Doctor of Philosophy (PhD), Ohio University, 2024, Physics and Astronomy (Arts and Sciences)

A nascent instrument called Synchrotron X-ray Scanning Tunneling Microscope (SXSTM), which challenges the limits of conventional X-ray absorption spectroscopy (XAS) methods by accessing elemental and chemical details of matter at the ultimate atomic limit, is employed in this dissertation to observe and investigate the magnetism at the ultimate atomic limit. First, a series of X-ray Magnetic Circular Dichroism (XMCD) signals deduced from near field XAS signatures in SXSTM tip channel are used to observe surface magnetism in Ni islands grown on Cu(111) while that of the sample channel is used to identify ensemble magnetism. We observe that the magnetic moments at the surface are enhanced compared to that of the sample. A comparative study also reveals that the magnetic moments of a magnetized sample are elevated compared to that of a nonmagnetized sample. In this work we establish the first ever detection of magnetism at the ultimate atomic limit by capturing the XMCD signature of an Eu atom caged in pcam ligands which are adsorbed on top of magnetized Ni islands on Cu(111), hence displaying magnetism due to a Van-Vleck like effect while coupling ferromagnetically to the host Ni layers. Differential conductance (dI/dV) measurements backed with theory demonstrate that the Eu3+ becomes magnetic by transitioning into a non-zero total angular moment (J>0). Dimer molecules are formed with a mixture of two different precursors containing Eu and Tb in this dissertation, using Ullmann reactions on Au(111) which exhibit different chirality and various types of clustering upon dimer formation, while sequences of near field XAS point spectra provide evidence towards dimers with different as well as similar rare earth (RE) atoms caged in the same dimer. They further reveal that both Eu and Tb are preserving their original +3 oxidation state in the dimers. We also report the first-ever radiograph of a single atom by means of X-ray images carried out at M5 edges of Eu (open full item for complete abstract)

Committee: Saw Hla (Advisor); Eric Masson (Committee Member); Eric Stinaff (Committee Member); Sergio Ulloa (Committee Member) Subjects: Condensed Matter Physics; Materials Science; Nanoscience; Physics

Doctor of Philosophy, University of Akron, 2022, Integrated Bioscience

Opioids have become one of the most misused classes of prescribed medication. Synthetic opioids (e.g., fentanyl) have been responsible for most opioid overdose deaths since 2017. As this epidemic shows no signs of slowing, it is imperative to study the effects of opioids on various aspects of health including bone maintenance. Endogenous opioids (e.g., met-enkephalin) are involved in osteogenesis and bone remodeling. Exogenous opioids can interfere with bone maintenance directly through binding to osteoblasts, limiting bone formation, or indirectly through a cascade of effects limiting sex hormone production. To understand how opioids affect bone microarchitectural and biomechanical properties we first examine bone microstructure throughout the human lifespan to see natural changes occurring without the effects of opioids. Using both Synchrotron Radiation micro-Computed Tomography and confocal laser microscopy, we found bone and lacunar volume fractions to decrease with advancing age while pore diameter increased in the anterior midshaft femur. After finding how bone changes with age under normal circumstances, we sought to examine how prolonged opioid administration affected trabecular microstructure in a model organism (rabbit). We used μCT to examine the proximal tibia by anatomical quadrant (e.g., anterior, posterior). We found that morphine animals had greater bone volume fraction and less trabecular separation than controls. Fentanyl animals had significantly thicker trabeculae and increased trabecular spacing than controls. Detected differences by anatomical region followed the same overall pattern, suggesting biomechanical or anatomical variation rather than due to opioids. We finally examined overall bone strength in a non-weight bearing bone (rib) of the rabbit using uniaxial compression testing to determine how opioids affect overall mechanical competency. We found no difference in mechanical variables between opioid and control groups. Only rib span leng (open full item for complete abstract)

Committee: Brian Bagatto (Advisor); Janna Andronowski (Committee Co-Chair); Henry Astley (Committee Member); David Cooper (Committee Member); Christine Dengler-Crish (Committee Member); Nita Sahai (Committee Member) Subjects: Biology; Biomechanics; Histology; Pharmaceuticals; Physiology

Doctor of Philosophy (PhD), Ohio University, 2022, Physics and Astronomy (Arts and Sciences)

