Shielding evaluation of a typical radiography department: a comparison between NCRP reports No.49 and 147
نویسندگان
چکیده مقاله:
Background: Designing and shielding of an appropriate radiography room has been one of the major concerns of radiation scientists since the first decade after the invention of X-rays. Recently, report No.147 of National Council on Radiation Protection and Measurements (NCRP) has been published. In this study the researchers have investigated the effect of new report recommendation on primary and secondary barriers thicknesses in comparison to NCRP 49, and 116 recommendations. Materials and Methods: To calculate the walls thickness of a conventional radiography room, the workload of a radiography room of a university hospital was determined by recording the number of exposures, mAs and kVp for each patient during six months. Three types of calculations were done: (1) Using NCRP 49 formulations and dose limits (2) Using the NCRP 49 formulations and NCRP116 dose limits and (3) Using the NCRP 147 recommendations. Results: The estimated workload was 172 mA min wk-1 for the studied radiography room which was slightly lower than the workload recommended by NCRP147. The results showed that using the NCRP49 formulation and NCRP116 dose limits, the barriers thickness increases substantially. Moreover, the dose limits were lower in NCRP 147, using the third method. The primary barrier thickness is decreased considerably in comparison to two other methods. For the secondary barrier the results of the two methods (1) and (3) did not differ and remained the same. Conclusion: Application of NCRP 49 and NCRP116 dose limits for radiography room shielding (second method) overestimated the primary and secondary barriers thickness, significantly. But, applying NCRP 147, not only the new dose limits were considered, but also the cost of primary barrier construction was reduced. Iran. J. Radiat. Res., 2009 6 (4): 183-188
منابع مشابه
shielding evaluation of a typical radiography department: a comparison between ncrp reports no.49 and 147
background: designing and shielding of an appropriate radiography room has been one of the major concerns of radiation scientists since the first decade after the invention of x-rays. recently, report no.147 of national council on radiation protection and measurements (ncrp) has been published. in this study the researchers have investigated the effect of new report recommendation on primary an...
متن کاملa comparison of linguistic and pragmatic knowledge: a case of iranian learners of english
در این تحقیق دانش زبانشناسی و کاربردشناسی زبان آموزان ایرانی در سطح بالای متوسط مقایسه شد. 50 دانش آموز با سابقه آموزشی مشابه از شش آموزشگاه زبان مختلف در دو آزمون دانش زبانشناسی و آزمون دانش گفتار شناسی زبان انگلیسی شرکت کردند که سوالات هر دو تست توسط محقق تهیه شده بود. همچنین در این تحقیق کارایی کتابهای آموزشی زبان در فراهم آوردن درون داد کافی برای زبان آموزان ایرانی به عنوان هدف جانبی تحقیق ...
15 صفحه اولa comparison of teachers and supervisors, with respect to teacher efficacy and reflection
supervisors play an undeniable role in training teachers, before starting their professional experience by preparing them, at the initial years of their teaching by checking their work within the proper framework, and later on during their teaching by assessing their progress. but surprisingly, exploring their attributes, professional demands, and qualifications has remained a neglected theme i...
15 صفحه اولthe investigation of the relationship between type a and type b personalities and quality of translation
چکیده ندارد.
assessment of deep word knowledge in elementary and advanced iranian efl learners: a comparison of selective and productive wat tasks
testing plays a vital role in any language teaching program. it allows teachers and stakeholders, including program administrators, parents, admissions officers and prospective employers to be assured that the learners are progressing according to an accepted standard (douglas, 2010). the problems currently facing language testers have both practical and theoretical implications but the first i...
منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ذخیره در منابع من قبلا به منابع من ذحیره شده{@ msg_add @}
عنوان ژورنال
دوره 6 شماره None
صفحات 183- 188
تاریخ انتشار 2009-03
با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023