Digital Commons Network^™

Comprehensive Fault Diagnostics And Performance Forecasting Of Wind Turbines Through Condition Monitoring Solutions, Shuo Zhang

Doctoral

The operation and maintenance (O&M) issues of wind turbines (WTs) are challenging because unplanned maintenance, caused by sudden component failures, can bring about durable downtimes and significant revenue losses. It is important to carry out effective fault diagnostics and prognostics schemes under the rapid development of wind power generation. Hence, Condition Monitoring (CM) solutions focus on measurements and detections of high-risk WT components, which could result in high failure rates and long downtimes. Machine Learning (ML) models have been commonly applied in CM to allocate imminent indications of failure or degradation for curtailing the O&M costs of WTs. By way …

The Tripartite Model Of Facial Recognition: Bridging The Gap Between Privacy, Public Safety, Technology And The Fourth And First Amendments, Shlomit Yanisky-Ravid, Kyle Fleming

Notre Dame Journal of Law, Ethics & Public Policy

No abstract provided.

Tackling The Intangible: Why The Supreme Court Needs To Define Intellectual Property And What Facebook Stands To Lose (Or Win), John Paul A. Galgano

Notre Dame Journal of Law, Ethics & Public Policy

No abstract provided.

The Development Of Stem Teachers' Conception On Stem Education, Abd Rauf Rose Amnah

Research Publications (2021 to 2025)

Abstract not available.

A Scientometric Methodology Based On Co-Word Analysis In Gas Turbine Maintenance, Ali Nekoonam, Reza Fatehi Nasab, Soheil Jafari, Theoklis Nikolaidis, Nader Ale Ebrahim, Seyed Alireza Miran Fashandi

Research Publications (2021 to 2025)

Evaluation of scientific journals has a profound effect on the future of scientific research so that different institutes and countries can set appropriate goals and invest with less risk in various scientific fields. Accordingly, this article presents a new method based on a combination of co-word analysis and social network analysis to extract the hotspot topics. Using HistCite, NodeXL, and VOSviewer, then combining their results, the desired analysis is conducted for six time periods. Based on the bibliographic parameters in HistCite and by defining an index, the first five periods are selected such that both quantity and quality of articles …

Blockchain In Supply Chain Management: A Feature-Function Framework For Future Research, James C. Brau, John Gardner, Hugo A. Decampos, Krista Gardner

Faculty Publications

Purpose – Blockchain technology offers numerous venues for supply chain applications and research. However, the connections between specific blockchain features and future applications have been unclear to date in its evolution. The purpose of this study is to fill this void.

Design/methodology/approach – The authors advance the understanding of blockchain in supply chain management by providing a new research framework built on unique blockchain features as applied across core supply chain functions.

Findings – This study’s framework is a feature-function matrix that integrates four overarching supply chain functions (i.e. supplier management, logistics, production processes and customer management) with nine blockchain …

Reliable Change In College Coursework Self-Efficacy, Nancy R. Patel, Matthew H. Kim, Justin E. Karr

Modern Psychological Studies

This study aimed to examine the test-retest reliability of the College Self-Efficacy Inventory-Coursework subscale (CSEI-C) and calculate cutoffs for determining reliable change. A sample of 39 college students from a U.S. university (M=19.0±1.0 years old, 84.6% women, 64.1% White) completed the CSEI-C twice (test-retest interval: M=55.4±12.4 days). The CSEI-C had good test-retest reliability, per the intraclass correlation (ICC=.85). The cutoffs of detecting reliable change were ±.91, ±1.12, and ±1.44 for 70%, 80%, and 90% confidence intervals, respectively. College students often experience mental health problems, and those presenting for psychotherapy may experience concurrent reductions in academic self-efficacy. Clinicians could use the …

Reasoning About The Conant Gasket, M. Douglas Mcilroy

Computer Science Technical Reports

Previously conjectured properties of the Conant gasket, a particular non-periodic tiling of the non-negative integer grid, are proved using new recurrences. A slabwise periodicity property is identified and proved. Further fractal properties are conjectured.

