SHAREOK Repository
Not a member yet
49261 research outputs found
Sort by
Plumbing the prairies: water management in the agricultural Midwest, 1850-1920
No full textThis dissertation examines the use of state authority to manage natural resources and how the application of that authority changed over time. Between 1850 and 1920, Iowans interacted with the state’s prairie environment by converting it into grain-producing croplands. While this remarkable environmental transformation is most apparent in the controlled aesthetics of Iowa’s agricultural landscape, it is through the construction and maintenance of water management systems, or drainage infrastructure, that such a high level of environmental control is achieved. Drainage systems are a form of public infrastructure that are managed locally, at the county level of government. Through a study of the institutional origins of locally-led management of public drainage infrastructure, this dissertation argues that state-led natural resource conservation in Iowa never centralized around a coherent multiple use program at the State of Iowa or federal level, but rather modernized around locally-led institutions that prioritized drainage over other natural resource uses and users
Where was I? Distractions during information gathering
Get PDFThe literature on creativity has long held that one of the most central processes central to the success of any creative problem-solving endeavor is the gathering of information that is pertinent for task completion, most notably the key facts and anomalies that are at play in the specific creative context. However, previous findings regarding the relationship between distractors and creative performance have been mixed. We review the arguments present in the literature surrounding the potential benefits or drawbacks of distractors for creativity. We then in turn investigate, using an undergraduate sample, the effects of task-relevant or task-irrelevant distractors as well as time pressure on the information gathering process as part of an educational leadership task requiring creative problem-solving. Participants were asked to take on the role of principal at a new experimental high school. These participants were required to read through a wealth of information related to task completion and were then tasked with creating a plan to “achieve academic excellence” in their new experimental high school. Outcomes included amount of information gathered, the extent to which gathered information included key facts and/or anomalies, and the quality, originality, and elegance of final plans. Findings indicate that distractors extend information search, but do not contribute to the gathering of key facts or anomalies. Distractors also did not impact quality, originality, or elegance of creative plans. Implications of these findings for practice and future research are discussed.
Keywords: creativity, distraction, information gathering, problem-solvin
Trauma-Informed Bal-A-Vis-X: An Evaluation Study
Get PDFThis evaluation study of Trauma-Informed Bal-A-Vis-X (TIB) training in Norman Public Schools investigated whether TIB training affected teacher perceptions of student behavior, teacher self-efficacy, and teacher usage of trauma-informed strategies in the classroom. Participants (N=230) were asked to complete a set of three surveys related to teaching students of trauma. The participants were comprised of three groups based on their self-reported background experiences of previous trauma training: those who have had no prior trauma training, those who have had prior trauma training other than TIB training, and those who have had prior TIB training. The mean scores of the three groups were compared. Results showed that those who reported having attended TIB training indicated a greater sensitivity to possible trauma-based motives for student behavior, higher self-efficacy for working with students of trauma, and greater usage of trauma-informed strategies compared with those who had not attended TIB training. Since this study was limited to the context of educators in Norman Public Schools, additional research is needed to determine if these results can be applied to other contexts
Constitutive Behavior of Wellbore Cement
Get PDFCement is one of the most integral components of a wellbore, yet minimal experimental research has been done to understand the basic processes as to what ensures a cement sheaths’ success. Globally, minimizing greenhouse gas emissions has become one of the most influential factors in material selection for both households and industries, and it is common knowledge that the manufacturing of cement is one of the largest contributors to greenhouse gas emissions, specifically, carbon dioxide. Industries that rely on cement for structural purposes, including the petroleum industry, have begun to investigate cement alternatives or cement replacement materials to minimize the emissions associated with cement manufacturing. Pozzolanic materials such as fly ash, slag, and metakaolin are common wellbore cement additives that have proven to be advantageous in achieving the required downhole mechanical properties but many of these materials have also become less prevalent as emissions are reduced due to their cost and availability. During the drilling process, there is an abundance of a pozzolanic material that has not been utilized as a cement additive or replacement material: shale. In this work, an investigation on the poroelastic constant for class H wellbore cement is conducted. The poroelastic constant is