Digital Commons Network^™

Pulsed Arc Additive Manufacturing Of A Functionally Graded Er2209 Duplex Stainless Steel And Hsla-100 Structure: Morphology, Characterization, And Mechanical Performance, Stevens G. Hill Jr

College of Graduate Studies: Theses & Dissertations

Wire arc additive manufacturing is a process well suited to the efficient production of large structures. Duplex stainless steel exhibits high corrosion resistance and good strength which can be highly beneficial for industrial use. However, its use is limited due to its cost and complexity in controlling microstructure to achieve desired properties. In many cases, it can be highly beneficial to manufacture a component which uses specialty steel grades such as duplex stainless steel only where necessary, and utilizes more affordable, commonly available steels for reinforcement or bulk structural support. A functionally graded material satisfies these requirements by providing a …

Temporal Analysis Of Construction Safety Incidents In Southeastern U.S. Using Machine Learning Techniques, Mayowa O. Oladele

College of Graduate Studies: Theses & Dissertations

Construction safety incidents remain a significant concern, particularly in the Southeastern U.S. due to the high-risk nature of the industry. Analyzing patterns in these incidents can help improve safety practices and reduce accidents. Machine learning (ML) techniques were employed in this study to identify temporal patterns in construction safety incidents, aiming to enhance proactive safety management. The machine learning methods used in this research included logistic regression, decision trees, random forest, support vector machine (SVM), and K nearest neighbors (KNN).

The objective of the study was to analyze temporal trends in safety incidents and identify the most effective machine learningtechnique …

Using Algal Turf Scrubber Biomass As A Feed Source For Juvenile Eastern Oysters, Taofeek Saka Jimoh

College of Graduate Studies: Theses & Dissertations

Algal turf scrubber (ATS) is an engineered system that promotes natural wastewater treatment processes and improves water quality by passing a shallow stream of nutrient rich water over the surface of a gently sloped flow-way. Algae turf scrubber biomass is a combination of micro and macroalgae, as well as micro-invertebrates, ciliates, bacteria, and more. The overall aim of the study was to reduce the feeding cost of juvenile eastern oysters by replacing the commercial microalgae diet with ATS biomass. The experiment was designed to assess the viability of replacing commercial microalgal diet with ATS biomass at different substitution levels (0, …

Comparative Analysis Of Lidar And Close-Range Photogrammetry Techniques For Inspection Of Mse Walls In Two Georgia Bridges, Md. Mehrab Hossain

College of Graduate Studies: Theses & Dissertations

Mechanically Stabilized Earth (MSE) retaining walls are durable, settlement tolerant, easy to install, and present cost-effectiveness, in highway bridges. Nevertheless, the cost of repairing MSE walls is high, and it is crucial to have an accurate, quantitative, and scalable inspection method for early detection of potential problems. This study aims to analyze and evaluate undesired displacements that may affect these walls over time. For this, two remote-sensing technologies are considered: Light Detection and Ranging (LiDAR) and 3D Close Range Photogrammetry (CRP). Their performances are compared against an accurate Robotic Total Station (RTS) device, serving as the benchmarking instrument. This work …

Quantifying Inositol Phosphate Dephosphorylation To Understand The Role Of Recalcitrant Organic Phosphorus Forms On Harmful Algal Blooms In Freshwater Systems, Iffat Tasnim

College of Graduate Studies: Theses & Dissertations

Organophosphorus such as phytic acid, a surrogate species of inositol phosphate (IP), may serve as a source for orthophosphate (OP) in freshwater. In absence of OP, competent aquatic microorganisms upregulate the production of specialized enzymes to obtain growth-sustaining OP from organic phosphorus (org-P) forms. The contribution of recalcitrant org-P to the OP pool has been overlooked due to the lack of capable tools to measure OP production from org-P accurately. The objective of this study was to quantify OP production from phytic acid (a surrogate form of recalcitrant org-P) to assess the contribution of recalcitrant org-P forms to the total …

