Unraveling asphaltene aggregation: Computational insights into sticky situations

Type: Graduate
Author(s): Gretel Stokes Chemistry & Biochemistry
Advisor(s): Benjamin Janesko Chemistry & Biochemistry

Asphaltenes are the heaviest component of crude oil and strongly aggregate during the oil refinement process, fouling equipment and increasing oil runoff. Understanding their propensity for aggregation at the molecular level is crucial for developing strategies to mitigate their role in equipment fouling. Using computational chemistry, we analyzed the dimerization energies of 67 previously published asphaltene structures by running CREST calculations on all possible molecular pairs. Our results reveal that diradical:diradical interactions drive strong aggregation, whereas radical-closed shell interactions are comparable in strength to closed-shell:closed-shell interactions. Additionally, we find that archipelago-type structures weaken dimerization as compared to island-type asphaltenes, likely due to self-association of archipelago structures. These findings provide key insights into asphaltene behavior and suggest potential strategies for disrupting aggregation. Future work will explore whether near-infrared light can be used to disaggregate asphaltenes, offering a novel approach to alleviate asphaltene-related challenges in industry.

Exploring molecular design: A triazine library reveals a surprisingly hydrophobic molecule

Type: Graduate
Author(s): Gretel Stokes Chemistry & Biochemistry Casey Patterson-Gardner Biology
Advisor(s): Eric Simanek Chemistry & Biochemistry
Location: Third Floor, Table 4, Position 1, 1:45-3:45

Macrocycles are promising drug candidates due to their ability to selectively interact with biological targets. However, predicting their solubility and membrane permeability remains challenging. To probe this, a library of 35 triazine macrocycles was synthesized and the hydrophobicity of each macrocycle was measured using octanol:water partition coefficients (logP).

Unexpectedly, a glycine-derived macrocycle with two primary amine groups displayed high hydrophobicity, contrary to prediction based on conventional computational methods for computing logP (AlogP). Computational analysis revealed that the diamine substitution stabilizes a closed conformation, tethering the macrocycle where its polar groups are shielded from solvent interaction, thus increasing hydrophobicity. Additionally, we found that logP values of heterodimer macrocycles closely approximated the average of their corresponding homodimers, suggesting a predictable trend in partitioning behavior.

We demonstrate how small molecular changes can significantly impact physical properties. By combining synthesis, physical measurements, and computational modeling, our work provides insights into macrocycle behavior that could aid in designing membrane-permeable drug candidates.

Assessing the Impact of Land Use Change on Water Quality in Lake Worth, Texas

Type: Graduate
Author(s): Portia Asare Environmental Sciences
Advisor(s): Environmental Sciences Esayas Gebremichael Geological Sciences
Location: SecondFloor, Table 7, Position 3, 11:30-1:30

Rapid urbanization in the Dallas-Fort Worth metropolitan area is increasing pressure on water resources, including Lake Worth. This project will investigate the relationship between land use, land cover change, and water quality degradation in Lake Worth, a reservoir facing increasing development pressure near Fort Worth. The project will use historical land data to quantify land use/land cover change (LULC) within the watershed between 2000 and 2023. This land use data will be integrated with the publicly available water quality data (nutrients, dissolved oxygen, pH, turbidity) from the Surface Water Quality Monitoring Program and locations of permitted industrial discharge points from the Texas Commission on Water Quality. GIS techniques, including spatial joins, buffer analysis, and statistical modeling (regression, hotspot analysis), will be used to analyze the correlation between LULC and water quality parameters and identify pollution hotspots. The expected outcomes include detailed land use maps, a geodatabase of water quality and discharge points, statistical models quantifying the land use-water quality relationship, and identifying areas requiring management intervention. The study's findings will inform land use planning, water resource management, and sustainable urban development practices in the region while acknowledging limitations related to data availability, spatial resolution, causality, and model generalizability.

