Etat Environnemental Des Sols De La Region De Casablanca

La pollution chimique, dans la région de Casablanca impacte la qualité des sols agricoles. Cinq sites de la région de Casablanca sont étudiés : les sites d’Oued Hassar, Oued Merzeg, Bouskoura, Benslimane-Mohammedia et Bouznika. L’objectif est l’analyse comparative de cinq éléments traces métalliques(Cadmium, Plomb, Cuivre, Zinc et Nickel) des sols afin d’évaluer l’état environnemental et de préserver les potentialités et l’innocuité des sites de la région de Casablanca . Un suivi des variations des paramètres physico-chimiques du sol (pH, carbonates de calcium et matières organiques) est réalisé, suite à la dégradation de l’eau d’irrigation par l’utilisation d’eaux usées, et de l’impact de la pollution chimique. L’étude statistique par le test d’Anova montre des différences significatives concernant les paramètres physico-chimiques entre tous les sites. L’analyse des éléments traces métalliques montre que les sols des sites irrigués par Oued Hassar présentent des teneurs en Cadmium de 2,91 ppm et en Plomb de 137,61ppm qui dépassent les normes préconisées par l’Organisation Mondiale de la Santé (O.M.S.), respectivement de 2 ppm et 100 ppm. Les teneurs en Cuivre dans les sols des sites irrigués par l’Oued Merzeg restent les plus élevées et sont de 896,62 ppm. Les teneurs en Zinc dans les sols proches de la cimenterie de Bouskoura sont prédominantes par rapport aux autres éléments et sont de 537,22 ppm. Dans les sols de MohammediaBenslimane, les teneurs de Cadmium sont de 2 ,36 ppm . Les teneurs en Plomb dépassent rarement 100 ppm.L’étude statistique par le test d’Anova montre des différences significatives entre tous les sites pour tous les éléments traces métalliques sauf pour le Nickel. Chemical pollution in the peri-urban area of Casablanca impacts the quality of agricultural soils.Five sites from the region of Casablanca have been studied: Oued Hassar, Oued Merzeg, Bouskoura, Benslimane-Mohammedia, and Bouznika.The objective is the comparative analysis of five trace metal elements in soils in order to assess the environmental state and to preserve the potential and harmlessness of sites in the Casablanca region.The environmental state of these sites requires knowledge of the physico-chemical parameters of the soil (PH, Calcium carbonates, organic matter), following the degradation of irrigation water by the use of wastewater or the impact of chemical pollution.The environmental state studied through metallic trace elements shows that the soils of sites irrigated by Oued Hassar have cadmium and lead contents which exceed the standards recommended by the World health organisation (WHO), respectively 2 ppm and 100 ppm.The contents are respectively 2,91 ppm and 137,61ppm.The copper contents in the soils irrigated by the Merzeg wadi remain the highest.The contents are 896,62 ppm. The zinc contents in soils near the Bouskoura cement plant are predominant compared to the other elements.The contents are 537,22 ppm. In Mohammedia-Benslimane soils, the cadmium contents are very variable, moderate and can exceed 2 ppm. Lead levels rarely exceed 100 ppm.The statistical study by the Anova test shows significant differences in the contents of metallic trace elements except for nickel

A MOS-based Dynamic Memetic Differential Evolution Algorithm for Continuous Optimization: A Scalability Test

Continuous optimization is one of the areas with more activity in the field of heuristic optimization. Many algorithms have been proposed and compared on several benchmarks of functions, with different performance depending on the problems. For this reason, the combination of different search strategies seems desirable to obtain the best performance of each of these approaches. This contribution explores the use of a hybrid memetic algorithm based on the multiple offspring framework. The proposed algorithm combines the explorative/exploitative strength of two heuristic search methods that separately obtain very competitive results. This algorithm has been tested with the benchmark problems and conditions defined for the special issue of the Soft Computing Journal on Scalability of Evolutionary Algorithms and other Metaheuristics for Large Scale Continuous Optimization Problems. The proposed algorithm obtained the best results compared with both its composing algorithms and a set of reference algorithms that were proposed for the special issue

Study of the magnetic order in chromium spinel systems

We present a study of the magnetic properties of the A1-x CuxCr2X4 (A=Dp,Zn,....; X=S,Se,O,...)chromium spinel systems. Using the mean field theory, we have evaluated the nearest neighbour, the next-neighbour super-exchange, and the third next nearest neighbour interaction J1(x), J2(x) and J3(x), respectively for the Zn1-xCuxCr2Se4and J1(x), J2(x) for the Cd1-xCuxCr2Se4systems in the whole range of concentration 0≤x≤1. By using the high-temperature series expansions combined with the Padé approximants method, we have obtained the magnetic phase diagrams in Tc versus dilution c. A spin glass phase is predicted for intermediate range of concentration. The obtained results are in agreement with experimental ones obtained by magnetic measurements for the systems studied. The critical exponents associated with the magnetic susceptibility g and the correlation lengths n have been deduced. The obtained values are comparable to those of 3D Heisenberg model, and are insensitive to the dilution c.We present a study of the magnetic properties of the A1-x CuxCr2X4 (A=Dp,Zn,....; X=S,Se,O,...)chromium spinel systems. Using the mean field theory, we have evaluated the nearest neighbour, the next-neighbour super-exchange, and the third next nearest neighbour interaction J1(x), J2(x) and J3(x), respectively for the Zn1-xCuxCr2Se4and J1(x), J2(x) for the Cd1-xCuxCr2Se4systems in the whole range of concentration 0≤x≤1. By using the high-temperature series expansions combined with the Padé approximants method, we have obtained the magnetic phase diagrams in Tc versus dilution c. A spin glass phase is predicted for intermediate range of concentration. The obtained results are in agreement with experimental ones obtained by magnetic measurements for the systems studied. The critical exponents associated with the magnetic susceptibility g and the correlation lengths n have been deduced. The obtained values are comparable to those of 3D Heisenberg model, and are insensitive to the dilution c

GPU-based Approaches for Multiobjective Local Search Algorithms. A Case Study: the Flowshop Scheduling Problem

International audienceMultiobjective local search algorithms are efficient methods to solve complex problems in science and industry. Even if these heuristics allow to significantly reduce the computational time of the solution search space exploration, this latter cost remains exorbitant when very large problem instances are to be solved. As a result, the use of GPU computing has been recently revealed as an efficient way to accelerate the search process. This paper presents a new methodology to design and implement efficiently GPU-based multiobjective local search algorithms. The experimental results show that the approach is promising especially for large problem instances

ParaDisEO-Based Design of Parallel and Distributed Evolutionary Algorithms

The original publication is available at www.springerlink.comInternational audienceParaDisEO is a framework dedicated to the design of parallel and distributed metaheuristics including local search methods and evolutionary algorithms. This paper focuses on the latter aspect. We present the three parallel and distributed models implemented in ParaDisEO and show how these can be exploited in a user-friendly, flexible and transparent way. These models can be deployed on distributed memory machines as well as on shared memory multi-processors, taking advantage of the shared memory in the latter case. In addition, we illustrate the instantiation of the models through two applications demonstrating the efficiency and robustness of the framework