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Optics Studies For Multipass Energy Recovery At Cebaf: Er@Cebaf, Isurumali Neththikumara

Physics Theses & Dissertations

Energy recovery linacs (ERLs), focus on recycling the kinetic energy of electron beam for the purpose of accelerating a newly injected beam within the same accelerating structure. The rising developments in the super conducting radio frequency technology, ERL technology has achieved several noteworthy milestones over the past few decades. In year 2003, Jefferson Lab has successfully demonstrated a single pass energy recovery at the CEBAF accelerator. Furthermore, they conducted successful experiments with IR-FEL demo and upgrades, as well as the UV FEL driver. This multi-pass, multi-GeV range energy recovery demonstration proposed to be carried out at CEBAF accelerator at Jefferson …

Faster, Cheaper, And Better Cfd: A Case For Machine Learning To Augment Reynolds-Averaged Navier-Stokes, John Peter Romano Ii

Mechanical & Aerospace Engineering Theses & Dissertations

In recent years, the field of machine learning (ML) has made significant advances, particularly through applying deep learning (DL) algorithms and artificial intelligence (AI). The literature shows several ways that ML may enhance the power of computational fluid dynamics (CFD) to improve its solution accuracy, reduce the needed computational resources and reduce overall simulation cost. ML techniques have also expanded the understanding of underlying flow physics and improved data capture from experimental fluid dynamics.

This dissertation presents an in-depth literature review and discusses ways the field of fluid dynamics has leveraged ML modeling to date. The author selects and describes …

Studies Of Flowfields And Dynamic Stability Characteristics Of A Quadrotor, Engin Baris

Mechanical & Aerospace Engineering Theses & Dissertations

Electric multirotor air vehicles have become a pervasive technology and research topic in industry, academia, and daily life, and small quadrotors are one of the most preferred designs in the multirotor marketplace. However, the configuration of the quadrotors makes aerodynamic interaction effects one of the key factors of the vehicle performance in both hover and non-axial forward flight conditions.

In the present work, aerodynamic characteristics of the cross-configured small quadrotor in hover, edgewise, and maneuvering flight modes were investigated in detail by performing static and dynamic wind tunnel tests at various RPM levels, wind speeds, pitch and yaw angles, and …

Factors Moderating The Association Between Social Network “Drinking Buddies” And Personal Drinking, Karolina Kazlauskaite

Psychology Theses & Dissertations

Peer relationships have been implicated as a salient factor on individual drinking outcomes. One specific subset of peers in one’s social network, identified as drinking buddies, have been associated with an elevated risk for harmful drinking in college students—beyond drinking peers in one’s network alone. Despite their salience on individual alcohol outcomes, little is known regarding what makes drinking buddies more or less influential. While moderators of peer influence have been examined, prior research on peer influence predominantly focuses on adolescent populations, presenting gaps in the literature regarding moderators of college student drinking buddies specifically. As such, the current study …

Nightmares And Self-Injury Among High-Risk Adolescents: Examining The Role Of Emotion Regulation, Kinjal K. Patel

Psychology Theses & Dissertations

Self-injurious thoughts and behaviors (SITBs) are a public health concern among youth. SITB rates rise drastically during adolescence -- a critical and sensitive developmental period characterized by dramatic changes in biological and social systems. Prior research has identified distal risk factors which tell us who is at risk for SITBs. Emerging research suggests proximal risk factors may be useful to identify when an individual may be at risk for SITBs. One promising proximal risk factor for SITBs is sleep problems. Although the relation between sleep problems and SITBs has been widely documented, little is known about the short-term, proximal links …

Public School Superintendents In Virginia: Innovating In The Educational Context, Daniel Firing Keever

Educational Foundations & Leadership Theses & Dissertations

This research study, using institutional theory as a framework, examines the role of superintendents in promoting and impacting innovation in Virginia's public schools. The study engaged fourteen current Virginia superintendents in semi-structured interviews, exploring their perspectives on fostering an innovative culture within their school districts. Three primary themes emerged from the research: defining innovation, the role of superintendents in leading innovation, and the challenges and barriers to innovation. Generally, the findings highlight that innovation fundamentally involves thinking differently, finding creative solutions, and bringing about meaningful organizational improvements. The study emphasizes that innovation is essential for adapting to the evolving needs …

Effects Of A Climbing-Specific Training Program On Upper-Body Power In Novice Climbers Compared To Advanced Climbers, Dallas E. Wood

Human Movement Sciences & Special Education Theses & Dissertations

Muscular strength and muscular endurance are integral physical components of rock climbing. The hypothesis of this study was that a climbing-specific training program would improve physical fitness specific to climbing and improve performance on a relevant indoor rock-climbing test in novice climbers.

