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See detailDynamic seasonal nitrogen cycling in response to anthropogenic N loading in a tropical catchment, Athi–Galana–Sabaki River, Kenya
Marwick, T. R.; Tamooh, F.; Ogwoka, B. et al

in Biogeosciences (2014), 11(2), 443--460

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See detailDynamic Simulation of Large-scale Power Systems Using a Parallel Schur-complement-based Decomposition Method
Aristidou, Petros ULg; Fabozzi, Davide; Van Cutsem, Thierry ULg

in IEEE Transactions on Parallel and Distributed Systems (2014), 25(10), 2561-2570

Power system dynamic simulations are crucial for the operation of electric power systems as they provide important information on the dynamic evolution of the system after an occurring disturbance. This ... [more ▼]

Power system dynamic simulations are crucial for the operation of electric power systems as they provide important information on the dynamic evolution of the system after an occurring disturbance. This paper proposes a robust, accurate and efficient parallel algorithm based on the Schur complement domain decomposition method. The algorithm provides numerical and computational acceleration of the procedure. Based on the shared-memory parallel programming model, a parallel implementation of the proposed algorithm is presented. The implementation is general, portable and scalable on inexpensive, shared-memory, multi-core machines. Two realistic test systems, a medium-scale and a large-scale, are used for performance evaluation of the proposed method. [less ▲]

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See detailDynamic simulation of residential buildings with seasonal sorption storage of solar energy - parametric analysis
Hennaut, Samuel ULg; Thomas, Sébastien ULg; Davin, Elisabeth ULg et al

in ISES solar world congress 2011 - Proceedings (2011, August 28)

This work focuses on the evaluation of the performances of a solar combisystem coupled to seasonal thermochemical storage using SrBr2/H20 as adsorbent/adsorbate couple. The objective is to determine the ... [more ▼]

This work focuses on the evaluation of the performances of a solar combisystem coupled to seasonal thermochemical storage using SrBr2/H20 as adsorbent/adsorbate couple. The objective is to determine the characteristics required for solar system and storage reactor to reach a 100 % solar fraction for a building with a low heating load. The complete system, including the storage reactor, is simulated, using the dynamic simulation software TRNSYS. The influence of some components and parameters of the system is estimated: weather, collectors and storage reactor parameters. [less ▲]

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See detailDynamic Simulations of Combined Transmission and Distribution Systems using Decomposition and Localization
Aristidou, Petros ULg; Van Cutsem, Thierry ULg

in Proc. IEEE PES 2013 PowerTech Conference (2013, June)

Simulating a power system with both transmission and distribution networks modeled is a challenging task. On the one hand, it is difficult to set up equivalents restituting the dynamic behavior of ... [more ▼]

Simulating a power system with both transmission and distribution networks modeled is a challenging task. On the one hand, it is difficult to set up equivalents restituting the dynamic behavior of aggregated loads and distributed generation units. On the other hand, representing all distribution networks in detail is computationally very demanding. In this paper, the combination of a domain-decomposition approach with the exploitation of the localized nature of power system responses to disturbances is proposed. Distribution networks marginally participating to the system dynamics are automatically replaced by simple models, while the others are simulated with full detail, thereby preserving simulation accuracy. [less ▲]

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See detailDynamic Simulations of Combined Transmission and Distribution Systems using Parallel Processing Techniques
Aristidou, Petros ULg; Van Cutsem, Thierry ULg

in Proceedings of the 18th PSCC (2014, August 22)

Simulating a power system with both transmission and distribution networks modeled in detail is a huge computational challenge. In this paper, we propose a Schur-complement-based domain decomposition ... [more ▼]

Simulating a power system with both transmission and distribution networks modeled in detail is a huge computational challenge. In this paper, we propose a Schur-complement-based domain decomposition algorithm to provide accurate, detailed dynamic simulations of the combined system. The simulation procedure is accelerated with the use of parallel programming techniques, taking advantage of the parallelization opportunities inherent in domain decomposition algorithms. The proposed algorithm is general, portable and scalable on inexpensive, shared-memory, multicore machines. A large-scale test system is used for its performance evaluation. [less ▲]

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See detailDynamic simulations of solar combisystems integrating a seasonal sorption storage: Influence of the combisystem configuration
Hennaut, Samuel ULg; Thomas, Sébastien ULg; Davin, Elisabeth ULg et al

in Strojarstvo: Journal for Theory and Application in Mechanical Engineering (2012, December), 54(6), 433-440

This paper focuses on the sizing of solar combisystems with adsorption seasonal storage to target autonomous solar space heating. Two main configurations of the combisystem are simulated, including one or ... [more ▼]

