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Willson, Robert MichaelThree-Pion HBT Interferometry at the STAR Experiment
Doctor of Philosophy, The Ohio State University, 2002, Physics
During the first year of Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory, 130 A·GeV collisions were observed and analyzed in the hopes of finding some signal of a new state of matter. This new state of matter, the quark-gluon plasma or QGP, can be described as a deconfined state of freely interacting quarks and gluons within a certain volume of the collision fireball. Since the lifetime and size of this state are both small (<10 fm) a direct observation is not possible. Instead, many different indirect methods are used in order to extract specific information about the source from the final state particles which are eventually detected. One of these methods, HBT interferometry, provides a means of determining the spatial extent and dynamical properties of the freeze-out region, after which the final-state particles have stopped interacting, by examining correlations between pairs of particles within an event. Two-particle interactions include those caused by the Coulomb and strong nuclear forces, however it is the quantum statistics governing the behavior of identical particles which leads to a relationship between the spatial properties of the source and the momentum correlations between pairs of particles. In this thesis, one of the central assumptions of HBT interferometry is examined, that of the chaoticity of the freeze-out region. Particles emitted from the freeze-out region carry an intrinsic quantum particle production phase, much like the initial phase of an electromagnetic wave. If these phases are random for each outgoing particle, the source is said to be fully chaotic. Using three-particle HBT interferometry, it is possible to obtain a measure of this chaoticity, and in so doing verify the results of two-particle HBT.

Committee:

Thomas Humanic (Advisor)

Subjects:

Physics, Nuclear

Keywords:

HBT Interferometry; Three Pion Interferometry; Relativistic Heavy Ion Collisions; STAR Experiment; Silicon Vertex Tracker

López Noriega, MercedesPion interferometry in AuAu collisions at a center of mass energy per nucleon of 200 GeV
Doctor of Philosophy, The Ohio State University, 2004, Physics

Quantum Chromodynamics predicts a phase transition from a state formed by hadrons to a plasma of deconfined quarks and gluons, the Quark Gluon Plasma, as a the energy density exceeds a critical value. This deconfined phase is believed to be the one in which the early universe existed in a time-scale ∼ 10-5 s after the Big Bang.

Ultrarelativistic Heavy Ion Collisions, like the ones that take place at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, reach energy densities above the critical value creating a deconfined phase of quarks and gluons that can be studied at the laboratory. This gives us the opportunity to study a phase of matter in the deconfined region of QCD, the properties of the strong interaction, the formation of hadronic matter and the interaction between hadrons.

In the analysis presented in this thesis, the dynamical evolution of the particle emitting source and its space-time structure at freeze-out is studied using the two particle intensity interferometry technique. The expansion of the source is also studied. We find indications that this expansion may be caused by the initial pressure gradient generated in the initial stages of the collision through particle rescattering in a very dense medium.

Committee:

Michael Lisa (Advisor)

Subjects:

Physics, Nuclear

Keywords:

Relativistic Heavy Ion Collisions; Two particle intensity interferometry; Pion intensity interferometry; HBT; STAR; RHIC

Stafford, Samuel JA Search for Ultra-high Energy Cosmic Neutrinos: Data Analysis of the Antarctic Impulsive Transient Antenna, Third Flight
Doctor of Philosophy, The Ohio State University, 2017, Physics
Ultra-high Energy (UHE) neutrinos represent an increasingly important messenger in astronomy and astrophysics. The Antarctic Impulsive Transient Antenna (ANITA) experiment campaign utilizes a balloon-borne phased antenna array to detect coherent Cherenkov radio-frequency pulses induced by UHE neutrinos interacting with the Antarctic ice. We analyzed the data from the third ANITA flight (ANITA-III) for evidence of Ultra-high energy neutrinos by augmenting interferometric methods used in analyses of previous ANITA flights. Continuous wave (CW) radio content from ground-based Antarctic habitations and orbiting geostationary communications satellites interferes with the detection and analysis of neutrino-induced radio signals; we developed circular polarization analysis methods to facilitate improved rejection of false positives induced by satellite CW. We also developed new methods of calculating signal-to-noise ratio (SNR) of event waveforms, and enhanced event localization by applying a probability distribution function (PDF) based on the measured resolution of our interferometry. We developed a final linear discriminant cut for rejecting thermal and anthropogenic signals by dividing the continent into equal-area bins and optimizing the cut to each individual bin, so as to obtain the strongest possible the upper limit on cosmic neutrino flux.

Committee:

James Beatty, PhD (Advisor); John Beacom, PhD (Committee Member); Amy Connolly, PhD (Committee Member); Richard Kass, PhD (Committee Member)

Subjects:

Astrophysics; Physics

Keywords:

neutrinos; interferometry; radio; antarctica; ANITA; antarctic impulsive transient antenna; ultra high energy neutrinos; astroparticle physics; askaryan;

Sander, Zachary HugoHeat Transfer, Fluid Dynamics, and Autoxidation Studies in the Jet Fuel Thermal Oxidation Tester (JFTOT)
Master of Science (M.S.), University of Dayton, 2012, Mechanical Engineering
Modern military aircraft use jet fuel as a coolant before it is burned in the combustor. Prior to combustion, dissolved O2 and other heteroatomic species react with the heated fuel to form insoluble particles and surface deposits that can impair engine performance. For safe aircraft operation, it is important to minimize jet fuel oxidation and resultant surface deposition in critical aircraft components. The Jet Fuel Thermal Oxidation Tester (JFTOT) is a thermal stability test that measures the tendency for fuel to form such deposits and delivers a pass/fail grade for each fuel tested. However, the extent of oxidation and the corresponding deposition occurring in the JFTOT is not fully understood. A JFTOT Model Mark II was modified to include a bulk outlet thermocouple measurement and a downstream oxygen sensor to measure bulk oxygen consumption. Experimental results show a direct relationship between the bulk outlet temperature and JFTOT setpoint temperature with the bulk outlet less than the setpoint temperature. Several fuels were also tested at varying setpoint temperatures with complete oxygen consumption by 320°C and a wide range of oxygen consumption from 10-85% at 260°C. Due to the complex fluid flows in the JFTOT, computational fluid dynamics (CFD) was used to model the heat transfer and fluid flow. A three-dimensional simulation showed considerable recirculation within the JFTOT due to buoyancy effects from gravity and resulted in complex residence time behavior. In addition, CFD simulations performed with a pseudo-detailed chemical kinematic mechanism showed an under prediction in both oxidation and deposition for similar fuels tested experimentally but yielded bulk outlet temperature predictions of less than 2% error. Simulations of deposition were of the right order of magnitude and matched the deposit profile of comparable experimental ellipsometry data.

