Retrospective studies of operating problems in air transport

An epidemiological model for the study of human errors in aviation is presented. In this approach, retrospective data are used as the basis for formulation of hypotheses as to system factors which may have contributed to such errors. Prospective experimental studies of aviation operations are also required in order to prove or disprove the hypotheses, and to evaluate the effectiveness of intervention techniques designed to solve operational problems in the aviation system

Segregation and precipitation of Er in Ge

Although Er-doped Genanomaterials are attractive for photonic applications, very little is known about the basic properties of Er in Ge. Here, the authors study the annealing behavior of Geimplanted with keV Er ions to doses resulting in ≲1at.% of Er. Large redistribution of Er, with segregation at the amorphous/crystalline interface, starts at ≳500°C, while lower temperatures are required for material recrystallization. However, even at 400°C, Er forms precipitates. The concentration of Er trapped in the bulk after recrystallization decreases with increasing temperature but is independent of the initial bulk Er concentration for the range of ion doses studied here.Work at the ANU was supported by the ARC

Simulation studies of air transport operational problems

An experimental evaluation of the monitored approach procedure for conducting low visibility instrument approaches is described. Four airline crews each flew 16 approaches using the monitored procedure and 16 using a modified standard procedure in a DC-10 simulator under various conditions of visibility, wind shear and turbulence, and radar vectoring scenarios. In terms of system measures of aircrew performance, no major differences were found. Pilot opinion data indicate that there are some desirable characteristics of the monitored procedure, particularly with reference to the increased role of the flight engineer in conducting low visibility approaches. Rationale for developing approach procedures is discussed

Water and cosmology in the prehistoric Maltese world: Fault control on the hydrogeology of Ġgantija, Gozo (Maltese Islands)

The dry limestone geology of the Maltese islands presented a challenging environment to prehistoric communities, who required reliable water sources to support agricultural subsistence. Ġgantija, one of the iconic Maltese Late Neolithic Temples on Gozo, and now a World Heritage Site, was surveyed using Ground Penetrating Radar to reveal a significant line of geological faulting running beneath the megalithic structure. The seepage of water from this fault had major implications for the siting of the monument. This seems to reflect a pattern of situating many of these key sites adjacent to ancient sources of water, as is shown by the close association of two thirds of these sites with toponym evidence for the presence of springs in the medieval period. It is possible that the prehistoric Maltese embraced this natural resource as part of the cosmology of their ritual sites. © 201

Positron annihilation studies of the AlOₓ/SiO₂/Si interface in solar cell structures

Film and film/substrate interfacecharacteristics of 30 and 60 nm-thick AlOₓfilmsgrown on Si substrates by thermal atomic layer deposition(ALD), and 30 nm-thick AlOₓfilms by sputtering, have been probed using variable-energy positron annihilation spectroscopy (VEPAS) and Doppler-broadened spectra ratio curves. All samples were found to have an interface which traps positrons, with annealing increasing this trapping response, regardless of growth method. Thermal ALD creates an AlOₓ/SiOₓ/Si interface with positron trapping and annihilation occurring in the Si side of the SiOₓ/Si boundary. An induced positive charge in the Si next to the interface reduces diffusion into the oxides and increases annihilation in the Si. In this region there is a divacancy-type response (20 ± 2%) before annealing which is increased to 47 ± 2% after annealing.Sputtering seems to not produce samples with this same electrostatic shielding; instead, positron trapping occurs directly in the SiOₓinterface in the as-deposited sample, and the positron response to it increases after annealing as an SiO₂ layer is formed. Annealing the film has the effect of lowering the film oxygen response in all film types. Compared to other structural characterization techniques, VEPAS shows larger sensitivity to differences in film preparation method and between as-deposited and annealed samples.T-T.A.L., S.R., and A.C. acknowledge funding from the Australian Research Council

Mapping a waste disposal site using Tellus airborne geophysical data

Leakage of fluids from unregulated and/or poorly engineered waste disposal sites poses a significant direct risk to groundwater quality. Characterisation and monitoring of waste disposal sites and potentially associated groundwater contaminant plumes are generally invasive, time-consuming and expensive, particularly when the extent of the plume is unknown. This study examines the value of incorporating of Tellus and Tellus Border airborne electromagnetic (AEM) data into current assessment protocols for the characterisation and monitoring of contaminant sources and subsurface contaminant plumes. The findings demonstrate the feasibility of using airborne and ground-based non-invasive geophysical data as part of existing tiered assessment protocols for prioritising suspected sites and for guiding targeted intrusive investigations and subsequent remediation efforts

