Chemistry Commons^™

Measurement Of The Ratio Of Double-To-Single Photoionization Of Helium At 2.8 Kev Using Synchrotron Radiation, Jon C. Levin, Dennis W. Lindle, N. Keller, R. D. Miller, Y. Azuma, N. Berrah Mansour, H. G. Berry, Ivan A. Sellin

Chemistry and Biochemistry Faculty Research

We report the first measurement of the ratio of double-to-single photoionization of helium well above the double-ionization threshold. Using a time-of-flight technique, we find He⁺⁺/He⁺=1.6±0.3% at hν=2.8 keV. This value lies between calculations by Amusia (2.3%) and by Samson, who predicts 1.2% by analogy with electron-impact ionization cross sections of singly charged ions. Good agreement is obtained with older shake calculations of Byron and Joachain, and of Åberg, who predict 1.7%.

Anisotropy Of Polarized X-Ray Emission From Molecules, S. H. Southworth, Dennis W. Lindle, R. Mayer, P. L. Cowan

Chemistry and Biochemistry Faculty Research

Strongly anisotropic, polarized Cl K-V x-ray emission from gas-phase CF₃Cl has been observed following resonant excitation with a linearly polarized x-ray beam. Distinctively different angular distributions are observed for x-ray emission involving molecular orbitals of different symmetries. A classical model of the x-ray absorption-emission process accurately describes the observed radiation patterns.

An Analysis Of Dissolved Organic Compounds And Their Contribution To Iron Complexation In The Shallow Leachate Plume Of The West Kl Landfill Kalamazoo, Michigan, Eric Fahle

Masters Theses

High concentrations of dissolved iron are present in downgradient groundwater samples adjacent to the western border of the West KL Landfill. Analysis by Rudder (1988) of groundwater samples indicates oversaturation of selected iron oxides, iron sulfides and siderite in monitoring wells TW-4 and M3.

Previous research suggests that pyrogallol, gallic acid, tannic acid and similar organic compounds may retard the oxidation of ferrous iron in the shallow leachate plume of the West KL landfill (Rudder, 1988). Present research utilizing solid phase extraction, reverse phase high performance chromatography, Fourier transform IR spectrophotometry, UV/Visible spectrophotometry, and gas chromatography/mass spectroscopy indicate that pyrogallol, …

Molecular-Orbital Studies Via Satellite-Free X-Ray Fluorescence: Cl-K Absorption And K–Valence-Level Emission Spectra Of Chlorofluoromethanes, Rupert C. Perera, P. L. Cowan, Dennis W. Lindle, R. E. Lavilla, T. Jach, R. D. Deslattes

Chemistry and Biochemistry Faculty Research

X-ray absorption and emission measurements in the vicinity of the chlorine K edge of the three chlorofluoromethanes have been made using monochromatic synchrotron radiation as the source of excitation. By selectively tuning the incident radiation to just above the Cl 1s single-electron ionization threshold for each molecule, less complex x-ray-emission spectra are obtained. This reduction in complexity is attributed to the elimination of multielectron transitions in the Cl K shell, which commonly produce satellite features in x-ray emission. The resulting "satellite-free" x-ray-emission spectra exhibit peaks due only to electrons in valence molecular orbitals filling a single Cl 1s vacancy. These …

Polarized X-Ray-Emission Studies Of Methyl Chloride And The Chlorofluoromethanes, Dennis W. Lindle, P. L. Cowan, T. Jach, R. E. Lavilla, R. D. Deslattes, Rupert C. Perera

Chemistry and Biochemistry Faculty Research

A new technique sensitive to molecular orientation and geometry, and based on measuring the polarization of x-ray emission, has been applied to the Cl-containing molecules methyl chloride (CH₃Cl) and the chlorofluoromethanes (CF₃Cl, CF₂Cl₂, and CFCl₃) in the gas phase. Upon selective excitation using monochromatic synchrotron radiation in the Cl K-edge (Cl 1s) near-threshold region, polarization-selective x-ray emission studies reveal highly polarized molecular valence x-ray fluorescence for all four molecules. The degree and the orientation of the polarized emission are observed to be sensitive to the incident excitation energy near …

Organic Geochemistry And Petrography Of Spanish Oil Shales, Michael A. Kruge, Isabel Suarez-Ruiz

