73 research outputs found

    Application of the JJ-matrix Method to Faddeev-Merkuriev equation: beyond pseudostates

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    A version of the JJ-matrix method for solving numerically the three-body Faddeev-Merkuriev differential equations is proposed. This version allows to take into account the full spectrum of the two-body Coulomb subsystem. As a result, a discrete analog of the Lippmann-Schwinger equation is obtained which allows to interpret correctly the three-body wave function in two-body domains. The scheme is applied to calculations of the fully resolved absolute differential cross sections for the He(e,2e)(e,2e)He+^+ and He(e,3e)(e,3e)He++^{++} reactions at small energy and momentum transfers. The results are in good agreement with the experiment both in shape and in absolute value.Comment: 22 pages, 7 figure

    Estimating the cutting force when skiving with a radius cutter

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    The paper considers the method of determining the components of the cutting force under cutting completed with a radius cutter. The authors provide the design of the experimental study. The authors provide the data on the cutting force change in the process of turning with a radius cutter according to the cutting edge inclination, cutting depth and supply obtained experimentally and calculated analytically. The paper also provides the results of experimental work approximation and theoretical error checking related to experimental data

    Continuous selections of multivalued mappings

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    This survey covers in our opinion the most important results in the theory of continuous selections of multivalued mappings (approximately) from 2002 through 2012. It extends and continues our previous such survey which appeared in Recent Progress in General Topology, II, which was published in 2002. In comparison, our present survey considers more restricted and specific areas of mathematics. Note that we do not consider the theory of selectors (i.e. continuous choices of elements from subsets of topological spaces) since this topics is covered by another survey in this volume

    Fractional Variations for Dynamical Systems: Hamilton and Lagrange Approaches

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    Fractional generalization of an exterior derivative for calculus of variations is defined. The Hamilton and Lagrange approaches are considered. Fractional Hamilton and Euler-Lagrange equations are derived. Fractional equations of motion are obtained by fractional variation of Lagrangian and Hamiltonian that have only integer derivatives.Comment: 21 pages, LaTe

    Test beam studies of the TRD prototype filled with different gas mixtures based on Xe, Kr, and Ar

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    Towards the end of LHC Run1, gas leaks were observed in some parts of the Transition Radiation Tracker (TRT) of ATLAS. Due to these leaks, primary Xenon based gas mixture was replaced with Argon based mixture in various parts. Test-beam studies with a dedicated Transition Radiation Detector (TRD) prototype were carried out in 2015 in order to understand transition radiation performance with mixtures based on Argon and Krypton. We present and discuss the results of these test-beam studies with different active gas compositions.Comment: 5 pages,12 figures, The 2nd International Conference on Particle Physics and Astrophysics (ICPPA-2016); Acknowledgments section correcte

    Some results of test beam studies of Transition Radiation Detector prototypes at CERN

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    Operating conditions and challenging demands of present and future accelerator experiments result in new requirements on detector systems. There are many ongoing activities aimed to develop new technologies and to improve the properties of detectors based on existing technologies. Our work is dedicated to development of Transition Radiation Detectors (TRD) suitable for different applications. In this paper results obtained in beam tests at SPS accelerator at CERN with the TRD prototype based on straw technology are presented. TRD performance was studied as a function of thickness of the transition radiation radiator and working gas mixture pressure

    DYNAMIC REGIMES IN PERMALLOY MAGNETIC FILMS OF DIFFERENT THICKNESSES IN СONSTANT MAGNETIC FIELD

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    This work deals with model of permalloy magnetic film in constant magnetic film. Micromagnetic simulation has shown that with change of film thickness and value of magnetic field different dynamic regimes existed depending on starting conditions. Between most interesting ones are movement of Neel walls with deformations for extremely thin films and cross-tie walls movement with periodical born and annihilation of 3D- topological structures for more thick films

    Heat conduction in 1D lattices with on-site potential

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    The process of heat conduction in one-dimensional lattice with on-site potential is studied by means of numerical simulation. Using discrete Frenkel-Kontorova, ϕ\phi--4 and sinh-Gordon we demonstrate that contrary to previously expressed opinions the sole anharmonicity of the on-site potential is insufficient to ensure the normal heat conductivity in these systems. The character of the heat conduction is determined by the spectrum of nonlinear excitations peculiar for every given model and therefore depends on the concrete potential shape and temperature of the lattice. The reason is that the peculiarities of the nonlinear excitations and their interactions prescribe the energy scattering mechanism in each model. For models sin-Gordon and ϕ\phi--4 phonons are scattered at thermalized lattice of topological solitons; for sinh-Gordon and ϕ\phi--4 - models the phonons are scattered at localized high-frequency breathers (in the case of ϕ\phi--4 the scattering mechanism switches with the growth of the temperature).Comment: 26 pages, 18 figure

    A study of hydroxyapatite nanocrystals by the multifrequency EPR and ENDOR spectroscopy methods

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    Specimens of powders of hydroxyapatite (Ca10(PO 4)6(OH)2) with average crystallite sizes in the range of 20-50 nm synthesized by the wet precipitation method have been investigated by the multifrequency (9 and 94 GHz) electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) methods. In specimens subjected to X-ray irradiation at room temperature, EPR signals that are caused by nitrogen compounds have been observed. Numerical calculations performed in terms of the density functional theory show that the observed EPR signal is caused by the occurrence of paramagnetic centers, the structure of which is NO 3 2- and which replace the positions of PO 4 3- in the hydroxyapatite structure. © 2014 Pleiades Publishing, Ltd

    MICROMAGNETIC SIMULATIONS OF PERIODIC CHAINS OF TRANSITION STRUCTURES IN VORTEX-LIKE DOMAIN WALLS (PARALLEL PROCESSING IN MUMAX 3)

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    Many properties of magnetically ordered materials depend on existence and dynamical behavior o f locally inhomogeneous transition structures (TS’s) in domain walls (DW’s). This work deals with TS’s, which emerge in asymmetric Bloch domain walls and their chains’ interaction. We achieve energies of domain walls as functions o f the distance between two TS’s in presence and absence of external field in order to determine the kind of interaction: repulsion, attraction or fixing on definite distance. We have adapted the OOMMF programs for the parallel processing package MuMAX 3
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