Committee:

Steven S. Zabarnick, PhD (Committee Co-Chair); Jamie S. Ervin, PhD (Committee Co-Chair); James T. Edwards, PhD (Committee Member)

Subjects:

Aerospace Engineering; Chemical Engineering; Chemistry; Energy; Engineering; Fluid Dynamics; Mechanical Engineering; Petroleum Engineering

Keywords:

JFTOT;CFD; heat transfer; oxidation; autoxidation; deposition; ellipsometry; jet fuel thermal oxidation tester; oxygen consumption; FT; fischer tropsh; hrj; jp-8; jet a-1; thermal stability; fluid mechanics; astm d3241; flir; interferometry; udri

Huang, Ching-YaoMeasurement and Comparison of Progressive Addition Lenses by Three Techniques
Master of Science, The Ohio State University, 2011, Vision Science

Purpose. To measure and evaluate variations in spherical power, astigmatism and higher-order aberrations (HOAs) in progressive addition lenses (PALs) by three techniques and to compare their differences.

Methods. Two experiments are described. The first measured and evaluated the optical properties of six PALs with adds from +1.25 D to +2.75 D by the Hartmann-Shack aberrometry. The second experiment compared the Hartmann-Shack aberrometry with the other two methods: Moiré interferometry and surface profilometry, on five PALs (plano distance power, +2.00 D add) under the condition of lateral displacement of lens. A Hartmann-Shack wavefront sensor (HSWFS) on a custom-built optical bench was used to capture and measure the spatially resolved wavefront aberrations of PALs. A Rotlex Class Plus lens analyzer operating as a Moiré interferometer was used to measure the spherical and cylindrical powers of PALs. A coordinate measuring machine (CMM) was used to measure front and back surface heights of PALs which were converted to surface powers and compared with the two optical measurement methods. The measurement data from the HSWFS, Rotlex, and CMM methods were analyzed and compared using custom MATLAB programs in terms of spherical equivalent power (M), cylindrical power (J), and HOAs. Pupil sizes up to a maximum of 4.5 mm were possible with the HSWFS system. Matrix techniques were used to scale Zernike expansion coefficients to different pupil sizes. Color contour plots of M, J, and HOAs in all PALs were then generated.

Results. As expected, in a typical PAL, spherical power increases along the progressive corridor, and unwanted astigmatism increases laterally from the vertical midline. Evaluation of six PALs from the HSWFS measurements indicates that the greater the add power, the greater the rate of power change and the unwanted astigmatism, but the narrower the progressive corridor width. Of the HOAs, 3rd order aberrations, coma and trefoil, are prominent at the progressive corridor area and around the near power zone. The impact of these HOAs is attenuated at smaller pupil sizes, which is consistent between the measurement and theoretical calculation. Comparison of three measurement methods shows good agreement for the optical properties of the five PALs. There are no meaningful differences in M and J among the HSWFS, Rotlex, and CMM methods. There are also no meaningful differences in the root mean square (RMS) of HOAs between the HSWFS and CMM methods.

Conclusions. The HSWFS method shows great potential for the measurements of the optical properties of PALs. It demonstrates that higher add power is associated with higher rate of power change and higher unwanted astigmatism, but narrower progressive corridor width. The 3rd order aberrations dominate HOAs and occur along the corridor and around the near zone, and are greatly affected by the pupil size. Comparisons of spherical equivalent power, cylindrical power, and HOAs on PALs indicate that the non-optical method, CMM, can be used to evaluate the optical properties of a PAL through front and back surface height measurements. In conclusion, the three measurement methods, HSWFS, Rotlex, and CMM, are comparable.

Committee:

Mark A. Bullimore, PhD (Committee Chair); Thomas Raasch, PhD (Committee Member); Allen Y. Yi, PhD (Committee Member)

Subjects:

Optics

Keywords:

progressive addition lenses; ophthalmic optics; wavefront aberrations; Hartmann-Shack aberrometry; Moir&233; interferometry; surface profilometry; coordinate measuring machine; Rotlex; freeform; Zernike polynomials

Wells, Randall CAzimuthal Dependence of Pion Interferometry in Au+Au Collisions at a Center of Mass Energy of 130AGeV
Doctor of Philosophy, The Ohio State University, 2002, Physics

The study of two-pion Bose-Einstein correlations provides a tool to extract both spatial and dynamic information regarding the freeze-out configuration of the emission region created in heavy ion collisions. Noncentral heavy ion collisions are inherently spatially and dynamically anisotropic. The study of such collisions through the φ dependence of the HBT radii, Rij2 , relative to the event plane allows one to observe the source from all angles, leading to a richer description of the interplay between geometry and dynamics.

The initial heavy ion running of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory provided Au + Au collisions at 130GeV. The focus of the heavy ion program at RHIC is the search for a new state of strongly interacting matter, the quark gluon plasma (QGP). STAR is a large acceptance detector at RHIC with azimuthal symmetry, allowing the study of a large variety of observables on an event-by-event basis to provide a better characterization of the freeze-out conditions. The detector geometry for the first year’s data consisted of a time projection chamber (TPC) immersed in a 0.25T magnetic field oriented along the symmetry axis to provide identification of particles with transverse momenta pT ≥100MeV/c.

The focus of this dissertation is the study of the φ dependence of the transverse HBT radii from ππ and π+π+ correlations in non-central collisions. 2nd order oscillations are observed in all transverse radii (Ro2 (φ), Rs2 (φ), and Ros2 (φ)). The oscillations are found to be consistent in phase and magnitude to both RQMD and hydrodynamic predictions, yet both models (over)underpredict (Ro2)Rs2 whose relative size indicates a short emission time-scale. A modified blast wave prameterization is successful at reproducing a variety of observables at RHIC (i.e. particle spectra, v2 (pT), Rij2 (pT), and Ro,s,os2 (φ)) with a univeral set of freeze-out parmeters. The results describe a freeze-out geometry extended out-of-plane indicative of a short source life-time.

