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See detailEmission and oxidation of methane in a meromictic, eutrophic and temperate lake (Dendre, Belgium)
Roland, Fleur ULg; Darchambeau, François ULg; Morana, Cédric ULg et al

in Chemosphere (2017)

We sampled the water column of the Dendre stone pit lake (Belgium) in spring, summer, autumn and winter. Depth profiles of several physico-chemical variables, nutrients, dissolved gases (CO2, CH4, N2O ... [more ▼]

We sampled the water column of the Dendre stone pit lake (Belgium) in spring, summer, autumn and winter. Depth profiles of several physico-chemical variables, nutrients, dissolved gases (CO2, CH4, N2O), sulfate, sulfide, iron and manganese concentrations and d13C-CH4 were determined. We performed incubation experiments to quantify CH4 oxidation rates, with a focus on anaerobic CH4 oxidation (AOM), without and with an inhibitor of sulfate reduction (molybdate). The evolution of nitrate and sulfate concentrations during the incubations was monitored. The water column was anoxic below 20 m throughout the year, and was thermally stratified in summer and autumn. High partial pressure of CO2 and CH4 and high concentrations of ammonium and phosphate were observed in anoxic waters. Important nitrous oxide and nitrate concentration maxima were also observed (up to 440 nmol L- 1 and 80 mmol L -1, respectively). Vertical profiles of d13C-CH4 unambiguously showed the occurrence of AOM. Important AOM rates (up to 14 mmol L -1 d- 1) were observed and often co-occurred with nitrate consumption peaks, suggesting the occurrence of AOM coupled with nitrate reduction. AOM coupled with sulfate reduction also occurred, since AOM rates tended to be lower when molybdate was added. CH4 oxidation was mostly aerobic (~80% of total oxidation) in spring and winter, and almost exclusively anaerobic in summer and autumn. Despite important CH4 oxidation rates, the estimated CH4 fluxes from the water surface to the atmosphere were high (mean of 732 mmol m- 2 d- 1 in spring, summer and autumn, and up to 12,482 mmol m- 2 d- 1 in winter). [less ▲]

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See detailThermal Conductivity of Straw Bales: Full Size Measurements Considering the Direction of the Heat Flow
Costes, Jean-Philippe; Evrard, Arnaud; Biot, Benjamin et al

in Buildings (2017), 7(11), 1-15

The thermal conductivity of straw bales is an intensively discussed topic in the international straw bale community. Straw bales are, by nature, highly heterogeneous and porous. They can have a relatively ... [more ▼]

The thermal conductivity of straw bales is an intensively discussed topic in the international straw bale community. Straw bales are, by nature, highly heterogeneous and porous. They can have a relatively large range of density and the baling process can influence the way the fibres are organised within the bale. In addition, straw bales have a larger thickness than most of the insulating materials that can be found in the building industry. Measurement apparatus is usually not designed for such thicknesses, and most of the thermal conductivity values that can be found in the literature are defined based on samples in which the straw bales are resized. During this operation, the orientation of the fibres and the density may not be preserved. This paper starts with a literature review of straw bale thermal conductivity measurements and presents a measuring campaign performed with a specific Guarded Hot Plate, designed to measure samples up to 50 cm thick. The influence of the density is discussed thoroughly. Representative values are proposed for a large range of straw bales to support straw-bale development in the building industry. [less ▲]

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See detailLibération conditionnelle
Bastard, Joséphine ULg

in Les mots de la Justice - Recht Spraak (2017)

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See detailRéinsertion
Bastard, Joséphine ULg

in Les mots de la Justice - Recht Spraak (2017)

L'ouvrage propose un regard sur les expériences de la Justice belge, dans une perspective de vulgarisation. La "réinsertion" désigne l’idée du retour à la société de ceux qui en ont été exclus par ... [more ▼]

L'ouvrage propose un regard sur les expériences de la Justice belge, dans une perspective de vulgarisation. La "réinsertion" désigne l’idée du retour à la société de ceux qui en ont été exclus par l’incarcération. Définir la réinsertion est pourtant complexe car la notion recouvre différentes dimensions. [less ▲]

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See detailDroit matériel européen - plan de cours 2017
Van Cleynenbreugel, Pieter ULg

Learning material (2017)

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See detailLe droit à des élections libres et Internet
Bouhon, Frédéric ULg

in Van Enis, Quentin; De Terwangne, Cécile (Eds.) L'Europe des droits de l'homme à l'heure d'Internet (2017)

