Fig. 4

Viscoelastic behaviour of algae slurries as a function of solids concentration and processing. Data were obtained from shear stress sweeps at 1 rad/s that show the storage (elastic) and loss (viscous) moduli of the slurries of harvested (a), incubated (b) and HPH ruptured (c) Nannochloropsis sp. cells at 12, 20 and 24% solids concentrations. All the slurries were elastic in nature, where the elastic modulus (G^’, solid squares) was greater than the viscous modulus (G^", hollow triangles) at low shear. The crossover between the viscous and elastic moduli, indicated by dashed arrow lines, is often used to characterise the gel-like to fluid-like transition. Duplicate data gave similar results, with a single data set shown for clarity