Theses and Dissertations

Nearly half a million miles of pipeline transport hazardous fluids around the United States. The potential for the release of flammable fluids poses a momentous hazard for the surrounding areas. Of particular concern to our built infrastructure is the accidental leakage and detonation of natural gas pipelines. Two Natural Gas (NG) leakage accidents are examined in detail. This includes the 2011 explosion in Allentown, PA and the 2014 explosion in Harlem, New York.

This dissertation presents a comprehensive examination of the underlying mechanics and design of precast concrete wall panels suited for blast-resistant design applications. This includes the development of a ductile shear tie system for insulated wall pa

The electromagnetic properties of a live biological system are extremely important to many medical applications. While information about electromagnetic properties of tissues are available in the literature, little or no data are available for a single cell or subcellular structures. Microwave biological/cell detection has been demonstrated to be useful and promising in many medical applications due to its internal properties such as non-invasive, fast and label-free.

Recent advances in additive manufacturing technologies for concrete construction have been limited to low resolution fused deposition methods, herein the author aims to advance high resolution binder jet printing methods for cement construction applications. The inherent challenge of additive binder jet cement printing is to achieve adequate mechanical strengths and maintain geometry without the agitation typical of conventional concrete fabrication.

For the first time, the impedance spectrum of live Jurkat T-lymphocytes human cells was characterized in a single sweep spanning six decades of frequency from 9 kHz to 9 GHz. The ultrawide bandwidth bridged the traditional impedance spectroscopy at kilohertz to megahertz frequencies with the recently developed microwave dielectric spectroscopy, which can probe the cell interior without being hindered by the cell membrane.

A closed-loop capacitance sensing and control mix-mode circuit with a dedicated sensor electrode and a proportional-integral controller was designed for MEMS varactors. The control was based on tuning the bias magnitude of the MEMS varactor according to t

A new short-span highway bridge system composed of inverted steel tee beams embedded in a concrete slab was developed for the Pennsylvania Department of Transportation. The connection between the concrete deck and steel tee beams is non-traditional, and is fabricated by drilling holes near the top of the steel tee beam stem, placing reinforcement bars through the holes and casting the tee beam stem into the deck.

This dissertation aims to evaluate the mechanical performance of segmental tunnel lining systems during construction and service and the fire performance of drop ceilings in roadway tunnels. To achieve this goal, the research focuses on several aspects, including the assessment and design approach development of tunnel lining segments under thrust jack load. This is accomplished via a combination of full-scale experimentation and numerical modeling. Furthermore, the study examines the radial joint rotational behavior of segmental tunnel lining systems through full-scale experimentation.

For the first time, wafer-scale fabrication of PtSe2 MOSFETs was demonstrated by photolithography. The on PtSe2 is grown by thermally assisted conversion (TAC) of Pt films under Se vapor at 400 °C. Taking advantage of the unique property of PtSe2 to transition from semiconductor to semimetal as its thickness increases beyond a few monolayers, channel recess was adapted for improving gate control while keeping the contact resistance as low as 0.008 Ω∙cm. The wafer-scale fabrication resulted in uniform device characteristics so that average vs. best results were reported, as well as RF vs.