Physical Sciences and Mathematics Commons^™

Satellite Rna Of Tobacco Ringspot Virus, Jennifer J. (Jennifer Jeane) Gilberd

WWU Honors College Senior Projects

The satellite RNA found with tobacco ringspot virus is capable of attenuating the symptoms of viral infection. Although the satellite appears within viral capsids after several passages of infected plants, the origin of this satellite RNA sequence has not been previously determined. Earlier work indicated a potential mitochondrial origin of this sequence. Using satellite specific primers and the polymerase chain reaction (PCR), the mitochondrial DNA of uninfected tobacco cells was probed for sequence corresponding to the satellite RNA. A new protocol was adapted for the isolation of mitochondrial DNA in which specific isolation of protoplasts and mitochondria was not required. …

Photodegradation Of Pcbs In Natural Waters, Adriana R. Nicolaescu

Masters Theses

PCBs are widely distributed in the environment and they are biologically refractory and toxic compounds. There is great interest in understanding their fate in the environment, and also for finding safe and effective degradation methods.

This study is concerned with the photodegradation of four PCB congeners: PCB 5, PCB 18, PCB 77, PCB 128 in natural waters. Natural waters contain humic substances which can greatly influence the environmental fate of the PCBs. The different degradation of the four congeners was studied in standardized systems and in humic acid or nitrate solutions, under environmental conditions. DMDE and Methoxyclor (whose environmental half-lifetimes …

Solid-State Deuterium Nuclear Magnetic Resonance Of The Methyl Dynamics Of Poly(Alpha-Methylstyrene) And Polymethylphenylsilane, Robert D. O'Connor, Eric J. Ginsburg, Frank D. Blum

Chemistry Faculty Research & Creative Works

The methyl-d3 dynamics of two relatively similar polymers, poly(alpha-methylstyrene) (PAMS-d3) and polymethylphenylsilane (PMPS-d3), are investigated via deuterium NMR relaxation experiments. Our analysis of the relaxation data uses the entire solid-echo spectra to maximize the precision of the experiments with regard to the information available on the methyl dynamics. The analysis is novel in that it does not use M[infinity] or M0 to fit the relaxation data. Additionally, the three-site symmetric jump model is shown to not have an observable azimuthal angular dependence for T1 relaxation. The methyl dynamics are quantified with taum, sigma, and f which are the log-average correlation …

Thermolysis Of Semicarbazones To The Corresponding Azines Through Reactive N-Substituted Isocyanate Intermediates, Shailesh N. Shah, N.K. Chudgar

Faculty Publications

Thermolysis of semicarbazones (I) to azines (II) occurs through reactive N-substituted isocyanate intermediates (Ia) which can be converted in situ to carbamates and N-substituted ureas.

Development Of Organoiron Methodology For Preparation Of The Polyene Natural Product Macrolactin A, Heiko Bärmann, Vadapalli Prahlad, Chunlin Tao, Young K. Yun, Zhi Wang, William Donaldson

Chemistry Faculty Research and Publications

Methodology for the synthesis of the C7–C13 segment (19) and C14–C24 segment (41) of macrolactin A have been developed. Dicarbonyl(methyl 7-nitro-2E,4Z-heptadienoate)triphenylphosphineiron (19) is prepared by nucleophilic addition to a (1-methoxycarbonylpentadienyl)iron cation. The C23 stereocenter of 41 is established by introduction of a C20 stereocenter, chirality transfer from C20 to C23 followed by (diene)iron mediated selective ionic reduction of the C20 hydroxyl. The C15 stereocenter may be established by nitrile oxide–olefin cyclocondensation.

