There has been a considerable accumulation of usage of voxel models for internal radiation dosimetry (Xu & Eckerman, 2009 ; Zaidi & Tsui, 2009). The human voxel models of the Reference Male and Reference Female have been introduced and used to evaluate the energy deposition in organs resulting from internal radiation exposures by the International Commission on Radiological Protection (ICRP) (I...

some of the most destructive accidents of 1980s and 90s which occurred in process industries were domino accidents. although domino accidents are among the most destructive industrial accidents, there are not much pioneering works done on quantification of them. the analytical formulation of the domino accidents is usually complex and need a deep knowledge of probability rules. even if the case...

in this paper, we focus on a continuously deteriorating critical equipment which its failure cannot be measured by cost criterion. for these types of systems like military systems, nuclear systems, etc it is extremely important to avoid failure during the actual operation of the system. in this paper we propose an approach which constrains failure probability to a pre-specified value. this valu...

atom transfer radical polymerization (atrp) of styrene was carried out at 105°c and a monte carlo simulation was employed to model the system. the variations of monomer conversion, the initiator concentration, average molecular weight, and molecular weight distribution were evaluated as the reaction proceeded. according to the results obtained, for similar reaction time, monomer conversion is h...

background: the presence of a wedge filter in the beam trajectory can modify the beam quality and cause some changes in the dosimetry parameters which are usually difficult to be measured directly and accurately. material and methods: in this study the mcnp-4c monte carlo code was used to simulate the 9 mv photon beam generated by a linear accelerator. upon getting a good agreement between the ...

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...

Background: The lack of lateral electronic disequilibrium (LED) becomes a main problem in small field. This factor affects the dose in target volume cannot predict correctly. In addition, utilization of high-energy linear accelerator (10 MV) can emit some unwanted particles (electron contamination). Therefore, the aim of this study was to characterize head linear accelerator (linac) Varian Clin...