Committee:

Michael Lisa (Advisor)

Subjects:

Physics, Nuclear

Keywords:

Nuclear Physics; Azimuthal Pion Interferometry; Relativistic Heavy Ion Physics

Wells, Randall C.Azimuthal dependence of pion interferometry in gold+gold collisions at a center of mass energy of 130 AGeV /
Doctor of Philosophy, The Ohio State University, 2002, Graduate School

Committee:

Not Provided (Other)

Subjects:

Physics

Keywords:

Interferometry

Siemer, Kyle WYou've got that Sinking Feeling: Measuring Subsidence above Abandoned Underground Mines in Ohio, USA
Master of Science, University of Toledo, 2013, Geology
As a result of more than 200 years of underground coal mining, many urbanized areas throughout Ohio, USA, are susceptible to land subsidence. Approximately 6,000 abandoned underground mines (AUMs), with a footprint of roughly 800mi2 of undermined land, have been identified by the Ohio Department of Natural Resources Geologic Hazards Division (ODNR GHD), with further estimates of as many as 8,000 AUMs beneath Ohio’s legacy coal mining region. Previously, efforts to monitor subsidence have been sparse or temporally discontinuous, leading to an incomplete understanding of how subsidence in these areas occurred. We apply a robust alternative to traditional land surveying using Persistent Scatterer (PS) radar interferometry, a refinement to traditional radar interferometry techniques. Wellston, OH, which continues to be an unstable AUM area based on subsidence damage claims, was investigated because the downtown area rests above several unstable ~100 year old room-and-pillar mines at an average depth of only 10 meters, overlain by a thin layer of unconsolidated material, a more significant unit of limestone, intermittent mudstone, and sandstone. Since 1993, 8 separate subsidence claims have been confirmed by state agencies in Wellston, which have cost more than $250,000. 18 ERS-1 and ERS-2 SAR images were acquired over Wellston, Ohio covering April 1992 and February 2000, and used to monitor subsidence over that time period. Resulting PS based displacement maps show ground movement for the town. In areas of higher numbers of damage claims at the surface, the movement is generally non-uniform. In areas with uniform ground movement, damage claims are minimal. As the time since abandonment of AUMs continues to increase, subsidence related damages are expected to increase, reinforcing the need for a predictive subsidence model. Using the georeferenced AUM maps, water well logs, and geologic information for Wellston, a multivariable GIS model was developed in order to predict areas at most risk to future subsidence hazards. Variables in the model included, (1) void space, (2) thickness of mine overburden (3) thickness of unconsolidated overburden, (4) presence or absence of pillars, and (5) proximity to mined out areas, (6) standard deviation of PS results. Results from the GIS model agree well with the current subsidence claims, and high magnitude subsidence determined via PS analysis

Committee:

Richard Becker (Advisor); Mark Camp (Committee Member); Donald Stierman (Committee Member)

Subjects:

Geographic Information Science; Geology; Mining; Remote Sensing

Keywords:

SAR interferometry; Persistent scatterers; ERS-1/2; Mine subsidence; Remote sensing; GIS

Oliveira, Rafael Figueiredo deEvaluation of Proposed Natural Corrosion Inhibitors for X-52 Carbon Steel in Ethanol Media
Master of Science in Engineering, University of Akron, 2015, Chemical Engineering
This work describes the testing performed for corrosion control actions for X-52 carbon steel in ethanol media by using inhibitors, the following compounds were included: linalyl formate, linalyl acetate, linalyl butyrate, citronellyl acetate and 1-pentylallyl acetate. The experiments were performed in an electrochemical 3 electrode system with an X-52 steel rotating cylinder electrode (RCE) with rotational speed adjusted to 130 RPM. The system was deaerated by bubbling nitrogen gas into the ethanol solution. The Electrochemical Impedance Spectroscopy (EIS) technique was used to characterize the metal/electrolyte interface. Experimental testing was performed in anhydrous ethanol solution with 5 mM or 10 mM of one inhibitor. Surface analyses for the corroded surfaces were obtained by scanning electron microscopy (SEM) and White light interferometry (WLI). The results suggest that linalyl formate promotes the highest corrosion inhibition efficiency at 10 mM, followed by citronellyl acetate and linalyl butyrate. At this concentration, 1-pentylallyl acetate and linalyl acetate have not promoted corrosion inhibition. At a concentration of 5 mM, linalyl formate, linalyl acetate and linalyl butyrate promoted high inhibition efficiencies during the first hours but none was able to promote a longer protection than one day, possibly due to chemical degradation, chemical reactions and/or reduced surface coverage. The linalyl formate is considered the best chemical for inhibition purposes, especially at the concentration of 10 mM.

Committee:

Homero Castaneda-Lopez, Dr. (Advisor); Hongbo Cong, Dr. (Committee Member); Qixin Zhou, Dr. (Committee Member)

Subjects:

Chemical Engineering; Materials Science

Keywords:

corrosion inhibitors; X52 steel; ethanol; linalyl formate; linalyl acetate; linalyl butyrate; citronellyl acetate; 1-pentylallyl acetate; electrochemical impedance spectroscopy; EIS; scanning electron microscopy; SEM; white light interferometry; WLI

Willson, Robert Michael.Three-pion HBT interferometry at the STAR experiment /
Doctor of Philosophy, The Ohio State University, 2002, Graduate School

Committee:

Not Provided (Other)

Subjects:

Physics

Keywords:

Interferometry;Heavy ion collisions

Coker, CarlThe Frequency of Binary Companions Around KELT Planet Host Stars
Doctor of Philosophy, The Ohio State University, 2017, Astronomy
I conducted a search for binary companion stars around 10 stars hosting hot Jupiter exoplanets from the KELT survey and a large comparison sample of stars shown by KELT to not host transiting hot Jupiters. The goal of the survey was to determine whether hot Jupiter hosts are more likely to have stellar companions than the general population of stars. The primary stars are bright (7.5 < V < 11) and of similar distance from Earth (100 < d < 300 pc). In this dissertation, I present the results of my observations using the Differential Speckle Survey Instrument (DSSI) on the 3.5-meter WIYN telescope and LMIRCam on the Large Binocular Telescope Interferometer (LBTI), on the 2x8.4-meter Large Binocular Telescope. Across both instruments, I observed 10 of the 16 KELT planet hosts which are visible from the Northern Hemisphere and 71 comparison stars, discovering seven new potential companions and re-observing four previously known possible binary systems, as well as one confirmed binary system. I estimate the distances and masses of each binary system, as well as place lower limits on their orbital periods. I also provide an estimate of the chance alignment probability for our observed candidate binaries. I find that the KELT planet hosts have a stellar companion fraction of 50+-8:1% compared to 36.8+-6.3% for the comparison sample. This is a 1.6-sigma excess, indicating that hot Jupiter hosts are slightly more likely to have stellar binary companions.

