Physical Sciences and Mathematics Commons^™

Chromatography-Mass Spectroscopy Analysis Of Native American Pottery For Maple Syrup Residues, Alexis Wirtz

Honors Program Theses

The research conducted regards whether or not Native Americans understood how to create maple syrup before the influence of Europeans. The analytical technique that was used is gas chromatography-mass spectrometry (GC-MS). This technique assisted in understanding what organic residues resided within the pottery and what those organic residues tell us about Native American history. An analysis of organic residues was performed on the following types of pottery: proof of concept pottery, weathered pottery (an analog of the proof of concept), and Native American pottery. The residues used in analysis were obtained through the usage of different solvent systems - Acetone: …

Analysis Of Vibrational Modes Of Chemically Modified Tone Wood, Madison Flesch

Honors Program Theses

It is generally accepted that every violin has different tone quality in terms of intonation and the depth of the harmonics produced. The best violins are made by experienced luthiers that craft each with precision to produce the best possible tonal quality. The quality of the finished violin is dependent upon both the specific shape and the vibrational response of the wood used in its construction. Because the hard wood used in violin construction is inhomogeneous, the composition and structure of material used is critical to the final product.¹ Luthiers would initially rely on their experience to feel the …

Detection And Determination Of Food Residues In Native American Pottery, Katherine A. Plotzke

Honors Program Theses

The purpose of this research was to develop a new method of analyzing organic residues left on Native American pottery using linear Raman spectroscopy. Native American pottery was replicated using terra cotta and maple syrup was boiled in each of the pots using boiling stones. The pottery shards were then analyzed using Raman spectroscopy. Shards of pottery with maple syrup residue were compared to the standards and the syrup residue was not only detected, but also matched to compounds in the instrument library. Typically, the study of Native American pottery has been done in a variety of different ways, many …

Formation Of Titan Aerosol From Co And Ch4, Tate Christensen

Honors Program Theses

In 1952 Stanley Miller and Harold Urey conducted an experiment that would simulate the conditions of early earth (Miller, 1953). The purpose was to observe the chemical origins of life, and the conclusion supported an earlier theory that such conditions favor the synthesis of more complex organic compounds from simpler inorganic molecules. The research conducted in Dr. Sebree’s lab is an extension of these early findings. It is believed that early Earth was composed mostly of nitrogen, carbon monoxide, carbon dioxide and methane as opposed to our atmosphere of nitrogen and oxygen today.

Saturn’s largest moon, Titan, has qualities relatively …

Magnetic Properties Of Polymeric Framework Materials With Cobalt, Cassara Higgins

Honors Program Theses

Single molecule magnets (SMM) are a new class of materials that have not been well studied. Metal-organic frameworks (MOFs) created with cobalt(II) metal centers have unpaired 3d electrons, which gives the frameworks interesting magnetic properties. Cobalt(II) nitrate centers can be linked together by varying numbers of 4,4´-bipyridine (bpy) ligands to create six different framework structures: four-coordinate 1D chain, five-coordinate 1D ladder, 2D bilayer, and 3D brick wall, and six-coordinate 2D square grid and 2D rhombic grid. The effects of framework structure and Co(II)-Co(II) distance on Weiss temperatures and μeff were investigated. By understanding which parameters of a framework has the …

Comparison Of Life Experiences Of Men And Women In The Sciences, Tori Nicole Quist

Honors Program Theses

A lack of sense of belonging and stereotype threat have been shown to contribute to women leaving the sciences (Seymour, 1997; Beasley & Fischer, 2012; Deemer et al., 2013). Contributing to this is the fact that most women find affirmation externally (through friends, family and professors) for their life decisions (Seymour, 1997; Zeldin, 2000). A set of comparative studies in 2000 and 2008 were done examining factors affecting women’s and men’s choices of majors and careers (Zeldin, 2000 and Zeldin, 2008). These studies concluded that men relied on achievements in science as the source of their career decisions to enter …

Liquid Sorption Properties And Structural Changes Of Metal-Organic Frameworks Of Cobalt Nitrate And 4,4'-Bipyridine, Kathryn Mauger-Sonnek

