Efficiency target

Eig. 5. Target efficiency of spheres, cylinders, and ribbons. The curves apply for conditions where Stokes law holds for the motion of the particle (see also N j ia Table 5). Langmuir and Blodgett have presented similar relationships for cases where Stokes law is not vaUd (149,150). Intercepts for ribbon or... 

Fig. 18. Target efficiency of a single water droplet in a gravitational spray tower (278,279). From Ref. 280,...

Fig. 20. Spray droplet target efficiency in a centrifugal spray tower with a centrifugal field of 100 g (140,281).

K Proportionality constant, for target efficiency of a single fiber in a bed of fibers Dimensionless Dimensionless ... 

Target efficiency of an isolated collecting body, fraction of dispersoid in swept volume collected on body Dimensionless Dimensionless Dimensionless... 

Calculation of the target efficiency T o of an isolated fiber in an air stream having a superficial velocity the same as that in the filter... 

Determining the difference between the target efficiency of the isolated fiber and that of an individual fiber in the filter array T ... 

Determining the collection efficiency of the filter T from the target efficiency of the individual fibers... 

The results of computations of T o for an isolated fiber are dhistrated in Figs. 17-62 and 17-63. The target efficiency T t of an individual fiber in a filter differs from T o for two main reasons (Pich, op. cit.) (1) the average gas velocity is higher in the filter, and (2) the velocity field around the individual fibers is influenced by the proximity of neighboring fibers. The interference effect is difficult to determine on a purely theoretical basis and is usually evaluated experimentally. Chen (op. cit.) expressed the effecd with an empirical equation ... 

This indicates that the target efficiency of the fiber is increased by the proximity of other fibers. The value of Ka averaged 4.5 for values of the void fraction ranging from 0.90 to 0.99. Extending use of the equation to values of , lower than 0.90 may result in large errors. 

The collection efficiency of the filter may be calculated from the fiber target efficiency and other physical characteristics of the filter (Chen, op. cit.) ... 

The foregoing procedure is commonly employed in reverse to determine or confirm fiber target efficiencies from the experimentally determined efficiencies of fibrous filter pads. 

The target efficiency for impingement units expresses the fraction of the particles in the entraining fluid, mor-ing past an object in the fluid, which impinge on the object. 

The target efficiencies for cylinders, spheres, and ribbonlike particles are given for conditions of Stokes Law in an infinite fluid by Figure 4-14. 

Figure 4-14. Target efficiencies for spheres, cylinders, and ribbons. By permission, Perry, J. H., Chemical Engineers Handbook, 3rd Ed., McGraw-Hiil Company, 1950 [13].

The pharmacokinetic processing of macromolecules used as targeting devices or drug carrier systems is different from that of conventional cytotoxic drugs and plays an important role in e.g. the targeting efficiency of these cytotoxic agents coupled to the macromolecules. 

A number of modified nucleotides have been tested and described in siRNA design. These are mostly modifications of the 2 OH group of the ribose. By the incorporation of chemically modified nucleotides into siRNAs, the on-target efficiency of the siRNAs can be increased (42 4). On the other hand, different types of siRNA off-target effects can be reduced by the use of chemically modified nucleotides immunostimulatory effects (reviewed in (20)) as well as sequence-dependent miRNA-like off-target effects (26, 44,45) and passenger strand incorporation (46, 47). In addition, chemical modifications can be used to improve the cellular delivery of siRNAs in living animals and are important tools to enhance the serum stability of siRNAs (48). 

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