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The microscopic folding model of optical potential (OP) is applied for calculations of the π±-nucleus scattering at energies of the (3 3) resonance region. Such OP depends on the nuclear density distribution and on parameters of the πN scattering amplitude which is fitted to the pion-nucleus elastic scattering experimental data. The scattering cross sections are calculated by solving the corresponding relativistic wave equation. The calculations in this theoretical framework are found to be in well agreement with the results obtained using the Kisslinger-type and Wood-Saxon potentials. The parameters of the πN scattering amplitude obtained in the pion-nucleus scattering case are compared with those for the pion scattering on free nucleons with the aim to estimate the role of nuclear matter in the πN scattering process. [ABSTRACT FROM AUTHOR]

The MPI/OpenMP/C++ /Fortran package of computer codes has been developed for high-performance numerical analysis of experimental data on elastic nucleus-nucleus scattering within a microscopic model of optical potential. In the package, a modified DWUCK4 Fortran-code for calculating the physical characteristics of elastic scattering based on a numerical solution of the corresponding Schrödinger equation has been incorporated into the C++ framework, which is responsible for the input-output procedure and a comparison of numerical results with experimental data. MPI-based parallelism allows efficient calculations of the observables depending on a wide range of parameters of real and imaginary parts of the microscopic optical potential. The package has been used to analyze experimental data on differential cross sections of nucleus-nucleus elastic scattering of neutron-rich exotic nuclei 12,14Be on the target nucleus 12C at energy about 56 MeV/nucleon. [ABSTRACT FROM AUTHOR]

The φ0-Josephson Dushanbe, Tajikistanjunction model with a coupling between the magnetic moment and the Josephson current in the "superconductor–ferromagnet–superconductor" system has been investigated. Numerical solution of the respective system of nonlinear differential equations is based on the two-stage Gauss–Legendre algorithm. For numerical simulation in a wide range of parameters which requires a significant computer time, a parallel MPI=C++ computer code has been developed. Results of numerical study of the magnetization effect depending on physical parameters, as well as results of methodological calculations demonstrating the efficiency of the parallel implementation, are presented. Calculations have been carried out at the Heterogeneous Platform "HybriLIT" and on the supercomputer "Govorun" of the Multifunctional Information and Computing Complex of the Laboratory of Information Technologies, JINR (Dubna). [ABSTRACT FROM AUTHOR]

The computation of the real part of the nucleus-nucleus optical potential based on the microscopic double-folding model was implemented within both the MPI and OpenMP parallelising techniques. Test calculations of the total cross section of the 6He + 28Si scattering at the energy 50 A MeV show that both techniques provide significant comparable speedup of the calculations. [ABSTRACT FROM AUTHOR]

The data on the 12,14Be + p elastic scattering cross sections at 700 Mev are compared with those obtained by solving the relativistic wave equation with the microscopic optical potentials calculated as folding of the NN amplitude of scattering with densities of these nuclei in the form of the symmetrized Fermi function with the fitted radius and diffuseness parameters, and also with the densities obtained in two microscopic models, based on the Generator Coordinate Method (GCM) and the other one – on the Variational Method of Calculations (VMC). For 12Be, above models turn out to be in a small disagreement with the data at "large" angles of scattering θ ≥ 9°, while for the 14Be one sees some inconsistence at smaller angles, too. [ABSTRACT FROM AUTHOR]

Numerical simulation of the photoexcited electron states formation in water under the action of the ultraviolet range laser irradiation is carried out on the basis of the polaron model with a time-dependent calculation of the hydrated electron absorption band width. This framework is shown to reproduce well the experimental data on the light absorption by the hydrated electron in polarized water. Effectiveness of parallel implementation is tested on the HybriLIT cluster. [ABSTRACT FROM AUTHOR]

The phase dynamics of a stack of long Josephson junctions has been studied. Both inductive and capacitive couplings between Josephson junctions have been taken into account in the calculations. The IV-curve, the dependence on the bias current of the radiation power and dynamics of each JJs of the stack have been investigated. The coexistence of the charge traveling wave and fluxon states has been observed. This state can be considered as a new collective excitation in the system of coupled Josephson junctions. We demonstrate that the observed collective excitation leads to the decrease of radiation power from the system. [ABSTRACT FROM AUTHOR]

Parameters of the phospholipid vesicular systems are determined by means of minimization of the discrepancy between experimental data on the small angle scattering intensity and the numerical results within the frame of the separated form factors method. Effectiveness of parallel implementation is tested at the cluster HybriLIT. Results of numerical analysis of small angle neutron scattering data on polydispersed population of unilamellar vesicles of phospholipid transport nanosystem are presented. [ABSTRACT FROM AUTHOR]

A user software for numerical study of a Josephson junction model with magnetic momenta is presented. Computer implementation has been done by means of Wolfram Mathematica using the extensive capabilities of this system to create interactive dynamic objects. Two methods for numerical solution of the respective system of ordinary differential equations are implemented: the four-step Runge-Kutta algorithm and the Runge-Kutta-Fehlberg method with predetermined accuracy. Results of numerical simulation are presented to confirm the correctness of the calculations done with the developed software. [ABSTRACT FROM AUTHOR]

Elastic scattering cross sections are calculated and compared to the data of π± + 28Si and 40Ca at energies 130, 180, and 230 MeV by using the both microscopic optical potentials (OP), the high-energy folding and the local Kisslinger type potentials. In the folding OP, we use the known nuclear density distributions while parameters of the elementary πN-scattering amplitude are fitted to the data with the aim to estimate the inmedium effect on pions scattered on bound nucleons. As to the local modified Kisslinger OP its parameters are known from the earlier studies. The cross sections for both OPs are calculated by solving the Klein-Gordon wave equation, and thus the relativistic and distortion effects on the process are accounted for exactly. A fairly well agreement with experimental data was obtained and the decisive role of a surface region of potentials was established where both OPs occur in close coincidence. [ABSTRACT FROM AUTHOR]

In this work we use an Asynchronous Differential Evolution (ADE) method to estimate parameters of the Separated Form Factor (SFF) model which is used to investigate a structure of drug delivery Phospholipid Transport Nano System (PTNS) unilamellar vesicles by experimental small angle synchrotron X-ray scattering spectra (SAXS). We compare the efficiency of different optimizing procedures (OP) for the search for the SFF-model parameters. It is shown that the probability to find the global solution of this problem by ADE-methods is significantly higher than that by either Nelder-Mead method or a Quasi-Newton method with Davidon-Fletcher-Powell formula. The parallel realization of ADE accelerates the calculations significantly. The speed-up obtained by the parallel realization of ADE and results of the model are presented. [ABSTRACT FROM AUTHOR]