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See detailContributions to handle maximum size constraints in density-based topology optimization
Fernandez Sanchez, Eduardo Felipe ULiege; Collet, Maxime ULiege; Bauduin, Simon ULiege et al

in Fiebig, Sierk; Bletzinger, Kai-Uwe; Maute, Kurt (Eds.) et al Advances in Structural and Multidisciplinary Optimization (2017, June 05)

The maximum size formulation in topology optimization restricts the amount of material within a test region in each point in the design domain, leading to a highly constrained problem. In this work the ... [more ▼]

The maximum size formulation in topology optimization restricts the amount of material within a test region in each point in the design domain, leading to a highly constrained problem. In this work the local constraints are aggregated into a single one by p-mean and p-norm functions, classically used for stress constraints. Moreover, a new test region is investigated which is a ring instead of the classical circle around the element. These developments were implemented for compliance minimization with the MBB beam test case. Results indicate that p-mean performs better in the maximum size field than p-norm, because it underestimates the most violated constraint. This gives some relaxation to the problem that allows stiffer connections. Similar effect has been observed for the ring-shaped region which reduces the amount of holes that are introduced in the structure, specially in the connection of solid members. In addition, it is shown that the maximum size formulation allows the definition of the minimum gap between solid members which gives designers more control over the geometry. The developments have been illustrated and validated with compliance minimization tests of 2D-domains. [less ▲]

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See detailFEMxDEM: a new efficient multi-scale approach for geotechnical problems with strain localization
Nguyen, Trung Kien; Argilaga, Albert ULiege; Caillerie, Denis et al

in EPJ Web of Conferences (2017, June 01), 140

The paper presents a multi-scale modeling of Boundary Value Problem (BVP) approach involving cohesive-frictional granular materials in the FEM × DEM multi-scale framework. On the DEM side, a 3D model is ... [more ▼]

The paper presents a multi-scale modeling of Boundary Value Problem (BVP) approach involving cohesive-frictional granular materials in the FEM × DEM multi-scale framework. On the DEM side, a 3D model is defined based on the interactions of spherical particles. This DEM model is built through a numerical homogenization process applied to a Volume Element (VE). It is then paired with a Finite Element code. Using this numerical tool that combines two scales within the same framework, we conducted simulations of biaxial and pressuremeter tests on a cohesive-frictional granular medium. In these cases, it is known that strain localization does occur at the macroscopic level, but since FEMs suffer from severe mesh dependency as soon as shear band starts to develop, the second gradient regularization technique has been used. As a consequence, the objectivity of the computation with respect to mesh dependency is restored. [less ▲]

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See detailVoltaire, Zaïre, (éd. Pierre Frantz)
Daubercies, Laurence ULiege

in Revue Voltaire (2017)

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See detailEvaluation of uncertainty sources in the determination of testosterone in urine by calibration-based and isotope dilution quantification using ultra high performance liquid chromatography tandem mass spectrometry
Pitarch-Motellón, Jorge; Roig-Navarro, Antoni F.; Sancho Llopis, Juan V. et al

in Journal of Chromatography A (2017)

Three quantification methodologies, namely calibration with internal standard (Cal-IS, non-weighted), weighted calibration with internal standard (wCal-IS) and isotope pattern deconvolution (IPD) have ... [more ▼]

Three quantification methodologies, namely calibration with internal standard (Cal-IS, non-weighted), weighted calibration with internal standard (wCal-IS) and isotope pattern deconvolution (IPD) have been used for the determination of testosterone in urine by LC-MS/MS. Uncertainty has been calculated and compared for the three methodologies through intra- and inter-laboratory reproducibility assays. IPD showed the best performance for the intra-laboratory reproducibility, with RSD and combined uncertainty values below 4% and 9% respectively. wCal-IS showed similar performance, while Cal-IS where not constant and clearly worse at the lowest concentration assayed (2 ng/mL) reaching RSD values up to 16%. The inter-laboratory assay indicated similar results although wCal-IS RSD (20%) was higher than IPD (10%) and Cal-IS get worse with RSD higher than 40% for the lowest concentration level. Uncertainty budgets calculated for the three procedures revealed that intercept and slope were the most important factors contributing to uncertainty for Cal-IS. The main factors for wCal-IS and IPD were the volumes of sample and/or standard measured. [less ▲]

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See detailGenetic architecture of flowering-time control in Brachypodium distachyon
Bouché, Frédéric ULiege; Woods, D.P.; Amasino, R.M.

