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Insights Into the Paleoclimate of the Western Interior Seaway Through the Analysis of Palynomorphs and Petrified Wood from the Short Canyon Member of the Cedar Mountain Formation
Get PDFThe Cedar Mountain Formation is a rich source of information on North American megafauna during the Cretaceous, preserving sediments deposited in floodplains related to the Western Interior Seaway. In this thesis, petrified wood, palynomorphs, and wood fragments are identified in the hopes of further building upon what is known about the environment within which Cretaceous megafauna lived. These remains come from the Short Canyon member at the Moore Road Cutoff section and are the first paleobotanical data from this informal member. The petrified wood is identified as Taxodioxylon albertense, a cupressaceous conifer with affinities to Sequoioidae, especially Sequoia and Sequoiadendron. The growth rings of this wood are analyzed and used to interpret water availability in the tree’s lifetime, using both seasonal and intraseasonal growth rings. A sediment sample for palynological analysis yielded pollen, spores, cuticle, and wood. Palynomorphs are identified to major group—pteridophytes (e.g., club mosses, ferns, and horsetails), gymnosperms (e.g., cycads, ginkgo, and conifers), or angiosperms (flowering plants)—and abundance counts are made to compare to previous palynological assessments in this formation. These produced pteridophyte-dominated abundances, with roughly equal proportions of angiosperm and gymnosperm pollen. Within the debris in these slides are angiosperm wood fragments. Hardwood features are identified and comparisons to angiosperms previously known from this formation (Icacinoxylon and Paraphyllathoxylon) are made. From each of these assessments, the paleoenvironment of the Short Canyon member of the Cedar Mountain Formation is interpreted to be a seasonally wet and temperate floodplain
A priori testing of subgrid-scale models for large eddy simulations in supersaturated conditions
Get PDFTurbulence is characterized by irregular movement in pressure and flow velocity. Better understanding of turbulent flow will help in the understanding of air movement including wind currents, dissipation of pollutants and storm formation. Although much research has been done on the nature of turbulence in the atmosphere, less work has been focused on humidity turbulence in supersaturated conditions. Supersaturation turbulence is found in clouds and plays a major role in the formation of precipitation. In an effort to better understand LES and the closure problem for turbulence fluctuations of supersaturation, temperature was monitored within a cloud chamber while turbulence was being induced. Several measurements were made with a thermistor array at various temperature differences and spacings. The data gathered was used for a priori testing. Two models, a scale-similarity model and a Gradient model, were tested with the data gathered. The scale-similarity showed to be very promising with correlation coefficients around 0.7. The Gradient model had correlation coefficients around 0.2. Although one of the models performed slightly better at the smallest horizontal spacing, there didn’t appear to be any significant patterns between horizontal spacing or temperature difference and how well the models performed. A posteriori tests will need to be performed in the future to better test how well the scale-similarity model behaves in various circumstances. Supersaturation LES models will further scientists’ understanding of the humidity turbulence present during the formation of clouds and precipitation
Study of CO2 Solubility in Brine and Mineralization in Mafic Basaltic Formations
Get PDFA huge amount of CO2 emissions should be mitigated for environmental benefits and to reach net zero by 2050. One method to mitigate these emissions is permanent CO2 sequestration through mineralization. CO2 can be mineralized as carbonate minerals such as calcite and magnesite if injected into igneous formations rich in reactive minerals such as olivine, pyroxene and plagioclase. The dissolution of CO2 in brine is the first geochemical reaction in the pore space that leads to CO2 mineralization eventually. The objective of this study is to understand the dynamics and controlling parameters of CO2 dissolution in brine and mineralization in mafic basaltic formations.
This study uses a 3D carbon sequestration numerical model to simulate the geochemical reactions of injecting CO2 into a saline aquifer in a basaltic formation. The model includes three main geochemical reactions: CO2 dissolution in water, dissolution of formation minerals, and precipitation of carbonate minerals. The first reaction results in forming carbonic acid that reacts with the formation minerals: anorthite, wollastonite, pyroxene, and olivine, which results in releasing calcium and magnesium ions. The reaction between divalent cations and dissolved CO2 in brine results in precipitating carbonate minerals: magnesite and calcite. CO2 is injected into the formation for four years and simulated for 200 years. The dynamics of reservoir pressure and CO2 plume migration are studied as CO2 mineralizes. In addition, the rate of mineral dissolution and precipitation is analyzed as the initial conditions of the reservoir change, including brine salinity, temperature, and pH. In addition, the change in porosity and permeability is investigated during CO2 mineralization process.
