Engineering Commons^™

Investigations Of Carbon Dioxide Storage In Low-Temperature Reservoirs For Non-Leaking Storage, Md Nahin Mahmood

Doctoral Dissertations

Carbon dioxide (CO₂) injection into subsea or low-temperature water zones has emerged as a promising strategy for long-term, non-leaking CO₂ storage through the formation of solid hydrates. This research investigates CO₂ injection into Berea sandstone cores saturated with water under simulated subsea conditions, focusing on hydrate formation behavior across varying temperatures, pressures, and injection flow rates. Experimental results demonstrate that CO₂ hydrate formation under dynamic (flowing) conditions occurs at significantly higher pressure compared to static conditions reported previously. At temperatures ranging from 0 °C to 5 °C, dynamic hydrate formation pressures were observed to be approximately double. This can be …

Radio Frequency Wave Propagation Modeling Within Obstructed Underground Mining Environments For Effective Miner Localization During Mine Emergencies, Emmanuel Atta Antwi

Doctoral Dissertations

The reliability of underground wireless communication systems remains a significant challenge, particularly during emergencies when the mine environment becomes severely obstructed by debris, dust, and humidity. These environmental and geometric conditions result in significant attenuation of electromagnetic (EM) waves and multipath effects that undermine miner localization and rescue operations. Existing Vector Parabolic Equation (VPE) models are efficient for straight or mildly curved tunnels but fail to account for the random and obstructive conditions typically encountered during underground emergencies. This research develops a novel radio propagation model for EM wave behavior in underground mine drifts under geometrically obstructed conditions. The model …

Advancing Refuge Alternatives In Mine Emergencies Using Advanced Numerical Simulation, Kutay Emre Karadeniz

Doctoral Dissertations

"Incidents and emergencies within underground coal mines can result in severe injuries or even loss of life, particularly due to the hazardous nature of mine explosions. One of the options for the miners to protect themselves from these hazards is to be sheltered in a refuge alternative (RA). However, the literature lacks an analysis of survivability constraints and the structural integrity of RAs when exposed to geomechanical changes and the ability to withstand the impact of coal mine explosions. In this study, based on the utilization and survivability constraints, basic human requirements and the required physical specifications of RAs during …

A Comprehensive Analysis Of Climate Resilience Strategies For Small Island Developing States, Ashley-Ann Davis

Doctoral Dissertations

Small Island Developing States (SIDS) face unique and disproportionate challenges in their efforts to achieve climate resilience due to their geographic vulnerabilities, limited resources, and systemic economic and social constraints. This dissertation provides a comprehensive analysis of climate resilience strategies tailored to SIDS, addressing critical systemic issues and exploring interdisciplinary solutions. It synthesizes findings across four interconnected studies, including an analysis of disaster preparedness and response mechanisms in developing countries to identify gaps and opportunities for improving resilience in extreme events. The research investigates economic factors influencing energy portfolio transitions in the Caribbean, emphasizing the complexities of renewable energy adoption. …

Integrated Study Of Heat Transfer And Local Gas Dynamics In A Pebble Bed Very High Temperature Nuclear Reactor Using Advance Measurement Techniques, Muhna N. Alshammari

Doctoral Dissertations

"The aim of this study, pebbles of diameter of 5 cm and a pebble-to-diameter ratio (aspect ratio) of 6 were used. In part I, the local gas velocities were studied at different radial and axial locations in the pebble bed using a sophisticated hot wire anemometry (HWA) technique, which was supported with a novel probe-protector case to protect the fragile probe, allowing the measurements to be taken between the pebbles for the first time. The local gas velocities were found to be significantly higher in the near wall region due to the higher void fractions in the near-wall region, compared …

Topography Of The 410 And 660 Km Discontinuities Beneath The Tibetan Plateau And Adjacent Areas, Zexin Miao

Doctoral Dissertations

"The Tibetan Plateau represents the ongoing geotectonic aftermath of a continental collision initiated approximately 65 million years ago. Despite numerous seismological studies, controversies remain regarding the structure, evolution, and dynamics of the crust and mantle beneath Tibetan Plateau. In this study, we used teleseismic broadband data to investigate the topography of the mantle transition zone (MTZ) discontinuities. A total of ~655,000 receiver functions from 735 stations was utilized to image the 410 and 660 km discontinuities bordering the MTZ. Combining the observed and velocity corrected results, several areas in the central Tibet exhibit a typical d410 and an anomalously deep …

