Digital Commons Network^™

Influence Of Alloy Composition On The Process Robustness Of Steels Consolidated Via Laser-Directed Energy Deposition, Jonathan Kelley

Masters Theses

"To ensure consistent quality of additively manufactured parts, it is advantageous to identify alloys which can meet performance criteria while being robust to process variations. Toward this end, this work investigated the effect of alloy composition on the robustness of steels consolidated via laser-directed energy deposition (L-DED). Ultra-high-strength low-alloy steel (UHSLA) and pure iron powders were mixed in-situ to produce 10 compositions containing 10-100% UHSLA by mass. JMatPro material simulations roughly predicted phases and mechanical properties. Two sets of experiments were used to evaluate the sensitivity of as-built hardness (all 10 compositions) and tensile properties (5 select compositions) to process …

Modeling Of Slot-Backed Microstrip Line For Emi Applications, Jongsuk Hyun

Masters Theses

Radiated emissions from printed circuit boards (PCBs) are a significant concern in electromagnetic interference (EMI) and radio frequency interference (RFI). Shielding cans are widely used to mitigate these emissions but evaluating requires accurate characterization of equivalent noise sources. Slot-backed microstrip antennas are employed for this purpose due to their near-zero height, low parasitic radiation, and PCB-compatible structure, offering a practical alternative to conventional loop antennas. This paper presents a physics-based analytical model that integrates both the discontinuity effects and radiated characteristics of slot-backed microstrip structures within a unified circuit framework. An analytical expression for the dipole moment is proposed based …

Characterization Of The Microstructural Changes Of Zrb2 Under Heavy Ion Irradiation For Molten Salt Reactor Applications, Narrie Loftus

Masters Theses

A primary challenge in finding suitable materials for Molten Salt Reactors (MSRs) lies in identifying those that concurrently exhibit high corrosion resistance, stability at elevated temperatures, resistance to radiation, and chemical compatibility with molten salts. 11B-enriched zirconium diboride (ZrB₂) is a potential candidate for applications in MSRs due to its unique combination of properties, including high melting point, high thermal conductivity, and resistance to corrosion in harsh environments. This ultra-high temperature ceramic (UHTC) has exhibited stability under extreme conditions, making it an attractive material for components within MSRs.

The microstructural response of ZrB₂ under heavy ion irradiation …

System Design For Highly Accurate And Efficient Target Detection In Triaxial Testing, Qingqing Fu

Masters Theses

Accurate and automated recognition of coded targets is crucial for high-precision photogrammetry-based measurements in triaxial testing. Traditional recognition methods, including those based on deep learning and table decoding, often struggle with issues such as perspective distortion, rotation, and variable lighting, leading to unreliable results. While deep learning approaches offer some improvements, they remain computationally intensive and sensitive to environmental factors.

This thesis introduces an innovative system that replaces deep learning algorithms with a blob analysis-based method for efficient and robust recognition of coded targets. The system also employs newly designed solid points of varying sizes and patterns, eliminating the need …

Gfrp Reinforced Bridge Barriers: Experiment Testing, Manish Kumar Gadhe

Masters Theses

This study focused on evaluating the performance of concrete bridge barriers reinforced with Glass Fiber Reinforced Polymer (GFRP) compared to those reinforced with conventional mild steel. Four full-scale barriers were constructed, three using GFRP bars as the reinforcement and one with mild steel reinforcement. These were cast on two concrete slabs to ensure consistent support conditions. The use of GFRP aims to address durability concerns associated with steel reinforced concrete (RC), particularly corrosion of these bars in harsh environments.

To simulate real-world impact scenarios, a weighted cart was launched at each barrier using a guided sled system. Sensors, including load …

Ground Testing Of Cryogenic Environments In Vacuum Conditions, Lucas A. Scott

Masters Theses

The environment in the vacuum of space is unforgiving and ever-changing. Not only facing the lack of a protective atmosphere, but powerful radiation and extreme temperature ranges as well. Equipment destined for space must be hardened to withstand them. Just launching satellites that are theoretically able to survive these conditions is unfeasibly costly in the event of failure. Because of this, spacecraft must be tested in a simulated environment that can match the harsh climate in space. Therefore, it is the goal of the Gas and Plasma Dynamics Lab's (GPDL) to test and prove specific methods of recreating these conditions. …

Development Of A Method To Measure Blast Overpressure Exposure Using Orthogonal Sensor Orientations, Nicholas Kuehl

