the root-solving module is the forcing of event occurrence in the localization procedure. [less ▲]

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See detailIntegrated farming systems in Kinshasa (DRC) Diversity of agricultural practices
Mafwila Kinkela, Patrick ULg; Bindelle, Jérôme ULg; WILLEMS, E, Emilie et al

Poster (2014, February 07)

In Kinshasa in the Democratic Republic of Congo, integrated farming of livestock and fish farming is little documented while it is an interesting way of ecological intensification systems. After ... [more ▼]

In Kinshasa in the Democratic Republic of Congo, integrated farming of livestock and fish farming is little documented while it is an interesting way of ecological intensification systems. After identifying the density of fish ponds in the territory of the city using satellite images, about 200 farms with at least one pond and located in 2 in peri-urban and rural areas were surveyed to characterize the practical integration of the agricultural system. The preliminary results in one of the valleys indicate that the practice of agriculture in synergy with the pig and fish farming is a common practice although flow of components are still insufficiently integrated and some of them are not optimized . The fish - pig farming associations with or without vegetable production are 44 % of the sample. The identification of flow on farms showed that the manure of pigs is mainly used for crops (51%) or sold (28%), while a small part is used to fertilize the ponds. This may be explained by the predominant share of income (67%) devoted to vegetable production while sludge of ponds is rarely used to fertilize area of vegetable production. Residues of vegetable crops are rarely used to feed pigs and fish because of their limited availability. Feeding pigs and fish is based primarily on agro-industrial by-products such as wheat bran (81%) and the spent brewery grains (62%) and forages (62%). The presentation will analyze the results obtained in the three sites visited and outline opportunities for improvement. [less ▲]

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See detailIntegrated field assessment of contaminant fate and transport in the unsaturated and saturated zone
Fernandez de Vera, Natalia ULg; Peña Hernandez, Juan Angel ULg; Jamin, Pierre ULg et al

Poster (2013, April 22)

In the poster, a multidisciplinary methodology is presented with the aim of characterizing fate and transport of pollutants in the vadose and the saturated zone of industrial sites. The methodology used ... [more ▼]

In the poster, a multidisciplinary methodology is presented with the aim of characterizing fate and transport of pollutants in the vadose and the saturated zone of industrial sites. The methodology used for the vadose zone consist in the combination of the Vadose Monitoring System, cross-hole and surface geophysics at a local scale. For saturated zone studies, the approach consist in the chemical and isotopic analysis of the various contaminants present on site at regional scale. [less ▲]

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See detailIntegrated flood risk analysis for assessing flood protection strategies
Ernst, Julien ULg; Dewals, Benjamin ULg; Detrembleur, Sylvain ULg et al

in Tagelsir, Gasmelseid (Ed.) Handbook of Research on Hydroinformatics: Technologies Theories and Applications (2010)

The present chapter describes an end-to-end methodology for assessing flood protection strategies, including the whole methodological process from hydrological statistics to detailed 2D hydraulic ... [more ▼]

The present chapter describes an end-to-end methodology for assessing flood protection strategies, including the whole methodological process from hydrological statistics to detailed 2D hydraulic modelling, damage calculation and flood risk evaluation. This risk-based approach serves as a component of a decision-support system (DSS) developed in Belgium for identifying cost-effective flood management strategies in the context of climate change. The DSS accounts for both hydraulic and socio-economic parameters to quantify the benefits (in terms of avoided risk) and the cost of each strategy. Besides reviewing fundamentals of flood risk assessment, including the inundation model and main concepts related to flood risk, a consistent methodology for micro-scale flood risk analysis is presented in detail, combining complementary sources of GIS information such as high resolution and high accuracy land use database as well as socio-economic datasets. Finally a case study on a main tributary of river Meuse in Belgium is described. [less ▲]

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See detailAn integrated history of paleoearthquakes along the North Anatolian Fault (Turkey)
Hubert, Aurelia ULg; Vanneste, Kriss; Avsar, U.

in Abstracts with Programs - Geological Society of America (2010, October)

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See detailIntegrated logic circuits using single-atom transistors
Mol, J.; Verduijn, J.; Levine, R. D. et al

in Proceedings of the National Academy of Sciences of the United States of America (2011), 108(34), 13969-13972