In this dissertation, studies on atomic-scale characterization and manipulation of molecular systems and heterostructures for potential applications in the emerging field of molecular nanotechnology are presented. Observing and investigating exotic properties of molecular systems often require novel techniques and state-of-the-art instrumentation; thus, we report the development and commissioning of the world's first synchrotron Xrays beamline, dubbed “XTIP”, dedicated to the synchrotron X-rays scanning tunneling microscopy (SX-STM) technique that was used on all the research projects in this dissertation. For the projects, first, we report on unexpected magnetic interface phenomena in molecular Co adsorbed on oxygenated Fe film as well as in Co/Ni/Cu(111) nanoscale heterostructure probed using the X-ray dichroism technique (XMCD). We observed that the magnetic moment of Ni islands in the heterostructure shows a considerable reduction due to partial filling of the unoccupied Ni 3d orbitals due to charge injection. In addition, using the SX-STM technique, we also report on the first-ever elemental and chemical characterization of individual Fe atoms in a molecular environment. Finally, guided by the X-rays absorption spectroscopy measurements on a rare-earth-based molecule, which shows the existence of net charges in the molecule on Au(111), we have developed a molecular motor with 100% control over its rotation direction mediated by counterions. These results open a new dimension of research where synchrotron X-rays are used to characterize materials one atom at a time.

Committee: Saw-Wai Hla (Advisor) Subjects: Condensed Matter Physics; Molecular Chemistry; Molecular Physics; Nanoscience; Nanotechnology; Physics

Doctor of Philosophy (PhD), Ohio University, 2020, Physics and Astronomy (Arts and Sciences)

Understanding thermionic cathodes is crucial for the future development of communication technologies operating at the terahertz frequency. Model cathode systems were characterized using multiple experimental techniques. These included Low Energy Electron Microscopy, X-Ray Photoemission Spectroscopy, and Auger Electron Spectroscopy. This was done to determine the mechanisms by which tungsten, barium, scandium, and oxygen may combine in order to achieve high current densities via thermionic emission. Barium and scandium films are found to dewet from the tungsten surfaces studied, and not diffuse out from bulk sources. The dewetted droplets were found to contribute the most to thermal emission. Barium oxide and scandium oxide are also found to react desorb from the emitting surface at lower temperatures then the metals themselves. The function of scandium in scandate cathodes was determined to act as an inhibitor to oxide formation. These observations are not compatible with certain models of cathode operation, mainly the dipole and semi-conductor models.

Committee: Martin Kordesch (Advisor) Subjects: Condensed Matter Physics; Experiments; High Temperature Physics; Materials Science; Physics

Doctor of Philosophy (PhD), Ohio University, 2018, Physics and Astronomy (Arts and Sciences)

Nanoscale materials have demonstrated unique properties in condensed matter studies and played a crucial rule in modern devices. Fundamental research on nanoscale systems provides deep understanding into science and enables advancing and reshaping of nanotechnology. Scanning tunneling microscopy is a comprehensive tool which is capable of characterizing topographic and electronic properties of nanoscale materials in real space down to atomic scale. To date many emerging techniques have been combined with scanning tunneling microscopy to discover and explore new phenomena. This dissertation explicitly demonstrates novel application of synchrotron X-ray scanning tunneling microscopy which combines synchrotron X-ray and scanning tunneling microscopy to study magnetic, electronic, and structural properties of materials interfaces. A scanning tunneling microscope tip is used to capture X-ray magnetic circular dichroism and near edge X-ray absorption fine structure signals, which explain charge transfer and magnetic properties of oxide materials interfaces with chemical and elemental sensitivities. Using X-ray absorption spectroscopy and spectroscopic imaging with a scanning tunneling microscope tip, the effect of charge transfer at the interfaces formed by transition metals of cobalt and nickel in nanoscale clusters and islands on a Cu (111) surface has been explored. Finally, X-ray standing wave formed by the interference of the incident and diffracted X-ray beams is used to characterize the structural properties of a cobalt thin film grown on a Au (111) surface. These results open novel research directions where material characterizations will be able to perform simultaneous chemical, structural and magnetic contrast potentially down to atomic scale.