Twenty-one novice recreational climbers were matched for sex and climbing performance and randomly assigned. The experimental (EXP, n = 11) group was provided a climbing-specific, six-week training program. The control (CON, n = 10) group continued training as usual. Pre- and post-tests involved anthropometric tests, the ape-index test (arm span to height ratio), a weighted pull-up test, a …

Relationship Between Learning Communities And Campus Residency On Sense Of Belonging Among First Year Undergraduates, Lanah Kathryn Stafford

Educational Foundations & Leadership Theses & Dissertations

In higher education, sense of belonging has been linked to improved outcomes such as retention and academic achievement (e,g., Pittman & Richmond, 2007). Previous research has also identified participation in learning communities and campus residency as interventions which improve sense of belonging for students in this context (e.g., Solanki et al., 2019; Soria & Roberts, 2021). However, little research has been conducted to empirically study sense of belonging as a multidimensional construct, and no research has investigated interactions between on-campus residency and learning community participation on its development.

Data were collected from 1,072 first-year students on the Sense of Belonging …

Dealing With The Effects Of Covid-19 Job Demands On Public Sector Employees’ Work Engagement And Job Burnout: The Role Of Public Service Motivation, Servant Leadership, And Mission Valence, Phillip Joseph Dillulio

Psychology Theses & Dissertations

The global recession stemming from the COVID-19 pandemic had a significant impact on the public sector of the U.S. economy. Specifically, reduced tax revenues from a dramatic decline in economic activity and increased demand for public services resulted in new and increased job demands for public sector employees (Eggers et al., 2020). However, limited research has examined the effects of COVID-19-related demands on job burnout and work engagement among public sector employees, and the role of personal, social, and organizational resources to protect their well-being (Demerouti & Bakker, 2023). The current study addressed this gap by employing the Job Demands …

The Effects Of Lifting With Intent On Hip And Knee Moments During Back Squats, Kyle A. Parrish

Human Movement Sciences & Special Education Theses & Dissertations

Back squatting is a widely used movement in the strength and conditioning community. Within the last few years, velocity-dependent training and its application of tracking intensity have increased in popularity. Biomechanics research has frequently examined force generation, joint loading, and muscle contributions of back squats with different bar placement, stance width, and increasing barbell loads. However, no information exists regarding whether lifting with intent increases velocity and how increased velocity is biomechanically achieved. This study aimed to examine how lifting with intent affects bar velocity and how joint moment alterations could contribute to these potential changes in velocity. Fifteen males …

The Effects Of Self-Regulated Learning On Community College Students Metacognition, Motivation And Achievement In Geoscience Courses, Melani A. Loney

Educational Foundations & Leadership Theses & Dissertations

This study investigated the impact of training in self-regulated learning on community college, geoscience students’ achievement, metacognition, time management, and science motivation scales. The study also investigated the impact of SRL training on these outcomes as a function of gender and ethnicity. During the Fall of 2022, 70 community college geoscience students from 9 different classes participated in the study. The classes were bifurcated with one half of the students in each class randomly assigned to the SRL treatment and the other half to the control condition. Each week, for 10 weeks during the semester, students in the treatment group …

Effect Of Acute Caffeine Ingestion On On-Field Performance In Division 1 Female Field Hockey Players, Nicole Danielle Fredricks

Human Movement Sciences & Special Education Theses & Dissertations

This study aimed to determine the effects of acute caffeine ingestion on on-field performance in collegiate female field hockey players. A placebo-controlled, double-blind, randomized, crossover experimental design was utilized. The participants (N=10) were female division 1 field hockey players (age: 20.0 ± 1.6 years). They competed in two 60-minute, off-season scrimmages separated by two weeks. They were randomly assigned to ingest the caffeine, 3 mg/kg of body weight, or placebo treatment 60 minutes before each scrimmage. They wore a PLAYERTEK (Catapult, Australia) global positioning system (GPS) device to track their total distance, sprint distances, power plays, and zone three and …

