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Application of Image-based Techniques to Analyze Coastal Flows and to Evaluate Temporal Wetland Changes
No full textCoastal transport processes occurring at the landward edge of tidal and wave action are important for the diversity of coastal ecosystems, determining nutrient fluxes, the dynamics of sediment and marine pollution during tidal mixing, and controlling coastal geomorphology. Understanding these processes requires large-scale field observations over modest spatial domains to fully resolve their governing mechanisms and to validate and update algorithms in existing numerical and laboratory simulations. This dissertation investigates the application of remote sensing techniques based on UAS and satellite imagery to monitor large-scale coastal processes along the Texas coast, particularly focusing on Galveston Bay, TX. First, surface current mapping methods using UAS video sequences are presented to provide a means of practical measurements of ocean surface currents for the effective prediction of tidal mixing exchange dynamics. The main method, introduced by Stre��er et al. (2017), utilizes a two-dimensional space-plus-time Fourier transform of UAS imagery, linked to the Doppler-shifted dispersion relation fitting technique for surface gravity waves. The resulting current fields reveal the flow structures of tidal currents through inlets at Freeport Harbor and Galveston Bay entrance in flexible spatial resolution. Second, satellite images from Sentinel-2 near Galveston Bay inlet are utilized to bridge the knowledge gap between a series of laboratory, numerical, and limited field studies on tidal vortices to observe their large-scale formation and the influence of coastal currents. A classification scheme is introduced to identify two types of vortex flow patterns observed in the satellite imagery. This classification scheme is validated at Galveston Bay using different satellite images from MODIS with a larger dataset. Lastly, shoreline change monitoring at coastal wetlands in Galveston Bay is explored, leveraging geospatial mapping from UAS imagery enhanced by a new georectification technique adapting the particle image velocimetry (PIV) algorithm. A time series of wetland maps, generated using a Structure-from-Motion (SfM) technique, facilitates the computation of shoreline change rates along the observed wetland boundaries. Subsequent statistical analysis of these rates allows for an assessment of the impact of seasonal variations and storm events on short-term wetland evolution
Interaction of Rhodococcus equi with Innate Immune Cells: In Vitro and In Vivo Studies
No full textRhodococcus equi is a facultative intracellular bacterium and an opportunistic pathogen that exploits foals��� immature immune system and causes severe pyogranulomatous pneumonia. Currently, no vaccine is available to prevent R. equi pneumonia in foals, and previous vaccine trials have focused on adaptive immune responses. Evidence exists about the importance of induction of enhanced innate immune responses; thus, we focused on studying the interaction of R. equi with the innate immune system. The first objective of this dissertation was to provide a literature review summarizing the current understanding of interactions between R. equi and the host innate immune system, and to describe features of the immune response that are associated with resistance or susceptibility to R. equi infection. Second, we evaluated in vitro the impact of Toll-like receptor 2 (TLR2), complement receptor 3 (CR3), and Fc gamma receptor III (Fc��RIII) on R. equi phagocytosis and intracellular replication in macrophages. Phagocytosis of R. equi was not affected the absence of TLR2 or CR3. Absence of TLR2, CR3, or Fc��RIII did not affect intracellular replication of virulent R. equi; however, avirulent R. equi had increased survival in TLR2-/- and CR3-/- macrophages than in WT or Fc��RIII-/-. Therefore, TLR2 and CR3 downstream pathways limit replication of avirulent but not virulent R. equi. Third, we examined in vivo the effects of enteral vaccination with live, virulent R. equi, the only foal vaccination strategy that protected against pneumonia, in the innate immune system. We demonstrated that administration of enteral R. equi to foals soon after birth overcame neonatal vaccination challenges and protected against pulmonary challenge with R. equi at age 28 days. Enteral R. equi reprogramed blood monocyte epigenetics, altered the expression of over 1,000 genes in neutrophils, and induced higher levels of R. equi-specific IgG���, IgG���/���, and Th1 response. Therefore, early life exposure to R. equi in the gastrointestinal tract enhanced innate immune cells response, possibly facilitating the development of adaptive immune responses, and protected neonates against pneumonia. Collectively, we unveiled the impact of macrophage receptors in controlling R. equi infection and the effects of enteral R. equi stimulation on foal innate immune cells
Lip Position Preferences as They Relate to Convexity and Divergence
No full textIntroduction: The aim of the present study was to assess lip position preferences as they relate to convexity and divergence. Of secondary interest were how sex, ethnicity, and age influenced these preferences.
