Digital Commons Network^™

Factors Impacting The Transport And Enhanced Oil Recovery Potential Of Polymeric Nanogel In Sandstone, Haifeng Ding

Doctoral Dissertations

"Enhanced oil recovery (EOR) using nanometer-sized particles has drawn great attention in the oil industry because of their various advantages brought by size. However, their applications on a field scale are very limited, especially for deformable nanoparticles. The objective of this research is to explore the transport behavior of deformable polymeric nanoparticles (nanogel), the factors impacting these behavior, and their EOR potentials. First, 240 published nanoparticle core flooding experiment data were collected and analyzed about the extent to what the nanoparticles can improve oil recovery. Results show that on the laboratory scale the incremental oil recovery could be as high …

Characterization And Recyclability Of 304l Stainless Steel Powder For Use In The Selective Laser Melting Process, Austin Taylor Sutton

Doctoral Dissertations

"Powder-bed fusion refers to a subset of additive manufacturing (AM) methods which successively melts and solidifies selected regions within a powder bed on a layer-by-layer basis to construct components directly from computer-aided design files. Laser Powder-Bed Fusion (L-PBF) is a process among the powder-bed fusion techniques that utilizes a laser to consolidate particles into a material with little porosity. During the L-PBF process, the large energy input from the laser causes the production of ejecta in the form of laser spatter and condensate, both of which have the potential to settle in the surrounding powder bed compromising its reusability. In …

Studies On The Stability Of Plasma Proteins And Their Fragments, Paul Praveen Nakka

Doctoral Dissertations

“The stability of a protein-based biological drug is an important concern during processing, storage or patient administration. There are various forces which contribute to the stabilizing of proteins. Both hydrogen bonds and hydrophobic interactions play an important role in protein stability. Improper folding or misfolding of proteins leads to aggregation, which is a major problem found in the bioprocessing industry. The objectives of this research are: 1) to determine the effect of environmental factors such as pH, temperature, additives or salts, and cosolvents on the stability human serum albumin (HAS), which is the most abundant protein in plasma, 2) to …

Development Of Novel Materials And Processes For Direct Conversion Of Co₂ Flue Gas To Chemicals And Fuels, Ahmed Al-Mamoori

Doctoral Dissertations

“This research focused on addressing the pressing issues of greenhouse gas emissions that greatly contribute to climate change. Specifically, the focus was given to the reduction of anthropogenic CO₂ emission and its subsequent conversion to commodity chemicals and fuels. In the first part of the research, a series of novel high temperature CO₂ adsorbents including double salts (K-Ca and Na-Ca) and metal-doped calcium oxide (Fe_x@CaO and Ga_x@CaO) was developed and evaluated. Both sets of materials exhibited high CO₂ capacity, fast kinetics, and long-term stability. In particular, at 650 °C, the doped adsorbents comprising …

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 …

Hydrokinetic Turbine Composite Blades And Sandwich Structures: Damage Evaluation And Numerical Simulation, Mokhtar Fal

Doctoral Dissertations

“Composite materials are gaining interest due to their high strength to weight ratio. This study deals with both experimental and numerical approaches to cover the aspects of the failure of composite materials in hydrokinetic turbine applications. In Part I, the location and magnitude of failure in the horizontal axis water turbine carbon fiber-reinforced polymer (CFRP) composite blades with different laminate stacking sequences were investigated. Two lay-up orientations were adopted for this work ([0⁰]₄ and [0⁰/90⁰]_2s). A finite element analysis model was generated to examine the stresses along the blade. Five angles were introduced to study the effect …

Comprehensive Study Of Bio-Diesel Continuous Flow Synthesis, Aso A. Hassan

Doctoral Dissertations

“Energy has become an indispensable factor in preserving economic growth since the commencement of the industrial revolution. In recent years, biodiesel has gained acceptance as a notable alternative to the widely used petroleum-derived diesel fuel because it is biodegradable, non-toxic, and generates fewer exhaust pollutants. Recently, biodiesel studies have focused on the development of process intensification technologies to resolve some technical challenges facing biodiesel production, such as long residence times and catalyst sensitivity. These intensification technologies enhance process mass/heat transfer to achieve a continuous, scalable process that can be easily transported to utilize locally available feed stocks. Five phases have …

