Leak-before-break: Global perspectives and procedures

Structural integrity of components containing fluids is critical for economic, environmental and safety issues. Any risk of catastrophic failure, in the form of either brittle or ductile manner, is not acceptable across the industries. Consequently, many efforts have been invested in the structural integrity aspect to improve the assessment methodologies. One of the ways to aid the decision whether or not to live with the defect is through the demonstration of Leak-Before-Break (LBB). LBB which is a well-established practice in the nuclear industry, albeit as a defence-in-depth argument or to justify the elimination of pipe whip restraints, also finds its applicability in other industries. A review of the available procedures, their associated limitations and the research carried out in the last thirty years is presented in this paper. Application of this concept within non-nuclear industries is also discussed

Taxonomies of regular tree algorithms

Algorithms for acceptance, pattern matching and parsing of regular trees and the tree automata used in these algorithms have many applications, including instruction selection in compilers, implementation of term rewriting systems, and model checking. Many such tree algorithms and constructions for such tree automata appear in the literature, but some deficiencies existed, including: inaccessibility of theory and algorithms; difficulty of comparing algorithms due to variations in presentation style and level of formality; and lack of reference to the theory in many publications. An algorithm taxonomy is an effective means of bringing order to such a field. We report on two taxonomies of regular tree algorithms that we have constructed to deal with the deficiencies. The complete work has been presented in the PhD thesis of the first author