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2024

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The Effectiveness Of Cybersecurity Training, Courtney Knight Jan 2024

The Effectiveness Of Cybersecurity Training, Courtney Knight

Electronic Theses & Dissertations (2024 - present)

This study seeks to answer the question of what kinds of cybersecurity training are effective by reviewing the existing literature, analyzing for gaps, and bridging the connection with known learning techniques. The research is exploratory in nature, and is inductive – intending to develop a theory. Additionally, this study seeks to offer a taxonomy of cybersecurity training methods to be evaluated.

This study did not include security operation center (SOC), cyber incident response teams (CIRTs), or other types of advanced cybersecurity professional training. This research specifically focuses on training to improve the average employee and population’s tactical cybersecurity skills.

Several …


Structural Biology Of Diaphanous-1 And Its Role In Human Pathology, Gregory G. Theophall Jan 2024

Structural Biology Of Diaphanous-1 And Its Role In Human Pathology, Gregory G. Theophall

Electronic Theses & Dissertations (2024 - present)

DIAPH1 is diaphanous related formin which polymerizes actin into filaments and is important to cytoskeleton dynamics.[1, 2] The dysregulation and aberrant activation of DIAPH1 is known to cause deafness[3, 4] and clotting disorders,[5] and is recently implicated in the inflammatory responses associated with cardiovascular and diabetic pathology.[6-9] Despite this, activation of the full length structure and its regulation are poorly understood.[10-12] Therefore, the main objective of this dissertation is to explore the structural, autoinhibitory, and regulatory properties of DIAPH1 in the context of disease pathology. Herein, I show that DIAPH1 has a dynamic structure which is regulated through negative cooperativity, …


Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb Jan 2024

Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb

BCES: Faculty Publications

Plasmids are mobile genetic elements known to carry secondary metabolic genes that affect the fitness and survival of microbes in the environment. Well-studied cases of plasmidencoded secondary metabolic genes in marine habitats include toxin/antitoxin and antibiotic biosynthesis/resistance genes. Here, we examine metagenome-assembled genomes (MAGs) from the permanently-stratified water column of the Cariaco Basin for integrated plasmids that encode biosynthetic gene clusters of secondary metabolites (smBGCs). We identify 16 plasmid-borne smBGCs in MAGs associated primarily with Planctomycetota and Pseudomonadota that encode terpenesynthesizing genes, and genes for production of ribosomal and non-ribosomal peptides. These identified genes encode for secondary metabolites that are …


Gnss Software Defined Radio: History, Current Developments, And Standardization Efforts, Thomas Pany, Dennis Akos, Javier Arribas, M. Zahidul H. Bhuiyan, Pau Closas, Fabio Dovis, Ignacio Fernandez-Hernandez, Carles Fernandez-Prades, Sanjeev Gunawardena, Todd Humphreys, Zaher M. Kassas, Jose A. Lopez Salcedo, Mario Nicola, Mario L. Psiaki, Alexander Rugamer, Yong-Jin Song, Jong-Hoon Won Jan 2024

Gnss Software Defined Radio: History, Current Developments, And Standardization Efforts, Thomas Pany, Dennis Akos, Javier Arribas, M. Zahidul H. Bhuiyan, Pau Closas, Fabio Dovis, Ignacio Fernandez-Hernandez, Carles Fernandez-Prades, Sanjeev Gunawardena, Todd Humphreys, Zaher M. Kassas, Jose A. Lopez Salcedo, Mario Nicola, Mario L. Psiaki, Alexander Rugamer, Yong-Jin Song, Jong-Hoon Won

Faculty Publications

Taking the work conducted by the global navigation satellite system (GNSS) software-defined radio (SDR) working group during the last decade as a seed, this contribution summarizes, for the first time, the history of GNSS SDR development. This report highlights selected SDR implementations and achievements that are available to the public or that influenced the general development of SDR. Aspects related to the standardization process of intermediate-frequency sample data and metadata are discussed, and an update of the Institute of Navigation SDR Standard is proposed. This work focuses on GNSS SDR implementations in general-purpose processors and leaves aside developments conducted on …


