Cavity initiation, growth, and coalescence phenomena during the hot tension testing of Ti–6Al–4V with several different transformed β-microstructures were established to obtain an understanding of the failure process during subtransus hot working. Samples with either a colony-type microstructure (containing grain-boundary α) or a martensitic, acicular α-microstructure were pulled to failure at strain rates between 0.01 and 3 s−1 and various subtransus temperatures ranging from 540 to 955°C. Metallographic analysis of sectioned tension samples with colony microstructures revealed that cavity initiation occurred at very low strains (≾0.2) irrespective of strain rate at temperatures below 900°C due to an apparent incompatibility of deformation between the grain-boundary α-layer and the Widmanstatten side plates. Initiation strains were somewhat higher (∼0.2–0.5) for samples with the acicular α-microstructure tested at temperatures below 900°C; however, failure was still intergranular. Subsequent cavity growth was more rapid for colony microstructures than that for the martensitic α-microstructure at these temperatures. Above 900°C, however, substantially higher cavity initiation strains and lower cavity growth rates were obtained for both microstructures. These latter behaviors were ascribed to the presence of a large volume fraction of ductile β-phase and moderate values of the strain-rate sensitivity of the flow stress, respectively.

The extent of development of digital adhesive toe-pads in sympatric species of microhylid frogs, Cophixalus and Sphenophryne, correlates with the degree of arboreality exhibited by the species. The same basic structures and cell types are found in the toe-pads of these microhylid frogs as are found in other arboreal and semi- arboreal frogs of many diverse evolutionary lineages. A variety of types of cell surface, with unknown functional significance but potential systematic use, are found on the feet of these frogs. Allometric increase in adhesive-pad area in larger species is by widening of the toe-pad, as opposed to acquisition of accessory pads as in some hylid tree frogs.