Observer-Based Event-Triggered And Set-Theoretic Neuro-Adaptive Controls For Constrained Uncertain Systems, Abdul Ghafoor

Doctoral Dissertations

"In this study, several new observer-based event-triggered and set-theoretic control schemes are presented to advance the state of the art in neuro-adaptive controls. In the first part, six new event-triggered neuro-adaptive control (ETNAC) schemes are presented for uncertain linear systems. These comprehensive designs offer flexibility to choose a design depending upon system performance requirements. Stability proofs for each scheme are presented and their performance is analyzed using benchmark examples. In the second part, the scope of the ETNAC is extended to uncertain nonlinear systems. It is applied to a case of precision formation flight of the microsatellites at the Sun-Earth/Moon …

Combustion And Emission Characteristics Of Ic Engines Fueled By Hydrogen And Hydrogen/Diesel Mixtures And Multi-Objective Optimization Of Operating Parameters, Abdulhakim Issa Jabbr

Doctoral Dissertations

“The present study considers combustion of hydrogen in IC engines. In general, the work focuses on simulating the engine performance and emissions at different operation parameters, and using optimization techniques. Task I work deals with the engine performance and emissions of a single cylinder spark-ignition (SI) engine fueled by hydrogen. The engine was simulated at different equivalence ratios, exhaust gas recirculation (EGR) and ignition timing. The results indicate that NOx emissions, engine power, and efficiency are reduced by increasing EGR level, and increased with increasing equivalence ratio and advanced ignition timing. The best operating conditions for hydrogen engines were obtained …

Geophysical Assessment Of The Lake Chesterfield Site, Missouri, Diya Ali Ahmad Alfuqara

Doctoral Dissertations

"Since construction of the Lake Chesterfield, Missouri in 1986, significant leaks have occurred causing the lake to lose substantive volumes of water. Mitigation efforts, have not solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate. Prior to authorizing additional mitigation work, the Lake Chesterfield. Home Owners Association (LCHOA) decided to acquire geophysical data across the drained and dry lake bed. These information would help a geotechnical engineering firm determine the most appropriate mitigation plan.

In the summer of 2018, electrical resistivity tomography, multichannel analysis of surface wave, and spontaneous-potential …

Imaging In Karst Terrain Using The Electrical Resistivity Tomography (Ert) And Multi-Channel Analysis Of Surface Waves (Masw) Methods, Hassan Abdullah Alzahrani

Doctoral Dissertations

"Electrical Resistivity Tomography (ERT) and Multi-channel Analysis of Surface Waves (MASW) methods were used to image the subsurface in karst terrain in the southeast of Missouri. A SuperSting R8 system was used to acquire the ERT profiles; a multi-channel engineering seismograph was used to acquire the MASW data. The latter data were used to constrain and verify the ERT interpreted depth to top-of-rock and soil thickness. The ERT data were used to delineate the soil/rock interface and to identify zones of anomalously high moisture content within the bedrock.

The primary objective of the research was to determine the cause of …

Operation And Analysis Of High-Voltage-Gain Dc-Dc Converters With Voltage Multipliers, Mohammad Rashed M. Altimania

Doctoral Dissertations

"This research analyzes and investigates the steady-state operations of four different high-voltage-gain step-up dc- dc converters to achieve a high gain. These topologies consist of a two-phase interleaved boost stage with three various voltage multiplier (VM) stages. The first stage of the first three topologies is the same, which is a two-phase interleaved boost stage implemented by using inductors. The first family used in this research is based on a modified Dickson charge pump voltage multiplier stage, and this family has been studied in discontinuous conduction mode (DCM). The second family relies on a non-inverting or inverting diode-capacitors voltage multiplier …

Towards Efficacy And Efficiency In Sparse Delay Tolerant Networks, Douglas John Mcgeehan

