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Full-Text Articles in Physical Sciences and Mathematics

Hydrogen Peroxide Triggers An Increase In Cell Surface Expression Of System XC In Cultured Human Glioma Cells, Leah A. Chase, Mary Verheulen Kleyn, Natasha Schiller, Abby Goltz King, Guillermo Flores, Sasha Balcazar Engelsman, Christina Bowles, Sara Lang Smith, Anne E. Robinson, Jeffrey Rothstein Mar 2020

Hydrogen Peroxide Triggers An Increase In Cell Surface Expression Of System XC− In Cultured Human Glioma Cells, Leah A. Chase, Mary Verheulen Kleyn, Natasha Schiller, Abby Goltz King, Guillermo Flores, Sasha Balcazar Engelsman, Christina Bowles, Sara Lang Smith, Anne E. Robinson, Jeffrey Rothstein

Faculty Publications

System xc exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System xc is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H2O2) triggers the translocation of System xc to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in 35S-L-cystine uptake following a 10 min exposure to 0.3 mM H2O2. This effect was dose-dependent with an EC50 for …


Cross-Linked Poly(4-Vinylpyridine-N-Oxide) As A Polymer-Supported Oxygen Atom Transfer Reagent, Anna M. Bauer, Erin E. Ramey, Kjersti G. Oberle, Gretchen A. Fata, Chloe D. Hutchison, Christopher R. Turlington Oct 2019

Cross-Linked Poly(4-Vinylpyridine-N-Oxide) As A Polymer-Supported Oxygen Atom Transfer Reagent, Anna M. Bauer, Erin E. Ramey, Kjersti G. Oberle, Gretchen A. Fata, Chloe D. Hutchison, Christopher R. Turlington

Faculty Publications

Oxygen atom transfer (OAT) reagents are common in biological and industrial oxidation reactions. While many heterogeneous catalysts have been utilized in OAT reactions, heterogeneous OAT reagents have not been explored. Here, cross-linked poly(4-vinylpyridine-N-oxide), called x-PVP-N-oxide, was tested as a heterogeneous OAT reagent and its oxidation chemistry compared to its molecular counterpart, pyridine-N-oxide. The insoluble oxidant x-PVP-N-oxide demonstrated comparable reactivity to pyridine-N-oxide in direct oxidation reactions of phosphines and phosphites in acetonitrile, but x-PVP-N-oxide did not react in other solvents. The polymer backbone of x-PVP-N-oxide, however, allowed …


Experimental And Computational Electrochemistry Of Quinazolinespirohexadienone Molecular Switches – Differential Electrochromic Vs Photochromic Behavior, Eric W. Webb, Jonathan P. Moerdyk, Kyndra B. Sluiter, Benjamin J. Pollock, Amy L. Speelman, Eugene J. Lynch, William F. Polik, Jason G. Gillmore Oct 2019

Experimental And Computational Electrochemistry Of Quinazolinespirohexadienone Molecular Switches – Differential Electrochromic Vs Photochromic Behavior, Eric W. Webb, Jonathan P. Moerdyk, Kyndra B. Sluiter, Benjamin J. Pollock, Amy L. Speelman, Eugene J. Lynch, William F. Polik, Jason G. Gillmore

Faculty Publications

Our undergraduate research group has long focused on the preparation and investigation of electron-deficient analogs of the perimidinespirohexadienone (PSHD) family of photochromic molecular switches for potential application as "photochromic photooxidants" for gating sensitivity to photoinduced charge transfer. We previously reported the photochemistry of two closely related and more reducible quinazolinespirohexadienones (QSHDs), wherein the naphthalene of the PSHD is replaced with a quinoline. In the present work, we report our investigation of the electrochemistry of these asymmetric QSHDs. In addition to the short wavelength and photochromic long-wavelength isomers, we have found that a second, distinct long-wavelength isomer is produced electrochemically. This …


Substrate-Dependent Photoconductivity Dynamics In A High-Efficiency Hybrid Perovskite Alloy, Ali Moeed Tirmzi, Jeffrey A. Christians, Ryan P. Dwyer, David T. Moore, John A. Marohn Feb 2019

