Digital Commons Network^™

Friction And Heat Transfer Modeling Of The Tool And Workpiece Interface In Friction Stir Welding Of Aa 6061-T6 For Improved Simulation Accuracy, Ryan Melander

Theses and Dissertations

Friction stir welding (FSW) is a solid-state joining process that offers advantages over traditional fusion welding. The amount of heat generated during a FSW process greatly influences the final properties of the weld. The heat is generated through two main mechanisms: friction and plastic deformation, with friction being the larger contributor in a FSW process. There is a need to develop better predictive models of the heat generation and heat transfer in FSW. Almost all models seen in the literature validate temperature predictions on only one side of the tool/workpiece interface, thus ignoring possible inaccuracy that comes from incorrect partitioning …

Extending Model Checking Using Inductive Proofs In Distributed Digital Currency Protocols, Kyle R. Storey

Theses and Dissertations

Model checking is an effective method to verify both safety and liveness properties in distributed systems. However, the complexity of model checking grows exponentially with the number of entities which makes it suitable only for small systems. Interactive theorem provers allow for machine-checked proofs. These proofs can include inductive reasoning which allows them to reason about an arbitrarily large number of entities. However, proving safety and liveness properties in these proofs can be difficult. This work explores how combining model checking and inductive proofs can be an effective method for formally verifying complex distributed protocols. This is demonstrated on a …

Characterizing Dust From National Wind Erosion Research Network Sites Using Strontium Isotopes, Major And Trace Element Chemistry, And Mineralogy, Abby L. Mangum

Theses and Dissertations

The frequency of dust storms is increasing globally yet it is often difficult to determine dust sources in mixed events. Dust events may negatively impact human health, but the composition of major dust sources is not well characterized in arid regions globally. In the western US, the National Wind Erosion Research Network (NWERN) has various sites evaluating seasonal dust emissions to quantify dust fluxes. We used existing dust samples to characterize the isotopic, chemical, and mineralogical composition of dust over multiple seasons from ten representative NWERN sites and compared with land use, vegetation, and surficial geology. Our results show variability …

Acoustic Directivity: Advances In Acoustic Center Localization, Measurement Optimization, Directional Modeling, And Sound Power Spectral Estimation, Samuel David Bellows

Theses and Dissertations

Sound radiation from an acoustic source typically exhibits directional behavior, as is the case for the human voice, musical instruments, and loudspeakers, to name just a few. The necessity of directional data for many applications, such as sound source modeling, microphone placement, room acoustical design, and auralization, motivates directivity measurements. However, these measurements require careful understanding and implementation to produce the most meaningful results. Accordingly, this dissertation addresses several topics relevant to directivity theory, measurement, processing, and application. It first expands and amends previously published concepts of an acoustic source center and demonstrates the close relationship between the center and …

Evaluation Of Personalized Learning, Jorly Thomas

Education Theses and Dissertations

The persistent challenges surrounding student achievement continue to raise questions about the effectiveness of personalized learning methods, and educators seek a reliable means to determine if the implementation of personalized learning can lead to improved academic outcomes. Improvement science presents a promising approach, providing iterative inquiry cycles and data-driven decision-making strategies that can empower teachers to make informed decisions (Regional Educational Laboratory Program, 2017). The purpose of this study was to examine the effects of personalized learning on reading achievement in sixth-grade students on a Texas middle-school campus. While prior research has demonstrated promising outcomes with this learning method (Pane …

Said-Ball Polynomials For Solving Linear Systems Of Ordinary Differential Equations, Mubark Al-Subaai Dr., Ahmes Saleh Kherd

Emirates Journal for Engineering Research

Said-Ball polynomials with collocation method are used to numerically solve a system of linear ordinary differential equations. The matrix forms of Said-Ball polynomials of the solution, derivatives, and conditions are done. The linear system of ordinary differential equations with appropriate conditions is reduced to the linear algebraic equations system with unknown Said-Ball coefficients. Solving the resulting system determines the coefficients of Said-Ball polynomials. By Substituting these values in the polynomial, we get the problem's exact and approximate solutions. The obtaining numerical results show the proposed method's accuracy and reliability when compared with the other works and exact solutions

Methods Of Magneto-Optical Spectroscopy And Analysis For Porphyrins And Polymer Thin-Films, Emigdio E. Turner

Chemistry and Chemical Biology ETDs

This dissertation describes the construction of two high precision magneto-polarimeters for performing Faraday rotation and Magnetic Circular Dichroism (MCD) measurements of polymer thin-films. There is a focus in materials science on the development of thin-film magneto-optically active materials. These materials could allow for the construction of a thin-film optical diode, an important device for next-generation photonic technology. Upon completion of the Faraday rotation spectrometer, two publications were generated from Faraday rotation measurements of novel polymer thin-film materials.

