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[en] Full text: Mine of Zaida (High Moulouya, Morocco) has been object of multiple research works (Saidi et al. 2002, Saidi 2004, Bouabdli et al. 2004, Bouabdli et al. 2005, El Hachimi 2005, El Hachimi 2006, Baghdad et al. 2006, Baghdad 2008, 2011, Berrah El Kheir et al. 2008, Berrah El Kheir et al. 2010, El Himer et al. 2012) which demonstrated the impact of a large volume of materials issued of the mining activities on the different compartments of the ecosystem. In fact, these materials are a potential source of trace metals, which induces a major risk for living beings because of their mobility and bioavailability. Among the techniques that minimize this problem the phytostabilization can be cited ; this method appears to be safe, alternative and usable regardless the level of pollution. It consists in revegetation of soils polluted by species tolerant to trace elements. In this context, the use of shrubs is particularly interesting because their root systems are well developed and dense, limiting the runoff and leaching of trace metals to different compartments of ecosystem. In our study we were interested in the culture of Jatropha curcas ; it is a perennial shrub belonging to the Euphorbiaceae family, this plant has been the subject of several research projects on the one hand due to its economic interest and low operating cost (biofuel, fertilizer, traditional medicine, fight against erosion, insecticides, soap production, ...), on the other hand due to its low requirements (easy to cultivate, rapid growth, drought resistance) and tolerance to marginal lands. This travel proposes to study the growth and ability of Jatropha curcas to extract trace metals in various substrates from Zaida mine (High Moulouya, Morocco) in order to evaluate its potential of phytostabilization. The results indicate that Jatropha curcas shows proper installation despite the high levels of trace metals in experimental substrates. This plant is characterized by the ability to adapt and grow in environments rich in trace metals. The power stabilizer of Jatropha curacs to minimize the dispersion of trace metals in the environment, indicating that Jatropha curcas is a potential candidate for phytostabilization of substrates that has a multi-metal contamination.
[en] The aim of the presented work was to determine the optimum parameters of inverter truncated rectangular pyramid with Fresnel lenses. The use of secondary optical element (SOE) in a concentrated photovoltaic system can be effective in redirecting the sun light into the solar cell, increasing the concentration as well as improving the energy uniformity on the solar cell Ray tracing technique was used to simulate the optical characteristics of the CPV unit with various design parameters of the component. Finally, a typical concentrator was designed by using three possible materials, the Fused Silica, the BK7 and the PMMA. (paper)
[en] In this work, the performances of two optimized reflective secondary optics elements a CPC (Compound Parabolic Concentrator) and a Cone for use in a CPV concentrator system are studied using ray-tracing simulation for the same primary optical element: a Fresnel lens. These optical elements are compared in terms of concentration, acceptance angle, exit angle and output light distribution. Our results show that the power distribution at the end of the concentrator is more uniform in the case of the cone. The optical efficiency is higher when the secondary element is placed at a distance with f the focal length; R the input radius of the secondary optical element and θ the acceptance angle of the secondary optical element. Also, we found that the length and the input radius of each optical element decrease when the Fresnel lens diameter increases but the input radius of the CPC stills the larger. Finally, our calculation show that the CPC is longer than the cone while the Fresnel lens diameter is less than 200 mm and beyond this value both the cone and the CPC mostly present the same length. (paper)