Recent Advances In Experimental Design And Data Analysis To Characterize Prokaryotic Motility, Megan M. Dubay, Jacqueline Acres, Max Riekeles, Jay Nadeau

Physics Faculty Publications and Presentations

Bacterial motility plays a key role in important cell processes such as chemotaxis and biofilm formation, but is challenging to quantify due to the small size of the individual microorganisms and the complex interplay of biological and physical factors that influence motility phenotypes. Swimming, the first type of motility described in bacteria, still remains largely unquantified. Light microscopy has enabled qualitative characterization of swimming patterns seen in different strains, such as run and tumble, run-reverse-flick, run and slow, stop and coil, and push and pull, which has allowed for elucidation of the underlying physics. However, quantifying these behaviors (e.g., identifying …

Pms And Gas Pollutants Removal By Electret Filter Media And Metal-Organic Frameworks (Mofs), Yu Zhang

Theses and Dissertations

Indoor air quality (IAQ) has been becoming a major concern worldwide because statistical data showed that the indoor concentrations of gas pollutants, e.g., volatile organic compounds (VOCs) and particulate matters (PMs) are often 2–5 times higher than that of outdoors. Especially, people spend 87% of their time indoors and increasing to more than 90% during COVID-19 pandemic. The high concentration of these indoor air pollutants is mainly due to the reduced air exchange rate for the design of energy-efficient building construction and the increased usage of furnishings, glues, paints, furnaces, etc., leading to VOC outgassing and particle emission. Evidence has …

Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding, Hao Tu

Theses and Dissertations

This dissertation emphasizes the need for efficient energy use in buildings and transportation due to global warming and the energy crisis. It suggests that improving energy efficiency can help reduce energy consumption and emissions and support sustainability. The dissertation introduces various transparent materials that can block near-infrared (NIR) radiation from solar radiation to save energy and money, and it highlights the growing market value of such products. The dissertation compares tungsten bronze with other NIR shielding materials and shows its advantages. The dissertation introduces a cheap and environmentally friendly method for continuously producing tungsten bronze particles via aerosol synthesis. Particle …

A Longitudinal Analysis Of Academic Self-Concept Among Preclinical Medical Students, Meagan Rawls Lewis

Theses and Dissertations

Medical school plays a pivotal role in the training of future physicians. Academic Self-Concept (ASC) represents a person’s beliefs about their academic ability, and it has been documented across educational contexts as an important factor in relation to academic performance. Despite decades of research into the relationship between ASC and academic performance, this relationship remains underexplored in medical education. The purpose of this study was to examine the ASC of preclinical medical students using longitudinal data to explore both the relationship between ASC and performance and ASC throughout the preclinical phase of medical school. Survey data from three cohorts of …

Code Beats - Teaching Computer Programming Coding Via Hip Hop Beats, Douglas Lusa Krug

Theses and Dissertations

Computer programming is a crucial skill for future professionals, not only those working as computer programmers but most modern workers. To train the next generation, society has created many initiatives to introduce computer programming to young students. These initiatives range from classes in a formal academic setting to informal, extracurricular sessions in after-school and summer camps. Even with the increasing offer of these initiatives to expand the opportunities to learn computer programming, the interest in computer programming remains low, especially among populations underrepresented in computing. This lack of interest could be impacted by stereotypical views of computer programming as tedious …

Natural Hazard Uncertainty Characterization And Risk Assessment For Pressurized Water Reactor Safety Based On System Level Reactor Safety Analysis Models, Tao Liu

Theses and Dissertations

Natural hazard accidents, especially the Fukushima Daiichi accident that occurred in 2011, have brought up significant safety concerns regarding the nuclear power plant (NPP) under external natural hazards. As a result, external natural hazards have been identified as one of the potentially most significant risk contributors to the core damage frequency of the NPPs, highlighting the need for a better understanding of the natural hazards and their associated uncertainties for probability risk assessments (PRAs). However, there are limited computational models and analysis tools to support the probabilistic evaluation of external hazards in PRAs, especially for natural hazards such as floods …

Patterns, Mechanisms, And Characterization Of Carbon Cycling Stability Following Partial Forest Disturbance, Kayla C. Mathes

Theses and Dissertations

Among the most essential questions in the era of climate change is how the forest carbon (C) cycle will respond to an increase in the extent of biotic disturbances from insects and pathogens. While research has focused on stand-replacing disturbance regimes, less is known about C cycling stability following partial disturbances that produce gradients of disturbance severity. Belowground C cycling responses to disturbance are especially poorly understood, even though temperate forest soils contain up to 50% of total ecosystem C and soil respiration (R_s) accounts for more than half of temperate forest C loss. Interpreting trends and mechanisms …

I. Preparation Of Strategic Synthetic Building Blocks For World Health Organization Essential Medicines. Ii. Applying The Principles Of Process Intensification To The Synthesis Of Fluoroquinolone Antibiotics., Jeffrey M. Noble

Theses and Dissertations

The synthesis of active pharmaceutical ingredients is often a time-consuming and expensive process. Due to the nature of pharmaceutical manufacturing, these costs are carried forward to the final purchase price by the consumer. Although there are many factors which are involved in the final costing of a pharmaceutical, the cost associated with the synthesis is the primary one which can be managed by chemists and engineers.

