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CHEM2018LE31589 CHEM

Silicon Nanotubes as A Platform for Platinum Nanocrystal Deposition

Type: Graduate
Author(s): Nguyen Le Chemistry & Biochemistry
Advisor(s): Jeffery Coffer Chemistry & Biochemistry

Porous silicon (pSi) is a unique nanostructured form of the elemental semiconductor Si. Due to its useful properties governed by its surface chemistry and porous morphology, pSi has been studied in the last few decades in diverse fields extending from electronic device technology to bio-relevant applications.1 Recently, one-dimensional porous nanotubes based on elemental Si (pSiNTs) with a tunable structure (sidewalls, inner void space and lengths) have been successfully synthesized.2 The well-defined structure of pSiNTs offers ample opportunities to study newly emerging properties of this material and innovative applications in multiple areas. For example, recent reports have revealed the use of SiNTs as an efficient template for loading superparamagnetic nanoparticles (Fe3O4), lithium storage and cycling, as well as acting as a template for formation of organometal perovskite nanostructures.3-5
Platinum (Pt) nanoparticles, both free-standing as well as anchored on various surfaces, have attracted widespread attention in nanocatalysis, electronics, and chemotherapeutics.6 In this work, it is suggested that pSiNTs after being functionalized with 3-(aminopropyl)triethoxysilane (APTES) can serve as a platform for Pt nanocrystal (Pt NC) formation. Particularly, incubation of APTES-functionalized SiNTs in potassium tetrachloroplatinate (II) (K2PtCl4) solution under ambient conditions subsequently yields Pt nanoclusters with sizes ranging from 1-3 nm on SiNTs. From high-resolution transmission electron microscopy (HRTEM), nanocrystals with characteristic lattice spacings associated with Pt (d = 0.21 nm) are observed on the nanotubes. The amount of Pt deposited on SiNTs can be sensitively tuned from 20-60 wt% (characterized by TEM Energy Dispersive X-ray Analysis, EDX) by varying concentration of K2PtCl4 and immersion time in this Pt salt precursor.
These findings suggest a new approach to prepare Pt NCs that are of potential benefit to a broad number of applications by using pSiNTs as a template. Further investigations into the properties of the newly discovered Pt NCs-SiNT composites are imperative to evaluate useful applications of this material.
REFERENCES
[1] Porous Silicon for Biomedical Applications, H. Santos, Ed. Cambridge: Woodhead Publishing, 2014.
[2] X. Huang, R. Gonzalez-Rodriguez, R. Rich, Z. Gryczynski, J.L. Coffer, Chem. Commun., 2013, 49, 5760-5762.
[3] P. Granitzer, K. Rumpf, R. Gonzalez, J. Coffer, M. Reissner, Nanoscale Res. Lett. 2014, 9, 413.
[4] R. Gonzalez-Rodriguez, N. Arad-Vosk, N. Rozenfeld, A. Sa'ar, J. L. Coffer, Small, 2016, 12, 4477-4480.
[5] A. T. Tesfaye, R. Gonzalez, J. L. Coffer, T. Djenizian, ACS Appl. Mater. Interfaces, 2015, 7, 20495-20498.
[6] A. Chen, and P. Holt-Hindle, Chem. Rev., 2010, 110, 3767-3804.

(Presentation is private)

CHEM2018LE33668 CHEM

New Eco-Friendly Porous Silicon Nanomaterials as Sustained Release Fertilizers

Type: Undergraduate
Author(s): Linh Le Chemistry & Biochemistry
Advisor(s): Jeffery L. Coffer Chemistry & Biochemistry

Urea is a low-cost, water-soluble fertilizer that is used as the major source of nitrogen in agricultural production. However, the problem with leaching, in which urea in soil is rapidly washed away through rain and irrigation, results in inefficiency in nutrient absorption, low crop yield, poor harvest, and economic failure for farmers (Broadbent 1958), as well as the environmental pollution of groundwater by the release of excessive amounts of nitrate, which adversely affects this non-rechargeable water source. Therefore, recent research attempts to design a suitable system to prolong the release of urea from water in soil to improve soil fertility, agricultural economy, and ground water protection. A prospective approach is to integrate urea into a stable matrix that releases the desired material with an optimal time window.

