Last 7 days
Bookmark and Share    
Full Text
Peer Reviewed
See detailTowards a large scale aqueous sol-gel synthesis of doped TiO2: Study of various metallic dopings for the photocatalytic degradation of p-nitrophenol
Mahy, Julien ULg; Lambert, Stéphanie ULg; Léonard, Géraldine ULg et al

in Journal of Photochemistry and Photobiology A : Chemistry (2016), 329

In this paper, an easy aqueous sol-gel synthesis developed previously by Mahy et al. [J. Sol-Gel Sci. Technol. (2016)] is adapted to produce highly active TiO2 catalysts doped with Fe3+, Ag+, Cu2+, Zn2 ... [more ▼]

In this paper, an easy aqueous sol-gel synthesis developed previously by Mahy et al. [J. Sol-Gel Sci. Technol. (2016)] is adapted to produce highly active TiO2 catalysts doped with Fe3+, Ag+, Cu2+, Zn2+, Cr3+, Al3+, Mn2+, and Co2+ ions and Pt metallic nanoparticles. Samples are characterized by inductively coupled plasma–atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), Mössbauer spectroscopy, transmission electron microscopy (TEM), nitrogen adsorption–desorption measurements and diffuse reflectance spectroscopy measurements. Results show that the samples are composed of anatase-brookite TiO2 nanoparticles with a spherical shape and mean diameter of around 5-8 nm and a surface area of between about 150 - 250 m2 g-1. In each doped sample, the dopant is present in the form added during the synthesis, given that the sample has not undergone any particular treatment. Photoactivity tests show improvement in catalyst activity for Fe3+, Ag+, Cu2+, Zn2+, and Al3+ ion and Pt metallic nanoparticle dopants, while a decrease of activity is obtained for Cr3+, Mn2+ and Co2+ ion dopants. For some dopants, the activity of TiO2 doped with metallic ions and synthesized from the aqueous sol-gel process is equal or superior to the activity of the commercial photocatalyst Degussa P25. Some mechanisms are proposed to explain these modifications of activity with doping. Furthermore, cost comparison at laboratory scale showed that Zn and Cu nitrate salt dopings are clearly less expensive for a halogen light (UV/visible) or low energy light enhanced catalyst and may be considered for industrial applications. Using this method, a large scale Zn-doped TiO2 photocatalyst is synthesized with properties homologous to the lab-scale product. Results show that the aqueous sol-gel synthesis developed previously can be easily adapted for doping in order to produce an up-scalable synthesis. [less ▲]

Detailed reference viewed: 64 (26 ULg)
Full Text
Peer Reviewed
See detailA large strain hyperelastic viscoelastic-viscoplastic-damage constitutive model based on a multi-mechanism non-local damage continuum for amorphous glassy polymers
Nguyen, Van Dung ULg; Lani, Frédéric; Pardoen, Thomas et al

in International Journal of Solids and Structures (2016), 96

A large strain hyperelastic phenomenological constitutive model is proposed to model the highly nonlinear, rate-dependent mechanical behavior of amorphous glassy polymers under isothermal conditions. A ... [more ▼]

A large strain hyperelastic phenomenological constitutive model is proposed to model the highly nonlinear, rate-dependent mechanical behavior of amorphous glassy polymers under isothermal conditions. A corotational formulation is used through the total Lagrange formalism. At small strains, the viscoelastic behavior is captured using the generalized Maxwell model. At large strains beyond a viscoelastic limit characterized by a pressure-sensitive yield function, which is extended from the Drucker-Prager one, a viscoplastic region follows. The viscoplastic flow is governed by a non-associated Perzyna-type flow rule incorporating this pressure-sensitive yield function and a quadratic flow potential in order to capture the volumetric deformation during the plastic process. The stress reduction phenomena arising from the post-peak plateau and during the failure stage are considered in the context of a continuum damage mechanics approach. The post-peak softening is modeled by an internal scalar, so-called softening variable, whose evolution is governed by a saturation law. When the softening variable is saturated, the rehardening stage is naturally obtained since the isotropic and kinematic hardening phenomena are still developing. Beyond the onset of failure characterized by a pressure-sensitive failure criterion, the damage process leading to the total failure is controlled by a second internal scalar, so-called failure variable. The final failure occurs when the failure variable reaches its critical value. To avoid the loss of solution uniqueness when dealing with the continuum damage mechanics formalism, a non-local implicit gradient formulation is used for both the softening and failure variables, leading to a multi-mechanism non-local damage continuum. The pressure sensitivity considered in both the yield and failure conditions allows for the distinction under compression and tension loading conditions. It is shown through experimental comparisons that the proposed constitutive model has the ability to capture the complex behavior of amorphous glassy polymers, including their failure. [less ▲]