A Finite Volume-Based Approach For Modeling Hyperbaric Oxygen Therapy For Healing Chronic Wounds, Cade M. Layser

College of Graduate Studies: Theses & Dissertations

The current number of people in America with diabetes is approximately 38.4 million, that population is expected to rise to 54.9 million by 2030. Chronic wounds, which are characterized by impaired or stalled healing, are commonly associated with diabetes. These wounds if not treated properly can cause significant complications such as sepsis, infection, and gangrene which can lead to limb amputation or death of the patient. Limb amputations can be a large financial burden and significantly reduce the patient’s quality of life. The timely and efficient treatment of chronic wounds is essential to prevent adverse patient outcomes. Hyperbaric Oxygen therapy …

Defect Detection In Extrusion-Based Bio-Printed Constructs Using Video-Based Vibration Analysis, Md Anisur Rahman

College of Graduate Studies: Theses & Dissertations

Bio-additive manufacturing has emerged as a transformative advancement in biomedical engineering, enabling the fabrication of complex biological structures. However, maintaining the precision and quality of printed constructs remains a significant challenge, particularly in applications such as bioprinted organ transplants. Among the key factors affecting structural integrity, dimensional inconsistencies and interlayer defects present major obstacles, potentially compromising mechanical stability and functionality. This study explores the detection of defects caused by variations in dimensional accuracy and layer-to-layer adhesion. To address these challenges, a video-based motion estimation technique is employed as a non-contact and non-destructive evaluation method. Traditional approaches, such as contact-based and …

Synthesis And Processing Of Co-Axial/Tri-Axial Multi-Layered Nano-Particles, Jannatul Ferdaus

College of Graduate Studies: Theses & Dissertations

Electro-spraying has been used as an effective processing method of nanoparticle fabrication for the application of targeted drug delivery. The study demonstrates the feasibility of a non-conventional triaxial electro-spraying setup for multi-layered nano-drug fabrication and proposes optimized parameters. Two different drugs, XAV939 and Dextran 40000, were used to study the process parameters (voltage and solution concentration) of coaxial electro spraying. The particle size of Dextran-PCL was an average of 166.3 nm for PCL-Dextran at 32.5 kV and 18-hour sonication. The SEM analysis and UV-spectrum showed the encapsulation of Dextran with PCL, though the in vitro study in mice after 24 …

Long-Term Ichthyoplankton Monitoring Of The Moon River (Savannah, Ga) With A Focus On Climate Change, Bradley Cayson

College of Graduate Studies: Theses & Dissertations

The presence of healthy fish populations is a cornerstone of many important ecological mechanisms. These populations are supported by the recruitment of ichthyoplankton, or the egg and larval stages of fishes, as the primary determinant of population growth. Increases in average global water temperatures can alter the composition of fish communities and thus the offspring found in planktonic stages. I compared a large data set of ichthyoplankton surveys completed from 2009-2011 to a replicated six-month sampling period from May – November of 2024. Collection was conducted weekly to biweekly during night flood tides using a fixed suspension ichthyoplankton net (1mm …

Microbial Community Stabilization By Restored Oyster Reefs: Implications For Blue Carbon Storage, Natalie Boydstun

College of Graduate Studies: Theses & Dissertations

Coastal ecosystems provide critical carbon sequestration services, yet the microbial mechanisms underlying carbon storage remain poorly understood, particularly in non-vegetated habitats. This study investigated whether restored oyster reefs (Crassostrea virginica) enhance sediment carbon storage potential by stabilizing microbial communities and promoting efficient organic matter processing. I hypothesized that reef-mediated sediment stabilization and organic deposition would create conditions favoring microbial degradation of complex carbon compounds into stable soil organic matter, ultimately supporting anaerobic carbon storage. To test this, I compared sediment biogeochemistry, enzyme activity, and microbial community structure between three restored oyster reef sites and two unstructured control sites …

