Digital Commons Network^™

Calibration Of The Extreme Universe Space Observatory, Malek Mastafa

Dissertations

The most energetic particles in the universe are ultra high energy cosmic rays UHECRs with energies up to 3×10^20 eV eV. However, their flux is strongly suppressed at the highest energies (~1 particles /〖km〗^2 /century for E = 10^19.75 eV), leaving the sources and the acceleration mechanisms unknown. The detection of UHECRs from space via fluorescence method is very compelling because of the large area that can be observed. The Extreme Universe Space Observatory on a Super Pressure Balloon (EUSO-SPB) collaboration is developing and flying balloon-brone prototypes of a satellite instrument to make such observations. The EUSO-SPB1 instrument is the …

Pmu-Events-Driven Dvfs Techniques For Improving Energy Efficiency In Modern Processors, Ranjan Hebbar

Dissertations

Energy-efficient computing is one of the most important challenges computer designers and operators are facing today, exacerbated by the ever-increasing demands for faster, smaller, lighter, and more affordable computing. The processor is the primary driver of the overall system power consumption of a computer system. Typical power management techniques rely on either running the processor at a fixed clock frequency or utilizing dynamic voltage and frequency scaling (DVFS) techniques that adjust the processor’s clock frequency in runtime based on its current level of activity. In this dissertation, we first describe the results of our measurement-based study that evaluates the impact …

Implications Of Alternative In-Situ Propellants Used In Nuclear Thermal Propulsion Engines, Daria Nikitaeva

Dissertations

Recently, the NASA Artemis Program has pushed for a return to the Moon with In-Situ resource utilization (ISRU) being the central focus to sustainably achieve this goal. Nuclear Thermal Propulsion (NTP) is one of the considered propulsion systems for Mars missions under this program which can theoretically use any propellant provided that significant core degradation does not occur. The propellant of choice for NTP is hydrogen. However, water and ammonia are both found on the Moon and are much more dense than liquid hydrogen, do not require post processing such as electrolysis, and can be used directly by NTP. Using …

Improved Isosurfacing Through Compression And Sparse Grid Orientation Estimation, Brian Wood

Dissertations

This dissertation focuses on increasing isosurfacing speed through novel compression approaches. The compression occurs on a cell-by-cell basis during isosurface extraction, as opposed to compressing the mesh in a post-processing step. The compression is applied to isosurfacing on cluster computers, and it postpones scalability plateauing of prior parallel isosurfacers by reducing communication on cluster computers (versus the prior state of the art). A novel view-dependent isosurface mesh decompressor and improved isosurface orientation estimator for sparse datasets via quadratic splines fit to tetrahedral decompositions of the datasets are also described. Experimental results for all efforts, which quantify their effectiveness, are also …

Network Based Pressure Drop Modeling Of Heterogeneous Porous Hybrid Rocket Motor Grains, Joseph Robert Kennedy Buckley

Dissertations

Analytic Transport Network Theory (ATN), a heuristic model developed for electrochemical systems, is adapted to predict the gas pressure drop across heterogeneous porous hybrid rocket motor grains. Experimental pressure drop estimations from previous studies of these grains disagree with existing empirical correlations that assume uniform morphology. An adapted ATN model could significantly improve the gas pressure drop prediction with relatively low resource requirements. To test the applicability of ATN, porous hybrid motor grain samples with length 40 mm, diameter 20 mm, and nominal pore size (NPS) of 200 and 100 microns, based on manufacturer specifications, were studied using microstructural analysis …

Time Wavelength Optical Sampling Spectroscopy, Srikamal Jaganraj Soundararajan

Dissertations

Real-time optical spectroscopy capable of tracking fast and rare events has attracted considerable interest in recent years due to its potential to significantly impact the study of chemical and biological reaction dynamics. However, the development of such capabilities faces major challenges in terms of instrument response time, spectral resolution, and power sensitivity. In this dissertation, a new spectroscopy method called time-wavelength optical sampling (TWOS) spectroscopy is proposed, analyzed, and experimentally demonstrated. This method combines the advantages of time-stretch spectroscopy (TSS) and ultrafast optical sampling, and offers several key benefits over conventional TSS based on direct power measurement. By developing a …

