Quemada function

Figure 17.22. Plots of the normalized self-diffusion coefficient (Z)s/A)) the inverse normalized low shear viscosity rj/ijo as a function of the hard-sphere volume fraction 0hs- The open circles correspond to rj/rjo and the filled circles to (A/A) while the continuous line represents the Quemada function, i.e. (1 — 0hs/O-63)...

Fig. 8 Plot of the inverse normalized self-diffusion coefficient (DJDo) and the normalized low shear viscosity rf/rio as a function of hard-sphere volume fraction pas- Open circles correspond to rj/rjo and filled circles to (DJDo). The solid line is the Quemada function (1 — (f)Hs/0.63) ...

Quemada et al. (1985) model (Equation 2.11) was used to analyze data on cocoa dispersions (Fang et al., 1996) and the role of cocoa butter replacers (Fang et al., 1997). Selected values of rheological properties of chocolate are given in Table 5-G. In addition, the data of Fang et al. (1996) (Table 5-H) before and after degasification as a function of temperature are note worthy. 

Figure 5.17 (a) Illustration of suspension of particles with volume fraction 0.4 (grey circles) with repulsive interaction extending to the dotted line, resulting in an effective volume fraction of 0.57. (b) Relative viscosity of suspensions of repulsive particles (black dots and dotted line) as a function of actual volume fraction. When the rheological results are plotted as a function of effective volume fraction (open dots) the data maps onto the Quemada model (solid line)... 

Figure 19-13. Relative zero shear stress viscosities of hard sphere silica suspensions as a function of volume fraction. The symbols represent the data of different researchers. The solid line is the Doolittle Eq. (19-13) with 0m = 0.638, and the dashed line is the Quemada equation with 4>m = 0.638 (Marshaall, 1990). Good agreement with the Doolittle equation suggests an exponential increase in viscosity in the glassy regime ( > 0.5).

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