Porous Silicon (pSi) has been studied as the material of diverse interest, due to its surface chemistry and porous morphology that has promoted many nanotechnology advances, in conjunction with its biocompatibility and biodegradability (Canham 2014). Since pSi degrades slowly in aqueous media and does not react with the soil component, it is selected to be a possible matrix for sustaining urea release. pSi is believed to interact with urea via hydrogen bonds (via surface silanol species), and thus its porous structure is the key to trap urea particles for relatively long periods in water, while exposing the fertilizer to plants. This bioactive pSi material is produced from the eco-friendly Tabasheer-derived silica, during which pSi porosity is maintained (Kalluri et al. 2016). Loading of urea into pSi is carried out using ethanol as a solvent, with theoretical loadings ranging from 27-33% of the composite mass. Release kinetics of urea from water is currently being investigated using highly sensitive colorimetric assay that applies Jung’s method (Jung et al. 1975).

The urea-loaded pSi prepared in these experiments were characterized using several different techniques. X-ray diffraction (XRD) evaluates the crystallinity of pSi after fabrication, with the presence of three peaks consistent with a cubic unit cell structure [Si (111), (220), and (311)]. Thermal gravimetric analysis (TGA) gives the mass loss percentage between melting (132oC) and boiling (203oC) points of urea, which represents the practical loading of urea in a given sample. The results deviate 1-2% from the theoretical loading percentage. TGA also shows the stability of the composite over two months at room temperature, with the recent loading measurement analyses consistent with the previous ones. Differential scanning calorimetry (DSC) analysis confirms that the urea is incorporated in the pSi matrix. Loading and characterization studies were conducted in triplicate to ensure reproducibility of results.

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CHEM2018MEHMOOD32880 CHEM

An Orbital-Overlap Complement to Atomic Partial Charge

Type: Graduate
Author(s): Arshad Mehmood Chemistry & Biochemistry
Advisor(s): Benjamin G. Janesko Chemistry & Biochemistry

Atomic partial charges obtained from computed wavefunctions are widely used for interpreting quantum chemistry simulations and chemical reactivities of molecules, solids, surfaces, and nanoparticles. In many cases, partial charge alone gives an incomplete picture of reactivity: PhS(-) is a better nucleophile compared to PhO(-) in SN2 reactions with MeI, though PhO(-) has a more negative charge on the nucleophilic atom, the carbons of benzene and cyclobutadiene, or those of diamond, graphene, and C60, possess nearly identical partial charges and very different reactivities, deprotonated amides perform nucleophilic attack via the less negative nitrogen, rather than the more negative oxygen, in anionic cyclization of o-alkynyl benzamides, halide anions F(-), Cl(-), Br(-) and I(-) have identical charges but different nucleophilicities, carbons in aromatic benzene and anti-aromatic cyclobutadiene have nearly identical partial charges, but different reactivities. Our atomic overlap distance complements computed partial charges by measuring the size of orbital lobes that best overlap with the wavefunction around an atom. Compact, chemically stable atoms tend to have overlap distances smaller than chemically soft, unstable atoms. Combining atomic charges and overlap distances captures trends in aromaticity, nucleophilicity, allotrope stability, and substituent effects. Applications to recent experiments in organic chemistry (counterintuitive Lewis base stabilization of alkenyl anions in anionic cyclization), nanomaterials chemistry (facile doping of the central atom in Au7 hexagons) and selective binding of ligands in proteins illustrate this combination’s predictive power.

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CHEM2018MONTOYA23430 CHEM

Steps Towards the Synthesis of Pancratistatin-Type Analogs

Type: Graduate
Author(s): Adam Montoya Chemistry & Biochemistry
Advisor(s): David Minter Chemistry & Biochemistry

Amaryllidaceae isoquinoline alkaloids, as well as their analogs, have long been of interest in research for drug discovery due to their biologically active nature. Many of these compounds have been found to be anti-tumor agents.1 Moreover, there have also been studies that show the effectiveness of these molecules against diseases such as Yellow Fever and other RNA-containing flaviviruses.2 Though these compounds are pharmaceutical drug prospects, their low natural abundance lowers that potential.3 For this reason, many synthetic chemists have pursued novel routes to synthesize a wide variety of these compounds.
Techniques toward the synthesis of Pancratistatin-type natural products are presented herein. Manipulations were tested and optimized on a model system 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 tetrasubstituted alkene reduction have been encountered. However, adjustments are being made to avoid such difficulties. Ideally, the proposed scheme will ultimately allow for the synthesis of multiple biologically active Phenanthridone analogs.

