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 …

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] …

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 …

Impact Of Turbulence Models And Shape Parameterization On Robust Aerodynamic Shape Optimization, Aslihan Vuruskan

Doctoral Dissertations

"Aerodynamic design optimization is typically performed at fixed flight conditions, without considering the variation and uncertainty in operating conditions. The objective of robust aerodynamic optimization is to design an aerodynamic configuration, which will keep its optimum performance under varying conditions such as the speed of aircraft. The primary goal of this study was to investigate the impact of turbulence models used in RANS simulations on the 2-D airfoil and 3-D wing designs obtained with gradient-based deterministic and robust optimization in transonic, viscous, turbulent flows. The main contribution of this research to the aerodynamic design area was to quantify the impact …

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 …

System Si/Pi Modeling And Analysis, Biyao Zhao

Doctoral Dissertations

"A physics-based circuit modeling methodology for 3D IC/packages is proposed here. The method is based on partial element equivalent circuit (PEEC) and layered Green's function (LGF). The LGFs are calculated from discrete complex image method (DCIM) with three terms, direct coupling, complex images, and surface wave, extracted to analyze the wave behavior. The dominate terms for LGFs are analyzed for four stack-ups in 3D IC/packages. Analytical formulas that include the contribution of complex images are proposed for partial capacitance calculation, with the complex image extracted from LGFs. A chip PDN geometry is used to illustrate the use of LGF in …

Frequency Selective Surface-Based Sensing: Theory And Applications, Mahboobeh Mahmoodi

Doctoral Dissertations

"Frequency selective surfaces (FSS) are periodic arrays of resonant elements with a specific (resonant) reflection/transmission response when illuminated by electromagnetic energy. FSSs have been utilized for different applications such as spatial filters, reflectors, lenses, radomes, and more recently, as sensors. FSS-based sensors have shown potential for numerous applications in structural health monitoring such as crack detection, concurrent strain and temperature sensing, normal and shear strain sensing, inspection of layered structures, etc. As FSS-based sensing is largely undeveloped, there are many critical aspects that must be fully understood before this sensing approach can be fully utilized. Therefore, the goal of this …

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 …

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 …

Modeling A Nuclear Research Reactor And Radiation Dose Estimation In An Accident Scenario, Abdulaleem Abdulmajeed Bugis

Doctoral Dissertations

“A detailed, flexible three-dimensional (3D) model of the Missouri S&T Reactor (MSTR) with a heterogeneous core geometry was developed using the Standardized Computer Analyses for Licensing Evaluation (SCALE). A Graphical User Interface (GUI) was developed for SCALE, which allows the user to generate an input file automatically. The SCALE model was validated with a Monte Carlo N-Particle Transport (MCNP) model of the MSTR. The validation process was based on the criticality calculations using the Criticality Safety Analysis Sequence (CSAS6). Three geometrical models were examined. The SCALE model that has the full detailed geometry showed a good agreement with the MCNP …

Understanding The Deformation Mechanisms In Ni-Based Superalloys With Using Crystal Plasticity Finite Element Method, Tianju Chen

Doctoral Dissertations

“Ni-based superalloy is considered as a good candidate due to its excellent resistance to elevated temperature deformation for long term period application. Understanding the deformation and failure mechanisms of Ni-Based superalloys is very helpful for providing design guidelines for processing Ni-based superalloys. Experimental characterization indicates that the deformation mechanisms of Ni based superalloy is strongly microstructure dependent. Besides, damage transform from the void nucleation to the macro cracks by voids growth leading to the failure of the Ni-based superalloys are also showing strong microstructure sensitivity. Therefore, this work focuses on the prediction and comprehension of the deformation and void growth …

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 …

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 …

Accurate Modeling Techniques For Power Delivery, Jingdong Sun

Doctoral Dissertations

“Power delivery is essential in electronic systems to provide reliable power from voltage sources to load devices. Driven by the ambitious user demands and technology evolutions, the power delivery design is posed serious challenges. In this work, we focus on modeling two types of power delivery paths: the power distribution network (PDN) and the wireless power transfer (WPT) system.

For the modeling of PDN, a novel pattern-based analytical method is proposed for PCB-level PDN impedance calculations, which constructs an equivalent circuit with one-to-one correspondences to the PCB’s physical structure. A practical modeling methodology is also introduced to optimize the PDN …

Cyber Physical Security Of Avionic Systems, Anusha Thudimilla

Doctoral Dissertations

“Cyber-physical security is a significant concern for critical infrastructures. The exponential growth of cyber-physical systems (CPSs) and the strong inter-dependency between the cyber and physical components introduces integrity issues such as vulnerability to injecting malicious data and projecting fake sensor measurements. Traditional security models partition the CPS from a security perspective into just two domains: high and low. However, this absolute partition is not adequate to address the challenges in the current CPSs as they are composed of multiple overlapping partitions. Information flow properties are one of the significant classes of cyber-physical security methods that model how inputs of a …

Integrated Approach To Investigate The Wellbore Integrity Under Downhole Conditions, Weicheng Zhang

Doctoral Dissertations

“The integrity of the cement sheath is the key part to maintain zonal isolation and prevent the inter-zonal communication. Loads arising from multiple stages of wellbore life span may induce various modes of cement failure within the cement (disking and radial cracks) and at the cement-casing and the cement-formation interfaces (debonding fractures). This research utilizes the integrated laboratory and numerical approach to investigate the cement hardening process, to predict the cement failure under various loading conditions. An innovative experimental setup is established to measure the cement pore pressure variation during the hardening process under downhole conditions, and a staged 3D …

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 …

Enabling Flexibility Through Strategic Management Of Complex Engineering Systems, Walter Louis Barnes Ii

Doctoral Dissertations

”Flexibility is a highly desired attribute of many systems operating in changing or uncertain conditions. It is a common theme in complex systems to identify where flexibility is generated within a system and how to model the processes needed to maintain and sustain flexibility. The key research question that is addressed is: how do we create a new definition of workforce flexibility within a human-technology-artificial intelligence environment?