Substrate-Dependent Photoconductivity Dynamics In A High-Efficiency Hybrid Perovskite Alloy, Ali Moeed Tirmzi, Jeffrey A. Christians, Ryan P. Dwyer, David T. Moore, John A. Marohn

Faculty Publications

Films of (FA0.79MA0.16Cs0.05)0.97Pb(I0.84Br0.16)2.97 were grown over TiO2, SnO2, indium tin oxide (ITO), and NiO. Film conductivity was interrogated by measuring the in-phase and out-of-phase forces acting between the film and a charged microcantilever. We followed the films’ conductivity versus time, frequency, light intensity, and temperature (233−312 K). Perovskite conductivity was high and light-independent over ITO and NiO. Over TiO2 and SnO2, the conductivity was low in the dark,increased with light intensity, and persisted for 10’s of seconds after the light …


Synthesis Of 5,6-Diaminoacenaphthylene By Reduction Of Sterically Crowded Nitro Groups With Sodium Dithionite, Amber J. Dood, Patrick A. Fisher, Christine L. Bodden, Luke J. Peterson, Kathryn A. Lindberg, Trevor A. Coeling, Douglas C. Yarbrough, Jason G. Gillmore Dec 2018

Synthesis Of 5,6-Diaminoacenaphthylene By Reduction Of Sterically Crowded Nitro Groups With Sodium Dithionite, Amber J. Dood, Patrick A. Fisher, Christine L. Bodden, Luke J. Peterson, Kathryn A. Lindberg, Trevor A. Coeling, Douglas C. Yarbrough, Jason G. Gillmore

Faculty Publications

5,6-Diaminoacenaphthylene was synthesized in four steps from acenaphthene. This seemingly simple molecule provides unique synthetic challenges because it is relatively difficult to reduce the nitro groups and the molecule contains a particularly reactive double bond. It was determined that the only feasible sequence for the synthesis was to nitrate acenaphthene, then brominate, eliminate, and finally selectively reduce. Several reduction methods were attempted before finding one that would completely reduce both nitro groups while leaving the double bond intact.


Dealloying Behavior Of Nico And Nicocu Thin Films, Benjamin Peecher, Jennifer R. Hampton Oct 2016

Dealloying Behavior Of Nico And Nicocu Thin Films, Benjamin Peecher, Jennifer R. Hampton

Faculty Publications

Porous metals and alloys, such as those fabricated via electrochemical dealloying, are of interest for a variety of energy applications, ranging from their potential for enhanced catalytic behavior to their use as high surface area supports for pseudocapacitor materials. Here, the electrochemical dealloying process was explored for electrodeposited binary NiCo and ternary NiCoCu thin films. For each of the four different metal ratios, films were dealloyed using linear sweep voltammetry to various potentials in order to gain insight into the evolution of the film over the course of the linear sweep. Electrochemical capacitance, scanning electron microscopy, and energy dispersive X-ray …


Physical And Electrochemical Area Determination Of Electrodeposited Ni, Co, And Nico Thin Films, Matthew Gira, Kevin Tkacz, Jennifer R. Hampton Jan 2016

Physical And Electrochemical Area Determination Of Electrodeposited Ni, Co, And Nico Thin Films, Matthew Gira, Kevin Tkacz, Jennifer R. Hampton

Faculty Publications

The surface area of electrodeposited thin films of Ni, Co, and NiCo was evaluated using electrochemical double-layer capacitance, electrochemical area measurements using the [Ru(NH3)6]3+/[Ru(NH3)6]2+ redox couple, and topographic atomic force microscopy (AFM) imaging. These three methods were compared to each other for each composition separately and for the entire set of samples regardless of composition. Double-layer capacitance measurements were found to be positively correlated to the roughness factors determined by AFM topography. Electrochemical area measurements were found to be less correlated with measured roughness factors as well as applicable …


Decarbonylative Cross Coupling Of Phthalimides With Diorganozinc Reagents—Efforts Toward Catalysis, Kimberly S. Deglopper, Sarah K. Fodor, Thomas Bd Endean, Jeffrey B. Johnson Jan 2016

