Master of Science, The Ohio State University, 1967, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Arts, The Ohio State University, 1940, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1972, Graduate School

Committee: Not Provided (Other) Subjects:

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

This thesis presents new measurement of the Λp → Λp elastic scattering cross section in the momentum range 0.9-2.0 GeV/c, which is the first data on this reaction since the bubble chamber experiments of the 1970's. This analysis looked at the reaction γp → K+Λ using data from the CLAS-g12 experiment located at Hall B of Jefferson Lab. In addition to its importance in understanding baryon-baryon interactions, as the hyperon-nucleon and hyperon-hyperon sectors are not fully understood, this reaction is important to the study of neutron stars. It is believed that strange matter exists in their cores. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state (EOS). Better measurements of hyperon-nucleon cross sections will guide future models. Preliminary work is also presented on the helicity dependent cross sections, which show that future measurements are possible with the data available and would be the first of their kind. New techniques are developed to study novel beams, whose short lived lifetimes have been the reason for the sparsity of hyperon-nucleon data. This analysis utilizes a secondary Λ beam produced from an initial reaction to study Λp elastic scattering with the target protons. Discussion on how this novel beam technique can be used to study other short lived particle reactions is included.

Committee: Kenneth Hicks (Advisor); Chaden Djalali (Advisor); Alexei Davydov (Committee Member); Julie Roche (Committee Member); Madappa Prakash (Committee Member) Subjects: Physics

Doctor of Philosophy (PhD), Ohio University, 2021, Physics and Astronomy (Arts and Sciences)

This thesis presents the study of the reaction γp→K+Λ* using the photoproduction data from the CLAS-g12 experiment performed in Hall B of Jefferson Laboratory. The decay of Λ* resonances, Λ(1520), Λ(1670), and Λ(1690), into two exclusive channels, Σ+ϖ- and Σ-ϖ+, is studied from the detected K+, ϖ+, and ϖ- particles. This work aims at understanding photoproduction mechanism to excited state baryons, and to facilitate phenomenological model predictions using precision experimental measurements. A good agreement is established for the Λ(1520) differential cross sections with the previous CLAS measurements. The differential cross sections as a function of CM angle are extended to higher photon energies. Newly added are the differential cross sections as a function of invariant 4-momentum transfer, t, which is the natural variable to use for a theoretical model based on a Regge-exchange reaction mechanism. No new N* resonances decaying into the K+Λ(1520) final state are found. The higher mass resonances, Λ(1670)1/2- and Λ(1690)3/2-, are studied for the first time using photoproduction. This work provides a model dependent preliminary cross sections for these excited states.

Committee: Kenneth Hicks (Advisor); Chaden Djalali (Committee Member); Paul King (Committee Member); Sergio Lopez-Permouth (Committee Member) Subjects: Particle Physics

MS, University of Cincinnati, 2018, Engineering and Applied Science: Civil Engineering

This paper presents an evaluation of the shear lag factor for HSS tension members connected with two side plate gussets with longitudinal welds as given in Case 6 of Table D3.1 of AISC 360-16. The current AISC Specification for Case 6 does not permit weld lengths less than the perpendicular distance between the welds, and has the potential of producing negative shear lag factors. Similar issues previously existed for members given in Case 4 of Table 3.1. However, the AISC 360-16 Specification has adopted a mathematical model proposed by Fortney and Thornton for Case 4 of Table D3.1. The work presented in this paper offers: (1) a mathematical model for calculating the shear lag factor for Case 6 derived by repurposing the model adopted by AISC for Case 4 of Table D3.1; (2) the results of a parametric study comparing the results of the new mathematical model to the results using the current AISC method, and; (3) discusses the protocols developed for use in finite element analysis to evaluate the effectiveness of the proposed mathematical model. The proposed new mathematical model will permit longitudinal weld lengths less than the perpendicular distance between the welds, and removes the possibility of calculating a negative shear lag factor, while better representing the redistribution of cross-sectional stress near the connection region.

