Merits of the system

Lasterra-Sanchez, M., Roberts, S.M. Current Organic Chemistry, 1997, 1, 187. 

Pure CMHP was obtained by the method in Purification of Laboratory Chemicals, 4th ed. Perrin, D.D., Armarego, W.L., Eds Butterworth-Heinemann Oxford, pp. 154, 1996. 

Edited by Stan M Roberts and Geraldine Poignant Copyright 2002 John Wiley Sons, Ltd. 

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In designing and selecting classification systems, the needs of both the laboratory scientists and the searchers should be studied, rather than merely the theoretical merits of the system. Even the failure of a system can be instructive. 

W, and burn time 10 s discharge frequencies of 10 s will be required for a 1000 MW plant. The merits of the system are simplicity, scalability to small power stations since the discharges can be arranged in modular form, and no impurity or first wall problems. Further experimental work on compression and laser-initiated gas embedded Z-pinches extending studies to higher currents of 10 A is required, with particular emphasis on large ion Larmor radius stabilisation. 

Hinton had left the AEA just before the decision to go ahead with the AGR, and was obviously not convinced of the merits of the system. There had been problems, principally with the canning, where beryllium had to be abandoned in favour of stainless steel, which meant using fuel of a higher enrichment. As a memo to Hailsham put it ... 

The most commercially successful of these systems has been the Convex series of computers. Ironically, these are traditional vector machines, with one to four processors and shared memory. Their Craylike characteristics were always a strong selling point. Interestingly, SCS, which marketed a minisupercomputer that was fully binary compatible with Cray, went out of business. Marketing appears to have played as much a role here as the inherent merits of the underlying architecture. 

ControUed release pharmaceuticals provide local or systemic treatment and differ in design depending on thek use and route of administration. The potential sites for controUed dehvery of therapeutic agents and some of the systems designed for those sites merit discussion. 

One of the merits of the above treatment, which justifies its inclusion in this review, is that it allows a quantitative comparison of the selectivity of nucleophilic heteroaromatic substitution (expressed by the reaction constant) with that for the analogous reaction with nitro-activated systems. Values for the latter are in the range 3.6 to 6.0. The fact that in both cases high p-values of similar magnitude are found is consistent with the hypothesis of similar mechanisms for both classes of compounds. 

If we consider the relative merits of the two forms of the optimal reconstructor, Eq. s 16 and 17, we note that both require a matrix inversion. Computationally, the size of the matrix inversion is important. Eq. 16 inverts an M x M (measurements) matrix and Eq. 17 a P x P (parameters) matrix. In a traditional least squares system there are fewer parameters estimated than there are measurements, ie M > P, indicating Eq. 16 should be used. In a Bayesian framework we are hying to reconstruct more modes than we have measurements, ie P > M, so Eq. 17 is more convenient. 

Another merit of the AhupL mutant is that its activity of hydrogen reabsorption is very small even at high cell densities (Masukawa et al., unpublished observation). These results indicate that deletion of the hupL gene could be employed as a source for further improvement of H2 production in a nitrogenase-based photobiological H2 production system. 

Unfortunately, we are still so ignorant of the electrochemistry of the systems involved, that it is not possible to construct a detailed, rigorous theory to explain these interesting phenomena, which certainly merit further investigation. 

Much emphasis has been placed on the selectivity of quaternary ammonium borohydrides in their reduction of aldehydes and ketones [18-20]. Predictably, steric factors are important, as are mesomeric electronic effects in the case of 4-substituted benzaldehydes. However, comparison of the relative merits of the use of tetraethyl-ammonium, or tetra-n-butylammonium borohydride in dichloromethane, and of sodium borohydride in isopropanol, has shown that, in the competitive reduction of benzaldehyde and acetophenone, each system preferentially reduces the aldehyde and that the ratio of benzyl alcohol to 1-phenylethanol is invariably ca. 4 1 [18-20], Thus, the only advantage in the use of the ammonium salts would appear to facilitate the use of non-hydroxylic solvents. In all reductions, the use of the more lipophilic tetra-n-butylammonium salt is to be preferred and the only advantage in using the tetraethylammonium salt is its ready removal from the reaction mixture by dissolution in water. 

It is difficult to assess the relative merits of the different approaches as they have not necessarily been applied to the same systems. They are further characterised by other differences such as the CVM cluster size, different characteristics of the liquid phase and, notably, by the adoption of different values for the lattice stabilities. The Ni-Al system is useful in this respect as it contains both ordered b.c.c. and ordered f.c.c. phases as well as having been tackled by many... 

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