This study examines the interannual variability of ocean circulation in the equatorial Atlantic, with a particular focus on the Equatorial Undercurrent (EUC) and its interactions with sea surface temperature (SST) and precipitation over West Africa. The analysis is based on SODA v2.2.4 ocean reanalysis data for the period 1900–2008 and CRU TS precipitation data spanning 1901-2022. Results reveal significant spatio-temporal variability in EUC depth and highlight strong relationships between EUC fluctuations, SST anomalies in the equatorial Atlantic, and rainfall variability over West Africa. Two main phases characterize the evolution of the EUC. From 1900 to 1960, the EUC exhibits increased depth, indicating a strengthening of ocean circulation. In contrast, the period 1961–2008 is marked by a shallower EUC and weakened circulation. The eastern basin shows greater sensitivity of EUC depth to interannual rainfall variability compared to the western basin, consistent with stronger SST variability in this region. During 1900–1960, a deeper EUC, especially in the eastern basin, is associated with a pronounced Atlantic SST dipole (warmer in the north and cooler in the south), leading to a northward shift of the Intertropical Convergence Zone (ITCZ). This results in increased rainfall over the Sahel and reduced precipitation over the Gulf of Guinea. Conversely, during 1961–2008, a shallower EUC corresponds to a reversal of this precipitation pattern. However, the precipitation dipole weakens in the eastern basin, likely due to changes in large-scale atmospheric circulation.

In the African context, where agricultural by-products and natural resources are often underutilized or considered waste or invasive species, this study aims to valorize locally available raw materials through the development of fully bio-based insulating composite materials. The materials were produced using typha, rice husk, residues from threshing millet ears, and cassava starch, through a simple and reproducible process accessible even at an artisanal scale. A total of 25 formulations were created by combining one to three of these raw materials with a natural binder. The resulting composites were characterized. The bulk density of the materials ranged from 198.64 to 361.02 kg/m3, while their thermal conductivity varied between 0.07 and 0.17 W/m·K. These results highlight the strong potential of these bio-based composites for use as thermal insulation in sustainable building applications.

It is essential to know the desorption isotherms to control the drying processes of agricultural products, food. The objective of this work is to determine the sorption isotherms of the local onion: the Violet de Galmi cultivated in the Niayes area. Desorption isotherms were studied for water activities ranging from 0.05 to 0.9 and for temperatures of 40 °C, 50 °C and 60 °C using the static gravimetric method. Six saturated salt solutions were used (KOH, K2CO3, NaBr, CuCl2, KCl and NaCl). The results show that the desorption isotherms of onion are type II and the equilibrium water content is temperature dependent. The experimental results are then smoothed by five models: Guggenheim - Anderson - De Boer (GAB), Brunauer - Emmett and Teller (BET), Henderson, Oswin and Peleg for the description of the equilibrium state of this product. From the modeling, it was concluded that both the Peleg model and the GAB model describe the desorption isotherms of onion well, but the Peleg model has the smallest relative errors, thus defining the Peleg model as the best model. From the results obtained, the isosteric heat of desorption is determined using the Clausius-Clapeyron equation.