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Diagrammatic Categories which arise from Directed Graphs
Get PDFThere is a categorical equivalence between the Temperley--Lieb category and the full subcategory of -\textbf{mod} with objects given by where is the tautological -module and is a non-negative integer. The first results in this dissertation develop new diagrammatic categories which are shown to be equivalent to similarly defined full subcategories of -\textbf{mod} for certain finite subgroups of . The diagrams which generate the Temperley--Lieb category are shown to be linear combinations of the generating diagrams for these newly defined diagrammatic categories. The main result of this paper utilizes the representation graph of a group , , and gives a general construction of a diagrammatic category . The proof of the main theorem shows that, given explicit criteria, there is an equivalence of categories between a quotient category of and a full subcategory of with objects being the tensor products of finitely many irreducible -modules
Abrupt Agricultural Flash Drought: An Investigation of Rapid Drought Development Across Vital Agricultural Zones of the United States
Get PDFFlash droughts are highly impactful, subseasonal to seasonal events that pose a severe risk to agricultural production. The 2012 flash drought event in the United States is a prime example, as this event resulted in tens of billions of dollars of crop loss and caused longer-lasting effects to the overall US economy. This study examined impactful flash drought events across two agricultural regions of the central United States, spanning the 40-year period from 1981 to 2020. The two regions, the Southern Great Plains and Midwest, were selected given the agriculturally-dense areas in distinctively unique climate regions.
Using the standardized evaporative stress ratio (SESR), flash drought events were selected based on several factors, including the overall spatial coverage, rapid onset, and spread across the region. The events, defined as abrupt agricultural flash droughts (AAFDs), provide critical information regarding the timing of rapid drought transition across different areas of the United States and the implications they bring to agricultural producers. Initial results show that over the last 20 years, AAFDs have increased in frequency across critical regions of agricultural growth. Within the Southern Great Plains, essential findings within the timing of events illustrate how AAFDs, in conjunction with a winter La Niña pattern, led to a consistently below-average harvest of winter wheat the following growing season. Across the Midwest domain, results indicate a greater seasonality in AAFD events, with a majority of events transpiring during the late Spring and early Summer months
Tenderhearted
No full textThis is a collection of non-fiction essays and one fictional short story that began with the idea of the psychological phenomenon of undermothering but eventually took shape around ways in which my coming of age was impacted by feelings of tenderheartedness and shame. The writing of this thesis serves as a personal attempt at recognizing the lifelong realities of my
tenderheartedness and the resulting feelings of shame and isolation that have emerged from various periods and occurrences of life such as childhood, friendship, being parented, experiencing parenting, dating, suffering injury, guilt, fear, and selfishness. Among the goals of this collection, upon considering some of the difficulties of existence, is to find healing in the understanding of the inherent value and worthiness of one’s own lif
Stories as Relations
Get PDFThis research will focus on understanding the personhood of Indigenous women and finding one’s light and autonomy. Here, I build on the work of Leanne Simpson and Laura Harjo about finding one’s light and autonomy and sharing that light in service to Indigenous communities. By utilizing both archival research and the invocation of Indigenous feminist and relationality theories, this paper will examine the key concepts of kin-space-time envelopes, relationality, autonomy, and stories as relatives. The specific material I researched was oral histories from the Doris Duke Collection of American Indian Oral History that are housed in the Western History Collections of the University of Oklahoma Libraries. By utilizing concrete examples from archival research, a better understanding of the context of Indigenous values through time and space will inform current Indigenous women of the power and light that is inherently ours. These stories are relations that teach us about autonomy, relationality, and how to be in the world
Nature and catalytic role of extra-framework aluminum and partially coordinated aluminum in MFI zeolite
No full textZeolites are extensively employed in the chemical and petroleum industries as an acid catalyst for cracking, isomerization, and alkylation reactions. Recently, they have also gained attention as potential catalysts for biomass conversion. The activity of Brønsted acid sites (BAS) contained within the microporous zeolite channels is known to be affected by the location and local environment that stabilizes reaction intermediates and transition states. Additionally, it has been reported that presence of extra-framework Al (EFAL) and partially coordinated Al (PFAL) species can significantly alter reaction rates. However, the mechanism behind these enhancements and the catalytic roles of individual EFAL and PFAL species are yet to be fully understood. In this project, we utilized Density Functional Theory (DFT) to elucidate the locations and local environments of active sites in H-ZSM-5. We also propose the mechanisms behind the synergistic effects generated by the BAS and EFAL/PFAL in proximity. Moreover, the individual catalytic effects of different EFAL and PFAL on alkane cracking reactions were investigated.
