Fluid structure interaction of submerged metallic and composite plates subjected to low velocity impact loading

An instrumented low velocity impact rig has been used to acquire experimental data for impacts in air and underwater for both metallic and composite plates when subjected to a low velocity drop-weight impact with a 2kg steel impactor. Initial impact studies were conducted in air and then repeated for submersed conditions underwater. Experimental results are compared for all tests with numerical solutions and are found to be in good agreement. For underwater impact, the numerical model incorporates the use of a Eulerian formulation for the water with a coupled fluid-structure interaction algorithm. The effect of the water surrounding the target plates was found to reduce the peak accelerations and also reduce the overall impact duration when compared to the same impacts in air. X-Ray imagery of the composite plates also showed visibly reduced damage for the submersed test specimens. This research provides data on the impact response of metallic and composite materials, and validates numerical methodologies for use in future work on fluid-structure interactions which show strong potential for relevant industrial applications

Measured Sensitivity of the First Mark II Phased Array Feed on an ASKAP Antenna

This paper presents the measured sensitivity of CSIRO's first Mk. II phased array feed (PAF) on an ASKAP antenna. The Mk. II achieves a minimum system-temperature-over-efficiency $T_\mathrm{sys}/\eta$ of 78 K at 1.23 GHz and is 95 K or better from 835 MHz to 1.8 GHz. This PAF was designed for the Australian SKA Pathfinder telescope to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array (SKA).Comment: 5 pages, 2 figures, accepted for publication in Electromagnetics in Advanced applications (ICEAA), 2015 International Conference o

Chemical kinetics and photochemical data for use in stratospheric modeling evaluation Number 8

This is the eighth in a series of evaluated sets of rate constants and photochemical cross sections compiled by the NASA Panel for Data Evaluation. The primary application of the data is in the modeling of stratospheric processes, with particular emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena. Copies of this evaluation are available from the Jet Propulsion Laboratory, Documentation Section, 111-116B, California Institute of Technology, Pasadena, California, 91109

Chemical kinetics and photochemical data for use in stratospheric modeling

As part of a series of evaluated sets, rate constants and photochemical cross sections compiled by the NASA Panel for Data Evaluation are provided. The primary application of the data is in the modeling of stratospheric processes, with particular emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena. Copies of this evaluation are available from the Jet Propulsion Laboratory

Evaluation of cost-effective strategies for rabies post-exposure vaccination in low-income countries

<b>Background:</b> Prompt post-exposure prophylaxis (PEP) is essential in preventing the fatal onset of disease in persons exposed to rabies. Unfortunately, life-saving rabies vaccines and biologicals are often neither accessible nor affordable, particularly to the poorest sectors of society who are most at risk and upon whom the largest burden of rabies falls. Increasing accessibility, reducing costs and preventing delays in delivery of PEP should therefore be prioritized.<p></p> <b>Methodology/Principal Findings:</b> We analyzed different PEP vaccination regimens and evaluated their relative costs and benefits to bite victims and healthcare providers. We found PEP vaccination to be an extremely cost-effective intervention (from $200 to less than$60/death averted). Switching from intramuscular (IM) administration of PEP to equally efficacious intradermal (ID) regimens was shown to result in significant savings in the volume of vaccine required to treat the same number of patients, which could mitigate vaccine shortages, and would dramatically reduce the costs of implementing PEP. We present financing mechanisms that would make PEP more affordable and accessible, could help subsidize the cost for those most in need, and could even support new and existing rabies control and prevention programs.<p></p> <b>Conclusions/Significance:</b> We conclude that a universal switch to ID delivery would improve the affordability and accessibility of PEP for bite victims, leading to a likely reduction in human rabies deaths, as well as being economical for healthcare providers.<p></p&gt

