Preliminary report on sand-streaming in Agadez and Tahoua Departments, Republic of Niger

There are no author-identified significant results in this report

Scaling results up from a plot and paddock scale to a property - a case study from a long-term grazing experiment in northern Australia

Grazing experiments are usually used to quantify and demonstrate the biophysical impact of grazing strategies, with the Wambiana grazing experiment being one of the longest running such experiments in northern Australia. Previous economic analyses of this experiment suggest that there is a major advantage in stocking at a fixed, moderate stocking rate or in using decision rules allowing flexible stocking to match available feed supply. The present study developed and applied a modelling procedure to use data collected at the small plot, land type and paddock scales at the experimental site to simulate the property-level implications of a range of stocking rates for a breeding-finishing cattle enterprise. The greatest economic performance was achieved at a moderate stocking rate of 10.5 adult equivalents 100 ha(-1). For the same stocking rate over time, the fixed stocking strategy gave a greater economic performance than strategies that involved moderate changes to stocking rates each year in response to feed supply. Model outcomes were consistent with previous economic analyses using experimental data. Further modelling of the experimental data is warranted and similar analyses could be applied to other major grazing experiments to allow the scaling of results to greater scales

Caraid nan Gaidheal and 'Friend of Emigration': Gaelic emigration literature of the 1840s

This study focuses on Gaelic emigration literature which was published in the aftermath of the Highland potato famine of 1836-37 and before that of 1846-50. The end of the eighteenth century had witnessed a steady flow of emigrants out of the Highlands in response to a complex mix of factors, including landlord pressure, population growth and the prospect of a more prosperous future elsewhere

A COMPARATIVE STUDY OF SALICYLALDOXIME, CYSTEINE AND BENZOTRIAZOLE AS INHIBITORS FOR THE ACTIVE CHLORIDE-BASED CORROSION OF COPPER AND BRONZE ARTIFACTS

This study aimed to investigate the effectiveness of salicylaldoxime and cysteine as potential replacements to benzotriazole, the widely used but environmentally unfriendly and not always effective copper corrosion inhibitor. Coupons of modern copper, 5% tin bronze, and 12% tin bronze samples were corroded using an accelerated electrochemical procedure, which involved anodically polarizing the coupons in a solution of 0.5M NaCl + 0.1M CuCl2.2H2O. X-ray diffraction analysis of the corrosion products showed the presence of copper (I) chloride (CuCl) on the surfaces of the three reference materials. Tin (IV) oxide (SnO2) was also detected on the surface of the 12% tin bronze.The interaction of the corrosion inhibitors with the corrosion products was investigated by visual examination and scanning electron microscopy. Benzotriazole and salicylaldoxime formed a surface adherent and aesthetically acceptable green complexes for the corroded copper and bronze, while cysteine formed grey patches that cover the green corrosion on copper and bronze. Accelerated corrosion in an environmental chamber of high relative humidity and temperature (84% RH and 38oC) showed that salicylaldoxime was the most effective inhibitor for the three reference materials against corrosion in these severe environmental conditions. However, electrochemical impedance spectroscopy's results showed that the benzotriazole was the most effective inhibitor in chloride solutions, and that the effective of cysteine increases with the increase of tin content in the alloy. It was concluded that salicylaldoxime presented a relevant and effective corrosion inhibitor for most conservation applications on corroded copper and bronze, while cysteine presented an environmentally friendly replacement for benzotriazole to protect uncorroded or previously treated by reduction back to metal artifacts

MMTF: The Maryland-Magellan Tunable Filter

This paper describes the Maryland-Magellan Tunable Filter (MMTF) on the Magellan-Baade 6.5-meter telescope. MMTF is based on a 150-mm clear aperture Fabry-Perot (FP) etalon that operates in low orders and provides transmission bandpass and central wavelength adjustable from ~5 to ~15 A and from ~5000 to over ~9200 A, respectively. It is installed in the Inamori Magellan Areal Camera and Spectrograph (IMACS) and delivers an image quality of ~0.5" over a field of view of 27' in diameter (monochromatic over ~10'). This versatile and easy-to-operate instrument has been used over the past three years for a wide variety of projects. This paper first reviews the basic principles of FP tunable filters, then provides a detailed description of the hardware and software associated with MMTF and the techniques developed to observe with this instrument and reduce the data. The main lessons learned in the course of the commissioning and implementation of MMTF are highlighted next, before concluding with a brief outlook on the future of MMTF and of similar facilities which are soon coming on line.Comment: 38 pages, 12 figures, 3 tables, now accepted for publication to the Astronomical Journa

Systematic management of stocking rates improves performance of northern Australian cattle properties in a variable climate

The risks for extensive cattle properties in the rangelands of northern Australia arising from high inter-annual rainfall variability are predominantly managed through adjustments in stocking rates (SR). This modeling study compared the performance of SR strategies that varied considerably in the extent that they adjusted SR annually at 3 locations in northern Australia. At all locations, land types and pasture condition states, the SR strategies that achieved the best pasture condition were those that least increased and most decreased SR annually in response to changes in forage avail-ability. At Donors Hill (Qld), these conservative strategies also achieved the highest cattle liveweight gains per hectare (LWG/ha). While conservative strategies produced the highest percent perennial pasture species at Fitzroy Crossing (WA), strategies which allowed larger increases and decreases in SR also performed well, enabling them to also achieve high LWG/ha with little deterioration of pasture condition. A similar trend occurred at Alice Springs (NT), although at this location the strategies with even larger annual increases and decreases in SR achieved relatively high percent peren-nials and the highest LWG/ha. While systematic management of SR appears to perform better than a constant SR strategy when rainfall variability is high, it is unclear if the magnitude of annual adjustments in SR needs to increase with increasing rainfall variability. © 2013

Identifying and addressing sustainable pasture and grazing management options for a major economic sector - The north Australian beef industry

Sustainable use of Australia's northern grazing lands is a long-standing issue for management and policy, heightened by projections of increased climatic variability, uncertainty of forage supplies, vegetation complexes and weeds and diseases. Meat & Livestock Australia has supported a large study to explore sustainable grazing management strategies and increase the capacity of the sector to address climate change. Potential options were explored by bio-economic modeling of 'representative' beef enterprises defined by pastoralists and supported by regional research and extension specialists. Typical options include diversification, infrastructure, flexible stocking rates, wet season resting and pre-scribed fire. Concurrent activities by another team included regional impact assessments and surveys of pastoralists' understanding of and attitudes towards climate change and adaptive capacity. The results have been widely canvassed and a program of on-ground demonstrations of various options implemented. The paper describes the structure of this program and highlights key results indicating considerable scope to address sustainability challenges. © 2013