Digital Commons Network^™

Design And Development Of A Half-Bridge Llc Resonant Converter Laboratory Module, Alyssa Lam

Master's Theses

Resonant DC-DC converters have become a well-known solution in power supplies due to their ability to improve efficiency by utilizing soft-switching techniques. This further has caused a growing interest in industry to use these converters for high-switching-frequency, high-efficiency, and high-power applications such as EV charging stations, photovoltaic systems, battery chargers, etc. One particular resonant topology that has gained popularity in recent years is the LLC resonant converter. Due to the prevalent use of the LLC resonant converter, it is therefore crucial for students preparing for a career path in power electronics to become well-versed in the concept and implementation of …

Tuned Liquid Damper Design Using Liquid Sloshing In A Horizontal Cylindrical Tank, Vedant M. Patel

Master's Theses

Vibration isolation is an essential design requirement for several real word applications including industrial machinery, automobiles and building structures. Different techniques of vibration isolation are employed in each of these applications. One such vibration isolator used in tall buildings is known as the Tuned Mass Damper , where a mechanical mass (pendulum, bogey, cylinder) is located at the top portion of the building and is connected to the building through a suspension. This mechanical mass – suspension system is designed to oscillate out of phase with the building in order to dissipate the vibration. Several buildings such as, Taipei 101, …

Coherent Synchronization For Distributed Digital Phased Arrays, Zachary C. Numa

Master's Theses

Distributed digital phased arrays are rising technologies that help enable applications such as search and rescue operations, wireless communication, radar navigation, and military operations, among many others. Due to their improved angular resolution, digital phased arrays offer superior direction-finding capabilities compared to traditional analog phased array systems. However, this improvement comes at the cost of increased complexity—specifically, the need for precise synchronization of phase, time, and frequency across physically separated nodes. Without synchronization, the distributed phased array's gain and direction-of-arrival (DoA) estimations deteriorate significantly.

There are multiple aspects to implementing and synchronizing a non-stationary distributed digital phased array. This research …

A Decision Support System For Conference Session Selection Using Natural Language Processing, Tillman E. Erb

Master's Theses

Conference attendees are faced with selecting from hundreds to thousands of presentations and sessions in pursuit of new findings and methods relevant to their area of interest, an overwhelming amount of information from which to clearly make a decision. To address this, we developed a decision support system leveraging natural language processing (NLP) techniques such as semantic matching. By creating and matching embeddings of conference presentation abstracts and titles, the application provides improved query matching compared to keyword searching. We introduce Session Scout, a novel conference decision support system built upon a semantic retrieval framework. Session Scout is designed to …

Open Source Microgrid Integration, Zachary J. Kwast

Master's Theses

Microgrids are small-scale electrical systems that operate in tandem with a centralized grid to provide power to a smaller group of target devices. These microgrids are used for a wide range of different purposes, which invites the need for a generalized model that can be tweaked for a variety of uses. This document goes over the theory used to design an open source AC and DC microgrid meant for use by anyone. The microgrid is created using a Raspberry Pi that controls two different power converters so that a wide range of voltage and current characteristics can be achieved. These …

Investigation Into Silicone-Silicate Conversion Due To Atomic Oxygen In The Low Earth Orbit Environment, Justin T. Self

Master's Theses

Silicones have been widely used over the years in spacecraft for a variety of functions, but atomic oxygen (AO) exposure in Low Earth Orbit causes a silicate (SiO₂) surface layer to rapidly develop on the silicone which results in a permanent change in its thermal and optical properties. Although this silicone to silicate conversion is known to occur, statistical predictions of layer formation as a function of time on orbit are not found in literature. This thesis utilized optical and scanning electron microscopy, Fourier-Transform Infrared Spectroscopy, diffuse reflectance spectroscopy, and nonlinear regression statistical techniques after RF plasma asher …

Density-Based And Model-Based Clustering With Tidyclust In R, Brendan S. Callender

Master's Theses

Clustering is a fundamental technique in unsupervised learning that can be used to find hidden patterns and structures within unlabeled data. The tidyclust package in R provides a unified interface for applying various clustering techniques to data. This paper outlines the addition of density-based clustering with DBSCAN, and model-based clustering using Gaussian mixture models (GMMs) to the tidyclust package. DBSCAN can be performed using the db_clust() function and makes use of the dbscan package implementation as its engine. GMMs can be fit using the gm_clust() function which makes use of the mclust package implementation. This paper highlights the changes made …

