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Nisen, Laurent ULg

Speech/Talk (2017)

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See detailLorrAgri: methodology and experience of a territorial transition lab
Feyereisen, Marlène ULg

Conference (2017, April 27)

Many scholars have underlined the potential of spatialized (or territorialized) approaches to analyse and guide the transition of the agrifood system. For example, scale reductions often associated with ... [more ▼]

Many scholars have underlined the potential of spatialized (or territorialized) approaches to analyse and guide the transition of the agrifood system. For example, scale reductions often associated with territorialisation offers the opportunity to modify power relations between actors and permits to improve their ability to act – or empower. While territorialized approaches to transition management are promising, to date only few studies have considered these aspects in unison. This study presents the methodology used to design and guide a transition management experience. We describe the tools used, issues raised, and potential benefits of the experience for transition, as well as challenges and limitations. Furthermore, we investigate how tools from transition theories were able to support the experience (multi-level perspective, transition management and strategic niche management). LorrAgri is a “territorial transition lab” organised from early 2016 until present day, and aims to develop the local agrifood system (in particular vegetables) in the rural area of Belgian Lorraine in the South of Belgium. This area has relatively well-developed non-conventional agriculture compared to the rest of Belgium, and recently developed market gardening. The present work is based on extensive data selection, including semi-structured interviews and participant observations. Strategic analysis sociology was used to identify possible strategies and challenges between actors of the agrifood system in the selected territory. From these diagnostics of the territory and its actors, the LorrAgri group was created in January 2016, initially with market gardeners. Over time, organisations joined also (both from the regime and niches) which work on local agrifood development, culminating today in the active support and involvement of local politics. Analyses were conducted at several of these stages, and fed by inputs from transition theories. Our study shows that the territorialized approach can enable cooperation between actors which oppose each other, in terms of norms and values. Therefore, LorrAgri is an interesting case study to analyse modes of cooperation between actors e.g. from the regime and the niches, and how norms and values from different levels can influence each other (transition in-the-making). This study also details how participants found a common objective for developing the local agrifood system, namely to supply local products to collective catering, e.g. school canteens and restaurants. [less ▲]

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See detailCharacterizing root system characteristics with Electrical resistivity Tomography: a virtual rhizotron simulation
Rao, Sathyanarayan; Ehosioke, Solomon ULg; Lesparre, Nolwenn et al

Conference (2017, April 24)

Electrical Resistivity Tomography (ERT) is more and more used for monitoring soil water content in a cropped soil. Yet, the impact of roots on the signal is often neglected and a topic of controversy. In ... [more ▼]

Electrical Resistivity Tomography (ERT) is more and more used for monitoring soil water content in a cropped soil. Yet, the impact of roots on the signal is often neglected and a topic of controversy. In several studies related to soil-root system, it has been showed that the measured root mass density statistically correlates with the electrical conductivity (EC) data obtained from ERT. In addition, some studies suggest that some roots are more electrically conductive than soil for most water content. Thus, higher EC of roots suggest that it might have a measurable impact on ERT signals. In this work, virtual rhizotrons are simulated using the software package called R-SWMS that solves water and solute transport in plant root-soil system, including root growth. The distribution of water content obtained from R-SWMS simulation is converted into EC data using pedo-physical models. The electrical properties of roots and rhizosphere are explicitly included in the EC data to form a conductivity map (CM) with a very detailed spatial resolution. Forward ERT simulations is then carried out for CM generated for various root architectures and soil conditions to study the impact of roots on ERT forward (current and voltage patterns) and inverse solutions. It is demonstrated that under typical injection schemes with lateral electrodes, root system is hardly measurable. However, it is showed that adding electrodes and constraints on the ERT inversion based on root architecture help quantifying root system mass and extent. [less ▲]

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See detailLessons learned from combined experimental and numerical modelling of urban floods
Archambeau, Pierre ULg; Bruwier, Martin ULg; Finaud-Guyot, Pascal et al

Conference (2017, April)

Field data for validating hydraulic models remain scarce, They are often limited to inundation extents and water marks, which provide little insights into the dynamic features of the flow in urbanized ... [more ▼]

