Evaluation of the onset of space charge and electroluminescence as a marker for cross linked polyethylene ageing

The aim of the “ARTEMIS” project is to investigate the ageing mechanisms for cross-linked polyethylene under thermo-electrical stress and to identify ageing markers, which can be used to carry out diagnostic procedures. A carefully selected set of techniques which can give cross-correlated information on space charge phenomenology and material degradation were used to investigate specimens peeled from reference and aged cables. The paper shows that ageing induces a change in the density and depth of trapping levels, and an increase in the number and size of mesovoids. Interpretation of these results is discussed in terms of physico-chemical modifications, which can affect trap distribution and microstructure

Justice Stevens and Constitutional Adjudication: The Law Beyond the Rules

This Article considers Justice Stevens’ approach to equal protection and free speech cases. It contrasts his longstanding attempts to pierce through mediating doctrinal rules in these areas and apply true constitutional meaning (“the law beyond the rules”) with the more rule-bound approach exemplified by Chief Justice Roberts and other members of the Court’s conservative bloc. While appreciating JusticeStevens’ efforts in this regard, this Article also recognizes some of the problems he encountered in his quest. However, it also notes that the more rule-bound approach suffers from flaws of its own, even when judged against the criteria more rule-friendly justices offer to evaluate a given method of constitutional adjudication. Thus, whatever one might think of the ultimate success of Justice Stevens’ project, it is surely the case that the more rule-bound approach has not proven its clear superiority

Developments in the negative-U modelling of the cuprate HTSC systems

The paper deals with the many stands that go into creating the unique and complex nature of the HTSC cuprates above Tc as below. Like its predecessors it treats charge, not spin or lattice, as prime mover, but thus taken in the context of the chemical bonding relevant to these copper oxides. The crucial shell filling, negative-U, double-loading fluctuations possible there require accessing at high valent local environment as prevails within the mixed valent, inhomogeneous two sub-system circumstance of the HTSC materials. Close attention is paid to the recent results from Corson, Demsar, Li, Johnson, Norman, Varma, Gyorffy and colleagues.Comment: 44 pages:200+ references. Submitted to J.Phys.:Condensed Matter, Sept 7 200