The School Of Becoming: Speculative Essays On Existential Possibility And Humanity In Education, Timothy A. Holman

College of Graduate Studies: Theses & Dissertations

This dissertation reimagines public education through an existential lens, advocating for a humanitarian approach that resists the prevailing dominance of standardized, data-driven systems. Drawing primarily from the philosophy of Jean-Paul Sartre (1936, 1940, 1943, 1947, 1965, 1992), it contends that education should honor freedom, nurture authenticity, embrace encounters with others, and cultivate imagination as essential to human development. Influenced by the works of William Ayers (1998, 2004, 2008, 2016, 2024), Maxine Greene (1967, 1973, 1978, 1988, 2000, 2001), Paulo Freire (1970, 2001, 2004), Christopher Emdin (2010, 2016, 2021), and Byung-Chul Han (2018, 2024), speculative essays—each focused on an existential theme—are …

A Phenomenological Study Exploring The Lived Experiences Of First-Generation African American Students To Improve Retention Rates, Jaleesa Porter

College of Graduate Studies: Theses & Dissertations

Colleges and universities play an important role in maintaining high retention rates and getting students from matriculation to graduation. There are several studies related to the reasons and barriers that result in low retention rates. This qualitative study examined how one university in southeast Georgia can improve retention rates among first-generation African American students by enhancing its practices. The findings from this study the revealed lived experiences of college students that resulted in a range of emotions, resources and barriers, and communication. Discussion and implications of the findings provide recommendations for practice and future research.

Principal Perceptions Of Leadership Preparedness To Promote Family Engagement In Urban Title I Elementary Schools, Marcus Kimber

College of Graduate Studies: Theses & Dissertations

This qualitative research examines urban Title I elementary school principals’ perceptions of their family engagement readiness based on university leadership preparation and/or district-level professional development. Based on Epstein's Theory of Overlapping Spheres of Influence, this research examines how educational leaders overcome socioeconomic inequities, trust problems, and communication failures to develop equitable relationships with families. Themes that revealed preparation deficiencies and prospective high-impact family engagement methods emerged from semi-structured interviews and ongoing comparison analysis. Principals value family engagement and recognize its impact on student achievement and school climate, but most feel unprepared to implement systematic, sustainable student engagement strategies. Leadership training …

Experimental Study Of Deformation Behavior For A Novel Elastohydrodynamic Seal For Supercritical Carbon Dioxide Power Cycles, William A. Adams

College of Graduate Studies: Theses & Dissertations

Supercritical carbon dioxide (sCO₂) Brayton cycles are a strong contender for future power generation systems due to their high thermal efficiency and compact nature. Sealing is one of the key challenges presented by such systems that has a direct impact on the system's overall efficiency. This research is the first experimental study to investigate the deformation behavior of an elastohydrodynamic (EHD) seal made from bearing-grade polyether ether ketone (PEEK). A testing apparatus was developed to integrate four strain gauges positioned along the seal to quantify the deformation occurring up to pressures of 13 MPa. Mass flow rate measurements …

Computational Investigation Of Underbody Slant Angle Variation Effect On A Hatchback Vehicle, Nufile Uddin Ahmed

College of Graduate Studies: Theses & Dissertations

Electric Vehicles, despite many advantages over their gasoline-powered counterparts, have the following main challenges towards mass adoption – the charging infrastructure and the range of the vehicle. Among the myriads of factors affecting the range, the coefficient of drag and the required power to overcome it are noteworthy. This study aims to investigate the effect of rear underbody slant angle on a common, simplified hatchback-shaped Electric Vehicle. The rear underbody slant angles (upward) assessed were 0°, 5°, 10°, and 15° and they were subjected to three freestream velocities representative of urban (16 m/s), highway (25 m/s) and interstate (40 m/s) …

Machine Learning For Automated Classification Of Tree Species Based On Color-Texture Fusion, Brandon C. Jones

