Dynamic dilution technology

Unlike light-scattering studies, for which dilution is often a prerequisite, ultrasound can measure food properties at concentrations that are technologically relevant. This aspect has obvious benefits for the analysis of inhomogeneous foods such as solidifying fats, dynamically changing dairy food systems, dough, and emulsions. 

There have been a number of studies of the breakup of viscoelastic filaments because of interfacial tension, all of which show that the viscoelastic response results in dynamics that differ markedly from the Rayleigh breakup of inelastic filaments, but the focus for interfacial tension-driven breakup has been on dilute polymer solutions of interest in aerial spraying and inkjet technology applications. The hterature is less extensive for breakup of polymer melts, and some of the issues relevant to dilute solutions are probably not of concern for melts because of the orders-of-magnitude difference in the ratio of interfacial to viscous (or elastic) stresses. 

Several studies have been reported on the determination of the mean-force potential between aqueous ion pairs at ambient conditions, " yet little is known about the speciation in aqueous solutions at near-critical and supercritical conditions " which are typically encountered in technological processes where supercritical water is either the reaction medium or the energy carrier. In this section we analyze the association, equilibrium, and the kinetic (interconversion) rate constants for an infinitely dilute aqueous Na /CI" solution as described by a water-electrolyte model at several supercritical state conditions. In Section 3.3.1 we briefly describe the statistical mechanical formalism for the determination of the thermodynamic constants and the molecular dynamic determination via constraint dynamics. In Section 3.3.2 we discuss the actual kinetics of the inteicon-version between two ion pair configurations leading to the definition of the corresponding equilibrium constant. Finally, in Section 3.3.3 we discuss the outcome of the comparison between the association constants from simulation and... 

Many ofthe technologies listed above can be used only with dilute suspensions. However, there are instances where particle characterization has to be performed in a concentrated phase in which dynamic processes such as aggregation, agglomeration, or flocculation may occur at a much faster rate. In other instances, such as in emulsion systems, dilution just is not feasible because the system may change due to the dilution process. The analysis of such concentrated samples is especially important in on-line processes where particles naturally exist in concentrated states. Since sound waves can travel through concentrated suspensions, ultrasonic analysis provides a mean to characterize particulate systems at concentrations up to 60% hy volume [34]. 

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