Paying for Our Keep: Grasslands Decision Support in More-Developed Countries

“Models in grassland science have come to stay, and so they must be made to pay for their keep. To do that, it will be necessary to improve their scientific sophistication and their management relevance...” (Seligman, 1993). Decision support (DS) tools in grassland agriculture have also come to stay. This review will examine the ways and means by which DS tools are being made to pay for their keep, with a focus upon DS efforts from the last decade and on the lessons that arise for those who develop DS tools for grasslands. A survey of the present state of grassland DS is presented, and a case made that there are grounds for modest optimism. As a more detailed case study, the history and impact of GrassGro (a simulation-based DS tool that has been in use since 1997; Moore et al., 1997) will be revisited. Lastly, some trends in technology and practice that will determine the effectiveness of DS tools in the coming decade will be examined. Throughout the review, the focus will be on those parts of the world where agriculture is well developed; consequently the term ‘grasslands’ should be read with this geographic caveat. A companion paper (Donnelly et al., 2005) addresses a number of technical issues in DS tool development and expands some points that are only touched on here

Paying for Our Keep: Grasslands Decision Support in More-Developed Countries

Key points 1. A survey of decision support (DS) tools in grassland agriculture illustrates the diversity of decisions supported and of delivery technologies that are used. Larger, whole-enterprise planning tools are undergoing a period where their user interfaces are being adapted to better reflect the requirements and practice of advisory users. 2. The history of use of GrassGro, a ‘versatile simulator’, is used to illustrate how versatile tools attract a diverse range of users and uses. Lessons learnt by the GrassGro team are discussed. 3. Uptake rates of DS tools in grasslands are generally lower than was expected a decade ago. Nevertheless, if return on investment is used as the criterion then some DS tools – especially smaller ones – are clearly successful. Uptake for educational use can be much more rapid

A Design Study of a Proposed Four-Seat, Amateur-Built Airplane

An airplane configuration suitable for construction by an amateur builder without the need for complex factory fixtures and tooling has been developed. The proposed high-wing configuration is intended to carry a 600 LB payload of up to 4 passengers arranged in 2 rows of side-by-side accommodations at a design cruise speed of 145 kts. It has been shown that the cantilevered wing components of the low-wing, 2-seat Mustang II kit airplane are ideally suited for the proposed airplane when properly matched with strut braced inboard wing panels. The structural implications of optimally sized ailerons on the baseline Mustang II wing structure is presented. Wing, fuselage, and strut reaction loads have been determined for the proposed flight envelope. A steel tube cabin structure has been proposed and limited structural optimization accomplished using a finite-element model. Detail analysis of the wing/fuselage, wing/strut and strut/fuselage attachment fittings has been accomplished

Electric vehicle battery performance investigation based on real world current harmonics

Electric vehicle (EV) powertrains consist of power electronic components as well as electric machines to manage the energy flow between different powertrain subsystems and to deliver the necessary torque and power requirements at the wheels. These power subsystems can generate undesired electrical harmonics on the direct current (DC) bus of the powertrain. This may lead to the on-board battery being subjected to DC current superposed with undesirable high- and low- frequency current oscillations, known as ripples. From real-world measurements, significant current harmonics perturbations within the range of 50 Hz to 4 kHz have been observed on the high voltage DC bus of the EV. In the limited literature, investigations into the impact of these harmonics on the degradation of battery systems have been conducted. In these studies, the battery systems were supplied by superposed current signals i.e., DC superposed by a single frequency alternating current (AC). None of these studies considered applying the entire spectrum of the ripple current measured in the real-world scenario, which is focused on in this research. The preliminary results indicate that there is no difference concerning capacity fade or impedance rise between the cells subjected to just DC current and those subjected additionally to a superposed AC ripple current

Estimated Effects of Climate Change on Grassland Production and Legume Content across Southern Australia

Climate changes caused by anthropogenic increases in greenhouse gases such as CO2 will affect southern Australia along with the rest of the globe. Dryland pastures supporting extensive beef, sheepmeat and wool production occupy a third of southern Australia’s farming zone. These livestock production systems are highly sensitive to climatic variation, because they depend almost entirely on pasture as their source of feed. Given the diversity of current climates, soils and pastures that are found across southern Australia, and the spatial variation in projected climate changes (CSIRO 2007), it can also be expected that the impacts of changing climates on pasture production will differ across space. Annual and perennial forage legumes are an important part of the feedbase across most of southern Australia; experimental research suggests that legumes are likely to be favoured by increasing atmospheric CO2 concentrations (e.g. Clark et al. 1997) and it is therefore possible that higher legume content in grasslands might be one positive effect of global climate change. In this study, therefore, we have modelled grassland and livestock production to examine the changes in amount, seasonal distribution and legume content of grass-based pastures at locations across southern Australia under climates projected for 2030, 2050 and 2070

