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See detailEugène Savitzkaya: une bibliographie
Demoulin, Laurent ULg; Virone, Carmelo; Parent, Sabrina et al

in Textyles : Revue des Lettres Belges de Langue Française (2013), 44

Tentative de bibliographie exhaustive concernant Eugène Savitzkaya.

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See detailThe EUI instrument on board the Solar Orbiter mission: from breadboard and prototypes to instrument model validation
Halain, Jean-Philippe ULg; Rochus, Pierre ULg; Renotte, Etienne ULg et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2012, June)

The Solar Orbiter mission will explore the connection between the Sun and its heliosphere, taking advantage of an orbit approaching the Sun at 0.28 AU. As part of this mission, the Extreme Ultraviolet ... [more ▼]

The Solar Orbiter mission will explore the connection between the Sun and its heliosphere, taking advantage of an orbit approaching the Sun at 0.28 AU. As part of this mission, the Extreme Ultraviolet Imager (EUI) will provide full-sun and high-resolution image sequences of the solar atmosphere at selected spectral emission lines in the extreme and vacuum ultraviolet. To achieve the required scientific performances under the challenging constraints of the Solar Orbiter mission it was required to further develop existing technologies. As part of this development, and of its maturation of technology readiness, a set of breadboard and prototypes of critical subsystems have thus been realized to improve the overall instrument design. The EUI instrument architecture, its major components and sub-systems are described with their driving constraints and the expected performances based on the breadboard and prototype results. The instrument verification and qualification plan will also be discussed. We present the thermal and mechanical model validation, the instrument test campaign with the structural-thermal model (STM), followed by the other instrument models in advance of the flight instrument manufacturing and AIT campaign. [less ▲]

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See detailEukaryotic algae: where lies the diversity of oxygenic photosynthesis.
Cardol, Pierre ULg; Franck, Fabrice ULg

in Photosynthesis Research (2010), 106(1-2), 1-2

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See detailEukaryotic complex I: functional diversity and experimental systems to unravel the assembly process
Remacle, Claire ULg; Barbieri, Rosario; Cardol, Pierre ULg et al

in Molecular Genetics & Genomics (2008), 280

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See detailEukaryotic organisms in Proterozoic oceans
Knoll, A. H.; Javaux, Emmanuelle ULg; Hewitt, D. et al

in Philosophical Transactions : Biological Sciences (2006), 361(1470), 1023-1038

The geological record of protists begins well before the Ediacaran and Cambrian diversification of animals, but the antiquity of that history, its reliability as a chronicle of evolution and the causal ... [more ▼]

The geological record of protists begins well before the Ediacaran and Cambrian diversification of animals, but the antiquity of that history, its reliability as a chronicle of evolution and the causal inferences that can be drawn from it remain subjects of debate. Well-preserved protists are known from a relatively small number of Proterozoic formations, but taphonomic considerations suggest that they capture at least broad aspects of early eukaryotic evolution. A modest diversity of problematic, possibly stem group protists occurs in ca 1800-1300 Myr old rocks. 1300-720 Myr fossils document the divergence of major eukaryotic clades, but only with the Ediacaran-Cambrian radiation of animals did diversity increase within most clades with fossilizable members. While taxonomic placement of many Proterozoic eukaryotes may be arguable, the presence of characters used for that placement is not. Focus on character evolution permits inferences about the innovations in cell biology and development that underpin the taxonomic and morphological diversification of eukaryotic organisms. [less ▲]

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See detailEULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 1: Prevalence of inflammation in osteoarthritis
D'Agostino, M. A.; Conaghan, P.; Le Bars, M. et al

in Annals of the Rheumatic Diseases (2005), 64(12), 1703-1709

Objectives: To assess the prevalence of inflammation in subjects with chronic painful knee osteoarthritis (OA), as determined by the presence of synovitis or joint effusion at ultrasonography (US); and to ... [more ▼]

