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Impact of minute-time-scale kinetics on the stabilization of the skyrmion-lattice in Cu2OSeO3
(IOP Publishing, 2017-04-20) Reim, JD; Makino, K; Higashi, D; Nambu, Y; Okuyama, D; Sato, TJ; Gilbert, EP; Booth, N; Seki, S
Using small angle neutron scattering measurements, we have previously demonstrated the influence of field-cooling (FC), field-warming (FW) and zero-field-cooling (ZFC) protocols on the thermodynamical stability of the skyrmion-lattice phases SkX(l) and SkX(2) in Cu2OSeO3. Here, we have discovered that small variations in these protocols can have a significant impact on the phase stabilization. Using the ZFC protocol the stabilization of either SkX(l) or SkX(2) can be tuned either by applying the magnetic field directly or with intermediate steps. Furthermore, introducing waiting times at intermediate temperature steps into the FC and FW protocol significantly influences the skyrmion-lattice stabilization. Although for the latter FC and FW experiment, the extrinsic temperature equilibration effect cannot be excluded, the influence of the temperature and magnetic field sweep rate indicates the importance of slow kinetics on the order of a few minutes for the stabilization process. © The Authors - CC-BY 3.0 - Open Access.
Characterisation of the deposition of n-octanohydroxamate on copper surfaces
(The Electrochemical Society, 2013-04-01) Parker, GK; Holt, SA; Hope, GA
The interaction of the flotation reagent, n-octanohydroxamate, with a copper electrode was investigated using cyclic voltammetry, contact angles, surface-enhanced Raman scattering, neutron reflectometry and X-ray reflectometry. The data demonstrated that hydroxamate did not undergo underpotential chemisorption. A hydrophobic non-passivating multilayer of copper n-octanohydroximate formed in the CuII stability region that was more stable than the oxide formed in the absence of hydroxamate. In the CuI and Cu0 stability regions the interface contained more than 50% water and the hydroxamate moiety was present in the keto tautomeric form. © IOP Publishing
Hydration study of soy protein in the ‘dry state’
(Royal Society of Chemistry, 2008-05-19) Kealley, CS; Rout, MK; Appelqvist, IAM; Strounina, EV; Whittaker, AK; Gidley, MJ; Gilbert, EP; Lillford, PJ
The work reported focuses on the methodology employed by the Australian Food Futures collaboration to the study of proteins in the dry state. To date, 'dry' proteins (here used to describe solids with a moisture content <30% w/w) have been characterised by differential scanning calorimetry (DSC), fourier transform - infrared spectroscopy (FT-IR), 1H t2 relaxation and 13C high resolution nuclear magnetic resonance (NMR) spectroscopy and small angle x-ray scattering (SAXS). The case study presented in this paper centres on the use of these techniques to characterise the differences in structure between native and denatured glycinin, a soy protein, at low and controlled moisture contents. The glass transition temperature of native soy glycinin (11S) at room temperature (∼ 27°C), is at a moisture content of 13.4%, whereas the denatured soy glycinin undergoes a glass transition at 46°C at the same moisture content. With increasing water content, NMR experiments show that proton exchange with protein surfaces (*H T2) and protein segmental mobility (13C) both increase. A β - sheet toβ - turn structural rearrangement is inferred as the position of the Amide-I FT-IR band shifts from 1634 to 1630 cm"1. Proton T2 relaxation rates range from < 1 ms to 25 ms, with shorter (< 1 ms) relaxation rates dominant up to 17.4% moisture for both native and denatured glycinin. ,13C NMR experiments show motional heterogeneity for native glycinin, with a more uniform and restricted mobility after denaturation. Small angle scattering data show an expansion of -7% in the unit cell of the material as the moisture content is increased from 4.6% up to 13.4%, however there are no significant crystalline or other major structural changes in the protein over the spatial dimension probed (1-100 nm). © The Royal Society of Chemistry 2008.
LET dependence of the charge collection efficiency of silicon microdosimeters
(Institute of Electrical and Electronics Engineers (IEEE), 2003-12) Cornelius, IW; Rosenfeld, AB; Siegele, R; Cohen, DD
A heavy ion microprobe was used to conduct ion beam induced charge (IBIC) collection imaging of silicon microdosimeters. The GEANT4 Monte Carlo toolkit was used to simulate these measurements to calculate ion energy loss in the device overlayer and energy deposition in the device sensitive volume. A comparison between experimental and theoretical results facilitated the calculation of charge collection efficiency profiles for several ions. © 2025 IEEE
Provenance studies of New Zealand obsidian artefacts
(Elsevier, 1984-04) Duerden, P; Bird, JR; Clayton, E; Cohen, DD; Leach, BF
A large scale obsidian analysis program at the AAEC Research Establishment uses an automated facility with a multisample capacity and simultaneous PIXE and PIGME measurement. A pinhole filter in front of the PIXE detector ensures that up to 20 element concentrations can be obtained from the samples in a 5 min irradiation. Spectrum analysis and data handling procedures have been set up together with a variety of parametric and non-parametric statistical procedures. The clustering programs have been used with data from a previously measured S. W. Pacific and New Zealand obsidian source collection to identify the origin of artefact material. The example used to illustrate this program is of obsidian artefacts from the Kermadec and Chatham Islands. © 1984 Published by Elsevier B.V.

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