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CHEM2019LE4831 CHEM

Formation of Platinum Nanocrystals on Silicon Nanotubes and in vitro Anti-cancer Activity of the composites

Type: Graduate
Author(s): Nguyen Le Chemistry & Biochemistry
Advisor(s): Jeffery Coffer Chemistry & Biochemistry Giridhar Akkaraju Biology
Location: Session: 2; 1st Floor; Table Number: 3

presentation location

The semiconductor Silicon (Si) remains a significant material in the electronic device and photovoltaic industries [1]. Especially, nanostructured forms of Si with a porous morphology (pSi) exhibit interesting properties which can be controlled via modulating pore structure and surface chemistry [1]. Recently, synthesis of a unique one-dimensional form of Si, namely nanotubes, with tunable structure (shell thickness, length, inner diameter and porous morphology) has been demonstrated, thereby suggesting newly emerging applications [2]. For instance, recent works have indicated Si nanotubes (SiNTs) can efficiently serve as a reaction vessel for formation of organometal perovskite nanostructures and a template for superparamagnetic iron oxide (Fe3O4) loading [3], [4]. In an observation of dissolution of SiNTs with a porous morphology (pSiNTs), the material readily resorbed in buffered media at physiological conditions in a similar manner to bioactive nanostructured porous silicon, thereby implying potential therapeutic applications of this material [2].
In chemotherapy, platinum-based cancer drugs, such as cisplatin and carboplatin, are widely used as effective drugs against various types of cancer [5]. Interestingly, while elemental platinum nanoparticles (Pt NPs) have been well investigated in diverse catalytic processes, in recent years, Pt NPs have also been discovered as a potent anti-cancer agent in nanomedicine, implying the use of the nanodrug to counteract chemoresistance in some cancer cell lines [6], [7]. Recent reports have also indicated that enhanced cytotoxicity against selected cancer cell lines is ascribed to ultra-small Pt NPs, especially those with size less than 3 nm [7]. In this report, pSiNTs were investigated as a template for the formation of Pt NPs, and in vitro cytotoxicity of the composites was evaluated against HeLa cancer cells.
Regarding fabrication, pSiNTs with short lengths (~500 nm) and thin walls (~10 nm) were synthesized via a ZnO nanowire sacrificial template method. Based on a combination of characterization techniques [High resolution transmission electron microscopy (HR-TEM) and energy dispersive X-ray analysis (TEM-EDX)], it is suggested that pSiNTs surface functionalized with 3-aminopropyltriethoxysilane can facilitate formation of Pt nanocrystals (Pt NCs) with size ranging from 1-3 nm utilizing a K2PtCl4 precursor. By varying reaction conditions (concentration of Pt salt and incubation time), the amount of Pt NCs deposited on SiNTs can be sensitively tuned from 20 to 55 wt%. In terms of cytotoxicity evaluation of the composites against HeLa cells, cellular viability was assessed using CellTiter-Glo assays, which quantified the amount of ATP in metabolically active cells. Our findings suggest that Pt NCs-SiNTs composites were toxic to HeLa cells, and less than 50% cells were still viable after 3 days of treatment with the composites at doses of 35 μg/ml and 50 μg/ml. Results from caspase 3/7 assays also showed that caspase 3/7 level in cells treated with Pt NCs-SiNTs approximately ranged from 1.5 to 2-fold increase compared to cells without treatment, thereby suggesting apoptosis as the likely mechanism. In vitro cellular uptake studies analyzed by confocal microscopy also confirmed accumulation of the composites within the cytoplasm of the cells after the treatment, consistent with a “Trojan horse” mechanism in which high concentrations of Pt NCs are internalized within cells assisted by pSiNTs and subsequently released via dissolution of the nanotube matrix.
The studies presented herein describe a novel strategy to form and immobilize highly compact clusters of Pt NCs by using pSiNTs as a template. In terms of bio-relevant applications, in vitro studies provide new insights into the anti-cancer properties of the newly discovered composites in inducing apoptosis in HeLa cells, thereby providing significant potential uses of Pt NCs-SiNTs in cancer treatment. Further investigations into gene expression profile(s) may be necessary in order to clarify the impact of the composites on cell survival in terms of molecular mechanisms.
References
1. H. Santos, Porous Silicon for Biomedical Applications, Ed. Cambridge: Woodhead Publishing, (2014).
2. X. Huang, R. Gonzalez-Rodriguez, R. Rich, Z. Gryczynski and J. L. Coffer, Chem. Commun., 49, 5760 (2013).
3. R. Gonzalez-Rodriguez, N. Arad-Vosk, N. Rozenfeld, A. Sa'ar and J. L. Coffer, Small, 12(33), (2016).
4. P. Granitzer, K. Rumpf, R. Gonzalez, J. Coffer, M. Reissner, Nanoscale Res. Lett., 9, 413 (2014).
5. T. C. Johnstone, K. Suntharalingam and S. J. Lippard, Chem. Rev., 116 (5), 3436–3486, (2016).
6. X. Li, G. Li, W. Zang, L. Wang and X. Zhang, Catal. Sci. Technol., 4, 3290-3297 (2014).
7. H. Xia, F. Li, X. Hu, W. Park, S. Wang, Y. Jang, Y. Du, S. Baik, S. Cho, T. Kang, D. Kim, D. Ling, K. M. Hui and T. Hyeon, ACS Cent. Sci., 2, 802−811 (2016).

