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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Effectiveness Of Multilayer Graded-Z Forms Of Radiation Shielding, Brinley Packer
Effectiveness Of Multilayer Graded-Z Forms Of Radiation Shielding, Brinley Packer
Physics Capstone Projects
This study explored how different forms of radiation shielding were more or less effective than standard single-layer shielding. Beta and gamma radiation sources were used and measured using a Geiger counter to determine how well the various forms of shielding protect against the radiation. The shielding effectiveness of standard homogeneous materials (e.g., graphite, carbon/epoxy composites, aluminum, and lead) of various thicknesses for different radiation sources was measured to provide standards for comparison. Once a basis of effective shielding was established, the study can go into greater depth into how to use shielding materials to be more effective, to better shield …
Optical Relaxation Of Defects In Kapton Caused By Irradiation, Ashlan Keeler Swainston
Optical Relaxation Of Defects In Kapton Caused By Irradiation, Ashlan Keeler Swainston
Physics Capstone Projects
Radiation can create atomic-scale defect states in polymers, leading to changes in their optical, electrical and mechanical properties. Recent studies of polymers have shown that these defect states are sensitive to oxygen or air exposure. It is believed that air cause the number of defect states to decrease and the polymers to revert to their original states. However, the time scale of this regression is not known. This experiment quantified the time that it takes one polymer to recover and the extent of said recovery; polymide (PI). In order to study the regression, optical transmission data were taken using a …
Relaxation Of Radiation Effects In Polymers, Alexandra Hughlett Nelson
Relaxation Of Radiation Effects In Polymers, Alexandra Hughlett Nelson
Physics Capstone Projects
Radiation can create atomic-scale defect states in polymers, leading to changes in their optical, electrical and mechanical properties. Recent studies of polymers have shown that these defect states are sensitive to oxygen or water exposure. It is believed that oxygen cause the number of defect states to decrease and the polymers to revert to their original states. However, the time scale of this regression is not known. This experiment quantified the time that it takes five polymers to recover and the extent of said recovery; polypropylene (PP), low density polyethylene (LDPE), fluorinated ethylene propylene (FEP), polymide (PI), and poly ether …
Dynamic Secondary Electron Emission In Rough Composite Materials, Leandro Olano, Maria E. Dávila, John R. Dennison, Petronilo Martín-Iglesias, Isabel Montero
Dynamic Secondary Electron Emission In Rough Composite Materials, Leandro Olano, Maria E. Dávila, John R. Dennison, Petronilo Martín-Iglesias, Isabel Montero
All Physics Faculty Publications
The interaction of ionizing radiation with matter is of critical importance in numerous areas of science and technology like space and vacuum technology and even medicine and biotechnology. Secondary electron emission is a consequence of electron irradiation on materials. We achieve extremely low secondary electron emission yield values smaller than 0.2, even up to incident electron energies ~1 keV, due to an undocumented synergy between neighbouring metal and dielectric domains in composite samples. To investigate this experimental discovery, we propose a simple 3D model where the dielectric and metallic domains are arranged in parallel and interleaved. The proposed surface profile …
Characterization Of The Effects Of Radiation On Skeletal And Smooth Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis
Characterization Of The Effects Of Radiation On Skeletal And Smooth Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis
Posters
Muscular atrophy is a serious issue for extended spaceflight. Understanding and preventing the role of ionizing radiation in skeletal muscle loss would preserve the strength and endurance of astronauts and enable longer duration space travel and exploration. Irradiation was performed in the USU material physics group's Space Suvivability Test Chamber. C2C12 and CRL-1999 cells were exposed to dosages ranging from 0.5 - 36.8 Gy. Cell viability and growth rate were measured immediately following irradiation.
Characterizing The Effects Of Radiation On Muscle Cells, Lori Caldwell, Elizabeth Vargis, Charles Harding, Jr Dennison
Characterizing The Effects Of Radiation On Muscle Cells, Lori Caldwell, Elizabeth Vargis, Charles Harding, Jr Dennison
Posters
One of the primary concerns for those spending time in low gravity and high radiation environments is muscle atrophy. A major cause of muscular atrophy is oxidative stress which is amplified by increased levels of ionizing radiation during spaceflight. Additionally, high levels of radiation can damage DNA, increasing the risk of cancer. Utah State University’s Space Environment Test Facility was used to irradiate C2C12 myoblasts and human vascular endothelial cells with a beta-radiation dosage mimicking that on the International Space Station and a 3-year deep space mission.
Characterizing The Effects Of Radiation On Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis
Characterizing The Effects Of Radiation On Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis
Posters
As longer space missions become more desirable to public and private institutions, the physiological impact on astronauts must be considered. One of the primary concerns for those spending time in low gravity and high radiation environments is muscle atrophy. A major cause of muscular atrophy is oxidative stress which is amplified by increased levels of ionizing radiation during spaceflight. Additionally, high levels of radiation can damage DNA, increasing the risk of cancer. Utah State University’s Space Environment Test Facility was used to irradiate C2C12 myoblasts and human vascular endothelial cells with a dosage mimicking that on the International Space Station …
Uv Degradation Of Polycarbonate, Katie Gamaunt
Uv Degradation Of Polycarbonate, Katie Gamaunt
Physics Capstone Projects
The decrease in visible and ultraviolet transmission spectra of polymeric and glass spacecraft materials has been measured to determine the extent of degradation due to high-energy UV radiation similar to the solar spectrum (both above and below the stratosphere, which is where most of the UV radiation is absorbed). This project looked at the effects that the atmosphere has in regards to blocking UV radiation and thus, slowing down the UV degradation process. A polycarbonate sample was exposed to radiation from a focused high intensity deuterium lamp source, which generates radiation in the UVA and UVB spectrum. A particularly severe …
Progress Towards Real-Time Radiation Measurements On Aircraft, L. Duane Bell, W. Kent Tobiska, Robert W. Schunk
Progress Towards Real-Time Radiation Measurements On Aircraft, L. Duane Bell, W. Kent Tobiska, Robert W. Schunk
Physics Student Research
The Space Weather Center (SWC) at Utah State University has created a team to deploy and obtain radiation effective dose rate data from dosimeters flown on commercial aircraft. The objective is to improve the accuracy of radiation dose and dose rate estimates for commercial aviation flight crews. There are two general sources of radiation exposure for flight crews: (1) the ever-present, background galactic cosmic rays (GCR), which originate outside the solar system, and (2) the solar energetic particle (SEP) events (or solar cosmic rays), which are associated with solar flares and coronal mass ejections lasting for several hours to days …