Field data for validating hydraulic models remain scarce, They are often limited to inundation extents and water marks, which provide little insights into the dynamic features of the flow in urbanized floodplains, such as the discharge partition in-between the streets and the velocity fields. To address this issue, a unique experimental setup representing a whole urban district was built in the laboratory ICube in Strasbourg and the state-of-the-art shallow- water model Wolf 2D was tested against the experimental measurements (An'ault et al, 2016), The numerical model was also used to extend and refine the analysis of the laboratory observations. The experimental model (5 m >< 5 m) represents a square urban district with a total of l4 streets of different Widths and 49 intersections (crossroads). The inflow discharge can be controlled in each street individually and the outflow discharges were measured downstream of each street. The numerical model Wolf was developed at the University of Liege and has been extensively used in flood risk research (Beckers et al, 2013, Bruwier et al. 2015, Detrembleur et al. 2015). Several lessons could be learned from this combined experimental and numerical analysis. First, we found that the discharge partition in—between the streets is primarily controlled by the street widths. Second, although the standard shallow-water equations reproduce satisfactorily tnost of the flow characteristics, adding a turbulence model improves the prediction of the shape and length of the flow recirculations in the streets. Yet, this has little influence on the discharge partition because the computed recirculation widths are hardly affected by the turbulence model. The experiments and the numerical model also show that the water depths in the streets remain fairly constant in~between two intersections, while they drop suddenly downstream of each intersection as a result of complex flow interactions at the intersections. This hints that friction has little influence on the water depths obtained in the experiments. However, tailored numerical tests demonstrate that this is a direct consequence of the distorted nature of the experimental setup. Indeed, the ratio between the water depth and the street width is close to 1 in the experiments, while it would be at least one order of magnitude lower in real-world conditions, even for extreme floods. Finally, remote sensing data, such as digital elevation models, are generally available on a regular grid, which makes it convenient to use also a Cartesian grid for hydraulic modelling, We show here that the discretization of the geometry of the buildings on such a Cartesian grid has a major influence on the modelling accuracy (overestimation of the overall flow resistance). An extended shallow-water model based on non-isotropic porosity parameters is shown to improve substantially the prediction of the discharge partition in-between the streets. It is therefore considered as a valuable tool to advance urban flood modelling in practice. From the lessons learned here, we recommend that future research focuses on the design and exploitation of a less distorted experimental model, as well as on the analysis of extra flow processes such as transient conditions and interactions between overland flow and pressurized flow in underground passages. [less ▲]

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See detailA laser profilometry technique for monitoring fluvial dike breaching in laboratory experiments
Dewals, Benjamin ULg; Rifai, Ismail; Erpicum, Sébastien ULg et al

Conference (2017, April)

A challenging aspect for experimental modelling of fluvial dike breaching is the continuous monitoring of the transient breach geometry. In dam breaching cases induced by flow overtopping over the whole ... [more ▼]

A challenging aspect for experimental modelling of fluvial dike breaching is the continuous monitoring of the transient breach geometry. In dam breaching cases induced by flow overtopping over the whole breach crest (plane erosion), a side view through a glass wall is sufficient to monitor the breach formation. This approach can be ex- tended for 3D dam breach tests (spatial erosion) ifthe glass wall is located along the breach centreline. In contrast using a side view does not apply for monitoring fluvial dike breaching, because the breach is not symmetric in this case. We present a non-intrusive, high resolution technique to record the breach development in experimental models of fluvial dikes by means of a laser profilometry (Rifai et al. 2016). Most methods used for monitoring dam and dike breaching involve the projection of a pattern (fringes, grid) on the dam or dike body and the analysis of its deformation on images recorded during the breaching (e.g., Pickett et al. 201 1, Frank and Hager 2014). A major limitation of these methods stems from reflection on the water surface, particularly in the vicinity of the breach where the free surface is irregular and rippled. This issue was addressed by Spinewine et al. (2004), who used a single laser sheet so that reflections on the water surface were strongly limited and did not hamper the accurate processing of each image. We have developed a similar laser profilometry technique tailored for laboratory experiments on fluvial dike breaching. The setup is simple and relatively low cost. It consists of a digital video camera (resolution of 1920 >< 1080 pixels at 60 frames per second) and a swiping red diode 30 mW laser that enables the projection of a laser sheet over the dike body. The 2D image coordinates of each defomied laser profile incident on the dike are transformed into 3D object coordinates using the Direct Linear Transformation (DLT) algorithm. All 3D object coordinates computed over a swiping cycle of the laser are merged to generate a cloud of points. The DLT-based image processing method uses control points and reference axes, so that no prior knowledge is needed on the position, orientation and intrinsic characteristics of the camera, nor on the laser position. Refraction of the light and laser rays across the water surface needs to be taken into account, because the dike is partially submerged during the experiments. An ad hoc correction is therefore applied using the Snell-Descartes law. For dtis purpose, planar approximations are used to describe the shape of the water surface. In the presen- tation, we will discuss the resulting uncertainty and will detail the validation of the developed method based on configurations of known geometry with various complexity. The presented laser profilometry technique allows for a rapid non-intrusive measurement of the dike geometry evolution. It is readily available for laboratory experiments and has proven its performance (Rifai et al. 2017). Further adjustments are needed for its application to cohesive dike material due to the reduced visibility resulting from the higher turbidity of water. [less ▲]

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See detailTransition between symmetric and asymmetric flow in rectangular shallow reservoirs — a case of maximum dissipation?
westhoff, Martijn; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Conference (2017, April)

