The two-microphone impedance tube test method is a well-established and widely used technique for determining the acoustic absorption coefficient and impedance ratio of materials. This method uses two closely spaced microphones to simultaneously measure the incident and reflected sound waves. A two-microphone impedance tube measurement system made of 6061-T6 Aluminum with a diameter of 3 inches, a 0.5 inch wall thickness, and microphones spaced 2.7 inches apart has been constructed for undergraduate research at Texas Christian University (TCU). These geometrical values suggest a usable frequency range of 50 Hz to 2637.77 Hz as referenced in ASTM Standard E1050-19. Validation of the system was achieved by taking measurements on Owen Corning Type 705 pressed fiberglass board with a 1-inch thickness and comparing them to absorption data provided by the manufacturer. Additional validation measurements were taken without a test sample in place. All validation tests suggest that the TCU impedance tube is an accurate measurement system.

Bacteria, the primary agents of infection in humans, are present on nearly all surfaces. To mitigate the spread of bacteria and infections, disinfectants are commonly used. This study explored the effectiveness of common disinfectants and different methods of disinfection, primarily focusing on the use of spray pumps and a transducer as a mechanism to disinfect surfaces using 70% IPA (Isopropyl Alcohol) or ethanol (often referred to by the brand name Lysol). Tests were conducted on bacterial lawns before incubation. The effectiveness of the tests was determined by observing bacterial growth over the next 24 hours after disinfection. Testing proved that both ethanol and 70% IPA are effective in stopping bacterial growth. While both the transducer and spray pump methods showed success, the transducer/ethanol combination was particularly efficient, using the least amount of disinfectant.

Thermal oxidation is an important process to create a thin film of silicon dioxide on silicon substrates in microfabrication. In this project, thermal oxidation characteristics on the silicon wafer will be analyzed through experiments in the clean room. The research method was conducted in the thermal oxidation furnace in the TCU Cleanroom on nine wafers with different placement orientations in the furnace and three different oxidation temperatures: 950°C, 1000°C, and 1050°C. In addition, oxide thickness measurements between different locations on the wafer were taken to investigate the film uniformity. The data analysis showed three trends: 1. oxide thickness varies across the wafers, 2. oxide thickness varies as a function of the furnace location, and 3. oxide growth rate varies as a function of furnace temperature. This project investigates how these factors impact thermal oxidation, one of the most critical steps in microfabrication

The Digital Micro-Mirror Device (DMD), which was originally developed for digital projection using visible light source, has seen numerous applications in automotive, manufacturing, spectroscopy, and underwater imaging that require wavelength beyond visible. The DMD window is an important part of the packaging that protects the digital mirror array. Since the light goes through the top and bottom surfaces of the window glass twice during operation, the transmittance of the window is usually optimized for the range of wavelengths specified by the applications through optical coatings. In this research work, we will explore the effectiveness of the optical coatings for different types of glasses for window transmittance improvement in visible and near-infrared wavelengths. We will evaluate the transmittance of the existing DMD window glasses and explore ideas of improving transmittance in the NIR range without compromising the effectiveness in the visible light range. In doing so, we would be the light efficiency of the DMD in a wider wavelength range.

Total knee arthroplasty (TKA) is commonly performed to treat severe knee osteoarthritis. Sclerotic subchondral bone may reduce tibial cement fixation by limiting cement interdigitation. Although drilling pilot holes is a common practice to improve fixation, its mechanical effects are not well quantified. In this study, finite element analysis (FEA) with static load fracture mechanics was used to evaluate the effect of drilling on fixation. Factor of safety (FOS) contours were used to define failure, and a failure metric—percent of cement-to-bone contact area failed (PCBCAF)—was introduced as the percentage of the interface with FOS < 1. The experimentally determined failure load of the no-hole model was simulated to obtain a baseline PCBCAF. This baseline was then used to predict the failure load of various drilled configurations (2 mm diameter holes) by identifying the load at which matching PCBCAF occurs.
These results establish PCBCAF as a consistent metric for comparing fixation strength across drilling configurations and guiding experimental design.

