background: use of contrast agents (cas) during ct simulation for treatment planing system leads to changes in  electron density. in this study we aimed to investigate the effect on  calculated dose of various concentrations of cas on treatment planing systems in different dose calculation algorithms. materials and methods: contrast agent (0.769 mg/ml iopromid) - water mixtures at concentration...

When the electron density in a crystal or a quasicrystal is reconstructed from its Fourier modes, the global minimum value of the density is sensitively dependent on the relative phases of the modes. The set of phases that maximizes the value of the global minimum corresponds, by positivity of the density, to the density having the minimum total charge that is consistent with the measured Fouri...

Ionospheric tomography is a method to investigate the ionospheric electron density in two or three dimensions. In this study, the function-based tomographic technique has been used for regional reconstruction of a 3D tomographic model of the ionospheric electron density using the GPS measurements of the Iranian Permanent GPS Network. Two-dimensional Haar wavelets and empirical orthogonal functi...

[1] The vertical structure of the nightside ionosphere of Mars and its dependence on solar zenith angle are currently poorly determined, as is the importance of two key sources of nightside plasma, electron precipitation and transport of dayside plasma. We examined 37 electron density profiles of the ionosphere of Mars at solar zenith angles of 101 –123 obtained by the Mars Express Radio Scienc...

First principle calculations were performed using Density functional theory within the local spin density approximation (LSDA) to understand the electronic properties of Au(100)+TBT system and compare the results with Au(100) and bulk Au properties. Band structure, the total DOS and charge density for these materials are calculated. We found that the HOMO for Au(100)+TBT becomes broader than Au...

Density functional theory calculations were carried out to investigate the structural and electronicproperties of the adsorption of O3 molecules on AlP-codoped monolayers to fully exploit the gas sensingcapability of these two-dimensional materials. Various adsorption sites of O3 molecule on the considerednanosheets were examined in detail. The side oxygen atoms of the O3 mole...

First principle calculations were performed using Density functional theory within the local spin density approximation (LSDA) to understand the electronic properties of Au(100)+TBT system and compare the results with Au(100) and bulk Au properties. Band structure, the total DOS and charge density for these materials are calculated. We found that the HOMO for Au(100)+TBT becomes broader than Au...

We compare a new classical water model, which features Gaussian charges and polarizability (GCPM) with ab initio Car-Parrinello molecular dynamics (CPMD) simulations. We compare the total dipole moment, the total dipole moment distribution, and degree of hydrogen bonding at ambient to supercritical conditions. We also compared the total dipole moment calculated from both the electron density (p...

Introduction: Total Skin Electron Therapy (TSET) and Total Body Irradiation (TBI) are kinds of treatment which use electron and photon beams to treat special types of cancers. The aim of these techniques are to deliver uniform dose to the entire skin while minimizing delivered dose to organs at risk. To check the homogeneity of dose delivery in TBI and TSET, using a humanoid ph...