abstract  introduction: recently uses of medium and high energy x-rays has been increased in iran and radiotherapy centers along with a variety of accelerators have been installed in some provinces. in the other hand there is no sufficient skill in designing and making radiotherapy treatment rooms. this study was conducted to evaluate the efficacy of different mixtures of barite concrete for sh...

Present study explores the effect of Hall current, non-linear radiation, irregular heat source/sink on magnetohydrodynamic flow of Casson nanofluid past a nonlinear stretching sheet. Viscous and Joule dissipation are incorporated in the energy equation. An accurate numerical solution of highly nonlinear partial differential equations, describing the flow, heat and mass transfer...

background: radiation therapy  uses high-energy radiation to kill cancer cells. photoneutron contamination and induced radioactivity of high energy therapeutic photon beams are considered as the main source of occupational exposure to radiation therapists who works with linear accelerators operating above 10 mv. materials and methods: the gamma dose rates were measured after termination of diff...

Multileaf Collimators (MLC) consist of (currently 20-100) pairs of movable metal leaves which are used to block radiation in Intensity Modulated Radiation Therapy (IMRT). The leaves modulate a uniform source of radiation to achieve given intensity profiles. The modulation process is modeled by the decomposition of a given non-negative integer matrix into a non-negative linear combination of mat...

  Today, nuclear medicine has rapidly been developed so that in some cases, plays a unique role in diagnosis but unfortunalty in spite of diagnostic and therapeutic advantages, the term “NUCLEAR” can induce worries in patients and society. In this article, base on new documents, we intend to show that this worries has no scientific basis. To produce a realistic view, ...