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Last 7 days
Huy / Ben Ahin : sondage dans le "Grand Abri"Noiret, Pierre ; Flas, Damien ![]() in Chronique de l'Archéologie Wallonne (2013), 20 Detailed reference viewed: 7 (2 ULg) Retour au travail après une absence de longue durée : Comment dynamiser le dispositif légal existant ?Mairiaux, Philippe ![]() in DAVAGLE, MICHEL (Ed.) Le maintien au travail de travailleurs devenus partiellement inaptes (2013) Detailed reference viewed: 17 (5 ULg) Decorating a domus during the second triumvirate. Iconographical program of the Dwarfs’ oecus at Ostia Antica.Machowski, Mélanie ; Morard, Thomas ![]() Conference (2013) Detailed reference viewed: 1 (0 ULg) Possibilities and limitations of the Prevost model for the modelling of cohesionless soil cyclic behaviourCerfontaine, Benjamin ; Charlier, Robert ; Collin, Frédéric ![]() in Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering (2013) The Prevost’s model is currently used to model cyclic behaviour of soils especially in earthquake engineering. The original model is able to capture the main features of cyclic behaviour: pore pressure ... [more ▼] The Prevost’s model is currently used to model cyclic behaviour of soils especially in earthquake engineering. The original model is able to capture the main features of cyclic behaviour: pore pressure build up and plastic deformation accumulation. But accurate modelling of laboratory tests requires improvements. Enhanced models exist but require a lot of parameters that make them cumbersome for practical purpose. A suction caisson, part of a tripod offshore foundation for wind turbines is modelled. Possibilities of the Prevost’s model are highlighted compared with a classical Drucker-prager model. [less ▲] Detailed reference viewed: 5 (0 ULg) Is it worth protecting groundwater from diffuse pollution with agri-environmental schemes? A hydro-economic modeling approach Journal of Environmental Management; Orban, Philippe ; Brouyère, Serge ![]() in Journal of Environmental Management (2013) In Europe, 30% of groundwater bodies are considered to be at risk of not achieving the Water Framework Directive (WFD) ‘good status’ objective by 2015, and 45% are in doubt of doing so. Diffuse ... [more ▼] In Europe, 30% of groundwater bodies are considered to be at risk of not achieving the Water Framework Directive (WFD) ‘good status’ objective by 2015, and 45% are in doubt of doing so. Diffuse agricultural pollution is one of the main pressures affecting groundwater bodies. To tackle this problem, the WFD requires Member States to design and implement cost-effective programs of measures to achieve the ‘good status’ objective by 2027 at the latest. Hitherto, action plans have mainly consisted of promoting the adoption of Agri- Environmental Schemes (AES). This raises a number of questions concerning the effectiveness of such schemes for improving groundwater status, and the economic implications of their implementation. We propose a hydro-economic model that combines a hydrogeological model to simulate groundwater quality evolution with agronomic and economic components to assess the expected costs, effectiveness, and benefits of AES implementation. This hydro-economic model can be used to identify cost-effective AES combinations at groundwater-body scale and to show the benefits to be expected from the resulting improvement in groundwater quality. The model is applied here to a rural area encompassing the Hesbaye aquifer, a large chalk aquifer which supplies about 230,000 inhabitants in the city of Liege (Belgium) and is severely contaminated by agricultural nitrates. We show that the time frame within which improvements in the Hesbaye groundwater quality can be expected may be much longer than that required by the WFD. Current WFD programs based on AES may be inappropriate for achieving the ‘good status’ objective in the most productive agricultural areas, in particular because these schemes are insufficiently attractive. Achieving ‘good status’ by 2027 would demand a substantial change in the design of AES, involving costs that may not be offset by benefits in the case of chalk aquifers with long renewal times. [less ▲] Detailed reference viewed: 2 (0 ULg) Downscaling transient climate change with a stochastic weather generator for the Geer catchment, Belgium; ; et al in Climate Research (2013) The coarse resolution of climate models creates the need for future scenarios which are downscaled to an appropriate spatial scale. Considerable effort has been devoted to the development of downscaling ... [more ▼] The coarse resolution of climate models creates the need for future scenarios which are downscaled to an appropriate spatial scale. Considerable effort has been devoted to the development