Modified Vaccine Vectors To Understand Adjuvant Functions Of Listeria During Chronic Schistosomiasis, Stephanie K. Norwood

Biological Sciences Theses & Dissertations

Vaccination is one of the most effective strategies employed to prevent infectious diseases. Successful vaccination is dependent upon the induction of a specific, robust, and prolonged immune response. One of the major challenges faced by vaccine development is vaccine failure due to host-related factors that can modulate the immune system, which leads to non-responsiveness to vaccinations. The generation of new vaccine strategies is imperative to combat these effects. Live bacterial vectors are one approach used as they can elicit humoral immunity, cellular immunity, or both. Listeria monocytogenes is a Gram positive, intracellular pathogen that is an effective bacterial vaccine vector …

Fabrication Of Smooth Sac305 Thin Films Via Magnetron Sputtering And Evaluations Of Microstructure, Creep, And Electrical Resistivity, Manish Ojha

Mechanical & Aerospace Engineering Theses & Dissertations

SAC305 (96.5%Sn-3%Ag-0.5%Cu) is the leading alternative to the traditional Sn-Pb solder eutectic alloy owing to its low melting temperature, better compatibility with other components, and excellent mechanical/structural properties. In the realm of modern electronics, where devices are increasingly miniaturized, the design and characterization of thin solder joints become paramount. The orientation and size of the grains within the solder can influence its ability to withstand mechanical stresses. However, research on SAC thin films remains sparse, and these films present unique challenges and characteristics compared to their bulk counterparts, influenced by factors like interfaces, stresses, thickness, microstructure, and the nature of …

A Reflection Of Experiences Of Adults With Type 1 Diabetes In Integrated Physical Education Classes, Kalleigh West

Human Movement Sciences & Special Education Theses & Dissertations

The purpose of this study was to gain an understanding of the experiences of type 1 diabetics in integrated physical education classes. In this study, we interviewed young type 1 diabetic adults and asked them to reflect on their school-based physical education experiences. An interpretative phenomenological analysis (IPA) approach was adopted to guide data collection, analysis, and interpretation for this retrospective study. Eight participants (ages 19 to 32) were enrolled in this study, and semi-structured interviews focused on their physical education experiences acted as the primary data. Transcribed interview data were analyzed using an IPA approach. Three interrelated themes emerged …

Assessing The Impact Of Substituting Interaction Types: An Empirical Study Of The Interaction Equivalency Theory, Scott Alan Hauert

STEMPS Theses & Dissertations

Multimedia technologies allow instructional designers to transform interpersonal interactions into interactions between learners and content. These learner–content interactions are more scalable in online, asynchronous distance education (DE) than interactions between learners and the instructor or interactions among learners. Additionally, learners sometimes prefer interactions with course content over interactions with their peers and instructor. Studies on learner–learner and learner–instructor interaction provide insight into the preferences and perceived effects of interaction types. However, the literature has not directly discussed the impact on performance resulting from substituting learner–content interaction for learner–learner interaction. This study examined the impact of substituting interaction types on perception …

Using Reciprocal Teaching Strategies To Improve Reading Comprehension For English As A Second Language Students With Learning Disabilities, Hana M. Almohamadi

Theses and Dissertations in Early Childhood Education

Students who have problems comprehending textual material tend to experience failing grades, peer rejection, and even social isolation. Furthermore, students with poor reading comprehension demonstrate poor academic performance in all subjects, not due to difficulty in learning specific subject content (i.e., math, history, etc.), but rather their inability to comprehend reading passages related to that subject knowledge. Reciprocal teaching (RT) is an effective tool for teaching children with Learning Disabilities (LD) to improve their reading comprehension abilities. These multiple cognitive strategies can meet the needs of many students in terms of more deliberate, directed, and self-regulated learning through students’ interaction …

Seeking Sabbath In Annie Dillard's Holy The Firm, Olivia Grace Dycus

English Theses & Dissertations

Annie Dillard’s third-ever publication, Holy the Firm, asks why an omniscient God allows natural evil to occur. In this deeply poetic and mystical series of essays, Dillard explores the relationship between time, artistry, and God in the face of devastating chaos. This thesis argues that Dillard’s emphasis on the importance of time reflects a Jewish notion of Sabbath as defined by Jewish theologian Abraham Heschel. Dillard offers time and creation as medium through which to commune with God just as Heschel does in his book, The Sabbath: Its Meaning for Modern Man. Heschel defines Sabbath as the coming …