Committee: Saw-wai Hla (Committee Chair); Nancy Sandler (Committee Member); Gang Chen (Committee Member); Hugh Richardson (Committee Member); Volker Rose (Committee Member) Subjects: Materials Science; Nanoscience; Physics

Doctor of Philosophy, The Ohio State University, 1975, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy (PhD), Ohio University, 2015, Physics and Astronomy (Arts and Sciences)

Since its inception, scanning tunneling microscopy (STM) has developed into an indispensible tool for surface science. Its sub-nanometer spatial resolution in both real space imaging and tip-sample interactions continue to demonstrate versatility in the study of novel phenomena at materials' surfaces. This dissertation explores the expansion of experimental techniques in STM through application of two uncommonly exploited interactions at the tip-sample junction: X-ray absorption and the electric field between the tip and sample. This study begins by targeting the STM tip-sample junction with X-ray photons tuned to core level electron energies of atomic species on the sample. Interactions of atomic islands with the incident light are employed to introduce elemental sensitivity in STM with a resolution of just 2 nm. Elementally sensitive images are produced simultaneously with conventional STM images, and exploited to probe X-ray cross section behavior for structures measuring just a few tens of nanometers in the lateral directions. Additionally, point spectroscopic measurements of X-ray absorption behavior vs. incident photon energy facilitate the detection of local variations in emitted electron density due to the X-ray interactions. Locally measured electron emission densities measured by specialized SXSTM smart tips demonstrate a clear dependence on incident photon energy. Next, electric field interactions between the tip and sample are used to investigate the behavior of strongly dipolar molecular rotor networks. Symmetry and structure in the molecular networks are found to inhibit rotation of molecular rotors that exhibit thermally induced switching at temperatures as low as 5 K for isolated molecules. Additionally, inelastic electron tunneling is employed to induce controlled directional rotation in a different, single molecule motor system. The directionality is explained through the structure of calculated potentials in the motor system. The mechanis (open full item for complete abstract)

Committee: Saw-Wai Hla Dr. (Advisor) Subjects: Condensed Matter Physics; Experiments; Low Temperature Physics; Molecular Physics; Molecules; Nanoscience; Nanotechnology; Physics

Doctor of Philosophy, The Ohio State University, 2015, Physics

Double perovskites have proven to be highly interesting materials, particularly in the past two decades, with many materials in this family exhibiting strong correlations. These materials are some of many novel complex oxides with potential spintronics application. Sr2CrReO6, in particular, is a double perovskite with one of the highest Curie temperatures of its class (> 620 K in bulk and ∼510-600 K in thin films), as well as high spin polarization, ferrimagnetic behavior, and semiconducting properties. This dissertation covers recent work in exploring and tuning physical properties in epitaxial films of Sr2CrReO6. It starts by providing a background for the field of spintronics and double perovskites, bulk and thin film synthesis of Sr2CrReO6, and standard and specialized characterization techniques utilized in both university and national laboratories, and then provides reports of work on Sr2CrReO6 epitaxial films. Examples of exploration and engineering of properties of Sr2CrReO6 include: (1) tuning of electrical resistivity, such as at T = 7 K by a factor of 18,000%, via control of oxygen partial pressure during film growth; (2) enhancement of interfacial double perovskite ordering, demonstrated with high-angle annular dark-field scanning transmission electron microscopy, via the use of double perovskite buffer layer substrates; (3) measurement of magnetization suppression near film/substrate interfaces via polarized neutron reflectometry, which reveals a reduction of thickness (from 5.6 nm to 3.6 nm) of the magnetically suppressed interface region due to buffer layer enhancement; (4) strain tunability of atomic spin and orbital moments of Cr, Re, and O atoms probed with x-ray magnetic circular dichroism, which demonstrates ferrimagnetic behavior and reveals important magnetic contributions of the oxygen sites (∼0.02 µB/site); (5) strain tunability of large magnetocrystalline anisotropy via applied epitaxial strain, revealing anisotropy fields of up to 10s of te (open full item for complete abstract)

Committee: Fengyuan Yang (Advisor); P. Chris Hammel (Committee Member); Ciriyam Jayaprakash (Committee Member); Richard Hughes (Committee Member) Subjects: Condensed Matter Physics