Decarbonylative Cross Coupling Of Phthalimides With Diorganozinc Reagents—Efforts Toward Catalysis, Kimberly S. Deglopper, Sarah K. Fodor, Thomas Bd Endean, Jeffrey B. Johnson

Faculty Publications

The decarbonylative coupling of phthalimides with diorganozinc reagents to form o-substituted benzamides has been previously demonstrated as a viable process, but only with stoichiometric nickel(0). Investigations into a number of reaction variables, including solvent, ligand, and substrate substitution, have yielded multiple sets of conditions capable of achieving up to 10 catalyst turnovers, most successfully with the use of electron withdrawing nitrogen substituents on the phthalimide. In addition, these investigations have provided insight into the intermediates within the catalytic cycle and have revealed new approaches to the development of a general catalytic methodology.


Comment On "Fluorotechnology Is Critical To Modern Life: The Fluorocouncil Counterpoint To The Madrid Statement", Ian T. Cousins, Simona A. Balan, Martin Scheringer, Roland Weber, Zhanyun Wang, Arlene Blum, Miriam Diamond, Tony Fletcher, Gretta Goldenman, Christopher Higgins, Avery E. Lindeman, Graham Peaslee Jul 2015

Comment On "Fluorotechnology Is Critical To Modern Life: The Fluorocouncil Counterpoint To The Madrid Statement", Ian T. Cousins, Simona A. Balan, Martin Scheringer, Roland Weber, Zhanyun Wang, Arlene Blum, Miriam Diamond, Tony Fletcher, Gretta Goldenman, Christopher Higgins, Avery E. Lindeman, Graham Peaslee

Faculty Publications

No abstract provided.


Building And Testing Correlations For The Estimation Of One-Electron Reduction Potentials Of A Diverse Set Of Organic Molecules, Dalvin D. Méndez-Hernández, Jason G. Gillmore, Luis A. Montano, Devens Gust, Thomas A. Moore, Ana L. Moore, Vladimiro Mujica Jan 2015

Building And Testing Correlations For The Estimation Of One-Electron Reduction Potentials Of A Diverse Set Of Organic Molecules, Dalvin D. Méndez-Hernández, Jason G. Gillmore, Luis A. Montano, Devens Gust, Thomas A. Moore, Ana L. Moore, Vladimiro Mujica

Faculty Publications

We describe and evaluate a method for computationally predicting reduction potentials of a diverse group of organic molecules by linearly correlating calculated lowest unoccupied molecular orbital energies with ground state reduction potentials measured in acetonitrile. The approach is shown to provide a unique combination of extreme computational simplicity and excellent accuracy across a diverse range of organic structures and a wide window of reduction potentials. A disparate set of molecules (74 compounds belonging to six distinct structural families, comprised of molecules containing C, H, N, O, F, Cl, and Br, with functional groups including esters, ketones, halides, nitriles, quinones, alkenes, …


Hydrogen Evolution Reaction Measurements Of Dealloyed Porous Nicu, Kyla Koboski, Evan Nelsen, Jennifer R. Hampton Dec 2013

Hydrogen Evolution Reaction Measurements Of Dealloyed Porous Nicu, Kyla Koboski, Evan Nelsen, Jennifer R. Hampton

Faculty Publications

Porous metals are of interest for their high surface area and potential for enhanced catalytic behavior. Electrodeposited NiCu thin films with a range of compositions were electrochemically dealloyed to selectively remove the Cu component. The film structure, composition, and reactivity of these samples were characterized both before and after the dealloying step using scanning electron microscopy, energy-dispersive spectroscopy, and electrochemical measurements. The catalytic behavior of the dealloyed porous Ni samples towards the hydrogen evolution reaction was measured and compared to that of the as-deposited samples. The dealloyed samples were generally more reactive than their as-deposited counterparts at low overpotentials, making …