Committee: Gian Andrea Rassati Ph.D. (Committee Chair); Patrick Fortney Ph.D. (Committee Member); Bahram Shahrooz Ph.D. (Committee Member) Subjects: Civil Engineering

Master of Arts in Rhetoric and Writing​, University of Findlay, 2017, English

The introduction of the comments section to online news articles enabled new forms of interaction, allowing readers to participate directly in the conversation. Scholars have hailed the comments sections as digital public spheres of democratic discourse. However, scant research has been done on how sexist rhetoric affects women's ability to participate in online discourse, despite research indicating that such rhetoric is a problem. This thesis project draws connections between research on the comments sections, uninhibited behavior and flaming, cybersexism, and women's participation in discourse to look at the impact of sexist rhetoric. I conduct a close reading of comments from BuzzFeed, MSNBC, and Fox News, analyzing the material using feminist and sociological rhetorical criticism. I argue that the presence of sexist rhetoric leads to a reduction in women's participation in the comments and negative effects on women's agency within the comments. Findings include consistent patterns of sexist rhetoric on all three sites, and consistent patterns of responses from women, the most predominant of which is silence. If the comments are to meet the ideal of a democratic public sphere, then the role of sexist rhetoric must be understood and mitigated.

Committee: Ron Tulley PhD (Committee Chair); Elkie Burnside PhD (Committee Member); Kathy Mason PhD (Committee Member); Christine Tulley PhD (Advisor) Subjects: Communication; Composition; Gender; Language Arts; Mass Communications; Mass Media; Multimedia Communications; Rhetoric; Technical Communication

Doctor of Philosophy, The Ohio State University, 1987, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy, The Ohio State University, 1981, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy, The Ohio State University, 1980, Graduate School

Committee: Not Provided (Other) Subjects: Physics

PHD, Kent State University, 2015, College of Arts and Sciences / Department of Mathematical Sciences

I consider the following problems from Tomography. Suppose that the projections (sections) of two given bodies onto (by) every subspace of a fixed dimension are related by a certain condition. Does this imply that the bodies satisfy a similar condition in the ambient space? There are two major parts to this dissertation. The first one is on bodies with directly congruent projections or sections. The second part is about containment of two bodies and relations between their volumes, provided the projections (sections) of the first body can be rotated to be contained in the corresponding projection (section) of the second one.

Committee: Dmitry Ryabogin (Advisor); Artem Zvavitch (Committee Member); Joseph Diestel (Committee Member); Feodor Dragan (Committee Member); Peter Tandy (Committee Member) Subjects: Mathematics

Doctor of Philosophy, The Ohio State University, 2014, Nuclear Engineering

Precise knowledge of prompt γ-ray intensities following neutron capture is critical for elemental and isotopic analyses, homeland security, modeling nuclear reactors, etc. A recently-developed database of prompt γ-ray production cross sections and nuclear structure information in the form of a decay scheme, called the Evaluated Gamma-ray Activation File (EGAF), is under revision. Statistical model calculations are useful for checking the consistency of the decay scheme, providing insight on its completeness and accuracy. Furthermore, these statistical model calculations are necessary to estimate the contribution of continuum γ-rays, which cannot be experimentally resolved due to the high density of excited states in medium- and heavy-mass nuclei. Decay-scheme improvements in EGAF lead to improvements to other databases (Evaluated Nuclear Structure Data File, Reference Input Parameter Library) that are ultimately used in nuclear-reaction models for generating the Evaluated Nuclear Data File (ENDF). In this work, gamma-ray transitions following neutron capture in 93Nb have been studied at the cold-neutron beam facility at the Budapest Research Reactor. Measurements have been performed using a coaxial HPGe detector with Compton suppression. Partial γ-ray production capture cross sections at a neutron velocity of 2200 m/s have been deduced relative to that of the 255.9-keV transition after cold-neutron capture by 93Nb. With the measurement of a niobium chloride target, this partial cross section was internally standardized to the cross section of the 1951-keV transition after cold-neutron capture by 35Cl. The resulting (0.1377 ± 0.0018) barn (b) partial cross section produced a calibration factor that was 23% lower than previously measured for the EGAF database. The thermal-neutron capture cross sections were deduced for the 93Nb(n,γ)94mNb and 93Nb(n,γ)94gNb reactions by summing the experimentally-measured partial γ-ray production cross sections associated with t (open full item for complete abstract)

Committee: Lei Cao PhD (Advisor); Tunc Aldemir PhD (Committee Member); Thomas Blue PhD (Committee Member); Shamsuzzoha Basunia PhD (Committee Member) Subjects: Nuclear Engineering

Doctor of Philosophy (PhD), Ohio University, 2014, Physics and Astronomy (Arts and Sciences)

