In this work, we valorized two wastes of plant origin in activated carbon (AC) by chemical activation, with a view to their use for the elimination of industrial dyes and artisanal dyeing simulated by methylene blue and iodine in the water. These are coconut shells (Coco nucifera) and teak wood chips (Tectona grandis). For the preparation of activated carbon based on coconut residues, the chemical activation was carried out by citric acid extracts of lemon juice (Citrus aurantiifolia) and then compared to that carried out with phosphoric acid and hydroxide of potassium. For the preparation of activated carbon from the teak residue, the activating agent used is potassium hydroxide. The results obtained show that activated carbon based on the coconut are microporous and mesoporous with an iodine number between 338.9 and 487.9 mg/g, a methylene blue number between 369.2 and 447.2 mg/g and a more pronounced post-treatment residual acidity for phosphoric acid than with lemon juice. The test conditions (the impregnation ratio, the duration, and the carbonization temperature) made it possible to prepare six activated carbons from the teak residue. The carbonization time does not have a significant effect on the adsorption efficiency although it does have a considerable effect on the carbonization efficiency. The adsorption kinetics of methylene blue on these materials is second order and the adsorption isotherm is more of the Langmuir type than that of the Freundlich model; this isotherm is characteristic of a wide distribution of microporosity and a well-developed mesoporosity. These activated carbons can therefore be used in the treatment of wastewater, in particular for the removal of industrial dyes and artisanal dyeing.

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Aims: Researchers are more and more focused on finding ways to optimize renewable energy sources. One of the more promising of these renewable energies is wind energy. However, these wind resources are very localized and selective. There is also significant potential for wind resources available at low densities or low wind speeds. The objective of this research is to exploit these resources. Methodology: To do so, this study proposes a new wind generating device coupled with a flow convergent in order to increase its performance at low wind speed. This new wind device is designed under Solidworks and analyzed with Matlab software. Several parameters are simulated. The effect of the pulley transmission ratio on the mechanical values of the generator, the impact of the operating gas in terms of angular velocity, power and torque on the generator shaft was clearly determined. Results: It appears that the power at the input of the wind device is multiplied by the square of the ratio of the output and input velocities, the flow passing through the convergent being constant. The torque on the generator decreases with the increase of the transmission ratio while its speed increases. However, for a fixed transmission ratio, the speed remains constant while the torque and power increase with the speed at the inlet of the convergent. On the other hand, it is noted that, the lower the adiabatic coefficient of the gas used, the higher the power generated. Conclusion: When used with a wind device, the output parameters of the convergent will result in better mechanical efficiency, which greatly improves electrical power generation.

The importance and the quality of the buildings, represent an index of development of a country. We attend so more and more in our countries and particularly in Benin, an unrestrained research for improvement of the energy performances of the building. Our work enter within this scope. It seeks the improvement of the quality of the envelope of the as well as possible being opposed building through materials, with the variations in external temperature i.e. having a great thermal holding capacity. This holding capacity is characterized by damping, dephasing, heat capacity and coefficient of transmission. During our study, four materials: composite cement and fibres of ronier, composite cement and rice balls, agglomerate and composite cement and ground of bar, were designed under the same conditions and according to same mixture. They were then subjected simultaneously to solar flow during four days. From the data of flow and temperatures collected as well as modeling of a semi-infinite medium, we succeeded in estimating then to compare their holding capacities. The classification of materials by descending order of holding capacity is: composite cement and rice balls, composite cement and fibres of ronier, composite cement and ground of bar and agglomerate.

Light Emitting Diode (LED) is a new kind of light source that is quickly being used into automotive lighting systems. In recent years, there have been increased expectations placed on vehicle headlamps, including that they not only be fully functional, affordable, and long-lasting, but also stylish, energy-efficient, and environmentally friendly. Since LED light sources are long-lasting, highly efficient, and energy-efficient, small in size, etc., they are frequently utilized in headlamps, turn signals, brake lights, position lights, etc. and will soon dominate the automotive light source industry. Although it has a greater energy conversion efficiency, the thermal management of LED headlamps is still a problem. In this research, the response surface method is used to optimize the heatsink designs for LED automotive headlamp module. The finite element (FE) approach and numerical simulation are used to model the test samples temperature distribution. Then, in order to maximize the heatsink potential for thermal dissipation, we tested different types of material, and used the response surface method. The LED headlamp hot spots decrease by 2 to 8 degrees when the heat sinks thickness, fin spacing, and height are optimized and decrease by 7.64 degrees when the heat sink and PCB substrate are made of 6063 aluminum alloy and AlN, respectively.