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Four of the principal oil shale units of Spain were examined by organic geochemical and petrographic methods. The samples included three lacustrine shales (Carboniferous from Puertollano, Cretaceous from Llames and Miocene from Rubielos de Mora) and one marine shale (Lower Jurassic from Punta del Cuerno ). The petrographic observations show a dominance of liptodetrinite associated with bitumen-stained mineral matter and alginite, as well as a paucity of structured terrestrial organic matter. Geochemical work shows that the soluble organic matter is a mixture of terrestrially derived and aquatic, with the lacustrine samples having the strongest land plant signatures. Low values of …

Aspects Of Sporinite Chemistry, Michael A. Kruge, John C. Crelling, Edwin J. Hippo, Stephen R. Palmer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

With the recent advent of the ability to separate coal into maceral concentrates of high purity, the individual constituents of coal can now be analyzed separately, without their mutual interference, giving a much better understanding of the macromolecular structure of coal. The sporinites from two Pennsylvanian age coal samples (Illinois Basin, U.S.A.) were studied, one from a vitrinite-rich high-volatile bituminous coal, the other from a liptinite-rich high-volatile bituminous coal of slightly higher rank. Sporinites were isolated from each coal by density gradient centrifugation. The sporinite of the vitrinite-rich coal was compared chemically and petrographically with the parent coal and with …

Direct Determination Of Molecular-Orbital Symmetry Of H2s Using Polarized X-Ray Emission, R. Mayer, Dennis W. Lindle, S. H. Southworth, P. L. Cowan

Chemistry and Biochemistry Faculty Research

X-ray emission from the molecule H₂S is strongly polarized following excitation of a sulfur K-shell electron to an unoccupied subthreshold molecular orbital with a polarized x-ray beam. Changes in the polarization of the emission spectrum are observed as the incident beam's energy is swept across the subthreshold absorption resonance. The previously unresolved absorption resonance is shown experimentally to be primarily associated with a molecular orbital of b₂ symmetry, but with a high-excitation-energy component due to an orbital with a₁ symmetry. Satellite emission intensity is shown to depend on the primary photon energy and is therefore associated …

Argon-Photoion–Auger-Electron Coincidence Measurements Following K-Shell Excitation By Synchrotron Radiation, Jon C. Levin, C. Biedermann, N. Keller, L. Liljeby, C.-S. O, R. T. Short, Ivan A. Sellin, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

Argon photoion spectra have been obtained for the first time in coincidence with K-LL and K-LM Auger electrons, as a function of photon energy. The simplified charge distributions which result exhibit a much more pronounced photon-energy dependence than do the more complicated noncoincident spectra. In the near-K-threshold region, Rydberg shakeoff of np levels, populated by resonant excitation of K electrons, occurs with significant probability, as do double-Auger processes and recapture of the K photoelectron through postcollision interaction.

Kinetics Of The Metal-Exchange Reaction Between Ortho-Phospho-Dl -Serinenickelate(Ii) And Copper(Ii), Jeffrey M. Peterman

Masters Theses

No abstract provided.

Telomere Structure In Euplotes Crassus: Characterization Of Dna-Protein Interactions And Isolation Of A Telomere-Binding Protein, Carolyn M. Price

Department of Chemistry: Faculty Publications

The nucleoprotein structure of telomeres from Euplotes crassus was studied by using nuclease and chemical footprinting. The macronuclear telomeres were found to exist as DNA-protein complexes that are resistant to micrococcal nuclease digestion. Each complex encompassed 85 to 130 base pairs of macronuclear DNA and appeared to consist of two structural domains that are characterized by dissimilar DNA-protein interactions. Dimethyl sulfate footprinting demonstrated that very sequence-specific and salt-stable interactions occur in the most terminal region of each complex. DNase I footprinting indicated that DNA in the region 30 to 120 base-pairs from the 5' end lies on a protein surface; …

Biological Markers In Lower Jurassic Synrift Lacustrine Black Shales, Hartford Basin, Connecticut, U.S.A., Michael A. Kruge, John F. Hubert, Jay F. Akes, Paul E. Meriney

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The East Berlin Formation (Lower Jurassic, Hartford basin, Connecticut, U.S.A.) is distinctive for its six cyclic units of lacustrine black shale and gray mudstone. separated by playa and fluvial redbeds. The black shales arc each about a meter thick and were deposited in subtropical, thermally stratified, oligomictic lakes, the youngest of which (lakes 3 through 6) were large enough to flood most of the basin and attained depths of several tens of meters.