Doctor of Philosophy, The Ohio State University, 2014, Biophysics

Radiosensitization of biological material such as cancer cells by heavy elements (high atomic number Z or HZ) has been studied as a possible means to improve radiation therapy and imaging for the diagnosis and treatment of cancer. In particular, the energy deposition by low vs. high energy X-rays (LEX & HEX, respectively) has been compared. Computations and simulations have shown that LEX interact favorably with HZ sensitizers by depositing more energy. In contrast, HEX interact predominantly by photon scattering regardless of Z of both the target and sensitizer. Monte Carlo simulations have shown that in comparison to unsensitized tissue models, irradiation of HZ sensitized models resulted in up to a factor of 2 enhancement in dose deposition when performed with LEX, while in contrast dose enhancement with HEX resulted in ~1.2 increase. To verify the computational studies, in vitro experiments were performed with two Pt-based sensitizers, carboplatin and a newly developed terpyridine platinum compound, Typ-Pt, and two different cancer models, the F98 rat glioma and B16 mouse melanoma as models for brain and skin cancer respectively. In agreement with the simulations, the in vitro experimental studies demonstrated decreased survival of HZ-sensitized cells irradiated with LEX compared to HEX. In addition, fundamental physics involving resonant absorption and fluorescence of monochromatic X-rays also was explored, with potential radiotherapeutic applications. Due to the very high probabilities for interaction at resonant X-ray energies, the amount of radiation damage at the site of the tumors could be significantly higher even in comparison to LEX. Promising but preliminary experiments were performed both on detecting resonant fluorescence at synchrotron X-ray intensities, and on the development of a broadband-to-monochromatic X-ray converter. The converter consists of using low energy broadband X-rays to preferentially ionize the K-shell electrons of a targe (open full item for complete abstract)

Committee: Anil Pradhan Ph.D. (Advisor); Rolf Barth M.D. (Committee Member); Nilendu Gupta Ph.D. (Committee Member); Michael Tweedle Ph.D. (Committee Member) Subjects: Biophysics; Radiation

MS, University of Cincinnati, 2000, Engineering : Materials Science

The residual stress profile is a major factor on the fatigue life of components that are subjected to cyclic loading.1 The residual stress profiles of two diesel engine components, a section removed from a connecting rod and a section removed from a finished crankshaft, were measured non-destructively using neutron, laboratory x-ray, and synchrotron x-ray diffraction techniques. The synchrotron source identified the near surface residual stresses, and the neutron diffraction technique used for measurements of the residual stresses from 1 mm below the surface on into the interior of the samples. The strains from the synchrotron measurements were corrected for the effect of the exponentially weighted averaging over the irradiated depth using a numerical linear inversion method. The neutron measurements did not require any corrections, as they are a measurement of strains, directly from the area of interest, and they are not weighted. After this determination of the residual stress profiles, the same locations on the components were measured using the common destructive x-ray diffraction etch layer removal technique. The measured data from this iterative etch technique were corrected for the effect of the removed material on the remaining stress field using equations put from the SAE J784a standard.2 These corrected data from this destructive technique is graphed in comparison to the residual stress profile data determined non-destructively. This data proves the etch layer removal method is as accurate as any of the other methods available due to the excellent correlation of the different techniques.

Committee: N. Jayaraman (Advisor) Subjects:

Master of Science (MS), Ohio University, 2010, Physics and Astronomy (Arts and Sciences)

We present multiwavelength observations of the ultraluminous blazar-type radio loud quasar PKS 0528+134 obtained in September 2009. Our main goal was to characterize this blazar in a quiescence state. We performed optical observations at the 1.3-m McGraw-Hill telescope of the MDM Observatory and also collected radio and optical data from the GASP. In the X-ray regime we collected data from the XMM-Newton Satellite in the 0.2 – 10 keV range. We also obtained gamma-ray data from the Fermi Large Area Telescope (LAT) in the 100 MeV – 300 GeV range. We found no evidence of significant flux or spectral variability in the radio, X-ray and gamma-ray regime. However, significant flux variability was found in the optical region, especially in the R and B bands, and we also found a spectral softening trend. We produced four SEDs with the data we were able to gather, and for the Leptonic combined SSC+ERC jet model that we used, acceptable fits were produced.

