Graduate Theses and Dissertations

Permanent URI for this collectionhttps://hdl.handle.net/10877/135

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2-D Transition Metal Cyanide Nanosheets as Precursor Material for an Ultra-Low Platinum Group Metal Catalyst
(2014-05) Nash, Tyler; Beall, Gary W.; Powell, Clois E.; Martin, Benjamin R.; Ji, Chang; Badrinarayanan, Vishag A.
Two methods were developed to coat activated carbon with NiPt(CN)4 nanosheets by reacting potassium tetracyanoplatinate(II) with nickel(II) sulfate in the presence of the carbon substrate. The modification of pH released nickel(II) ions from the carbon surface to participate in the reaction. Upon pyrolysis, a Pt-Ni alloy was formed. Based on EDS and XPS data, platinum had segregated to the surface of the metallic structure in higher concentration samples. The Pt-Ni catalyst exhibited significant activity in the hydrogenation of styrene to ethylbenzene. When compared to a catalyst prepared by traditional methods, the Pt-Ni catalyst prepared from NiPt(CN)4 nanosheet precursors exhibited up to 2.8x the activity on a platinum metal basis.
2-Dimensional Intercalated Cyano-Metallate Complexes- Approach to Ultrafiltration
(2019-05) Adebiyi, Babatunde Mattew; Beall, Gary W.; Martin, Benjamin R.; Lewis, Kevin; Zakhidov, Alexander; Chittenden, William T.
The discovery of graphene and other two-dimensional (2-D) materials has opened the way for a huge opportunity in material development, manipulation, and their corresponding potential applications. 2-D materials including graphene have been shown to have unique properties such as high electrical conductivity, high mobility, and high surface area. These properties have made 2-dimensional materials amenable to small scale electronic applications, molecular sieves and for high strength composite applications. Despite the promise graphene holds, it has been difficult to completely harness its potential because it is difficult and expensive to produce single layer graphene sheets in substantial quantity. A unique class of 3-dimensional nanomaterials that can be produced in substantial quantity and cost effectively processed into 2-dimensional hybrid structures are the Metal Organic Frameworks (MOFs). MOFs, which are basically a composition of molecular complexes formed between metals and salts, organic and inorganic molecules, have been rationalized to be a coordination complex with a stereospecific structure. Transition Metal Cyanates are a unique class of 3-dimensional cyanometallate network. The most common are hexacyano transition metal complexes with divalent transition metal counter ions. We have prepared and exfoliated transition metal cyanates into 2-dimensional structures by exfoliation into separates sheets. Hybrid 2-D structures have also been produced and studied by intercalation with organic linkers. Density Function Theory (DFT) studies have predicted an increase in the d spacing of potassium tetra-cyanonickelate, on substitution with di-metallic cation such as Fe2+, Mn2+, Cd2+ and Co2+, and additional processing with organic linkers. Dodecyl pyrrolidone (DDP) was used to intercalate the metal complexes and X-ray diffraction results showed significant peak shifts to the left on all metal complexes, corroborating the DFT predictions. The increased distance between layers allows for further separation into exfoliated sheets. In this report, we have demonstrated an approach for producing a long range defect-free 2-D sheets. We have grown di-metallic cation complexes of Fe2+, Mn2+, Ni2+ and Co2+ on Teflon supports. This was done by placing hydrophilic 1.0 micron Teflon as a barrier between a desired salt of the complex and potassium tetracyano nickelate. The desired metal complex was formed by diffusion of the opposing solution in the Teflon support. The membrane was dried and used as barrier for Na+ ion selectivity test. The test was carried with 1.0 M NaCl. The solution was pumped under vacuum through the membrane, and a pristine membrane was used as a control. Results showed that the Fe and Mn tetracyano nickelate selectively reject Na+ ion salts while control experiments proved otherwise. These results hold promise for material applications in waste water remediation, separations, desalination, and purification. In this work, we also reported a simple process of synthesizing Nickel Ferrite-graphitic layers with inverted magnetic hysteresis.
2020 Golden-Cheeked Warbler (Setophaga chrysoparia) Range Wide Breeding Habitat Availability and Change Detection
(2022-12) Colgan, Kevin S.; Jensen, Jennifer L. R.; Duarte, Adam; Krause, Samantha
No abstract prepared.
