443 research outputs found

    An economic analysis of options for utilising additional land on a high rainfall Gippsland dairy farm

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    A range of options for utilising additional land on a dairy farm in the high rainfall area of Gippsland were analysed. The aim was to determine if additional land may assist the owners/operators in maintaining or increasing profit in the medium term (5-10 years). Historical trends have been towards fewer, larger, more intensive enterprises, and this project studies the value of additional land in continuing or altering this trend. A case study farm and spreadsheet modelling approach was used to examine these issues. Five different uses for additional land were identified by an expert steering committee, and were compared to the base farm system over a 10-year development period. The results suggest that expanding the milking area by purchasing additional land without a significant increase in herd size (2A) increased annual operating profit by approximately 70,000/yearwithoutincreasingvariabilitywhencomparedtothebasefarmsystem.Thiswastheonlyoptionexaminedtoearnahighenoughinternalrateofreturnonadditionalcapitalinvestmenttojustifytheinvestmentwithoutcapitalgains.Additionalmilkingareawithasubstantialincreaseinstockingrate(2C)significantlyreducedannualoperatingprofit(byapproximately70,000/year without increasing variability when compared to the base farm system. This was the only option examined to earn a high enough internal rate of return on additional capital investment to justify the investment without capital gains. Additional milking area with a substantial increase in stocking rate (2C) significantly reduced annual operating profit (by approximately 70,000/year) and notably increased the variability of these returns. The purchase of an outblock for conserved fodder production improved profitability, but would require some capital gains to be an attractive option on profit measures alone. The most appropriate changes to dairy farm businesses in response to changes in the operating environment will vary from farm to farm. The analysis indicated that simple following previous industry trends may not be appropriate on many farms. Optimising the amount of home grown feed and efficiently using purchased supplements are important, particularly if the milk produced is subject to the fluctuations of an export milk price.Farm Management,

    Botanical composition, production and nutrient status of an originally Lolium perenne-dominant cut grass sward receiving long-term manure applications

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    Effects of long-term applications (50, 100 and 200 m(3) ha(-1)y(-1)) of pig and cow slurries on yield, botanical composition and nutrient content of herbage of an original perennial ryegrass sward were assessed in a three-cut silage system and compared with unamended and fertilized controls in the 36th year of the experiment. Cow slurry at 50 m(3) ha(-1) produced similar annual herbage DM yield to 200 kg ha(-1) fertilizer N in 2006, whereas about 100 m(3) ha(-1) pig slurry were required to produce a similar amount of DM. The highest slurry application rate significantly influenced sward botanical composition without depressing DM yield. The principal invading species were creeping bent and meadow grasses (similar to findings at a previous assessment in 1981) except in the unamended control (which were common bent and Yorkshire fog). Perennial ryegrass remained a main species in plots receiving fertilizer (31 % annual DM yield) and low slurry rates (38 %) but declined to 3 % annual DM yield at the highest slurry rate where the ability of ryegrass to utilize slurry N and P may have been affected by chemically or physically induced deficiencies of other nutrients (e.g. Ca) or direct physical effects such as smothering

    A solution scan of societal options to reduce transmission and spread of respiratory viruses: SARS-CoV-2 as a case study

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    Societal biosecurity – measures built into everyday society to minimize risks from pests and diseases – is an important aspect of managing epidemics and pandemics. We aimed to identify societal options for reducing the transmission and spread of respiratory viruses. We used SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) as a case study to meet the immediate need to manage the COVID-19 pandemic and eventually transition to more normal societal conditions, and to catalog options for managing similar pandemics in the future. We used a ‘solution scanning’ approach. We read the literature; consulted psychology, public health, medical, and solution scanning experts; crowd-sourced options using social media; and collated comments on a preprint. Here, we present a list of 519 possible measures to reduce SARS-CoV-2 transmission and spread. We provide a long list of options for policymakers and businesses to consider when designing biosecurity plans to combat SARS-CoV-2 and similar pathogens in the future. We also developed an online application to help with this process. We encourage testing of actions, documentation of outcomes, revisions to the current list, and the addition of further options.</p

    Collaborative futures:discursive realignments in austere times

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    This paper explores the future of collaboration in an era of austerity. Boundary object theory provides a framework to examine the significance and role of four key discourses in collaboration – efficiency, effectiveness, responsiveness and cultural performance. Crisis provides a way of examining how and in what ways discourses realign. The exploration of discourses aids critical analysis of collaboration across sectoral, geographical and disciplinary boundaries, highlighting the importance of understanding the contextual roots of collaboration theory and practice, and the implications of local/global dynamics

    Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

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    We present the first measurement of directed flow (v1v_1) at RHIC. v1v_1 is found to be consistent with zero at pseudorapidities η\eta from -1.2 to 1.2, then rises to the level of a couple of percent over the range 2.4<η<42.4 < |\eta| < 4. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure

    Azimuthal anisotropy: the higher harmonics

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    We report the first observations of the fourth harmonic (v_4) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding

    Plasma Wakefield Acceleration with a Modulated Proton Bunch

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    The plasma wakefield amplitudes which could be achieved via the modulation of a long proton bunch are investigated. We find that in the limit of long bunches compared to the plasma wavelength, the strength of the accelerating fields is directly proportional to the number of particles in the drive bunch and inversely proportional to the square of the transverse bunch size. The scaling laws were tested and verified in detailed simulations using parameters of existing proton accelerators, and large electric fields were achieved, reaching 1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found in this case.Comment: 9 pages, 7 figure

    The energy dependence of ptp_t angular correlations inferred from mean-ptp_{t} fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

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    We present the first study of the energy dependence of ptp_t angular correlations inferred from event-wise mean transverse momentum fluctuations in heavy ion collisions. We compare our large-acceptance measurements at CM energies $\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure suggests that the principal source of $p_t$ correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with $\ln \sqrt{s_{NN}}$ from the onset of observable jet-related fluctuations near 10 GeV.Comment: 10 pages, 4 figure

    All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators

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    We review our recent work on tunable, ultrahigh quality factor whispering-gallery-mode bottle microresonators and highlight their applications in nonlinear optics and in quantum optics experiments. Our resonators combine ultra-high quality factors of up to Q = 3.6 \times 10^8, a small mode volume, and near-lossless fiber coupling, with a simple and customizable mode structure enabling full tunability. We study, theoretically and experimentally, nonlinear all-optical switching via the Kerr effect when the resonator is operated in an add-drop configuration. This allows us to optically route a single-wavelength cw optical signal between two fiber ports with high efficiency. Finally, we report on progress towards strong coupling of single rubidium atoms to an ultra-high Q mode of an actively stabilized bottle microresonator.Comment: 20 pages, 24 figures. Accepted for publication in Applied Physics B. Changes according to referee suggestions: minor corrections to some figures and captions, clarification of some points in the text, added references, added new paragraph with results on atom-resonator interactio
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