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Chemistry

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1996

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Articles 1 - 30 of 123

Full-Text Articles in Physical Sciences and Mathematics

A Chemical Pathway To The Formation Of Chlorinated Compounds During Combustion, Xiaodong Yang Dec 1996

A Chemical Pathway To The Formation Of Chlorinated Compounds During Combustion, Xiaodong Yang

Masters Theses & Specialist Projects

Two reactions, the Deacon reaction and the chlorination of phenol, which are the postulated starting steps for the formation of chlorinated dioxins during the incineration of the refuse derived fuel, were investigated in this work. Reactions were conducted in a tube furnace, and the products were trapped and analyzed by gas chromatography/mass spectroscopy. It was shown that the Deacon reaction was favored at higher temperatures. The chlorination of phenol in vapor phase was found to begin at temperatures as low as 250°C and to be favored at higher temperatures. The ortho and para positions in the phenol ring are the …

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Elucidation Of Vancomycin's Enantioselective Binding Site Using Its Copper Complex, Usha B. Nair, Samuel S.C. Chang, Daniel W. Armstrong, Yasir Y. Rawjee, Drake S. Eggleston, James V. Mcardle Dec 1996

Elucidation Of Vancomycin's Enantioselective Binding Site Using Its Copper Complex, Usha B. Nair, Samuel S.C. Chang, Daniel W. Armstrong, Yasir Y. Rawjee, Drake S. Eggleston, James V. Mcardle

Chemistry Faculty Research & Creative Works

Vancomycin forms a stable complex with Cu2+ in neutral aqueous solutions. The enantioselectivity of native vancomycin was compared to that of the copper-vancomycin complex using capillary electrophoresis (CE). There were significant differences in their enantioselectivities. This can be attributed to the fact that copper ion coordinates with some of the same functional groups in vancomycin that are essential for chiral recognition and enantioresolution. An amine moiety that provides one of the more important enantioselective interactions was identified. This chiral interaction site was illustrated using a color-coded, space-filling model of the X-ray crystal structure of the copper-vancomycin complex. Successful enantioselective interactions …

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Inhomogeneity In Gelation And Nonuniversality Of Sol-To-Gel Transitions Studied By A Computer Simulation Model, Yi-Min Liu, R.B. Pandey Dec 1996

Inhomogeneity In Gelation And Nonuniversality Of Sol-To-Gel Transitions Studied By A Computer Simulation Model, Yi-Min Liu, R.B. Pandey

Faculty Publications

No abstract provided.

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A Study Of The Behavior Of Chlorine And Organic Compounds During Combustion In An Afbc System, Jenny Heidbrink Dec 1996

A Study Of The Behavior Of Chlorine And Organic Compounds During Combustion In An Afbc System, Jenny Heidbrink

Masters Theses & Specialist Projects

The purpose of this study is to understand the behavior of chlorine and the emission of organic compounds during combustion in an atmospheric fluidized bed combustion (AFBC) system. Inefficient, uncontrolled use of coal gives rise to organic emissions which can be detrimental to health. The chlorine in coal may cause corrosion problems during utilization, if its concentration is high enough. The method for collection of the emissions of organic compounds involved the use of a Tenax resin as an absorbent for the organic compounds as they were emitted from the combustor. A combined gas chromatography - mass spectrometry (GC-MS) technique …

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Investigating The Evolution Of Multifragmenting Systems With Fragment Emission Order, E. W. Cornell, T. M. Hamilton, D. Fox, Y. Lou, R. T. De Souza, M. J. Huang, W. C. Hsi, C. Schwarz, C. Williams, D. R. Bowman, J. Dinius, C. K. Gelbke, D. O. Handzy, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, L. Phair, M. B. Tsang, G. Vanburen, R. J. Charity, L. G. Sobotka, W. A. Friedman Nov 1996

