17179 research outputs found
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Oral history interview: Frances Campbell
No full textEdited and unedited video files available with closed captioning. Unedited, raw transcript available.Gloria Gallagher is interviewed about her mother, Frances Campbell. Frances served in the United States Army
Macrocyclic Ni Complexes Model the Methyl-Coenzyme M Reductase Active Site Structure
No full textNo abstract prepared.Chemistry and Biochemistr
Oral history interview: Frank Zertuche
No full textEdited and unedited transcript files (.pdf) and edited and unedited video files available with closed captioning.Interview with James Zertuche about his father, Frank Zertuche. James discusses his father's life, his memories of him, and his parent's life together
The Biopsychosocial Experiences of Drum Corps International Members, A Descriptive Study
No full textThe purpose of this study was to describe the biological, psychological, and social aspects and environment of Drum Corps International (DCI) through the analysis and evaluation of anonymous survey questions. Survey participants (N = 584) reflected on their past marching experiences, and answered questions split into biological, psychological, and social categories. The data from the survey is written out as a descriptive study for other researchers to use as statistically significant data. Key findings include relevant statistics that present a large majority from the participants’ responses, along with a general pattern of participants having experienced a higher amount of time spent on DCI than on non-DCI.Musi
Exploring Latent Patterns in U-Turn Crashes: A Dual-Model Approach Using Association Rules Mining and Cluster Correspondence Analysis
No full textU-turns are essential maneuvers in modern roadway networks, enabling vehicles to reverse direction and improve network connectivity. Despite their operational benefits, U-turns are often associated with elevated crash risks due to their complex interactions with opposing traffic, geometric design, driver behavior, technological challenges, and environmental conditions. Existing research frequently aggregates U-turn crashes within broader intersection studies, limiting the understanding of maneuver-specific crash severity. This thesis addresses this gap by applying advanced data-driven analytical methods to examine U-turn crash patterns and contributing factors using Ohio crash data from 2017 to 2021. Association Rule Mining with Lift Increase Criterion (ARM-LIC) was employed to identify significant combinations of factors associated with higher crash severity, highlighting key interactions among risk elements. Notably, multi-vehicle involvement, high posted speed limits (65–70 mph), commercial motor vehicle presence, and poor lighting conditions were found to elevate crash severity with lift values exceeding 40.5 in the most severe scenarios. Cluster Correspondence Analysis (CCA) further classified crash records into six clusters with distinct severity profiles. Clusters characterized by factors such as high posted speed limits, driver impairment, and multi-vehicle involvement consistently demonstrated higher severity risks, while others emphasized environmental contributors like dark, unlit roads. These findings demonstrate the multifactorial nature of U-turn crash risks and underscore the importance of utilizing both ARM-LIC and CCA as complementary analytical tools. The combined use of ARM-LIC and CCA provided comprehensive insights into risk patterns, enabling a solid foundation for developing targeted safety interventions and informed design practices aimed at improving U-turn facility safety.Engineerin
Money, money, money
No full textIn this workshop we will discuss what researchers need to know about how federal policy changes are impacting research sharing. Join Assistant Director of Research & Data Services Alexa Hight as she covers information about public access policies for some of the larger federal funding agencies.University Librarie
Advancing Diamond Growth Techniques: Investigating the Impact of Multi-Stage Methane Concentration on Diamond Growth using HFCVD
No full textThis dissertation presents a comparative study of polycrystalline diamond films grown using a two-step methane concentration approach in hot filament chemical vapor deposition (HFCVD), with the goal of achieving high-quality films in shorter growth times. The research investigates how the sequencing of methane concentrations affects the coalescence of diamond seeds, total growth rate and final diamond quality.
