Hyperbranched polymers with both highly branched structures and numerous vinyl functional groups have been synthesized via reversible activation/deactivation controlled polymerization of multifunctional vinyl monomers. By controlling the competition between propagation and reversible termination using a deactivation enhanced method, the growth rate of polymer chains is decreased and the onset of gelation is prevented until the system has achieved much higher levels of conversion than has previously been reported for nonenhanced systems. Here, we demonstrate this strategy by synthesizing highly branched, irregular dendritic polymers with a multiplicity of reactive functionalities such as vinyl and halogen functional groups, and controlled chain structure via deactivation enhanced atom transfer radical polymerization (ATRP) of a commercially available multifunctional vinyl monomerdivinylbenzene (DVB) and ethylene glycol dimethacrylate (EGDMA).

No abstract

A three dimensional vnrinble dimensioned computer model of it man has been developed which can be used as it conversational mode design tool. This papor illustrates the use of this model fur equipment, design, in particular to determine whether controls CUll be reached and whether equipment dimensions nrc suitable to match different members of the population. The equipment may be described either by special purpose or general purpose environmental modelling systems. The modules of the general purpose system may be assembled into it model of the equipment and then evaluated by taking the operator, represented by the computer rnu.n, through a typical work sequence. If t.110 dimensions or positions (If the modules are unsatisfactory they mny be altered conversationally and the new design retested. IntroductionThere is much to be gained by good ergonomic design. The user gains in improved health, comfort and performance, the employer gains in greater productivity and the manufacturer gains by producing a more marketable product.Nevertheless the tools available to assist the designer even for the simplest anthropometric matching of machine to man are either primitive or expensive. The tools include tabulated data and design recommendations based on measurements of sample groups (e.g. Damon et al, (1966)) mannikins, dummies, cadavers for crash simulations, evaluation of prototypes and consumer feedback.Useful as these methods are, each has its limitations. Tabulated data is often difficult to apply and time consuming to use. Mannikins are two dimensional whereas typical work sequences involve motion in three dimensions. Dummies arc three dimensional but are difficult to manipulate through a work sequence and only a limited set of limb lengths is available. Mock ups should give a good evaluation of any design but they are expensive and take time to construct. It is rarely practical to use large and representative samples for practical tests on mock ups or prototype designs although one may eliminate the worst defects of a design by these means.In short, good ergonomic design is expensive and time-consuming and this militates against its use other than for the design of (a) systems where man has to work under extreme environmental conditions;