An Analysis Of Precision: Occlusion And Perspective Geometry’S Role In 6d Pose Estimation, Jeffrey Choate, Derek Worth, Scott Nykl, Clark N. Taylor, Brett J. Borghetti, Christine M. Schubert Kabban Jan 2024

An Analysis Of Precision: Occlusion And Perspective Geometry’S Role In 6d Pose Estimation, Jeffrey Choate, Derek Worth, Scott Nykl, Clark N. Taylor, Brett J. Borghetti, Christine M. Schubert Kabban

Faculty Publications

Achieving precise 6 degrees of freedom (6D) pose estimation of rigid objects from color images is a critical challenge with wide-ranging applications in robotics and close-contact aircraft operations. This study investigates key techniques in the application of YOLOv5 object detection convolutional neural network (CNN) for 6D pose localization of aircraft using only color imagery. Traditional object detection labeling methods suffer from inaccuracies due to perspective geometry and being limited to visible key points. This research demonstrates that with precise labeling, a CNN can predict object features with near-pixel accuracy, effectively learning the distinct appearance of the object due to perspective …


Garbage In ≠ Garbage Out: Exploring Gan Resilience To Image Training Set Degradations, Nicholas Crino, Bruce A. Cox, Nathan B. Gaw Jan 2024

Garbage In ≠ Garbage Out: Exploring Gan Resilience To Image Training Set Degradations, Nicholas Crino, Bruce A. Cox, Nathan B. Gaw

Faculty Publications

Generative Adversarial Networks (GANs) have received immense attention in recent years due to their ability to capture complex, high-dimensional data distributions without the need for extensive labeling. Since their conception in 2014, a wide array of GAN variants have been proposed featuring alternative architectures, optimizers, and loss functions with the goal of improving performance and training stability. This manuscript focuses on quantifying the resilience of a GAN architecture to specific modes of image degradation. We conduct systematic experimentation to empirically determine the effects of 10 fundamental image degradation modes, applied to the training image dataset, on the Fréchet inception distance …


Does Money Matter? Exploring Pay Disparities For Nursing Faculty Educators, Jacqueline Christianson, Jessica L. Zemlak, Kathryn J. Malin, Lisa M. Grabert Jan 2024

Does Money Matter? Exploring Pay Disparities For Nursing Faculty Educators, Jacqueline Christianson, Jessica L. Zemlak, Kathryn J. Malin, Lisa M. Grabert

College of Nursing Faculty Research and Publications

Key Takeaways:

  • The nurse faculty shortage must be addressed to meet the healthcare needs of the public.
  • The salary gap between academic nurse educators and clinical practice nurses likely contributes to the nurse faculty shortage.
  • Additional investments are necessary to recruit and retain sufficient nursing faculty.


In Vivo Measurement Of Nadh Fluorescence Lifetime In Skeletal Muscle Via Fiber-Coupled Time-Correlated Single Photon Counting, Kathryn M. Priest, Jacob V. Schluns, Nathania Nischal, Colton L. Gattis, Jeffery C. Wolchok, Timothy J. Muldoon Jan 2024

In Vivo Measurement Of Nadh Fluorescence Lifetime In Skeletal Muscle Via Fiber-Coupled Time-Correlated Single Photon Counting, Kathryn M. Priest, Jacob V. Schluns, Nathania Nischal, Colton L. Gattis, Jeffery C. Wolchok, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Nicotinamide adenine dinucleotide (NADH) is a cofactor that serves to shuttle electrons during metabolic processes such as glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation (OXPHOS). NADH is autofluorescent, and its fluorescence lifetime can be used to infer metabolic dynamics in living cells. Fiber-coupled time-correlated single photon counting (TCSPC) equipped with an implantable needle probe can be used to measure NADH lifetime in vivo, enabling investigation of changing metabolic demand during muscle contraction or tissue regeneration. This study illustrates a proof of concept for point-based, minimally-invasive NADH fluorescence lifetime measurement in vivo. Volumetric muscle loss (VML) injuries were …


