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Chad has done the study and development of renewable resources a priority in its energy mix. Wind energy is one of the renewable sources that can help Chad to develop rural areas and preserve the environment. This study presents from data obtained from NASA, the wind characteristics in Amdjarass, and Fada over thirty (30) years. The wind distribution density and energy potential at different heights were evaluated using the Weibull statistical analysis method. The aim of this paper is to evaluate the wind energy potential of two important sites in Chad. The study shows that over the 30 years, the mean annual wind speeds vary randomly between 4.7 m/s and 5.4 m/s over an average period of 2 years. Eight months of good average wind speeds were recorded, ranging from 5.01 m/s to 6.31 m/s at Amdjarass and 4.92 m/s to 5.70 m/s at Fada. The 04 months of low velocities observed are in the range of 3.211 m/s - 4.064 m/s at Amdjarass and 3.504 m/s - 4.516 m/s at Fada. The power density varies between 21.53 W/m2 and 111.89 W/m2 in Amdjarass, while in Fada, it varies from 19.85 W/m2 to 86.92 W/m2.

This study is all about of cocoa beans moisture content behavior and prediction, during drying and experimental determination of effective moisture diffusivity and activation energy of thin-layer. Experiments were carried out on fermented cocoa beans using an oven at 40, 45, 50, 55 and 60°C. Seven semi-empirical models based on the drying kinetics were used for the modeling. This work determined the effective moisture diffusivities and activation energy of cocoa beans using respectively a variable diffusivity model based on Fick's second diffusion law and Arrhenius standard equation. The aim was to obtain the evolution of moisture content in cocoa beans considering temperature, moisture content ratio and time. The results revealed and demonstrated the reliability of some theoretical models with natural drying for temperatures below 45 °C and others with convective hot-air drying for temperatures above 50°C. All of these models seemed to be the most appropriate for describing the type of drying of cocoa beans. Values of the apparent diffusion coefficient are between 2.33275 x 10 -11 m 2 /s and 2.8561 x 10 -11 m 2 /s. The effective moisture diffusivity increases as a function of the drying temperature and decreases as a function of the decrease in moisture content of the product. Values of Do and Ea were estimated respectively as 1.23 10 -6 m 2 /s and 43.56 kJ/mol respectively, in accordance with material and literature. It was observed that, pH values of different cocoa beans samples were between 4.82±0.26 and 5.43±0.41.