282,736 research outputs found

    The impact of charge symmetry and charge independence breaking on the properties of neutrons and protons in isospin-asymmetric nuclear matter

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    We investigate the effects of charge independence and charge symmetry breaking in neutron-rich matter. We consider neutron and proton properties in isospin-asymmetric matter at normal densities as well as the high-density neutron matter equation of state and the bulk properties of neutron stars. We find charge symmetry and charge independence breaking effects to be very small.Comment: 6 pages, 8 figure

    Minimum Altitude-Loss Soaring in a Specified Vertical Wind Distribution

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    Minimum altitude-loss flight of a sailplane through a given vertical wind distribution is discussed. The problem is posed as an optimal control problem, and several numerical solutions are obtained for a sinusoidal wind distribution

    Grid service orchestration using the Business Process Execution Language (BPEL)

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    Modern scientific applications often need to be distributed across grids. Increasingly applications rely on services, such as job submission, data transfer or data portal services. We refer to such services as grid services. While the invocation of grid services could be hard coded in theory, scientific users want to orchestrate service invocations more flexibly. In enterprise applications, the orchestration of web services is achieved using emerging orchestration standards, most notably the Business Process Execution Language (BPEL). We describe our experience in orchestrating scientific workflows using BPEL. We have gained this experience during an extensive case study that orchestrates grid services for the automation of a polymorph prediction application

    Non-volatile Optical Switch Based on a GST-Loaded Directional Coupler

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    We present a non-volatile optical switch based on a directional coupler comprising a silicon-Ge2Sb2Te5 (GST) hybrid waveguide. The non-volatility of GST makes it attractive for reducing static power consumption in optical switching. Experimental results show that the optical switch has an extinction ratio of >20 dB in the bar state and >25 dB in the cross state around 1578 nm wavelength. The insertion loss is 2 dB and 7 dB for the bar and cross states, respectively

    Asymptotic quasinormal modes of a coupled scalar field in the Gibbons-Maeda dilaton spacetime

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    Adopting the monodromy technique devised by Motl and Neitzke, we investigate analytically the asymptotic quasinormal frequencies of a coupled scalar field in the Gibbons-Maeda dilaton spacetime. We find that it is described by eβω=[1+2cos(2ξ+12π)]eβIω[2+2cos(2ξ+12π)] e^{\beta \omega}=-[1+2\cos{(\frac{\sqrt{2\xi+1}}{2} \pi)}]-e^{-\beta_I \omega}[2+2\cos{(\frac{\sqrt{2\xi+1}}{2}\pi)}], which depends on the structure parameters of the background spacetime and on the coupling between the scalar and gravitational fields. As the parameters ξ\xi and βI\beta_I tend to zero, the real parts of the asymptotic quasinormal frequencies becomes THln3T_H\ln{3}, which is consistent with Hod's conjecture. When ξ=91/18\xi={91/18} , the formula becomes that of the Reissner-Nordstr\"{o}m spacetime.Comment: 6 pages, 1 figur
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