We have investigated the segregation of Pt atoms to the surfaces of Pt-Re nanoparticles using the Monte Carlo method and modified embedded-atom method potentials that we have developed for Pt-Re alloys. The Pt(75)Re(25) nanoparticles (containing from 586 to 4,033 atoms) are assumed to have disordered fcc configurations and cubo-octahedral shapes (terminated by [111] and [100] facets), while the...

The problem of a thin spherical linearly-elastic shell, perfectly bonded to an infinite linearly-elastic medium is considered. A constant axisymmetric stress field is applied at infinity in the matrix, and the displacement and stress fields in the shell and matrix are evaluated by means of harmonic potential functions. In order to examine the stability of this solution, the buckling problem of ...

We present a practical solution to the " sign problem " in the auxiliary field Monte Carlo approach to the nuclear shell model. The method is based on extrapolation from a continuous family of problem-free Hamiltonians. To demonstrate the resultant ability to treat large shell-model problems, we present results for 54 Fe in the full f p-shell basis using the Brown-Richter interaction. We find t...

A method of truncating the large shell model basis is outlined. It relies on the order given by the unperturbed energies of the basis states and on the constancy of their spreading widths. Both quantities can be calculated by a simple averaging procedure. The method is tested in the sd shell where the JT dimensions are of the order of a few thousand. It proves to be very effective in the middle...

We propose a procedure to determine the effective nuclear shell-model Hamiltonian in a truncated space from a self-consistent mean-field model, e.g., the Skyrme model. The parameters of pairing plus quadrupole-quadrupole interaction with monopole force are obtained so that the potential energy surface of the Skyrme HartreeFock + BCS calculation is reproduced. We test our method for N = Z nuclei...

A method of truncating the large shell model basis is outlined. It relies on the order given by the unperturbed energies of the basis states and on the constancy of their spreading widths. Both quantities can be calculated by a simple averaging procedure. The method is tested in the sd shell where the JT dimensions are of the order of a few thousand. It proves to be very effective in the middle...

Abstract This paper presents a stress analysis of pressed joint two conical pipes with the aim to find out whether this kind connection is suitable for telecommunication masts. The can be considered complex spatial problem thin-walled shell, where local bending influence might dominant. In solution using engineering approach and numerical finite element method (FEM) will compared.

Abstract Underwater torpedo interception could be conducted by shell perforation or even warhead impact detonation with high speed projectiles. This work deals the projectile water entry and sequent penetration into underwater whereby both aluminium explosive are numerically studied. The model aluminum validated against test data for penetration. Targets located under 20 cm depth where shells a...

A conical shell-tube design with non-uniform fins was addressed for phase change latent heat thermal energy storage (LHTES). The shell filled nano-enhanced material (NePCM). cone aspect ratio of the and were adopted as geometrical parameters. type volume fraction nanoparticles other investigated alumina, graphite oxide, silver, copper. finite element method employed to solve natural convection ...

Kelvin probe force microscopy (KPFM) is a widely used technique to measure the local contact potential difference (CPD) between an AFM probe and the sample surface via the electrostatic force. The spatial resolution of KPFM is intrinsically limited by the long range of the electrostatic interaction, which includes contributions from the macroscopic cantilever and the conical tip. Here, we prese...