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Nonlinear Mechanics and Applications of Bipyridine-Based Associative Polymer Networks
No full textAssociative polymer networks are inspired by the dynamic nature of biomaterials and have broad applications as stimuli-responsive materials. This dissertation investigates the fundamental structure-property relationships in associative networks and explores applications of polymers and networks containing bipyridine ligands in the backbone for photochromism and electrocatalysis.In Chapter 2, we investigated the nonlinear extensional response of associative polymer networks, with a focus on tensile strain softening. Biological systems often exhibit strain stiffening to prevent deformation and softening to avoid catastrophic failure, yet the mechanisms underlying their nonlinear mechanics remain poorly understood. Metallo-supramolecular networks formed by pendant group crosslinking with different metal ions and with a low degree of entanglements were used to access different network temporal parameters. While all networks exhibited shear-thinning, the ones with fast metal-ligand crosslinks showed tensile strain softening with a yield point, while networks with slow crosslinks did not. The mechanism of yielding was explained by comparing the changing instantaneous extension rate at different stages of the tensile test with the network relaxation times probed by sticky Rouse model and KWW fitting.
Chapter 3 expands on the work of strain softening associative networks by implementing dual-crosslinked networks to investigate the effect of mixing metals on yielding and softening behavior. Ideally, the yield stress and recoverable strain of softening materials can both be increased. This chapter discusses the approaches used towards advancing the complex and dynamic mechanical properties of associative networks.
Chapter 4 reports two applications of the bipyridine-containing polymers with the first being a novel and tunable photochromic small molecule complex formed between 4,4’-disubstituted-2,2’-bipyridine and sulfur oxides via a light-activated interaction. Later, a photochromic bipyridine polymer was also developed. The photoactivated N-oxide-SO2 complex absorbs visible light and exhibits reversible photochromism. Second, in collaboration with the Barile Group, we explored the utilization of bipyridine polymers for electrochemical catalysis, namely oxygen reduction reactions (ORR). ORR catalysis is essential for energy conversion applications; however, the reactions are challenged by sluggish kinetics and large overpotentials required for activation. Therefore, we probed structure-activity relationships of copper-coordinated bipyridine small molecules and bipyridine-containing polymers for potential applications in electrocatalysis for ORR.
Lastly, in collaboration with the Urban Group at Clemson University, Chapter 5 analyzes the rheological behavior of poly(ionic liquid)s. Poly(ionic liquid)s are of importance because they possess the properties of high conductivity, high thermal stability, low vapor pressure, and tunable chemical structure. The structural advantages of polymers result in material properties that can be tuned by manipulation of the polymer backbone for various applications
Judging AI: Exploring Professional Identity and Attitudes Toward Artificial Intelligence in the Legal System
No full textIntegrating artificial intelligence (AI) into the legal system can enhance judicialefficiency, consistency, and access to justice. However, concerns about bias, legitimacy,
and judicial discretion raise critical questions regarding the judiciary's willingness to
adopt these technologies. This dissertation explores how judges perceive and are
influenced by AI in legal decision-making through the lens of Social Identity Theory
(SIT), the Technology Acceptance Model (TAM), procedural justice, and legitimacy. This
study investigates how professional identity, trust, and message framing impact judges’
attitudes and behavioral intentions toward AI. Participants were randomly assigned to one
of three message framing conditions—professional role enhancement, efficiency
emphasis, or a neutral message—and completed scales measuring professional identity,
trust in AI, procedural justice, legitimacy, and AI adoption. The findings revealed that
judges exposed to professional role framing reported a higher perceived usefulness, trust,
and willingness to adopt AI than those in neutral or efficient conditions. Trust in AI and
perceptions of procedural justice emerged as key adoption predictors, with legitimacy as
a mediating factor. Qualitative response summaries further illuminated nuanced
perspectives. While many judges recognized AI’s potential to streamline legal research
and manage caseloads, others voiced concerns about bias, ethical oversight, and the
erosion of judicial discretion. These findings underscore the importance of professional
identity and procedural values in shaping judicial receptivity to emerging technologies.
