Mojtaba Shamsaei Zafarghandi

Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran

[ 1 ] - An alternative mathematical modeling of the scintillation camera and framework for performance analysis of gamma-ray positioning algorithms

Introduction: Substantive amount of work has been done in modeling and analyzing the scintillation camera system processes including positioning and image formation. The goal of this work is to develop a framework for analyzing performance of nonlinear positioning methods upon construction of a mathematical model of the system. In this study, the photodetector array counts are ...

[ 2 ] - محاسبه ضریب تضعیف جرمی چوب ریزوفورا به عنوان ماده معادل بافت با کمک کد MCNPX

Rhizophora wood exhibits characteristics of interaction with radiation similar to those of water. Recently, a novel model based on MCNP4C code has been proposed for calculation of mass attenuation coefficients for some polymers. The aim of this study is to determine the mass attenuation coefficients for Rhizophora wood in energy range 15.77-60 keV using this model. First, the mentioned model wa...

[ 3 ] - تخمین دز پروستات و اندام های مجاور آن در حین براکی تراپی پروستات و بررسی پراکندگی بر میزان دز با استفاده از کد MCNP4C

In regard with increasing use of brachytherapy for treatment of cancer, especially prostate cancer, dosimetry of the organs surrounding prostate is necessary. The received dose by prostate is relatively high and the healthy organs surrounding prostate are potentially at a risk of high dose too. In this paper, the doses delivered to the prostate and organs of interest were calculated by MCNP4C c...

[ 4 ] - ساخت و آزمایش آشکارساز ترموپیلی نوترون در ستون حرارتی رآکتور تحقیقاتی تهران

Upon increasing needs and vast application of neutron detectors, especially in nuclear reactors and growing number of linear accelerators, design and manufacturing of neutron detectors is a serious demand. The aim of this project is building neutron detectors capable of compensating gamma and temperature response in a radiation media. A special thermocouple coated with Boron carbide at the junc...

[ 5 ] - محاسبۀ ضخامت کمینۀ حفاظ برای اتاق ماموگرافی به‌کمک کد MCNP-4C

In this study MCNP-4C code is used to simulate the least shielding requirements for a mammography room. In order to simulate the X-ray tube, a molybdenum target is irradiated by 28 keV electrons. Then, a molybdenum filter with a thickness of 30 micrometers was used to remove the low-energy parts of X-ray spectrum. Finally the dosimetry evaluations were conducted after designing the lead shield ...

[ 6 ] - ارزیابی حفاظ سامانه تصویربرداری PET/CT بیمارستان شریعتی تهران به‌کمک روش مونت‌کارلو

Nowadays medical imaging systems like PET/CT are widely used in cancer diagnosis. Due to serious and irreversible harms of ionization radiations, protection of all those who are exposed is the main concern of health issues. The main basis of the calculation of the shielding design in the medical imaging systems is that the absorbed dose should not exceed the allowed limit. Using the Monte Carl...

[ 7 ] - بررسی ایمنی و دز دریافتی کارکنان آزمایشگاه نوترون دانشگاه صنعتی امیرکبیر با استفاده از کد MCNP

Nuclear radiation protection and safety is one of the most important principles needed to consider in nuclear labs. At this article, Dr. Shahriari Nuclear Laboratory, was selected as a case study for investigation of total absorbed dose at the different points of the lab to determine the safe or hazardous points in it, according to nuclear radiations safety rules. Therefore, the environment of ...

[ 8 ] - تعیین پارامترهای دزیمتری یک چشمۀ طراحی‌شدۀ جدید 125I با مارکر Ag + Al2O3 در فانتوم آب

The purpose of this study is to determine the dosimetric parameters of a new 125I brachytherapy seed model, using Monte Carlo (MC) simulations according to the TG-43U1 recommendation. The Monte Carlo simulated dosimetric parameters of this sourse have been provided with MCNPX v.2.6 code. The source contains a cylindrical Ag+Al2O3 marker which is located at the center of the seed and onto which...

[ 9 ] - ارزیابی دز رسیده به پروستات و چند اندام حساس در براکی تراپی پروستات با استفاده از کد مونت کارلو در سه رادیوایزوتوپ131Cs ، 103Pd و 125I

  Using the Monte Carlo N-Particle computer code (MCNP), doses were calculated for organs of interest such as the stomach, prostate, liver, and kidneys while patients were undergoing prostate brachytherapy. This research is important because the doses delivered to the prostate are extremely high and the organs near the prostate are potentially at risk of receiving high doses of radiation, ...

[ 10 ] - Synthesis and biodistribution study of a chlorotoxin derivative peptide labeled with 131- iodine for tumor therapy

Background: Chlorotoxin is a 36-amino acid peptide found in the venom of the Leiurus quinquestriatus which blocks small-conductance chloride channels. Chlorotoxin binds preferentially to glioma cells that allow development of new methods for the treatment and diagnosis of several types of cancer. Thus chlorotoxin derivative was labeled with 131I for further investigation. Materials and...

[ 11 ] - Monte Carlo-based optimization of a gamma probe system for sentinel lymph node mapping

Introduction: Sentinel lymph node biopsy (SLNB) is a standard surgical technique to identify sentinel lymph node (SLN) for the staging of early breast cancer. Nowadays, two methods are used for the identification of SLN: blue dye method aiding visually and radioactive dye using gamma detector. A wide range of gamma probe systems with different design and performance are used in...

[ 12 ] - An Analysis to Wealth Distribution Based on Sugarscape Model in an Artificial Society

In this paper an artificial society is being assumed as a multi agents system. A sugarscape model consisting of a cellular landscape of resources is used to form an interaction among the agents of the population. In the model, agents find the resources to survive. They are supposed to move and search and because of this movement, an evolutionary social behavior will develope. From model analys...

[ 13 ] - Comparative assessment of the accuracy of maximum likelihood and correlated signal enhancement algorithm positioning methods in gamma camera with large square photomultiplier tubes

Introduction: The gamma cameras, based on scintillation crystal followed by an array of photomultiplier tubes (PMTs), play a crucial role in nuclear medicine. The use of square PMTs provides the minimum dead zones in the camera. The camera with square PMTs also reduces the number of PMTs relative to the detection area. Introduction of a positioning algorithm to improve the spat...

[ 14 ] - Novel 175Yb-Poly (L-lactic acid) microspheres for transarterial radioembolization of unrespectable hepatocellular carcinoma

Novel biodegradable Poly (L-lactic acid) (PLLA) microspheres containing ytterbium were designed for intra-tumoral radiotherapy, especially for radioembolization. 175Yb possess both therapeutic beta and diagnostic gamma radiations. In this work, process to make ready radiomicrospheres 175Yb(acac)3-loaded PLLA for more consideration has been investigated. The radiomicrospheres were prepared with ...