Detailed reference viewed: 72 (38 ULg)
Full Text
Peer Reviewed
See detailA Stochastic Multi-Scale Approach for the Modeling of Thermo-Elastic Damping in Micro-Resonators
Wu, Ling ULg; Lucas, Vincent ULg; Nguyen, Van Dung ULg et al

in Computer Methods in Applied Mechanics & Engineering (2016), 310

The aim of this work is to study the thermo-elastic quality factor (Q) of micro-resonators with a stochastic multi-scale approach. In the design of high-Q micro-resonators, thermo-elastic damping is one ... [more ▼]

The aim of this work is to study the thermo-elastic quality factor (Q) of micro-resonators with a stochastic multi-scale approach. In the design of high-Q micro-resonators, thermo-elastic damping is one of the major dissipation mechanisms, which may have detrimental effects on the quality factor, and has to be predicted accurately. Since material uncertainties are inherent to and unavoidable in micro-electromechanical systems (MEMS), the effects of those variations have to be considered in the modeling in order to ensure the required MEMS performance. To this end, a coupled thermo-mechanical stochastic multi-scale approach is developed in this paper. Thermo-mechanical micro-models of polycrystalline materials are used to represent micro-structure realizations. A computational homogenization procedure is then applied on these statistical volume elements to obtain the stochastic characterizations of the elasticity tensor, thermal expansion, and conductivity tensors at the meso-scale. Spatially correlated meso-scale random fields can thus be generated to represent the stochastic behavior of the homogenized material properties. Finally, the distribution of the thermo-elastic quality factor of MEMS resonators is studied through a stochastic finite element method using as input the generated stochastic random field. [less ▲]

Detailed reference viewed: 43 (14 ULg)
Full Text
Peer Reviewed
See detailAdvancing the integration of corporate sustainability measurement, management and reporting
Maas, Karen; Schaltegger, Stefan; Crutzen, Nathalie ULg

in Journal of Cleaner Production (2016), 133

Detailed reference viewed: 43 (4 ULg)
Full Text
See detailHautes Valeurs de Conservation (HVC) dans les Unités Forestières d'Aménagement du Cameroun : concepts, choix et pratiques
Daïnou, Kasso ULg; Bracke, Charles; Vermeulen, Cédric ULg et al

Book published by Presses Agronomiques de Gembloux (2016)

Le système de certification FSC (Forest Stewardship Council) vise à promouvoir la gestion durable des forêts. Il repose sur un ensemble de normes dont une est particulièrement complexe à mettre en oeuvre ... [more ▼]

Le système de certification FSC (Forest Stewardship Council) vise à promouvoir la gestion durable des forêts. Il repose sur un ensemble de normes dont une est particulièrement complexe à mettre en oeuvre en Afrique Centrale, le principe 9 traitant des Hautes Valeurs de Conservation (HVC). Ce principe devrait être interprété aux échelons nationaux afin de prendre en compte les spécificités de chaque pays. Bien que des ouvrages aient déjà été élaborés par diverses organisations, aucun ne cible particulièrement les grandes concessions forestières. Au Cameroun, ces concessions ou Unités Forestières d’Aménagement (UFA), représentent pourtant 40 % du domaine forestier national. Le présent guide ambitionne de fournir aux acteurs de la gestion forestière au Cameroun les connaissances les plus pertinentes afin de leur permettre d’identifier, de gérer et de suivre les Hautes Valeurs de Conservation dans les UFA. Il se démarque des précédents guides par plusieurs points : (i) une revue bibliographique détaillée est fournie sur le sujet épineux de l’identification de chaque HVC, et l’opinion des auteurs y est mise en exergue; (ii) la démarche d’identification est appuyée par les références les plus pertinentes, évitant au gestionnaire de se disperser dans sa quête de documentation; (iii) sur la base de leur expérience, les auteurs proposent une série de menaces pouvant affecter les HVC, de mesures de gestion et d’indicateurs de suivi. L’approche développée se base sur des méthodes empiriques et pragmatiques d’une part et, d’autre part, sur des études scientifiques. Cet ouvrage devrait constituer une base intéressante pour une interprétation solide des HVC au Cameroun. De plus, bien que ciblant les UFA camerounaises, il pourrait inspirer d’autres acteurs forestiers œuvrant dans le Bassin du Congo. [less ▲]

