Engineering Commons^™

Stress Analysis Of Operating Gas Pipeline Installed By Horizontal Directional Drilling And Pullback Force Prediction During Installation, Hongfang Lu

Doctoral Dissertations

With the development of the natural gas industry, the demand for pipeline construction has also increased. In the context of advocating green construction, horizontal directional drilling (HDD), as one of the most widely utilized trenchless methods for pipeline installation, has received extensive attention in industry and academia in recent years. The safety of natural gas pipeline is very important in the process of construction and operation. It is necessary to conduct in-depth study on the safety of the pipeline installed by HDD method.

In this dissertation, motivated by the following considerations, two aspects of HDD are studied. First, through the …

Feature Space Modeling For Accurate And Efficient Learning From Non-Stationary Data, Ayesha Akter

Doctoral Dissertations

A non-stationary dataset is one whose statistical properties such as the mean, variance, correlation, probability distribution, etc. change over a specific interval of time. On the contrary, a stationary dataset is one whose statistical properties remain constant over time. Apart from the volatile statistical properties, non-stationary data poses other challenges such as time and memory management due to the limitation of computational resources mostly caused by the recent advancements in data collection technologies which generate a variety of data at an alarming pace and volume. Additionally, when the collected data is complex, managing data complexity, emerging from its dimensionality and …

Electrolytic Metallization Of Halloysite Nanotubes And Antimicrobial Applications, Ahmed Humayun

Doctoral Dissertations

Due to increased reports of infections and biofouling arising from the use of invasive medical devices, novel antimicrobial agents with suitable anti-biofouling properties are critically needed. Transition metals exhibit substantial antimicrobial activity; however, their use is limited because of their inherent toxicity to eukaryotic cells. In this regard, naturally occurring halloysite clay nanotubes (HNTs) show significant promise. HNTs possess a high surface area for adsorption while its hollow lumen can be used for loading different materials.

Herein, we demonstrate an electrolytic method for generating and depositing metal nanoparticles (NPs) on the HNTs outer surface and we propose an optimized method …

A Multicarrier Technique For Monte Carlo Simulation Of Electrothermal Transport In Nanoelectronics, Tyler J. Spence

Doctoral Dissertations

The field of microelectronics plays an important role in many areas of engineering and science, being ubiquitous in aerospace, industrial manufacturing, biotechnology, and many other fields. Today, many micro- and nanoscale electronic devices are integrated into one package. e capacity to simulate new devices accurately is critical to the engineering design process, as device engineers use simulations to predict performance characteristics and identify potential issues before fabrication. A problem of particular interest is the simulation of devices which exhibit exotic behaviors due to non-equilibrium thermodynamics and thermal effects such as self-heating. Frequently, it is desirable to predict the level of …

Application Of Halloysite Nanotubes In Bone Disease Remediation And Bone Regeneration, Yangyang Luo

Doctoral Dissertations

Customized patient therapy has been a major research focus in recent years. There are two research fields that have made a significant contribution to realizing individualized-based treatment: targeted drug delivery and three-dimensional (3D) printing technology. With benefit from the advances in nanotechnology and biomaterial science, various drug delivery systems have been established to provide precise control of therapeutic agents release in time and space. The emergence of three-dimensional (3D) printing technology enables the fabrication of complicated structures that effectively mimic native tissues and makes it possible to print patient-specific implants. My dissertation research used a clay nanoparticle, halloysite, to develop …

Increasing The Functionality Of Additive Manufacturing Through Atmospheric Microplasma And Nanotechnology, Alexander Jon Ulrich

Doctoral Dissertations

Additive Manufacturing (AM) has been changing the manufacturing landscape for the last 20 years. As the interest and demand for both polymer and metal-based 3D printing has grown, the materials and machines used have increased in capabilities. Despite the growth and advancement, there are still a large number of improvements that can be made to add functionality to 3D printers. Metal AM, a subcategory of 3D printing, has garnered much attention among industrial applications with large companies such as General Electric trying to implement the technology to increase innovative designs for motors. Some of the limitations on AM have to …

Design, Microfabrication And Characterization Of Concentric Gold Nanoring Electrode For Neurochemical Sensing, Haocheng Yin

Doctoral Dissertations

Nanoelectrodes have become widely used in electrochemical sensing in recent decades. When compared to microelectrodes, it has many unique advantages such as high signal to noise ratio, small sample volume requirement, and lower detection limits.

