Physical Sciences and Mathematics Commons^™

Thermal Degradation Of Polystyrene, Poly(1,4-Butadiene) And Copolymers Of Styrene And 1,4-Butadiene Irradiated Under Air Or Argon With 60co-Γ-Rays, W. Schnabel, Galina F. Levchik, Charles Wilkie, David D. Jiang, Sergei V. Levchik

Chemistry Faculty Research and Publications

⁶⁰Co-γ-irradiated samples of polystyrene (PSt), poly(1,4-butadiene), (PBD), and two poly(styrene-co-butadiene)s containing 25 and 75% BD were subjected to thermogravimetric analysis (TGA), in the presence and absence of O₂. In the case of PSt the irradiation caused a significant shift in T_onset, the onset temperature for mass loss, to higher temperatures, whereas in the cases of the BD-containing polymers irradiation caused a decrease in T_onset (oxic irradiation) or had little or no effect on T_onset (anoxic irradiation). The amount of non-volatile residue formed in the cases of BD-containing polymers was augmented by …

Use Of Evolutionary Factor Analysis In The Spectroelectrochemistry Of Escherichia Coli Sulfite Reductase Hemoprotein And A Mo/Fe/S Cluster, Robert L. Keesey, Michael D. Ryan

Chemistry Faculty Research and Publications

The deconvolution of spectroelectrochemical data is often quite difficult if the spectra of intermediates are not known. Factor analysis, however, has been shown to be a powerful technique which can make it possible to deconvolute overlapping spectra. In this work, evolving factor analysis will be used to determine the number of intermediates and the spectra of those species for two typical spectroelectrochemical experiments:  linear scan voltammetry and chronoabsorptometry in a thin-layer cell. The first system was the reduction of E. coli sulfite reductase hemoprotein (SiR-HP). Principal factor analysis indicated that three species were present. By using evolving factor analysis, …

An On-Line Test For Polycyclic Aromatic Hydrocarbons In The Flue Gas From Coal Combustion In An Fbc System, Wenjun Han

Masters Theses & Specialist Projects

Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants that have received considerable attention because of their carcinogenic and mutagenic effects. Due to the extensive amount of data suggesting the hazards of these compounds, 16 PAHs are on the Environmental Protection Agency (EPA) Priority Pollutant List. These compounds are often emitted into the atmosphere by way of combustion processes. Thus, analysis of these compounds during coal combustion is an important task. Three 1000-hour coal combustion burns were performed using the 0.1 MW (0.3 m) bench-scale Fluidized Bed Combustor (FBC) in the Combustion Laboratory at Western Kentucky University. The data for this thesis …

Analysis Of Fats And Fat-Soluble Components In Foods Using Supercritical Fluid Extraction And Chromatographic Techniques, Sneha Patel

Masters Theses & Specialist Projects

The purpose of this study was to develop experimental procedures for the extraction of fats from common foods using SFE and to determine by chromatographic techniques the fat-soluble components that are extracted with the fats. In this study various food samples were examined including french fries from Wendy's, McDonald's and Burger King, as well as potato chips, peanut butter and donuts. Soxtec extraction was used as the standard method for comparison of results (percentage of fat) obtained from SFE. Gas chromatography and gas chromatography/mass spectrometry were used for the determination of fat-soluble components (fatty acids), after extraction of fat from …

An Immobolized Surfactant Extraction Technique Compatible With High Performance Liquid Chromatography-Ultraviolet Visible Detection, Ming Zhu

Masters Theses & Specialist Projects

Surfactant mediated extractions are analogous to liquid-liquid extractions (LLE) except surfactants are used as extractants instead of organic solvents. The benefit for using surfactants for extractions includes lower toxicity, lower associated costs and direct compatibility with high performance liquid chromatography techniques. In this study, a novel immobilized surfactant extraction method was developed. In this method, the cationic alklytrimethylamrnonium surfactants are immobilized onto a strong cationic exchange resin through ion exchange. This surfactant-resin material is placed in a column and aqueous solutions containing analytes are passed through. The analytes are retained by the long carbon chain of the surfactant molecules and …

The Role Of Iron And Reactive Oxygen Species In Particulate Air Pollution-Dependent Biochemical And Biological Activities, Kevin Richard Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particulate air pollution is known to exacerbate respiratory diseases, such as asthma and chronic obstructive pulmonary disease, in humans. It has been proposed that transition meta ls from inhaled particles may play a role in this exacerbation by generating radical species leading to damage in the lungs.