Effectiveness and Efficiency of UV-C Lights at Killing Bacteria:

Bacteria lie on surfaces all around us, resulting in a desire to clean or disinfect them to avoid the adverse effects of bacteria. One popular method is UV-C light, which has a wavelength of 200-280 nanometers. This study aimed to determine the effectiveness of UV-C lights in killing bacteria. Tests were conducted using a power sensor and bacterial lawns to determine the impacts of different variables on the effectiveness of UV-C lights. Testing measures were taken to ensure that all data was collected independently and identically. It was found that height, surface placement under UV-C lights, electrical power to lights, and reflectivity had the most significant impact on the effectiveness of the light. When optimizing these variables, it was found that with three and two lights there was a substantial bacteria kill rate once the exposure exceeded 3 seconds. This study has proven that UV-C is an effective and efficient way to kill bacteria on surfaces.

This project delved into the multifaceted world of blacksmithing, merging scientific inquiry with traditional craftsmanship to understand the nuances of metal work and material sciences. The primary objective was to immerse in the practicality of the craft, with the intent of learning the use of essential tools, the operational aspects of a forge, and further developing my knowledge of material properties of metals. In the aspect of material properties, a target was made to cultivate a comprehensive understanding of the manipulation of metal properties, utilizing heat treatment, cooling, and knowledge of metallurgical behavior.

Key milestones were set, including the acquisition of competencies in manipulating metal through heating, working, and cooling to craft rudimentary objects like hooks and nails, progressing towards more intricate creations such as knives and ornamental ironworks. The project's methodology was twofold: an investigative theoretical approach entailing the study of literature and visual resources to build a foundational knowledge base, and an empirical approach through active participation in local blacksmithing workshops.

The culmination of the project saw the successful completion of a functional coat rack and a knife forged from a railroad spike, reflecting both the learned techniques, material science, and personal creative expression. The analytical engagement with metals and forging methods paved the way for producing personalized, high-quality metalworks. The endeavor not only honed a distinctive skillset but also unveiled the potential for a post-graduate entrepreneurial venture specializing in custom-made tools and decorative arts, thereby intertwining the art of blacksmithing with contemporary business opportunities.

Urban trees provide a variety of ecosystem services to an area that allows both humans and animals to thrive in their vicinity. The ecosystem services provided are able to be determined through specific aspects of a tree and their location in relation to buildings and ground cover. These ecosystem services include carbon sequestration, air quality improvement, avoided runoff, and energy effects. Texas Christian University (TCU) was designated a tree campus by the Arbor Day Foundation meaning they commit to making sure that they are planting and preserving the trees that are in their care. This study’s purpose was to determine the ecosystem services provided by the trees in TCU’s care, including the costs of each tree and the services that they provide. By surveying the diameter at breast height (DBH), total height, crown base height, species, crown health and exposure, canopy size, ground cover, and health we are able to determine what services are being provided by the TCU trees. Determining the services is possible through the service iTree Eco where the data was inputted allowing its use in the estimation of the services that the trees provide.

Although bats are extremely important ecosystem service providers, they face challenges accessing suitable drinking resources in urban environments. The objective is to conduct a comprehensive geospatial analysis to assess water sources within Tarrant County. Factors such as tree cover, surface area, and proximity to roads will be evaluated and mapped to determine the suitability of these water sources for bats. The resulting data will contribute valuable insights into the spatial distribution of drinking resources for local bat populations, aiding in conservation efforts and habitat management in the region.

Along the coastlines of America, specifically along the Pacific Coast and the Gulf of Mexico, rising sea levels are causing great levels of coastal erosion, leading to the loss of coastal homes and ecologically valuable land. Climate change affects the rate at which sea levels rise, which in turn determines how quickly coastlines are eroded. The objective is to analyze coastal maps of California and the Gulf of Mexico to determine which coastal factors facilitate or hinder the degradation of coastlines.