Summary and Future Opportunities

Especially for the liquid-containing systems, development of an engineering model to generalize Eq. (30.4) is needed badly to assist in material design and optimization. Considering partition coefficients for liquid components into the polymer would be a valuable step forward. Also, including effects of sorbed liquid on polymer matrix permeabUities should be included in any extension, since Eq. (30.4) uses pure permeation properties of the dispersed and continuous phases in its standard form. 

However, with the current research activity, it is beheved that the parameters mentioned above will be identified and understood in the near future. When that happens, one would expect to find commercial mixed-matrix membranes for some specific applications. 

(1998). Industrial membrane separation processes. CHEMTECH 28(4), 33-44. 

Matsuura, T. (1994). Synthetic Membranes and Membrane Separation Processes. CRC Press, Boca Raton, FL, Chapter 2. 

Costello, L. M., Walker, D. R. B., and Kotos, W. J. (1994). Analysis of a thermally stable polypyrrolone for high temperature membrane-based gas separations. J. Membr. Sci. 90(1-2), 117-130. 

Amperometric techniques can also be useful in gaining information on the state of a catalyst. These techniques tend to be more complex than potentiometric methods and are as a result less developed. In particular, early work with the technique of cyclic voltammetry has produced some promising results. 

Sensors could easily be miniaturised for such applications. During laboratory experiments it is most common to use a reference electrode exposed to air. This would be inconvenient if the sensor were to be used in a reactor. Instead the sensor could be miniaturised by using a mixed metal/metal oxide reference electrode. The reference oxide would be depleted under reducing conditions because of electronic leakage across the electrolyte but should be easily regenerated with the application of an appropriate potential. 

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Figure 30.8 Selectivity vs. DEA loading for DEA NaX-polymer mixed-matrix membranes. 30.3 SUMMARY AND FUTURE OPPORTUNITIES...

My job of discussing Keith Gubbins paper [1] would be easier if I disagreed with his summary of the current status and future opportunities in the use of thermodynamics in chemical engineering. Unfortunately for me, his is a fine paper, and it touches on most of the important areas that are likely to prosper during the next couple of decades. However, there are some areas that 1 believe he underemphasizes or whose importance he underestimates. 

This chapter provides a summary of main contributions of this book to support companies move towards a demand driven supply chain operation, and also opportunities for future developments. 

The paper closes with a summary of the opportunities that can be gained for engineering of automated production systems by means of Semantic Web Technologies and with directions for future research. 

The above summary of recent results indicates the remarkable scope, within the as-yet-undiscovered chemistry of the reagents 1 and 2, for the formation of unusual structures and the observation of new chemical processes. The future potential of these molecules stems from the union of alkylidyne-metal and metallacarbaborane complexes which they represent, and appears to offer unlimited opportunity for exploration. 

As natural resources are getting depleted, the reliance on biorenewable resources will continue to grow. The field of biorenewable polymers is still in its infancy and has much potential for growth. In summary, the use of metathesis complements the other multiple processes for the polymerization of plant oils, which range from cationic to thermal and radical type polymerizations by allowing control of the polymerization process through the selection of the metathesis catalyst or the addition of CTAs. Moreover, the ability to control polymerizations with new metathesis catalysts and the capability to influence metathesis polymerization by the addition of CTAs promise a future full of many exciting opportunities in biorenewable polymers via metathesis. 

We end this summary, as we began, with a reminder of the limitations of the technique of neutron inelastic scattering because of the large samples required. By the standards of most techniques in solid-state research enormous samples, often of single-crystal form, are required. The fact that so much progress has been made is a testament to the unique information obtained from the technique - but think of the opportunities with new more powerful sources and polarization devices. That remains a challenge for the future ... 

The instructional agent should be able to arbitrarily set the simulation s time and state for its own pedagogical purposes. (This goes beyond the standard simulation tactic of time compression in order to achieve future states faster than real time). We are envisioning a system that can rewind the simulation to an earlier critical juncture and either step through what happened with the learner as a form of review or to give the learner another opportunity to practice with either the same simulation state first encountered or a similar one. Another potential use of this capability would be to provide episodic summaries of learner behavior to an interested third party such as a teacher, mentor, or fellow learner cast in the role of critic. 

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