exposure buildup factors have been calculated by monte carlo method for point isotropic gamma ray sources, penetrating a two-layer spherical shield of water surrounded by lead, and the effect of bremsstrahlung radiation on buildup factors has, in particular, been investigated, the results of which are in good agreement with previous works. the buildup factors were then calculated for various co...

serum albumin is the most aboundant protein in blood plasma. its two major roles aremaintaining osmotic pressure and depositing and transporting compounds. in this paper,albumin-methanol solution simulation is carried out by three techniques including montecarlo (mc), molecular dynamic (md) and langevin dynamic (ld) simulations. byinvestigating energy changes by time and temperature (between 27...

introduction: scattered photon is one of the main defects that degrade the quality and quantitative accuracy of nuclear medicine images. accurate estimation of scatter in projection data of spect is computationally extremely demanding for activity distribution in uniform and non-uniform dense media. methods: the objective of this paper is to develop and validate a scatter correction technique t...

Kinetic processes play a crucial role in the formation and evolution of molecular layers. In this perspective we argue that adaptive kinetic Monte Carlo is a powerful simulation technique for determining key kinetic processes in molecular solids. The applicability of the method is demonstrated by simulating the diffusion of a CO admolecule on a water ice surface, which is an important process f...

Abstract. An efficient, semi-rigorous synchronous algorithm for parallel kinetic Monte Carlo simulations is presented. The accuracy and parallel efficiency are studied as a function of processor size, number of processors, and the ratio D/F of monomer hopping rate (D) to deposition rate (F ) for two different simple models of epitaxial growth. Since only local communication is required, the alg...

We present a new method for computing the electrical impedance of solid oxide electrolyte from kinetic Monte Carlo simulations of oxygen vacancy diffusion. The impedance values at all frequencies are obtained from a single equilibrium simulation based on the fluctuation–dissipation theorem, leading to a significant gain of efficiency over existing methods.This allows us to systematically examin...

We use a first-principles based kinetic Monte Carlo simulation to study the movement of a solid iron nanocrystal inside a carbon nanotube driven by the electrical current. The origin of the iron nanocrystal movement is the electromigration force. Even though the iron nanocrystal appears to be moving as a whole, we find that the core atoms of the nanocrystal are completely stationary, and only t...