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See detailGeometrical guidance and trapping transition of human sperm cells
Guidobaldi, Alejandro; Jeyaram, Yogesh; Berdakin, Ivan et al

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2014), 89

The guidance of human sperm cells under con finement in quasi 2D microchambers is investigated using a purely physical method to control their distribution. Transport property measurements and simulations ... [more ▼]

The guidance of human sperm cells under con finement in quasi 2D microchambers is investigated using a purely physical method to control their distribution. Transport property measurements and simulations are performed with diluted sperm populations, for which eff ects of geometrical guidance and concentration are studied in detail. In particular, a trapping transition at convex angular wall features is identi ed and analyzed. We also show that highly efficient microratchets can be fabricated by using curved asymmetric obstacles to take advantage of the spermatozoa specifi c swimming strategy. [less ▲]

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See detailDefinition of vocal pitch accuracy in a melodic context
Larrouy, Pauline ULg

Scientific conference (2014, March 28)

If we easily categorize sung performances as “in tune” or “out of tune”, it is not so evident to explicitly describe on which criteria our evaluation is based. This presentation reports recent work on ... [more ▼]

If we easily categorize sung performances as “in tune” or “out of tune”, it is not so evident to explicitly describe on which criteria our evaluation is based. This presentation reports recent work on pitch accuracy perception in a melodic context. The results allow to refine the notion of pitch accuracy and therefore to design objective tools for the evaluation of singer quality. [less ▲]

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See detailCharacterization of thin layers into concrete with Ground Penetrating Radar
Van der Wielen, Audrey ULg

Doctoral thesis (2014)

The Ground Penetrating Radar (GPR) is a non-destructive method used for roads and buildings inspection: it is well adapted to detect the different layers constituting the structures. The objective of this ... [more ▼]

The Ground Penetrating Radar (GPR) is a non-destructive method used for roads and buildings inspection: it is well adapted to detect the different layers constituting the structures. The objective of this thesis is to develop a method for a fast determination of the properties of a buried layer on the basis of surface GPR measurements. The observation of the GPR waves propagation in numerical simulations led to develop an analytical model, which could be applied to the experimental determination of laboratory layered structures. [less ▲]

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See detailAdding Value to Agricultural Products and Agrifood Byproducts by Highlighting Functional Ingredients
Besbes, Souhail; Besbes, Souhail; Attia, Hamadi et al

in Journal of Chemistry (2014), 2014(848231), 1-2

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See detailPésentation du Professeur Eugenio Amato
Rochette, Bruno ULg

Diverse speeche and writing (2014)

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See detailNonlinear Modal Analysis of Conservative and Nonconservative Aerospace Structures
Renson, Ludovic ULg

Doctoral thesis (2014)

The concept of nonlinear normal modes (NNMs) provides a solid and rigorous theoretical framework for the analysis of the nonlinear oscillations of mechanical systems. If NNMs have been studied since more ... [more ▼]