This study contributes to social psychology and legal technology literature by identifying
theoretical and practical factors influencing judicial attitudes toward AI. It discusses
implications for policy, training, and ethical implementation and offers pathways to foster
responsible and accepted AI use in the judiciary
Evaluating the Representativeness of Snow Sampling Sites in the Western United States and Alaska
No full textSnowpack is a critical water resource threatened by climate change. This isparticularly true in the western United States. NASA’s SnowEx program measured
snow cover at numerous sites in the western United States and Alaska in preparation
for future space-based missions. These snow cover sites were chosen largely based
on snow cover classes created using subjectively defined thresholds. However, there
has not been a systematic classification of snow cover in the US or SnowEx sites
in terms of variables that affect snow water equivalent (SWE). Random Forest
is a machine learning method that uses groups of decision trees to create robust
predictions and identify important variables. SHAP (Shapley Additive Explanatory
Values) is a modeling framework which uses game theory to evaluate the local
importances of different predictors in a model by estimating their contributions in
different coalitions of predictors. Using these advanced machine learning methods,
I have created new snow cover classifications for the western United States and
Alaska based on key predictor variables of peak SWE for Water Years 1993-2020
and assessed the representativeness of SnowEx sites in terms of these classes. These
new snow classes are compared with the snow cover classification system created
by Sturm and Liston (2021). This work will help NASA identify data gaps and
enhance future snow monitoring effort
Understanding Assignment Prompts
No full textThis handout is designed to guide students through understanding assignment prompts by identifying key words, content, and formatting
Advancing Pandemic Preparedness by Developing Antivirals for Human Coronaviruses and Mitigating Viral Infections through Inactivation and Neutralization
No full textThe COVID-19 pandemic, driven by the highly transmissible SARS-CoV-2, remains a primary global health concern, supporting the critical need for effective strategies to combat the virus. This study addresses three critical areas: developing antiviral drugs effective in controlling virus replication, decontaminating the viruses from PPE for sustainability, and evaluating vaccine efficacy against emerging variants. The existing antiviral treatments primarily target the main protease; developing drugs against additional viral targets, such as the RdRp to inhibit the viral transcription and replication, could be an attractive for broad-spectrum antiviral drug development against SARS-CoV-2 and other human coronaviruses. In this study, identified the broad-spectrum antiviral activity of small molecules through a cell-based assay to determine the enzymatic activity of SARS-CoV-2 RdRp through a luciferase reporter assay. Among the tested small molecules, TK018, a potent inhibitor of SARS-CoV-2 RdRp with minimal cytotoxicity. TK018 demonstrated broad-spectrum antiviral activity against SARS-CoV-2 and other HCoVs such as HCoV-OC43, and HCoV-229E positioning as a promising candidate for therapeutic and prophylactic use. The inhibitory effect of TK018 was further evaluated on SARS-CoV-2 replication in cell-based infection assay by determining the levels of replicated and cell-free infectious virions following treatment of infected cells. The broad-spectrum antiviral activity of CADA compounds was evaluated using cell-based infection assays. Cells infected with HCoVs were treated with the compounds, and the levels of virus production were measured post-treatment. Using HCoV-229E (an alpha-coronavirus) and HCoV-OC43 (a beta-coronavirus) as representative strains, we found that TK018 effectively inhibited the replication of both viruses, confirming its potential as a broad-spectrum antiviral agent.
Developing effective, scalable, and sustainable decontamination methods is essential for safely removing viral pathogens from PPE, enabling reuse, and reducing exposure to infectious agents. O₃ has emerged as a promising, eco-friendly disinfectant due to its strong oxidative properties, fast action, and residue-free breakdown into oxygen. We evaluated a Trinion Disinfector (FATHHOME Inc.), an ozone-based sterilization device, for sustainable PPE decontamination. In this study, we investigated the effectiveness of ozone in inactivating viral pathogens. After treating with 60 ppm of ozone for 10 minutes, the Trinion Disinfector significantly reduced SARS-CoV-2, AAV, HSV-1, and HBV on PPE surfaces. Contamination from SARS-CoV-2 on face shields and N95 masks was decreased by 99.9%, while AAV infectivity was nearly eliminated. A similar level of effectiveness was observed against HSV-1 and HBV, with substantial reductions in infectious virus particles following ozone exposure.
Finally, we evaluated the neutralizing efficacy of various COVID-19 vaccines by testing pooled sera from vaccinated individuals against a comprehensive panel of SARS-CoV-2 variants and subvariants, including the ancestral strain WA1, Delta, and multiple Omicron lineages, using the gold-standard PRNT. The rapid emergence of SARS-CoV-2 variants, particularly those within the Omicron lineage, poses a significant challenge due to their extensive mutations in the spike protein, especially within the RBD. These mutations have been linked to increased transmissibility and enhanced immune escape, diminishing the effectiveness of vaccine-elicited neutralizing antibodies.
In this study, we assessed serum samples collected after both primary vaccinations and booster doses across multiple platforms. Our findings revealed that the neutralization capacity was highest against WA1 and Delta, consistent with the antigenic match to the original vaccine formulations. However, the neutralization potency declined markedly against Omicron subvariants, particularly in samples collected after single-dose regimens or heterologous booster strategies, suggesting limited cross-protective immunity.
Conversely, sera from individuals who received homologous mRNA booster doses (Moderna or Pfizer) demonstrated broader and more potent neutralizing responses against several Omicron subvariants, including BA.1, BA.2.12.1, and BA.5. While neutralization against the most recent subvariants (e.g., XBB.1.5 and JN.1) remained limited, homologous boosters still provided improved cross-variant protection compared to heterologous approaches.
These results emphasize the importance of booster vaccinations in maintaining protective immunity and highlight the relative advantage of homologous mRNA booster regimens in extending the breadth of neutralization. Furthermore, they reinforce the need for continuous surveillance of emerging variants and the adaptation of vaccine formulations to ensure effectiveness against evolving SARS-CoV-2 lineages.