Effectiveness Of Clay Nanotube Blended Coating Materials For Thermal Insulation, Hawa Hashm

Doctoral Dissertations

Studies conducted by the U.S. Department of Energy reported that heating and cooling systems use nearly 60% of the total energy consumed in a building, while approximately 31% of that energy loss occurs through the improperly insulated floor, walls, and ceiling. Hot summers or severely cold weather can make these problems worse. The passing of conditioned air through these building materials is a substantial source of energy loss, which has driven significant investigation into new environmentally friendly, sustainable, and cost-effective solutions. The main objective of the research was to experimentally evaluate the thermal conductivity of paints blended with halloysite nanotubes …

Wind Flow Characteristics Of Multi-Vortex Tornadoes And Their Wind Effects On Residential Houses, Yi Zhao

Doctoral Dissertations

"Tornadoes strike the USA very frequently, with an average of 1200 reports per year, and the average annual tornado-induced property loss has reached $10B. The devastation from recent tornadoes have prompted a renewed interest in better understanding tornado dynamics, their interactions with the built environment, and the performance of civil structures during tornadoes. In the past, the wind effects caused by single-vortex tornadoes have been widely studied, while the multi-vortex tornadoes were rarely considered. In fact, many previous deadly, costly tornadoes involved multiple vortices. Therefore, it is important to understand the wind flow characteristics of multi-vortex tornadoes in order to …

Evaluation Of Recrosslinkable Preformed Particle Gel (Rppg) As A Fluid Loss Control Material During Drilling Operations, Mohamed Saad M. Ahdaya

Doctoral Dissertations

"One of the most intense, expensive, and time-consuming problems during drilling operations is the loss of circulation, which could result in several consequences, including wellbore collapse, fluid inflow, formation damage, environmental issues, and nonproductive time. This research aims to evaluate novel materials that can mitigate lost circulation and overcome the limitation of other materials. In this research, a comprehensive evaluation of a re-crosslinkable preformed particle gel (RPPG) has been conducted to determine the extent to which it can be used to control drilling fluid losses during drilling operations. The RPPG consists of swellable gel particles that can self-crosslink to form …

Gis And Remote Sensing Groundwater Potentiality Investigation Of Gulu District, Uganda Using Synthetic Aperture Radar And Magnetic Geophysics, Rachel Ann Jones

Doctoral Dissertations

“Developing countries have few resources for ground-based hydrological investigations to determine optimal placement of boreholes for community water access. Remote sensing data are available at a variety of resolutions and sense different parameters, and are useful inputs for hydrologic models, but these data are rarely obtainable in developing countries with the parameters or resolutions necessary for hydrologic applications. This research seeks to use and improve existing remote sensing and GIS techniques to identify areas of optimal water supply in locations with limited geologic or hydrologic information, such as Gulu District, Uganda. Fusing different remotely sensed data sets can produce higher …

Studies On Protein Solubility, Ke Li

Doctoral Dissertations

"Solubility is a critical factor of protein-based drugs during processing and patient administration. This study focused on two aspects of solubility: one was the poly (ethylene) glycol (PEG) precipitation of monoclonal antibodies (mAbs) and another was crystallins aggregation that is associated with cataracts. Protein precipitation by PEG is a common technique for downstream processing. The effects of pH, ionic strength and the exclude volume effect on the protein precipitation by PEG were extensively studied, but the effects of glycosylation on protein precipitation by PEG has not been examined. Protein aggregation is not only a problem in downstream processing, but it …

Deep Learning For Digitized Histology Image Analysis, Sudhir Sornapudi

Doctoral Dissertations

“Cervical cancer is the fourth most frequent cancer that affects women worldwide. Assessment of cervical intraepithelial neoplasia (CIN) through histopathology remains as the standard for absolute determination of cancer. The examination of tissue samples under a microscope requires considerable time and effort from expert pathologists. There is a need to design an automated tool to assist pathologists for digitized histology slide analysis. Pre-cervical cancer is generally determined by examining the CIN which is the growth of atypical cells from the basement membrane (bottom) to the top of the epithelium. It has four grades, including: Normal, CIN1, CIN2, and CIN3. In …