Wetland Treatment Systems For Municipal Wastewater At A Bourbon Distillery And Potential Value Of Incorporating Stillage For Water Treatment Enhancement, Katherine Ristola, Tiffany Messer, Czarena Crofcheck, Tyler Barzee, Wayne Sanderson

Epidemiology and Environmental Health Faculty Publications

The use of constructed treatment wetlands as a secondary treatment method for wastewater effluent from package treatment plants and distillery stillage has the potential to be an innovative, sustainable method for improving water quality. However, the use of constructed wetlands to treat bourbon whole stillage and a distillery bottling facility’s wastewater treatment plant effluent has been limited. Therefore, the objectives of this study were to (1) quantify constructed wetland water quality improvement as a secondary treatment method for a distillery’s municipal wastewater, (2) optimize treatment design to meet wastewater effluent discharge limits, and (3) quantify the potential to enhance constructed …

Using Computerized Instruction To Increase Professional Competence With Cognitive Behavioral Therapy (Cbt) Modifications, Paige Lee Sherlund-Pelfrey

Masters Theses

One in thirty-six children receive an Autism Spectrum Disorder (ASD) diagnosis, and an estimated 5.4 million adults in the United States have previously received an ASD diagnosis (Centers for Disease Control and Prevention [CDC], 2022). At least seventy percent of individuals with ASD have one comorbid disorder (Valderas et al., 2009). Some common comorbid disorders for individuals with ASD include depression, anxiety, and obsessive-compulsive disorders. Cognitive Behavioral Therapy is an evidence-based therapy that can support depressive, anxiety and OCD symptoms, and has empirically supported modifications that can be used with the ASD population. However, research reports that clinicians are not …

Presidential Supremacy Over Administrative Agencies, Gary Gensler, Lev Menand

Faculty Scholarship

In the United States, the public has long benefited from the role played by administrative agencies with a degree of autonomy from the White House, each agency with distinct duties and authorities to implement the law as set out by Congress.

In its first hundred days, the second Trump administration has moved rapidly to centralise control over all administrative agencies, including so-called independent agencies, which have long operated at a greater remove from the White House than ‘executive’ agencies like the Department of State and the Department of Commerce. The administration is asserting an interpretation of the Constitution known as …

Preferences Or Confounders? Persistent Gender Gap In Competition Across Four Continents, Natalia I. Valdez-Gonzalez, Adriana Gaviria, Antonio M. Espin

ESI Working Papers

The gender gap in willingness to compete is thought to underlie enduring inequalities in education, career choice, and labor market outcomes. Yet it remains unclear whether the gap reflects true preference differences or results from confounding factors such as task stereotypes, overconfidence, or risk aversion. We test gender differences in competition entry across eight pre-registered studies in seven countries spanning four continents (Dominican Republic, Ivory Coast, El Salvador, Madagascar, Spain, The Philippines, and Uruguay; total n = 1,833), using an experimental design that systematically minimizes these confounds: (i) based on a non-male-stereotyped task (the Reading the Mind in the Eyes …

Atomic Oxygen Considerations For Low Earth Orbit Spacecraft, Hannah Rost, Justin Self

Baker/Koob Endowments Awarded Projects

In Low Earth Orbit (LEO), spacecraft are exposed to a harsh environment which includes atomic oxygen (AO) and vacuum ultraviolet radiation (VUV). AO interaction with spacecraft materials results in erosion, structural, and optical property degradation. This damage is often accelerated during concurrent vacuum ultraviolet (VUV) radiation exposure. This study utilized laboratory equipment in the Cal Poly aerospace and materials engineering departments to characterize changes in material properties after AO and VUV radiation exposure. This proposal requested funds for a replacement bulb that will allow for two separate but related studies that investigate synergistic effects of AO and VUV on spacecraft …

