
Melissa, Matthew (Matthew J.)
Populations are subject to mutations conferring beneficial effects, as well as mutations conferring deleterious effects. Even if deleterious mutations occur much more frequently than beneficial mutations, the contribution of deleterious mutations to the overall rate of change of the populationwide mean fitness may be limited, due to the efficient action of selection. However, in particularly rapidly evolving populations, the stochastic accumulation of deleterious mutations may negate a significant fraction of the fitness increments provided by beneficial mutations, or even result in an overall decrease in fitness over time. Here we obtain a constraint on beneficial and deleterious mutation rates and...

Archer, Lucy Elizabeth
In this thesis I made a study of the properties of reactively sputtered ultrathin films of niobium nitride (NbN) and niobium titanium nitride (NbTiN). Using Variable Angle Spectral Ellipsometry (VASE), I found that the optical properties of NbN films appear to have a critical thickness above which the optical parameters stabilize. I also found that the deposition process has better stability over time for thicker films than for thinner ones; that is, when films are deposited weeks apart, the thinner films show more variation in thickness and optical properties than do the thicker films. The data also suggest that the...

Geller, Sarah (Sarah R.)
In this thesis, I have addressed the question of how to calculate the total relativistic mass for a patch of a sphericallysymmetric matterdominated spacetime of negative curvature. This calculation provides the openuniverse analogue to a similar calculation first proposed by Zel'dovich in 1962. I consider a finite, sphericallysymmetric (SO(3)) spatial region of a FriedmannRobertsonWalker (FRW) universe surrounded with a vacuum described by the Schwarzschild metric. Provided that the patch of FRW spacetime is glued along its boundary to a Schwarzschild spacetime in a sufficiently smooth manner, the result is a spatial region of FRW which transitions smoothly to an asymptotically...

CristeaPlaton, Tudor
The realm of the dynamics of bouncing droplets is a rather recent development in physics and mathematics. Just over a decade old, it holds many exciting avenues of exploration. In this thesis, I will present my research on millimetric liquid droplets, which walk across the surface of a vibrating fluid bath through a resonant interaction with their own wave fields. These walking droplets, or 'walkers', exhibit several features previously thought to be peculiar to the microscopic, quantum realm. In particular, walkers in confined circular corrals exhibit a wavelike statistical behaviour similar to that of electrons inside quantum corrals. My results...

Montag, Peter Katsumi
In this thesis, I analyzed the behavior of the plasma instability known as the tearing mode in parameter regimes relevant to magneticallyconfined fusion plasmas. This included a derivation of the relevant equations and a method of solving them using Fourier analysis. This method allowed the derivation of several analytic results and efficient calculation of numeric results about the growth rates and frequencies of the analyzed modes, and demonstrated the existence of a second type of unstable tearing mode related to electron inertia. The results of the analysis of this inertial mode proved consistent with experimental data on the tearing mode...

Sharkoff, Eugene G. (Eugene Gibb)
by Eugene G. Sharkoff.

Mohanmurthy, Prajwal
Under the broad topic of scattering, in this thesis we particularly investigate Lorentz invariance using Compton Scattering at the Compton Polarimeter located in HallC at Thomas Jefferson National Accelerator Facility. The Mississippi State Axion Search, an axion search experiment which uses light shining through a wall technique is described in detail, including its instrumentation, initial tests and future impact. Furthermore, a novel method of detection of solar antineutrinos based on coherent neutrino scattering is described. Additionally, on the instrumentation side, development of a multipurpose beam instrument based on synchrotron light to measure the electron beam polarization, beam profile and intensity...

Allis, William P. (William Phelps), 19011999
by William Phelps Allis.

Bodiya, Timothy Paul
This thesis describes the theory and experimental implementation optomechanically induced transparency utilizing ultra low loss mechanical oscillators and high laser power to achieve extremely strong optical induced transparency effects. This system modifies the light transmission properties of the optical cavity reducing the transmission by a factor of 3 x 10 3 at the highest power levels. A linewidth reduction of 5 x 10 5, from 10 kHz to 20 mHz, has been achieved.

Chudzicki, Christopher A
We present results from two treatment / control experiments in the 8.MReV: Mechanics ReView massive open online course (MOOC) run on edX.org during summer 2014. We compare the efficacy of physics homework problems: (1) traditional physics problems involving many skills, (2) deliberatepractice activities that train individual skills using the draganddrop format, and (3) analogous deliberate practice activities in multiple choice format. Using a common assessment, our results suggest that traditional instruction is more effective than deliberate practice activities cast in the multiplechoice format; comparison of traditional problems and draganddrop deliberate practice is so far inconclusive. Some evidence suggests users prefer...