This work discusses the synthetic routes of four active pharmaceutical ingredients as well as the synthetic techniques and equipment used with an emphasis on how the application of specific techniques can be applied to …

Material Extrusion-Based Additive Manufacturing: G-Code And Firmware Attacks And Defense Frameworks, Haris Rais

Theses and Dissertations

Additive Manufacturing (AM) refers to a group of manufacturing processes that create physical objects by sequentially depositing thin layers. AM enables highly customized production with minimal material wastage, rapid and inexpensive prototyping, and the production of complex assemblies as single parts in smaller production facilities. These features make AM an essential component of Industry 4.0 or Smart Manufacturing. It is now used to print functional components for aircraft, rocket engines, automobiles, medical implants, and more. However, the increased popularity of AM also raises concerns about cybersecurity. Researchers have demonstrated strength degradation attacks on printed objects by injecting cavities in the …

Variability In Causal Effects On A Binary Outcome And Noncompliance In A Multisite Randomized Trial, Xinxin Sun

Theses and Dissertations

Noncompliance to treatment assignment is widespread in randomized trials and presents challenges in causal inference. In the presence of noncompliance, the most commonly estimated effect of treatment assignment, also known as intent-to-treat (ITT) effect, is biased. Of interest in this setting is the complier average causal effect (CACE), the ITT effect among compliers. Further complication arises when the outcome variable is partially observed.

My research focuses on estimating the distribution of a site-specific CACE in a multisite randomized controlled trial (MRCT) by maximum likelihood (ML). Assuming compliance missing at random (MAR). We express the likelihood as an integral with respect …

Novel Development Of A Low-Cost, Micrometer-Scale Tip-Enhanced Raman Spectroscopy System, John Yates

Theses and Dissertations

Modern scientific instruments are significant capital investments for universities. These investments can be outside of the funding capabilities of some smaller universities or departments and can be a significant barrier in the pursuit of scientific breakthroughs. This project aims to provide a template for universities or research groups to upgrade, at a reasonable price, an existing Raman spectroscopy system to a Tip-Enhanced Raman Spectroscopy (TERS) system. This system can serve as a permanent upgrade to an existing system or as a bridge necessary to prove the viability of a research path before significant capital investment in a commercial TERS system. …

Understanding The Role Of A Regional Magnet School In Creative Identity Development Of Ethnically And Culturally Diverse Adolescents: A Case Study, Preeti Kamat

Theses and Dissertations

The purpose of this dissertation exploratory case study was to examine the creativity-supportive practices at an innovative regional magnet school shaping Ethnically & Culturally Diverse (ECD) students’ creative identity development as perceived by different stakeholders including ECD students enrolled in the first three cohorts, teachers, and school administrators of RichTech Regional Magnet High School [RRMHS] (pseudonym). This single qualitative case study employed a small component of a quantitative survey, the results of which guided in part the design of interview protocols and sampling procedures for recruiting qualitative participants. Using a pragmatic research lens, I obtained and analyzed the diverse qualitative …

Development Of Tangible Code Blocks For The Blind And Visually Impaired, Hyun Woo Kim

Theses and Dissertations

The fields of Science, Technology, Engineering, and Mathematics (STEM) have been growing at an accelerating rate in recent times. Knowing how to program has become one key skill for entering all of these STEM fields. However, many students find programming difficult. The block based programming language, Scratch, was specifically designed to lower hurdles to learning how to program for sighted students. Unfortunately, although very effective and widely used in K12 classrooms, Scratch, similar to other block based languages, is inaccessible to students who are blind and visually impaired (BVI). This thesis is part of a larger project to make the …

Investigating The Dynamics And Fragmentation Of Nitroaromatic Radical Cations Through Femtosecond Time-Resolved Mass Spectrometry And Computational Chemistry, Hugo Andres Lopez Pena

Theses and Dissertations

Chemists have sought to control molecular dissociation with lasers for decades. Effective control of unimolecular dissociation was only achieved with the development of high-intensity ultrashort pulsed lasers and coherent control techniques that operate on timescales faster than vibrational energy redistribution. In view of this, our lab has specialized in the study of polyatomic radical cations using femtosecond time-resolved mass spectrometry (FTRMS). The interest in radical cations stems from the fact that they are highly reactive species that contribute to many physical, chemical, and biological processes. For instance, radical cations participate in shock initiation of detonated energetic materials used as explosives …

Asymmetric Cuh-Catalyzed Reductive Coupling Of Allenamides With Carbonyl Electrophiles & Development Of Nanocatalysts For Heterogeneously Catalyzed Buchwald-Hartwig Amination, Raphael K. Klake