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CHEM2019MEHMOOD38923 CHEM

An Orbital-overlap Scale for Solvent Hardness and Softness: Method and Application to Ionic Liquids

Type: Graduate
Author(s): Arshad Mehmood Chemistry & Biochemistry
Advisor(s): Benjamin G. Janesko Chemistry & Biochemistry
Location: Session: 1; 2nd Floor; Table Number: 1

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The chemical hardness of a solvent can play a decisive role in solubility and reactivity in solution. Several empirical scales of solvent softness have been proposed. We explore whether computed properties of solvent molecules can reproduce these empirical scales. Our "orbital overlap distance" quantifying the size of orbitals at a molecule's surface effectively reproduces the Marcus μ-scale of solvent softness. The orbital overlap distance predicts that the surfaces of chemically hard solvent molecules is dominated by compact orbitals possessing a small orbital overlap distance. In contrast, the surface of chemically soft solvent molecules has a larger contribution from diffuse orbitals and a larger orbital overlap distance. Other "conceptual density functional theory" descriptors, including the global hardness and electronegativity, can also reproduce empirical solvent scales. We further introduce a "solvent versatility" RMSD Dsurf scale quantifying variations in the surface orbital overlap distance. "Good" solvents such as DMSO, which combine chemically "hard" and "soft" sites within a single molecule, possess a large RMSD Dsurf. We conclude by applying this approach to predict the Marcus μ-parameters for widely-used ionic liquids and ionic liquid - cosolvent systems.

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CHEM2019MEKHAIL60535 CHEM

Functional groups effect on the electronics of macrocyclic pyridinophane

Type: Graduate
Author(s): Magy Mekhail Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry
Location: Session: 2; 3rd Floor; Table Number: 8

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The use of macrocyclic pyridinophane has been growing in the fields of bioinorganic modeling, catalysis and imaging. However, the functionalization of the pyridine has not been fully explored. Therefore, the Green Research Group we produce a series of 12-membered tetra-aza N-heterocyclic amines, derived from pyclen with different functional groups substituted at the para position. Using Hammett plot analysis, X-ray diffraction, electrochemistry and C-C coupling catalytic results, we aim to understand the impact of these functional groups on the donating) of the ligand. From the Hammett plot results we predict how other functional groups will affect the electronics and reveal whether the resonance or inductive effects will mitigate the coordination environment.
The use of macrocyclic pyridinophane has been growing in the fields of bioinorganic complexes modeling, catalysis, and imaging. However, the functionalization of the pyridine has not been fully explored. Therefore, the Green Research Group produced a series of 12-membered tetra-aza macrocycles derived from pyclen with different functional groups substituted at the para position. Using Hammett plot analysis, X-ray diffraction, electrochemistry, and C-C coupling catalytic results, we aim to understand the impact of these functional groups on the donor ability of each ligand. From the Hammett plot results we hope to predict how other functional groups will affect the electronics and reveal whether the resonance or inductive effects will mitigate the coordination environment and reactivity of each complex.

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CHEM2019MONTOYA22550 CHEM

Steps Towards the Total Synthesis of Amaryllidaceae Alkaloids

Type: Graduate
Author(s): Adam Montoya Chemistry & Biochemistry
Advisor(s): David Minter Chemistry & Biochemistry
Location: Session: 1; 3rd Floor; Table Number: 6

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Phenanthridone-type alkaloids isolated from certain plants of the Amaryllidaceae family are of interest due to their pharmaceutically active nature. The compounds are commonly used in research concerning cancer, Alzheimer’s disease and other human illnesses. One of the main hindrances to such research is the limited availability of many of these compounds. The Minter group is interested in the development of procedures for synthesizing such alkaloids in a cost-effective and time efficient manner, while at the same time maintaining fair to excellent yields.
Techniques toward the synthesis of natural products of the Phenanthridone type are presented herein. Manipulations were tested and optimized on a model system in order to save both time and funds while developing a synthetic pathway to be utilized in the formation of more complex compounds. Setbacks such as controlling the stereochemistry of a tetra-substituted double bond reduction have been encountered. However, adjustments are being made to avoid such difficulties in the future. Ideally, the proposed scheme will ultimately allow for the synthesis of multiple phenanthridone analogs.

