Digital Commons Network^™

An Emi Characterization And Modeling Study For Consumer Electronics And Integrated Circuits, Chunyu Wu

Doctoral Dissertations

“As internet-of-things (IoT) applications surge, wireless connectivity becomes an essential part of the network. Smart home, one of the most promising application scenarios of IoT, will improve our life quality enormously. However, electromagnetic interference (EMI) to the receiving antenna, either from another electronic product or from a module/an integrated circuit(IC) inside the same wireless device, will degrade the performance of wireless connectivity, thus influencing the user experience. Characterization and modeling of the EMI become increasingly important.

In the first part, an improved method to extract equivalent dipoles from magnitude- only electromagnetic-field data based on the genetic algorithm and back-and-forth iteration …

Fuzzy Logistic Regression For Detecting Differential Dna Methylation Regions, Tarek M. Bubaker Bennaser

Doctoral Dissertations

“Epigenetics is the study of changes in gene activity or function that are not related to a change in the DNA sequence. DNA methylation is one of the main types of epigenetic modifications, that occur when a methyl chemical group attaches to a cytosine on the DNA sequence. Although the sequence does not change, the addition of a methyl group can change the way genes are expressed and produce different phenotypes. DNA methylation is involved in many biological processes and has important implications in the fields of biomedicine and agriculture.

Statistical methods have been developed to compare DNA methylation at …

History Of Natural And Anthropogenic Activities In Lake Izabal, Eastern Guatemala: Using Geochemical Evidence To Record Recent Contamination, Elisandra Hernandez

Doctoral Dissertations

”Water is essential for human subsistence. Stable freshwater supplies are needed as a source of food, drinking water, for transportation, recreation and economic development. Despite their recognized importance, anthropogenic activities have altered freshwater ecosystems around the world. Lake Izabal is the habitat for diverse aquatic species of flora and fauna, some of which are endemic and endangered. Its importance notwithstanding, anthropogenic activities developed in Lake Izabal’s catchment in recent years have compromised its status. This study used paleolimnological techniques to link past and recent anthropogenic activities such as mining operations and recent tilapia aquaculture. Relative abundances and concentrations of Pb, …

Development Of Radiation Transport Techniques For Modelling A High-Resolution Multi-Energy Photon Emission Tomography System, Seth Kilby

Doctoral Dissertations

”Nondestructive characterization techniques such as gamma tomography represent powerful tools for the analysis and quantification of physical defects and radionuclide concentrations within nuclear fuel forms. Gamma emission tomography, in particular, has the ability to utilize the inherent radiation within spent nuclear fuel to provide users with information about the migration and concentration of fission and activation products within the fuel form. Idaho National Laboratory is interested in using this technology to analyze new nuclear fuel forms for potential use in next generation nuclear reactors. In this work, two aspect of the system are analyzed. The first is a semi-analytic radiation …

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 …

Studying The Effects Of Various Process Parameters On Early Age Hydration Of Single- And Multi-Phase Cementitious Systems, Rachel Cook

Doctoral Dissertations

”The hydration of multi-phase ordinary Portland cement (OPC) and its pure phase derivatives, such as tricalcium silicate (C₃S) and belite (ß-C₂S), are studied in the context varying process parameters -- for instance, variable water content, water activity, superplasticizer structure and dose, and mineral additive type and particle size. These parameters are studied by means of physical experiments and numerical/computational techniques, such as: thermodynamic estimations; numerical kinetic-based modelling; and artificial intelligence techniques like machine learning (ML) models. In the past decade, numerical kinetic modeling has greatly improved in terms of fitting experimental, isothermal calorimetry to kinetic-based modelling …

Investigation On Nanoparticle Based Combination Therapy For Targeted Cancer Treatment, Muhammad Raisul Abedin