Poster (2017, June)

Controlling the timing to flowering is an essential aspect of agriculture, either by delaying flowering to maximize storage in root crops or by initiating flowering when conditions are favorable to ... [more ▼]

Controlling the timing to flowering is an essential aspect of agriculture, either by delaying flowering to maximize storage in root crops or by initiating flowering when conditions are favorable to maximize seed or fruit production. The extensive studies carried out on the model Brassicaceae Arabidopsis thaliana revealed dozens of genes whose mutation alters flowering time (Bouché et al., 2016). Comparatively, relatively little is known about the genetic mechanisms controlling flowering in Pooideae, a group of grasses that includes important crops such as wheat, barley, and oat. In recent years, Brachypodium distachyon—a small diploid grass from the Pooideae group—has been increasingly used as a model plant to study the genetic mechanisms controlling developmental processes in temperate grasses. In our lab, we combine forward and reverse genetic approaches to identify and characterize new genes controlling the timing of flowering in Brachypodium distachyon. [less ▲]

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See detailUn classique : Georg Simmel. Les grandes villes et la vie de l'Esprit (1903).
Dawans, Stéphane ULiege

in Schreuer, François (Ed.) Dérivations n°4 (2017)

il s'agit de la présentation d'un classique de la sociologie urbaine. Nous tentons de situer Simmel dans le cadre de la naissance de la sociologie urbaine. Nous répertorions les traductions du texte en ... [more ▼]

il s'agit de la présentation d'un classique de la sociologie urbaine. Nous tentons de situer Simmel dans le cadre de la naissance de la sociologie urbaine. Nous répertorions les traductions du texte en français. [less ▲]

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See detailPolynomial nonlinear state-space modelling of vortex-induced vibrations: Black-box vs grey-box approach
Decuyper, Jan; Noël, Jean-Philippe ULiege; De Troyer, Tim et al

in Proceedings of the International Forum on Aeroelasticity and Structural Dynamics (2017, June)

The kinematics of oscillating bluff bodies in a fluid flow have been a hot research topic for decades. Most important are the potentially harmful vortex-induced vibrations (VIVs) where the structure is ... [more ▼]

The kinematics of oscillating bluff bodies in a fluid flow have been a hot research topic for decades. Most important are the potentially harmful vortex-induced vibrations (VIVs) where the structure is excited by alternating vortex shedding in its wake. Classical examples are the vibration of chimney stacks exposed to wind, pipelines on the sea-bed excited by the ocean currents or water tubes in heat exchangers. For these kind of fluid-structure interactions, typically an analytical solution cannot be found. Yet accurate predictions of the kinematics and the resulting dynamics are vital during for instance a design process, in monitoring applications or for control. Obtaining predictions with high fidelity have so far been restricted to solving the Navier-Stokes equations via computation fluid dynamic (CFD) simulations or to performing experiments. Both approaches are cumbersome and, in the case of CFD, requires a lot of computing power. These drawbacks make the current methods disadvantageous towards many intended applications where only limited time and resources are available to assess a certain risk. What is needed is an efficient and powerful model, flexible enough to span a wide domain in parameter space with a single set of coefficients. A task for which, we believe, system identifi cation can be a very powerful tool. [less ▲]

See detail"Rear Window" d'Alfred Hitchcock. Le cinéma disséqué par le cinéma
Tomasovic, Dick ULiege

Conference given outside the academic context (2017)

Analyse du film "Fenêtre sur cour" d'Alfred Hitchcock

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See detailSynthèse et conclusions du Congrès national 2017 des Géomètres-Experts
Guillaume, Jean-François ULiege

Conference given outside the academic context (2017)

Mais à quoi « sert-il » de créer un Ordre professionnel des géomètres-experts ? Défendre les intérêts collectifs ? Gérer collectivement les évolutions structurelles ? Consolider une profession ? La ... [more ▼]

Mais à quoi « sert-il » de créer un Ordre professionnel des géomètres-experts ? Défendre les intérêts collectifs ? Gérer collectivement les évolutions structurelles ? Consolider une profession ? La constitution d'un ordre professionnel recouvre au moins trois défis majeurs : situer le groupe professionnel dans l'organisation du travail ; fixer les conditions de reproduction du groupe professionnel ; fixer les modalités de reconnaissance mutuelle des membres. [less ▲]

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See detailHuman Nature and Nature in Kant and Hegel: A modal Approach
Lejeune, Guillaume ULiege

Conference (2017, May 23)

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See detailInnovation et créativité : un nouvel objet d’apprentissage en formation
Hausman, Matthieu ULiege; Vincent, Coline

Conference (2017, May 19)

Comment amener les futurs-enseignants à innover pour faire face à leurs futurs défis professionnels ? Depuis deux ans, notre formation initiale propose un dispositif ayant pour visée principale de ... [more ▼]