Doctoral Dissertations

"The ubiquitous adoption of portable smart devices has enabled a new way of communication via Delay Tolerant Networks (DTNs), whereby messages are routed by the personal devices carried by ever-moving people. Although a DTN is a type of Mobile Ad Hoc Network (MANET), traditional MANET solutions are ill-equipped to accommodate message delivery in DTNs due to the dynamic and unpredictable nature of people's movements and their spatio-temporal sparsity. More so, such DTNs are susceptible to catastrophic congestion and are inherently chaotic and arduous. This manuscript proposes approaches to handle message delivery in notably sparse DTNs. First, the ChitChat system [69] …

The Combined Toxic Effect Of Nanoparticles And Lead In The Presence Of Algae (Raphidocelis), Xuesong Liu

Doctoral Dissertations

"The elevated toxicity of toxic metals in the presence of nanoparticles (NPs) has raised significant concerns on the NP environmental safety. This research focuses on the impact of environmental conditions, specifically algae, on this type of toxicity. An indicator aquatic organism, Ceriodaphnia dubia (C. dubia), was used to examine the combined toxicity and toxicity mitigation from algae by monitoring its 24-h mortality. Four papers are included in this research, which focus on four aspects of the combined toxicity and the corresponding algae (Raphidocelis) impact. The first paper examines the algae impact on the combined toxicity of …

Experimental Investigation Of Ionic Liquid Mixtures For Electrospray Propulsion, Mitchell J. Wainwright

Doctoral Dissertations

"In recent years, there has been a dramatic increase in the number of small satellites (namely MicroSats, NanoSats, and CubeSats) in earth orbit; many of these are launched without propulsion systems. Multi-mode propulsion systems, capable of operating in either chemical or electric mode, have been proposed as attractive candidates for use in small satellites. Such systems are mass and volume optimal and flexible in terms of thrust requirements. Most previous work on multi-mode systems has focused on chemical mode performance.The work in this dissertation focuses on the electric mode performance of these propulsion systems.

The work in this research is …

Strengthening Qc Relaxations Of Optimal Power Flow Problems By Exploiting Various Coordinate Changes, Mohammad Rasoul Narimani

Doctoral Dissertations

"Motivated by the potential for improvements in electric power system economics, this dissertation studies the AC optimal power flow (AC OPF) problem. An AC OPF problem optimizes a specified objective function subject to constraints imposed by both the non-linear power flow equations and engineering limits. The difficulty of an AC OPF problem is strongly connected to its feasible space's characteristics. This dissertation first investigates causes of nonconvexities in AC OPF problems. Understanding typical causes of nonconvexities is helpful for improving AC OPF solution methodologies.

This dissertation next focuses on solution methods for AC OPF problems that are based on convex …

Experimental Study On A Novel Eor Method -- Polymeric Nanogel Combined With Surfactant And Low Salinity Water Flooding To Enhance Oil Recovery, Mustafa M. Almahfood

Doctoral Dissertations

“Extracting higher amounts of oil from current reservoirs is a necessity for the oil industry to enhance their profitability and sustainability. The desire to recover more oil from the existing reservoirs has led to a growing interest of nanoparticle application in enhanced oil recovery (EOR). However, most researchers have focused on the evaluation and surface modification of non-deformable nanoparticles. This dissertation evaluates the potential of deformable nanogel particles as an EOR material when they are combined with two other promising technologies - surfactant and low salinity water floodings. The particle size distribution, ζ-potential and interfacial tension were measured for a …

An Integrated Wellbore Stability Study To Mitigate Expensive Wellbore Instability Problems While Drilling Into Zubair Shale/Sand Sequence, Southern Iraq, Ahmed Khudhair Abbas

