3D Monte Carlo Simulations Research Articles

Effects of location uncertainties on the observed distribution of gamma-ray bursts detected by BATSE

The Burst and Transient Source Experiment (BATSE) on NASA's Compton Gamma-Ray Observatory has shown that the sources of gamma-ray bursts have an angular distribution consistent with isotropy, yet the bursts are spatially inhomogeneous. Detection of a statistically significant deviation from isotropy in the burst distribution would provide a clue to the distance of the burst sources. BATSE's ability to detect slight deviations of the angular distribution from isotropy is, in part, dependent on the accuracy of the computed burst locations. Using bursts whose locations have been determined accurately and independently, we estimate BATSE's location uncertainties and incorporate them into 3D Monte Carlo simulations of the burst distributions to show that, despite individual burst location uncertainties of about 5 deg, the ability of BATSE to place stringent limits on the anisotropy present in the angular distribution of the gamma-ray bursts is not significantly degraded. Observational effects of possible galactic halo distributions of the burst sources are noted.

Moisture in the menu

Polymer-matrix composites containing hybrid fillers can exhibit electric performance due to synergistic conductive effect. In this work, the nonlinear synergistic enhancement electric conductive effect (NSECE) in nanocomposites containing carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) is studied by the 3D Monte Carlo simulation. The 3D model with random distribution based on tunnel theory for nanocomposites filled with cylindrical CNTs and disc-shaped GNPs is developed. The morphology of CNTs and GNPs are researched for the NSECE in percolation threshold. The results show that the reason of NSECE is the different network construction ability of CNTs and GNPs with different morphology. When the monofiller nanocomposites of each of those exact fillers have similar percolation thresholds and the length of CNTs is smaller than the diameter of GNPs, hybrid nanocomposites filled with CNTs and GNPs is more likely to exhibit NSECE in their electrical performance.