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See detailMacroevolution of Specificity in Cyanolichens of the Genus Peltigera Section Polydactylon (Lecanoromycetes, Ascomycota)
Magain, Nicolas ULg; Miadlikoswka, Jolanta; Goffinet, Bernard et al

in Systematic Biology (2017), 66(1), 74-99

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See detailOn the Dynamics of the Deployment of Renewable Energy Production Capacities
Fonteneau, Raphaël ULg; Ernst, Damien ULg

in Furze, James N.; Swing, Kelly; Gupta, Anil K. (Eds.) et al Mathematical Advances Towards Sustainable Environmental Systems (2017)

This chapter falls within the context of modeling the deployment of renewable en-ergy production capacities in the scope of the energy transition. This problem is addressed from an energy point of view, i ... [more ▼]

This chapter falls within the context of modeling the deployment of renewable en-ergy production capacities in the scope of the energy transition. This problem is addressed from an energy point of view, i.e. the deployment of technologies is seen as an energy investment under the constraint that an initial budget of non-renewable energy is provided. Using the Energy Return on Energy Investment (ERoEI) characteristics of technologies, we propose MODERN, a discrete-time formalization of the deployment of renewable energy production capacities. Be-sides showing the influence of the ERoEI parameter, the model also underlines the potential benefits of designing control strategies for optimizing the deployment of production capacities, and the necessity to increase energy efficiency. [less ▲]

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See detailDrought, conflict and children’s undernutrition in Ethiopia 2000–2013: a meta-analysis
Delbiso, Tefera Darge; Rodriguez-Llanes, Jose Manuel; Donneau, Anne-Françoise ULg et al

in Bulletin of the World Health Organization (2017), 95

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See detailCorn stover as feedstock for the production of ethanol: chemical composition of different anatomical fractions and varieties
Berchem, Thomas ULg; Roiseux, Olivier; Vanderghem, Caroline et al

in Biofuels, Bioproducts and Biorefining (2017)

The available grain corn stover produced in Belgium is estimated at 290 000 dry tons, a suffi cient amount to supply a biorefi nery. Differences regarding size, prematurity, and drying speed have been ... [more ▼]

The available grain corn stover produced in Belgium is estimated at 290 000 dry tons, a suffi cient amount to supply a biorefi nery. Differences regarding size, prematurity, and drying speed have been observed among the cultivated grain corn varieties in Wallonia (Belgium). This study aims to evaluate the variation in composition of different anatomical fractions (stalks, leaves, cobs, and husks) of three Walloon varieties of grain corn stover (SyMultitop, Padrino, and Alduna) with significant production volumes. In addition, the Padrino variety was assessed for variation in chemical composition at three harvesting times. Walloon grain corn stover contains large amounts of polysaccharides (33.4% to 41.3% of glucans and 13.9% to 28.2% of xylans) and lignin (10.4% to 15.3%). Some différences were noted between varieties and anatomical fractions. Depending on how the feedstock is harvested, it is possible to produce between 79 and 81 M liters of ethanol per year without adversely affecting soil sustainability. [less ▲]

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See detailSedimentologic and paleoclimatic reconstructions of carbonate factory evolution in the Alborz Basin (northern Iran) indicate a global response to Early Carboniferous (Tournaisian) glaciations
Sardar Abadi, Mehrdad; Kulagina, E.; Voeten, D.F.A.E. et al

in Sedimentary Geology (2017), 348

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See detailPour une sémiotique des pratiques émergentes, ou: à quoi pense un médium?
Badir, Sémir ULg; Provenzano, François ULg

in Badir, Sémir; Provenzano, François (Eds.) Pratiques émergentes et pensée du médium (2017)

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See detailPratiques émergentes et pensée du médium
Badir, Sémir ULg; Provenzano, François ULg

Book published by Academia-L'Harmattan (2017)

Qu’y a-t-il de commun entre le street art, les mooc ou les forums médicaux en ligne ? Il s’agit, dans tous les cas, de pratiques culturelles qui dépendent fortement des techniques qui en soutiennent ... [more ▼]

Qu’y a-t-il de commun entre le street art, les mooc ou les forums médicaux en ligne ? Il s’agit, dans tous les cas, de pratiques culturelles qui dépendent fortement des techniques qui en soutiennent l’émergence dans l’espace public. Le projet du présent volume est d’interroger ces pratiques émergentes pour la pensée médiatique qu’elles délivrent. La perspective d’analyse est sémiotique et se décline à travers une série d’études de cas qui cartographient notre imaginaire culturel contemporain. [less ▲]

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See detailAssessment of landslide hazard in the environmental hotspot areas of the Kyrgyz Tien-Shan: Spatial analysis and Numeric modelling
Torgoev, Almazbek ULg

Doctoral thesis (2017)

This PhD research was initiated in parallel with the Nato Science for Peace project “Prevention of Landslide Dam Disasters in the Tien Shan, Kyrgyz Republic”. During this project a large amount of ... [more ▼]

