Engineering Commons^™

Study And Simulation Of Model-Reference Adaptive Control Via The Heffron-Philips Model For Enhanced Power System Stability, Laila Ayman Dallol

Graduate Theses and Dissertations

Improving power transmission and quality has been an area of research interest over the past decades and was improved using renewable energy resources, mainly wind, and solar generation. Renewable energy penetration into power grids aims to replace some traditional synchronous generators, affecting the overall power system with reduced gas emissions that help with climate change and pollution issues. However, renewable generation in power systems ranging from microgrids to national grids is subjected to large disturbances that affect its transient stability, which is measured by its critical clearing time. As increased amounts of renewable generation connected to power systems have resulted …

Auction Consensus Algorithm With Loss Mechanism For Decentralized Task Allocation, Jose Rodriguez, Wenjie Dong, Constantine Tarawneh, Qi Lu

Electrical and Computer Engineering Faculty Publications

This paper presents an Auction-Consensus Algorithm with a Loss Mechanism (ACALM), a decentralized task allocation method for multi-robot systems that enhances the existing Consensus-Based Auction Algorithm (CBAA) by incorporating a novel loss propagation mechanism. In contrast to purely greedy bidding strategies, it enables agents to dynamically update task priorities based on the accumulated loss from previously unsuccessful bids. This extended work reduces globally inefficient allocations caused by early suboptimal decisions. The proposed approach is evaluated through large-scale simulations in thousands of randomized scenarios and swarm sizes ranging from 5 to 120 robots. Compared to existing CBAA and GCAA algorithms, ACALM …

Advancements In Visualization, Post-Processing And Ai-Enhanced Modeling Of Multi-Scale Micromechanics For Composite Materials, Joao Guilherme Brites Rei

Masters Theses

This study addresses some of the primary deficits of a localization/homogenization workflow for composite materials by focusing on the visualization and enhancement of models based on GMC and HFGMC, with emphasis on their implementation within the NASMAT ecosystem.

This thesis details the development of two dynamic, ParaView-based plugins that convert large hierarchical simulation outputs into interactive insights. While NASMATDiscreteElement systematizes RUC creation with transparent parametrization in a reproducible GUI, NASMATExplorerRUC enables the inspection of deeply nested datasets through accurate cell picking and synchronizes comparisons between parent and child views. Additionally, a shallow U-Net neural network is optimized on HFGMC data …

Evaluating Psychosocial Stressors And Mental Well-Being Of Construction Professionals From The Management Standpoint: An Exploratory Study, Md Tauhidul Karim

Masters Theses

Construction professionals face persistent workplace stressors that undermine their mental well-being outcomes. Despite progress in general job-related stressors, social and interpersonal aspects of psychosocial stressors traditionally remain underexplored in the construction management research. The present study examines how social and interpersonal factors influence construction workers’ mental well-being and how management’s awareness, responsiveness, and strategic roles evolved in the transition of the COVID-19 pandemic at the organizational level. An integrative mixed-methods approach was employed, combining a systematic literature review, a bibliometric analysis, and an exploratory case study to capture the current landscape of mental well-being and management standpoints in the US …

Design, Optimization, And Initial Results Of An Automatic Impedance Matching Network For Nitrogen Inductively Coupled Plasma, Logan Anthony Alvesteffer

Masters Theses

The electric propulsion industry is witnessing a strategic interest toward the utilization of molecular propellants as alternatives to noble gases due to increasing cost constraints and logistical requirements. This transition is hindered by a fundamental deficiency in the understanding of molecular plasma and radio frequency physics, including the excitation, dissociation, and ionization cross-sections, which mandates a reliance on computationally inefficient, empirically modified atomic thruster designs. Furthermore, current state-of-the-art electric propulsion devices, such as gridded ion thrusters and Hall effect thrusters, utilize an electrode (cathode) for ionization and are thus susceptible to chemical poisoning and material erosion, which is prevalent while …

Impact Of Equipment Type On Measured Particle Size Of Civil Engineering Materials, Tanner Turben, Tasnimul R. Ferdous, Andrew Braham, Wen Zhang

