A transonic two-phase reaction turbine for use with low and high temperature fluid flow mediums includes at least two wheels that are configured to rotate in opposite directions, at least one of the at least two wheels being equipped with one or multiple kinetic energy harvesters.

Disclosed is a method and system for blending a foam modifier with foaming agent online, e.g., as may be particularly useful for gypsum or cement slurries. The foam modifier comprises a fatty alcohol that is added to a gypsum or cement slurry that includes foaming agent, such as an alkyl sulfate surfactant. The fatty alcohol can be a C.sub.6-C.sub.16 fatty alcohol in some embodiments. The use of such a foam modifier can be used, for example, to stabilize the foam, reduce waste of foaming agent, improve void size control in the final product, and improve the gypsum board manufacturing process.