Dobbs, State Policies, And Minors’ Interests In An Open Future, Lois A. Weithorn

UC Law SF Journal on Gender and Justice

The United States Supreme Court discarded five decades of established federal constitutional doctrine with its decision in Dobbs v. Jackson Women’s Health Organization. Following Dobbs, legislators in some states rushed to restrict the decisions of pregnant persons. Litigation, executive actions, and voter initiatives, including attempts to amend state constitutions, quickly followed. At the time of this writing, access to abortion is severely restricted in large swaths of the country. Increasing numbers of pregnant persons have sought out-of-state services through telehealth or cross-border travel. Some states have created new forms of criminal or civil liability in an effort to prevent its …

Enabling Automatic Solar Pv Array Identification Using Big Satellite Imagery, Qi Li, Keyang Yu, Carson Snow, Dong Chen

Computer Science Faculty Research and Publications

Recently, there has been a growing interest in automatically collecting distributed solar photovoltaic (PV) installation information in smart grid systems, including the quantity and locations of solar PV deployments, as well as their profiling information across a given geospatial region. Most recent approaches are still suffering low detection accuracy due to insufficient sample and principal feature learning when building their models and also separation of rooftop object segmentation and identification during their detection processes. In addition, they cannot report accurate multi-deployment results. To address these problems, we design a new system-SolarDetector+, which can automatically and accurately detect and profile distributed …

Finger Orthoses For Rehabilitation―Part I: Biomedical Insights And Additive Manufacturing Innovations, Alireza Nouri, Lijing Wang, Hamed Bakhtiari, Yuncang Li, Cuie Wen

Research outputs 2022 to 2026

Background: Finger orthoses are essential for treating injuries, deformities, and disorders of the upper limbs by supporting, immobilizing, or correcting deformities. Recent advances in three-dimensional (3D) printing have significantly enhanced precision and customization compared to traditional fabrication methods such as thermoplastic molding, plaster or fiberglass casting, and the use of prefabricated splints. Methods: The present review was conducted using PubMed, Scopus, and other databases with keywords such as “hand therapy”, “additive manufacturing”, “finger and thumb”, and “orthosis”. Only English-language publications were considered, with a primary focus on articles published between 2010 and 2025. Key themes were identified and categorized into …

Exploring New Mexico 4-H Volunteers’ Acceptance And Use Of Technology: A Qualitative Approach, Kayla Dawn Hinrichs

Electronic Theses and Dissertations

Integrating technology into youth development programs like 4-H is increasingly vital for enhancing communication, education, and engagement. However, technology adoption among 4-H volunteers remains inconsistent. This qualitative study explored the barriers to technology adoption among New Mexico 4-H volunteers. The researcher aimed to understand the factors influencing their willingness and ability to integrate digital tools into their volunteer roles. Guided by Rogers’s (2003) diffusion of innovation theory and framed by Creswell and Poth’s (2024) qualitative research design, this study employed semistructured interviews with a purposive sample of 4-H volunteers across the state. Following Braun and Clarke’s (2006) six- phase approach, …

Enhanced Removal Of Microplastic Fibres Using Aluminium And Chitosan-Based Coagulants Assisted With Microbubble Technology, Nimesha Thathsarani, Mehdi Khiadani, Muhammad Rizwan Azhar, Masoumeh Zargar

Research outputs 2022 to 2026

Microplastic (MP) pollution has emerged as a threat to drinking water quality, where fibres are the dominant type of MPs found in drinking/wastewater treatment plant influents. The potential of MP removal through conventional treatment has not been vastly studied. Accordingly, this study investigates the removal of MP fibres using two-hybrid methods: coagulation-flocculation followed by sedimentation (CFS); and coagulation-flocculation combined with flotation using microbubbles (CFm) in the presence of two different water matrices, deionised water (DI) containing surfactants and DI water in the presence of humic acid (HA). A typically used Aluminium-based coagulant (AlCl3.6H2O) and a green-based coagulant, Chitosan, were employed …

A Predictive Model For The Shear Capacity Of Ultra-High-Performance Concrete Deep Beams Reinforced With Fibers Using A Hybrid Ann-Anfis Algorithm, Hossein Mirzaaghabeik, Nuha S. Mashaan, Sanjay Kumar Shukla