of downscaling methods but a number of important issues remain in the development of robust, usable climate scenarios. These include the incorporation of various sources of uncertainty into future scenarios and the production of scenarios at timescales relevant to planners. This paper describes a new procedure which addresses these issues by producing a multi-model ensemble of transient climate change scenarios. This method couples an existing stochastic rainfall model to a new, transient implementation of a weather generator, using changes projected by an ensemble of regional climate model (RCM) experiments. The methodology is demonstrated by the generation of transient scenarios of daily rainfall, temperature and potential evapotranspiration (PET) for the Geer catchment in Belgium for the period 2010 to 2085. The utility of these scenarios is demonstrated by assessing the changes projected by the simulated time series of several temperature indices. The Geer is projected to experience a decrease in the occurrence of frost days with a corresponding shortening of the frost season and lengthening of the growing season. By examining a large ensemble of transient scenarios the range of uncertainty in these projections is assessed, but further, it is suggested that additional information on the projected timing of specified threshold events or system responses may be provided which could aid planners in assessing the likely timescales of required interventions and adaptation responses. [less ▲] Detailed reference viewed: 10 (1 ULg) DMFSGD: A Decentralized Matrix Factorization Algorithm for Network Distance PredictionLiao, Yongjun ; ; Geurts, Pierre et alin IEEE/ACM Transactions on Networking (2013) The knowledge of end-to-end network distances is essential to many Internet applications. As active probing of all pairwise distances is infeasible in large-scale networks, a natural idea is to measure a ... [more ▼] The knowledge of end-to-end network distances is essential to many Internet applications. As active probing of all pairwise distances is infeasible in large-scale networks, a natural idea is to measure a few pairs and to predict the other ones without actually measuring them. This paper formulates the prediction problem as matrix completion where the unknown entries in a pairwise distance matrix constructed from a network are to be predicted. By assuming that the distance matrix has a low-rank characteristics, the problem is solvable by lowrank approximation based on matrix factorization. The new formulation circumvents the well-known drawbacks of existing approaches based on Euclidean embedding. A new algorithm, so-called Decentralized Matrix Factorization by Stochastic Gradient Descent (DMFSGD), is proposed. By letting network nodes exchange messages with each other, the algorithm is fully decentralized and only requires each node to collect and to process local measurements, with neither explicit matrix constructions nor special nodes such as landmarks and central servers. In addition, we compared comprehensively matrix factorization and Euclidean embedding to demonstrate the suitability of the former on network distance prediction. We further studied the incorporation of a robust loss function and of non-negativity constraints. Extensive experiments on various publicly-available datasets of network delays show not only the scalability and the accuracy of our approach, but also its usability in real Internet applications. [less ▲] Detailed reference viewed: 49 (11 ULg) Dietro, il paesaggio: Misura e ritmo di una strada tra le colline e il Piave.; ; Szanto, Catherine ![]() in Architettura del Mondo. Ricerche e progetti dal mondo universitario (2013) The Alta Marca Trevigiana (Colli del Piave), between Valdobbiadene and Conegliano, doesn't have a definite recognized identity, despite its strong visual character. However, for the visitor driving along ... [more ▼] The Alta Marca Trevigiana (Colli del Piave), between Valdobbiadene and Conegliano, doesn't have a definite recognized identity, despite its strong visual character. However, for the visitor driving along the “Sinistra Piave”, the landscape is seen as a rhythmical composition of invitation to movement at different scales and at various intensity, that can be compared to a musical composition. The question then is how to transform the road from a simple through-way into an occasion to engage with the Colli del Piave, to transform a “landscape scenery” into an “experienced landscape”. [less ▲] Detailed reference viewed: 15 (1 ULg) Lexique du Moyen Egyptien. Avec une introduction grammaticale et une liste des mots présentés selon le classificateur sémantique.Winand, Jean ; Stella, Alessandro ![]() Book published by PULg (2013) Detailed reference