The saturate fractions of solvent extracts of organic-rich black shales from each of the six lakes, collected at fresh roadcuts near East Berlin, arc dominated by extended …

Characterization Of Organic Sulfur Compounds In Coals And Coal Macerals, Stephen R. Palmer, Edwin J. Hippo, Michael A. Kruge, John C. Crelling

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Peroxyacetic acid oxidation has been used to investigate the type and distribution of organic sulfur species in samples of vitrinite, sporinite and inertinite, separated from the Herrin No.6 and an Indiana No.5 coal seam. It was established that organic sulfur species were selectively preserved during oxidation and their analysis led to some of the first sulfur-33 NMR spectra obtained for coal. The effects of maceral separation processes on model compounds were also studied. Results from our studies support the following conclusions: 1). Different macerals have different distributions and types of organic sulfur species. 2). Organic sulfur compounds in coal occur …

Organic Geochemistry Of A Lower Jurassic Synrift Lacustrine Sequence, Hartford Basin, Connecticut, U.S.A., Michael A. Kruge, John F. Hubert, David F. Bensley, John C. Crelling, R Jay Akes, Paul E. Meriney

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Synrift terrestrial strata of the Lower Jurassic East Berlin Formation (Hartford basin, Connecticut, U.S.A.) record cyclical expansion and contraction of major lakes, six of which were deep enough to develop anoxic bottom waters. We have studied one representative lacustrine sequence in detail, sampling a new roadcut near the village of East Berlin. The section examined is 4 m thick, with a gray siltstone at the base, deposited in shallow water, overlain by an organic-rich black shale (deep water), succeeded in turn by another gray siltstone, deposited as the lake waters gradually receded. The upper gray siltstone is chemically distinct from …

Mounting Sex Pheromone: A Novel Pheromone Responsible For Mate Recognition In The Ixodidae, Jgc Hamilton

Theses and Dissertations in Biomedical Sciences

Cholesterol oleate was demonstrated to be the cuticular contact sex pheromone of Dermacentor variabilis. This pheromone which has been termed the Mounting Sex Pheromone (MSP) was also demonstrated to be present on the surface of D. andersoni, Amblyomma maculatum and A. americanum. This contact sex pheromone enables males excited and attracted by 2,6-dichlorophenol to identify the female as a potential mating partner. The MSP is the second in the series of three sex pheromones guiding the hierarchy of behavioral responses which constitute tick courtship behavior. Tests with D. variabilis and D. andersoni showed that this pheromone …

Solid-Phase Electrochemical Enzyme Immunoassay With Attomole Detection Limit By Flow Injection Analysis, Yan Xu, H. Brian Halsall, William R. Heineman

Chemistry Faculty Publications

A sandwich electrochemical enzyme immunoassay with flow injection analysis for the model antigen mouse IgG has been developed with alkaline phosphatase as the enzyme label. The enzyme substrate, 4-aminophenyl phosphate and its enzymatic reaction product, 4-aminophenol have been studied by cyclic and hydrodynamic voltammetry. The determination of 4-aminophenol by flow injection analysis with electrochemical detection (FIAEC) has a linear range of 5.0 × 10−8 to 1.0 × 10−5 M, a detection limit of 2.4 × 10−8 M, and a sample throughput of 72 samples/h. The detection limit is set by a background capacitance response, which depends on the ionic strength …

Medium Resolution Atmospheric Pressure Ionization Mass Spectrometer, Andrew H. Grange, Robert J. O'Brien, Douglas F. Barofsky

Chemistry Faculty Publications and Presentations

An atmospheric pressure ionization (API) source for a VG 7070E‐HF mass spectrometer has been built and successfully operated at an accelerating potential of 6 kV. Hydrated protons and hydrated organic ions formed in the API source can be either partially or completely disaggregated by collisionally induced dissociation before entering the mass analyzer. The protonated molecular ions of pinacolone and 2,4‐pentanedione can be fully separated (R=2800, m/z 101,

Characterization Of The Lipopolysaccharides From Rhizobium Phaseoli Symbiotic Mutants, Francisca Garcia

