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JournalISSN: 1728-4554

Iranian Journal of Radiation Research 

About: Iranian Journal of Radiation Research is an academic journal. The journal publishes majorly in the area(s): Dosimetry & Monte Carlo method. It has an ISSN identifier of 1728-4554. Over the lifetime, 875 publications have been published receiving 4193 citations.


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Book ChapterDOI
TL;DR: The measured dosimetric characteristics of grid block indicate that the mega-voltage grid therapy can be applied as a possible clinical modality for palliative cases.
Abstract: In conventional radiation therapy, regarding normal tissue tolerance, the treatment of bulk tumors is one of the remaining challenges. In order to cope with, Grid Radiation Therapy (GRT) is a technique to deliver high doses, approximately 15 - 20 Gy per fraction, to several small volumes located in a large radiation field. This can be performed using a grid block. The current work concentrates on the dosimetric characteristics of a designed mega-voltage grid, used for a unique treatment modality. A square 16 × 16 array grid block was designed and fabricated. Several dosimetric characteristics including: depth dose, Valley To Peak (VTP) ratio, and grid out-put factor were evaluated using a calibrated diode dosimeter for a range of radiation fields. The percent depth dose curves, measured in the presence of grid block, lie within those measured for the corresponding open field and a narrow beam. At the Dmax, the VTP ratio was fond to be within 17% -28%, while these ranges between 23% - 35% at a depth of 10 cm. The grid out-put factor found to be 0.78 and it slightly decreases with increasing of radiation field size. The measured dosimetric characteristics of grid block indicate that the mega-voltage grid therapy can be applied as a possible clinical modality for palliative cases.

65 citations

Journal Article
TL;DR: The most commonly encountered radionuclide's are 238 U, 232 Th, their decay products and 40 K in soil and building materials, extensive studies have been carried out all over the world as discussed by the authors.
Abstract: Background: Health hazards associated with exposure due to the natural radioactivity which is a part of our physical environment are of great concern. In order to assess the risks associated with exposure due to the natural radioactivity in soil and building materials, extensive studies have been carried out all over the world. The most commonly encountered radionuclide’s are 238 U, 232 Th, their decay products and 40K. Materials and Methods: In order to study the concentration of these radionuclides soil, sand, gravel aggregates, bricks and marble, samples were collected from different sites and local suppliers of the district Mirpur, Azad Kashmir (Pakistan). 226 Ra, 232 Th, and 40 K activities in the collected samples were measured using HPGe detector. The measured specific radioactivity concentration of 226 Ra, 232 Th and 40 K in the studied samples ranged from 10 ±1 to 47 ± 2, 18 ± 1 to 75 ± 4 and 40 ± 3 to 683 ±3 Bq.kg-1, respectively. Results: From the measured activity concentration, radium equivalent activity, external and internal hazard indices, gamma and alpha indices, terrestrial absorbed dose and annual effective dose were calculated. Maximum value of radium equivalent activity of 197.1 ± 9 Bq.kg-1 was observed in soil sample whereas minimum value of 45.9 ± 2 Bq.kg -1 was found in gravel aggregates. Relatively higher mean values of hazard indices were found in brick samples. Annual effective dose varied from 0.06 ± 0.01 to 0.47 ± 0.02 mSv.y-1. Conclusion: Current values of annual effective dose, radium equivalent activity and hazard indices have been found to be within the recommended limits. Iran. J. Radiat. Res., 2011; 9(2): 77­87

