73 research outputs found
Application of the -matrix Method to Faddeev-Merkuriev equation: beyond pseudostates
A version of the -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 HeHe and HeHe
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
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
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
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
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
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
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
The process of heat conduction in one-dimensional lattice with on-site
potential is studied by means of numerical simulation. Using discrete
Frenkel-Kontorova, --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 --4
phonons are scattered at thermalized lattice of topological solitons; for
sinh-Gordon and --4 - models the phonons are scattered at localized
high-frequency breathers (in the case of --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
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)
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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