Modeling And Optimization Of Froth Flotation Of Low-Grade Phosphate Ores: Experiments And Machine Learning, Ashraf Alsafasfeh

Doctoral Dissertations

”In this research work, bench-scale and micro-scale flotation tests were conducted to separate “minerals from silicate minerals using direct and reverse flotation approaches, respectively. Experiments were conducted at different flotation conditions including reagents’ type, reagents’ dosages, pulp’s pH, and flotation time.

In the direct flotation process, two polymers were selected to promote the depression of silicates: hybrid polyacrylamide-based polymers (Hy-PAM) and chitosan. Results indicated that the highest recovery of P₂O₅ (86.82%) was obtained when the Hy-PAM polymer was used compared with 66.7% and 40% when chitosan and commercial inorganic depressant were used, respectively. The experimental datasets obtained …

Application Of Geophysics And Remote Sensing Techniques For Economic Mineral Exploitation In Libya, Awad Abdussalam Henish Lemnifi

Doctoral Dissertations

“This study investigates crustal thickness and properties within the north central Africa region. Results obtained from 15 seismic stations belonging to the Libyan Center for Remote Sensing and Space Science are reported, in addition to 3 seismic stations publically available, using receiver functions, the first P-to-S receiver function investigation of the 410 km and 660 km depth discontinuities bounding the mantle transition zone (MTZ), and P wave tomography methods. The results from the first method show crustal thicknesses ranging from 24 km to 36 km (with uncertainties ranging between ±0.10 km and ±0.90 km). More specifically, crustal thickness ranges from …

Integrating Resilience Into Military Infrastructure Mission Assurance Assessments And Decision Making, John Richards

Doctoral Dissertations

“This research created the Mission Assurance Resilience Matrix, a decision framework that integrates existing infrastructure assessment methods with emerging resilience research to model resilience under uncertainty as part of a detailed infrastructure management system. This framework enables military decision makers to easily visualize deficiencies in infrastructure resilience and assess where to most efficiently allocate resources. This research further extends results by including modules on training and education as a component of the scope of work.

There are three significant contributions of this research. The first identifies the gaps of how and where modeling under uncertainty, infrastructure systems management, and resilient …

Geophysical Characteristics Of Nickel And Copper Deposits In Wadi Al Khadra Prospect, Southwestern Of Saudi Arabia, Abdulrahman Ahmed Aljabbab

Doctoral Dissertations

“Three geophysical datasets (self-potential, magnetics, and time - domain electromagnetics) were acquired at Wadi Al Khadra Ni-Cu prospect in southwest Saudi Arabia, and were processed and interpreted for the Saudi Geological Survey. The primary objectives were to map the distribution of metallic mineralization, map structures, verify the integration of the geophysical interpretations and its signatures in conjunction with boreholes information, distinguish the similarities and differences in the integrated interpretation of geophysical data, and design optimal processing and interpretation data parameters. The self-potential tool was used to map the variation in natural surface potential differences to map lateral variations in the …

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 …

Improving Base Metal Electrowinning, Charles Ebenezer Abbey

Doctoral Dissertations

"In zinc electrowinning, Mn oxidizes to form MnO₂ on Pb-Ag anodes, cell walls and pipes. MnO₂ reduces anode corrosion but also leads to short circuits and maintenance issues. MnO₂ is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb-Ag anodes. Increasing the average Mn/Cl^- ratio from ~7:1 to ~11:1 reduced the anode corrosion rate. Anode scales produced with Mn/Cl …

Plenum-To-Plenum Heat Transfer Characteristics Under Natural Circulation In A Scaled-Down Prismatic Modular Reactor, Salman Mohammed Alshehri