Framing Automation Trust: How Initial Information About Automated Driving Systems Influences Swift Trust In Automation And Trust Repair For Human Automation Collaboration, Scott Anthony Mishler

Psychology Theses & Dissertations

The study examines how trust in automation is influenced by initial framing of information before interaction and how later active calibration methods can further influence trust repair or dampening after an automation error in a three-experiment study. As more human drivers begin to use automated driving systems (ADSs) for the first time, their initial understanding of the system can influence their trust leading to a miscalibration of trust. Prior studies have investigated how trust develops through interactions with an automated system, but few have looked at integrating swift trust and framing to calibrate trust before interaction and investigate further active …

Framework For Implementing Advanced Radar Plotting Aid Capability For Small Maritime Vessels, Jason Stark Harris

Electrical & Computer Engineering Theses & Dissertations

Every year in the United States many people are killed or injured when maritime vessels collide with other vessels or fixed objects. According to the United States Coast Guard, the top contributing factors to these collisions are operator inattention, operator inexperience and an improper lookout. Larger commercial vessels are required to have RADAR systems which support Automatic RADAR Plotting Aid (ARPA) which can automatically detect collisions and alert an operator to change course. These systems can be very expensive which put them out of reach of the average recreational boater. It is however possible to implement a low cost ARPA …

Biomechanical Adaptations While Performing Bilateral Drop Landings With A Unilateral Ankle Tape Application, Eric Daniel Jenkins

Rehabilitation Sciences Theses & Dissertations

Ankle sprains are the most common injury in sport and exercise performance, which makes the utilization of ankle taping a common procedure to both prevent potential sprain, as well as protect against reinjury. However, unilateral ankle taping may have unintended consequences on the mechanics of the ankle and other joints of both legs. The aim of this dissertation was to determine the effects of ankle taping on lower body kinetics and kinematics, stiffness, and coordination during a bilateral landing task.

Twelve female participants completed a total of 90 drop landings across two visits, randomized from landing platforms of 30, 45, …

Do Microplastics, Vibrio Bacteria, And Warming Water Temperatures Cause Disease In The Northern Star Coral, Astrangia Poculata?, Heather Leigh Sheffey

OES Theses and Dissertations

As marine plastic pollution increases, it becomes imperative to study the effects of microplastics on marine fauna. Marine plastic debris is a vector for disease to marine invertebrates (Lamb et al., 2018; Rotjan et al., 2019). In this context, studies have shown Astrangia poculata will consume microplastics as they do their normal food (Allen et al, 2017; Rotjan et al., 2019). Further, with temperatures increasing worldwide, there is a concern the virulence of disease-causing bacteria will increase (Vezzulli et al., 2015). In a series of manipulative laboratory experiments, this study quantified changes in respiration rates and visual health of Astrangia …

The Prevalence Of Burnout In Saudi Arabia Dental Hygienists, Nouf Hamad Aldayel

Dental Hygiene Theses & Dissertations

Purpose: The purpose of this pilot study was to assess the prevalence of burnout in Saudi Arabian dental hygienists and identify risk factors associated with burnout. Methods: A descriptive survey design using the Copenhagen Burnout Inventory (CBI) assessed burnout among a convenience sample of n=123 Saudi dental hygienists. The survey was disseminated electronically to 1,000 Saudi Arabian dental hygienists. The CBI measures three subscales: personal, work-related, and client/patient-related burnout on a five-point Likert-type scale. The survey also included six demographic questions, two Likert-type, one “yes/no,” and one openended question, related to burnout. Descriptive statistics, one-way between subject’s ANOVA, independent samples …

Genotyping Of The Tick-Borne Pathogen Rickettsia Parkeri, Rebecca Lynn Ferrara

Biological Sciences Theses & Dissertations

Rickettsia parkeri is a pathogen of interest to public health as the causative agent of R. parkeri rickettsiosis. Amblyomma maculatum, a vector of R. parkeri, is currently undergoing a range expansion out of its historic range along the Gulf Coast of the United States, including northwards into Southeastern Virginia. Within this expansion front, the prevalence of R. parkeri within A. maculatum differs from the historic range; the historic range has a prevalence of 7.9- 38.6% while the expansion front in SE VA has a prevalence of 41.8-55.7%. While the reason for this disparity has not been established, one …