The results show that 95% of the injected CO2 is mineralized within the first 7 years. After 200 years, 98% of injected CO2 is mineralized, 1.5% is dissolved in brine and 0.5% is residually trapped. Due to the mineralization of CO2 in the form of magnesite, and calcite, the porosity decreased by 5% maximum due to the extra cement in the pore space. Likewise, permeability decreases by 71%. The reservoir pressure increases during the injection but reduces by 15% after 200 years due to continuous CO2 mineralization. Lower reservoir temperature increases the amount of CO2 mineralized due to the higher CO2 solubility in water. Brine salinity has minimal effect on CO2 mineralization. The rate of CO2 mineralization is higher when the initial pH in a reservoir is lower.
The carbon storage numerical model built for this study considers the effect of the formation water chemistry and rocks mineralogy on the amount of CO2 sequestrated. In addition, it shows the advantage of targeting basaltic formations for CO2 storage compared to sedimentary formations. In addition, this study shows that CO2 can be stored permanently in the subsurface with no risk of leakage
Theory-Guided Algorithm Design for Scalable Machine Learning
Get PDFMy thesis focuses on designing scalable machine learning algorithms leveraging theoretical advances in mathematics. In particular, I investigate two directions where scalability plays an important role: fair machine learning and randomized feature representations. In fair machine learning, my research concentrates on achieving individual fairness in the single model and decoupled model settings with minimum data labeling budgets. For randomized feature representations, I propose a model-agnostic framework for designing computationally efficient randomized machine learning algorithms with provable performance guarantees, which demonstrates that it is not necessary for individual models to be weakly trained before they are optimally ensembled. Furthermore, I also contribute to the scalable estimation of Kernel matrix spectral norm. Specifically, I propose to apply sketching techniques to efficiently estimate the spectral norm, theoretically derive the estimation error and empirically demonstrate the estimation efficiency in a time-constrained setting
Electrochemical conversion of PCB milling machine into a 3-axis CNC
No full textIn the fast-growing technological world that we live in today, out-of-date embedded technologies are now replaced with compact, more powerful and energy efficient electronic hardware that ensures safer use, flexible productivity, ease of maintenance and more autonomy. In many cases the associated mechanical hardware and components are perfectly functional, nonetheless incompatible, and oftentimes costlier to upgrade. This was the case for the decommissioned LPKF ProtoMatS100 circuit board plotter (i.e., PCB printer) housed in the electronics lab at the University of Central Oklahoma. All attempts to restore the device were unsuccessful due to the higher cost of repair hence the machine was left unused. The subject of the current research is the transformation of the decommissioned PCB printer to a fully operational 3- Axis CNC milling router for machining small mechanical devices. To achieve this objective, we devised and implemented an in-house system control hardware and software that employs the original power distributor, newer stepper and DC motor drives, a spindle, an AVR Microcontroller, and a custom-built user-friendly control interface. The upgrades are currently on schedule and the project completion date is set for the spring 2023. The reinvented CNC milling router is expected to machine soft materials with accuracy comparable to modern CNC milling machines
Petrophysical rock typing in Uinta Basin using models powered by machine learning algorithms
Get PDFPetrophysical characterization is key to identifying different rock types for hydrocarbon production optimization. Rock-typing, a petrophysical characterization technique, can be performed using wireline measurements, such as triple combo and special logs; however, this identification needs to be verified using laboratory characterization to enhance the accuracy of rock-typing prediction models.
In this work, we implement an integrated characterization workflow for 600 ft of the core from the Uinta Basin, including total organic carbon, source rock analysis, elemental (X-ray Fluorescence) and mineral (Fourier-transform Infrared Spectroscopy) composition, total porosity (High-pressure pycnometer, Nuclear Magnetic Resonance), pore throat size distribution (Mercury Injection Capillary Pressure), and microstructure (Scanning Electron Microscopy). Wireline measurements include the triple combo and the sonic logs. Principal Component Analysis and K-means (as an unsupervised machine learning algorithm) were applied to both datasets (core and log) to cluster and classify different rock types. In parallel, the petrophysical systematic for each rock type was evaluated.
The Uinta group is vastly diverse, having a wide range of porosity (2-18%) and TOC (0.5-10%). Three main rock types were identified type 1-siliceous rich, type 2-calcite rich, and type 3-dolomite rich. The relative contribution of types 1, 2, and 3 is 37, 42, and 21 %, respectively. The top section of the analyzed core is dominated by rock type 1, which generally has the highest porosity and relatively higher TOC. Most of the bottom section is carbonate-rich rock types, in which calcite-rich and dolomite-rich layers are interbedded. SEM analyses suggest that a fraction of the porosity is associated with organic matter. Between rock types 3 and 2, further studies indicate that the high dolomite rock type and high total porosity tend to have larger pore size, and better-sorted grains, while the high calcite rock type has lower porosity and small pore size. There is a fair agreement in rock type identification between using core-derived and log-derived models.