Doctoral Dissertations

“Gas-cooled reactor (GCR) is being developed under the Next Generation Nuclear Plant Program (NGNP) in nuclear engineering studies. As the world searches for an energy source with high energy density, clean, abundant, and storable nature to avoid global warming issues, GCR seems to be a promising solution, particularly the possibility of producing hydrogen. Studying and developing the safety analysis and GCR technologies are required for the optimum design and safety of GCR system. Multiphase Reactors Engineering and Applications Laboratory (mReal) at Missouri University of Science and Technology (S&T) has developed a natural convection heat transfer test facility with one riser …

Computational Dynamics And Virtual Dragline Simulation For Extended Rope Service Life, Muhammad Wardeh

Doctoral Dissertations

"The dragline machinery is one of the largest equipment for stripping overburden materials in surface mining operations. Its effectiveness requires rigorous kinematic and dynamic analyses. Current dragline research studies are limited in computational dynamic modeling because they eliminate important structural components from the front-end assembly. Thus, the derived kinematic, dynamic and stress intensity models fail to capture the true response of the dragline under full operating cycle conditions. This research study advances a new and robust computational dynamic model of the dragline front-end assembly using Kane's method. The model is a 3-DOF dynamic model that describes the spatial kinematics and …

Mitigation Of Environmental Hazards Of Sulfide Mineral Flotation With An Insight Into Froth Stability And Flotation Performance, Muhammad Badar Hayat

Doctoral Dissertations

"Today's major challenges facing the flotation of sulfide minerals involve constant variability in the ore composition; environmental concerns; water scarcity and inefficient plant performance. The present work addresses these challenges faced by the flotation process of complex sulfide ore of Mississippi Valley type with an insight into the froth stability and the flotation performance. The first project in this study was aimed at finding the optimum conditions for the bulk flotation of galena (PbS) and chalcopyrite (CuFeS₂) through Response Surface Methodology (RSM). In the second project, an attempt was made to replace toxic sodium cyanide (NaCN) with the biodegradable chitosan …

Investigation Of The Hydrodynamics And Scale-Up Of Advanced Triso Nuclear Fuel Manufacturing Using Sophisticated Measurement Techniques, Thaar M. Aljuwaya

Doctoral Dissertations

"The successful performance and safety of the Very-High-Temperature Nuclear Reactors (VHTR) extremely depend on the quality of the TRISO nuclear fuel coated particles. However, the coating of the TRISO particles is delicate process and impacted by the hydrodynamics of spouted beds. Therefore, in this work, we applied advanced non-invasive measurement techniques which are gamma-ray computed tomography (CT) and radioactive particle tracking (RPT), to investigate foremost the local parameters to advance the fundamental understanding of the hydrodynamics and scale-up of gas-solid spouted beds. The CT technique has been applied to study the effects of particle density, particle size, bed size, and …

Guayule Plant Extracts As Binder Modifiers In Flexible (Asphalt) Pavement Mixtures, Steven Michael Lusher

Doctoral Dissertations

"The guayule (pronounced, 'why-YOO-lee') plant is a woody perennial shrub that is native to areas of the southwestern United States and northern Mexico, and is a well-documented source of high-quality natural rubber. The U.S. needs a domestic source of natural rubber to allay concerns about its future availability. Cultivation of guayule in North America has been attempted many times since the late 19th century, and companies, including major tire manufacturers, are again investing in guayule research. However, full-scale commercialization of guayule rubber needs established markets for the two basic by-products of guayule rubber extraction: the plant resins (primarily non-rubber compounds) …

A New Signal Processing Method For Acoustic Emission/Microseismic Data Analysis, Charles Mborah

Doctoral Dissertations

"The acoustic emission/microseismic technique (AE/MS) has emerged as one of the most important techniques in recent decades and has found wide applications in different fields. Extraction of seismic event with precise timing is the first step and also the foundation for processing AE/MS signals. However, this process remains a challenging task for most AE/MS applications. The process has generally been performed by human analysts. However, manual processing is time consuming and subjective. These challenges continue to provide motivation for the search for new and innovative ways to improve the signal processing needs of the AE/MS technique. This research has developed …

Imaging A Fly Ash Landfill Using Non-Invasive Technologies (Ert And Masw), Atiat Shaban Qasim Alsaaideh

Doctoral Dissertations

"Electrical resistivity tomography (ERT) data were acquired across a segment of an existing fly ash landfill in southwestern Missouri. The objective was to map potential karst features and identify probable groundwater seepage through and beneath the landfill.

