Global ETD Search
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 19 of 19 for “"one dimensional models"”.
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Computational and experimental time domain, one dimensional models of air wave propagation in human airways
… system, in separating forward and backward components of pressure and velocity also for the air case. After validating the 1-D modelling in space and time variables, several models for human airways have been considered starting from simplified versions (bifurcation trachea- main bronchi, series …
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Studies of Integrable One-Dimensional Quantum Systems
… I use the Bethe Ansatz (BA) to study various one-dimensional models. I first go through some background on the BA (both the coordinate and algebraic forms). I start the study by using the BA to compare bound state occurrences between the 2-particle XXZ, Bose–Hubbard, and Fermi– Hubbard models. …
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Mass transport in the cathode electrode of a molten carbonate fuel cell
… for mobile applications. In this thesis, three one-dimensional models of a MCFC are presented based on different types of diffusion and convection. Comparisons between models are performed so as to assess their validity. Regarding ion transport, it is shown that there exists a limiting case for …
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One-Dimensional Performance Modeling of Centrifugal Flow Vaned Diffusers
The Two Element in Series (TEIS) and Two Zone models stand out as powerful tools that enable deeper understanding of compressor stage designs after they have been tested. The insights gained from these investigations have aided in improving new stage designs. Up to now, it has only been possible to …
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Micro-electromagnetic formation flight of satellite systems
… distances and requiring small forces. Simple one-dimensional models investigate this concept and the optimal mass implementations are compared to traditional propulsion systems as well as HTS EMFF and shown to be advantageous in close proximity formations. Because the forces involved with …
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Temperature and heat flow modeling of three-dimensional bodies in a two-layered half space
… between polygonal prism and finite difference models, three-dimensional and one-dimensional models, and half space and two-layered half space models. To illustrate the interpretation of heat flow anomalies a heat flow model was prepared for the Rolesville batholith and Castalia pluton, in Nash …
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Electronic signatures of large amplitude motions
… measure of progress along a reaction coordinate. One-dimensional models of the large amplitude bending reaction coordinates and their associated electronic signatures are constructed for two prototypical unimolecular isomerizations: acetylene<-->vinylidene (HCCH<-->CCH2), and hydrogen …
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Reaction-Diffusion Models of Cancer Dispersion
… spatial distribution and temporal evolution of one-dimensional models of cancer dispersion are studied. The models discussed pertain primarily to the transition of a tumor from an initial neoplasm to the dormant avascular state, i.e. just prior to the vascular state, whenever that may occur. …
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Investigation of pressure-tube and calandria-tube deformation following a single channel blockage event in ACR-700
… CTs is filled with the heavy-water moderator. One postulated accident scenario for ACR-700 is the complete coolant flow blockage of a single PT. The flow is not monitored within each individual PT, thus during the early stages of this accident the reactor remains at full power and full …
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Exergy Methods for the Generic Analysis and Optimization of Hypersonic Vehicle Concepts
… consisting of inlet, combustor, and nozzle components. A number of key design and operational decision variables are identified as those which govern the hypersonic vehicle flow physics and thermodynamics and detailed one-dimensional models of each component and sub-system are developed. Rates …
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Phase Space Structure of Disequilibrium in the Milky Way
… system from data snapshots. We apply this to two one-dimensional models for the vertical structure of the Milky Way: the homogeneous slab, and the isothermal plane. We found that the eigenfunctions, or modes, determined for a self-gravitating system undergoing phase mixing comprise a set of modes …
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Optimization of Hypersonic Airbreathing Propulsion Systems through Mixed Analysis Methods
… and implemented using three different engine components: the isolator, combustor, and nozzle. For each component a set of intensive properties are iterated to match prescribed conditions, namely the mass flow. These low-fidelity one-dimensional models of hypersonic propulsion systems are used in …
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Flow and pressure drop on the shellside of cylindrical heat exchangers
… leakage. Results are also presented of three-dimensional modelling of shellside flows using the Harwell Laboratory's FLOW3D code. Flow visualisation provided flow patterns in the central plane of the bundle and adjacent to the shell wall. Comparison of these high-lighted significant radial …
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Water quality modelling of eutrophied reservoirs in South Africa
… altered phosphate inputs. Most of the work was done on the hypertrophic Hartbeespoort Dam reservoir. The models utilised were empirical, zero-dimensional models that treated the reservoir as a completely mixed reactor. Usually these models considered only the steady state, or at most, annual …
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Design and analysis of a composite wire-socket attachment
… failure mode. However, the experimental data alone do not provide enough information about the behavior of the anchorage to be used exclusively in the design process. The results are used to modify the design of the anchorage system. It is shown that for a successful anchorage system the choice …
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A Meshless Method for Magnetohydrodynamics and Applications to Protoplanetary Disks
… A set of standard test problems, including one part in a million amplitude linear MHD waves, magnetized shock tubes, and Kelvin-Helmholtz instabilities are presented. Finally we demonstrate good agreement with analytic predictions of linear growth rates for magnetorotational instability in a …
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Dynamics of super-absorbent hydrogels
… of hydrogels, showing how the dynamics of three-dimensional swelling is qualitatively different from simple one-dimensional models, and underlining a distinct difference between the dynamics of gels and other colloidal materials where such stresses do not arise. Furthermore, it is seen how …