Digital Commons Network^™

Isolation, Purification, Crystallization And Preliminary X-Ray Data Analysis Of The B Family Dna Polymerase From Thermococcus Thioreducens, Emika Miyamoto

Theses

Family B DNA polymerases are the core polymerizing enzymes that carry out the essential process of DNA replication in many Archaeal organisms. Archaea depend on the unique properties of their DNA polymerases to faithfully replicate DNA within extreme environments. Variation in the catalytic properties of DNA polymerases from different organisms can be elucidated through detailed structural analysis by means of macromolecular X-ray crystallography. Crystallization is the crucial and bottleneck step in the process of determining the protein’s three-dimensional structure by X-ray diffraction—essentially no crystal, no structure. This study optimizes the isolation and purification of recombinant DNA polymerase B from Thermococcus …

Data Remanence Vulnerabilities In Embedded Sram At Low Temperature, Farzana Hoque

Theses

Static Random Access Memory (SRAM) memory is prevalent as cache memory in computing platforms and embedded systems. SRAM frequently stores essential information such as cryptographic keys, passwords, and other confidential data. Consequently, a data remanence-based attack on SRAM can result in significant damage. When power is removed, SRAM gradually loses data rather than immediately, especially at lower temperatures. This phenomenon, known as data remanence, poses a significant security risk, as it can be exploited through cold boot attacks targeting encryption keys and other sensitive data. Understanding temperature-induced vulnerabilities in embedded SRAM is crucial for enhancing the security and reliability of …

The Effects Of Reducing Carbon Content In The Processing Of Superalloy Inconel 718, Glenn "Joey" Scott

Theses

The properties of Inconel 718 (IN718) are dependent on the elemental composition and microstructure. Applications using IN718 include rocket and jet engine parts. These parts are often complex and difficult to machine, making IN718 ideal for additive manufacturing processes such as laser-powder bed fusion (L-PBF). The various phases that form in IN718 rely on the niobium (Nb) content including the carbides. The precipitates also include Nb in the strengthening phases of gamma prime and gamma double prime. Overaging of gamma double prime transforms the metastable phase into the stable delta phase, which also controls grain size. This study evaluates the …

Aerodynamic Losses Of Additively Manufactured Blades In Transonic Conditions With Different Surface Treatments, Chase Allen Herrin

Theses

Additive manufacturing (AM) allows the production of high strength and high temperature alloys to increase the operational temperature of turbines and other engine components. AM inherently has high surface texturing, inclusive of waviness due to the layering effect in the laser powder bed fusion (L-PBF) process, and roughness due to surface defects such as partially sintered powder, deep notches, and micro-cracks. This thesis investigates how different surface treatments affect the surface static pressure variations and wake aerodynamic loss characteristics for each blade. A supersonic transonic blow down wind tunnel with a linear cascade test section is used to acquire this …

Assessing The Mesoscale Variability And Rapid Tornadogenesis In The High-Shear/Low-Cape, Surging Qlcs In Northern Alabama On 01 April 2023, Joshua L. Huggins

Theses

On 01 April 2023, a severe QLCS impacted Northern Alabama during the PERiLS field campaign under High-Shear/Low-CAPE (HSLC) conditions, with CAPE below 1000 J/kg and 0-6 km wind shear exceeding 25 m/s. This study examines the mesoscale variability and tornadogenesis within the QLCS. Ceilometer and Radar Wind Profiler data indicated lowering cloud bases and shifts in the boundary layer winds. Surface analyses revealed a cold pool strength of -9◦C at the tornadogenesis location, with significant spatial variability. Storm Relative Helicity values decreased from nearly 900 to 350 m2/s2 by 0800 UTC. A lightning jump around 0756 UTC coincided with a …

Analyzing Qualitative Data Collection Methods In Systems Engineering, Rosemary Cortelli

Theses

The goal of this thesis is to expand the research on human decision-making in engineering systems by exploring qualitative data collection methods utilized in systems engineering. Analyses are performed to identify differences in qualitative data collection method use across the life cycle and throughout technical processes. 495 sources were evaluated for qualitative data collection method use identified from systems engineering literature and analyzed using statistical analyses. Of these, 93 sources utilized data collection methods of documentary analysis, narratives, focus groups, observations, and interviews which traced across every life cycle phase and most technical processes. The findings show there are significant …

