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See detailInvestigating missing sources of formic acid
Franco, Bruno ULg; Taraborrelli, Domenico; Schultz, Martin G.

Scientific conference (2016, September 28)

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See detailEvolution récente des extrêmes pluviométriques au Niger (1950-2014)
Ozer, Pierre ULg; Laminou, Manzo Ousmane; Tidjani, Adamou Didier et al

Conference (2016, September 28)

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See detailPerformance et circuit de commercialisation des principaux produits agricoles des cuvettes oasiennes du département de Gouré
Malam Boukar, Awa Krou; Yahaya, Abdou; Yamba, Boubacar et al

Conference (2016, September 28)

Les cuvettes oasiennes du département de Gouré sont sources de production alimentaire et de revenus pour les populations locales. Elles jouent un rôle important dans la lutte contre l’insécurité ... [more ▼]

Les cuvettes oasiennes du département de Gouré sont sources de production alimentaire et de revenus pour les populations locales. Elles jouent un rôle important dans la lutte contre l’insécurité alimentaire et la pauvreté. L’objectif de cet article est de démontrer l’efficacité économique des principaux produits agricoles de cuvettes ainsi que les plateformes de commercialisation. Pour ce faire, trois démarches méthodologiques complémentaires ont été adoptées. La première permet d’identifier les produits agricoles les plus rentables selon le point de vu des producteurs, la seconde permet déterminer les principaux produits agricoles de cuvettes à travers le « test de Kendall » et la troisième permet de calculer la rentabilité économique des produits à travers des indicateurs de performance. Pour cela, neuf cuvettes ont été choisies suivant le niveau de nappe phréatique et le type de valorisation. Les enquêtes réalisées et les constats effectués montrent que toutes les spéculations sont rentables, puisque leur RPN dépasse les 50%. Les producteurs indiquent que le manioc est la spéculation la plus importante du fait de sa mise en culture, de sa consommation et de sa conservation facile. Les deux autres tests montrent les cultures à cycle court comme le chou (75%) et l’oignon (69%) sont plus attrayants. Il est aussi ressorti que les produits agricoles de cuvettes sont plus destinés à la vente (73%) qu’à l’autoconsommation (27%) et les marchés locaux représentent les principales plateformes commerciales. [less ▲]

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See detailPratiques foncières dans les cuvettes oasiennes du Niger oriental
Malam Boukar, Awa Krou; Yamba, Boubacar; Ouassa, Tiekoura et al

Conference (2016, September 28)

La situation foncière en Afrique de l’Ouest francophone rurale se caractérise par la coexistence de différents systèmes de normes : aux règles foncières sociales, issues d’hybridations successives, se ... [more ▼]

La situation foncière en Afrique de l’Ouest francophone rurale se caractérise par la coexistence de différents systèmes de normes : aux règles foncières sociales, issues d’hybridations successives, se superpose un système juridique et réglementaire étatique (LAVIGNE Ph. 2000). L’Etat du Niger s’est engagé depuis les années 80 dans un processus visant à mettre en place des règles de gestion durable du foncier à travers le Code rural (Code Rural du Niger. 2013). De ce fait, la mise en perspective des spécificités des cuvettes oasiennes du Niger oriental ainsi que le cadre législatif devant permettre de gérer théoriquement le foncier est d’un intérêt croissant étant donné le nombre de problèmes récurrents et conjoncturels dans cette zone (ensablement, pression démographique, conflit foncier, enclavement). À la suite de ces constats, la mise en place de notre protocole de recherche tente d’établir un état des lieux du mode de fonctionnement et d’accès aux cuvettes oasiennes. La question de recherche s’énonce comme suit : « Comment s’effectue la pratique foncière dans les cuvettes oasiennes du département de Gouré ? ». La principale hypothèse du travail repose sur le fait que l’ensemble des cuvettes oasiennes du département de Gouré ont une gestion foncière relativement dépendante des chefs coutumiers et que ces derniers ne sont pas impliqués dans le processus du Code Rural Nigérien. [less ▲]