Investigating The Evolution Of Multifragmenting Systems With Fragment Emission Order, E. W. Cornell, T. M. Hamilton, D. Fox, Y. Lou, R. T. De Souza, M. J. Huang, W. C. Hsi, C. Schwarz, C. Williams, D. R. Bowman, J. Dinius, C. K. Gelbke, D. O. Handzy, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, L. Phair, M. B. Tsang, G. Vanburen, R. J. Charity, L. G. Sobotka, W. A. Friedman

Faculty Publications

Multifragment decays of central collisions in 84Kr+197Au at E/A=70MeV are studied. By utilizing a technique sensitive to the emission order of fragments, it is deduced that carbon fragments are emitted prior to beryllium fragments when these fragments have the same velocity. This observation is consistent with the cooling of a thermally decaying source.

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Reactions Of Singlet Oxygen And Singlet Oxygen Mimics With Dicyclopropylethylenes: Comparison Of Reactivity And Mechanisms, Gina Elizabeth Alume Nov 1996

Reactions Of Singlet Oxygen And Singlet Oxygen Mimics With Dicyclopropylethylenes: Comparison Of Reactivity And Mechanisms, Gina Elizabeth Alume

FIU Electronic Theses and Dissertations

An extensive study of the reaction pathways of 1,1- dicyclopropyl ethylene, cis- and trans- 1,2-dicyclopropylethylenes has been undertaken with different electrophiles 4-methyl-1,2,4- triazoline-3,5-dione (MTAD), tetracyanoethylene (TCNE), and singlet oxygen (102). Comparison of reactivity and reaction mechanisms among the electrophiles is investigated. Singlet oxygen exhibits significantly lower reactivity compared to the other electrophiles. MTAD and TCNE react with dicyclopropylethylenes to produce predominantly "2+2" adducts and a small amount of the "ene" adducts. The "2+2" is the major product presumably because of the high activation energy leading to the highly strained "ene" products. Solvent trapping studies provide strong evidence of …

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Protein-Protein And Protein-Dna Interactions At The Bacteriophage T4 Dna Replication Fork. Characterization Of A Fluorescently Labeled Dna Polymerase Sliding Clamp, Daniel J. Sexton, Theodore E. Carver, Anthony J. Berdis, Stephen J. Benkovic Nov 1996

Protein-Protein And Protein-Dna Interactions At The Bacteriophage T4 Dna Replication Fork. Characterization Of A Fluorescently Labeled Dna Polymerase Sliding Clamp, Daniel J. Sexton, Theodore E. Carver, Anthony J. Berdis, Stephen J. Benkovic

Chemistry Faculty Publications

The T4 DNA polymerase holoenzyme is composed of the polymerase enzyme complexed to the sliding clamp (the 45 protein), which is loaded onto DNA by an ATP-dependent clamp loader (the 44/62 complex). This paper describes a new method to directly investigate the mechanism of holoenzyme assembly using a fluorescently labeled cysteine mutant of the 45 protein. This protein possessed unaltered function yet produced substantial changes in probe fluorescence intensity upon interacting with other components of the holoenzyme. These fluorescence changes provide insight into the role of ATP hydrolysis in holoenzyme assembly. Using either ATP or the non-hydrolyzable ATP analog, adenosine …

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Searching For The Nuclear Liquid-Gas Phase Transition In Au + Au Collisions At 35 Mev/Nucleon, M. Belkacem, P. F. Mastinu, V. Latora, A. Bonasera, M. D'Agostino, M. Bruno, J. D. Dinius, M. L. Fiandri, F. Gramegna, D. O. Handzy, W. C. Hsi, M. Huang, G. V. Margagliotti, P. M. Milazzo, C. P. Montoya, Graham F. Peaslee, R. Rui, C. Schwarz, G. Vannini, C. Williams Nov 1996

Searching For The Nuclear Liquid-Gas Phase Transition In Au + Au Collisions At 35 Mev/Nucleon, M. Belkacem, P. F. Mastinu, V. Latora, A. Bonasera, M. D'Agostino, M. Bruno, J. D. Dinius, M. L. Fiandri, F. Gramegna, D. O. Handzy, W. C. Hsi, M. Huang, G. V. Margagliotti, P. M. Milazzo, C. P. Montoya, Graham F. Peaslee, R. Rui, C. Schwarz, G. Vannini, C. Williams