Civil Engineering Faculty Publications and Presentations

Particle size analysis (PSA) captures the size distribution of finely graded materials with particles generally smaller than 1000 microns. Many civil engineering materials do not leverage PSA for material specifications or acceptance despite the insight into material performance and quality gained through understanding the particle size. The objectives of this study are to compare PSA measurement principles by testing 13 civil engineering materials by laser diffraction, Coulter counter, and microscopy. Asphalt emulsions, cementitious materials, sands, clays, and biological samples were selected to represent a wide set of interests and shapes. It was found that between laser diffraction and Coulter counter …

Simulation, Modeling, And Economical Optimization Of Small Modular Reactors For Flexible Power System Operations, Javier Bejarano

Open Access Theses & Dissertations

The transition toward a low-carbon and increasingly renewable electric grid has heightened the need for generation technologies that can deliver both stability and operational flexibility. Small Modular Reactors (SMRs), with their modularity, reduced geographical footprint, and capacity for flexible operation, have emerged as promising resources for supporting modern power systems. However, a comprehensive evaluation of their technical performance across steady-state conditions, fault-induced disturbances, and economically optimized dispatch is necessary to understand their role in future grid architectures. This thesis provides an assessment of SMR capabilities using benchmark test systems, data-driven forecasting, dynamic simulation, and unit commitment modeling to evaluate how …

Effect Of Build Parameters On Mechanical Properties And Residual Stresses Of Lp-Ded Inconel 718 Overhanging Structures, Angel Fernando Bravo

Open Access Theses & Dissertations

Additive manufacturing of Inconel 718 via laser powder direct energy deposition (LP-DED) offers design flexibility for repair and fabrication of large components. However, mechanical properties remain sensitive to process parameters and geometric constraints, which impact the consistency of material properties. This study investigates the effect of different build angles (0°, 20°, 30°, and 35°) at different laser powers (1070W and 2000W) on the mechanical properties and residual stresses. Eight overhanging structures were fabricated using Inconel 718 and subjected to various heat treatments (SR + HIP + SOL + Aging). Numerical simulations were developed to predict residual stresses in the samples, …

Comparison Of Ti-6al-4v Powder And Bulk Specimen Properties Across Manufacturers In Laser Powder-Blown Ded, Alejandro Javier Hernandez

Open Access Theses & Dissertations

The investigation and comparison of 4 different Ti64 powder feedstocks from 3 different manufacturers was done to determine if the quality of the powder had a profound effect on the properties of the bulk specimens despite using the same processing parameters. The characteristics of the powder observed are the atomization process used, particle size distribution, flowability, and its density. The Ti64 printing parameters for directed energy deposition that were kept consistent were the feed rate, scanning speed, and laser power. Coupons with varying build angles (0-30°) were printed to measure the impact of overhangs on bulk specimen properties (ultimate tensile …

Air Force Institute Of Technology Research Report 2023, Air Force Institute Of Technology

AFIT Documents

This report summarizes the research activities of the Air Force Institute of Technology's Graduate School of Engineering and the Graduate School of Logistics and Acquisition Management. It describes research interests and faculty expertise; list student theses/dissertations; identifies research sponsors and contributions; and outlines the procedure for contacting either school.

Effect Of Powder Recycling On Powder Characteristics And Mechanical Properties Of Materials Produced By Laser Powder Bed Fusion (Lpbf): A Review, Mihiretu Ganta, Marta Kurek, Arezoo Emdadi, Tadeusz Łagoda, Marek Pagáč

Materials Science and Engineering Faculty Research & Creative Works

As the Laser powder bed fusion (LPBF) process advances toward industrial-scale production, the sustainability of metal powder feedstocks has become a focal point of research. The powder recycling approach, while environmentally and economically favorable, results in a series of physicochemical variations that could compromise the part quality. The resulting variation in powder characteristics with powder recycling could affect the powder layer density and melt pool dynamics, resulting in defect formation and hindering the structural integrity of LPBFed parts. These alterations pose significant constraints to mechanical performance, particularly in fatigue-sensitive applications where even minor imperfections can substantially reduce service life. The …

Polypropylene/Polyethylene Blends With Asymmetric Viscosity: Fabrication, Characterization, And Recycling Potential, Bernadine Daichendt

