M.Sc. / This project involves the analysis of data obtained through membership of the Kepler Asteroseismic Science Consortium Working Group 9, viz. proprietary data received from the Kepler Space Telescope. In this work, Kepler data on KIC011175495 are de-trended, and subject to a lengthy iteration of refined and sophisticated analysis routines, using many software platforms based on sound physical principles. The iteration is shown to converge to final values for the binary parameters and the pulsation frequencies present in the system. Conclusions are made on the interpretation of these results and the way forward for further analysis of this and related systems.

M.Sc. / Just as the observations of oscillations of ordinary stars can be used to determine their composition and structure, the oscillations of neutron stars could potentially be used to determine the nature of the dense nuclear matter from which they are made. The superfluidity of the interiors of neutron stars is normally probed by observations of pulsar glitches. It turns out that the superfluidity affects the oscillations in a neutron star core. In particular, it results in a class of oscillation modes specifically associated with the superfluid core. Although these modes have not been detected from observations, it is hoped by some that gravitational wave data may be used to probe the superfluidity of neutron star cores. In this dissertation, a simple equilibrium model is used in order to calculate the superfluid modes in the context of newtonian gravity. The equilibrium model that is used is the same combination of the Serot equation of state and the Harrison-Wheeler equation of state that was used formerly by Lee and by Lindblom & Mendell. Numerical calculations of the superfluid modes are done for 20 different neutron star models ranging in mass between 0.5 and 2 solar masses. The frequencies of the oscillations for the 0.5 and 1.4 solar masses agree fairly well with Lee's results, which strongly validates the computer code written for numerical calculation in this work. In all the models, the eigenfrequencies of the super uid or s-modes are found among those of the f and p-modes. For the equation of state that is used, it is shown that the dimensionless frequencies of the p-modes increase with an increase in mass of the neutron star while those of the s-modes decrease with an increase in neutron star mass. The plan of the dissertation is as follows. Chapter 1 gives a short introduction to stellar oscillations and mentions the oscillations of neutron stars. Chapters 2 and 3 provide the general theoretical background of stellar structure and stellar oscillations respectively. Chapter 4 is a review of the equations of state of neutron star matter derived previously in the literature. Chapter 5 provides the method of calculation as well as the results. Chapter 6 provides a discussion of the results. Chapter 7 briefly gives a review of a mathematical framework for fluids that could be used in order to calculate the oscillations in a general relativistic context and then briefly describes the effects of rotation and magnetic fields. Appendix B liststhe source code for the programs used to do the calculations and also explains some of the extra numerical procedures used for the computation.

In this thesis a mathematical model for the combined effects of vortex-induced oscillation and galloping of a square section cylinder in cross flow is examined. The model equations are obtained by simply combining Parkinson and Smith's Quasi-Steady Model for galloping with the Hartlen-Currie model for vortex-induced vibration, which is essentially the same model used by Bouclin in the hydrodynamic case. The semi-empirical model is solved using three popular approximate analytical methods, and the methods of solution are evaluated. The solution of the model is compared with recent experimental data. The methods of solution used are the Method of Van Der Pol, (also called the method of Harmonic Balance), the Method of Multiple Scales, and some results from the Hopf Bifurcation Theory. The Method of Multiple Scales provides the most useful solutions, getting good results even with just the ༠(1) terms, although the next-order terms are necessary for the solution in the resonance regions. The phenomenon of subharmonic resonance, observed in recent experiments, is also observed in the solution of the model equations. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

NOvA is a two detector long-baseline neutrino oscillation experiment using Fermilab's 700 kW NuMI neutrino beam. It studies the disappearance of muon (anti)neutrinos and the appearance of electron (anti)neutrinos in the beam over a distance of 810 km be- tween the detectors. This thesis presents the latest 2020 update of the NOvA neutrino oscillation analysis within the standard model of three neutrinos mixing. With about +50% new data in NuMI neutrino mode (+22% of the total available data) and nu- merous analysis upgrades compared to the previously reported results, the experiment has made over 4σ-significant observation of electron antineutrino appearance in muon antineutrino beam and constrained the oscillation parameters |∆m2 32|, sin2 θ23 and δCP. The text closely depicts the analysis and all its novelties and changes. A detailed inspec- tion is dedicated to the systematic uncertainties and their estimation and validation. Although statistical uncertainties currently dominate in these measurements, under- standing the major sources of systematic uncertainties and their correlations is vital for both the interpretation and precision of the results and for further improvements of the analysis. 1

One possibility for detecting low-amplitude pulsational variations is through gravitational microlensing. During a microlensing event, the temporary brightness increase leads to improvement in the signal-to-noise ratio, and thereby better detectability of pulsational signatures in light curves. We explore this possibility under two primary considerations. The first is when the standard point-source and point-lens approximation applies. In this scenario, dividing the observed light curve by the best-fitted microlensing model leads to residuals that result in pulsational features with improved uncertainties. The second is for transit events (single lens) or caustic crossing (binary lens). The point-source approximation breaks down, and residuals relative to a simple best-fitted microlensing model display more complex behaviour. We employ a Monte Carlo simulation of microlensing of pulsating variables toward the Galactic bulge for the surveys of OGLE and of KMTNet. We demonstrate that the efficiency for detecting pulsational signatures with intrinsic amplitudes of <0.25 mag during single and binary microlensing events, at differences in χ2 of Δχ2 > 350, is $\sim \!50\!-\!60{{\ \rm per\ cent}}$. The maximum efficiency occurs for pulsational periods P ≃ 0.1-0.3 d. We also study the possibility that high-magnification microlensing events of non-radially pulsating stars could be misinterpreted as planetary or binary microlensing events. We conclude that small asymmetric features around light curve peaks due to stellar pulsations could be misdiagnosed with crossing (or passing close to) small caustic curves.

No description available.

Hurricanes are the leading cause of economic loss in the United States, and recent studies have shown that they have increased in intensity. The growth of population and wealth to coastal regions has exacerbated catastrophic losses. The purpose of this study is to examine the role of three modes of natural climate variability as well as hurricane intensification on destructiveness along the Gulf Coast. The study utilized R programming software to create raster grids and evaluate spatial and temporal relationships between intensification, intensity, sea surface temperatures and destructiveness. Destructiveness was synthesized using the Pielke Landsea 2018 (PL18) normalized losses dataset. The principal findings revealed that the Atlantic Multidecadal Oscillation (AMO) has the greatest influence on hurricane intensification and associated damages. The study offers a contribution to research on hurricane intensification and destructiveness associated with natural climate variability and urges stakeholders to dedicate funds for mitigation measures to reduce the vulnerability to Gulf Coast counties.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

This study investigated the effects of ENSO on annual growth rings of pine trees in coastal Alabama. Tree cores from 28 pines were collected in Mobile County and Baldwin County Alabama, and the ring widths of these cores were measured to the nearest 0.001 mm. Tree ring widths were then cross-dated and standardized using standard procedures. The standardized ring width (SRI) was examined to determine if years of strong ENSO activity were evident. Additionally, SRI values were correlated with other climate variables, including temperature, precipitation, and drought. It appears that strong ENSO episodes are not clearly evident in the tree ring record. Additionally, the climate variables showed inconsistent relationships with SRI. It is possible that a positive annual water balance limits the influences of ENSO on tree ring widths. Furthermore, it is suggested that differences in localized tree environments and mesoscale sea-breeze thunderstorms may obscure the impacts of climatic variables.

No description available.