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See detailPoly(methyl methacrylate)/graphene oxide nanocomposites by a precipitation polymerization process and their dielectric and rheological characterization
Thomassin, Jean-Michel ULg; Trifkovic, Milana; Alkarmo, Walid et al

in Macromolecules (2014), 47(6), 2149-2155

We report a method for achieving controlled dispersion of graphene oxide (GO) in poly(methyl methacrylate) (PMMA) via the precipitation polymerization process in a water/ methanol mixture. GO acts as a ... [more ▼]

We report a method for achieving controlled dispersion of graphene oxide (GO) in poly(methyl methacrylate) (PMMA) via the precipitation polymerization process in a water/ methanol mixture. GO acts as a surfactant and adsorbs on the interface between polymerized PMMA particles and solvent mixture. Scanning electron and transmission electron microscopy confirmed that the precipitate consists of polymer particles (<1 μm) surrounded by the GO sheets. Compression molding of the precipitate yields a polymer nanocomposite with the GO organized into a regularly spaced 3D network which percolates at 0.2 wt % GO. Simple thermal reduction of the GO sheets dispersed in PMMA at relatively low temperature (210 °C) achieved electrical conductivity higher than 10−2 S/m at 0.4 wt % of GO. Parallel dielectric and rheological characterization demonstrated that the thermal reduction is a quite fast process without significant degradation of the polymer. The study should open up new opportunities in the design of GO-based polymer nanocomposites. [less ▲]

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See detail"Types de productions langagières" et canevas de séquences didactiques en langues modernes
Simons, Germain ULg; Pagnoul, Pierre ULg

Conference (2014, April 25)

Cette communication était structurée en quatre grands volets. Dans le premier, nous avons exploré la notion de "genre" et celle de "type de production langagière" ainsi que leur présence ou absence dans ... [more ▼]

Cette communication était structurée en quatre grands volets. Dans le premier, nous avons exploré la notion de "genre" et celle de "type de production langagière" ainsi que leur présence ou absence dans les prescrits légaux (référentiels, programmes, outils d'évaluation) en langues modernes en Fédération Wallonie-Bruxelles mais aussi dans le Cadre européen commun de référence pour les langues. Dans le deuxième volet, nous avons présenté et analysé le document "Familles de tâches en langues modernes" où apparaît, pour la première fois, la notion de "types de productions langagières à dominante... descriptive/informative, incitative/injonctive, narrative et argumentative", et avons tenté une clarification opérationnelle des notions de genre et de productions langagières en didactique des langues modernes. Dans le troisième volet, nous avons présenté deux canevas didactiques, un linéaire et l'autre par situation-problème, et avons montré en quoi ce dernier se prêtait particulièrement bien au travail sur le genre. Le concept de "noticing the gap" a été ici convoqué et nous avons fourni un exemple de DEBAT organisé avec la technique dite de "l'aquarium", procédé didactique destiné à mettre tous les élèves à la tâche. Enfin, dans le quatrième et dernier volet, nous avons évoqué les problèmes liés à ce champ de recherche sur le genre et avons proposé quelques pistes de solutions. Différentes références bibliographiques relatives aux quatre parties de l'exposé ont également été proposées au terme de la communication. [less ▲]

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See detailLa démarche RAI, historique, philosophie, outils
Delye, Samuel ULg; Maggi, Patrick ULg; Gosset, Christiane ULg

Conference (2014, April 25)

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See detailAltered Desferrioxamine-mediated Iron Utilization is a Common Trait of bald Mutants of Streptomyces coelicolor
Lambert, Stéphany ULg; Traxler, Matthew F; Craig, Matthias et al

in Metallomics (2014)

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See detailTowards an Archaeological Information System: improving the core data model
Van Ruymbeke, Muriel ULg; Carré, Cyril ULg; Delfosse, Vincent ULg et al

Conference (2014, April 25)

Grounded on archaeological information modeling works undertaken at the Geomatics Unit of the University of Liege, this paper goes a step further in handling time and function imperfection, interpretative ... [more ▼]