This work reports on the microfabrication and characterization of a gold nanoring electrode (Au NRE) patterned on top of a silicon (Si) micropillar. An NRE of 165  10 nm in width was micropatterned on 4.6  1 µm diameter  17.5  2.5 µm long Si micropillar with an intervening 50 nm thick hafnium oxide insulating layer. Scanning electron microscopy and energy dispersive spectroscopy …

Development Of A Low Profile, Endoscopic Implant For Long Term Brain Imaging, Benjamin Scott Kemp

Doctoral Dissertations

The increased public awareness of concussion and traumatic brain injury has motivated continued research into the brain, its functions, and especially its response to injury, with a focus on improving the brain’s repair capabilities. However, due to the critical nature of the tissue, it is currently difficult for researchers to acquire high resolution images below the cortex without sacrificing a lab animal. Sacrificing an animal greatly reduces the amount of data that can be obtained from it, making longitudinal studies unappealing or unfeasible because a large number of animals is needed to obtain useful data over multiple time points. Additionally, …

Migration And Electropolymerization Of Methyl Methacrylate In Hardened Cement Paste Via Electrokinetic Treatment, Xi Xie

Doctoral Dissertations

Porous concrete structures are susceptible to the intrusion of chemical species, such as sulfates, chlorides, and carbon dioxide. Many technologies have been developed to repair or rehabilitate damaged concrete. These include cathodic protection, corrosion inhibitor addition, or the use of coatings and sealers. In recent years, a developing technology, electrokinetic nanoparticle treatment, has been shown to reduce concrete porosity, increase strength, promote corrosion resistance, and extend durability. This dissertation was conducted to explore a novel treatment to reduce the porosity of concrete via the application of electrokinetic transportation and electro-initiated polymerization of methyl methacrylate (MMA).

Potassium persulfate (PSP) was used …

Organically Modified Inorganic Nanoparticles For Halochromic Ionophores And Nucleic Acids, William Johnston

Doctoral Dissertations

In this dissertation, four nanoparticle reaction schemes were developed as substrates for halochromic dyes or nucleic acids. The reaction schemes include the use of two substrates: silica nanoparticles and halloysite nanotubes. The protocols can incorporate silica (SiO2) nanoparticles and halloysite aluminosilicate (AlO2SiO2) nanotubes due to the presence of silane groups on the surface of either substrate. The reaction schemes are presented along with detailed protocols which were written to facilitate both reproducibility and to serve as an aid to further study and for easy modification of the protocol to suit a researcher's needs. The data is discussed in the materials …

Two And Three-Dimensional Models For Material And Cells Interaction, Nam H. Nguyen

Doctoral Dissertations

Three-dimensional (3D) cell spheroid model has been long considered a better model to mimic in vivo physiology compared to two-dimensional (2D) cell culture model. Traditional 2D cell models provide a simple, convenient and quick technique for drug screening but fail to simulate the complexity and heterogeneity of cells in the in vivo environment. The last few decades have remarked substantial progress toward the advancement of three-dimensional (3D) cell cultures as systems which better mimic cellcell and cell-matrix interaction in the in vivo physiology. Nowadays, 3D cell models have been emerging, not only as an important approach in drug discovery and …

Evaluation Of Carbon Footprint During The Life-Cycle Of Four Different Pipe Materials, Alhossin Alsadi

Doctoral Dissertations

As the world is moving to provide a better and cleaner environment for future generations, there is a critical need to quantify and try to reduce the environmental emission footprints of various industries. The construction industry, which emits a large amount of carbon dioxide (CO₂ ), is one of the targeted industries to decrease these emissions. Underground utility installations, especially in the development of residential communities in urban areas, are one of the largest construction projects across North America and, consequently, one primary source of emissions. Most of the pipelines in the U.S. are rapidly reaching the end of their …

