We have now commissioned a new piece of sample-environment apparatus on our Wombat powder diffractometer, this time using the rheometer (normally used on the small-angle scattering instruments like Quokka) to shear a sample whilst collecting diffraction data.
This was done for an experiment with forensic applications in collaboration with Barbara Stuart and Paul Thomas from the University of Technology Sydney.
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| A crystal structure change (alpha to beta) tracked with WOMBAT whilst the sample was undergoing shear. |
A model of tripalmitin was tested because forensic pathologists sometimes find crystals in fat tissue from individuals who are involved in fatal accidents. It is not known if the crystals form as the body cools or are the result of an impact injury. Shear stress can be caused by the application of force.
"The goal is to establish for pathologists whether or not the crystal structures are due to high-speed impact," said Associate Professor Barbara Stuart of the Centre for Forensic Science at the University of Technology Sydney.
Studying a sample of deuterated tripalmitin (made by Anna Leung at the National Deuteration Facility), the form of crystallisation and material volume was tracked as a function of temperature and shear on the sample.
Thanks to Norman Booth for his support in getting this new sample environment (new to Wombat) working and collecting great data.
Published: 30/03/2015