Cross-Species Malaria Immunity Induced By Chemically Attenuated Parasites, Michael F. Good, Jennifer M. Reiman, I. Bibiana Rodriguez, Koichi Ito, Stephanie K. Yanow, Ibrahim M. El-Deeb, Michael R. Batzloff, Danielle I. Stanisic, Christian Engwerda, Terry Spithill, Stephen L. Hoffman, Moses Lee, Virginia Mcphun Aug 2013

Cross-Species Malaria Immunity Induced By Chemically Attenuated Parasites, Michael F. Good, Jennifer M. Reiman, I. Bibiana Rodriguez, Koichi Ito, Stephanie K. Yanow, Ibrahim M. El-Deeb, Michael R. Batzloff, Danielle I. Stanisic, Christian Engwerda, Terry Spithill, Stephen L. Hoffman, Moses Lee, Virginia Mcphun

Faculty Publications

Vaccine development for the blood stages of malaria has focused on the induction of antibodies to parasite surface antigens, most of which are highly polymorphic. An alternate strategy has evolved from observations that low-density infections can induce antibody-independent immunity to different strains. To test this strategy, we treated parasitized red blood cells from the rodent parasite Plasmodium chabaudi with secocyclopropyl pyrrolo indole analogs. These drugs irreversibly alkylate parasite DNA, blocking their ability to replicate. After administration in mice, DNA from the vaccine could be detected in the blood for over 110 days and a single vaccination induced profound immunity to …


Vpt2+K Spectroscopic Constants And Matrix Elements Of The Transformed Vibrational Hamiltonian Of A Polyatomic Molecule With Resonances Using Van Vleck Perturbation Theory, Andreana M. Rosnik, William F. Polik Jul 2013

Vpt2+K Spectroscopic Constants And Matrix Elements Of The Transformed Vibrational Hamiltonian Of A Polyatomic Molecule With Resonances Using Van Vleck Perturbation Theory, Andreana M. Rosnik, William F. Polik

Faculty Publications

Vibrational levels of polyatomic molecules are analysed with Van Vleck perturbation theory to connect experimental energy levels to computed molecular potential energy surfaces. Vibrational matrix elements are calculated from a quartic potential function via second-order Van Vleck perturbation theory, a procedure that treats both weak and strong interactions among vibrational states by approximately block-diagonalising the vibrational Hamiltonian. A clear and complete derivation of anharmonic and resonance constants as well as general expressions for both on- and off-diagonal matrix elements of the transformed Hamiltonian is presented. The equations are written in partial fraction form and as a constant multiplied by a …


Observation Of Ground-State Two-Neutron Decay, M Thoennessen, Z Kholey, A Spyrou, E Lunderberg, Paul A. Deyoung, H Attanayake, T Baumann, D Bazin, B A. Brown, G Christian, D Divaratne, S M. Grimes, A Haagsma, J E. Finck, N Frank, B Luther, S Mosby, T Nagi, Graham F. Peaslee, W A. Peters, A Schiller, J K. Smith, J Snyder, M Strongman, A Volya Mar 2013

Observation Of Ground-State Two-Neutron Decay, M Thoennessen, Z Kholey, A Spyrou, E Lunderberg, Paul A. Deyoung, H Attanayake, T Baumann, D Bazin, B A. Brown, G Christian, D Divaratne, S M. Grimes, A Haagsma, J E. Finck, N Frank, B Luther, S Mosby, T Nagi, Graham F. Peaslee, W A. Peters, A Schiller, J K. Smith, J Snyder, M Strongman, A Volya

Faculty Publications

Neutron decay spectroscopy has become a successful tool to explore nuclear properties of nuclei with the largest neutron-to-proton ratios. Resonances in nuclei located beyond the neutron dripline are accessible by kinematic reconstruction of the decay products. The development of two-neutron detection capabilities of the Modular Neutron Array (MoNA) at NSCL has opened up the possibility to search for unbound nuclei which decay by the emission of two neutrons. Specifically, this exotic decay mode was observed in16Be and 26O.


