Computational strategies radical

The modes of thinking about structures and reactions and intermediates facilitated or even demanded by these conceptual innovations meshed productively with new tools of a different sort to drive the progress of recent decades. Advances in electronics and computers, all sorts of spectroscopy, laser optics and physics, chromatography, mass spectrometry, quantum theory and computational strategies, molecular beam experiments, and so on, radically expanded the limits of experimental and theoretical investigations. 

Sometimes to take full advantage from these features all is needed is a restructure of those parts of the computer code which perform vector and matrix manipulations and a parallel execution of its independent tasks. More often, a deeper restructure has to be carried out. This may involve the problem of choosing a suitable computational strategy or the more radical alternative of changing the theoretical treatment. There are cases, in fact, where theoretical approaches found to be inefficient on a scalar computer exhibit their full computational strength on a supercomputer. 

In this short initial communication we wish to describe a general purpose continuous-flow stirred-tank reactor (CSTR) system which incorporates a digital computer for supervisory control purposes and which has been constructed for use with radical and other polymerization processes. The performance of the system has been tested by attempting to control the MWD of the product from free-radically initiated solution polymerizations of methyl methacrylate (MMA) using oscillatory feed-forward control strategies for the reagent feeds. This reaction has been selected for study because of the ease of experimentation which it affords and because the theoretical aspects of the control of MWD in radical polymerizations has attracted much attention in the scientific literature. 

Reed and coworkers developed a strategy for automatic continuous online monitoring of polymerization (ACOMP). The method may be used during the initial development of the polymerization process, its optimization and monitoring of the continuous reaction. ACOMP automatically dilutes samples from the reactor and measures its properties, e.g., refractive index, near infrared (NIR) spectra, LSc, [ ]], etc., from which it computes evolution of MW, MWD, degree of conversion, copolymer composition (in copolymerization) and others. The method has been applied to a variety of the free radical homo- and co-polymerizations, including the reactions in emulsion or suspension. ... 

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