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See detailSystème d’exploitation et potentialités économiques des cuvettes oasiennes du sud-est du Niger
Malam Boukar, Awa Krou; Yamba, Boubacar; Lebailly, Philippe ULg

Poster (2016, September 28)

Les cuvettes oasiennes du sud-est nigérien sont sources de production alimentaire (JAHIEL. 1998). C’est pourquoi, les populations locales sont dépendantes des cuvettes pour leurs productions alimentaires ... [more ▼]

Les cuvettes oasiennes du sud-est nigérien sont sources de production alimentaire (JAHIEL. 1998). C’est pourquoi, les populations locales sont dépendantes des cuvettes pour leurs productions alimentaires et leurs revenus (TYCHON B. et al. 2009). Cette étude vise à démontrer l’importance socio-économique des cuvettes oasiennes du sud-est nigérien. [less ▲]

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See detailLa table ronde prospective Horeca en Région de Bruxelles-Capitale
Remy, Céline ULg; Bertrand, Amandine

Scientific conference (2016, September 28)

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See detailComparison of temperature from DTS and ERT with direct measurements during heat tracer experiments in heterogeneous aquifers
Nguyen, Frédéric ULg; Hermans, Thomas ULg; Jamin, Pierre ULg et al

Conference (2016, September 27)

Geothermal field characterization and heat tracer experiments often rely on scarce temperature data collected in boreholes. Electrical resistivity tomography (ERT) and distributed temperature sensing (DTS ... [more ▼]

Geothermal field characterization and heat tracer experiments often rely on scarce temperature data collected in boreholes. Electrical resistivity tomography (ERT) and distributed temperature sensing (DTS) have the potential to provide spatial information on temperature changes in the subsurface. In this contribution, we show how DTS and ERT have been used to investigate the heterogeneity of a heterogeneous aquifer during a heat tracing experiment under forced gradient conditions. Optic fibers were installed in the heat injection well and in two piezometers intersecting the main flow directions at 8 m from the injection well. These piezometers were also equipped with ERT. The DTS measurement in the injection well clearly shows the two-layer nature of the aquifer. After the end of injection, the temperature in the bottom part of the well decreases faster than in the upper part due to the higher water fluxes. Those results are confirmed by DTS measurements in natural flow conditions during a heating wire test. DTS and ERT in the cross-panel both show the vertical and lateral heterogeneity of the aquifer. Temperatures only increase significantly in the bottom part of the aquifer where advection is predominant. However, strong differences are observed laterally. ERT additionally shows that the hot plume is divided in two main flow paths, which is confirmed by direct temperature measurements. The comparison of DTS and ERT shows that one of the well is suffering from water mixing. Indeed, temperature from DTS are homogeneous over the whole tichkness of the aquifer, whereas ERT temperature, less affected by local variations, are varying. Our study demonstrate the value of spatially distributed measurements for the monitoring of heat tracer experiment and highligths the issue of multilevel sampling. The detailed temperature measurements can be subsequently used in hydrogeological model to better estimates heat flow and transport parameters. [less ▲]

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See detailAn old slate mine as lower reservoir for UPSH (Underground Pumping Storage Hydroelectricity)- groundwater interactions and limitations
Bodeux, Sarah ULg; Pujades, Estanislao ULg; Orban, Philippe ULg et al

Conference (2016, September 27)

Renewable energy sources have an increasing role to play in the future energy framework but their intermittence cannot afford a stable production according to the demand. Pumped Storage Hydroelectricity ... [more ▼]