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See detailIntegrated management of wild chamomile populations by tillage
Jaunard, Delphine ULg; Monty, Arnaud ULg; Mahy, Grégory ULg et al

in Agricultural and Apllied Biological Sciences (2013, May 21)

Gembloux, Belgium Chemical weeding in agriculture increasingly raises environmental, health and economic preoccupations. European authorities has set up legislations (directive 91/414, settlement 1107 ... [more ▼]

Gembloux, Belgium Chemical weeding in agriculture increasingly raises environmental, health and economic preoccupations. European authorities has set up legislations (directive 91/414, settlement 1107/2009, directive 2009/128) aiming to reduce risks related to the use of pesticides and encouraging integrated pest management. This situation leads professionals and scientists to take interest in the biology and population dynamics of weeds and to study the impacts of integrated pest management on weeds and crops. Tillage can potentially be an efficient weed control method in winter wheat (Triticum aestivum L.). We studied wild chamomile (Matricaria chamomilla L.) population dynamics and crop yields in an experimental winter wheat crop, in relation to tillage methods. Five modalities (i.e. different combinations of a stubble cultivator and/or a moldboard plow, including a no-tillage control) were applied during three years (2009-2012), with four replications, in Gembloux (Belgium). In each plot, M. chamomilla density was recorded throughout the seasons. In summer 2012, wild chamomile density was significantly lower in plots tilled with a moldboard plow. The use of a stubble cultivator did not significantly affect M. chamomilla density. In addition, we found higher wheat yields in ploughed plots, indicating that the decrease in M. chamomilla density reduced competition for wheat. To confirm these results, experiments are still under investigation in similar conditions. [less ▲]

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See detailAn integrated mathematical modelling framework for the study of bone fracture healing
Geris, Liesbet ULg; Vander Sloten, Jos; Van Oosterwyck, Hans

in Journal of Biomechanics (2008), 41

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See detailIntegrated Methodology of Instream Flow Assessment : Study of a Belgian River, the Crupet
Hirtt, Laura; Degre, Aurore ULg

in AgroEnviron2010: VII international symposium Environmental sustainability of Agricultural management systems in an ever changing world (2010, May)

Pumping stations and dams generate modifications of rivers’ state flow. In this work, we propose to implement and compare the results of three instream flow assessments. We are studying a Belgian river ... [more ▼]

Pumping stations and dams generate modifications of rivers’ state flow. In this work, we propose to implement and compare the results of three instream flow assessments. We are studying a Belgian river called Crupet, which has some pumping stations on its catchment. The Crupet medial flow is 0.56 m3/s at the point of discharge of the catchment. The three methods are : the Range of Variability Approach, the Instream Flow Incremental Methodology and the Wetted Perimeter Method. The aim of the first method is to find an instream flow so that the river conserves as much as possible its natural behaviour after pumping. This method is usually based on twenty years of flow data, before and after the construction of the pumping stations. In our case, the data were not available, especially because there are no stage gauging stations. So we had to generate hydrologic data based on some approximations and hypotheses (estimation of the quantity of water pumped on the catchment, method of regionalisation). Next, we used the IHA software to analyse the alteration of thirty-three hydrologic parameters, and we formulated an equation that calculates how much water could be pumped to minimize the alteration of the parameters. The second method is based on hydrological, morphological, and biological (fish habitat) data to assess the minimum flow in a river at low water. The third method, the Wetted Perimeter Method, is used to find the minimum flow knowing the morphology of the transect (relation between wetted perimeter and flow). For the last two methods, we found the minimum flow for the studied section being equal to 1.5 m3/s. The RVA methodology recommends, however, a higher minimum flow and imposes to reduce the pumping, at least if all our hypotheses are correct. [less ▲]

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See detailAn integrated micro-simulation modeling framework to measure and predict emissions and dynamic exposure
Janssens, Davy; Cools, Mario ULg; Vanhoof, Koen et al

Conference (2010)

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See detailAn integrated modeling approach for the calculation of the mass pollutant transport within the Scheldt estuary towards the North Sea
Moens, M.; Billen, G.; De Jonge, E. et al

in Actes du colloque: Marine and estuarine gradients, (1991)

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See detailIntegrated modelling and uncertainty analysis for assessment of climate change effects on groundwater resource
Goderniaux, Pascal; Wildemeersch, Samuel ULg; Dassargues, Alain ULg

Conference (2014, September 15)