Faculty Publications

Within the framework of classical molecular dynamics, we study the collision Au+Au at an incident energy of 35 MeV/nucleon. It is found that the system shows a critical behavior at peripheral impact parameters, revealed through the analysis of conditional moments of charge distributions, Campi scatter plot, and the occurrence of large fluctuations in the region of the Campi plot where this critical behavior is expected. When applying the experimental filters of the MULTICS-MINIBALL apparatus, it is found that criticality signals can be hidden due to the inefficiency of the experimental apparatus. The signals are recovered by identifying semiperipheral and peripheral …

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The Carboxyl Terminus Of The Bacteriophage T4 Dna Polymerase Is Required For Holoenzyme Complex Formation, Anthony J. Berdis, Patrice Soumillion, Stephen J. Benkovic Nov 1996

The Carboxyl Terminus Of The Bacteriophage T4 Dna Polymerase Is Required For Holoenzyme Complex Formation, Anthony J. Berdis, Patrice Soumillion, Stephen J. Benkovic

Chemistry Faculty Publications

To further elucidate the mechanism and dynamics of bacteriophage T4 holoenzyme formation, a mutant polymerase in which the last six carboxyl-terminal amino acids are deleted, was constructed, overexpressed, and purified to homogeneity. The mutant polymerase, designated ΔC6 exo−, is identical to wild-type exo− polymerase with respect to kcat, kpol, and dissociation constants for nucleotide and DNA substrate. However, unlike wild-type exo− polymerase, the ΔC6 exo− polymerase is unable to interact with the 45 protein to form the stable holoenzyme. A synthetic polypeptide corresponding to the carboxyl terminus of the wild-type exo− polymerase was tested as an in vitro inhibitor of …

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Mass Dependence Of Directed Collective Flow, M. J. Huang, R. C. Lemmon, F. Daffin, W. G. Lynch, C. Schwarz, M. B. Tsang, C. Williams, P. Danielewicz, K. Haglin, W. Bauer, N. Carlin, R. J. Charity, R. T. De Souza, C. K. Gelbke, W. C. Hsi, G. J. Kunde, M. C. Lemaire, M. A. Lisa, U. Lynen, Graham F. Peaslee, J. Pochodzalla, H. Sann, L. G. Sobotka, S. R. Souza, W. Trautmann Oct 1996

Mass Dependence Of Directed Collective Flow, M. J. Huang, R. C. Lemmon, F. Daffin, W. G. Lynch, C. Schwarz, M. B. Tsang, C. Williams, P. Danielewicz, K. Haglin, W. Bauer, N. Carlin, R. J. Charity, R. T. De Souza, C. K. Gelbke, W. C. Hsi, G. J. Kunde, M. C. Lemaire, M. A. Lisa, U. Lynen, Graham F. Peaslee, J. Pochodzalla, H. Sann, L. G. Sobotka, S. R. Souza, W. Trautmann

Faculty Publications

Sidewards directed fragment flow has been extracted for 84Kr+197Au collisions at E/A=200MeV, using techniques that are free of reaction plane dispersion. The fragment flow per nucleon increases with mass, following a thermal or coalescencelike behavior, and attains roughly constant limiting values at 4≤A≤12. Comparisons of the impact parameter dependences of the measured coalescence-invariant proton flow to Boltzmann-Uehling-Uhlenbeck calculations clearly favor a momentum dependent nuclear mean field.