The objective of this research work is to study the ground state wavefunction of 24O, building on recent work conducted on this topic by various experimentalists and theorists. The ultimate goal is to determine how exactly doubly magic 24O is. Motivated by observations and guided by theoretical perspectives applicable to the nuclear structure of neutron-rich isotopes, the cross section and related spectroscopic factors of dierent final states in 23O are determined to investigate the ground state wave function of 24O. The experiment was conducted at the National Superconducting Cyclotron Laboratory at Michigan State University using the S800 spectrograph and a 470-mg/cm2 Be reaction target with 92.3-MeV/u 24O beam energy. The neutron knockout cross section of 24O to the 1/2+ ground state of 23O and two neutron removal cross section to 22O were measured. The cross section values to the dierent final states of 23O along with the related spectroscopic factors convey to us the composition of the 24O ground state wave function and eventually the magicity of it. Specific details of the experiment, the analysis carried out, and the interpretation of the measured knockout cross sections and longitudinal momentum distributions of residual nuclei are discussed herein

Committee: Carl Brune (Advisor) Subjects: Nuclear Physics

Doctor of Philosophy, University of Akron, 2013, Chemistry

This dissertation focuses on coupling mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to thermal degradation, liquid chromatography (LC) and/or ion mobility (IM) spectrometry for the characterization of complex mixtures. In chapter II, an introduction of the history and the principles of MS and LC are discussed. Chapter III illustrates the materials and instrumentation used to complete this dissertation. Polyethers have been characterized utilizing MS/MS, as presented in Chapter IV and Chapter VI. Diblock copolymers of polyethylene oxide and polycaprolactone, PEO-b-PCL, have been characterized by matrix-assisted laser desorption/ionization quadrupole/time-of-flight mass spectrometry (MALDI-Q/ToF) and LC-MS/MS (Chapter V). Thermoplastic elastomers have been characterized by thermal degradation using an atmospheric solids analysis probe (ASAP) and ion mobility mass spectrometry (IM-MS), as discussed in Chapter VII. Interfacing separation techniques with mass spectrometry permitted the detection of species present with low concentration in complex materials and improved the sensitivity of MS. In chapter IV, the fragmentation mechanisms in MS/MS experiments of cyclic and linear poly(ethylene oxide) macroinitiators are discussed. This study aimed at determining the influence of end groups on the fragmentation pathways. In the study reported in Chapter V, ultra high performance liquid chromatography (UHPLC) was interfaced with MS and MS/MS to achieve the separation and in-depth characterization and separation of amphiphilic diblock copolymers (PEO-b-PCL) in which the architecture of the PEO block is linear or cyclic. Applying UPLC-MS and UPLC-MS/MS provides fast accurate information about the number and type of the blocks in the copolymers. Chapter VI reports MS/MS and IM-MS analyses which were performed to elucidate the influence of molecular size and collision energy on the fragmentation pathways of polyethers subjected to collisionally activated dissocia (open full item for complete abstract)

Committee: Chrys Wesdemiotis Dr. (Advisor); Michael J. Taschner Dr. (Committee Member); Peter L. Rinaldi Dr. (Committee Member); Matthew Espe Dr. (Committee Member); Yu Zhu Dr. (Committee Member) Subjects: Analytical Chemistry; Chemistry

Doctor of Philosophy, The Ohio State University, 2013, Electrical and Computer Engineering

Automobile safety system has received tremendous attention in the past few years. Radar used in such system must be capable of detecting not only other vehicles but also pedestrian. Automobile radar working at 24GHz has been used in blind-spot detection (BSD) and automatic cruise control (ACC) system to track the distance and relative speed of on-road object. However, existing radars are limited to short detection range (30m) and low spatial resolution, making them less useful for pedestrian detection. A new frequency band 76-77GHz, recently designated by the Federal Communication Commission (FCC), the International Telecommunication Union (ITU) in Europe, and the Ministry of Internal Affairs and Communications (MIC) in Japan for vehicular radar. At such high frequencies, a longer detection range (100m-150m) and better resolution can be achieved. As such, it will enable more reliable detection of pedestrians in front of vehicles with lower false alarm rate. In on-road environment, multiple radar reflections may be generated from clutters like trees, trash cans, road surface, curbs and other vehicles. Therefore, it is necessary to identify unique pedestrian radar signatures in the 76-77GHz band to help discriminate them from clutters. Experimental characterization of radar response of human targets at such high frequencies is not trivial and often inaccurate due to extremely short wavelength which makes radar measurement very sensitive to uncertainties associated with body position, orientation, and breathing motion. The variations produced by these uncertainties severely affect the reliability of the radar features extracted from measurement. In addition, the almost infinite combination of clothes, accessories and body postures significantly increase the time and resource required by this approach. In this dissertation, analysing pedestrian radar signatures in the 76-77GHz band via numerical simulations is proposed to overcome the issues with measurements. (open full item for complete abstract)