Objectives: To assess the prevalence of inflammation in subjects with chronic painful knee osteoarthritis (OA), as determined by the presence of synovitis or joint effusion at ultrasonography (US); and to evaluate the correlation between synovitis, effusion, and clinical parameters. Methods: A cross sectional, multicentre, European study was conducted under the umbrella of EULAR-ESCISIT. Subjects had primary chronic knee OA (ACR criteria) with pain during physical activity >= 30 mm for at least 48 hours. Clinical parameters were collected by a rheumatologist and an US examination of the painful knee was performed by a radiologist or rheumatologist within 72 hours of the clinical examination. Ultrasonographic synovitis was defined as synovial thickness >= 4 mm and diffuse or nodular appearance, and a joint effusion was defined as effusion depth >= 4 mm. Results: 600 patients with painful knee OA were analysed. At US 16 (2.7%) had synovitis alone, 85 (14.2%) had both synovitis and effusion, 177 (29.5%) had joint effusion alone, and 322 (53.7%) had no inflammation according to the definitions employed. Multivariate analysis showed that inflammation seen by US correlated statistically with advanced radiographic disease (Kellgren-Lawrence grade >= 3; odds ratio (OR) = 2.20 and 1.91 for synovitis and joint effusion, respectively), and with clinical signs and symptoms suggestive of an inflammatory "flare'', such as joint effusion on clinical examination (OR = 1.97 and 2.70 for synovitis and joint effusion, respectively) or sudden aggravation of knee pain (OR = 1.77 for joint effusion). Conclusion: US can detect synovial inflammation and effusion in painful knee OA, which correlate significantly with knee synovitis, effusion, and clinical parameters suggestive of an inflammatory "flare''. [less ▲]

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See detailEULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 2: exploring decision rules for clinical utility
Conaghan, P.; D'Agostino, M. A.; Ravaud, P. et al

in Annals of the Rheumatic Diseases (2005), 64(12), 1710-1714

BACKGROUND: Synovial inflammation (as defined by hypertrophy and effusion) is common in osteoarthritis (OA) and may be important in both pain and structural progression. OBJECTIVE: To determine if ... [more ▼]

BACKGROUND: Synovial inflammation (as defined by hypertrophy and effusion) is common in osteoarthritis (OA) and may be important in both pain and structural progression. OBJECTIVE: To determine if decision rules can be devised from clinical findings and ultrasonography (US) to allow recognition of synovial inflammation in patients with painful knee OA. METHODS: A EULAR-ESCISIT cross sectional, multicentre study enrolled subjects with painful OA knee who had clinical, radiographic, and US evaluations. A classification and regression tree (CART) analysis was performed to find combinations of predictor variables that would provide high sensitivity and specificity for clinically detecting synovitis and effusion in individual subjects. A range of definitions for the two key US variables, synovitis and effusion (using different combinations of synovial thickness, depth, and appearance), were also included in exploratory analyses. RESULTS: 600 patients with knee OA were included in the analysis. For both knee synovitis and joint effusion, the sensitivity and specificity were poor, yielding unsatisfactory likelihood ratios (75% sensitivity, 45% specificity, and positive LR of 1.36 for knee synovitis; 71.6% sensitivity, 43.2% specificity, and positive LR of 1.26 for joint effusion). The exploratory analyses did not improve the sensitivity and specificity (demonstrating positive LRs of between 1.26 and 1.57). CONCLUSION: Although it is possible to determine clinical and radiological predictors of OA inflammation in populations, CART analysis could not be used to devise useful clinical decision rules for an individual subject. Thus sensitive imaging techniques such as US remain the most useful tool for demonstrating synovial inflammation of the knee at the individual level. [less ▲]

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See detailEuler
Dupont, Pascal ULg

in Courtois, Luc; Pirotte, Jean (Eds.) Mémoires de Wallonie : Les rues de Louvain-la-Neuve racontent... (2011)

Biographical notice of Leonhard Euler.

