The impact of superphosphate and surface-applied lime on the profitability and sustainability of wool production on the tablelands of NSW

Soil acidification is one of the major forms of soil degradation in higher rainfall areas of the tablelands of NSW. A grazing experiment was conducted near Sutton, NSW, to assess the effect of various rates of superphosphate, lime, sewage ash and stocking rates on wool production and sustainability between 1999 and 2008. The results from the discounted cash flow analysis show that the net present value of the treatment without lime, the lower rate of superphosphate and the lowest stocking rate returned the highest net present value of $266.30/ha. Raising the application of superphosphate from 125kg/ha every two to three years to 250kg/ha every year on un-limed and limed soil reduced the net present value by$278.70/ha and $249.30/ha, respectively. The addition of lime at the rate of 4t/ha on un-limed soil at the low superphosphate level reduced the net present value by about$234.60/ha. The net present value fell by $205.24/ha when the level of superphosphate rate increased to 250kg/ha every year. The net present value decreased as the level of stocking rate increased. We conclude that wool producers will be unlikely to use lime to ameliorate acid soil, even though production will not be sustainable, unless there are more favourable input and commodity prices in the market and government intervention.economic, acid soil, lime, superphosphate, sewage ash, stocking rate, policy,

(2E)-N-(3,5-Dibromo-4-methoxy­phen­yl)-2-(hydroxy­imino)acetamide

The title compound, C9H8Br2N2O3, is planar (r.m.s. deviation = 0.030 Å) with the exception of the terminal methyl group which lies out of the plane [1.219 (3) Å]. The conformation about the C=N double bond [1.268 (3) Å] is E. An intra­molecular N—H⋯N hydrogen bond occurs. Linear supra­molecular chains along the b axis mediated by O—H⋯O hydrogen-bonding inter­actions feature in the crystal structure. These chains are also stabilized by weak C—H⋯N contacts

Quenched QCD with O(a) improvement: I. The spectrum of light hadrons

We present a comprehensive study of the masses of pseudoscalar and vector mesons, as well as octet and decuplet baryons computed in O(a) improved quenched lattice QCD. Results have been obtained using the non-perturbative definition of the improvement coefficient c_sw, and also its estimate in tadpole improved perturbation theory. We investigate effects of improvement on the incidence of exceptional configurations, mass splittings and the parameter J. By combining the results obtained using non-perturbative and tadpole improvement in a simultaneous continuum extrapolation we can compare our spectral data to experiment. We confirm earlier findings by the CP-PACS Collaboration that the quenched light hadron spectrum agrees with experiment at the 10% level.Comment: 36 pages, 7 postscript figures, REVTEX; typo in Table XVIII corrected; extended discussion of finite-size effects in sections III and VII; version to appear in Phys. Rev.

Light hadron spectroscopy with O(a) improved dynamical fermions

We present the first results for the static quark potential and the light hadron spectrum using dynamical fermions at $\beta=5.2$ using an O(a) improved Wilson fermion action together with the standard Wilson plaquette action for the gauge part. Sea quark masses were chosen such that the pseudoscalar-vector mass ratio, m_PS/m_V$, varies from 0.86 to 0.67. Finite-size effects are studied by using three different volumes, 8^3\cdot 24, 12^3\cdot 24 and 16^3\cdot 24. Comparing our results to previous ones obtained using the quenched approximation, we find evidence for sea quark effects in quantities like the static quark potential and the vector-pseudoscalar hyperfine splitting.Comment: 38 pages, 14 Postscript figure, LaTe

Dynamic star formation in the massive DR21 filament

The formation of massive stars is a highly complex process in which it is not clear whether the star-forming gas is in global gravitational collapse or in an equilibrium state, supported by turbulence. By studying one of the most massive and dense star-forming regions in the Galaxy at a distance of less than 3 kpc, the filament containing the well-known sources DR21 and DR21(OH), we expect to find observational signatures that allow to discriminate between the two views. We use molecular line data from our 13CO 1-0, CS 2-1, and N2H+ 1-0 survey of the Cygnus X region obtained with the FCRAO and high-angular resolution observations of CO, CS, HCO+, N2H+, and H2CO, obtained with the IRAM 30m telescope. We observe a complex velocity field and velocity dispersion in the DR21 filament in which regions of highest column-density, i.e. dense cores, have a lower velocity dispersion than the surrounding gas and velocity gradients that are not (only) due to rotation. Infall signatures in optically thick line profiles of HCO+ and 12CO are observed along and across the whole DR21 filament. From modelling the observed spectra, we obtain a typical infall speed of 0.6 km/s and mass accretion rates of the order of a few 10^-3 Msun/yr for the two main clumps constituting the filament. These massive (4900 and 3300 Msun) clumps are both gravitationally contracting. All observed kinematic features in the DR21 filament can be explained if it is formed by the convergence of flows at large scales and is now in a state of global gravitational collapse. Whether this convergence of flows originated from self-gravity at larger scales or from other processes can not be settled with the present study. The observed velocity field and velocity dispersion are consistent with results from (magneto)-hydrodynamic simulations where the cores lie at the stagnation points of convergent turbulent flows.Comment: Astronomy and Astrophysics, in pres