Comment amener les futurs-enseignants à innover pour faire face à leurs futurs défis professionnels ? Depuis deux ans, notre formation initiale propose un dispositif ayant pour visée principale de stimuler la créativité des étudiants et, par extension, celle de leurs futurs élèves. Actuellement, la créativité n’apparait pas explicitement dans le référentiel de compétences des enseignants en Belgique francophone (2000). Nous y voyons néanmoins une compétence professionnelle indispensable à développer à l’heure où l’innovation est aussi au centre des préoccupations des acteurs de l’éducation. Un processus créatif est donc mené au sein d’activités visant à la fois une meilleure compréhension du concept et son appropriation en tant que démarche fonctionnelle. Les futurs-enseignants y développent des pistes d’innovations pédagogiques en référence aux étapes d’un modèle inspiré du Creative Problem Solving (Osborn et Parnes, 1926). Pour la seconde année consécutive, c’est donc la capacité à innover de nos étudiants que nous souhaitons développer. La créativité étant le moyen choisi pour y parvenir, l’hypothèse principale que nous allons vérifier suite aux ajustements qui ont suivi notre première analyse (2015-2016) est la suivante : Le dispositif permet aux étudiants de faire évoluer leurs représentations du métier en y intégrant le processus créatif comme démarche fonctionnelle. [less ▲]

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See detailDose-Dependant effect of Estetrol on Angiogenesis and Tumor growth
Gallez, Anne ULiege; BLACHER, Silvia ULiege; Lenfant, Françoise et al

Conference (2017, May 19)

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See detailMobile researcher? A challenge! How a Euraxess Mobility centre can help
Ernst, Brigitte ULiege

Conference given outside the academic context (2017)

How can Euraxess help mobile researchers integrate a new professional environment? Practical examples of good practices at Université de Liège Belgium

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See detailTumour microenvironment affects the composition of endothelial cell-derived extracellular vesicles: impact in tumour progression
Njock, Makon-Sébastien ULiege; O’Grady, christina; Dequiedt, Franck et al

in Journal of Extracellular Vesicles (2017, May 15)

The tumor microenvironment plays a crucial role in the progression of tumor growth and metastasis by deregulating various physiological processes including angiogenesis and inflammation. Several studies ... [more ▼]

The tumor microenvironment plays a crucial role in the progression of tumor growth and metastasis by deregulating various physiological processes including angiogenesis and inflammation. Several studies have previously demonstrated that tumor-derived extracellular vesicles (EVs) are actively involved in the mediation of tumorigenesis by “reprogramming” target cells (e.g. endothelial cells (ECs)) through transfer of pro-angiogenic microRNAs. But the function of EVs released by target cells is poorly studied. Consequently, we sought to determine the composition of EVs released by ECs under tumor microenvironment, and to assess whether these vesicles present different functional properties. Using RNA-seq approaches, we demonstrated that EVs released by ECs in tumor microenvironment context present a specific repertory of microRNAs associated to tumor angiogenesis and inflammatory pathways. Interestingly, some of the dysregulated microRNAs are differently expressed at the cellular and exosomal levels. Furthermore, we showed that these vesicles were able to deregulate angiogenesis pathway by transferring several dysregulated microRNAs to target cells. Currently, we are identifying the molecular targets and pathways modulated by EC-derived EVs under tumor microenvironment. [less ▲]

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See detailDiabetes affects extracellular vesicle content and function
Njock, Makon-Sébastien ULiege; Chandy, Mark; Veitch, Shawn C. et al

in Journal of Extracellular Vesicles (2017, May 15)

Introduction: The role of circulating extracellular vesicles in cardiovascular diseases remains incompletely understood.We previously demonstrated that extracellular vesicles circulating in plasma of ... [more ▼]

Introduction: The role of circulating extracellular vesicles in cardiovascular diseases remains incompletely understood.We previously demonstrated that extracellular vesicles circulating in plasma of healthy mice can suppress monocyte activation through transfer of anti-inflammatory microRNAs. Here we set out to determine the effect of diabetes on the function of plasma extracellular vesicles since diabetes is known to negatively affect vascular function, playing a contributory role in cardiovascular diseases. Methods: Circulating plasma extracellular vesicles were isolated from mouse and rat models of type 2 diabetes. Extracellular vesicles were characterised with nanoparticle tracking analysis. Furthermore, qPCR and RNA-sequencing approaches were used to characterise vesicle content and function. Results: We found that vesicle abundance and size were increased in mouse and rat models of type 2 diabetes. MicroRNAs in plasma extracellular vesicles were dysregulated during the progression of diabetes in thesemodels. Finally, we demonstrate that vesicles isolated from diabetic plasma can activate inflammatory pathways in endothelial cells. Current studies are seeking to determine the contribution of microRNA transfer to endothelial dysfunction. Conclusions: These studies suggest that the microRNA content and function of extracellular vesicles are dysregulated during diabetes. Advancements in this area could facilitate the development of more effective non-invasive diagnostics, prognostics, and therapeutics. Funding: Supported by funding from the Canadian Vascular Network and the Canadian Institutes of Health Research. [less ▲]

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