Grounded on archaeological information modeling works undertaken at the Geomatics Unit of the University of Liege, this paper goes a step further in handling time and function imperfection, interpretative sequences and people interacting with historical objects. Designed in 2011, the initial model already gathered both geometrical and historical information. It was partially based on the urban data standard City GML mainly for interoperability purposes. Its specificity, the version concept, allowed multiple geometries experiments. That property enabled us to handle geometrical ambiguity and incompleteness. To validate this model, and in a showcase purpose, a first prototype has been realized. One year later this prototype’s model has been improved to manage in a better way all objects’ versions and possible representations. Until now, this model integrates and manages imperfect archaeological data but only partially: the version concept being only dedicated to express geometric ambiguity or imprecision. Henceforth, with the version notion widening, we propose to encompass function and time imperfection as well. It is an important progress because on an archaeological point of view, time and function are quite generally incomplete, uncertain, imprecise or contradictory. Another enhancement must be highlighted: the agent enlistment. Historical characters, on one hand, and contemporaneous people (like authors, archaeologists etc.) on another hand are key elements of archaeological game pieces. Finally, we will describe the way of structuring versions into interpretative sequences. With those improvements, we wish to carry on feeding the scientific debate as much as drafting Archaeological Information Systems. [less ▲]

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See detailHow to locate intermodal terminals for achieving economic and environmental competitiveness?
Mostert, Martine ULg; Limbourg, Sabine ULg

Conference (2014, April 25)

Europe has a strong commitment to the development of competitive and sustainable transportation. An intermediate objective cited in the “White Paper” is to shift 30% of 300 km and above road freight ... [more ▼]

Europe has a strong commitment to the development of competitive and sustainable transportation. An intermediate objective cited in the “White Paper” is to shift 30% of 300 km and above road freight transportation to more environmentally-friendly modes of transport such as rail and water by 2030. Improving and expanding the intermodal network is one way to achieve this goal. However, intermodal transport requires intermodal terminals where the transfer from one mode to another can occur. The location of those terminals is of strategic importance for the competitiveness of intermodal transport. The objective of this paper is therefore to develop a network design model which allows the optimal location of intermodal terminals to be determined, subject to both economic and environmental efficiency. Three possible combinations are considered: (i) Road-only, (ii) Intermodal transport using road (drayage) and rail (long-haul) and (iii) Intermodal transport using road (drayage) and inland waterways (long-haul). External costs are also included in the analysis, i.e. costs that are generated by an economic agent but supported by other agents of the society. This strategy is in line with the willingness of Europe to internalize external costs. The developed model can be used to test how modal split is influenced by the undertaken policies, such as internalizing external costs in the transportation costs. Tests are carried out on the case study of Belgium. [less ▲]

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See detailNanostructured catalysts by sol-gel process
Lambert, Stéphanie ULg; Heinrichs, Benoît ULg

Conference (2014, April 25)

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See detailIntroduction aux deux journées d'études : "Questions de genres"
Letawe, Céline ULg; Simons, Germain ULg

Conference (2014, April 24)

Lors de cette brève introduction, nous avons a) rappelé les objectifs de l'Entité de recherche structurelle en Langues et littératures modernes de l'ULg ; b) fourni quelques éléments généraux sur l'objet ... [more ▼]

Lors de cette brève introduction, nous avons a) rappelé les objectifs de l'Entité de recherche structurelle en Langues et littératures modernes de l'ULg ; b) fourni quelques éléments généraux sur l'objet de recherche "genre" ; c) présenté le programme complet des deux journées dans les quatre grands domaines : littérature (en ce compris la littérature pour la jeunesse), linguistique, traduction, didactique, et d) remercié les différents partenaires qui ont contribué à la réalisation de ce symposium. [less ▲]

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See detailPredicting Grain Protein Content of Winter Wheat
Mansouri, Majdi ULg; Dumont, Benjamin ULg; Destain, Marie-France ULg

in ESANN 2014 Proceedings (2014, April 24)

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See detailMachine learning techniques to assess the performance of a gait analysis system
Pierard, Sébastien ULg; Phan-Ba, Rémy; Van Droogenbroeck, Marc ULg

in European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN) (2014, April 24)

This paper presents a methodology based on machine learning techniques to assess the performance of a system measuring the trajectories of the lower limbs extremities for the follow-up of patients with ... [more ▼]