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Electronic Spectroscopy Of Jet-Cooled Benzylidenecyclobutane, A Sterically Hindered Styrene, John R. Cable, V. P. Manea Oct 1996

Electronic Spectroscopy Of Jet-Cooled Benzylidenecyclobutane, A Sterically Hindered Styrene, John R. Cable, V. P. Manea

Chemistry Faculty Publications

The electronic spectrum of the styrene derivative, benzylidenecyclobutane, seeded in a supersonic jet expansion has been recorded using resonantly enhanced two-photon ionization spectroscopy. The main vibronic features in the spectrum are associated with a low frequency progression assigned to the torsional motion of the phenyl ring. Analysis of the observed torsional levels reveals an excited state potential energy surface characteristic of a planar equilibrium geometry which undergoes large amplitude motion and a ground state surface having a minimum at a torsional angle of 25° between the phenyl and vinyl groups. Ab initio calculations of the ground state torsional potential surface …

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Mechanism Of Signal Suppression By Anionic Surfactants In Capillary Electrophoresis-Electrospray Ionization Mass Spectrometry, Kimber L. Rundlett, Daniel W. Armstrong Oct 1996

Mechanism Of Signal Suppression By Anionic Surfactants In Capillary Electrophoresis-Electrospray Ionization Mass Spectrometry, Kimber L. Rundlett, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Micellar-mediated capillary electrophoresis (CE) is used for a wide variety of applications, including the separation of pharmaceuticals, environmental contaminants, illicit drugs, DNA fragments, and many other biological samples. The electrospray ionization interface is one of the most common CE-MS interfaces. Coupling micellar-mediated CE separations with MS detection combines two very powerful, widely applicable analytical techniques. Some types of surfactants strongly interfere with electrospray ionization mass spectrometric (ESI-MS) detection of analytes, and in many cases the ESI-MS analyte signals are completely quenched. Only a few reports have appeared that describe the ESI-MS detection of analytes in the presence of surfactants; however, …

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Universality Of Spectator Fragmentation At Relativistic Bombarding Energies, A. Schüttauf, W. D. Kunze, A. Wörner, M. Begemann-Blaich, Th. Blaich, D. R. Bowman, R. J. Charity, A. Cosmo, A. Ferrero, C. K. Gelbke, C. Groß, W. C. Hsi, J. Hubele, G. Immé, I. Iori, J. Kempter, P. Kreutz, G. J. Kunde, V. Lindenstruth, M. A. Lisa, W. G. Lynch, U. Lynen, M. Mang, T. Möhlenkamp, A. Moroni, W. F.J. Müller, M. Neumann, B. Ocker, C. A. Ogilvie, Graham F. Peaslee, J. Pochodzalla, G. Raciti, F. Rosenberger, Th. Rubehn, H. Sann, C. Schwarz, W. Seidei, V. Serfling Sep 1996

Universality Of Spectator Fragmentation At Relativistic Bombarding Energies, A. Schüttauf, W. D. Kunze, A. Wörner, M. Begemann-Blaich, Th. Blaich, D. R. Bowman, R. J. Charity, A. Cosmo, A. Ferrero, C. K. Gelbke, C. Groß, W. C. Hsi, J. Hubele, G. Immé, I. Iori, J. Kempter, P. Kreutz, G. J. Kunde, V. Lindenstruth, M. A. Lisa, W. G. Lynch, U. Lynen, M. Mang, T. Möhlenkamp, A. Moroni, W. F.J. Müller, M. Neumann, B. Ocker, C. A. Ogilvie, Graham F. Peaslee, J. Pochodzalla, G. Raciti, F. Rosenberger, Th. Rubehn, H. Sann, C. Schwarz, W. Seidei, V. Serfling

Faculty Publications

Multi-fragment decays of 129Xe, 197Au and 238U projectiles in collisions with Be, C, Al, Cu, In, Au and U targets at energies between View the MathML source and 1000 MeV have been studied with the ALADIN forward-spectrometer at SIS. By adding an array of 84 SiCsI(Tl) telescopes the solid-angle coverage of the setup was extended to θlab = 16°. This permitted the complete detection of fragments from the projectile-spectator source. The dominant feature of the systematic set of data is the Zbound universality that is obeyed by the fragment multiplicities and correlations. These observables are invariant with respect to the …