Committee: Chi-Chih Chen (Advisor); John Volakis (Advisor); Baker Christopher (Committee Member); Olli Tuovinen (Committee Member) Subjects: Electrical Engineering; Electromagnetism

MS, University of Cincinnati, 2001, Engineering : Civil Engineering

Analysis and design of three-layered Portland Cement Concrete (PCC) pavement systems incorporating a base layer have long been hampered by the scarcity of theoretically sound closed-form approaches. This study is focused on verifying and extending the Method of Transformed Sections (MTS), a closed-form approach derived in 1992 on the basis of dimensional analysis and engineering mechanics. The applicability of the MTS to the Dense Liquid (DL) and Elastic Solid (ES) foundations is studied in detail using a wide range of numerical test data for all three fundamental loading conditions (interior, edge and corner). Both unbonded and bonded interface conditions between the two Man-Made Layers (MML) are considered in the study. To make the analysis easier, the MTS is incorporated into computer program WESTERX , a compendium of closed-form solutions for two-and three -layered PCC pavements. Maximum responses (bending stresses, deflections and subgrade stresses) predicted by plate theory MTS are compared with those obtained from finite element computer program ILSL2X. Formulae developed to apply a compressibility correction to these responses are verified using results obtained from layer elastic analysis (computer program DIPLOMAT. Critical responses from plate theory MTS are presented in the form of dimension less charts, which can be used as an alternative to the closed-form approach with either the DL or the ES subgrade idealizations, for all three fundamental loading positions. Graphical solutions are also developed for maximum responses that account for the compressibility of the two MML under interior loading conditions, for both the DL and the ES foundations.

Committee: Dr. Anastasios Ioannides (Advisor) Subjects: Engineering, Civil

MS, University of Cincinnati, 2006, Engineering : Civil Engineering

The focus of the research in this thesis is on the structural behavior and design of two aluminum “E–type” structural sections that are used in unitized curtain wall systems today. Moment capacities of the two “E-type” sections as one are analyzed by three methods - hand calculations using Minimum Moment Capacity Approach and Total Moment Capacity Approach, the finite element method using ABAQUS program, and via an experimental investigation. A comparison of moment capacities determined using the three methods is presented. Upon the evaluation and comparison of the results obtained by the three methods in this study, the Total Moment Capacity Approach is determined to be an accurate method to predict moment capacities of the two “E-type” structural sections functioning as one structural member and is recommended for the evaluation of moment capacities of complex thin-walled sections and assembled sections to supplement the Specification for Aluminum Structures (2000).

Committee: Dr. James Swanson (Advisor) Subjects: Engineering, Civil

MS, University of Cincinnati, 2004, Engineering : Electrical Engineering

There is a growing need for compact, efficient rare-earth doped waveguide optical amplifiers for use in optical communications. Zn2Si0.5Ge0.5O4 (ZSG) is a promising new host material for Erbium(Er) due to the high concentration of Er which can be incorporated and the high optical activity of the incorporated Er. In this thesis, the absorption and emission cross-sections of Er in Er-doped ZSG are measured both through an analysis of the photo-luminescence spectra, and from direct absorption measurements. Peak cross sections are about 3 x 10-24 m2, comparable to measurements on other oxide-based glass amplifiers. The population statistics of the excited Er-level (4I13/2), along with the excited state lifetime, are determined through a novel rate-equations-based frequency domain method in which the spontaneous emission power at 1534 nm is measured as a function of pump power (980nm) and pump modulation frequency. The determined lifetime of 2ms is comparable to the 2.3ms measured using a conventional pump probe technique. The novel analysis technique yields the Er population statistics and lifetime under different pumping conditions independent of the unknown and variable coupling in and out of the waveguide. This method predicts zero net gain at 70mW, about what is observed. Comparison of calculated gain (based on Er density and measured cross-sections) with measured gains suggest that only about 20-30% of the Er in the material is optically active. Thus, by a systematic study of cross sections, Er population statistics and lifetime, and fraction of optically active Er as a function of Er density, the mechanisms for gain quenching with concentration can be studied. A 4.7cm long sample demonstrated a peak fiber-to-fiber net gain of ~2 dB and a signal enhancement of >13 dB. Cavity characteristics were measured using an analysis of coherent reflection under no pumping. The facet reflectivity was determined to be 0.27 and the scattering/absorption loss was 1.05/cm. These l (open full item for complete abstract)