(Presentation is private)

CHEM2018NIEBUHR15382 CHEM

Functional modifications and electronic influences on tetra-aza macrocyclic Cu(II) complexes

Type: Undergraduate
Author(s): Brian Niebuhr Chemistry & Biochemistry Marianne Burnett Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry

A library of novel tetra-aza macrocyclic molecules, specifically 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene derivatives, capable of chelating metal ions in vivo have been synthesized. Applications of these complexes are currently being pursued as a 1) therapeutic focusing on radical scavenging and metal chelation and 2) diagnostic tool such as magnetic resonance imaging (MRI) contrast agents when complexed with specific metal ions. However, a full study of the electronic effects imparted by substitution to the pyridyl moiety (position 13) and the subsequent impact on the metal center have not been explored. The objective of the present study is to characterize metal complexes of four tetra-aza macrocyclic metal chelating molecules. The pyridyl functional groups studied include: A) unmodified pyridyl, B) p-hydroxyl, C) p-nitrile, and D) m-hydroxyl modified pyridyls on a pyclen base structure (position 13). Notable progress has been made in developing an optimal procedure for obtaining copper (II) complexes and will be presented. Analysis of the resulting copper (II) complex of the p-nitrile tetra-aza macrocycle indicate a six-coordinate metal center based on X-ray diffraction. UV-Visible spectroscopy and electrochemistry help to confirm donor strength among the ligand series as well as a comparison to other tetra-aza macrocycles. Ultimately, this project is focused on understanding the electronic contribution of these functional groups on the pyridine ring and the influence of the ligand and complexed systems as therapeutic and diagnostic agents.

(Presentation is private)

CHEM2018OCHOA41556 CHEM

Intramolecular de Mayo Photocyclization: The Total Synthesis of Hippadine and Pratosine

Type: Graduate
Author(s): Charles Ochoa Chemistry & Biochemistry
Advisor(s): David Minter Chemistry & Biochemistry

Hippadine and pratosine are lycorine-type pharmacologically active Amaryllidaceae alkaloids. Various total syntheses of these natural products have been developed. However, most of these synthetic routes require prohibitively expensive materials and/or achieve yields that are subpar, making these schemes unlikely to be used in an industrial setting. Current research involves developing better synthetic methods for these two alkaloids starting with a 6,7-disubstituted isoquinoline. These syntheses are appealing since they utilize readily available starting materials and avoid expensive catalysts. The key step in the synthetic scheme centers around an intramolecular de Mayo photocyclization which involves a reaction between an alkene moiety in the isocarbostyril system and a 1,3-diketone (a functionalized tether on nitrogen), which forms a third ring in the structure of the molecule. When the photochemical reaction was attempted, an unexpected cyclic photoproduct was obtained; fortunately, this product is a cyclic hemiketal of the expected 1,5-dicarbonyl compound. A base-catalyzed aldol addition affords the final ring in the system; dehydration of this product affords a β-enone that can be transformed to a diene. Oxidation of the diene with DDQ affords the target natural products after simple chromatographic purification. This new synthetic pathway circumvents the need for catalysts that are either expensive or contain metals such as palladium or iridium; moreover, our method allows for the synthesis of various natural and unnatural alkaloids in high yields by modification of the N-tether.

(Presentation is private)

CHEM2018PARKER27356 CHEM

Enhancing Blood-Brain Barrier Permeability Through Glycosylation of Antioxidant Compound

Type: Undergraduate
Author(s): Jack Parker Chemistry & Biochemistry Marianne Burnett Chemistry & Biochemistry Hannah Johnston Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry

Molecules previously developed by the Green Research Group (L2 and L3) have been shown to reduce reactive oxygen species (ROS) through multiple pathways of activity. Although unclear if ROS is the only source, Alzheimer’s disease and other neurodegenerative disorders are known to be initiated from the formation of these ROS. For these molecules to appropriately execute their antioxidant and radical scavenging ability, they must enter into the brain where the damaging ROS are located. The blood brain barrier (BBB) is a natural obstacle that prevents toxins and infections from reaching the brain. The L2 and L3 ligands must penetrate this barrier to be in the desired site of action to reduce the number of ROS. Addition of a glucose moiety to other therapeutic molecules has been shown to increase permeability across the BBB. The target of this project is to enhance these synthetic pathways of glycosylation and increase product yield. Initially, direct addition of the glucose moiety to the L2 and L3 molecules was achieved. However, challenges with purification techniques suggested a different route to purification or design should be considered and one new route is presented here. With L2 and L3 being inherently hydrophilic, addition of an aliphatic chain to the hydroxyl group of L2 or L3 should increase the hydrophobicity of the molecule allowing for different purification techniques, which can ultimately be glycosylated to give purified desired compounds.