Spectropolarimetric Properties Of Vortex Retarders, Ella Elizabeth James

Theses

Vortex retarders are unique optical elements that create a uniform electric field phase retardance, but the traditional fast axis varies azimuthally over the area of the optic. This affects the radial and azimuthal polarization components of the incoming beam. The vortex retarders discussed here generate TEM10 and TEM20 Laguerre-Gaussian beams. While several varieties of these TEM10 and TEM20 vortex retarders exist, designed to function at specific wavelengths–and a few studies have reported their use at those wavelengths–almost no data exists detailing their polarimetric properties outside those wavelengths. Using a Mueller matrix spectropolarimeter with dual-rotating retarders, the polarization properties of four …

Physiological Effects Of Facial Expressions During Cognitive And Social Stress, Emily X. Sorrells

Theses

This study explored the dynamics of facial expressions during stress. This 2 X 2 (Facial Expression by Task) mixed design evaluated how smiling and grimacing affected physiological and self-report measures of cognitive and social stress. The study implemented continuous monitoring of electrodermal activity (EDA). Facial expression was manipulated between-subjects as a genuine smile or grimace using chopsticks in the mouth. Task was manipulated as a counterbalanced within-subjects as a cognitive stressor using the Paced Auditory Serial Addition Task (PASAT) and a social stressor using Cyberball. Time was analyzed as repeated measures of change from baseline of EDA. Participants provided ratings …

Characterization Of Thin-Walled W-24re Structures Fabricated Using Laser-Powder Bed Fusion, Madelyne Rushing

Theses

W-24Re is a refractory alloy used in high temperature applications due to its high melting point, recrystallization temperature, and tensile strength. Due to the high melting point, fabrication is more commonly achieved through powder metallurgy processing, which relies on diffusion. As the material is available as a powder, it is a good candidate for laser-powder bed fusion (L-PBF) processing. This study focuses on characterization of L-PBF of W-24Re thin-walled structures to determine the feasibility and primary failure mechanisms under tension compared to that of bulk W-24Re. A laser parameter set was developed, and samples were provided by Quadrus Corporation for …

Functionalization Of Silicon Oxide-Like Surfaces Using A Fluorosilane, Elizabeth Cantrell

Theses

The project goal was to functionalize silicon oxide-like surfaces to become hydrophobic using 1H, 1H, 2H, 2H perfluorooctyltrimethoxysilane CF3(CF2)7(CH2)2Si(OCH3)3 (PTFMS). The objective was to find the reaction conditions that will make glass and silicon (Si) wafers hydrophobic. The parameters studied were time, solution concentration, and temperature. Contact angle goniometry was used to measure the hydrophobicity of the samples. The threshold reaction time on glass was 150 hours, and the threshold reaction time for Si wafers was 300 hours. A significant difference in hydrophobicity on glass surfaces exists after 300 hours when the concentration is lowered by a factor of 10. …

Development Of Tungsten Rhenium Hafnium Carbide Tooling For Friction Stir Welding Of Nickel Based Superalloys, Zachary H. Perrin

Theses

Development of advanced high strength and high temperature tool materials are required for solid-state friction stir welding (FSW) of nickel-based superalloys. FSW tooling must be able to survive at the temperatures experienced in the FSW weldment in conjunction with very high mechanical loading. Thus improving the durability of FSW tool materials is critical to producing acceptable welds and expanding FSW application areas. The refractory alloy Tungsten-Rhenium-Hafnium Carbide (W-25%Re-4%HfC) is able to operate at temperatures of over 1000 °C, while maintaining the ductility required for good. Building upon previous research that demonstrated the 4% Hafnium Carbide (HfC) additive’s ability to yield …

Generation Of True Random Numbers With A First Order Chaotic Circuit, Austin Davis

Theses

True randomness backed by first principles theory is surprisingly rare in physically implemented circuit for cybersecurity applications. This thesis provides an illustrative case of a chaotic one-dimensional map circuit with a design driven by a need for rudimentary theory concerned with the limits of its entropy production. Analysis, simulation, and hardware measurements are evaluated against statistical randomness tests issued by the National Institute of Standards and Technology. Interestingly, the results provided here highlight strong relationships between first principles theory of design and measured results when varying parameters. We observe matching characteristics between analytic, simulated and measured hardware results for NIST …

