Availability of potential

The availability of potential reactant species is changed by spillover from one site, where reaction does not occur, to another site, where the reaction may occur. We believe the most significant expression of these phenomena is the retention or induction of activity. Secondary reaction involving the spillover species can retain or induce activity on other sites. As discussed... 

The continued use of nitrous oxide in anesthetic practice has been questioned on the basis of its serious adverse effects and the availability of potentially safer short-acting potent analgesic drugs, such as xenon and remifentanil (2). 

It has been stated above that the fact that no interatomic potential is required is one advantage of RMC. The determination of suitable potentials that will accurately reproduce the experimental diffraction data on even comparatively simple systems may be a complex task, as discussed elsewhere in this book. However, if it has been achieved then structural models produced this way are clearly equally as possible as those produced by RMC. The availability of potentials is then advantageous because (a) different thermodynamic states of the same system can be investigated (though potentials may not be transferable across, e.g., a metal-insulator transition), whereas RMC would require separate data sets and (b) some parts of potentials are transferable between systems. 

The readily active sites can be gasified, and in this process they may generate a new set of active sites, either because they have uncovered new sites that laid beneath them, or because their gasification provided a new access to sites having a low activity, rendering them more active. We will consider, then, that for each carbon site that is gasified, a certain number of potentially active sites is converted into readily active sites of course, this generation depends upon the availability of potentially active carbon. 

The present chapter gives an overview of the ap>plication of Attenuated total reflection -Infrared spectroscopy (ATR-IR) to the environmentally important mineral - aqueous electrolyte interface. At these interfaces the important adsorption processes occur that limit the availability of potentially toxic solutes. These retention processes may retard for example the migration of solutes in aquifer systems or even immobilize them on the aquifer material, which is usually a natural mineral. Selected solutes may also via a preliminary adsorption process, which weakens bonds, enhance both dissolution kinetics and the equilibrium solubihty of a given mineral. 

Potential surfaces pervaded the whole of our discussions, however it was usefiil to have a special section in which to concentrate on the accuracy and availability of potential surfaces. The H + CO2 and OH + CO surface again featured strongly our understanding of this potenti surface is reaching a useful stage of maturity but the apparent conflict between theory (Schatz) and experiment (Bernstein, Zewail, et al) over the lifetime of the HOCO" complex shows that further work is needed in at least one of these areas. 

More recently, because of the availability of potential natural resources for the manufacture of improved environment-friendly materials, and reduced dependency on petroleum resources, bio-based biodegradable plastics have garnered attention from researchers, industries, and governments as possible substitutes for conventional plastics. PHAs are one such class of biopolymers. The LCA apphed to a potential pathway for PH B production, from the ceUulosic fraction of organic residuals, normally disposed of by landfill (Figure 15.11) [175], shows GHG emissions lower than a PHB produced from a dedicated agricultural feedstock. 

The application of computer simulation methods to molecular systems is in a relatively early stage. The Monte Carlo studies on water by Barker and Watts (1969) and Sarklsov et. al. (197A)9 and the molecular dynamics study of water by Rahman and Stillin-ger (1971) were the forerunners of computer simulation work on chemical problems. Progress has generally been slow in this area due to the magnitude of computer facilities required and the limited availability of potential functions for diverse chemical applications. Quite recently several computer simulation studies... 

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