This paper presents a methodology based on machine learning techniques to assess the performance of a system measuring the trajectories of the lower limbs extremities for the follow-up of patients with multiple sclerosis. We show how we have established, with the help of machine learning, four important properties about this system: (1) an automated analysis of gait characteristics provides an improved analysis with respect to that of a human expert, (2) after learning, the gait characteristics provided by this system are valuable compared to measures taken by stopwatches, as used in the standardized tests, (3) the motion of the lower limbs extremities contains a lot of useful information about the gait, even if it is only a small part of the body motion, (4) a measurement system combined with a machine learning tool is sensitive to intra-subject modifications of the walking pattern. [less ▲]

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See detailEnforcement of accounting standards, financial crisis, and their impact on impairment of non financial assets
Yammine, Mira ULg; Olivier, Henri ULg

Conference (2014, April 24)

The consistent application of IFRS is a concern for the different users of financial statements. In this context this study aims to investigate the impact exercised by the enforcement of accounting ... [more ▼]

The consistent application of IFRS is a concern for the different users of financial statements. In this context this study aims to investigate the impact exercised by the enforcement of accounting standards and the financial crisis on the consistent application of IAS 36 `impairment of assets¿. Listed companies from17 European countries applying IFRS are selected. Two groups of countries are selected based on government indicators namely rule of law, control of corruption, regulatory quality, and government effectiveness. Enforcement of accounting standards is determined from a survey addressed to the institutional oversights bodies that supervise and enforce accounting standards applications in each country. We find that the enforcement of accounting standards has decreased the impairment of assets registrations. But this observation appears to be true only in high government indicators countries. In these same countries the financial crisis has a positive impact on the impairment of assets magnitude. [less ▲]

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See detailLogistics hub: the case of Liège
Limbourg, Sabine ULg; Mostert, Martine ULg; Paquay, Célia ULg

Conference (2014, April 24)

A logistics hub can be defined as a specific area where all the activities relating to transport, logistics and goods distribution are carried out. With its central location in Europe, highly developed ... [more ▼]

A logistics hub can be defined as a specific area where all the activities relating to transport, logistics and goods distribution are carried out. With its central location in Europe, highly developed infrastructures, airport and inland terminals, the region of Liège claims to be a logistics hub. This paper applies a strategic decision model based on seven relevant criteria (infrastructure, proximity to market, land availability, government and industry support, labour supply, origin/destination distances and congestion) to assess the efficiency of the logistics hub of the region of Liège. Two SWOT analyses are performed in parallel to evaluate the positions of Liège Airport and of the inland freight hub, Trilogiport, in relation to their own performances and the competition. The two main development factors of inland freight hubs are considered: the possibility of modal shift from road transport to more environmentally friendly transportation modes and the avoidance of the congestion of the two seaport areas of Antwerp and Rotterdam. This article concludes by highlighting that the bid of the region of Liège and its characteristics should contribute to a more efficient intermodal transport in Europe, helping to boost the distribution of products, and at the same time, encourage the reduction of greenhouse gas emissions. However, the development of Liège as an inland freight hub depends on its ability to generate a critical mass, notably thanks to the local businesses, in order to realise economies of scale. [less ▲]

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See detailLes préférences alimentaires : comment préserver son équilibre alimentaire et sa qualité de vie? De l'enfant à l'adulte.
Etienne, Anne-Marie ULg

Scientific conference (2014, April 24)

Dans notre société actuelle, nous observons un engouement pour les émissions culinaires : Master Chef, Top Chef, un dîner presque parfait, … En même temps, plusieurs études montrent que de nombreuses ... [more ▼]

Dans notre société actuelle, nous observons un engouement pour les émissions culinaires : Master Chef, Top Chef, un dîner presque parfait, … En même temps, plusieurs études montrent que de nombreuses personnes ne mangent pas selon les recommandations actuelles. D’où un intérêt grandissant pour la compréhension des mécanismes liés aux préférences alimentaires : Que se passe-t-il quand un enfant a le choix entre plusieurs aliments ? Comment ces préférences alimentaires évoluent-elles à l’âge adulte ? Les mécanismes d’apprentissage social fournissent des réponses quant aux choix concernant la nourriture ; ceci comprend en particulier les parents et les médias qui véhiculent de l’information ou présentent de nouveaux modèles. Partant de là, nous discuterons de comment concilier nos préférences alimentaires avec un équilibre alimentaire, sans basculer dans une restriction alimentaire qui elle, risque d’affecter notre qualité de vie. [less ▲]

