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See detailEnolates in macromolecular science: current situation and future outlook
Lecomte, Philippe ULg; Jérôme, Christine ULg

in Zabicky, Jacob (Ed.) The Chemistry of Metal Enolates (Volume 2) (2017)

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See detailDeformations of soap bubbles in a uniform electric field
Mawet, Sébastien ULg

Conference (2017, March 15)

The study of the deformations undergone by a soap bubble submitted to an electrical force began with Taylor and Wilson 1 and the observation of the so-called Taylor’s cones. Beyond this particular ... [more ▼]

The study of the deformations undergone by a soap bubble submitted to an electrical force began with Taylor and Wilson 1 and the observation of the so-called Taylor’s cones. Beyond this particular structure, few studies analyzed the bubble deformations. For example, what is the link between the deformations and the electrical force ? Or, how do charges move in the thin soap film formed by the bubble ? To answer those questions, we characterize the shape variations of the surface of the bubble immersed in the uniform electric field of a plan capacitor. In particular, our study focuses on hemispherical bubbles lying on the bottom electrode of a plane capacitor. This study allows us to observe some interesting phenomena like the appearance of a hysteresis cycle in the deformation amplitude. [less ▲]

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See detailCabinet de curiosités contemporains : de l'oeuvre au musée
Bawin, Julie ULg

Conference (2017, March 15)

Detailed reference viewed: 6 (0 ULg)
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See detailOffline Policy-search in Bayesian Reinforcement Learning
Castronovo, Michaël ULg

Doctoral thesis (2017)

This thesis presents research contributions in the study field of Bayesian Reinforcement Learning — a subfield of Reinforcement Learning where, even though the dynamics of the system are un- known, the ... [more ▼]

This thesis presents research contributions in the study field of Bayesian Reinforcement Learning — a subfield of Reinforcement Learning where, even though the dynamics of the system are un- known, the existence of some prior knowledge is assumed in the form of a distribution over Markov decision processes. In this thesis, two algorithms are presented: OPPS (Offline Prior- based Policy Search) and ANN-BRL (Artificial Neural Networks for Bayesian Reinforcement Learning), whose philosophy consists to analyse and exploit the knowledge available beforehand prior to interacting with the system(s), and which differ by the nature of the model they make use of. The former makes use of formula-based agents introduced by Maes et al. in (Maes, Wehenkel, and Ernst, 2012), while the latter relies on Artificial Neural Networks built via SAMME (Stagewise Additive Modelling using a Multi-class Exponential loss function) — an AdaBoost algorithm developed by Zhu et al. in (Zhu et al., 2009). Moreover, we also describe a comprehensive benchmark which has been created to compare Bayesian Reinforcement Learning algo- rithms. In real life applications, the choice of the best agent to fulfil a given task depends not only on their performances, but also on the computation times required to deploy them. This benchmark has been designed to identify the best algorithms by taking both criteria into account, and resulted in the development of an open-source library: BBRL (Benchmarking tools for Bayesian Reinforcement Learning) (https://github.com/mcastron/BBRL/wiki). [less ▲]

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See detailUnderground pumped storage hydropower plants using open pit mines: How do groundwater exchanges influence the efficiency?
Pujades, Estanislao ULg; Orban, Philippe ULg; Bodeux, Sarah ULg et al

in Applied Energy (2017), 190

Underground Pumped Storage Hydropower (UPSH) is a potential alternative to manage electricity production in flat regions. UPSH plants will interact with the surrounding porous medium through exchanges of ... [more ▼]