Verification And Validation Methods For Extended Petri Nets Modeling Cyberattacks, Walter Alan Cantrell

Dissertations

Verification and validation are crucial to establishing the credibility of the results of a modeling and simulation project. Conclusions drawn from an unverified and unvalidated model are at best unconvincing, and at worst have the potential to be dangerous if decisions are made based on outputs from an incorrect model. In general, the most effective methods of verification and validation involve comparisons of simulation results with data from observations of the system or event being simulated. However, such methods cannot be used if system data is not available. This is often true of cyberattacks, because the victims of cyberattacks conceal …

Pottery Horizons Of The Jalul Ceramic Assemblage In The Iron Age Iia-C From Square G4 In Its Historical And Geographical Context, Michael Christian Orellana Mendez

Dissertations

Problem

Several scholars have debated the traditional and low chronology of the Iron Age in Southern Levant using pottery as one of their main pieces of evidence. Both approaches disagree in regards to the dates assigned to the early Iron Age II pottery. To achieve a better understanding of the problem, the still rudimentary knowledge of Iron Age II pottery in Transjordan needs to be improved. Since 1992, Tall Jalul—the largest tell site in the central Jordan plateau—has been due for a comprehensive study of its ceramic assemblages. The site produced Iron Age IIA-C pottery in stratified layers, and it …

Self-Efficacy And Self-Regulation As Predictors Of Academic Motivation Among Undergraduate Students In The United States, Fatimah Aljuaid

Dissertations

Problem

Some undergraduate students demonstrate lack of academic motivation which negatively affects engagement and perseverance in higher education (Busse & Walter, 2017; Rizkallah & Seitz, 2017; Dresel & Grassinger, 2013). Amotivated students are more likely to drop out of school and disengage from learning activities or underachieve (Wang & Pomerantz, 2009). Although the lack of academic motivation is correlated with deficiency in self-regulation and self-efficacy, relatively little studies have been conducted to examine the impact of these factors on academic motivation particularly in the U.S. This study constructed a hypothesized model to investigate the role of self-regulation and self-efficacy in …

The Effect Of The Vocabulary Spelling City App On Student Performance In Spelling, Vocabulary, And Reading Comprehension In Grades 5-8 At Glenview Adventist Academy, Fernando Oleynick Lista

Dissertations

Problem and Purpose

Students in fifth through eighth grades at Glenview Adventist Academy (GAA) presented difficulties in the subjects of spelling, vocabulary and reading comprehension. The school had not followed the previous 10-year trend of technology implementation in the classroom, in spite of conclusive research on its advantages. This study was conducted to determine to what extent teaching methodology and the use of technology could affect academic performance in the areas of spelling, vocabulary, and reading comprehension. Research on the implementation of software and the use of tablets (iPad Minis) in the classroom has been scarce and contradictory in the …

Measures Of Student Engagement As Predictors Of Grade Point Average (Gpa) And Degree Completion At Andrews University, Michael D. Milmine

Dissertations

Purpose of the Study

In a time of rising costs, social discourse questioning value of an undergraduate degree, and declining enrollment, institutions of higher education are under increasing pressure to provide stakeholders and potential students with measures of accountability and student success. These pressures renew the need to leverage student engagement data to understand what makes undergraduates successful in their academic programs. An understanding of student engagement factors is key to helping all students succeed, but especially to identifying areas that colleges and universities can devote their attention in order to improve their students’ likelihood of success. The purpose of …

The Influence Of Mentoring, Self-Efficacy And Perceived Organizational Support On Commitment Among Novice Adventist Teachers, Kathleen E. Forbis

Dissertations

Problem

Previous research indicated that mentoring impacts teacher commitment positively. However, there was a gap in the knowledge regarding the influence of mentoring on novice Seventh-day Adventist (SDA) teacher commitment in North America. The Adventist education system differs in significant ways from the public school system, and novice teachers need support.

