Transparent conducting oxide (TCO) nanoparticles based on zinc oxide doped with aluminium and gallium (Al-and Ga-co-doped ZnO, AGZO) were synthesized using a continuous hydrothermal flow synthesis (CHFS) reactor by rapid hydrolysis and dehydration of aqueous metal salt precursors, in the presence of formic acid as an in-process reducing agent. The as-synthesised powders were characterized by powder X-ray diffraction (pXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The as-synthesised powders were pressed into ceramic compacts and heat treated to ensure phase-pure wurtzite structure. The electrical properties of the materials were evaluated by Hall Probe measurements on the compacts, showing resistivities as low as 4 55 × 10 −2 cm, which represents a very high conductivity for such a pressed disc based on ZnO.

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Composite laminate thickness tapering is essential for weight efficient structures. This is achieved by terminating specific plies, but these can in turn act as sites for delamination initiation. One area of importance is the spacing between adjacent ply drops, which can have a significant impact on the delamination stress. In this work, a novel tape scarfing method that applies a tapered profile to dropped ply ends was used on unidirectional tapered laminate specimens with multiple ply drops. The effect of ply drop spacing on the delamination stress of both conventional and scarfed plies in tension was studied experimentally. The results showed that the scarfed ply drop configurations can completely suppress delamination in certain configurations. The scarfed ply drops also retained higher performance with smaller ply drop spacings. This indicates that in using scarfed plies, conventional laminate design rules could be relaxed and the weight of the structure could be further reduced. The underlying failure mechanisms were also investigated using both analytical and numerical methods. A simple stress-based formula for estimating the delamination stress of scarfed plies was introduced and shown to be consistent with both experimental and numerical results, which could be used (and further developed) to make tapered laminate design easier.