viewed: 58 (8 ULg) Milk and serum standard reference materials for monitoring organic contaminants in human samples; Eppe, Gauthier ; Focant, Jean-François et alin Analytical and Bioanalytical Chemistry (2013), 405 Detailed reference viewed: 22 (4 ULg) Appui scientifique à la mise en oeuvre et à l’entretien des méthodes agro-environnementales bandes de parcelles aménagées (MAE 9)Piqueray, Julien ; Gilliaux, Valentin ; Mahy, Grégory ![]() Report (2013) Detailed reference viewed: 2 (1 ULg) Etude histologique des embryons avortés lors des croisements entre Phaseolus vulgaris L. et Phaseolus coccineus L.; Toussaint, André ; Baudoin, Jean-Pierre ![]() in International Journal of Biological and Chemical Sciences (2013) Detailed reference viewed: 8 (0 ULg) Passive designs and strategies for low-cost housing using simulation-based optimization and different thermal comfort criteriaNguyen, Anh Tuan ; Reiter, Sigrid ![]() in Journal of Building Performance Simulation [=JBPS] (2013) An optimum design of low-cost housing offers low-income urban inhabitants great opportunities to obtain a shelter at an affordable price and acceptable indoor thermal conditions. In this paper, the design ... [more ▼] An optimum design of low-cost housing offers low-income urban inhabitants great opportunities to obtain a shelter at an affordable price and acceptable indoor thermal conditions. In this paper, the design and operation of a low-cost dwelling were numerically optimized using a simulation-based approach. Three multi-objective cost functions including construction cost, thermal comfort performance and 50-year operating cost were applied for naturally ventilated and air-conditioned buildings. Thermal environment inside the house was controlled and assessed by two thermal comfort models. Optimization problems which consist of 18 design parameters and 6 ventilation strategies were examined by two population-based probabilistic optimization algorithms (particle swarm optimization and hybrid algorithm). Optimum designs corresponding to each objective function, differences in optimal solutions, energy saving by the adaptive comfort approach and optimization effectiveness were outlined. The optimization method used in this paper shows a considerable potential of comfort improvement, energy saving and operating cost reduction. [less ▲] Detailed reference viewed: 18 (2 ULg) Associative memory in aging: The effect of unitization on source memoryBastin, Christine ; ; Simon, Jessica et alin Psychology & Aging (2013), 28(1), 275-283 In normal aging, memory for associations declines more than memory for individual items. Unitization is an encoding process defined by creation of a new single entity to represent a new arbitrary ... [more ▼] In normal aging, memory for associations declines more than memory for individual items. Unitization is an encoding process defined by creation of a new single entity to represent a new arbitrary association. The current study tested the hypothesis that age-related differences in associative memory can be reduced following encoding instructions that promote unitization. In two experiments, groups of 20 young and 20 older participants learned new associations between a word and a background color under two conditions. In the item detail condition, they had to imagine that the item is the same color as the background; an instruction promoting unitization of the associations. In the context detail condition, that did not promote unitization, they had to imagine that the item interacted with another colored object. At test, they had to retrieve the color that was associated to each word (source memory). In both experiments, the results showed an age-related decrement in source memory performance in the context detail but not in the item detail condition. Moreover, Experiment 2 examined receiver operating characteristics in older participants and indicated that familiarity contributed more to source memory performance in the item detail than in the context detail condition. These findings suggest that unitization of new associations can overcome the associative memory deficit observed in aging, at least for item-color associations. [less ▲] Detailed reference viewed: 41 (5 ULg) The impact of visual perceptual learning on sleep and local slow wave initiationMascetti, Laura ; Muto, Vincenzo ; et alin Journal of Neuroscience (2013) Detailed reference viewed: 35 (18 ULg) Impacts du changement climatique sur l’hydrologie et la gestion des ressources en eau du bassin de la Meuse : une synthèseBauwens, Alexandra ; Sohier, Catherine ; Degré, Aurore ![]() in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(1), 76-86 Detailed reference viewed: 42 (11 ULg) First retrievals of HCFC-142b from ground-based high resolution FTIR solar