Low Velocity Ionized Winds from Regions Around Young O Stars

We have observed seven ultracompact HII regions in hydrogen recombination lines in the millimeter band. Toward four of these regions, there is a high velocity (full width to half maximum 60-80 km/s) component in the line profiles. The high velocity gas accounts for 35-70% of the emission measure within the beam. We compare these objects to an additional seven similar sources we have found in the literature. The broad recombination line objects (BRLOs) make up about 30% of all sources in complexes containing ultracompact HII regions. Comparison of spectral line and continuum data implies that the BRLOs coincide with sources with rising spectral indices, >=0.4 up to 100 GHz. Both the number of BRLOs and their frequency of occurrence within HII region complexes, when coupled with their small size and large internal motions, mean that the apparent contradiction between the dynamical and population lifetimes for BRLOs is even more severe than for ultracompact HII regions. We evaluate a number of models for the origin of the broad recombination line emission. The lifetime, morphology, and rising spectral index of the sources argue for photo- evaporated disks as the cause for BRLOs. Existing models for such regions, however, do not account for the large amounts of gas observed at supersonic velocities.Comment: 36 pages, 8 figure

Effect of Soil pH on Emergence and Survival of \u3ci\u3eAustrodanthonia\u3c/i\u3e spp.

We evaluated the effects of soil acidity on seedling emergence and seedling persistence of several ecotypes of Austrodanthonia spp. collected from the Central, Southern and Monaro Tablelands of New South Wales (NSW) in southern temperate Australia. A pot experiment was conducted outdoors to identify the most promising material tolerant to soil acidity for domestication. In the experiment, 183 ecotypes and two commercial cultivars of Austrodanthonia were grown in pots at three levels of pHCa (3.9, 4.4 and 5.3). The pH treatments were achieved by adding either aluminium sulphate or lime to an acid earthy sandy loam soil collected from a grazing farm. Seedling emergence and persistence were recorded for 170 days after sowing (DAS). Establishment of all lines was severely reduced by soil acidity. At pH 3.9, average seedling emergence over all lines was 11%, whereas, at higher pH (pH 4.4 and 5.3) emergence was about 72%. Of the seeds sown, survival at 170 DAS was, on average, less than 1% at pH 3.9, compared with 25% at pH 4.4 and 5.3. Further investigations on species/ecotypes, particularly those favoured at low soil pH, should provide a useful basis for selection programmes

Effects of non-perturbatively improved dynamical fermions in QCD at fixed lattice spacing

We present results for the static inter-quark potential, lightest glueballs, light hadron spectrum and topological susceptibility using a non-perturbatively improved action on a $16^3\times 32$ lattice at a set of values of the bare gauge coupling and bare dynamical quark mass chosen to keep the lattice size fixed in physical units ($\sim 1.7$ fm). By comparing these measurements with a matched quenched ensemble, we study the effects due to two degenerate flavours of dynamical quarks. With the greater control over residual lattice spacing effects which these methods afford, we find some evidence of charge screening and some minor effects on the light hadron spectrum over the range of quark masses studied ($M_{PS}/M_{V}\ge0.58$). More substantial differences between quenched and unquenched simulations are observed in measurements of topological quantities.Comment: 53 pages, LaTeX/RevTeX, 16 eps figures; corrected clover action expression and various typos, no results change

Outflows from Massive YSOs as Seen with the Infrared Array Camera

The bipolar outflow from the massive star forming cluster in DR21 is one of the most powerful known, and in IRAC images the outflow stands out by virtue of its brightness at 4.5 um (Band 2). Indeed, IRAC images of many galactic and extragalactic star formation regions feature prominent Band 2 morphologies. We have analyzed archival ISOSWS spectra of the DR21 outflow, and compare them to updated H2 shocked and UV-excitation models. We find that H2 line emission contributes about 50% of the flux of the IRAC bands at 3.6 um, 4.5 um , and 5.8 um, and is a significant contributor to the 8.0 um band as well, and confirm that the outflow contains multiple excitation mechanisms. Other potentially strong features, in particular Br alpha and CO emission, have been suggested as contributing to IRAC fluxes in outflows, but they are weak or absent in DR21; surprisingly, there also is no evidence for strong PAH emission. The results imply that IRAC images can be a powerful detector of, and diagnostic for, outflows caused by massive star formation activity in our galaxy, and in other galaxies as well. They also suggest that IRAC color-color diagnostic diagrams may need to take into account the possible influence of these strong emission lines. IRAC images of the general ISM in the region, away from the outflow, are in approximate but not precise agreement with theoretical models.Comment: Accepted for publication in the Astrophysical Journal; 32 pages; 7 figure