Purpose

The primary purpose of this study was to examine the influences of mentoring, self-efficacy, and organizational support on SDA novice teacher commitment (0 - 5 years’ experience). The secondary purpose included identifying the characteristics of effective mentors and mentoring programs, while exploring novice teachers’ current experiences of mentoring, …

Involvement In Community Service And Spiritual Activities As Correlates Of Socially Responsible Leadership Among Undergraduate Students At Asia-Pacific International University, Thailand, Naltan Lampadan

Dissertations

Problem

Institutions of Higher Education invest considerable resources to provide students with leadership experiences through extracurricular activities, especially in community service and spiritual programming. The inter-relationship among these variables (socially responsible leadership, spiritual and community involvement) have not been investigated in faith-based institutions of higher education in Southeast Asia.

Purpose of the Study

This study had four purposes: (a) to examine the extent of student involvement in community service and spiritual activities; (b) to investigate the level of socially responsible leadership among undergraduate students; (c) to examine whether socially responsible leadership might be related to gender, nationality, class status, and …

Marketing Adventist Higher Education In North America : College Choice - Motivators And Barriers, George Charles Dart Jr.

Dissertations

Purpose/Problem

It is estimated more than 75% of Seventh-day Adventist (SDA) college-bound students (rising freshmen) who live in the North American Division (NAD) do not attend an SDA college/university. This is a major challenge for the NAD colleges/universities. Discovering motivators and barriers for SDA college-bound students is vital in understanding what influences this population in their college choice selection.

Method

This is a quantitative, cross-sectional, comparative study. An electronic survey using Qualtrics was sent to over 14,000 students with 461 respondents as the sample size. Respondents were sorted into four study groups, using the type of high school attended and …

An Exploratory Study Of Mathematics Anxiety In Caribbean Preservice Teachers, Franka Atwell-Chin Hong

Dissertations

The Problem

Correlational studies suggest that gender, attitudes to mathematics, mathematics performance, the number of college mathematics courses taken, and mathematics teacher efficacy beliefs may be related to mathematics anxiety among preservice teachers (Boyd et al., 2014; Gresham, 2018; Jaggernauth & Jameson-Charles, 2015). Exploratory studies of mathematics anxiety and teacher self-efficacy among elementary teachers exist in Trinidad and Tobago (Jaggernauth 2012; Jaggernauth & Jameson-Charles, 2015). However, the differences in samples, and weakness in methodology, may make it challenging to generalize the results to the preservice teacher population. In addition, no studies have found which variable or combination of variables is …

How Faculty And Student Preferences For Active And Traditional Instructional Methods Relate To Their Beliefs, Quantity, And Quality Of Experiences, Knowledge Of The Benefits, And Professional Training, Tammy R. Shilling

Dissertations

Purpose

The complexity of preparing students for clinical practice and the mitigating factors that influence pedagogical preferences impact the current realities of health professional education. The purpose of this quantitative, correlational study is to explain the relationships between faculty preferences and student preferences for active over traditional methods and their beliefs, the frequency and positiveness of their experiences, and the amount and extent of the knowledge or training they have had regarding active and traditional teaching methods. Results may further inform and refine health professional education infrastructure changes to support faculty in pedagogical change as they prepare students with the …

Healthcare Leadership In The Context Of Cognitive Diseases Of Aging: A Community-Based Participatory Research Model, Dean Sherzai

Dissertations

The Problem

The world is facing a tsunami of chronic diseases of the brain such as dementia, Parkinson's, and stroke. But all populations are not affected equally. Though we are all at greater risk of developing these diseases, minority communities such as the Black and Hispanic populations are at much greater risk of succumbing to these conditions. To date we have spent billions of dollars on research and public health measures that have repeatedly failed, but over the last decade it has become evident that much of these diseases can simply be averted through effective public health and community-based measures …

Coping Skills, Emotional Intelligence, Attachment, And Resilience On Post-Traumatic Stress Disorder In Private Sector Emergency Medical Technicians, Brenda-Joyce Gonzales Orozco Markert-Green

Dissertations

Problem

Private sector Emergency Medical Technicians (EMTs) are first responders who respond to traumatic incident scenes along with firefighters and police officers. However, news agencies and the public do not acknowledge private sector EMTs with the same vigor or accolade as public sector EMTs, nor are the risks to life, health, and mental well-being recognized among this population. Thus, the research literature has been sparse regarding how private sector EMTs experience PTSD, and what unique risk factors and needs may be present.