Renewable energy sources have an increasing role to play in the future energy framework but their intermittence cannot afford a stable production according to the demand. Pumped Storage Hydroelectricity (PSH) is an efficient technology to store and release electricity. However, the development of new PSH plants is limited by environmental and topographic constraints. An innovative alternative consists in using old underground mines as lower reservoirs of Underground Pumped Storage Hydroelectricity (UPSH) plants. In this configuration, large amount of water is pumped and injected in underground cavities and these cyclic stresses impact the groundwater system. A hybrid 3D finite element mixing cell method is used to numerically simulate the use of an UPSH facility, in the case of an abandoned slate mine. Different scenarios are computed with varying pumping injection time-sequences. In order to assess the impact on the surrounding groundwater conditions, the resulting head evolution in the cavity and at different distances is analyzed in terms of groundwater oscillation magnitude, drawdown, and seepage into the cavity. Results show clearly the influence of the pumping injection time-sequence (rates, regularity, timing and duration of no-activity periods) on the actual head evolution in the surrounding medium and consequently on the magnitude of interactions with the cavity. For a given hydraulic conductivity of the surrounding medium (i.e. slates in this case study), the main conclusion is that the resulting interaction seepage flows (in and out of the cavity) are highly dependent on the chosen pumping injection sequences. The future impact of UPSH operation must be assessed taking this fact into account. [less ▲]

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See detailLa fluidothérapie chez le bovin adulte
Lecomte, Denis; Casalta, Hélène ULg; Djebala, Salem ULg et al

Conference (2016, September 27)

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See detailDe la crise à l’entreprise, en passant par vous…
Choffray, Jean-Marie ULg

Book published by Amazon, Kindle Edition (2016)

« Si un homme a de la chance, avant de mourir, il rassemblera autant qu'il le peut son patrimoine culturel pour le transmettre à ses enfants. Et jusqu’à son dernier souffle, il sera reconnaissant d’avoir ... [more ▼]

« Si un homme a de la chance, avant de mourir, il rassemblera autant qu'il le peut son patrimoine culturel pour le transmettre à ses enfants. Et jusqu’à son dernier souffle, il sera reconnaissant d’avoir pu laisser cet héritage inépuisable, sachant que c'est notre mère nourricière et notre vie éternelle. » (W. and A. Durant, 1968) « De la crise à l’entreprise, en passant par vous » est une invitation à l’action, à la prise de responsabilité, à la création responsable de valeur économique et à la recherche obstinée d’une croissance rentable. Oui ! Notre monde vient d’échapper à un effondrement systémique dont 1929 n’aurait constitué qu’un aimable préambule. Oui ! L’entreprise privée est le seul acteur social créateur de richesse économique et la solution la plus adaptée au mal qui se répand. Oui ! Il est extrêmement difficile de changer quoi que ce soit sur terre et d’apprendre à dire « non ! » En cas d’échec, le coût est connu : licenciement, exil, condamnation à mort ! L’objet de cet ouvrage est de partager le fruit d’une réflexion menée au cours de ces dernières années sur le rôle de l’entreprise dans l’environnement exceptionnel que nous connaissons depuis la Grande Récession de 2008-2009. Il aborde les causes et les conséquences de cet événement financier, industriel et politique historique ; le rôle de l’entreprise privée, de l’innovation et des entrepreneurs – eh oui ! vous… –, dans la recherche d’une solution ; et, enfin, les principales leçons de l’histoire à la lumière de ce qu’advint de l’œuvre de quelques grands hommes, innovateurs et agents du changement : Steve Jobs, Napoléon Bonaparte, et Jésus de Nazareth. Ecrire sur des thèmes aussi complexes, et aussi lourds de conséquences pour notre devenir commun, est un véritable défi et invite à la modestie. J’espère que les choix effectués mériteront votre investissement, votre attention et votre temps ! [less ▲]

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See detailGenomics and ecological adaptation: metal hyperaccumulation in Arabidopsis halleri
Hanikenne, Marc ULg

Conference (2016, September 27)

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See detailDEVELOPMENT OF NOVEL CATIONIC AND LIGAND-GRAFTED ANIONIC LIPOSOMES FOR BRAIN-TARGETED DRUG DELIVERY
Karim, Reatul ULg; Palazzo, Claudio ULg; Laloy, Julie et al

Poster (2016, September 27)