Who Holds The Keys?, Daniel C. Peterson

Interpreter: A Journal of Latter-day Saint Faith and Scholarship

While, for understandable reasons, Protestant Christendom tends to downplay the question, the more ancient Christian churches have historically placed considerable weight on what is often termed “apostolic succession.” The Catholic church, for instance, strongly affirms the “primacy of Peter” and the status of the Bishop of Rome, the Pope, as ancient Peter’s lineal successor. Curiously, perhaps, The Church of Jesus Christ of Latter-day Saints, although it was founded on the American frontier in the early nineteenth century, takes a view of the matter that crucially resembles the Catholic viewpoint more than it does a western Protestant one. But the Latter-day …

Container Port Selection In The Asean Region: Korean Shipping Companies’ Perspective, Inhyeok Yeo

Plymouth Business School Theses

Ports are crucial platforms that connect the sea and inland transportation to foster logistics and transfer of goods and information. Thus, selection of the most optimal ports is ever crucial for decision makers. However, the increasing globalisation and international trade add to the already competitive and saturated market for marine container cargo shipping. Consequently, it may be of best interest to shift focus and find niche market, such as trading to the Southeast Asia, to increase profitability. In near proximity to Southeast Asia, South Korean multinational corporations’ investment and interest in the Southeast Asian countries are significant. South Korea maintains …

Benchmarking Best-In-Class Corporate Governance Practices In Uk Sme (Small And Medium-Sized Enterprises) Charities: Accountability And Transparency., Rita Davies Ukachi-Lois

Plymouth Business School Theses

The study explores the implementation of corporate governance, accountability, and transparency (the Core Constructs) within UK SME charities to provide the most sort after answers to address the endless criticisms, demands for scrutiny, and requests for accountability and transparency to enhance their performance and credibility. This area of study is sparse on Small and Medium-sized charities, very little has been written on corporate governance, on occasions coupled with accountability or transparency but never with both. Nothing similar to this study has been done. The study seeks to investigate whether UK Small and Medium-sized charities implement effective corporate governance within their …

Luxury Value Perceptions In An Emerging Economy: A Comparative Analysis Of Luxury Products And Services In Thailand, Thanwarat Jaroenpanich

Plymouth Business School Theses

This research aims to clarify what values constitute the meaning of luxury and set luxury products and services apart from non-luxury ones based on the perceptions of consumers in Thailand. Underpinned by the theory of psychological ownership, it proposes that consumers’ sense of possession and emotional bond with target luxuries can take the place of material ownership in luxury consumption. This is the first study to integrate immaterial luxury services as a standalone business sector when examining luxury value perceptions. Rich qualitative data was gathered through in-depth semi-structured interviews conducted with 40 individuals who are regular consumers of luxury products …

Employee Engagement: Understanding The ‘Personal’ Dimension Of Engagement, Hannah Newbury

Plymouth Business School Theses

Kahn’s ‘personal engagement’ (PE) concept centres on the ways which ‘people employ and express themselves physically, cognitively, and emotionally during role performances’ (1990, p.694). However, engagement has been viewed through a predominantly positivistic, unitarist framework (Sambrook, 2021; Shuck, Kim & Fletcher, 2021) that has ‘bent’ engagement through its appropriation to managerialist agendas, and ‘stretched’ in its meaning away from being an individual state of mind (Truss et al., 2013). This study explores Kahn's (1990) original framing of engagement as a deeply personal experience, considering what PE is and how it is understood and experienced by individual employees. This considers engagement …

Exploring The Use Of Digital Technologies And Stakeholder Perspectives Of Online Harms And Harassment In The Higher Education Sector, Julie Swain

Plymouth Business School Theses

Julie Swain - Exploring the use of digital technologies and stakeholder perspectives of online harms and harassment in the Higher Education sectorThis research investigates the significant changes in the Higher Education (HE) sector over the past decade, driven by government policies, neo-liberal influences, and technological advancements. These changes have impacted accessibility, tuition fees, and living costs, shaping the HE landscape (Brown, 2011; Evitts, 2023). The study highlights the significant role of digital technologies in transforming communication and daily interactions, with the immediacy and pervasiveness of technology altering societal behaviours and expectations.Despite the widespread adoption of digital technologies, there remains a …

