Master of Science (MS), Wright State University, 2014, Earth and Environmental Sciences

Wright State University acquired two vibroseis-sourced seismic reflection lines over the Dominion East Ohio Gabor Gas Storage field near Canton, Ohio. The data were gathered over a fully charged reservoir within the Clinton interval. Seismic attributes were applied to the seismic data for interpretation. The seismic response of nearby wells was modeled for comparison with the seismic lines. Within the seismic data a gas shadow was observed. The gas shadow coincides with an area of high initial production of wells targeting the Clinton interval for production. The gas shadow is also associated with broadening of the Packer Shell sidelobe. Modelling of the seismic response of well API# 3416925010000 shows a broadening effect of the Packer Shell sidelobe similar to that seen in the seismic data. This broadening is also associated with low porosity, implying that broadening of the Packer Shell sidelobe is indicative of a poor hydrocarbon reservoir.

Committee: Doyle Watts Ph.D. (Committee Chair); Ernest Hauser Ph.D. (Committee Member); David Dominic Ph.D. (Committee Member) Subjects: Earth; Energy; Geology; Geophysics; Petroleum Geology

Master of Science in Electrical Engineering (MSEE), Wright State University, 2019, Electrical Engineering

Wideband technology has been applied to many wide bandwidth applications when there is a need to send much different information in a short time from one point and received from another point in high precision and accuracy. A wideband receiver reports a signal without tuning if the signal is within the input bandwidth. The analog Instantaneous Frequency Measurement (IFM) receiver has been used for decades to cover a very wide input bandwidth and report one accurate frequency on a short pulse at a time. The digital IFM use a high sampling rate ADC to operate in a wide bandwidth, Hilbert transform to produce two output channels that have a 90-degree phase shift and autocorrelation to measure the frequency by comparing different delayed lines of the input signal with the original one. This research discusses the sensitivity of the existing digital IFM receiver and optimizes the Hilbert transform as well as the autocorrelation architectures to report a fine frequency within a noisy wide bandwidth environment after improving its sensitivity.

Committee: Henry Chen Ph.D. (Advisor); Saiyu Ren Ph.D. (Committee Member); Yan Zhuang Ph.D. (Committee Member) Subjects: Electrical Engineering; Engineering

Doctor of Philosophy, The Ohio State University, 2013, Mechanical Engineering

This scholarly research investigates the transient vibration amplification problem in nonlinear torsional systems with application to vehicle engine-clutch damper-transmission system. This particular system includes several discontinuous nonlinear elements such as multi-staged (piecewise linear) stiffness, clearance(s) in the gear pair(s), multi-staged hysteresis and preload. The torsional system is excited by the engine start-up (or shut-down) process with an instantaneous firing frequency from the engine. Transient vibration amplification is observed when the speed passes through the torsional vibration resonance(s). The role of abovementioned nonlinear components in influencing the amplification level is not well understood. Therefore, the development of new or improved analytical, semi-analytical and numerical solutions of a nonlinear system, in time (or order) domain, is the focus of this dissertation. First, the problem is formulated in the context of a generic single-degree-of-freedom torsional system. A new closed form solution of the linear torsional oscillator, given motion input with an instantaneous excitation frequency term, is found. The solution for a linear system is able to approximate the transient response (such as peak to peak value of the amplified displacement) of a piecewise linear oscillator under a rapidly varying frequency. Analytical and semi-analytical methods are utilized next to find the transient envelope and to quantify the amplification level. Second, new closed form solutions of the transient envelopes of torsional displacement, velocity, and acceleration for a linear damped oscillator are developed and verified in the order domain. Analytical approximations of the peak frequency and the corresponding maximum amplification are mathematically derived which are also verified by comparing with previously reported analytical or empirical formulas. Dynamic characteristics of a nonlinear torsional path during the non-stationary (open full item for complete abstract)

Committee: Rajendra Singh (Advisor); Ahmet Selamet (Committee Member); Mo-How Herman Shen (Committee Member); Junmin Wang (Committee Member); Jason Dreyer (Committee Member) Subjects: Mechanical Engineering