Methods: A sample of 1000 internet users were asked to rank the relative attractiveness of a series of modified 3D facial profiles with differing lip projections. One Caucasian male served as the model, and the model's facial scan underwent mandibular augmentation in the sagittal and vertical dimensions resulting in nine distinct facial profiles. Following these augmentations, the lips were adjusted anteriorly and posteriorly in 1.5 mm increments from baseline.
Results: Each of the nine facial profiles experienced significant within-group differences in preferred lip position. Females preferred more protrusive lips in all profiles than males. African Americans preferred more retrusive lips for nearly all profiles than Caucasians and Hispanics. Younger generations tolerated more retrusive lip positions compared with older generations for nearly all profiles.
Conclusions: Preferred lip positions are a function of convexity as opposed to divergence; facial types with vertical imbalances followed similar trends to those seen in other facial types with similar convexity. Sex, ethnicity, and age-related preferences persisted despite most facial imbalances
Architecture and Facies of the Sullivan Peak Member Within the Lower Permian Wolfcamp-A Equivalent Skinner Ranch Formation on the Southern Margin of the Delaware Basin, from Outcrop in the Glass Mountains in West Texas
No full textStrata of the Sullivan Peak Member within the Lower Permian Skinner Ranch Formation are well exposed along the Lenox Hills of the Glass Mountains in Brewster County, West Texas. These outcrops provide a unique opportunity to describe equivalent strata of the prolific Wolfcamp-A Formation along the southern margin of the Delaware Basin. The Sullivan Peak Member is exposed along a 1.5 mi wide by 100 ft vertical exposure of carbonate-rich, coarse-grained, and conglomeratic strata interbedded with mudstone. Three coarse-grained facies and one mudstone facies were characterized from an outcrop aerial photogrammetry model, hand samples, and thin section petrography. These include: 1) a Normally-Graded Carbonate-Clast Conglomerate facies (CCC), 2) a Normally-Graded Skeletal Grainstone facies (NmGs), 3) a Massive Skeletal Grainstone-Packstone facies (MaGs), and 4) a Mudstone facies (Mdst). Three Facies Associations (FA-1, FA-2, FA-3) w ere defined and correlated using the facies scheme and the photogrammetry model. Three Lowstand Systems Tracts (LST���s) w ere delineated within the Sullivan Peak Member (LST-1, LST-2, and LST-3)
Nuclear Safeguards Feasibility Study for a Molten Salt Reactor Using MCNP Modeling and Simulations
No full textThe technological developments within the last couple of decades have exponentially increased the demand for reliable and sustainable energy. The successful fulfillment of this energy demand shows a strong correlation with the Human Development Index, which is based on health, education, and income parameters. Among other energy sources, nuclear energy has become prominent in providing clean energy by protecting air quality, having a small footprint with high energy density, and being a reliable and stable option. However, considering the dual nature (peaceful and non-peaceful uses) of nuclear energy, nuclear safeguards are an important international instrument to prevent nuclear material diversion for non-peaceful purposes. This work focused on developing a nuclear safeguards monitoring approach for a generic Molten Salt Reactor (MSR) designed at Texas A&M University.
This thesis includes a comprehensive neutronics modeling of the MSR using the Monte Carlo radiation transport code, MCNP��6.2. The modeled MSR has a 300 MWth power and operates in a thermal neutron spectrum at 900 K. It uses molten fluoride salt (2LiF:BeF2) as a coolant with UF4 fuel mixture with 3.5% low-enriched uranium (LEU). The reactor core design used graphite as the neutron moderator and reflector. Non-soluble fission products (FP) were extracted through gaseous extraction, and FP removal was conducted to improve the performance. A High-Purity Germanium (HPGe) detector, a widely used Non-Destructive Assay (NDA) equipment was modeled for Special Nuclear Material (SNM) mass quantification. In this methodology, the first step was determining the relationship between the Pu amount and fuel burnup. In the second step, the fuel burnup relationships with the radioactivity of 137Cs, the radioactivity ratios of 134Cs/137Cs, and 154Eu/137Cs were established. In the last step, these relationships were used to estimate SNM mass.