All Dissertations

Polyolefin materials, polypropylene (PP) and polyethylene (PE), are widely used in day-to-day life both commercially and industrially, offering versatile applications due to their mechanical and chemical properties. The high consumption rate of these materials makes them important targets for recycling efforts. However, there are multiple contributing factors leading to low recycling of PP and PE, chiefly sorting factors: chemical similarity, changed properties after multiple rounds of processing, and the use of processing aids. It is necessary to point out that, because of multiple melt processing cycles, recycled PP has decreased molecular weight due to chain scission. Conversely, recycled PE molecular …

Accident Data Analytics And Ai-Based Auditory Enhancement For Highway Construction Safety, Thinh Nguyen

All Dissertations

This research develops data-driven and AI-enhanced approaches to improve worker safety in highway construction environments. The study integrates advanced analytics and auditory signal enhancement to identify high-risk worker behaviors and improve real-time safety warnings. The work consists of three core studies. The first study applies Sequential Pattern Mining and Social Network Analysis to more than 1,000 construction accident reports to identify high-risk worker actions and their hidden sequential relationships with accident types and consequences. These insights reveal sector-specific risk patterns, supporting the creation of targeted, data-informed safety interventions. The second study introduces an AI-based auditory enhancement model built on a …

Degradation Of Cobalt Chrome Molybdenum Hip And Knee Implants In Vivo And In Vitro, Peter William Kurtz

All Dissertations

Cobalt Chrome Molybdenum (CoCrMo) remains a popular material choice for femoral condyles in total knee arthroplasty and for acetabular liners in dual mobility total hip designs. CoCrMo has been phased out of conventional THA designs due to its correlation with adverse effects such as ALTR and ALVAL. It is less understood if the mechanisms (i.e. abrasive wear to the surface of the implant) that release metal ions into the surrounding tissue occur at similar rates as seen in conventional THA. Additionally, it is unknown what effect the secondary damage modes such as electrocautery damage and adhesive wear have on these …

Power Distribution Controller For Formula Sae Vehicles, Michael Yuen

Electrical Engineering

The Power Distribution Controller (PDC) is designed for low-voltage (12V) automotive applications, specifically Formula SAE vehicles. It aims to replace the current and outdated MOSFET-based system, which suffers from inefficiencies such as lossy current sense resistors and limited configurability. Instead, this new system uses a PROFET-based architecture controlled over the Controller Area Network (CAN) and an updated microcontroller, enabling intelligent power management and data logging.

Designed with FSAE regulations in mind, the PDC not only enhances the reliability of low-voltage systems but also provides a quickly adaptable solution to fuse boxes. It achieves this by providing firmware-adjustable overcurrent protection, incorporating …

Curvilinear Image Segmentation Using Multiscale Variational U-Net, Rebekah Fortes

LSU New Orleans Theses and Dissertations

Segmentation of curvilinear structures such as water contours, cracks in cement, and vascular networks in biomedical imaging, poses unique challenges due to extreme class imbalance, irregular morphology, low contrast against complex backgrounds, and the need to preserve global connectivity while detecting fine-scale details. We propose a Multiscale Variational U-Net (MSVU-Net) architecture designed specifically to address these challenges. The model integrates multiscale convolutional filters to capture both global context and local detail, while embedding a variational model in the bottleneck layer to enhance structural representation. To mitigate class imbalance and improve fidelity, the network optimizes a hybrid loss function that combines …

Private Sand Mining In The Mississippi River: Sediment Budget And Morphology Implications Between Baton Rouge And Belle Chasse, Louisiana, Brett Mcmann

LSU New Orleans Theses and Dissertations

This analysis examined how private sand mining within the Mississippi River between Baton Rouge, LA and Belle Chasse, LA affected its sand budget from 2004-2012.

Records assembled indicated that private mining removed an annual average of 2.8 million cubic yards of sand. A HEC-RAS one-dimensional sediment transport model was utilized to assess this practice. Three scenarios were simulated: a baseline without mining, conditions reflecting documented mining rates, and a hypothetical case with excessive extraction.

Results suggest that private mining constituted approximately 26 percent of the total sand deficit between Baton Rouge and Belle Chasse. Mining appeared to cause localized changes …

The Hunga Volcanic Eruption Atmospheric Impacts Report, Simon Carn

Michigan Tech Publications

No abstract provided.