Rabies elimination research: juxtaposing optimism, pragmatism and realism

More than 100 years of research has now been conducted into the prevention, control and elimination of rabies with safe and highly efficacious vaccines developed for use in human and animal populations. Domestic dogs are a major reservoir for rabies, and although considerable advances have been made towards the elimination and control of canine rabies in many parts of the world, the disease continues to kill tens of thousands of people every year in Africa and Asia. Policy efforts are now being directed towards a global target of zero human deaths from dog-mediated rabies by 2030 and the global elimination of canine rabies. Here we demonstrate how research provides a cause for optimism as to the feasibility of these goals through strategies based around mass dog vaccination. We summarize some of the pragmatic insights generated from rabies epidemiology and dog ecology research that can improve the design of dog vaccination strategies in low- and middle-income countries and which should encourage implementation without further delay. We also highlight the need for realism in reaching the feasible, although technically more difficult and longer-term goal of global elimination of canine rabies. Finally, we discuss how research on rabies has broader relevance to the control and elimination of a suite of diseases of current concern to human and animal health, providing an exemplar of the value of a ‘One Health’ approach

Processing blur of conflicting stimuli during the latency and onset of accommodation

The accommodative response (AR) to changes in dioptric accommodative stimulus (AS) during the latency period and onset of accommodation was investigated. Participants monocularly observed one period of a square wave in AS, with a 2-D baseline and mean, and amplitude 1 D or 2 D; the period of the square wave ranged from 0.10 s to 1.00 s; both increases and decreases were used for the first step in AS. At periods of 0.30 s and longer, accommodation was found to respond to both levels of the stimulus. Rapid retinal monitoring appeared to be taking place for such stimuli. The amplitudes of peaks in AR did not usually depend on whether a particular level of AS occurred first or second, but for 8/40 conditions, a significant difference was found, with a stronger response when the level of AS occurred second. Null or incorrect responses were also observed in many trials, possibly linked with the natural microfluctuations of accommodation. Minimum response times to the changes in AS were observed, which increased with decreasing period of the AS. The time interval between peaks in the AR decreased with decreasing period of the AS. The findings were consistent with a parallel processing model previously proposed for saccades, where input from a later change in stimulus may enter an element of the control system when that element has finished processing an earlier change. More than one change in stimulus may therefore be passing through the multi-element control system at a time

A review of composite structures subjected to dynamic loading

The following review of composite impact work summarises key research interests and provides a brief overview for the development of theoretical, experimental and numerical methods for low, high, and hyper velocity impact. Particular attention is given to experimental apparatus and techniques used for the different impact velocity regimes, and the implementation of failure criteria in finite element (FE) modelling methods which predict material behaviour. Areas are then identified for which limited research has been currently undertaken and suggestions are made for possible future research topics

On the path to rabies elimination: The need for risk assessments to improve administration of post-exposure prophylaxis.

Costs of rabies post-exposure prophylaxis (PEP) often remain high in regions where rabies has been controlled in dogs, presenting a challenge for sustaining rabies elimination programmes. We investigated the potential for bite patient risk assessments to improve PEP provision and surveillance in settings approaching elimination of dog-mediated rabies. We conducted a longitudinal study of patients presenting to animal bite treatment centres (ABTCs) on the island province of Bohol in the Philippines to investigate the health status of biting dogs and to quantify current expenditure on PEP. Incidence of bite patients presenting to ABTCs was high (>300/100,000 persons/year) and increasing, resulting in substantial health provider costs. Over $142,000 was spent on PEP in 2013 for a population of 1.3 million. From follow up of 3820 bite patients we found that  >92% were bitten by healthy dogs (alive 14 days after the bite) and just 1.4% were bitten by probable or confirmed rabid dogs. The status of dogs that bit 6% of patients could not be determined. During the course of investigations of bites by suspect dogs, we were able to obtain samples for case confirmation, identify exposed persons who had not sought PEP as well as in-contact dogs at risk of developing rabies. We calculate that expenditure on PEP could at least be halved through more judicious approaches to provision of PEP, based on the histories of biting animals determined through risk assessments with bite patients. We conclude that a One Health approach to surveillance based on Integrated Bite Case Management could improve the sustainability and effectiveness of rabies elimination programmes while also improving patient care by identifying those genuinely in need of lifesaving PEP