Physical Sciences and Mathematics Commons^™

Opening Of An Epoxide Ring Using Azide To Form A Triazole, Emily Hufnagel, Jeffrey A. Hansen

Annual Student Research Poster Session

No abstract provided.

Synthesis Of Ether Alcohols With Varying Catalysts, Hannah Grady, Frida Li, Jeffrey A. Hansen

Annual Student Research Poster Session

No abstract provided.

Polycarbodiimides And Polyguanidines : Their Reactivity And Applications In Covalent Adaptable Networks, Alberto Melchor Bañales

Scholars Week

We have recently discovered a new chemical transformation in which N,N’,N’’ tri-substituted guanidines undergo a thermal exchange reaction. Kinetic investigations indicate that the transformation is first order with respect to the guanidine, indicating a dissociative mechanism in which a carbodiimide and amine are formed as intermediates. This new reaction has been applied to polymer systems. Polycarbodiimides were shown to undergo postpolymerization modification with amines to form polyguanidines at room temperature under an hour. Polyguanidines undergo the newly found chemical transformation to form different substituted polyguanidines. This exchange reaction will be applied to the preparation of a covalent adaptable network by …

Synthesis And Evaluation Of Novel Silica Hydride-Based Stationary Phases For Bioanalytical Application, Seiichiro Watanabe

Seiichiro Watanabe

Titanium Dioxide Sensitized With Porphyrin Dye As A Photocatalyst For The Degradation Of Water Pollutants, Kevin Reyes, Ivana Jovanovic

Publications and Research

TiO2 was sensitized with a porphyrin, Tetra(4-carboxyphenyl) porphyrin(TCPP) and used as photocatalyst under visible light for degradation of aqueous solutions of methylene blue (MB) dye. The quantification of the degradation of MB was assessed by UV-Vis spectroscopy. The results of this procedure showed the decrease in concentration of MB over time when reaction is exposed to visible light. The TiO2-TCPP complex was tested as well for the recovery of metals from the AgNO3 aqueous solution. The reduction of silver cations to silver metal was observed through formation of black precipitate.

Quantitative Analysis Of Iron In Beer Using Cloud Point Extraction, Joshua Rempfer

Student Scholar Showcase

Determination of Iron concentration in Apocalypse Ale beer using a preconcentration method coupled with UV-Vis spectroscopy. Samples will be cross checked with MP-AES to ensure precise and accurate results.

The Relationship Between Insect Visitors And Chemical Fragrance Composition Of Cypripedium Parviflorum Var. Pubescens In Central Virginia., Ruth Elkins

Student Scholar Showcase

Due to its rarity, little is known regarding which insects pollinate Cypripedium parviflorum var. pubescens, large yellow lady slipper orchids, and why they do so when offered no reward. Insect identification and fragrance composition data have been collected from two populations of large yellow lady slippers in Central Virginia for more than a decade. This research analyzed data in order to determine potential relationships between visiting insects and fragrance compositions of the orchid. The results of this research can be used to establish and protect populations of Cypripedium parviflorum var. pubescens.

Elemental Analysis Of Legacy Sediments At College Lake, Amelia Dalton

Student Scholar Showcase

College Lake is a large reservoir located on the campus of the University of Lynchburg. College Lake’s ecosystem has degraded over the years due to the buildup of sediment, nutrients, and raw sewage. Increased urbanization in the area has also most likely contributed to the contaminants present within the system. Because of flooding issues during the summer of 2018, Lynchburg CIty officials drained College Lake, which caused sediment to be released downstream. To better understand the transport of heavy metals in the sediments released from College Lake, sediment core samples were taken from College Lake, Hollins Mill Park, and Sandusky …

Abiotic Stress And Anthocyanins Biosynthesis In Arabidopsis Thaliana, Carolanne Bekus

Student Scholar Showcase

Crops and farmers today are facing unprecedented challenges due to the changing environment. The plants of the future need to be hardy to survive harsh environmental conditions such as increased temperature, and prolonged droughts. It is imperative to understand the mechanisms plants employ to protect themselves under these types of stresses. Anthocyanins are pigments of the flavonoid subclass produced by plants. They impart red to purple color to flowers, fruits, and seeds. They also have antioxidant properties and they contribute to stress tolerance in plants. They are understood to be produced under abiotic stresses in order to protect the plant. …

Evaluating The Scalability Of Graphene Synthesis, Evan Dexter

Scholar Week 2016 - present

Graphene is a new material, first isolated in 2004, consisting of one to a few atomic layers of carbon in a lattice sheet structure. Graphene has high tensile strength, high surface area, very low electrical resistance, and various other special properties that make it an excellent material for use in emerging technologies in the categories of electrical components, energy systems, and high strength applications. The production scale of graphene sheets and its variations is currently limited to laboratory use, with a great amount of current research going into the development of manufacturing techniques of the material. I conducted experiments to …

Mobilization Of Calcium Across Mineralized Tissues In Yellow Perch, Perca Flavescens, Taylor Bopp

Student Scholar Showcase

Bones in many higher teleost fish, such as percids and centrarchids, lack osteocytes that function as both chemo- and mechano-sensors, and thus, are not actively involved in homeostasis of blood calcium level. Nonetheless, the vertebrae of yellow perch, Perca flavescens (P. flavescens), living in darker and low calcium (Ca) water, have demonstrated adaptive modeling and remodeling of vertebrae to be more mineralized and thus enhance transmission of the axial muscle torque into the thrust force for the C-start predator escape behavior. The prey-predator interaction is expected to occur at closer range between prey fish and predator fish in …