The aim of this research was to determine the role that iron from particulate air pollution played in the generation of reactive oxygen species and subsequently the induction of inflammatory mediators in cells in culture. The production of reactive oxygen species by particulate air pollution was found to be dependent on the mobilization …

Insight Into The Selectivity Of Molecular Imprinted Polymers, Thomas Patrick O'Brien

Seton Hall University Dissertations and Theses (ETDs)

.

The Correlation Of Physical Properties Of Organic Molecules With Computed Molecular Surface Areas., Robert Mebane, Shannon Schanley, Thomas Rybolt, Chrystal Bruce

Chrystal D. Bruce

The objective of this paper is to show that a student's understanding of molecular properties can be enhanced with the study of molecular surface areas obtained from readily available molecular modeling software.

Growth Of Nanotubes For Probe Microscopy Tips, Jason H. Hafner, Chin Li Cheung, Charles M. Lieber

Barry Chin Li Cheung Publications

Carbon nanotubes, which have intrinsically small diameters and high aspect ratios and which buckle reversibly, make potentially ideal structures for use as tips in scanning probe microscopies, such as atomic force microscopy (AFM)^{1, 2, 3, 4}. However, the present method of mechanically attaching nanotube bundles for tip fabrication is time consuming and selects against the smallest nanotubes, limiting the quality of tips. We have developed a technique for growing individual carbon nanotube probe tips directly, with control over the orientation, by chemical vapor deposition (CVD) from the ends of silicon tips. Tips grown in this way may become …

Aluminum And Phosphorus Separation: Application To Preparation Of Target From Brain Tissue For 26Al Determination By Accelerator Mass Spectrometry, Russell D. Brauer, J. David Robertson, Pankaj Sharma, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Acid digested brain containing 4 mg added ²⁷Al was ashed at 1000°C to prepare an Al₂O₃ target for accelerator mass spectrometry (AMS) analysis of ²⁶Al. A glass-like material usually resulted which was thought to be aluminum (Al) oxyphosphate. The separation of Al and phosphate was investigated. Al, but not phosphate, was bound by a cation exchange resin (AG 50-X8). Hydrofluoric acid eluted the Al from the resin. Removal of phosphate from acid digested brain by this method produced an amorphous material after ashing that was easier to recover from the porcelain crucible and had a …

Synthesis And Crystal Structure Of Tetrachloro (1,10-Phenanthroline) Platinum (Iv), Robert M. Granger Ii, Jill N. Granger, Kelly Del Campo, Molly B. Becherer, Phillip E. Fanwick

Virginia Journal of Science

We report the crystal structure determination of tetrachloro( l,10-phenan­throline)platinum(IV). X-ray data indicate there is little steric repulsion between the cx.-hydrogens on the phenanthroline ligand and the chloride ligands in the equatorial plane.

Hydrogen Bonding And Cooperative Effects In Mixed Dimers And Trimers Of Methanol And Trifluoromethanol: An Ab Initio Study, Ruben D. Parra, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Ab initio calculations are used to provide information on the mixed dimers and cyclic trimers of the methanol-trifluoromethanol system. In order to better understand the systems, the monomers and their corresponding dimers and trimers are also investigated. Molecular structures and harmonic frequencies are obtained at the B3LYP/6-311++G(d,p) level. Interaction energies are calculated with the MP2 and B3LYP methods using the 6-311++G(d,p), 6-311++G(2d,2p), and 6-311++G(3d,2p) basis sets for the dimers and heterodimers. The 6-311++G(d,p) basis set was used to calculate the …

20. Hiroshi Inagaki, Otto Vogl, Takeshi Fukuda, Masaki Tsuji

Otto Vogl

No abstract provided.