With growing interest by materials scientists in magneto-optically active transition-metal containing materials, an MCD spectrometer was constructed to study these materials. This spectrometer …

Evaluating The Impact Of Math Self-Efficacy, Math Self-Concept, And Gender On Stem Enrollment And Retention In Postsecondary Education, Marcia Bingham

Theses and Dissertations

Low enrollment and high attrition of women in science, technology, engineering, and mathematics (STEM) continues to be an issue for postsecondary institutions. Improvements in representation of women has been seen in some of the agricultural and biological sciences; however, in many of the more math intensive areas such as geosciences, engineering, mathematics/computer science, and physical sciences (GEMP), women continue to be underrepresented leading to underrepresentation in the workforce and further exacerbating gender gaps. Studies suggest the lack of representation is not due to a gap in math ability between men and women, yet underrepresentation remains predominantly within math intensive STEM …

Ultracold Neutral Plasma Evolution In An External Magnetic Field, Chanhyun Pak

Theses and Dissertations

We study the expansion velocity and ion temperature evolution of ultracold neutral plasmas (UNPs) of calcium atoms under the influence of a uniform magnetic field that ranges up to 200 G. In the experiments, we use a magneto-optical trap (MOT) to capture the neutral atoms and laser-induced fluorescence (LIF) to take images of the plasma. We vary the magnetic field strengths and the initial electron temperatures and observe the plasma evolution in time. We compare the ion temperature evolution to the theory introduced in the paper by Pohl et. al. [Phys. Rev. A 70, 033416 (2004)]. The evolution of the …

Polyvinyl Alcohol (Pva)-Based Nanoniosome For Enhanced In Vitro Delivery And Anticancer Activity Of Thymol, Mohammadreza Abdihaji, Masoumeh Mirzaei Chegeni, Alireza Hadizadeh, Negar Farrokhzad, Zahra Kheradmand, Parastoo Fakhrfatemi, Fardad Faress, Kasra Moeinabadi-Bidgoli, Hassan Noorbazargan, Ebrahim Mostafavi

Information Systems Faculty Publications

Introduction: There is an unmet need to develop potent therapeutics against cancer with minimal side effects and systemic toxicity. Thymol (TH) is an herbal medicine with anti-cancer properties that has been investigated scientifically. This study shows that TH induces apoptosis in cancerous cell lines such as MCF-7, AGS, and HepG2. Furthermore, this study reveals that TH can be encapsulated in a Polyvinyl alcohol (PVA)-coated niosome (Nio-TH/PVA) to enhance its stability and enable its controlled release as a model drug in the cancerous region.

Materials and Methods: TH-loaded niosome (Nio-TH) was fabricated and optimized using Box–Behnken method and the …

Comments For The Draft Residential Metals Abatement Program – Interior School Dust – Investigation Summary Report – Emerson Elementary (May 22, 2023), Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Bend And Not Break: Examining Hispanic Engineering Student's Academic Challenges During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Student success in higher education remains an area of interest, particularly for underrepresented minorities. Studies reveal that while Latino college enrollment has increased, retention rates continue to be an ongoing struggle. Several factors that attribute to such low rates include academic self-concept, family support, cognitive mapping, managing resources, background characteristics, and separation and maintenance of family ties. In the wake of COVID-19, most institutions responded by terminating in-person instruction, mandating to seek off-campus housing, and shifting to a fully remote context. As such, students were unable to utilize campus resources and engage in established educational campus practices. In this research …

Re: Approval For The Request For Change Bg-2023-01 To Final Bpsou Hydrocarbon Sampling And Treatability Study, Quality Assurance Project Plan (Qapp) (Dated May 15, 2023), Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Comments For The Draft Residential Metals Abatement Program – Interior School Dust – Investigation Summary Report – Emerson Elementary (May 22, 2023), Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Approval For The Request For Change Bg-2023-01 To Final Bpsou Hydrocarbon Sampling And Treatability Study, Quality Assurance Project Plan (Qapp) (Dated May 15, 2023), Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

2023-06-26 Message From The President, Morehead State University. Office Of The President.

