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Showing 1 to 20 of 20 for “"Cobalt-60"”.
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The measurement of the output spectrum of a cobalt 60 teletherapy unit
… energy radiation in addition to the primary Co60 -rays with energies of 1.17 and 1.33 Mev. Since the beam strength is approximately 2 x 109 photons/cm2/sec at 80 cm from the source, direct measurement of this spectrum was not practicable. The spectral distribution of single scattered radiation …
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Cytogenetic Evaluation Of Low Dose Hyper-Radiosensitivity In Human Lymphoblastoid Cell Lines Exposed To Cobalt-60 Gamma Radiation.
… lymphoblastoid cell lines to 0 - 400 cGy of Cobalt-60 gamma radiation. The cytokinesis block micronucleus assay was used to determine the frequencies of micronuclei and nucleoplasmic bridges. To characterize the dependence of the cytogenetic damage on dose, univariate and multivariate …
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Late Effects of Fission Neutron and Cobalt-60 Gamma-Radiation on the Hematopoietic Stem Cell Compartment in the Mouse
Made available in DSpace on 2014-12-14T13:39:40Z (GMT). No. of bitstreams: 1 7715033.pdf: 2940664 bytes, checksum: e5829618942bc352c272e90ba6f0926f (MD5) Previous issue date: 1977
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Comparison of the Effects of Cobalt-60 [gamma]-Rays and Tritium [beta][superscript -]Particles on Water Radiolysis and Aqueous Solutions and Radiolysis of the Ceric-Cerous Sulfate Dosimeter at Elevated Temperature
… initial energy of ~5.7 keV) with [superscript 60]Co [gamma]-rays (~1 MeV electrons). Our simulations showed that, for [superscript 3]H [beta][superscript -], we observe lower radical and higher molecular yields than in γ-radiolysis. These differences in yields are consistent with differences in …
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MONTE CARLO MODELING OF THE GAMMA KNIFE PERFEXION<sup>TM</sup>
… malfunctioning nerves. It uses 192 high activity Cobalt-60 sources collimated to a common focus to impart radiological damage to the target structure while minimizing dose to adjacent healthy tissue a few millimeters away. Tungsten collimators are organized into eight sectors of 24 sources each, …
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A Complete Dosimetric Model of the Gamma Knife Perfexion Using Penelope Monte Carlo Codes
… targets in the head. It uses 192 high-activity Cobalt-60 sources collimated to a common focus to impart radiological damage to the target structure while minimizing dose to adjacent healthy tissue. Tungsten collimators are organized into eight sectors of 24 sources each; each sector can be set …
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Development of a Hybrid Alanine-calorimetry Absorbed-dose Standard for Linac Electron Beams
… 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 measurements at the …
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Assessment and Analysis of Commercial Off the Shelf Devices for Space Applications
… and assessments of total dose effects with cobalt-60 radiation. The findings demonstrate that electronic switching regulators and DACs exhibit acceptable performance under total dose conditions for short term missions on the International Space Station (ISS). However, high energy proton …
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Development and Implementation of A Homogeneous and A Heterogeneous Anthropomorphic End to End Quality Assurance Audit System Phantom For Magnetic Resonance Guided Radiotherapy Modalities Ranging From 0.35 T to 1.50 T
… either a linear accelerator or three radioactive cobalt-60 sources. Before institutions participate in multi-institutional NCI-sponsored clinical trials, they are required to perform a credentialing test provided by IROC-Houston. During the credentialing test, end-to-end phantoms are used to …
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Bystander Effects Due To Neutrons, And Low-Dose Hyper-Radiosensitivity To Gamma Rays In Human Cells Using Cytogenetics
… a bystander effect, cells were irradiated with cobalt-60 at doses equivalent to the percent contamination for each neutron dose. No significant increase in the frequencies of micronuclei or bridges was observed at these doses of photons for either cell line when cultured in ICCM. As expected, …
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Comparative Analysis of Source Term Removal at Cook Nuclear Plant
… Michigan. Specialty resin was employed to remove Cobalt-60 CRUD and other contaminates from the primary coolant piping and fuel cladding. Cook is a two unit Ice Condenser Pressurized Water Reactor (Westinghouse). Unit 1 has completed 22 cycles and refueling outages and Unit 2 has completed 18 …
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Characterization of Mechanical Properties of Gamma Irradiated Additively Manufactured Articles for In-Space Manufacturing
… at different dosages from 1 to 1400 kGy using a Cobalt-60 gamma irradiator to simulate space radiation environment. The correlation between the mechanical properties of irradiated samples and accumulated radiation dosage were evaluated by a series of tensile and flexural tests. Findings showed a …
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End-to-end testing of the Leksell Gamma Knife Icon system
… treat brain lesions. It incorporates 192 fixed cobalt-60 sources, which ensures the highest degree of accuracy during treatment due to the minimization of potential error from stationary sources. The gamma knife’s precision and special modifications for conformity to the human brain ensure …
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Recombination lifetimes in gamma-irradiated silicon
… and after irradiation at room temperature by cobalt 60 gamma rays. The resistivity of the boron doped samples ranged between 10 and 5000 ohm-cm, and the resistivity of the phosphorus doped samples was between 20 and 220 ohm-cm. Both crucible and floating zone grown materials were investigated. …
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Gamma irradiation response of photonic crystal and standard optical fibre Bragg grating sensors for radiation dosimetry
… that the FBGs performance, when exposed to Cobalt-60 gamma irradiation, can suffer cross sensitivity problems resulting from different external effects such as temperature. However, FBGs written in PCFs may be able to overcome these problems due to their design, flexibility of the shape, and …
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Understanding defects in germanium and silicon for optoelectronic energy conversion
… via deep-level transient spectroscopy (DLTS). Cobalt-60 gamma rays were used to generate isolated vacancies and interstitials which diffuse and react with impurities in the material to form four defect states (E₃₇, E₃₀, E₂₂, and E₂₁) in the upper half of the bandgap. Irradiations at 77 K and …
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Cytogenetic Analysis Of Depleted Uranium Exposure And Age-Dependent Susceptibility To Ionizing Radiation
… of 10 newborns. Samples were acutely exposed to Cobalt 60 gamma rays to doses of 0 (control), 1, 2, 3 and 4 Gy. Cells in metaphase were labeled with whole chromosome paints and evaluated for structural chromosome aberrations. Regression analyses were used to evaluate the frequencies of each of …
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Assessing the synergy between the Sterile Insect Technique and Classical Biological Control for sustainable management of the invasive pest Bagrada hilaris (Hemiptera: Pentatomidae)
… achieved by exposure to γ-rays emitted from a cobalt-60 source at the Calliope Irradiation Facility of ENEA (Rome, Italy). To identify the irradiation dose that ensures a good balance between sterility, longevity, and the ability to mate and compete with their wild counterparts, the parameters …
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The role of tomato and lycopene consumption on prostate carcinogenesis and prostate cancer treatment
… with 7.5 gy (Rad) or 0 gy (sham) with a Cobalt-60 source. In the pilot study, mice were euthanized after 0, 24, or 72 hours. Based on the results of the pilot study, mice in the main Diet study were euthanized 24 hours after radiation or sham treatment. Within the Diet study, prostate …