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Charge Correlations And Dynamical Instabilities In The Multifragment Emission Process, L. G. Moretto, Th. Rubehn, L. Phair, N. Colonna, G. J. Wozniak, D. R. Bowman, Graham F. Peaslee, N. Carlin, R. T. De Souza, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, C. Williams Sep 1996

Charge Correlations And Dynamical Instabilities In The Multifragment Emission Process, L. G. Moretto, Th. Rubehn, L. Phair, N. Colonna, G. J. Wozniak, D. R. Bowman, Graham F. Peaslee, N. Carlin, R. T. De Souza, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, C. Williams

Faculty Publications

A new, sensitive method allows one to search for the enhancement of events with nearly equal-sized fragments as predicted by theoretical calculations based on volume or surface instabilities. Simulations have been performed to investigate the sensitivity of the procedure. Experimentally, charge correlations of intermediate mass fragments emitted from heavy ion reactions at intermediate energies have been studied. No evidence for a preferred breakup into equal-sized fragments has been found.

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Open-Path Fourier Transform Infrared Studies Of Large-Scale Laboratory Biomass Fires, Robert J. Yokelson, David W. T. Griffith, Darold E. Ward Sep 1996

Open-Path Fourier Transform Infrared Studies Of Large-Scale Laboratory Biomass Fires, Robert J. Yokelson, David W. T. Griffith, Darold E. Ward

Chemistry and Biochemistry Faculty Publications

A series of nine large-scale, open fires was conducted in the Intermountain Fire Sciences Laboratory (IFSL) controlled-environment combustion facility. The fuels were pure pine needles or sagebrush or mixed fuels simulating forest-floor, ground fires; crown fires; broadcast burns; and slash pile burns. Mid-infrared spectra of the smoke were recorded throughout each fire by open path Fourier transform infrared (FTIR) spectroscopy at 0.12 cm−1 resolution over a 3 m cross-stack pathlength and analyzed to provide pseudocontinuous, simultaneous concentrations of up to 16 compounds. Simultaneous measurements were made of fuel mass loss, stack gas temperature, and total mass flow up the …

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Α-Vinyllysine And Α-Vinylarginine Are Time-Dependent Inhibitors Of Their Cognate Decarboxylases, David B. Berkowitz, Wan Jin Jahng, Michelle L. Pedersen Sep 1996

Α-Vinyllysine And Α-Vinylarginine Are Time-Dependent Inhibitors Of Their Cognate Decarboxylases, David B. Berkowitz, Wan Jin Jahng, Michelle L. Pedersen

Chemistry Department: Faculty Publications

(±)-α-Vinyllysine and (±)-α-vinylarginine display time-dependent inhibition of L-lysine decarboxylase from B. cadaveris, and L-arginine decarboxylase from E. coli, respectively. A complete Kitz-Wilson analysis has been performed using a modification of the Palcic continuous UV assay for decarboxylase activity.

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Investigation On Enantiomeric Separations Of Fluorenylmethoxycarbonyl Amino Acids And Peptides By High-Performance Liquid Chromatography Using Native Cyclodextrins As Chiral Stationary Phases, Y. Tang, J. Zukowski, Daniel W. Armstrong Sep 1996

Investigation On Enantiomeric Separations Of Fluorenylmethoxycarbonyl Amino Acids And Peptides By High-Performance Liquid Chromatography Using Native Cyclodextrins As Chiral Stationary Phases, Y. Tang, J. Zukowski, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

A systematic study was carried out to investigate enantiomeric separations of fluorenylmethoxycarbonyl (FMOC) amino acids and their peptides. Twenty amino acids were derivatized by 9-fluorenylmethyl chloroformate (FMOC-Cl) and its analogues, FMOC-glycyl-Cl and FMOC-β-alanyl-Cl. All derivatives were chromatographed on native β- and γ-cyclodextrin columns using acetonitrile as the main mobile phase component. The results indicated that glycyl and β-alanyl groups between FMOC and amino acid moieties enhanced chiral selectivities of amino acid derivatives. The addition of modifiers, triethylamine, acetic acid and methanol, into the mobile phase caused alterations in retention, enantiorecognition and elution order. The structures of amino acids and the …