Climate change will bring new pressure on surface and groundwater resources (e.g. Allen et al., 2004; Goderniaux et al., 2009; Van Roosmalen et al., 2009) in many parts of the world. Additional work is ... [more ▼]

Climate change will bring new pressure on surface and groundwater resources (e.g. Allen et al., 2004; Goderniaux et al., 2009; Van Roosmalen et al., 2009) in many parts of the world. Additional work is required to help water managers to plan for future changes. For example, most of studies provide projections for a stationary climate representative of the end of the century, although information is demanded for the near-future. A sophisticated transient weather generator (WG) in combination with an integrated surface-subsurface hydrological model (HydroGeoSphere) are used for producing a stochastic generation of large numbers of equiprobable climatic time series, representing transient climate change, and assess impacts on groundwater resources in a probabilistic way. This new methodology is applied for the unconfined chalky aquifer of Hesbaye (Geer basin in Belgium). The following uncertainty sources are studied : (1) the uncertainty linked to the calibration of the hydrological model, using 'UCODE_2005' (Poeter et al., 2005); (2) the uncertainty linked to the global and regional climatic models (GCMs and RCMs), by using a multi-model ensemble; (3) the uncertainty linked to the natural variability of the weather, by using stochastic climate change scenarios. 30 equiprobable climate change scenarios from 2010 to 2085 have been generated for each of 6 different RCMs. Results show that although the 95% confidence intervals calculated around projected groundwater levels remain large, the climate change signal becomes stronger than that of natural climate variability by 2085. Additionally, the WG ability to simulate transient climate change enabled the assessment of the likely timescale and associated uncertainty of a specific impact. This methodology constitutes a real improvement in the field of groundwater projections under climate change conditions as it enables water managers to analyse risks and take decisions with full knowledge of projected impact and their degree of confidence. [less ▲]

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See detailIntegrated Modelling for river basin management planning
Safiolea, Eleftheria; Baki, Sotiria; Makropoulos, Christos et al

in Proceedings of ICE : Water Management (2011), 164(WM8), 405-419

Complex spatio-temporal environmental problems call for an integrated assessment of environmental systems due to their interdisciplinary nature. Within this context, the approach of Integrated Water ... [more ▼]

Complex spatio-temporal environmental problems call for an integrated assessment of environmental systems due to their interdisciplinary nature. Within this context, the approach of Integrated Water Resource Management (IWRM) at the catchment scale, which is at the heart of advanced European environmental policy such as the Water Framework Directive (WFD), argues for integrated modelling tools and approaches. This paper examines recent technological developments that facilitate integrated modelling and focuses on a novel approach, the Open Modelling Interface (OpenMI), which allows models built by different developers to communicate at runtime. The individual models, when made compliant with the OpenMI standard, can be considered as “components” of an integrated model and seamlessly exchange data. Two OpenMI-enabled integrated modelling case studies are presented and their results critically discussed. The paper concludes with opportunities and challenges towards the design of flexible, component-based models supporting integrated environmental policy in general and the WFD implementation in particular. [less ▲]

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See detailIntegrated modelling of the Belgian Coastal Zone
Delhez, Eric ULg; Carabin, G.

in Estuarine Coastal & Shelf Science (2001), 53(4), 477-491

The management of the water resources in coastal or delta plains asks for an integrated modelling of the water system at a regional scale. In the SALMON project, detailed descriptions of the groundwater ... [more ▼]

The management of the water resources in coastal or delta plains asks for an integrated modelling of the water system at a regional scale. In the SALMON project, detailed descriptions of the groundwater, river and marine domains are provided by coupling appropriate numerical models of these different sub-systems. The application of this three-fold model to the Scheldt and Belgian Coastal Zone reveals a marked river plume extending along the Belgian Coast with strong offshore gradients. This plume cannot be explained by the Eulerian residual transport velocity field but requires Lagrangian aspects to be taken into account. The computation of the age of this water mass shows that the different parts of the coastal zone are influenced by a discharge in the Grote Schijn River after a delay that varies between a few days (for the marine part of the estuary) to about 100 days (for the centre of the residual gyre). The computation shows also that the groundwater around Antwerp can also be contaminated by a pollution in the river but the resulting mass loss from the river does not lead to a significant reduction of the flux to the coastal zone. (C) 2001 Academic Press. [less ▲]

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