The Effect of Urban Development-Driven Tree Removals on Land Surface Temperature in a Growing City

Type: Graduate
Author(s): Hannah Buckhalter Environmental Sciences
Advisor(s): Brendan Lavy Environmental Sciences

Development and Socioeconomic Drivers of Permitted Tree Removals in Austin, Texas

Type: Graduate
Author(s): Adam Buckmeier Environmental Sciences
Advisor(s): Brendan Lavy Environmental Sciences
Location: Basement, Table 9, Position 2, 1:45-3:45

In urban environments, trees provide a range of services including pollution removal, temperature regulation, and increased property values. In an effort to accrue these services, municipalities enact tree preservation ordinances that seek to protect public and private trees. Despite the protections of these ordinances, many trees are removed legally each year due to urban (re)development, risks associated with tree growth, and tree death. This research examines the spatiotemporal trends of permitted tree removals in the City of Austin, Texas, from 2013 to 2023. Specifically, we created a geographic information system to explore the differences between development-related and non-development-related removals, as well as between healthy and unhealthy removals. We also explored the extent to which sociodemographic characteristics explained differences in tree removals. Preliminary findings reveal that most trees removed are healthy and for development-related reasons, a reflection of Austin’s accelerating urban growth. We identified areas with high to moderate development pressure, high health impacts, and low activity. Our analysis also revealed significant patterns in tree removals associated with demographic and socioeconomic characteristics. Areas with higher proportions of non-White populations experience fewer tree removals. This, however, correlates with lower overall canopy cover, suggesting these areas have fewer trees to begin with. Conversely, neighborhoods with higher household incomes show more tree removals but also higher canopy cover, indicating more active tree management in wealthier areas with greater tree resources. Our research highlights location-specific tree removal patterns to inform strategies that account for both environmental and socioeconomic factors.

Do Income-Driven Differences Between Urban Neighborhoods Shape Prey Availability and Bat Foraging Activity?

Type: Graduate
Author(s): Elizabeth Hargis Environmental Sciences
Advisor(s): Victoria Bennett Environmental Sciences
Location: SecondFloor, Table 7, Position 1, 11:30-1:30

Urbanization alters habitat structure and resource availability, influencing wildlife distribution and behavior. In particular, invertebrates are affected by the differences in urban landscape that are caused by distinct socio-economic differences throughout urban areas. These changes in invertebrate abundance and diversity may affect bat populations that rely on these invertebrates as a food source. This study investigates how neighborhood income influences invertebrate diversity and bat foraging activity in Fort Worth, Texas, USA. We hypothesize that variations in landscape management and the income-driven use of pesticides can alter invertebrate diversity and subsequently bat activity. We conducted invertebrate sampling and acoustic bat monitoring across ten urban greenspaces; five high-income and five low-income neighborhoods in Tarrant County, TX, USA. We then quantified invertebrate and bat abundance and diversity using Shannon’s and Simpson’s diversity indices and examined correlations between invertebrate diversity, bat activity, and household income. This study will help to understand the ecological consequences of socio-economic disparities in urban habitats, which can inform conservation strategies to enhance urban biodiversity and bat conservation efforts.

Assessing Soil Carbon Dynamics in Amended Urban Farms in Fort Worth Using Thermal Analysis

Type: Graduate
Author(s): Md Simoon Nice Environmental Sciences Esayas Gebremichael Geological Sciences Brendan L. Lavy Environmental Sciences
Advisor(s): Omar Harvey Geological Sciences Gehendra Kharel Environmental Sciences
Location: Third Floor, Table 4, Position 1, 11:30-1:30

Fort Worth, the fastest-growing city in Texas, contains many vacant land plots suitable for urban agriculture—an opportunity to address local food deserts. However, unsustainable farming can degrade soil organic carbon and reduce productivity. This study assessed soil carbon dynamics in a food waste compost–amended urban farm in Fort Worth. Experimental plots, including compost-amended and control treatments (triplicated), were established and monitored monthly from January 2023 to July 2024. Thermo-gravimetric Analysis (TGA) was used to calculate the recalcitrance index (R50), indicating carbon stability. Results showed compost-treated soils had more stable carbon and structured lignin degradation. In contrast, untreated soils exhibited unstructured decomposition and faster carbon loss. Compost enhances soil health and carbon cycling, and future research should explore combining compost with cover crops to maximize carbon sequestration and microbial activity in urban farming systems.

