A preliminary proposal for a test to determine the impact damage resis tance of composite materials and their structures is offered. This test is centered on the utility of contact force as a parameter directly related to the damage that occurs during the event. This is demonstrated through work previously published as well as via new experi ments conducted on various graphite/epoxy material systems and laminates in both mono lithic laminate and sandwich configurations. Static indentation and impact tests were con ducted and show a similarity in regards to the structural response and the damage that occurs. This proposal is discussed in terms of the laminates tested and the results, the test's general applicability and utility, and issues that need to be addressed further. The proposal makes a significant step towards providing a common reference point and language for (impact) damage resistance.

A set E of edges of a graph G is said to be a dominating set of edges if every edge of G either belongs to E or is adjacent to an edge of E. If the subgraph 〈E〉 induced by E is a trail T, then T is called a dominating trail of G. Dominating circuits are defined analogously. A sufficient condition is given for a graph to possess a spanning (and thus dominating) circuit and a sufficient condition is given for a graph to possess a spanning (and thus dominating) trail between each pair of distinct vertices. The line graph L(G) of a graph G is defined to be that graph whose vertex set can be put in one-to-one correspondence with the edge set of G in such a way that two vertices of L(G) are adjacent if and only if the corresponding edges of G are adjacent. The existence of dominating trails and circuits is employed to present results on line graphs and second iterated line graphs, respectively.

The use of microbore liquid chromatography columns for high-performance liquid chromatography/mass spectrometry provides improved sensitivity for interfaces of the direct liquid introduction and moving belt types. In the latter case the use of the technique also assists in the handling of mobile phases containing a high percentage of water. Methods for improving the efficiency of microbore columns made from PTFE are described together with the use of a manual column switching technique to assist in some of the problems encountered due to column overload with microbore liquid chromatography columns. The utility of microbore liquid chromatography/mass spectrometry is illustrated by the analysis of an aqueous solution of phenolic compounds.

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