Detailed reference viewed: 20 (6 ULg)
Full Text
See detailOceanBrowser: on-line visualization of gridded ocean data and in situ observations
Barth, Alexander ULg; Watelet, Sylvain ULg; Troupin, Charles et al

Conference (2016, October)

Detailed reference viewed: 9 (1 ULg)
See detailComment élaborer des tarifs en assurance non vie
Esch, Louis ULg

Scientific conference (2016, October)

Detailed reference viewed: 6 (0 ULg)
See detailThe fabrication of Otherness. Leeds Kirkgate Market
Dobbels, Rachel ULg

Scientific conference (2016, October)

Detailed reference viewed: 24 (1 ULg)
Full Text
Peer Reviewed
See detailA review of Silurian dispersed spore assemblages from the Arabian Plate: biostratigraphy and palaeogeography
Wellman, CH; Steemans, Philippe ULg; Breuer, P et al

Conference (2016, October)

Detailed reference viewed: 24 (2 ULg)
See detailQuality Control Laboratories involved in the WHO Prequalification
Marini Djang'Eing'A, Roland ULg

Conference (2016, October)

Detailed reference viewed: 12 (0 ULg)
Full Text
Peer Reviewed
See detailL’approche sémiotique de Charles Goodwin : langage visuel, énonciation et diagramme
Dondero, Maria Giulia ULg

in Tracés. Revue de Sciences Humaines (2016), 3(automne),

This text investigates the connexion between the work of Charles Goodwin and contemporary semiotics. I initially address the relations between verbal, visual, and gestural languages in semiotic terms by ... [more ▼]

This text investigates the connexion between the work of Charles Goodwin and contemporary semiotics. I initially address the relations between verbal, visual, and gestural languages in semiotic terms by exploring the Goodwin’s notational system (transcription of exchanges) from the point of view of its constituent units. Secondly, I consider the meeting points between Goodwin’s concept of the substrate and Fontanille’s enunciative praxis in order to examine the dynamic relationship between sedimentation and transformation. Finally, I analyse the concept of diagrammatic reasoning by elaborating on the example of the geologists’ “first inscriptions” studied by Goodwin. The form of diagrammatic reasoning examined here functions as a discovery device that exemplifies the dynamics of sedimentation and novelty, and it can thus be studied in the framework of Goodwin’s transcription practices. [less ▲]

Detailed reference viewed: 29 (0 ULg)
Full Text
Peer Reviewed
See detailUn chantier de modernisation des contextes de travail: le "New Way of Working" dans une compagnie d'assurances
Jemine, Grégory ULg

Conference (2016, October)

Dans les réflexions récentes portant sur l’organisation du travail en entreprise, nombreux sont les auteurs qui s’intéressent à la question des « nouvelles formes d’organisation ». Sous cette appellation ... [more ▼]

Dans les réflexions récentes portant sur l’organisation du travail en entreprise, nombreux sont les auteurs qui s’intéressent à la question des « nouvelles formes d’organisation ». Sous cette appellation se rassemblent des courants aux dénominations différentes (entreprise libérée, entreprise virtuelle, « holacracie »…) partageant cependant des principes fondateurs communs (tels que la flexibilité, l’autonomie du collaborateur ou encore la digitalisation des pratiques de travail). A travers une étude de trois mois au sein d’un département de protection juridique d’une importante compagnie d’assurances située à Bruxelles, nous étudions un projet de changement basé sur le « New Way of Working » (NWoW) – un chantier managérial se développant principalement aux Pays-Bas et en Belgique depuis une dizaine d’années, proposant une « nouvelle » vision des travailleurs dans le secteur tertiaire. Nous rendons compte des trois composantes clés du projet NWoW telles qu'il est problématisé dans notre étude de cas: les Bricks (travail en open-space, bureaux flexibles, travail à distance), les Bytes (nouveaux outils numériques, travail sans papier, connectivité) et les Behaviors (autonomie et responsabilité des collaborateurs, passage du contrôle à la confiance). Nous concluons par une réflexion structurée autour des "4C": dans ces nouveaux environnements de travail, de nouvelles questions émergent en termes de confiance, de contrôle, de cohésion et de coordination. [less ▲]

