Master of Science, The Ohio State University, 2020, Electrical and Computer Engineering

Baud rate clock and data recovery circuits are critical to high speed serial links since these require only one sample per data period thereby requiring low speed samplers and comparators. This work models and discusses the backend of one particular Baud rate CDR – Mueller Muller, and analyses some of the building blocks of the CDR – Phase Detector, Phase Interpolator and the Quadrature Phase Generator. Firstly, a PAM-4 Quadrature Phase Detector operating at 80Gb/s is discussed. The challenges associated with designing a Mueller-Muller PD for an asymmetric channel are discussed and one way to resolve this issue is proposed. Then the underlying digital blocks that make up the Phase detector are expanded upon. Secondly, a 64-step digitally controlled Phase Interpolator running at 16GHz clock rate is analyzed and its design challenges with regards to achieving linearity and ensuring duty cycle fidelity are explored. Finally, a Quadrature Phase Generator with digital delay control is analyzed. It is modeled at 16GHz clock rate and the range/resolution problem and its impact on clock jitter is explored.

Committee: Tawfiq Musah (Advisor); Ayman Fayed (Committee Member) Subjects: Electrical Engineering

Doctor of Philosophy, University of Toledo, 2019, Physics

Thin film solar cells are promising candidates for generation of low cost and pollution-free energy. The materials used in these devices, mainly the active absorber layer, can be deposited in a variety of industry-friendly ways, so that the cost associated with manufacturing is generally lower than for competing technologies such as crystalline silicon. This dissertation will focus on the fabrication and characterization of nanocrystalline hydrogenated silicon (nc-Si:H) and polycrystalline cadmium telluride (CdTe) thin films by industrially scalable, non-toxic, and comparatively simple magnetron sputtering. The performance of the solar cells incorporating these films as an active absorber layers are discussed. In this work, spectroscopic ellipsometry is used as the primary tool for the characterization of optical and structural properties of thin films and bulk material. As a first case study, the anisotropic optical properties of single crystal strontium lanthanum aluminum oxide (SrLaAlO4) in the form of birefringence and dichroism is obtained from Mueller matrix ellipsometry. SrLaAlO4 exhibit uniaxial anisotropic optical properties and the indirect optical band gap of 2.74 eV. A parametric model consisting of parabolic band critical points (CPs) for electronic transitions and a gap function is used to describe the complex dielectric function spectra in both the ordinary and extra-ordinary directions. The modeling in this case study has applications to both nc-Si:H, an indirect band gap semiconductor, and CdTe which may exhibit microstructural anisotropy depending upon the deposition method. Fabrication and characterization of hydrogenated silicon (Si:H) thin films produced by reactive magnetron sputtering is the second case in this study. RTSE and a virtual interface analysis (VIA) are used to track the growth evolution of sputtered Si:H. From these studies, growth evolution diagrams depicting the nucleation of nanocrystallites from the amorphous phase and (open full item for complete abstract)

Committee: Nikolas Podraza (Committee Chair); Robert Collins (Committee Member); Yanfa Yan (Committee Member); Michael Cushing (Committee Member); Sylvain Marsillac (Committee Member) Subjects: Energy; Materials Science; Optics; Physics

Doctor of Philosophy (Ph.D.), University of Dayton, 2017, Theology

This dissertation is thematically organized around the U.S. debate about “supernatural sociology” from 1940 through 1946. Formally, it examines how this debate engaged the emerging science of sociology in order to conceive anew the natural-supernatural distinction. And materially, it focuses on the contributions of the debate's three leading lights. These figures included American priest-sociologist Paul Hanly Furfey (1896-1992), German social-scientist Franz Mueller (1900-1994), and Italian priest-social theorist Luigi Sturzo (1871-1959). Of these three figures, this dissertation focuses especially on Luigi Sturzo and two key areas of his life and work. The first is centered on Sturzo's evaluation of the trailblazing “philosophy of the supernatural” of French philosopher Maurice Blondel (1861-1949). And the second is centered on Sturzo's adaptation of Blondel's thought through his own trailblazing “sociology of the supernatural.” Finally, this dissertation seeks to show how the U.S. debate about “supernatural sociology” paralleled the 1930s debate about “Christian philosophy” in France. Thus, it seeks to show how, just as the debate about “Christian philosophy” examined the opening of philosophy to the supernatural, so too did the debate about “supernatural sociology” examine the opening of sociology to the same.

Committee: William Portier Ph.D. (Advisor); Dennis Doyle Ph.D. (Committee Member); John Inglis Ph.D. (Committee Member); Sandra Yocum Ph.D. (Committee Member); Peter Bernardi S.J., Ph.D. (Committee Member) Subjects: History; Sociology; Theology