Purpose Statement

The purpose of this study was to examine the relationship between PTSD symptoms and coping skills, …

An Analysis And Comparison Of The Missional Doctrine Hermeneutics Of Kevin J. Vanhoozer And Veli-Matti KäRkkäInen, With Emphasis On Their Notions Of God, Eschatology, And Mission, Elmer Arrais Guzman

Dissertations

This dissertation analyzes Veli-Matti Kärkkäinen’s and Kevin J. Vanhoozer’s theological method, in order to understand its structural elements, and thereby to facilitate comprehension of their missional doctrinal hermeneutics, and the ramifications of those hermeneutics for the construction and development of Christian theology. Missional doctrinal hermeneutical models conceive the missional dimension of doctrine in various ways. Some privilege the maintenance of theological identity cohering with the foundational sources of theological authority. Others privilege theological constructions that assimilate the context and the missional situational framework of understanding. This dissertation strives to examine the diverging missional hermeneutics of Kärkkäinen and Vanhoozer, the foundational …

Perceived Effectiveness Of A Mentoring Program For Training Adventist Chinese Evangelists, Terry Man-Yuen Tsui

Dissertations

Problem

The fact that evangelism in the Unorganized Territories of the Chinese Union Mission was done mainly as personal evangelism and that public evangelism was limited to a one-day seed sowing meeting had led to a serious need for equipping pastors in effective public evangelism methods. It required a model of public evangelism, which is adaptable to the local Chinese culture, and a mentoring program that accompanies evangelists, who were still developing their skills in public evangelism.

Method

This study used a parallel mixed methods design to measure the perceived effectiveness of selected methods in the mentoring program. This design …

Administrator Stress And Well-Being: Lessons Learned From Retired Administrators, Carrie Bosco

Dissertations

School and district leaders work in stressful jobs and a better understanding is needed about how these conditions affect their personal and professional lives. This study presents the stories of experienced K–12 public school and district administrators contending with and managing administrative stress and its effects on administrators. Through qualitative inquiry and narrative analysis, the learning that comes from experience is explored as a way of understanding administrative practice. Storied examples of stressful situations range from the most serious and traumatic events a school administrator might face to the daily grind of always being “on.” Powerful themes that emerged from …

An Analysis Of Job Stress As Experienced By Public School Site Administrators, Joseph A. Bosco

Dissertations

Public school site administrators face enormous challenges day in and day out. COVID-19 has created more challenges than ever for any organization, but for public school site administrators these types of challenges are once in a lifetime. When crisis hits, leaders are expected to be strong and levelheaded. However, these leaders are experiencing high levels of stress which can lead to burnout, depersonalization, or worse. Using a quantitative method, the study was done to better understand the stress public school site administrators are under. Public school administrators in Silicon Valley were surveyed using the Administrator Stress Index, which is the …

Investigating The Roles Of Lipids In Staphylococcus Aureus Infection, Xi Chen

Dissertations

The Gram-positive bacterium Staphylococcus aureus is a major threat to public health and causes a multitude of infections, ranging from mild skin and soft infection, to more severe diseases including sepsis, osteomyelitis and infective endocarditis. As a successful pathogen, S. aureus employs various mechanisms to invade host tissues, evade immune responses, and survive in the host environment. One critical adaptive trait of S. aureus that promotes virulence and survival is the ability to maintain membrane homeostasis via flexible modifications to its lipid composition in response to the surrounding lipid environment. Phospholipids are the major component of the bacterial membrane and …

Reading Ethics: Modernism, Narrative, Violence, Katie Dyson

Dissertations

Reading Ethics hinges on the relationship between its two central terms, tracing how modernist narrative innovations reimagined reading as an ethical practice. To ask how we read is to return to a core question for the discipline. Building on recent reevaluations of reading methodologies by Rita Felski, Sharon Marcus and Stephen Best, and other scholars, I argue that modernist narrative forms foreground the ethical dynamics between text, reader, and world, asking readers to rethink how we understand the world even as they work to build new ones. Focusing on British and American modernist and meta-modernist fiction from writers such as …

Il-27 Signaling In The Maintenance Of Intestinal Barrier Following Ethanol Intoxication And Burn Injury, Marisa Luck