Thermal Degradation Of Cross-Linked Polyisoprene And Polychloroprene, David D. Jiang, Galina F. Levchik, Sergei V. Levchik, Caroline Dick, John J. Liggat, C.E. Snape, Charles A. Wilkie

Chemistry Faculty Research and Publications

Polyisoprene and polychloroprene have been cross-linked either in solution or in solid state using free radical initiators. In the comparable experimental conditions higher cross-linking density was observed in the solid state process. Independent of the cross-linking method, polychloroprene tended to give a higher gel content and cross-link density than does polyisoprene. Infrared characterization of the cross-linked materials showed cis-trans isomerization occurred in the polyisoprene initiated by benzoyl peroxide, whereas no isomerization was found in the samples initiated by dicumyl peroxide. Polyisoprene does not cross-link by heating in a thermal analyzer, whereas polychloroprene easily undergoes cross-linking in such conditions. Infrared …

A Systematic Study Of The Correlations Between Meteorite Impacts And Soot Formation, Susanna L. Widicus '00

Honors Projects

A massive extinction of more than 50 percent of existing life forms on Earth occurred 65 million years (Ma) ago. This event is marked in the geological record by the Cretaceous-Tertiary (KT) boundary and corresponds to the Chicxulub meteorite impact in the Yucatan Peninsula. Since 1985, large quantities ofreduced elemental carbon in the form of characteristic spheroidal clusters of soot have been found in twelve KT boundary sites from across the globe. Because ofthe wide geographic distribution ofthese sites, the data was interpreted to indicate that deposition ofsoot was a global phenomenon. The source of this global soot layer is …

Binding Of Pb And Zn To Aluminium Oxide And Proton Stoichiometry, Wing H. Leung, A. Kimaro

Virginia Journal of Science

The interaction of Pb and Zn with Al₂O₃ in aqueous solution was studied as a function of pH and metal ion concentration. Results indicated the complexation of metal ions by oxide surfaces is strongly pH dependent; the extent of adsorption is a function of pH with an abrupt change within approximately 2 pH units. The adsorption of Pb and Zn on aluminium oxide can be interpreted in terms of a surface complexation formed by association with one surface AlOH group, thus releasing one bound hydrogen ion. -AlOH + M²⁺ = -AlOM⁺ + H⁺ . …

Jeffress Research Grant Awards

Virginia Journal of Science

Announcements of the Jeffress Research Grants that have been awarded in 1999.

Fertilisers For Wine Grapes : An Information Package To Promote Efficient Fertiliser Practices, B. H. Goldspink, Neil Lantzke, Bob Paulin, Diana Louise Fisher, Colin Gordon, N. Cross, J M. Campbell-Clause

Bulletins 4000 -

No abstract provided.

The Noesy Jigsaw: Automated Protein Secondary Structure And Main-Chain Assignment From Sparse, Unassigned Nmr Data, Chris Bailey-Kellogg, Alik Widge, John J. Kelley Iii, Marcelo J. Berardi, John H. Bushweller, Bruce Randall Donald

Dartmouth Scholarship

High-throughput, data-directed computational protocols for Structural Genomics (or Proteomics) are required in order to evaluate the protein products of genes for structure and function at rates comparable to current gene-sequencing technology. This paper presents the Jigsaw algorithm, a novel high-throughput, automated approach to protein structure characterization with nuclear magnetic resonance (NMR). Jigsaw consists of two main components: (1) graph-based secondary structure pattern identification in unassigned heteronuclear NMR data, and (2) assignment of spectral peaks by probabilistic alignment of identified secondary structure elements against the primary sequence. Jigsaw's deferment of assignment until after secondary structure identification differs greatly from traditional approaches, …

Formation Of Uniaxial Molecular Films By Liquid-Crystal Imprinting In A Magnetic Field, Joseph D. Mougous, Andrew J. Brackley, Katherine Foland, Robert T. Baker, David L. Patrick

Chemistry Faculty and Staff Publications

Scanning tunneling microscopy was used to study molecular order in monolayer organic films formed by solution-phase growth from thermotropic liquid crystal solvents. The films develop macroscopically uniaxial alignment, with adlayer orientation controlled by an external magnetic field through interactions mediated by the liquid crystal. Results are presented for two films deposited from nematic and smectic- A solvents, along with a discussion of the alignment mechanism.