Expanding And Testing A Computational Method For Predicting The Ground State Reduction Potentials Of Organic Molecules On The Basis Of Empirical Correlation To Experiment, Eugene J. Lynch, Amy L. Speelman, Bryce A. Curry, Charles S. Murillo, Jason G. Gillmore Aug 2012

Expanding And Testing A Computational Method For Predicting The Ground State Reduction Potentials Of Organic Molecules On The Basis Of Empirical Correlation To Experiment, Eugene J. Lynch, Amy L. Speelman, Bryce A. Curry, Charles S. Murillo, Jason G. Gillmore

Faculty Publications

A method for predicting the ground state reduction potentials of organic molecules on the basis of the correlation of computed energy differences between the starting S-0 and one-electron-reduced D-0 species with experimental reduction potentials in acetonitrile has been expanded to cover 3.5 V of potential range and 74 compounds across 6 broad families of molecules. Utilizing the conductor-like polarizable continuum model of implicit solvent allows a global correlation that is computationally efficient and has improved accuracy, with r(2) > 0.98 in all cases and root mean square deviation errors of(mean absolute deviationsmV) for either B3LYP/6-311+G(d,p) or B3LYP//6-31G(d) with an appropriate choice …


Publish And Flourish, Stephen K. Taylor Jan 2012

Publish And Flourish, Stephen K. Taylor

Faculty Publications

At primarily undergraduate institutions (PUIs), teaching is usually the primary responsibility, and many PUI professors do not regularly produce publications, even if they were hired to include research as an important responsibility. Most instructors at these schools are busy enough with just teaching and other academic responsibilities. It can seem intimidating to think of doing research, writing a research proposal, then a publication, and so on. Perhaps the sum of these duties may seem like a daunting set of tasks, and a "fear factor," consciously or subconsciously, may slow or even stop the research initiative. But at PUIs, it is …


Analysis Of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission, Alyssa Frey, Nicholas Wozniak, Timothy Nagi, Matthew Keller, J. Mark Lunderberg, Graham F. Peaslee, Paul Deyoung, Jennifer R. Hampton Jan 2011

Analysis Of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission, Alyssa Frey, Nicholas Wozniak, Timothy Nagi, Matthew Keller, J. Mark Lunderberg, Graham F. Peaslee, Paul Deyoung, Jennifer R. Hampton

Faculty Publications

The elemental composition of electrodeposited NiFe thin films was analyzed with particle-induced X-ray emission (PIXE). The thin films were electrodeposited on polycrystalline Au substrates from a 100mM NiSO4, 10 mM FeSO4, 0.5M H3BO3, and 1M Na2SO4 solution. PIXE spectra of these films were analyzed to obtain relative amounts of Ni and Fe as a function of deposition potential and deposition time. The results show that PIXE can measure the total deposited metal in a sample over at least four orders of magnitude with similar fractional uncertainties. The technique is …


Pltl Impacts A Career – From Peer Leader To The Professoriate, Jason Gillmore Oct 2010

Pltl Impacts A Career – From Peer Leader To The Professoriate, Jason Gillmore

Faculty Publications

No abstract provided.


An Electrochemical Cell For The Efficient Turn Around Of Wafer Working Electrodes, Nicholas Wozniak, Alyssa Frey, Lucas Osterbur, Timothy Boman, Jennifer R. Hampton Mar 2010

An Electrochemical Cell For The Efficient Turn Around Of Wafer Working Electrodes, Nicholas Wozniak, Alyssa Frey, Lucas Osterbur, Timothy Boman, Jennifer R. Hampton

Faculty Publications

We present a new design for an electrochemical cell for use with wafer working electrodes. The key feature of the design is the use of half turn thumb screws to form a liquid-tight seal between an o-ring and the sample surface. The assembly or disassembly of the cell requires a half turn of each thumb screw, which facilitates the quick turn around of wafer samples. The electrochemical performance of the cell is demonstrated by cyclic voltammetry and double step chronoamperometry measurements of the ferricyanide/ferrocyanide couple.


