The effect of addition of NaCl on rheological properties of suspensions containing vacuum freeze dried starch nanoparticles was studied. These starch nanoparticles were produced through high pressure homogenization and emulsion cross-linking technique. Rheological properties such as continuous shear viscosity, storage and loss moduli and creep-recovery were measured. The presence of NaCl at concentration (5-15%, w/v) increased viscosity marginally (p > 0.05) while at 20% (w/v) it significantly (p < 0.05) increased viscosity. The presence of NaCl enhanced heat stability and weakened gelling capacity of suspensions. NaCl concentration below 15% (w/v) marginally (p > 0.05) increased the storage and loss moduli of suspensions. At 20% (w/v), NaCl increased both moduli significantly (p < 0.05) within frequency range tested (0.1-10 rad/s). Creep-recovery behavior was affected by NaCl and recovery rate was the highest (98.6%) at 20% (w/v) NaCl. The Cross, Power Law and Burgers' models followed experimental shear viscosity, storage and loss moduli and creep-recovery data reasonably well ((R
A numerical model is employed to simulate a single tube reactor featuring a downward particle flow counter to an upward inert gas flow for ceria reduction in the dilute flow regime. The coupled phenomena of mass and momentum transfer as well as chemical kinetics are simulated assuming isothermal operation for the reactor. The model predicts the reduction extent under varying reaction kinetics as well as design and operational choices. The reduction extent is found to increase with the reaction rate constant until achieving the thermodynamic upper limit at a certain critical value. This critical rate constant signifies a transition from a chemical kinetics limited conversion to a gas advection limited conversion. The effect of the reactor length and the particle size on reaction extent is studied for a range of realistic cases. An empirical correlation is developed to quantify the effects of particle and gas flow rates on reduction extent at both slow and fast kinetics. The present work offers insights to help guide reactor design and operation towards achieving the maximum reduction extent. (C) 2020 Elsevier Ltd. All rights reserved.