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CHEM2019SHARMA21186 CHEM

Exploring Cyanuric Chloride Chemistry to Synthesize Macrocycles of Different Sizes

Type: Graduate
Author(s): Vishal Sharma Chemistry & Biochemistry
Advisor(s): Eric Simanek Chemistry & Biochemistry
Location: Session: 1; 3rd Floor; Table Number: 4

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In chemistry, cyclic compounds of twelve or more atoms are considered macrocycles. Many bioactive, natural products containing macrocycles have been isolated and synthesized. Still, construction of macrocycles is usually considered a challenging step in their synthesis. Here, a route to different-sized macrocycles is described. These macrocycles arise from spontaneous cyclization of two identical subunits comprising a central triazine displaying both a masked aldehyde and hydrazine group. The aldehyde portion is presented on a linker that can comprise varying number of carbons. By varying this linker, macrocycles of 22, 24, and 26 atoms have been prepared. Future study focuses on probing macrocycle size with increasingly larger linkers.

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CHEM2019WINTERS65295 CHEM

The Cost of Academic Methodologies

Type: Graduate
Author(s): Karen Winters Chemistry & Biochemistry Olivier Berger Chemistry & Biochemistry Sergei Dzyuba Chemistry & Biochemistry Axel Sabourin Chemistry & Biochemistry
Advisor(s): Jean-Luc Montchamp Chemistry & Biochemistry
Location: Session: 2; 1st Floor; Table Number: 6

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The cost of reagents and catalysts employed in synthetic methodologies developed in academia is very rarely discussed. Yet these costs are very real as they represent a significant portion of any grant proposal budget. The Cost of Academic Methodologies (CAM) is a novel concept, which should be considered when evaluating synthetic methodologies. CAM will allow for one to quantitatively evaluate with a numerical value a particular synthetic methodology that prepares a particular product. CAM will allow for a comparison among distinctly different reactions conditions, reagents, catalytic versus stoichiometric systems, etc. Cost considerations are almost always avoided in academic publications; however CAM is a parameter that can be useful to gauge seemingly non-comparable methodologies. Unlike specious or poorly-defined considerations often seen in manuscripts, such as “harshness” of conditions, “metal-free”, “precious metals are expensive”, etc., the CAM parameter is a real, tangible, aspect of academic methodologies, which is applicable to any chemical reaction.

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ENSC2019HALL12981 ENSC

Elevation analysis of Foster and Overton parks for radio-tracking bats

Type: Graduate
Author(s): Ellen Hall Environmental Sciences
Advisor(s): Victoria Bennett Environmental Sciences Tamie Morgan Geological Sciences
Location: Session: 1; 1st Floor; Table Number: 1

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Bats are critical to their surrounding environment, thus we need to know what resources bats need to survive, such as water. Many available water resources in urban areas are ephemeral and dry up during the hot Texas summers. We explored bat resource use in an urban environment by radio-tracking bats in local Fort Worth parks, Foster Park and Overton Park. We used Lidar and 3D mapping in ArcGIS 10.6 to portray our study site where bats were tracked. Using digital elevation, we evaluated high elevation points in the parks that can be used in conducting future surveys.

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ENSC2019HOOD26539 ENSC

GIS Analysis of Healthcare Deserts in the Permian Basin

Type: Graduate
Author(s): Adam Hood Biology
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 2; 3rd Floor; Table Number: 9

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Healthcare deserts are an emerging problem in the United States, especially in rural areas. Individuals in these areas do not have access to adequate healthcare, and in most cases they are forced to travel long distances to receive the care they need. In the Permian Basin, this can be of concern for those working in the oil industry as well as their families. A GIS analysis was conducted to identify healthcare deserts in this area.