Peroxyl Radical Clocks, Bill Roschek, Keri A. Tallman, Christopher L. Rector, Jason G. Gillmore, Derek A. Pratt, Carlo Punta, Ned A. Porter Apr 2006

Peroxyl Radical Clocks, Bill Roschek, Keri A. Tallman, Christopher L. Rector, Jason G. Gillmore, Derek A. Pratt, Carlo Punta, Ned A. Porter

Faculty Publications

A series of peroxyl radical clocks has been developed and calibrated based on the competition between the unimolecular β-fragmentation (kβ) of a peroxyl radical and its bimolecular reaction with a hydrogen atom donor (kH). These clocks are based on either methyl linoleate or allylbenzene and were calibrated directly with α-tocopherol or methyl linoleate, which have well-established rate constants for reaction with peroxyl radicals (kH-tocopherol = 3.5 × 106 M-1 s-1, kH-linoleate = 62 M-1 s-1). This peroxyl radical clock methodology has been successfully applied to determine inhibition and propagation rate constants ranging from 100 to 107 M-1 s-1.


Isobaric Analog States As A Tool For Spectroscopy Of Exotic Nuclei, G. V. Rogachev, A. A. Aprahamian, F. D. Becchetti, P. Boutachkov, Y. Chen, G. Chubarian, P. A. Deyoung, A. Fomichev, V. Z. Goldberg, M. S. Golovkov, J. J. Kolata, Yu. Ts. Oganessian, Graham F. Peaslee, M. Quinn, A. Rodin, B. B. Skorodumov, R. S. Slepnev, G. Ter-Akopian, W. H. Trzaska, A. Wohr, R. Wolski Dec 2005

Isobaric Analog States As A Tool For Spectroscopy Of Exotic Nuclei, G. V. Rogachev, A. A. Aprahamian, F. D. Becchetti, P. Boutachkov, Y. Chen, G. Chubarian, P. A. Deyoung, A. Fomichev, V. Z. Goldberg, M. S. Golovkov, J. J. Kolata, Yu. Ts. Oganessian, Graham F. Peaslee, M. Quinn, A. Rodin, B. B. Skorodumov, R. S. Slepnev, G. Ter-Akopian, W. H. Trzaska, A. Wohr, R. Wolski

Faculty Publications

Spectroscopy of neutron rich exotic isotopes via their isobaric analog states (IAS) in less exotic nuclei is discussed. Several different experimental techniques, which can be applied to search for IAS of exotic isotopes, are described. Successful application of these techniques to the studies of heavy helium isotopes7He and 9He led to the observation of unknown IAS in 7Li and 9Li. Spectroscopic information for these states were obtained, and implication of these findings to the structure of 7,9He is considered.


Quantum Amplified Isomerization:  A New Concept For Polymeric Optical Materials, Jason G. Gillmore, J. D. Neiser, K. A. Mcmanus, Y. Roh, G. W. Dombrowski, T. G. Brown, J. P. Dinnocenzo, S. Farid, D. R. Robello Sep 2005

Quantum Amplified Isomerization:  A New Concept For Polymeric Optical Materials, Jason G. Gillmore, J. D. Neiser, K. A. Mcmanus, Y. Roh, G. W. Dombrowski, T. G. Brown, J. P. Dinnocenzo, S. Farid, D. R. Robello

Faculty Publications

The preparation and evaluation of a new class of photoresponsive polymers are described on the basis of a process called quantum amplified isomerization (QAI). The QAI process utilizes photoinitiated, cation radical isomerization chemistry in a polymeric medium. Two classes of materials are described:  one where the QAI reactant is molecularly doped in the polymer matrix and another where the reactant is part of a functionalized polymer. Quantum yield experiments demonstrate that the isomerization reaction can proceed by a chain process with modest efficiencies. Photochemical conversion experiments show that high extents of conversion of the QAI reactants are possible. The rate …


Doppler Shift As A Tool For Studies Of Resonant (P,N) Reactions With Ribs: Spectroscopy Of 7he, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wöhr Sep 2005

Doppler Shift As A Tool For Studies Of Resonant (P,N) Reactions With Ribs: Spectroscopy Of 7he, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wöhr

Faculty Publications

We report on a new methods for studies of neutron rich systems through resonant (p,n) reaction with radioactive ion beams. A specific example of the spectroscopy of 7He and future application of the proposed methods are discussed.