(Presentation is private)

CHEM2018RODRIGUEZ3379 CHEM

Formation of New Perovskite Nanostructures Templated by Porous Silicon

Type: Undergraduate
Author(s): Adriana Rodriguez Chemistry & Biochemistry
Advisor(s): Jeff Coffer Chemistry & Biochemistry

A recent and promising development in solar energy involves a class of materials known as organometal halide perovskites, capable of efficiencies (>20%) comparable to the current industry standard of silicon. These materials also demonstrate strong light emission, a key property associated with energy-efficient sources of lighting, suggesting potential applications in light-emitting devices such as light-emitting diodes (LED). The goal of this project was to investigate the fundamental photoluminescence (PL) properties of perovskites housed in a nanoporous material known as semiconducting porous silicon (pSi).

pSi provides a nanoscale template to control the growth of the light-emitting perovskite structure and is an electrically-responsive host matrix, ideally regulating the flow of charge to/from the perovskite. Samples were prepared within the pores of surface oxidized pSi and hydride-terminated pSi, each with a mesoporous width in the 5 – 50 nm range. The perovskite-loaded pSi was fabricated through solution-loading of perovskite precursors into warmed pSi (60ºC), removal of excess reactant solution, and drying. While perovskites can feature a wide range of halide compositions (including mixed halides), this research thus far has focused on methylammonium lead iodide (MAPbI3) perovskite.

These perovskite nanostructures formed within pSi were characterized using a variety of techniques. Following synthesis, the stability of each prepared sample was monitored for 3 weeks through tracking its relative photoluminescence intensity at its maximum value. Perovskite morphology was evaluated by SEM (scanning electron microscope) and TEM (transmission electron microscope) imaging, crystalline structure was evaluated by XRD (x-ray powder diffraction), and elemental analysis was evaluated by EDX (energy-dispersive x-ray spectroscopy).

In this study, SEM imaging showed consistent perovskite particle size and ununiformed perovskite infiltration. It is found that the emission intensity for MAPbI3 formed within hydride-terminated pSi (at ~730nm) and oxidized pSi (at ~740nm) were relatively stable over a 3 week period, but the emission intensity for perovskite microrods formed in the absence of any pSi template actually decreased over time. More detailed measurements of the long term stability of these new nanoscale materials are currently under evaluation.

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CHEM2018TRETTE12261 CHEM

Fabrication Methods of Polycaprolactone (PCL) Fibers and their Thermal Properties

Type: Undergraduate
Author(s): Sayre Trette Chemistry & Biochemistry Nelli Bodiford Chemistry & Biochemistry Nathan Shurtleff Chemistry & Biochemistry
Advisor(s): Jeffery Coffer Chemistry & Biochemistry

Significant increases in average life expectancy in the last century have brought a growth in human illnesses related to aging: chronic wounds, bone diseases, eye diseases and cancer. In this work, we demonstrate fabrication of biodegradable polymer scaffolds that can be used for drug delivery and tissue engineering to treat the above-mentioned ailments. Tissue engineering can be defined as the use of a combination of engineering and materials methods and appropriate biochemical factors to improve or replace biological tissues.
This project includes fabrication of solid and porous fibers from the biocompatible PCL polymer. This polymer is currently used for surgical sutures, nerve guides and three-dimensional scaffolds for use in tissue engineering. The drug release rate is faster when it is loaded into porous PCL fibers compared to solid PCL fibers, creating an advantage for porous fiber fabrication. Use of a technique known as electrospinning of a solution of PCL and chloroform results in solid fibers that are 4 (± 2.0) micrometers (μm) in diameter. The porous fiber scaffolds are fabricated using a 50% weight of PCL compared to volume of solvent (w/v) solution prepared in a mixture of solvents 9:1 dichloromethane (DCM):dimethyl sulfoxide (DMSO) and 60% w/v PCL in 8:2 DCM:DMSO. The porous fibers are collected at 0-5 oC with a pore size of 50.0 (± 10.0) nanmoeters (nm) and fiber diameter of 3.0 (± 1.0) μm. The porosity for 50% w/v PCL and 60% w/v PCL fibers ranges from 40-50%.
Fiber surface morphology is characterized using field emission scanning electron microscopy (FESEM). In addition, the melting temperature and percent crystallinity are determined via differential scanning calorimetry (DSC). The melting temperature was collected of PCL bulk, 30%w/w PCL solid fibers, 50% w/v PCL and 60% w/v PCL. The crystallinity of PCL in solid fiber and porous fiber forms ranges from 52-55%, compared to the 60% crystallinity of PCL bulk. Solid PCL fibers showed to be more crystalline compared to porous PCL fibers, which in turn can effect the degradation time.
In order for these composites to be identified as a major technological advancement, the aging and degradation of the polymer scaffold must also be understood. The degradation of a given polymer matrix impacts the potential drug delivery behavior when testing in vitro. Degradation studies of the above mentioned materials are currently ongoing.

