ORCID Profile
0000-0002-7339-3082
Current Organisation
University of Tasmania
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Publisher: International Union of Crystallography (IUCr)
Date: 2021
DOI: 10.1107/S1600577520013995
Abstract: Analyser-based phase-contrast imaging (ABPCI) is a highly sensitive phase-contrast imaging method that produces high-contrast images of weakly absorbing materials. However, it is only sensitive to phase gradient components lying in the diffraction plane of the analyser crystal [ i.e. in one dimension (1-D)]. In order to accurately account for and measure phase effects produced by the wavefield-s le interaction, ABPCI and other 1-D phase-sensitive methods must achieve 2-D phase gradient sensitivity. An inclined geometry method was applied to a Laue geometry setup for X-ray ABPCI through rotation of the detector and object about the optical axis. This allowed this traditionally 1-D phase-sensitive phase-contrast method to possess 2-D phase gradient sensitivity. Tomographic datasets were acquired over 360° of a multi-material phantom with the detector and s le tilted by 8°. The real and imaginary parts of the refractive index were reconstructed for the phantom.
Publisher: Elsevier BV
Date: 08-2018
Publisher: MDPI AG
Date: 23-03-2023
Abstract: Foliar application of nitrogen (N) may supplement soil-applied N in sweet cherry orchards. The proteinogenic amino acid L-proline is a potential source of organic N. However, little is understood about its uptake and effects on fruit quality. In this study, 15N-labelled L-proline was spray-applied to branches of the cultivar ‘Lapins’ either pre- or post-harvest. Leaves, fruit, and whole branches were s led to investigate the uptake and allocation of foliar-applied N. Both treatments resulted in elevated 15N levels in leaves, with N derived from proline (%NDP) comprising 0.22% and 0.45% after pre- and post-harvest applications, respectively. The fruit was a sink for pre-harvest L-proline, with the highest %NDP in the pedicel (0.21%), followed by the skin (0.17%) and flesh (0.12%). Quality outcomes of smaller, darker fruit with lower stem retention indicate advanced maturity following L-proline application. Both pre- and post-harvest treatments resulted in the recovery of 15N in branches at late dormancy, with %NDP in bark (0.12%), buds (0.15%), and wood (0.02%) of the post-harvest treatment twice as high compared with those from the pre-harvest treatment. This study demonstrates proof of concept of the uptake of L-proline into the leaves of sweet cherry plants and translocation into the fruit and storage organs of the branch.
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/SR19333
Abstract: The application of nitrate (NO3–) fertiliser is important worldwide in providing nitrogen (N) nutrition to perennial fruit trees. There is little information available on N losses to the environment from commercial cherry orchards, in relation to different timings of NO3– application. The emission of nitrous oxide (N2O) gas is an important greenhouse gas loss from NO3– application, being responsible for 6% of anthropogenic global warming and a catalyst for depletion of stratospheric ozone. In a commercial sweet-cherry orchard in southern Tasmania, we applied 373 g NO3–-N m–2 (equivalent to 90 kg NO3–-N ha–1) either pre- or post-harvest, or equally split between the two, to study the resultant N2O emissions. Emissions averaged 8.37 mg N2O-N m–2 day–1 during the pre-harvest period, primarily driven by a heavy rainfall event, and were significantly greater (P & 0.05) than the average 4.88 × 10–1 mg N2O-N m–2 day–1 from post-harvest NO3– application. Discounting the emissions related to the rainfall event, the resultant average 1.88 mg N2O-N m–2 day–1 for the rest of the pre-harvest emissions remained significantly greater (P & 0.05) than those post-harvest. Ongoing studies will help to build on these results and efforts to minimise N2O emissions in perennial tree cropping systems.
No related grants have been discovered for Peter Quin.