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See detailClassifying pairs with trees for supervised biological network inference
Schrynemackers, Marie ULg; Wehenkel, Louis ULg; Madan Babu, Mohan et al

E-print/Working paper (2014)

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See detailA Frequency-domain Approach to Subspace Identification of Nonlinear Systems, Application to Aerospace Structures
Noël, Jean-Philippe ULg

Doctoral thesis (2014)

The construction of mathematical models from experimental data is an essential step in the design process of engineering systems. The different tasks involved in this activity, from the measurement and ... [more ▼]

The construction of mathematical models from experimental data is an essential step in the design process of engineering systems. The different tasks involved in this activity, from the measurement and processing of data to the validation of the model, fall into the general field of system identification. In structural dynamics, the theoretical and experimental aspects of linear system identification have been successfully addressed since the early seventies, and mature analytical, computational and testing tools have emerged. Nonlinear system identification of vibrating structures has also enjoyed significant advances during the past few years. However, the common practice in industry is to ignore nonlinearities, arguably because their analysis is still regarded as impractical. The objective of this doctoral thesis is precisely to progress towards the development of a practical system identification methodology dedicated to real-life nonlinear structures. The first facet of the thesis is to introduce a nonlinear generalisation in the frequency domain of the so-called subspace identification methods. The proposed frequency-domain nonlinear subspace identification (FNSI) approach yields accurate models of large-scale systems comprising strong nonlinearities, closely-spaced modes and high damping. Because it can also estimate a large number of parameters while maintaining an acceptable computational burden, the second facet of this research is to investigate the utilisation of cubic splines as a very flexible means to model complex nonlinearities. Finally, the third facet of the present work is to derive nonlinear models with optimal statistical properties in the presence of measurement noise. This is achieved by embedding the FNSI method into the maximum likelihood identification framework. The scope of the identification and modelling tools developed in this thesis encompasses nonlinear structural systems originating from the various areas of vibration engineering, including the aerospace, mechanical or civil fields, amongst others. Throughout the dissertation, these tools are illustrated using numerical and experimental structures of increasing complexity, mainly related to aerospace applications. [less ▲]

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See detailCirculating microRNAs as diagnostic markers in breast cancer patients and their deregulation under neoadjuvant chemotherapy
FRERES, Pierre ULg

Poster (2014, April 24)

Breast cancer is the leading cause of death by cancer among women and there is an urgent need to improve its diagnosis and prognosis. MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression ... [more ▼]

Breast cancer is the leading cause of death by cancer among women and there is an urgent need to improve its diagnosis and prognosis. MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression and many have been implicated in breast cancer. In this article, we focus on circulating miRNAs as biomarkers for breast cancers and we describe the deregulation of their expression during neoadjuvant chemotherapy (NAC). [less ▲]

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See detailStochastic exposure to sub-lethal high temperature enhances exopolysaccharides (EPS) excretion and improves Bifidobacterium bifidum cell survival to freeze-drying
Nguyen, Huu Thanh ULg; Razafindralambo, Hary; Blecker, Christophe ULg et al

in Biochemical Engineering Journal (2014), 88

Exposure of microbial cells to sub-lethal stresses is known to increase cell robustness. In this work, a two-compartment bioreactor in which microbial cells are stochastically exposed to sub-lethal ... [more ▼]

Exposure of microbial cells to sub-lethal stresses is known to increase cell robustness. In this work, a two-compartment bioreactor in which microbial cells are stochastically exposed to sub-lethal temperature stresses has been used in order to investigate the response of the stress sensitive Bifidobacterium bifidum THT 0101 to downstream processing operations. A stochastic model validated by residence time distribution experiments has shown that in the heat-shock configuration, a two-compartment bioreactor (TCB) allows the exposure of microbial cells to sub-lethal temperature of 42°C for a duration comprised between 100 and 300 seconds. This exposure resulted in a significant increase of cell resistance to freeze-drying by comparison with cells cultivated in conventional bioreactors or in the TCB in the cold shock mode (CS-TCB). The mechanism behind this robustness seems to be related with the coating of microbial cells with exopolysaccharide (EPS), as assessed by the change of the zeta potential and the presence of higher EPS concentration after heat shock. Conditioning of Bifidobacteria on the basis of the heat shock technique is interesting from the practical and economical point of view since this strategy can be directly implemented in the bioreactor during stationary phase preceding cell recovery and freeze-drying [less ▲]