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High-Power Broadly Tunable Picosecond Ir Laser System For Use In Nonlinear Spectroscopic Applications, D. E. Gragson, B. M. Mccarty, G. L. Richmond, D. S. Alavi Sep 1996

High-Power Broadly Tunable Picosecond Ir Laser System For Use In Nonlinear Spectroscopic Applications, D. E. Gragson, B. M. Mccarty, G. L. Richmond, D. S. Alavi

Chemistry and Biochemistry

We developed a high-power tunable picosecond IR laser system suitable for nonlinear spectroscopic investigations. We employ a Ti:sapphire regenerative amplifier that produces 1.9-ps, 17-cm−1, 800-nm pulses at 1 kHz as a pump source. White-light generation in ethylene glycol and optical parametric amplification in potassium titanyl phosphate are used to produce the IR pulses. The tuning range extends from 2.4 to 3.8 μm in the idler and 1.0 to 1.2 μm in the signal. A total efficiency (signal plus idler) as high as 20% was achieved. The spatial, spectral, and temporal characteristics of the IR beam are presented along …

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Proton Spin-Lattice Relaxation Of Water Molecules In Ferrous-Ferric/Agarose Gel System, Tadashi Tokuhiro, Alan Appleby, Armin A. Leghrouz, Rodney Metcalf, Robert Tokarz Sep 1996

Proton Spin-Lattice Relaxation Of Water Molecules In Ferrous-Ferric/Agarose Gel System, Tadashi Tokuhiro, Alan Appleby, Armin A. Leghrouz, Rodney Metcalf, Robert Tokarz

Chemistry Faculty Research & Creative Works

Proton spin-lattice relaxation time (T1) of water in aqueous solutions of ferrous and ferric ions and in the corresponding agarose gel systems have been studied in the light of NMR relaxation theory. The theoretical analysis of 1/T1's has revealed that, at the microscopic level, changes in the solvation states of paramagnetic ions in aqueous or gel environment are greater than difference in the paramagnetism between ferric and ferrous ions. The former change is the primary factor for the exhibition of radiation effect. At the phenomenological level, we have confirmed and demonstrated that: (1) Radiation effect is …

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First Results From The High-Brightness X-Ray Spectroscopy Beamline 9.3.1 At Als, W. Ng, G. Jones, Rupert C. Perera, D. Hansen, J. Daniels, Oliver Hemmers, P. Glans, S. B. Whitfield, H. Wang, Dennis W. Lindle Sep 1996

First Results From The High-Brightness X-Ray Spectroscopy Beamline 9.3.1 At Als, W. Ng, G. Jones, Rupert C. Perera, D. Hansen, J. Daniels, Oliver Hemmers, P. Glans, S. B. Whitfield, H. Wang, Dennis W. Lindle

Environmental Studies Faculty Publications

Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1–6 keV photon energy range. This beamline is designed to achieve the goal of high brightness at the sample for use in the x‐ray atomic and molecular spectroscopy (XAMS) science, surface and interface science, biology and x‐ray optical development programs at ALS. X‐ray absorption and time‐of‐flight photoemission measurements in 2–5 keV photon energy range along with the flux, resolution, spot size and stability of the beamline will be discussed. Prospects for future XAMS measurements will also be presented.

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Kinetic-Energy- And Angular-Resolved Fragmentation Of Co In Vibrational-Resolved C 1s Excitation, N. Saito, Franz Heiser, Oliver Hemmers, K. Wieliczek, J. Viefhaus, U. Becker Sep 1996

Kinetic-Energy- And Angular-Resolved Fragmentation Of Co In Vibrational-Resolved C 1s Excitation, N. Saito, Franz Heiser, Oliver Hemmers, K. Wieliczek, J. Viefhaus, U. Becker

Environmental Studies Faculty Publications

Angular distributions of C++O+ from CO were measured, following vibrationally resolved C 1s excitations into the 2pπ, 3sσ, and 3pπ orbitals as well as into higher unresolved orbitals. A time-of-flight mass spectrometer, with a multihit-type position-sensitive anode, was used for the measurements. The anisotropy parameters (β) of C++O+ approach their theoretically expected values as the released kinetic energy in the fragmentation increases. The value of the β parameters remains constant for all vibrational states within each orbital.