Design, Synthesis, And Evaluation Of A Novel Serine Protease Inhibitor Based On Monocyclic Β-Lactams, Ian M. Paquette

All Theses And Dissertations

Serine proteases are a large family of proteolytic enzymes which utilize a serine residue as a reactive nucleophile in the active site. Some of the more common serine proteases are chymotrypsin, trypsin, thrombin, human leukocyte elastase (HLE), human cathepsin G, and human cytomegalovirus protease (HCMV protease). Unregulated serine protease activity has been implicated in several common ailments, including rheumatoid arthritis, emphysema, pancreatitis, atherosclerosis, cystic fibrosis, and Alzheimer’s disease. Since serine proteases are responsible for the onset of such a wide range of diseases, there is an equivalent need for a large library of synthetic serine protease inhibitors to selectively counteract …

The Nonplanarity Of The Peptide Group: Molecular Dynamics Simulations, Steven W. Rick

Chemistry Faculty Publications

The general properties of the peptide bond can be described from a linear combination of two states: a single bond neutral form and a double bond zwitterionic form. However, environmental effects can shift the balance of the linear combination. This would cause the rigidity of torsional rotations of the peptide bond to be environmentally dependent and, in fact, an analysis of protein structures in the protein data bank reveals a different degree of nonplanarity for different secondary structure elements. A potential is presented in which the peptide bond is treated as a linear combination of two states; the coefficients of …

Freezing Transition Of A Strongly Dipolar Simple Fluid, G.T. Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The freezing transition of a strongly dipolar Lennard-Jones fluid is investigated using Monte Carlo simulation. It is found that the system undergoes a ferroelectric liquid-to-solid transition when cooled under a constant pressure. Near the triple point the stable solid phase is a body-centered orthorhombic ferroelectric crystal; a metastable ferroelectric solid phase with distorted hexagonal lattice structure is also discovered. To locate the freezing point, Gibbs free energies of the solid and liquid phase are determined using a thermodynamic integration method.

Molecular Dynamics Simulation Of Supersaturated Vapor Nucleation In Slit Pore, K. Yasuoka, G.T. Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Molecular dynamics simulations of nucleation of Lennard-Jones vapor confined in a slit pore have been performed. The walls of the slit pore are structureless walls; each wall interacts with vapor molecules via Lennard-Jones 9–3 potential. The rate of nucleation in the steady state is determined by analyzing time evolution of the cluster size distribution. At the same vapor density and temperature, the nucleation rate in the slit pore is higher than in the homogeneous vapor [K. Yasuoka and M. Matsumoto, J. Chem. Phys. 109, 8451 (1998)], irrespective of the strength of attraction between the wall and vapor molecules. However, this …

Effect Of Interfacial Tension On Propagating Polymerization Fronts, R. Texier-Picard, John A. Pojman, Vitaly Volpert

Faculty Publications

This paper is devoted to the investigation of polymerization fronts converting a liquid monomer into a liquid polymer. We assume that the monomer and the polymer are immiscible and study the influence of the interfacial tension on the front stability. The mathematical model consists of the reaction-diffusion equations coupled with the Navier-Stokes equations through the convection terms. The jump conditions at the interface take into account the interfacial tension. Simple physical arguments show that the same temperature distribution could not lead to Marangoni instability for a nonreacting system. We fulfill a linear stability analysis and show that interaction of the …

In Situ Treatment Of Chlorinated Ethene-Contaminated Groundwater Using Horizontal Flow Treatment Wells, Derek R. Ferland

Theses and Dissertations

The limitations of conventional containment technologies for groundwater contaminated with chlorinated solvents have motivated development of innovative technologies to achieve national groundwater remediation objectives. One inn9vative technology that is currently under development involves metal reductants or catalysts to chemically destroy the dissolved chlorinated solvent. Models are important tools that can be used to help transition this technology to the field. Model studies can be used to gain understanding about the technology, help determine when the prospective technology might work for a given site, and design full-scale field applications.