Masters Theses

Measuring and recording blast exposure to military personnel from shoulder-fired weaponry or improvised explosive devices to correlate health outcomes like mild traumatic brain injury has been a goal for many years. As such, many wearable sensors have been developed and tested for accuracy and reliability. Despite this, knowing the sensor orientation in relation to the blast source is important to fully correlate the actual personnel exposure to clinical outcomes. This research investigates whether pressures recorded at three independent orientations in the x, y and z planes can be combined to a representative pressure that is independent of orientation. Important metrics …

Auto-Tuning And Applications Of Transient Voltage Suppressor Models In Full-Wave Simulations, Daniel Peter Szanto

Masters Theses

System efficient electrostatic design (SEED) combines full-wave geometry information with SPICE models of non-linear protection devices, typically transient voltage suppression (TVS) diodes, to allow optimization and validation of electrostatic design (ESD) protection early in the design process. TVS models have previously been developed which may be used in SPICE simulation tools like Keysight ADS, but these models could not be used directly in full-wave simulation tools like CST Studio. A process was developed for converting existing ADS models of TVS devices to a form that can be used within a CST full wave/SPICE hybrid simulation. Three TVS models were converted …

Overpressure Waveform Comparison Of High Explosive, Methane, And Coal Dust Explosions, Frank James Schott

Masters Theses

Methane and coal dust explosions remain a leading cause of catastrophic mining accidents, making it critical to understand their overpressure characteristics for better hazard modeling, mitigation, and regulation. Although high explosives (HE), flammable gases, and dusts have been studied separately, direct waveform comparisons in identical environments are rare. This study addresses that gap by comparing overpressure waveforms from HE, methane-air mixtures, and coal dust explosions to assess differences in peak pressure, impulse, rise time, and phase duration. Twenty-seven tests were conducted using standardized instrumentation and sensor arrays. Results showed that HE generated the highest peak pressures with short positive phases …

Frequency-Tracker And Power Supply For Piezoelectric Lunar Dust Removal Actuator, Praneeth Uddarraju

Masters Theses

"This work presents a reconfigurable phase-locked loop (PLL)-based control system for the resonant excitation of piezoelectric actuators aimed at automated removal of particulate contaminants from photovoltaic (PV) surfaces—particularly in extraterrestrial environments such as the lunar surface. Regolith or lunar dust buildup on solar panels is a serious hazard to the effectiveness of energy harvesting on extended missions. By using high-frequency structural excitation and inertial forces the suggested system removes surface impurities. Tunable Sallen-Key low-pass filters for reliable feedback conditioning are used in conjunction with a digitally implemented PLL on an FPGA (XLR8 platform) to precisely lock the drive frequency to …

An Experimental Study Into The Methods Of Water Coupling And Their Impact On Kinetic Energy And Blast Over Pressure Through The Use Of A Ballistic Pendulum, Jeremiah Alan Cohn

Masters Theses

Water coupled charges utilize the material properties of water to alter their behavior for reductions in overpressure and increases in kinetic energy. Although water coupling has been studied directly, combined usage of the two primary methods of water coupling, tamping and pushing, hinders further research. This study addresses the gap in literature by comparing ballistic pendulum and blast data for charges with water tamping and pushing to determine differences in kinetic energy, peak overpressure, impulse, noise and duration of fireball. The results showed that water tamping provided a 69.1% increase in kinetic energy, an 18.6% reduction in incident overpressure, a …

Aerodynamic Design Workflow Optimization For Fsae: Advanced Cfd And Hpc Automation, Kyle Maynor

Masters Theses

This research identifies and resolves inefficiencies in the Computational Fluid Dynamics (CFD) workflow of the Missouri S&T Racing Formula SAE Team’s aerodynamic development. Key bottlenecks were found in simulation runtime, laborious simulation preparation, an overly manual simulation submission process, and unchecked mesh quality. A fully reimagined workflow was implemented with simulation parameters to adjust vehicle attitudes. From this, an automated design sweep could be executed to generate aero maps of the developing vehicle using the Design Manager Project. A Python-based submission app handles the terminal interfacing and macro editing that significantly slowed the job submission process before. Using a university …