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See detailThe Euler number as an index of spatial integrity of landscapes: evaluation and proposed improvement.
Bogaert, Jan ULg; Van Hecke, P; Ceulemans, R

in Environmental Management (2002), 29(5), 673-682

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See detailEulerian Formulation for an Extensible Elastic Rod
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the Fifth International Conference on Structural Engineering, Mechanics and Computation (2013, September)

This paper reformulates the governing equations of an extensible elastic rod by reference to a given spatial curve. This Eulerian formulation is motivated by the need to solve efficiently the constrained ... [more ▼]

This paper reformulates the governing equations of an extensible elastic rod by reference to a given spatial curve. This Eulerian formulation is motivated by the need to solve efficiently the constrained elastica problem encountered in many medical and engineering applications, in which a thin rod is inserted in a tortuous conduit. The Eulerian reformulation of the equations hinges on the restatement of the rod local equilibrium in terms of derivatives with respect to the curvilinear coordinate associated with the reference curve and the description of the rod deflection as a perturbation of this curve. The originality of the proposed formulation lays in the axially unconstrained character of the resulting system such that the determination of the rod configuration between two fixed points reduces to the resolution of a classical boundary value problem. [less ▲]

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See detailEulerian Formulation of a Drillstring Constrained inside a Curved Borehole
Denoël, Vincent ULg; Detournay, Emmanuel

Conference (2011)

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See detailEulerian Formulation of Constrained Elastica
Denoël, Vincent ULg; Detournay, Emmanuel

in International Journal of Solids and Structures (2011), 136

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See detailEulerian Formulation of Elastic Rods
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2016), 472(2190),

In numerous biological, medical and engineering applications, elastic rods are constrained to deform inside or around tube-like surfaces. To solve efficiently this class of problems, the equations ... [more ▼]

In numerous biological, medical and engineering applications, elastic rods are constrained to deform inside or around tube-like surfaces. To solve efficiently this class of problems, the equations governing the deflection of elastic rods are reformulated within the Eulerian framework of this generic tubular constraint defined as a perfectly stiff canal surface. This reformulation hinges on describing the rod deformed configuration by means of its relative position with respect to a reference curve, defined as the axis or spine curve of the constraint, and on restating the rod local equilibrium in terms of the curvilinear coordinate parameterizing this curve. Associated with a segmentation strategy, which partitions the global problem into a sequence of rod segments either in continuous contact with the constraint or free of contact (except for their extremities), this approach not only trivializes the detection of new contacts but also suppresses the isoperimetric constraints resulting from the self-feeding feature of these elementary problems and the imposition of the rod position at the extremities of each rod segments. [less ▲]

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See detailEulerian Formulation of Spatially Constrained Elastic Rods
Huynen, Alexandre ULg

Doctoral thesis (2015)

Slender elastic rods are ubiquitous in nature and technology. For a vast majority of applications, the rod deflection is restricted by an external constraint and a significant part of the elastic body is ... [more ▼]

Slender elastic rods are ubiquitous in nature and technology. For a vast majority of applications, the rod deflection is restricted by an external constraint and a significant part of the elastic body is in contact with a stiff constraining surface. The research work presented in this doctoral dissertation formulates a computational model for the solution of elastic rods constrained inside or around frictionless tube-like surfaces. The segmentation strategy adopted to cope with this complex class of problems consists in sequencing the global problem into, comparatively simpler, elementary problems either in continuous contact with the constraint or contact-free between their extremities. Within the conventional Lagrangian formulation of elastic rods, this approach is however associated with two major drawbacks. First, the boundary conditions specifying the locations of the rod centerline at both extremities of each elementary problem lead to the establishment of isoperimetric constraints, i.e., integral constraints on the unknown length of the rod. Second, the assessment of the unilateral contact condition requires, in principle, the comparison of two curves parametrized by distinct curvilinear coordinates, viz. the rod centerline and the constraint axis. Both conspire to burden the computations associated with the method. To streamline the solution along the elementary problems and rationalize the assessment of the unilateral contact condition, the rod governing equations are reformulated within the Eulerian framework of the constraint. The methodical exploration of both types of elementary problems leads to specific formulations of the rod governing equations that stress the profound connection between the mechanics of the rod and the geometry of the constraint surface. The proposed Eulerian reformulation, which restates the rod local equilibrium in terms of the curvilinear coordinate associated with the constraint axis, describes the rod deformed configuration by means of either its relative position with respect to the constraint axis (contact-free segments) or its angular position on the constraint surface (continuous contacts.) This formulation circumvents both drawbacks that afflict the conventional Lagrangian approach associated with the segmentation strategy. As the a priori unknown domain, viz. the rod length, is substituted for the known constraint axis, the free boundary problem and the associated isoperimetric constraints are converted into a classical two-point boundary value problem. Additionally, the description of the rod deflection by means of its eccentricity with respect to the constraint axis trivializes the assessment of the unilateral contact condition. Along continuous contacts, this formulation expresses the strain variables, measuring the rod change of shape, in terms of the geometric invariants of the constraint surface, and emphasizes the influence of the constraint local geometry on the reaction pressure. Formalizing the segmentation strategy, a computational model that exploits the Eulerian formulation of the rod governing equations is devised. To solve the quasi-static deflection of elastic rods constrained inside or around a tube-like surface, this computational model identifies the number of contacts, their nature (either discrete or continuous), and the rod configuration at the connections that satisfies the unilateral contact condition and preserves the rod integrity along the sequence of elementary problems. [less ▲]