Dissertations

Roughly half of burn patients that are hospitalized in the United States each year have detectable blood alcohol levels. Alcohol intoxication at the time of burn injury leads to worse outcomes, including longer hospital stays, increased rates of infection, and death. One of the severe consequences of intoxication and burn injury is the disruption of the gastrointestinal (GI) tract, which houses the largest reservoir of bacteria in the human body. Leakiness of the gut barrier can contribute to inflammation, infection, or sepsis from gut-derived microbes. Interleukin-27 (IL-27) is a cytokine that has shown some beneficial effects in other models of …

Comparative Studies On Biochemical And Pharmacological Profiles Of Unfractionated Heparins & Their Depolymerized Derivatives From Bovine, Ovine And Porcine Origins, Ahmed Kouta

Dissertations

Heparin and heparin related drugs have remained the anticoagulant of choice for medical and surgical indications. These drugs are comprised of poly-component sulfated chains of varying length and biophysical structure with direct and indirect pharmacological effects. Heparins produce their therapeutic effects by multiple mechanisms involving both the cellular and humoral targets. These drugs represent natural products which are isolated from mammalian tissue rich in mast cells. Currently used heparin and LMWHs are obtained from porcine mucosal tissue. Other animal sources including bovine and ovine tissues also provide additional sources for the manufacturing of heparins. While there may be microchemical and …

F Plasmids In Escherichia Coli Decrease Permissivity To Coliphage, Cesar Eber Montelongo Hernandez

Dissertations

The urinary tract contains a community of bacteria called the urinary microbiota (urobiota) thatmay be relevant to health; the genomic component of the urobiota is the urinary microbiome (urobiome). Urinary bacteria have been associated with both asymptomatic states and disease conditions, such as urinary tract infection (UTI), overactive bladder (OAB), and urge urinary incontinence (UUI). Some bacteria, such as E. coli, are considered urinary pathogens (uropathogens) but also can be commensals. Bacteriophage (phage) are ubiquitous in nature and likely shape bacterial populations in every niche; thus, phage may be one factor that modulates the urobiota. Phages have a specific host …

Relationships Among Nursing Presence, Openness, And Fatigue In Acute Care Nurses, Barbara Therese Pudelek

Dissertations

Nursing presence was first identified when Florence Nightingale established a physical nursing presence or "being" and providing compassionate care or "doing" in the military hospitals during the Crimean War (Watson, 1998; Boeck, 2014; Dossey, 2000). Nursing presence has been a central focus in nursing throughout the past several decades (Turpin, 2014) and has been positively linked to the development of nurse-patient relationships. Nursing presence has been hypothesized to transpire when a joint relationship develops between the patient and the nurse. The patient allows the nurse into a relationship in which the nurse recognizes the patient as a unique being and …

Identification Of New Pathways For Co Oxidation On Rh(111) & Spatial And Structural Control Of O-Induced Reconstruction Of Ag(111), Marie Turano

Dissertations

Understanding the fundamentals of oxygen surface structures under a variety of conditions is pivotal to determining reactivity of heterogeneous catalysis. Exposure of catalytically active metal surfaces to high oxygen coverages results in a myriad of surface structures. A further complication is the formation of subsurface oxygen (Osub) or oxygen present in the near subsurface region of the metal. It is known to form in transition metals yet the absorption of oxygen and resultant formation of Osub is not equivalent across all catalytically relevant metals. As a result, it is difficult to predict the stability and efficacy of the formation of …

Clarifying Coaching: A Mixed Methods Analysis Of A Math Content-Focused Model And Its Impact On Teachers' Practice, Content Knowledge, And Dispositions, Lauren A. Solarski

Dissertations

Coaching is increasingly becoming required or recommended as a form of teacher professional development, but the education field has only begun to define the practice and understand its features, especially in regard to its potential to improve math teaching in early childhood contexts. Using mixed methods and a Whole Teacher Approach theoretical framework, this study examined a math content-focused coaching model and its impact on teachers' math content knowledge, teaching practice, and dispositions including attitudes, beliefs, and confidence. Participants included 141 lead and assistant teachers and 5 coaches working in 27 Head Start centers in Chicago. Teachers at centers randomly …