A Stock Optimization Problem In Finance: Understanding Financial And Economic Indicators Through Analytical Predictive Modeling, Aditya Chakraborty, Chris Tsokos Jan 2024

A Stock Optimization Problem In Finance: Understanding Financial And Economic Indicators Through Analytical Predictive Modeling, Aditya Chakraborty, Chris Tsokos

Epidemiology, Biostatistics, & Environmental Health Faculty Publications

Given the significant impact of healthcare stock changes on the global economy, including its GDP and other financial factors, we endeavored to create an analytical prediction model for forecasting the annual percentage change of these stocks. Our model, which is nonlinear, incorporates five key discoveries. We focused on predicting the average weekly closing price (pWCP) of AbbVie Inc. (North Chicago, IL, USA)'s healthcare stock (ABBV) from 1 August 2017 to 31 December 2019. The stock was chosen based on the low beta risk, high dividend yield, and high yearly percentage return criteria. Alongside predicting the weekly stock price, our model …


A Model For International Summer Research Experiences For Stem Students, Mika Munakata, Su San Lim, Carlos A. Molina Jan 2024

A Model For International Summer Research Experiences For Stem Students, Mika Munakata, Su San Lim, Carlos A. Molina

Department of Mathematics Faculty Scholarship and Creative Works

In this article, we report on a National Science Foundation-funded immersive international summer research program for biology students. Six students, representing Cohort 1 of a three-year program, spent 9 weeks at one of three institutes in Japan, working on related molecular, cellular, and developmental research projects under the mentorship of a Japanese researcher. We describe the recruitment process, pre-departure activities, orientation week, research projects, and mentorship structure. Data were collected to determine the impact of the program on students’ views about science and to seek feedback about the structure of the program. The pre-, mid- and post-program interviews with the …


Savings Associated With Surgical Aortic Valve Replacement With A Resilia Tissue Valve Based On Seven-Year Commence Trial Results, Tom Nguyen Jan 2024

Savings Associated With Surgical Aortic Valve Replacement With A Resilia Tissue Valve Based On Seven-Year Commence Trial Results, Tom Nguyen

All Publications

Background: Bioprostheses with RESILIA tissue demonstrate a reduction in calcification and improve health outcomes in pre-clinical and clinical studies. Prior economic analyses which relied on 5 years of evidence from the COMMENCE trial demonstrate financial savings for RESILIA tissue valves relative to mechanical valves after surgical aortic valve replacement (SAVR). Given the recent release of 7-year COMMENCE data, this economic evaluation updates the estimate for long-run savings of bioprosthetic valves with RESILIA.

Methods: Simulation models estimated disease progression across two hypothetical SAVR cohorts (tissue vs. mechanical) of 10,000 patients each in the US. The primary comparison calculated the SAVR-related expenditures …


The Ithildin Library For Efficient Numerical Solution Of Anisotropic Reaction-Diffusion Problems In Excitable Media, Desmond Kabus, Marie Cloet, Christian Zemlin, Olivier Bernus, Hans Dierckx Jan 2024

The Ithildin Library For Efficient Numerical Solution Of Anisotropic Reaction-Diffusion Problems In Excitable Media, Desmond Kabus, Marie Cloet, Christian Zemlin, Olivier Bernus, Hans Dierckx

2020-Current year OA Pubs

Ithildin is an open-source library and framework for efficient parallelized simulations of excitable media, written in the C++ programming language. It uses parallelization on multiple CPU processors via the message passing interface (MPI). We demonstrate the library's versatility through a series of simulations in the context of the monodomain description of cardiac electrophysiology, including the S1S2 protocol, spiral break-up, and spiral waves in ventricular geometry. Our work demonstrates the power of Ithildin as a tool for studying complex wave patterns in cardiac tissue and its potential to inform future experimental and theoretical studies. We publish our full code with this …


