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See detailComprehensive study of the thermo-reversibility of Diels-Alder based PCL polymer networks
Defize, Thomas ULg; Thomassin, Jean-Michel ULg; Alexandre, Michaël et al

in Polymer (2016), 84

Chemical crosslinking is an efficient tool to improve or impart new properties to conventional polymers. Especially, crosslinking imparts remarkable shapeememory properties to poly-ε-caprolactone (PCL ... [more ▼]

Chemical crosslinking is an efficient tool to improve or impart new properties to conventional polymers. Especially, crosslinking imparts remarkable shapeememory properties to poly-ε-caprolactone (PCL) materials. Nevertheless, the processing of networks is often tricky due to infusibility and insolubility of cross-linked chains. Therefore, the synthesis of PCL networks including thermo-reversible crosslinks based on (retro)-Diels-Alder (DA) reaction were developed to allowpreserving the melt-processing while keeping the required mechanical properties below the melting point. This paper aims at studying in depth, such thermo-dependent network formation and stability. Besides conventional swelling experi- ments, Raman spectroscopy was revealed as a powerful tool to follow the formation of the DA adduct during the crosslinking. In combination with rheological measurements, we were able to determine the most appropriate temperatures to form the network (DA crosslinking) and to process it (retro-DA re- action) without degradation of the material. [less ▲]

Detailed reference viewed: 37 (3 ULg)
See detailSéismes et glissements de terrain sous-marins en Grèce: caractérisation par les archives sédimentaires marines
Beckers, Arnaud ULg

Scientific conference (2016, February 10)

Les séismes, tsunamis et glissements de terrain sous-marins constituent un risque majeur pour les régions côtières. Prédire ces évènements reste très difficile en raison de la complexité des processus ... [more ▼]

Les séismes, tsunamis et glissements de terrain sous-marins constituent un risque majeur pour les régions côtières. Prédire ces évènements reste très difficile en raison de la complexité des processus impliqués dans leur déclenchement. L’analyse de longues séries temporelles permet d’évaluer leur fréquence et leur éventuelle cyclicité, mais des données de ce type restent rares. J'ai étudié ces processus dans le Golfe de Corinthe en Grèce, où ils constituent une menace majeure pour les populations. Notre approche a consisté en l’étude des sédiments marins de la partie ouest du Golfe via des profils sismiques, sortes d’échographie des fonds marins, et des carottes sédimentaires. Grâce à ces nouvelles données, un inventaire des grands glissements de terrain sous-marins au cours des derniers 130 000 ans a été réalisé. Par l’analyse de carottes sédimentaires, nous avons aussi identifié des périodes d’intense activité sismique au cours du dernier millénaire. Elles témoignent de l’irrégularité des grands séismes dans la région. Enfin, des failles actives localisées en mer ont pu être cartographiées pour la première fois et leur activité a été estimée. [less ▲]

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See detailEffect of ultrafiltration process on physico-chemical, rheological, microstructure and thermal properties of syrups from male and female date palm saps
Makhlouf-Gafsi, Ines; Baklouti, Samia; Mokni, Abir et al

in Food Chemistry (2016), 203

This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied ... [more ▼]

This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied syrups switched from pseudoplastic rheological behaviour (n = 0.783) to Newtonian behaviour (n〰1) from 10 to 50 s‾1 respectively and present similar thermal profiles. Results revealed that the ultrafiltration process significantly affects the rheological behaviour of the male and female syrups. These differences on rheological properties are attributed to the variation of chemical composition between sap and sap permeate syrups. Furthermore, the effect of temperature on viscosity of the syrups was investigated during heating and cooling processes at the same shear rate (50 s 1). This study provides idea of the stability of the syrup by evaluating the area between heating and cooling curves. Actually, the syrup prepared from male sap permeate is the most stable between the four studied syrups. [less ▲]

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See detailJe suis un professionnel de la voix, je suis un enseignant.
Morsomme, Dominique ULg; Remacle, Angélique ULg

Conference given outside the academic context (2016)

Detailed reference viewed: 28 (2 ULg)
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See detailDe la magie au magique. Conscience, réalité-humaine et être-dans-le-monde chez Sartre (1927-1948)
Dassonneville, Gautier ULg

Doctoral thesis (2016)