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ENSC2019HUDGENS33438 GEOL

Monarch Butterfly Population Decline

Type: Graduate
Author(s): andrew hudgens Geological Sciences
Advisor(s): Tami Morgan Geological Sciences
Location: Session: 2; Basement; Table Number: 2

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Monarch butterfly populations in North America have declined by approximately 80% over the last 20 years. Many contributing factors are responsible for this decline, however the loss of Milkweed has been identified as a major factor. Milkweed is the primary food source for Monarch caterpillars. A GIS analysis was performed to identify milkweed resources in the North Texas area.

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ENSC2019MARTINEZ48752 ENSC

Water Clarity of Texas Lakes Before and After Zebra Mussel Infestation

Type: Graduate
Author(s): Julianna Martinez Biology
Advisor(s): Michael Misamore Biology Tamie Morgan Geological Sciences
Location: Session: 2; Basement; Table Number: 3

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Zebra mussels, Dreissena polymorpha, are an invasive species of freshwater bivalves that have recently spread into bodies of water across North America. Zebra mussels inhabit the shallow waters of lakes and tightly attach to any and all hard surfaces. They are efficient filter feeders and can filter up to 1 L of water per day per mussel. This increases the clarity of water dramatically which alters the lake habitat for other lake species. In this analysis, water clarity data was mapped for “infested” lakes for the years 2008 (pre-zebra mussels), 2010 (one year after zebra mussel infestation), and 2016 (seven years after infestation). The average clarity of the lakes increased by 9.36%, with larger lake clarity increasing the most dramatically.

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ENSC2019MCQUEEN16945 ENSC

Ghost surveillance: The importance of monitoring acoustic activity in bat diversity hotspots.

Type: Graduate
Author(s): Martin McQueen Environmental Sciences
Advisor(s): Victoria Bennett Environmental Sciences
Location: Session: 1; 3rd Floor; Table Number: 7

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Habitat loss, disease, and land-use change has led to a sudden decline in bat populations in the US. Thus, there is a need to determine the extent of the impact before we can effectively implement counter-measures. One way to assess the impacts is to monitor areas with a high abundance and species diversity, such as Big Bend National Park with 25 of the U.S.’s 47 native bat species. We therefore assessed whether 1) acoustic monitoring at the park was a feasible technique and 2) if the diversity of species recorded and their activity patterns could contribute to national long-term monitoring.

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ENSC2019PAYBLAS51093 ENSC

Spatial and Temporal Variation in Nitrate Contamination as a Function of Well Depth in the Seymour Aquifer

Type: Graduate
Author(s): Caitlin Payblas Environmental Sciences
Advisor(s): Omar Harvey Geological Sciences
Location: Session: 1; 1st Floor; Table Number: 2

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Nitrate contamination of groundwater in the Seymour Aquifer is a well-known issue that has been documented since the 1960's. Concentrations as high as 35 ppm NO3-N have been reported, which is a startling 3.5 times the EPA allowable standard for drinking water. While most water from the Seymour Aquifer is used for agricultural irrigation, a portion is still used for domestic purposes and therefore poses a risk to human health. While this problem may have been recognized, the specific source of this contamination remains unknown. Three potential sources of nitrate within the aquifer are being considered in this study—the geological makeup of the aquifer, the agricultural contribution of nitrate from fertilizers, and the historical land use change of the area above the aquifer.

My research will combine various statistical and geospatial technologies in order to 1) view nitrate contamination as a function of well depth and 2) Determine the temporal change in NO3-N concentrations over a distribution of well depth. Readily available groundwater quality data from the Texas Water Development Board will be used in conjunction with geospatial analysis and statistical analysis to identify well depth distribution and changes in the aquifer's water quality with respect to well depth over time. After a thorough analysis of the site area via the aforementioned methods and technologies, a portrait that depicts the both spatial and temporal changes of nitrate contamination in Texas's Seymour Aquifer ought to be painted.

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ENSC2019SMITH22883 ENSC

Assessing the potential impacts of transmitters on bat flight and behavior in a controlled environment using 3D technology.

Type: Graduate
Author(s): Kathryn Smith Environmental Sciences
Advisor(s): Victoria Bennett Environmental Sciences
Location: Session: 1; 3rd Floor; Table Number: 5

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Telemetry is an effective method for collecting movement data, however, transmitters have the potential to negatively impact the maneuverability and behavior of wildlife, particularly volant species. Despite concerns, no studies have assessed the potential effect of transmitters on bats. Thus, we conducted a behavioral study on evening bats (Nycticeius humeralis) in a controlled environment. We found that while there was not a decrease maneuverability, it did alter behavior. Bats flew 79.5% less with the transmitter attached. Furthermore, these impacts did not diminish over time (3 day period), which in turn could have consequences for telemetry survey data collection and interpretation.