Detailed reference viewed: 32 (10 ULg)
Full Text
Peer Reviewed
See detailL’étau et le réseau. Recompositions des contextes de travail des équipes de direction pénitentiaire
Dubois, Christophe ULg

in Justice et Sécurité/Justitie en Veiligheid (2016), 7

Résumé : En parcourant les nombreuses études qui décrivent et analysent, depuis plus de vingt ans, le fonctionnement des organisations et des politiques pénitentiaires, trois questions semblent avoir ... [more ▼]

Résumé : En parcourant les nombreuses études qui décrivent et analysent, depuis plus de vingt ans, le fonctionnement des organisations et des politiques pénitentiaires, trois questions semblent avoir jusqu’ici suscité un moindre intérêt scientifique : qui dirige ces organisations ? En quoi consiste le travail des équipes de direction ? Quelle position les membres de ces équipes occupent-ils dans le système organisationnel et politique pénitentiaire belge ? Cet article apporte quelques éléments de réponse à ces questions tout en éclairant les recompositions des contextes de travail des équipes de direction pénitentiaire. Cet éclairage souligne la nécessité de définir politiquement et avec les principaux intéressés un processus de professionnalisation de la fonction qu’ils exercent. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Full Text
Peer Reviewed
See detailHet net en het netwerk. Werkomgevingen van penitentiaire directieteams
Dubois, Christophe ULg; Winant, Ben

in Justice et Sécurité/Justitïe en Veiligheid (2016), 7

Detailed reference viewed: 9 (1 ULg)
Full Text
See detailLa viande des uns, la faune des autres. Analyse anthropologique de la conservation de la faune dans trois villages Badjoué de la zone forestière de l'Est-Cameroun
Dieudonné, Mélodie ULg

Doctoral thesis (2016)

The Cameroonian forestry and environmental policies adopted in 1994 come within the scope of a will to manage forests sustainably and to involve local populations in the management of their environment ... [more ▼]

The Cameroonian forestry and environmental policies adopted in 1994 come within the scope of a will to manage forests sustainably and to involve local populations in the management of their environment. The aim of this doctoral thesis is to take an anthropological look at the wildlife conservation at the “microsociological” level of three Badjoué villages from the East region while putting these observations in the larger context of Cameroonian forest governance. In what way are wildlife community management measures appropriated, transformed and distorted by the actors? How do interactions between local populations and conservation organizations help transform local contexts and relations to wildlife? By applying an approach at the crossroads of the anthropology of conservation, the anthropology of development and an anthropology of nature which considers human-animal relations in an interactive and dynamic perspective, this thesis aims at paying a particular attention to the relations that the Badjoué of the Dja entertain with their environment, the intertwining of these relations in the local social, economic and political dynamics as well as to the evolution of these problems in the context of the community management of forest resources in Cameroon. The thesis so allows a reflection on the place of participation and local community autonomy in the management of natural resources and a questioning of the impact of coercive models on the environmental practices and conceptions. It finally raises the question of the intertwining between global environmental issues and the necessary consideration of peoples’ right to self-determination. [less ▲]

Detailed reference viewed: 25 (2 ULg)
See detailDetection and characterization of transiting hot Jupiters
Delrez, Laetitia ULg

Doctoral thesis (2016)

Detailed reference viewed: 26 (4 ULg)
Full Text
See detailL'apprentissage des conversations de conception. Analyse exploratoire des pratiques discursives et graphiques médiées par ordinateur.
Joachim, Guillaume ULg

Doctoral thesis (2016)

A large proportion of architects’ educational and professional activities take place in the form of informal and formal discussions revolving around design artefacts, such as blueprints, sketches and ... [more ▼]