Committee:

Scott Gaudi (Advisor); Richard Pogge (Advisor); Paul Martini (Committee Member)

Subjects:

Astronomy

Keywords:

exoplanets; hot Jupiters; astronomical instrumentation; speckle interferometry; adaptive optics; binary stars

Ramamoorthy, PadmapriyaHIGH MOLECULAR WEIGHT TEAR PROTEINS AND OCULAR SURFACE MUCINS IN CONTACT LENS-RELATED DRY EYE
Doctor of Philosophy, The Ohio State University, 2011, Vision Science

Purpose

To assess high molecular weight (HMW) tear proteins, mucins, inflammatory proteins and contact lens wettability in contact lens wearers with dry eye in comparison to normal contact lens wearers.

Methods

The study was a cross-sectional study including 100 healthy, daily (non-overnight), experienced soft contact lens wearers (50 normal and 50 CLDE). Eligible subjects were classified into normal/ CLDE groups based on Contact Lens and Dry Eye Questionnaire scores, tear break up time (TBUT, normal ≥ 7 seconds, CLDE < 7 seconds) and difference between total and comfortable daily lens wear hours (normal < 2, CLDE ≥ 2).

Up to 5 µl unstimulated basal tear samples and wash samples from each eye were collected for lab analyses. HMW tear proteins and mucins in the ocular surface were studied using gel electrophoresis, liquid chromatography-mass spectrometry, Western blotting and periodic acid Schiff (PAS) staining. Tear inflammatory proteins were analyzed using quantibody arrays. Imaging interferometry was used to assess in vivo contact lens wettability.

Results

The CLDE group demonstrated higher grades of papillary conjunctivitis, conjunctival redness and folds (p < 0.0001 for all listed), blepharitis and meibomian gland dysfunction (p = 0.002), conjunctival and corneal staining (p = 0.002 and 0.005). The average TBUT was higher in the normal group (8.02 ± 1.03 and 4.15 ± 1.04 seconds, p < 0.0001). The in vivo contact lens wettability was found to be significantly lower in the CLDE group at all time points analyzed (p < 0.0001).

Two HMW tear bands were observed at 450 kDa and 300 kDa. The band area of the 450 kDa HMW band was significantly greater in CLDE samples (p = 0.003). LC-MS analyses of the HMW bands revealed immunoglobulin fragments, cytokeratins and common tear proteins. Several of these were unique or different in abundance between the subject groups.

Three MUC4 positive bands were observed at ~433, 271 and 52 kDa. Two MUC5AC bands were observed at ~460 and 250 kDa. MUC4/ MUC5AC band characteristics were not different between normal and CLDE samples. PAS-positive glycoprotein bands were observed at 440 kDa and 70 kDa; the latter was more intense in the normal group (p = 0.002).

Of the 50 tested inflammatory proteins, 21 were increased 2-fold or more in the CLDE group. These included IL-4, IL-7, IL-8, IL-12 p70, IL-13, IL-15, GRO, GCF (p < 0.005 for all listed), IL-1b (p=0.006) and IL-11 (p=0.008). EGFR, eotaxin, GCF, GRO, HB-EGF, IFNg, IL -1ra, IL-2, IL-5, IL-6, IL-6 sR, IL-12 p40, MCSF were also elevated in CLDE (p < 0.04).

Conclusions

Characterization of the HMW proteome and differences in immunoglobulins, cytokeratins and tear proteins detected between normal and CLDE subjects offer insight into the potential relevance of HMW proteins in CLDE pathophysiology.

MUC4 and MUC5AC were not different between normal contact lens wearers and those with CLDE. CLDE was also characterized by differences in the lower molecular weight glycoprotein band. Numerous inflammatory markers including a majority of interleukins were elevated in CLDE, indicating a significant role of inflammation in CLDE.

Committee:

Jason Nichols, OD, MPH, PhD (Advisor); Heather Chandler, PhD (Committee Member); Karla Zadnik, OD, PhD (Committee Member)

Subjects:

Bioinformatics; Ophthalmology

Keywords:

Contact lens; dry eye; Tear proteomics; High molecular weight proteins; Mucins; Tear glycoproteins; Imaging interferometry

Hamilton, Andrew J.Plasma Property Estimation from Dual-Wavelength Interferometry
Master of Science in Engineering (MSEgr), Wright State University, 2017, Electrical Engineering
Diagnostics are necessary for measurement of plasma parameters such as electron, ion and atomic densities, electron temperature, plasma expansion velocity and spatial resolution of density gradients. These parameters play a critical role in defining how a plasma will interact with electromagnetic radiation. For example, the plasma black-out phenomenon occurs when electromagnetic waves are at frequencies below the plasma frequency, where plasma frequency is a function of electron density. Wave propagation diagnostics can improve understanding of a plasma when measurement supports parameter estimation. In this report, the dual-wavelength interferometry method provides a single diagnostic capability to measure plasma expansion velocity, atomic density and electron densities. Using a laboratory plasma created with wire-ablation pulsed-power techniques and the Sarkisov model, electron and atomic densities are estimated for copper and aluminum plasmas.