Staff Congress Records

A message sent on June 26, 2023 from the President of Morehead State University to the campus community regarding the Board of Regents latest meeting, summer sessions, construction projects, and significant dates in the upcoming weeks.

Analyzing The Translanguaging Strategies In Educational Setting: A Book Review Of Multimodal Conversational Analysis And Interpretative Phenomenological Analysis, Farida Amansyah, Ismail Anas

The Qualitative Report

Translanguaging strategies have emerged as a paramount area of inquiry within educational contexts and qualitative studies. The book "Multimodal Conversational Analysis (MCA) and Interpretative Phenomenological Analysis (IPA)," written by Kevin W. H. Tai and published by Routledge in 2023, presents a well-crafted and highly recommended source for second language (L2) researchers seeking a comprehensive guide to analyzing translanguaging practices in multilingual and diverse linguistic educational settings. It offers valuable insights for L2 teachers and researchers seeking to delve into the investigation and comprehension of the intricate process and underlying factors involved in classroom translanguaging. Moreover, the book presents a compelling …

Islamic Banks' Decomposed Financing And Industrial Output Growth In Pakistan, Sadia Yasmin, Mohammad Ayaz Dr

Business Review

Abstract

Finance is considered as "the lifeblood of an economy" and imperative to a country's growth and stability. However, this perception has been called into two propositions, "More finance more growth "and "Does too much finance harm economic growth”? Existing literature considered only a single indicator i.e. total financing, assuming all financing has the same effect on growth. Furthermore, these studies also overlooked the nonlinear dynamics of Islamic decomposed financing and sectoral growth. As the composition of every economic sector is different, therefore financing can impact differently. This gap is covered in this study by decomposing Islamic financing into Islamic …

Giving And Taking Care During The Covid-19 Pandemic: Secondary Teachers’ Experiences Of Social Emotional Learning, Janna Jobel, Rebecca J. Lloyd

Journal of Contemplative and Holistic Education

Social Emotional Learning (SEL) has been primarily researched in elementary schools, and within this context, SEL curriculum is often presented as an isolated, preplanned curriculum, with a list of curricular objectives to be delivered. A phenomenological inquiry was conducted to better understand the ways in which SEL and SEL curriculum are understood and experienced in a high school context. Data gathered from close phenomenological observations and interviews with three high school teachers in mathematics and physical education afforded the opportunity to orient, interpret, and describe the phenomenon of SEL-in-action. Rich descriptions of SEL as it is lived were generated and …

Learning In Transition: Developing And Employing Pedagogical Supports To Enhance Student Learning In Engineering Education, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Scholarly research indicates that classroom environment and conditions influence the degree of student learning, levels of engagement, and overall success in engineering education. In the wake of COVID-19, educational institutions transitioned to fully online delivery that disrupted traditional and effective channels of communication enacted in classroom contexts. For a substantial number of faculty members, this rapid transition to a fully remote instructional context marked the start a novel style of teaching and learning environment, a grand departure from the traditional, direct face-to-face setting. Such rapid and disruptive change required creative solutions to routinized instructional practices and compelling faculty to adjust …

Keeping Calm And Staying Balanced: Exploring The Academic Pressures Faced By Engineering Students To Attain High Grades And Their Impact On Mental Health, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Studies reveal that grades have a short-term impact on students’ self-efficacy, motivation, and decision making. Earning high grades has become a focal point for engineering students to secure three types of opportunities: internships, post-graduation employment, and graduate school acceptance. Nonetheless, the desire to attain a competitive grade-point-average may lead to negative psychosocial effects such as increased mental exertion, physical exhaustion, anxiety, and overall lack of work-life balance. In this paper, the authors extend their prior study on the impact of grades in engineering education. The first study was conducted in the spring of 2019 at a tier one, small private …

Leveling The Playing Field: Enacting Equitable Pedagogy To Teach Rigid Body Dynamics, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Research examining the quality of engineering programs across different instructions of learning has revealed that no two programs are alike. Each program has unique and distinctive features that influence the quality and rigor of education that students receive. Institutional culture, leadership, faculty preparedness, funding and many other factors influence program quality. Additionally, researchers have also noted that many institutional gaps and equity related issues are persistent and troublesome facets that further exacerbate the academic gaps in STEM education. It is within this context, that students attending top tier universities will likely have remarkedly vast academic experiences in terms of level …

Classification Of Finite Topological Quandles And Shelves Via Posets, Hitakshi Lahrani

USF Tampa Graduate Theses and Dissertations

The objective of this dissertation is to investigate finite topological quandles and topological shelves. Precisely, we give a classification of both finite topological quandles and topological shelves using the theory of posets. For quandles with more than one orbit, we prove the following Theorem.

