Physics & Astronomy Undergraduate Honours Theses
http://hdl.handle.net/2429/547
2015-11-30T08:25:11ZThermal susceptibility study of the Canadian Hydrogen Intensity Mapping Experiment Pathfinder Instruments
http://hdl.handle.net/2429/54845
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) will study
Baryon Acoustic Oscillations (BAO) in the redshift range when the expansion
of the Universe began to accelerate due Dark Energyâ€™s dominating influence.
CHIME will measure the Hubble parameter, H(z), and constrain the equation
of state parameter, w, of Dark Energy. These measurements are critical in
furthering our understanding of the expansion history of the Universe and
Dark Energy.
CHIME will observe the faint cosmological signal and map expansion from
its location at the Dominion Radio Astrophysical Observatory (DRAO) near
Penticton, BC. In order to make the required measurements, the CHIME
telescope requires an accurate calibration plan. Of the many components of
the overall calibration plan, this paper specifically addresses the system gain
calibration, with respect to exploring the relationship between system gain
and temperature in the development of a thermal model. The model presented
here describes the relationship to first order and lays the foundation for more
detailed study. Findings provide insight into system gain configuration and
facilitate subsequent development of the thermal model.
The results presented here are critical steps in the system gain calibration,
contributing to a successful overall calibration plan that will ultimately lead to
reliable data from which new science results will emerge. The analysis of these
data has the potential to lead to an increased understanding of the expansion
of the Universe and the nature of Dark Energy.
2015-05-01T00:00:00ZInvestigation of damaged tibiofemoral articular cartilage through susceptibility-weighted MR phase imaging and frequency mapping
http://hdl.handle.net/2429/53387
Degenerative articular cartilage damage, such as osteoarthritis, is one of the most common
causes of chronic disability, so early detection and accurate assessment is essential
for effective treatment. Magnetic resonance imaging, a non-invasive imaging modality,
provides excellent soft tissue contrast in the knee and enables visualization of all zones
of cartilage. In this project, a 3D multiple echo gradient echo sequence was used to
assess articular cartilage damage in patients with osteoarthritis or other cartilage disorders.
Frequency maps and susceptibility weighted images were generated to examine
the anisotropic and isotropic orientation of collagen fibres and the presence of cartilage
damage. It is anticipated that these techniques could be a more sensitive method of
detecting changes in cartilage structure than current clinical procedures.
2014-04-01T00:00:00ZBorn-Infeld action geometries
http://hdl.handle.net/2429/50709
In this thesis, we present a novel way of studying noncommutative geometries in string theory based on an effective Hamiltonian given by Berenstein and Dzienkowski[1]. We work in the context of the study of two magnetic monopoles deforming a D3 brane as considered by Karczmarek and Sibilia[2]. We present numerical evidence that for surfaces defined using n-dimensional generators of the SU(2) algebra in an auxiliary Hilbert space with this effective Hamiltonian, the surface represents a set of eigenvalues for 2n-dimensional eigenvectors that demonstrate the property of splitting into two parallel n-dimensional sub-eigenvectors. We conjecture that these sub-eigenvectors can then be used to study coherent states in these noncommutative geometries based on the the fact that the annihilation operator appears in block form in the effective Hamiltonian acting on the eigenvector. Lastly, we derive a useful formula for studying the geometric rate of change of these 3-dimensional surfaces in 4 dimensions that may prove handy in preparing numerical solutions of the Nahm equation.
2014-05-31T00:00:00ZSearching for solitons in the magnetosphere of a magnetar
http://hdl.handle.net/2429/46354
We describe a non-pertrubative method of searching for solitary waves travelling through the
magnetosphere of a magnetar. The wave will be supported by the combined effects of nonlinearity
and dispersion caused by the presence of a quantum electrodynamic (QED) vacuum in a strongly
magnetized field and by a strongly magnetized plasma of the magnetosphere. Using this method,
we have found a soliton in the form of an infinite current sheet. The method and the results of
this paper could be conducive to research studying the emission of strongly magnetized stars.
2013-04-01T00:00:00Z