Surface Ocean CO2 Atlas (SOCAT) gridded data products

in Earth System Science Data (2013), 5(1), 145-153

As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community ... [more ▼]

As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community developed the Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is a collection of 6.3 million quality controlled surface CO2 data from the global oceans and coastal seas, spanning four decades (1968–2007). The SOCAT gridded data presented here is the second data product to come from the SOCAT project. Recognizing that some groups may have trouble working with millions of measurements, the SOCAT gridded product was generated to provide a robust, regularly spaced CO2 fugacity (fCO2) product with minimal spatial and temporal interpolation, which should be easier to work with for many applications. Gridded SOCAT is rich with information that has not been fully explored yet (e.g., regional differences in the seasonal cycles), but also contains biases and limitations that the user needs to recognize and address (e.g., local influences on values in some coastal regions). [less ▲]

Importance of LUC and ILUC on the carbon footprint of bioproduct:case of bio-HDPE

Conference (2013)

Due to the depletion of fossil fuels and the increase of greenhouse gas emissions, solutions are needed to replace petrol based products. As a consequence, the number of biobased products developed using ... [more ▼]

Due to the depletion of fossil fuels and the increase of greenhouse gas emissions, solutions are needed to replace petrol based products. As a consequence, the number of biobased products developed using agricultural feedstock is continuously increasing. This study focuses on the carbon footprint of bio-HDPE produced either from Brazilian sugar cane or Belgian sugar beet. The goal of this study is to compare the carbon footprint of bio-HDPE with the fossil one, taking into account the effect of land use change. Common boundaries of the agricultural systems comprise the cultivation step for both crops, i.e. sugar cane and sugar beet, with all associated energy and fertilizer consumptions, the transportation step from field to the industrial plant, the sugar crops transformation into hydrate bioethanol, the by-products valorisation, the dehydration and polymerization steps and the HDPE incineration as end of life issue. Fossil scenario includes the production of ethylene, its polymerization and its incineration. When comparing the entire life cycle of bio and fossil HDPE, the GHG emissions are lower for the biobased product which is the willing effect. This result is only valid if no Land Use Change (LUC) or Indirect Land Use Change (ILUC) effect appears. To assess the environmental impact of the deforestation or of the transformation of a pasture into a field, the EC-Guidelines from the European Union were used in order to calculate the CO2 emissions depending on several parameters. For sugar cane, LUC consists in the transformation of pastures into fields in the region of Sao Paulo in Brazil. Three scenarios can be developed based on different agricultural practices for pasture and field (tillage and fertilizers inputs): the best, the worst and the average. The best case leads to a supplementary environmental gain. The worst and average achieve additional emissions. A payback time, considering the time needed to find again an environmental gain compared to the fossil counterpart, was calculated for the average scenario which is equal to 12 years. The ILUC effect for sugar cane is assumed to be deforestation due to the transformation of forest into pasture induced by the previous LUC effect. The rate of deforestation can vary between 16% or 100% depending on used statistics and leads to a payback time of respectively 26 and 101 years. For sugar beet, no LUC is considered. Indeed, no land expansion is available in Belgium due to small available areas. In the case of an increase of bioplastics production, Belgium should import sugar beet from neighboring countries which can induce ILUC. In this study, sugar beet is assumed to be provided by the Netherlands on pastures previously transformed into fields. The average scenario implies a payback time of 8 years. This study permits to highlight the importance of LUC and ILUC especially for energetic crops dedicated to replace fossil products. This effect can reverse expected results and induce long payback times. [less ▲]

Huy / Ben Ahin : sondage dans le "Grand Abri"

in Chronique de l'Archéologie Wallonne (2013), 20

Decorating a domus during the second triumvirate. Iconographical program of the Dwarfs’ oecus at Ostia Antica.

Conference (2013)

Is it worth protecting groundwater from diffuse pollution with agri-environmental schemes? A hydro-economic modeling approach Journal of Environmental Management

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 ▲]

DMFSGD: A Decentralized Matrix Factorization Algorithm for Network Distance Prediction

in 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 ▲]

Lexique du Moyen Egyptien. Avec une introduction grammaticale et une liste des mots présentés selon le classificateur sémantique.

Book published by PULg (2013)

Appui scientifique à la mise en oeuvre et à l’entretien des méthodes agro-environnementales bandes de parcelles aménagées (MAE 9)

Report (2013)

Passive designs and strategies for low-cost housing using simulation-based optimization and different thermal comfort criteria

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 ▲]

The impact of visual perceptual learning on sleep and local slow wave initiation

in Journal of Neuroscience (2013)