Methyl-Substituted Dispiro-1,2,4,5-Tetraoxanes:  Correlations Of Structural Studies With Antimalarial Activity, Kevin J. Mccollough, James K. Wood, Walter Reed Army Institute Of Research, Yuxiang Dong, Jonathan L. Vennerstrom

Chemistry Faculty Publications

Two tetramethyl-substituted dispiro-1,2,4,5-tetraoxanes (7,8,15,16-tetraoxadispiro[5.2.5.2]- hexadecanes) 3 and 4 were designed as metabolically stable analogues of the dimethylsubstituted dispiro-1,2,4,5-tetraoxane prototype WR 148999 (2). For a positive control we selected the sterically unhindered tetraoxane 5 (7,8,15,16-tetraoxadispiro[5.2.5.2]hexadecane), devoid of any substituents. Tetraoxanes 3 and 4 were completely inactive in contrast to tetraoxanes 2 and 5. We hypothesize that the two inactive tetraoxanes possess sufficient steric hindrance about the tetraoxane ring due to the two additional axial methyl groups to prevent their activation to presumed parasiticidal carbon radicals by inhibiting electron transfer from heme or other iron(II) species. For each of the tetraoxanes 2-4, …

Synthesis Of The Fungicide Propiconazole A Systemic Foliar Fungicide., Hazel Delaney

Masters

Propiconazole, 1-[[2-(2,4-dichlorophenyl)-4-propyl-1, 3-dioxol-2-yl[methyl]-1H-1,2,4-triazole, commercially know as “Tilt” is a systemic foliar fungicide for cereals and is widely used in agriculture. The aim of this project was to develop an economically feasible process for the production of propiconazole and to maximise the yields of the intermediates in the developed process. Processes investigated included the original Ciba-Geigy process. In addition an investigation into the synthesis and characterisation of the impurities formed, and reported to be formed in each step of the reaction process was carried out and seven of the reported impurities were synthesised. One impurity was shown not to be present …

Electric-Octupole And Pure-Electric-Quadrupole Effects In Soft X-Ray Photoemission, Andrei Derevianko, Oliver Hemmers, S. Oblad, P. Glans, H. Wang, S. B. Whitfield, R. Wehlitz, I. A. Sellin, W. R. Johnson, Dennis W. Lindle

Environmental Studies Faculty Publications

Second-order [O(k²), k = ω/c] nondipole effects in soft-x-ray photoemission are demonstrated via an experimental and a theoretical study of angular distributions of neon valence photoelectrons in the 100–1200 eV photon-energy range. A newly derived theoretical expression for nondipolar angular distributions characterizes the second-order effects using four new parameters with primary contributions from pure-quadrupole and octupole-dipole interference terms. Independent-particle calculations of these parameters account for a significant portion of the existing discrepancy between experiment and theory for Ne 2p first-order nondipole parameters.

4-Chloroacetophenone [1-(4-Methoxyphenyl)Ethylidene]Hydrazone, Michael A. Lewis, Charles Leslie Barnes, Rainer Glaser

Chemistry Faculty Research & Creative Works

The crystal structure of the title mixed azine, C₁₇H₁₇CIN₂O, contains four independent molecules, A-D, and molecule B is disordered. All four molecules have an N-N gauche conformation, with C-N-N-C torsion angles of 136.5 (4), 137.0 (4), -134.7 (4) and -134.7 (4)°, respectively. The phenyl rings are also somewhat twisted with respect to the plane defined by C_ipso and the imine bond. On average, the combined effect of these twists results in an angle of 64.7° between the best planes of the two phenyl rings. Arene-arene double T-contacts are the dominant intermolecular interaction. The …

Conceptual Problems With Remote Element Synthesis, Oliver Manuel

Chemistry Faculty Research & Creative Works

The notion of remote element synthesis has recently been modified to explain the presence of nucleogenetic isotopic anomalies and decay products of short-lived nuclides by injection of a small amount of exotic nucleogenetic material. Even with this modification, remote element synthesis seems inconsistent with the following observations: Evidence of coupled variations in the chemical and isotopic compositions of the source material for meteorites. Residual coupling of chemical and isotopic heterogeneities across planetary distances in the solar system today. The mass-fractionation relationship seen across isotopes of elements in the planetary system, in the solar wind, and in solar flares. Linkage of …

Modeling Chlorinated Ethene Removal In Constructed Wetlands: A System Dynamics Approach, Colby D. Hoefar