(Presentation is private)

CHEM2018VILLEGAS47591 CHEM

The Anomalous Stabilization of the Cis-2-Butenyl Anion by both Through-Space and Through-Bond Interactions

Type: Undergraduate
Author(s): Hector Villegas Chemistry & Biochemistry
Advisor(s): Benjamin Janesko Chemistry & Biochemistry

While cis/Z-substituted alkenes are usually less stable than their trans/E-substituted counterparts, the cis-2-butenyl anion shows a higher preference over the trans-isomer. Calculations suggest that the discrepancy is due to two cooperating effects: electrostatic interactions between the anionic center (C1) to the methyl group (C4) and coupling between the C=C pi* antibonding orbital and both the CH2 pz and CH3 C-H sigma bonds. Supporting the charge transfer is the fact that substitution on C1 with EDG stabilizes the cis more while substitution on C4 with EWG stabilizes the cis more. For the coupling interaction the C=C bond was stretched which increased the cis stabilization by lowering the pi* orbital energy and increasing the coupling between the lone pair on C1 and pi*.

(Presentation is private)

COSC2018COX17551 COSC

RAFTER: Software for the Geological Analysis of River Stream Data

Type: Undergraduate
Author(s): Connor Cox Computer Science Kaitlin Hendrick Computer Science Kiet Nguyen Computer Science Jim Pfluger Computer Science
Advisor(s): Lisa Ball Computer Science

Geology is better known for work done in the field than software applications, but by combining software with science, researchers can acquire results more efficiently and make better determinations about data. Stream input data, which consists of variables like stream size, depth, and sediment density, can be used to predict the location of oil deposits. Without a software application to automate the process, this is difficult to calculate manually.
This application will provide a useful resource and tool by which researchers can input geological data and have results returned based on that input. Specifically, users will enter data about streams and select one of two primary methods of calculation which will return results that refine sediment discharge estimates and give the user the yearly averaged bankfull flow duration. To achieve this we have implemented a database to store all of the necessary information concerning the stream data, such as location, climate ID, and Koeppen classification, established software to function as middleware between the database and the user interface, and built a web application that can be readily accessed online. With no knowledge of the middleware or database, the expected user can simply go on the website, select the desired method of calculation, and have the data returned to them in an easily understandable format.

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COSC2018GONZALEZ13220 COSC

Naturally Curly Cook Baking Application

Type: Undergraduate
Author(s): Rebecca Gonzalez Computer Science Daniel Fletcher Computer Science Ford McDonald Computer Science Luke Reddick Computer Science
Advisor(s): Lisa Ball Computer Science

Naturally Curly Cook is a baking business that does catering, standing coffee shop orders, and Farmer’s Markets. Currently, Naturally Curly Cook is having difficulty with its current pen and paper ordering system and inefficient invoicing. The purpose of the Naturally Curly Cook Team is to create an iOS application that streamlines ordering and invoicing. The application will display a daily baking list and what the bakers must bake with a check box system to ensure everything has been baked. It will also display weekly orders. Orders can be added, edited, and deleted while still maintaining the orders that do not change week to week. Excel will act as the database for all customers, orders and quantities to be stored. In addition to the ordering process, an invoicing process will allow invoices to be automatically generated from the week’s orders. The new invoicing process will be generated from Excel and will allow for different pricing options and it will update with week to week changes. The intent of this project is to create a more automatic and efficient business while cutting costs and most importantly retaining data integrity.

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COSC2018HENDRICK21849 COSC

Analysis of Artificial Intelligence Techniques for Konane

Type: Undergraduate
Author(s): Kaitlin Hendrick Computer Science
Advisor(s): Michael Scherger Computer Science

This research analyzes artificial intelligence techniques for Konane. The game Konane, also known as Hawaiian checkers, is a two-player, zero-sum strategy board game ideally suited for this research. The game ends when a player does not have a move in which they can capture an opponent’s piece. In order to have a successful strategy, a player must consider many future possibilities. For this reason, this project compares computing agents that use informed and uninformed searching algorithms. We focus our investigation on the effectiveness of the minimax and minimax with alpha-beta pruning algorithms. By altering several variables, specifically the cutoff depth for searching the game tree, we begin to see varying levels of success from the competing computing agents. The outcome of this research will be an analysis of the effectiveness of each computing agent. One of our evaluation metrics will be games statistics, such as ratio of wins to losses, time to win, and how many pieces lost.

