Numerical analysis of matter transfer is an area that pharmacists find difficult, but which is a technique frequently used in preparing controlled drug release and oral dosage forms. This book provides clear and straightforward information enabling the reader to carry out numerical analysis of matter transfer - a vital processs when looking at the formulation of oral dosage forms with controlled drug release. The drug is dispersed in a polymeric matrix (either biodegradable or not), the basis of which is the transfer of the liquid and the drug through dosage form. Information on this diffusion is found either through mathematical treatment (when the problem is simple), or through numerical analysis (for more complex problems). Professor Vergnaud demonstrates and clarifies these, modelling the process of drug delivery by using numerical analysis and computerization. A simulation of the process is provided, together with a determination of the effects of all parameters, and the author uses both mathematical and numerical models to predict the preparation of new dosage forms able to fulfil specific conditions.

Featuring the work one of the worlda (TM)s foremost authorities on rubber curing, this uniquely comprehensive resource provides valuable data that will allow researchers and engineers to find solutions to their own curing problems. It delves into a variety of current evaluation practices for unvulcanized and vulcanized rubber and curing methods, including the use of molds and injection molding. It also explores a number of solutions to on-going challenges with recycling scrap rubber. In all cases, theoretical treatments are offered in a didactic manner, so that readers not fully familiar with the terms can, nevertheless, easily understand the developments in this field.

The process of cure of thermosets is rather complex, and good knowledge of the various steps and different problems is necessary for the user. For instance, the following basic facts characterise the cure of thermosets: 1. In the same way as rubbers, thermosets are generally polymerised and processed in a simple operation which involves the irreversible transformation of a low molecular weight resin in viscous liquid state into a solid network polymer. The process of cure is thus much more important for thermosets or rubbers than for thermo plastics, because if something goes wrong during the cure process of thermosets, the final products may have undersirable properties and will be of no use or value, while the thermoplastic material can be melted again to make a new material. 2. In contrast with rubbers, a high exothermic cure reaction is the aspect of fundamental importance in the cure process for thermo sets. This high enthalpy of cure associated with a rather low thermal conductivity can give rise to an excessively high tem perature which may cause discoloration and degradation of the material, and also to substantial temperature gradients. The mat erial is thus heterogeneous during the process of cure, and these temperature-time histories in the resin may have some effects on the properties of the final material. 3. Moreover, the increase in production following the reduction in time of the cure cycle necessitates the use of a higher mould temperature.

Drying of Polymeric and Solid Materials shows for the first time how the process of drying can be enhanced by combining mathematical and numerical models with experiments. The main advantages of this method are a significant saving of time and money. Numerical modelling can predict the kinetics of drying and the profiles of liquid concentration through the solid. This helps in the selection of optimal operational conditions. The simulation of the process is also crucial in the assessment of diffusity and the rate of evaporation.