Slide plate

A sliding plate rheometer (simple shear) can be used to study the response of polymeric Hquids to extension-like deformations involving larger strains and strain rates than can be employed in most uniaxial extensional measurements (56,200—204). The technique requires knowledge of both shear stress and the first normal stress difference, N- (7), but has considerable potential for characteri2ing extensional behavior under conditions closely related to those in industrial processes. 

Sliding angle (a), contact angle and drop size and, 22 113-114 Sliding plate rheometer, 22 738, 740 Slightly toxic substances, 23 113... 

Cross flow control for automatic compensation of pressure fluctuations between the sterile and washing areas Sliding plate adjustment to raise the separating baffle plates between the individual zones to a required height Filter monitoring system to indicate when a filter has reached its maximum degree of contamination... 

Place slides m Terasaki plates (2 slides/plate)... 

The dustiness index of coal is a means of determining the relative values that represent the amount of dust produced when coal is handled in a standard manner. Thus, a 50-lb sample of coal is placed on a slide plate in a metal cabinet of prescribed size. When the plate is withdrawn, the sample falls into a drawer, and after 5 seconds, two slides are inserted into the box. The slides collect suspended dust particles for 2 minutes (coarse dust) or for 10 minutes (fine dust). The dustiness index is reported as 40 times the gram weight of dust that has settled after either 2 minutes or after an additional 8 minutes. 

Conventional rheometer geometries such as concentric cylinders, cone and plate and parallel discs are unsuitable, even when the rheometer is designed to allow measurement of normal forces. Many of the disadvantages of such geometries are overcome in the sliding-plate viscometer (Gunasekaran and Ak, 2002). In this instrument (Figure 22.9), the sample (the exact shape and size of which need not be known) is held between a... 

Figure 22.9. Schematic diagram of a true shear sliding-plate rheometer. (Reproduced with permission from Gunasekaran and Ak, 2002.)...

In this subsection we review experimental reports of weak wall slip in drag flows, i.e., non-pressure-driven flows, involving parallel plate or sliding plate geometry. Such studies are particularly challenging because one has to identify a very small correction as due to wall slip and not due to other artifacts. 

Fig.8. Apparent wall slip of a HDPE (Mw=177,800) inferred from the gap dependence of the sliding plate rheometry measurements involving bare steel surfaces, calculated based on the data from HD s paper [37]...

The experimental device constructed to orient uniformly thick samples in simple shear is schematically represented in Fig. 3. It is basically a sliding-plate rheometer, the polymer sample being sheared between two temperature-controlled parallel plates. The upper plate is fixed whereas the lower plate can be displaced both horizontally and vertically with two pneumatic jacks. 

Specimens were sheared by using the above described sliding plate rheometer at two different shear stresses Oxyi 0.05 and 0.2 MPa. For axy=O.05 MPa, the behaviour of the melt was found to be nearly Newtonian. One sample was sheared at the highest shear stress up to a final shear strain of y=2.4. For the lowest shear stress, two samples with different shear strains were prepared y=2.8 and y=4. These samples are referenced in Table 7. 

As will be shown below, the experiment in the sliding plate rheometer does not allow one to determine Nl, since the normal force is in fact related to the second normal stress difference. For this reason, we studied the stress-optical law in shear by assuming that the principal directions of shear and refractive index are close to each other in the x-y plane. It is then straightforward to express the difference of principal stresses in the x-y plane... 

All rotary extractors employ deep beds of solids to be extracted, sometimes as much as two or more meters deep. Hence, rotary extractors are also termed deep-bed extractors. There are several mechanical variations of these extractors. Two variations have already been mentioned. Another variation is where the individual cells have hinged bottoms that swing open whenever the cell is to be emptied. In this variation, the solids slide against a common one-piece bottom that has an opening to allow solids to fall through when extraction is completed. Termed sliding plate. 

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