Design Of A Spacecraft Power System Experiment, Jay Bakulkumar Kamdar

Masters Theses

This research delves into the design, implementation, and analysis of a controlled experimental framework for photovoltaic cell characterization and its application in spacecraft power systems. Such a system was simulated and validated by benchmarking characteristics of a photovoltaic module and implementing them in a system design simulation yielding performance data for comparative analysis. A hardware setup was developed to perform IV characterization tests under steady state thermal conditions. Experiments conducted across various thermal regulation profiles helped quantify the effects of temperature on the photovoltaic performance parameters. Active cooling reduced the steady state cell temperature by 17.9% and improved the cell …

Enabling Drone-Integrated Active Microwave Thermography Via A Slot Antenna Design, Alec P. Fitzmaurice

Masters Theses

Civil infrastructure inspection quality and inspector safety may be enhanced from the advancement in the capabilities of nondestructive testing and evaluation of remote or otherwise hard-to-reach areas such as nuclear power plants, wind turbines, bridges, or other civil infrastructure using drone-based Active Microwave Thermography (AMT). AMT is a nondestructive testing technique that utilizes high frequency energy (often radiated from an antenna) to induce heating in a specimen. Following this thermal excitation, an infrared camera is used to measure the resulting surface thermal profile. From this, defect indications may be detected. To enable drone-based deployment of AMT, where the antenna size …

Application Of Edge-Enhanced Phase Analysis To Active Microwave Thermographic Measurements, Douglas Blaine Fleetwood

Masters Theses

Nondestructive testing and evaluation (NDT&E) encompasses a range of inspection techniques that assess materials, components, and structures while maintaining their integrity and performance. Among these techniques, thermography is particularly attractive due to its non-contact imaging approach with easy-to-interpret results. Active Microwave Thermography (AMT) has emerged as a promising NDT&E inspection technique that utilizes electromagnetic energy to heat materials through dielectric and magnetic absorption, with subsequent infrared imaging used to detect subsurface defects. While AMT offers significant advantages including material-specific heating optimization and lower power requirements compared to conventional thermographic methods, the technique faces a persistent challenge related to the thermal …

Biological Computing From Microscopic To Macroscopic Evolution, Xiaofeng Ding

Masters Theses

A unified theory from microscopic to macroscopic DNA-based biological systems is explained in terms of the rule components used when the system size is increased. Even though the eight female rules in each ruleset are provided with an equal probability of the computation-state outcomes, the initial ensemble of the computation states will exponentially settle into one dominant rule that supports the nutrition needed for growth. The remaining seven rules form into two minority groups to provide the biological characteristics of the system's growth from a micro to macroscopic evolution. The object of this study is to prove that such a …

Perspectives Of Corporate Instructional Design Experts On Effectiveness, Personal Traits And Attributes, And Technology, Thomas A. Gant

Theses and Dissertations

This qualitative phenomenological descriptive study explored corporate instructional design experts' perspectives on effectiveness, personal traits and attributes, and technology that enhance their expertise. Three central themes emerged: "Mastering Instructional Design: The Journey of Continuous Learning and Skill Development," highlighting the importance of mentorship, lifelong learning, and professional development; "Accessing Instructional Design Expertise Through Individual Strengths," emphasizing adaptability, problem-solving, and empathy; and "Navigating Technological Integration and Innovation in Instructional Design," showcasing the transformative role of tools such as virtual reality, learning management systems, and authoring software. Semi-structured interviews conducted via Zoom with 10 corporate instructional designers with at least 10 years …

Exploring Facilitators’ Experiences Addressing Students’ Needs In A Higher Education Work-Based Engineering Program, Cody D. Mann

All Graduate Theses, Dissertations, and Other Capstone Projects

This study addresses a critical gap in higher education by examining the unique facilitator position at Iron Range Engineering (IRE), a work-based program at Minnesota State University, Mankato. Facilitators are full-time teaching staff in support roles that focus on helping students achieve positive outcomes, such as students successfully transitioning into working professionals. No formal research has been conducted to explore the comprehensive support and overall implications of this role. This qualitative study focused on phenomenography to capture the different experiences of 12 facilitator participants. Data collection was guided by role theory to explore the expectations and perceptions of facilitators, and …

Laser Based Metal 3d Printer, Inura Goonawardena

All Graduate Theses, Dissertations, and Other Capstone Projects

The technology and applications of additive manufacturing (AM) have advanced significantly in recent years. Research from hobbyist to industrial scale has evolved and has seen advancements in materials that can be utilized for industrial manufacturing. The Institute for Machine Tools and Industrial Management at the Technical University of Munich (TUM) developed the reAM250, an open-source research platform for Powder Bed Fusion with a Laser (LPBF). It was made available to facilitate study into component-level innovation, control techniques, and process monitoring without the budgetary and intellectual property constraints of commercial machines. This paper delves into the concept and production of the …

