Purpose: Calibration of a radiotherapy electronic portal imaging device (EPID) using the pixel-sensitivity-map (PSM) in place of the flood field correction improves the utility of the EPID for quality assurance applications. Multiple methods are available for determining the PSM and this study provides an evaluation to inform on which is superior. Methods: Three different empirical methods (“Calvary Mater Newcastle” [CMN], “Varian,” and “WashU”) and a Monte Carlo-based method of PSM determination were investigated on a single Varian TrueBeam STx linear accelerator (linac) with an aS1200 EPID panel. PSM measurements were performed for each empirical method three successive times using the 6 MV beam. The resulting PSM from each method was compared to the Monte Carlo method as a reference using 2D percentage deviation maps and histograms plus crossplane profiles. The repeatability of generated PSMs was also assessed via 2D standard deviation (SD) maps and histograms. Additiona
The Finke River in central Australia is counted among the world's oldest drainage systems; this raises the prospect of investigating how (tectonic and sub-lithospheric) processes have shaped the landscape in the long term. The Finke's upper reaches display an enigmatic set of intertwined active and relict bedrock gorges that suggest a complex history of incision, aggradation and re-incision. We measured cosmogenic 10Be and 26Al in fluvial gravels preserved in the gorges, and we applied a Markov chain-Monte Carlo-based inversion model to test two limiting-case hypotheses about the timing of gravel deposition and exhumation. Our results suggest that the nuclide memory contained within the gravels was essentially erased during sediment storage exceeding several million years. Previous studies attribute central Australia's geomorphic development to intensified post-Miocene aridity in tune with the perception of a quiescent tectonic regime. However, the close correlation betw
Michael Kauter and his professor husband look set to leave the Sydney abode where their $150,000 BMW was accidentally crushed in its garage car stacker.
Political lobbyist Michael Kauter and his medico husband David Gracey look set to swap their Woollahra home for the historic former post master’s residence in Mosman.
Political lobbyist Michael Kauter and his medico husband David Gracey look set to swap their Woollahra home for the historic former post master’s residence in Mosman.