Class of exceptions

There are, however, two broad classes of exceptions to this conclusion. The first comes with the slow reaction of a gas with a very porous solid. Here reaction can occur throughout the solid, in which situation the continuous reaction model may be expected to better fit reality. An example of this is the slow poisoning of a catalyst pellet, a situation treated in Chapter 21. 

Of commercial interest are benzo- and other fused aromatic 1,2,3-diazaborine derivatives which have exhibited good antibacterial activity against a variety of microorganisms (155—157). The reaction of pyrazole or C-substituted pyrazoles with boranes yields the pyrazabole system, a class of exceptionally stable compounds. More than 70 species in this system have been reported and the subject comprehensively reviewed (158). These compounds have been used as ligands in transition-metal complexes (159). 

One important class of exceptions to the preceding discussion is provided by prereactive or postreactive van der Waals (vdW) complexes. The lifetimes for such resonances can be much longer than that for conventional transition state resonance trapped near the saddle point. In the discussion of the F+HCl reaction below, we shall see that resonances of this sort can have lifetimes much longer than the rotational period of the complex and thus may show INR signatures. 

After normal chromosomal disjunction in the parental stocks, all zygotes receive aneuploid sex chromosomes and a normal euploid maternal complement as a result of this genetic imbalance, they die before eclosion. Different phenotypic classes of exceptional progeny routinely are... 

Abstract New polymeric supports, that can be used for preparation of novel catalytic systems, were obtained by grafting poly(vinylmethyl-co-dimethyl)siloxane arms onto multifunctional carbosilane moieties which belong to the class of exceptionally sterically hindered tris(silyl)methanes (Tj,.). Three types of Tj, molecules were applied 3-functional HCCSiMe Br) (type A), 9-functional HC[SiMe2(CHj)j-C (SiMejBr) ] (type B) and 4-functional Tg -derivative [SiMe2C(SiMe2Br)j]j (type C). The periphery-functionalized carbosilane-siloxane materials offer uniformly distributed and accessible sites for coordination of active catalytic species. New catalytic systems were thus prepared by coordination of platinum to vinyl moieties of the reported polymers, and used in hydrosilylation of vinyltrimethylsilane with 1,1,3,3-tetramethyldisiloxane. 

The third and largest class of exceptions consists of molecules or polyatomic ions in which there are more than eight electrons in the valence shell of an atom. When we draw the Lewis structure for PF5, for example, we are forced to place ten electrons around the central phosphorus atom ... 

Previous chapters concerned themselves with demonstrating the concentration dependence of various transport parameters. With a few uncommon classes of exception, concentration dependences were reduced to stretched exponentials exp(—ac ). This section examines how the exponential parameters depend on polymer molecular weight and other variables. 

To start, the robot control system must monitor the actions of the robot. The monitoring runs parallel to the execution of the off-line generated robot program. Different classes of exceptions can be detected by thresholding on the relevant sensor output. For an assembly robot system, five groups of exceptions are identified ... 

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