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Cross Sections For The Production Of He+ (Np) 2p0 States By 50 To 150 Kev Proton Impact On Helium, Wayne C. Stolte, R. Bruch Sep 1996

Cross Sections For The Production Of He+ (Np) 2p0 States By 50 To 150 Kev Proton Impact On Helium, Wayne C. Stolte, R. Bruch

Chemistry and Biochemistry Faculty Research

Cross sections have been measured for the production of He+ (np) 2Po states, n=2,3,4, by proton impact on helium over a projectile velocity range of 1.42–2.45 a.u. (50 ≤E≤150 keV). Cross sections were determined by measuring the extreme ultraviolet photons emitted from excited He1 ions. The data indicate a lower energy than expected for the maximum cross section. A comparison of the present results in terms of projectile energy dependance with the cross sections for excitation to He (1snp) 1Po, ionization, and total electron capture suggests the primary mechanism …

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Kinetics And Jamming Coverage In A Random Sequential Adsorption Of Polymer Chains, Jian-Sheng Wang, Ras B. Pandey Aug 1996

Kinetics And Jamming Coverage In A Random Sequential Adsorption Of Polymer Chains, Jian-Sheng Wang, Ras B. Pandey

Faculty Publications

No abstract provided.

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Comparison And Modeling Study Of Vancomycin, Ristocetin A, And Teicoplanin For Ce Enantioseparations, Mary P. Gasper, Alain Berthod, Usha B. Nair, Daniel W. Armstrong Aug 1996

Comparison And Modeling Study Of Vancomycin, Ristocetin A, And Teicoplanin For Ce Enantioseparations, Mary P. Gasper, Alain Berthod, Usha B. Nair, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

The structurally related glycopeptide antibiotics vancomycin, ristocetin A, and teicoplanin can all be used as chiral selectors in capillary electrophoresis (CE). Both experimental and modeling studies were done to elucidate their similarities and differences. There are identifiable morphological differences in the aglycon macrocyclic portions of these three compounds. In addition, there are other structural distinctions that can affect their CE enantioselectivity, migration times, and efficiency. Teicoplanin is the most distinct of the three and is the only one that is surface active. Its aggregational properties appear to affect its enantioselectivity among other things. The similar but not identical structures of …

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The Role Of Written And Verbal Expression In Improving Communication Skills For Students In An Undergraduate Chemistry Program, Brian P. Coppola, Douglas S. Daniels Aug 1996

The Role Of Written And Verbal Expression In Improving Communication Skills For Students In An Undergraduate Chemistry Program, Brian P. Coppola, Douglas S. Daniels

Chemistry Faculty Publications

Proofreading, editing, and critique, the customary assessment tools scientists use to evaluate professional journal articles, grant applications, and any other writing, can be applied equally well in introductory science instruction. Such feedback is, in fact, crucial to growth and development. When learning anything new, students and faculty alike rely heavily on sources other than themselves (‘external editors’) to assess their understanding as they develop self-assessment skills (or ‘internal editors’). Although they rarely describe it in these terms, faculty nonetheless assume that students have developed and refined their internal skills by the time they take examinations and write term papers. Unfortunately, …

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Synthesis And Characterisation Of New Dimolybdenum (Ii,Ii) Dicarboxylates And Their Use As Polymerization Catalysts, Elizabeth Whelan Aug 1996

Synthesis And Characterisation Of New Dimolybdenum (Ii,Ii) Dicarboxylates And Their Use As Polymerization Catalysts, Elizabeth Whelan

Masters

The purpose of this work was to prepare a series of new dimolybdenum(II,II) dicarboxylate complexes, to characterize the complexes and to investigate their use as potential catalysts for the ring-opening metathesis polymerization (ROMP) of the bicyclic monomer norbornene.