The Uinta basin leads the hydrocarbon production in Utah. The study provides a comprehensive core analysis dataset highlighting the vertical complexity of the Uinta group. The agreement in rock-typing using core and wireline inputs suggests that log-derived rock-typing can be utilized to identify sweet zones
Silk, supplies and socialism : how women exercised public power in the American West, 1890-1920
Get PDFIn my thesis, I reframe the long-held assumption that because women in the United States prior to 1920 were blocked from access to the vote, women did not exercise political or economic influence in their communities. I illuminate the lives of three women from Oklahoma, Utah and Idaho, who defied historical assumptions of the "women's sphere," leveraging the fluidity of power in western states and territories during the turn of the century to wield political, religious, social and commercial influence. The history of women's political access in the American West has shown that women there had unique access to political, social, and commercial spaces in their communities and states. As women in the west expanded their assigned domestic roles, women's power and participation also grew on a national level. This new influence culminated in the national women's suffrage amendment, which passed in 1920. In Oklahoma, Idaho, and Utah, how did women navigate religious, commercial, marital, and political constructs to increase their participation in civic life, leading to state suffrage that pre-dated the national amendment? Cora Diehl Harvey was the first woman elected to territorial office when she was elected as County Assessor in Oklahoma in 1891. Her election was challenged by members of her own Populist party, and she was later sued in court in regard to a bond she was forced to sign to ensure her seat. Cora divorced her husband and traveled as a single woman with the International Brotherhood Welfare Association, a socialist advocacy group speaking on the rights of the homeless. Cora's beginnings in politics in a territory with little political construction allowed her to move outside customary domestic roles. Leah Mariah Gorton was the wife of George Washington Gorton, a Civil War pensioner in Soda Springs, Idaho. After Leah defied her parents in marrying George, together, the Gortons built a business empire in the rural community and led civil groups. Later, as George's widow, Leah retained her standing in the business community and was active in political circles. Beyond her family's joint interests, Leah grew beyond her traditional role as wife and mother and strongly influenced her community, interacting with and reacting to both the local Mormon and Presbyterian churches. Margaret Ann Caine was born in Salt Lake City in 1859, just as the Mormons were embarking on building a white American settlement in land populated by Indigenous peoples and trappers. Mormonism was straddling a line between isolationism and national participation as Margaret grew up and was educated in a culture that uniquely valued women's participation in religious spaces. Margaret was active in the state and national suffrage movements, represented Utah's women nationally at the World's Fair in Chicago and the International Council of Women in London and toured on behalf of the Utah Silk Industry, lecturing on the advantages of domestic silk production, one of her own commercial interests. As the first and only woman elected as Salt Lake County Auditor, Caine moved beyond her "sphere," working both within and outside of societal restraints to impact Utah and its economy. Harvey, Gorton and Caine all utilized the newness of western political systems to leverage influence in their communities. Though excluded from traditional political and commercial spaces, each wielded power in addition to their "feminine" domestic power within their homes. These examples reflect that western spaces provided opportunities for women to participate in their societies in non-traditional ways. In this project, I focus on understudied aspects of women's American western scholarship: contrasting access to power for women in different states, women's business' holdings and participation in commerce, and the ways women interacted with prevalent religious and social movements. By studying Harvey, Cain and Gorton, I will be able to illuminate the ways these principles actually influenced women's lives, thereby changing the gendered power balances of their communities, states, and ultimately, the nation
Simulating CO2 Sequestration in the Arbuckle Group of Oklahoma and Exploring the Extent of Applicability of an Analytical Model in Predicting Pressure Buildup
Get PDFThis thesis presents the groundwork for a proposed CO2 sequestration project in Osage County, Oklahoma. It describes the flow simulation of the CO2 plume in the saline aquifer of the Arbuckle Group, a dolomite formation, proposed as a potential large-scale storage reservoir for CO2 in the state of Oklahoma. Geological storage of CO2 is one of the most potent tools today in reducing atmospheric CO2 and battling climate change. With governments around the world putting policies in place to significantly reduce carbon emissions within the next two decades, there is an expectation for more CO2 sequestration projects across the world.