observations: application to high altitude Jungfraujoch spectraMahieu, Emmanuel ; ; et alin Geophysical Research Abstracts (2013), 15 Hydrofluorocarbons (HCFCs) are the first substitutes to the long-lived ozone depleting halocarbons, in particular the chlorofluorocarbons (CFCs). Given the complete ban of the CFCs by the Montreal ... [more ▼] Hydrofluorocarbons (HCFCs) are the first substitutes to the long-lived ozone depleting halocarbons, in particular the chlorofluorocarbons (CFCs). Given the complete ban of the CFCs by the Montreal Protocol, its Amendments and Adjustments, HCFCs are on the rise, with current rates of increase substantially larger than at the beginning of the 21st century. HCFC-142b (CH3CClF2) is presently the second most abundant HCFC, after HCFC-22 (CHClF2). It is used in a wide range of applications, including as a blowing foam agent, in refrigeration and air-conditioning. Its concentration will soon reach 25 ppt in the northern hemisphere, with mixing ratios increasing at about 1.1 ppt/yr [Montzka et al., 2011]. The HCFC-142b lifetime is estimated at 18 years. With a global warming potential of 2310 on a 100-yr horizon, this species is also a potent greenhouse gas [Forster et al., 2007]. First space-based retrievals of HCFC-142b have been reported by Dufour et al. [2005]. 17 occultations recorded in 2004 by the Canadian ACE-FTS instrument (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer, onboard SCISAT-1) were analyzed, using two microwindows (1132.5–1135.5 and 1191.5–1195.5 cm-1). In 2009, Rinsland et al. determined the HCFC-142b trend near the tropopause, from the analysis of ACE-FTS observations recorded over the 2004–2008 time period. The spectral region used in this study extended from 903 to 905.5 cm-1. In this contribution, we will present the first HCFC-142b measurements from ground-based high-resolution Fourier Transform Infrared (FTIR) solar spectra. We use observations recorded at the high altitude station of the Jungfraujoch (46.5°N, 8°E, 3580 m asl), with a Bruker 120HR instrument, in the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, visit http://www.ndacc.org). The retrieval of HCFC-142b is very challenging, with simulations indicating only weak absorptions, lower than 1% for low sun spectra and current concentrations. Among the four microwindows tested, the region extending from 900 to 906 cm-1 proved to be the most appropriate, with limited interferences, in particular from water vapor. A total column time series spanning the 2004-2012 time period will be presented, analyzed and critically discussed. After conversion of our total columns to concentrations, we will compare our results with in situ measurements performed in the northern hemisphere by the AGAGE network. [less ▲] Detailed reference viewed: 31 (8 ULg) L'équilibre des rations alimentaires des bovins: Quelques pistes pour améliorer l'efficience azotée ?Beckers, Yves ![]() in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(SPL1), 243-250 The main aim of this paper was to present some feeding recommendations, which, when applied on the farm, would increase nitrogen use by bovines and to give information as to how the effects of the ... [more ▼] The main aim of this paper was to present some feeding recommendations, which, when applied on the farm, would increase nitrogen use by bovines and to give information as to how the effects of the nitrogen produced can be reduced. Ruminants have the ability to digest structural carbohydrates and to produce meat and milk proteins for human consumption. At the animal cells level, amino acids are essential for biological functions, mainly involving their maintenance and production. These amino acids are supplied by the intestinal digestion of microbial protein and feed protein that escapes microbial degradation in the rumen. Today, the efficiency of nitrogen utilization is typically low and highly variable in ruminants. Nitrogen excretion by ruminants mainly depends on the level of nitrogen intake and of the animal's productivity. Optimal N utilization may be achieved through an understanding of the key mechanisms involved in the control of N digestion and metabolism. These include the efficiency of N capture in the rumen and the protein degradation according to the type of diet and forage, the control of the rumen microorganisms involved in protein degradation and the proper formulation of the diet, avoiding feeding excess protein in relation to requirements. The dependence on energy supply in transferring feed nitrogen into milk and meat protein is strong both at the rumen and the cell levels of ruminants. The rumen metabolism is identified as the single most important factor contributing to the low level of efficient use of nitrogen in ruminants and partially