نتایج جستجو برای: attenuation coefficient concrete

تعداد نتایج: 290873  

A. Amiri, F. Rahmani, M. Baradaran-Ghahfarokhi, M.A. Mosleh Shirazi, S. Jarideh, S.M.J. Mortazavi, S.M.R. Aghamiri,

Background: High density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. Over the past eight years, some efficient galena-based concrete samples for shielding X or gamma rays was produced. The goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. Materials an...

2015
Kien Dinh Nenad Gucunski Jinyoung Kim Trung H. Duong Hung M. La

Reflection amplitude at top rebar layer has been used as a main criterion for evaluating attenuation of ground-penetrating radar (GPR) data from concrete bridge decks. However, a recent study has pointed out the limitation of this practice. Motivated by that same research, the current paper presents a robust method for performing GPR attenuation analysis. Also based on correlation between A-sca...

Journal: :The International Journal of Advanced Manufacturing Technology 2008

2003
J. S. Popovics J. Zhu

A technique to estimate the depth of surface-breaking cracks in concrete is presented. The surface wave transmission coefficient across the crack plane is determined and used to estimate the depth. A self-compensating testing scheme is applied to eliminate experimental difficulties. Here the self-compensating testing scheme is introduced, and the approach used to estimate crack depth from the m...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1392

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

Journal: :Health physics 2003
K R Kase W R Nelson A Fasso J C Liu X Mao T M Jenkins J H Kleck

Optimum shielding of the radiation from particle accelerators requires knowledge of the attenuation characteristics of the shielding material. The most common material for shielding this radiation is concrete, which can be made using various materials of different densities as aggregates. These different concrete mixes can have very different attenuation characteristics. Information about the a...

Journal: :journal of biomedical physics and engineering 0
f seif arak university of medical sciences m j tahmasebi-birgani ahvaz jundishapur university of medical sciences m r bayatiani arak university of medical sciences

background: in this study, a method for linear attenuation coefficient calculation was introduced. methods: linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. the calculation was done for cerrobend as a common radiotherapy modifier and mercury. results: the valu...

Journal: :journal of biomedical physics and engineering 0
p mehnati ph.d., department of medical physics, school of medicine, tabriz university of medical sciences, tabriz, iran m jafari tirtash m.s. student, department of medical physics, school of medicine, tabriz university of medical sciences, tabriz, iran m ghavami department of radiology, school of medicine, tabriz university of medical sciences, tabriz, iran

normal 0 false false false en-us x-none ar-sa aim: ct number (hu) and linear attenuation coefficient contain useful information which  can be determined during usual ct scanning for the prediction of breast cancerous cells existence based on hemoglobin concentration. methods: this study used breast phantom containing major and minor vessels with diameters of 10 and 5 mm, respectively. the major...

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