In summary, the findings highlight the potential of TK018 as a lead compound for developing therapeutic and prophylactic strategies against SARS-CoV-2 and potentially future coronaviruses, offering a valuable tool to enhance pandemic preparedness and improve treatment outcomes. Additionally, optimizing ozone concentration and exposure time was shown to significantly enhance the pathogen-inactivation capability of the FATHHOME decontamination device, supporting its potential role in infection control. Finally, evaluating vaccine efficacy remains critical for understanding the breadth and durability of immune protection, informing the design of next-generation vaccines, and equipping global health systems to respond more effectively to current and future viral threats
Glimpses of Identity: the Archaeology of Consumption at Boca-HOTH FS#05-17-57-00845
No full textThis thesis details the historical archaeology of a late 19th-early 20th centurydomestic site within the eastern Sierra Nevada industrial company town of Boca,
California (1867-1927). Located on the modern US I-80 corridor east of Truckee, Boca
served as an important source of lumber, ice, and beer, and was a significant economic
driver for most of its lifetime. As a company town, Boca was devoted to industrial
production, and is largely remembered for its businesses, rather than for the people who
once lived there. As a result, workers and their families are largely unknown, especially if
they were not wealthy or company management. To gain a better idea of everyday life at
Boca, as well as to understand adaptations and choices made for living within an
industrial company town, the project surveyed a site designated Boca-HOTH (House on
the Hill) at the top of a nearby ridgeline. The recovered artifacts were examined from a
consumption theory standpoint, considering actor choice as a way to understand potential
self and group identification, meanings, and aspects of personal values and identity.
Special attention was paid to artifacts with potential gender associations and/or cultural
significance, including adornment items such as jewelry and personal dress along with
Chinese-associated cultural artifacts including opium-smoking paraphernalia. Comparing
and contrasting the results with the historic archival record provides insight into the
personal lives, culture, and potential identities of the occupants of Boca-HOTH, and help
gain a fuller, more holistic understanding of the site, its residents, and Boca itself
Decrepitation of Crushed Leach Copper Ore Under Sulfuric Acid Leaching Conditions-Part 1
No full textThis paper was presented at the Heap Leach Solutions Conference, October 19-21, 2025, Sparks, Nevada.Historically, stockpiles constructed from crushed leach copper ore for the purpose of copper recovery through sulfuric acid leaching have been assumed to be freely draining throughout their lifetimes based on initial hydraulic conductivity tests completed using fresh or column test samples during the design stage. However, decrepitation of copper ore can produce fine-grained layers that significantly hinder vertical percolation of raffinate, redirecting flow laterally with a possible mound forming, and potentially creating seepage points. As a result, certain areas of a stockpile may experience partial and/or impeded drainage through time, necessitating the installation of additional collection systems to direct solution from within the stockpile into process ponds. These seepage challenges can also reduce copper recovery from deeper lifts during secondary leaching via surface irrigation. Sulfuric acid leaching on copper stockpiles thus requires careful management to maximize copper extraction before permeability limits copper recovery and potentially requires operational adjustments. Therefore, understanding the effects of decrepitation is essential for evaluating its impact on copper recovery, slope stability, and operational costs. A review of technical literature revealed that geotechnical data aimed specifically at quantifying decrepitation of crushed leach copper ore is limited, mainly because collection of such data involves significant resources associated with repeated drilling, sampling, and testing through the lifetime of the stockpile. Within this paper, we present laboratory geotechnical properties, including grain size distribution, Atterberg Limits, and in-situ measurements of hydraulic conductivity using two different methodologies collected at existing crushed leach copper stockpiles with various ages to quantify decrepitation of crushed leach copper ore under sulfuric acid leaching conditions. Using depth within a stockpile as a proxy for time under leach that ranges from 0 days to 25 years, we show that decrepitation of crushed leach copper ore as a result of sulfuric acid leaching can result in an increase of fines content, an increase of liquid limit, and a decrease of hydraulic conductivity
Nevada State Climate Office Drought Report September 2025
No full textThis report was created by the Nevada State Climate Office to provide a statewide drought summary for September 2025
Analyzing Primary Sources - Worksheet
No full textWorksheet for an instructional activity about analyzing primary sources
Informal Mentoring within the Tenure track Faculty Experience: A Phenomenological Study
No full textThis descriptive phenomenological inquiry expanded the knowledge that exists about the beneficial extensions of informal mentoring for tenure track faculty members. The pertinence of interactions between seasoned faculty and junior faculty suggests that when a genuine commitment is made to communicate openly and objectively, an educator may gain insight essential to their performance success and employment continuity. The perspectives gained through participant interviews illustrate the potential for mentoring to assist tenure track faculty’s transition into their institution and achieve success. The study explored the ways in which informal mentoring is experienced by tenure track faculty in at least their third year of employment at the institution. Key theories explored in the interview series included Kram’s (1983) phases of the mentorship relationship (1983) and Bourdieu’s (1986) forms of capital. The study findings suggest that tenure track faculty engage in informal mentoring for both career-related and psychological support, functions of mentoring previously identified by Todoran (2023). Additionally, participant experiences shed light on the need for institutionalized support of mentoring, specifically the importance of recognizing and funding mentoring that occurs both formally and informally