The results indicate that the Pu amount relationships with 137Cs radioactivity and the ratio of 134Cs/137Cs can be utilized to quantify SNM mass at all fuel burnup levels. The ratio of 154Eu/137Cs is applicable even for very-high fuel burnup levels. However, it does not provide accurate results at ultra-high fuel burnup levels due to its saturation. The proposed safeguards monitoring approach in this thesis provides a method for estimating the Pu mass in the MSR at different fuel burnup levels so that any diversion of Pu for non-peaceful purposes can be prevented through early detection and deterrence
A Novel ML-based Approach for the Prediction of the Oceanic Heat Flux in a Slab Ocean Model Coupled to a Physics-Based Model of the Atmosphere
No full textA slab-ocean model is a thermodynamic model of the ocean mixed layer. It provides a prognostic variable for the sea surface temperature (SST), and when coupled to a model of the atmospheric circulation, it allows for two-way ocean-atmosphere interactions at a low computational cost. The standard formulation of a slab ocean model accounts for the spatially varying thermal effects of the oceanic circulation by a prescribed two-dimensional static estimate of the oceanic heat flux field. A downside to using such a static estimate is that it cannot capture the effects of changes in the ocean circulation. This work presents a methodology to introduce a temporarily changing two-dimensional oceanic heat flux field in a slab ocean model. It also introduces a novel machine learning-based approach to dynamically evolve this field. The approach is tested on the low resolution atmospheric global circulation model SPEEDY, which has an optional slab ocean component. This component is modified to implement the proposed methodology. It is first demonstrated that the static estimate of the oceanic heat flux can be further improved by an iterative method. Then, it is shown that with the temporally varying estimate of the oceanic heat flux the model produces more realistic sea surface temperature variability than with the static estimate. Finally, it is demonstrated that the machine learning-based approach can be used to replace the prescribed estimates with a dynamically evolving field of the oceanic heat flux
Art (Spaces) Imitates Life? An Exploration of Arts-Centered Spaces and Their Degree of Accessibility to Immigrant Communities
No full textThis literature review is designed to answer two questions. First, whether art spaces are welcoming spaces for immigrants? Second, what conditions may prompt immigrants to interact or disengage with art spaces? Literature from cultural geography, sociology of culture, urban studies, race, ethnicity, and migration have demonstrated that institutions such as the art museum have historically been sites of domination (Anderson 2006; Cooks 2011; Lonetree 2012). Despite this, museums have displayed an effort to change, while marginalized communities embody the capacity to partake in placemaking endeavors regardless of these constraints (Hooper-Greenhill 2000; Roberts 2018, 2020; Lipsitz 2011; Cook 2011; Lonetree 2012; Jenkins 2010; Jamal 2010, Espiritu 2010, Maira 2010, Stern et. al. 2010). Moreover, art-spaces have been shown to benefit people in both an individual and communal sense (Grodach 2010, 2011; Eaves 2014; Eisner 2012). At the same time, the literature shows that immigrants tend to prefer more informal or private venues to partake in the consumption or creation of art. Although this is the case, we cannot discern exactly why this dynamic is occurring (Stern et. al 2010). Literature regarding cultural capital and strategic assimilation point to possible theoretical explanations of this dynamic, but further research must be conducted to fully address this discrepancy (Bourdieu 1977; Lamont and Lareau 1988; Lacy 2007). In the completion of this literature review, I also offer suggestions to improve existing art spaces based upon the concepts of the Black Spatial Imaginary and Community Asset Mapping (Lipsitz 2011; Villanueva 2020, 2021)
OSHA Citations and Beyond: Strategies for Ensuring Combustible Dust Compliance
No full textManaging dust in the ever-changing world of industrial operations cannot be emphasized enough. Dust, frequently observed due to numerous industrial processes, poses several complex challenges that require careful consideration and proactive control. The appropriate handling of dust emerges as a crucial component of industrial processes, from the standpoints of safety and health to the optimization of operational efficiency. This project outlines the OSHA (Occupational Safety & Health Administration) citation data that was gathered against the citations obtained in response to the "dust" query from 2019 to 2023. The data from the citations was studied to understand which type of industries had received the most citations from OSHA. Furthermore, the equipment of concern was studied and analyzed, and the citations received from 2019 to 2023 were then compared with 2018, explaining the relevance of the shifting industries, citations, and industrywide concerns about handling dust within the above-mentioned timeframe. In total, there were 45 citations related to dust in 2018, which decreased over the years. In 2023, 42 citations were found under the general duty clause in the term "dust." There were also some citations where NFPA (National Fire Protection Association) standards were outlined, referred to, and explained. In the years considered in the project, over 95 percent of citations were classified as ' serious, ' with scarce instances of 'failure to abate' and ���willful��� violations. All penalties were compared case-wise, industry-wise, and year-wise to understand the cost relationships with incidents. New citations after the year 2018 were also assessed and evaluated. Further measures and standard requirements to ensure safety compliance against dust hazards were discussed in detail. This project emphasizes the critical significance of managing dust in industrial operations, highlighting its multifaceted challenges and pivotal role in safety, health, and operational efficiency. Through a detailed analysis of OSHA citation data from 2019 to 2023, industry trends, equipment concerns, and penalty assessments were investigated, providing a comprehensive understanding of the evolving landscape and imperative measures for ensuring safety compliance in handling dust hazards
