An Economic Evaluation of Conservation Farming Practices for the Central West of NSW

Economic benefits that arise from conservation farming practices need to be assessed over several years to account for improvements in soil structure and nutrient levels. A gross margin model was used to assess benefits over the eight-year period 1999-2006 for 12 regions in the central west of NSW. The annual benefits from improved soil structure ranged from $2.46 to$12.82 per hectare (ha). A reduction in tractor power produced annual savings in the range of $0.60 to$4.05 per ha. The cost of soil compaction by livestock grazing on crop areas ranged from $3.41 to$14.90 per ha. The break-even time to pay back costs for the conversion of machinery for no-till seeding was two to three seasons.No-till, conservation, farming, tillage, cropping systems, Environmental Economics and Policy, Farm Management,

Grower representation and its impact on the governance structure of the Australian Grains Industry

The Australian wheat industry has changed considerably in structure and governance during the past 15 years. The most important changes have been the deregulation of the domestic market and privitisation of the former Australian Wheat Board into AWB Limited. Through these changes growers have become shareholders in the various companies. Governance of the monopolistic relationship between AWB Limited and AWB International by the Federal Minister of Agriculture and the Grains Council of Australia through the Wheat Export Authority has proved ineffective. Hence a national organisation that represents shareholders is recommended to increase grower governance of the supply chain and marketing of wheat.grain, marketing, infrastructure, competition, governance, Agricultural and Food Policy, Crop Production/Industries, Marketing,

Identification of substitute muscle groups for retail beef demand and supply equations

In modelling retail meat demand and supply equations it is difficult to identify close substitutes or competing products. However, close substitutes can be identified through a comparison of meat attributes, especially cooking method and sensory attributes. The Meat Standards Australia (MSA) grading system can be used to identify primals (whole muscles) with similar attributes. The MSA system is based on carcase attributes, cooking methods and sensory properties and it allocates 3, 4 or 5 stars to beef primals. Prices for different star grades are affected by the quantity of meat allocated into each grade and this is determined by cooking method, which is dependent upon season. Estimating demand and supply by MSA grades and cooking methods requires fewer variables and therefore reduces multicollinearity and increases model efficiency.MSA, beef cuts, sensory attributes and cooking methods.,

Full potential solution of transonic quasi-3-D flow through a cascade using artificial compressability

The three-dimensional flow in a turbomachinery blade row was approximated by correcting for streamtube convergence and radius change in the throughflow direction. The method is a fully conservative solution of the full potential equation incorporating the finite volume technique on body fitted periodic mesh, with an artificial density imposed in the transonic region to insure stability and the capture of shock waves. Comparison of results for several supercritical blades shows good agreement with their hodograph solutions. Other calculations for these profiles as well as standard NACA blade sections indicate that this is a useful scheme analyzing both the design and off-design performance of turbomachinery blading

On the domain of the assembly map in algebraic K-theory

We compare the domain of the assembly map in algebraic K-theory with respect to the family of finite subgroups with the domain of the assembly map with respect to the family of virtually cyclic subgroups and prove that the former is a direct summand of the later.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-35.abs.htm

A hedonic model of lamb carcass attributes

Lamb carcass value is widely reported to be a function of lean meat yield, which is the relationship between muscle, fat and bone. Five retailers and five wholesalers assessed 47 lamb carcasses from diverse genotypes and scored seven attributes. A hedonic model reveals that conformation attributes were more highly valued (16 c/kg) relative to yield characteristics (4 c/kg). Meat colour and fat distribution were significant for retailers, but less important for wholesalers. Genotype was not a strong indicator of conformation. Eye muscle area and depth were correlated with Fat C; however, these were not significant. These results indicate that carcass conformation, meat colour and fat distribution should be incorporated into carcass grading models.Hedonic, lamb, conformation and meat value, attributes, Livestock Production/Industries,

Advanced space system analysis software. Technical, user, and programmer guide

The LASS computer program provides a tool for interactive preliminary and conceptual design of LSS. Eight program modules were developed, including four automated model geometry generators, an associated mass properties module, an appendage synthesizer module, an rf analysis module, and an orbital transfer analysis module. The existing rigid body controls analysis module was modified to permit analysis of effects of solar pressure on orbital performance. A description of each module, user instructions, and programmer information are included

Simplified methods for calculating photodissociation rates

Simplified methods for calculating the transmission of solar UV radiation and the dissociation coefficients of various molecules are compared. A significant difference sometimes appears in calculations of the individual band, but the total transmission and the total dissociation coefficients integrated over the entire SR (solar radiation) band region agree well between the methods. The ambiguities in the solar flux data affect the calculated dissociation coefficients more strongly than does the method. A simpler method is developed for the purpose of reducing the computation time and computer memory size necessary for storing coefficients of the equations. The new method can reduce the computation time by a factor of more than 3 and the memory size by a factor of more than 50 compared with the Hudson-Mahle method, and yet the result agrees within 10 percent (in most cases much less) with the original Hudson-Mahle results, except for H2O and CO2. A revised method is necessary for these two molecules, whose absorption cross sections change very rapidly over the SR band spectral range

Detailed Structure and Dynamics in Particle-in-Cell Simulations of the Lunar Wake

The solar wind plasma from the Sun interacts with the Moon, generating a wake structure behind it, since the Moon is to a good approximation an insulator, has no intrinsic magnetic field and a very thin atmosphere. The lunar wake in simplified geometry has been simulated via a 1-1/2-D electromagnetic particle-in-cell code, with high resolution in order to resolve the full phase space dynamics of both electrons and ions. The simulation begins immediately downstream of the moon, before the solar wind has infilled the wake region, then evolves in the solar wind rest frame. An ambipolar electric field and a potential well are generated by the electrons, which subsequently create a counter-streaming beam distribution, causing a two-stream instability which confines the electrons. This also creates a number of electron phase space holes. Ion beams are accelerated into the wake by the ambipolar electric field, generating a two stream distribution with phase space mixing that is strongly influenced by the potentials created by the electron two-stream instability. The simulations compare favourably with WIND observations.Comment: 10 pages, 13 figures, to be published in Physics of Plasma