Expansion index

As liquid flowrate inereases beyond the minimum required to suspend the partieles, the bed expands. Unfortunately, however, the expansion index n is not eonstant over all flow regimes but is a funetion of the flow. Thus... 

Interestingly, it turns out that despite the differing functions of the expansion index, , the correction factor, g(e), is approximately constant at the extremes of the flow regimes due to the particular values of the expansion index. The value of n is not known entirely theoretically but can be obtained from the Richardson and Zaki equation. Thus At low RCp ( = 4.6)... 

The expansion index [51,102,103], defined as the ratio of cell fresh weight to dry weight evaluated at the time of maximum fresh weight, is a more qualitative indicator of changes in cell/aggregate size, under various cultivation conditions. Wongsamuth and Doran [58] identified the filtration characteristics of suspensions of Atropa belladonna, specifically cake permeability, which is at least partially related to morphology, as a useful indicator of shear effects. 

Investigating coextrusion of com meal and WPI, Onwulata et al. (2003b) found that the melt temperature of the extmdate was more of an indicator of physical properties than specific mechanical energy. Quality attributes such as breaking strength, color, and expansion index were related to melt temperature measured at the die. 

Applying the hermitian property of we see that the left-hand side vanishes. Substitution of the expansion (9.54) for 0 2 using y as the dummy expansion index gives... 

Growth and lysis kinetics Expansion index Esterase release... 

Richardson and Zaki expansion index n0 fluid behavior index... 

Grinder, extruder Grinder type, particle size Volumetric expansion index Mathew et al. (1999a)... 

Expansion index—terminal Reynolds number correlation,... 

The fluidization model indicated in Fig. 6.46 is not elaborated on here in detail. An algorithm is proposed by these authors, as already stated, correlating bed porosity e determined through the expansion index n, which corresponds to the bioparticle terminal Re number Ret as a measure of the terminal settling velocity calculated from Newton s law in the following manner With... 

Other index tests include tests for specific gravity, maximum and minimum density, expansion index, and sand equivalent. 

F = fractional free area of perforated plate n = expansion index exceeding for e > Ec,... 

Thomas CR, Yates JG. Expansion index for biological fluidised beds. Chem Eng Res Des 63 67-70, 1985. 

Benezet et al. (2012) reported that the addition of fibers increased the expansion index and led to a reduction in water adsorption of extruded potato starch foams. They also reported that the fiber additions at a 10% level generally improved the starch foam s properties. 

The nanocomposites were prepared in a single-screw extruder using different starch contents (97.6-55.2 g/100 g formulation), PVA (0-40 g/100 g formulation), and Na-MMT (0-4.8 g/100 g formulation), and glycerol was used as a plasticizer. The addition of Na-MMT resulted in an increase of expansion index and mechanical strength of the foams. Na-MMT addition also resulted in a decrease of water absorption capacity of the samples. 

Degree of acetylation plays an important role in defining material properties. Acetylated nanocellulose in composites is believed to enhance transparency, mechanical properties, reduce refractive and thermal expansion indexes and decrease hygroscopicity [29-31]. 

Mitrus [35] showed that the radial expansion index value determined for TPS granulates strongly depended on extruder working conditions. This parameter was greatly affected by extruder screw rotation and, regardless of the mixture s material composition, the expansion index of the manufactured granulates increased with higher screw rotahon speed. 

No information concerning the expansion index ofTPS is available in the professional world literature. Therefore, the results of research into this parameter can only be considered by reference to expansion indexes of other starchy products, for which it varies over a broad range from 1 to 10 or, in the case of expanded grains, even up to a factor of 17. 

For TPS granulate produced in a modified TS-45 extruder a relatively low radial expansion index was determined for the samples examined it did not exceed a value of 3.5 (Figure 4.9), thus being a favorable property. A clear upward tendency... 

Figure 4.9 Changes in granulate expansion index produced from potato starch as a function of glycerol content for varied screw rotations.

Analysis of the expansion indexes of potato starch granulate with different amylose contents established a relation between this parameter and glycerol percentage (Figure 4.10). 

Figure 4.10 Changes in expansion index of granulate manufactured from potato starch with varied amylose content.

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