کاردان, محمدرضا
[ 1 ] - دز دریافتی مردم رامسر در اثر مواجهه با پرتوهای گاما در داخل منازل
The coastal area of Ramsar in northern of Iran located in the province of Mazandaran has been known as the highest levels of natural radiation background in the world. The background radiation is mainly due to the presence of radioactive isotopes of the radium element and its decay products, which is brought to the surface by hot springs. In this study, the indoor gamma dose rate in Ramsar wa...
[ 2 ] - الگوهای پراکندگی مواد پرتوزای رهاشده در اثر وقوع سوانح در نیروگاه های هسته ای اطراف ایران
Released radioactive materials from a nuclear power plant due to an accident can be transported to far regions by wind. Some models are available to predict the dispersion. This article reports some parts of the results of a research in which using one of the models, named HYSPLIT, to predict the dispersion of some isotopes of iodine and cesium released from ten nuclear power plant to the atmos...
[ 3 ] - مطالعه مقایسه‌ای دو ساختمان با زیر ساخت متفاوت از نظر نفوذ‌پذیری در برابر گاز پرتوزای رادن
Radon concentration was measured in ground floor of two buildings with moisture controlled sub slab construction and slab on the ground. Results show that radon concentration in ground floor of the building with moisture controlled sub construction is more than 11 times smaller than that of the building with slab on the ground. Also indoor radon concentration in this building is about %41 highe...
[ 4 ] - شبیه‌سازی شار ذرات آلفای ساطع‌شده از دختران رادن استنشاق‌شده در مسیرهای هوایی استوانه‌ای برونشیال ریه با استفاده از کد MCNPX
Biological effects of radiation are due to energy deposition arising from the alpha particles hits with cell nuclei. A simulation has been done to calculate the flux density of Radon progeny alpha particles induced from uniform inner surface source distributed in lung cylindrical airway using Monte Carlo method. Number of hits, transformation frequency and dose has been calculated using obtaine...
[ 5 ] - ارزیابی کیفیت تصویر و دز دریافتی بیماران در ماموگرافی فیلم اسکرین و ماموگرافی کامپیوتری‌شده در ایران
In this study, a quantitative parameter is introduced that evaluate three important features of a mammography exam ,contrast, spatial resolution and patient dose. Two kinds of regular mammography system used in screening mammography were evaluated in automatic exposure control mode (AEC) by this parameter. To evaluate the contrast and detail of the mammography images, the contrast-detail phanto...
[ 6 ] - ارزیابی خطرات پرتوهای نوری در کاربردهای عمومی آن از دیدگاه حفاظت در برابر اشعه
Use of consumer products applying optical radiation (ultraviolet, visible and infrared radiation) sources is growing, in the society which also simplifies everyday ordinary jobs as well as raising the accuracy. There is some phobia in general public on such instruments that have not been approved scientifically. On the other hand optical radiation can cause health hazards especially for eyes an...
[ 7 ] - Calibration and optimization of a low cost diffusion chamber for passive separated measurements of radon and thoron in soil by Lexan PC SSNTD
Background: Separate radon and thoron measurements in soil are very important in assessment of internal exposure due to inhalation of such radioactive gases. Materials and Methods: In this study, a low cost, small size, passive diffusion chamber has been developed for simple measurement of Radon-222 and Radon-220(Thoron) gases separately in soil. The diffusion chamber consists of two films and ...
[ 8 ] - شناسایی فازهای گذار از بحران هستهای نیروگاه فوکوشیما- دایچی بر مبنای تحلیل زمانی حادثه
حادثهی نیروگاه هستهای فوکوشیما- دایچی در ژاپن، باور برخورداری از ایمنی کافی در نیروگاههای هستهای موجود را به سختی به چالش کشید. تأسیسات پیشرفته و آمادگیهای ایجاد شده در پاسخگویی به بحران در نیروگاه مورد اشاره نتوانست مانع از گسترش سریع حادثه شود که پیآمد آن وقوع جدیترین بحران نیروگاهی در تاریخ جهان، پس از حادثهی چرنوبیل بود. این نوشتار با بررسی زمانی حادثهی نیروگاه فوکوشیما- دایچی و ا...
[ 9 ] - Evaluation of a constructed head phantom response in comparison with RANDO head phantom in the same gamma field
Human tissue equivalent phantoms are widely used in medicine. They are used for dosimetry, calibration of medical devices, and quality control of radiotherapy equipment, as well as training students. Regarding to development of radiotherapy techniques for treatment of cancers and also development of educational centers in the country, the human equivalent phantoms are needed. Several phantoms h...
[ 10 ] - Comparative Measurements of Radon Concentration in Soil Using Passive and Active Methods in High Level Natural Radiation Area (HLNRA) of Ramsar
Background: Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of rado...
[ 11 ] - Evaluation of gray scale changes of CBCT system images in different axis using the DICOM file
The images of dental CBCT imaging systems used in conic shaped beams, stored in the DICOM format, have various applications in the dentistry, including bone density estimation to select the location of the orthodontic implant, bone loss detection and etc. In these systems, unlike CT imaging systems, the resulting images exhibit gray-scale non-uniformity in each of the different axis in FOV. Thi...
[ 12 ] - Measurement of Contemporary and Retrospective Radon Concentration in Ramsar Dwellings Using Polycarbonate Detector
The origins of radon gas are the amount of uranium decay in the soil that is released into space and through the interior gaps of buildings. Radon can enter the respiratory system and cause radiation hazards. Recently research has identified Radon as the second leading cause of lung cancer after cigarette smoking. The indoor concentration of Radon progeny is mentioned as an important issue reg...
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