A-Stripping Reactions With Exotic Nuclei: 12c7be,3he)16o, H. Amro, F. D. Becchetti, Yu Chen, H. Jiang, M. Ojaruega, H. C. Griffin, J. J. Kolata, B. B. Skorodumov, J. D. Hinnefeld, Graham F. Peaslee Sep 2005

A-Stripping Reactions With Exotic Nuclei: 12c7be,3he)16o, H. Amro, F. D. Becchetti, Yu Chen, H. Jiang, M. Ojaruega, H. C. Griffin, J. J. Kolata, B. B. Skorodumov, J. D. Hinnefeld, Graham F. Peaslee

Faculty Publications

The 12C(7Be,3He)16O reaction has been studied at E(7Be)=34 MeV. At this energy this Reaction exhibits a high selectivity for populating known α‐cluster states in 16O (Jπ = 0+,3−,2+,1−,4+, and 6+). The angular distributions for the 0+,3−,2+,1−, and 4+ levels are obtained at forward angles. Likewise, large reaction rates were measured for the 3He transfer channel, i.e. 12C(7Be,α)15O


Cyclopropylcarbinyl → Homoallyl-Type Ring Opening Of Ketyl Radical Anions. Structure/Reactivity Relationships And The Contribution Of Solvent/Counterion Reorganization To The Intrinsic Barrier, J. M. Tanko, Jason G. Gillmore, Robert Friedline, M'Hamed Chahma May 2005

Cyclopropylcarbinyl → Homoallyl-Type Ring Opening Of Ketyl Radical Anions. Structure/Reactivity Relationships And The Contribution Of Solvent/Counterion Reorganization To The Intrinsic Barrier, J. M. Tanko, Jason G. Gillmore, Robert Friedline, M'Hamed Chahma

Faculty Publications

Following a protocol developed by Mathivanan, Johnston, and Wayner (J. Phys. Chem. 1995, 99, 8190−8195), the radical anions of several cyclopropyl- and oxiranyl-containing carbonyl compounds were generated in an effort to measure the rate constants for their ring opening (ko) by laser flash photolysis. The results of these experiments are compared to those obtained from earlier electrochemical studies, and the combined data set is used to rationalize the kinetics of radical anion ring opening in a general context by using Savéant's theory pertaining to stepwise dissociative electron transfer (Acc. Chem. Res. 1993, 26, 455−461). Compared to cyclopropylcarbinyl → homoallyl rearrangements …


Two-Neutron Transfer In The 6he + 209bi Reaction Near The Coulomb Barrier, Paul A. Deyoung, Patrick J. Mears, J. J. Kolata, E. F. Aguilera, F. D. Becchetti, Y. Chen, M. Cloughesy, H. Griffin, C. Guess, J. D. Hinnefeld, H. Jiang, Scott R. Jones, U. Khadka, D. Lizcano, E. Martinez-Quiroz, M. Ojaniega, Graham F. Peaslee, A. Pena, J. Reith, S. Vandendriessche, J. A. Zimmerman May 2005

Two-Neutron Transfer In The 6he + 209bi Reaction Near The Coulomb Barrier, Paul A. Deyoung, Patrick J. Mears, J. J. Kolata, E. F. Aguilera, F. D. Becchetti, Y. Chen, M. Cloughesy, H. Griffin, C. Guess, J. D. Hinnefeld, H. Jiang, Scott R. Jones, U. Khadka, D. Lizcano, E. Martinez-Quiroz, M. Ojaniega, Graham F. Peaslee, A. Pena, J. Reith, S. Vandendriessche, J. A. Zimmerman

Faculty Publications

The cross section for α-particle emission in the He6+Bi209 reaction at energies near the Coulomb barrier is remarkably large. Possible reactions that may produce the observed α particles include two-neutron transfer, one-neutron transfer, and direct projectile breakup. Each of these mechanisms results in a distinctive angular correlation between the α particle and the outgoing neutron(s). A neutron-α-particle coincidence experiment was performed to study two-neutron transfer to unbound states of Bi211. It is shown that approximately 55% of the observed α-particle yield at and beyond the grazing angle is because of this process. This is more than 2.5 times the fraction …