Doctor of Philosophy, The Ohio State University, 1979, Graduate School

Committee: Not Provided (Other) Subjects: Fine Arts

Doctor of Philosophy in Engineering, University of Toledo, 2005, Bioengineering

In this dissertation, multiple investigations on the implementation and use of polarized light for noninvasive diagnostics in turbid media are reported on and discussed. The first study focuses on the development and construction of an automated Mueller matrix imaging system. In the first investigation, a method was developed to estimate the scattering coefficient contribution as a function of particle size in complex mixtures of polystyrene spheres. A partial least squares approach is used to accurately predict the individual scattering coefficient contributions in phantoms containing 0.2, 0.5, 1, and 2 µm diameter spheres. It is also shown how scattering type is encoded within the Mueller matrix. In addition, the backscattered Mueller matrix of cultured normal human melanocytes, HEMn-LP, and melanoma cells, WM115 and WM793, are investigated for potential cell characterization. These results indicate that the mitochondria contribute significantly to the backscattering polarization signals. In the second investigation, Mueller matrix imaging is applied for in vitro collagen degradation classification. Four different levels of collagen degradations were imposed on in vitro human dermis via collagenase type IA-s. Polar decomposition of the Mueller matrix was performed to better interpret the image-based measurements for the optical differentiation between the degraded and normal dermis. Combining these results in conjunction with the Mueller matrix elements, the extracted features were analyzed by classification tree to develop an accurate classification model. Such methods may eventually lead to the development of improved diagnostic tools capable of characterizing and distinguishing between tissue abnormalities. The final investigation involves the application of diffuse reflectance polarization imaging to detect glucose concentration levels in highly scattering turbid media. Through the application of partial least squares regression, it is shown that accurate gluc (open full item for complete abstract)

Committee: Brent Cameron (Advisor) Subjects: Engineering, Biomedical

Master of Science (M.S.), University of Dayton, 2010, Electro-Optics

Seven series of thin films encompassing metallic, dielectric, and semiconductor materials were deposited onto a substrate by means of electron-beam evaporation. Tilting the substrate at an oblique angle relative to the evaporant source causes an atomic shadowing effect to occur at adjacent deposition locations and results in the growth of a columnar morphology. Scanning electron micrographs for each series validate a film structure and porosity that varies with substrate tilt angle. Angle resolved spectroscopic ellipsometry reveals the anisotropic nature of the different series and determines the optical properties utilizing a best model fit calculation. In some instances, the optical properties of the columnar thin film and its bulk material differ significantly.

Committee: Andrew Sarangan PhD (Advisor); Joseph Haus PhD (Committee Member); Qiwen Zhan PhD (Committee Member) Subjects: Aerospace Materials; Automotive Materials; Engineering; Materials Science; Optics; Physics

Master of Science in Engineering, University of Akron, 2012, Electrical Engineering

The work done in this study supported the development of the United States Air Force Research Laboratory (AFRL) Polarimetric Multifunction Imaging Platform. Polarimetry can be used for identification, classification, and analysis of a material's optical properties using polarization as the key discriminator. Polarimetry has great potential to be used in space applications because it has the useful ability to interrogate objects at great distance using relatively low power. In a polarimetric system, the determination of material properties are not dependent upon the magnitude of the returned signal, rather the transformation of the polarization that the incident light has undergone after interacting with the object. The presented system is an automated full polarimetric system utilizing liquid crystal devices which can be controlled electronically with no moving parts. In this study several materials typically used in space applications were tested for their full Mueller Matrix at varying aspect angles. Additionally, Mueller Matrices were decomposed into constituent matrices representing key material characteristics and several figures-of-merit were calculated. The outcome of this study provides a wealth of information in terms of system design, calibration techniques, testing, and applying remote measuring methodologies.

Committee: George Giakos Dr. (Advisor); Arjuna Madanayake Dr. (Committee Member); Lee Kye-Shin Dr. (Committee Member) Subjects: Electrical Engineering; Optics

Master of Science in Engineering, University of Akron, 2013, Electrical Engineering

In the year 2012, there were approximately 226,160 cases of lung cancer and 160,340 deaths out of it as per the National Cancer Institute. There are mainly two types of lung cancer, small cell lung cancer and non-small cell lung cancer, of which 87% are diagnosed as non-small cell. A physical algorithm and a systematic study relating the morphological, chemical and metabolic properties of lung cancer to the physical and optical parameters of the polarimetric detection process are missing. Therefore, one of the purposes of the study is to explore the polarimetric phenomenology of near infrared light interaction with healthy and lung cancer monoline cells by using efficient polarimetric backscattering detection techniques. Preliminary results indicate that enhanced discrimination between healthy and different types of lung cancer cells can be achieved based on their backscattered intensities, Mueller matrix, diattenuation and depolarization properties. Also, various optical parameters like linear depolarization ratio and degree of linear polarization play an important role in discriminating healthy and different lung cancer cells. Specifically, the sizes of the nuclei of the cancer cells and the nucleus-to-cytoplasmic ratios appear to have potential impact on the detected polarimetric signatures leading to enhanced discrimination of lung cancer cells. The second work in this thesis has been done with the support of the Air Force Research Laboratory (AFRL). Polarimetric signals have always played an important role in the identification, discrimination and analysis of a material's optical properties. This work presents a novel remote sensing approach based on polarimetric fractal detection principles. Backscattered polarimetric signals contribution from different materials used in space applications have already been detected using a laboratory LADAR testbed and this thesis presents implememtation of the LADAR testbed and analysis techniques of these backscatt (open full item for complete abstract)

Committee: George Giakos Dr. (Advisor); Kye-Shin Lee Dr. (Committee Member); Nghi Tran Dr. (Committee Member) Subjects: Biomedical Engineering; Electrical Engineering; Experiments; Optics; Remote Sensing