نتایج جستجو برای: finite element gafchromic film

تعداد نتایج: 481855  

2012
Hirokazu Mizuno Yutaka Takahashi Atsushi Tanaka Takamitsu Hirayama Tsuyoshi Yamaguchi Hiroaki Katou Keiko Takahara Yoshiaki Okamoto Teruki Teshima

EBT2 film is widely used for quality assurance in radiation therapy. The purpose of this study was to investigate the homogeneity of EBT2 film among various lots, and the dose dependence of heterogeneity. EBT2 film was positioned in the center of a flatbed scanner and scanned in transmission mode at 75 dpi. Homogeneity was investigated by evaluating gray value and net optical density (netOD) wi...

Mahbod Esfahani Mahmoud Allahverdi, Mehdi Aghili Somayeh Nourollahi, Vahid Changizi,

Introduction: The complex geometry of breast and also lung and heart inhomogeneities near the planning target volume (PTV) result in perturbations in dose distribution. This problem can result in overdosage or underdosage in the match region of the three treatment fields. The purpose of this study is to create a homogeneous dose distribution in the match region between the supraclavicular and t...

2016
Farideh Farokhi Moghadam Hozan Mohammadi

Small photon field used in the intensity modulated radiotherapy (IMRT) and stereotactic radio surgery (SRS). It is difficult to measure beam profile and output factor because of electron disequilibrium, partial shutting of source because of this challenges, we need the good detector. This article is collection of 5 or more article and summary of the results of EBT3 that compared with EBT2 film ...

A. Jabbary Arfaee, A.S. Meigooni, E. Rajab Bolookat, H.A. Nedaie, H.R. Mirzaei, R. Jaberi, S. Gholami, S. Rabi Mahdavi,

Background: One major challenge in brachytherapy is to verify the accuracy of dose distributions calculated by the treatment planning system. In this project, a new phantom design has been introduced for quality assurance of dose distributions in gynocological (GYN) brachytherapy implants using EBT GafChromic film. Materials and Methods: This phantom has been designed and fabricated from 90 sla...

2005
Y. Xiang X. Chen J. J. Vlassak

The plane-strain bulge test is a powerful new technique for measuring the mechanical properties of thin films. In this technique, the stress–strain curve of a thin film is determined from the pressure-deflection behavior of a long rectangular membrane made of the film of interest. For a thin membrane in a state of plane strain, film stress and stain are distributed uniformly across the membrane...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی امیرکبیر(پلی تکنیک تهران) - دانشکده مهندسی مکانیک 1386

جهت ایجاد تغییر شکلهای در ابعاد میکرو و نانو و یا میرا نمودن ارتعاشات در سازه های پیشرفته هوشمند ، استفاده از المانهای پیزوالکتریک بهترین راه حل شناخته شده می باشد. بنابراین برای بررسی دقیق این سازه ها احتیاج به دانش و ابزار تحلیل می باشد. در این پژوهش، هدف اصلی بررسی و تحلیل دقیق میدانهای جابجایی مکانیکی، الکتریکی، تنش و کرنش در پوسته های استوانه ای چند لایه اورتوتروپ با لایه ساخته شده از مواد...

Journal: :iranian journal of medical physics 0
somayeh nourollahi m.sc.in medical physics, faculty of medicine, tehran university of medical sciences, tehran, iran mahmoud allahverdi associate professor, medical physics dept., faculty of medicine, tehran university of medical sciences, tehran, iran mahbod esfahani m.sc.in medical physics, radiotherapy dept., cancer institute, tehran university of medical sciences, tehran, iran mehdi aghili assistant professor, radiotherapy dept., cancer institute, tehran university of medical sciences, tehran, iran vahid changizi assistant professor, radiology technology dept., faculty of allied medical sciences, tehran university of medical sciences, tehran, iran

introduction: the complex geometry of breast and also lung and heart inhomogeneities near the planning target volume (ptv) result in perturbations in dose distribution. this problem can result in overdosage or underdosage in the match region of the three treatment fields. the purpose of this study is to create a homogeneous dose distribution in the match region between the supraclavicular and t...

2005
C. Tsou Y. S. Huang H. C. Chang

The accurate value of thermal expansion coefficient ( ) of thin film is an important thermal property in the design of microelectronic devices and microsystem. This research presents a microbridge buckling deformation caused by the residual stresses to determine the of thermal oxide (SiO2) film. The extraction of is supported through experimental means and finite element analysis (FEM) of the b...

2016
Navid Ayoobian Akbar Sarabi Asl Hosein Poorbaygi Mohammad Reza Javanshir

High-dose-rate (HDR) brachytherapy is a popular modality for treating cancers of the prostate, cervix, endometrium, breast, skin, bronchus, esophagus, and head and neck as well as soft-tissue sarcomas. Because of different source designs and licensing issues, there is a need for specific dosimetry dataset for each HDR source model. The main objective of the present work is to measure 2D relativ...

Journal: :Physics in medicine and biology 2001
T Cheung M J Butso P K Yu

This note investigates the increase of the sensitivity of radiochromic film by layering the film together. Investigations with up to five layers of radiochromic film placed together as a single dosimeter have allowed accurate two-dimensional dosimetry at low radiotherapy doses. The sensitivity of the response of the layered film increases with the number of layers, with the five-layer dosimeter...

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