Challenges Facing Islamic Banks: Evidence From Iraq And Gcc Countries, Abdullah Hama

Plymouth Business School Theses

AbstractIslamic banking is a new system that has started operating several decades ago. Its principles emanate from the religion of Islam and it is different from conventional banking system. Due to its characteristics and novelty of the system, it faces many challenges wherever it operates in various degrees. While many studies have been conducted on the subject in general, there is insufficient research on Iraq. The objective of this research is to investigate challenges facing Islamic banks (IBs) in Iraq and GCC countries in terms of Shariah, Legal and regulation, institutional and operational aspects. For this purpose, Semi-structured interviews and …

Open Access And U. S. Federal Information Policy, Eric Harbeson

Copyright, Fair Use, Scholarly Communication, etc.

Federal agencies are directed, as a matter of United States Federal policy, to provide free, immediate public access to peer-reviewed scholarly publications that are produced with support from Federal research grant funding. Because copyright vests in the author of the work, agencies must have permission from the author in order to provide that access. A government-wide regulation, in place since 1976, constitutes one possible source for the needed permission. The “Federal Purpose License” provides that, as a condition of Federal funding, grant recipients issue the granting agency a non-exclusive license to use all works subject to copyright and either developed …

Triangulating The Likelihood Of Confusion: Linguistics And Consumer Surveys, Eric D. Derosia, Jesse Egbert, Thomas Lee

Faculty Publications

This Article highlights contributions that linguistic analysis can offer in the assessment of the likelihood of confusion in trademark infringement cases. Parties in such cases often engage an expert witness to conduct a survey that measures the likelihood of consumer confusion. We show how an expert linguist can provide important, nonintuitive dynamics of corroboration. We introduce “expert triangulation” as a conceptual framework to analyze whether, and to what extent, experts in linguistics and consumer surveys can corroborate one another. That is, having two different sources of empirical evidence which lead to similar conclusions should be a benefit to the courts, …

The Efects Of Cryptocurrency Wealth On Household Consumption And Investment, Darren Aiello, Scott R. Baker, Tetyana Balyuk, Marco Di Maggio, Mark Johnson, Jason Kotter

Faculty Publications

We use bank transaction data from millions of U.S. households to:

1. Characterize retail crypto investing
2. Examine the efect of crypto wealth on consumption and investment behavior
3. Zoom in on the efect of crypto wealth on housing spending
4. Document spillovers of crypto wealth to the local economy

Assembling Hyperpop: Genre Formation On Wikipedia, Eliot Bates, Sophie Delphis, Romulo Moraes, Julia Santoli

Publications and Research

In this article, we analyze how a music genre is reciprocally defined online, through the crowdsourced ‘facts’ of Wikipedia. What are the traditional implicit and explicit exclusionary practices in this sort of genre formation? And how can internet-specific sociabilities create new exclusionary practices in the process of defining music? By analyzing the edit history of Wikipedia’s ‘hyperpop’ page, we locate ongoing debates, controversies, and contestations that point to shaping forces around online genre formation. These potentially have a huge impact on how hyperpop is understood both inside and outside of the music community. In locating the most active editors of …

Sociodemographic Correlates Of Low Health Literacy Skills Among Cancer Survivors: National Findings From Brfss 2016 And Implications For Precision Survivorship Care, Qi Chen, John Moore, Lailea Noel, Kirk Von Sternberg, Barbara Jones

Publications and Research

Purpose: This study aimed to explore associations of sociodemographic factors with difficulties in three health literacy (HL) skills and the severity of low HL skills.

Design: Cross-sectional secondary data analysis. Subjects: Data came from 17,834 adults who responded to the HL module with a response rate of 47% in the 2016 Behavioral Risk Factor Surveillance System.

Measures: Independent variables included sex, age, race/ethnicity, education, employment and income. Dependent variables are three HL skills: obtaining, understanding oral, and understanding written health information.

Analysis: We conducted weighted Chi-square tests and multinominal logistic regressions.