The concept of nonlinear normal modes (NNMs) provides a solid and rigorous theoretical framework for the analysis of the nonlinear oscillations of mechanical systems. If NNMs have been studied since more than fifty years, it is only very recently that contributions dealing with their numerical calculation have been reported in the literature. Although these methods pave the way for the application of NNMs to more complex systems, they have not yet reached the necessary maturity. In this context, the purpose of this research is (i) to further investigate the performance of an existing method for computing the NNMs of conservative systems and (ii) to propose two new methods for the computation of NNMs of nonconservative systems. The first contribution of this thesis is to calculate the NNMs of a real-life aerospace structure, the SmallSat spacecraft developed by EADS Astrium. An algorithm that combines an advanced shooting method with the pseudo-arclength continuation technique is utilized. We show that the NNMs provide a very useful interpretation of the strongly nonlinear dynamics of the spacecraft. One specific contribution is to numerically reproduce with great fidelity several interactions between modes with noncommensurate linear frequencies that were observed experimentally. The second original contribution of this thesis is to develop two new methods for computing the NNMs of damped systems. The first method solves the partial differential equations (PDEs) governing the geometry of the NNM. The PDEs are recognized as hyperbolic, and it is shown that they require appropriate numerical treatments including specific boundary conditions. The proposed method combines a streamline upwind Petrov-Galerkin finite-element formulation with a resolution strategy based on annular domains to grow sequentially the manifold. The algorithm is demonstrated using a wide variety of systems ranging from two-degree-of-freedom to multi-degree-of-freedom nonlinear systems with linear and nonlinear damping. The applicability of the algorithm to complex real-life structures is demonstrated using a full-scale aircraft. The second method presented in this work computes a NNM as a collection of trajectories defined with boundary value problems (BVPs). The method has the distinctive advantage that it does not rely on a parameterization of the NNM. It is demonstrated on two-degree-of-freedom examples featuring linear and nonlinear damping. [less ▲]

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See detailLes fins du monde peuvent-elles faire littérature ? Exemplarités du récit dystopique
Stienon, Valérie ULg

Scientific conference (2014, March 27)

S’il est possible d’observer de nombreuses œuvres qui, depuis le XIXe siècle et particulièrement au tournant du XXe siècle, se présentent comme des fictions de fins du monde déclinant les situations ... [more ▼]

S’il est possible d’observer de nombreuses œuvres qui, depuis le XIXe siècle et particulièrement au tournant du XXe siècle, se présentent comme des fictions de fins du monde déclinant les situations-catastrophes, il est plus difficile d’appréhender ces textes en mots et en images comme un ensemble cohérent et de les associer à un genre littéraire particulier. Entre désignations d’époque et catégorisations rétrospectives, un corpus se dessine toutefois, qui développe ses propres caractéristiques internes et connaît une histoire éditoriale complexe. La communication propose de réfléchir aux modalités d’appartenance de ces « récits dystopiques » à l’histoire littéraire et aux critères possibles de leur rassemblement pour une étude poétique transversale. [less ▲]

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See detailIssues related to protein fermentation in the intestines of pigs
Bindelle, Jérôme ULg

Scientific conference (2014, March 27)

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See detailPiété et impiété dans les rapports entre Grecs et étrangers
Delli Pizzi, Aurian ULg

Scientific conference (2014, March 27)

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See detailQuaternary rainforests of the Northern Congo Basin: contribution of charcoal analysis
Morin-Rivat, Julie ULg; Bremond, Laurent; Gillet, Jean-François ULg et al

Conference (2014, March 27)

In comparison with the wood charcoals uncovered in the soils of the temperate regions, charcoals from the tropical regions remain little studied yet, in particular those from the dense humid forests of ... [more ▼]

In comparison with the wood charcoals uncovered in the soils of the temperate regions, charcoals from the tropical regions remain little studied yet, in particular those from the dense humid forests of Central Africa. Here we aim at showing the interest of the analysis of soil charcoals so as to understand the current environments through some examples of taxonomical identifications conducted on charcoals sampled in several soil pits in Cameroon and in the Republic of the Congo. These charcoals were hand-split then observed under an incident light microscope. The anatomical features that are hold in the charcoals and described according to a standard method were compared to wood samples from the reference collection of the RMCA. Results demonstrated that the identified species are still present in the vegetal environment today and that only limited changes occurred over the past two millennia. Charcoal analysis can thus allow a better understanding of the past history of the forests in relationship with the ancient disturbances. The temporal and spatial framework of human settlements as well as the impact of the colonial period on the evolution of the forest is also discussed. [less ▲]

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See detailDroit électoral et principe d'égalité. L'élection des assemblées législatives nationales en droit allemand, belge et britannique
Bouhon, Frédéric ULg

Doctoral thesis (2014)

