An optimisation approach to the location and sizing of multiple leaks in a duct

A single leak in a duct can be located, and its size predicted, by measuring the input impedance of the duct and then solving an inverse problem. However, extending this procedure to a duct containing several leaks is non-trivial, with the resulting mathematical expressions proving to be highly complex. In this paper, an optimisation approach to the location and sizing of multiple leaks in a duct is described. The approach employs a standard theoretical model of a duct that contains several leaks. The initial parameters of the duct model (e.g. duct radius, number of leaks, leak positions and sizes) are chosen arbitrarily. An optimisation function then adjusts the parameters of the model until its input impedance matches the measured impedance of the duct under investigation. Results are presented which demonstrate the success of this optimisation approach in both locating and sizing multiple leaks in a duct

Lockheed experiment on ATS-5 Quarterly report, 1 Jun. - 31 Aug. 1970

Auroral particle measurements at synchronous altitude by ATS

The Post-2015 Development Agenda: Keeping Our Focus On the Worst Off

Non-communicable diseases now account for the majority of the global burden of disease and an international campaign has emerged to raise their priority on the post-2015 development agenda. We argue, to the contrary, that there remain strong reasons to prioritize maternal and child health. Policy-makers ought to assign highest priority to the health conditions that afflict the worst off. In virtue of how little healthy life they have had, children who die young are among the globally worst off. Moreover, many interventions to deal with the conditions that cause mortality in the young are low-cost and provide great benefits to their recipients. Consistent with the original Millennium Development Goals, the international community should continue to prioritize reductions in communicable diseases, neonatal conditions, and maternal health despite the shifts in the global burden of disease

Long-term stability of fibre-optic transmission for multi-object spectroscopy

We present an analysis of the long-term stability of fibre-optic transmission properties for fibre optics in astronomy. Data from six years of operation of the AAOmega multi-object spectrograph at the Anglo-Australian Telescope is presented. We find no evidence for significant degradation in the bulk transmission properties of the 38 m optical fibre train. Significant losses (<20% relative, 4% absolute) are identified and associated with the end termination of the optical fibres in the focal plane. Improved monitoring and maintenance can rectify the majority of this performance degradation.Comment: Accepted for publication (September 2012) Monthly Notices of the Royal Astronomical Societ

ISEE-1 data reduction and analysis plasma composition experiment

The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given

The impacts for stone curlews of increased traffic on the A11. Model and predictions

Stone curlew nest density in the Breckland region of Eastern England was shown to be negatively related to ‘nearby’ housing density and ‘nearby’ trunk road traffic (based on new traffic data for the period 1988-2006). However, no statistically significant additional relationship with non-trunk A-road traffic could be detected. We recommend using the statistical modelling predictions in the report Table 5 as the best currently available estimates of the potential effect of a 70% increase in A11 average daily (March-August)two-way traffic above the average All traffic levels in 2002-06. The predicted effect of a 70% increase in A11 traffic is for a reduction from current observed nest numbers on suitable arable land of 3.7% with no changes in housing density or 4.9% when combined with the predicted effect of housing options. A reduction of 7.3% is predicted for semi-natural grassland and SSSI habitats. Taking both semi-natural grassland/SSSI and arable habitats together, the observed total average nest numbers for the period 2002-2006 was 221.4, and the prediction following a 70% increase in traffic on the A11 is 210.8, a reduction of 10.6 nests (4.8%)

Study of storm time fluxes of heavy ions

Ion composition data sets from Lockheed instruments on a variety of spacecraft were used in combination with each other and with data from other instruments to address a variety of problems regarding plasma sources, energization and transport within the magnetosphere. The availability of data from several differing orbits has given a highly flexible approach to attacking the continually evolving questions of magnetospheric physics. This approach is very successful and should be continued in the future

Lockheed experiment on ATS-5 Quarterly progress report, 1 Mar. - 31 May 1971

ATS 5 observational data on isolated magnetospheric substor