Age Status Effects On Female Silk Production And Male Courtship Response In Dolomedes Scriptus, Joseph Osborne

Student Scholar Showcase

Female Dolomedes scriptus, the striped fishing spider, serve as model organisms exhibiting pheromone production as a means of chemical signaling. Previous work has shown that male fishing spiders are responsive to female silk, and preferentially court in the presence of silk from mature virgins. In our research, we hypothesized that mature females produced larger quantities of silk than penultimate females in an attempt to elicit greater male mating response. Female spiders of both age statuses were kept for two days in a gridded tank. Sub-sampling of silk lines that crossed a random portion of the grid produced results signifying …

A Chemical In Filter Paper Interferes With Trail Following Behavior In The Termite Reticulitermes Hesperus (Banks), Kathryn Vest

Student Scholar Showcase

Termites follow chemical trails. In previous experiments we dissolved and diluted chemicals in acetone to test if they elicited trail following. Each trail was a straight line across the arena drawn with 10 µl using a glass capillary (Microcaps). We noticed a minor but stable response to trails laid with pure acetone. The response could be caused by contaminated acetone or by a chemical in the filter paper (Watman #5) that lined our arena (petri dish, 10cm diameter). We could confirm that the termites respond to acetone alone. Soxkhlet extraction for 8 hours removed the signal from the filter paper. …

Synthesis Of Cyclopropyl Analogs Of Acetylcholine, Douglas Armstrong, Zachary Emptage

Scholar Week 2016 - present

The Ph.D. research by Douglas Armstrong was highly successful for the synthesis of the trans cyclopropyl analog of acetylcholine, but only marginally successful for the cis isomer. In recent years he has developed novel ideas as to how the synthesis of the cis isomer may be improved upon, in ways using more current methods. He has done experiments using some of those methods, and the results, although preliminary, look good.

Lake Sediment Analysis At Heron Haven Nature Center, Erik Lato

UNO Student Research and Creative Activity Fair

Understanding the chemical composition of a wetland sanctuary lakebed can help us understand how recent developments may have changed the chemical composition. Due to recent dredging by the U.S. Army Corps of Engineers and previous research on water composition at Heron Haven, the goal of this project was to determine the chemical composition as a function of sediment depth. The concentration of seven different metals and nutrients were analyzed in terms of depth. The aluminum, iron, and phosphate concentrations had no real discernible concentration change as a function of depth. There is some hint of a steady increase of manganese …

Investigating Daily Variation In Lotic Prairie Ecosystems, Dominick Caniglia

UNO Student Research and Creative Activity Fair

The goal of this project is to investigate the hydrochemistry of the prairie stream system at Glacier Creek Preserve, namely to determine the chemical behavior as it varies over time. Past sampling revealed annual/seasonal trends, which prompted this study investigating possible changes over the course of a day. To accomplish this, water samples were taken hourly for a twelve hour period in September and November 2018, and were analyzed at the Durham Science Center. All samples were obtained at the furthest downstream site available. The main focus was to study alkalinity and dissolved mineral content. Preliminary data suggests that alkalinity …

Synthesis Of A Sulfur Variant For Treatment Of Trypanosomiasis, Carlos Vera-Esquivel

UNO Student Research and Creative Activity Fair

Previous work in our lab has found diphenyl ether benzylamines showed a successful response with a micromolar concentration of our lead compound to treat the deadly Trypanosamiosis rhodesience. Furthermore, mammalian cell lines saw promising resistance towards damages. The goal of this study was to synthesize a diphenyl thio benzylamine variant. This variant was more active toward T. b. rhodesience but showed more toxicity to both rat 10 (IC₅₀ mM) and human cell lines (HFF, HC-₀₄, U-₂ OS, and HEK₂₉₃). The selectivity index (ratio of toxicity to activity in the same concentration units (SI)) …

Information Literacy For Chemistry In The Real World, Alyssa H. Valcourt

Alyssa H. Valcourt

No abstract provided.

Solar Cells, D. Venkataraman

Science and Engineering Saturday Seminars

Solar cells convert the sun's energy into electrical energy. In this workshop, I will discuss the processes involved in solar cell and various types of solar cells that are being developed as an alternative to silicon solar cells. I will also demonstrate how students can build a solar cell from readily available materials.

Atomic Theory #5: Molecules And Compounds, Emmanuel J. Chang, Kevin J. Mark

Open Educational Resources

Video lectures on atomic theory incorporating a simulated student class working problems to increase accessibility and relatablility.

Open Educational Resource funded by a City University of New York OER Grant. Produced by the Department of Chemistry, York College/CUNY and the Department of Natural Sciences, LaGuardia Community College/CUNY

Synthesizing Polyhydroxylated Indolizidines From D-Glucopyranoside, Stephanie Bryson

SURE (Stonehill Undergraduate Research Experience)

The individual sugars that constitute more complex carbo-hydrates are joined together by glycosidic bonds. Glycosidase enzymes catalyze the hydrolysis of these glycosidic bonds. The action of glycosidases plays an important role in viral infections, cancer, and diabetes. Iminosugars are nitrogen containing sugar analogs that are known to inhibit glycosidase function. The main objective of this research is to synthesize four of the possible 32 stereoisomers of a tetrahydoxylated indolizidine iminosugar (Figure 1) starting from a commercially available D-glucopyranoside. After synthesizing pyrrolidine 6 (39.3%), a ring-closing metathesis was performed to generate the indolizidine 7. A ruthenium catalyzed dihydroxylation followed by acetylation …