Workforce flexibility is the management of organizational labor capacities and capabilities in operational environments using a broad and diffuse set of tools and approaches to mitigate system imbalances caused by uncertainties or changes. …

Removal Of Non-Metallic Inclusions From Molten Steel By Ceramic Foam Filtration, Soumava Chakraborty

Doctoral Dissertations

”Ceramic filters are routinely used in steel foundries to remove non-metallic inclusions from steel melt. Removal efficiency for both solid and liquid inclusions by magnesia-stabilized zirconia foam filters (10ppi) were evaluated and distribution of the captured inclusions through the filter thickness was also investigated. A mold design was developed using a commercial computational fluid dynamics software package to produce two castings that fill simultaneously, one with a filter and the other without a filter, from a single ladle pour, while also matching the fill rates and avoid turbulence and reoxidation during pouring. An industrial-scale experiment was also performed to investigate …

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 …

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 …

Strategies To Improve The Electrochemical Performance Of Lithium-Ion Batteries By Stabilizing The Interface Of Electrode/Electrolyte, Ye Jin

Doctoral Dissertations

”Lithium-ion batteries (LIBs) provide great potential for electric vehicles, and smart grids as future energy-storage devices. However, there are many challenges in the development of the LIB industry, including low energy and power density of electrode materials, poor rate performance, short cycle life of electrode materials, and safety issues caused by the flammability of the conventional organic liquid electrolytes.

In this research, we were committed to using general approach to efficiently and economically synthesize or modify LIB materials by stabilizing the interface between electrode and electrolyte. Atomic layer deposition (ALD) method was used to coat metal oxide thin films on …

Thermodynamic Investigations Of Pure And Blended Cement Mixtures, Jonathan Lapeyre

Doctoral Dissertations

” This research is made up of several studies. The first study focused on understanding the reaction kinetics of Ca₃SiO₅ and metakaolin (MK) mixtures compared to Ca₃SiO₅ and silica fume (SF) mixtures. It was shown that MK was a more effective additive than SF at small replacement levels (i.e. ≥ 10% by mass) while higher replacement levels of MK became a detriment due to excess (Al(OH)₄¯) ions preventing the nucleation and growth of C-S-H. In a follow-up study where the MK particle size distribution (PSD) was modified, similar effects were observed but …

Catalytic Utilization Of Carbon Dioxide As Renewable Feedstock For Production Of Chemicals And Fuels, Abbas Alaa Jawad

Doctoral Dissertations

"The utilization of CO₂ as a renewable feedstock for producing commodity chemicals and fuels is an interesting challenge to explore new concepts and opportunities in catalysis and industrial chemistry. This sustainable approach not only leads to production of useful chemicals, but also has the potential to mitigate anthropogenic CO₂ emissions to the atmosphere. CO₂ itself is a sustainable and inexhaustibly available carbon source, however, it is inextricably linked to its inherent inertness. It is a thermodynamically stable molecule (ΔG_f = -394.01 kJ.mol^-1) with high oxidation state, hence, reactions of CO₂ must be combined …

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 …

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 …

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 …

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 …

Structurally And Electronically Diverse Polyanion-Based Cathode Materials For Alkali-Ion Batteries, Prashanth Sandineni

Doctoral Dissertations

”Through this investigation polyanion-based cathode materials including sulfates, phosphates, and phosphites of transition metal have been synthesized for lithium and sodium-ion batteries and their electrochemical performances were evaluated. The emphasis was on soft chemical routes to discover metastable phases which are often missed in high temperature synthesis. Iron-based compounds were the main focus of this investigation, however, concurrently a few vanadium-analogues of iron compounds were investigated to evaluate the effect of multi-electron process on achievable voltage and capacity.

This investigation resulted in the discovery of several compounds with unique crystal structures, namely AFe₃(SO₄)₂(OH)_{6 …}

Regulation Of Derivatives In Asia: When Technology Meets Financial Engineering, Christopher C. H. Chen

Research Collection Yong Pung How School Of Law

This chapter introduces the current state of derivatives market regulation in Asia following the global financial crisis. It focuses on Singapore and Hong Kong, the two largest international financial centres in the region. Singapore and Hong Kong have adopted international regulatory reforms, including mandatory trade reporting, centralized clearing, exchange trading requirements and the initial margin rule. The implementation has varied greatly because reporting requirements and initial margin rules have been implemented whereas clearing and trading requirements are waiting for full implementation. The arrival of financial technology may help Asian regulators oversee derivatives markets, by improving cross-border information sharing, reporting or …