Committee:

Michael Saville, Ph.D., P.E. (Advisor); Amit Sharma, Ph.D. (Committee Member); Vladimir Sotnikov, Ph.D. (Committee Member)

Subjects:

Electrical Engineering; Physics

Keywords:

interferometry; plasma

Kimball, Samuel H.Evaporation is the Primary Mechanism of Tear Film Thinning
Master of Science, The Ohio State University, 2009, Vision Science
The purpose of this study was to determine the contribution of evaporation in the thinning of the pre-corneal tear film. The human tear film is essential to the optical and physiological function of the eye. A malfunctioning tear film can be visually disruptive as well as cause damage to the ocular surface. Dry eye disease is an ocular surface disorder that is essentially a manifestation of a faulty tear film. Dry eye disease represents a significant public health concern and a better understanding of the mechanisms involved in the eradication of the tear film will be needed in order to better treat and manage this significant disease. There are three possible mechanisms of tear film thinning and they include absorption (inward flow), tangential flow, and evaporation (outward flow) of the tears. Previous research, designed to establish the contribution of each of the three proposed mechanisms of tear film thinning, has led to disagreement as to the significance of evaporation or outward flow in the thinning of the human tear film. This study was designed to discover the contribution of evaporation in the thinning of the pre-corneal tear film. Tear thickness values and tear film thinning rates were gathered using spectral interferometry from the right eye of 39 subjects with a mean age of 30.0 ± 9.5 years. Tear film data was gathered under two differing conditions for each subject: open-air and airtight goggles. Two separate recordings of the tear film were first made given the open-air condition then two recordings were made for subjects wearing the airtight goggles. Each subject also completed an Ocular Surface Disease Index (OSDI) questionnaire. Data analysis revealed that the mean initial thickness for subjects under open-air conditions was 3.46 ± 0.83 µm compared to 3.54 ± 0.83 µm for subjects wearing goggles (p = 0.53). The mean tear film thinning rate for subjects in open-air was 3.53 ± 4.12 µm/min and -0.16 ± 1.78 µm/min for the same subjects wearing airtight goggles. The mean OSDI score was 10.8 ± 7.1, with four subjects being classified as dry eye (OSDI > 22). A significant reduction in the tear film thinning rate is seen when evaporation is controlled with airtight swimming goggles. In fact on average the tear film thinning rate is reduced to nearly zero when simulating a non-evaporative environment. This suggests that evaporation is the primary means by which the tear film thins. The reason for the contradictory evidence put forth in the literature concerning the contributions of the three proposed mechanisms of tear film thinning may be explained by the difference in testing methodology. It appears conclusive from this current study data that evaporation is the primary mechanism of tear film thinning.

Committee:

Jason Nichols, PhD, OD, MPH (Advisor); Kelly Nichols, PhD, OD, MPH (Committee Member); Ewen King-Smith, PhD (Committee Member)

Subjects:

Ophthalmology

Keywords:

tear film; dry eye; evaporation; tear film thinning; interferometry; mechanisms of tear film thinning

Cheng, Yan Don

Underwater acoustic imaging: Image reconstruction using speckle interferometry.

Master of Science (MS), Ohio University, 1994, Electrical Engineering & Computer Science (Engineering and Technology)

The objective of this thesis is to study a new technique to underwater acoustic imaging system to obtain high resolution, high contrast images through turbulence. Our technique, which incorporates classic speckle interferometry with the spatial bispectrum, is based on imaging procedures developed by optical astronomers. A sensor array is used to perform imaging by decomposing the image into a Fourier series. The simulation results show that our technique can be used to estimate the magnitude and phase spectrum of the Fourier series coefficients.

Committee:

John Tague (Advisor)

Keywords:

Underwater acoustic imaging; Image reconstruction; Speckle interferometry

Bekele, SelemonNeutral kaon correlations in Au-Au collisions at center of mass energy of 200 GeV per nucleon pair
Doctor of Philosophy, The Ohio State University, 2004, Physics
A few microseconds after the Big Bang, the universe is believed to have existed in the form of a plasma composed of strongly interacting particles known as quarks and gluons. Although the quarks and gluons behave as asymptotically free particles in a Quark Gluon Plasma (QGP), free quarks and gluons have never been discovered in the laboratory. Experiments at the Relativistic Heavy Ion Collider (RHIC) aim to create conditions similar to the early universe by colliding heavy ions at the highest energies possible in the hope of observing a phase transition from a QGP into hadronic degrees of freedom. The response of the space time structure of the hot reaction zone created in a heavy ion collision to a phase transition is one of the many observables being studied at RHIC. Making use of the techniques of two particle intensity interferometry, also known as the HBT effect, the RHIC experiments are studying the space-time structure and dynamical properties of the region from which particles are emitted. A large spatial size and long duration of particle emission are the predicted signals for a phase transition from a QGP to a hadronic phase. In this thesis we present results on the first measurement of one dimensional K0s K0s interferometry by the STAR experiment at RHIC in central (small impact parameter) Au-Au collisions at center of mass energy of 200 GeV per nucleon pair. The λ parameter, which is a measure of the sources chaoticity, is found to be consistent with unity confirming the fact that the source is mostly chaotic as measured by STAR using three particle correlations. Without taking into account the effect of the strong interaction, the invariant radius Rinv is found to be large for the mean transverse mass Mt of the pair, which is about 980 MeV/c, compared to expectations from charged pion correlations at the same Mt . Including the effect of the strong interactions makes the radius parameter for the K0s K0s system fall within the charged pion Mt systematics. Our result serves as a valuable cross-check of charged pion measurements which are mainly affected by contributions from resonance decays and final state interactions. This is also an important first step towards a full three dimensional analysis of neutral kaon correlations as high statistics data from RHIC will be available in the near future.

Committee:

Thomas Humanic (Advisor)

Subjects:

Physics, Nuclear

Keywords:

HBT interferometry; Neutral kaons

Abeywickrema, Haburugala Vithanage Ujitha A.Applications of Induced Gratings in Nonlinear Media
Doctor of Philosophy (Ph.D.), University of Dayton, 2015, Electro-Optics
Materials exhibiting effective nonlinearity through refractive index modulation at relatively low optical powers can be exploited for various applications. Examples of such materials include liquids where the refractive index is modified through heating, and photorefractives where the refractive index modulation is caused by the induced space charge field due to optically generated charges and their redistribution. Optical probing techniques of these and related effects include digital holography, holographic interferometry, and diffraction. First, the effect of self-phase modulation of a focused laser beam in a thermal medium such as a liquid is studied using a low power probe beam. Beyond self-phase modulation, thermal blooming occurs, due to bubbles generated in the liquid. These bubbles are characterized using the same probe and digital holography. An application of these bubbles to nanoparticle agglomeration and transport for drug delivery systems is proposed. Next, the use of recording materials such as photorefractive lithium niobate for implementing real-time phase shifting holographic interferometry is examined in detail. Holographic interferometry is a convenient tool for 3D characterization of deformations of an object. The hologram of an object is first written in the material using a reference beam, and then read out by the same reference beam and light from the deformed object. It is shown that the use of both Bragg and non-Bragg orders during conventional two-beam coupling in a photorefractive material facilitates the simultaneous generation of phase shifts necessary for this type of holographic interferometry. In certain applications involving liquid crystals, the spatial modulation of the director axis can yield improved energy coupling in hybrid liquid crystal – photorefractive devices. Nanoscale engineering of the director axis is possible using the surface corrugation in photorefractives induced by the space charge field through the piezoelectric effect. This surface corrugation is characterized by monitoring the diffraction of a probe beam from the surface of the photorefractive material, taking care to eliminate any Fabry-Perot effects and diffraction from the volume grating in the material.