Shallow reservoirs are often used in hydraulic engineering as sediment traps or storage basins, Sedimentation within these reservoirs depends on the flow pattern, which in turn depends on the shape of the ... [more ▼]

Shallow reservoirs are often used in hydraulic engineering as sediment traps or storage basins, Sedimentation within these reservoirs depends on the flow pattern, which in turn depends on the shape of the reservoir. For short rectangular reservoirs, the main jet flows straight from the inlet to the outlet with on both sides identical recirculation zones. In longer reservoirs, however, the main jet reattaches to the side of the reservoir leading to a small and a large recirculation zone. Previous studies have found an empirical geometric relation describing the switch between these two different flow patterns. In this study, we demonstrate that this switch in flow pattern coincides with a maximization of energy dissipation in the shear layer between the main jet and the recirculation zones. To show this we described the power received from the jet by the recirculation zone as the product of a fluid-fluid friction coefficient and the square of the velocity difference times the shear velocity of the recirculation zone. This power is balanced by the bottom friction of the recirculation zone. Energy dissipation in the shear layer is then determined as the difference between the power performed by the jet and the power received by the recirculation zone. In this setup, energy dissipation is maximized by optimizing the friction coefficient. We show that for short reservoir lengths, energy dissipation is higher in the case of a symmetric flow pattern, while for longer reservoir the energy dissipation is higher for asymmetric flow patterns. The simulated switch between the two flow patterns appears to be very close to the empirical relation. This suggests that the flow pattem adapts in order to maximize energy dissipation between the jet and recirculation zones. The strength of this approach lies in the fact that no detailed knowledge of small scale processes is needed, while large scale structure formation can still be predicted. [less ▲]

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See detailFluvial dike breaching due to overtopping: how different is it from dam breaching?
Rifai, Ismail; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Conference (2017, April)

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See detailCartographie de la disponibilité en eau et en éléments nutritifs des stations forestières de Wallonie
Wampach, Florent ULg; Lisein, Jonathan; Cordier, Sophie ULg et al

in FORÊT.NATURE (2017), avril-mai-juin(143), 47-60

Grâce aux données cartographiques de plus en plus nombreuses et disponibles, il est maintenant possible d'analyser l'adéquation essence-station à l'échelle d'un massif ou d'un cantonnement. A l'échelle ... [more ▼]

Grâce aux données cartographiques de plus en plus nombreuses et disponibles, il est maintenant possible d'analyser l'adéquation essence-station à l'échelle d'un massif ou d'un cantonnement. A l'échelle plus locale, cette nouvelle cartographie constitue un outil d'aide à l'interprétation des stations pour les gestionnaires, forestiers ou naturalistes. [less ▲]

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See detailLe projet Massif Rouge
Couturaud, Barbara ULg; Butterlin, Pascal; Hageneuer, Sebastian

Scientific conference (2017, March 24)

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See detailDevelopment of nuclear SNP markers for genetic tracking of Iroko, Milicia excelsa and Milicia regia
Blanc-Jolivet, Céline; Kersten, Birgit; Daïnou, Kasso ULg et al

in Conservation Genetics Resources (2017)

Iroko, Milicia excelsa, is an economically important tropical hardwood species widely distributed in tropical Africa, from Ivory Coast in Western Africa to Tanzania in Eastern Africa. The species occurs ... [more ▼]

Iroko, Milicia excelsa, is an economically important tropical hardwood species widely distributed in tropical Africa, from Ivory Coast in Western Africa to Tanzania in Eastern Africa. The species occurs at low densities in contrasting habitats such as rainforest and woodlands. Former studies using chloroplast and nuclear sequences, as well as nSSRs, revealed a strong differentiation within the species among West and Central African populations and the presence of three genetic groups in Central Africa (Daïnou et al. 2010, 2014). The genus Milicia also includes another species, M. regia, co-occurring with M. excelsa in West Africa. Both species can be identified genetically and morphologically (Daïnou et al. 2014), but identification is difficult in the field. Although the spatial genetic structure of the species is well described, it is mostly based on nSSRs. Despite their lower diversity, SNP markers provide several advantages including the uncomplicated standardization of data among laboratories and the easy, rapid and low-cost development of markers for large sets of loci. These features make SNPs the ideal markers for setting up genetic reference data for timber tracking (Blanc-Jolivet and Liesebach 2015; Degen et al. 2017; Jardine et al. 2016; Pakull et al. 2016). In this paper, we describe the development of a new set of nuclear SNPs on M. excelsa meant to be used for genetic timber tracking. [less ▲]

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See detailDevelopment of a prototype of errors prediction in a geodetic network
Nys, Gilles-Antoine ULg

Conference (2017, March 16)

Presentation made by Gilles-Antoine Nys, University of Liège at the Geospatial Awards.