Doctoral Dissertations

“The current treatment methods in cancer are associated with toxicity in healthy tissues, partial therapeutic response, drug resistance and finally recurrence of the disease. The cancer drugs are challenged by non-specific binding, undesired toxicity in healthy cells, low therapeutic index and finally poor therapeutic outcome. In this work, a targeted nanoscale therapeutic system Antibody Drug Nanoparticle (ADN) was engineered to selectively inhibit the breast cancer cell growth with reduced toxicity in healthy cells. The ADNs were designed by synthesizing rod shaped anoparticles using pure chemotherapeutic drug and covalently conjugating a therapeutic monoclonal antibody (mAb) on the surface of the drug …

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 …

Improved Attenuation And Crosstalk Modeling Techniques For High-Speed Channels, Shaohui Yong

Doctoral Dissertations

”As digital systems are moving in the direction of faster data transmission rate and higher density of circuits, the problem of the far-end crosstalk (FEXT) and frequency-dependent attenuation are becoming the major factors that limit signal integrity performance. This research is focusing on providing several more comprehensive and accurate modeling approaches for striplines on fabricated printed circuit board (PCB). By characterizing the dielectric permittivity of prepreg and core, dielectric loss tangent, and copper foil surface roughness using measurement data, a better agreement between the stripline model and measurement is achieved. First, a method is proposed to extract dielectric loss tangent …

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 …

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 …

Continuous-Flow Synthesis Of Fine Chemicals And Pharmaceutical Compounds Over Intelligent Organocatalysts With Bifunctional Reactivity, Abdo-Alslam Alwakwak

Doctoral Dissertations

“Many biological systems that utilize organic active sites to catalyze reactions under mild conditions invoke cooperative catalytic pathways, whereby two or more active sites work together to activate the reactant(s). The use of cooperative (bifunctional) catalysts and continuous flow chemistry (a reaction within the narrow channels of a micro‐ or microfluidic reactor) are commonplace in sustainable chemical transformation and attract a great deal of interest with respect to economic and environmentally-sustainable production of fine chemicals, pharmaceuticals, and agrochemicals, water treatment, as well as upgrading of biomass feedstocks. Although, some methods have been developed for immobilization of bifunctional catalysts for cooperative …

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 …}

Transition Metal Chalcogenide Hybrid Systems As Catalysts For Energy Conversion And Biosensing, Siddesh Umapathi

Doctoral Dissertations

"Generation of hydrogen and oxygen through catalyst-aided water splitting which has immense applications in metal air batteries, PEM fuel cells and solar to fuel energy production, has been one of the critical topics in recent times. The state of art oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) catalysts are mostly comprised of precious metals. The current challenge lies in replacing these precious metal-based catalysts with non-precious earth-abundant materials without compromising catalytic efficiency.

This research explores mixed metal selenides containing Fe-Ni, Fe-Co and RhSe which were hydrothermally synthesized and/or electrodeposited and tested for OER and ORR …

Minimizing The Negative Effect Of Pumping On Scc Freeze-Thaw Durability, Daniel Galvez-Moreno

Doctoral Dissertations

“The durability of concrete must be ensured to reduce the carbon footprint of the production of portland cement. If concrete is properly designed to preserve its integrity under adverse exposure conditions, the service life of the material can be extended with minimum maintenance. Nevertheless, bad handling, placing, finishing or curing practices can abate the durability potential and service life of even the best mix design. Pumping concrete is a very efficient placing technique that offers significant cost reduction and versatility at the jobsite, but it also has the potential of altering the air void system parameters, which are key to …

Enhanced Electrochemical Performance Of Li-Ion Battery Cathodes By Atomic Layer Deposition, Yan Gao

Doctoral Dissertations

”Li-ion battery now plays an irreplaceable role in supplying green and convenient energy. In this work, atomic layer deposition (ALD) was used to modify Li-ion battery cathode particles for performance enhancement.

An ultrathin and conductive CeO₂ ALD film was deposited on Li-rich layered cathode particles, of which the specific capacity and cyclic stability were significantly improved. On the same cathode particles, FeO_x ALD and post-annealing resulted in a stable and conductive surface spinel phase to improve the performance.