Masters Theses

The lipopolysaccharides (LPSs) of the Rhizobium phaseoli CE3 and its mutants CE109, CE309 and the transconjugate Rhizobium leguminosarum LB2/109.11 were isolated and analyzed by gas chromatography (GC) and ¹H nuclear magnetic resonance (NMR) spectroscopy. CE3 is the wild type strain which is nodulation-proficient (Nod⁺). Strain CE109 and CE309 have a transposon, Tn5, inserted into Region I and Region III of their respetive chromosomes. Mutants CE109 and CE309 are defective in nodule development (Ndv^-). Transconjugate R. leg. LB2/109.11 has the DNA of the R. leg. LB2 wild type and also Region I portion of the CE109 …

Kinetics Of The Metal-Exchange Reaction Between N-(2-Pyridylmethyl)Iminodiacetatonickel(N) And Copper(Ii), Kassahun W. Beyene

Masters Theses

The reaction between N-(2-pyridylmethyl)iminodiacetatonickel(II) and copper(II) was studied spectrophotometrically between pH 2.30 and 3.30 over a 10-fold variation in copper concentration at an ionic strength of 1.25M, and a temperature of 25.0+0.1^oC. The reaction is first order in both NiPyIDA and copper(II). Terms involving proton attack and a copper dependent dissociation of the nickel complex were resolved from the data. Evidence is given for a stepwise unwrapping mechanism PyIDA from the nickel complex, followed by copper attack to give a dinuclear intermediate. A general mechanism is presented which is consistent with the kinetic data.

Comparisons to analogous nickel-aliphatic …

High Performance Liquid Chromatographic Determination Of Thromboxane B2 In Human Serum As A Methoxime-Panacyl Ester Derivative, Robert H. Pullen

Masters Theses

No abstract provided.

Reactive Counterion Surfactant Catalysis Of Hydroxamic Acid Hydrolysis With Perfluorooctanoic Acid, Mohamed El-Sayed Ayoub

Masters Theses

A micellar effect upon the rate of hydrolysis of hydroxamic acids in aqueous perfluorooctanoic acid has been demonstrated for hydroxamic acids with chain lengths of six , eight, and ten carbons. In this system the counterion, hydrogenion, is a catalyst. Typical rate constant-surfactant concentration profiles for micellar catalysis were obtained. The results for these hydrolyses are consistent with the pseudo-phase model for micellar effects.

In addition the Arrhenius activation energies were determined for the reaction of octanohydroxamic acid at surfactant concentrations above and below the critical micelle concentration of the surfactant. The activation energy is lower for reaction in the …

Geometric Photoisomer Investigation Of Bilirubin (Z,Z)-Ixα, Robert Howe Walker Iii

Chemistry & Biochemistry Theses & Dissertations

Numerous investigations of bilirubin have been reported in the literature. Correlation among these investigations can not be made because of multiple behavioral changes characteristic of the solubilized pigment. This research was initiated to evaluate bilirubin and its associated isomers in identical chemical environments.

Two different solvent systems were experimentally selected to study chemical behavior of bilirubin and occurring photoisomers. A ternary solution consisting of 1:3:1 chloroform:methanol:water was used exclusively in visible spectrophotometric analyses. Also, a pH 10.00 buffer was utilized. This latter system has successfully been used in spectrophotometric and voltammetric work.

Four different photochemical processes have been detected spectrophotometrically, …

Biomarker Geochemistry Of The Miocene Monterey Formation, West San Joaquin Basin, California: Implications For Petroleum Generation, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Much of the Miocene Monterey Formation of California is rich in biogenic sediment, especially organic matter and silica. Because of the geologic structure, the Monterey in the subsurface near Lost Hills in the San Joaquin Basin forms a natural laboratory for the study of the diagenetic responses of these materials. Rocks of similar age and lithology are buried to depths ranging between 500 and 3500 m, and are thus exposed to a temperature range of 45–130°C. The diagenetic progression of silica from opal-A to opal-CT to microquartz is well-documented in Monterey burial history studies. However, diagenetic indicators need to be …

Predicting The Self-Heating Potential Of Coal, Seyed Mohammad Fatemi-Badi

Masters Theses & Specialist Projects

Self-heating in coal has been studied for well over one hundred years, yet there is no accurate or reliable method for predicting the potential of certain coals to undergo self-heating. Fires caused by self-heating, and eventually spontaneous combustion, have occurred in the high wall of surface mines, in underground mines, in coal stockpiles, and on trains, barges and ships. Self-heating in coal is brought about through a complex interplay of conditions depending on the specific properties of the coal as well as many external factors involved in the mining and handling of coal.