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See detailLa dynamique des profondeurs. Les réinventions de l’espace dans Alice Comedies, Oswald the Lucky Rabbit et Mickey Mouse
Tomasovic, Dick ULg

Conference (2016, September 27)

Détaillant les mises en scènes de l’espace dans trois séries essentielles de l’histoire du dessin animé (Alice Comedies (1923-1927), Oswald the Lucky Rabbit (1927-1928) et Mickey Mouse (dès 1928)) comme ... [more ▼]

Détaillant les mises en scènes de l’espace dans trois séries essentielles de l’histoire du dessin animé (Alice Comedies (1923-1927), Oswald the Lucky Rabbit (1927-1928) et Mickey Mouse (dès 1928)) comme autant d’étapes dans la définition d’une nouvelle spatialité servant au mieux les créations de personnages animés d’un nouveau type, analysant précisément certaines images dans la manière dont elles articulent avant-plan et arrière-plan, cette intervention pointe également les présupposés idéologiques du simulacre de la profondeur chez Disney. Reposant plus particulièrement sur le commentaire de quelques films emblématiques tels que Alice’s Wonderland (1923), Trolley Troubles (1927), ou Plane Crazy (1928), entre autres, l’intervention, en revenant notamment sur les contributions des spécialistes de l’histoire et de l’esthétique disneyenne (Donald Crafton, Jay P. Telotte, Leonard Maltin, J.B. Kaufman…), tente d’apporter un nouvel éclairage sur l’évolution de la conception de l’espace (en tant que problème esthétique, dramatique et psychologique) dans le dessin animé industriel américain, mais aussi, indirectement et plus largement, dans l’histoire des films d’animation. [less ▲]

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See detailFirst characterization and validation of FORLI-HNO3 vertical profiles retrieved from IASI/Metop
Ronsmans, G.; Langerock, B.; Wespes, C. et al

in Atmospheric Measurement Techniques (2016), 16

Knowing the spatial and seasonal distributions of nitric acid (HNO3) around the globe is of great interest to apprehend the processes regulating stratospheric ozone, especially in the polar regions ... [more ▼]

Knowing the spatial and seasonal distributions of nitric acid (HNO3) around the globe is of great interest to apprehend the processes regulating stratospheric ozone, especially in the polar regions. Thanks to its unprecedented spatial and temporal sampling, the nadir-viewing Infrared Atmospheric Sounding Interferometer (IASI) allows sounding the atmosphere twice a day globally, with good spectral resolution and low noise. With the Fast Optimal Retrievals on Layers for IASI (FORLI) algorithm, we are retrieving, in near-real time, columns as well as vertical profiles of several atmospheric species, amongst which is HNO3. We present in this paper the first characterization of the FORLI-HNO3 profile products, in terms of vertical sensitivity and error budgets. We show that the sensitivity of IASI to HNO3 is highest in the lower stratosphere (10–20km), where the largest amounts of HNO3 are found, but that the vertical sensitivity of IASI only allows one level of information on the profile (DOFS 1). The sensitivity near the surface is negligible in most cases, and for this reason, a partial column (5–35km) is used for the analyses. Both vertical profiles and partial columns are compared to FTIR ground-based measurements from the Network for the Detection of Atmospheric Composition Change (NDACC) to characterize the accuracy and precision of the FORLI-HNO3 product. The profile validation is conducted through the smoothing of the raw FTIR profiles by the IASI averaging kernels and gives good results, with a slight overestimation of IASI measurements in the Upper Troposphere-Lower Stratosphere (UTLS) at the 6 chosen stations (Thule, Kiruna, Jungfraujoch, Izaña, Lauder and Arrival Heights). The validation of the partial columns (5–35km) is also conclusive with a mean correlation of 0.93 between IASI and the FTIR measurements. An initial survey of the HNO3 spatial and seasonal variabilities obtained from IASI measurements for a one year (2011) data set shows that the expected latitudinal gradient of concentrations from low to high latitudes and the large seasonal variability in polar regions (cycle amplitude around 30% of the seasonal signal, peak-to-peak) are well represented with IASI data. [less ▲]

