String phases

Whether the string phase corresponds to a real situation or is an artifact of the simulations due to the use of an inaccurate expression for the secondary flow in regimes where the hydrodynamic stability of planar Couette flow is lost is difficult to ascertain at the present time [205]. Experiments on colloidal suspensions have not provided a clear answer, though at moderate strain rates structural behavior similar to that found in the simulations is observed [222]. 

Kadoma I A, van Egmond JW (1998) Flow-induced nematic string phase in semidUute wormlike micelle solutions. Phys Rev Lett 80(25) 5679-5682... 

The structure formation in an ER fluid was simulated [99]. The characteristic parameter is the ratio of the Brownian force to the dipolar force. Over a wide range of this ratio there is rapid chain formation followed by aggregation of chains into thick columns with a body-centered tetragonal structure observed. Above a threshold of the intensity of an external ahgn-ing field, condensation of the particles happens [100]. This effect has also been studied for MR fluids [101]. The rheological behavior of ER fluids [102] depends on the structure formed chainlike, shear-string, or liquid. Coexistence in dipolar fluids in a field [103], for a Stockmayer fluid in an applied field [104], and the structure of soft-sphere dipolar fluids were investigated [105], and ferroelectric phases were found [106]. An island of vapor-liquid coexistence was found for dipolar hard spherocylinders [107]. It exists between a phase where the particles form chains of dipoles in a nose-to-tail... 

Rotary tables, as structural members The rotary table rotates to turn the drill string. It is also used to support the drill string during some phases of operation. 

Eight samples from each set (A and D) were split into two groups, one incubated in 0.15 M phosphate buffered solution (PBS) and the other in PBS containing 0.1% of the phase transfer catalyst, tricapryl methyl ammonium chloride (Aldrich Aliquot 336) (PBS, catalyzed), both at pH 7.4. The samples were suspended in centrifuge tubes with 10 mL of incubation solution by nylon string and the tubes were placed in a shaker bath at a constant temperature of 37°C. Periodically, the samples were taken out of the tubes, placed on lint free paper towels, allowed to dry for exactly one hour, weighed and placed in fresh incubation media. The total time of the study was 48 weeks (330 days). 

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