Variations in the moisture content were mapped below and above the two liners (clay and synthetic) systems, the soil and bedrock. Seepage pathways were mapped through the fly ash and the underlying soil and rock. No visual evidence was found on any of the 3D ERT profiles of the presence of either pre-existing air-filled voids or pre-existing or newly infilled clay-filled voids. There …

Modeling Dynamic Community Acceptance Of Mining Using Agent-Based Modeling, Mark Kofi Boateng

Doctoral Dissertations

"This research attempts to provide fundamental understanding into the relationship between perceived sustainability of mineral projects and community acceptance. The main objective is to apply agent-based modeling (ABM) and discrete choice modeling to understand changes in community acceptance over time due to changes in community demographics and perceptions. This objective focuses on: 1) formulating agent utility functions for ABM, based on discrete choice theory; 2) applying ABM to account for the effect of information diffusion on community acceptance; and 3) explaining the relationship between initial conditions, topology, and rate of interactions, on one hand, and community acceptance on the other …

Experimental Investigations Of Natural Circulation In A Separate-And-Mixed Effects Test Facility Mimicking Prismatic Modular Reactor (Pmr) Core, Mahmoud M. Taha

Doctoral Dissertations

"After the Fukushima Daiichi nuclear power plant accident in 2011, significant attention was directed to investigate natural circulation thermal-hydraulics in Prismatic Modular Reactors (PMRs). Natural circulation is employed as a passive safety feature that passively removes the decay heat released after the loss of flow accidents (LOFA). Several computational studies have addressed such phenomena, however, validation of Computational Fluid Dynamics (CFD) is needed by providing high-quality data obtained from separate test facilities designed with reference to the corresponding reference PMRs. To address this need, a separate effects Plenum-to-Plenum Facility (P2PF) was designed and developed with dual channels and plena for …

Evaluating Of Scale-Up Methodologies Of Gas-Solid Spouted Beds For Coating Triso Nuclear Fuel Particles Using Advanced Measurement Techniques, Neven Y. Ali

Doctoral Dissertations

"The work focuses on implementing for the first time advanced non-invasive measurement techniques to evaluate the scale-up methodology of gas-solid spouted beds for hydrodynamics similarity that has been reported in the literature based on matching dimensionless groups and the new mechanistic scale up methodology that has been developed in our laboratory based on matching the radial profile of gas holdup since the gas dynamics dictate the hydrodynamics of the gas-solid spouted beds. These techniques are gamma-ray computed tomography (CT) to measure the cross-sectional distribution of the phases' holdups and their radial profiles along the bed height and radioactive particle tracking …

Subterranean Photobioreactors For Commercial-Industrial Scale Algal Culture, Daniel James Vidt

Doctoral Dissertations

"There are many potential benefits to the mining industry accruing from the application of algal biotechnology. The main benefits are in the production of biodiesel and in the remediation of mining brownfields. The research in this study was centered in the original idea that these brownfields represent a tremendous opportunity for use as a hybrid model for redevelopment into sustainable "mines" of biomass. The ability of these underground spaces serving as bioreactors to control all aspects of the growing environment, from lighting, to temperature, to biosecurity, are key advantages that have been identified in the literature. The many benefits inherent …

Impact Of Thorium Based Molten Salt Reactor On The Closure Of The Nuclear Fuel Cycle, Safwan Qasim Mohammad Jaradat

Doctoral Dissertations

"Molten salt reactor (MSR) is one of six reactors selected by the Generation IV International Forum (GIF). The liquid fluoride thorium reactor (LFTR) is a MSR concept based on thorium fuel cycle. LFTR uses liquid fluoride salts as a nuclear fuel. It uses ²³²Th and ²³³U as the fertile and fissile materials, respectively. Fluoride salt of these nuclides is dissolved in a mixed carrier salt of lithium and beryllium (FLiBe). The objective of this research was to complete feasibility studies of a small commercial thermal LFTR. The focus was on neutronic calculations in order to prescribe core design …