3D Sketch Recognition Using The Microsoft Kinect
(2014-05) Bulgerin, Travis; Lu, Yijuan; Ngu, Anne; Zong, Ziliang
The concept of sketch-based recognition has recently been used to enhance object categorization and speed up image retrieval. However, in each of the previous studies, the user was required to sketch on a two-dimensional plane. Currently there haven’t been any studies on the performance of incorporating depth information into a sketch. The motivation behind this project is to develop software that will allow a user to draw in a three-dimensional space, incorporating this information, as well as determining whether this depth information will result in higher accuracies for object categorization. First, utilizing the Microsoft Kinect, software was developed to establish a virtual drawing board for three-dimensional sketching. Second, a new learning-based approach is proposed to allow for model feature extraction and recognition. The experimental results demonstrate the validity of the study as well as the effectiveness of the proposed solution.
5-Bromodeoxyuridine- and Ethyl Methanesulfonate-Induced Temperature-Sensitive Mutants of Bacteriophage SH-133: Isolation, Complementation, and Partial Phenotypic Characterization
(1977-12) Friedrichs, William Eugene; Aron, Gary Michael; Meyer, George; Willms, Charles
No abstract prepared.
A (Re)Vision of Critical Pedagogy for Inclusion
(2013-05) Pina, Manuel Agustin; Jackson, Rebecca; Pimentel, Octavio; Balzhiser, Deborah
No abstract prepared.
A 4-Week Neuromuscular Stimulation Intervention on Skeletal Muscle Fatigue in Older Adults
(2020-08) Mendoza, Monica A.; Mettler, Joni A.; Kipp, Lindsay E.; Doucet, Barbara M.
No abstract prepared.
A Biaxial Magneto-optical Kerr Magnetometer for Studying Magnetic Thin Films
(2000-05) Watts, Charles B.; Geerts, Wilhelmus; Galloway, Heather; Michalk, Victor
I have designed and built a biaxial magneto-optical Kerr magnetometer to study thin magnetic films. The design enables researchers to measure perpendicular and in-plane hysteresis curves of ultra thin films down to a thickness of 9 A. The optical components are fastened to a vibration isolation table and the sample is suspended between the pole pieces of an electromagnet resting on the floor. The magnetometer allows for the examination of two independent Kerr effect measurements for application in magneto-optical recording. I have tested the equipment on ferromagnetic films and Fe/ Al2O3 multilayers. Angle dependent measurements show that the polar magneto-optical Kerr effect diminishes as the poles are rotated towards an in-plane applied magnetic field. Polar and longitudinal measurements on the Fe/ Al2O3 multilayers show that a change in the reversal mechanism occurs for films thicker than 15 A.
A Brief Historical-Legal-Political Perspective of the Arab-Israeli Conflict
(2008-12) Sherman, Trent Anderson
No abstract prepared.
A Brief History of the Civilian Conservation Corps, 1932-1937
(1966-08) Smith, Richard Gary; Conrad, David E.; Pool, William C.; Hughes, Marshall
No abstract prepared.
A Brief History of the United States Magazine and Democratic Review and its Attitude Toward the Issues of Temperance, Peace, and Abolition
(1971-05) Kennedy, Larry J.
No abstract prepared.
A Brief Study of the Effects of a Regular Program of Physical Activity on Basal Metabolism
(1945-08) Brown, Jonnie June; Crosslin, Hiawatha; Smith, C.S.; Wiley, E.O.
No abstract prepared.
A Brief Survey of the Historical Background and of the Present Status of Music Education in the Negro Schools of Texas
(1950-08) Bartley, Ruby Ruth; Tampke, R.A.; Buchanan, Mary G.; Grusendorf, A.A.
No abstract prepared.
A Broader View of Conservation: Mapping Nature and Culture in Gillespie County, Texas
(2023-05) Weathersby, Joanna; Julian, Jason; Sansom, Andrew; Currit, Nathan
Working landscapes are cultural landscapes with natural value that provide tangible and intangible benefits to people. The development of working landscapes and other rural lands has been increasing, especially in regions experiencing rapid urban growth. Ensuring the future of working landscape benefits is especially challenging where private ownership is dominant. Available conservation options (e.g., conservation easements, cultural designations) rely on the preference of private landowners that also face a heightened incentive to subdivide or sell. To advance the conservation of working landscapes, this research developed a spatial inventory of broad landscape benefits (ecosystem services) beginning with a case study at a private ranch. The inventory was then adapted and expanded at the county level where benefits from cultural, regulating, and provisioning categories were mapped from publicly accessible sociocultural and environmental data repositories. Based on categorical and spatial variation in the mapped benefits inventory, four conservation targets zones were identified and framed within the context of conservation planning and tradeoff analyses.
