the creation of an intellectual work by a group of people could take different forms. sometimes, the cooperation of the members of the group takes the form of mutual consultation, in this case the work is called joint work. sometimes it is realized under the management of a real or legal person. in this case the work is a collective work. there are some occasions where the intellectual work is ...

introduction: globally, the need for radiotherapy as a part of cancer management increases every year. thus, the shielding for megavoltage radiotherapy rooms is of great importance. materials and methods: in the present study, 14 types of developed high-density concrete with densities ranging from 2.45 to 5.11 were simulated by using monte carlo method. the linear attenuation coefficient and th...

In this chapter we give an overview of the effects of various microstructural features on the resulting magnetic properties of magnetic thin films. The role of microstructure on certain properties of materials has a long history of investigation, starting in the discipline of physical metallurgy where the role of microstructure on properties was investigated in great detail [1]. It became clear...

introduction: the main goal of spect imaging is to determine activity distribution inside the organs of the body. however, due to photon attenuation, it is almost impossible to do a quantitative study. in this paper, we suggest a mathematical relationship between activity distribution and its corresponding projections using a transfer matrix. monte carlo simulation was used to find a precise tr...

Using Ly α line profiles generated from a grid of M dwarf model atmospheres we calculate the attenuation factor [i.e. Ly α (obs)/ Ly α (intrin)] due to the interstellar medium as a function of hydrogen column density. Then using selected model atmospheres, attenuation factors were calculated for thoseM dwarfs with available Ly α observations. The prime motivation in this work has been to look a...