Shear studies

Samples are most frequently shock deformed under laboratory conditions utilizing either explosive or gun-launched flyer (driver) plates. Given sufficient lateral extent and assembly thickness, a sample may be shocked in a onedimensional strain manner such that the sample experiences concurrently uniaxial-strain loading and unloading. Based on the reproducibility of projectile launch velocity and impact planarity, convenience of use, and ability to perform controlled oblique impact (such as for pressure-shear studies) guns have become the method of choice for many material equation-of-state and shock-recovery studies [21], [22]. 

Table 2. Defined flow field shear studies involving plant cell suspension cultures...

In capillary shear studies involving M. citrifolia, the extent of cell damage was found to increase with the prevailing level of shear stress (Fig. 2). Trials involving capillary tubes of different lengths yielded similar levels of viability loss at equivalent exposure times, indicating that the death rate is determined by the shear stress alone. 

In shear studies, the most commonly used type of device for the generation of well-defined flow fields is the rotational viscometer. The use of these devices for the rheological characterization of liquids is well established [137]. Compared with the capillary and jet devices (Sects. 5.1 and 5.2), rotational viscometers allow the investigation of the effects of continuous rather than intermittent shearing. 

Table 3. Shear studies (post-1993) involving plant cell suspensions in STR or shake flask systems. Studies prior to 1993 are summarized by Meijer et al. [1993]... 

Carbanion mechanisms may give either syn or anti elimination. For example, Hunter and Shearing studied the butoxide-catalyzed elimination of methanol from 35 and 36. Since deuterium exchange with solvent is in close competition with elimination, the mechanism is probably (EjcB)b. The ratio ofsyn/anti... 

Simple shear studies with the CTA solutions showed various textures were obtained dq>ending upon the solution concentration, but they were not stable. 

I84a. — — Correlations for non-Newtonian flow viscosity-shear studies of entanglement in linear polymers. Trans. Soc. Rheolc 6, 107 (1962). 

Test polymers for visualization studies were polyurethane (Pellethane, 2363-80A, Upjohn), filler-free polydimethylsiloxane (Sil-Med Corporation), two forms of Teflon, sintered (TFE, DuPont) and Fluorofilm (Dilectrix Corporation), and polyurethane-silicone rubber copolymer (AVCOthane 51, AVCO). Samples of 1 cm2 or, for shear studies, 5 X 20 X 0.5-cm sheets, were washed in ionic detergent solution (Alconox) at 60°C for 1 h, rinsed in deionized water, and refluxed in absolute ethanol for 1 h. Materials were dried and stored in a desiccator until use. 

Lap-shear studies for several polyurethane-epoxy SINs and semi-SINs are reported in Figure 7.17. A distinct maximum in lap-shear strength is noted at midrange compositions. By contrast, the peel strength shows a... 

EINAV We did quite a few experiments on both high shear and low shear studies and found both of them to be important in the process. In other words, it s not the shape of the endothelial cell but the injury to the intima which is important at high shear. So let me represent the high shear group although I fully agree with Dr. Nerem that low shear has its importance as well. 

Shear studies of powder bed can also be carried out to evaluate the cohesiveness of powders. There are many variations of shear cells for evaluation of powder cohesiveness. 

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