Research outputs 2022 to 2026

Ultra-high-performance concrete (UHPC) has attracted considerable attention from both the construction industry and researchers due to its outstanding durability and exceptional mechanical properties, particularly its high compressive strength. Several factors influence the shear capacity of UHPC deep beams, including compressive strength, the shear span-to-depth ratio (λ), fiber content (FC), vertical web reinforcement (ρsv), horizontal web reinforcement (ρsh), and longitudinal web reinforcement (ρs). Considering these factors, this research proposes a novel hybrid algorithm that combines an adaptive neuro-fuzzy inference system (ANFIS) with an artificial neural network (ANN) to predict the shear capacity of UHPC deep beams. To achieve this, ANN and …

Robust Adaptive Fractional-Order Pid Controller Design For High-Power Dc-Dc Dual Active Bridge Converter Enhanced Using Multi-Agent Deep Deterministic Policy Gradient Algorithm For Electric Vehicles, Seyyed Morteza Ghamari, Daryoush Habibi, Asma Aziz

Research outputs 2022 to 2026

The Dual Active Bridge converter (DABC), known for its bidirectional power transfer capability and high efficiency, plays a crucial role in various applications, particularly in electric vehicles (EVs), where it facilitates energy storage, battery charging, and grid integration. The Dual Active Bridge Converter (DABC), when paired with a high-performance CLLC filter, is well-regarded for its ability to transfer power bidirectionally with high efficiency, making it valuable across a range of energy applications. While these features make the DABC highly efficient, they also complicate controller design due to nonlinear behavior, fast switching, and sensitivity to component variations. We have used a …

Nd:Yag Laser Annealing: Impact On The Photoconductive Properties Of Cds Thin Films, Ausama Khudiar

Journal of Applied Sciences and Nanotechnology

This study investigates the effects of pulsed Nd:YAG laser annealing at a wavelength of 532 nm on the photoconductivity properties of cadmium sulfide (CdS) thin films prepared by thermal evaporation. In addition, measurements at room temperature showed an ohmic behavior in the voltage-current characteristics of the CdS thin films. It was observed that after laser irradiation, the photosensitivity of the film increased due to the improved crystallinity and decreased defect density of the thin films, as shown by the increase in the ratio of light to dark current (Iph/Id) from 0.35 to 0.42. The photocurrent also follows the relationship (Iph∝FγI), …

Occupational Stress: Lifestyle And Health In Blue- And White-Collar Workers In The United States, Carice T. Craffey

Dissertations and Theses

ABSTRACT

Occupational Stress: Lifestyle and Health in Blue- and White-Collar Workers in the United States

by

Carice Craffey

Advisor: Catherine M. Schooling, Ph.D.

Background: Heart disease and diabetes are leading causes of death in the United States and globally, particularly heart disease in men. Employment conditions can contribute to illness and death. Occupational or job stress (OS) is a potential contributor to heart disease and diabetes, but its conceptualization and role for men and women remain unclear. To address this gap, I conceptualized OS, then examined the role of OS in heart disease and diabetes.

Methods: I used a literature …

“Everything Is A New Challenge For Each Of Us”: A Qualitative Exploration Of Elementary Newcomer Students’ And Families’ Lived Experiences Of Acclimating To U.S. Schooling, Maureen Margaret Medeiros

Social Justice in Educational Leadership EdD Dissertations

Newcomer students, defined as foreign-born children who have attended U.S. schools for less than three years, are entering U.S. schools in ever-increasing numbers. Schools are often the first institutions to welcome immigrants to local communities, and meeting the linguistic, socioemotional, and academic needs of newcomer students and their families is essential to their success. However, data on newcomers is not publicly accessible, which makes them not easily visible in the school system. Furthermore, newcomers may have socioemotional challenges due to their prior life experiences, the immigration process, and then the likely challenges of limited English fluency which can lead to …

Criminal Organizations And Nuclear Threats In Southeast Asia, Gary Ackerman, Thomas Guarrieri, Justin V. Hastings, Steven Hoodjer

International Journal of Nuclear Security

Increasing global interest in nuclear energy and peaceful uses of nuclear technology has led to facilities in emerging countries with nuclear materials and radioactive sources that could be stolen, sabotaged, or otherwise accessed by criminals. In this paper, we created a framework to assess the motivations and capabilities of criminal networks and measure the threats they may pose to different stages of the nuclear fuel cycle in emerging nuclear states. We applied the framework to a unique dataset, capturing characteristics of criminal organizations active in Southeast Asia, which allowed us to assess which criminal organizations are most likely to pose …

Climate Resilience: A Typology, Shi-Ling Hsu

UMKC Law Review

No abstract provided.