depends on practical farming operations. [less ▲] Detailed reference viewed: 16 (5 ULg) Analysis of mainstream tobacco smoke particulate phase using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometryBrokl, Michal ; ; et alin Journal of Separation Science (2013), 31 In tobacco research, the comparison of different tobacco blends as well as the puffdependent <br />behaviour of cigarettes is a matter of particular interest. For the investigation <br />of smoke ... [more ▼] In tobacco research, the comparison of different tobacco blends as well as the puffdependent <br />behaviour of cigarettes is a matter of particular interest. For the investigation <br />of smoke characteristics, GC6GC offers different ways for data analysis, <br />namely, compound target analysis, automated peak-based compound classification <br />and comprehensive pixel-based data analysis. This study will show the application <br />as well as the pros and cons of these types of data analysis for very complex matrices <br />like cigarette particulate matter. In addition, new aspects about the recently discovered <br />puff-dependent behaviour of compounds in cigarette smoke will be presented. <br />Automated peak-based compound classification including mass spectrometric pattern <br />recognition is used for the classification of tobacco particulate matter samples <br />and the puff-dependent investigation of different compound classes. This compound <br />group specific analysis is further reinforced by applying an even more comprehensive <br />pixel-based analysis. This kind of analysis is used to generate fingerprints of <br />different types of cigarettes. The combination of fast feature reduction methods like <br />analysis of variance (ANOVA) and t-test with multivariate feature transformation <br />methods like partial least squares discriminate analysis (PLSDA) for feature selection <br />provides a powerful tool for a detailed inspection of different types of cigarettes. [less ▲] Detailed reference viewed: 34 (11 ULg) Assessment of the functional role of tree diversity: the multi-site FORBIO experiment; ; et al in Plant Ecology and Evolution (2013), 146(1), 26-35 Context – During the last two decades, functional biodiversity research has provided strong support for the hypothesis that more biodiverse ecosystems have the potential to deliver more and better ... [more ▼] Context – During the last two decades, functional biodiversity research has provided strong support for the hypothesis that more biodiverse ecosystems have the potential to deliver more and better services. However, most empirical support for this hypothesis comes from simple structured communities that are relatively easy to manipulate. The impact of forest biodiversity on forest ecosystem functioning has been far less studied. Experiment design – In this paper, we present the recently established, large-scale FORBIO experiment (FORest BIOdiversity and Ecosystem Functioning), specifically designed to test the effects of tree species diversity on forest ecosystem functioning. FORBIO’s design matches with that of the few other tree diversity experiments worldwide, but at the same time, the FORBIO experiment is unique as it consists of a similar experimental set-up at three sites in Belgium (Zedelgem, Hechtel-Eksel and Gedinne) with contrasting edaphic and climatological c haracteristics. This design will help to provide answers to one of the most interesting unresolved questions in functional biodiversity research, notably whether the effects of complementarity on ecosystem functioning decrease in less stressful and more productive environments. At each site, FORBIO consists of 41 to 44 plots (127 plots in total) planted with monocultures and mixtures up to four species, selected from a pool of five site-adapted, functionally different tree species. When allocating the treatments to the plots, we maximally avoided any possible covariation between environmental factors. Monitoring of ecosystem functioning already started at the Zedelgem and Gedinne sites and will start soon in Hechtel-Eksel. Multiple processes are being measured and as the trees grow older, we plan to add even more processes. Expected results – Not only basic science, but also forest management will benefit from the results coming from the FORBIO experiment, as FORBIO is, for instance, also a test case for uncommon, not well-known tree species mixtures. To conclude, FORBIO is an important ecosystem experiment that has the potential to deliver badly needed insights into the multiple relationships between biodiversity and ecosystem functioning, which will be valuable for both science and practice. [less ▲] Detailed reference viewed: 13 (2 ULg) |
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