Synergetic TiN coating and Ti doping were performed on a LiFePO₄ (LFP) cathode and extended its cycle life. The …

Complexities Observed During The Development Of A Rheological Testing Procedure For Small Cement Paste Samples, Aida Margarita Ley-Hernandez

Doctoral Dissertations

“Rheology has been widely used to describe the flow properties of fresh cement-based suspensions. The use of a rheometer to characterize these properties is not a straightforward task due to the dependency to different preparation conditions, mixing processes, testing procedures and measuring instruments employed. In addition, shear and time dependency of the material which undergoes chemical and physical particle bonding, caused by hydration of cement and flocculation. Nevertheless, the characterization and understanding of the rheological behavior of cement-based materials have become essential with the recent introduction of novel applications like digital construction in the field of civil engineering, among others. …

Structured Catalysts Designed And Manufactured By 3d-Printing Technique For Functional Integration Of Catalytic Systems, Fatima Magzoub

Doctoral Dissertations

"Microporous zeolites are widely used as heterogeneous catalysts in a wide variety of chemical and petrochemical industries to produce value-added chemicals and fuels, owing to their large surface area, acid-base properties, high thermal stability, and excellent shape-selectivity.

The overall goal of this research was to shape engineer composite zeolites and fine-tune their physiochemical properties to improve the catalytic production of dimethyl ether (DME) and light olefins that are typically used as substitution to diesel fuel and polymer precursors, respectively. Specifically, HZSM-5 and silicalite-1 zeolites were formulated into monolithic contactors using 3D printing technique, followed by subsequent SAPO-34 crystals growth through …

Additive Manufacturing Of Customized Lithium-Ion Batteries: Process Fundamentals And Applications, Xiaowei Yu

Doctoral Dissertations

“In the pasting decades, considerable efforts have been spent in developing the next-generation lithium-ion batteries (LIBs), from advanced active materials to new manufacturing methods. The development of additive manufacturing (AM) has brought new opportunities to LIBs. In this work, two AM methods are introduced for fabricating electrodes of LIBs. The first method is aerosol printing, which is a solvent-based wet additive method. Whereas the second method is a solvent-free, dry printing method. The commonly used materials for current collectors and active materials (including cathodes and anodes) of LIBs are aerosol printed and the electrochemical functionalities of the printed materials are …

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 …

Finite Time Suboptimal Control Design Of Nonlinear Systems With Θ-D Technique And Implementation To Aerospace Applications, Jie Yao

Doctoral Dissertations

“A finite time suboptimal control strategy (named θ - D approximated algorithm) was proposed in this study, which can provide the control engineers with a novel effective and efficient design tool from the finite time optimal perspective. Based on the framework of this proposed method, the original nonlinear dynamics were formulated in pseudo-linear form, and the performance index was denoted by a linear quadratic regulator prototype in this research. After that, the approximated solutions to intractable Hamilton-Jacobi-Bellman (HJB) equation were acquired by putting vanishing perturbation terms into the performance index. By tuning the parameters in perturbation terms, semi-global stability and …

Design And Fabrication Of Field-Effect Iii-V Schottky Junction Solar Cells, Amirhossein Ghods

Doctoral Dissertations

“A new concept of field-effect photovoltaic devices with a focus on design and fabrication of single and multi-junction solar cells using III-V materials has been shown and proved. Schottky solar cells based on metal-(insulator)-semiconductor (M-I-S) structure have been designed and fabricated using various wide bandgap semiconductors, such as GaAs and Al_0.3Ga_0.7As. A secondary bias layer has been introduced to the device structure, in which it creates additional band bending and subsequently depletion region at the flat band regions on the top surface of the device. It should be mentioned that the bias layer is designed to …

Attention Mechanism In Deep Neural Networks For Computer Vision Tasks, Haohan Li

Doctoral Dissertations

“Attention mechanism, which is one of the most important algorithms in the deep Learning community, was initially designed in the natural language processing for enhancing the feature representation of key sentence fragments over the context. In recent years, the attention mechanism has been widely adopted in solving computer vision tasks by guiding deep neural networks (DNNs) to focus on specific image features for better understanding the semantic information of the image. However, the attention mechanism is not only capable of helping DNNs understand semantics, but also useful for the feature fusion, visual cue discovering, and temporal information selection, which are …