This PhD research was initiated in parallel with the Nato Science for Peace project “Prevention of Landslide Dam Disasters in the Tien Shan, Kyrgyz Republic”. During this project a large amount of thematic data on slope instabilities and landslide dams in the Kyrgyz Tien-Shan was collected. The thesis uses this information to investigate applied and fundamental aspects of the regional mapping of the landslide susceptibility, hazard and, partially, risk. The target areas selected for the PhD research are the Mailuu-Suu River Valley (southern Kyrgyzstan) and the surroundings of the Minkush settlement (central Kyrgyzstan). They represent the areas of former uranium mining hosting numerous storage sites of tailing material and waste rock. Additionally, these areas are characterised by a high level of landslide activity induced by the human and environmental impacts. The landslides in those areas present a high risk to the society and infrastructure, potentially triggering serious environmental consequences. Structurally, the thesis is composed of two parts: Part A and Part B. These parts are different both with respect to the research methodology and the scientific targets. The common goal of both parts is the development effective techniques to regionally assess landslide hazard in mountainous areas marked by complex geomorphological, tectonic and geological settings. Due to the remote access, such areas are often lacking background information and in-situ data that are required for the precise prediction of landslide occurrence and impacts. In such cases the spatial analysis often helps to better characterise regional and, partly, local landslide susceptibility. The regional studies allow us to outline the basic relationships between affecting factors and landslide occurrence. Such results also become the basis for effective planning of in-situ investigations and localised measurements. Part A of thesis is focused on the applied aspects of spatial analysis. This part assembles a set of the well-established approaches and methods to model landslide susceptibility, hazard and risk. The studies start with the compilation of database spatially combining various thematic information. The first type of such thematic data is represented by the multi-temporal landslide inventories. These inventories are extracted applying different sources of remote sensing data, including the satellite and aerial imagery. The second type of thematic data describes the spatial distribution of factors affecting the level of landslide activity. The mapping of affecting factors is performed by applying conventional remote sensing techniques and spatial analysis tools. The collected thematic data are then used to extract the landslide susceptibility, hazard and risk maps. In total, four conceptually different approaches are applied to map the landslide susceptibility, both on a qualitative and quantitative basis. The results of the quantitative susceptibility mapping and thematic data are further used to calculate the landslide hazard for each part of the studied area. The calculated landslide hazard is characterized both by spatial and temporal components. The results of the landslide hazard assessment are finally used to estimate the risk of the direct impacts of landslides on selected exposed elements, including the uranium tailings sites. One of the well-established approaches used in Part A is the Newmark method. It maps the seismically triggered landslide susceptibility based on the computed co-seismic displacements. The simplicity of this method is attractive to many researches around the world studying seismically-triggered landslide hazards. Nevertheless, the simplifications adopted in this method strongly limit the reliability of the final predictions. In the second part of thesis we provide a critical overview of the Newmark method and attempt to propose conceptual improvements of the existing mapping practice. To reach the targeted challenges we combine the spatial analysis with the dynamic simulations in the 2D and 3D domains. The studied models represent the actual topographic and geologic settings of the landslide-prone slopes. The simulations provide acceleration time histories that are recorded in different parts of the model surface. The analyses of these records allow us to outline the amplification impacts related to the topographic and geological site effects. The modelled amplification factors are analysed with respect to their link to the local geological and topographic settings. Thus, we study how the structural or material settings of the model can impact the recorded geological amplification. Such impacting parameters can be represented by the layer thickness, inclination of the underground contacts or the contrast of the shear wave velocity (Vs) values. The 2D topographic modelling investigates the way how the pure topographic amplification factors can be predicted based on the surface morphology. The studies show that the surface curvature can be considered as a key parameter to predict the amplification factors. This idea is further investigated in the 3D modelling studies applying different input signals and the materials of varying Vs. The results of this modelling are integrated into a single database which is subjected to spatial analysis. This finally allows us to develop a simple proxy which maps the impacts of the topographic site effects based on morphological parameters extracted from the Digital Elevation Model of the target area. Additionally, the subset of the 2D dynamic tests analyses the shear displacements triggered by the seismic shaking. Those displacements are recorded in the models with simplified geometry, as well as in the ones presenting the real topographic settings. The recorded displacements are cross-correlated with parameters characterising the seismic impacts. The results of analyses allow us to develop a new law which can easily be used in the GIS-based studies. The proposed law applies a set of the conventional parameters as well as a novel predictor which has never been used by any regional law before.The conceptual improvements proposed in Part B are finally tested by applying them to the geodatabase compiled in the first part of thesis. Related results are then compared with those that were produced by using the conventional Newmark method. The validation tests should assess performance of the developed proxies to improve the predictions of seismically-triggered landslides. [less ▲]

