Abstract
This paper presents a revised model for the titled "Unsteady Mixed Nano-Bioconvection Flow in a Horizontal Channel with Its Upper Plate Expanding or Contracting" [18]. In this paper, the authors used a two phase model for the nanofluid presented in International Journal of Thermal Sciences 77 (2014), Mar., pp. 126-129 [15] in which the nanofluid particle volume at the wall is passively rather than actively controlled. Here, we observed that the boundary conditions are not satisfied in all curves of the nanoparticle volume fraction, phi, i. e. the curves do not match the boundary conditions presented in eq. (19). The second note is that all values of phi are positive which contradicts with the results presented in [15]. Since the equations are coupled then it can be said that not only the behaviors of phi are wrong but also all the results presented in that paper is not correct. The main reason for conducting this investigation is performing a revision for the mentioned paper and presenting a set of curves to show the corrected behaviors for dependent variables.