Fully inverse parametric linear/quadratic programming problems via convex liftings

International audiencen this chapter, we present in an unified manner the latest developments on inverse optimality problem for continuous piecewise affine (PWA) functions. A particular attention is given to convex liftings as a cornerstone for the constructive solution we advocate in this framework. Subsequently, an algorithm based on convex lifting is presented for recovering a continuous PWA function defined over a polyhedral partition of a polyhedron. We also prove that any continuous PWA function can be equivalently obtained by a parametric linear programming problem with at most one auxiliary one-dimensional variable

GEMAS: adaptation of weathering indices for European agricultural soil derived from carbonate parent materials

Carbonate rocks are very soluble and export elements in dissolved form, and precipitation of secondary phases can occur on a large scale. They leave a strong chemical signature in soil that can be quantified and classified by geochemical indices, and which is useful for evaluating chemical weathering trends (e.g. the Chemical Index of Alteration (CIA) or the Mafic Index of Alteration (MIA)). Due to contrasting chemical compositions and high Ca content, a special adaptation of classical weathering indices is necessary to interpret weathering trends in carbonate-derived soil. In fact, this adaptation seems to be a good tool for distinguishing weathering grades of source-rock types at the continental scale, and allows a more robust interpretation of soil parent-material weathering grade and its impact on the current chemical composition of soil. An increasing degree of weathering results in Al enrichment and Mg loss in addition to Fe loss and Si enrichment, leaching of mobile cations such as Ca and Na, and precipitation of Fe-oxides and hydroxides. The relation between soil weathering status and its spatial distribution in Europe provides important information about the role played by climate and terrain. The geographical distribution of soil chemistry contributes to a better understanding of soil nutritional status, element enrichment, degradation mechanisms, desertification, soil erosion and contamination

Radioactivity levels and heavy metals in the urban soil of Central Serbia

Radioactivity concentrations and heavy metal content were measured in soil samples collected from the area of Kragujevac, one of the largest cities in Serbia. The specific activities of Ra-226, Th-232, K-40 and Cs-137 in 30 samples were measured by gamma spectrometry using an HPGe semiconductor detector. The average values +/- standard deviations were 33.5 +/- 8.2, 50.3 +/- 10.6, 425.8 +/- 75.7 and 40.2 +/- 26.3 Bq kg(-1), respectively. The activity concentrations of Ra-226, Th-232 and Cs-137 have shown normal distribution. The annual effective doses, radium equivalent activities, external hazard indexes and excess lifetime cancer risk were also estimated. A RAD7 device was used for measuring radon exhalation rates from several samples with highest content of Ra-226. The concentrations of As, Co, Cr, Cu, Mn, Ni, Pb and Zn were measured, as well as their EDTA extractable concentrations. Wide ranges of values were obtained, especially for Cr, Mn, Ni, Pb and Zn. The absence of normal distribution indicates anthropogenic origin of Cr, Ni, Pb and Zn. Correlations between radionuclide activities, heavy metal contents and physicochemical properties of analysed soil were determined by Spearman correlation coefficient. Strong positive correlation between Ra-226 and Th-232 was found