Are Markets Better Than Law In Achieving Sustainability And Water Security In The Face Of Climate Disruption?, Joseph W. Dellapenna

UMKC Law Review

No abstract provided.

Aggregator Zone Selection For Ev Smart Controls Based-On Ml Clustering Of Grid Strength, Distance, And Charging Homogeneity, Rosemary E. Alden, Sam H. Lowe Ii, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Smart electric vehicle (EV) charging control methods from a central utility hub often require communication infrastructure over a large service area of electric power distribution systems with a large number of nodes. Industry standards such as Open Charge Point Protocol (OCPP) 2.1 have evolved to include topologies for local controllers to the individual chargers, i.e. EV aggregator zones. A machine learning (ML) application of k-means clustering is proposed to establish zones for coordination of EV charging based on grid strength and EV owner decision-making to charge per day. Very large-scale distribution networks including the IEEE 123 and 8500 benchmark feeders …

Cluster-Based Volt/Var Optimization On A Utility Distribution Feeder With Forecasted Ev Penetration, Steven B. Poore, Grant M. Fischer, Rosemary E. Alden, Evan S. Jones, Aron Patrick, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

With significant increase in EV adoption expected in the near future and the associated impacts on power systems, the effect of volt/var optimization (VVO) as the next step to conservation voltage reduction (CVR), requires reevaluation. Implementation of a cluster-based VVO control strategy employs a novel approach with machine learning (ML) load forecasting to reduce device adjustments through k-means clustering of contiguous time steps with similar active power load in which a single adjustment would be sufficient. The cluster-based VVO method is tested on a complex real world utility distribution feeder with 2,018 nodes, 8.65MW peak load, 9 capacitor banks (CBs), …

Hybrid Fea And Meta-Modeling For De Optimization Of A Pm Stator-Excited Motor With A Reluctance Rotor, Oluwaseun A. Badewa, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents an innovative method for designing high-performance electric motors by integrating machine learning (ML) based meta-modeling with a differential evolution (DE) optimization algorithm. The approach utilizes finite element analysis (FEA) data to train the ML meta-model, allowing for efficient optimization of high-power-density machines, such as the reluctance rotor and permanent magnet (PM) stator combined excitation motor, which is characterized by nonlinearities. The meta-modeling process employs an Artificial Neural Network (ANN) with 3 hidden layers and uses the motor’s geometrical variables as inputs. The accuracy of the meta-model in capturing the nonlinear relationships between design parameters, core losses, and …

Three And Two Phase Rotating Field Inductive Couplers For Wireless Power Transfer With One Phase Per Layer Windings, Donovin D. Lewis, Lucas Gastineau, Omer Onar, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Multiphase inductive wireless charging coils have been proposed recently to improve coupler surface power density, reduce component stress and size, and provide near-constant power delivery to charge mobile electric systems. Several aspects for the fundamental characterization of multiphase coils are explored up to six phases including approximate mutual inductance with size and turn variation, induced voltage, and output power estimation. The relative component stress and size of passive components for resonant operation are compared between the multiphase variants. A combination of an experimentally validated 3D electromagnetic finite element analysis (FEA) and power electronic co-simulations are used to validate the estimated …

Cryogenic Thermal System For Coreless Axial Flux Pm Machine With Litz Wire Winding For Electric Aircraft Propulsion, Matin Vatani, Chaianan Sailabada, Philippe Masson, Juan C. Ordonez, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Electric machines for aviation demand ultra-efficient, compact designs with high specific power density, which can be achieved through advancements in both electromagnetic design and thermal management. This paper proposes and investigates an integrated thermal management approach for a coreless stator axial flux permanent magnet (AFPM) machine featuring a double-sided Halbach array PM rotor, two stators, and an aluminum nitride (AlN) cold plate positioned between the stators for direct cooling. The cold plate incorporates internal serpentine channels for liquid hydrogen circulation. The electromagnetic performance and efficiency of the machine at cryogenic temperatures are assessed using temperature-dependent data from the literature, indicating …