a common input parameter for wellbore modelling and is regularly assumed to be the same as unconsolidated material. The poroelastic constant is a key parameter for determining effective stress and has an impact on cement design in wellbores. Consolidated isotropic drained (CID) testing on class H cement is also performed at three confining stress to obtain a Mohr-Coulomb failure envelope. During CID testing, the samples are sheared and an understanding of shear behavior is evaluated. This information can be used to generate more detailed failure criteria for wellbore cements and be applied to cement system designs and modeling programs. From the results of this work, it can be concluded that cement is indeed a poroelastic material. An investigation on curing time, particle size, and additive quantity is also conducted to determine the feasibility of using shale cuttings as a cement additive or replacement material. It has been determined that the samples containing micron particle sized shale tended to have superior results for all quantities when compared to the millimeter and micron samples, possibly due to these particles being similar to the size of the cement. While this work is preliminary, future validation of the findings could be instrumental in decreasing the amount of waste and emissions produced both from cement manufacturing as well as from the recycling of drill cuttings
Rid of me
Get PDFIn the novella Rid of Me, Ridley Royko is a smart, 15-year-old teenager with a parent problem. His mother and father do not trust him and tear him down constantly about his grades and his behavior. When he hears them plotting to send him to military school, Ridley dashes out the front door, barefoot, shirtless and in a panic. His sudden departure sends Ridley on a quest to change his situation, abetted by his teenage crush, high school newspaper editor Blanca Serrano. And in that process, they must help Blanca's sister, the victim of a terrible crime committed by someone in Ridley's orbit. The novella explores child trauma and its psychological effects while also delving into the elements of both positive and negative parenting, through a prism of 1990s music and culture and the early days of the Internet
Performance evaluation of a Cadre Forensics TopMatch-GS 3D system for cartridge case comparisons
No full textThis research presented a series of commonly used firearms and commonly used ammunition brands to evaluate the Cadre Forensics TopMatch-GS 3D system overall and to test for differences between same ammunition and different ammunition comparison scores. For this study, ten casework firearms were shot, producing 30 cartridge cases from each, except two firearms that only had 20 cartridge cases fired from each; for a total of 280 cartridge cases. The ammunition manufacturers used were Blazer, CCI, MaxxTech, Wolf, Remington, and Winchester. This study utilized match and nonmatch scatterplots and ROC curves to evaluate the overall performance of the Cadre Forensics TopMatch-GS 3D. All cartridge cases were inter-compared using TopMatch breech face impression and aperture sheer algorithms for 39,060 comparisons. This research aimed to validate the Cadre Forensics TopMatch-GS 3D, evaluate automated algorithm performance on various casework firearms, and examine possible differences in automated scores between ammunition manufacturers on system performance. The tested firearms and ammunition brands performed well using the Cadre Forensics algorithms. The AUC for all firearms in this study was 0.956 indicating the automated breech face algorithm can differentiate between same and different sources. The same source and same ammunition AUC was 0.988 while the same source and different ammunition comparisons performed slightly worse with an AUC of 0.952. A procedure for comparing AUCs based on the Mann-Whitney test was used to test for significance and the resulting p-value was less than the 0.05 threshold (or 95% level of confidence) indicating that same ammunition brands performed significantly better than different ammunition brands. MaxxTech and Wolf were brass primed and scored exceptionally well regardless of the firearm. Winchester and Remington resulted in lower scores when compared to other ammunition brands. Aperture shears under 800 microns in length provided misleading aperture shear results. Running the breech face algorithm over the combined score feature is recommended as the combined score defaults to the breech face score if the system believes the aperture shear values may be misleading. The data collected in this research will allow for further development and improvement to the Cadre Forensics comparison algorithm and open the door for future research opportunities using this system
Minutes of a Regular Meeting & Retreat, The University of Oklahoma Board of Regents, June 14-15, 2023
No full textEnhancing Performance and Reducing Emissions in Natural Gas Aspirated Engines through Machine Learning Algorithm
Get PDFIn an era where the global energy landscape is increasingly defined by the dual imperatives of efficiency and sustainability, the natural gas sector stands at a crucial juncture. The engines powering this sector, especially Natural Gas Fired Reciprocating Engines (NGFRE), are well known for their performance as well as considerable emissions, posing a stark challenge to environmental sustainability goals. This thesis addresses this pivotal issue, presenting a machine learning-based solution to optimize NGFRE performance while substantially reducing their environmental footprint.
