The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

  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, ...

The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

Introduction Natural and artificial radionuclides are the main sources of human radiation exposure, which enter the food chain from the environment. Radionuclides can affect human health by transferring from soil to plants and entering the human body. In this research study, we aimed to determine the activity concentrations of radionuclides and calculate the average annual committed effective d...

Combined radiation and natural convection within the annular region of two infinitely long horizontal concentric cylinders are investigated numerically in this research. Radial and tangential radiation effects ate considered using Milne-Eddington approximation for a two-dimensional radiative transfer. The basic conservation equations are discretized with the finite volume method and SIMPLER alg...

iran is one of several countries that has regions of high dose natural ionizing radiation. two wellknown villages in the suburb of ramsar town in the caspian sea strip, taleshmahaleh and chaparsar, have background radiation that is 13 times higher than normal. this radiation is the result of radium 226 and radon gas both of which are highly water soluble. while people living in these regions do...

Considering current controversies regarding the health effects of low doses of ionizing radiation, study of the high background radiation areas such as Ramsar, Iran can help scientists better evaluate the validity of linear no-threshold (LNT) hypothesis. Ramsar is a coastal city in northern Iran with some areas known to have the highest levels of natural background radiation in the world. The m...

Many of our students seem to have well-defined but not necessarily well-founded opinions on the biological effects of ionizing radiation. During discussions of nuclear transformations in introductory chemistry and physics courses we might be able to help these students better understand the magnitude of these effects, and perhaps sort out the plethora of units with which radiation measurements ...