Drag, variation

The study of bubble formation in non-Newtonian fluids has not been reported in literature in spite of the great industrial uses of these fluids. Recently, Subramaniyan and Kumar (S16) have studied bubble formation under constant flow conditions in fluids following the Ostwald-de-Waele rheological model. The model of Kumar and Kuloor (K16, K18, K19) has been extended to take into consideration the drag variation caused by the complexity of the rheological equation. 

The variation of r and f through 3.0 GPa and 5.4 GPa shock waves is shown in Fig. 7.7 [38]. This figure shows clearly that the shock-wave path is in the dislocation drag regime (r > f). The mechanical threshold stress f increases from 10 MPa to 80 MPa in the 5.4 GPa shock thus from (7.37)... 

Lu B, Zheng Y, Scriven LE, Davis HT, Talmon Y, Zakin JL (1998) Effect of variation counterion-to-surfactant ratio on rheology and micro-structures of drag reducing cationic surfactant systems. Rheol Acta 37 528-548... 

Brown (1967) noted that a vapor bubble in a temperature gradient is subjected to a variation of surface tension which tends to move the interfacial liquid film. This motion, in turn, drags with it adjacent warm liquid so as to produce a net flow around the bubble from the hot to the cold region, which is released as a jet in the wake of the bubble (Fig. 4.10). Brown suggested that this mechanism, called thermocapillarity, can transfer a considerable fraction of the heat flux, and it appears to explain a number of observations about the bubble boundary layer, including the fact that the mean temperature in the boundary layer is lower than saturation (Jiji and Clark, 1964). 

Estimates based on European data are more scarce, and present other problems. In universal public insurance systems, in which financing is not based on premiums, there is no interpersonal (intra-group) variability in the drag copayment rates, or if there is it is very small. Therefore, temporal data are used to quantify the reactions of demand to normative changes in co-payment rates. The problem here is that such changes have occurred on very few occasions, and concurrently with other sources of variation in demand. 

Single-base substitutions, which affect the amino acid sequence of proteins and lead to altered protein function, are the most frequent type of polymorphisms associated with many disease phenotypes as well as with variation in drag response... 

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