The study concerns the election law and the equality principle in three European legal systems, i.e. the Federal Republic of Germany, the Kingdom of Belgium and the United Kingdom. In this framework, the ... [more ▼]

The study concerns the election law and the equality principle in three European legal systems, i.e. the Federal Republic of Germany, the Kingdom of Belgium and the United Kingdom. In this framework, the research is structured into two principal questions. I firstly wonder whether the election law guarantees equality among the governed people. Should the answer to that question be negative, I secondly check if the inequality can be legally justified in democratic systems. My thesis is a nuanced answer to these questions. The work shows that election law, considered under the scope of the equality principle, includes two categories of legislations which effect is opposed: some legal rules tend to distribute equally the faculty to influence the composition of the elected assemblies, while others tend to distribute unequally that faculty. Among the rules of the second category, I argue that the tendency to inequality can be partly legally justified by the purposes of these rules, but is also a mean – hardly justifiable in a democratic system – that helps persons and parties in government to remain in power. [less ▲]

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See detailProgramming of neuroendocrine self-tolerance in the thymus and its defect in the development of neuroendocrine autoimmunity
Geenen, Vincent ULg

Conference (2014, March 27)

The thymus may be compared to a computer highly specialized in the programming of central immunological self-tolerance. A unique thymus first appeared some 500 million years ago in cartilaginous fishes ... [more ▼]

The thymus may be compared to a computer highly specialized in the programming of central immunological self-tolerance. A unique thymus first appeared some 500 million years ago in cartilaginous fishes, at the same time or shortly after the emergence of the adaptive immune system. A new paradigm of neuroendocrine self-peptides has been proposed, together with the definition of neuroendocrine self. Neuroendocrine self-peptides are secreted by thymic epithelial cells (TECs) not according to the classic model of neurosecretion, but are processed for presentation by the thymic major histocompatibility complex (MHC) machinery. The autoimmune regulator (AIRE) gene/protein controls the transcription of neuroendocrine genes in TECs. Presentation of neuroendocrine self-peptides in the thymus is responsible for the clonal deletion of self-reactive T cells directed toward neuroendocrine antigens, which emerge during the random recombination of gene segments encoding variable parts of the T cell receptor for the antigen (TCR). Quite paradoxically, neuroendocrine self-peptide presentation in the thymus also generates regulatory T (tTreg) cells that inhibit, in the periphery, those self-reactive T cells having escaped thymic negative selection. Several arguments indicate that the origin of autoimmunity directed against neuroendocrine glands results from a primary defect in the intrathymic programming of self-tolerance to neuroendocrine principles. This defect may be genetic or acquired, for example during a viral infection. This novel knowledge of normal and pathologic functions of the thymus constitutes a solid scientific basis for the development of a novel type negative self-vaccination against type 1 diabetes. (Supported by NFSR of Belgium, Wallonia and FP6 Eurothymaide.) [less ▲]

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See detailRedefinition of Political and Social Thoughts during the Italian Wars: France and Burgundy
Dumont, Jonathan ULg

Scientific conference (2014, March 27)

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See detailLa forêt luxembourgeoise en chiffres - Résultats de l'Inventaire Forestier National au Grand-Duché de Luxembourg 2009 - 2011
Rondeux, Jacques ULg; Alderweireld, Matthieu ULg; Saidi, Mohammed ULg et al

Book published by Administration de la nature et des forêts du Grand-Duché de Luxembourg - Service des forêts (2014)

Results from the second Luxembourg's national forest inventory (2009-2011) and comparison with the first inventory (1998-2000).

Detailed reference viewed: 23 (10 ULg)
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See detailComment améliorer les taux de matières utiles dans le lait ? Solutions actuelles et perspectives ...
Beckers, Yves ULg

Conference given outside the academic context (2014)

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See detailValuation and price expectation mismatch in SME business transfer
Lambert, Marie ULg

Conference (2014, March 26)

Detailed reference viewed: 12 (1 ULg)