“…(see Shenoy and Mashelkar [6] for general review on the experiments on natural convection of shear thinning and viscoelastic fluids and Larson [7] for a general review on the instabilities in viscoelastic fluids). Nonlinear RB convection of non-Newtonian fluids was considered by Eltayeb [8], Rosenblat [9], Martinez-Mardones & Perez-Garcia [10], Martinez-Mardones et al [11], Harder [12], and, more recently by Khayat [4,[13][14][15], Park & Lee [16], Parmentier et al [17], Li & Khayat [18], and Zhang, Vola & Frigaard [19]. Khayat investigated nonlinear RB convection of viscoelastic [13][14][15] and shear-thinning [4] fluids by adopting a dynamical system constituting a generalization of the Lorenz model (Lorenz [20]) to include elastic normal stress effects.…”