444 research outputs found

    A New Method of Marking Fresh-water Mussels for Field Study

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    A review of previously used methods of marking mussels and a description of a new system developed for field use are presented. A code numbering system, utilizing holes drilled into the shell, is described and evaluated

    A Life Cycle Analysis of Land Use in US Pork Production

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    The goal of this study was to analyze land use in the production of US pork using Life Cycle Assessment (LCA). LCA is a comprehensive methodology for quantitatively analyzing potential environmental impacts associated with complex systems. Identification of processes contributing to high environmental impacts often highlights opportunities for gains in efficiency, which can increase the profitability and sustainability of US pork. The environmental impact category analyzed in this assessment was land use. After reviewing existing information regarding land use in agriculture and livestock production, analysis for US pork production was performed at two scales: cradle-to-grave and cradle-to-farm gate. The cradle-to-grave analysis provided a scan-level overview of land use associated with the production and consumption of lean pork at an aggregated national level. The cradle-to-farm gate analysis provided a more granular assessment of the land use required for live swine production, and evaluated the use of alternate ration formulation as a tool for reducing environmental impacts. [Excerpt from report]

    Sustainability Assessment of U.S. Beef Production Systems

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    With increasing public concern and awareness of agricultural sustainability issues, comprehensive methodologies such as life cycle assessment are required to benchmark the beef industry and identify areas of opportunity for continuous improvement. To that end, the Beef Checkoff completed a retrospective sustainability assessment benchmark in 2013 by using Eco-efficiency analysis to compare the years 2005 and 2011. At the time of the analysis, the methodology used was the most up-to-date and comprehensive – indeed the analysis remains one of the only complete cradle-to-grave assessments of the U.S. beef industry. In 2015, a further refined version of the Eco-efficiency analysis was completed to incorporate new primary data sources from the beef value chain for the years 2011-2013. As the young and dynamic field of sustainability science continues to evolve, there is a need to adapt and update the methodologies used in life cycle and broader sustainability assessments of the beef industry. Consequently, this project updated and expanded the original Eco-efficiency analysis to the SimaPro™ computational platform. The move to the SimaPro™ platform will allow for direct linkages with the Integrated Farm Systems Model (USDA-ARS), which is the simulation model that has been used to generate life cycle inventories from the feed production, cow-calf, and backgrounding/feedlot segments of the beef industry. Additionally, the SimaPro™ platform will allow for even more transparent reporting of our inventories and results to the broader life cycle assessment, sustainability science, and beef communities, which is key to advancing the field and benchmarking beef’s sustainability. Finally, this project further expanded the economic sustainability evaluation of U.S. beef industry to include the direct, indirect, and induced economic activity and value that is generated from beef production. [Excerpt from report]

    A Retrospective Assessment of US Pork Productions: 1960 to 2015

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    The primary goal of this study is to assess the carbon, energy, water and land footprints per kg (2.2 pounds) of live weight (LW) pork produced at five-year increments between 1960 and 2015. This assessment utilizes the Life Cycle Assessment (LCA) methodology, which is a technique to assess the potential environmental impacts associated with a product system by compiling an inventory of relevant energy and material flows, evaluating the associated burdens, and interpreting the results to assist in making more informed decisions and to provide an understanding of the drivers of change over the past 55 years. This LCA is “cradle-to-farm gate” e.g. covering the material and energy flows associated with the full supply chain beginning with extraction of raw materials through the production of live, market-weight swine, inclusive of culled sows, at the farm gate. On average, production-weighted metrics declined across all four categories over the assessment period. The largest decrease was seen in land use (75.9 percent), followed by water use (25.1 percent), then global warming potential (7.7 percent), and finally energy use (7.0 percent). [Excerpt from report]

    Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)

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    Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the hb(1P)h_b(1P) spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid Communications

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
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