Theses and Dissertations

The purpose of this study is to gain understanding of the dynamics of the processes that degrade Perchloroethene (PCE) to ethylene, or carbon dioxide (CO₂), within the confines of a constructed wetland. A system dynamics approach will be used. This model is focused on identifying and optimizing the naturally occurring processes in stratified wetland sediment that reduce mass, toxicity, mobility, volume or concentration of contaminants in groundwater. Contaminant fate and transport within a wetland system is extremely complex and the mechanisms that drive wetland behavior are dynamic. Confidence in the model was built through verification and testing. Reasonable …

Chromate Dissociation From Primer Paint In Simulated Lung Fluid, Tiffany J. R. Morgan

Theses and Dissertations

OSHA has proposed a new strontium chromate exposure standard that would potentially cause Air Force paint facilities to be in violation of the proposed standard if adopted. This proposed reduction make the continued use of chromate containing primer paints very difficult. There is currently no acceptable replacements for chromate containing primer paints on AF aircraft. This study suggests that paint particles with chromate bound in primer paint may be unavailable for bodily absorption if inhaled and a reduced standard for painting applications may be unnecessary. Primer paint overspray was collected into simulated lung fluid (SLF) and allowed 6 hr, 24 …

One-Dimensional Chains In Sodium Tetraphenylphosphonium Bis(2-Mercapto-4-Methylphenolato-O,S)Oxo-Vanadate(Iv), Paul Challen, D. Mcconville, W. Youngs

Paul R. Challen

No abstract provided.

The Vaporization Enthalpies Of Some Crown And Polyethers By Correlation Gas Chromatography, Gary Nichols, Jennifer Orf, Sarah M. Reiter, James Chickos, George W. Gokel

James Chickos

No abstract provided.

Sprayed And Thermally Evaporated Carbon Films As Anodes For Lithium Ion Batteries, Shu-Gao Zhang, M.Schleich Donald

Journal of Electrochemistry

Carbon films were made using spray_thermal evaporation from a kind of pyrolytic carbon powder. The films obtained with graphite structure were both potentio_statically and galvanostaically tested. Cycling patterns indicated a reduction peak on the first cycle corresponding to the formation of solid electrolyte interface, and the capacity values and x values were quite acceptable compared to theoretical ones when charging_discharging current density was suitable. Based on the experimental results, the obtained carbon films could be used as anode materials for relatively determining the electrochemical performances of cathode materials.

Electro-Oxidation Of Glyoxal To Glyoxalic Acid, Yin-Sheng Chen, Xin-Sheng Zhang, Jun Hu, Ying-Chun Dai

Journal of Electrochemistry

An investigation has been made to obtain the glyoxalic acid by the electrochemical oxidation of glyoxal solution with hydrochloric acid under various experimental conditions.The cell used consists of a lead cathode, a DSA anode and a cation_exchange membrane of model CM001.The current efficiency and yield for glyoxalic acid generation were 80.0% and 91.1% respectively, under optimal operating conditions: velocity of electrolyte flow 1.4 m·s -1 ,current density 450A·m -2 ,temperature 30～40 ℃,initial concentration of glyoxal and hydrochloric acid 9.1%～16.0%, 4%～6%, respectively.

Studies Of Abnormal Infrared Effects Of Nanometer Thin Films Of Transition Metals And Alloys In Acid Solutions, Shi-Gang Sun, Ming-Sen Zheng, Guo-Qiang Lu, Li-Rong Cai, Sheng-Pei Cehn, Xiao-Yin Xiao

Journal of Electrochemistry

The adsorption of CO on electrodes of nanometer thin films of transition metals (Pt, Pd, Rh, Ru) and alloys (PtPd, PtRu) prepared under cyclic voltammetric conditions has been studied by in situ FTIR spectroscopy. The abnormal infrared effects (AIREs) have been explored as a novel and general phenomenon. The AIREs consist mainly in the inversion of the direction of IR band and the significant enhancement of IR absorption by adsorbed CO species. It was revealed that the enhanced IR absoroption of adsorbed species in AIREs depends strongly on the nature of metal or alloy, and on the structure and the …