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See detailEnhanced silicate weathering of tropical shelf sediments exposed during glacial lowstands: a sink for atmospheric CO2
Wan, Shiming; Clift, Peter D.; Zhao, Debo et al

in Geochimica et Cosmochimica Acta (2017), 200

Atmospheric CO2 and global climate are closely coupled. Since 800 ka CO2 concentrations have been up to 50% higher during interglacial compared to glacial periods. Because of its dependence on temperature ... [more ▼]

Atmospheric CO2 and global climate are closely coupled. Since 800 ka CO2 concentrations have been up to 50% higher during interglacial compared to glacial periods. Because of its dependence on temperature, humidity, and erosion rates, chemical weathering of exposed silicate minerals was suggested to have dampened these cyclic variations of atmospheric composition. Cooler and drier conditions and lower non-glacial erosion rates suppressed in situ chemical weathering rates during glacial periods. However, using systematic variations in major element geochemistry, Sr-Nd isotopes and clay mineral records from Ocean Drilling Program Sites 1143 and 1144 in the South China Sea spanning the last 1.1 Ma, we show that sediment deposited during glacial periods was more weathered than sediment delivered during interglacials. We attribute this to subaerial exposure and weathering of unconsolidated shelf sediments during glacial sealevel lowstands. Our estimates suggest that enhanced silicate weathering of tropical shelf sediments exposed during glacial lowstands can account for ~9% of the carbon dioxide removed from the atmosphere during the glacial and thus represent a significant part of the observed glacial-interglacial variation of ~80 ppmv. As a result, if similar magnitudes can be identified in other tropical shelf-slope systems, the effects of increased sediment exposure and subsequent silicate weathering during lowstands could have potentially enhanced the drawdown of atmospheric CO2 during cold stages of the Quaternary. This in turn would have caused an intensification of glacial cycles. We attribute this to subaerial exposure and weathering of unconsolidated shelf sediments during glacial sealevel lowstands. Our estimates suggest that enhanced silicate weathering of tropical shelf sediments exposed during glacial lowstands can account for ~9% of the carbon dioxide removed from the atmosphere during the glacial and thus represent a significant part of the observed glacial-interglacial variation of ~80 ppmv. As a result, if similar magnitudes can be identified in other tropical shelf-slope systems, the effects of increased sediment exposure and subsequent silicate weathering during lowstands could have potentially enhanced the drawdown of atmospheric CO2 during cold stages of the Quaternary. This in turn would have caused an intensification of glacial cycles. [less ▲]

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See detailInstances for the 3D Multiple Bin Size Bin Packing Problem
Paquay, Célia ULg; Limbourg, Sabine ULg; Schyns, Michael ULg

Textual, factual or bibliographical database (2017)

The subject of this work is to solve the problem of packing a set of shipments (various cuboid boxes) into containers of various shapes without wasting loading space. All the boxes have to be loaded and ... [more ▼]

The subject of this work is to solve the problem of packing a set of shipments (various cuboid boxes) into containers of various shapes without wasting loading space. All the boxes have to be loaded and few are identical. As it is the case for all the packing problems, the packing has to satisfy geometry constraints: the items cannot overlap and have to lie entirely inside the bins. The richness of our application is to manage additional and common constraints: the bin weight capacity, the rotations of the boxes, the stability and the fragility of the boxes and the uniformity of the weight distribution inside the ULDs. The last constraint is crucial in air transportation: when ULDs are packed inside the airplane, the centre of gravity is computed assuming each ULD has a centre of gravity close to the geometrical centre of its basis. This type of constraints can be adapted to road transportation for the axle weight limits, which plays a key role since the weigh-in-motion systems become more common. [less ▲]

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See detailSystématiser les associations. Le concept hjelmslévien de paradigme et son héritage greimassien
Badir, Sémir ULg; Cigana, Lorenzo ULg

in Signata. Annales des Sémiotiques = Annals of Semiotics (2017), 8

This paper aims to explore the notion of “paradigm” by following its development in the epistemology of linguistics and semiotics of the twentieth century through three landmarks: its first use within ... [more ▼]

This paper aims to explore the notion of “paradigm” by following its development in the epistemology of linguistics and semiotics of the twentieth century through three landmarks: its first use within linguistics, by Ferdinand de Saussure, its redefinition by Louis Hjelmslev, and its reinterpretation in textual semiotics by Algirdas J. Greimas. The concept of “paradigm” represents, more than others, the very target of structuralist theorisation. Marking the transition between openness and closeness of linguistic categories, it crystallises the structuralist ambition to bring the dynamic variability and richness of semiotic phenomena back to a closed, or at least stable, inventory of functional ground elements. [less ▲]

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