نتایج جستجو برای: finite element gafchromic film

تعداد نتایج: 481855  

Journal: :Journal of cancer research and therapeutics 2013
Allahverdi Mahmoud Nourollahi Somayeh Esfahani Mahbod Aghili Mehdi Changizi Vahid Geraily Ghazale

AIM Complex geometry of breast tissue causes perturbation in dose distribution. This problem can beget overdose or under-dose points in match region of three fields. The aim of this study is to create dose homogeneity distribution in match region between tangential and supraclavicular fields (SCF) with Gafchromic external beam therapy (EBT) film. MATERIALS AND METHODS In this study, an anatom...

Journal: :Medical physics 2000
G I Kaplan A B Rosenfeld B J Allen J T Booth M G Carolan A Holmes-Siedle

Measurement of the lateral profile of the dose distribution across a narrow x-ray microbeam requires a dosimeter with a micron resolution. We investigated the use of a MOSFET dosimeter in an "edge-on" orientation with the gate insulating oxide layer parallel to the direction of the beam. We compared results using this technique to Gafchromic film measurements of a 200 micrometer wide planar x-r...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان 1371

the effect of the presence of perforations on he stresses of a plate is a problem which is of great interest in structural design and in the mathemattical theory of elasticity. among the many hole patterns that are likely to require consideration is the ring of equally spaced circular holes. the present worke investigates stress & strain analysis of a thin isotropic circular plate containing a ...

Journal: :مکانیک سیالات و آیرودینامیک 0
اصغر دشتی رحمت آبادی محسن نکوئی مهر محمد سفید

in this paper, static performance characteristics for a finite lenght two-lobe journal bearing lubricated with micropolar fluid is studied. using finite element method, steady-state film pressure is obtained by solving modified reynolds equation, based on micropolar lubrication theory. with the help of film pressure in bearing, the static performance characteristics in terms of load carrying ca...

Journal: :Physics in medicine and biology 2003
Martin J Butson Peter K N Yu Tsang Cheung

Multi-leaf penumbral doses have been investigated for 6 MV x-rays and a Varian millennium multi-leaf collimator (MLC) using Gafchromic MD-55-2, radiochromic film and X-omat V radiographic film. An advantage of Gafchromic film for multi-leaf penumbral dose measurement is the relatively low energy dependence of the film. A comparison of penumbral dose measurements has also ascertained the effects...

Ahad Zeinali Kamal Mostafanezhad Leila Mahani Milad Zeinali Kermani

Introduction: The presence of heterogeneities such as air-filled cavities in the head and neck treatment fields region, may result in potential dosimetric disagreement because the losses of charged particle equilibrium. Most of treatments planning systems are not able to predict dose distribution of inhomogeneities region accurately. Therefore, dose calculation algorithms need to...

Journal: :Physics in medicine and biology 2005
Tsang Cheung Martin J Butson Peter K N Yu

Gafchromic EBT (International Specialty Products, NJ, USA), radiochromic film is one of the newest radiation-induced auto-developing x-ray analysis films available for therapeutic radiation dosimetry in radiotherapy applications. Part of any radiochromic film product which undergoes a polymerization reaction for automatic darkening is an associated post-irradiation colouration whereby the film ...

Journal: :Physics in medicine and biology 2003
Martin J Butson Peter K N Yu Tsang Cheung Dean Inwood

A new high-sensitivity radiochromic film has been tested for its polarization properties. Gafchromic HS film has been shown to produce a relatively small (less than 3%) variation in the optical density measured at 660 nm wavelength when the light source is fully linear polarized and the film is rotated through a 360 angle. Similar variations are seen when the detector is linearly polarized. If ...

2012
Mahdi Ghorbani Mohammad Taghi Bahreyni Toossi Ali Asghar Mowlavi Shahram Bayani Roodi Ali Soleimani Meigooni

UNLABELLED BACKGROUND.: The aim of this study is to evaluate the performance of a color scanner as a radiochromic film reader in two dimensional dosimetry around a high dose rate brachytherapy source. MATERIALS AND METHODS A Microtek ScanMaker 1000XL film scanner was utilized for the measurement of dose distribution around a high dose rate GZP6 (60)Co brachytherapy source with GafChromic® EBT...

Journal: :Physics in medicine and biology 2002
Tsang Cheung Martin J Butson Peter K N Yu

The use of a diabetic blood glucose meter for radiochromic film dosimetry in blood irradiation using x-ray beams on a medical linear accelerator has been investigated. The glucose meter provides optical density analysis in the visible and infrared region using a reflectance measurement technique. By comparing the 'blood sugar' level output with standard calibration gafchromic films a calibratio...

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