62 research outputs found

    Evaluation of electrothermal vaporization for sample introduction aiming at Cu isotopic analysis via multicollector-inductively coupled plasma mass spectrometry

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    A new method for Cu isotopic analysis was developed using a commercially available electrothermal vaporization (ETV) device coupled to multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). The method demonstrated potential for the isotopic analysis of microsamples (e.g., 5 mu L) in a biological context. For example, Cu isotopic analysis of NIST 3114 (diluted to 1 mg L-1 Cu) using self-bracketing provided average delta Cu-65 values of 0.00 +/- 0.17%0 (2SD, n = 10) and internal precision values of 712 ppm. In order to achieve this level of accuracy and precision, it is critical to properly deal with the short transient signals generated by the ETV-MC-ICP-MS, which implies using point by point calculations and time lag detector correction (TDC), as well as a criterion to reject potential outliers. The results of this technique were compared with the results obtained via femtosecond-laser ablation-MC-ICPMS using the same pre-treated serum samples. No significant differences were observed among the results obtained in both cases, while external precision was 0.26%0 for ETV-MC-ICP-MS and 0.24%0 for fs-LA-MC-ICP-MS, expressed as median value of 2SD (n = 27), further proving the usefulness of the approach proposed in this context, as the use of ETV results in a more straightforward approach

    Initial modelled outputs at field scale

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    This report comprises Deliverable 6.16 in the project, which contributes to the third objective as it presents field-scale evaluation of innovations, in order to adapt and evaluate agroforestry designs and practices for locations where agroforestry is currently not-widely practised or declining. The modelling of outputs at field scale to support best agroforestry practices is an ongoing activity during the AGFORWARD project. This report highlights some of the outputs which has been produced in the form of three papers (either submitted or about to be submitted to a peer-reviewed journal) or in four presentations at the Third European Agroforestry Conference in May 2016N/

    DynACof, a model fro growth, yield, carbon, water, energy balances and ecosystem services of Coffea in agroforestry

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    Agroforestry systems (AFS) are complex to model mainly due to the high spatial variability induced by the shade trees. Recently, the microclimate and lighf heterogeneity issue in AFS has been addressed using the 30 ecophysiological process-based model MAESPA (Charbonnier et al., 2013; Vezy et al., 2018). MAESPA surpassed the classical sun/shade dichotomy in AFS (Charbonnier et al., 2014) and provided continuous maps of e.g. available light, light-use~ fficiency and canopy temperature within Coffea Agroforestry Systems (GAS). A step further was to design a crop model for Coffea grown under agroforestry that would benefit from this continuum to estimate ecosystem services on the long term and under climate change scenarios. We designed DynA_Cof, a new process-based growth and yield model to compute plot-scale net and gross primary productivity, carbon allocation, growth, yield, energy, and water balance of GAS according to shade tree species and management, while accounting for fine-scale spatial effects using MAESPA metamodels (Figure 1). DynA_Cof satisfactorily simulated the daily plot-scale gross primary productivity (RMSE= 1.69 gc m-2 d-1 on 1562 days) and the energy and water balances (RMSE: AET = 0.63 mm d-1 , H= 1.27 MJ m-2 d-1, Rn= 1.98 MJ m-2 d-1) compared to measurements from an eddy-flux tower in Aquiares (Costa Rica) and also the NPP for above and below-ground organs, coffee bean yield and shade tree wood production compared to a comprehensive database from this site

    Discrepancy-based method for hierarchical distributed optimization

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    Negotiation-based distributed wood procurement planning within a multi-firm environment

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    The complex task of wood procurement planning includes a multitude of factors that must be taken into consideration. Shared procurement areas and co-production further complicate the task, elements which typify the eastern Canadian forest industry. A procurement forester must routinely coordinate and synchronize forest operations with those of other companies over several procurement areas. In a multi-firm context, collaboration cannot be taken for granted and decision-making power cannot be centralized. First, this paper presents a formalization of firms' procurement interdependence in a context of shared procurement areas and co-production. A planning and coordination approach is then presented for the context under study. Four different planning and coordination modes are tested, including a central planning mode used as a benchmark (i.e., upper bound). Statistics on profitability and timber license fulfillment are gathered. Pair wise comparisons among the different modes are performed and profitability gains from greater coordination within and among firms are quantified. The proposed collaborative planning and coordination mode results in local and global profitability increases, especially in difficult economic setting, when compared to the planning and inter-firm coordination approach currently in use.Wood procurement planning Inter-firm coordination Negotiation Agent-based system Operations research
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