Streamlining principle

Substitution of Equation (3.62) into Equation (3.60) gives the relative zero shear viscosity. When the shear rate makes a significant contribution to the interparticle interactions, the mean minimum separation can be estimated from balancing the radial hydrodynamic force, Fhr, with the electrostatic repulsive force, Fe. The maximum radial forces occur along the principle axes of shear, i.e. at an orientation of the line joining the particle centres to the streamlines of 6 = 45°. This is the orientation shown in Figure 3.19. The hydrodynamic force is calculated from the Stokes drag, 6nr 0au, where u is the particle velocity, which is simply... 

Lb. The Principle of Streamlining (from Empiric to Definitive Therapy)... 

When particles change their direction of movement, as for example around bluff bodies such as cylinders or bends in tubing, inertial forces tend to modify their flow paths relative to the suspending gas. Particles may depart from the path of gas molecules (streamlines) and collide with the larger body (Fig. 2). This is the principle underlying inertial particle collectors. 

Virtual impaction uses the principle of inertial separation, but the impaction plate is replaced by a zone of relatively stagnant air below the nozzle. The virtual surface formed by deflecting streamlines gives separation conditions similar to those in conventional impactors. Large particles travel straight through into the low-flow region,... 

The establishment of the model equations of a detailed and a streamlined network and the shortsightedness principle are illustrated with cases of olefin hydroformylation. 

Streamlines are hypothetical lines without width drawn parallel to all points to the motion of the fluid. As velocity increases, pressure decreases. Pressure field around an object is the reverse of velocity field. This may appear to contradict common experience. However, it follows from the principle of conservation of energy and finds expression in Bernoulli s theorem. 

The throughput flow results from the difference in pressure caused by charging the batch and withdrawing (pulling) the melt. The streamlines are in principle parallel... 

However, in the long term, ELISA is an ephemeral format. Even when streamlined and automated, it has too many steps. Certainly we should realize that it will be replaced by other systems, the most exciting of which will be biosensors. Also, other formats offer a proprietary edge in the market place which will be very important in the maturation of immunoassay systems in the environmental field. Finally, different formats will lend themselves to different environmental problems. We should continually emphasize that the same reagents can be used in many formats. Possibly in small letters we also should caution that certain antibody characteristics may be more important in one format than another, that some formats are more resistant to matrix effects, and that relative cross reactivities of compounds can change as one changes the subtle principles upon which an immunoassay works. For this reason a clear choice of formats should be made before initiating validation studies. 

Hydrophobic interaction chromatography (HIC) was selected because the separation principle is complementary to ion exchange and because a minimum amount of sample conditioning was required since the sample was already in a high salt buffer after elution from STREAMLINE SR... 

STREAMLINE is able to handle crude, particulate feedstock, eliminating the need for significant sample preparation steps. Adjustment of pH or ionic strength may be required according to the separation principle being used (IEX, AC, HIC)... 

When guided by these principles, simulation in drug development will be streamlined and effective. 

Figure 1. Hydrophoretic separation principle, (a) Schematic showing a hydrophoretic device with anisotropic microfluidic obstacles, (b and c) Simulated streamlines in the device. The slanted groove patterns on the channel generate rotational flows by using a steady axial pressure gradient, (d) Different particle ordering according to particle size by steric hindrance mechanism. (Reproduced with permission from Ref [20] Copyright 2009, American Chemical Society.)...

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