This research deals with Sartre's early existential philosophy by resituating it in the field of French post-Comtian philosophy in the early twentieth century and by re-establishing an anthropological ... [more ▼]

This research deals with Sartre's early existential philosophy by resituating it in the field of French post-Comtian philosophy in the early twentieth century and by re-establishing an anthropological moment in which the issue of magic is explored in the psychological and social sciences. Following the different paths of the conceptual exchange through which the notion of magic becomes that the magical in Sartre's view, we study three poles of sartrian phenomenological ontology : intentional consciousness, human reality and being-in-the-world. The hypothesis advanced by this thesis is that the magical, according to different modes ranging from topicalization through obliteration, plays a determining role in the elaboration of existentialism whose genesis is traced here from Sartre's very first writings in 1927.  Faced with the legacy of a positivist anthropology in terms of an analytical methodology, Sartre privileges a synthetic approach and conceives consciousness in its affective and irrational aspects. Images of magical thought are called upon for rethinking openness to the world of consciousness and its relationship to itself and to Others. Returning to Sartrian anthropology, we question how consciousness can be grasped as an irreflexive and absolute spontaneity and how human reality is interpreted through its attitudes and behaviours; in particular through the way it faces its own freedom which is fundamentally and irremediably exposed to contradiction. This structure of human reality as existential project leads Sartre to reconsider being-in-the-world as based in originary dispossession through which ontology is brought back to the magical. [less ▲]

Detailed reference viewed: 54 (9 ULg)
See detailThe dynamics of inequality in Katanga, D.R.Congo. A conversation with Bourdieu
Rubbers, Benjamin ULg

Scientific conference (2016, February 10)

Detailed reference viewed: 35 (0 ULg)
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See detailAbout the Enhanced Formability of Single Point Incremental Forming
Habraken, Anne ULg; Guzmán Inostroza, Carlos Felipe ULg

Scientific conference (2016, February 09)

Analysis of the formability in Single Point Incremental Forming Process: deformation mechanism, link witth Forming Limit Curves and damage approach, bad prediction of Gurson model for DC01 steel.

Detailed reference viewed: 37 (1 ULg)
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See detailFigures de l'identité et régimes de fiction dans l'espace public
Servais, Christine ULg

Conference (2016, February 09)

Cette communication interroge la notion de figure comme opérateur de publicisation de l'identité singulière, et distingue à cette fin différents régimes de fiction. Il s'agit d'analyser les dynamiques à ... [more ▼]

Cette communication interroge la notion de figure comme opérateur de publicisation de l'identité singulière, et distingue à cette fin différents régimes de fiction. Il s'agit d'analyser les dynamiques à l’œuvre entre la (re)présentation de soi et sa réception dans la formation de jugements publics, ce qui suppose de considérer ensemble le niveau de l'histoire racontée et le niveau de sa lecture. L'objectif est de proposer, pour l’analyse des scènes de publicisation de la singularité, un outillage qui soit en lien avec les questions de jugement et de responsabilité. [less ▲]

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See detailLocal thermal history during the laser additive manufacturing of steel
Mertens, Anne ULg; Hashemi, Seyedeh Neda ULg; Tchuindjang, Jérôme Tchoufack ULg et al

Conference (2016, February 09)

Laser additive manufacturing techniques – such as laser cladding − were developed in the late 1990s as economic layer-by-layer near-net-shape processes allowing for the production or restoration of ... [more ▼]

Laser additive manufacturing techniques – such as laser cladding − were developed in the late 1990s as economic layer-by-layer near-net-shape processes allowing for the production or restoration of complex metallic parts. These techniques are characterised by ultra-fast solidification and cooling rates, thus giving rise to ultra-fine out-of-equilibrium microstructures with potentially enhanced mechanical properties. However, the general quality of a component, as well as its dimensional accuracy, microstructure and final usage properties are strongly influenced by the local thermal history experienced during fabrication. As a consequence, a deeper understanding of the influence of the various processing parameters on the local thermal history during fabrication is of paramount importance, and it can only be reached by combining detailed experimental studies and modeling. Keeping this in mind, the present paper reviews on-going investigations carried out in the Metallic Materials Science Unit of the University of Liege in the laser additive manufacturing of HSS and of stainless steel 316L. [less ▲]

