Evidence requirements

Part of the evidence required is the result of at least one complete internal audit and management review cycle. 

The Sn2 mechanism as shown above involves the simultaneous movement of three pairs of electrons. However, Bordwell and co-workers contended that there is no evidence requiring that this bond making and bond breaking be in fact concerted, and that a true Sn2 mechanism is a myth. There is evidence both for and against " this proposal. There is also a review of the Sn reaction. ... 

This structure type evidently requires the simultaneous existence of two differently sized halide types, and thus exists only in mixed hahde systems. Recent investigations revealed this cubic stracture also for cluster phases with other interstitial atoms, i.e., the cation-free Si-centered [(Zr6Si)Cli2-xl2+x] [28]. 

The universe initially went through a phase of rapid expansion, the so-called inflation. Fail Elegant theory, but still no evidence requires huge extension of the laws of physics. 

It has recently been established that carbozirconation with organylzirconocene derivatives evidently requires dipolar (and mostly bimetallic) activation and/or small-ring zirconacycles, especially three-membered ones, that can undergo cyclic carbozirconation (Generalization 6 ) [149]. One of the recent examples has been shown to involve both bimetallic and cyclic organo-zirconium species [150], These reactions can be either stoichiometric or catalytic in Zr. 

Fe /V reactions (both of which exhibit AS = -25 eu) suggest that there is no dramatic mechanistic difference for electron transfer in these two systems. Although such comparisons must be made with caution, I know of no strong evidence requiring 3+ 2+... 

The central importance of the electrode potential has been discussed in Sect. 2.3.2. The potentiostatic operation mode evidently requires a reliable potential measurement. Only experiments at constant current can operate without knowledge of the potential. But here too the potential of the working electrode imparts interesting information, for example, a change in this potential - probably not detectable in the... 

The evidence required by the laboratory to demonstrate traceabihty for the mercury result is here given. 

One of today s basic requirements for economical nodular iron production is a base (or untreated) iron having between 0,004% and 0,05% sulfur. In most practices, the sulfur level is held at approximately 0,01% in order to minimize the necessary addition of nodulizing elements. On the other hand, a minimal sulfur level is evidently required in order to facilitate adequate nucleation (12). 

Finally, it is clear that much more research needs to be performed to connect the disciplines of colloid science and nutrition, especially in the application areas of functional foods and delivery systems. The combination of information from both in vitro and in vivo studies is evidently required in order to be able to understand properly the complex physicochemical processes that can occur during the digestion of food colloids. Our ultimate objective must be to make use of this knowledge to produce effective strategies for the formulation of a healthier diet with optimized bioavailability of the most desirable ingredients. 

It would appear from the foregoing that the reactions of recombination and disproportionation of radicals fall into a reasonable relation with each other and with abstraction reactions if in the approach of the radical pair, either head-to-head as in recombination or head-to-tail as in disproportionation, there occurs an appreciable contribution of ionic structures to the attractive potential of the radical pair. These then also fall into a consistent relation with the insertion reactions of carbenes and the snap-out reactions of stable molecules from which latter, the present experimental evidence requires a large charge separation in the transition state. 

Until more concrete structural information is obtained, the discussion on the catalytic mechanism of carbonic anhydrase must remain rather speculative. The experimental evidence requires the presence in the active site of a basic group being in some manner linked to the metal ion. This group is generally thought to play a critical role either as a nucleophile in a direct reaction with the substrate, or through general base catlysis. Several schemes for the function of carbonic anhydrase have been proposed (16, 41, 50, 78, 79) ... 

There is, at this time, no strong evidence requiring one to go beyond the simple picture of the A-SE2 transition state shown in Fig. 3. Adopting... 

An observation reminiscent of this denitration is the corresponding ready decarboxylation or desulfonation of the acids (107) by action of hot mineral acid.46 This reaction evidently requires the o-i-amino group since the 2-nitro-4-carboxylic acid (107a), the corresponding sulfonic acid (107a), as well as p-nitrophenylanilines (104) are un-... 

To date, no piece of experimental evidence requires a concerted mechanism. On the other hand, considerable data, although often circumstantial or indirect, support the intermediacy of a biradical. The initial postulation of a biradical... 

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