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See detailLe rôle du commerce frontalier des produits alimentaires avec le Rwanda dans l'approvisionnement des ménages de la ville de Bukavu (Province du Sud-Kivu)
Vwima Ngezirabona, Stany ULg

Doctoral thesis (2014)

This thesis aims at highlighting the importance of food supply from the Rusizi District (Rwanda) in the food security of the city Bukavu (Democratic Republic of Congo). Due to the informal nature of this ... [more ▼]

This thesis aims at highlighting the importance of food supply from the Rusizi District (Rwanda) in the food security of the city Bukavu (Democratic Republic of Congo). Due to the informal nature of this supply, it was necessary to characterize its magnitude, drivers, and consequences as well as to develop policies that are likely to improve this supply and facilitate regional integration. The fieldwork consisted of two series of investigations. The first series of data collection included scoring the flow of food supply from Rusizi District during three months and for each of the food supply axes of Bukavu city. Secondly, a questionnaire was administered to a sample of 233 households, wherein 76 consuming households and 157 reselling households. Results from the scoring exercise show that 2,021 households on average cross both borders (Rusizi 1 and Ruzizi 2) for their food supply daily. A total of 661 of these households (about 32.7%) are direct food consumers and 1,360 households (about 67.3%) are food resellers. Excepted for cassava (which is a traditional staple of South Kivu), plantains (because of conservation problem, much more coming from within the province), and beans (much more from North Kivu), other major food products are imported from Ruzizi district in Rwanda. In this regard, the dependency ratios towards Rwanda remain much higher for products such as maize (66%), potatoes (82%), sorghum (73%), groundnut (69%), sweet potato (98%), rice (70%), and beef and pork meat (85%). With such dependency ratios, Bukavu is a major food market of the Rusizi District (Rwanda) food products. This is however far from being confirmed by official import statistics of the Congolese Control Office (CC0) which, except for rice, underestimates the border trade for a large portion of food commodities flows. The commodities analyzed provide the population of the city of Bukavu 1027 kcal per person per day from which 593.5 kcal, 338.9 kcal and 92.4 kcal are provided by products respectively from Rwanda, North-Kivu and South-Kivu. The calories consumed in the city of Bukavu are mainly of vegetable origin dominated by maize (563.1 kcal), cassava (120 kcal) and beans (167.1 kcal), which play a strategic role given their importance in the food habits of Bukavu. The significant flows of food supplies from Rusizi district are a major contribution to the livelihood of thousands of families in the city of Bukavu. It emerges that all products supplied from Rusizi district by reselling households generate positive return per month demonstrating a positive remuneration not only for the invested capital, but also for the time and effort invested in the activity (average 5.67 hours). More than 68 % of reselling households claim are satisfied with the result of this activity and allocate the generated income mainly to cover subsistence needs. In this sense, the economic impact of border trade on incomes of reselling households is a reality. The analysis of budgets of consuming households shows that 69.1% of food expenditure and 48.8% of total expenditure of consuming households cross the border. The significant impact of food supplies from the Rusizi district on reducing households’ income poverty, reflects the interests of border trade which only reinforces the structural and relative decline of the agricultural sector in South Kivu already confronted to various problems. The free trade policy advocated by a large number of sub-regional and regional communities such as CEPGL and COMESA will make the Rusizi originating food supply of Bukavu more efficient, but it remains a short-term solution of food security of the city and the province in general. In the long term, it would be better to stimulate the production and promote local food trade. To achieve this, investments need to be channeled to the agricultural sector. It is at this price that the agricultural sector in South-Kivu can be revived and reach the threshold of self-sufficiency, and even create a surplus for export. Admittedly, this solution then poses the problem of reconversion of consuming households and sellers-households that we should rethink from the outset. [less ▲]

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See detailEnjeux autour des forêts congolaises. Conflits d’usage, conflits sans arbitres
Vermeulen, Cédric ULg

Conference given outside the academic context (2014)

Detailed reference viewed: 21 (5 ULg)