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COSC2018LARSEN32693 COSC

Distinct Sound

Type: Undergraduate
Author(s): Nicholas Larsen Computer Science Harrison Cao Computer Science Minh Hoang Computer Science
Advisor(s): Liran Ma Computer Science

Distinct Sound
In the United States alone, 48 million people suffer from hearing loss. Sadly, about only 20 percent of them who could benefit from a hearing aid can afford to wear one. However, most people have a smartphone. Therefore, Distinct Sound strives to create an iPhone application that possesses similar functionalities of a conventional hearing aid at a fraction of the price. The two main objectives of our application are to remove background noise and to amplify sound in certain frequency ranges needed for speech comprehension. To complete those tasks, our app will take input sound, process that sound and amplify the frequencies that the user cannot hear as well, then replay the processed sound to the speakers through headphones. Those tasks will involve the fast fourier transform, and some sound processing to make sure that the sound does not have gaps. The app also provides a test to check the accuracy of the prescription in the current environment. If the current environment needs to adjust the prescription to make it more comfortable for the user, then a calibration test will work to fix the prescription according to the current environment. In conclusion, the research project will be considered a success if the application can successfully serve as a hearing aid with some functions that are unique on the market. It should benefit people who cannot afford traditional hearing aids.

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COSC2018REDDICK19284 COSC

An Ethereum-based Decentralized Voting Platform

Type: Undergraduate
Author(s): Luke Reddick Computer Science
Advisor(s): Liran Ma Computer Science

This paper covers a comprehensive implementation of a blockchain based voting platform. Blockchain, in its infancy, has shown remarkable use cases with cryptocurrencies and we would like to expand upon its possibilities. Voting is a system ripe with opportunity for blockchain; it requires security, consensus, and portability- all qualities inherited from blockchain technology. In this paper, we discuss the appeal of blockchain technology and why we want to elevate voting to 21st century technology. Next, we survey the needs of a voting platform and how blockchain might satiate those requirements. Finally, we propose a voting platform that will run on the Ethereum network and systematically discuss how this application could come to fruition.

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ENGR2018DEVOOGHT32056 ENGR

FDM 3D Printing Mechanical Properties

Type: Undergraduate
Author(s): Luke Devooght Engineering Melina Aguera Engineering
Advisor(s): Becky Bittle Engineering

In this experiment, the mechanical properties of 3D printed specimens of different printing parameters were tested under tension. The printing parameters of these specimens were: surface resolution, infill density, and print orientation. Parts were printed in Acrylonitrile Butadiene Styrene (ABS) plastic with a Fused Deposition Modeling (FDM) printer called the Stratasys UPrint SE Plus. Specimens were first printed similar to Stratasys published material properties standards and then tested to form a control on these known properties. Factorial sets of specimens using all various parameters were then printed and tested to create a reference table for future engineering projects.

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ENGR2018ELLIOTT14728 ENGR

Rare Earth Elements

Type: Undergraduate
Author(s): Lindsey Elliott Engineering
Advisor(s): Robert Bittle Engineering Efstathios Michaelides Engineering Ken Morgan Geological Sciences

From an engineering perspective, Rare Earth elements have the potential to transform technology in previously unprecedented ways. Their magnetic, luminescent, and electromechanical capabilities are allowing electronic devices to become more compact, reduce emissions, operate more efficiently, and cost less to produce and purchase. Such developments are proving beneficial to the economies of many developed nations because of their use in popular everyday consumer technologies as well as industries such as healthcare and education.

Along with this positive impact comes a political overlay that threatens the longevity of Rare Earth use. Presently, Rare Earths are expensive and dangerous to extract. This is largely due to the fact that they are not found together in large concentrations, so it is only economically feasible to extract them with another material, such as coal. The process of extraction is also hazardous and cumbersome; separating Rare Earths from other materials involves processes with high levels of emissions that may be dangerous to human beings if overexposure occurs. On the other hand, nations with more flexible safety and health regulations are investing in the development of Rare Earths and setting themselves apart as production leaders. Nations with more stringent health and safety regulations are becoming dependent on these nations to provide the Rare Earths for their applications. As a result, leaders in engineering industry can only benefit from Rare Earths if they develop systems that use Rare Earths more effectively than other materials commercially available and develop a reliable business relationship with a Rare Earth supplier. This condition is not likely to be encountered frequently in today's intricate social webs and economic systems.