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ENSC2019WINER65351 ENSC

Urbanization in a sector of DFW

Type: Graduate
Author(s): Zane Winer Biology
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 1; 3rd Floor; Table Number: 2

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Urbanization is a central theme to humanity’s progress in large metropolitan areas. However, desire for greenspace and nature are also shown to be integral for citizen happiness and peace. At what rate does urbanization occur within a small area of DFW that is often considered suburban? Is this urbanization mostly residential or is this the fault of corporate land usage? This study uses GIS to investigate the differences over time in natural spaces vs. manmade structures by looking at differences in vegetation to assess the rate of urbanization in one of the most quickly developing areas in Texas.

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GEOL2019CAVES50910 GEOL

Understanding Metal-Silicate Mixing in Mesosiderites

Type: Graduate
Author(s): Lindsay Caves Geological Sciences
Advisor(s): Rhiannon Mayne Geological Sciences
Location: Session: 1; 1st Floor; Table Number: 5

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Mesosiderites are meteorites composed of equal parts metal and crustal silicate material, which have been linked to the HED parent body 4Vesta. The metal portion of mesosiderites is also compositionally similar to the IIIAB irons. Mesosiderite silicates were mixed with metal, recrystallized and rapidly cooled. The slow metallographic cooling rates recorded by mesosiderite metal indicate mixing followed by deep burial within an asteroidal body. Several models for the formation of mesosiderites have been proposed, but no single model can completely explain their multi-stage history. Oxygen isotope compositions of mesosiderites and eucrites are identical, consistent with the HEDs and mesosiderites originating from a common parent body. However, there are notable differences between the two groups. These include the differing Fe-Mn-Mg systematics in mesosiderite pyroxenes, which reflect an FeO reduction trend and not the magmatic trend seen in the HEDs. Phosphates and tridymite are also more abundant in mesosiderites than howardites and eucrites. These differences have been attributed to redox reactions that occurred during the metal-silicate mixing stage of mesosiderite formation. As previous work focused mainly on the silicate portion, this study examines the metal of five mesosiderite samples of varying petrologic class and degree of metamorphism. Thick sections of each meteorite containing both matrix metal and metal nodules were requested on loan from the National Meteorite Collection, located in the National Museum of Natural History, Department of Mineral Sciences. Electron microprobe (EMP) analyses of both silicate and metal portions of each mesosiderite were collected, as well as LA-ICP-MS analyses of the matrix metal and metal nodules within each section. The dataset will be analyzed for evidence of redox reactions and other processes that may have been occurring during the metal-silicate mixing phase of mesosiderite formation. If redox reactions occurred between the metal and silicate portions of mesosiderites, then: 1) the matrix metal within mesosiderites may be depleted in readily oxidizable elements (e.g. P, W) relative to the metal nodules that are not in contact with the silicate phase; or, 2) all metal in mesosiderites is depleted in readily oxidizable elements. This depletion should be visible when compared to IIIAB irons of a similar composition.

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GEOL2019DEBONE30636 GEOL

Newly discovered old volcano in Big Bend National Park

Type: Graduate
Author(s): Kristin DeBone Geological Sciences Tamie Morgan Geological Sciences
Advisor(s): Richard Hanson Geological Sciences
Location: Session: 2; Basement; Table Number: 8

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Recent field work has discovered a volcanic complex within the Paleocene Black Peaks Formation in the northwestern part of Big Bend National Park in west Texas. This is the only known Paleocene volcano in west Texas. We have identified pyroclastic deposits consisting of ash-sized and coarser clasts, including volcanic bombs and blocks, which were erupted explosively from a nearby vent. Margins of the volcanic complex have been mapped using remote sensing because the volcanic rocks are distinctly different in color from the adjacent shale. Characteristics of the pyroclastics suggest derivation from phreatomagmatic eruptions, which occurred when magma and groundwater violently interacted in the shallow subsurface.

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GEOL2019DONAHOO65357 GEOL

Using Non-Invasive Geophysical Techniques in Near-Surface Infrastructure and Agricultural Planning and Management

Type: Graduate
Author(s): Michaela Donahoo Geological Sciences
Advisor(s): Omar Harvey Geological Sciences
Location: Session: 2; 3rd Floor; Table Number: 7

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Using Non-Invasive Geophysical Techniques in Near-Surface Infrastructure Planning and Management

Michaela Donahoo1, Karim Ouamer-ali2,3, Youcef Daoud2, Kaddour Djili3, Omar R. Harvey1
1Department of Geological Sciences, Texas Christian University, Fort Worth, Texas, USA.
2 National Institute of Agronomic Research of Algeria (INRAA), El-Harrach, Algeria.
3Ecole Nationale Supérieure Agronomique (ENSA), El-Harrach, Algeria.