Underground Pumped Storage Hydropower (UPSH) is a potential alternative to manage electricity production in flat regions. UPSH plants will interact with the surrounding porous medium through exchanges of groundwater. These exchanges may impact the surrounding aquifers, but they may also influence the efficiency of the pumps and turbines because affecting the head difference between the reservoirs. Despite the relevance for an accurate efficiency assessment, the influence of the groundwater exchanges has not been previously addressed. A numerical study of a synthetic case is presented to highlight the importance of considering the groundwater exchanges with the surrounding porous medium. The general methodology is designed in order to be further applied in the decision making of future UPSH plants introducing each case specific complexity. The underground reservoir of a hypothetical UPSH plant, which consists in an open pit mine, is considered and modelled together with the surrounding porous medium. Several scenarios with different characteristics are simulated and their results are compared in terms of (1) head difference between the upper and lower reservoirs and (2) efficiency by considering the theoretical performance curves of a pump and a turbine. The results show that the efficiency is improved when the groundwater exchanges increase. Thus, the highest efficiencies will be reached when (1) the underground reservoir is located in a transmissive porous medium and (2) the walls of the open pit mine do not constrain the groundwater exchanges (they are not waterproofed). However, a compromise must be found because the characteristics that increase the efficiency also increase the environmental impacts. Meaningful and reliable results are computed in relation to the characteristics of the intermittent and expected stops of UPSH plants. The frequency of pumping and injection must be considered to properly configure the pumps and turbines of future UPSH plants. If not, pumps and turbines could operate far from their best efficiency conditions. [less ▲]

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See detailImprinting superconducting vortex footsteps in a magnetic layer
Brisbois, Jérémy ULg

Conference (2017, March 14)

We experimentally show that the principle of local polarization of a magnetic layer, a well-known method to store information, namely in hard drives and credit cards, can be applied for imprinting into a ... [more ▼]

We experimentally show that the principle of local polarization of a magnetic layer, a well-known method to store information, namely in hard drives and credit cards, can be applied for imprinting into a soft magnetic layer of permalloy (Py) the trajectory of vortices moving in a superconducting film (Nb). In full analogy with a magnetic drawing board, vortices act as tiny magnetic scribers leaving a wake of polarized magnetic media in the Py layer. We have used the magneto-optical imaging technique to investigate the mutual interaction between superconducting vortices and ferromagnetic domains. In general, we observe that the flux propagation is delayed at the border of the magnetic layer. Interestingly, in thin Py layers without stripe domains, vortices leave clear imprints of locally polarized magnetic moments along their trajectories. Furthermore, the printings were found to be stable and could still be observed at room temperature, allowing for ex situ observation of the flux penetration in superconductors. We expect our findings to pave the way for further studies for optimizing magnetic recording of superconducting vortex trajectories. [less ▲]

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See detailHieroglyphic encoding & hieroglyphic sign-lists. From the Ramses Project to the Thot Sign-List
Polis, Stéphane ULg

Scientific conference (2017, March 14)

Based on systematic observations regarding the encoding of hieroglyphs in an electronic corpus, specifically the Ramses corpus (ramses.ulg.ac.be), the aim of this presentation was to introduce and discuss ... [more ▼]

Based on systematic observations regarding the encoding of hieroglyphs in an electronic corpus, specifically the Ramses corpus (ramses.ulg.ac.be), the aim of this presentation was to introduce and discuss the data-model of the Thot Sign-List (under development at the university of Liège) and to present online resources made available for documenting the elements of this model (http://thot.philo.ulg.ac.be/index.html). Among the future goals is a strengthened collaboration between the AKU project and the Thot Sign-List (e.g., a shared hieroglyphic sign-list and a connection between the graphemes analysed by the AKU project and the texts of Ramses Online). [less ▲]

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See detailLa réalisation et les complications de la césarienne dans la race Blanc-bleu Belge
Djebala, Salem ULg; Casalta, Hélène ULg; Rao, Anne-Sophie ULg et al

Conference given outside the academic context (2017)

La césarienne est la chirurgie la plus couramment réalisée en Belgique. Bien que celle-ci soit une intervention de routine le taux de complications post-opératoires est non négligeable. Deux enquêtes ont ... [more ▼]

La césarienne est la chirurgie la plus couramment réalisée en Belgique. Bien que celle-ci soit une intervention de routine le taux de complications post-opératoires est non négligeable. Deux enquêtes ont été réalisées au près des éleveurs et des vétérinaires sur la préparation, le déroulement de la césarienne et les soins post-opératoires. Ces deux enquêtes nous ont permis de tirer des conclusions et formuler des recommandations afin de réduire le taux de complication. [less ▲]

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See detailEvaluation de la fonction rénale
DELANAYE, Pierre ULg

Conference (2017, March 14)

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See detailApport de l'ENMG aux syndromes douloureux diffus
WANG, François-Charles ULg

Scientific conference (2017, March 14)

