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Traces of sperm cells recovered on clothing impose challenges as to the interpretation of such findings in sexual assault cases. The manner of deposition may not be readily determined, clothing may have been washed, or the findings may not be related to the incidence under investigation. Spermatozoa survived on cotton underwear machinewashed at 40 8C and 60 8C. Interpretational caution must be applied when examining evidence in connection with sexual assault, even when testing positive for acid phosphatase (AP) activity, which may come from normal vaginal secretions, but may be coinciding with spermatozoa retained after laundering.

Highly oriented epitaxial rutile titanium dioxide (TiO) nanowire arrays have been hydrothermally grown on polycrystalline TiO templates with their orientation dependent on the underlying TiO grain. Both the diameter and areal density of the nanowires were tuned by controlling the precursor concentration, and the template surface energy and roughness. Nanowire tip sharpness was influenced by precursor solubility and diffusivity. A new secondary ion mass spectrometer technique has been developed to install additional nucleation sites in single crystal TiO templates and the effect on nanowire growth was probed. Using the acquired TiO nanowire synthesis knowhow, an assortment of nanowire arrays were installed upon the surface of undoped TiO photo-electrodes and assessed for their photo-electrochemical water splitting performance. The key result obtained was that the presence of short and dispersed nanowire arrays significantly improved the photocurrent when the illumination intensity was increased from 100 to 200 mW cm. This is attributed to the alignment of the homoepitaxially grown nanowires to the [001] direction, which provides the fastest charge transport in TiO and an improved pathway for photo-holes to find water molecules and undertake oxidation. This result lays a foundation for achieving efficient water splitting under conditions of concentrated solar illumination.

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