A Burkeian Analysis of Three Organizations According to General Systems Theory
(1975-08) Carpenter, Hellen I.; Salem, Phil; Gabbard-Alley, Anne; Stedman, Alex
No abstract prepared.
A call recognition approach for endangered or threatened chorusing amphibian species using deep learning architectures
(2020-12) Islam, Shafinaz; Valles, Damian; Forstner, Michael; Stern, Harold
Audio signal analysis has become prominent in biological domains for detecting endangered or threatened species like Houston toad and Crawfish frog. Researchers at Texas State University and Texas A&M University are working on a project to steward these species and understanding the causes of their decline. The researchers are currently using an Automated Recording Device (ARD), the Toadphone 1, which is an embedded solution. The hardware platform can perform detection tasks without human interruption and can provide near real-time notification. However, this device’s predictive model for the software solution has limited success to serve the primary purpose for which it was developed, which is to provide proper identification of Houston toad calls. Also, the current predictive model for Toadphone 1 was only designed for the Houston toad calls. There is another near-threatened chorusing amphibian, the Crawfish frog, which has become a concern of the researchers working to protect this species. This thesis research experimented with a modified predictive model for the existing Toadphone 1 software solution, predicting a Houston toad call with decreased false-positive rates. The model can also perform the call recognition task for Crawfish frog calls. This work used the audio data for Houston toad and Crawfish frog collected by the Department of Biology to train the predictive model. Before training, the audio data spectrum was studied to find the frequency range of Houston toad and Crawfish frog call. Next, the audio data have been iteratively preprocessed using digital filters and then applying framing, the Hamming window function to each frame. Mel-frequency Cepstral Coefficients (MFCCs) with their first and second derivatives or Spectral Sub-band Centroids (SSCs) or Mel-spectrograms audio features have been extracted for each frame. These features were used to train the predictive or classification model for Houston toad or Crawfish frog call prediction. Advanced Recurrent Neural Network (RNN) algorithms such as Long Short-Term Memory unit (LSTM) or Gated Recurrent Unit (GRU) and Convolutional Neural Network (CNN) were utilized, which are sub-fields of deep learning network architectures. Several model architectures were experimented with using different combinations of classifiers and audio features with tuned hyperparameters to build the best predictive model. The voting mechanism of ensemble learning was developed to make the final prediction from the three-best models. Lastly, the predictive model was evaluated on a near real-time prediction system.
A Cambridge Mass by Ralph Vaughan Williams: A History, Context, and Analysis
(2013-12) McClarney, Kevin Blake; Schmidt, John C.; Mooney, Kevin; Babcock, Jonathan
Ralph Vaughan Williams is recognized as being one of England’s most prolific and nationalistic composers of the early 20th century, incorporating such nationalistic elements as English folksong, imagery of English pastoralism, and Tudor music. Nevertheless, Vaughan Williams’s mature style familiar to both scholars and fans did not begin to take shape until the beginning of the 20th century. In 1899, Vaughan Williams completed a mass as his doctoral music composition, later known as A Cambridge Mass.1 The 1890s was a time of musical development, inspiration, and education for Vaughan Williams. This mass, written for double chorus, four vocal soloists, and orchestra, is an example of his musical development at the end of the nineteenth century along with some foreshadowing elements of his mature style. Predating A Sea Symphony (1909), his other massive choral work and possibly his most well known, A Cambridge Mass remained hidden in the Cambridge University Library for 111 years until scholar and conductor Alan Tongue discovered it in 2007. This thesis will discuss Vaughan Williams’s educational background and influences during the 1890s by examining biographies, his autobiography, personal letters, documentaries, and other secondary literature in relation to A Cambridge Mass in order to fully understand which composers and teachers and what compositional techniques influenced Vaughan Williams. In the first chapter, drawing from articles, reviews, and interviews of Tongue and details surrounding the background of this piece, I will describe Tongue’s discovery, editing process, and performance history. Finally, I will investigate the similarities and differences between this early work and his later style, highlighting musical examples of his early influences in the second chapter and the hints of Vaughan Williams’s mature style in the mass along with the conclusion in the final chapter. Also, the third chapter will address the significance of this early work of Vaughan Williams while discussing which scholars and musicians have been studying and performing this work and others who have not been researching and performing such early Vaughan Williams compositions as A Cambridge Mass.