60 citations

Journal Article
TL;DR: The concentrations of 40K and 137Cs in different imported foodstuff are comparable with those from the other countries yet 232Th concentration is higher than the reported values.
Abstract: Background: Knowledge of radioactivity levels in human diet is of particular concern for the estimation of possible radiological hazards to human health. However, very few surveys of radioactivity in food have been conducted in Iran; therefore the baseline values of the natural radionuclides concentration (40K, 226Ra and 232 Th), and man made radionuclide, 137Cs, were determined in twenty six samples of imported foodstuff in Iran. Materials and Methods: Twenty six samples of different kinds of imported foodstuff were selected for analysis. These samples, after pretreatment and washing (if necessary), were measured by a low level gamma spectrometry system. Results: All samples were found to contain detectable 40K content in range 6.4 to 778.4 Bq.kg -1 fresh weights (fw). 137Cs, 226Ra and 232Th were detectable in most of the samples. The maximum concentration of 40K, 226Ra and 232Th were found in tea sample, equal to 778.4±23.4, 2.9±0.1 and 5.4±0.2 Bq.kg -1 (fw), respectively, where as for 137Cs it was 3.2±0.1 Bq.kg -1 (fw) in milk powder. Conclusion: The concentrations of 40K and 137Cs in different imported foodstuff are comparable with those from the other countries yet 232Th concentration is higher than the reported values. Also, 226Ra results appear to be higher than the reported values in some cases. Iran. J. Radiat. Res., 2006; 4 (3): 149-153

55 citations

Journal ArticleDOI
TL;DR: The experiment clearly shows that the smaller size of nano-structured WO3 parcles can guarantee a beer radiaon shielding property, and it is too early to draw any conclusion on the possible mechanisms of enhanced aenuaon of Nano-sized WO 3 parcles.
Abstract: Background : It has recently been shown that the parcle size of materials used for radiaon shielding can affect the magnitude of radiaon aenuaon. Over the past years, applicaon of nano-structured materials in radiaon shielding has aracted aenon world-wide. The purpose of this study was to invesgate the shielding properes of the lead-free shields containing micro and nano-sized WO3 against low energy x-rays. Materials and Methods : The radiaon shields were constructed using nano and micro WO3 parcles incorporated into an EPVC polymer matrix. The aenu aon coefficients of the designed shields were evaluated for low energy x-rays (diagnosc radiology energy range). Results : The results indicate that nano-structured WO3/PVC shields have higher photon aenuaon properes comp ared to those of the micro-sized samples. Conclusion: Our experiment clearly shows that the smaller size of nano-structured WO3 parcles can guarantee a beer radiaon shielding property. However, it is too early to draw any conclusion on the possible mechanisms of enhanced aenuaon of nano-sized WO3 parcles.

52 citations

Journal Article
TL;DR: Based on the findings obtained by studies on the health effect of high levels of natural radiation in Ramsar, as well as other high background radiation areas, no consistent detrimental effect has been detected so far.
Abstract: *Corresponding author: Prof. Seyed Mohammad Javad Mortazavi, Department of Medical Physics and Medical Engineering, School of Medicine, and the Center for Research in Radiation Sciences (CRRS), Shiraz University of Medical Sciences, Shiraz, Iran. Fax: + 98 711 2349332 E-mail: mmortazavi@sums.ac.ir Although there are substantial experimental, epidemiological and clinical evidences that high doses of ionizing radiation cause cancer and other detrimental biological effects, the health effects of human exposure to chronic low dose radiation exposures are still poorly known. People in some areas around the world live in dwellings with radiation and radon levels as much as more than 200 times the global average. Inhabited areas with high levels of natural radiation are found in different areas around the world including Yangjiang, China; Kerala, India; Guarapari, Brazil and Ramsar, Iran. Ramsar in northern Iran is among the world’s well-known areas with highest levels of natural radiation. Annual exposure levels in areas with elevated levels of natural radiation in Ramsar are up to 260 mGy y-1 and average exposure rates are about 10 mGy y-1 for a population of about 2000 residents. Due to the local geology, which includes high levels of radium in rocks, soils, and groundwater, Ramsar residents are also exposed to high levels of alpha activity in the form of ingested radium and radium decay progeny as well as very high radon levels in their dwellings. Based on the findings obtained by studies on the health effect of high levels of natural radiation in Ramsar, as well as other high background radiation areas, no consistent detrimental effect has been detected so far. Further research is needed to clarify if the regulatory authorities should set limiting regulations to protect the inhabitants against such extraordinary elevated levels of natural radiation. Iran. J. Radiat. Res., 2012; 10 (3‐4): 111‐116

42 citations

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Performance
Metrics
No. of papers from the Journal in previous years
YearPapers
202187
202098
201975
201856
201751
201654