Ge, Yufei, S.M. Massachusetts Institute of Technology
Trapped ions are a promising approach to quantum computation. This approach uses a qubit state which is the atomic state and quantum motional state of a trapped ion to encode information, and uses laserion interactions to manipulate the qubit state. A major obstacle to the realization of a practical ion trap quantum computer is decoherence. In trapped ion quantum computation experiments, decoherence is dominated by the uncontrolled heating of ion motional states. In this thesis, we present the detailed microfabrication of several series of surface electrode linear Paul traps made from different electrode materials, followed by the ion motional heating...

Murskyj, Mykola
One of the fundamental questions in quantum physics is whether measurements reveal preexisting values. Leggett and Garg derived an inequality that is satisfied by systems featuring both macroscopic realism and noninvasive measurability. The LeggettGarg Inequality places a quantumclassical limit on a linear combination of correlation functions of a series of measurement outcomes. The flavor oscillations of solar neutrinos provide an interesting way to test the LeggettGarg inequality, and on an astrophysical length scale. Beginning as electron neutrinos in the solar core, they undergo the MikheyevSmirnovWolfenstein Effect and exit the sun in either of two mass eigenstates, depending on their energy....

Sullivan, Peter William
Optical timedomain astronomy is in the midst of significant developments due to new instruments, data processing techniques, and space missions. The Kepler mission has identified thousands of exoplanet systems with the transit technique, allowing the first statistical analyses of the exoplanet population. The upcoming Transiting Exoplanet Survey Satellite (TESS) mission will complement Kepler by identifying the brightest transiting exoplanet systems on the sky. These planets will offer the most insight into their radius, mass, and composition. At approximately the same time that TESS launches, the Advanced Laser Interferometer GravitationalWave Observatory (aLIGO) will reach full operation, allowing the detection of gravitational...

Varma, Mukund Madhav
Measurements of twoparticle angular correlations between unidentified charged particles and [phi]mesons are shown over a wide pseudorapidity range ([delta] [eta] < 2) in pPb collisions. The data, collected during 2013 pPb run at a nucleonnucleon centerofmass energy of 5.02 TeV with the CMS detector, corresponds to a total integrated luminosity of aproximately 35nb1. [Phi]mesons are reconstructed via their hadronic decay channel, [phi] > K+K, for high multiplicity events. The observed twoparticle long range correlations are quantified by the secondorder Fourier coefficients (v2) as a function of transverse momentum. The v2 of [phi]mesons is compared to that of other identified particles,...

Lewis, William Hargrove
by William Hargrove Lewis.

Sierchio, Jennifer Marie
In the past, two methods for analyzing data from the Gas Puff Imaging diagnostic on Alcator CMod have been used. One uses temporal and spatial Fourier analysis to obtain wavenumberfrequency spectra, from which a phase velocity is computed [1, 2]. The other is based on timedelay crosscorrelation of successive images used to track the motion of discrete emission structures [3, 4]. Several GasPuffImaging experiments were conducted to obtain data taken using the GPI Phantom Camera. The analysis of and results from these data are discussed in [3]. The results showed that the tracking timedelayestimation technique found poloidal velocity magnitudes in...

Son, Nguyen Thanh
Inflation is a substantial modification to the big bang theory, and supernatural inflation is a hybrid inflation motivated from supersymmetry. In this thesis we carry out a one dimensional numerical simulation to verify the untested analytic approximation of Radall et al. The results show a good agreement for a wide range of parameters. We also propose a new method for calculating density perturbations in hybrid inflation, which shows an excellent agreement with the simulation in one dimension.

Han, Tianheng, Ph. D. Massachusetts Institute of Technology
An ideal spin% kagomé lattice has been a long sought material. This system is characterized by strong magnetic frustration and is a likely candidate for a spinliquid ground state. The spinliquid state was originally proposed to exist in the parent compounds of the high temperature superconducting cuprates as originally proposed by Anderson. However, the lack of ideal samples have hampered experimental tests of the theories. A few years ago, a kagomé lattice material called herbertsmithite (ZnCu3(OH)6Cl2) has been successfully synthesized and studied. Since then, many experiments have been performed which have produced a lot of new guidance for our theoretical...

Tekle, Ephraim Adane, 1974
by Ephraim Adane Tekle.

Williamson, Lyndie Ruth, 1974
by Lyndie Ruth Williamson.