The theoretical calculations provide precise assignments of NMR spectra for acid sites and their surrounding in zeolites. The well-known signal 4.2 - 4.5 ppm is attributed from BAS at the intersection and main channels (straight and sinusoidal channels). The broad signal 5-9 ppm is assigned for framework BAS at 5-MR/6-MR or silanol groups in silanol nests for the first time. It is noteworthy that the broad signal 11-18 ppm rise from BAS forming hydrogen bonds with adjacent EFAL/PFAL species. Additionally, for different EFAL and PFAL species, the 27Al NMR chemical shift values are in the broad range of 55-85 ppm, which is rational to the expansion of aluminum peak up to 85 ppm for steamed samples.
The synergistic sites are formed via the hydrolysis of Al framework atoms and migration of EFAL in the presence of water. During the initial stages of hydrolysis, incomplete hydrolysis of BAS site pairs creates BAS/PFAL synergistic sites. The formation of synergistic sites in pulsed water treatment is not related to dealumination but rather involves the migration of EFAL to BAS to generate synergistic effect. In both propane and hexane conversions, the cracking reactions are more influenced by EFAL and PFAL species than the dehydrogenation reaction. The charge distributions reveal that EFAL and PFAL interact with transition states, resulting in lower activation barriers.
This work elucidated the underlying mechanism of EFAL and PFAL for enhancing alkane conversion and pave the way to investigate the function of broader extra-lattice species such as rare earth and phosphorous in zeolite
Fus Fixico Classification System
Get PDFWestern cataloging systems organize information by subject and are created through a western lens. Indigenous communities organize information according to other factors, notably: cosmology, geography, language, and a sense of being. Our library created and actively uses the Fus Fixico (“Angry Bird” in Muskogee 'Creek' Language) Classification System (FFCS). FFCS is named after the Fus Fixico letters, which were written by Alexander Posey, a Muscogee Humorist, who served as secretary at the Sequoyah Constitutional Convention. FFCS borrows elements from the Brian Deer Classification System, Dewey, and Graph Theory to create a more inclusive system that empowers improved metadata and LoC subjects to thrive, while also still providing for user-friendly collocatio
Crime scene investigators: exploring the reasons and impact of career longevity and gender diversity in forensic science
Get PDFCareer longevity among crime scene investigators (CSIs) is a topic for which there has been little research. This is surprising given the increased popularity of this profession as well as forensic science in general. Understanding the profession and the career dynamics of those who serve as CSIs can provide valuable insight which can be used to improve efficiency and effectiveness on the job and promote lengthy and successful careers. This study examines the career longevity of female versus male crime scene investigators and identifies the key reasons behind early departures from the field. The study looks at career inspirations, expectations, and professional pathways for both male and female forensic science students and those already working as career CSIs. Two similar surveys were sent out, one to currently working, and retired crime scene investigators and/or death scene investigators, and one to forensic science students at the University of Central Oklahoma. The sample pool included 45 survey responses from current and former professionals in the field, and 57 responses from forensic science students. From the surveys that were received, we discovered that female crime scene investigators are more likely to leave the profession early than their male counterparts. We identified the various reasons why this was so and formulated suggestions for addressing these issues. We also discovered that the main incentive for students to choose forensic science was because they thought it was an interesting career and they wanted to serve the community in a unique manner, however some apparently did not think beyond this to the demands of the job and the effect it would have on lifestyle and family. From this result, we concluded female CSIs tend to quit the profession early more than their male counterparts and that there are articulable reasons which could be better addressed
Characterization of the subsurface from evaluating low amplitude seismic recordings