Exploratory Diver Geotechnical Equipment (Edge), Angel Villicana, Merrick Zellers, Erik Heuchert, Lucas Heuchert

Mechanical Engineering

The goal of this report is to showcase how our final Core Sampler design and prototype address the needs of Navy Divers. Geotechnical equipment for Navy divers has not been updated since the early to mid-1980s, resulting in imprecise and outdated sampling methods. The primary purpose of this project is to enhance, modernize, and redesign a tool to collect a minimally disturbed core sample of the seabed for geotechnical evaluation. This report presents the full development of our project from concept to verification and final outcomes. It begins with the statement of disclaimer, followed by a four-panel executive summary and …

Calibration And Validation Of Cyclic Stretching Platform For Stiffness Testing Of Engineered Heart Tissue, Jillian Welsh

Chemical Engineering Undergraduate Honors Theses

Cardiac fibrosis (CF) is a major contributor to the high mortality rate of heart failure which affects over 23 million people worldwide. CF involves cardiac fibroblasts depositing extracellular matrix, made primarily of collagen type I, which stiffens the heart walls over time. As testing new drugs for CF is deterred by the high cost and time required for animal and clinical trials, this research helps to solve the problem by providing an in vitro platform to study fibrosis.

The work involved creating tissues containing human cardiac fibroblast (HCFB) cells. Spring testing was conducted to determine the force applied by the …

Life Cycle Assessment Of A Prefabricated Modular Timber Building, Bryan Mai

Construction Management

Traditional concrete construction carries a high carbon footprint, motivating interest in lower-impact alternatives such as prefabricated modular timber systems. This project conducts a process-based life cycle assessment (LCA) using OpenLCA to evaluate the environmental impacts of a modular timber building. Material quantities from major processes were modeled as flow inputs and converted into standardized OpenLCA units. Impact categories—including acidification potential, human toxicity, and energy/resource use—were analyzed to determine which materials and processes contribute most to overall environmental burden. Results show that transportation and plumbing materials drive the largest acidification impacts, while interior finishes dominate human toxicity. This LCA establishes a …

Implementation Of A Three-Port Solar Converter With A Battery Energy Storage System, Maison Christopher Phipps

Graduate Theses and Dissertations

The increasing deployment of distributed solar and energy storage systems has created the need for integrated power converters that can efficiently manage photovoltaic (PV) generation, battery energy storage, and grid-tied AC output. This thesis presents the implementation and validation of a 5kW non-isolated Three-Port Converter (TPC) adapted for residential solar applications. The converter consolidates three power stage into a high-frequency, compact architecture: a unidirectional boost converter for PV input, a bidirectional interleaved buck-boost converter for battery energy storage, and a configurable DC/AC inverter for 120Vac single-phase output. The system is controlled using a central controller implemented on a TI C2000™ …

Design And Optimization Of High-Frequency Medium-Voltage Dual Active Bridge Dc/Dc Converter Using Sic Device, Hui Cao

Graduate Theses and Dissertations

High frequency Dual Active Bridge (DAB) converters have become a key enabling technology in medium- and high-power applications such as renewable energy integration, electric vehicle fast charging, and emerging DC power distribution systems. However, when operating at high power and high frequency, DAB converters face critical challenges including limited soft-switching range, uneven semiconductor loss distribution, deadtime-induced resonance, switching-frequency constraints of wide-bandgap (WBG) devices, and transformer DC bias during dynamic transitions. This dissertation addresses these challenges through advancements in modulation strategies and converter architecture. First, an enhanced triple-phase-shift (E-TPS) modulation scheme is proposed to achieve balanced switching and conduction losses across …

Optical Characterization Of Ge And Gesn Grown In Aspect Ratio Trapping Structures For Enhanced Emitter Performance, Abdulla Said Ali

Graduate Theses and Dissertations

Silicon (Si) began dominating the electronics industry since 1960s, the dominance came due to its affordability and well developed fabrication processes. But when it comes to light emitting devices and photonics devices in general, the indirect bandgap of Si has caused many scientists to search for alternative semiconductor materials that can deliver better light emission, materials that can also improve wavelengths detection which is also very limited when it comes to Si, reduce losses and greater light amplification, all this while still being affordable. Despite these limitations, Si has been widely used in Complementary Metal Oxide Semiconductor (CMOS) manufacturing and …