Committee:

Partha Banerjee, Dr. (Committee Chair); Joseph Haus, Dr. (Committee Member); Andrew Sarangan, Dr. (Committee Member); Sergei Lyuksyutov, Dr. (Committee Member); Georges Nehmetallah, Dr. (Committee Member)

Subjects:

Engineering; Optics

Keywords:

Digital Holography; Holographic Interferometry; Photorefractive Materials

Mulaka, Brahmananda ReddyDEVELOPMENT OF A METHOD TO EVALUATE WRINKLING TENDENCY OF INK-JET PAPERS
Master of Science, Miami University, 2005, Paper Science and Engineering
This thesis presents the development of an apparatus and method to characterize the propensity of papers to form wrinkles in commercial ink-jet printing. An apparatus was developed to apply ink to the paper and then capture the dynamic features of wrinkle development using Shadow Moiré fringe technique and quantify the severity of wrinkling. The developed techniques enable the study of structural and manufacturing variables of the ink-jet papers that affect the severity of wrinkling. A parametric study was carried out to evaluate the influence of specimen dimensions, width of inked region, and tensile load on wrinkling severity. From the fringe images, a set of wrinkle parameters were determined. Finally, twelve different commercial ink-jet papers were studied using the test conditions determined from the parametric study. The proposed method provides a reasonable laboratory technique to evaluate wrinkle tendency of papers.

Committee:

Douglas Coffin (Advisor)

Keywords:

Surface Topography; Shadow Moir&233;; Ink-jet papers; Ink-jet Printing; Dimensional Stability; Wrinkles; Cockle; Interferometry; Ronchi plate; Continuous Ink-jet

Zemba, Michael JSite Characterization of Phase Instability via Interferometer Measurement
Master of Science in Engineering, University of Akron, 2013, Electrical Engineering
Single-dish reflector antennas are often used for their ability to produce a highly directive (narrow beam) radiation pattern which increases in directivity as the diameter of the reflector increases. However, as reflectors grow larger in the pursuit of more directivity, they become more expensive and unwieldy to construct, maintain, and operate. A more practical solution is to employ an array of elements which are smaller individually, but which can yield similar or better gains when arrayed together. However, one trade-off associated with this approach is that antenna arrays are subject to losses introduced by atmospheric turbulence. Inhomogeneous cells of water vapor in the troposphere change the refractivity of the air along the path of the propagating wave, distorting the wavefront and introducing a phase error between the elements of the array. These losses are stochastic and site-dependent. Techniques have been developed over the past several decades to compensate for such losses on the receiving end, but uplink arraying remains challenging as it requires prediction of atmospheric conditions to effectively compensate the signal before transmitting. This is especially true at higher frequencies such as Ka-band given that atmospheric phase noise increases with frequency. Thus, a critical first step in system planning is to determine the losses a particular array configuration will experience based on the phase statistics of a given site. To this end, NASA Glenn Research Center has deployed site test interferometers to three ground-station sites with the intent to characterize their phase instability ahead of upgrades to Ka-Band operation. The sites to be studied are Goldstone, California; White Sands, New Mexico; and the island of Guam. Using three years of data collected from these campaigns, the primary goal of this thesis is to develop a thorough characterization of the phase statistics of each site which may then be used to determine the sites’ suitability for uplink arraying. In addition, a secondary goal is the development of the data analysis software suite that was used to process the data, which it is hoped will facilitate easy analysis of future sites for system designers.

Committee:

Nathan Ida, Dr. (Advisor); Igor Tsukerman, Dr. (Committee Member); Subramaniya Hariharan, Dr. (Committee Member)

Subjects:

Aerospace Engineering; Electrical Engineering; Electromagnetics; Electromagnetism; Engineering

Keywords:

Antenna Arrays; Phase Noise; Atmospheric Phase Instability; Propagation Measurements; Interferometry; NASA; Ka-Band; Radio Frequency; Electrical Engineering; Electromagnetics; Antennas; Propagation; Site Test Interferometer

Yang, RuiCoupling Two-Dimensional (2D) Nanoelectromechanical Systems (NEMS) with Electronic and Optical Properties of Atomic Layer Molybdenum Disulfide (MoS2)
Doctor of Philosophy, Case Western Reserve University, 2016, EECS - Electrical Engineering
The discovery of two-dimensional (2D) materials has attracted tremendous interest and led to a great deal of investment due to their unique properties that are not present in three-dimensional (3D) or one-dimensional (1D) materials. Though graphene as the flagship 2D material has been extensively studied, it is a semimetal without a natural bandgap, and the difficulties in creating a useful bandgap has limited its applications in logic circuits, photonic devices and tunable devices. 2D semiconductors such as molybdenum disulfide (MoS2) compensate for graphene because they have a natural sizable bandgap, and thus can largely extend the applications of 2D materials. In order to fully exploit the distinct properties of these 2D semiconductors toward advantageous performance as applicable devices, it would be ideal to synthetically consider the electronic, mechanical, and optical properties of these materials. While MoS2 field-effect transistors (FETs), nanoelectromechanical systems (NEMS), and optoelectronic devices have been demonstrated, there are still numerous problems that need to be solved before applying the devices for sensing, computing, and communication applications that require high performance (sensitivity, reliability, responsivity, etc.). In this dissertation, state-of-the-art studies of MoS2 electronics are first introduced and surveyed. The electrical breakdown limit of MoS2 FETs is investigated because it determines the current carrying capability and failure modes, which are critical for integrated circuit applications. A completely-dry transfer method combined with vacuum thermal annealing is developed to fully harness the intrinsic properties of MoS2 without inducing residue on the surface. Then the mechanical properties and devices of MoS2 are presented. The first MoS2 nanomechanical resonator on a flexible PDMS substrate that is tolerant to a large amount of bending and straining is demonstrated, showing promise for flexible and foldable electronics. The temperature dependence of MoS2 resonators is also studied. Finally, the coupling of electrical and mechanical properties of MoS2 are explored using the first all-electrical readout of 1-, 2-, 3-layer MoS2 NEMS resonators, with the thickness confirmed with both Raman and photoluminescence (PL) characterization. The devices take the form of vibrating-channel transistors, with multimode resonances highly tunable by the gate voltage, which holds promises and intriguing potential for real-time sensing and signal processing applications.

