No abstract

SUMMARYAn analogy is described between the TLM algorithm and discrete state-space control theory. The analogy is used to derive the characteristic equations corresponding to parametrized model structures. Characteristic equations corresponding to several widely used node structures are derived by this means and found to be consistent with the observed behaviour of corresponding TLM models. An example is given of the use of the analogy in the predictive mode.

SUMMARYMany heat transfer situations are adequately described by the parabolic thermal diffusion equation. However, in situations in which very rapid heating occurs or in slower heating regimes for particular materials, the hyperbolic heat conduction equation is a better representation. Here, a parameterized nodal structure for transmission line modelling (TLM) representation of hyperbolic heat conduction processes is devised. A TLM model based on the nodal structure is implemented and temperature field predicted by the model are compared with analytical results for the same physical situation.

This study focuses on the ability of U‐PVC to be processed a number of times. Three different types of U‐PVC were investigated: virgin lead‐stabilized material; virgin calcium/zinc‐stabilized material; and reground, 20‐year‐old, post‐consumer windows. Each material was extruded four times, without any addition of any stabilizers. Samples were taken at each stage for rheological and mechanical analysis. J. Vinyl Addit. Technol. 10:174–178, 2004. © 2004 Society of Plastics Engineers.

No abstract