Comparative Analysis of Climate Change Adaptation Options across the Southern Australian Livestock Industry

Climate change is predicted to have a substantial negative effect on the productivity of grasslands across southern Australia (Moore and Ghahramani 2013). We used the GRAZPLAN biophysical simulation models to assess several possible grassland management and animal genetic improvement adaptations under SRES A2 climate change scenario. Simulations spanned the five dimensions of geography, time, global circulation models, enterprise, and adaptations. Impact of climate change was predicted to reduce profitability of livestock industry by 46%, 58%, and 72% at 2030, 2050 and 2070, respectively. Increasing soil fertility could return the average profitability of five livestock enterprises to its historical level at 54%, 50%, and 25% of locations in 2030, 2050, and 2070. Increasing the proportion of Lucerne in pasture was effective for 35%, 22%, and 15% of locations in 2030, 2050, and 2070. Increasing fleece growth rates was the most effective genetic adaptation that could return profitability of sheep enterprises to its historical level for 24%, 52%, and 28% of locations in 2030, 2050, and 2070. Removing annual legumes in an attempt to preserve ground cover by replacing annual grass and larger sire body size were less effective options. The incremental adaptations we examined could significantly increase profitability of the enterprises at 2030. However, at many locations in drier regions it appears unlikely that a single adaptation can return profit to the historical level. In most of the high rainfall zone, systemic adaptation using a combination of grassland management and animal genetic improvement could return livestock systems to historical profitability in 2030 and 2050

Comparative analysis of climate change adaptation options across the southern Australian livestock industry

Climate change is predicted to have a substantial negative effect on the productivity of grasslands across southern Australia (Moore and Ghahramani 2013). We used the GRAZPLAN biophysical simulation models to assess several possible grassland management and animal genetic improvement adaptations under SRES A2 climate change scenario. Simulations spanned the five dimensions of geography, time, global circulation models, enterprise, and adaptations. Impact of climate change was predicted to reduce profitability of livestock industry by 46%, 58%, and 72% at 2030, 2050 and 2070, respectively. Increasing soil fertility could return the average profitability of five livestock enterprises to its historical level at 54%, 50%, and 25% of locations in 2030, 2050, and 2070. Increasing the proportion of Lucerne in pasture was effective for 35%, 22%, and 15% of locations in 2030, 2050, and 2070. Increasing fleece growth rates was the most effective genetic adaptation that could return profitability of sheep enterprises to its historical level for 24%, 52%, and 28% of locations in 2030, 2050, and 2070. Removing annual legumes in an attempt to preserve ground cover by replacing annual grass and larger sire body size were less effective options. The incremental adaptations we examined could significantly increase profitability of the enterprises at 2030. However, at many locations in drier regions it appears unlikely that a single adaptation can return profit to the historical level. In most of the high rainfall zone, systemic adaptation using a combination of grassland management and animal genetic improvement could return livestock systems to historical profitability in 2030 and 2050

Climate Change Impact and Adaptation in Temperate Grassland and Livestock Industries

Climate is projected to have negative impact on temperate grassland and livestock productions across the globe. Moderately elevated atmospheric CO2 in the near future is expected to increase plant photosynthetic rates but this is likely to be limited by soil nitrogen deficits. However, in Australia at least it is unlikely that positive effect of elevated CO2 on plant production be able to offset the negative impacts of climate change. Currently there is a considerable gap between actual and achievable production and profit in Australian grazing systems and many management and genetic improvements for climate adaptation would operate by filling this gap. Because of likely substantial declines in efficiency frontier of grazing systems under changing climate compared to the historical climate, filling the production gap will be a more challenging task in coming decades. Research into climate change impact and adaptation in managed grasslands has been mostly limited to Europe, North America and Australasia. Large areas of managed grasslands exist in South America, China, Africa and south-west Asia for which there is little understanding of the likely impact of climate change impact and effectiveness of potential adaptation options. These grasslands are typically managed at lower intensity than European or North American systems and often form part of crop-livestock farming systems. There is a clear need for research into the direct and indirect impacts of climate change on these grasslands and on the livestock and people they support

5D Black Rings and 4D Black Holes

It has recently been shown that the M theory lift of a IIA 4D BPS Calabi-Yau black hole is a 5D BPS black hole spinning at the center of a Taub-NUT-flux geometries, and a certain linear relation between 4D and 5D BPS partition functions was accordingly proposed. In the present work we fortify and enrich this proposal by showing that the M-theory lift of the general 4D multi-black hole geometry are 5D black rings in a Taub-NUT-flux geometry.Comment: 8 pages; version 2, with additional references and explanation