College of Graduate Studies: Theses & Dissertations

This study aimed to develop robust machine learning tools for the classification of southeastern United States tree species based on bark images, addressing challenges posed by significant intraspecies variation in bark texture and color. The primary objectives included constructing specialized machine learning libraries and classification models, identifying optimal algorithms and parameters to maximize accuracy, and integrating the best-performing texture and color classifiers into a unified system to enhance the overall classification performance. The methodology involved collecting a dataset of 360 field images, extracting hue and saturation histograms for color features, and employing Histogram of Gradients (HOG) and Histogram of Binary …

An Investigative Study Of Thermal Fluid Properties When Introducing Metallic Nanoparticles Through A Heat Exchanging System, Levi P. Mckinney

College of Graduate Studies: Theses & Dissertations

Heat-exchanging systems are essential in applications ranging from automobiles to air-conditioning units, and ongoing improvements aim to enhance efficiency while reducing system size. Conventional coolant upgrades often rely on ethylene glycol, which increases thermal stability and lowers freezing point but reduces water’s inherent heat-transfer capability. Advances in nanotechnology provide an alternative approach: suspending nanoparticles in base fluids can significantly modify thermal properties, with some formulations exhibiting conductivity increases of up to 60%. This thesis examines the thermal and tribological performance of three working fluids—distilled water, a 50:50 water–ethylene glycol mixture, and the same mixture enhanced with Al₂O₃ nanoparticles. Distilled water …

Accelerated Test Method (Atm) For The Evaluation Of External Sulfate And Chloride Attack On Concrete Using Artificial Climate Environment (Ace): An Assessment Of Methodology, Eli Walker

College of Graduate Studies: Theses & Dissertations

This study seeks to investigate a testing methodology that utilizes accelerated testing methods (ATM) in conjunction with nondestructive testing methods (NDT) to assess destructive ion attacks on concrete. Through the testing of concrete samples, the impacts of chloride and sulfate ions on concrete will be tested by subjecting concrete to cyclic testing in an artificial climate environment. Electrical resistivity (ER) and ultrasonic pulse velocity (UPV) testing will evaluate the impact of the accelerated testing on the migration of destructive ions within the pore structure of the tested concrete. Based on this investigation, comparisons between accelerated, non-accelerated, and control samples will …

Evaluating The Effectiveness Of Lidar And Photogrammetry For Inspecting Mse Walls In Bridges, Shakil Ahmed

College of Graduate Studies: Theses & Dissertations

Mechanically Stabilized Earth (MSE) retaining walls are vital components of transportation infrastructure, providing structural support for embankments and bridge approaches. As many walls approach or exceed their design life, concerns regarding long-term stability, settlement, and displacement have increased. Traditional visual inspection remains the most common assessment method; however, it is subjective and often unable to detect subtle geometric changes that may precede structural distress or failure. This study evaluates Terrestrial LiDAR (Light Detection and Ranging) Scanning (TLS) and Close-Range Photogrammetry (CRP) as nondestructive, noncontact alternatives for detecting displacement in MSE retaining walls. Three representative sites were investigated: a Control Wall …

Hybrid Rans-Les Analysis Of Turbulent Flame Under Near Blow-Off Condition In A Multi-Stage Swirl Combustor, Brandon O'Brien

College of Graduate Studies: Theses & Dissertations

Advances in computational resources are making computational fluid dynamics (CFD) increasingly accessible for a variety of engineering applications. However, certain complex problems, such as simulating detailed flame kinetics, remain computationally prohibitive for many users. Developing cost-effective methods to simulate these challenges would greatly benefit applications involving flame dynamics, such as turbine engines or industrial burners. This study investigates the effect of main stage swirler intensity on near lean blow-off characteristics in a multi-staged swirl combustor using Ansys Fluent. The hybrid RANS-LES turbulence model, Stress Blended Eddy Simulation (SBES) coupled with Flamelet Generated Manifold (FGM) combustion model was selected to model …

Carceral Bonds, Tyler E. Dougherty

Lewis & Clark Law Review

Over the past 50 years, the U.S. financed a massive physical and fiscal expansion of prisons via the municipal bond market—with devastating results. This project is the first to shine a light on the role of municipal debt in state-level carceral decision making, spotlighting the ways that the municipal bond market affects states’ capacities to incarcerate.