This paper focuses on the sizing of solar combisystems with adsorption seasonal storage to target autonomous solar space heating. Two main configurations of the combisystem are simulated, including one or two tanks. The influence of the seasonal storage on the sizing of the tanks is also discussed. Results show that performances of the system with two tanks are better (2 to 4 % with seasonal storage) but some improvements should be possible for the single tank configuration. The sizing of the sensible storage is nearly independent of the solar collectors area if there is a seasonal storage. The sensible storage size increase with the collectors area without adsorption storage. The analysis is conducted in simulation using the TRNSYS program. [less ▲]

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See detailDynamic single-cell analysis of Saccharomyces cerevisiae under process perturbation: comparison of different methods for monitoring the intensity of population heterogeneity
Delvigne, Frank ULg; Baert, Jonathan ULg; Gofflot, Sébastien et al

in Journal of Chemical Technology & Biotechnology (in press)

BACKGROUND: Single cell biology has attracted a lot of attention these past few years and has led to numerous fundamental results pointing out the heterogeneity of clonal cell populations. In this context ... [more ▼]

BACKGROUND: Single cell biology has attracted a lot of attention these past few years and has led to numerous fundamental results pointing out the heterogeneity of clonal cell populations. In this context, microbial phenotypic heterogeneity under bioprocessing conditions needs to be further investigated. In this study, yeast based processes have been investigated by using on-line flow cytometry in combination with a fluorescent transcriptional reporter (GFP) and viability fluorescence tags (propidium iodide, PI). Methods aiming at expressing the dispersion of these fluorescence tags among the yeast populations have been investigated for different bioreactor operating conditions. RESULTS: Yeast viability was determined on the basis of PI uptake. Segregation between PI negative and positive subpopulations could be efficiently quantified on the basis of the mean-to-median ratio or the amplitude of the interquartile range. On the other hand, the same quantification could not be made for the segregation occurring at the level of GFP synthesis. Indeed, when cells were exposed to sub-lethal or mild stresses (such as in scale-down reactors) two GFP subpopulations could be visualized by real-time FC, but quantification by one of the above-mentioned methods was not possible. CONCLUSIONS: Yeast population heterogeneity was observed in representative bioreactor operating conditions. Difficulties for the determination of segregation at the level of GFP synthesis point out the fact that one needs to understand the segregation mechanisms for the applied fluorescent reporters, to judge whether simple mathematical tools may be applied or if more sophisticated computational tools are needed for the quantification of the microbial population segregation. [less ▲]

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See detailDynamic Stall and Stall Flutter Simulations for a 2D Airfoil Using Viscous-Inviscid Coupling
Rothkegel Ide, José Ignacio ULg; Dimitriadis, Grigorios ULg

in Proceedings of the 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference (2013, April 10)

An interactive boundary layer model has been developed and coupled with a pitch plunge airfoil in 2d in order to solve the unsteady flow around the airfoil when undergoing light dynamic stall. The ... [more ▼]

An interactive boundary layer model has been developed and coupled with a pitch plunge airfoil in 2d in order to solve the unsteady flow around the airfoil when undergoing light dynamic stall. The inviscid problem is solved by means of a panel method, by the discretization of the airfoil into vortex panels. The boundary layer is solved in a mixed manner, starting the solution in a direct way by imposing the external velocity and continuing it in an inverse way by imposing the displacement thickness. The solution of the boundary layer equations is carried out using a finite volume scheme. Viscous-inviscid coupling is preformed through the imposition of a permeation velocity on the skin panels of the airfoil and the addition of a free wake at each separation point. [less ▲]

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See detailDynamic state estimation techniques for large-scale electric power systems
Rousseaux, Patricia ULg; Pavella, Mania ULg

in Leondes, Cornelius T. (Ed.) Control and Dynamic Systems - Advances in Theory and Applications (Theme : Analysis and Control System Techniques for Electric Power Systems) (1991)

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See detailDynamic state estimator for large electric power systems
Rousseaux, Patricia ULg; Van Cutsem, Thierry ULg; Ribbens-Pavella, Mania

in Proceedings of the 9th IFAC World Congress (1984)

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See detailDynamic state prediction and hierarchical filtering for power system estimation
Rousseaux, Patricia ULg; Van Cutsem, Thierry ULg; Mallieu, Didier et al

in Automatica (1988), 25(5), 595-618

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See detailDynamic state prediction and hierarchical filtering for power system estimation
Rousseaux, Patricia ULg; Van Cutsem, Thierry ULg; Mallieu, Didier et al

in Proceedings of the 4th IFAC Symposium on Large Scale Systems : Theory and Applications (1986)

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See detailA Dynamic Stiffness-Transfer Matrix Method for Forced Response Analysis of One-Dimensional Structures
Chen, S. L.; Golinval, Jean-Claude ULg; Géradin, Michel ULg

in Journal of Modal Analysis (1994), (Avril),

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See detailDynamic Stress and Fatigue Life Prediction Using Modal Testing and Model Correlation
Simon, Daniel; Golinval, Jean-Claude ULg

Conference given outside the academic context (1996)