Intrinsic Disinfection Byproducts In Free Chlorine And Chloramine Systems: Formation Of Chlorite, Chlorate, Perchlorate, And Chloronitramide Anion, Julian L. Fairey, Ashley D. Pifer, David G. Wahman

Civil Engineering Faculty Publications and Presentations

Intrinsic disinfection byproducts are formed by reactions between disinfectant species and/or their decomposition products. In this review, we focus on a subset that accumulates in free chlorine and chloramine drinking water systems. First, we review the sequential formation of chlorite, chlorate, and perchlorate in hypochlorite feedstocks. Model simulations indicate chlorate and perchlorate can accumulate under realistic dosing conditions and can be managed with less concentrated feedstocks and climate-controlled storage. Second, we review the formation pathways of dichloramine and chloronitramide anion. Chloronitramide anion accumulation may be mitigated by increasing monochloramine stability and quenching reactive nitrogen species in its formation pathway.

Deterministic Methods To Improve The Field-Of-View For Direction Finding Using Sparse Digital Arrays, Nolan J. Egging

Master's Theses

Direction finding algorithms are used with digital phased arrays to determine the incoming angle of arrival (AoA) of an incident signal. These algorithms, and direction finding as a whole, have a wide range of civilian and military applications from radar, electronic reconnaissance, mobile communication, et cetera. However, for situations where the spacing between antenna elements needs to be large, gating lobes appear in the radiation pattern of analog arrays. This work demonstrates that for digital beamforming algorithms, the field of view (FoV) of a uniform linear digital array matches the grating lobe free range of a similarly spaced analog array. …

Development And Test Of An Automatic Mass Balancing System For Cal Poly's Spacecraft Attitude Dynamics Simulator, Cameron B. Zorio

Master's Theses

The Cal Poly Spacecraft Attitude Dynamics Simulator (SADS) is an ongoing project to develop an air-bearing platform capable of recreating on-orbit rotational dynamics with near frictionless and torque-free rotations. However, any offset between the platform's center of rotation and its center of mass will introduce a torque due to gravity.

This thesis presents the design, implementation, and experimental evaluation of a low-cost, automatic mass balancing system for the SADS to address this challenge. A new modular sliding mass system was developed that overcomes issues faced in previous iterations of the SADS, providing real-time positional control of the masses and a …

Using Hydraulic And Hydrologic Modeling To Determine Scour At Toro Creek Under Climate Change Conditions, Gabriel E. Alaniz

Master's Theses

ABSTRACT

This study evaluates bridge scour at the Toro Creek crossing of Highway 1 in Morro Bay, California, under present conditions and future climate conditions with more frequent extreme rainfall events. California infrastructure is becoming increasingly vulnerable to extreme storm events and increased intense precipitation events brought by climate change. This analysis focuses on the calculation of scour for both the northbound and southbound spans. Highway 1 plays a vital role in California’s coastal transportation infrastructure by carrying more than 20,000 vehicles daily (Caltrans, 2017). In this thesis, a hydrological model (HEC-HMS) is used to simulate runoff under present-day and …

Concrete Masonry Unit Construction: Creating Educational Modules On Sustainability, Eric Dam

Construction Management

Concrete Masonry Units are one of the most widely used building materials due to their durability, fire resistance, low maintenance, and specifications. With the growing trend for sustainable construction, it is necessary to teach students how CMUs can contribute to improving environmental performance and dive deeper into multiple resource efficiency. This project developed an instructional module that introduces CMU materials, reviews performance and durability attributes of these materials, and how they are linked to well-known rating systems. The final module includes a presentation, three assignments, and one quiz that will reinforce student learning and refresh industry professionals' knowledge. The following …

Particle Migration In Non-Newtonian Fluid Flows Through Curved Microchannels, Sanskruti Ramesh Raut

All Dissertations

Innovations in microfabrication over the past three decades have enabled the development of microfluidic devices with intricate channel geometry. Microfluidic platforms offer controlled manipulation of fluids and particles by leveraging the internally induced and/or externally imposed force field(s). The demand for compact microchannel geometry has turned the attention toward curved microchannels with significantly reduced footprints. However, most of the previous studies in curved microchannels have been limited to particle migration in Newtonian fluids. The influence of fluid rheology has remained largely unexplored.

In the first part of this dissertation, we present a systematic experimental study on the influences of fluid …