Previous study shows that using a higher methane concentration increases the growth rate as well as non-diamond carbon (NDC) content due to the availability of more methyl radicals. And using low methane concentration (1.5% or 1.0%) results in enhanced quality (low NDC content) diamonds due to more H-etching than higher methane concentration growth. However, doing so requires longer growth time due to the availability of less methyl radical. Consequently, processes within the HFCVD framework are needed to minimize the growth rate while keeping the diamond quality comparable to lower-concentration methane growth. This dissertation presents a detailed study on the growth and characterization of polycrystalline diamond films using a two-step methane concentration growth in HFCVD. The goal was to balance growth rate and film quality by combining the advantages of both high and low methane concentration during the growth.
Multiple samples were grown using both two-step and single-step methane concentration growth using methane concentration varying from 1.0%-3.0%. The two-step growths included sequences with high-to-low and low-to-high methane concentrations, while the single-step processes used either high or low methane concentration throughout the growth. The samples morphology was thoroughly characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), high-resolution scanning transmission electron microscopy (HRSTEM), X-ray diffraction (XRD) and diamond quality was assessed using in-built UV-Raman spectroscopy.
Two different approaches were used to study diamond films using a two-step methane concentration growth. In the first approach, growth was initiated with a low methane concentration followed by a transition to a higher concentration. In the second approach, a high methane concentration was used in the initial phase, followed by a lower concentration in the subsequent phase. For similar thickness samples, comparative analysis of these methods revealed that initiating growth with low methane concentration resulted in lower-quality diamond films, as indicated by a reduced Raman peak intensity ratio and full width half maxima (ΔFWHM) values (~0.31 and 4.1 cm⁻¹, respectively). In contrast, the high-to-low methane growth produced better film quality, with a higher Raman peak ratio (~0.48) and narrower ΔFWHM (~3.9 cm⁻¹). This improvement is attributed to the fact that higher methane concentration in the initial phase promotes faster coalescence of diamond seeds, while the subsequent lower methane phase provides a hydrogen-rich environment that enhances the etching of non-diamond carbon (NDC). Thus, the high-to-low methane transition proved to be a more effective strategy for producing high-quality diamond films.
Another significant outcome of the two-step methane concentration growth is its ability to achieve comparable diamond film quality in a significantly shorter growth duration compared to conventional single step lower methane concentration growth. For instance, the two-step growth using 3.0%-1h+1.5%-3h, yielded a Raman peak ratio and ΔFWHM of ~0.68 and 3.40 cm⁻¹, respectively. These values are comparable to those obtained from, single-step growth using 1.5%-7h, which showed a peak ratio and ΔFWHM of ~0.68 and 2.96 cm⁻¹. This indicates that the two-step approach can produce similar crystalline quality while reducing the total deposition time by nearly 40%.
Overall, this research validates an efficient two-step methane growth method for producing high-quality polycrystalline diamond films with fewer defects, better morphology at reduced growth time. These findings offer a promising pathway toward integrating diamond into next-generation high-power electronics and thermal spreaders.Materials Science, Engineering, and Commercializatio
Impacts of Human Land Use and Environmental Factors on Gray Fox (Urocyon cinereoargenteus) Morphology and Diet
No full textEvaluating species that thrive in anthropogenically changed environments can provide insight into the traits that promote success when living in close proximity to humans, along with the traits that may change in response to these habitats. Not all animals are capable of surviving in anthropogenic areas given the way that these habitats affect diets, habitat usage, and resource availability. Human land use has been shown to be detrimental to certain species such as apex predators, but beneficial for mesocarnivores, given their smaller home ranges, faster reproduction rates, and wider dietary preferences. Urbanization can lead to differences in the diets and seasonal resources available to wildlife and has been associated with changes in mesocarnivore diets due to supplemented food items and seasonal food resources becoming strained. Gray foxes (Urocyon cinereoargenteus) have a highly opportunistic diet that varies geographically and seasonally, with contrasting reports regarding their success in anthropogenic areas. These ecological characteristics make them an ideal study species to