Development Of An Astrocyte/Glioma Co-Culture System For Measuring Cellular Dynamics, Urna Kansakar

Doctoral Dissertations

Gliomas are brain tumors that primarily arise from glial cells. Gliomas account for 70% of the brain tumors and they are more prevalent in older adults. About 60% of the people with gliomas experience at least one seizure. Brain tumors can grow and metastasize to neighboring areas, thereby destroying normal brain cells. In a brain tumor microenvironment, both malignant cancer cells and healthy brain cells are present. Studies have shown that astrocytes may have a role in tumor growth in the brain. Monocultures cannot evaluate interactions between two cell types and does not accurately represent in vivo conditions. Thus, a …

Development Of A Counter-Flow Thermal Gradient Microfluidic Device, Shayan Davani

Doctoral Dissertations

This work presents a novel counter-flow design for thermal stabilization of microfluidic thermal reactors. In these reactors, precise control of temperature of the liquid sample is achieved by moving the liquid sample through the thermal zones established ideally through the conduction in the solid material of the device. The goal here is to establish a linear thermal distribution when there is no flow and to minimize the temperature change at flow condition. External convection as well as internal flowinduced effects influence the prescribed thermal distribution. The counter-flow thermal gradient device developed in this study is capable of both stabilizing the …

Use Of Wicking Geotextile To Dehydrate Road Embankments, Chuang Lin

Doctoral Dissertations

“Excess water within a pavement structure is the major cause of pavement deteriorations. A roadway is often constructed with soils compacted at the optimum water contents to achieve the best performance. After construction, the soil water content variation is controlled by the ambient environment. The base course aggregate is very sensitive to water content variations. Unfortunately, conventional drainage system can only drain gravity water, but not capillary water, and it cannot work under unsaturated conditions. Consequently, no matter how well the road is constructed, the water content is expected to increase with time and the excess water will inevitably accelerate …

Scaleable Nanomanufacturing Of Metasurfaces Using Microsphere Photolithography, Chuang Qu

Doctoral Dissertations

“The cost-effective manufacturing of metasurfaces over large areas is a critical issue that limits their implementations. Microsphere photolithography (MPL) uses a scalable self-assembled microsphere array as an optical element to focus collimated light to nanoscale photonic jets in a photoresist layer. This dissertation investigates the fabrication capabilities, process control, and potential applications of MPL. First, the MPL concept is applied to the fabrication of metasurfaces with engineered IR absorption (e.g. perfect absorption with multiband/broadband and wavelength/polarization dependences). Improving the patterning of the photoresist requires a fundamental understanding the photochemical photonic jet interactions. The dissertation presents a model of the MPL …

Solvent-Free Additive Manufacturing Of Electrodes For Li-Ion Batteries, Brandon Joshua Ludwig

Doctoral Dissertations

"A new Li-ion battery electrode manufacturing process using a solvent free additive manufacturing method has been developed. Li-ion battery electrodes consist of active material particles, a binder additive, and a conductive additive. Traditionally, Li-ion battery electrodes are manufacturing using the "slurry casting" technique. In this method, the electrode materials are mixed with a solvent to create a slurry. Electrodes fabricated in this method are readily implemented for small platforms, such as portable electronics. However, this method isn't as economically viable in large platforms due to high material and manufacturing costs. High material and manufacturing costs are mostly attributed to the …

Pressure Versus Impulse Graph For Blast-Induced Traumatic Brain Injury And Correlation To Observable Blast Injuries, Barbara Rutter

Doctoral Dissertations

"With the increased use of explosive devices in combat, blast induced traumatic brain injury (bTBI) has become one of the signature wounds in current conflicts. Animal studies have been conducted to understand the mechanisms in the brain and a pressure versus time graph has been produced. However, the role of impulse in bTBIs has not been thoroughly investigated for animals or human beings.

