http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7075 Experimental and analytical techniques are introduced for the quantitative, nanoscale mapping of chemical bonding information in carbon-based materials. With these techniques, the spatial orientation of graphitic crystallites in tetrahedrally bonded amorphous carbon was imaged. Simultaneously, the percentage of sp²- and sp³-bonded carbon could be mapped quantitatively, all with spatial resolution of just a few nanometers. Two electron energy-loss spectroscopy (EELS) techniques were compared: low-loss mapping of the plasmon energy and core-loss mapping of the carbon ionization edge. The recently developed EELS acquisition routine of binned gain averaging was applied, together with multivariate statistical analysis, providing a robust method for obtaining real-space, two-dimensional bonding maps. 2012-01-30T05:03:07.621Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5495 Inversion-based feedforward techniques have been known to deliver accurate tracking performance in the absence of plant parameter uncertainties. Piezoelectric stack actuated nanopositioning platforms are prone to variations in their system parameters such as resonance frequencies, due to changes in operating conditions like ambient temperature, humidity and loading. They also suffer from nonlinear effects of hysteresis, an inherent property of a piezoelectric actuator; charge actuation is applied to reduce the effects of hysteresis. In this work, we propose and test a technique that integrates a suitable feedback controller to reduce the effects of parameter uncertainties with the inversion-based feedforward technique. It is shown experimentally that the combination of damping, feedforward and charge actuation increases the tracking bandwidth of the platform from 310 to 1320 Hz. 2011-09-13T00:40:05.782Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2599 The nine regular papers and five brief papers in this special issue focus on dynamics and control of micro- and nanoscale systems. A brief overview of the issue is provided. 2010-04-27T06:46:35.160Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:4833 We investigate the influence of annealing on the morphology of intimately mixed blends of the conjugated polymers poly(9,9'-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylene-diamine)(PFB) and poly(9,9'-dioctylfluorene-co-benzothiadiazole)(F8BT) with scanning transmission x-ray microscopy (STXM). Through the use of a zone plate with theoretical Rayleigh resolution of 30 nm, we are able to resolve sub-100 nm bulk structure in these films. Surprisingly, for unannealed films spin-coated from chloroform we observe features with an average diameter of 85 nm. The high degree of photoluminescence quenching in these as-spun films (>95%) implies that there is significant intermixing within the 85 nm structures, indicating that a hierarchy of phase separation exists even on the length scale of less than 100 nm. With annealing up to 160°, close to the Tg of the components, there is little change in the feature sizes observed by STXM,although an increase in variation of the composition is observed.With annealing above 160°C the imaged features begin to evolve in size,increasing to 225 nm in extent, alongside large changes in composition with annealing to 200°C. Comparing the evolution of morphology imaged by STXM with the change in photoluminescence quenching with annealing, we propose that phase separation first evolves via the evolution of relatively pure phases on the length scale of a few to tens of nanometres within the larger 85 nm structures. Once the length scale of compositional fluctuations exceeds 85 nm (for anneal temperatures above 160°C) the hierarchy of phase separation is lost and the subsequent morphological evolution is readily imaged by STXM.Applying the results of an exciton diffusion and quenching model, we find good agreement between the size of the domains measured by STXM (above 180°C) and the results of the model for an exciton diffusion length of 15 nm. The growth in domain size and towards purer structures has also been observed with resonant soft x-ray scattering. 2010-04-27T04:59:40.442Z ]]>