Climate Variability Study For Arid Regions, Faisal Almutairi

Electronic Theses and Dissertations

Water is the primary source for all living species to thrive, and water scarcity has been a primary concern for biological species and plants in arid regions due to urban planning, population growth, poor water management, and overgrazing. The objective of this research was to study the climate variability in precipitation and temperature for an arid region. This research encompasses two distinct studies. The first study examined the impact of climate variability on precipitation in Phoenix. Precipitation data were acquired from NOAA from 1948 to 2023 and the study was broken down into three time scales: annually, seasonally, and monthly. …

Semantic Think-On-Graph (Semtog) : Enhancing Graphrag Through Semantic Community Detection, Sugam Mishra

Electronic Theses and Dissertations

Graph-based Retrieval-Augmented Generation (GraphRAG) enhances large language models (LLMs) by grounding their reasoning in structured knowledge graphs, making them more reliable for multi-hop reasoning and factual QA. A central mechanism in Think-on-Graph systems such as ToG[14] and FastToG[7] is community detection, which groups locally related nodes into compact subgraphs so that LLMs can reason over focused, information-rich neighborhoods instead of traversing the entire graph. However, these methods rely purely on structural connectivity, often scattering semantically related entities across different communities and weakening the evidence provided to the LLM. We propose Semantic Think-on-Graph (SemToG), a semantic-aware extension of FastToG[7] that integrates …

Quantum-Resilient Architectures For Enterprise And Cloud Information Systems, Implications Of Quantum Computing For Enterprise Cybersecurity And Data Integrity, Manikantha Varaprasad Inakollu

Computer Science and Engineering Faculty Publications

The emergence of quantum computing presents unprecedented challenges to contemporary enterprise cybersecurity frameworks. Current cryptographic systems that protect sensitive data and secure communications will become vulnerable to quantum attacks within the next decade. This research examines the implications of quantum computing advancement for enterprise and cloud information systems, proposing quantum-resilient architectural frameworks that can withstand both classical and quantum threats. We analyze the timeline of quantum computing development, assess vulnerabilities in existing enterprise security infrastructures, and evaluate post-quantum cryptographic approaches suitable for organizational implementation. Through comparative analysis of quantum-resistant algorithms and architectural patterns, this study demonstrates that enterprises must begin …

Blockchain-Enabled Trust Frameworks For Enterprise Information Systems, Establishing Verifiable Trust In Distributed Organizational Environments, Manikantha Varaprasad Inakollu

Computer Science and Engineering Faculty Publications

Enterprise information systems increasingly operate in distributed environments where traditional trust mechanisms based on centralized authority prove insufficient. This research develops a comprehensive blockchain-enabled trust framework that establishes verifiable, decentralized trust mechanisms for enterprise systems operating across organizational boundaries. The study addresses critical gaps in current enterprise architectures where trust depends on centralized intermediaries, creating single points of failure and limiting inter-organizational collaboration. Through examination of existing trust models and blockchain capabilities, we propose an integrated framework that combines cryptographic verification, distributed consensus, and smart contract automation to establish trust without centralized control. Our framework enables organizations to verify data …

Flame Boundary Effects Of Hydrogen-Air Premixing, Alecson L. De Lima Junior

Honors Undergraduate Theses

The objective of this research was to investigate the reaction of hydrogen and heated air premixing when injected into a combusting ethylene-air crossflow, and to study the flame stabilization location with varying premixing levels. The main parameter of this investigation was the flame stabilization diagnosed through chemiluminescence, based on recorded equivalence ratio, temperature, and flame boundaries, and maintaining a constant air temperature, hydrogen and air mass flow, and momentum flux ratios. Testing was conducted at different ratios of hydrogen and air premixing achieved through alternating the distance between the point where hydrogen and air are mixed and the combusting crossflow. …

Bibliometric Analysis With R Biblioshiny On Safety Behavior In Aviation, Büşra Yıldırım, İnan Eryılmaz, Ahmet Karacan, Nusret Erceylan