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See detaildynamic structure of the radial glial fiber system of the developing murine cerebral wall.an immunocytochemical analysis
Gadisseux, Jean-François; Evrard, Philippe; Misson, Jean-Paul ULg et al

in Developmental Brain Research (1989), 50

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See detailDynamic Style Analysis with Errors in Variables
Bodson, Laurent ULg

Master of advanced studies dissertation (2007)

This paper revisits the traditional return-based style analysis (RBSA) in presence of time-varying exposures and errors in variables. We apply a selection algorithm using the Kalman filter to identify the ... [more ▼]

This paper revisits the traditional return-based style analysis (RBSA) in presence of time-varying exposures and errors in variables. We apply a selection algorithm using the Kalman filter to identify the more appropriate benchmarks and we compute their corresponding higher moment estimators (HME), i.e. the measurement error series introducing the (cross) moments of order three and four. Then, we retain the most significant HME and we add them to the selected benchmarks. Therefore, we obtain the most relevant benchmarks with none, some or all their HME as benchmarks explaining the analyzed fund return. We finally run the Kalman filter on the principal components of this set of selected benchmarks to avoid multicollinearity problems. Analysing EDHEC alternative indexes styles, we show that this technique improves the factor loadings and permits to identify more precisely the return sources of the considered fund. [less ▲]

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See detailDynamic surface properties of the proteose-peptone fraction of bovine milk
Innocente, N.; Corradini, C.; Blecker, Christophe ULg et al

in Journal of Dairy Science (1998), 81(7), 1833-1839

Proteose-peptone is a heat-stable and acid-soluble protein fraction of milk that has important functional properties. Component 3, which is the most hydrophobic fraction, appears to be largely responsible ... [more ▼]

Proteose-peptone is a heat-stable and acid-soluble protein fraction of milk that has important functional properties. Component 3, which is the most hydrophobic fraction, appears to be largely responsible for the physicochemical properties of proteose-peptones and for their important biological role in milk. In this study, total proteose-peptone was prepared from bulk skim milk by precipitation with ammonium sulfate, and the hydrophobic fraction was purified by FPLC(R) (Pharmacia Fine Chemicals, Uppsala, Sweden). The drop volume method was used to investigate the dynamic surface activity of total proteose-peptone and component 3 of proteose-peptone at the air-water interface and at the oil-water interface. In general, proteose-peptones are good surfactants at both interfaces. Of all proteose-peptones, component 3 causes a more rapid reduction of interfacial tension in both interfaces. A system for measuring film balance was used to obtain more information about the surface and mechanical properties of proteose-peptone monolayers. We deduced from the compression isotherms that component 3 of proteose-peptone and total proteose-peptone films spread at the air-water interface present different mechanical properties. [less ▲]

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See detailDynamic T cell receptor clonotype changes in synovial tissue of patients with early rheumatoid arthritis: effects of treatment with cyclosporin A (Neoral)
VanderBorght, Ann; De Keyser, Filip; Geusens, Piet et al

in Journal of Rheumatology (2002), 29(3), 416-426

OBJECTIVE: To study T cell receptor (TCR) repertoire changes in synovial membrane over a 16 week period in patients with early rheumatoid arthritis (RA); and to study the influence of cyclosporin A (CSA ... [more ▼]

OBJECTIVE: To study T cell receptor (TCR) repertoire changes in synovial membrane over a 16 week period in patients with early rheumatoid arthritis (RA); and to study the influence of cyclosporin A (CSA) on TCR repertoire in a subgroup of these patients. METHODS: Synovial tissue biopsies and paired blood samples were obtained from 12 patients with early RA at 2 time points. Seven patients were treated with CSA (Neoral-Sandimmun, 3 mg/kg/day) and 5 patients with placebo for 16 weeks. TCR V gene repertoires were analyzed by semiquantitative PCR-ELISA. CDR3 spectratyping and sequence analysis was used to compare TCR clonotype distributions. RESULTS: TCR-specific mRNA was detected in all synovial tissue biopsies at the first sampling, but in only 8/12 biopsies 16 weeks later (4/7 CSA group, 4/5 placebo group). Overrepresented TCR BV genes were found in biopsies of 10/12 patients at the first time point, and in 7/12 patients after 16 weeks (3/7 CSA, 4/5 placebo). CDR3 sequence analysis revealed dynamic repertoire changes with only a few persisting clonotypes in the synovial tissue of placebo controls. Persisting T cell clonotypes were more frequently found in the synovial tissue of CSA treated patients compared to the placebo group. CONCLUSION: These data suggest a dynamic process of T cell recruitment in the joints of RA patients. This process, possibly due to activation and subsequent infiltration of new T cell clones, apparently is influenced by CSA treatment. Synovial tissue T cells were no longer detected after 16 weeks' CSA treatment in 3 patients. In the other CSA treated patients, new T cell clones infiltrated, while other clones were persistently represented in the joints. These data may have important consequences for the design of T cell targeted therapies for RA. [less ▲]

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