Detailed reference viewed: 15 (1 ULg)
See detailFormation and characterization of artificial lipid bilayers on optical fibers
Toussaint, Pauline ULg; Dreesen, Laurent ULg

Conference (2017, March 14)

Transports across cellular membranes are at the basis of a lot of biological processes such as the transmission of information in neurons. Their characterization is therefore of crucial interest. As they ... [more ▼]

Transports across cellular membranes are at the basis of a lot of biological processes such as the transmission of information in neurons. Their characterization is therefore of crucial interest. As they are equivalent to biological membranes, artificial lipid bilayers can be created to study membranes and transmembrane proteins properties or transmembrane transports. The aim of this work is to develop a new method for the fabrication of artificial membranes based on the use of optical fibers as support for the bilayer, and for their characterization by fluorescence measurements. We use microfluidics on fibers to create two phospholipid monolayers that we approach close enough to form a bilayer. The membrane formation is checked using fluorescein or a fluorescent sodium probe, Tetra (tetramethylammonium) salt (sodium green), whose optical signal depends on sodium concentration. [less ▲]

Detailed reference viewed: 16 (4 ULg)
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See detailQSAR models and the flexible regulation of chemicals
Thoreau, François ULg

Scientific conference (2017, March 14)

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See detailRealization of the Najafi-Golestanian microswimmer
Hubert, Maxime ULg; Grosjean, Galien ULg; Lagubeau, Guillaume et al

Conference (2017, March 14)

The development of artificial microswimmers, microscopic robots that swim in a fluid like sperm cells and motile bacteria, could cause a leap forward in various fields such as microfluidics, microsystems ... [more ▼]

The development of artificial microswimmers, microscopic robots that swim in a fluid like sperm cells and motile bacteria, could cause a leap forward in various fields such as microfluidics, microsystems, or minimally invasive medicine. Nature provides plenty of examples of efficient microswimmers. However, a bottom-up approach, looking at the simplest ingredients needed to generate a microswimmer, can lead to a deeper under- standing of the swimming problem. First described by Najafi and Golestanian 1 , a paradigmatic microswimmer is the three-linked-spheres model, which follows a minimalist approach for propulsion by shape shifting. In this presentation, we describe the experimental realisation of this microswimmer using self-assembled ferromagnetic particle at an air-water interface, powered by an uniform oscillating magnetic field 2 . A model, using two har- monic oscillators, reproduces the experimental findings. Because the model remains general, the same approach could be used to design a variety of efficient microswimmers. [less ▲]

Detailed reference viewed: 9 (1 ULg)
See detailL'Europe à l'épreuve du populisme
Debras, François ULg

Conference given outside the academic context (2017)

Face aux élites nationales et internationales, politiques et économiques qui auraient confisqué le pouvoir aux citoyens, le populiste se présente comme le véritable défenseur du peuple. En faveur d'une ... [more ▼]

Face aux élites nationales et internationales, politiques et économiques qui auraient confisqué le pouvoir aux citoyens, le populiste se présente comme le véritable défenseur du peuple. En faveur d'une démocratie plus directe, plus proche du citoyen, le leader populiste s'oppose frontalement aux partis traditionnels jugés technocratiques, clientélistes, œuvrant au profit de certains intérêts particuliers et au détriment de l’intérêt général. Que signifie être populiste? Est-ce une idéologie ou une rhétorique? Quels partis, quelles personnalités politiques pouvons-nous qualifier de populistes? Le populisme est-il systématiquement opposé à la notion de démocratie, est-il "antisystème"? Au travers d'un tour de l'Europe et de certains partis en particulier, nous proposons d'apporter des clés de compréhension du populisme, un concept flou mais qui n'est certainement pas vide de sens. [less ▲]

Detailed reference viewed: 39 (7 ULg)
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See detailMechanisms of Igf2 inhibition in thymic epithelial cells infected with CVB4 E2
Michaux, Hélène ULg; Charlet-Renard, Chantal; Martens, Henri ULg et al

Poster (2017, March 12)

Detailed reference viewed: 10 (1 ULg)
See detailRéflexions psychopathologiques sur la psychopathie
Englebert, Jérôme ULg

Scientific conference (2017, March 11)

Detailed reference viewed: 18 (0 ULg)