Committee:

Philip Feng (Advisor); Christian Zorman (Committee Member); Hongping Zhao (Committee Member); Xuan Gao (Committee Member); Soumyajit Mandal (Committee Member)

Subjects:

Electrical Engineering; Nanotechnology

Keywords:

2D Semiconductor; MoS2; 2D NEMS Resonator; 2D Field-Effect Transistor; Electrical Readout; Optical Interferometry; Dry Transfer; Electromechanical Coupling

Kuhlman, Anthony JosephThe beginning and end of heavy ion collisions: using uranium beams and Bose-Einstein correlations as probes of the collision fireball
Doctor of Philosophy, The Ohio State University, 2007, Physics
In this work, we begin by examining the possibility of using collisions between large deformed nuclei, such as uranium, at the Relativistic Heavy Ion Collider (RHIC) facility at Brookhaven National Laboratory. We present calculations that highlight the advantages of such an endeavor over the current gold-gold (Au+Au) program. These calculations are examined both within a Glauber model framework and using a color glass condensate (CGC) type picture. We discuss event selection techniques and analyze these procedures using a Monte Carlo simulation. We also explore the use of two-particle interferometry to probe the final size and shape of the particle emitting source. We develop a computer program capable of computing the azimuthally dependent spatial correlation tensor and Hanbury Brown-Twiss (HBT) radii. The accuracy of this program is tested by comparing its output with a number of analytic calculations. We then employ symmetries of the source function to greatly reduce the computational effort necessary to evaluate the Fourier expansions of the correlation tensor and the HBT radii. We close by examining the effects of final state interactions on the measured HBT radii. We derive a nonrelativistic expression for the two-particle probability and examine this expression in various limits, assuming a time-independent interaction with the medium. We explore the effects of weak rescattering on the measured radii by performing a perturbative calculation in the case with only a time-independent medium interaction, obtaining a surprisingly straightforward result.

Committee:

Ulrich Heinz (Advisor)

Subjects:

Physics, Nuclear

Keywords:

Heavy ion collisions; Hanbury Brown-Twiss interferometry; final state interactions; ultrarelativistic uranium-uranium collisions

Hager, Michele LynnManecaA Study of Contact Lens Comfort in Patients Wearing Comfilcon A Soft Contact Lenses Compared to Their Habitual Soft Contact Lenses
Master of Science, The Ohio State University, 2009, Vision Science
Contact lens discomfort, especially contact lens-related ocular dryness, is a major cause of contact lens wear discontinuation. Many studies have evaluated different contact lens materials for their comfort in both normal patients and sufferers of contact lens-related dry eye. This study seeks to evaluate a new silicone hydrogel soft contact lens material (comfilcon A) in terms of comfort, measurable tear film parameters, and total contact lens-extracted lipid in normal and contact lens-related dry eye contact lens wearers as compared to their habitual contact lenses. Thirty four participants completed this study consisting of two visits—the first with participant wearing their habitual soft contact lenses and the second with the study contact lenses. Interferometric measurements of the pre-lens tear film thinning rate (PLTF thinning rate), the lipid layer thickness (LLT), and the initial pre-lens tear film thickness (PLTF) were recorded, the Contact Lens Dry Eye Questionnaire (CLDEQ) was peformed, and the participants’ lenses were collected for lipid analysis at each visit. The CLDEQ scores at the first study visit of the non-dry eye and dry eye group were shown to be significantly different from one another (p <0.0001). Total extracted lipid amounts showed a significant difference for the non-dry eye group between the first and second study visits (p = 0.01) but not for the dry eye group (p = 0.10). A significant correlation was found between LLT and PLTF thinning rate for the first visit (r = 0.39, p = 0.03), but not for the second visit (r = 0.14, p = 0.43). A significant correlation was found between CLDEQ score and PLTF thinning rate for the dry eye group (rs = -0.55, p = 0.03) but not for the non-dry eye group (rs = 0.11, p = 0.71) at the first visit. A significant correlation was found between CLDEQ score and LLT for the non-dry eye group (rs = -0.53, p = 0.04) but not for the dry eye group (rs = -0.18, p = 0.53) at the first visit. A significant correlation was found between contact lens-extracted lipid quantity and number of days for which the habitual contact lenses were worn (r = 0.37, p = 0.03). One month of wear of comfilcon A silicone hydrogel contact lenses did not significantly improve subjective dryness symptom severity in either normals or contact lens-related dry eye sufferers as compared to their habitual lens materials. Further research is needed to determine a quantifiable tear film parameter or other marker by which to diagnose or grade contact lens-related dry eye and is also needed to find or develop a soft contact lens material that can be comfortably worn by contact lens-related dry eye sufferers.

Committee:

Jason Nichols, OD, PhD, MPH (Advisor); Kelly Nichols, OD, PhD, MPH (Committee Member); P. Ewen King-Smith, PhD (Other)

Subjects:

Ophthalmology

Keywords:

dry eye; comfilcon A; interferometry; lipid layer thickness; pre-lens tear film thinning rate; pre-lens tear film thickness; contact lens dry eye questionnaire

Chae, Chun SikStudies of the Interferometric Phase and Doppler Spectra of Sea Surface Backscattering Using Numerically Simulated Low Grazing Angle Backscatter Data
Doctor of Philosophy, The Ohio State University, 2012, Electrical and Computer Engineering

Range-resolved interferometric phase and Doppler spectra are two subjects of interest with regard to the retrieval of sea surface height profiles from coherent marine radar measurements. The studies of this dissertation attempt to improve understanding of the properties and associated measurement errors of these quantities through the use of numerically simulated low-grazing-angle backscatter data.