International Journal of Aviation, Aeronautics, and Aerospace

Safety behaviors in aviation are not limited to technical knowledge and skills in ensuring the safety of flight operations, but also include the attitudes, decision-making processes and collaborations of individuals and teams. In this context, in this study, a bibliometric analysis of publication and citation trends, key concepts and interactions of studies in the field was conducted to identify current and potential trends in aviation and safety behavior-based research, and to explore the intersections between safety behavior and aviation studies and the areas waiting to be explored. The bibliometric analysis using the RStudio-based Biblioshiny program was conducted on 1065 articles …

Afit Generative Ai Teaching Guidebook, Afit Faculty Learning Community, Mark G. Bateman, Brett J. Borghetti, Allen W. Dukes, Nicholas C. Francis, Mike Frick, Bobbie Oh, Kevin Patterson, Hiren J. Patel, Mark G. Reith, Erick S. Tyndall, Teresa M. Walton, Torrey J. Wagner, Timothy S. Wolfe, Jonathan Zemmer

AFIT Documents

AFIT is proud to highlight the Generative AI Teaching Guidebook, a resource designed to provide military educators with practical insights, strategies, and use cases for integrating Generative AI (Gen AI) into their teaching practices. Developed through a collaborative effort involving AFIT faculty across various departments within the Graduate School of Engineering and Management and the School of Systems and Logistics, this digital resource serves as a starting point for educators exploring how to leverage Gen AI in their classrooms. It offers accessible examples and best practices, ensuring utility for instructors of all technical backgrounds. The guidebook provides a comprehensive overview …

The Effect Of Need For Cognition & Need For Affect On Human Reliance And Artificial Intelligence Interactions, Aliyah Mcgowan

Doctoral Dissertations and Master's Theses

Abstract

With the increased use of Artificial Intelligence (AI) automations in fields like medical diagnoses and mental health queries, there are concerns regarding an individual’s trust and reliance on the technology. Reliance on AI output may lead an individual to accept inaccurate or incorrect information without further analysis. Trust may influence reliance and trust formation may be a product of affective processing. This study investigated the relationship between Need for Affect (NFA), Need for Cognition (NFC), and trust and reliance on AI interactions. Participants were assessed on the NFA scale for willingness to approach or avoid emotional stimuli, the NFC …

Safe Data-Enabled Control Of Human-In-The-Loop Robotic Manipulator Systems, Ritirupa Dey, Avimanyu Sahoo, Vignesh Narayanan

Publications

Safe control of human-in-the-loop (HIL) robotic manipulators is critical for applications such as assistive robotics, teleoperation in hazardous environments, and collaborative manufacturing. However, this remains challenging due to the lack of a unified framework that simultaneously addresses safety constraints, external disturbances, unmodeled dynamics, and dynamic role switching in the HIL setting. In this paper, we propose a novel NN-driven HIL control framework in which human–robot dyadic interaction occurs through the haptic channel. Using Lyapunov stability analysis, we theoretically show that the proposed NN-based controller ensures accurate joint trajectory tracking, compensates for system uncertainties, and adapts to human inputs modeled as …

Mobile Air Quality Assessment Using Public Transportation: A Community-Focused Study In The Capital Region, Allen Pronith Reddy Yeddula

Electronic Theses & Dissertations (2024 - present)

The monitoring of air quality plays a crucial role in establishment of concentrations of air pollutants over space and time in relation to human health, urban planning, and environmental conservation. This research offers a new strategy of monitoring the air quality in the Capital Region of New York State utilizing public transit buses as air quality moving sampling platforms. To assess the level of pollutants, a Capital District Transportation Authority (CDTA) bus network was used across the urban, suburban, and rural areas thus filling a research gap where public transit has most of the time been disregarded as a mobile …

Investigation Of Electromigration Stresses Of Advanced Node Conductors Through Pulsed Power Behavior, Mohd Mueen Ul Islam Mattoo

Electronic Theses & Dissertations (2024 - present)

The microelectronics industry continues to put a heavy focus on preventing electromigration (EM) failures at advanced node conductors. The continuous scaling coupled with higher operating current densities further accentuate the problem. Most of the electromigration testing in the industry is performed with DC currents to evaluate the electromigration reliability of metal interconnects. However, most of the real-world applications operate using a pulsed current rather than a constant direct current. EM testing with pulsed direct current (PDC) show interesting results with how the current induced stress gradient evolves in absence of the electromigration driving force. It is generally assumed that the …