In a study supported by the United …

Investigation Of Matrix Effects On The Furnace Atomic Absorption Signals Of Chromium, Nickel And Selenium, Susan Marie Viet

Chemistry & Biochemistry Theses & Dissertations

The flameless atomic absorption signals of chromium, nickel and selenium are subject to matrix interferences arising from inorganic salts and anions commonly found in urine. The effects of such salts on the atomic absorption signals were investigated using Polarized Zeeman Effect background correction in conjunction with a detector/readout system capable of resolving absorbance signals in 18 msec readings. Both optical temperature control and current temperature control were employed for each analysis. Peak area, peak height, peak shape and appearance time were compared for matrix-free standards and matrix-containing standards.

The influence of the inorganic salts on the metal analyses was found …

The Purification And Partial Characterization Of The Surface Polysaccharides From Three Fast-Growing Rhizobium Japonicum Strains, Madhav P. Yadav

Masters Theses

The fast-growing strains of R. japonicum were originally isolated from China. They are acid-producing Rhizobia and are capable of nodulating soybeans. These isolates share a common host-specificity (Peking soybean) with the slow-growing R. japonicum strains even though their biochemical properties are more closely related to other fast-growing Rhizobium species. The surface polysaccharides from three fast-growing R. japonicum strains--USDA201, USDA205, and HC205--were isolated and partially characterized. Strain HC205 is a nod⁻ mutant of USDA205 which lacks the symbiotic plasmid. These surface polysaccharides consist of extracellular, capsular and lipopolysaccharides (EPSs, CPSs and LPSs). The EPSs from all three strains are very similar …

A Microprocessor Controlled Pulsed Hollow Cathode Lamp For An Atomic Absorption Spectrometer, James B. Schilling

Masters Theses

A Jarrell-Ash Atomic Absorption/Flame Emission 82-360 Spectrometer was interfaced to a Heathkit ETA-3400 microprocessor. The microprocessor is used to pulse the hollow cathode lamp from a "steady" current to a "peak " current during the opening of the chopper. The current from the photomultiplier-tube is converted to a proportional voltage which is supplied to a sample-and-hold circuit. A successive approximation routine is used to convert the voltage to a representative digital value. Digital values are obtained for the "blank" and "sample" and are used to calculate percent absorption values. The system can also be used to obtain emission values.

The …

Generalized Response Of Chemiluminescence Analyzers, A. A. Mehrabzadeh, Robert J. O'Brien, Thomas M. Hard

Chemistry Faculty Publications and Presentations

The mass flow and chemical kinetic equations for a gaseous chemiluminescence (CL) analyzer are formulated and solved. The resultant equation can be used to predict the absolute response of the analyzer as a function of the sample flow rate, the sample gas pressure, the chamber pressure, the chamber volume, the mass flow rate and mole fraction of the reagent gas, and the rate constants of the relevant chemical processes. Thus, the equation allows optimization of these parameters. It is shown that for varying sample pressure the analyzer can be used to measure either concentration or mole fraction and that interfering …

A Study Of Temperature Dependent Electrical Properties Of Ion-Implanted Gallium Arsenide, Shanmugam Sundaram

Master's Essays (1922 - )

Two samples, GaAs:Mg (p-type) and GaAs:Si (n-type), ion-implanted to the same does of 5x10¹² ions/cm². were investigated to study their temperature dependent electrical properties. The resistivities and Hall constant were determined directly by Van der Pauw Technique. Sheet carrier concentration and carries mobility were then calculated. The Silicon sample, in which the properties were relatively temperature independent, was found to be in the metallic conduction range. Hence the magnesium sample was chosen for further temperature dependency investigation.

Internal Rotation Effects And Nuclear Hyperfine Structure In The Microwave Spectrum Of Propyne-Hf, Roger E. Bumgarner

Masters Theses

The microwave spectrum of the weakly bound propyne-HF/DF complex in the region between 6 and 16 GHz was analyzed. The spectrum was characteristic of a distorted T-shaped asymmetric top exhibiting torsional splitting caused by a low barrier to internal rotation of the methyl top relative to the propyne-HF frame. Deuterium substitution of HF confirms that the acid proton of HF is located between the F atom and the propyne triple bond. The spectroscopic constants given below are consistent with the fluorine atom being displaced toward the methyl group from a line perpendicular to and bisecting the propyne triple bond, suggesting …