Kinetics Of The Photosubstitution Of Cis-Bis(Benzonitrile)Dichloroplatinum(Ii) In Chloroform, Eric M. Jaryszak, Son L. Phan, Patrick E. Hoggard

Chemistry and Biochemistry

Under 254 nm irradiation cis-[Pt(C6H5CN)2Cl2] is converted to H2PtCl6. Absorption of light by both the metal complex and the solvent contribute to the first step of this process, suggested to form HPt(C6H5CN) Cl3. A linear dependence of the reaction rate on light intensity appears to rule out chlorination by trichloromethyl radicals. However, at higher light intensities a higher order dependence on intensity develops, and under 313 nm irradiation is dominant, and a reaction between trichloromethyl radical and the excited state complex is proposed to account for this.

Structural And Kinetic Studies Of A Cisplatin-Modified Dna Icosamer Binding To Hmg1 Domain B*, Elizabeth R. Jamieson, Matthew P. Jacobson, Carmen M. Barnes, Christine S. Chow, Stephen J. Lippard

Chemistry: Faculty Publications

The high mobility group (HMG) domain is a DNA-binding motif found in the non-histone chromosomal proteins, HMG1 and HMG2, and some transcription factors. Experimental evidence has demonstrated that HMG-domain proteins can play a role in sensitizing cells to the anticancer drug cisplatin. Fluorescence resonance energy transfer (FRET) experiments were performed in the present study to investigate structural changes that accompany complex formation between the HMG domain B of HMG1 and a cisplatin-modified, 20-base pair double-stranded DNA probe containing fluorescein and rhodamine tethered at its two ends. The binding affinity of HMG1 domain B for the cisplatin-modified DNA probe was investigated …

Gas Sparging And Humic Acid Sorption/Desorption, Masaki Sakakibara

Masters Theses

Partition coefficients (K_DOC) for sorption of PAHs and chlorinated benzenes to dissolved humic acids (HA) were measured using gas-sparging methodology. The resulting K_DOC values were significantly lower than the K_OW-based K_DOC values, which generally appear to provide reliable estimates for K_DOC values. The K_DOC values measured by gas sparging were also strongly influenced by the concentration of HA in solution, as measured by dissolved organic carbon content (DOC). Increasing DOC concentration consistently resulted in decreased K_DOC values for all compounds investigated. Previous studies have claimed that K_DOC values measured using …

Synthesis And Antimalarial Activity Of 11 Dispiro-1,2,4,5-Tetraoxane Analogues Of Wr 148999. 7,8,15,16-Tetraoxadispiro[5.2.5.2]Hexadecanes Substituted At The 1 And 10 Positions With Unsaturated And Polar Functional Groups, Yuxiang Dong, F. Hoffmann-Laroche Ltd., Jacques Chollet, Ronald Kaminsky, James K. Wood, Jonathan L. Vennerstrom

Chemistry Faculty Publications

Eleven novel dispiro-1,2,4,5-tetraoxanes 3 bearing unsaturated and polar functional groups were designed to enhance the oral antimalarial activity of the prototype tetraoxane 2 (WR 148999). With the exception of 3g and 3h, tetraoxanes 3 were available via the peroxidation of corresponding cyclohexanone derivatives in H2SO4/CH3CN. Tetraoxanes 3g and 3h were prepared by hydrolysis of ester tetraoxanes 3e and 3i, respectively. Five of the 11 tetraoxanes were inactive, but six tetraoxanes had IC₅₀ values of 6-26 nM against the K1 and NF54 strains of Plasmodium falciparum compared to corresponding IC₅₀ values of 28 and 39 nM for …

Synthesis Of A Novel ??-Amino Acid Capable Of Stabilizing A 310-Helix Via Side-Chain Salt-Bridging, Reema K. Thalji

Honors Theses

No abstract provided.

Visible And Resonance Raman Spectra Of Low Valent Iron Porphyrins, Chathra De Silva, Kazimierz Czarnecki, Michael D. Ryan

Chemistry Faculty Research and Publications

The resonance Raman spectrum of Fe(TPP)²⁻ was obtained after the three-electron electrochemical reduction of Fe(TPP)(Cl). The coulometric reduction was carried out in the presence of bis(triphenylphosphoanylidine)ammonium chloride in DMF in order to avoid the formation of iron–σ-alkyl complexes. The resonance Raman spectrum of the intermediate oxidation states (Fe(TPP) and Fe(TPP)⁻) were consistent with previous work. The spectrum of the three-electron product, Fe(TPP)²⁻, obtained at 442 nm, was qualitatively similar to the two-electron reduced product, Fe(TPP)⁻, with an intense ν₂ band at 1537 cm⁻¹. The high frequency bands generally decreased in …