Committee: Dr. David Klotzkin (Advisor) Subjects:

Doctor of Philosophy, The Ohio State University, 2010, Soil Science

In Ohio, approximately 55% of agricultural land needs drainage to overcome occasional water ponding, reduce soil erosion, improve fields to support farm equipment and reduce crop yield variability. In recent years, many Ohio farmers converted to non-tillage systems without understanding the system constraints especially on poorly drained soils. Due to Ohio being a major coal-burning state for electricity production, enormous amounts of coal combustion by-products such as gypsum are readily available for agricultural use. Gypsum is a source of calcium which may improve the physical properties of the soil by promoting soil aggregation, increasing water surface infiltration rates and movement into and through the soil profile. Several studies in the Midwest have focused on the effect of gypsum controlling surface structure, crusting, sealing and erosion. However few studies have analyzed the structural and hydrologic effects of gypsum on the whole profile of non-sodic soils, especially in subsurface horizons.For that reason, undisturbed soil columns from Brookston loam and Celina silt loam soils with different gypsum application regimes were collected to determine the effect of gypsum on physical-chemical soil properties and hydrology of these two non-sodic soils with contrasting drainage from no-till fields. Higher exchangeable calcium and Ca:Mg ratios were found on both gypsum treated soils. Soil turbidity and light transmittance studies showed a positive effect with respect to gypsum application rate. Clearer suspensions and higher light transmittance were found under long-term gypsum. However, there was no consistent response for gypsum application regimes in both soils for water stable aggregates, water stable aggregates by aggregate size and mean weight diameter on the whole soil profile. Positive gypsum effects on both Brookston treated soils were observed. Greater water stable aggregates were found for > 4mm aggregates in the top 60 cm of short-term gypsum trea (open full item for complete abstract)

Committee: Brian Slater K (Advisor); Warren Dick A (Committee Member); Edward McCoy L (Committee Member); David Barker J (Committee Member) Subjects: Soil Sciences

Doctor of Philosophy, The Ohio State University, 2007, Mechanical Engineering

This dissertation uses a robotics-inspired approach to develop a low-dimensional forward dynamic model of normal human walking. The analytical model captures the dynamics of walking over a complete gait cycle in the sagittal plane. The model for normal walking is extended to model asymmetric gait. The asymmetric model is applied to study the gait dynamics of a transtibial prosthesis user. Modeling human walking is complex because walking involves (i) the body's many degrees of freedom (DOF), (ii) constraints that change, and (iii) intermittent contact with the environment that may be impulsive. Complex forward dynamic models that attempt to capture details such as joints with multiple DOF, musculature, etc., are analytically intractable; it is impossible to describe the model's behavior in mathematically manageable terms because of the enormous number of variables and redundancies involved. Observation of human walking from a systems point of view reveals that the human body coordinates its many DOF in a parsimonious manner to accomplish the task of moving the body's center of mass from one point to another. This dissertation's approach exploits this parsimony to derive an analytically tractable model that has the minimum DOF necessary to describe the task of walking in the sagittal plane. The low-dimensional hybrid model is derived as an exact sub-dynamic of a higher-dimensional anthropomorphic hybrid model. The hybrid nature is the result of continuous sub-models of single support (SS) and double support (DS), and discrete maps that model the transitions from SS to DS and DS to SS. The modeling is validated using existing gait data. To extend the clinical usefulness of the modeling approach, the model for normal walking is extended to model asymmetric gait. The asymmetric model can accommodate asymmetries in the parameters and joint motions of the left and right legs. The asymmetric model is applied to analyze the gait dynamics of a transtibial prosthesis user. Co (open full item for complete abstract)

Committee: Eric Westervelt (Advisor) Subjects: