Mechanics of gelation distinction between a sol (solution) and a gel therefore appears to be understood in a manner analogous to the practical distinction between the elastic and plastic deformation ranges of a metal. The distinction lies in the ability to respond to an applied shear force via macroscopic viscous flow. In a dynamic sense, the response of a gel to an alternating force (oscillation or vibration) will depend upon the period or frequency of vibration. As indicated here, even most simple liquids will exhibit some elastic response at shear rates or frequencies exceeding 5 x 10 cycles per second. Experiments on such
Pound per hour Pound per hour Pound per hour is a mass flow unit. It is abbreviated as PPH or more conventionally as lb/h. Fuel flow for engines is usually expressed using this unit. It is particularly useful when dealing with gases or liquids, as volume flow varies more with temperature and pressure. In the US utility industry, steam and water flows throughout turbine cycles are typically expressed in PPH, while in Europe these mass flows are usually expressed in metric tonnes per hour: Minimum fuel intake on a jumbo jet can be as low as 150 lb/h when idling; however, this is