In the first part of the dissertation, studies of the interferometric phase are described. Backscattered fields computed using the method of moments for one dimensional ocean-like surface profiles are used to examine statistical properties of the single-look interferometric phase estimator, in order to investigate the applicability of standard expectations for height retrieval accuracy in this problem. The results show that shadowing and multipath propagation effects cause errors in interferometric phase estimation beyond those caused by speckle effects alone. In addition, the decorrelation between the fields received at two antennas is found to be impacted by shadowing and multipath propagation effects, making standard models for this quantity less applicable as well. These results show that modeling the expected performance of interferometric sea surface height retrieval approaches at low grazing angles is difficult.

The second part of the dissertation involves studies of the range-resolved Doppler spectra at low-grazing-angles. Backscattered fields are computed for a single realization of a one-dimensional ocean-like surface profile as the realization evolves in time. Transformation into the range-Doppler domain enables examination of properties of the resulting Doppler spectra (for both HH and VV polarizations) and their relationship to properties of the surface profile. In general, a strong correspondence between the long wave orbital velocity of the surface and the Doppler centroid frequency is observed for visible portions of the surface, as well as some evidence of relationships between the width of the Doppler spectrum and variations of the orbital velocity in time at a given range point. Evidence of similar relationships even in some shadowed portions of the surface is also provided. Doppler spectra from HH and VV polarizations are qualitatively similar in most respects, although the portion of shadowed surface points from which Doppler information is available is somewhat larger in VV polarization. A further examination is conducted using backscattered fields computed with a "single scattering" method that neglects shadowing and any multiple scattering effects. The remarkable similarities observed in Doppler spectra for the complete and single scattering models even in some shadowed portions of the surface suggests that non-line-of-sight propagation effects do not significantly in fluence Doppler properties in such regions.

The studies in this dissertation provide improved understandings of range-resolved interferometric phase and Doppler spectra at low grazing angles. These results provide new information for the design of coherent marine radars for the retrieval of sea surface profiles.

Committee:

Joel Johnson (Advisor); Robert Burkholder (Committee Member); Fernando Teixeira (Committee Member)

Subjects:

Electrical Engineering

Keywords:

electromagnetic scattering; surface scattering; interferometric phase; sea doppler spectra; retrieval of sea surface height; microwave remote sensing; method of moments; interferometry; doppler radar; low grazing angle; ocean remote sensing

Gillespie, Shane MatthewCharacterizing Phase Noise for Beam Steering Devices
Master of Science (M.S.), University of Dayton, 2014, Electro-Optics
In this thesis we assemble a type of Mach-Zehnder interferometer to measure the complex signal after passage through a device under test placed in one arm. The signal's phase is extracted from the complex signal dataset and is analyzed to study the phase noise added due to the device. We are studying a liquid crystal beam steering system, which is a combination of two optical devices; the first is a variable liquid crystal half-waveplate and the second is a liquid crystal phase grating. The variable liquid crystal waveplate is the active element that has voltages applied to achieve a specific birefringence, whereas the liquid crystal phase grating is a passive device. For the beam steering devices of interest the liquid crystal phase grating is passive and therefore unlikely to impart appreciable amounts of phase noise, so the focus of this research was on the potential phase noise due to variable liquid crystal waveplate. The phase noise using the variable liquid crystal waveplate is measured in three operational states: a non-energized off state, an energized state having zero-phase change,and an energized state with voltage set for a half-wave phase change. We examine the phase spectrum |Φ(ƒ)|2, obtained from the frequency analysis of the temporal phase. A comparison is made between the phase noise spectrums in several cases: pre-device insertion to a post-device insertion of the variable liquid crystal waveplate for the three different states. We examine the signal spectrum over frequencies spanning the range from 1 Hz to 107 Hz and tentatively conclude that the active devices add little additional noise to the system. Further data is needed to solidify this conclusion given the data being analyzed is from one data capture, and the system required readjustment between captures, and we observe a drift of the noise floor.

Committee:

Joseph Haus, Ph.D. (Committee Chair); Paul McManamon, Ph.D. (Committee Member); Tim Finegan (Committee Member); David Rabb (Committee Member)

Subjects:

Military Studies; Optics; Technology

Keywords:

phase noise; beam steering; liquid crystal polarization gratings; mach zehnder; interferometry; polarization IQ;

Fugate, Joseph MMeasurements of Land Subsidence Rates on the North-western Portion of the Nile Delta Using Radar Interferometry Techniques
Master of Science, University of Toledo, 2014, Geology

The Nile Delta is home to around 75 million people and most of Egypt’s farmland and agricultural production. This area is currently threatened by Mediterranean Sea waters due to factors such as sediment starvation, climate change, and sea level fluctuations as well as subsidence. The low elevation and relief of the Nile Delta exposes many coastal communities, including the city of Alexandria, to potential inundation. This situation has become a concern for the area’s residents but a better understanding of the processes occurring there can aid in deciding a suitable response. Recent studies have documented Holocene subsidence rates in the northeast part of the Nile Delta that average up to 8mm/year. In this study, PS-InSAR techniques are used to measure modern land subsidence rates on the north-central and north-western Nile Delta.

Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) techniques were applied to 23 ESA radar scenes from 2 orbital tracks spanning from 1992 to 2000 in the north-central and north-west portions of the Nile Delta. The area includes the cities of Alexandria, Greater Mahala, and Mansoura as well as the Rosetta promontory and lake Burullus, Idku Lagoon, and Maryut Lagoon. Results indicate that modern average-vertical ground motion velocities for the north-western and north-central Nile Delta range from emergent to subsidence of 8.5 mm/yr. The range of velocities measured are spatially varied in a complex way across the study area. Patterns of subsidence correlate closely to areas of most recent sediment deposition such as along coastlines and rivers, as well as in lagoons and lakes. Average subsidence velocities are also lower across the western sections of the Nile Delta than in the northeastern delta.

Committee:

Richard Becker, Dr (Advisor); Mohamed Sultan, Dr (Committee Member); Donald Stierman, Dr (Committee Member)

Subjects:

Geology; Remote Sensing

Keywords:

Egypt; Nile Delta; subsidence; Radar Interferometry; Persistent Scatterers; InSAR