Introduction: Physical wedge as a useful tool has been utilized in radiotherapy to modify photon beam shape and intensity such that it distributes dose uniformly in tumor site and reduces hot points. Since during Linac commissioning dosimetric parameters like output factors and lateral dose profiles are measured only for symmetric open and wedged fields, so calculation the par...

Although the Monte Carlo (MC) method allows accurate dose calculation for proton radiotherapy, its usage is limited due to long computing time. In order to gain efficiency, a new macro MC (MMC) technique for proton dose calculations has been developed. The basic principle of the MMC transport is a local to global MC approach. The local simulations using GEANT4 consist of mono-energetic proton p...

INTRODUCTION Gold nanoparticles have been used as radiation dose enhancing materials in recent investigations. In the current study, dose enhancement effect of gold nanoparticles on tumor cells was evaluated using Monte Carlo (MC) simulation. METHODS We used MCNPX code for MC modeling in the current study. A water phantom and a tumor region with a size of 1×1×1 cm3 loaded with gold nanopartic...

In this paper elastic lateral-torsional behavior of simple beams is discussed. The motivation the presented research observation that classic analytical prediction and finite element are, typically, considerably different, when second-order nonlinear with initial imperfections analyzed. order to understand explain observed differences, a novel solution for geometrically analysis geometric imper...

Abstract A cantilevered rod’s endpoint has a symmetric stiffness profile throughout its range of motion. Generally, this is not the case for spatially curved compliant beams, particularly if they are asymmetric, i.e., their fixation in symmetry plane operating field. This paper discusses technique obtaining kinetostatic behavior from type asymmetric beam over relatively large To accomplish this...

We present the experimental observation of 1D and 2D self-accelerating nonlinear beams in quadratic media, which are also the first nonlinear self-accelerating beams in any symmetric nonlinearity. Notably, we show that the intensity peaks of the first and second harmonics are asynchronous with respect to one another, but the coupled harmonics exhibit joint acceleration within the nonlinear medi...

We study the nonlinear optical propagation of two different classes of light beams with space-varying polarization-radially symmetric vector beams and Poincaré beams with lemon and star topologies-in a rubidium vapor cell. Unlike Laguerre-Gauss and other types of beams that quickly experience instabilities, we observe that their propagation is not marked by beam breakup while still exhibiting t...