Understanding soil characteristic variability geospatially as a function of depth and time is key to the optimal implementation of subsurface infrastructure planning and expansion. The soils physical behavior as well as its interaction with piping and road materials determine where such a system could divert and predict future maintenance frequency. Central to the development of site-specific, precision management strategies is the quantification and mapping of the geospatial variability in soil properties at significantly higher resolutions than provided in current soil surveys. The presentation will cover results from ongoing collaborative research efforts between researchers at Texas Christian University and two Algerian institutions in using non-invasive measurements of bulk apparent electrical conductivity (ECa) to quantify and map 3-D soil variability in semi-arid and arid areas of Algeria, Northern Africa. The focus will be on the derivation and application of depth-specific ECa-ECe (saturated paste), ECa-clay content and ECa-water content relationships for use in understanding seasonal salinity and water dynamics within potential depths of construction interest.

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GEOL2019LAMB52985 GEOL

A Source to Sink Analysis of the Dockum Group in the West Texas Highplains

Type: Graduate
Author(s): Grayson Lamb Geological Sciences
Advisor(s): John Holbrook Geological Sciences
Location: Session: 1; 3rd Floor; Table Number: 9

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The fundamental understanding of any geologic basin stems from ascertaining the relationship between its source and sink. Every basin is therefore identified as a “sink” and has a provisional “source.” The investigation of this fundamental relationship is the preliminary exploration step to further basin development.
The Late Triassic Dockum Group of the west Texas high plains is an understudied group that begs investigation into the source to sink relationship. A comprehensive study of the Dockum Group as a “sink” is here undertaken in order to better understand the paleoclimate and its implications on the Dockum group depositional style. This study focuses on the northern most section of the Dockum group outcrop system. Within the study area it is subdivided into three main formations, the Tecovas mud, Trujillo sand, and Cooper Canyon sand-mud mix system.
This study showcases a forward stratigraphic modeling software, Dionisos Flow. From field based outcrop work: grain size, channel thickness, water discharge, and lithofacies assemblages were quantified as model inputs in Dionisos Flow.
The study aims to model Dockum Group sedimentation in order to determine the plausible paleoclimate, and its related depositional environment and depositional style. To do so, an outcrop study and fluvial architecture analysis was completed to serve as model input variables. Then a forward stratigraphic Dionisos Flow model of the three main Dockum Group formations was generated. It was then analyzed and coupled with the outcrop study to draw conclusions on the necessary Triassic climate conditions to produce the Dockum Group deposits.
Per the modeling exercise and outcrop study it is concluded that the Triassic climate was highly variable, shifting between semi-arid to humid. Its variability has been underemphasized in previous studies. Climate alterations are on a scale of 103 years. Additionally, the Dockum Group’s sedimentation style has been a forum of contradicting theories. This study has concluded that Dockum sands were deposited in a predominantly upper flow regime environment during humid climate cycles, while its abundant muds were deposited in lower flow during semi arid climate cycles.

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GEOL2019LAURENTI12129 ENSC

Energetics and Bonding Dynamics in Amino and non-Amino Organic Molecules and Iron Oxides

Type: Graduate
Author(s): Alec Laurenti Environmental Sciences
Advisor(s): Omar Harvey Geological Sciences
Location: Session: 1; Basement; Table Number: 13

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Iron oxides have a controlling effect on how carbon and contaminants move through the which has impacts on climate change and pollution. Carbon held more tightly to the soil can be sequestered for longer periods of time. These tightly held contaminants are less of a threat to spread and impact groundwater. The driving factor in the movement of these compounds are the binding-debinding energies. This study will use flow adsorption microcalorimetry to systematically analyze the energetics and bonding dynamics involved in different combinations of iron oxides and organic molecules of varying carbon chain lengths (along with the presence of amine functional groups). This will allow us to isolate the effect that these different chain lengths have as well as the presence of amine functional groups. The study will focus on the systematic collection and analysis of experimental data that can be used to support the development, validation, and refinement of computational models of interactions involving natural organic matter at the metal oxide-water interface while facilitating the further development of experimentally-driven understandings of binding-debinding dynamics of organic molecules onto mineral surfaces.

