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An investigation into 5-lobe lung modellingVuong, Xuan Tung Unknown Date (has links)
To understand how the input impedance of the respiratory system relates to pressure and volume airflow of the airway branched structure, this thesis focuses on developing a mathematical model of the branched airway including trachea and branching airways. The 5-Lobe lung model is developed mathematically and experimentally. A computer model is constructed in the MathlabTM programming environment. It accounts for the effects of airways with varying cross-sectional area, flexible wall properties, and the bronchial tree within the lung using the mathematical methods developed in previous researches. The terminal impedances are determined by proposed idealized lobe models. A range of frequencies up to 256 Hz are tested on this model. Cases of study on obstructions by varying lung stiffness from healthy to unhealthy conditions are investigated.Mathematical model is validated by experiment investigations on the mechanical lung simulator, which is built in Diagnostic & Control Research Centre at Auckland University of Technology. The results conclude that mathematical methods used in this research are capable to produce predictable results of the input impedance.
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On short-crested water wavesMarchant, Timothy Robert. January 1988 (has links) (PDF)
Typescript. Bibliography: leaves 145-150.
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A new approacch to the analysis of the third heart soundEwing, Gary John. January 1988 (has links) (PDF)
Errata sheet inserted. Bibliography: leaves 99-102.
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Mathematical programming models for traffic network problemsTomlin, John Anthony January 1967 (has links)
viii, 102 leaves : ill., 3 pams in back pocket / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) from the Dept. of Mathematics, University of Adelaide, 1968
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A stochastic analysis of the effect of fire on remote vegetationWilkins, Christopher Ward January 1977 (has links)
vi, 164 leaves : ill., tables, maps, photos ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1978) from the Dept. of Applied Mathematics, University of Adelaide
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The behaviour of pipe network analysis solution techniques / by David J. Ellis.Ellis, D. J. (David John) January 2001 (has links)
"November 2001" / Includes bibliographical references (leaves 235-240) / xiii, 285 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2003
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A numerical model of heat transfer to the atmosphere from an Arctic leadShreffler, Jack H. 13 January 1975 (has links)
Graduation date: 1975
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A modeling study of katabatic flowsSmith, Craig M. 04 September 2003 (has links)
A modeling study is undertaken to better understand the physics of
katabatic flows. This study is divided into three topics; a comparison between a
large eddy simulation (LES) and a mesoscale model of katabatic flows, a sensitivity
study of katabatic flows to various physical parameters, and an investigation into
the effect of subgrid scale terrain features on katabatic flow models. In the first
topic, a comparison between LES, and a mesoscale model, ARPS, of katabatic
flows is made to better quantify the accuracy of subgrid parametenzation in ARPS.
It is shown that, although the modeled flows agree on a number of parameters, the
LES model produces a lower and faster jet than that of ARPS, and also cools more
near the surface. The momentum budgets of the two models agree well with each
other. The ARPS model has a higher amount of TKE than the LES model, due to
an overproduction by shear in the ARPS subgrid parameterizations.
The second portion of this thesis represents a sensitivity study of katabatic
flows to various physical parameters. The depth and strength of katabatic flows are
shown to vary with surface heat fluxes, slope angle, and ambient stratification.
Katabatic flows are shown to grow in depth and magnitude as slope angle
increases, due to an increase in entrainment of overlying ambient air. The ratio of
advection to mixing is shown to collapse to a near universal value regardless of
surface heat fluxes. With increasing ambient stratification, entrainment in katabatic
flows becomes small and the momentum equation is reduced to a two-way balance
between buoyancy and drag. In this case, the heat flux of entrained air into the
katabatic flow approaches that of the surface cooling, and the flow ceases to grow
in the down-slope direction. Finally, predictions for bulk velocity and buoyancy
strength scales are developed as a function of slope angle and surface heat fluxes.
The last portion of this study focuses on the effect of subgrid scale terrain
features on katabatic flows. It is shown that in areas of inadequate terrain
resolution, the effect of the terrain smoothing routine in ARPS is to increase the
slope height in areas of concave mountains. The concept of energy conversion in
katabatic flows is introduced, and it is shown that the effect of raising terrain is to
assign parcels more buoyant potential energy than they would otherwise have, and
thus over-predict the magnitude of katabatic flows. Finally, an investigation into
the effect of changing upper slope angle on katabatic flows over combined slopes is
made. It is concluded that a combined slope cannot be predicted using a linear
combination of simple slopes, since the transition portion of the slope results in a
turbulent hydraulic jump with enhanced mixing. The magnitude of mixing in the
turbulent hydraulic jump in combined slopes is shown to depend on the difference
between upper and lower slope angle. / Graduation date: 2004
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Numerical simulations of nonlinear baroclinic instability with a spherical wave-mean flow modelWang, Chunzai 11 June 1991 (has links)
A global, multi-level, wave-mean flow model based on an
approximate version of the primitive equations is developed to
investigate the development of a baroclinic wave field initially
confined to a single zonal wavenumber. The effects of physical
processes (surface drag and thermal damping) and internal diffusion
on the evolution have been examined. The nature of the mean flow
adjustment by the nonlinear baroclinic waves is also studied.
For a simulation with a relatively strong internal diffusion it is
found that a single life cycle characterized by baroclinic growth and
barotropic decay is obtained (as in Simmons and Hoskins, 1978),
whereas with weaker diffusion the wave undergoes secondary life
cycles before a nearly wave-free state is reached (as in Barnes and
Young, 1991). In an experiment with weak 4th order diffusion
secondary life cycles occur with little net decay. Relatively strong
barotropic growth follows the initial life cycle.
In experiments with surface drag (Rayleigh friction) and thermal
damping (Newtonian cooling), repeated life cycles of baroclinic
growth and barotropic decay can be obtained. It is found that in the
complete absence of surface drag, the flow evolves to a nearly
wave-free state after one secondary cycle. This demonstrates that
surface drag plays an important role in nonlinear baroclinic
instability. With relatively strong surface drag multiple life cycle
behavior is found for sufficiently strong thermal damping. Such a
behavior strengthens for very strong thermal damping. A steady
wave state in which the wave amplitude equilibrates at an
essentially constant level has only been obtained with very strong
"potential vorticity damping".
Both the "barotropic governor" process (James and Gray, 1986)
and the baroclinic adjusment process are responsible for major
parts of the stabilization of the mean flow in simulations with and
without surface drag and thermal damping. However, the "barotropic
governor" process dominates the flow evolution in the model
simulations without surface drag and thermal damping. The
"barotropic governor" modifies the meridional gradient of zonal
mean potential vorticity, which influences the baroclinic
adjustment. / Graduation date: 1992
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A study of flow acceleration over a coastal headlandWilkinson, David R. 05 May 1978 (has links)
The thesis examines the applicability of a two-dimensional flow
acceleration model to describe a terrain-induced flow perturbation as
measured at Yaquina Head on the central Oregon coast. The geometry of
Yaquina Head together with the upstream wind values were used in estimating
hilltop winds. These estimates compare well with the observed wind
values.
A second method to estimate the hilltop winds was attempted by
developing a mean ratio of Yaquina Head winds to the upstream Yaquina
South Jetty winds. This ratio was taken from one winter's data and
used to estimate the next winter hilltop winds. The same upstream wind
values were used with this method as were used with the geometric model.
Statistical evaluation in the form of regression analysis was performed
to determine the ability of the geometric and statistical models
to estimate the hilltop wind on Yaquina Head. It was found that both
models did reasonably well but that neither model was appreciably better
than the other. / Graduation date: 1979
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