Doctoral Dissertations

”The Zubair Formation is the most prolific reservoir in Iraq, which is comprised of sandstones interbedded with shale sequences. Due to the weak nature of the shale sequence, the instability of a wellbore is one of the most critical challenges that continuously appears during drilling across this formation. Historically, over 90% of wellbore problems in the Zubair Formation were due to wellbore instability. Problems associated with wellbore instability, such as tight hole, shale caving, stuck logging tools along with subsequent fishing, stuck pipe, and sidetracking result in increasing the non-productive time. This non-productive time has cost an enormous amount of …

Multi-Physics-Based Approach To Active Microwave Thermography, Seyed Ali Mirala

Doctoral Dissertations

“The goal of this work is to advance a novel nondestructive testing (NDT) method for controlled, rapid, and effective inspection of a structure through the integration of microwave NDT and thermography, referred to as Active Microwave Thermography (AMT). In AMT, the structure under test is exposed to microwave radiation and the thermal profile of the structure is monitored via a thermal camera in order to obtain desired information regarding the structure. This new technique is applicable across a wide range of NDT needs including detection of voids, delamination, water ingress, debonding, and cracks in numerous structures such as carbon fiber …

Magnetic Control Of Transport Of Particles And Droplets In Low Reynolds Number Shear Flows, Jie Zhang

Doctoral Dissertations

“Magnetic particles and droplets have been used in a wide range applications including biomedicine, biological analysis and chemical reaction. The manipulation of magnetic microparticles or microdroplets in microscale fluid environments is one of the most critical processes in the systems and platforms based on microfluidic technology. The conventional methods are based on magnetic forces to manipulate magnetic particles or droplets in a viscous fluid.

In contrast to conventional magnetic separation method, several recent experimental and theoretical studies have demonstrated a different way to manipulate magnetic non-spherical particles by using a uniform magnetic field in the microchannel. However, the fundamental mechanism …

Geo-Engineered Induced Seismicity And The Effects On Federal Infrastructure, Merissa L. Zuzulock

Doctoral Dissertations

“The study of human-induced seismicity and the effects on civil engineering systems are not completely understood or often studied. Moreover, existing studies are focused on the cause of the seismicity and not on the potential damage to infrastructure from these seismic events. There are recent studies that are beginning to focus on shallow induced seismic activity and the effects on infrastructure by establishing innovative ways to quantify that damage. These studies that focus on the potential damage neglect to included considerations for small magnitude cluster events. As geo-induced seismic events increase, soil fatigue becomes of greater concern to structures within …

Advanced Control Methods On Three-Phase Inverters In Distributed Energy Resources, Sara Yazdani

Doctoral Dissertations

“This research is an endeavor to apply new and well-established control methodologies to improve transient response, stability and reliability of three-phase inverters in grid-connected and isolated mode of operation. In the course of studying the effect of these methodologies, model-based control is introduced and is extensively applied which is relatively a new approach. In addition, the application of this concept has been studied on developing “grid-forming” controls to allow wind and solar inverters to support voltage and frequency levels like traditional generators.

This research encloses the details of three major works of this research and their possible contributions on improving …

An Approach To System Of Systems Resiliency Using Architecture And Agent-Based Behavioral Modeling, Paulette Bootz Acheson

Doctoral Dissertations

”In today’s world it is no longer a question of whether a system will be compromised but when the system will be compromised. Consider the recent compromise of the Democratic National Committee (DNC) and Hillary Clinton emails as well as the multiple Yahoo breaches and the break into the Target customer database. The list of exploited vulnerabilities and successful cyber-attacks goes on and on. Because of the amount and frequency of the cyber-attacks, resiliency has taken on a whole new meaning. There is a new perspective within defense to consider resiliency in terms of Mission Success.