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GEOL2019MIRKIN10373 GEOL

Background Color Matching in Texas Horned Lizards

Type: Graduate
Author(s): Stephen Mirkin Biology
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 2; Basement; Table Number: 1

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Texas horned lizards are a threatened species in the state of Texas with declines attributed to a variety of factors including: habitat conversion, pesticide use and red imported fire ants. These cryptic lizards in their natural habitats utilize a variety of anti-predator defense mechanisms. The primary defensive adaptation to avoid predators is often cited as their cryptic coloration, which is often suggested to color match the background substrates of the regions where they are found. Although background color-matching is purported to be an important factor in horned lizard defensive strategies it has never been empirically tested. Here we present the first known study of background color matching of Texas horned lizards in the state of Texas. We used a GIS analysis using soils and satellite imagery data to test how well Texas horned lizards match the soils and substrate in different regions of Texas.

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GEOL2019STIEFFEL51148 GEOL

Evidence for an Old Parana delta and Diachroneity in Global Highstands

Type: Graduate
Author(s): Rodney Stieffel Geological Sciences
Advisor(s): John Holbrook Geological Sciences
Location: Session: 1; 2nd Floor; Table Number: 4

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The highstand deltas of the Holocene tend to each initiate with the peaking of eustatic sea level rise at about 7000 y.b.p. While generally tied to this time, the initiation of highstand shorelines is not necessarily synchronous. Local impacts on relative sea level can impact this timing. In particular, the Parana Delta, Argentina, appears to have initiated as early as 8100 y.b.p., well before the global sea level peak and potentially before any comparable highstand shorelines. The Parana Delta encompasses an area of ~17,400 km2 enclosed in the Rio de la Plata estuary, growing steadily at a rate of approximately 2 km2 yr-1 for roughly the past 6000 yrs. This deltaic system has shifted from fluvial, to wave-dominated, and then back to its present day fluvial dominated system. Aerial and satellite imagery, shallow boreholes, radiometric dating of shells and sand, and Ground Penetrating Radar are used to define the distinctive sedimentary features of the delta. New data from the upper part of the delta indicates the Parana Delta initiated well before the 6000 y.b.p. previously reported. Sediment cores collected from across the upper delta are used to identify sedimentary facies and construct a stratigraphic framework. Three OSL samples collected from the oldest set of beach ridge s indicate the first ridges formed approximately 8100 years ago. These beach ridges are <3 m above sea level and argue for an early peak in relative sea level. Highstand strata are about 6 m thick above a thin (1-2 m) condensed section above transgressive shoreface deposits. The Parana delta initiated at least 1500 years before the sea level peak. Assumptions of synchronicity of highstands with eustatic sea level accordingly must be tempered with comparable allowance for local error.

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GEOL2019TALBERT42796 GEOL

Lower Permian and Pennsylvanian Stratigraphy and Shale Gas Potential of the Palo Duro Basin

Type: Graduate
Author(s): Brendan Talbert Geological Sciences
Advisor(s): Cheyenne Xie Geological Sciences
Location: Session: 2; Basement; Table Number: 11

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The Palo Duro Basin is a northwest-southeast trending cratonic basin in the Texas Panhandle that formed from uplift of the Amarillo/Wichita Mountains during the Pennsylvanian, and subsequent subsidence during the Permian. Sediments were deposited in a number of environments, the most prominent being fan-delta, carbonate shelf, and deep basin settings. Major lithologies in the Pennsylvanian are granite wash, shelf-margin carbonates, and basinal shales, while the Permian hosts the same lithologies, as well as numerous evaporites and red-bed sequences.
This study analyzes log data from 100+ wells in the Palo Duro Basin to correlate and determine the lateral extent of different facies throughout the basin during the Pennsylvanian and Permian. Cross-sections made will help to generate isopach, structure, and other geological maps to identify areas where further geochemical and/or petrophysical analyses can be performed to evaluate Pennsylvanian and lower Permian shale gas potential of the Palo Duro Basin. This project will establish a more detailed stratigraphic framework of Pennsylvanian and lower Permian aged sediments of the basin, as well as determine source rock quality and thermal maturity for potential shale gas plays within the Palo Duro Basin, with a more thorough look along the southern fringes of the basin near the Matador Arch.

