Extended Power Law Research Articles

MODELLING of FLOW PROPERTIES of STARCH PASTES PREPARED BY DIFFERENT PROCEDURES

ABSTRACTThe flow properties of starch pastes prepared by different procedures were measured and modelled. an extended power law model was developed to describe the shear stress over wide ranges of shear rates, temperatures and concentrations (6‐450 s−1, 10‐90°C, 3‐10%). Each pastes preparation procedure required its own set of parameter values to be modelled since different preparation procedures produced pastes with considerably different flow properties. These effects have to be considered before the flow properties can be predicted with satisfactory precision for process applications. Such a method is presented in a subsequent paper. the exactness in the modelling was restricted by the changes of the flow properties during the measuring process.

Modelling of infrared multiphoton absorption and dissociation for design of reactors for isotope separationby lasers.

A series of experiments were performed on infrared laser beam absorption (multiphoton absorption) and subsequent dissociation (multiphoton dissociation) of CF3Cl to propose models for the design of reactors for isotope separation by lasers. A parallel beam geometry was utilized in batch irradiation experiments to make direct compilation of lumped-parameter data possible. Multiphoton absorption is found to be expressed by a power-law extension of the law of Lambert and by an addition of a new term for buffer gas effect to the law of Beer. For reaction analysis, a method to evaluate the effect of incomplete mixing on apparent reaction rates is first presented. Secondly, multiphoton dissociation of CF3Cl is found to occur in pseudofirst order fashion and the specific reaction rates for different beam fluence are shown to be correlated to the absorbed energy.