A Case Study - Hydraulic Fracturing Geography: The case of the Eagle Ford Shale, TX, USA
(2012-08) Wenzel, Cortney; Dixon, Richard; Zhan, Benjamin; Butler, David
The use of horizontal drilling in conjunction with hydraulic fracturing has increased the ability of producers to extract natural gas and oil from previously non-viable areas. By extracting natural gas and oil from low permeability geologic plays, or shale plays, the United States may have enough natural gas to burn for the next one hundred years. However, there are growing concerns about the effect hydraulic fracturing may have on the environment and surrounding ecosystems. These activities cause an increased potential for surface water contamination resulting from spills, leaks, soil erosion, large amounts of truck traffic, and habitat disturbance. With increasing amounts of hydraulic fracturing activity in the Eagle Ford structure, there is a greater chance that a spill may occur and cause adverse effects on the hydrologic processes in the area. In order to determine the risk spills pose to hydrologic processes, hydraulic fracturing wells were identified and mapped to show the distance from wells to streams as well as determining that spills in the Eagle Ford structure were not spatially auto-correlated.
A Case Study of Middle School Teachers' Perceptions of Their Professional Development Experiences With TAP -The System for Teacher and Student Advancement
(2011-12) Womack, Damaris; Ross-Gordon, Jovita M.; Gordon, Stephen P.; Huling, Leslie L.; Jacobs, Jennifer L.
This research was undertaken to understand the experiences of teachers using The System for Teacher and Student Advancement (TAP) professional development (PD) methods. The study focused on the perceptions of experienced teachers in their first year in a TAP system school. Five teachers were interviewed and observed in the professional development, (TAP/PD) - meetings during the study. This research provides insight into experiences with a professional development model within a new school improvement system in order to contribute to the literature about professional development. This research addresses the following major questions: a) How did TAP/PD come to be adopted at the selected middle school, and b) What are the perceptions of teachers at a selected middle school of their professional development experiences with TAP/PD? This qualitative study included multiple data collection strategies. Through this case study, teachers were observed during their TAP/PD meetings. They were asked to participate in two to three follow-up interviews after the observations to understand the nature of their experiences with TAP/PD and how professional development in this model compared with their previous experiences with professional development. They were also asked about their perception of the influence of using the TAP/PD learning on their classroom practice, their professional growth, and on their students' achievement. Regular visits to the school community also allowed for the collection of artifacts before, during, and after the author concluded the interview stage at the site. The qualitative analysis of the teachers' experiences of their professional development during their first year of implementation as a TAP system school involved open and axial coding, drawing on all the data sources as well as analytic memos. The findings revealed a) limited administrator participation in TAP/PD meetings or involvement as instructional leaders; b) unclear roles of mentor teachers; c) coaching support that focused mainly on first year teachers, limiting the impact on more experienced teachers such as the study participants; d) blurring of the focus on instructional support by master teachers due to their many duties; e) increased time participating in professional development compared to other models; f) valuable strategies and rubrics supported school-wide learning; and, g) teachers' increased levels of reflection on their classroom practice.
A Case Study of Qualitative Factors in Making Venture Capital Investment Decisions
(2017-05) Brunner, Frances; Stokes, Alexis; Minifie, Jana; Hood, Matthew
When a startup requires large capital backing, it can expect to seek out the venture capitalist. Understanding the process and priorities of the venture capitalist is necessary to gain funding approval on more than just a good business plan, a positive revenue model, or being a likeable person. This study gives a current view of the modern venture capitalist and the elements of their decision making for the edification of entrepreneurs in the funding stage, to understand and avoid pitfalls of their presentation and unspoken communication for nonfinancial components of their business persona. Five interviews have been conducted with venture capitalists residing in the Austin area and two interviews with subject matter experts (SMEs) who have been directly influenced and are consultants in venture capital decision making. These individuals have shared their experiences and methodologies in finding inimitable opportunities for high growth ventures. An explanation of venture capital review methods is presented, followed by a case study and summary of commonalities and contradictions between interview outcomes.

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