ضیائی, فرهود
سازمان انرژی اتمی ایران
[ 1 ] - به کارگیری روش تداخل سنجی تمام نگاری دیجیتال با نوردهی دوگانه برای محاسبه توزیع دز جذبی در پلیمر پلی متیل متاآکریلات
Double-exposure digital holographic interferometry is a powerful and widespread technique for fine measurement of the induced changes in special physical properties, like density, refractive index and etc. In this paper, application of this technique for measuring the absorbed dose from an electron radiation source in poly (methyl methacrylate) material is studied through modeling. The method o...
[ 2 ] - بررسی خواص ترمولومینسانس نانوساختار هیدروکسی اپتایت آلاییده با یوروپیوم
Nano-structured hydroxyapatite doped with europium in different mole percentages of 1 to 5 have been synthesized using a hydrolysis route. Structural and thermoluminescence (TL) properties of the samples have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy confirm the phase purity and nano structure nature of synthesized powder. The samples were irradiated by...
[ 3 ] - ساخت فیلم پلی وینیل کلرید آلاییده شده با کوئیناکرین دی هیدروکلرید و مطالعه ویژگی‌های دزیمتری آن
Ionization radiation induced decomposition of dyes is a concept frequently exploited to develop devices to measure the radiation dose. In this study, using this concept, preparation of polyvinyl chloride films doped with different amounts of quinacrine dihydrochloride were done and their capabilities for dosimetry of gamma radiation doses in the range of 0 to 60 kGy were evaluated. The results ...
[ 4 ] - مطالعه اثر توزیع فاز سخت بر رسانندگی الکتریکی کامپوزیت پلیمر- نانولوله کربن به عنوان دزیمتر پرتو با بهرهگیری از روش مونت‌کارلو
The object of this research is the investigation of carbon nanotube (CNT) distribution effect on electrical conductivity of polymer-CNT composite as dosimetry response of this system. Thus, electrical conductivity of this composite was simulated for aligned, homogenous, and agglomerated distributions in 2D, and 3D situations. The results of simulation were compared and validated by experimental...
[ 5 ] - مطالعه اثر کربن بر پاسخ EPR نمونه هیدروکسی اپتایت سنتز شده به روش شیمیایی تحت تابش پرتوهای گاما
In this research work, effect of carbonate content on EPR response of gamma irradiated HAP were investigated. The carbonated HAP samples were prepared by substitution of carbonate group into HAP structure via chemical method. Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) methods were used to investigate the structural changes of the samples. Then, the samples were s...
[ 6 ] - سنتز و مشخصه‌یابی نانوپودر سوسوزن کادمیم تنگستات بر پایه استات و نیترات و مقایسه ویژگی آنها به عنوان شمارشگر ذرات آلفا
Cadmium tungstate nano powder (CdWO4) was synthesized with co-precipitation method. Two different types of material (based on acetate and nitrate) were used as precursors. The synthesized powder was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transfer Infrared absorption (FTIR) spectrum, and photoluminescent (PL) spectrum. According to the X...
[ 7 ] - شبیه‌سازی کالریمتر آب برای گسترۀ دز پایین باریکۀ الکترون سطح درمانی با استفاده از کد کامپیوتری MCNP4C
In this research, a water calorimeter that can be used for dosimetry of electron beams from therapy accelerators at low absorption dose has been simulated using MCNP4C computer code. Then the depth dose curves were calculated and compared with experimental values. In addition, the effect of back scattering layers in depth of maximum dose was studied and it was found that these layers absorb the...
[ 8 ] - تأثیر عملیات پخت بر پاسخ ترمولومینسانس هیدروکسی اپاتیت نانوساختار فراهم‌‌شده به روش هیدرولیز از دیدگاه دزیمتری
In this study, the pure nano-structure hydroxyl apatite samples were synthesized via hydrolysis method. The powder samples were sintered at various temperatures of 500°C, 700°C and 900°C in a furnace. X-ray diffraction (XRD) and Fourier transform infra-red (FTIR) spectroscopy systems were used to characterize the synthsized samples. Comparison of the glow curves shows that the most ...
[ 9 ] - مطالعۀ خواص الکتریکی یک دزیمتر جدید بر پایۀ نانوکامپوزیت پلیمر-نانولوله کربن
Use of carbon nanotubes (CNTs) in dosimetry is a promising technique for real time in vivo dose measurements with high resolution for nuclear medicine and also dose rate monitoring for radiation protection utilizations. In this research with respect to extraordinary electrical properties of CNTs for several order of magnitudes increasing in electrical conductivity of polymeric matrix, the idea ...
[ 10 ] - شبیه‌سازی کالریمتر گرافیتی با بهرهگیری از کد EGS4
In this paper, graphite calorimeter device which is using to calibrate the electron beam of therapy accelerators in the range of the low dose was simulated using the EGS4 calculation code. Then, the electron beam dose distributions were calculated in it and the effects of parameters such as thickness of the calorimeter core, the distance to the source, thickness of air gap around the core, thic...