A large proportion of architects’ educational and professional activities take place in the form of informal and formal discussions revolving around design artefacts, such as blueprints, sketches and models. However, there has been little investigation into the multimodal resources mobilized by designers in order to collectively simulate experiments on their projects. In this thesis, we focus on remote mediated-by-computer design conversations in which architects jointly mobilise speech, inscription practices and artefacts handling for the purpose of examining how these function in the negotiation and joint development of architectural design knowledge. On the basis of a cross-cutting theoretical appraisal to the design conversation and on-field observations of remote synchronous meetings between professional designers, this exploratory study aims to describe and define the interactional processes implemented by architects in order to develop a shared reasoning on their project. The cross-disciplinary approach developed in the course of this research results in the formulation of a theoretical and analytical framework for studying the interactional organization behind jointly constructing the meaning of an architectural design. It also offers a better understanding of the fundamental links between graphical and discursive activities in communication between architects, while examining their digital mediations. [less ▲]

Detailed reference viewed: 12 (1 ULg)
Full Text
See detailIdentification de mécanismes moléculaires d’induction de la réponse immunitaire de type Th2 par les cellules dendritiques conventionnelles CD11b+ du poumon
Janss, Thibaut ULg

Doctoral thesis (2016)

Currently, the activation mechanisms of type 2 helper T cells (Th2) by dendritic cells are not yet fully understood. In recent years, more and more evidences show that there is a functional specialization ... [more ▼]

Currently, the activation mechanisms of type 2 helper T cells (Th2) by dendritic cells are not yet fully understood. In recent years, more and more evidences show that there is a functional specialization of the different dendritic cells populations. Therefore, in our laboratory, it was demonstrated that lung CD11b+ conventional dendritic cells (cDC) are the cells responsible for the allergic sensitization after an inhalation of house dust mite extracts in mice. Because this population is responsible for priming Th2 response, we decided to study them in an allergic context as a model in order to identify new mechanisms involve in Th2 induction. So far, few transcription factors required for the pro-Th2 activity of dendritic cells have been identified. Their discovery could considerably improve the understanding of Th2 activation by dendritic cells. Transcriptomic profiling of lung CD11b+ cDCs exposed to HDM in vivo revealed first that HDM triggered an antiviral defence-like response and second that the majority of HDM-induced transcriptional changes depended on the transcription factor Inresterferon Response Factor-3 (Irf3). Validating the functional relevance of these observations, Irf3-deficient CD11b+ cDCs displayed reduced pro-allergic activity. Indeed, Irf3-deficient CD11b+ cDCs induced less Th2, more regulatory T cell, and similar Th1 differentiation in naïve CD4+ T cells compared to their wild-type counterparts. The altered APC activity of Irf3 CD11b+ cDCs was associated with reduced expression of CD86 and was phenocopied by blocking CD86 activity in wild-type CD11b+ cDCs. Altogether, these results establish Irf3, mostly known for its role in antiviral responses, as a transcription factor involved in the induction of Th2 responses through the promotion of pro-Th2 costimulation in CD11b+ DCs. [less ▲]

Detailed reference viewed: 93 (0 ULg)
Peer Reviewed
See detailTransition to parenthood of lesbian parents: key processes and clinical implications
Scali, Thérèse ULg; D'Amore, Salvatore ULg; Haxhe, Stéphanie ULg et al

Conference (2016, September 29)

The transition to parenthood is a key process for understanding the development of family relationships in a systemic perspective. This process has been studied mostly in heterosexual families but very ... [more ▼]

The transition to parenthood is a key process for understanding the development of family relationships in a systemic perspective. This process has been studied mostly in heterosexual families but very few studies focus on families with same-sex families. This exploratory study analyzes the key passages of the transition from 17 lesbian headed families through a quantitative analysis of socio-demographic data, information about the coming-out, pair formation, project of the child, the child's arrival, as well as social and cultural pressures towards family and stressors. The main results show that the decision making to become parents is generally harmonious (70%) between the members of the couple, and only a few had substantial conflicts (17,1%). Moreover, the motivation to become parents seems to be stronger for the mother who carried the child (57, 1%)than for the social mother. The majority of the lesbian mothers reported no medical homophobia (64,3%) Regarding the caregiving tasks, they seem to be equally shared between social and biological mothers. In regards to the child, almost 70% are aware of their parents’ sexual orientation (as only 5.7% are not fully aware). Finally, no changes in the quality of relationship with the family of origin have been found after the birth of the baby. Clinical implications of these results will be discussed. [less ▲]

Detailed reference viewed: 14 (1 ULg)