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Full-Text Articles in Engineering
Vacancy-Induced Enhancement Of Electron-Phonon Coupling In Cubic Silicon Carbide And Its Relationship To The Two-Temperature Model, Salah Al Smairat, Joseph T. Graham
Vacancy-Induced Enhancement Of Electron-Phonon Coupling In Cubic Silicon Carbide And Its Relationship To The Two-Temperature Model, Salah Al Smairat, Joseph T. Graham
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
The electron-phonon coupling factor was calculated for both pristine and vacancy-rich 3C-SiC. Ab initio calculations were performed within the framework of the density functional perturbation theory. Wannier functions were used to interpolate eigenvalues into denser grids through the electron-phonon using Wannier code. The coupling factor was determined through calculations of the electron self-energy, electron-phonon relaxation time, and electronic specific heat. These parameters were extrapolated to high temperatures using a hybrid model which mixes band calculations for electrons below an energy cutoff with the free electron gas model for electrons above the energy cutoff. The electron relaxation times, specific heats, electron …
Fluid-Cooled Compact X-Ray Tube And System Including The Same, Hyoung-Koo Lee, V Ashish Avachat, Wesley William Tucker
Fluid-Cooled Compact X-Ray Tube And System Including The Same, Hyoung-Koo Lee, V Ashish Avachat, Wesley William Tucker
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
A fluid-cooled compact x-ray system includes a compact x-ray tube and a coolant channel coupled thereto. The compact x-ray tube includes a tube housing defining a longitudinal axis, and an electron source in the tube housing and coaxial with the tube housing. The electron source is configured to generate an electron beam. The compact x-ray tube also includes an anode coaxial with the tube housing, the anode defining a plane perpendicular to the longitudinal axis and including a target material, and an electron focusing mechanism in the tube housing and configured to focus and accelerate the electron beam to the …
Numerical Investigation Of The Thermo-Hydraulic Performance Of Water-Based Nanofluids In A Dimpled Channel Flow Using Al₂O₃, Cuo, And Hybrid Al₂O₃-Cuo As Nanoparticles, Farid Ahmed, Md Atrehar Abir, Muhtasim Fuad, Farhana Akter, Palash K. Bhowmik, Syed B. Alam, Dinesh Kumar
Numerical Investigation Of The Thermo-Hydraulic Performance Of Water-Based Nanofluids In A Dimpled Channel Flow Using Al₂O₃, Cuo, And Hybrid Al₂O₃-Cuo As Nanoparticles, Farid Ahmed, Md Atrehar Abir, Muhtasim Fuad, Farhana Akter, Palash K. Bhowmik, Syed B. Alam, Dinesh Kumar
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
In this study, the authors study the impact of spherical dimple surfaces and nanofluid coolants on heat transfer and pressure drop. The main objective of this paper is to evaluate the thermal performance of nanofluids with respect to different Reynolds numbers (Re) and nanoparticle compositions in dimpled channel flow. Water-based nanofluids with Al2O3, CuO, and Al2O3-CuO nanoparticles are considered for this investigation with 1%, 2%, and 4% volume fraction for each nanofluid. The simulations are conducted at low Reynolds numbers varying from 500 to 1250, assuming constant and uniform heat flux. The …
Real-Time Identification Of Oxygen Vacancy Centers In Linbo₃ And Srtio₃ During Irradiation With High Energy Particles, Miguel L. Crespillo, Joseph T. Graham, Fernando Agulló-López, Yanwen Zhang, William J. Weber
Real-Time Identification Of Oxygen Vacancy Centers In Linbo₃ And Srtio₃ During Irradiation With High Energy Particles, Miguel L. Crespillo, Joseph T. Graham, Fernando Agulló-López, Yanwen Zhang, William J. Weber
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
Oxygen vacancies are known to play a central role in the optoelectronic properties of oxide perovskites. A detailed description of the exact mechanisms by which oxygen vacancies govern such properties, however, is still quite incomplete. The unambiguous identification of oxygen vacancies has been a subject of intense discussion. Interest in oxygen vacancies is not purely academic. Precise control of oxygen vacancies has potential technological benefits in optoelectronic devices. In this review paper, we focus our attention on the generation of oxygen vacancies by irradiation with high energy particles. Irradiation constitutes an efficient and reliable strategy to introduce, monitor, and characterize …
Simultaneous Experimental Evaluation Of Pulse Shape And Deadtime Phenomenon Of Gm Detector, Bader Almutairi, Syed B. Alam, Cameron S. Goodwin, Shoaib Usman, Tayfun Akyurek