This research proposes a new method of presenting bTBI data by using a pressure versus impulse (P-I) graph. P-I graphs have been found useful in presenting lung lethality regions and building damage thresholds. To present the animal …

Dynamic Impact Induced By Tornadoes Through Simulations Based On Two-Way Wind-Structure Interactions, Tiantian Li

Doctoral Dissertations

"Tornadoes have become a significant cause of property damage, injuries and life losses. Investigations of tornadoes indicate that most fatalities were caused by building failure. For example, in the Joplin, MO tornado of 22 May 2011, 161 people were killed, and 84% fatalities were related to building failure. Therefore, it is imperative to develop science-based tornado-resistant building codes, in order to provide a better level of occupant protection from tornadoes and to minimize the tornado-induced damage. This requires in-depth understanding of the wind characteristics of tornadoes and their wind effects on civil structures, based on which design tornadic wind loading …

Application Of Computational Intelligence To Explore And Analyze System Architecture And Design Alternatives, Gene Lesinski

Doctoral Dissertations

"Systems Engineering involves the development or improvement of a system or process from effective need to a final value-added solution. Rapid advances in technology have led to development of sophisticated and complex sensor-enabled, remote, and highly networked cyber-technical systems. These complex modern systems present several challenges for systems engineers including: increased complexity associated with integration and emergent behavior, multiple and competing design metrics, and an expansive design parameter solution space. This research extends the existing knowledge base on multi-objective system design through the creation of a framework to explore and analyze system design alternatives employing computational intelligence. The first research …

Ferrite Characterization Techniques & Particle Simulations For Semiconductor Devices, Nicholas Erickson

Doctoral Dissertations

"This dissertation is divided into three papers, covering two major topics. The first topic, techniques for ferrite characterization, is discussed over the course of two papers. The second topic, particle simulations for semiconductor devices, is discussed in the last paper. In the first paper, the method for extracting permeability from ferrite materials is discussed for the Keysight 16454A permeability extraction fixture, where the ferrite material to be characterized is assumed to be homogeneous. Then the method is updated to account for layered materials. The updated method is verified through full-wave simulations. In the second paper, a planar printed circuit board …

Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu

Doctoral Dissertations

"Engineers always encounter time-dependent uncertainties that ubiquitously exist, such as the random deterioration of material properties and time-variant loads. Therefore the reliability of engineering systems becomes time-dependent. It is crucial to predict the time-dependent reliability in the design stage, given possible catastrophic consequences of a failure. Although extensive research has been conducted on reliability analysis, estimating the reliability accurately and efficiently is still challenging. The objective of this work is to develop accurate and efficient reliability methodologies for engineering design. The basic idea is the integration of traditional reliability methods with saddlepoint approximation (SPA), which can accurately approximate the tail …

Experimental Investigation Of Liquid Contact In The Developing Post-Dryout Chf Flow Boiling Regime Using Surface Mounted Thermistors, Hiralkumar Harshadbhai Patel

Doctoral Dissertations

"Understanding heat transfer in the post-critical heat flux (CHF) flow boiling regime is important for determining the performance of the heat transfer equipment for various industrial applications requiring high heat transfer rates, e.g., heat exchangers, boilers, chemical and nuclear reactors. Liquid can be present in the core of the flow channel in the form of entrained liquid droplets, especially immediately downstream of film dryout. These droplets are suspected to provide an important heat transfer mechanism as they impinge on the heated wall. The objective of the current study is to investigate liquid contact with the heated wall in this flow …

Polyurea Aerogels: From Nanoscopic To Macroscopic Properties, Tahereh Taghvaee

Doctoral Dissertations

"The morphology of a material is intrinsically a qualitative property and in order to relate nanomorphology to synthetic conditions, it is necessary to express nano/micro-structure quantitatively. In this context, polyurea aerogels were chosen as a model system with demonstrated potential for rich nanomorphology and being guided by a statistical Design-of-Experiments model, a large array of materials (208) with identical chemical composition, but quite different nanostructures were prepared. By reflecting upon the SEM images, it was realized that our first pre-verbal impression about a nanostructure is related to its openness and texture; the former is quantified by porosity (Π), and the …

