383 research outputs found
Issues in front-end decision-making on projects
No full textThe importance of the front-end decision-making phase in projects is being increasingly recognized - the need to do the right project is on a par with doing the project right. This area is underrepresented in the literature, but there are a number of key themes that run throughout, identifying key issues or difficulties during this stage. This article looks at some of these themes and includes: the need for alignment between organizational strategy and the project concept; dealing with complexity, in particular the systemicity and interrelatedness within project decisions; consideration of the ambiguity implicit in all major projects; taking into account psychological and political biases within estimation of benefits and costs; consideration of the social geography and politics within decision-making groups; and preparation for the turbulence within the project environment, including the maintenance of strategic alignment
Adebiyi etal: absorption of shortwave radiation by North African dust
No full textThe codes and datasets contained here are for the paper with the information below
Titled: "North African dust absorbs substantially less solar radiation than estimated by climate models and remote-sensing retrievals"
Author: Adeyemi A. Adebiyi, Yue Huang, Bjørn H. Samset and Jasper F. Kok
Please see the ReadMe.txt for additional details.
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Corresponding Authors:
Adeyemi Adebiyi
Email: [email protected];
Department of Life and Environmental Sciences,
University of California-Merced,
5200 North Lake Road Merced, CA 95343
The latest results from the ATLAS experiment
No full textThe ATLAS detector at the LHC is a general purpose experiment for studying p+p collisions at TeV energies. This talk presents early ATLAS physics measurements, based on O(10pb-1) of data from the first half year of LHC running. Topics include minimum bias and soft QCD physics, W and Z observation, and various measurements of detector performance
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV with the ATLAS detector
No full textThe 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 √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<p T<400 GeV and rapidity in the range |y|<2.1. The bb− -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 χ 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 bb− -dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta
Measurement of the b-hadron production cross section using decays to D∗ +μ −X final states in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV with the ATLAS detector
No full textThe b-hadron production cross section is measured with the ATLAS detector in pp collisions at
√<span style="text-decoration:overline">s</span>=7 TeV, using 3.3 pb−1
of integrated luminosity, collected during the 2010 LHC run. The b-hadrons
are selected by partially reconstructing D∗+μ
−X final states. Differential cross sections are measured as
functions of the transverse momentum and pseudorapidity. The measured production cross section for a
b-hadron withpT
>9 GeV and |η|<2.5 is 32.7±0.8(stat.)+4.5
−6.8
(syst.) µb, higher than the next-to-leadingorder QCD predictions but consistent within the experimental and theoretical uncertainties
A system for visualization and automatic placement of the endoclamp balloon catheter
No full textThe European research network "Augmented Reality in Surgery" (ARIS*ER) developed a system that supports minimally invasive cardiac surgery based on augmented reality (AR) technology. The system supports the surgical team during aortic endoclamping where a balloon catheter has to be positioned and kept in place within the aorta. The presented system addresses the two biggest difficulties of the task: lack of visualization and difficulty in maneuvering the catheter. The system was developed using a user centered design methodology with medical doctors, engineers and human factor specialists equally involved in all the development steps. The system was implemented using the AR framework "Studierstube" developed at TU Graz and can be used to visualize in real-time the position of the balloon catheter inside the aorta. The spatial position of the catheter is measured by a magnetic tracking system and superimposed on a 3D model of the patient's thorax. The alignment is made with a rigid registration algorithm. Together with a user defined target, the spatial position data drives an actuator which adjusts the position of the catheter in the initial placement and corrects migrations during the surgery. Two user studies with a silicon phantom show promising results regarding usefulness of the system: the users perform the placement tasks faster and more accurately than with the current restricted visual support. Animal studies also provided a first indication that the system brings additional value in the real clinical setting. This work represents a major step towards safer and simpler minimally invasive cardiac surgery.Industrial Design Engineerin
Search for a light charged Higgs boson in the decay channel H+→cs¯ in tt¯ events using pp collisions at s√=7 TeV with the ATLAS detector
No full textA search for a charged Higgs boson (H +) in tt¯ decays is presented, where one of the top quarks decays via t→H + b, followed by H +→ two jets ( cs¯ ). The other top quark decays to Wb, where the W boson then decays into a lepton (e/μ) and a neutrino. The data were recorded in pp collisions at s√=7 TeV by the ATLAS detector at the LHC in 2011, and correspond to an integrated luminosity of 4.7 fb−1. With no observation of a signal, 95 % confidence level (CL) upper limits are set on the decay branching ratio of top quarks to charged Higgs bosons varying between 5 % and 1 % for H + masses between 90 GeV and 150 GeV, assuming B(H+→cs¯)=100 %
Standard climate models radiation codes underestimate black carbon radiative forcing
No full textRadiative forcing (RF) of black carbon (BC) in the atmosphere is estimated
using radiative transfer codes of various complexities. Here we show that
the two-stream radiative transfer codes used most in climate models give too
strong forward scattering, leading to enhanced absorption at the surface and
too weak absorption by BC in the atmosphere. Such calculations are found to
underestimate the positive RF of BC by 10% for global mean, all sky
conditions, relative to the more sophisticated multi-stream models. The
underestimation occurs primarily for low surface albedo, even though BC is
more efficient for absorption of solar radiation over high surface albedo
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