Get PDFA geoscientist yearns to learn more about the subsurface and one way of characterizing the subsurface is through active seismic methods which utilize a local source to initiate a strong waveform (e.g., explosives, vibroseis, sledgehammer). However, active sources are generally costly to operate, and logistically complicated since, depending on location, they require approval from an authorizing body, and are very intrusive and disturbing to the environment. Alternatively, passive seismic methods are preferred due to their low cost, ease of instrument deployment, and low environmental impact. Passive seismic is not without its caveats. Passive seismic relies on the surrounding ambient seismic noise for measurements, which can be influenced by local noise sources (e.g., vehicles, strong wind), effectively lowering the signal-to-noise ratio. I will present an array of exciting results from low-amplitude seismic recordings and novel approaches to measuring them to understand the seismic noise environment and microseismic events, which have implications for the field of seismology. I will show an improved analysis of seismogenic potential from magnitude calibration, an interpreted resonant subsurface boundary determined from resonance frequencies, and a correlation of wind speed and seismic recordings. I use an induced seismicity catalog recorded by two nearby boreholes to apply a novel workflow of waveform correlation to 2074 earthquakes for magnitude calibration and subsequent evaluation of seismogenic potential. Waveform correlation reveals statistically significant differences in b-value and seismogenic potential after calibration and suggests a dependence of the earthquake statistics upon their optimal or suboptimal orientation to the local stress field. In another study, we utilize distributed acoustic sensing (DAS) recording, which allows for a high density of receivers with minimal field deployment. The technique leverages novel sensors to measure backscatter from a telecommunication dark fiber, resulting in a time series of strain along the cable, effectively 100s to 1000s of “seismometers.” Comparison between this novel sensing device and traditional sensors reveals the higher noise level of DAS. However, the higher spatial resolution of DAS allows for stacking measurements along channels and identifying noise sources that were previously not easily recognizable in traditional arrays. Recorded measurements are often subject to increased background noise in an urban or noisy environment. From seismic recordings across Oklahoma from dense arrays, I examine the effects of wind and wind turbines on recorded seismic noise via single-station site response techniques to determine site resonance frequencies and noise source origin
Enzymatic and non-enzymatic bioanodes: novel materials for glucose oxidase and polyviologen biosensors and biofuel cells
No full textA fundamental study of the interaction of iodide and glucose oxidase (GOx) was carried out, showing that the iodide acts as a direct mediator with GOx in enzymatic glucose biosensors. This direct mediation may be happening in parallel with the known electron transport chain through hydrogen peroxide. The aqueous I-/I3-/I2 redox reactions are discussed and studied through the use of cyclic voltammetry and chronoamperometry in conjunction with glucose and GOx. These results are compared with water soluble ferrocenyl salts known to mediate GOx biosensors. This study shows that iodide can mediate GOx in the presence and absence of oxygen, making this the first work, to our knowledge, to show iodide can act as a direct mediator, rather than an indirect mediator for GOx.
Layer-by-layer (LBL) modification of gold electrodes with GOx has been an effective way to make enzymatic electrochemical glucose bioanodes for biofuel cells and biosensors. The use of a cystamine attachment layer is usually used to establish a functionalizable initial layer upon which to build up more material for these systems. While this is an easy and fast way to functionalize gold, it was unknown how this attachment layer affects access to the electrode surface. This work explores the use of carbon disulfide (CS2) substituted linear- and branched-polyethylenimine (LPEI and BPEI respectively) as the first layer of these LBL bioanodes. The dithiocarbamate groups attached to the polymer allows it to react with the gold surface and establish a polymeric-first layer. This work shows that the polymeric first layer immobilizes ~2.5 times more material than the first three layers of the cystamine-modified electrodes. The inclusion of ferrocenyl groups in the first-layer PEI also wires the upper layers to the electrode resulting in a ~6 fold increase in current density in the 3-layer system. The Fc-CS2-LPEI- and Fc-CS2-BPEI-based electrodes are also more stable than the cystamine-first layer electrodes. The 9L Fc-CS2-LPEI anode was found to produce 978 µA/cm2 current density, and 271 µW/cm2 peak power at saturating glucose conditions as a biofuel cell while the 19L Fc-CS2-BPEI anode was found to produce 2.1 mA/cm2 current density, and 677 µW/cm2 peak power. Under physiological glucose concentrations the Fc-CS2-LPEI had a sensitivity of 47 µA/cm2 mM while the Fc-CS2-BPEI anode had a sensitivity of 64 µA/cm2 mM, making these some of the most sensitive enzymatic glucose bio-anodes made to date.
This work also explores electropolymerization techniques for the fabrication cucurbit[7]uril (CB7)/Polyviologen-based bioanodes. This non-enzymatic electrode was fabricated using cyclic voltammetry, constant potential and pulsed potentials. It was found that the cyclic voltametric method was the best technique to fabricate functional glucose anodes. This method was used to functionalize the high surface-area material carbon felt, and highly stable glucose electrodes were made that produced ~20 µW/cm2 peak power and were able to also utilize sucrose as a fuel source