Committee: Markus Boettcher Dr. (Advisor); David Drabold Dr. (Committee Co-Chair); Justin Frantz Dr. (Committee Member) Subjects: Astronomy; Astrophysics; Physics

Doctor of Philosophy, Miami University, 2010, Geology and Environmental Earth Science

Due to increasing risk associated with the contamination of the environment with heavy metals and radionuclides, societies worldwide are facing a pressing need for new more efficient environmental remediation techniques. One approach that gained considerable attention over the last two decades is in situ metal stabilization by phosphate amendments – a technique based on the coprecipitation of contaminant species with phosphates and the formation of insoluble metal(M)-substituted minerals, such as apatite Ca5-xMx(PO4)6(OH,Cl,F). One of the major results of this dissertation is that formation of apatite at Earth-surface conditions is preceded by crystallization of other less stable calcium phosphates (precursors) that ultimately transform to apatite. The first part of this dissertation investigates formation and evolution of calcium phosphate precursors under conditions simulating those found in Earth-surface environments. The pathways of phase development in the Ca(OH)2-H3PO4-H2O system were studied using conventional ex situ as well as in situ time-resolved X-ray diffraction. The results clearly indicate formation of precursors under conditions found at the Earth-surface, which may be relevant not only in the context of natural soil environments, but also in the context of engineered conditions, like those found during metal stabilization by phosphate amendments. In the second part of the dissertation, pathways of calcium phosphate development in the presence of different metal ions (Zn, Cd, Sr, U, and Th) are studied by time-resolved X-ray diffraction. The results clearly indicate a significant influence of contaminant species on the pathways of phase development in the Ca(OH)2-H3PO4-H2O system. Secondary metal-bearing phases, far more soluble than hydroxylapatite, were often formed in the presence of the metals studied. Finally, the role of precursor formation on the heavy metal sequestration and fate during crystal growth of apatite was studied by a combination (open full item for complete abstract)

Committee: John Rakovan PhD (Advisor); Hughes John PhD (Committee Member); Cahill Christopher PhD (Committee Member); Dong Hailiang PhD (Committee Member); Rech Jason PhD (Committee Member); Sommer Andre PhD (Committee Member) Subjects: Mineralogy

PHD, Kent State University, 2009, College of Arts and Sciences / School of Biomedical Sciences

In mammalian cells the sequence of events and the players involved in the biosynthesis of adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl) from vitamin B12 (cyanocobalamin, CNCbl) are only partially understood. A central objective of this work was to gain a mechanistic understanding of how mammalian cells process incoming cobalamins for coenzyme biosynthesis. In Specific Aim 1 cobalamins with potential biological activity were synthesized and characterized. Nitrosylcobalamin, NOCbl, the elusive complex formed between nitric oxide and cobalamin, was synthesized via a novel reaction between aquacobalamin and the nitric oxide donor DEA-NONOate. NOCbl was obtained in high yield (85%) and purity (≥ 95% by 1H NMR spectroscopy) under alkaline and strictly anaerobic conditions. In addition to NOCbl, the synthesis and characterization of a number of other cobalamin forms were also carried out, some of which were utilized to assess the mechanisms of intracellular cobalamin processing in mammalian cells. In Specific Aim 2, a method for the accurate assessment of intracellular cobalamins, hereafter referred to as “cold-trapping”, was developed. The procedure, which was tested in cultured cells, facilitated the identification and quantification of intracellular cobalamin forms that present exchangeable beta-axial ligands. A series of in vivo and in vitro experiments describing a new role for the MMACHC gene product (cblC protein) is also presented. Our in vivo studies strongly suggested that the cblC protein is responsible for early processing of both CNCbl (decyanation) and alkylcobalamins (dealkylation). Our in vitro studies confirmed that the cblC protein catalyzed the dealkylation of Co-C bonded cobalamins by a reaction involving the nucleophilic attack of the Co-C bond by the thiolate anion of glutathione. In Specific Aim 3, I investigated the protein changes that accompany functional cobalamin deficiency in humans. The proteome of normal and cblC mutant fibroblast (open full item for complete abstract)

Committee: Donald Jacobsen PhD (Committee Chair); Nicola Brasch PhD (Advisor); Soumitra Basu PhD (Committee Member); Thomas McIntyre PhD (Committee Member); Dennis Stuehr PhD (Committee Member) Subjects: Biochemistry; Biology; Cellular Biology; Chemistry; Pathology