Electron Affinities Of The Oxides Of Aluminum, Silicon, Phosphorus, Sulfur, And Chlorine, Nicole R. Brinkmann, Gregory S. Tschumper, Henry F. Schaefer

Chemistry Faculty Research & Creative Works

The adiabatic electron affinities of five second row atoms (Al, Si, P, S, Cl) and their monoxides and dioxides were determined using six different densities functional or hybrid Hartree-Fock/density functional methods. The 15 species selected form a convenient closed set for which reliable experimental electron affinities exist for 13 of the species. Zero-point vibrational energy corrected electron affinities are also reported. Equilibrium geometries and vibrational frequencies were determined with each density functional method. The method based on the Becke exchange functional and the Lee-Yang-Parr correlation (BLYP) functional reproduced the experimental electron affinities most accurately, having an average absolute error of …

Magnetic And Mössbauer Spectral Study Of Mixed Valent La₀.₂Sr₀.₈Cu₀.₂Fe₀.₈O2.68 And Related Perovskites, Gary J. Long, Dimitri Hautot, Amitabh Mohan, Ingeborg Kaus, Harlan U. Anderson, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The La_0.2Sr_0.8Cu_1-xFe_xO _3-δ perovskites are important because they are mixed electron and oxygen anion conductors and thus are able to serve as dense oxygen separation membranes. In order to better understand the mechanism for this separation a Mössbauer spectral study has been carried out to determine the ratio of iron(III) to iron(IV) in these mixed valent compounds. The Mössbauer spectra of La_0.2Sr_0.8Cu_0.2Fe_0.8O _3-δ obtained between 4.2 and 78 K reveal that its Néel temperature is ~75 K and the two well-resolved magnetic sextets observed …

Structural, Magnetic, And Mössbauer Spectral Properties Of Pr₂Fe₁₇Hₓ Where X Is 1, 2, And 3, Fernande Grandjean, Dimitri Hautot, Gary J. Long, Olivier Isnard, Salvatore Miraglia, Daniel Fruchart

Chemistry Faculty Research & Creative Works

The 295 K unit cell parameters of Pr₂Fe₁₇H_x, where x is 0, 1, 2, and 3, have been determined by x-ray diffraction. Upon hydrogenation, the unit cell volume expands anisotropically with a 1.2% expansion of the a axis and no expansion of the c axis for x=3. The Curie temperatures are 286, 374, 440, and 484 K, for x=0, 1, 2, and 3, respectively. The Mössbauer spectra have been measured between 4.2 and 295 K, and the spectra of Pr₂Fe₁₇H and Pr₂Fe₁₇H₂, obtained above …

Atomic Structure And Magnetism Of Ordered And Disordered Al₀.₅Fe₀.₅₋ₓmnₓ Alloys, V. G. Harris, D. J. Fatemi, K. B. Hathaway, Q. Huang, Amitabh Mohan, Gary J. Long

Chemistry Faculty Research & Creative Works

The equiatomic FeAl alloy has been modified by partial substitution of Mn for Fe, and its magnetic and structural properties investigated by neutron diffraction (ND), x-ray absorption fine structure (XAFS) spectroscopy, Mössbauer spectroscopy (MS), and SQUID magnetometry both for the ordered (B2) and disordered states. The unit cell volume is measured to increase linearly with Mn concentration. XAFS measurements indicate local structural displacements occur at the Mn sites in both ordered and disordered states that may act to frustrate long-range magnetic order (LRMO). Although MS and ND show no evidence of LRMO, SQUID magnetometry indicates an induced movement in the …

In Situ Measurement Of The Aerosol Size Distribution In Stratospheric Solid Rocket Motor Exhaust Plumes, Martin N. Ross, Philip D. Whitefield, Donald E. Hagen, Alfred R. Hopkins