Results: Cancer survivors younger than 65 (aged 18-39: AOR=4.46, …

Effective Size Of A Parity-Time-Symmetric Dimer, Li Ge

Publications and Research

Parity-time (PT)-symmetric dimers were introduced to highlight the unusual properties of non-Hermitian systems that are invariant after a combined parity and time reversal operation. They are also the building blocks of a variety of symmetry and topologically protected structures, especially on integrated photonic platforms. As the name suggests, it consists of two coupled oscillators, which can be optical, mechanical, electronic, and so on in nature. In this article, we show that its effective size, defined by the number of lattice sites inversely proportional to the lattice momentum, is surprisingly three instead of two from the perspective of energy quantization. More …

Legacy Of Labour: The Impact Of Parental Occupations On Children’S Careers Choices And Income Inequality, Swapnil Landge

Publications and Research

This paper investigates how intergenerational occupational mobility and self-selection into occupations are influenced by the occupations of parents. The results demonstrate that children who pursue their parents’ occupations, particularly those in the lowest earnings percentiles, are more negatively self-selected compared to those whose parents are in the highest earning deciles. In particular, 65% of the children who pursue their parents’ occupation in Decile 1, 49% in Decile 2, 32% in Decile 3 and 26% in Decile 4 would have achieved higher productivity and earned higher earnings in high-income occupations (specifically in Decile 10 occupations). In contrast, children from high-income backgrounds …

Drosophila Parasitoids Go To Space: Unexpected Effects Of Spaceflight On Hosts And Their Parasitoids, Jennifer Chou, Johnny R. Ramroop, Amanda M. Saravia-Butler, Brian Wey, Matthew P. Lera, Medaya L. Torres, Mary Ellen Heavner, Janani Iyer, Siddhita D. Mhatre, Sharmila Bhattacharya, Shubha Govind

Publications and Research

While fruit flies (Drosophila melanogaster) and humans exhibit immune system dysfunction in space, studies examining their immune systems’ interactions with natural parasites in space are lacking. Drosophila parasitoid wasps modify blood cell function to suppress host immunity. In this study, naive and parasitized ground and space flies from a tumor-free control and a blood tumor-bearing mutant strain were examined. Inflammation-related genes were activated in space in both fly strains. Whereas control flies did not develop tumors, tumor burden increased in the space-returned tumor-bearing mutants. Surprisingly, control flies were more sensitive to spaceflight than mutant flies; many of their …

Photo-Induced Charge State Dynamics Of The Neutral And Negatively Charged Silicon Vacancy Centers In Room-Temperature Diamond, G. Garcia-Arellano, G. I. López-Morales, N. B. Manson, J. Flick, A. A. Wood, C. A. Meriles

Publications and Research

The silicon vacancy (SiV) center in diamond is drawing much attention due to its optical and spin properties, attractive for quantum information processing and sensing. Comparatively little is known, however, about the dynamics governing SiV charge state interconversion mainly due to challenges associated with generating, stabilizing, and characterizing all possible charge states, particularly at room temperature. Here, multi-color confocal microscopy and density functional theory are used to examine photo-induced SiV recombination — from neutral, to single-, to double-negatively charged — over a broad spectral window in chemical-vapor-deposition (CVD) diamond under ambient conditions. For the SiV⁰ to SiV^‒ transition, …

Prosocial Behavior And Workplace Safety: Analysis Of The Role Of Emotional Intelligence And Perceived Organizational Support In Two Uk And Us Samples, Giacomo Moserle, Giulia Foti, Georgia Libera Finstad, Andrea Bazzoli, Matteo Curcuruto, Jim Morgan

Publications and Research

Prosocial safety behavior (PSB) is a critical element of workforce participation in the promotion of safety in the workplace. This study aims to examine the influence of various antecedents on PSB. Based on an analysis of the existing literature on prosocial behaviors, we investigate whether emotional intelligence (EI) and perceived organizational support (POS) significantly influence PSB. Furthermore, we analyze the mediating role of employees’ intrinsic motivation (IM) and affective commitment (AC) in these relationships. The research was conducted by administering an online questionnaire to a large sample of 488 workers employed in safety-critical industries based in the United States and …

Reflections On Williamson On Logic And Validity, Graham Priest

Publications and Research

Over many years now, Tim Williamson and I have engaged in debates over fundamental issues concerning logic. On some things, we have disagreed strongly; on others, we have agreed.