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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 217 for “"Fluence"”.
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Low fluence neutron radiography techniques
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1997.
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Fluence-based Dosimetry using Fluorescent Nuclear Track Detectors
… for treatment planning and verification. Current fluence-based dosimeters have the potential to measure required quantities, but because of their size and electronic components, the majority of them is not suitable for in vivo applications. Fluorescent nuclear track detectors (FNTDs) are small and …
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Micrometeoroid Fluence Variation in Critical Orbits Due to Asteroid Disruption
<p>Micrometeoroids and orbital debris (MMOD) is a growing issue with international importance. Micrometeoroids are naturally occurring fragments of rock and dusk that exist throughout the solar system. Orbital debris is human made material like rocket bodies, paint flakes, and the effluent of …
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Computer simulation of high fluence ion beam surface modification processes
… and N into Fe are modeled to demonstrate the influence of radiation-damage induced migration. The precipitation of second phases during irradiation is modelled using thermodynamic considerations but with solubility values under irradiation obtained from experiment. In the model the solute atoms …
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Fluence-limited burnup as a function of fast reactor core parameters
… but also the maximum permissible fast-neutron fluence in the cladding, especially for reduced uranium enrichment cores using high-albedo MgO reflectors. The intent of this thesis was to determine the best design parameters - fuel type, fuel compound, fuel arrangement, and coolant - while …
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A Forward-Backward Fluence Model for the Low-Energy Neutron Boltzmann Equation
… describing forward and backward neutron fluence in selected materials. Linear B-splines were used to change the integro-differential equations into a coupled system of ordinary differential equations (O.D.E.'s). Difference approximations were then used to recast the O.D.E.'s into a …
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Modeling of high fluence Ti ion implantation and vacuum carburization in steel
Concentration-versus-depth profiles have been calculated for Ti and C in Ti-implanted 52100 steel. A computer formalism was developed to account for diffusion and mixing processes, as well as sputtering and lattice dilation. A Gaussian distribution of Ti was assumed to be incorporated at each time …
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Combined methods and instrumentation for dosimetric monitoring of the large fluence hadron irradiations /
Dosimetry 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 …
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Measurement of fluence at the D-line fast neutron facility at iThemba LABS
Measurements of fluence were made for the neutron beams produced at the fast neutron beam facility of iThemba LABS, using an NE213 organic liquid scintillator detector and a 238U fission ionisation chamber. Neutron beams were produced by irradiating a 6 mm natural lithium target with pulsed proton …
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A sensitivity-driven greedy approach to fluence map optimization in intensity-modulated radiation therapy
… a local minimum of the stated formulation of the fluence map problem. Numerical comparison is made to an approach representative of the leading commercial software for IMRT planning. We find our method produces plans of competitive quality with a notable improvement in computational performance. …
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Measurement of neutron fluence at En=20-100 MeV using a stacked scintillator spectrometer
The present work demonstrates a new application of a stacked spectrometer which has been developed in the Physics Department of the University of Cape Town. The spectrometer used in the present work consists of two identical segments of NE213 liquid scintillator, of dimensions 13.0 x 13.0 x 7.0 cm³ …
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Implementation of scattering pinhole diagnostic for detection of fusion products on CR-39 at high particle fluence
… has been implemented in order to reduce the fluence on the CR-39. This paper details the design and implementation of a scattering pinhole to detect protons born from D3He nuclear reactions: D +3 He = p+(14.7MeV) + [alpha](3.7MeV). To do so, basic models relating the scattering angle to …
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Irradiation assisted stress corrosion cracking susceptibility of low fluence stainless steels evaluated by in-flux slow strain rate tests
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1996.
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Calculation of Neutron Fluence-to-Dose Index Conversion Factors for the Standard Icru Tissue Phantom by the Monte Carlo Method
Made available in DSpace on 2014-12-14T06:26:06Z (GMT). No. of bitstreams: 1 7811221.pdf: 6872930 bytes, checksum: f215c7f7d666eb9881298cc5aefe2a5e (MD5) Previous issue date: 1978
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Comparison of Two Advanced Oxidation Processes for Their Production of Hydroxyl Radicals and Evaluation of a UV/Ozone AOP at Varying UV Fluence for Treating Diclofenac
… consequential difference in degradation for the fluence indicator atrazine (ATZ) or the emerging contaminant DCF. Further testing with thicker sleeves would be important to determine the necessary amounts of UV and reasonably scale this technology for a water treatment facility.</p>
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Single cell gel electrophoresis-based investigations of UVR- and visible light-induced single strand breakage in cultured human cells
Single strand breaks induced by very low fluence UVR (20 µW cmˉ² , 310 nm) and visible light (70 µW cmˉ² , 405 nm) and higher fluence unfiltered xenon arc lamp radiation (3 mW cmˉ² ) were measured by single cell gel electrophoresis. The normal responses of 6 cell lines to the low fluence radiation …
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Investigation of different light delivery schemes in photodynamic therapy of human glioma spheroids
… is investigated. In particular, the effects of fluence, fluence rate, light dose fractionation and long-term repeat PDT is considered. Improved PDT response was found for low fluence rate photodynamic treatments i.e. those at or below 25 mW cm-2 . Results are consistent with the self-sensitized …
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Effects of ion irradiation on 4H- SiC p-n junction
… device parameters in a wide range of irradiation fluence is necessary. In the present thesis, 4H-SiC p-n junctions were irradiated with 700 keV He+ ions in the fluence range 10^12 - 10^15 cm^-2. The effects of irradiation on devices electric properties were investigated by current-voltage (I-V) …
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A Numerical Solution of Low-Energy Neutron Boltzmann Equation
… is created to calculate low energy neutron fluence due to the elastic scattering of evaporation neutrons produced in interactions of high energy particles with target nuclei. This multigroup method is added to NASA Langley Research Center's HZETRN particle transport code. This new code is …
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