Dissertations and Theses @ UNI

Metal-organic frameworks consist of metal ions connected by organic ligands. When the metal ions and organic ligands link together in the right geometry, polymeric and infinite 1D chains or 2D and 3D networks are formed. Porous metal-organic frameworks were synthesized from the organic ligand 4,4′-bipyridine (bpy) and cobalt(II) nitrate. The metal-organic frameworks synthesized in this study grew into both a previously known 2D bilayer structure, [Co2(bpy)3(NO3)4]n, and a new, orange 1D chain structure, [Co(bpy)NO3)2(H2O)2]n, within ethanol. It was found that the presence of water was the main factor of causing formation of the orange 1D chain crystals. Drying the orange …

Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter

Honors Program Theses

Thin manganese films were grown by thermal evaporation in high vacuum. The growth rate was varied to determine how the growth rate affects the continuity of ultra-thin films. The resistance was measured with the two-point method in situ and the data was recorded digitally. The resistance was converted to resistivity and this was plotted against thickness. It was found that resistivity decreases exponentially as the film begins to form in islands. The film reaches a critical thickness as the islands coalesce and the data can then be fitted with Fuchs’ equation. The resistivity continues to decrease but the minimum resistivity …

Synthesis And Characterization Of A [Ru(Bpy)2(Ncs)2] Derivative For Use As A Dye-Sensitizer In Nanocrystalline Solar Cells, Joel Thomas Kirner

Honors Program Theses

After extensive review of the field of dye-sensitized solar cells, the molecule [Ru(4,4’- dicarboxy-2,2’-bipyridine)(4,4’-di-(2-(2-pyridyl)ethenyl)-2,2’-bipyridine)(NCS)2] has been designed as an original contribution to the field. This dye sensitizer was chosen by derivatizing upon the structure of the standard sensitizer, cis-diisothiocyanatobis(4,4’-dicarboxylic acid-2,2’- bipyridine)ruthenium(II) (N3), by extending the conjugation of one bipyridine ligand. This structural derivatization should enhance light harvesting by red-shifting the dye’s absorbance and increasing the dye’s molar absorptivity, which should result in a dye-sensitized solar cell with higher efficiency. The Density Functional Theory (DFT) molecular orbital calculations of the new dye complex indicate that the HOMO is highly localized …

The Redox Potential Of Ddt: An Environmental Perspective, Anne Lewis, Christopher Cramer, John Bumpus

Presidential Scholars Theses (1990 – 2006)

Due to their low water solubility, the reduction potentials of DDT and dicofol are difficult to determine experimentally. Through computational methods, we calculated the one and two electron reduction potentials for DDT as 0.51 V and 0.67 V, respectively, and those for dicofol were 0.50 V and 0.74 V. This study is significant because we are able to calculate reliable redox potentials that may be utilized to predict chemical behavior and degradation pathways of environmental pollutants. To assess the accuracy of theoretical chemistry, we compared experimental and computational data and examined whether our calculated redox potentials fit with the known …

The Coupling Of Biotechnology With Electrochemistry: Electrodenitrification Of Water Using The Enzyme Nitrate Reductase, Cyril Geyer

Dissertations and Theses @ UNI

Nitrate is a worldwide contaminant that causes environmental (eutrophication) and human health (methemoglobinemia, cancers) concerns. Very few techniques are available to eliminate it from natural environment and they suffer from major drawbacks, such as production of unwanted byproducts (toxins or brine). The electrochemical reduction of nitrate on any electrode is relatively slow and catalysts or electron mediators are needed. The goal of this project was to develop a new process that could overcome these disadvantages. The project demonstrates the feasibility of using an enzyme, nitrate reductase, and a mediator, methyl viologen to transfer the electrons from the electrode to nitrate, …

Photodecomposition Of Crystal Violet Dye In Water Solution And Suspensions Of Metal Oxides, Tatiana Yurievna Zakharian

Dissertations and Theses @ UNI

Photodecomposition and photodecolorization of crystal violet dye were studied in water solution, hydrogen peroxide solution and suspensions of metal oxides. Spectroscopic evidence for the formation of methylated pararosanilines and demethylated derivatives of Michler's ketone as the reaction intermediates was obtained for the photodecomposition of crystal violet in water solution. The mechanism of formation of the intermediates was discussed in terms of charges of individual atoms calculated using Spartan software.