Four-Dimensional Ecology Education (4dee) For Everyone: Teaching Ecology To Non-Majors, Vikki L. Rodgers, Sara E. Scanga, Justin R St Juliana, Erica S. Tietjen, Jon M. Honea, Loren B. Byrne, Zakiya H. Leggett, George Middendorf Jan 2024

Four-Dimensional Ecology Education (4dee) For Everyone: Teaching Ecology To Non-Majors, Vikki L. Rodgers, Sara E. Scanga, Justin R St Juliana, Erica S. Tietjen, Jon M. Honea, Loren B. Byrne, Zakiya H. Leggett, George Middendorf

Arts & Sciences Faculty Publications

Originally developed for application to ecology courses for undergraduate majors, the Four-Dimensional Ecology Education (4DEE) Framework offers possibilities for adaptation to courses with ecology content for many other audiences. Recognizing the extraordinary range of classroom contexts and constraints, we developed some general, flexible recommendations and approaches to guide instructors in adapting the 4DEE Framework for an array of non-major audiences and classroom context needs. Our hope is that 4DEE-aligned courses for non-majors will provide these students with greater appreciation of ecology and inspire them to use their knowledge to address many critical environmental issues in their personal and professional lives. …


Prospective Math Teachers’ Vision Of High-Quality Mathematics Instruction With Technology: A Focus On Role Of The Teacher, Allison W. Mcculloch, Lara K. Dick, Nina G. Bailey, Jennifer N. Lovett, Joshua Wilson, Purity Muthitu Jan 2024

Prospective Math Teachers’ Vision Of High-Quality Mathematics Instruction With Technology: A Focus On Role Of The Teacher, Allison W. Mcculloch, Lara K. Dick, Nina G. Bailey, Jennifer N. Lovett, Joshua Wilson, Purity Muthitu

Department of Mathematics Faculty Scholarship and Creative Works

We report on a study of preservice secondary mathematics teachers’ instructional vision evolves as a result of engaging in practice-based approach to learning how to teach mathematics. Findings show that preservice teachers developed a more sophisticated vision of the role of the teacher.


Rainbow Spanning Trees In Randomly Colored Gk-Out, Deepak Bal, Alan Frieze, Paweł Prałat Jan 2024

Rainbow Spanning Trees In Randomly Colored Gk-Out, Deepak Bal, Alan Frieze, Paweł Prałat

Department of Mathematics Faculty Scholarship and Creative Works

Given a graph G = (V, E) on n vertices and an assignment of colors to its edges, a set of edges S \subseteq E is said to be rainbow if edges from S have pairwise different colors assigned to them. In this paper, we investigate rainbow spanning trees in randomly colored random Gk-out graphs.


Reasoning Quantitatively About The Lunar Phases, Nicole Panorkou, Amanda Provost Jan 2024

Reasoning Quantitatively About The Lunar Phases, Nicole Panorkou, Amanda Provost

Department of Mathematics Faculty Scholarship and Creative Works

We discuss how students’ reason quantitatively as they explored the lunar phases in an interactive computer simulation we designed to integrate math and science learning. We illustrate different forms of students’ quantitative operations as they reason about the moon in its orbit.


High-Precision Digital Light Processing (Dlp) Printing Of Microstructures For Microfluidics Applications Based On A Machine Learning Approach, Xinhui Wang, Jinghang Liu, Ruihai Dong, Michael D. Gilchrist, Nan Zhang Jan 2024

High-Precision Digital Light Processing (Dlp) Printing Of Microstructures For Microfluidics Applications Based On A Machine Learning Approach, Xinhui Wang, Jinghang Liu, Ruihai Dong, Michael D. Gilchrist, Nan Zhang

Articles

Digital light processing (DLP) is renowned for its precision, but the challenge lies in the identification of optimal print parameters to minimise print errors and enhance overall print accuracy. This study introduces a groundbreaking approach by integrating 'Random Forest' (RF) models with DLP printing to construct a predictive model for printing errors to achieve unparalleled precision. We conducted experiments using common commercial resins to print, resulting in a comprehensive dataset of 690 experimental datasets. Consequently, we validated this approach by fabricating Y-type microfluidic structures with a minimum feature size printing of 2 µm and herringbone mixer structures with feature sizes …