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See detailInfluence of groundwater exchanges on the efficiency of Underground Pumped Storage Hydroelectricity plants using open pit mines
Pujades, Estanislao ULg; Bodeux, Sarah ULg; Orban, Philippe ULg et al

Poster (2016, September 27)

Underground Pumped Storage Hydropower (UPSH) plants can be used to manage the production of electrical energy according to the demand. These plants consist in two reservoirs, the upper one is located at ... [more ▼]

Underground Pumped Storage Hydropower (UPSH) plants can be used to manage the production of electrical energy according to the demand. These plants consist in two reservoirs, the upper one is located at the surface while the lower one is underground. The energy is stored by pumping water from the lower to the upper reservoir and produced by releasing water from the upper to the lower one. As a result, the hydraulic head in the lower reservoir varies continuously. UPSH plants interact with the surrounding aquifers exchanging groundwater. These groundwater exchanges, which play an important role in the evolution of the hydraulic head inside the underground reservoir, are a fact of concern in the selection of pumps and turbines because their efficiency varies with respect to the head difference between the two reservoirs. Therefore, the aquifer parameters should be considered in the selection of pumps and turbines. In this context, with an UPSH plant made up by an open pit mine, we study numerically (1) the influence of groundwater exchanges on the efficiency and (2) how the hydraulic head evolution varies depending on the aquifer properties. The relation among the groundwater exchanges, the efficiency of pumps and turbines and the aquifer parameters is considered by comparing the numerical results of several simulations. It is shown that groundwater exchanges are not negligible when optimizing the efficiency of UPSH plants. A priori, low hydraulic conductivity geological media were preferred to decrease interactions with the open-pit or the cavity used as lower reservoir. Taking into account the pump/turbine performance curves, it appears that, on the contrary, the global efficiency would be increased if the surrounding medium facilitates large groundwater exchanges because hydraulic head variations are softened. [less ▲]

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See detailClimatic and management drivers of CO2 exchanges by a production crop: Analysis over three successive 4-year crop rotation cycles
Buysse, Pauline ULg; Manise, Tanguy ULg; De Ligne, Anne ULg et al

Poster (2016, September 27)

Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and crop management drivers. The investigated crop, situated at the Lonzée Terrestrial Observatory (LTO ... [more ▼]

Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and crop management drivers. The investigated crop, situated at the Lonzée Terrestrial Observatory (LTO, candidate ICOS site) in Belgium and managed for more than 70 years using conventional farming practices, was monitored over three complete sugar beet/winter wheat/potato/winter wheat rotation cycles from 2004 to 2016. Continuous eddy-covariance measurements and regular biomass samplings were performed in order to obtain the daily and seasonal Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP), Total Ecosystem Respiration (TER), Net Primary Productivity (NPP), and Net Biome Production (NBP). Meteorological data and crop management practices were also recorded. Over the 12 years, NEE was negative (-4.34 kg C m-2) but NBP was positive (1.05 kg C m-2), i.e. as soon as carbon exportation by harvest and carbon importation (manure, slimes) are included in the budget, the site behaves as a carbon source. At the crop rotation scale (4 years) it was quite remarkable to observe that NBP was very similar over the three rotations (0.30-0.36 kg C m-2), despite climatic and management differences between years. Crop type impacted carbon exchanges, with sugar beet and winter wheat crops leading to higher net carbon sequestration than seed potato crops. For one given crop, larger growth length and cumulated global radiation drove larger cumulated NEE. Net carbon emissions were observed during intercrops, but growing mustard during these periods reduced their rates and provided carbon residues to the soil. NBP values suggest that one sixth of the total soil organic carbon stock at LTO (6.23 ± 0.16 kg C m-2 in [0, 60] cm) would be lost in 12 years. Large uncertainties (mostly due to biomass measurements) affect NBP estimates, but still, this figure is huge and should encourage cultural practices returning carbon to the soil. [less ▲]

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