5,757 research outputs found

    Impact analysis of TOTEM data at the LHC: black disk limit exceeded

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    We discuss the profile of the impact--parameter dependent elastic scattering amplitude. Extraction of impact-parameter dependence from the dataset with inclusion of the experimental data on elastic scattering at the LHC energies helps to reveal the asymptotics of hadron interactions. Analysis of the data clearly indicates that the impact-parameter elastic scattering amplitude exceed the black disk limit at the LHC energy 7TeV and the inelastic overlap function reaches its maximum value at b>0b>0Comment: 5 pages, 5 figure

    Analysis of the Efficiency PETSc and PETIGA Libraries in Solving the Problem of Crystal Growth

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    We present an analysis of high performance computational method for solving the problem of crystal grows. The method uses PETSc and PETIGA C-language based libraries and supports parallel computing. The evolution of calculation process was studied in series of special computations are obtained on innovative mobile cluster platform, which provides exclusive system tuning abilities. The results of research confirm the high efficiency of the proposed algorithm on multi-core computer systems and allow us to recommend the use of PETSc and PETIGA for solving high order differential equations

    Influence of impurity-vacancy disorder on characteristics of gadolinium-doped ceria oxide: Molecular dynamics study

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    By high-speed MD method using GPU the CGO nanocrystals of about 40,000 particles during about 0.1 μs, in the temperature range (2500-700) K, were simulated. The influence of different dopant distributions on the nanocrystal characteristics, for two potentials sets, was investigated. For a given potentials set Gd distribution does not affect the lattice parameter and the anion diffusion coefficients. Five types of impurity vacancies were defined, by the Gd number in the nearest neighborhood, and temperature dependences were built. The formation energies of vacancies of all types were obtained. Calculated by the MD conductivity activation energy of 0.6 eV acceptable coincides with the experimental 0.7 eV, just as the absolute conductivity values. The supposition that helium in CGO ceramics dissolve in vacancies, surrounded only by cerium ions, was discussed. Analysis of the MD, conductivity measurements and helium defectoscopy shows that up to the melting temperature the vacancies are mainly associated with impurity ions. © 2013 Elsevier B.V. All rights reserved
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