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See detailLes exemples lexicographiques et leur traduction : quel(s) rôle(s) dans la pratique du traducteur ?
Belleflamme, Clémence ULg

Conference (2017, March 10)

L'exemple lexicographique remplit toute une série de fonctions, tant sémantiques ou stylistiques que grammaticales (syntaxiques et morphologiques). Selon Michael Toope, dans un dictionnaire bilingue, les ... [more ▼]

L'exemple lexicographique remplit toute une série de fonctions, tant sémantiques ou stylistiques que grammaticales (syntaxiques et morphologiques). Selon Michael Toope, dans un dictionnaire bilingue, les exemples ont, en outre, des fonctions de traduction. Ils devraient, notamment, suggérer à l'utilisateur des procédures de traduction indirecte, l'incitant dès lors à ne pas opter systématiquement pour une traduction isomorphe, mais à privilégier une solution plus conforme à l'usage. Par ailleurs, Xavier Blanco et Philippe Humblé s'accordent sur le fait que les exemples lexicographiques et leur traduction devraient mettre en évidence les différences existant entre deux systèmes linguistiques. Dans notre travail de fin d'études en traduction, nous avons cherché à identifier les questions de linguistique contrastive illustrées par les exemples lexicographiques et leur traduction, ainsi qu'à déterminer quelles solutions les dictionnaires apportaient à l'utilisateur effectuant une tâche de traduction vers sa langue maternelle. Cette analyse reposait sur l'observation des divergences, ces «différences de structures syntaxiques de surface », que présentaient l'exemple et sa traduction. À l'occasion de notre communication, nous avons livré à l'assemblée les résultats de notre analyse et nous nous sommes penchée sur une série d'exemples significatifs, issus de trois dictionnaires bilingues généraux allemand-français, afin de montrer en quoi les exemples lexicographiques peuvent aider le traducteur (ou l'étudiant en traduction) à résoudre certains problèmes liés à des obstacles d'ordre syntaxique. [less ▲]

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See detailEclairage théorique et conceptuel sur les phénomènes à l’œuvre dans l’insertion
Nisen, Laurent ULg

Conference given outside the academic context (2017)

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See detailL’ (ir) responsabilité du pouvoir judiciaire : fondements et mise à l’épreuve de l’immunité judiciaire en droits québécois et belge
Bouhon, Frédéric ULg; Lacroix, Mariève

Scientific conference (2017, March 09)

L'intervention visait à présenter la synthèse des travaux menés par les auteurs dans le domaine de la responsabilité civile extracontractuelle pour la faute commise par le juge, en droits québécois et ... [more ▼]

L'intervention visait à présenter la synthèse des travaux menés par les auteurs dans le domaine de la responsabilité civile extracontractuelle pour la faute commise par le juge, en droits québécois et belge. Voy. les autres références pertinentes sur le site Orbi. [less ▲]

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See detailTraduction et retraduction françaises de Conversación en La Catedral: Étude des paratextes
Belleflamme, Clémence ULg

Conference (2017, February 08)

Étude des paratextes des traductions de Conversación en la Catedral, toutes deux publiées chez Gallimard. La première, intitulée Conversation à « La Cathédrale » (1973), est l'œuvre de Sylvie Léger et ... [more ▼]

Étude des paratextes des traductions de Conversación en la Catedral, toutes deux publiées chez Gallimard. La première, intitulée Conversation à « La Cathédrale » (1973), est l'œuvre de Sylvie Léger et Bernard Sesé ; la deuxième, Conversation à La Catedral (2015), est signée Albert Bensoussan et Anne-Marie Casès. Notre analyse porte tant sur l'« épitexte » — en particulier, sur les essais d'Albert Bensoussan à propos son travail de traducteur — que sur le « péritexte » (Genette). Ces éléments fournissent en effet de précieuses informations, non seulement pour déterminer la stratégie globale adoptée par les traducteurs par rapport au texte source, mais aussi pour observer l'évolution des « normes de traduction » (Toury) à l'œuvre dans chacune des versions françaises. Les notes du traducteur, notamment, soulèvent les questions de l'implicite et de l'explicite, des connaissances supposées du lecteur cible et de la visibilité du traducteur. [less ▲]

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See detailPour une histoire globale des Sciences humaines à l’Université de Liège
Genin, Vincent ULg

Conference (2017, February 08)

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See detailRéflexions sur la matérialité des images de guerre au Bronze ancien
Couturaud, Barbara ULg

Scientific conference (2017, February 02)

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See detailLa preuve contraire et le faux
Stassin, Maxime ULg

in Boufflette, Sophie (Ed.) La preuve et le faux (2017)

Analyse du faux en droit civil et des procédures liées: la vérification d'écriture et l'inscription de faux civil.

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