Theses and Dissertations

Many drugs and natural products contain multiple stereogenic carbons bearing heteroatoms throughout their carbon framework. Therefore, methods that can efficiently install multiple heteroatoms on a molecule are valuable. Reductive coupling reactions have been extensively studied, and the allylation of carbonyls via the reductive coupling approach has been a key method for generating chiral tertiary and secondary allylic alcohols. This work utilizes inexpensive Cu for the asymmetric reductive coupling of allenamides with carbonyls to simultaneously install two heteroatoms (oxygen and nitrogen) on the product. These molecules have a polarity profile that make them difficult to make using traditional methods. Herein, we …

Synthesis And Application Of Redox-Active Covalent Organic Frameworks In Rechargeable Batteries, Mohammad K. Shehab

Theses and Dissertations

Synthesis and Application of Redox-Active Covalent Organic Frameworks in Rechargeable Batteries

Mohammad K. Shehab

Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States

Abstract

In recent years, lithium-ion batteries (LIBs) have been considered the dominant energy storage devices for portable electronics and electric vehicles due to their high energy density, low self-discharge rate, and long cycle life. In LIBs, the traditional positive electrodes employed are mainly derived from metal-containing inorganic compounds composed of cobalt, iron, nickel, or manganese (LiCoO₂, LiMn₂O₄, and LiFePO₄) coupled with graphite as the negative electrode. Despite …

Blockchain Security And Applications, Phuc D. Thai

Theses and Dissertations

Cryptocurrencies, such as Bitcoin and Ethereum, have proven to be highly successful. In a cryptocurrency system, transactions and ownership data are stored digitally in a ledger that uses blockchain technology. This technology has the potential to revolutionize the future of financial transactions and decentralized applications. Blockchains have a layered architecture that enables their unique method of authenticating transactions. In this research, we examine three layers, each with its own distinct functionality: the network layer, consensus layer, and application layer. The network layer is responsible for exchanging data via a peer-to-peer (P2P) network. In this work, we present a practical yet …

Innovations In Drop Shape Analysis Using Deep Learning And Solving The Young-Laplace Equation For An Axisymmetric Pendant Drop, Andres P. Hyer

Theses and Dissertations

Axisymmetric Drop Shape Analysis (ADSA) is a technique commonly used to determine surface or interfacial tension. Applications of traditional ASDA methods to process analytical technologies are limited by computational speed and image quality. Here, we address these limitations using a novel machine learning approach to analysis. With a convolutional neural network (CNN), we were able to achieve an experimental fit precision of (+/-) 0.122 mN/m in predicting the surface tension of drop images at a rate of 1.5 ms^-1 versus 7.7 s^-1, which is more than 5,000 times faster than the traditional method. The results are validated on real images …

Model Based Systems Engineering Approaches To Chemicals And Materials Manufacturing, Quang Le

Theses and Dissertations

Model-based systems engineering (MBSE) is part of a long-term trend toward model-centric approaches adopted by many engineering disciplines. This work establishes the need for an MBSE approach by reviewing the importance, complexity, and vulnerability of the U.S. chemical supply chains. The origins, work processes, modeling approaches, and supporting tools of the systems engineering discipline (SE) are discussed, along with the limitations of the current Process Systems Engineering (PSE) framework. The case is made for MBSE as a more generalizable and robust approach. Systems modeling strategies for MBSE are introduced, as well as a novel MBSE method that supports the automation …

A Tenth Of A Second, Natalia Andrea Mejía Murillo

Theses and Dissertations

A Tenth of a Second is an installation that explores modes of cartographic representation of the universe, specifically the moon, in dialogue with poetic language. The work is based on research and reflection on disciplines such as astronomy and archaeology and addresses issues such as the fragility of the reference and categorization systems we use to approach reality, tactility and the body as a standard of measurement.

Totem Impulse, Tendai T. Mupita

Theses and Dissertations

In this reading, I explore the performative and complexities of indigenous mythologies, cosmologies, and epistemologies, through totems, folklore, architecture, and games. This paper extracts references from indigenous philosophies in thinking about form and image. These forms and images are my sculptures, my installations, and my lines.

Mechanisms Of Emulsion Destabilization: An Investigation Of Surfactant, Stabilizer, And Detergent Based Formulations Using Diffusing Wave Spectroscopy, Jordan N. Nowaczyk

Theses and Dissertations

Conventional approaches for studying emulsions, such as microscopy and macroscopic phase tracking, present challenges when it comes to establishing detailed mechanistic descriptions of the impact of emulsifier and stabilizer additives. Additionally, while a combination of sizing methods and macroscopic phase tracking can provide insights into droplet size changes and concentration, the use of multiple measurements can be cumbersome and error-prone. It is the focus of this work, to present a new method for studying water in oil (W/O) emulsions that involves using diffusing wave spectroscopy (DWS) to examine the impact of three different surface stabilizing additives at varying concentrations. By …