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Showing 1 to 20 of 51 for “"absorbed dose"”.
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An Absorbed Dose to Water Primary Standard for Ir-192 Brachytherapy
The goal of this work was to develop an absorbed dose to water primary standard for Ir-192 brachytherapy by using a Fricke dosimeter. The radiation chemical yield (G-value) of the Ferric ions in the Fricke solution was measured at Co-60 and 250 kVp X-ray, yielding 1.610 ± 0.010 μmol J-1 and 1.602 ± …
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Development of a Hybrid Alanine-calorimetry Absorbed-dose Standard for Linac Electron Beams
… calorimeter is well-established for measuring dose to water in cobalt-60, linac photon beams and high-energy linac electron beams. However, for lower-energy electron beams, given the short range of electrons and the physical dimensions of the calorimeter, it is impossible to perform …
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Estimating the dermally absorbed dose from chemical exposure: data analysis, parameter estimation, and sensitivity to parameter uncertainties
Includes bibliographical references (page 464).
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Voxel-Level Absorbed Dose Calculations With A Deterministic Grid-Based Boltzmann Solver For Nuclear Medicine and The Clinical Value of Voxel-Level Calculations
<p>Voxel-level absorbed dose (VLAD) is rarely calculated for nuclear medicine (NM) procedures involving unsealed sources or 90Y microspheres (YM). The current standard of practice for absorbed dose calculations in NM utilizes MIRD S-values, which 1) assume a uniform distribution in organs, 2) do …
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An In Vitro Measured Enhancement of the Absorbed Dose in B-10 Assisted Fast Neutron Cancer Therapy using the Solid state Nuclear Track Detector CR-39
Made available in DSpace on 2017-07-06T18:55:06Z (GMT). No. of bitstreams: 3 Less_Timmy_J_MS.pdf: 29842925 bytes, checksum: 0edf54027e5d6b0659ddc0f728bb1c58 (MD5) Less_Timmy_J_MS_ABS.pdf: 1061592 bytes, checksum: 84927eb19cf1fca5b87eb3a9b76516a7 (MD5) license.txt: 4813 bytes, checksum: …
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Combined methods and instrumentation for dosimetric monitoring of the large fluence hadron irradiations /
… in the routine sense is the measurement of the absorbed dose in biological tissues and matter delivered by ionizing radiation or particle beams. Dosimetry is widely applied in the field of medical physics where it is inevitable for assessment of the radiation dose received by personnel and …
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Didelių įtėkių hadronų apšvitų dozimetrijos kombinuoti metodai ir įranga /
… in the routine sense is the measurement of the absorbed dose in biological tissues and matter delivered by ionizing radiation or particle beams. Dosimetry is widely applied in the field of medical physics where it is inevitable for assessment of the radiation dose received by personnel and …
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Image Quality Optimisation and Dose Management in CT, SPECT/CT, and PET/CT
… approaches for minimising patient radiation absorbed dose and maintaining or improving image quality in CT, SPECT/CT, and PET/CT. One way to achieve optimisation is to use automatic exposure control (AEC) systems in CT. The reduction in radiation absorbed dose ranges from 35-60% for an …
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The development and use of fifteen year-old equivalent mathematical phantom for internal dose calculations
… for a proficient means of obtaining estimates of absorbed dose for children of that age. Dimensions representative of an average fifteen year-old human, obtained from various biological and medical research, were transformed into a mathematical construct of idealized shapes of the exterior, …
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In vivo imaging of cortical porosity by synchrotron phase contrast micro computed tomography
… use of in vivo µCT is limited by the radiation dose created by the x-ray beam, with commercially available in vivo systems generally operating in the 10-20 um resolution range and delivering an absorbed dose between 0.5-1 Gy. Because dose scales to the power of four with resolution, in vivo …
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Neutron dosimetry with a water calorimeter
… large uncertainties in the measurement of absorbed dose in neutron beams this consistency is difficult to achieve. This work describes the application of a recently developed dosimetry method, namely water calorimetry, to the field of neutron dosimetry. The concept of absorbed dose and its …
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An Investigation of the Singlet Delta Oxygen and Ozone Yields From the Pulsed Radiolysis of Oxygen and Oxygen-Noble Gas Mixtures
… with a novel NO(,2) titration scheme and the absorbed dose was estimated from the ozone concentrations measured in pure oxygen. The results of these experiments revealed an O(,2)(a('1)(DELTA)) production efficiency of 0.14% for direct nuclear pumping in an argon-oxygen mixture. Extensive …
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An evaluation of the natural radioactivity in the soils of Okahandja and Karibib, Namibia
… These concentrations were used to calculate the absorbed dose rates and effective dose rates in air in the two towns. The average absorbed dose rate in air in Okahandja is 77.3 ± 18.0 nGy/hr while that in Karibib is 77.6 ± 10.9 nGy/hr. However, the resulting average effective dose rate in …
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Creation and modification of polymeric materials using electron beam radiation
… and that this reduction is proportional to the absorbed dose. The last study examines the crosslinking behavior of a polystyrene - poly(vinyl methyl ether) blend as a function of absorbed dose, composition, and phase separation. It is shown that the crosslinking behavior (in terms of the gel …
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Impact of acquisition protocol variations on effective dose and risk for CT head examinations
… across a wide range of protocol variations. Dose measurements were made using metal oxide semiconductor field effect transducers (MOSFETs). Effective doses and lifetime attributable cancer risks were calculated from MOSFETs organ and tissue absorbed dose measurements in both phantoms. The …
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Development of A Remote Dosimetric Audit Framework For Carbon Therapy
… used for day-to-day clinical measurements of absorbed dose, there are few options for remote dosimetry. The availability of such tools would support the development of a robust remote audit program for carbon ion therapy.</p> <p>The Imaging and Radiation Oncology Core (IROC) conducts remote …
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SIMULATIONS OF SPACE RADIATION INTERACTIONS WITH MATERIALS, WITH APPLICATION TO DOSE ESTIMATES FOR LUNAR SHELTER AND ABOARD THE INTERNATIONAL SPACE STATION
… with materials and quantify the biological dose onboard the International Space Station (ISS) and in a lunar shelter for future manned missions. High-energy space radiation of Trapped Protons, Solar Particle Events, and GCRs particles interactions are simulated using MCNPX and PHITS …
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Deposition of Energy From Low-Energy Neutrons in the Icru Tissue Sphere
… all the way from 0.3 MeV down to thermal. Absorbed dose and dose equivalent values have been obtained throughout the spherical phantom having the ICRU-prescribed 4-element tissue composition. The basic studies involved broad, parallel beams; but the data were easily used to provide …
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Point-based Ionizing Radiation Dosimetry Using Radiochromic Materials and a Fibreoptic Readout System
Real-time feedback of absorbed dose at a point within a patient can help with radiological quality assurance and innovation. Two radiochromic materials from GafChromic MD-55 and EBT films have been investigated for applicability in real-time in vivo dosimetry of ionizing radiation. Both films were …
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The Role of Cell Sterilization In Population Based Studies of Radiogenic Second Cancers Following Radiation Therapy
… relevant quantity, cancer equivalent dose (<em>D</em><sub>CE</sub>), to estimate risk instead of mean absorbed dose (<em>D</em><sub>MA</sub>). Our objective was to demonstrate that when <em>D</em><sub>CE</sub> is used fewer subjects are needed for clinical trials. Thus, we compared the …
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