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See detailEulerian Formulation of the Constrained Spatial Elastica
Huynen, Alexandre ULg

Report (2013)

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See detailEulerian Formulation of the Torque and Drag Problem
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Detournay, Emmanuel; Denoël, Vincent; van de Wouw, Nathan (Eds.) Third International Colloquium on Nonlinear Dynamics and Control of Deep Drilling Systems (2014, May)

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See detailEulerian-Lagrangian Treatment of Contact Problems. Application to Metal Forming Simulation via FEM
Ponthot, Jean-Philippe ULg

in Proceedings of "New Advances in Computational Structural Mechanics (1991)

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See detailEuler–Lagrange approach to model heterogeneities in stirred tank bioreactors – Comparison to experimental flow characterization and particle tracking
Delafosse, Angélique ULg; Calvo, Sébastien ULg; Collignon, Marie-Laure ULg et al

in Chemical Engineering Science (2015), 134

The aim of this work is the validation of an Euler–Lagrange modeling approach coupling a CFD-based compartment model (Eulerian approach) and a stochastic model based on a Continuous-Time Markov Chain ... [more ▼]

The aim of this work is the validation of an Euler–Lagrange modeling approach coupling a CFD-based compartment model (Eulerian approach) and a stochastic model based on a Continuous-Time Markov Chain (Lagrangian approach). The turbulent flow structure and the mixing process in a bioreactor stirred by an axial Mixel TT impeller is characterized by PIV and tracer experiments. Comparison between experimental and numerical data shows that the CFD-based compartment model is able to reproduce accurately the spatial heterogeneities inside the bioreactor. The trajectory of a small tracer particle which perfectly follows the fluid flow is measured by optical trajectography. It is then simulated by a stochastic model which is either based on an homogeneous or on an inhomogeneous Continuous Time Markov Chain (CTMC). Comparison of residence and circulation time distributions in three zones defined inside the bioreactor shows that the inhomogeneous CTMC model predicts with an excellent accuracy the particle trajectories inside the bioreactor. The modeling approach proposed here could be an useful tool to design scale-down bioreactors in order to reproduce at lab-scale the stress levels encountered in large-scale production bioreactors and to characterize and compare different bioreactor configurations. [less ▲]

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See detailEupen-Malmedy
Brüll, Christoph ULg

in Daniel, Ute; Gatrell, Peter; Janz, Oliver (Eds.) 1914-1918-online. International Encyclopedia of the First World War (2014)

Eupen-Malmedy is the name given to the two districts that Germany ceded to Belgium in 1920 as a consequence of the Treaty of Versailles. This cession and the semblance of a “referendum”, organised in 1920 ... [more ▼]

Eupen-Malmedy is the name given to the two districts that Germany ceded to Belgium in 1920 as a consequence of the Treaty of Versailles. This cession and the semblance of a “referendum”, organised in 1920, turned the territory into a Belgian-German conflict space during the interwar years. [less ▲]

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See detailEupen-Malmedy
Brüll, Christoph ULg

in Gruner, Wolf; Osterloh, Jörg (Eds.) The Greater German Reich and the Jews. Nazi Persecution Policies in the Annexed Territories 1935-1945 (2015)

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