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GEOL2019TERRELL64068 GEOL

Pennsylvanian and Mississippian Stratigraphy, Little Hoss Ranch, Johnson County, Fort Worth Basin, Texas

Type: Graduate
Author(s): Aro Terrell Geological Sciences
Advisor(s): Richard Denne Geological Sciences
Location: Session: 1; 2nd Floor; Table Number: 7

presentation location

The primary objective of this study is to test my hypothesis that the stratigraphy within Little Hoss Ranch is very complex and diverse but correlative to the surrounding strata of similar depth and characteristics. The second objective is to identify characteristics of the stratigraphic facies to better aid in the production via recompletion or other determined methods within the Little Hoss area. Seismic data that will be analyzed within Little Hoss Ranch are made available by TEP Barnett. Seismic analysis will be done using Kingdom and will be assisted by the TEP geophysicist when possible. The goal is to use these data to better identify faults and other significant structural features within the area as well as the Barnett Shale stratigraphy for LHR. A map will be made using the seismic data and logs will be included in the map for reference and quality check purposes. The seismic, well log, and cutting data for the LHR that will be analyzed was originally acquired by Chesapeake as early as 2008 and is now owned by TEP, Barnett. 127 well logs will be analyzed using PETRA, within and immediately adjacent to the Little Hoss Ranch area, to better correlate and map the stratigraphy within the Little Hoss Ranch and will be tied to the LHR wells with surrounding wells in Johnson County and Tarrant County to create regional cross-sections. An additional cross-section will be created with the wells to the north in Tarrant County to display structural trends and stratigraphic facies correlation. The 127 LHR wells will be used to create a detailed structure map that can be compared to the seismic time structure map. The BHT will be used from the well logs as well as production data (oil to gas ratio) to determine if differential thermal maturity occurred within the area The overall goal of this project is to analyze the stratigraphy and structure of the Barnett Shale play within the Little Hoss Ranch confines and to identify any geologic effects or geologic solutions to marginal production for the area of study. Seismic data, well-logs, core and cuttings, mud-log descriptions, and background literature research will be used to conduct a thorough investigation into the stratigraphy affecting the LHR. The wells in the LHR will be used with wells in northern parts of the Fort Worth Basin to create a cross section spanning a larger area. This will help to better correlate the stratigraphy for the basin and help identify depositional and erosional changes in the Fort Worth Basin. Additionally, the OGIP data and calculations will be used to help define what the remaining hydrocarbon value is for the Barnett Shale within LHR.

(Presentation is private)

MATH2019RABBY57606 MATH

Invariants of Triple Conics in Projective Three Space

Type: Graduate
Author(s): Fazle Rabby Mathematics
Advisor(s): Scott Nollet Mathematics
Location: Session: 1; Basement; Table Number: 12

presentation location

An algebraic curve is a one-dimensional set defined by polynomial equations, such as a parabola in the plane (given by y-x^2=0) or the z-axis in the space (given by x=y=0). Let Y be an algebraic curve. Then a multiplicity structure on Y is another curve Z, which as a set has the same points as Y but with a higher and fixed multiplicity at each point. For example, the y-axis in the plane is given by the equation x=0 and if we intersect it with horizontal lines, say with y-b=0, we get the points (0,b) on the y-axis. Now if we take the line given by x^2=0 and intersect it with the horizontal lines as above we get the points (0,b) with multiplicity 2. Hence we call the later curve a double structure on the previous one. Similarly the equation x^3=0 gives a triple structure on the y-axis in the plane and so on. Structures like these might sound naive but they are crucial to understand the behaviors of families of curves. For example, the family of parabolas ty-x^2=0 deforms into the double line x^2=0 as t approaches 0. Although the notion of multiplicity is pretty geometric, we can use tools from abstract algebra to make it rigorous. This makes the subject challenging and yet very interesting at the same time. Classifying the multiplicity structures on a curve is still a wide open field in algebraic geometry. It is now well understood how the double and triple structures on a line look. A natural question then arises how do the double and triple structures look on conics? It turns out that the answers are much more complicated than for lines. In this poster I am going to show some of my research in that direction.

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MATH2019WAGNER64069 MATH

The Crossed Product Structure of C*-Algebras Arising from Uniformly Recurrent Subgroups

Type: Graduate
Author(s): Douglas Wagner Mathematics
Advisor(s): José Carrión Mathematics
Location: Session: 1; 3rd Floor; Table Number: 2

presentation location

A group is a mathematical construct that represents the symmetries of an object. These symmetries transform the object through what is called a group action. Graphs—Cayley graphs, in particular—provide a rich source of symmetries for forming groups. A graph and its group action can be modeled by a collection of infinite matrices known as a C*-algebra. In a paper in the Journal of Functional Analysis, Gábor Elek used dynamical systems called Uniformly Recurrent Subgroups (URS) to construct a new type of C*-algebra. We relate this C*-algebra to a well-known construction called the crossed-product. This reinterpretation more prominently displays the group action, which proves useful as we further study the C*-algebra’s structure.

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