This research develops a …

Development Of Tools For Water Management In The Hatra Watershed (Northwestern Iraq) Using Satellite Technologies, Majid S. Mohamod

Doctoral Dissertations

“All around the world the demand for water is increasing, especially in arid and semi-arid regions, including Iraq which subject to continuous desertification that is worsening, more importantly the Jezira region in northwestern Iraq. Thus, it’s crucial to have a better strategy for water management. One of these strategies is to promote groundwater recharge for restoring the aquifer depletion. The successful groundwater recharge is limited by some potential data such as the annual water budge and precipitation measurements. The atomospheric and hydrological observations are limited by sparse population which tends to be less in arid and semi-arid regions. Therefore, an …

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 …

Tools To Evaluate Nanodiamond-Mediated Delivery Of Tiopronin For Cataract Prevention, Justin Beltz

Doctoral Dissertations

”There is a growing demand for non-surgical means of cataract treatment. This dissertation presents three bodies of work that reflect the early-stage development of eye drop formulations aimed at delaying cataract progression. These formulations consist of the antioxidant 2-mercaptopropionylglycine (MPG) loaded onto nanodiamond particles.

Cataractogenesis is linked to oxidative damage to lens proteins. To investigate the potential of MPG for protection against oxidative damage, A549 cells were incubated in 0.6 mM tert-butylhydroperoxide (tBHP). Cells exposed to tBHP without MPG exhibited elevated levels of reactive oxygen species, which led to the depletion of the vital antioxidant glutathione and, ultimately, apoptosis. Co-administration …

Predictive Geohazard Mapping Using Lidar And Satellite Imagery In Missouri And Oklahoma, Usa, Olufeyisayo B. Ososami

Doctoral Dissertations

”Light Detection and Ranging (LiDAR) and satellite imagery have become the most utilized remote sensing technologies for compiling inventories of surficial geologic conditions. Point cloud data obtained from multi-spectral remote sensing methods provide a detailed characterization of the surface features, in particular, the detailed surface manifestations of underlying geologic structures. When combined, point clouds eliminate bias from visual inconsistencies and/or statistical values. This research explores the competence of point clouds derived from LiDAR and Unmanned Aerial Systems (UAS) as a predictive tool in evaluating various geohazards. It combines these data sets with other remote sensing techniques to evaluate the sensitivity …

Investigation Of Wide Bandgap Semiconductors For Room Temperature Spintronic, And Photovoltaic Applications, Vishal Saravade

Doctoral Dissertations

"Suitability of wide bandgap semiconductors for room temperature (RT) spintronic, and photovoltaic applications is investigated.

Spin properties of metal-organic chemical vapor deposition (MOCVD) – grown gadolinium-doped gallium nitride (GaGdN) are studied and underlying mechanism is identified. GaGdN exhibits Anomalous Hall Effect at room temperature if it contains oxygen or carbon atoms but shows Ordinary Hall Effect in their absence. The mechanism for spin and ferromagnetism in GaGdN is a combination of intrinsic, metallic conduction, and carrier-hopping mechanisms, and is activated by oxygen or carbon centers at interstitial or similar sites. A carrier-related mechanism in MOCVD-grown GaGdN at room temperature makes …

Development Of Horizontal Axis Hydrokinetic Turbine Using Experimental And Numerical Approaches, Abdulaziz Abutunis

Doctoral Dissertations

“Hydrokinetic energy conversion systems (HECSs) are emerging as viable solutions for harnessing the kinetic energy in river streams and tidal currents due to their low operating head and flexible mobility. This study is focused on the experimental and numerical aspects of developing an axial HECS for applications with low head ranges and limited operational space. In Part I, blade element momentum (BEM) and neural network (NN) models were developed and coupled to overcome the BEM’s inherent convergence issues which hinder the blade design process. The NNs were also used as a multivariate interpolation tool to estimate the blade hydrodynamic characteristics …

Novel Approaches For Constructing Persistent Delaunay Triangulations By Applying Different Equations And Different Methods, Esraa Habeeb Khaleel Al-Juhaishi

Doctoral Dissertations

“Delaunay triangulation and data structures are an essential field of study and research in computer science, for this reason, the correct choices, and an adequate design are essential for the development of algorithms for the efficient storage and/or retrieval of information. However, most structures are usually ephemeral, which means keeping all versions, in different copies, of the same data structure is expensive. The problem arises of developing data structures that are capable of maintaining different versions of themselves, minimizing the cost of memory, and keeping the performance of operations as close as possible to the original structure. Therefore, this research …