Doctor of Philosophy, Case Western Reserve University, 1993, Chemistry

Electrochemical interfaces, especially structural changes and spectroscopic properties of adsorbed species on electrode surfaces induced by electrode potential have been examined by means of X-ray absorption fine structure and optical spectroscopic techniques. Spectral changes accompanying the one-electron reduction of μ-oxo(bis) (iron meso-tetrakis(methoxyphenyl)porphyrin) (FeTMPP)2O irreversibly adsorbed on Black Pearl (BP) in aqueous electrolyte have been examined in situ through X-ray absorption fine structure. In the pH range 5-10.8, the average iron-to-porphinato nitrogen distance, d(Fe-N p) (2.08 ± 0.01 A) for the ferric species was found to be very similar to that for crystalline (FeTMPP)2O. At extreme pHs, d(Fe-N p) values smaller than those observed in the intermediate pH range, which strongly suggest an axially coordinated dihydroxy (at very high pH) and diaquo (at very low pH) complexes as the predominant species. Potential modulation reflectance spectroscopy and wavelength modulation reflectance technique have been used to monitor the spectral properties of cobalt tetrasulfonated phthalocyanine (CoTsPc) and methylene (MB) blue irreversibly adsorbed on electrode surfaces. With a combination of cyclic voltammetry, linear relationship has been found between the relative reflectivity and the coverage of oxidized species of CoTsPc on the basal plane of highly oriented pyrolytic graphite (HOPG(bp)). Wavelength modulation study has shown that CoTsPc and MB on electrode surfaces exhibit almost the same spectral properties with those when they are in solution phase. In contrast, the corresponding ferrous counterpart displayed values for d(Fe-N p) (2.04 ± 0.01 A) consistent with the iron center placed in the plane of the ring over the whole pH region examined. The XAFS studies of Ni and 9:1 Ni/Fe and 9:1 Ni/Co composite hydroxide have shown that (i) Ni-O and Ni-Ni distances in Ni(OH)2 system are larger than those in NiOOH produced by oxidation; (ii) iron and coba (open full item for complete abstract)

Committee: Daniel Scherson (Advisor) Subjects: Chemistry, Physical

PhD, University of Cincinnati, 2013, Engineering and Applied Science: Materials Science

Laser shock peening (LSP) for improving fatigue life of IN718Plus superalloy is investigated. Fatigue geometry and LSP parameters were optimized using finite element method (FEM). Residual stress distributions estimated by FEM were validated using Synchrotron XRD and line focus lab XRD, and correlated with microhardness. An eigenstrain analysis of LSP induced edge deflections (measured with optical interferometry) was also conducted. Transmission electron microscopy (TEM) of single-spot LSP coupons shows sudden increase in dislocation density under LSP treated region. Total life fatigue was conducted at R=0.1 at 298K and 923K, with and without LSP. S-N curve endurance limit increases at both temperatures with FEM optimized LSP samples. Based on TEM of fatigue microstructure and LSP coupons, mechanistic description of observed fatigue improvement is attempted. Often need arises to weld components, and weld heat-affected-zone reaches near-solvus temperatures. To simulate this treatment, sub-solvus hot-rolled IN718Plus is aged at 923K. We observe precipitation of thin eta-Ni3(Al, Ti) plates after 1000 hours, making the material susceptible to cracks, and lowering fatigue life. Effect of LSP on fatigue crack growth (FCG) is studied following ASTM guidelines on M(T) geometry at R=0.1. Acceleration in FCG rate with LSP is observed for this geometry and LSP condition. Prior FEM optimization was not conducted for FCG tests, and may account for lower FCG resistance after LSP. FCG results were corroborated with COD compliance based analysis. Crack measurements were done using potential drop method, and crack closure was analyzed. Effect of LSP on overload FCG was investigated by single-cycle 100% overload followed by single-spot LSP on the crack-tip plastic zone. Crack retardation occurs after application of overload+LSP. Effective contribution of overload+LSP to crack retardation is estimated. Fractographic analysis of LSP treated fatigue samples suggests sub-surface (open full item for complete abstract)

Committee: Vijay Vasudevan Ph.D. (Committee Chair); Kristina Langer Ph.D. (Committee Member); Dong Qian Ph.D. (Committee Member); Rodney Roseman Ph.D. (Committee Member); Dale Schaefer Ph.D. (Committee Member) Subjects: Materials Science