Proposition 0.0.1. Let X be a finite quandle with n orbits X₁, ... , X_n. Then any right continuous poset on X is n-partite with vertex sets X₁, ... , X_n.

For connected quandles, we prove the following Theorem.

Theorem 0.0.2. There is no T …

Exploratory Data-Driven Models For Water Quality: A Case Study For Tampa Bay Water, Sandra Sekyere

USF Tampa Graduate Theses and Dissertations

Water, a crucial resource for sustaining life, covers approximately 70% of the earth's surface. Nonetheless, the quality of water is deteriorating rapidly due to the rapid growth of urban areas and industries, which is a worrying trend causing harm to human health and the ecosystem. Water quality forecasting has a key role in water resources management by enabling effective pollution control, ecosystem monitoring, and decision-making.

Previously, traditional statistical models were used to forecast water quality, but they were unable to examine the non-linear relationships between water quality parameters, and they assumed that all datasets were distributed normally. This study uses …

Twenty-First Century Receptions Of Tolkien (2022), Edited By Will Sherwood, Kristine Larsen

Journal of Tolkien Research

Book review, by Kristine Larsen, of Twenty-first Century Receptions of Tolkien (2022), edited by Will Sherwood

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Preparation And Properties Of Acrylate Grouting Material Used In Coal Mine, Zeng Juanjuan, Li Huizhi, Wei Daidong, Xue Wei, Zhu Kaipeng

Coal Geology & Exploration

Water leakage control on the coal mine roof is an inevitable challenge in the process of coal mining. In this regard, chemical grouting provides an effective method to solve this problem. Specifically, acrylate grouting materials were prepared using the synthesized magnesium acrylate solution, cross-linking agent, initiator, and accelerator as the raw materials. Based on this, the effects of the concentration of magnesium acrylates, the type and dosage of crosslinking agent and the dosage of initiator on the properties of the gels of the acrylate grouting materials were investigated. The test results indicate that the type and dosage of crosslinking agent …

Current Situation And Development Trend Of Pressure-Relief Gas Extraction In The Protective Layer Mining In Coal Mines In China, Xue Junhua, Xiao Jian, Du Xuanhong, Shi Yu

Coal Geology & Exploration

Deep coal mining in China is seriously restricted by factors including high stress, high gas pressure, and low coal seam permeability. Moreover, with the gradual deterioration of the mining conditions of deep coal seams, it is increasingly difficult to control the gas in these coal seams. Fortunately, the pressure-relief mining of protective layers serves as an efficient way to control gas and eliminate coal and gas outbursts. To meet the demand of practical projects, this paper reviews the studies on the mining technology for protective layers, the law of change in the stress of protected layers, the evolutionary law of …

Retention Of Female Minority Students In Bachelor Stem Degree Programs: An Exploratory Study Of Five Cohorts, Elizabeth Milonas

Publications and Research

Minority female students are under-represented in computer-related fields such as computer science, information systems, and computer engineering. Yet, minority female students are also under-represented in computer-related degree programs (Botella et al. 2019). This group of students faces unique challenges that can discourage them from continuing with a computer-related degree (Varma 2003). These challenges include a lack of writing and degree readiness skills such as mathematical and computational thinking skills (Varma 2003). Minority female students are also faced with economic challenges and family commitments which can hinder or discourage them from continuing in a degree program (Varma 2003). In addition, minority …

Effects Of Increasing Sintering Pressure On The Performance Of Impregnated Diamond Bit, Yang Zhan, Tan Songcheng, Fang Xiaohong, Yang Kaihua

Coal Geology & Exploration

The matrix formulas of conventional hot-pressed impregnated diamond bits are mostly elemental metal systems, using WC or YG8 as the skeleton materials, Cu alloys as the bonding materials, and Ni, Co, Fe and Mn as the intermediate materials. Due to the compositions and contents of the bonding and skeleton materials in the formulas, the suitable sintering pressure is limited (≤16 MPa), while the sintering temperature is relatively high (≥ 930℃), resulting in a lower relative ratio of the actual and theoretical densities (≤98%) for the diamond bit matrix. However, the high sintering temperature will cause thermal damage to the diamonds, …