Synthesis And Characterization Of Quantum Materials, Yunsheng Qiu Jan 2024

Synthesis And Characterization Of Quantum Materials, Yunsheng Qiu

Doctoral Dissertations

"In this study, attempts were made to grow quantum materials that have recently undergone a profound change of perspective. These materials are involved in intricate macroscopic properties rooted in the subtle nature of quantum physics. To explore our understanding of quantum materials, this study includes three projects: Magnetic Topological Insulators, Topological Superconductors, and high-temperature superconductors.

A Cr-doped Sb2Te3 is added to the category for the magnetic topological insulators project. Their transport properties are studied, and the origin of ferromagnetism is studied. Anomalous Hall effect is observed in the Hall measurements, and serval factors (cooling rate, dopant deficiency) …


Re-Evaluating Missouri’S Strategic Element Potential: A Geochemical Study Of The Mesoproterozoic Fe-Cu-Co-Ree Deposits In Southeast Missouri, Usa, Brandon James Sullivan Jan 2024

Re-Evaluating Missouri’S Strategic Element Potential: A Geochemical Study Of The Mesoproterozoic Fe-Cu-Co-Ree Deposits In Southeast Missouri, Usa, Brandon James Sullivan

Doctoral Dissertations

"Iron-oxide-copper-gold (IOCG) deposits are poorly understood mineral systems. For example, we do not know why Cu- and Co-rich IOCG deposits typically occur proximal to Fe ore deposits that are notably Cu and Co-poor, such as Iron Oxide Apatite (IOA) deposits. To better understand the formation of IOA and IOCG deposits in Missouri, USA, this PhD thesis examines the genesis of the Kratz Spring IOA and the Boss Central Dome IOCG deposits. This study presents the first constraints on formation conditions and fluid sources in the studied deposits using integrated petrographic, mineral composition, and Fe isotope analyses of oxide minerals. Observations …


Control And Optimization Of Energy Storage System In Power Distribution System, Waqas Ur Rehman Jan 2024

Control And Optimization Of Energy Storage System In Power Distribution System, Waqas Ur Rehman

Doctoral Dissertations

"The widespread adoption of electric vehicles (EVs) and transportation electrification is encumbered by two chief barriers: i) the limited driving range of EVs in the market today and ii) inadequate fast-charging infrastructure for long-distance trips. Extreme fast charging (XFC) technology can recharge EVs in less than 10 minutes for 200 miles range. Firstly, a novel robust optimization-based mixed integer linear programming model is proposed to size a battery energy storage system (BESS) and PV system in an XFCS. In this part, it is assumed that the sizing and location of the XFCS are known. Secondly, the aforesaid assumption is relaxed, …


Investigation Of Asphaltene Instability Under Gas Injection In Unconventional Reservoirs And Its Impact On Oil Recovery Performance, Mukhtar Elturki Jan 2024

Investigation Of Asphaltene Instability Under Gas Injection In Unconventional Reservoirs And Its Impact On Oil Recovery Performance, Mukhtar Elturki

Doctoral Dissertations

"Unconventional reservoirs, such as shale gas and tight oil formations, have become an important source of energy in recent years. However, these reservoirs often contain high levels of asphaltenes, which can lead to deposition and blockages in production wells and reduce the flow of hydrocarbons during gas enhanced oil recovery (GEOR) techniques. This study aims to experimentally evaluate the impact of miscible and immiscible carbon dioxide (CO₂) and nitrogen (N₂) on asphaltene deposition and its impact on oil recovery performance in unconventional shale reservoirs.