assess how anthropogenically changed areas can impact mesocarnivore ecology, however; the effects of urbanization have not been fully explored in this species. This study assessed the morphological variation of gray foxes among various spatiotemporal and anthropogenic gradients as well as the diet of gray foxes seasonally and among urban and non-urban areas. For the morphological analysis, I used 2D geometric morphometrics to investigate how gray fox skull shapes are related to environmental conditions and anthropogenic disturbances, using the geographic coordinates where skulls were collected. I extracted climatic conditions from the HCLIM database and anthropogenic data associated with the collection period for each sampled location from Anthroecology.org. Using General Linear Models and Tukey’s pairwise comparison analyses, I found that gray fox skulls show moderate variation due to differing degrees of anthropogenic change, although spatial factors were more consistently related to morphological variation. To examine if seasonal and anthropogenic factors influence gray fox diets, I used chi-square (χ2) analyses to test whether the frequency of prey items in gray fox scats varied between summer and winter seasons, and between non-urban and urban areas, with diet data sourced from the CarniDiet.v1.0 database and local collections around San Marcos, TX. Results indicated significant seasonal differences between summer and winter diets, and significant differences in gray fox diet between urban and non-urban areas. This study will continue to augment our understanding of how anthropogenic land use impacts mesocarnivore ecology and how natural resource use might be influenced by humans.Biolog
Preliminary Mechanistic Optimization of Two-Mat Reinforcement Design in Continuously Reinforced Concrete Pavement
No full textIn thick continuously reinforced concrete pavement (CRCP), thicknesses greater than 356 mm, the Texas Department of Transportation (TxDOT) places longitudinal steel in two mats, with equal amount of steel in both top and bottom mats. These longitudinal steel layouts may not be optimal for restraining concrete volume changes from temperature and moisture variations (environmental loading), which are most severe near the surface. This study mechanistically evaluated and optimized two-mat reinforcement layouts by placing more steel in the top layer while reducing the amount in the bottom layer. A total of 2160 three-dimensional finite-element models were developed in ANSYS to examine how variations in steel depth and spacing influence steel stress, concrete stress, and crack width under different environmental loading conditions. The results indicated that top-focused configurations with reduced bottom reinforcement satisfied all performance thresholds for steel and concrete stresses as well as crack width, reducing concrete stress by about 4% and 11% for 356 mm slabs and about 13% for 381 mm slabs, and reducing crack width by about 2% for 356 mm slabs and about 5% for 381 mm slabs. These optimized designs achieved performance better than the existing TxDOT two-mat design standards while requiring less steel amount. The findings in this study will be validated in the field experiment in the second phase of the study.EngineeringMaterials Science, Engineering, and Commercializatio
Insanity or Accountability? Evaluating the Viability of the Insanity Plea for Individuals with Antisocial Personality Disorder
No full textThis thesis explores the intersection of antisocial personality disorder (ASPD) and the insanity plea, assessing whether or not those diagnosed with ASPD qualify for legal exculpation through the insanity plea. This thesis will explore the intersection between law, psychology, and criminal justice while raising critical questions regarding how legal policies account for human behavior, mental health, and public perception. Although ASPD is often linked to criminal behavior, the criteria for both the insanity plea and ASPD rarely align, creating tension between psychiatric diagnosis and legal responsibility. While there are historically negative attitudes and misconceptions regarding the insanity plea, case studies and legal precedents, such as State v. Meiser and high-profile trials involving James Holmes highlight the complexity of mental health and the separation between volitional incapacity and intentional acts. While being diagnosed with ASPD has a greater risk for violence, research shows that individuals have a general understanding of the wrongfulness of their actions, undermining the criteria for the insanity plea. This paper argues that while individuals diagnosed with ASPD rarely qualify for the insanity plea, it does, however, raise questions regarding the fairness of the legal system surrounding mental health while highlighting the weaknesses of both psychiatric frameworks and legal standards, raising questions about culpability, fairness, and the treatment of mental illness in the criminal justice system.Englis