7,868 research outputs found
Evaluation and recommendations for work group integration within the Materials and Processes Lab
The goal of this study was to evaluate and make recommendations for improving the level of integration of several work groups within the Materials and Processes Lab at the Marshall Space Flight Center. This evaluation has uncovered a variety of projects that could improve the efficiency and operation of the work groups as well as the overall integration of the system. In addition, this study provides the foundation for specification of a computer integrated manufacturing test bed environment in the Materials and Processes Lab
Measurement of the differential cross-section of B + meson production in pp collisions at âs=7 TeV at ATLAS
The production cross-section of B + mesons is measured as a function of transverse momentum p T and rapidity y in proton-proton collisions at centre-of-mass energy sâ=7 TeV, using 2.4 fbâ1 of data recorded with the ATLAS detector at the Large Hadron Collider. The differential production cross-sections, determined in the range 9 GeV < p T < 120 GeV and |y| < 2.25, are compared to next-to-leading-order theoretical predictions
Dynamics of isolated-photon plus jet production in pp collisions at âs=7 TeV with the ATLAS detector
The dynamics of isolated-photon plus jet production in pp collisions at a centre-of-mass energy of 7 TeV has been studied with the ATLAS detector at the LHC using an integrated luminosity of 37 pbâ1. Measurements of isolated-photon plus jet bin-averaged cross sections are presented as functions of photon transverse energy, jet transverse momentum and jet rapidity. In addition, the bin-averaged cross sections as functions of the difference between the azimuthal angles of the photon and the jet, the photonâjet invariant mass and the scattering angle in the photonâjet centre-of-mass frame have been measured. Next-to-leading-order QCD calculations are compared to the measurements and provide a good description of the data, except for the case of the azimuthal opening angle
Measurement of jet shapes in top-quark pair events at âs =7 TeV using the ATLAS detector
A measurement of jet shapes in top-quark pair events using 1.8 fbâ1 of âs=7 TeV pp collision data recorded by the ATLAS detector at the LHC is presented. Samples of top-quark pair events are selected in both the single-lepton and dilepton final states. The differential and integrated shapes of the jets initiated by bottom-quarks from the top-quark decays are compared with those of the jets originated by light-quarks from the hadronic W-boson decays WâqqÂŻâČ in the single-lepton channel. The light-quark jets are found to have a narrower distribution of the momentum flow inside the jet area than b-quark jets
Measurement of the production cross section of jets in association with a Z boson in pp collisions at âs=7 TeV with the ATLAS detector
Measurements of the production of jets of particles in association with a Z boson in pp collisions at sâ=7 TeV are presented, using data corresponding to an integrated luminosity of 4.6 fbâ1 collected by the ATLAS experiment at the Large Hadron Collider. Inclusive and differential jet cross sections in Z events, with Z decaying into electron or muon pairs, are measured for jets with transverse momentum p T > 30 GeV and rapidity |y| < 4.4. The results are compared to next-to-leading-order perturbative QCD calculations, and to predictions from different Monte Carlo generators based on leading-order and next-to-leading-order matrix elements supplemented by parton showers
Design and specification of a centralized manufacturing data management and scheduling system
As was revealed in a previous study, the Materials and Processes Laboratory's Productivity Enhancement Complex (PEC) has a number of automated production areas/cells that are not effectively integrated, limiting the ability of users to readily share data. The recent decision to utilize the PEC for the fabrication of flight hardware has focused new attention on the problem and brought to light the need for an integrated data management and scheduling system. This report addresses this need by developing preliminary designs specifications for a centralized manufacturing data management and scheduling system for managing flight hardware fabrication in the PEC. This prototype system will be developed under the auspices of the Integrated Engineering Environment (IEE) Oversight team and the IEE Committee. At their recommendation the system specifications were based on the fabrication requirements of the AXAF-S Optical Bench
Separated Fringe Packet Observations with the CHARA Array III. The Very High Eccentricity Binary HR 7345
After an eleven year observing campaign, we present the combined
visual{spectroscopic orbit of the formerly unremarkable bright star HR 7345 (HD
181655, HIP 94981, GJ 754.2). Using the Separated Fringe Packet (SFP) method
with the CHARA Array, we were able to determine a difficult to complete orbital
period of 331.609 +/- 0.004 days. The 11 month period causes the system to be
hidden from interferometric view behind the Sun for 3 years at a time. Due to
the high eccentricity orbit of about 90% of a year, after 2018 January the
periastron phase will not be observable again until late 2021. Hindered by its
extremely high eccentricity of 0.9322 +/- 0.0001, the double-lined
spectroscopic phase of HR 7345 is observable for 15 days. Such a high
eccentricity for HR 7345 places it among the most eccentric systems in catalogs
of both visual and spectroscopic orbits. For this system we determine nearly
identical component masses of 0.941 +/- 0.076 Msun and 0.926 +/- 0.075 Msun as
well as an orbital parallax of 41.08 +/- 0.77 mas.Comment: 20 pages, 3 figures, 4 table
An expert opinion in speech and language therapy: The Queen Square Intensive Comprehensive Aphasia Programme
Less is more, right? Wrong: more is more. Here we make the case that the total dose of speech and language therapy (SLT) is a key factor in improving persons with aphasiaâs (PWA) outcomes. The challenge is: how can we deliver high-dose therapy when resources are stretched? We review the recent evidence for dose and timing of SLT and then describe one solution to the problem of dose that we are trialing at Queen Square, an Intensive Comprehensive Aphasia Programme (ICAP)
Measurement of the azimuthal angle dependence of inclusive jet yields in Pb+Pb collisions at âsNN=2.76ââTeV with the ATLAS detector
Measurements of the variation of inclusive jet suppression as a function of relative azimuthal angle, ÎÏ, with respect to the elliptic event plane provide insight into the path-length dependence of jet quenching. ATLAS has measured the ÎÏ dependence of jet yields in 0.14âânb-1 of âsNN=2.76ââTeV Pb+Pb collisions at the LHC for jet transverse momenta pT>45ââGeV in different collision centrality bins using an underlying event subtraction procedure that accounts for elliptic flow. The variation of the jet yield with ÎÏ was characterized by the parameter, v2jet, and the ratio of out-of-plane (ÎÏâŒÏ/2) to in-plane (ÎÏâŒ0) yields. Nonzero v2jet values were measured in all centrality bins for pT<160ââGeV. The jet yields are observed to vary by as much as 20% between in-plane and out-of-plane directions
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