Exploring Wellbore And Reservoir Temperature Profiles In Fluid Circulation And Production Operations, Ahmed Qasim Al Saedi

Doctoral Dissertations

"The wellbore heat flow occurs during different well operations resulting from any temperature differences between the wellbore fluid and the adjacent formation. Understanding the direction and mechanism of heat flow whether it is conduction or convection help to represent this heat exchange mathematically. However, the only available factor used to understand the heat flow behavior is the measured wellbore temperature which can be obtained from the direct measurement while drilling or circulation operations, well logging, well test, or from the production operations. Also, the initial geothermal formation temperature resulting from the geothermal gradient will help to understand the undistributed formation …

Physical And Biological Factors Affecting Oxygen Transfer In The Activated Sludge Wastewater Treatment Process, Kenneth A. Campbell

Doctoral Dissertations

“The activated sludge (AS) process is widely utilized for wastewater treatment due to its versatility and general resiliency, but is energy intensive, requiring aeration and mixing energy inputs to maintain the biochemical reaction and optimize treatment performance. This study is focused on determining different factors that influence oxygen transfer and consequently its energy demand.

AS morphology, as described by the d₁₀, d₂₀, d₃₂, specific filament length (SFL), 30 min settleability (SV₃₀), etc., does influence the OTE. Filamentous organisms increase the hydrodynamic radius of suspended particles, which dilates mixed liquor apparent viscosity (µ …

Investigating The Factors Impacting The Success Of Immiscible Carbon Dioxide Injection In Unconventional Shale Reservoirs: An Experimental Study, Sherif M. Fakher

Doctoral Dissertations

"Unconventional shale reservoirs are currently gaining significant interest due to the huge hydrocarbon volumes that they bear. Enhanced oil recovery (EOR) techniques have been suggested to increase recovery from shale reservoirs. One of the most promising EOR methods is gas EOR (GEOR), most notably carbon dioxide (CO₂). Not only can CO₂ increase oil recovery by interacting with the oil and the shale, but it has also been shown to adsorb to the shale rock and thus is effective in both EOR applications and also carbon storage purposes. This research aims to experimentally investigate several of the interactions …

Computational Model For Neural Architecture Search, Ram Deepak Gottapu

Doctoral Dissertations

"A long-standing goal in Deep Learning (DL) research is to design efficient architectures for a given dataset that are both accurate and computationally inexpensive. At present, designing deep learning architectures for a real-world application requires both human expertise and considerable effort as they are either handcrafted by careful experimentation or modified from a handful of existing models. This method is inefficient as the process of architecture design is highly time-consuming and computationally expensive.

The research presents an approach to automate the process of deep learning architecture design through a modeling procedure. In particular, it first introduces a framework that treats …

Microgrid Design, Control, And Performance Evaluation For Sustainable Energy Management In Manufacturing, Md. Monirul Islam

Doctoral Dissertations

"This research studies the capacity sizing, control strategies, and performance evaluation of the microgrids with hybrid renewable sources for manufacturing end use customers towards a distributed sustainable energy system paradigm. Microgrid technology has been widely investigated and applied in commercial and residential sector, while for manufacturers, it has been less explored and utilized. To fill the gap, the dissertation first proposes a cost-effective sizing model to identify the capacities as well as control strategies of the components in microgrids considering a commonly used energy tariff, i.e., Time of Use (TOU). Then, the sizing model is extended by integrating control strategies …

Evaluation Of The Performance Of Different Polymer Gel Systems As An In-Depth Gel Treatment Using Numerical Simulation, Tariq K. Khamees

Doctoral Dissertations

"Oil production from heterogeneous and naturally fractured reservoirs are usually hindered due to the presence of high-permeability streaks and natural fractures networks. Oil production could be more lowered if there is a crossflow from the high- to the low-permeability layers and high mobility ratio. These problems are called conformance problems and the treatment is called conformance improvement technologies (CITs). The aims of CIT is to correct the heterogeneity of the reservoir and to lower the unfavorable mobility ratio. These technologies are leading to the diversion of post-treatment water into the low-permeability layers and to increase the viscosity of the displacing …