Norfolk UST Risk Assesment

Type: Graduate
Author(s): Joshua Benford Geological Sciences
Advisor(s): Esayas Gebremicael Geological Sciences
Location: Basement, Table 1, Position 2, 11:30-1:30

Leaking underground storage tanks (USTs) pose a significant environmental hazard in Norfolk, Virginia, where factors such as weather, casing materials, and varying ground conditions contribute to potential leaks over time. Corrosion, exacerbated by Norfolk's coastal location and harsh soil conditions, is a primary cause of these leaks. Geographic Information System (GIS) tools can be utilized to develop a predictive model for identifying at-risk UST locations by integrating data from multiple sources, including UST records from the state of Virginia and other relevant datasets. This model would employ various spatial analysis techniques to generate maps and web applications, enabling field teams to validate its accuracy and support the City of Norfolk in mitigating risks associated with leaking USTs. The goal of this research is to produce valuable insights that help safeguard the health of Norfolk's residents and protect the delicate surrounding ecosystem, including the Atlantic Ocean, marshes, rivers, and Chesapeake Bay.

A Study of the Coll de Montllobar to Further Characterize Channelization as the Units Shift Through Transgressive-Regressive Sequences

Type: Graduate
Author(s): Samuel Knox Geological Sciences
Advisor(s): John Holbrook Geological Sciences
Location: Basement, Table 4, Position 2, 1:45-3:45

The Tremp-Graus basin, located in Northern Spain, is a foreland piggyback basin that sits on the foot of Pyrenees Mountains. More specifically within the Montsec range, North of the Montsec thrust belt. The basin is a result of an east to west trending syncline area between the Boxial and Montsec Thrusts, North and South of Tremp, Spain, respectively. During the end of the Cretaceous period, syntectonic sedimentation began and carried throughout the Miocene. Thus, forming the basin that is structurally open in the west and open in the east, possibly due to structural events and quite possibly a shallow sea that protruded the area during the Ypresian (56 – 47.8 Ma). The sediments came from sources in the North, East, and the South in less quantities. The Pyrenees Mountains to the north are the main source of the sedimentation in the area as an influx of sediment occurred over time as the thrust sheets became proximal to the basin. The Boxial thrust supplied alluvial fans during the Maastrichtian in a localized setting (Arevalo, 2022; Busquests, 2022).
There is an overall transition from continental to deltaic sediments in the east to a western section that is mainly slope mudstones, thin-bedded turbidite wedges, proximal turbidites, channel-fills, distal turbidities and basin-plain deposits. This study will focus on a vertical section in the Coll del Montllobar Cliffs to help identify and differentiate channel characteristics as the rocks shift from continental/terrestrial deposits to marine influence deposits (tracking transgressive-regressive cycles) within the Upper Ager Group through the Lower Montanyana Group. The study will include at least five highly detailed measured sections, fluvial mapping conducted through drone footage and 3D modeling as well as possible point counting root density within the sections. In the conclusion of this study researchers will have a reliable Type Section as well as a basic understanding of how transgressive – regressive cycles alter channel behavior within the region, as well as the defining characteristics of the fluvial channels.

THE GEOLOGY OF THE WICHITA MOUTAINS, SOUTH OKLAHOMA

Type: Graduate
Author(s): Michael Mbah Geological Sciences Esayas Gebremichael Geological Sciences
Advisor(s): Richard Hanson Geological Sciences
Location: SecondFloor, Table 8, Position 3, 1:45-3:45

The Wichita Mountains in southwestern Oklahoma hold over a billion years of geological history, offering valuable insights into rift dynamics, magmatism, and basin evolution. These mountains are remnants of the Southern Oklahoma Aulacogen, a failed rift that initially formed during the Cambrian period through crustal extension but was later uplifted due to tectonic inversion. The region features a diverse range of igneous and sedimentary rocks, including the Carlton Rhyolites, gabbroic anorthosites, and granites of the Wichita Granite Group, which reflect a complex magmatic history. Over time, major tectonic events such as the Pennsylvanian uplift during the formation of Pangea and subsequent Permian burial played a key role in shaping the area's present landscape. This study utilizes Geographic Information Systems (GIS) tools to examine the spatial relationships, structural features, and lithological distribution of the Wichita Mountains. Using remote sensing, digital elevation models (DEMs), and geospatial analysis, this research provides a deeper understanding of the regions geological history and demonstrates the effectiveness of GIS technology in structural geology and regional mapping.