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See detailAssessing and modeling economic and environmental impact of wheat nitrogen management in Belgium
Dumont, Benjamin ULg; Basso, Bruno; Bodson, Bernard ULg et al

in Environmental Modelling & Software (2016), 79

Future progress in wheat yield will rely on identifying genotypes and management practices better adapted to the fluctuating environment. Nitrogen (N) fertilization is probably the most important practice ... [more ▼]

Future progress in wheat yield will rely on identifying genotypes and management practices better adapted to the fluctuating environment. Nitrogen (N) fertilization is probably the most important practice impacting crop growth. However, the adverse environmental impacts of inappropriate N management (e.g., lixiviation) must be considered in the decision-making process. A formal decisional algorithm was developed to tactically optimize the economic and environmental N fertilization in wheat. Climatic uncertainty analysis was performed using stochastic weather time-series (LARS-WG). Crop growth was simulated using STICS model. Experiments were conducted to support the algorithm recommendations: winter wheat was sown between 2008 and 2014 in a classic loamy soil of the Hesbaye Region, Belgium (temperate climate). Results indicated that, most of the time, the third N fertilization applied at flag-leaf stage by farmers could be reduced. Environmental decision criterion is most of the time the limiting factor in comparison to the revenues expected by farmers. [less ▲]

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See detailSeasonality in human cognitive brain responses
Meyer, Christelle ULg; Muto, Vincenzo ULg; Jaspar, Mathieu ULg et al

in Proceedings of the National Academy of Sciences of the United States of America (2016)

Detailed reference viewed: 34 (10 ULg)
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See detailBioncontrol of wheat against Septoria Tritici Blotch: new elicitors
Le Mire, Géraldine ULg; SIAH, Ali; Jijakli, Haissam ULg

Poster (2016, February 05)

Wheat is one of the most cultivated crop plants in the world. However, this plant must constantly face numerous biotic challenges, including major yield losses every year (up to 30-50%) due to a foliar ... [more ▼]

Wheat is one of the most cultivated crop plants in the world. However, this plant must constantly face numerous biotic challenges, including major yield losses every year (up to 30-50%) due to a foliar disease known as Septoria Tritici Blotch (STB). This persistent and harmful disease is caused by the fungus Zymoseptoria tritici. Disease control mainly depends on phytosanitary products. However, conventional agriculture is evolving towards more sustainable practices, out of respect for human health and the environment. Elicitors are considered as promising biological control tools for Integrated Plant Management (IPM) strategies. Contrary to conventional products, these natural compounds do not inhibit directly the pathogen but induce a general and systemic resistance in the plant to a large spectrum of diseases. The natural defense mechanisms of the plant are thus stimulated. Few elicitors have yet been successfully tested and formulated to protect wheat against STB. This study focuses on the screening of ten potential elicitor products of various origins and structures to protect winter wheat against Zymoseptoria tritici. Greenhouse trials were carried out to measure the ability of the different products to reduce disease foliar symptoms (necrosis, chlorosis and pycnidia). In addition, the biocide activity of these products directly towards the pathogen was evaluated under greenhouse and laboratory conditions, respectively. The corresponding results will be presented and discussed with the perspective to choose the best elicitor candidates for field trials and to undertake further investigations on the signaling pathways, and the influence of environmental parameters, on the elicitation capacity. [less ▲]

Detailed reference viewed: 38 (6 ULg)
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See detailIn vitro evaluation of protein precipitation capacity of temperate browse species
Vandermeulen, Sophie ULg; Leblois, Julie ULg; Ramírez-Restrepo, Carlos Alberto et al

Poster (2016, February 05)

European agri-environmental policies are promoting the establishment of shrubs and trees on grasslands. The use of browse as fodder requires knowledge on their nutritive value since intensive production ... [more ▼]