The possibility of extracting Rare Earths through more efficient, safer processes is becoming recognized as a relevant topic of research. Additionally, investigation into alternatives to Rare Earths in some of the more common applications may allow for safer and less politically charged production methods for many 21st century advancements.

Through literary investigation, this research project seeks to highlight the main characteristics that makes Rare Earths desirable from an engineering perspective, proposed alternatives to Rare Earths based on engineering demands, and the direction of the Rare Earth industry as a result.

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ENGR2018KRAUSE24985 ENGR

Autonomous Vehicle with Room Mapping and Obstacle Avoidance

Type: Undergraduate
Author(s): Ben Krause Engineering Chris Prasai Engineering Bao Thach Engineering
Advisor(s): Morgan Kiani Engineering

The goal of this project is to design and construct a small modular autonomous car with room mapping and obstacle avoidance capabilities. The vehicle would be useful in cases where it is dangerous for a human to complete a task, or where it is more efficient to have an autonomous vehicle to scout ahead. A key design goal for this project was also to create an inexpensive platform for research into the realm of autonomous vehicles. The car uses lidar technology to create real time 2D room map and detect obstacles. It is programmed to explore rooms and move without human input. We designed the car with a powerful on board computer, enabling it to run complicated programs and operate without the need of an outside computer.

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ENGR2018TASMIM18442 ENGR

Development of a Device for controlling a Light Switch with a Remote Controller

Type: Undergraduate
Author(s): Seelay Tasmim Engineering Annie Le Engineering
Advisor(s): Sue Gong Engineering

The goal of this project is to develop a low cost and user-friendly device for remote actuation of light switches. We envision a product that is simple to install, easy to control via a remote, and able to function with a variety of light switch geometries. This device can minimize the inconvenience as well as the risk of injuries from turning the light on and off in the dark, especially for elderly people. For this target end user, the device must be simple and require no technical knowledge. Because of this, we have designed a mechanical actuator that will be mounted to the outside of a light switch without the need for tools and controlled by a simple button remote to be kept at the bedside.

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ENGR2018TOLBERT23197 ENGR

Tracking High Velocity Metal Objects

Type: Undergraduate
Author(s): Jacob Tolbert Engineering Lindsey Elliott Engineering Maya Hall Engineering John Hofmeister Engineering Darian Nezami Engineering Matt Spallas Engineering Cole Vallow Engineering
Advisor(s): Mike Harville Engineering Stephen Weis Engineering

Tracking and recording data from high velocity objects is a difficult task, especially when the object is hidden from view during portions of its flight path. When tasked with this problem, the process of solving it began with copious amounts of research into existing and developing technologies. From thermal imaging to radar detection, many options were explored.
Through a rigorous process of elimination to determine the most efficient and cost effective option, induction coils were chosen as the speed sensing device needed to track the desired objects. Normally when current is induced in one of these coils, there is an unchanging frequency of that current. However, when a conductive material passes through the center of a coil, the original frequency changes. This change can be monitored, giving valuable information about an object's location when evaluated over a specific time period.
After hours of bench top testing, several conclusions were made about the production and effectiveness of the induction coils. Chiefly, it was found that the smaller the induction coil diameter the more effective, the object passing through the coil has a larger effect if it does not pass through the exact center, and the "sweet spot" for the number of coil turns falls between 15-25 turns.

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ENGR2018VICTORIAN55314 ENGR

ACME senior design

Type: Undergraduate
Author(s): Brandon Victorian Engineering Matt Leonard Engineering Lauren Trost Engineering
Advisor(s): Robert Bittle Engineering

Senior design SRS submission:

For our presentation we hope to speak on three of our major groups of our senior design team:
Our first piece involves using programmable logic controllers (PLCs) that are used as the electrical interface between the programming and the mechanical system. Through its own ladder logic program, the code enables the PLC user to dictate when certain relays should be opened or closed for the purpose of turning on and off the vacuum supply and power sources. The PLC then collects data from the pressure transducers so that a signal indicating the next step is sent back to the design. After reading the pressure associated with a certain head, the user can then close a solenoid valve by sending a signal to it via the PLC which will stop the flow of air. With the PLC, the user is in control of where the flow is going to and is consequently, able to modify it through the code. Although the PLC is not a power supply, it does have the ability of processing information by receiving and sending out specified actions, set by the user, to different electronic and mechanical components.
The second piece is based of a tool from a company called pave more. The “pave more” design is a design that picks up bricks from the hack to a separate location to pack them. The design uses separate heads that pick-up bricks using foam that creates a seal on the brick. The heads are connected to a vacuum that allows us to pick up the bricks efficiently. The heads are each on their own spring system that allows them to be picked up at different heights. They are also each on a separate solenoid valve that will sense a missing brick and close the valve to still allow the system to pick up the bricks. The vacuum system is connected to a filter to protect it from the dust and dirt that are on the bricks.