This research began with a comprehensive literature review and data analysis of GEOR methods in unconventional …


The Science Of Gravitational-Wave Sources And Beyond Compact Binary Coalescences, Yanyan Zheng Jan 2024

The Science Of Gravitational-Wave Sources And Beyond Compact Binary Coalescences, Yanyan Zheng

Doctoral Dissertations

"This work focuses on the field of gravitational-wave astronomy by extending the scope of detectable sources beyond compact binary coalescences, All the gravitational-wave detections so far come from compact binary coalescences. Focusing on core-collapse supernovae as promising sources for short gravitational-wave transients, this work reports optically targeted searches for gravitational-wave emitted by core-collapse supernovae during the third observing run of the LIGO and Virgo detectors. It also predicts the search sensitivity for the ongoing fourth and forthcoming fifth observing runs. Moreover, the work introduces a novel computational framework for testing the spatial distribution of binary black hole sources, allowing for …


Material Models For Simulation Of Steel Hot Rolling Process Using Experimentally Determined Properties At Elevated Temperatures And Strain Rates, Siva Sai Krishna Dasari Jan 2024

Material Models For Simulation Of Steel Hot Rolling Process Using Experimentally Determined Properties At Elevated Temperatures And Strain Rates, Siva Sai Krishna Dasari

Doctoral Dissertations

"Hot rolling is one of the most important and complex process that includes large material deformation, different contact conditions, complex geometries and different temperature gradients along with micro structural changes such as viscoplasticity, dynamic recrystallization, and static softening. In the present work, the viscoplasticity, damage evolution, static softening and void closure of alloyed metal during hot rolling process was numerically investigated. GleebleTM hot compression and double hit tests were performed to provide experimental stress-strain curves at recrystallization temperatures and at different strain rates. Johnson-Cook viscoplastic model was calibrated using experimental stress-strain curves. Static softening model was developed at varying …


Design, Synthesis, And Characterization Of Complex Chalcogenides For Energy Storage And Energy Conversion Applications, Srikanth Balijapelly Jan 2024

Design, Synthesis, And Characterization Of Complex Chalcogenides For Energy Storage And Energy Conversion Applications, Srikanth Balijapelly

Doctoral Dissertations

"Through this investigation, complex chalcogenides with the combination of main group metals, transition metals, and rare earth metals have been synthesized using the building block approach and their structure-property relationships are evaluated. The main emphasis of research is on rationally designing new materials for applications in sodium and lithium ion conducting solid electrolytes, cathodes, thermoelectrics, and nonlinear optics. Along with the experimental studies, theoretical calculations are also employed to better understand the physicochemical properties of the synthesized compounds.

The first part of the research will discuss designing alkali ion containing complex chalcogenides using the building block approach. This investigation resulted …


Advanced Mass Spectrometry Method Development And Applications For Assessment Of Traumatic Brain Injury And Legionella Pneumophila Dissinfection With Copper, Austin Chase Sigler Jan 2024

Advanced Mass Spectrometry Method Development And Applications For Assessment Of Traumatic Brain Injury And Legionella Pneumophila Dissinfection With Copper, Austin Chase Sigler

Doctoral Dissertations

"Pathological processes often involve complex biochemical changes which can be assessed using advanced mass spectrometry. In this present dissertation, two fields were studied: traumatic brain injury (TBI), and water contamination by L. pneumophilia. TBI is a pressing public health concern for which current clinical tools remain inadequate. We present newly developed mass spectrometric methods to access metabolites associated with blast induced TBI. We applied these methods to the biofluids of soldiers conducting explosives training. Significant changes in several metabolites were observed between pre- and post-blast specimens, including changes that increased with repeated exposure. These changes point to the possibility of …


Deep Learning Techniques For Image Segmentation In Dermoscopic Skin Cancer Images, Norsang Lama Jan 2024

Deep Learning Techniques For Image Segmentation In Dermoscopic Skin Cancer Images, Norsang Lama

Doctoral Dissertations

"Melanoma is recognized as the most lethal type of skin cancer, responsible for a significant proportion of skin cancer-related deaths. However, early detection of melanoma is essential for successful treatment outcomes. Computer-aided skin cancer diagnosis tools can save lives by enabling earlier detection of skin cancer. Image segmentation is a crucial step in computer-aided diagnosis as it allows the detection of critical features or regions in an image. Thus, an accurate image segmentation method is necessary to create a more precise computer-aided diagnostic tool for skin cancer diagnosis. This dissertation includes investigating and developing deep learning techniques to improve image …


