background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

ABSTRACT Background: The radiological impact of the use of phosphate fertilizers in soil is due to the internal irradiation of the lung by the alpha particles, short lived radon-thoron progeny and the external irradiation of the body by gamma rays emitted from radionuclides in situ. This paper describes the results of gamma spectrometric measurements of the concentration ...

By LEWIS M. SCHIFFEII, HAII0u L. knar’s, AIIJUN D. CIIANANA, EUGENE P. CRoNKITE, MICHAEL L. GREENBERG, HORTON A. JOHNsoN, J AMES S. ROBERTSON AND PIERRE A. STIIYCKMANS T HE FIRST SUCCESSF’UL EXPERIMENTS utilizing extracorporeal irradiation of the blood ( ECIB ) to deplete the body of lymphocytes were performed by Cronkite et al. using the cow as an experimental animal.1’m It soon became evident...

background : in spite of clinically useful photon and electron beams, high energy linacs produce secondary particles such as neutrons (photo-neutron production). neutrons have important roles during treatment with high energy photons in terms of protection and dose escalation. in this project, neutron dose equivalent of 18 mv varian accelerators is calculated by tld600 and tld700. materials and...

In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of (232)Th and (238)U series, and (40)K are determined and discussed. Effective dose rate...

background: the activity concentrations of some radionuclides in soil samples collected from 20 locations in 8 major towns in oyo state, southwestern nigeria have been determined by gamma-ray spectrometry technique. materials and methods: the activity concentrations were determined using high-purity germanium (hpge) detector (canberra industries inc.). the outdoor absorbed dose rates in air at ...

UNLABELLED Targeted radiotherapy is a potentially useful treatment for some cancers and may be potentiated by bystander effects. However, without estimation of absorbed dose, it is difficult to compare the effects with conventional external radiation treatment. METHODS Using the Vynckier - Wambersie dose point kernel, a model for dose rate evaluation was created allowing for calculation of ab...

Poly N-isopropylacrylamide was successfully grafted onto a polystyrene cell culture dish by gamma ray. In this study, the effect of a radiation dose (radiation absorbed dosages of 10, 20, 30, 40 KGy) under appropriate temperature and grafting conditions was investigated. The FTIR analysis showed the existence of the graft PNIPAAm on the substrate. The optimal value of the dose for grafting was ...

Introduction Radioactive materials naturally exist in the world. Indeed, approximately 82% of human-absorbed radiation doses, which are out of human control, arise from natural sources of radiation including cosmic, terrestrial, and exposure through inhalation or ingestion. Thus, the aim of the present study was to estimate health risk, as well as the effective and organ doses from naturally oc...