Open Research Oklahoma (Oklahoma State Univ.)
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Beef cattle research: Fort Reno Livestock Research Station
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
How accurate are people's assessments of inter-seasonal temperature change?
No full textThis thesis explains the gap between Oklahoma citizens’ perceptions of inter-seasonal temperature changes and recorded meteorological temperature changes. Data are from a representative survey of Oklahoma households and Oklahoma’s Mesonet meteorological stations. The study examines the influence of individual-level characteristics, political ideology, and party affiliation on the gap. Findings suggest that demographic factors are less predictive of the identified gap, with Oklahomans likely to inaccurately predict changes in inter-seasonal temperatures and overestimate changes in average temperatures over time. However, personal experience with extreme weather events is stronger in influencing the gap. Older people tend to over predict changes in average temperature over time. Interestingly, concern about fiscal spending significantly influences temperature change perceptions, indicating a potential link between environmental tax attitudes and climate change engagement. Overall, the analysis indicates that factors beyond political ideology and party affiliation influence how accurately people assess changes in their local temperatures
Control of Bermuda grass and Johnson grass with TCA (trichloroacetate)
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Advancing transboundary water resources assessment, monitoring and modeling using grace, machine-learning, and land-hydro models
No full textThe Indus Basin is facing water scarcity intensified by a drier climate and growing water demands for irrigation and population consumption. Ensuring environmental sustainability and resilience in the Indus Cascade necessitates a comprehensive understanding of human activities and climate influences on terrestrial water storage and groundwater depletion. The primary goal of this research is to promote food and water security in Indus Basin by providing place-based water management solutions. To do so, we used GRACE data, spatial downscaling, hydrological and land surface modeling and machine learning tools to advance the predictability of water resources across time and space. Results indicated that spatial downscaling of GRACE data to 1km resolution largely improved the groundwater storage estimations when compared with the groundwater monitoring data. All twenty sub-regions in the Indus Basin indicated irreversible decline in terrestrial water storage (TWS) and groundwater storage (GWS) between 2002 and 2023. However, the declining rate was dominant in the downstream areas where human activities are major influencing factors. By employing machine learning models, we reconstructed high-resolution (1km) data of groundwater level, enabling better monitoring and understanding of groundwater changes and facilitating more accurate groundwater management in these regions. By combining downscaled GRACE data with SWAT hydrological fluxes in spatial water balance, we also seek to improve groundwater depletion estimations in 55 canal command areas for understanding impacts of different cropping systems, growing food productions and unequal distributions of surface water. The significance of PhD dissertation research is amplified by the generation of high-resolution terrestrial water storage dynamics, precipitation, water table, and groundwater depletion datasets in data-sparse areas across transboundary Basin, which we made publicly available on platforms such as Figshare, enabling researchers and policymakers to access valuable information for informed decision-making. The methodologies and programming tools developed during this research are applicable globally, offering solutions to regions grappling with environmental challenges
TikTok poetry: The death of art or a new frontier?
No full textPoetry as an art form shifts and evolves alongside new developments in communication and technology. The emergence of TikTok has provided a new medium for poets to experiment with. My thesis will investigate how poets engage with TikTok’s trends, algorithms, and formats. Much like popular Instagram poetry during the 2010s, TikTok poetry tends to be broad in an effort to be relatable and easy to consume. However, the app’s unique combination of audio and visual elements adds a new dimension to poetry written for social media: sound. TikTok poets certainly draw inspiration from slam poetry, though with a few significant departures. TikTok poetry also follows trends and is largely written to gain followers and popularity, not just for the sake of writing poetry. Its surface-level nature also garners criticism from people who don’t consider it “real poetry.” However, there are some instances of TikTok users stumbling upon poetry as a vehicle for critiquing the state of society and internet culture at large. Alongside the poems reminiscent of popular Instapoetry, a whole new type of TikTok poetry is emerging—the type that can only exist because of TikTok itself
Reactive uptake of ozone onto thin films of brown carbon and azo dyes
No full textOnce carbonaceous aerosols are emitted or formed in the atmosphere, they are subjected to aging through irradiation and oxidation. The variable evolution during aging dictates the climate impacts of these species. Using a coated-wall flow-tube, we investigated the uptake of ozone onto thin films of whole, water-soluble, and waterinsoluble polarity-fractionated biomass burning organic aerosol (BBOA), generated from eastern red cedar sapwood. We explored how ultraviolet (UV) irradiation affected the uptake of ozone for both whole and polarity-fractionated films and also how relative humidity (RH) affected it specifically for the polarity fractions. After 16 hours of irradiation, equivalent to three days of irradiation in the atmosphere, the mass absorption coefficient at visible wavelengths of the whole BBOA increased, associated with an increased warming effect on climate. UV irradiation significantly decreased the reactive uptake of ozone for all BBOA films investigated, as a result of oligomerization leading to increased viscosity, associated with an increased lifetime with respect to oxidation. Effects of RH on the polarity-fractionated films highlight how liquid-liquid phase separation to form core-shell particles could also hinder oxidation. Together, these laboratory observations demonstrate important processes dictating the fate and impact of BBOA in the atmosphere.