Hydrodynamics Of Trickle Bed Reactors (Tbrs) Packed With Industrial Catalyst Using Advanced Measurement Techniques, Mohammed Jaber Al-Ani

Doctoral Dissertations

"The impacts of the packing characteristics on the hydrodynamics od a trickle bed reactor (TBR) have been investigated using advanced measurements techniques of Gamma-ray densitometry (GRD) and Optical fiber probe and conventional measurement techniques of high-frequency differential pressure transducer and load cell. Two different reactor sizes of bench and pilot plant scale were used. Bench-scale TBR carried out the experiments to assess phase distribution and catalyst utilization with 1.18 cm inside diameter and 72 cm length at ambient pressure and temperature. The mixture of catalyst and fine particles displayed considerable improvements in the phase distribution, liquid holdup profile, and catalyst …

Modeling Strategies For Estimating And Suppressing Electromagnetic Interference And Improving Power Integrity, Tamar Makharashvili

Doctoral Dissertations

"Decoupling capacitors are used to suppress high-frequency noise in power distribution networks. The inductance associated with a mounted decoupling capacitor can vary by 26% depending on characteristics of the printed circuit board. Here, simple and accurate inductance models of 2- and 8-terminal capacitors including connections to the power and return plane are developed. Circuit models of the capacitors and layout are created using the partial equivalent element circuit method which provide options for circuit-level simulations as well as analytic estimation of inductance. The circuit solution matches results from the full-wave simulation model within 9% for the 8-terminal capacitor and within …

Hardware Architectures For Compact Microwave And Millimeter Wave Cameras, Matthew Jared Horst

Doctoral Dissertations

"Millimeter wave SAR imaging has shown promise as an inspection tool for human skin for characterizing burns and skin cancers. However, the current state-of-the-art in microwave camera technology is not yet suited for developing a millimeter wave camera for human skin inspection. Consequently, the objective of this dissertation has been to build the necessary foundation of research to achieve such a millimeter wave camera. First, frequency uncertainty in signals generated by a practical microwave source, which is prone to drift in output frequency, was studied to determine its effect on SAR-generated images. A direct relationship was found between the level …

Plugging Performance Of Preformed Particle Gels In Fractures And Its Influencing Factors, Ze Wang

Doctoral Dissertations

"Preformed particle gels (PPG) has been successfully applied to combat the water channeling caused by fractures or fracture-like channels. Understanding the placement and plugging of PPG in fractures is crucial for gel treatment design. The objective of the dissertation is to explore the plugging performance of three PPG products in two types of fracture models, the partially and fully open fractures. The following studies has been conducted and conclusions have been drawn based on the results and analysis. First, the placement and plugging performance of conventional PPG was investigated using core flooding experiments conducted partially open fractures. The plugging efficiency …

Improvements In Digital Image Correlation And Application In Material Mechanical Test, Yunlu Zhang

Doctoral Dissertations

"Digital image correlation (DIC) is a non-contact full-field optical measurement method. With the advantages of high accuracy, low cost, and simple implementation, it has been widely applied in the area of experimental mechanics. In this study, DIC algorithm has been improved in the aspects of the pixel-level searching method and reference frame update strategy. The feature matching based method is proposed to provide an initial guess for all points of interest with semi-subpixel level accuracy in cases with small or large translation, deformation, or rotation. The bisection searching strategy is presented to automatically adjust the frame step for varying practical …

Chemically-Bonded Enamel-Coated Steel Pipelines For Corrosion Protection And Flow Efficiency, Liang Fan

Doctoral Dissertations

"This study is to explore and develop chemically-bonded enamel coating (200-300 um) on steel pipes, when subjected to soil and thermal environments, in order to improve the corrosion protection and safety of hazardous liquid and natural gas pipelines while reducing pressure loss. Out of five types of enamels and their various mixtures, Tomatec slurry and GP2118 powder were selected for steel pipeline applications. They were applied at approximately 810 °C to the inside surface of steel pipes in wet and electrostatic processes, respectively. The thickness and surface roughness of the enamel coating were measured using a gauge and an optical …