Optimal disassembly of complex products

This paper presents a method for determining the optimum disassembly sequence for selective disassembly of discarded complex products. This methodology has been developed within the framework of the increasing need for formulation of a theory on selective disassembly and the various purposes of it. The objective of the optimization is maximizing the economic performance of the disassembly process within given technical and environmental constraints. It is demonstrated that the method, that is based on graphs, can be used to generate optimum sequences according to various objectives in a straightforward way. Also a ranking of the most favourable alternative sequence is possible. This is important to the inclusion of other criteria in the model and in adaptation of the disassembly system to fluctuating parameters like material yields and constraints. Contrary to earlier work on generation of disassembly sequences, in selective disassembly all possible incomplete disassembly sequences are included. This considerably increases the number of disassembly sequences to be studied with respect to the number of possible assembly sequences. According to the method described here, the number of viable sequences is determined in a straightforward way. On the basis of a specific example the general methodology is discussed

Damping and dispersion of linear longitudinal oscillations in a multi-component plasma. II

Linear dispersion phenomena in Vlasov-Poisson plasma's with drift are studied in order to be able to test the relevance of linear theory for plasma turbulence. Especially the effect of the addition of light ions, giving rise to stabilisation, is taken into account. Emphasis is laid on approximate methods that give the possibility to investigate the influence of parameters like ion-mass-ratio, temperature ratio etc. Numerical results are given for a He-A plasma.</p