Fracture Strength of 3D Printed Resin Interim Fixed Partial Dentures Varying Connector Sizes
No full textThe aim of this in vitro study is to determine the minimum connector size for 3-unit FPD���s comparing two different types of 3D printed resin to zirconia. A mandibular typodont quadrant was prepared for first premolar and molar all ceramic crowns with 0.5mm chamfer margins and total 6-degree convergence angle. The model was scanned via intraoral scanner (3Shape, Trios 4) and uploaded into CAD software (Exocad). 3-unit FPD with various connector sizes 9mm^2, 12mm^2, and 16mm^2 were designed. 3D printed two resins (OnX and Dentca C&B) with SprintRay Pro55. After the prints are completed, the interim FPDs were removed from the build plate, cleaned, and cured using manufacturer recommendations. FPDs were printed at a 0 degree build angle with 100��m layer thickness. 15 samples were printed per test group (N=90). Control group comparison made with a milled 3Y-zirconia 9mm^2 group (n=15). Fracture load tested with Instron machine with vertical pressure applied through pontic site at 1mm/min. FPDs placed onto typodont abutments and mounted on Instron machine. Failure was defined as the moment when the load dropped by 10% under the maximum value. The force (in Newtons) was recorded at the time of failure. Statistical analysis was completed using SPSS software to analyze the differences between the groups. Results were normally distributed, so one-way ANOVA was performed. Descriptive statistics will be added based on the location of fracture, and type of fracture. OnX had significantly higher maximum force at fracture (1236��135N) than Dentca C&B (884��136N, p<.001) and zirconia (456��87N; p<.001). Connector size had a significant difference for OnX for all sizes (p<.001), while significance for Dentca was only between 9 mm^2 and 16mm^2 (p=.006). The resins shattered upon failure, whereas zirconia simply split. Connector size and material type played significant roles in fracture resistance, with both resins withstanding significantly more force than typically generated during chewing
Assessing the Potential for Antibiotics to Alter Horizontal Gene Transfer Rates in Aquifers via Artificial Recharge of Treated Wastewater
No full textThe managed artificial recharge (MAR) of groundwater is a topic of growing interest regarding water resource management. MAR utilizes alternative sources of water, including treated wastewater effluent, to augment natural recharge rates and slow water table declines. MAR can be accomplished through constructed infiltration basins with high infiltration rates to the water table, or injection wells screened at the depth of the aquifer bypassing the vadose zone. One emerging contaminant commonly detected in treated wastewater is antibiotics used to treat bacterial infections in humans and agriculture. Sulfamethoxazole and trimethoprim antibiotics are commonly co-detected in treated wastewater. This thesis aims to examine the potential dissemination of antibiotic resistance in groundwater influenced by the artificial recharge of treated wastewater effluent. Recent research suggests that antibiotics can potentially modify the dissemination of antibiotic-resistant bacteria in the environment by inducing horizontal gene transfer (HGT) frequencies. HGT is the exchange of antibiotic resistance, mainly through conjugation, from resistant bacteria to susceptible bacteria. While native subsurface bacteria are often resistant to antibiotics, they pose no direct risk to humans unless pathogens acquire that resistance and an exposure pathway exists. Experimental work includes investigating the background levels of antibiotic resistance in soils and changes in antibiotic resistance after subjecting soil microbiomes to varying antibiotic concentrations. A literature review on artificial recharge, wastewater treatment, bacterial and antibiotic transport in the subsurface influenced by artificial recharge was also conducted. A series of one dimensional, variably saturated flow and solute transport simulations were conducted for an artificial recharge environment using Hydrus 1D and a range of reported concentrations and solute transport parameters in soils from the literature review. Expected results include that artificial recharge of treated wastewater may provide rapid antibiotic solute transport through the soil column and into the water table, highly dependent upon linear sorption coefficients and first-order degradation constants. Significant further research on horizontal gene transfer frequencies in native subsurface microbiomes at sulfamethoxazole and trimethoprim concentrations many times below the minimum inhibitory concentrations is needed to determine the potential risks of enhancing the environmental antibiotic resistance problem in managed artificial recharge