Global correlations between maximum magnitudes of subduction zone interface thrust earthquakes and physical parameters of subduction zones

Peer reviewedPublisher PD

Redescription and ecology of the endemic Tasmanian Scincid lizards Leiolopisma microlepidotum and L. Pretiosum

Two species of scincid lizard, both hitherto identified as Leiolopisma pretiosum, occur syntopically on Mt Wellington, near Hobart, Tasmania. One of these is conspecific with the holotype of Moeoa pretiosa O'Shaughnessy, 1874, while the other is conspecific with the holotype of Mocoa microlepidota O'Shaughnessy, 1874, which has been regarded as a synonym of L. pretiosum since 1887. The two species are redescribed as members of an endemic Tasmanian subgroup within the Australian radiation of the genus Leiolopisma (sensu Greer 1982). Leiolopisma mierolepidotum is confined to disjunct alpine populations in the south and west of Tasmania. It differs from L. pretiosum in colour pattern, larger size and more robust, less depressed head and body. Aspects of the biology and ecology of these and other Tasmanian endemic Leiolopisma species are also discussed

Generic protease detection technology for monitoring periodontal disease

Periodontal diseases are inflammatory conditions that affect the supporting tissues of teeth and can lead to destruction of the bone support and ultimately tooth loss if untreated. Progression of periodontitis is usually site specific but not uniform, and currently there are no accurate clinical methods for distinguishing sites where there is active disease progression from sites that are quiescent. Consequently, unnecessary and costly treatment of periodontal sites that are not progressing may occur. Three proteases have been identified as suitable markers for distinguishing sites with active disease progression and quiescent sites: human neutrophil elastase, cathepsin G and MMP8. Generic sensor materials for the detection of these three proteases have been developed based on thin dextran hydrogel films cross-linked with peptides. Degradation of the hydrogel films was monitored using impedance measurements. The target proteases were detected in the clinically relevant range within a time frame of 3 min. Good specificity for different proteases was achieved by choosing appropriate peptide cross-linkers.<br/

Inherited crustal deformation along the East Gondwana margin revealed by seismic anisotropy tomography

Acknowledgments We thank Mallory Young for providing phase velocity measurements in mainland Australia and Tasmania. Robert Musgrave is thanked for making available his tilt-filtered magnetic intensity map. In the short term, data may be made available by contacting the authors (S.P. or N.R.). A new database of passive seismic data recorded in Australia is planned as part of a national geophysics data facility for easy access download. Details on the status of this database may be obtained from the authors (S.P., N.R., or A.M.R.). There are no restrictions on access for noncommercial use. Commercial users should seek written permission from the authors (S.P. or N.R.). Ross Cayley publishes with the permission of the Director of the Geological Survey of Victoria.Peer reviewedPublisher PD

Automatic differentiation in geophysical inverse problems

Automatic differentiation (AD) is the technique whereby output variables of a computer code evaluating any complicated function (e.g. the solution to a differential equation) can be differentiated with respect to the input variables. Often AD tools take the form of source to source translators and produce computer code without the need for deriving and hand coding of explicit mathematical formulae by the user. The power of AD lies in the fact that it combines the generality of finite difference techniques and the accuracy and efficiency of analytical derivatives, while at the same time eliminating 'human' coding errors. It also provides the possibility of accurate, efficient derivative calculation from complex 'forward' codes where no analytical derivatives are possible and finite difference techniques are too cumbersome. AD is already having a major impact in areas such as optimization, meteorology and oceanography. Similarly it has considerable potential for use in non-linear inverse problems in geophysics where linearization is desirable, or for sensitivity analysis of large numerical simulation codes, for example, wave propagation and geodynamic modelling. At present, however, AD tools appear to be little used in the geosciences. Here we report on experiments using a state of the art AD tool to perform source to source code translation in a range of geoscience problems. These include calculating derivatives for Gibbs free energy minimization, seismic receiver function inversion, and seismic ray tracing. Issues of accuracy and efficiency are discussed

Technical feasibility of storage on large dish stirling systems

Dish-Stirling systems have been demonstrated to provide high-efficiency solar-only electrical generation, holding the world record at 31.25%. This high efficiency results in a system with a high possibility of meeting the DOE SunShot goal of $0.06/kWh. Current dish-Stirling systems do not incorporate thermal storage. For the next generation of non-intermittent and cost-competitive solar power plants, we propose a thermal energy storage system that combines latent (phase-change) energy transport and latent energy storage in order to match the isothermal input requirements of Stirling engines while also maximizing the exergetic efficiency of the entire system. This report takes an initial look at the technical advantages of dish Stirling with storage as well as the technical challenges, in order to make a preliminary estimate as to the technical feasibility of such a system. We find that a storage system using metallic eutectic phase change storage results in a feasible physical embodiment, with mass, volume, and complexity suitable for 25kWe dish Stirling systems. The results indicate a system with 6 hours of storage and a solar multiple of 1.25 provides the optimum impact to LCOE and profit. Further, for no negative impact on LCOE, the optimal storage system may cost as much as$82/kWhth or $33k/dish, a substantial departure from the SunShot goals for tower systems. The storage system also is shown to have substantial structural benefits to the dish design. In addition, there may be benefits in terms of capacity payments or failure-to-deliver penalties. A dish storage system design must take into account the value placed on storage by the PUC or utility

Development and application of the GIM code for the Cyber 203 computer

The GIM computer code for fluid dynamics research was developed. Enhancement of the computer code, implicit algorithm development, turbulence model implementation, chemistry model development, interactive input module coding and wing/body flowfield computation are described. The GIM quasi-parabolic code development was completed, and the code used to compute a number of example cases. Turbulence models, algebraic and differential equations, were added to the basic viscous code. An equilibrium reacting chemistry model and implicit finite difference scheme were also added. Development was completed on the interactive module for generating the input data for GIM. Solutions for inviscid hypersonic flow over a wing/body configuration are also presented