Photooxidation of crystal violet was shown to occur faster in hydrogen peroxide solution due to the higher oxidation potential of hydrogen peroxide and hydroxyl radicals. A mechanism similar to photooxidation in …

Monitoring The Effects Of Indoor Pollution Using Fourier Transform Infrared Spectroscopy, Rachel Farrell

Presidential Scholars Theses (1990 – 2006)

Fourier Transform Infrared Spectroscopy {FTIR) was used to develop an effective way to monitor indoor pollution and to observe the effects of such indoor pollution under various conditions of the ventilation system of McCollum Science Hall of the University of Northern Iowa, Cedar Falls, Iowa. This was done by monitoring the absorbance of acetone as it evaporated over time, and the data were used to create concentration vs. time plots. Several parameters from these plots were used to judge the ventilation system, with some general conclusions including that having the system on reduces peak time and end time. Also, the …

Inactivation Of Soybean Peroxidase During Sodium Azide Oxidation: A Comparative Study, Mohamed Yehia Zakaria Aboul Eish

Dissertations and Theses @ UNI

Azide ion is a mechanism-based inactivator of a number of peroxidases. However, there are often variations in the manner in which inactivation occurs. Soybean Peroxidase (SBP) is found in the plant's seed coat. Unlike many other peroxidases, a single enzyme rather than several isozymes are produced thus making more simple the purification and characterization of the enzyme. In this research it was shown that, as with other peroxidases, SBP is inactivated by azide during turnover. During azide oxidation SBP forms a ferrous-NO intermediate. In this respect, SBP is similar to the lignin peroxidases from Phanerochaete chrysosporium which also form ferrous-NO …

The Corrosive Effects Of Salt Spray On Electrolytic Zinc Plated Mechanical Fasteners: The Case Of Clear Chromate And Yellow Dichromate Coatings On Medium Carbon Plated Bolts, Souleymane Boukari

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the relationship between plating thickness and corrosion resistance of zinc coated medium carbon steel bolts under salt spray moisture conditions. Two types of zinc coatings were chosen for the study: the clear chromate zinc and the yellow dichromate zinc. One hundred and eighty 3/8-16 x 5 3/4 inch medium carbon steel bolts were selected for the test and divided into groups of 18. Two types of salt solution were used in the study: the low salt and the high salt. Bolts with various coatings tested with low salt concentration were composed of …

New Reaction Conditions For The Synthesis Of Wieland-Miescher Ketone, Jonathan J. Bates

Presidential Scholars Theses (1990 – 2006)

Natural products chemistry is a very important field of chemistry to chemists, biochemists, and biologists. The ability to synthesize a naturally occurring chemical in the laboratory is necessary for some experiments. Often it is difficult to isolate a large quantity of a compound from its natural source when needed for certain experiments. Established procedures for artificial synthesis of this compound can produce higher yields. Sometimes, the function of a natural product is tested by observing the behavior of analogues in the same biological system. The differences in behavior can be related to differences in structure . Since such analogues are …

A Study Of The Esterification Of 2,2,4,4-Tetramethyl-1,3-Cyclobutanediol, Lewis Metzler Naylor

Dissertations and Theses @ UNI

The purpose of this research was to prepare, identify, and characterize 2,2,4,4-tetramethyl-1,.3-cyclobutanediol bischloroacetate using 2,2,4,4-tetramethyl-1,3-cyclobutanediol and monochloroacetic acid as starting materials. The synthesis of this diester has not been reported previously.

Catalyzed and uncatalyzed reactions were attempted, with the uncatalyzed having, in general, the better yield. The diester, trans-2,2,4,4-tetrametbyl-1,3-cyclobutanediol bischloroacetate (mp, 103.5-104; n²², 1.516-1.520), was isolated from a mixture of the isomers. The trans configuration of the diester was confirmed by comparing known nuclear magnetic resonance spectra to that of the diester. Infrared spectroscopy was used to confirm functional groups. Standard analytical techniques were used to determine chloride …