A New Method To Determine The Posterior Distribution Of Coefficient Alpha, John Mart V. Delosreyes

Psychology Theses & Dissertations

There is a focus within the behavioral/social sciences on non-physical, psychological constructs (i.e., constructs). These constructs are indirectly measured using measurement instruments that consist of questions that capture the manifestations of these constructs. The indirect nature of measuring constructs results in a need of ensuring that measurement instruments are reliable. The most popular statistic used to estimate reliability is coefficient alpha as it is easy to compute and has properties that make it desirable to use. Coefficient alpha’s popularity has resulted in a wide breadth of research into its qualities. Notably, research about coefficient alpha’s distribution has led to developments …

Community College Academic Advisors’ Considerations Of Ethical Issues Related To The Use Of Learning Analytics, Anna Elizabeth Jones

Educational Foundations & Leadership Theses & Dissertations

Learning analytics is an emerging trend in American community colleges brought about by technological advancements, institutional accountability, and external pressure on institutions to substantiate and improve learning. Learning analytics can potentially improve student engagement, retention, and success but also possess inherent ethical and legal challenges like student privacy and confidentiality violations and users’ bias and discrimination. Researchers know little about the ethical considerations of advisors who serve diverse student populations enrolled at community colleges, and there is a need to better understand various users’ experiences to mitigate poor ethical use and to protect multiple stakeholders. This multiple case study employed …

The Impact Of Mandatory Substance Abuse Counselor Reporting Requirements On Child Maltreatment Reporting Outcomes, Bilgé Özgé Yilmaz

Psychology Theses & Dissertations

The present study sought to examine how state-level mandatory reporting policies are associated with child maltreatment reporting through analysis of the National Data Archive on Child Abuse and Neglect (NDACAN, 2021). This study aimed: 1) to examine how the implementation of substance abuse counselor reporting requirements is associated with the reporting process, including the disposition of reports and the presence of substance abuse; and 2) to examine differences in the above outcomes based on associations between non-specific reporting requirements and specific requirements that mention substance use counselors. A quasi-experimental approach with repeated cross-sectional data was utilized, as it is a …

Dental Hygiene Students Reported Physiological Symptoms Associated With Wearing An N95 Respirator Mask, Peyton Shea Butler

Dental Hygiene Theses & Dissertations

Purpose: Physiological symptoms and comfort levels while wearing an N95 respiratory mask has not been examined with dental hygienists. The purpose of this study was to investigate dental hygiene students reported physiological symptoms and comfort perception while wearing an N95 respirator mask during patient care appointments. Methods: After IRB approval (IRB #1987754-2), a 16-item questionnaire was distributed through email to a convenience sample of 65 dental hygiene students. Questions assessed respiratory, dermatologic, cardiac, mask mouth and general physiological symptoms, as well as comfort levels. Additionally, participants were asked to respond to demographic questions and one open ended question inquiring about …

The Implications Of Dual Enrollment Participation On Black/African American Students’ Success, Yousef Abraham

Educational Foundations & Leadership Theses & Dissertations

This dissertation presents a thorough investigation into the impact of dual enrollment programs on postsecondary achievement among students who identify as Black/African American. Dual enrollment initiatives have gained significant attention in recent years as a promising approach to enhance students' readiness for higher education and facilitate smoother transitions to college. This research seeks to provide valuable insights into the effectiveness and implications of such programs, shedding light on their potential to improve postsecondary outcomes for Black/African American students. This study also acknowledges inherent limitations and delves into potential practical applications of the research outcomes, exploring how educators and policymakers can …

Age, Lower Extremity Muscle Strength, And Running Biomechanics In Healthy Female Recreational Runners, Heather Mcconchie Hamilton

Rehabilitation Sciences Theses & Dissertations

Middle-age and older runners demonstrate differences in running biomechanics compared to younger runners. Females and males demonstrate differences in running biomechanics, and females experience additional hormonal changes with age due to menopause. Despite the biomechanical and physiological differences between females and males, little research has investigated the effect of age specifically in female runners. The overall purpose of this research was to determine the relationships among age, lower extremity muscle strength, and running biomechanics in healthy female recreational runners. Healthy female recreational runners aged 25 – 65 years were recruited. Participants ran on an instrumented treadmill at a training pace …