Isobaric Analog States Of Neutron-Rich Nuclei. Doppler Shift As A Measurement Tool For Resonance Excitation Functions, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wohr Apr 2005

Isobaric Analog States Of Neutron-Rich Nuclei. Doppler Shift As A Measurement Tool For Resonance Excitation Functions, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wohr

Faculty Publications

We present a new approach for the measurement of resonance excitation functions of neutron-rich nuclei using Doppler shift information. Preliminary data from the first application of the method is presented in the spectroscopy studies of 7He isobaric analog states in 7Li.


Quantum Amplified Isomerization: A New Chemically Amplified Imaging System In Solid Polymers, Douglas R. Robello, Joseph P. Dinnocenzo, Samir Farid, Jason G. Gillmore, Samuel W. Thomas Iii Aug 2004

Quantum Amplified Isomerization: A New Chemically Amplified Imaging System In Solid Polymers, Douglas R. Robello, Joseph P. Dinnocenzo, Samir Farid, Jason G. Gillmore, Samuel W. Thomas Iii

Faculty Publications

A new imaging system based on a photoinitiated electron transfer chain reaction is reported. Specifically, irradiation of 9,10-dicyanoanthracene (sensitizer) leads to the conversion of Dewar benzene derivatives (reactants) to benzene derivatives (products) within solid polymer films. The mechanism of the reaction may involve chemical amplification with cation radicals ("holes") as the catalytic species. We present herein studies of both molecularly doped polymers and polymers containing Dewar benzene moieties attached to side chains. The refractive index of the materials could be tuned within a narrow range using this photochemical reaction, as demonstrated by the writing of persistent gratings in forced Rayleigh …


A High Throughput Method For The Conversion Of Co2 Obtained From Biochemical Samples To Graphite In Septa-Sealed Vials For Quantification Of 14c Samples Via Accelerator Mass Spectrometry, Ted J. Ognibene, Graham Bench, John S. Vogel, Graham F. Peaslee, Steve Murov Apr 2003

A High Throughput Method For The Conversion Of Co2 Obtained From Biochemical Samples To Graphite In Septa-Sealed Vials For Quantification Of 14c Samples Via Accelerator Mass Spectrometry, Ted J. Ognibene, Graham Bench, John S. Vogel, Graham F. Peaslee, Steve Murov

Faculty Publications

The growth of accelerator mass spectrometry as a tool for quantitative isotope ratio analysis in the biosciences necessitates high-throughput sample preparation. A method has been developed to convert CO2 obtained from carbonaceous samples to solid graphite for highly sensitive and precise 14C quantification. Septa-sealed vials are used along with commercially available disposable materials, eliminating sample cross contamination, minimizing complex handling, and keeping per sample costs low. Samples containing between 0.25 and 10 mg of total carbon can be reduced to graphite in 4 h in routine operation. Approximately 150 samples per 8-h day can be prepared by a single technician.


A New Accelerator Mass Spectrometry System For 14c-Quantification Of Biochemical Samples, Ted J. Ognibene, Graham Bench, Tom A. Brown, Graham F. Peaslee, John S. Vogel Jul 2002

A New Accelerator Mass Spectrometry System For 14c-Quantification Of Biochemical Samples, Ted J. Ognibene, Graham Bench, Tom A. Brown, Graham F. Peaslee, John S. Vogel

Faculty Publications

A compact accelerator mass spectrometry (AMS) system that meets our requirements for View the MathML source-quantification of biochemical samples is described. The spectrometer occupies approximately 5 m2 of floor space and can measure >300 samples per day with 3% precision. A long diffuse gas cell is used to destroy interfering molecules and to charge exchange injected negative ions. System sensitivity is <1 amol View the MathML source/mg carbon on milligram-sized samples with a dynamic range that extends over 4 orders magnitude. All components, with the exception of the ion source, are commercially available and the system operates reliably with low maintenance.