[ 11 ] - مقایسه تجربی پاسخ آشکارسازی و دزیمتری میکرو/ نانو کامپوزیت پلی وینیل الکل- اکسید تنگستن به پرتوهای گاما و نوترون
Recently, polymeric nanocomposites have been used in dosimetry and detection of gamma rays, but due to their low photon absorption cross section, they exhibit a small sensitivity to gamma rays. In order to overcome this problem, metal oxide particles with a high atomic number are added to the polymer matrix. For this purpose, in this work, tungsten oxide particles (WO3) were distributed in poly...
[ 12 ] - استفاده از هیدروکسی آپاتیت تهیه شده به روش سل- ژل برای دزیمتری پرتوهای گاما و باریکه‌ی الکترونی
در این مقاله دزیمتری میدان پرتو از طریق اندازهگیری رادیکالهای آزاد القاء شده در هیدروکسی آپاتیت مصنوعی با بهرهگیری از طیفبینی تشدید اسپین الکترون یا تشدید پارامغناطیسی الکترون (EPR) مورد بررسی قرار گرفته است. ابتدا نانو پودر هیدروکسی آپاتیت مصنوعی (HAP) به روش سل- ژل تهیه و پس از آمایش حرارتی، توزین و بستهبندی شد. در ادامه، نمونهها با پرتوهای گامای حاصل از چشمهی کبالت-60 و باریکه...
[ 13 ] - Experimental investigation of dosimetry response of nanocomposite of polystyrene-multiwall carbon nanotube in gamma radiation field
Recently, polymeric nanocomposites have been used as real-time detectors and dosimeters of gamma radiation. In this experimental work, multi-wall carbon nanotubes (MWCNT) were dispersed in polystyrene (PS) martix with a weight percentage of 0.05 wt%. SEM images confirmed the appropriate and uniform distribution of carbon nanotubes in the polymer matrix. The dark current and photocurrent of the ...
[ 14 ] - Measuring the temperature dependence of refractive index in water phantom for precise monitoring of the absorbed dose by radiation therapy techniques
In this paper, an experimental setup is used to measure the temperature dependence of the refractive index of a water phantom. In radiation calorimetry by laser beams and interferometric systems, the amount of change induced by radiation within the phantom can be accurately measured. Absorption of dose and the resulted change in temperature changes the refractive index within the material. In o...
[ 15 ] - اندازهگیری تغییرات دمایی پلی‌متیل متاآکریلات با استفاده از روش تداخل‌سنجی تمام‌نگاری دیجیتال
تداخل‌سنجی تمام‌نگاری یکی از روشهای دقیق مورد استفاده برای اندازهگیری کمیتهای فیزیکی نظیر تنش، فشار، ارتعاش، و تغییرات ضریب شکست و دما به خصوص در مواد جامد شفاف است. در این مطالعه، از یک چیدمان تجربی تداخل‌سنجی تمام‌نگاری دیجیتال ماخ-زندر برای اندازهگیری میزان تغییرات دمایی ایجاد شده در یک سلول پلی متیل متاآکریلات تحت تابش لیزر مادون قرمز استفاده شد. نتایج حاصل از روش تداخل‌سنجی توافق خوبی ب...
[ 16 ] - Study on Effects of Hydroxyapatite Synthesis Conditions Using Hydrothermal Method on its Thermoluminescence Response from Dosimetry Viewpoint
In the current research, hydroxyapatite samples, synthesized by hydrothermal methods was studied from the perspective of thermoluminescence dosimetry. The results of the study were compared and studied with different aspects of dosimetry, including dose-response variations of synthesized samples, degree of its linearity, and the percentage of response fading, as well as the position of the main...
[ 17 ] - Retrospective dosimetry using fingernail in nuclear industries: A review paper
Generally, doses greater than 2Gy can produce acute biological effects in humans. For this reason, to measure and record the cumulative dose, especially in radiation users, the need for a personal dosimeter has been strongly felt by the researchers. The purpose of this study is to introduce retrospective dosimetric techniques, in particular the use of nails as a natural tool for determining cum...
[ 18 ] - Measuring the deposited energy from a non-ionizing laser beam in water by digital holographic interferometry
Digital Holographic interferometry is a powerful and widely used optical technique for accurate measurement of variations in physical quantities such as density, refractive index, and etc. In this study, an experimental digital holographic interferometry setup was designed and used to measure the amount of energy changes induced by absorption of radiation from a non-ionizing infrared laser beam...
[ 19 ] - Measurement and comparison of the temperature-dependence of refractive index of water and Plexiglas phantoms by interferometry method for their use in optical calorimetry
In radiation calorimetry by using laser beams and interferometry setups, variations induced by dose absorption in phantom can be precisely measured. Dose absorption and the induced temperature change result in refractive index variation of the material. In order to be able to measure the low amount of absorbed dose in the phantom, temperature dependence of refractive index of the material must ...
[ 20 ] - Determination of the electrical percolation threshold of Polystyrene-Graphene Oxide nanocomposite using the experiment and simulation methods
Carbon nanostructures via adding to a polymer matrix, while improving the electrical, mechanical and optical properties of the nanocomposites, are widely used in the industry, medicine, and agriculture. The authors presented several investigations on a new type of gamma dosimeter based on the polymer-carbon nanostructures nanocomposite. In this research, the electrical percolation threshold of ...
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