This study used Milad et al.’s (2022) geological model that was built by integrating core data and well logs in estimating stratigraphic and petrophysical properties of the formation. A black-oil model with 1 injection well was successfully built to simulate injection for 30 years. Local grid refinement was used around the injection well to improve the level of detail and accuracy of the model in this region. The formation was divided into 10 layers and the injection well was perforated in the bottom four (4) layers of the structure. These layers were selected based on the depth of existing injection wells in the region, some of which are intended to be remodeled for use should the project kick-off. The layers also had a good permeability distribution thus making it suitable for large-scale CO2 injection at low pressure. Pressure management is important in CO2 storage because adding large volumes of CO2 to a reservoir without any fluid removal mechanism runs the risk of potentially rupturing cap-rock seals or generating flow through faults that would otherwise restrict flow. The pressure buildup and CO2 plume evolution in the 50 years post-injection was also observed, recorded, and analyzed.
The analytical model for predicting pressure buildup developed by Mathias et al. (2011b) was also explored to determine the extent of its applicability. In carrying this out, a single well cylindrical CMG model with specified values of the reservoir properties was built to meet all the assumptions made in the analytical method. The reservoir pore volume was then altered by changing the radial extent of the reservoir to see how well the analytical model performed when compared to a corresponding CMG GEMS model at different injection/pore volume ratios.
After 30 years of injection, the CO2 plume covered an area of 5827 acres of the 1.2 million acres of the Osage Arbuckle, (less than 0.5%). The dominant CO2 trapping mechanism was structural trapping with increased residual trapping at the end of injection. Sensitivity analysis revealed that injection had to be carried out with the maximum bottom hole pressure at least 80% of the reservoir fracture pressure and no less than 96 mD permeability to meet the required injection of 50 million metric tons of CO2. It was observed that the analytical pressure buildup model performed well when the ratio of injected reservoir volume to the pore volume was less than 0.1%. Beyond this number, the slope of the pressure buildup curve calculated analytically deviated from the slope of the corresponding CMG GEMS model. With the aid of a correction factor applied to the time variable, this variation could be corrected.
This thesis provides a reference that would be useful during potential deployment of CO2 injection in the Arbuckle Group while providing more insight into the use of an analytical model in predicting pressure buildup. It also provides slope correcting factors that could be used in applying the analytical model when the ratio of injected reservoir volume to pore volume in this system exceeds 0.1%. This study could assist decision making during field development in Arbuckle as we work to ensure a sustainable future
Experimental production of dust by replicating aeolian and glacial abrasion
No full textDust is a highly mobile and influential class of sediment. Dust influences the climate, biosphere, and soils, and holds information about Earth’s paleoclimate when preserved in the rock record. In this work we define dust as rock and mineral fragments, generally less than 100 µm, which are transported in suspension by the wind (Tsoar & Pye, 1987). We adopt size categories of dust proposed by Adebiyi et al. (2023, preprint) with fine dust 0-2.5 µm, coarse dust 2.5-10 µm, super coarse 10-62.5 µm, and giant dust >62.5 µm. When transported through the atmosphere, dust interacts with incoming solar radiation, outgoing infrared radiation, and clouds, altering the climate of the planet (Conen et al., 2011; Dufresne et al., 2002; 2023; Rosenfeld et al., 2001; Tang et al., 2016). The exact radiative effects are poorly understood and difficult to quantify and are the subject of ongoing research. One of the limitations in studying the radiative effects of dust is accurate particle size distributions (PSDs) for dust in the atmosphere (Kok et al., 2017). The effects of dust on the atmosphere depend on the composition, shape, and size of the dust particles. Fine dust (2.5 µm) tends to have a warming effect by absorbing and reemitting longwave radiation (Adebiyi & Kok, 2020; Kok et al., 2023). Dust can influence cloud formation, precipitation, and nucleation of ice crystals, although the relationships are poorly understood (Kok et al., 2023).
When deposited in oceans or into soils, dust brings nutrients that promote biological productivity, which generally draws CO2 out of the atmosphere, causing cooling (Bristow et al., 2010; Mahowald et al., 2011; Okin et al., 2011; Skiles et al., 2018). When deposited on snow and ice it reduces albedo and the amount of solar radiation reflected from the surface. Dusty snow with its lower albedo is also easier to melt as it absorbs incoming solar radiation (Bristow et al., 2010; Mahowald et al., 2011; Okin et al., 2011; Skiles et al., 2018). Dust as a sediment in soils and the rock record preserves information about the climate and environment at the time of deposition (Jordanova et al., 2022; Daniel R. Muhs, 2013). For example, loess and paleosol sequences preserve intervals of aridity and rapid dust accumulation followed by stability and a low sedimentation rate where a soil horizon develops. If the source of dust is identified, then paleowind patterns can be determined, yielding information about the climate of the past.