Catalytic Control Of The Nanomorphology And Mechanical Properties Of Aliphatic Shape-Memory Aerogels, A B M Shaheen Ud Doulah Jan 2024

Catalytic Control Of The Nanomorphology And Mechanical Properties Of Aliphatic Shape-Memory Aerogels, A B M Shaheen Ud Doulah

Doctoral Dissertations

"Shape-memory poly(isocyanurate-urethane) (PIR-PUR) aerogels are nanoporous solids that can return to their original shape after being compressed, through a heating actuation step. This thesis compares the effectiveness of various metal ions as catalysts in the formation of PIR-PUR aerogels, and explores the correlation between catalytic activity, nanomorphology, and mechanical properties of the resulting aerogels. The gelation rate was found to increase from Fe to Cu and then decline from Cu to Ga in the periodic table. CuCl2 was found to be the fastest catalyst, and FeCl3 the slowest. The morphology of the aerogels changed from bicontinuous to spheroidal …


Understanding Catalyst Design Principles In Transition Metal Mixed Anionic Chalcogenides For Electrocatalytic Energy Conversion, Ibrahim Abdullahi Jan 2024

Understanding Catalyst Design Principles In Transition Metal Mixed Anionic Chalcogenides For Electrocatalytic Energy Conversion, Ibrahim Abdullahi

Doctoral Dissertations

"This research focused on the synthetic design of transition metal mixed anionic chalcogenide catalysts containing various ligand types around the central metal atom (chalcogen anion and chalcogen-based organic ligand) generating diverse crystal structure types applied for water splitting and carbon dioxide reduction reactions (CO2RR).

A series of catalysts were synthesized starting with isolated metal complexes (MEn) with a central metal core (M = Co, Ni, Cu, and Cr) through molecular clusters, to bulk nanostructured solids of similar M-E coordination. Bis(dichalcogenoimidodiphosphinato) were employed as ligands in the metal complexes, and anionic chalcogen (E = S, Se, and …


Experimental Investigation Of High-Temperature Brine-Shale Interactions, Anna Atasha Hoffmann Jan 2024

Experimental Investigation Of High-Temperature Brine-Shale Interactions, Anna Atasha Hoffmann

Doctoral Dissertations

"Hydrofracturing (fracking), a common practice in the Petroleum Industry to induce or improve fluid flow in tight formations, creates chemical disequilibrium that further alters the porosity and permeability of host rocks and results in the production of saline and contaminated produced waters (PW). The PW of the Tuscaloosa Marine Shale (TMS) are Na-Ca-Mg-K-Cl brines with mean concentrations of approximately 16% Total Dissolved Solids (TDS) and circumneutral pH. Analysis of composition suggests the PW result from a 20 to 80% dilution of formation waters (relict brines of the Louann Salt) by fracking fluid. Trace element concentrations generally show moderate to strong …


Improving Decision-Making Processes In Construction And Infrastructure Bidding: Qualitative And Quantitative Approaches Including Graph Theory, Game Theory, And Machine Learning, Muaz Osman Elzubeir Ahmed Jan 2024

Improving Decision-Making Processes In Construction And Infrastructure Bidding: Qualitative And Quantitative Approaches Including Graph Theory, Game Theory, And Machine Learning, Muaz Osman Elzubeir Ahmed

Doctoral Dissertations

"Construction and infrastructure bidding is a highly competitive process that entails various uncertainties faced by contractors. Contractors weigh various factors to determine the expected benefits of a construction project and decide their bid value. However, the situation is more complex in multi-stage bidding (MSG), where general contractors must account for the bids of their subcontractors and face a greater threat of the winner’s curse (i.e., situation where the winning contractor underestimates the actual cost of the project). As such, bidding-related complexities, risks, and uncertainties, if uncontrolled, can lead to the rise of claims and disputes between stakeholders. Existing research falls …