Sir GI Taylor (1886 - 1975) and Professor G. K. Batchelor (1920-2000) (University of Cambridge). Batchelor was founding head of the Department of Applied Mathematics and Theoretical Physics (DAMTP). He was the leader of Microhydrodynamics research group during my PhD in DAMTP-Cambridge (1991-1995). In 1956 he founded the influential Journal of Fluid Mechanics which he edited for some forty years. GI Taylor was his supervisor in Cavenish Laboratory - Cambridge University. He was the leader of the Microhydrodynamics research group in Complex Fluids during my PhD in DAMTP-Cambridge (1991-1995).

São Francisco river - ("Old Chico"). Alagoas/Sergipe Março-2020.