The research is anchored in an experimental framework involving the AJAX DPC-81 engine compressor, evaluated across a spectrum of operational loads from 40% to 75%. The study leverages an extensive array of sensors to collect detailed real-time data on engine performance, emissions, and vibration parameters. Central to the methodology is the strategic adjustment of the Air Management System (AMS), varying air/fuel ratio to explore their impact on engine dynamics and emissions. The study also incorporates a comprehensive vibration analysis, providing critical insights into the engine's operational stability under different load conditions. Machine Learning (ML) techniques, including Linear Regression, Artificial Neural Networks (ANN), and Support Vector Machines (SVM), are integrated with a Programmable Logic Controller (PLC). This integration not only facilitates a nuanced analysis of the collected data but also enables the accurate prediction of engine performance, paving the way for real-time adaptive control systems.
The findings of this research are both revealing and impactful. A notable instance is observed at a 40% engine load with a 70% bypass valve opening, where emissions of methane (CH4) plummet by 64%, nitrogen oxides (NOx) by 52%, and Volatile Organic Compounds (VOC) by 50%. This substantial decrease highlights the effectiveness of the ML-driven approach in curbing harmful emissions. Further, the study unveils the manipulation of the bypass valve position can lead to enhanced fuel efficiency and improved engine stability. For example, at a 75% engine load, the research demonstrates that optimal emission reduction is achieved with a mere 10% bypass valve opening, illuminating the delicate interplay between engine load parameters and environmental emissions.
In conclusion, the study demonstrates the effectiveness of ML in enhancing NGFRE performance. It sets a foundation for developing intelligent engine systems that can self-adjust for optimal performance and minimal environmental impact, forging a path to a future where the two are seamlessly integrated
Training status differences in torque and neuromuscular system variability and complexity during maximal and submaximal fatiguing exercise
No full textNonlinear methods are useful in studying systems where outputs are not proportional or predictable given the inputs and are becoming increasing popular to analyze EMG signal. Complexity and entropy are two of the most used nonlinear methods to examine physiological systems. Physiological complexity has been shown to allow a wider range of adaptable states for the system to deal with stressors. Previous research has shown that complexity is reduced in response to fatiguing exercise. To date no studies have examined the effect of training status on neuromuscular system complexity. Purpose: Therefore, the purposes of this study are to investigate whether training status (aerobic or resistance) affects neuromuscular system complexity at baseline compared to untrained individuals and to investigate whether training status changes the loss of complexity due to fatigue compared to untrained individuals. Methods: The study was split into two experimental visits: a maximal fatiguing test and a submaximal fatiguing test. Thirty-three individuals participated in the maximal test, while 30 individuals participated in the submaximal test. The participants were split into three groups: untrained (UT), aerobic trained (AT), and resistance trained (RT). During the maximal test, the participants performed 30 maximal intermittent isometric knee extensions (6-second contraction/4 second rest) over a 5-minute test. For the submaximal test, the participants maximal voluntary contraction was obtained. The participants then performed a time to task failure protocol by completing as many intermittent isometric knee extensions (6-second contraction/4 second rest) until failure. Surface EMG (sEMG) of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) was recorded continuously during the protocols. The torque signals and sEMG recordings from the contractions were analyzed for complexity using Detrended Fluctuation Analysis (DFA), Sample Entropy (SampEn), Recurrence Rate (REC), and Determinism (DET). The first three contractions (Fresh) and last three contractions (End-Task) of each test were averaged together. Results: During the maximal test, complexity of the torque and EMG signals was reduced at End-Task compared to Fresh (p<0.05). The AT group had lower torque complexity (SampEn) than the UT and RT groups during at Fresh (p<0.05). In addition, the AT group had higher sEMG complexity (DET and SampEn) in the RF and VL at Fresh (p<0.05). During the submaximal test, complexity of the torque signals and sEMG was reduced at task end (p<0.05). The AT group had higher torque complexity (SampEn) and higher sEMG complexity (DET and SampEn) than the UT and RT groups at Fresh (p<0.05). Conclusion: Decreases in complexity and entropy have been shown when there is high motor unit synchronization and conduction velocity. The lower complexity and entropy due to fatigue may be due to changes in central and peripheral mechanisms to continue to achieve task output. Aerobic training may provide increased neuromuscular system complexity