Chemistry Faculty Research & Creative Works

The concentration and size distribution of aerosol in the stratospheric exhaust plumes of two Space Shuttle rockets and one Titan IV rocket were measured using a two component aerosol sampling system carried aboard a WB‐57F aircraft. Aerosol size distribution in the 0.01 µm to 4 µm diameter size range was measured using a two component sampling system. The measured distributions display a trimodal form with modes near 0.005 µm, 0.09 µm, and 2.03 µm and are used to infer the relative mass fractionation among the three modes. While the smallest mode has been estimated to contain as much as 10% …

The Discovery-Oriented Approach To Organic Chemistry 1. Nitration Of Unknown Organic Compounds. An Exercise In 1H Nmr And 13C Nmr Spectroscopy For Sophomore Organic Laboratories, Ram Mohan, Sonia Mcelveen, Kostas Gavardinas, Jean Stamberger

Scholarship

Nitration is one of the most fundamental reactions in organic chemistry. However, the majority of the nitration experiments found in the standard lab textbooks are of the "cookbook" variety and convey none of the excitement associated with discovery in experimental chemistry. We have developed two simple nitration experiments that present the student with a puzzle and are a good exercise in 1H NMR and 13C NMR spectroscopy. 13 C NMR spectroscopy is a powerful structure elucidation tool and yet not many examples of the use of 13C NMR spectroscopy in organic lab experiments can be found. The experiment involves nitration …

The Discovery-Oriented Approach To Organic Chemistry 1. Nitration Of Unknown Organic Compounds. An Exercise In 1H Nmr And 13C Nmr Spectroscopy For Sophomore Organic Laboratories, Ram S. Mohan, Sonia R. Mcelveen, Kostas Gavardinas, Jean A. Stamberger

Ram S. Mohan

Monomer-Dimer Equilibrium Constants Of Rna In The Dimer Initiation Site Of Human Immunodeficiency Virus Type 1, Michael F. Shubsda, Mark P. Mcpike, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

The genome of the human immunodeficiency virus (HIV) exists as a dimer of two identical RNA molecules hydrogen bonded to each other near their 5' ends. The dimer, known to be important for viral infectivity, is formed by two monomers interacting through a stem-loop structure called the dimer initiation site (DIS). An initially formed intermediate, the "kissing" dimer, is unstable and rearranges to the stable, duplex form. In this report we use nondenaturing polyacrylamide gel electrophoresis to measure the monomer-dimer equilibrium constant of three RNA sequences, 41-, 27-, and 19-mers, located in the DIS of the MAL isolate of HIV-1. …

Novel Carbon-Carbon Bond Oxidative Cleavage Of Hexabenzyl-Hexaazaisowurtzitane By N-Buono And (Nh4)2ce(No3)6, Xiao-Pei Guan, Hong Yan, Jian-Guang Sun, Yong-Zhong Yu

Publications and Research

Treatment of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazatetracyclo-[5.5.0.05,9.03,11]dodecane with n-butyl nitrite or ammonium cerium nitrate results in novel C(1)-C(7) oxidative cleavage to give 1,3,4,5,7,8-hexabenzyl-cis-cisoid-cis-hexahydro-1H,5H-diimidazolinium[4,5-b:4′,5′-e]pyrazine dinitrate.

Activated Carbon Produced From Agricultural Residues, Daniel W. Armstrong, V. J. Flanigan, William Joseph James, Jui-Lung Li, Kimber L. Rundlett

Chemistry Faculty Research & Creative Works

A process for producing activated carbon from agricultural residues by heating the residues to a temperature in the range of about 250° C. to about 550° C. to volatilize organic compounds in the residues and to carbonize the residues and further heating to activate the carbonized residues. Activated carbon produced from agricultural residues.

Monte Carlo Study Of The Capacitance Of The Double Layer In A Model Molten Salt, Douglas Henderson, Dezso Boda, Kwong-Yu Chan

Faculty Publications

Monte Carlo simulations are reported for charged hard spheres at high density near a charged wall. This system is a simple model for a molten salt double layer. Unfortunately, the reduced temperatures that correspond to experiment are very small. This results in a large Boltzmann factor. As a result, we are unable to obtain meaningful results for such low values and report results only for moderately low values of the reduced temperature. Even so, our results should be a useful benchmark. Further, we are able to give a qualitative answer to an interesting question. We find that at low temperatures …