background: gold nanoparticles (gnps) have been shown as a good radiosensitizer. in combination with radiotherapy, several studies with orthovoltage x-rays have shown considerable dose enhancement effects. this paper reports the dose enhancement factor (def) due to gnps in 18 megavoltage (mv) beams. materials and methods: different geometrical 50-nm gnps configurations at a concentration of 5 m...

background: exposure conditions in ct examinations are quite different from conventional xray. in ct examination higher dose is given to patient in comparison with the dose in other diagnostic examinations. in order to calculate organ effective dose in chest ct, monte carlo simulation has been used in this study. materials and methods: the impact survey data were used to determine the parameter...

An efficient method for the simulation of strained heteroepitaxial growth with intermixing using kinetic Monte Carlo is presented. The model used is based on a solid-on-solid bond counting formulation in which elastic effects are incorporated using a ball and spring model. While idealized, this model nevertheless captures many aspects of heteroepitaxial growth, including nucleation, surface dif...

Vapor deposited multilayers consisting of alternating ferromagnetic and nonferrous metals are being used for magnetic sensing and data storage devices. Their performance is dependent upon interface morphology which is a sensitive function of deposition condition such as the deposition rate, deposition temperature, and flux angle of incidence. A two-dimensional kinetic Monte Carlo method has bee...

The effects of a patterned substrate on island nucleation are investigated using kinetic Monte Carlo simulations. Two different models are formulated by incorporating an inhomogeneous energy surface into the basic solid-on-solid model of epitaxial growth to describe surface diffusion and consequent island nucleation on a patterned substrate. These models are related to two examples of real syst...

introduction: radioiodine therapy is an effective method for treating thyroid cancer carcinoma, but it has some affects on normal tissues, hence dosimetry of vital organs are important to weigh the risks and benefits of this method. the aim of this study is to measure the absorbed doses of important organs by mcnp (monte carlo n particle) simulation and comparing the results of different method...

Diverse phenomena in physical, chemical, and biological systems exhibit significant stochasticity and therefore require appropriate simulations that incorporate noise explicitly into the dynamics. We present a lattice kinetic Monte Carlo approach to simulate the trajectories of tracer particles within a system in which both diffusive and convective transports are operational. While diffusive tr...

Upcoming organic devices like thin lm transistors or light emitting diodes require novel architectures and materials. In most cases, two main problems, namely poor carrier mobility in the bulk and elusive interface effects, are closely related due to contact dominated device behavior. A three-dimensional Kinetic Monte Carlo simulator has been developed mimicking simultaneously charge injection ...

We use three dimensional kinetic Monte Carlo simulations on super-lattices to analyze the nucleation and evolution of several defects during the homoepitaxial growth of 4H silicon carbide. We show also that stacking faults can either extend throughout the entire epilayer (i.e. extended from the substrate up to the surface) or close in dislocation loops, in dependence of the surface kinetics, fi...

Introduction: The key characteristics of positron emission tomography (PET) are its quantitative capability and its sensitivity, which allow the in vivo imaging of biochemical interactions with small amounts of tracer concentrations. Therefore, accurate quantification is important. However, it can be sensitive to several physical factors. The aim of this investigation is the assessment of the e...