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Neutron Diffraction Structural Study Of Ce₂Fe₁₇₋ₓgaₓ, H. Luo, Z. Hu, William B. Yelon, Sanjay R. Mishra, Gary J. Long, Oran Allan Pringle, D. P. Middleton, K. H. J. Buschow Aug 1996

Neutron Diffraction Structural Study Of Ce₂Fe₁₇₋ₓgaₓ, H. Luo, Z. Hu, William B. Yelon, Sanjay R. Mishra, Gary J. Long, Oran Allan Pringle, D. P. Middleton, K. H. J. Buschow

Physics Faculty Research & Creative Works

Six samples of Ce2Fe17-xGax with nominal Ga content x equal to 0, 0.3, 0.5, 0.7, 1.0, 2.0 have been studied by powder neutron diffraction at room temperature. Both crystalline and magnetic refinements have been carried out. All six samples adopt the Th2Zn17-type rhombohedral structure. The only additional phase found is α-iron. Gallium atoms are found to have high affinity for the iron 18h site, and are absent from the 9d and 18f sites. The Ga substitution for Fe leads to an expansion of both the a and c axes. The Curie …

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Degradation Product Analysis Of Bismaleimide Composite, Wendy Zhong Aug 1996

Degradation Product Analysis Of Bismaleimide Composite, Wendy Zhong

Masters Theses & Specialist Projects

This study evaluates the thermal and oxidative stabilities of a bismaleimide (BMI) polymer composite reinforced with an intermediate modulus graphite fiber, Cytec®5260/IM7. The composite is aged in helium, nitrogen, and air at elevated temperatures up to 600°C. Its weight change is followed thermogravimetrically for stability assessment. The effect of aging gas environment is also studied. The use of on-line gas cell fourier transform IR spectrometer (FTIR) and mass spectrometer (MS) allows for the identification of decomposition products by evolved gas analysis. This combination of thermogravimetric analysis (TGA) and evolved gas analysis by FTIR and MS yields complementary information regarding pyrolysis …

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Directed Ortho-Metalation Of The Three Methyl Anisoles In Various Media, Carl Friesen Aug 1996

Directed Ortho-Metalation Of The Three Methyl Anisoles In Various Media, Carl Friesen

Masters Theses & Specialist Projects

Directed ortho-metalation (DoM) is a very useful alternative to electrophillic aromatic substitution (EAS) for the synthesis of substituted aromatic compounds. DoM is highly regiospecific providing metalation chiefly in the ortho-position. However, lateral (a-) metalation of an alkyl side-chain and ortho-metalation of a second ortho-position can compete. Investigation of the three methylanisoles was therefore undertaken to determine the interplay between these factors and to discover metalation conditions to achieve selectivity. This goal was uniquely achieved for p-methylanisole where conditions were discovered which allowed > 85% ortho-metalation as determined by GC analysis with virturally no competing lateral metalation. Three derivitives of this ortho-lithio …

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A Study Of The Effect Of The Extraction Procedure In The Analysis Of Organic Compounds Adsorbed On Coal Ash, Shobha Purushothama Aug 1996

A Study Of The Effect Of The Extraction Procedure In The Analysis Of Organic Compounds Adsorbed On Coal Ash, Shobha Purushothama

Masters Theses & Specialist Projects

The organic compounds found adsorbed on coal fly ash have been a cause for concern since the early days of the industrial revolution. A vast majority of the compounds reported as being adsorbed on the ash are polyaromatic hydrocarbons (PAHs). This study represents an attempt to evaluate the parameters involved in the extraction, detection and quantitation of these organic compounds. Though no definite conclusions could be reached as to the most efficient method of extraction, interesting results were obtained with regarding the choice of the solvent and the temperature programming on the GC/MS used for analysis. The solvent of choice …

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