This Article argues that the two primary controls of states’ use of the carceral bond market—(1) market discipline and (2) states’ fiscal constitutions—are particularly ineffective at limiting states’ spending on prisons. This failure to restrain states’ spending through the carceral bond market enables private …

The Legal Ramifications Of Israel’S Destruction Of Gaza’S Healthcare System, Serene Mistkawi

Lewis & Clark Law Review

This Comment argues that Israel’s attacks on the medical infrastructure of Gaza are a violation of international law because hospitals are protected zones and medical personnel are civilians. To Israel’s response that Hamas is attack-ing from hospitals, thereby rendering them legitimate targets, this Comment presents a number of responses: (1) there is little to no evidence that Hamas is doing this; (2) even if Hamas is doing this, the military gains from attacking hospitals are outweighed by the civilian deaths; (3) even if Hamas is doing this and there is significant military gain from attacking hospitals, the interna-tional rules have …

Enhanced Audio Encryption Scheme: Integrating Blowfish, Hmac-Sha256, And Md5 For Secure Communication, Jenan Ayad, Noor Qaddoori, Hasanain Maytham

Mesopotamian Journal of CyberSecurity

In today's communications, it is vital to protect audio data privacy before and after transfer. This work therefore introduces the enhanced audio encryption scheme (EAES), which employs the most effective techniques of cryptography and processes them to make it impossible for unauthorized persons or programs to access or change the contents of audio files. This method uses RSA to encrypt the Blowfish key, which is used for data encryption, the HMAC-SHA256 algorithm for integrity checks, and the Message-Digest algorithm (MD5) for the checking phase. The performance of the EAES is measured statistically via the MSE, PSNR, and correlation coefficient. For …

Enhancing Traffic Data Security In Smart Cities Using Optimized Quantum-Based Digital Signatures And Privacy-Preserving Techniques, Tuqa Ghani Tregi, Mishall Al-Zubaidie

Mesopotamian Journal of CyberSecurity

Securing big data in power plants is an important and fundamental step in the infrastructure of smart cities. In addition, it becomes a barrier if it is not controlled from the beginning. Security must be a combination of fast and robust properties. This research presents a traffic security system (TSS) in a smart city (SC). It is a novel paradigm meant to improve data security and integrity by means of a multilayered method. Advanced fault analysis, dual-stage pseudonymizing, quantum key distribution via the BB84 protocol, and Falcon signatures (FS) are combined in the proposed system. TSS enhances data security by …

Learning Techniques-Based Malware Detection: A Comprehensive Review, Sarah Fouad Ali, Musaab Riyadh Abdulrazzaq, Methaq Talib Gaata

Mesopotamian Journal of CyberSecurity

The rapid proliferation of Internet of Things (IoT) devices has significantly increased the threat landscape, with malwares arising as a critical concern. Advanced learning methods such as machine learning (ML), deep learning (DL), and federated learning (FL) are essential for handling complex IoT data. ML provides tools for pattern identification and detecting anomalies. DL boosts malware detection by automatically extracting features and identifying patterns. FL enables collaborative model training across decentralized devices, ensuring data privacy, which is crucial for diverse IoT systems. This comprehensive review specifically synthesizes ML, DL and FL for malware detection in the IoT environment, highlighting key …

Robust And Efficient Methods For Key Generation Using Chaotic Maps And A2c Algorithm, Ali A. Mahdi, Mays M. Hoobi