Several processes have been proposed as mechanisms capable of producing dust including glacial grinding, aeolian saltation, explosive volcanism, high-altitude alpine weathering, chemical weathering, and biogenic siliceous diatoms (Aleinikoff et al., 1999, 2008; McTainsh, 1989; Nahon & Trompette, 1982; Smalley, 1995; Smalley, 1966; Smalley & Vita-Finzi, 1968). Not all of these processes have been thoroughly investigated, however. Many loess accumulations—structureless deposits of eolian silt—have been linked to glacial erosion by spatial proximity to the margins of former ice sheets. However not all loess deposits are geographically proximal to loess. For example, the Chinese Loess Plateau (CLP) is an immense loess deposit composed of silt-sized dust, but it is not proximal to any recently glaciated area (Muhs, 2013). This has led to speculation of other processes capable of producing dust. The CLP is downwind of a large desert and this has spurred debate about whether aeolian abrasion of sand grains in desert environments could produce abundant silt-sized dust. A series of experiments followed, attempting to replicate the process of aeolian saltation in the lab to determine if the mechanism was viable (Whalley et al. 1987; Wright et al. 1998; Bullard et al. 2004, 2007). Experiments have also been performed in the lab replicating glacial grinding. Initially, glacial grinding experiments did not produce abundant silt; however subsequent experiments determined that this was because crushed Brazilian vein quartz, which contained few crystal defects compared to plutonic quartz, was used in the experiments (Wright, 1995; Jefferson et al. 1997; Kumar et al., 2006). Experiments using sand from Cretaceous sandstones readily produced silt when ground in a ring-shear device, considered an analog for glacial grinding (Jefferson et al. 1997; Kumar et al., 2006).
While there have been several experiments exploring the physical abrasion processes capable of producing silt and dust, several knowledge gaps remain. Few studies have adequately investigated abrasion of basalt sands via aeolian abrasion and these previous results are not scalable to determine the geological significance. Most experiments have focused on the abrasion of quartz or granitic rocks, with few studies investigating the production of dust by abrading basalts, sedimentary rocks, or metamorphic rocks. Previous glacial grinding experiments that did not use ring shear devices used wheels of rock and sediment, ground against each other, rather than focusing on subglacial clasts and their shapes (Matthews, 1979; Lee and Rutter, 2004).
In this study two new experimental devices are used, which have been designed to better replicate aeolian abrasion and glacial grinding. The aeolian abrasion chamber is designed to simulate grain-on-grain collisions of sand saltating in a windstorm at high velocities (~40 m/s). The glacial grinding device abrades small rock fragments cut with flat and pyramidal (pointed) surfaces against a flat rock slab to emulate the grinding of clasts beneath a glacier. The aeolian abrasion experiment focuses on the abrasion of basalt sands from Hawaii and Iceland as analogs for Mars and compares them to results from quartzose sand from the Imperial Sand Dunes of southern California. The glacial grinding device abrades five basalts as analogs for Mars and eleven different rocks (granitoids, quartzites, a schist, sandstones, and limestones) as analogs for Earth-based glaciation.
We compare our results with previous dust production experiments and studies of dust to test two questions: (1) Do different abrasion mechanisms produce representative particle size distributions (PSDs) tied to the mechanism of production? (2) When abraded, do different lithological compositions produce dust at different rates and PSDs with defining traits based on composition? Results show that basaltic sand from Iceland produced 4 times more dust and 2.5 times more fine sand than Hawaiian samples. These experiments demonstrate the significance of dust production by aeolian saltation of basalt sand at the planetary scale and infer the possible influence of produced dust on the climate of early Mars. Results are scaled to determine dust production at the planetary level and suggest Mars would produce a geologically significant amount of dust capable of influencing the climate.
Results from experimental glacial grinding of small (~3 cm) clasts of varying lithologies (representing Earth and Mars) show that rock-on-rock abrasion produces sediment with PSDs containing silt modes (~30 µm). Pointed styluses generally produce more sediment than flat styluses. Pointed and flat styluses of the same lithologies generally produce similar PSDs. PSDs across all lithology and stylus types produce similar modes at 0.5 µm, 4-8 µm, 30 µm, and 100-300 µm. When our PSD results are compared to natural dust sources and previous experiments replicating a range of abrasion processes (e.g., volcanic dust, lunar dust, glacial grinding, aeolian abrasion, fluvial abrasion, mechanical crushing) the same modal ranges occur. Our study suggests an underlying physical process operating across abrasion mechanisms, varying mineralogical compositions, and clast shapes that limits PSD modes to specific ranges