Simultaneous Experimental Evaluation Of Pulse Shape And Deadtime Phenomenon Of Gm Detector, Bader Almutairi, Syed B. Alam, Cameron S. Goodwin, Shoaib Usman, Tayfun Akyurek
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
Analysis of several pulse shape properties generated by a Geiger Mueller (GM) detector and its dependence on applied voltage was performed. The two-source method was utilized to measure deadtime while simultaneously capturing pulse shape parameters on an oscilloscope. A wide range of operating voltages (600-1200 V) beyond the recommended operating voltage of 900 V was investigated using three radioactive sources (204Tl, 137Cs, 22Na). This study investigates the relationship between operating voltage, pulse shape properties, and deadtime of the detector. Based on the data, it is found that deadtime decreases with increasing voltage from 600 to 650 …
Delayed Fast Neutron As An Indicator Of Burn-Up For Nuclear Fuel Elements, T. Akyurek, Shoaib Usman, S. B. Shoaib
Delayed Fast Neutron As An Indicator Of Burn-Up For Nuclear Fuel Elements, T. Akyurek, Shoaib Usman, S. B. Shoaib
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
Feasibility study of burn-up analysis and monitoring using delayed fast neutrons was investigated at Missouri University of Science and Technology Reactor (MSTR). Burnt and fresh fuel elements were used to collect delayed fast neutron data for different power levels. Total reactivity varied depending on the burn-up rate of fuel elements for each core configuration. The regulating rod worth was 2.07E-04 Δk/k/in and 1.95E-04 Δk/k/in for T121 and T122 core configurations at 11 inch, respectively. Delayed fast neutron spectrum of F1 (burnt) and F16 (fresh) fuel elements were analyzed further, and a strong correlation was observed between delayed fast neutron emission …
Development Of Complex Lattice Cell In Benchmark Model Of Particle Bed Critical System, Elijah Chamberlain Lutz
Development Of Complex Lattice Cell In Benchmark Model Of Particle Bed Critical System, Elijah Chamberlain Lutz
Masters Theses
“Criticality safety benchmark evaluations require the creation of models that most accurately represent the experiment being evaluated. In some cases this can be relatively trivial with experiments containing rather simple or standard geometry. In others, such as packed bed systems, this becomes unique and a more difficult process. The importance of accurate modeling of packed bed systems for the use of criticality safety benchmark evaluations was looked at. Four models were created of various complexities and accuracy. First the multi-particle bed, consisting of a fuel particle (UC1.7 kernel with C shell) and two filler particles (Zircaloy-4 and C + …
Effect Of Radiation Damage On Organic Phase Change Materials Thermal Storage Properties, Ryan Phillip Steere
Effect Of Radiation Damage On Organic Phase Change Materials Thermal Storage Properties, Ryan Phillip Steere
Doctoral Dissertations
"This work discusses the effects of radiation damage on organic phase change materials for use in nuclear reactor containments and space craft. The effects of radiation on the latent heat of polyethylene wax (PEW) and a eutectic of methyl palmitate and lauric acid (EMPaLA) are evaluated. These PCMs were irradiated in three locations: the Missouri University of Science and Technology research reactor (MSTR), the University of Missouri research reactor (MURR) and cyclotron (MUC) up to a total dose of 2826, 2895 and 662 Gy, respectively. The samples irradiated at the MSTR showed latent heat changes up to 15.5% lower than …
Scaling, Experiments, And Simulations Of Condensation Heat Transfer For Advanced Nuclear Reactors Safety, Palash Kumar Bhowmik
Scaling, Experiments, And Simulations Of Condensation Heat Transfer For Advanced Nuclear Reactors Safety, Palash Kumar Bhowmik
Doctoral Dissertations
“The purpose of this research was to perform scaled experiments and simulations to validate computational fluid dynamics (CFD) and empirical models of condensation heat transfer (CHT) for the passive containment cooling system (PCCS) of Small Modular Reactors (SMRs). SMRs are the futuristic candidates for clean, economic, and safe energy generation; however, reactor licensing requires safety system evaluations, such as PCCS. The knowledge in the reviewed relevant literature showed a gap in experimental data for scaling SMR’s safety systems and validating computational models. The previously available test data were inconsistent due to unscaled geometric and varying physics conditions. These inconsistencies lead …