Mesopotamian Journal of CyberSecurity

In the current digital landscape, information security has become a critical necessity given the escalating frequency and sophistication of cyberattacks across global computing networks. Cryptography is the science and practice of securing information by transforming it into a format that is unreadable or inaccessible to unauthorized parties. The strength of the cryptography algorithm lies in the strength of used encryption key. Recently, the nonlinear behavior of chaotic maps has been utilized as a random source to generate robust key stream bits for cryptographic purposes. The aim of this paper is to introduce an efficient and robust system for generating strong …

Therapeutic Potential Of Brassica Carinata Microgreens Extract In Alleviating Symptoms Of Type 2 Diabetes In Wistar Rats, Lilian Nakakaawa, Ifeoluwa D. Gbala, Joel L. Bargul, Xavier Cheseto, John M. Wesonga

All Peer-Reviewed Publications

Microgreens of Brassica plants have attracted increasing research interest in the management of the prevailing epidemic of Type 2 diabetes mellitus (T2DM) because of their high nutritional value. This study evaluated the antidiabetic effects of Brassica carinata Microgreens Ethanolic Extract (BMEE) in type-2 diabetic rats. For the normoglycemic assay, rats were divided into five groups and received a single oral dose of 100, 250, and 500 mg/kg of BMEE while the control groups received distilled water and Glibenclamide. Fasting blood glucose (FBG) levels were determined on a weekly basis for 28 days in diabetic rats after treatment with BMEE at …

Earth Observations Reveal Impacts Of Climate Variability On Maize Cropping Systems In Sub-Saharan Africa, Adomas Liepa, Michael Thiel, Hannes Taubenböck, Doris Klein, Ingolf Steffan-Dewenter, Marcell K. Peters, Sarah Schönbrodt-Stitt, Insa Otte, Tobias Landmann, Zeyaur R. Khan, Michael Ochieng Obondo, Frank Chidawanyika, Emily A. Martin, Tobias Ullmann

All Peer-Reviewed Publications

In Kenya, climate variability and change threaten smallholder, rainfed farms, with crop failures, yield reductions, and pest infestations. Efficient agroecological strategies, such as Push-Pull intercropping, offer documented benefits including pest control, improved soil fertility, and water conservation compared to traditional maize monocropping. To date, no studies exist comparing traditional maize monocropping and Push-Pull intercropping using earth observation tools over several growing seasons in East Africa. Our research addresses this by harmonizing Landsat 7, 8, 9 with Sentinel-2 remote sensing time series from 2016 to 2023. Phenological metrics of 15 growing seasons are extracted based on a threshold method using the …

Enhancing Intrusion Detection Systems With Adaptive Neuro-Fuzzy Inference Systems, Jitender Sharma, Sonia ., Karan Kumar, Pankaj Jain, Pankaj Jain, Hussein Alkattan

Mesopotamian Journal of CyberSecurity

Network security has become increasingly critical in recent years. Among the various aspects of network security and considering several approaches to network security, intrusion detection systems (IDSs) have gained considerable attention. The prominence of this factor, among other factors of network security, is due to its ability to address the complex and uncertain nature of security breaches. Whenever data flow over the network, precise categorization of normal and malicious data is necessary. Past IDS systems lack precise categorization. Thus, the present study focuses on the use of the adaptive neuro-fuzzy inference system (ANFIS) as a classifier to categorize network instances …

Encrypting Text Messages Via Iris Recognition And Gaze Tracking Technology, Sura Abed Sarab Hussien, Basim Najim Al-Din Abed, Kamaran Adil Ibrahim

Mesopotamian Journal of CyberSecurity

This study explores the integration of eye-tracking technology, specifically the gaze point (GP3) eye tracker, to develop a novel encryption and decryption model that leverages an individual's unique eye patterns as a cryptographic key. This research addresses the critical problem of balancing user-friendly encryption mechanisms with robust security. This study aims to design a gaze-based encryption system that uses the eye's binary matrix as a dynamic encryption key. The methodology involves capturing an eye image, converting it into a binary matrix, and using the extracted matrix to generate a unique iris key (IK) applied to encrypt and decrypt text messages …