European agri-environmental policies are promoting the establishment of shrubs and trees on grasslands. The use of browse as fodder requires knowledge on their nutritive value since intensive production systems are still relying on expensive and environment-costing protein sources. However, information on the influence of temperate condensed tannins (CT)-containing browse forage on rumen protein metabolism is elusive. The study aimed to assess the protein precipitation capacity (PPC) of 10 temperate browse species and establish the correlation between PPC values and plants CT content. PPC of foliage of 3 individuals per woody plants was measured using 2 model proteins: bovine serum albumin (BSA) and casein. The N content in protein solutions (4.6g/L; pH=6.8) was determined before and after adding each forage sample. Extractable CT concentration was quantified by spectrophotometry. The PPC varied across plant species (P<0.001). Corylus avellana had the highest ability to precipitate casein (52.4%). In contrast, the BSA precipitation (18.3%) of this plant was similar to Cornus sanguinea (12.7%), Quercus robur (12.1%) and Crataegus monogyna (11.0%). CT content ranged from 1.4 in Fraxinus excelsior to 82.7g/kg of depigmented sample in Corylus avellana (P<0.001) and was correlated to BSA (r=0.70; P<0.001) and casein PC (r=0.51; P<0.01). It was concluded that woody species could play a significant role in modifying protein metabolism, but further in vivo trials are required. [less ▲]

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See detailEarly life programming of pigs' intestinal microbiota, intestinal functioning and hepatic metabolism by maternal wheat bran supplementation
Leblois, Julie ULg; Bindelle, Jérôme ULg; Dehareng, Frédéric et al

Poster (2016, February 05)

The gastrointestinal (GI) microbiota plays many roles on the host’s health, acting as a barrier against pathogens and influencing the development and maturation of the mucosa, important for host’s ... [more ▼]

The gastrointestinal (GI) microbiota plays many roles on the host’s health, acting as a barrier against pathogens and influencing the development and maturation of the mucosa, important for host’s immunity. Microbial colonization occurs pre- and postnatally, via maternal transfer i.e. by milk and by the contact with sows faeces. Hence, the early establishment of a beneficial gastrointestinal microbiota in piglets was investigated by supplementing the sows with wheat bran that we consider as a prebiotic (rich in non-starch polysaccharides). Sows were fed either a wheat bran-enriched diet (25% in gestation, 14% in lactation) either a control diet. Piglets were suckling during 4 weeks, receiving a standard creep feed containing no pre- or probiotic from the second week until weaning. The direct effect of wheat bran on the fecal microbial composition of the sow has been analyzed as well as the chemical composition and immunoglobulins content of the colostrum and milk. Sows and piglets growth performances have been recorded at different time points to verify that wheat bran doesn’t impair performances. At weaning, piglets have been euthanized and the impact of the maternal treatment was investigated at different levels: growth performances, ileal and colonic microbiota, intestinal physiology and immunological response and metabolism. A second animal experiment will be performed next year including a metabolic challenge by giving half of the piglets a high-energy diet post-weaning. [less ▲]

Detailed reference viewed: 131 (4 ULg)
See detailRecent and rapid radiation of the lichen genus Sticta in the Western Indian Ocean islands
Simon, Antoine ULg; Magain, Nicolas ULg; Goffinet, Bernard et al

Poster (2016, February 05)

In the framework of a global project on the phylogeny of the lichen genus Sticta (Lobariaceae), extensive sampling was performed on the islands of Reunion and Mauritius as well as in several parts of ... [more ▼]

In the framework of a global project on the phylogeny of the lichen genus Sticta (Lobariaceae), extensive sampling was performed on the islands of Reunion and Mauritius as well as in several parts of Madagascar (mainly in two National Parks : Marojejy and Amber Mountain). The aim of this study is to provide the first comprehensive molecular phylogeny of the genus in the Western Indian Ocean islands (and more specifically of a presumably local endemic lineage), and to date its local radiation. DNA sequences were obtained from 69 specimens for four loci and phylogenetic relationships were inferred using maximum likelihood and Bayesian inferences methods. We estimated divergence times using BEAST. Thirty putative species can be recognized, only 5 have a validly published epithet. All these species form a well-supported monophyletic group within the genus Sticta, and display interesting patterns of endemism: a single species is present in all islands, while the others are restricted either to Madagascar, to Reunion and Mauritius, or to Reunion only. The estimated divergence time of the radiation of this clade occurred in the upper Miocene, apparently concurrent with the emergence of Mauritius. The tree topology obtained supports an original diversification of the clade in the Mascarenes archipelago rather than in Madagascar. [less ▲]

Detailed reference viewed: 39 (8 ULg)