Needs for future work

A second obvious line of research for the future must be that related to the development and improvement of computer-based simulation of long-term environmental behaviour of radionuclides. Most currently available models are still comparatively simple compared with the physical, chemical and biological complexity of environments they purport to represent but, as noted in Section 13.5, our ability to construct ever more complex conceptual models for predicting the future behaviour of radionuclides is improving. However, the more complex the model, the more demands it places on the basic thermodynamic data and knowledge of likely speciation. The challenge for the future will therefore be to produce high-quality data for model construction and to devise realistic ways to validate those models once produced. 

and Fraga, E. (1996) Some physical and chemical features of the variability of IQ distribution coefficients for radionuclides./. Environ. Radioactivity, 30(3), 253-270. 

Anderson, R.F. (1982) Concentration, vertical flux and remineralization of particulate uranium in seawater. Geochim. Cosmochim. Acta, 46, 1293-1299. 

and Stanners, DA. (1981) Observations on the deposition, mobility and chemical associations of plutonium in intertidal sediments. In Techniques for Identifying Transuranic Speciation in Aquatic Environments. IAEA, Vienna, pp. 209-218. 

Beasley, T.M. and Lorz, H.V (1986) A review of the biological and geochemical behaviour of technetium in the marine environment./. Environ. Radioactivity, 3, 1-22. 

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Zbigniew Galus relates equilibrium potentials and kinetic parameters of electrode reactions in pure and mixed nonaqueous solvents to relevant properties of the media involved. Available experimental data are interpreted in the light of most recent theoretical models, with indication of difficulties, sources of inaccuracies, and needs for future work. 

The invention of new reactions is a form of exploration, in many ways analogous to the discovery new lands. Newfound reactions create synthetic routes for bench-scale and commercial production of high-value compounds. Additionally, new transformations allow the scientific community to map the mechanistic pathways by which chemical bonds are broken and formed. Ironically, one of the original amination reactions that inspired the author and his research team (Scheme 2) has yet to be developed, underscoring the need for future work in this field. 

Flow-induced degradation is intimately related to the nonequilibrium conformation of polymer coils and any attempt to interpret the process beyond the phenomenological stage would be incomplete without a sound understanding of chain dynamics. To make the paper self-contained and to provide a theoretical basis for the discussion, we have included some fundamental models of polymer dynamics in the next section which may also serve as a guideline for future work in the field of polymer degradation in flow. For the first-time reader, however, this section is not absolutely necessary. Further, any reader familiar with molecular rheology or interested only in experimental results can skip this section, only to go back whenever a reference is needed. 

The many-electron theory of charge transfer discussed here possesses the versatility needed in order to treat different mechanisms within the same quantum-mechanical framework. However, it remains for future work to decide how successful the present formalism will be in providing a comprehensive many-electron theory of surface charge transfer. 

There is clearly a strong need for further developments of analytical schemes for description of turbulent reacting flows. Based on the authors work, as summarized in this chapter and also recent contributions by others, there are some suggestions for future work. These suggestions are outlined briefly in this section together with a projection of achievements within the foreseeable future. 

Despite his own achievements, Furukawa s chapter indicates the need for future research. How did chemists and physicists work together in the 1940s and 1950s to create a new unified discipline of polymer science It would also be useful to look at how the discipline was taught in the period between 1940 and 1965, especially in the United States. To do this, one would need to examine which courses were taught, the launch of new journals and the evolution of textbooks across various editions. As the polymer science in America started in a few key institutions, notably Brooklyn Polytechnic, it would also be valuable to look at the diffusion of the new discipline from these seed institutions, tracing the careers of the early alumni and coworkers such as Charles Overberger. 

Recommendations for future work Either an empirical or a theoretical correlation for the pressure drop in a three-phase fluidized bed is needed. More experimental data for the pressure drop are needed with hydrocarbon systems. Equations (9-8o) and (9-8b) need to be tested against the experimental data with hydrocarbon systems. 

Control of polymer purity and curability are the critical areas for future work. Some purity requirements will become quantified as this discussion proceeds. With regard to fiber cure, gas-phase chemical cure and energetic methods have been most effective to date 16,18). Fiber processing involving the dry spinning of thermally unstable polymers 4,11,19) may be of future importance, because the need for a separate cure step is eliminated. 

Einally, there is now increasing recognition of a critical need for detailed characterization of the mechanisms of solid phase association of hydrocarbons in sediments or aquifer solid phase. The likelihood that the sorption/desorption behavior, bioavailability, and overall cycling of hydrocarbons depend critically on the nature of solid phase association provides a strong impetus for future work. 

In the experimental realm, several areas can be identified for future work. To better understand sensitivity, we need a better idea of what happens when energetic materials are subjected to mild insults. For example, more studies of what happens in a drop-hammer test seem warranted. These might include sub-critical experiments such as the studies of Sharma and co-workers [63,205] who analyzed the chemical composition and molecular structure of samples after subthreshold drop hammer impact, or real time IR imaging of hot spot formation such as the studies of Woody and co-workers [55,56]. For some reason, sub-critical experiments seem not very popular in the energetic materials community perhaps missing out on the big explosion is not satisfying enough. 

Obviously, this estimation is only grossly approximate, and much experimental and theoretical work is needed in order to more precisely determine the entropic contribution for chymotrypsin and other enzymes. The striking feature of this analysis, however, is that entropic factors alone can make such a major contribution to the turnover rates of enzymes, even without inclusion of the advantages which the enzyme derives from differential stabilization of the TS versus the S. The detailed quantitative description of all of the factors which contribute to enzymic catalysis for individual enzymes remains a major goal for future work, but it now appears likely that enzymic catalysis can be accounted for on the basis of known chemical principles. 

This all makes good business sense and should eliminate the need for corrective work because the original validation was deficient. Both pharmaceutical manufacturers and their suppliers should know what is required, and where points of clarification with GxP regulatory authorities are required. An established industry approach may also provide the basis for the international acceptance of validation work by various GxP regulatory authorities. The acceptance by GxP regulatory authorities of each other s inspection findings, however, is not expected in the near future. 

For future work it was established that a clear understanding of roles and responsibilities would smooth progress and ensure that vendor and owner team members better understood other participants problems and needs. 

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