The use of geoscience methods for aquatic forensic searches

There have been few publications on the forensic search of water and fewer still on the use of geoforensic techniques when exploring aqueous environments. Here we consider what the nature of the aqueous environment is, what the forensic target(s) may be, update the geoforensic search assets we may use in light of these, and provide a search strategy that includes multiple exploration assets. Some of the good practice involved in terrestrial searches has not been applied to water to-date, water being seen as homogenous and without the complexity of solid ground: this is incorrect and a full desktop study prior to searching, with prioritized areas, is recommended. Much experimental work on the decay of human remains is focused on terrestrial surface deposition or burial, with less known about the nature of this target in water, something which is expanded upon here, in order to deploy the most appropriate geoforensic method in water-based detection. We include case studies where detecting other forensic targets have been searched for; from metal (guns, knives) to those of a non-metallic nature, such as submerged barrels/packages of explosives, drugs, contraband and items that cause environmental pollution. A combination of the consideration of the environment, the target(s), and both modern and traditional search devices, leads to a preliminary aqueous search strategy for forensic targets. With further experimental research and criminal/humanitarian casework, this strategy will continue to evolve and improve our detection of forensic targets

Effects of carbon on ion-implantation-induced disorder in GaN

Wurtzite GaN films bombarded with 40keV C ions to high doses (5×10¹⁷ and 1×10¹⁸cm⁻²) are studied by a combination of Rutherford backscattering/channeling spectrometry, transmission electron microscopy, and soft x-ray absorption spectroscopy. Results show that, contrary to other ion species, implanted C forms nitrilelike carbon-nitride bonds (—C≡N) and suppresses ion-beam-induced material decomposition involving the formation and agglomeration of ≳5-nm-large N₂ gas bubbles.Work at the ANU was supported by the ARC. The ALS is supported by the Director, Office of Science, Office of BES, Materials Sciences Division, of the U.S. DOE under Contract No. DE-AC03-76SF00098 at LBNL

What side effects are problematic for patients prescribed antipsychotic medication? the Maudsley Side Effects (MSE) measure for antipsychotic medication

Background Capturing service users' perspectives can highlight additional and different concerns to those of clinicians, but there are no up to date, self-report psychometrically sound measures of side effects of antipsychotic medications. Aim To develop a psychometrically sound measure to identify antipsychotic side effects important to service users, the Maudsley Side Effects (MSE) measure. Method An initial item bank was subjected to a Delphi exercise (n = 9) with psychiatrists and pharmacists, followed by service user focus groups and expert panels (n = 15) to determine item relevance and language. Feasibility and comprehensive psychometric properties were established in two samples (N43 and N50). We investigated whether we could predict the three most important side effects for individuals from their frequency, severity and life impact. Results MSE is a 53-item measure with good reliability and validity. Poorer mental and physical health, but not psychotic symptoms, was related to side-effect burden. Seventy-nine percent of items were chosen as one of the three most important effects. Severity, impact and distress only predicted 'putting on weight' which was more distressing, more severe and had more life impact in those for whom it was most important. Conclusions MSE is a self-report questionnaire that identifies reliably the side-effect burden as experienced by patients. Identifying key side effects important to patients can act as a starting point for joint decision making on the type and the dose of medication

Development of a non-cloggable subsea data logger for harsh turbidity current monitoring

Large submarine flows of sediment (sand and mud), known as turbidity currents, transfer and bury significant amounts of organic carbon and pollutants to the deep sea via submarine canyons. They are also significant geohazards, regularly breaking networks of seabed telecommunications cables that carry > 99% of global data that underpin the internet. Despite this, key parameters (notably their sediment concentration) in these flows are yet to be directly measured in real-time due to their inherently harsh environment that is unsuitable for commercial conductivity sensors. To address this issue, a subsea datalogger (SSDL) is developed with a planar conductivity sensor head that can measure the sediment concentration within dense turbidity currents. Unlike conventional sensors, the planar design of the SSDL’s sensor prevents clogging at high sediment concentrations, allowing for continuous measurements within turbidity currents. The conductivity sensor is developed with a temperature sensor which is measured using an external 16-Bit ADC which is controlled with a SAMD21 32-Bit ARM microcontroller. The SSDL measures the temperature and the conductivity of the seawater once every 4 seconds for over a year. In an initial device test, the SSDL can record a turbidity current within the Bute Inlet, Canada. It is found that the seawater’s conductivity increases with salinity concentration and decreases with sediment concentration. The SSDL developed here can thus be used for both conventional subsea datalogging applications and high turbidity current applications