background: the natural radionuclides are always present in soil and care needs to be taken to minimize the radiation dose to humans. these radionuclides are mostly gamma ray emitting radionuclides which contribute to the radiation dose in long term behavior of radionuclides in soil. health hazards associated with natural radioactivity are of great concern and it is necessary to assess risk due...

background: changes in body composition may be used for monitoring progression/ regression of a disease. prompt γ-rays in vivo neutron activation analysis (ivnaa) has been widely used for the measurement of body composition in recent years. objective: in this paper, we tried to improve the safety of ivnaa operator. methods: the most important factor for reducing the operator receiving dose is t...

background: presently, the british-american tobacco company (bat) located in ibadan, oyo state is the only tobacco producing company in nigeria accounting for about nine different brands of cigarette tobacco smoked in the country. the tobacco leaves are produced from some farmlands located in oke-ogun area of ibadan where special fertilizers are used for the growing of the tobacco leaves. the u...

background: natural radiation is constantly present in the environment and is emitted from a variety of natural and artificial sources. it affects human body and environment. materials and methods: the activity concentrations of 238u, 232th and 40k have been determined by gamma ray spectrometer with an hpge detector in sediments of cauvery river, tamilnadu, india. results: the absorbed dose rat...

background: natural radionuclides are always present in the environment. human exposure to the background radiation is inevitable. it is therefore important to assess health risk associated with these radionuclides. materials and methods: the distribution of natural radionuclides 238u, 232th and 40k in soil samples collected from all the twenty (20) local governments headquarter areas in ogun s...

Histological preparations of ultrasonically produced lesions in cat brain, at 3 and 4 MHz, have been studied microscopically. The relationship of the delivered acoustic intensity at the lesion site, the energy absorbed per unit volume of the lesion, and the lesion volume is exhibited. It is suggested that universal responses to ultrasonic exposure may exist for different tissues.

background: the shielding methods in radiotherapy due to delivering an accurate radiation dose to cancer tissues and avoiding unnecessary dose to normal tissues are very important. these methods include lead standard blocks, individual molding and multi leaf collimator (mlc). the mlc method is not still common in iran radiotherapy centers. individual molding is better than the lead block shield...

introduction in computed tomography (ct) technology, an optimal radiation dose can be achieved via changing radiation parameters such as ma, pitch factor, rotation time and tube voltage (kvp) for diagnostic images. materials and methods in this study, the brain, abdomen, and thorax scaning was performed using toshiba 16-slice scannerand standard aapm and ctdi phantoms. aapm phantom was used for...

large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. therefore, radiation unwanted dose is created in kidney. as a result, exact calculation of prescribed radiopharmaceuticals amount is important. monte carlo method is used for simulation of radiation transport in body due to random nature of radiation. in this research, for the first time...