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ENSC2018CLARK52950 ENSC

The Impact of Residential Swimming Pools on Bat Populations

Type: Undergraduate
Author(s): Delaney Clark Environmental Sciences
Advisor(s): Tamie Morgan Environmental Sciences Victoria Bennett Biology

Habitat loss due to urbanization is a primary cause of declining bat populations globally. As a result of this, research has been conducted to review swimming pools as an alternative source of water for bats in urban areas. After collecting data, GIS analysis utilizing color infrared imagery was performed to assess the impact that residential swimming pools have on bat populations.

(Presentation is private)

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External Influences Impacting the Fluctuations in Texas Groundwater

Type: Undergraduate
Author(s): Dorothy Gilliam Environmental Sciences
Advisor(s): Tamie Morgan Environmental Sciences Becky Johnson Environmental Sciences

In the state of Texas, groundwater resources are utilized for irrigation, mining, municipal use, manufacturing, livestock and steam electric. Over the past 20 years however, there have been shifts and significant trends in groundwater pumpage that can be attributed to changes in annual precipitation, drought, declining industries, and the status of livestock. A multi-year GIS analysis was conducted to analyze trends in Texas Groundwater and the overall factors that impacted pumpage.

(Presentation is private)

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Impacts of Megaherbivores on the Vegetation in a Size Restricted Game Reserve

Type: Graduate
Author(s): Jimmy Greene Environmental Sciences
Advisor(s): Tory Bennett Environmental Sciences

South Africa is unique in that the majority of its wildlife is managed in privately owned game reserves. One major challenge for reserves is maintaining healthy stable populations, particularly large species, such as the big five (white rhinoceros (Ceratotherium simum), African elephant (Loxodonta africana), Cape buffalo (Syncerus caffer), African leopard (Panthera pardus), and lion (Panthera leo)). Nevertheless, there has been very little research on management of these charismatic species in such size restricted reserves. To address this need, we are studying the impacts of megaherbivores on the structure and spatial distribution of vegetation in Amakhala Game Reserve. The reserve was created in 1999 from 7,500 ha of agricultural land. Since the formation of the reserve, succession of vegetation has been encouraged to create a more natural environment. However, the introduction of large herbivores, such as elephants and rhinos, may have altered or slowed down this succession. To explore this hypothesis, we conducted a GIS analysis using Landsat imagery and megaherbivore GPS tacking data. Vegetation type was classified to quantify historic changes, and we performed kernel densities and an emerging hotspot analysis with the tracking data (2011-2018) to determine megaherbivore distribution. We determined that the megaherbivores hindered the natural succession of vegetation by maintaining grasslands and preventing woodland encroachment. These findings will facilitate game reserve management by identifying Amakhala’s limitations for increasing browsing herbivores as well as the potential for the addition of grazing herbivores.

(Presentation is private)

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Does a textured coating alter bat activity at wind turbine towers?

Type: Graduate
Author(s): Brynn Huzzen Environmental Sciences
Advisor(s): Tory Bennett Environmental Sciences Amanda Hale Biology

Large numbers of migratory tree bats are killed at wind turbines globally. Recent studies have predicted potential population-level impacts as a result, highlighting the need for strategies alleviating bat-wind turbine collisions. Research has shown bats active in close proximity to turbines, approaching and interacting with tower surfaces as if they provided resources, such as water sources and foraging opportunities. Evidence indicates that the smooth surface of the towers can be misperceived by bats as water, and it can also create an acoustic mirror that can enhance foraging success. We hypothesized that a textured coating would disrupt the smooth tower surfaces. Thus, the focus of our study was to determine if texture application would result in decreased bat activity in proximity to tower surfaces, which in turn would reduce collision risk. From May to September 2017, we used thermal cameras, night vision technology, and ultrasonic acoustic bat detectors to assess bat activity at two pairs of wind turbines in north central Texas. Each pair comprised a texture-treated turbine and a control, and bat proximity and behavior at towers were compared. In this first year of testing, we conducted 76 survey nights, observed 1030 confirmed bats on video, and recorded 1215 acoustic calls from 7 bat species. To fully assess the effectiveness of the texture coating, we will be repeating surveys from June to September 2018.

(Presentation is private)