نتایج جستجو برای: Free-lead composite shield
تعداد نتایج: 955098 فیلتر نتایج به سال:
Introduction: Nowadays, applications of free-lead radiation shields are increased specially for weighting factor and toxicity of lead elements. Although touching the lead may be results in the nervousand blood system of body, it is not exactly proven yet. Protective measures are the fundamental parts of radiation protection. On the other hand, high weighting factor of lead sh...
exposure buildup factors have been calculated by monte carlo method for point isotropic gamma ray sources, penetrating a two-layer spherical shield of water surrounded by lead, and the effect of bremsstrahlung radiation on buildup factors has, in particular, been investigated, the results of which are in good agreement with previous works. the buildup factors were then calculated for various co...
background: lead-based radiation shields are widely used in radiology departments to protect both workers and patients from any unnecessary exposure to ionizing radiation. recently there has been a great deal of concern expressed about the toxicity of lead. human lead toxicity is well documented. in that light, production of environmentally-friendly lead-free radiation shields with less weight ...
Introduction: Ionizing radiation can cause damage to biologically important DNA molecules. Radiation in nuclear medicine radiation exposes people working in from two main positions; administer in gradiopharmaceuticals (the barn and squeezing a generator, procurement, distribution and drug infusion) and patients that receive radiation treatment (patients that are prescribed a ra...
Background: Lead-based radiation shields are widely used in radiology departments to protect both workers and patients from any unnecessary exposure to ionizing radiation. Recently there has been a great deal of concern expressed about the toxicity of lead. Human lead toxicity is well documented. In that light, production of environmentally-friendly lead-free radiation shields with less weight ...
the cancer of oral cavity is related to lesions of mucous membrane of tongue and gum that can be treated with radiation therapy. a lateral photon field can be used to treat this kind of tumor, which has a side‑effect on normal tissue in the opposite side of the oral cavity. in this study the dosimetric effect of the various shields in oral cavity is evaluated. in this study, a special phantom s...
Background: In recent years, there has been an increased interest toward non-lead radiation shields consisting of small-sized filler particles doped into polymer matrices. In this paper, we study a new polyvinyl alcohol (PVA)/WO3 composite in the presence of high-energy gamma photons through simulation via the Monte Carlo N-Particle (MCNP) simulation code. Materia...
composites with micro- and nano-metal fillers has attracted the attention of researchers for radiation shielding applications. Lead toxicity and heaviness have oriented extensive research toward the use of non-lead composite shields. The present study aimed to systematically review the efficiency of the composite shields of various micro- and nano-sized materials as composite shields have been ...
Introduction: In this study, a specific combination (70% W 18.61% Ni and 11.39% C) of lead free and flexible putty metal is introduced and validated as internal shielding by Mont Carlo study Materials and Methods: To evaluate putty metal as an internal shielding by Mont Carlo study Varian 2100 C/D was validated within measurement and then by given energy spect...
The exposure buildup factors are important for determining the shield thickness of gamma and X-ray. Without taking this factor into account, the estimated thickness of the shield is less than what is expected which leads to an excessive received radiation exposure of staffs or patients. Given that the exposure buildup factor for the monoenergetic homogenous point sources have been calculated by...
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