Nano- and microplastics are an emerging contaminant. Like many commercial products, these plastics are typically colored by azo dyes. A crucial first step for understanding their direct effect on climate, through the absorption and scattering of solar radiation, is learning how susceptible they are to oxidation. We demonstrated appreciable uptake of ozone onto three commercial azo dyes. The uptake coefficients were (2.0 ± 0.5) x 10⁻⁷ for sunset yellow, (2.7 ± 0.6) x 10⁻⁷ for amaranth, and (3.2 ± 0.3) x 10⁻⁷ for tartrazine at 80% RH and 100 ppb of ozone. Reactive uptake increased with increasing RH, due to plasticization, and decreased with increasing initial ozone mixing ratio, due to depletion of unreacted dye at the surface. These observations demonstrate that azo dyes in nanoplastics may react with gas-phase ozone, motivating further studies of how the optical properties of nanoplastics change during their residence time in the atmosphere
4-H Handicraft manual: Woodwork
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Safe farming for 1925
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Modeling the coupling between viscoelasticity and soft elasticity in nematic liquid crystal elastomers
No full textLiquid crystal elastomers (LCEs) are a unique class of smart materials with attractive mechanical properties, including high energy dissipation and soft elasticity. These behaviors arise from the structure of LCEs, where liquid crystal molecules (mesogens) are embedded within a polymer chain network. Under deformation, mesogens reorient along the applied load, producing soft elasticity—a notable increase in strain at a constant stress level. The rotation of mesogens, coupled with the viscoelastic nature of the polymer, results in a complex, nonlinear viscoelastic response. While these properties make LCEs appealing for many applications, several challenges limit their practical use, particularly the need to understand and model their nonlinear, coupled responses under various loading conditions.In this study, we first evaluated the presence of soft elasticity in polydomain LCEs under compressive loading and then investigated the coupling between soft elasticity and viscoelastic mechanisms in nematic LCEs under tensile and compressive conditions. We examined the compressive behavior of LCEs, focusing on the influence of mesogen orientation on viscoelastic mechanisms and assessing the presence of soft elasticity in compression.
To model these complex behaviors, we initially proposed a rheological model in which meso- gen rotation is represented by a reversible slider, and viscoelastic relaxation mechanisms are modeled with a series of Maxwell elements that are either coupled or decoupled from mesogen rotation. Fitting this model to experimental tensile data revealed partial coupling between polymer chain viscoelasticity and mesogen rotation; specifically, long-term relaxation mechanisms are coupled to mesogen alignment, while short-term mechanisms remain decoupled. This finding deepens our understanding of the time-dependent mechanical response of LCEs during the polydomain-monodomain (PM) transition.
We extended this model to a finite strain framework to accurately predict LCE stress responses under large deformations. By fitting the finite strain model to experimental data from both tensile and compressive tests, we examined differences in relaxation mechanisms and the effects of mesogen rotation across loading conditions. Finally, the finite strain model was implemented in the finite element software FEAP and FEBio, where its performance was evaluated through a plate with a hole simulation to capture complex stress distributions, demonstrating its ability to predict LCE behavior at various strain rates
Establings freezing and thawing fabrication techniques and guidelines for foodservice
No full textThe objective of this study was to establish freezing and thawing techniques and guidelines of beef steaks for foodservice. USDA Choice paired beef strip loins (n = 44) were obtained from a commercial beef processing facility. Strip loins were wet-aged 21 d at 4°C, then frozen for 14 d at -21°C to indicate the first freezing cycle. Loins were then designated to be fabricated in a frozen or thawed state. Loins designated to be thawed were held at 4°C for 7 d while loins designated to the frozen treatment remained at -21°C until fabrication. From each loin, 2.54 cm steaks were cut and designated to one of three freezing storage temperatures: -12°C, -18°C, or -21°C and frozen for 6 mo. Steaks within each frozen storage temperature were assigned to one of three tests: consumer sensory panel, trained sensory panel, or Warner-Bratzler Shear Force (WBSF). Consumer panel results showed no differences (P > 0.05) for tenderness, juiciness, flavor liking, overall liking, and off-flavor detection for either fabrication state or storage temperature. Correspondingly, trained sensory panels found no differences (P > 0.05) in initial juiciness, sustained juiciness, tenderness, connective tissue amount, off-flavor, or beef flavor. Furthermore, trained sensory panel results indicated no differences (P > 0.05) in internal cooked color ratings or instrumental cooked color. Steaks thawed for fabrication had lower (P 0.05) in steak cook loss regardless of fabrication state or freezing storage temperature. In addition, there were no (P > 0.05) differences in lipid oxidation values between treatments. By fabricating steaks in a frozen state before long-term storage, product yield is increased without significantly affecting palatability, therefore product destined for foodservice could be fabricated frozen