Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative–convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures ${\geqslant}150$ eV and electron densities ${\geqslant}7\times 10^{21}~\text{cm}^{-3}$. The iron will be probed using continuum X-rays emitted in a ${\sim}200$ ps, ${\sim}200~\unicode[STIX]{x03BC}\text{m}$ diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design, $2/3$ of the NIF beams deliver 500 kJ to the ${\sim}6$ mm diameter hohlraum, and the remaining $1/3$ directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.

The collective response of electrons in an ultrathin foil target irradiated by an ultraintense (${\sim}6\times 10^{20}~\text{W}~\text{cm}^{-2}$) laser pulse is investigated experimentally and via 3D particle-in-cell simulations. It is shown that if the target is sufficiently thin that the laser induces significant radiation pressure, but not thin enough to become relativistically transparent to the laser light, the resulting relativistic electron beam is elliptical, with the major axis of the ellipse directed along the laser polarization axis. When the target thickness is decreased such that it becomes relativistically transparent early in the interaction with the laser pulse, diffraction of the transmitted laser light occurs through a so called ‘relativistic plasma aperture’, inducing structure in the spatial-intensity profile of the beam of energetic electrons. It is shown that the electron beam profile can be modified by variation of the target thickness and degree of ellipticity in the laser polarization.

The material properties of atomic layer deposited hybrid organic-inorganic aluminate thin films have been evaluated for potential low dielectric constant (i.e. low-k) applications. The hybrid aluminates were deposited using trimethyl aluminum and various linear and aromatic carboxylic acids. The observed electrical and mechanical properties for the hybrid aluminate films varied greatly depending on the selected organic acid with k values ranging from 2.5 to 5.1 and Young’s modulus ranging from 6 to 40 GPa. Leakage currents as low as 4 x 10-10 A/cm2 (at 2 MV/cm) were obtained for films grown using saturated linear carboxylic acids. These results suggest the potential of ALD hybrid aluminate thin films for low-k dielectric applications.

We investigated the adverse effect of phytate on mineral absorption and the effect of dietary phytate and age on the relationship between faecal phytate and faecal mineral excretion. Fourteen young women (aged 19–24 years) and fourteen elderly women (64–75 years) were studied for two metabolic periods (MP). In MP1, the subjects consumed a controlled high-phytate (HP) diet for 10 d; in MP2, they were on a low-phytate (LP) diet for 10 d. In each period, diet samples and complete faecal samples for 5 d were collected to analyse phytate and mineral contents. Mineral concentrations in diet and faeces were measured by inductively coupled plasma–atomic emission spectrometry. Linear regression analysis was used to examine the associations between faecal phytate and mineral excretion. The degradation rate of dietary phytate was about 77 % for young women, which was significantly lower than that of elderly women (86 %) (P < 0·05). Faecal phytate excretion was positively correlated with mineral excretion (Ca, P, Fe and Zn) in both the HP and LP diet groups in young women (P < 0·05). The linear relationship tended to be greater during the LP diet period compared with the HP diet period in young women. However, no association was found between phytate excretion and mineral excretion in elderly women. In summary, undegraded dietary phytate (10–20 %) had a negative effect on mineral absorption in young women, and the relationship between faecal phytate and mineral excretion was affected by both dietary phytate and age.

This paper explores how separated fathers, who may have limited or no contact with their children, can be understood from a non-deficit perspective (Fleming 2002; Hawkins & Dollahite 1997; King 2000, 2001, 2005; King, Sweeney & Fletcher 2004). It describes how the generative fathering framework is used as a model to assist separated fathers to rebuild their connection with their children. The paper also examines parent/child contact time from a child focused perspective.

Following on from the article appearing in Children Australia Vol 30 No 2 (King 2005), this short paper develops a checklist for organisations working with fathers for assessing the programs they provide to men. The checklist uses four categories – environment, language, initial contact and marketing, and service provision – to assess their programs’ strengths and weaknesses.

The paper provides an opportunity for organisations to benchmark their approach in working with male service users and provides guidance on how program delivery can be improved.

We describe a new classifier for protein secondary structure prediction that is formed by cascading together different types of classifiers using neural networks and linear discrimination. The new classifier achieves an accuracy of 76.7% (assessed by a rigorous full Jack-knife procedure) on a new nonredundant dataset of 496 nonhomologous sequences (obtained from G.J. Barton and J.A. Cuff). This database was especially designed to train and test protein secondary structure prediction methods, and it uses a more stringent definition of homologous sequence than in previous studies. We show that it is possible to design classifiers that can highly discriminate the three classes (H, E, C) with an accuracy of up to 78% for β-strands, using only a local window and resampling techniques. This indicates that the importance of long-range interactions for the prediction of β-strands has been probably previously overestimated.

We describe the results of an investigation into the formation and properties of dislocations in electronic devices. We have made electron transparent specimens from metastable GeSi/Si p-n junction diodes and introduced dislocations into the devices by heating in situ in the electron microscope. A modification made on the specimen holder for our microscope enables us to measure the characteristics of these devices while they remain under observation in the microscope. We can therefore observe the changes in the electrical properties of the devices as dislocations form. We confirm that the introduction of dislocations has a deleterious effect on parameters such as the reverse leakage current through a diode. However the magnitude of the effect we observe can not be explained by a generation-recombination process and instead we suggest a model based on the creation of point defects or the diffusion of metals during the formation of dislocations. We also consider the kinetics of dislocation formation, and in particular how the extent of dislocation formation in a device depends on the subsequent processing steps which it undergoes.

This paper reports the most recent results from the cluster chemistry program at the Naval Research Laboratory, in which our efforts in the characterization of gas-phase cluster properties have been extended to studies of condensed-phase species. First, in an attempt to investigate the fundamental interactions between mass-selected cluster ions and surfaces, two tandem mass spectrometers were constructed or modified, and the results of the initial experiments will be discussed. The emphasis will be on illustrating the general utility of ion/surface collisions to study fragmentations, reactions, and deposition. Second, clusters were deposited into a matrix in order to perform spectroscopic analyses. The initial experiments have been directed at optimization of the techniques. Finally, recent measurement of the ionization potentials of large carbon clusters will be reported. These results are especially significant because of the new developments in large-scale production, isolation, and characterization of these species.